001-user.svg Become a member

Your form has been submitted.

Thanks for contacting us! We will be in touch with you shortly.

Rehabilitation and postoperative protocols

Year of publishing 2023

Niederer D, Keller M, Jakob S, Petersen W, Mengis N, Vogt L, Guenther D, Brandl G, Drews BH, Behringer M, Groneberg DA, Stein T. Quadriceps and hamstring anterior cruciate ligament reconstruction differ only marginally in function after the rehabilitation: a propensity score-matched case-control study. Knee Surg Sports Traumatol Arthrosc. 2023;30:1–13.

Abstract Purpose: To determine potential quadriceps versus hamstring tendon autograft differences in neuromuscular function and return to sport (RTS)-success in participants after an anterior cruciate ligament (ACL) reconstruction. Methods: Case-control study on 25 participants operated on with an arthroscopically assisted, anatomic ipsilateral quadriceps femoris tendon graft and two control groups of 25 participants each, operated on with a semitendinosus tendon or semitendinosus-gracilis (hamstring) tendon graft ACL reconstruction. Participants of the two control groups were propensity score matched to the case group based on sex, age, Tegner activity scale and either the total volume of rehabilitation since reconstruction (n = 25) or the time since reconstruction (n = 25). At the end of the rehabilitation (averagely 8 months post-reconstruction), self-reported knee function (KOOS sum scores), fear of loading the reconstructed knee during a sporting activity (RSI-ACL questionnaire), and fear of movement (Tampa scale of kinesiophobia) were followed by hop and jump tests. Front hops for distance (jumping distance as the outcome) were followed by Drop jumps (normalised knee joint separation distance), and concluded by qualitative ratings of the Balanced front and side hops. Between-group comparisons were undertaken using 95% confidence intervals comparisons, effect sizes were calculated. Results: The quadriceps case group (always compared with the rehabilitation-matched hamstring graft controls first and versus time-matched hamstring graft controls second) had non-significant and only marginal higher self-reported issues during sporting activities: Cohen's d = 0.42, d = 0.44, lower confidence for RTS (d = - 0.30, d = - 0.16), and less kinesiophobia (d = - 0.25, d = 0.32). Small and once more non-significant effect sizes point towards lower values in the quadriceps graft groups in the Front hop for distance limb symmetry values in comparison to the two hamstring control groups (d = - 0.24, d = - 0.35). The normalised knee joint separation distance were non-significantly and small effect sized higher in the quadriceps than in the hamstring groups (d = 0.31, d = 0.28). Conclusion: Only non-significant and marginal between-graft differences in the functional outcomes at the end of the rehabilitation occurred. The selection of either a hamstring or a quadriceps graft type cannot be recommended based on the results. The decision must be undertaken individually. Level of evidence: III.
Keywords: Autograft; Functional capacity; Propensity score; Return to sports.

Year of publishing 2010

Quelard B, Sonnery-Cottet B, Zayni R, et al. Isolated posterior cruciate ligament reconstruction: is non-aggressive rehabilitation the right protocol?. Orthop Traumatol Surg Res. 2010;96(3):256-262.

Introduction: Reconstruction Surgery of the posterior cruciate ligament (PCL) has not yet been fully standardized, and associated rehabilitation protocols have not been clearly defined. The aim of this study is to report the results of a consecutive series of patients who underwent the same surgical technique for isolated PCL reconstruction and were submitted to the same specific rehabilitation protocol. A non-aggressive rehabilitation protocol which protects the graft from excess mechanical stress produces satisfying and reproducible clinical and laxity results in the knee. Materials and methods: Our series included 17 patients who underwent single bundle arthroscopic reconstruction of the PCL with an autologous quadriceps tendon graft and who followed the same non-aggressive rehabilitation protocol. All patients were followed up for an average of 30 months (range 12-60 months). The preoperative evaluation and the last follow-up included objective and subjective IKDC scores as well as the Tegner & Lysholm knee scales. The side to side laxity was measured radiologically with the Telos stress testing device. A statistical analysis was performed to compare preoperative and postoperative results. Results: Preoperatively, no patients were classified as A or B on the IKDC objective score. At last follow-up visit, 88.2% of patients were classified as A or B. Average side to side anteroposterior laxity was 11.9 mm (range 8-18) in the preoperative evaluation and 3.8mm (range 1-7) in the final follow-up (p=0.01) The average subjective IKDC score was 37.7 before surgery and 74.7 at last follow-up (p< 0.01). The Tegner & Lysholm scores were significantly improved by surgery. Discussion: Although the results are still less successful than ACL reconstruction, successful PCL reconstruction results were obtained with a standardized single bundle reconstruction technique and an adapted specific postoperative rehabilitation protocol. A non-aggressive rehabilitation protocol can limit postoperative mechanical stress on the graft. Type of study: Retrospective Level IV.

Year of publishing 2023

Wenning M, Mauch M, Heitner AH, Bode G, Sofack G, Ritzmann R. Early ACL reconstruction shows an improved recovery of isokinetic thigh muscle strength compared to delayed or chronic cases. Arch Orthop Trauma Surg. 2023:10.1007/s00402-023-04863-5.

Abstract Introduction: The recovery of periarticular strength is a major criterion in return-to-play testing. The rationale of the study was to assess the impact of the delay of surgery (∆ between injury and surgery) on knee extensor and knee flexor strength of anterior cruciate ligament (ACL)-deficient patients six months after reconstruction. Materials and methods: In a retrospective cohort study, all patients with ACL ruptures between 03/2015 and 12/2019 were analyzed. Inclusion criteria were isolated ACL rupture without any associated lesions undergoing a reconstruction using ipsilateral hamstring tendon autograft and adherence to isokinetic strength testing before and at 5-7 months postoperatively. These patients were then clustered into three groups: EARLY reconstruction (∆ < 42 days), DELAYED reconstruction (∆42-180d), and CHRONIC (∆ > 180d). Knee extensor and flexor strength of the ipsi- and contralateral leg were analyzed by concentric isokinetic measurement (60°/s). Primary outcomes were the maximal knee extension and flexion torque, hamstrings-to-quadriceps ratio (H/Q) ratio), and the corresponding limb symmetry indices. Results: n = 444 patients met the inclusion criteria. From EARLY to DELAYED to CHRONIC, a progressive reduction in postoperative strength performance was observed in knee extension (1.65 ± 0.45 to 1.62 ± 0.52 to 1.51 ± 0.5 Nm/kg resp.) and flexion (1.22 ± 0.29 to 1.18 ± 0.3 to 1.13 ± 0.31 Nm/kg resp.) strength on the ACL reconstructed leg. This general loss in periarticular strength was already apparent in the preoperative performance even on the healthy side. When controlling for the preoperative performance using ANCOVA analysis, EARLY performed significantly better than DELAYED (extension p = 0.001, flexion p = .02) and CHRONIC (extension p = 0.005, flexion p < 0.001). Also, there were significantly higher values for H/Q ratio in the injured leg across all groups where the H/Q ratio increased from EARLY to CHRONIC and from pre- to postoperative values. Conclusions: With respect to the force generating capacity when returning-to-play, it is advantageous to seek for an early ACL reconstruction within the first 12 weeks after the injury. The increasing loss of thigh muscle strength observed in delayed or chronic cases affects the injured and also the non-injured leg. Level of evidence: III, retrospective cohort study.

Year of publishing 2023

Brightwell BD, Samaan MA, Johnson D, Noehren B. Dynamic knee joint stiffness during bilateral lower extremity landing 6 months after ACL reconstruction. Knee. 2023;42:73-81.

Abstract Background: Anterior cruciate ligament (ACL) reconstructions are associated with long-term functional impairments. Improved understanding of dynamic knee joint stiffness and work may provide insights to help address these poor outcomes. Defining the relationship between knee stiffness, work and quadriceps muscle symmetry may reveal therapeutic targets. The purposes of this study were to investigate between-limb differences in knee stiffness and work during early phase landing 6-months after an ACL reconstruction. Additionally, we investigated relationships among symmetry of knee joint stiffness and work during early-phase landing and quadriceps muscle performance symmetry. Methods: Twenty-nine participants (17 M, 20.0 ± 5.3 years) were tested 6-months after ACL reconstruction. Motion capture analysis was used to assess between-limb differences in knee stiffness and work during the first 60 ms of a double-limb landing. Quadriceps peak strength and rate of torque development (RTD) were assessed with isometric dynamometry. Paired t-tests and Pearson's product moment correlations were used to determine between-limb differences of knee mechanics and correlations of symmetry respectively. Findings: Knee joint stiffness and work were significantly reduced (p < 0.01, p < 0.01) in the surgical limb (0.021 ± 0.01 Nm*(deg*kg*m)-1, -0.085 ± 0.06 J*(kg*m) -1) compared to the uninvolved limb (0.045 ± 0.01 Nm*(deg*kg*m)-1, -0.256 ± 0.10 J*(kg*m) -1). Greater knee stiffness (51 ± 22%) and work (35 ± 21%) symmetry were significantly associated with greater RTD symmetry (44.5 ± 19.4%) (r = 0.43, p = 0.02; r = 0.45, p = 0.01) but not peak torque symmetry (62.9 ± 16.1%) (r = 0.32, p = 0.10; r = 0.34, p = 0.10). Interpretation: Dynamic stiffness and energy absorption are lower in the surgical knee during landing from a jump. Therapeutic interventions that target increasing quadriceps RTD may help optimize dynamic stability and energy absorption during landing.
Keywords: Anterior Cruciate Ligament; Joint Stiffness; Knee Joint; Patellar Tendon; Quadriceps Rate of Torque Development; Rehabilitation.

