Introduction

The question of which of the available autografts is the most appropriate choice for anterior (ACL) and posterior cruciate ligament (PCL) reconstruction remains challenging. Since the early years of Ligament reconstruction in the 1960s, the main focus was on the use of BTPB grafts as the most adequate autograft for Ligament reconstruction. The advocates of BTB prefer this graft choice mostly due to its high strength, measured to be twice that of a native ACL. Additionally, this graft is harvested with two bone-blocks at each end, whose placement in bone tunnels is believed to help both graft-fixation, as well as osteointegration. Despite the well-described and widely documented high incidence of postoperative surgical morbidities such as residual donor site morbidity, postoperative kneeling pain, and strength deficit, and numbness, many surgeons around the world still consider the BTB autograft to be the gold standard in autograft selection. On the other hand, proponents of Hamstring tendon autograft – which is the most commonly used autograft in clinical practice today – cite low donor site morbidity and absence of extensor strength deficit, and claim that the best choice lays in Hamstring autograft as the most reproducible and applicable autograft. However, reported a relatively high incidence of residual flexor mechanism strength deficit and unpredictability of graft length and diameter preoperatively, pose significant downsides. Injury to neurovascular structures and sensitivity loss in the donor site area have also been reported and are considered as disadvantages to its application. A recent meta-analysis conducted by Freedman et al. with the goal of comparing different parameters and clinical outcomes of the most common grafts, the Patellar tendon, and Hamstrings tendon, showed that even tough graft failure rate was lower in the BTPB group, on one hand, there was a significantly higher incidence of postoperative stiffness and patellofemoral pain compared to Hamstrings group, on the other. The Quadriceps tendon autograft is the least utilized and thus the least researched autograft option, with many questions regarding its anatomical and Biomechanical aspects, as well as harvesting techniques and clinical outcomes, which still remain open. The concept of using Quadriceps tendon autograft was first advocated in 1979. by Marshall et al. followed by a report on potential harvesting technique by Blauth in 1984. In the early years of orthopedic ligament reconstruction, the accent was in recognizing the graft of the highest strength. In the early tests, QT autograft had proven to have a lower ultimate load at failure values than the 14mm-wide BTPB graft, which was an initial step to its general rejection. Quadriceps tendon graft had since then been revised every five to ten years, but due to its initial poor clinical outcome and biomechanical results, has been mostly abandoned, with its application reserved for revision surgeries or as an ultimate choice in absence of other graft options.

In the last three decades, the interest in Quadriceps autograft and its clinical application has been rapidly increasing, with series of publications and studies being published each year.

Insofar, several authors led by Staubli and colleagues, and Fulkerson et al. continued further advocating the use of QT in knee ligament reconstruction techniques. The authors emphasized on the beneficial aspect of the QT as the graft source; it provides a graft of good tensile properties, advantagous cross-sectional volume and sufficient strength for restoration of knee stability, along with significantly smaller incision required for harvest and less knee extension morbidity, as to why QT should be considered as an appropriate substitution for BTB autograft. Recent meta-analysis performed by Mulford et al. including 1580 ACL reconstructed knees showed no significant difference in clinical outcome, when comparing all three graft options, and further concluded that in regards to donor-site morbidity QT graft presents a more reproducible graft option than BTPB graft. In support of QT as the appropriate graft, choice come the findings of Xerogeanes et al. who found that QT not only yields a graft of significantly higher intra-articulate cross-sectional volume than the Patellar tendon but at the same time preserves much more native tissue at the donor-site.

Due to this renewed interest and significantly more frequent application, the need for precise knowledge of its anatomical and biomechanical characteristics, as well as clinical outcomes and rehabilitation protocols following the use of QT are of utmost importance in the future.

The purpose of this review is to summarize the presentations and discussion panels, held during the meeting, and to provide insight into the general conclusions and proposed research ideas established by the participants.

Additionally, the summary of this meeting findings and the interactive and educational character of this webpage aims to present to the broader orthopedic population up-to-date findings on potentials and limits of this graft choice for knee ligament reconstruction surgery.

Traditional bone-patellar tendon-bone and hamstring tendon ACL grafts are not without limitations. A growing body of anatomic, biomechanical, and clinical data has demonstrated the utility of quadriceps tendon autograft in arthroscopic knee ligament reconstruction. The quadriceps tendon autograft provides a robust volume of tissue that can be reliably harvested, mitigating the likelihood of variably sized grafts and obviating the necessity of allograft augmentation. Modern, minimally invasive harvest techniques offer the advantages of low rates of donor site morbidity and residual extensor mechanism strength deficits. New data suggest that quadriceps tendon autograft may possess superior biomechanical characteristics when compared with bone-patella tendon-bone (BPTB) autograft. However, there have been very few direct, prospective comparisons between the clinical outcomes associated with quadriceps tendon autograft and other autograft options (eg, hamstring tendon and bone-patellar tendon-bone). Nevertheless, quadriceps tendon autograft should be one of the primary options in any knee surgeon’s armamentarium.