Year of publishing 2023

Kuenze C, Weaver A, Grindstaff TL, et al. Age-, Sex-, and Graft-Specific Reference Values From 783 Adolescent Patients at 5 to 7 Months After ACL Reconstruction: IKDC, Pedi-IKDC, KOOS, ACL-RSI, Single-Leg Hop, and Thigh Strength. J Orthop Sports Phys Ther. 2023;53(4):1-8

Abstract OBJECTIVE: To describe age-, sex-, and graft source-specific reference values for patient-reported, physical function, and strength outcome measures in adolescents at 5 to 7 months after anterior cruciate ligament reconstruction. DESIGN: Cross-sectional study. METHODS: Data were collected at 3 universities and 2 children's hospitals. The participants completed at least one of the International Knee Documentation Committee (IKDC) Subjective Evaluation Form, Pediatric IKDC (Pedi-IKDC), Knee Injury and Osteoarthritis Outcomes Score (KOOS), and Anterior Cruciate Ligament Return to Sport After Injury (ACL-RSI) Scale. Participants also completed single-leg hop tests and/or isokinetic quadriceps and hamstrings strength assessments (at 60°/s). Reference values were summarized using descriptive statistics and stratified for age, sex, and graft source. RESULTS: Reference values were reported for common patient-reported outcomes and measures of physical function and strength from 783 participants (56% females, age = 16. 4 ± 2.0 years) who were in early adolescence (12-14 years, N = 183, 52% females), middle adolescence (15-17 years, N = 456, 58% females), or late adolescence (18-20 years, N = 144, 55% females). Three hundred seventy-nine participants (48.4%) received a bone-patellar tendon-bone autograft, 292 participants (37.3%) received hamstring tendon autograft, and 112 participants (14.3%) received autograft or allograft from an alternative source. CONCLUSION: Reference values for common patient-reported outcomes and measures of physical function and strength differed depending on a patient's age, sex, and graft source. Using patient-specific reference values, in addition to previously described age-appropriate cutoff values, may help clinicians monitor and progress patients through rehabilitation and return to physical activity after anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther 2023;53(4):1-8. Epub: 23 January 2023. doi:10.2519/jospt.2023.11389.
Keywords: adolescent athlete; isokinetic knee extension and flexion; limb symmetry indices; return to sport/activity; single-leg hopping.

Year of publishing 2023

Letter MI, Parrino RL, Adams W, Ripic Z, Baraga MG, Kaplan LD, Harrah T, Tremblay J, Luxenburg D, Conti J, Signorile JF. The Associations Between Quadriceps Tendon Graft Thickness and Isokinetic Performance. Am J Sports Med. 2023;51(4):942-948.

Abstract Background: Anterior cruciate ligament reconstruction (ACLR) using the quadriceps tendon is an increasingly popular technique. Both partial-thickness quadriceps tendon (PT-Q) and full-thickness quadriceps tendon (FT-Q) graft depths are employed. Hypothesis/purpose: This study was designed to assess isokinetic peak torque, average power, and total work during knee extension in patients with FT-Q or PT-Q grafts for ACLR. We hypothesized that both groups would show lower isokinetic values for the operated side, with greater deficits in the FT-Q group than in the PT-Q group. Study design: Cohort study; Level of evidence, 3. Methods: A total of 26 patients who underwent ACLR with either an FT-Q or PT-Q graft were recruited between June 2021 and November 2021. Patients underwent isokinetic knee extension testing at > 1 year after surgery. Mixed repeated-measures analysis of covariance with least square difference post hoc testing was used to determine significant differences or interactions for all variables. Results: Peak torque was significantly lower for the operated limb than the nonoperated limb in the FT-Q group (mean difference [MD] ± standard error [SE], -38.6 ± 8.3 Nċm [95% CI, -55.7 to -21.5 Nċm]; P < .001; d = 0.90) but not in the PT-Q group (MD ± SE, -7.3 ± 7.7 Nċm [95% CI, -23.2 to 8.5 Nċm]; P = .348; d = 0.20). Similarly, average power for the operated limb was lower than that for the nonoperated limb in the FT-Q group (MD ± SE, -53.6 ± 13.4 W [95% CI, -81.3 to -26.9 W]; P < .001; d = 0.88) but not in the PT-Q group (MD ± SE, -4.1 ± 12.4 W [95% CI, -29.8 to 21.5 W]; P = .742; d = 0.07), and total work was lower for the operated limb compared with the nonoperated limb in the FT-Q group (MD ± SE, -118.2 ± 27.1 J [95% CI, -174.3 to -62.2 J]; P < .001; d = 0.96) but not in the PT-Q group (MD ± SE, -18.3 ± 25.1 J [95% CI, -70.2 to 33.6 J]; P = .472; d = 0.15). Conclusion: The FT-Q group showed significant deficits in the operated limb compared with the nonoperated limb for all isokinetic variables. In contrast, no significant differences were found between the nonoperated and operated limbs for the PT-Q group.
Keywords: ACL; isokinetic; knee; quadriceps.

Year of publishing 2023

Rizvanovic D, Waldén M, Forssblad M, Stålman A. Surgeon's experience, sports participation and a concomitant MCL injury increase the use of patellar and quadriceps tendon grafts in primary ACL reconstruction: a nationwide registry study of 39,964 surgeries. Knee Surg Sports Traumatol Arthrosc. 2023;31(2):475-486.

Abstract Purpose: To investigate the influence of surgeon-related factors and clinic routines on autograft choice in primary anterior cruciate ligament reconstruction (ACLR). Methods: Data from the Swedish National Knee Ligament Registry (SNKLR), 2008-2019, were used to study autograft choice (hamstring; HT, patellar; PT, or quadriceps tendon; QT) in primary ACLR. Patient/injury characteristics (sex, age at surgery, activity at time of injury and associated injuries) and surgeon-/clinic-related factors (operating volume, caseload and graft type use) were analyzed. Surgeon/clinic volume was divided into tertiles (low-, mid- and high-volume categories). Multivariable logistic regression was performed to assess variables influencing autograft choice in 2015-2019, presented as the odds ratio (OR) with a 95% confidence interval (CI). Results: 39,964 primary ACLRs performed by 299 knee surgeons in 91 clinics were included. Most patients received HT (93.7%), followed by PT (4.2%) and QT (2.1%) grafts. Patients were mostly operated on by high-volume (> 28 ACLRs/year) surgeons (68.1%), surgeons with a caseload of ≥ 50 ACLRs (85.1%) and surgeons with the ability to use ≥ two autograft types (85.9%) (all p < 0.001). Most patients underwent ACLR at high-volume (> 55 ACLRs/year) clinics (72.2%) and at clinics capable of using ≥ two autograft types (93.1%) (both p < 0.001). Significantly increased odds of receiving PT/QT autografts were found for ACLR by surgeons with a caseload of ≥ 50 ACLRs (OR 1.41, 95% CI 1.11-1.79), but also for injury during handball (OR 1.31, 95% CI 1.02-1.67), various other pivoting sports (basketball, hockey, rugby and American football) (OR 1.59, 95% CI 1.24-2.03) and a concomitant medial collateral ligament (MCL) injury (OR 4.93, 95% CI 4.18-5.80). In contrast, female sex (OR 0.87, 95% CI 0.77-0.97), injury during floorball (OR 0.71, 95% CI 0.55-0.91) and ACLR by mid-volume relative to high-volume surgeons (OR 0.62, 95% CI 0.53-0.73) had significantly reduced odds of receiving PT/QT autografts. Conclusion: An HT autograft was used in the vast majority of cases, but PT/QT autografts were used more frequently by experienced surgeons. Prior research has demonstrated significant differences in autograft characteristics. For this reason, patients might benefit if surgery is performed by more experienced surgeons. Level of evidence: Level III.
Keywords: Caseload; Concomitant injuries; Hamstring; Knee; Ligament reconstruction; Operating volume; Patellar; Quadriceps; Surgical technique.

Year of publishing 2023

Runer A, Keeling L, Wagala N, Nugraha H, Özbek EA, Hughes JD, Musahl V. Current trends in graft choice for primary anterior cruciate ligament reconstruction - part II: In-vivo kinematics, patient reported outcomes, re-rupture rates, strength recovery, return to sports and complications. J Exp Orthop. 2023;10(1):40

Abstract Postoperative patient satisfaction after anterior cruciate ligament reconstruction (ACL-R) is influenced mainly by the degree of pain, the need for reoperation, and functional performance in daily activities and sports. Graft choice has shown to have an influence on postoperative outcomes after ACL-R. While patient reported outcomes measurements do not differ between graft options, evidence shows that normal knee kinematics is not fully restored after ACL-R with an increase in postoperative anterior tibial translation (ATT). Postoperative graft rupture rates seem to favor bone-patella-tendon-bone (BPTB) and quadriceps tendon (QT) autografts over HT or allografts. While return to sports rates seem comparable between different graft types, postoperative extensor strength is reduced in patients with BPTB and QT whereas flexion strength is weakened in patients with HT. Postoperative donor site morbidity is highest in BPTB but comparable between HT and QT. With all graft options having advantages and drawbacks, graft choice must be individualized and chosen in accordance with the patient.

Year of publishing 2023

Solie B, Monson J, Larson C. Graft-Specific Surgical and Rehabilitation Considerations for Anterior Cruciate Ligament Reconstruction with the Quadriceps Tendon Autograft. Int J Sports Phys Ther. 2023;18(2):493-512.

Abstract Anterior cruciate ligament reconstruction (ACLR) with a bone-patellar tendon-bone (BPTB) or hamstring tendon (HT) autograft has traditionally been the preferred surgical treatment for patients returning to Level 1 sports. More recently, international utilization of the quadriceps tendon (QT) autograft for primary and revision ACLR has increased in popularity. Recent literature suggests that ACLR with the QT may yield less donor site morbidity than the BPTB and better patient-reported outcomes than the HT. Additionally, anatomic and biomechanical studies have highlighted the robust properties of the QT itself, with superior levels of collagen density, length, size, and load-to-failure strength compared to the BPTB. Although previous literature has described rehabilitation considerations for the BPTB and HT autografts, there is less published with respect to the QT. Given the known impact of the various ACLR surgical techniques on postoperative rehabilitation, the purpose of this clinical commentary is to present the procedure-specific surgical and rehabilitation considerations for ACLR with the QT, as well as further highlight the need for procedure-specific rehabilitation strategies after ACLR by comparing the QT to the BPTB and HT autografts. Level of evidence: Level 5.
Keywords: anterior cruciate ligament reconstruction; autograft; physical therapy; quadriceps tendon autograft; rehabilitation.

Year of publishing 2023

Parker MC, Lang SD, Lakehomer H, O'Neil S, Crall TS, Gilmer BB. Harvest of All-Soft Tissue Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction With or Without Closure of Resulting Defect Has No Effect on Patellar Height. Arthrosc Sports Med Rehabil. 2023;5(1):143-150.

Abstract Purpose: To evaluate the radiographic effect of quadriceps tendon harvest on patellar height and to determine whether closure of a quadriceps graft harvest defect resulted in a significant change in patellar height compared to nonclosure. Methods: We conducted a retrospective review of prospectively enrolled patients. The institutional database was queried and all patients who underwent quadriceps autograft anterior cruciate ligament reconstruction between 2015 and March 2020 were included. Graft harvest length in millimeters and final graft diameter after preparation for implantation were obtained from the operative record and demographic data were obtained from the medical record. Radiographic analysis was performed of eligible patients using standard ratios of patellar height: Insall-Salvati (IS), Blackburn-Peele (BP), and Caton-Deschamps (CD). Measurements were performed using digital calipers on a digital imaging system by 2 postgraduate fellow surgeons. Preoperative and postoperative radiographs were performed at 0° according to a standard protocol. Postoperative radiographs were performed 6 weeks postoperatively in all cases. Preoperative patellar height ratios were compared with postoperative patellar height ratios for all patients using t-tests. Subanalysis was then performed to compare the effect of closure of with nonclosure on patellar height ratios using repeated-measures analysis of variance. Interrater reliability between the 2 reviewers was assessed using an intraclass correlation coefficient calculation. Results: In total, 70 patients met final inclusion criteria. There were no statistically significant changes from pre- to postoperative values for either reviewer for IS (reviewer 1, P = .47; reviewer 2, P = .353), BP (reviewer 1, P = .98; reviewer 2, P = .907), or CD (reviewer 1, P = .107; reviewer, 2 P = .188). The closure and nonclosure groups were adequately powered and no statistically significant demographic differences between the closure and nonclosure groups was identified for sex (P = .066), age (P = .343), weight (P = .881), height (P = .42), laterality (P = 1), meniscal repair (P = .332), graft diameter (P = .068), or graft length (P = .183). According to the repeated measures analysis of variance, closure of the quadriceps defect had no significant impact on any of the knee ratios. However, reviewer identity had a significant influence on the CD ratio. Intraclass correlation coefficient analysis revealed excellent agreement between reviewers for the IS (0.982) and BP (0.954) ratios, but only moderate-to-good agreement for the CD (0.751) ratio. Conclusions: Harvest of quadriceps tendon graft does not result in radiographic changes in patellar height. Furthermore, closure of the quadriceps defect does not appear to result in radiographic changes in patellar height. Level of evidence: III, retrospective comparative trial.

Year of publishing 2022

Straub RK, Mandelbaum B, Powers CM. Predictors of Quadriceps Strength Asymmetry after Anterior Cruciate Ligament Reconstruction: A Chi-Squared Automatic Interaction Detection Decision Tree Analysis. Med Sci Sports Exerc. 2022;54(12):2005-2010

Abstract Introduction: The influence of graft type on the restoration of quadriceps strength symmetry after ACL reconstruction (ACLR) has been widely studied. However, an important consideration when evaluating quadriceps symmetry is the fact that this measure can be influenced by numerous factors beyond graft type. This study sought to determine if graft type is predictive of quadriceps strength asymmetry during the first 12 months post-ACLR taking into consideration potentially influential factors (i.e., age, sex, body mass index, time post-ACLR). Methods: We retrospectively reviewed quadriceps strength data from 434 patients (303 female patients and 131 male patients) who had previously undergone ACLR with an autograft (hamstring tendon, quadriceps tendon [QT], patellar tendon [PT]) or allograft. Chi-Squared Automatic Interaction Detection decision tree analysis was used to evaluate if graft type is predictive of quadriceps strength asymmetry during the first 12 months post-ACLR taking into consideration age, sex, body mass index, and time post-ACLR. Results: The best predictor of quadriceps strength asymmetry was graft type. Specifically, three graft categories were identified: 1) allograft and hamstring tendon autograft, 2) PT autograft, and 3) QT autograft. The average quadriceps strength asymmetry for each of the three identified categories was 0.91, 0.87, and 0.81, respectively, and differed statistically from each other ( P < 0.001). The second-best predictor of quadriceps strength asymmetry was sex, albeit only in the PT and QT groups (with female patients having increased asymmetry). Female patients post-ACLR with a QT autograft were at highest risk for quadriceps strength asymmetry. Conclusions: Graft type and sex are important predictors of quadriceps strength asymmetry after ACLR. Clinicians should take these factors into consideration when designing rehabilitation protocols to restore quadriceps strength symmetry during the postoperative period.

Year of publishing 2022

Baker HP, Bhattacharjee S, Poff C, Bartolotta C, Athiviraham A. Postoperative Anterior Cruciate Ligament Reconstruction Quadricep and Patella Tendon Rupture, Infection, and Lysis of Adhesions Decreased Despite Changing Graft Trends Over the Past Decade. Arthrosc Sports Med Rehabil. 2022;4(4):1437-1443.


Purpose: To investigate recent trends in postoperative complications following anterior cruciate ligament (ACL) reconstruction. Methods: Patients who underwent ACL reconstruction surgery were identified in a national insurance database and separated into 2 cohorts based on the date of their initial surgery comprising the years 2010 to 2012 and 2016 to 2018, respectively. Patients were matched 1:1 based on comorbidities and Elixhauser Comorbidity Index. All patients were assessed for postoperative complications within 18 months of surgery. Rate of complication was compared between cohorts. Results: Overall, the all-cause complication rate was 2%. There were significantly more quadriceps tendon rupture, patella tendon rupture, lysis of adhesion, and infection in the early cohort. There were significantly more instances of deep vein thrombosis in the late cohort. We found no significant difference in manipulations under anesthesia between the 2 cohorts. Conclusions: Patients who underwent surgery in the late cohort had lower rates of postoperative complications, except for deep vein thrombosis. The rate of postoperative quadriceps tendon rupture decreased despite considerable increase in the use of quadriceps tendon autograft. Clinical relevance: As there has been an increased use of quadriceps tendon autografts, but little is known about the postoperative complications after ACL reconstruction with these grafts. This information has the potential to improve patient outcomes.

Year of publishing 2022

Johnston PT, Feller JA, McClelland JA, Webster KE. Knee strength deficits following anterior cruciate ligament reconstruction differ between quadriceps and hamstring tendon autografts. Knee Surg Sports Traumatol Arthrosc. 2022 Apr;30(4):1300-1310.

Abstract Purpose: To compare patient reported outcomes and functional knee recovery following anterior cruciate ligament (ACL) reconstruction using either a quadriceps tendon (QT) or hamstring tendon (HT) autograft. Methods: Thirty-five QT patients (age 20; range 15-34 years) participated in this study and were matched for gender, age and pre-injury activity level to 70 HT (age 20; range 15-32 years) patients. The following assessments were performed at 6 and 12 months post-operatively; standardized patient-reported outcome measures (IKDC, KOOS-QOL, ACL-RSI, Marx activity, anterior knee pain), knee range of motion (passive and active), anterior knee laxity, hop tests (single and triple crossover hop for distance), and isokinetic strength of the knee extensors and flexors. All dependent variables were analysed using a two-way mixed ANOVA model, with within (Time; 6 and 12 months) and between-subject (Graft; QT and HT) factors. Results: Patient reported outcome measures and hop performance improved between 6 and 12 months (p < 0.001), however no significant differences in either patient-reported outcomes or hop performance were found between the two grafts. Isokinetic strength testing showed both groups improved their peak knee extensor strength in the operated limb between 6 and 12 months (p < 0.001), but the QT group had significantly lower knee extensor strength symmetry at both time points compared to HT at 60 deg/s (p < 0.001) and 180 deg/s (p < 0.01). In contrast, the QT group had significantly greater knee flexor strength symmetry at both time points compared to HT at 60 deg/s (p < 0.01) and 180 deg/s (p = 0.01), but knee flexor strength limb symmetry did not significantly improve over time in either group. Conclusion: Recovery of knee function following either QT or HT ACL reconstruction continues between 6 and 12 months after surgery. However, knee extensor strength deficits in the QT group and knee flexor strength deficits in the HT persisted at 12 months. This may have implications for decisions regarding return to sport. Level of evidence: III.
Keywords: Anterior cruciate ligament reconstruction; Knee; Quadriceps tendon autograft.

Year of publishing 00.00.0000

Hofer KL, Lucas BL, Prohaska DJ, Zackula R, Manske RC. Quadriceps Strength and Knee Function After Anterior Cruciate Ligament Reconstruction with Quadriceps Tendon Bone Autograft: A Preliminary Report. Kans J Med. 2022;15:412-417.

Abstract Introduction: The purpose of this study was to evaluate quadriceps strength and knee function after anterior cruciate ligament (ACL) reconstruction using a quadriceps tendon bone (QTB) autograft. Methods: Preliminary data were extracted from an ongoing prospective cohort study in which the operative extremity was compared to non-operative extremity. Patients from 14 to 40 years of age who had an ACL reconstruction with QTB autograft volunteered to have knee assessment including quadriceps isokinetic strength measures and functional knee testing at 6 and 12 months post-operatively. Paired t-tests were conducted to compare post-operative strength and function scores on participants who had minimum one-year post-surgical follow-up. Results: Patients had a significant recovery of quadriceps strength as determined by isokinetic testing and single leg hop test. For 31 participants, quadriceps strength of the operative leg measured at 60 deg/sec was 63% of the non-operative leg at six months, increasing to 79% at one year (p < 0.001); when measured at 180 deg/sec, these values were 68% at six months, increasing to 82% at one year (p < 0.001). For 30 participants, single leg hop functional scores of the operative leg were 80% of the non-operative leg at six months, increasing to 91% at one year (p < 0.001). Conclusions: After QTB autograft for ACL reconstruction, there were significant gains in quadriceps strength and knee function from six months to one year post-operative. These findings indicated the QTB is an acceptable ACL reconstruction option.
Keywords: anterior cruciate ligament reconstruction; anterior cruciate ligament tear; isokinetic quadriceps strength; knee joint; quadriceps muscle.

Year of publishing 2022

Schwery NA, Kiely MT, Larson CM, Wulf CA, Heikes CS, Hess RW, Giveans MR, Solie BS, Doney CP. Quadriceps Strength following Anterior Cruciate Ligament Reconstruction: Normative Values based on Sex, Graft Type and Meniscal Status at 3, 6 & 9 Months. Int J Sports Phys Ther. 2022;17(3):434-444.

Abstract Background: Higher postoperative quadriceps function has been positively associated with surgical outcomes after anterior cruciate ligament reconstruction (ACLR). However, the impact of autograft harvest and/or a concomitant meniscal procedure on the recovery of quadriceps strength is not well defined. Purpose: To describe postoperative recovery of quadriceps strength following ACLR related to autograft selection, meniscal status, and sex. Study design: Retrospective Cohort. Methods: One hundred and twenty-five participants who underwent ACLR with either a hamstring tendon (HT), bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) autograft were included. At postoperative months 3, 6 and 9, each participant completed an isometric quadriceps strength testing protocol at 90-degrees of knee flexion. Participants' quadriceps average peak torque (Q-AvgPKT), average peak torque relative to body weight (Q-RPKT), and calculated limb symmetry index (Q-LSI) were collected and used for data analysis. Patients were placed in groups based on sex, graft type, and whether they had a concomitant meniscal procedure at the time of ACLR. At each time point, One-way ANOVAs, independent samples t-test and chi-square analyses were used to test for any between-group differences in strength outcomes. Results: At three months after ACLR, Q-RPKT was significantly higher in those with the HT compared to the QT. At all time points, males had significantly greater Q-RPKT than females and HT Q-LSI was significantly higher than BPTB and QT. A concomitant meniscal procedure at the time of ACLR did not significantly affect Q-LSI or Q-RPKT at any testing point. Conclusion: This study provides outcomes that are procedure specific as well as highlights the objective progression of quadriceps strength after ACLR. This information may help better-define the normal recovery of function, as well as guide rehabilitation strategies after ACLR. Level of evidence: 3.
Keywords: anterior cruciate ligament reconstruction; isometric; meniscus; quadriceps; strength.

Year of publishing 2022

Weaver A, Ness BM, Roman DP, Giampetruzzi N, Cleland JA, Pace JL, Crepeau AE. Short-term isokinetic and isometric strength outcomes after anterior cruciate ligament reconstruction in adolescents. Phys Ther Sport. 2022;53:75-83.

Objectives: To examine differences in knee strength outcomes after ACL reconstruction according to quadriceps tendon (QT) or hamstring tendon (HT) autograft in adolescents. Abstract Design: Retrospective cohort. Methods: Surgical and clinical outcome data were collected. Analyses were conducted separately for female and male cohorts and grouped by graft type (HT or QT). A Mann-Whitney U test of independent samples was used to examine group differences according to graft type. Results: 107 females (age = 15.6 ± 1.5 years) and 94 males (age = 15.7 ± 1.5 years) were included. Mean time since surgery ranged from 7.2 to 7.9 months. Those with a QT autograft had decreased normalized isokinetic quadriceps peak torque on the involved limb compared to the HT group (p < 0.01, ES = 0.71-0.89). Normalized isometric hamstring peak torque was decreased for those with HT autograft in the female cohort (p = 0.02, ES = 0.57). Conclusion: Normalized isokinetic quadriceps peak torque was reduced by 18-20% on the involved limb in those with a QT autograft. Normalized isometric hamstring peak torque was decreased by 13% for those with HT autograft in the female cohort. Method of strength testing may be an important consideration to fully appreciate strength deficits after ACL reconstruction according to graft type.
Keywords: ACL reconstruction; Anterior cruciate ligament; Graft; Strength.

Year of publishing 2022

Herbawi F, Lozano-Lozano M, Lopez-Garzon M, et al. A Systematic Review and Meta-Analysis of Strength Recovery Measured by Isokinetic Dynamometer Technology after Anterior Cruciate Ligament Reconstruction Using Quadriceps Tendon Autografts vs. Hamstring Tendon Autografts or Patellar Tendon Autografts. Int J Environ Res Public Health. 2022;19(11):6764.

Abtsract Background: This systematic review and meta-analysis compared the isokinetic strength of the muscular knee joint between quadriceps tendon autografts (QTAs) and hamstring tendon autografts (HTAs) or patellar tendon autografts (PTAs) after anterior cruciate ligament (ACL) reconstruction by determining the isokinetic angular velocity and follow-up time points. The functional outcomes and knee stability at the same time points were also compared using isokinetic technology. Methods: Two independent reviewers searched the Medline (via PubMed search engine), Scopus, Web of Science and Cochrane Library databases to include full text comparative studies that assessed isokinetic strength test following ACL reconstruction. The DerSimonian and Laird method was used. Results: In total, ten studies were included; seven compared studies QTAs vs. HTAs, and three compared QTAs vs. PTAs. Five studies were included in the meta-analysis. Isokinetic strength data were reported 3, 6, 12 and 24 months after ACL reconstruction. Conclusions: The QTAs showed better and significant results with knee flexion compared with HTAs, similar results to PTAs at 6 and 12 months. While HTAs showed better and significant results with knee extension at 6 months and similar results at 12 months compared to QTAs. Furthermore, a standardized isokinetic strength test must be followed to achieve a more specific conclusion and better clinical comparison among participants.
Keywords: anterior cruciate ligament reconstruction; isokinetic test; quadriceps tendon autograft.

Year of publishing 2022

Zhang K, Beshay T, Murphy B, Sheean A, de Sa D. Quadriceps Tendon Anterior Cruciate Ligament Reconstruction: A Systematic Review of Postoperative Rehabilitation and Complication Profiles. Arthroscopy. 2022;38(6):2062-2072.


Purpose: The purposes of this study are to explore current elements for postoperative rehabilitation protocol after quadriceps tendon-anterior cruciate ligament reconstruction (QT-ACLR), outline general timelines for progression of those elements, and explore their associated complication rates and profiles. Methods: In accordance with PRISMA guidelines, 5 online databases (EMBASE, MEDLINE, CINAHL, Cochrane, and PubMed) were searched and screened in duplicate using predetermined criteria for studies on the aforementioned patient population. Descriptive statistics are presented. Results: A total of 56 studies were included, with 31 studies using quadriceps tendon with bone block (B-QT) and 26 studies using all-soft tissue quadriceps tendon (S-QT). The majority of studies permitted full weightbearing and range of motion (ROM) within the first 12 postoperative weeks, and motion-controlled braces within 6 weeks. Isometric exercises were initiated within 1 week after surgery, closed-chain exercises within 12 weeks, and open-chain and sports-specific exercises within 36 weeks. Complication profiles were similar between graft types and included graft failure (1.2%-1.6%), cyclops syndrome (0.4%-0.7%), and persistent stiffness (0.9%). Conclusions: Current postoperative rehabilitation strategies in ACLR with QT offer a complication profile comparable to those reported with other graft types. Based on the included rehabilitation regimen, these protocols should focus on early ROM, specifically on achieving full extension, alongside isometric quadriceps strengthening. Progression to closed- and open-chain exercises should follow in a progressive manner, similar to existing protocols in ACLR. Adjuncts such as motion-controlled bracing and continuous passive motion machines may be used if graft protection is prioritized. This review highlights the need for comparison of defined protocols against one another in the setting of QT-ACLR. Level of evidence: IV, systematic review of Level I-IV studies.

Year of publishing 2021

Ortmaier R, Fink C, Schobersberger W, Kindermann H, Leister I, Runer A, Hepperger C, Blank C, Mattiassich G. Return to Sports after Anterior Cruciate Ligament Injury: a Matched-Pair Analysis of Repair with Internal Brace and Reconstruction Using Hamstring or Quadriceps Tendons. Sportverletz Sportschaden. 2021;35(1):36-44.

Purpose: The purpose of this study was to evaluate sports activity before anterior cruciate ligament (ACL) injury and after surgical treatment of ACL rupture comparing ACL repair with an Internal Brace to ACL reconstruction using either a hamstring (HT) or quadriceps tendon (QT) autograft. Methods: Between 12/2015 and 10/2016, we recruited 69 patients with a mean age of 33.4 years for a matched-pair analysis. Twenty-four patients who underwent Internal Brace reconstruction were matched according to age (± 5 years), gender, Tegner activity scale (± 1), BMI (± 1) and concomitant injuries with 25 patients who had undergone HT reconstruction and 20 patients who had undergone QT reconstruction. The minimum follow-up was 12 months. Results: Overall, the return-to-sports rate was 91.3 %. There were no significant differences (p ≥ 0.05) in the number of sports disciplines and the time before return to sports within or among the groups. Overall and within the groups, the level of sports participation did not change significantly (p ≥ 0.05) postoperatively. The patients' sense of well-being was excellent after either ACL repair with an Internal Brace or ACL reconstruction with autologous HT or QT. Conclusion: At short-term follow-up, ACL repair using an Internal Brace enables sports activity and provides a sense of well-being similar to that of classic ACL reconstruction using hamstring or quadriceps tendon autografts in a selected patient population. Level of evidence: Level III Retrospective comparative study.

Year of publishing 2021

Aizawa J, Hirohata K, Ohji S, Ohmi T, Mitomo S, Koga H, Yagishita K. Correlations between isokinetic knee torques and single-leg hop distances in three directions in patients after ACL reconstruction. BMC Sports Sci Med Rehabil. 2021;13(1):38.

Background: When planning rehabilitation and conditioning for performance enhancement and a return to sports after anterior cruciate ligament reconstruction, identifying the elements of physical function associated with single-leg hop is important. The purpose of this study was to clarify the relationship between single-leg hop distances in three directions and knee extensor and flexor strengths at 6 months after reconstruction. Methods: Participants were 47 patients taking part in training sessions for sports involving cutting, pivoting, and jump-landing 6 months after reconstruction using a hamstring tendon. Single-leg hop distances in 3 directions (anterior, lateral, and medial) and isokinetic concentric strengths of knee extension and flexion were assessed at an angular velocity of 60°/s and 180°/s. Simple regression analyses using Spearman's rank correlation coefficient were performed to assess relationships between single-leg hop distances and knee strengths. Results: In the involved limb, correlations between single-leg hop distances in 3 directions and knee strengths were significant (P < 0.01) and correlation coefficients ranged from 0.48 to 0.65. Correlation coefficients between all single-leg hop parameters and knee extension/flexion strengths at an angular velocity of 180°/s were greater than those of 60°/s. Conclusions: In this cross-sectional study of patients who participated in sports training sessions that required jump-landings and cutting approximately 6 months after reconstruction using hamstring grafts, isokinetic knee flexor, and extensor torques were moderately to strongly associated with single-leg hop distances in lateral, medial, and anterior directions. Given these relationships, assessments and exercises for knee strength and single-leg hop distances should be planned.
Keywords: Anterior cruciate ligament; Hamstring; Isokinetic strength; Jump-landing; Quadriceps; Side direction.

Year of publishing 2021

Hoit G, Rubacha M, Chahal J, Khan R, Ravi B, Whelan DB. Is There a Disadvantage to Early Physical Therapy After Multiligament Surgery for Knee Dislocation? A Pilot Randomized Clinical Trial. Clin Orthop Relat Res. 2021;479(8):1725-1736.

Background: Multiligament knee injuries, though rare, can be profoundly disabling. Surgeons disagree about when to initiate rehabilitation after surgical reconstruction due to the conflicting priorities of postoperative stability and motion. Questions/purposes: (1) Does early or late initiation of physical therapy after multiligament knee surgery result in fewer postoperative manipulations? (2) Does early versus late physical therapy compromise stability postoperatively? (3) Does early initiation of physical therapy result in improved patient-reported outcomes, as measured by the Multi-ligament Quality of Life (ML-QOL) score? Methods: Between 2011 and 2016, 36 adults undergoing multiligament repair or reconstruction were prospectively enrolled in a randomized controlled trial and randomized 1:1 to either early rehabilitation or late rehabilitation after surgery. Eligibility included those with an injury to the posterior cruciate ligament (PCL) and at least one other ligament, as well as the ability to participate in early rehabilitation. Patients who were obtunded or unable to adhere to the protocols for other reasons were excluded. Early rehabilitation consisted of initiating a standardized physical therapy protocol on postoperative day 1 involving removal of the extension splint for quadriceps activation and ROM exercises. Late rehabilitation consisted of full-time immobilization in an extension splint for 3 weeks. Following this 3-week period, both groups engaged in the same standardized physical therapy protocol. All surgical reconstructions were performed at a single center by one of two fellowship-trained sports orthopaedic surgeons, and all involved allograft Achilles tendon PCL reconstruction. When possible, hamstring autograft was used for ACL and medial collateral ligament reconstructions, whereas lateral collateral ligament and posterolateral reconstruction was performed primarily with allograft. The primary outcome was the number of patients undergoing manipulation during the first 6 months. Additional outcomes added after trial registration were patient-reported quality of life scores (ML-QOL) at 1 year and an objective assessment of laxity through a physical examination and stress radiographs at 1 year. One patient from each group was not assessed for laxity or ROM at 1 year, and one patient from each group did not complete the ML-QOL questionnaires. No patient crossover was observed. Results: With the numbers available, there was no difference in the use of knee manipulation during the first 6 months between the rehabilitation groups: 1 of 18 patients in the early group and 4 of 18 patients in the late group (p = 0.34). Similarly, there were no differences in knee ROM, stability, or patient-reported quality of life (ML-QOL) between the groups at 1 year. Conclusion: With the numbers available in this study, we were unable to demonstrate a difference between early and late knee rehabilitation with regard to knee stiffness, laxity, or patient-reported quality of life outcomes. The results of this small, randomized pilot study suggest a potential role for early rehabilitation after multiligament reconstruction for knee dislocation, which should be further explored in larger multi-institutional studies. Level of evidence: Level II, therapeutic study.

Year of publishing 2020

Hunnicutt JL, Slone HS, Xerogeanes JW. Implications for Early Postoperative Care After Quadriceps Tendon Autograft for Anterior Cruciate Ligament Reconstruction: A Technical Note. J Athl Train. 2020;55(6):623-627.

The quadriceps tendon (QT) has become increasingly used by orthopaedic surgeons as an alternative autograft choice in anterior cruciate ligament reconstruction. As its use increases, athletic trainers and other rehabilitation clinicians will treat a greater number of patients with this autograft type. The recently developed, minimally invasive technique for harvest of the all-soft tissue autograft has many benefits, including versatility, decreased donor-site morbidity, and enhanced cosmesis. Early clinical trials revealed that the QT autograft resulted in decreased anterior knee pain and similar strength and functional outcomes to those of more common autograft types. From a rehabilitation perspective, many characteristics should be considered, such as the importance of early knee extension and quadriceps activation. Therefore, the purpose of this technical note is to expose athletic trainers to the QT autograft so that they may provide the best care for patients after anterior cruciate ligament reconstruction.
Keywords: knee; rehabilitation; therapy.

Year of publishing 2021

Bayle-Iniguez X, Cassard X, Vinciguerra B, Murgier J. Postoperative thromboprophylaxis does not reduce the incidence of thromboembolic events after ACL reconstruction. Orthop Traumatol Surg Res. 2021:102904. doi: 10.1016/j.otsr.2021.102904.

Introduction: Anterior cruciate ligament (ACL) reconstructive surgery is one of the most common ligament-related surgeries performed in France. The French Society of Anesthesia & Intensive Care Medicine (SFAR) recommends the systematic use of low-molecular weight heparin postoperatively to prevent venous thromboembolisms (VTE). However, these recommendations differ from one country to another; several national societies do not recommend them. To specify the benefits of such a treatment, we did a retrospective case-control study to evaluate the incidence of symptomatic VTE after ACL reconstruction. Hypothesis We hypothesized that the rate of symptomatic VTE would be the same, whether a course of postoperative anticoagulants is prescribed or not. Methods: This was a retrospective, multicenter, multi-surgeon study. Of the four participating surgeons, two never prescribed thromboprophylaxis after surgery while the other two always prescribed a 10-day course of low-molecular weight heparin. All patients who underwent primary ACL reconstruction using an autologous graft between the 1st of January 2019 and the 15th of February 2020 were included. The 535 patients who had undergone ACL reconstruction were divided into two groups: (Group 1) 279 patients in the group without anticoagulants; 96% received a four-strand semi-tendinosus graft (ST4) and 4% received a quadriceps tendon (QT) graft; the mean age of these patients was 30 years (14-58); 41% of them were women and 22% of them were smokers; the mean body mass index was 24.4 (18-37); the mean tourniquet time was 37minutes. (Group 2) 256 patients in the group with anticoagulants; 81% received a semi-tendinosus/gracilis graft, 15% received a ST4 and 4% a QT; the mean age of these patients was 29 years (14-60); 38% of them were women and 21% of them were smokers; the mean body mass index was 25.0 (18-38); the mean tourniquet time was 34minutes. The two groups were comparable in all respects except for the type of graft used. All patients were contacted at a minimum interval of 3 months after their surgery, by telephone. Doppler ultrasonography was done solely when a VTE was suspected. Results: In the group without anticoagulants, 249 of 279 patients were contacted, while in the group with anticoagulants, 221 of 256 were contacted. The two groups were comparable in terms of age, gender ratio, tourniquet time, body mass index and proportion of smokers. Two cases of deep vein thrombosis (all in the calf region) were found in each group with no associated pulmonary embolism. There was no difference between groups in the VTE rate. Discussion: Our hypothesis was confirmed since the incidence of symptomatic VTE was the same whether postoperative anticoagulants were prescribed or not. The incidence of symptomatic VTE after ACL reconstruction was identical whether thromboprophylaxis was used or not. This casts doubt on the need for postoperative thromboprophylaxis, especially in younger patients who do not have risk factors, and brings into question whether the recommendations in France should be changed. Level of evidence: III (retrospective case-control study).
Keywords: ACL surgery; Anticoagulants; Deep venous thromboembolism; Pulmonary embolism.

Year of publishing 2006

Shelbourne KD, Klotz C. What I have learned about the ACL: utilizing a progressive rehabilitation scheme to achieve total knee symmetry after anterior cruciate ligament reconstruction. J Orthop Sci. 2006;11(3):318-25.

Anterior cruciate ligament surgery and rehabilitation have changed drastically during the past 30 years. The patellar tendon autograft fixed with buttons provides tight bone-to-bone placement of the graft and quick bony healing, which allows accelerated rehabilitation to obtain full range of motion and strength. Although surgical stability is easily reproducible, long-term patient satisfaction is difficult to guarantee. Full knee range of motion should be compared to that of the contralateral normal knee, including full hyperextension. We followed the progress of all patients to gauge the utility of our rehabilitation program. In order of importance, the lack of normal knee range of motion (within 2 degrees extension and 5 degrees of flexion compared with that of the normal knee), partial or total medial meniscectomy, partial or total lateral meniscectomy, and articular cartilage damage were related to lower subjective scores. Rehabilitation after ACL reconstruction must first strive to achieve full symmetrical knee range of motion before aggressive strengthening can begin. Our current perioperative rehabilitation starts at the time of injury and preoperatively includes aggressive swelling reduction, hyperextension exercises, gait training, and mental preparation. Goals after surgery are to control swelling while regaining full knee range of motion. After quadriceps strengthening goals are reached, patients can shift to sport-specific exercises. When using a graft from the contralateral knee, the conflicting goals of strengthening the donor site and achieving full knee range of motion are divided between the knees. Thus, normal range of motion and strength can be achieved more easily and more quickly than when using an ipsilateral graft. Regardless of the graft source, a systematic rehabilitation program that emphasizes the return to symmetrical knee motion, including hyperextension, is necessary to achieve the optimum result.

Year of publishing 2013

Petrofsky JS, Laymon M, Lee H. Effect of heat and cold on tendon flexibility and force to flex the human knee. Med Sci Monit. 2013;19:661-7.

Background: It is commonly believed in medicine that using heat will increase the distensability and flexibility of soft tissue. If true, increased flexibility would be a positive factor to reduce injuries in sports. However, cold should have the opposite effect and is often used to treat sports injuries. This study was accomplished to quantify the effect of heat and cold on the force needed to flex the knee and laxness of the anterior and posterior cruciate ligaments. Material and methods: The present study examined 20 male and female subjects to determine if heat would increase extensibility of the anterior and posterior cruciate ligaments of the knee and reduce the force needed to flex the knee. Cold exposure was examined to see if it would have the opposite effect. There were 4 experiments in the series: The first was a room temperature series; the second was a series where cold was applied with an ice pack for 20 minutes; in the third, hydrocollator heat packs were applied for 20 minutes; and in the fourth, ThermaCare heat wraps were applied for 4 hours on the quadriceps and knee. Tendon extensibility was measured with a KT2000. The force for flexing the knee was measured by passive movement being applied (CPM) to the knee through 30° and the force required to move the leg was measured. Results: The results show that the anterior and posterior cruciate ligament flexibility increased and the force needed to move the knee decreased with heat by about 25% compared to cold application. Conclusions: Heat is beneficial in increasing muscle and ligament flexibility and may help reduce athletic injuries, but cold treatment may have the opposite effect.

Year of publishing 2013

Petersen W, Zantop T. Return to play following ACL reconstruction: survey among experienced arthroscopic surgeons (AGA instructors). Arch Orthop Trauma Surg. 2013 Jul;133(7):969-77. doi: 10.1007/s00402-013-1746-1. Epub 2013 Apr 21. PMID: 23604790.

Purpose: There is a lack of consensus regarding appropriate criteria attesting patient's unrestricted sports activities after ACL reconstruction. The purpose of this study was to perform a survey among experienced arthroscopic surgeons regarding their return to play guidelines in these patients. Methods: A six-item questionnaire was distributed among experienced arthroscopic surgeons (instructors of the German speaking society of arthroscopy, AGA). Study participants were asked to choose from multiple choice answers and had the possibility answering in an open discussion field. Results: The response rate of the survey was 85.7 %. A total of 83.5 % used autologous hamstring grafts for ACL reconstruction in athletes followed by BPTB (37.2 %) and quadriceps tendon graft (12 %). Approximately 63.5 % recommended a time point later than 6 months allowing return to play after ACL reconstruction in the athlete (after 4 and 6 months 2.3 and 35.3 %, respectively). 76.6 % recommended starting with sports specific rehabilitation after 4 months (21.6 % after 6 months). The most frequent criterion (multiple answers) to allow return to play was negative Lachman test (81.7 % positive answers) followed by free range of motion (78.4 %), negative pivot shift (60.1 %), anterior drawer (45.4 %), proprioception test (43.1 %), muscular strength analysis (40.8 %), single-leg hop jump test (39.0 %), KT 1000 measurement (16.1 %), and MRI (4.1 %). Of the surgeons 85.8 % did not use any of the given scores as criterion to allow return to competitive sports (subjective IKDC score 10.6 %, Lysholm score 8.3 %, objective IKDC score 7.4 %, Tegner activity scale 3.7 %). Conclusion: In conclusion, the majority of surgeons do not consider muscle function, jump tests, alignment tests, and proprioception as relevant return to sports criterion. However, these are two crucial parameters for return to sports.

Year of publishing 2016

Pamukoff DN, Pietrosimone B, Lewek MD, Ryan ED, Weinhold PS, Lee DR, Blackburn JT. Whole-Body and Local Muscle Vibration Immediately Improve Quadriceps Function in Individuals With Anterior Cruciate Ligament Reconstruction. Arch Phys Med Rehabil. 2016;97(7):1121-9.

Objective: To determine the immediate effects of a single session of whole-body vibration (WBV) and local muscle vibration (LMV) on quadriceps function in individuals with anterior cruciate ligament reconstruction (ACLR). Design: Singe-blind, randomized crossover trial. Setting: Research laboratory. Participants: Population-based sample of individuals with ACLR (N=20; mean age ± SD, 21.1±1.2y; mean mass ± SD, 68.3±14.9kg; mean time ± SD since ACLR, 50.7±21.3mo; 14 women; 16 patellar tendon autografts, 3 hamstring autografts, 1 allograft). Interventions: Participants performed isometric squats while being exposed to WBV, LMV, or no vibration (control). Interventions were delivered in a randomized order during separate visits separated by 1 week. Main outcome measures: Quadriceps active motor threshold (AMT), motor-evoked potential (MEP) amplitude, Hoffmann reflex (H-reflex) amplitude, peak torque (PT), rate of torque development (RTD), electromyographic amplitude, and central activation ratio (CAR) were assessed before and immediately after a WBV, LMV, or control intervention. Results: There was an increase in CAR (+4.9%, P=.001) and electromyographic amplitude (+16.2%, P=.002), and a reduction in AMT (-3.1%, P<.001) after WBV, and an increase in CAR (+2.7%, P=.001) and a reduction in AMT (-2.9%, P<.001) after LMV. No effect was observed after WBV or LMV in H-reflex, RTD, or MEP amplitude. AMT (-3.7%, P<.001), CAR (+5.7%, P=.005), PT (+.31Nm/kg, P=.004), and electromyographic amplitude (P=.002) in the WBV condition differed from the control condition postapplication. AMT (-3.0% P=.002), CAR (+3.6%, P=.005), and PT (+.30Nm/kg, P=.002) in the LMV condition differed from the control condition postapplication. No differences were observed between WBV and LMV postapplication in any measurement. Conclusions: WBV and LMV acutely improved quadriceps function and could be useful modalities for restoring quadriceps strength in individuals with knee pathologies.
Keywords: Knee; Muscles; Osteoarthritis; Rehabilitation; Resistance training.

Year of publishing 2016

Kyritsis P, Bahr R, Landreau P, Miladi R, Witvrouw E. Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. Br J Sports Med. 2016;50(15):946-51.

Background: The decision as to whether or not an athlete is ready to return to sport (RTS) after ACL reconstruction is difficult as the commonly used RTS criteria have not been validated. Purpose: To evaluate whether a set of objective discharge criteria, including muscle strength and functional tests, are associated with risk of ACL graft rupture after RTS. Materials and methods: 158 male professional athletes who underwent an ACL reconstruction and returned to their previous professional level of sport were included. Before players returned to sport they underwent a battery of discharge tests (isokinetic strength testing at 60°, 180° and 300°/s, a running t test, single hop, triple hop and triple crossover hop tests). Athletes were monitored for ACL re-ruptures once they returned to sport (median follow-up 646 days, range 1-2060). Results: Of the 158 athletes, 26 (16.5%) sustained an ACL graft rupture an average of 105 days after RTS. Two factors were associated with increased risk of ACL graft rupture: (1) not meeting all six of the discharge criteria before returning to team training (HR 4.1, 95% CI 1.9 to 9.2, p≤0.001); and (2) decreased hamstring to quadriceps ratio of the involved leg at 60°/s (HR 10.6 per 10% difference, 95% CI 10.2 to 11, p=0.005). Conclusions: Athletes who did not meet the discharge criteria before returning to professional sport had a four times greater risk of sustaining an ACL graft rupture compared with those who met all six RTS criteria. In addition, hamstring to quadriceps strength ratio deficits were associated with an increased risk of an ACL graft rupture.
Keywords: ACL; Rehabilitation; Risk factor; Sports.

Year of publishing 2006

Joseph M, Fulkerson J, Nissen C, Sheehan TJ. Short-term recovery after anterior cruciate ligament reconstruction: a prospective comparison of three autografts. Orthopedics. 2006;29(3):243-8.

Sixty-four patients with three different autografts were prospectively evaluated following anterior cruciate ligament (ACL) reconstruction for motion return, thigh girth, quadriceps activity, assistive device usage, and duration of pain medication usage. The quadriceps tendon group achieved knee extension sooner than the patellar tendon group. The hamstring group used assistive devices for less time than the patellar tendon group. The quadriceps group required less pain medication than either of the groups. There are significant differences in short-term pain medication requirements and restoration of function among patients following ACL reconstruction using different autografts.

Year of publishing 2016

Jacopetti M, Pasquini A, Costantino C. Evaluation of strength muscle recovery with isokinetic, squat jump and stiffness tests in athletes with ACL reconstruction: a case control study. Acta Biomed. 2016 May 6;87(1):76-80. PMID: 27163899.

BackgroundThe anterior cruciate ligament (ACL) rupture accounting for about 50% of all knee ligament injuries. The rehabilitation program requires a long time to rebuild muscle strength and to reestablish joint mobility and neuromuscular control. The purpose of the study is to evaluate the muscle strength recovery in athletes with ACL reconstruction. MethodsWe enrolled soccer atlethes, with isolated anterior cruciate ligament rupture treated with bone-patellar tendon-bone autograft artroscopic reconstruction. Each patients were evaluated comparing operated and controlateral limb by isokinetic test and triaxial accelerometer test. Isokinetic movements tested were knee flexion-extension with concentric-concentric contraction. Accelerometer test were Squat Jump Test (SJT) and Stiffness Test (ST). Results17 subjects were selected, there was no significant difference in isokinetic quadriceps and hamstrings results in strength and endurance values. Parameters of ST were comparable between the operated and unoperated side. In SJT a significant statistical difference was in height of jump (p=0,02) no statistical difference was evidenced in the other measures.ConclusionCurrently complete recovery of symmetric explosive strength seems to be an important parameter for evaluating the performance after ACL reconstruction and the symmetry in test results jump could be associated with an adequate return to sports. In our study the explosive strenght is lower in the limb operated than the healthy one. Explosive strength recovery with pliometric training should be included in the post-surgical rehabilitation protocol and its measurement should be performed to assess the full recovery before the restart of sport activities.
Keywords: Anterior cruciate ligament rehabilitation, Explosive strength, Bone patellar tendon bone autograft, Muscular recovery.

Year of publishing 2016

Iriuchishima T, Ryu K, Okano T, Suruga M, Aizawa S, Fu FH. The evaluation of muscle recovery after anatomical single-bundle ACL reconstruction using a quadriceps autograft. Knee Surg Sports Traumatol Arthrosc. 2017;25(5):1449-1453.

Purpose: The purpose of this study was to reveal the degree of muscle recovery and report the clinical results of anatomical single-bundle ACL reconstruction using a quadriceps autograft. Methods: Twenty subjects undergoing anatomical single-bundle ACL reconstruction using a quadriceps autograft were included in this study. A 5-mm-wide, 8-cm-long graft, involving the entire layer of the quadriceps tendon, was harvested without bone block. The average graft diameter was 8.1 ± 1.4 mm. An initial tension of 30 N was applied. The femoral tunnel was created from the far-medial portal. Each femoral and tibial tunnel was created close to the antero-medial bundle insertion site. For the evaluation of muscle recovery (quadriceps and hamstring), a handheld dynamometer was used. The evaluation of muscle recovery was performed pre-operatively, and at 3, 6, 9, and 12 months after surgery. Muscle recovery data were calculated as a percentage of leg strength in the non-operated leg. Anterior tibial translation (ATT), pivot shift test, and IKDC score were evaluated. Results: The average quadriceps strength pre-operatively, and at 3, 6, 9, and 12 months after ACL reconstruction was 90.5 ± 19, 67.8 ± 21.4, 84 ± 17.5, and 85.1 ± 12.6 %, respectively. The average hamstring strength pre-operatively, and at 3, 6, 9, and 12 months after ACL reconstruction was 99.5 ± 13.7, 78.7 ± 11.4, 90.5 ± 19, and 96.7 ± 13.8 %, respectively. ATT pre-operatively and at 12 months after surgery was 5.4 ± 1.3 and 1.0 ± 0.8 mm, respectively. No subjects exhibited positive pivot shift after surgery. Within 6 months following surgery, quadriceps hypotrophy was observed in all subjects. However, the hypotrophy had recovered at 12 months following surgery. No subjects complained of donor site pain after surgery. Conclusion: Anatomical single-bundle ACL reconstruction using a quadriceps autograft resulted in equivalent level of muscle recovery and knee stability when compared with previously reported ACL reconstruction using hamstrings tendon with no donor site complications. Level of evidence: Case controlled study, Level III.
Keywords: Anatomical; Anterior cruciate ligament; Muscle recovery; Quadriceps tendon.

Year of publishing 2000

Hoffman M, Koceja DM. Hoffmann reflex profiles and strength ratios in postoperative anterior cruciate ligament reconstruction patients. Int J Neurosci. 2000;104(1-4):17-27. d

Rupture of the anterior cruciate ligament (ACL) typically leads to surgical reconstruction followed by an extensive rehabilitation program. One of the most commonly experienced complications associated with ACL rupture and reconstruction is quadriceps muscle atrophy. A clear understanding of the exact mechanisms associated with ACL related atrophy remains undocumented. The purpose of the present study was to investigate maximum H-reflex to maximum M-wave ratio as well as quadriceps deficit for both isometric and isokinetic peak torques in a post ACL reconstruction population. Forty subjects volunteered for participation in this study. The experimental group comprised 20 subjects who had undergone patellar tendon graft reconstruction of a torn ACL. A matched control group of 20 subjects were also measured for comparative purposes. The results indicated the control group had significantly higher quadriceps to quadriceps ratio than did the ACL group [t(38) = 9.05 p < .001]. In contrast, there was no difference in the H-max/M-max ratio for either group or leg. The strength findings of this study support previous findings. The spinal reflex results support the need for additional research in this area, specifically with more acutely injured subjects.

Year of publishing 2005

Grant JA, Mohtadi NG, Maitland ME, Zernicke RF. Comparison of home versus physical therapy-supervised rehabilitation programs after anterior cruciate ligament reconstruction: a randomized clinical trial. Am J Sports Med. 2005;33(9):1288-97.

Background: Because of health care funding and policy changes, there is a need to examine the effects of an evolution toward patient-directed (ie, home-based) rehabilitation programs on clinical outcomes of patients undergoing anterior cruciate ligament reconstruction. Hypothesis: There will be no difference in the effectiveness of a home-based rehabilitation program and a standard physical therapy-supervised rehabilitation program in patients 3 months after nonacute anterior cruciate ligament reconstruction with bone-patellar tendon-bone grafts. Study design: Randomized controlled clinical trial; Level of evidence, 1. Methods: There were 145 patients (16-59 years) who attended a presurgery education class. Home-based patients attended 4 physical therapy sessions, and physical therapy-supervised patients attended 17 physical therapy sessions over the first 12 weeks after surgery. All patients followed the same standardized rehabilitation program. Study outcome measures included active-assisted knee flexion and passive knee extension range of motion, knee range of motion during walking, KT computerized arthrometer results, and isokinetic quadriceps and hamstrings strength. Patient outcomes were dichotomized as either clinically acceptable or unacceptable. Rehabilitation programs were compared by the proportion of acceptable patients in each group. Results: The home-based group had a significantly higher percentage of patients with acceptable flexion and extension range of motion compared to the standard physical therapy group (flexion, 67% vs 47%; extension, 97% vs 83%). There were no significant differences between the groups in range of motion during walking, ligament laxity, and strength. Conclusion: A structured, minimally supervised rehabilitation program was more effective in achieving acceptable knee range of motion in the first 3 months after anterior cruciate ligament reconstruction than a standard physical therapy-based program. Clinical relevance: Recreational athletes undergoing nonacute anterior cruciate ligament reconstruction can successfully reach acceptable rehabilitation goals in the first 3 months after surgery with a limited number of purposeful physical therapy education sessions, allowing recreational athletes more flexibility when integrating the necessary postoperative rehabilitation into their daily activities.

Year of publishing 2010

Grant JA, Mohtadi NG. Two- to 4-year follow-up to a comparison of home versus physical therapy-supervised rehabilitation programs after anterior cruciate ligament reconstruction. Am J Sports Med. 2010 Jul;38(7):1389-94.

Background: There have been no long-term follow-up studies comparing a predominantly home-based rehabilitation program with a standard physical therapy program after anterior cruciate ligament (ACL) reconstruction. Demonstrating the long-term success of such a cost-effective program would be beneficial to guide future rehabilitation practice. Purpose: To determine whether there were any differences in long-term outcome between recreational athletes who performed a physical therapy-supervised rehabilitation program and those who performed a primarily home-based rehabilitation program in the first 3 months after ACL reconstruction. Study design: Randomized clinical trial; Level of evidence, 1. Methods: Patients were randomized before ACL reconstruction surgery to either the physical therapy-supervised (17 physical therapy sessions) or home-based (4 physical therapy sessions) program. Eighty-eight of the original 129 patients returned 2 to 4 years after surgery to assess their long-term clinical outcomes. Primary outcome was the ACL quality of life questionnaire (ACL QOL). Secondary outcomes were bilateral difference in knee extension and flexion range of motion, sagittal plane knee laxity, relative quadriceps and hamstring strength, and objective International Knee Documentation Committee score. Unpaired t tests and a chi-square test were used for the comparisons. Results: The home-based group had a significantly higher mean ACL QOL score (80.0 +/- 16.2) than the physical therapy-supervised group (69.9 +/- 22.0) a mean of 38 months after surgery (P = .02, 95% confidence interval [CI]: 1.7, 18.4). The mean change in ACL QOL score from before surgery to follow-up was not significantly different between the groups (physical therapy = 40.0, home = 45.8, P = .26, 95% CI: -15.8, 4.4). There were no significant differences in the secondary outcome measures. Conclusion: This long-term study upholds the short-term findings of the original randomized clinical trial by demonstrating that patients who participate in a predominantly home-based rehabilitation program in the first 3 months after ACL reconstruction have similar 2- to 4-year outcomes compared with those patients who participate in a more clinically supervised program.

Year of publishing 2006

Gerber JP, Marcus RL, Dibble LE, Greis PE, LaStayo PC. Early application of negative work via eccentric ergometry following anterior cruciate ligament reconstruction: a case report. J Orthop Sports Phys Ther. 2006;36(5):298-307.

Study design: Case report. Objectives: To present a progressively increasing negative-work exercise program via eccentric ergometry early after anterior cruciate ligament reconstruction (ACL-R) and to suggest the potential of negative work to amplify the return of quadriceps size and strength. Case description: The patient was a 26-year-old highly active recreational athlete who sustained an ACL tear while skiing in January 2004 and then again while skiing in February 2005. This individual underwent an arthroscopically assisted ACL-R with a double-loop semitendinosusgracilis autograft initially, then a patellar tendon autograft following his ACL graft rupture. Beginning within 3 weeks after surgery, a progressive negative-work exercise program was initiated using an eccentric ergometer. The patient completed 31 training sessions of 5 to 30 minutes in duration over a 12-week period following the ACL-R and 33 training sessions of the same frequency and duration following the ACL revision. Outcomes: Following ACL-R, quadriceps volume increased 28% (involved lower extremity) and 14% (uninvolved lower extremity) during the 12-week training program. Following revision, quadriceps volume returned to similar levels at the same postoperative period as those achieved after the initial surgery (2% less on the involved side and 2% greater on the uninvolved side). Quadriceps strength, 15 weeks after ACL-R, exceeded preoperative measures by an average of 20% (involved) and 14% (uninvolved). Quadriceps strength after ACL revision exceeded all previous measures. Discussion: This case report suggests that if gradually and progressively applied, negative work via eccentric ergometry can be both safe and efficacious early after ACL-R. Eccentric exercise may mitigate the prevalent muscle size and strength deficits commonly observed after ACL-R. The results of this case suggest a need for continued research with early negative work interventions following ACL-R.

Year of publishing 2009

Gerber JP, Marcus RL, Dibble LE, Greis PE, Burks RT, LaStayo PC. Effects of early progressive eccentric exercise on muscle size and function after anterior cruciate ligament reconstruction: a 1-year follow-up study of a randomized clinical trial. Phys Ther. 2009;89(1):51-9.

Background and purpose: The authors previously reported that focused eccentric resistance training during the first 15 weeks following anterior cruciate ligament reconstruction (ACL-R) induced greater short-term increases in muscle volume, strength, and measures of function relative to standard rehabilitation. The purpose of this study was to evaluate the effects of early progressive eccentric exercise on muscle volume and function at 1 year after ACL-R. Participants and methods: Forty patients who had undergone an ACL-R were randomly assigned to 1 of 2 groups: a group that received early progressive eccentric exercise (n=20) and a group that received standard rehabilitation (n=20). Seventeen participants in the eccentric exercise group and 15 participants in the standard rehabilitation group completed a 1-year follow-up. Magnetic resonance images of the thighs were acquired 1 year after ACL-R and compared with images acquired 3 weeks after surgery. Likewise, routine knee examinations, self-report assessments, and strength and functional testing were completed 1 year after surgery and compared with previous evaluations. A 2-factor analysis of variance for repeated measures (group x time) was used to analyze the data. Results: Compared with the standard rehabilitation group, improvements in quadriceps femoris and gluteus maximus muscle volume in the involved lower extremity from 3 weeks to 1 year following ACL-R were significantly greater in the eccentric exercise group. Improvements in quadriceps femoris and gluteus maximus muscle volume were 23.3% (SD=14.1%) and 20.6% (SD=12.9%), respectively, in the eccentric exercise group and 13.4% (SD=10.3%) and 11.6% (SD=10.4%), respectively, in the standard rehabilitation group. Improvements in quadriceps femoris muscle strength and hopping distance also were significantly greater in the eccentric exercise group 1 year postsurgery. Discussion and conclusion: A 12-week focused eccentric resistance training program, implemented 3 weeks after ACL-R, resulted in greater increases in quadriceps femoris and gluteus maximus muscle volume and function compared with standard rehabilitation at 1 year following ACL-R.

Year of publishing 2013

Fukuda TY, Fingerhut D, Moreira VC, Camarini PM, Scodeller NF, Duarte A Jr, Martinelli M, Bryk FF. Open kinetic chain exercises in a restricted range of motion after anterior cruciate ligament reconstruction: a randomized controlled clinical trial. Am J Sports Med. 2013;41(4):788-94.

Background: Recent studies have shown that an early start of open kinetic chain (OKC) exercises for quadriceps strengthening in a full range of motion (ROM) could increase anterior knee laxity after anterior cruciate ligament (ACL) reconstruction with flexor tendons. However, there are no clinical trials that evaluated outcomes of OKC exercises in a restricted ROM for pain, function, muscle strength, and anterior knee laxity at 1 year after surgery. Purpose: To determine if an early start of OKC exercises for quadriceps strength in a restricted ROM would promote a clinical improvement without causing increased anterior knee laxity in patients after ACL reconstruction. Study design: Randomized controlled clinical trial; Level of evidence, 1. Methods: A total of 49 patients between 16 and 50 years of age who underwent ACL reconstruction with semitendinosus and gracilis autografts were randomly assigned to an early start OKC (EOKC) exercise group or a late start OKC (LOKC) exercise group. The EOKC group (n = 25; mean age, 26 years) received a rehabilitation protocol with an early start of OKC (fourth week postoperatively) within a restricted ROM between 45° and 90°. The LOKC group (n = 24; mean age, 24 years) performed the same protocol with a late start of OKC exercises between 0° and 90° (12th week postoperatively). Quadriceps and hamstring muscle strength, 11-point numerical pain rating scale (NPRS), Lysholm knee scoring scale, single-legged and crossover hop tests, and anterior knee laxity were measured to assess outcomes at the 12-week, 19-week, 25-week, and 17-month postoperative follow-up (range, 13-24 months). Results: No difference (P < .05) was noted between groups with respect to demographic data. Both groups (EOKC and LOKC) had a higher level of function and less pain at the 19-week, 25-week, and 17-month assessments when compared with 12 weeks postoperatively (P < .05). The EOKC group had improved quadriceps muscle strength at the 19-week, 25-week, and 17-month follow-up when compared with 12 weeks postoperatively (P < .05); the LOKC group showed improvement only at the 17-month postoperative assessment. However, the analysis between groups showed no difference for all pain and functional assessments, including anterior knee laxity (P > .05). Conclusion: An early start of OKC exercises for quadriceps strengthening in a restricted ROM did not differ from a late start in terms of anterior knee laxity. The EOKC group reached the same findings in relation to pain decrease and functional improvement when compared with the LOKC group but showed a faster recovery in quadriceps strength. The nonweightbearing exercises seem appropriate for patients who have undergone ACL reconstruction, when utilized in a specific ROM. The magnitude of difference in quadriceps strength between the 2 rehabilitation protocols was around 5%; however, this difference was not clinically significant, especially because both groups had equal function on the hop tests.

Year of publishing 2007

Fabiś J. The impact of a isokinetic training program on the peak torque of the quadriceps and knee flexors after anterior cruciate ligament reconstruction with hamstrings. Ortop Traumatol Rehabil. 2007 Sep-Oct;9(5):527-31.

Background: The purpose of this study was to evaluate the peak torque of the knee flexors (H) and the quadriceps muscle (Q) at 12 and 24 weeks after isolated anterior cruciate ligament reconstruction with semitendinosus and gracilis autografts. Materials and methods: There were 20 patients (8 females, 12 males), with the mean age of 31.5 years. An isokinetic examination of the muscles was performed with a Biodex System 3 isokinetic dynamometer at a speed of 180 degrees/sec. All patients underwent 12 weeks of isokinetic training for 20 minutes 5 times a week (240 degrees/sec for 6 weeks and 180 degrees/sec for 6 weeks) beginning 12 weeks after surgery. Results: The average peak torque difference between the healthy and operated limb at 12 and 24 weeks postoperatively was 38% and 14% for Q and 25% and 4.3% for H respectively. The decrease in peak torque differences was statistically significant for both H and Q (p=0.05). The decrease in Q peak torque was significantly higher than that of H peak torque 12 and 24 weeks after surgery. Conclusions: These results indicate that 12-week isokinetic training can increase the peak torque of H and Q by 20% and 24% respectively. An isokinetic examination of Q and H peak torques should become a standard procedure for evidence-based monitoring of the rehabilitation process after anterior cruciate ligament reconstruction.

Year of publishing 2015

Cvjetkovic DD, Bijeljac S, Palija S, Talic G, Radulovic TN, Kosanovic MG, Manojlovic S. Isokinetic Testing in Evaluation Rehabilitation Outcome After ACL Reconstruction. Med Arch. 2015;69(1):21-3.

Introduction: Numerous rehab protocols have been used in rehabilitation after ACL reconstruction. Isokinetic testing is an objective way to evaluate dynamic stability of the knee joint that estimates the quality of rehabilitation outcome after ACL reconstruction. Our investigation goal was to show importance of isokinetic testing in evaluation thigh muscle strength in patients which underwent ACL reconstruction and rehabilitation protocol. Subjects and methods: In prospective study, we evaluated 40 subjects which were divided into two groups. Experimental group consisted of 20 recreational males which underwent ACL reconstruction with hamstring tendon and rehabilitation protocol 6 months before isokinetic testing. Control group (20 subjects) consisted of healthy recreational males. In all subjects knee muscle testing was performed on a Biodex System 4 Pro isokinetic dynamo-meter et velocities of 60°/s and 180°/s. We followed average peak torque to body weight (PT/BW) and classic H/Q ratio. In statistical analysis Student's T test was used. Results: There were statistically significant differences between groups in all evaluated parameters except of the mean value of PT/BW of the quadriceps et velocity of 60°/s (p>0.05). Conclusion: Isokinetic testing of dynamic stabilizers of the knee is need in diagnostic and treatment thigh muscle imbalance. We believe that isokinetic testing is an objective parameter for return to sport activities after ACL reconstruction.
Keywords: ACL reconstruction; isokinetic test; rehabilitation.

Year of publishing 2015

Clagg S, Paterno MV, Hewett TE, Schmitt LC. Performance on the modified star excursion balance test at the time of return to sport following anterior cruciate ligament reconstruction. J Orthop Sports Phys Ther. 2015;45(6):444-52.

Study design: Cross-sectional. Objectives To compare performance on the modified Star Excursion Balance Test (SEBT) between participants with anterior cruciate ligament reconstruction (ACLR) at the time of return to sport and uninjured control participants. Background: The modified SEBT is a clinical tool to assess neuromuscular control deficits. Deficits in dynamic stability and neuromuscular control persist after ACLR, but assessment with the modified SEBT in this population at the time of return to sport has not been reported. Methods: Sixty-six participants (mean age, 17.6 years) at the time of return to sport following unilateral primary ACLR (ACLR group) and 47 uninjured participants (mean age, 17.0 years) serving as a control group participated. For the modified SEBT, the anterior, posteromedial, and posterolateral reach distances were recorded. Lower extremity muscle strength was quantified with isokinetic dynamometry. Independent-sample t tests were used to evaluate performance differences between the ACLR group and the control group and between the ACLR subgroups. In the ACLR group, bivariate correlations determined the association of modified SEBT performance with time since surgery and lower extremity muscle strength. Results: The ACLR group had lower anterior reach distances on the involved and uninvolved limbs compared to the control group. There were no differences observed between groups in reach distances for the posteromedial and posterolateral directions or in limb symmetry indices for any of the reach directions. In the ACLR group, time from surgery and meniscal status at the time of ACLR did not influence modified SEBT performance, whereas participants with patellar bone-tendon-bone grafts had a lower posterolateral reach distance compared to those with hamstring grafts. In the ACLR group, involved-limb hip abduction strength positively correlated with all reach distances, and quadriceps strength positively correlated with posterolateral reach. Conclusion: At the time of return to sport, participants post-ACLR demonstrated reduced modified SEBT anterior reach in both involved and uninvolved limbs compared to uninjured participants, with no other group differences. In the ACLR group, modified SEBT reach distance was associated with lower extremity muscle strength, but not with time from reconstruction or meniscal status at the time of ACLR. Lower extremity muscle strength and graft type may interact to influence modified SEBT posterior reach performance, but this requires further study. Level of evidence: Prognosis level 2b-.
Keywords: ACL; ACL reconstruction; dynamic stability; knee; performance.

Year of publishing 2012

Christanell F, Hoser C, Huber R, Fink C, Luomajoki H. The influence of electromyographic biofeedback therapy on knee extension following anterior cruciate ligament reconstruction: a randomized controlled trial. Sports Med Arthrosc Rehabil Ther Technol. 2012;4(1):41.

Background: Loss of knee extension and a deficit in quadriceps strength are frequently found following anterior cruciate ligament (ACL) reconstruction. The aim of this study was to investigate whether the addition of Eletromyographic Biofeedback (EMG BFB) therapy for the vastus medialis muscle to the in the early phase of the standard rehabilitation programme could improve the range of knee extension and strength after ACL reconstruction more than a standard rehabilitation programme. The correlation between EMG measurement and passive knee extension was also investigated. Method: Sixteen patients, all of whom underwent endoscopic ACL reconstruction using patellar tendon autograft, were randomly assigned to two groups:• Control group (8 patients): standard rehabilitation protocol; with full weight-bearing postoperative, knee brace (0° extension, 90° flexion), electrical stimulation, aquatics and proprioceptive training.• The EMG BFB group (8 patients): EMG BFB was added to the standard rehabilitation protocol within the first postoperative week and during each session for the next 6 weeks.Each patent attended a total of 16 outpatient physiotherapy sessions following surgery. High-Heel-Distance (HHD) Test, range of motion (ROM) and integrated EMG (iEMG) for vastus medialis were measured preoperatively, and at the 1, 2, 4 and 6-week follow ups. Additionally, knee function, swelling and pain were evaluated using standardized scoring scales. Results: At 6 weeks, passive knee extension (p < 0.002) and the HHD Test were significantly (p < 0.01) better in the EMG BFB group compared to controls. Integrated EMG (vastus medialis) of the EMG BFB group also showed a significant increase after 2 (p < 0.01) and 6 (p < 0.01) weeks. At the 6-week follow up, no significant (p > 0.01) differences were found between the two groups for the assessment of knee function, swelling and pain. Conclusion: The results indicate that EMG BFB therapy, in the early phase of rehabilitation after ACL reconstruction, is useful in enhancing knee extension. Improved innervation of the vastus medialis can play a key role in the development of postoperative knee extension. EMG BFB therapy is a simple, inexpensive and valuable adjunct to conventional therapeutic modalities.