Summary
The study demonstrated that harvesting the quadriceps tendon graft does not result in negative impacts on patellofemoral joint function, with normalization of patellar position and functional assessment taking at least 6 months
Abstract
Background
The technique of utilizing the quadriceps femoris tendon (QTA) as a graft for anterior cruciate ligament reconstruction (ACLR) may significantly influence the position of the patella and overall knee function. This approach can lead to alterations in quadriceps muscle activity, resulting in muscle atrophy and restricted patellar mobility, particularly in the early postoperative phase. In addition, the formation of scar tissue at the donor site may further decrease the flexibility of the knee extension apparatus, potentially exacerbating functional limitations and contributing to complications such as anterior knee pain. Understanding these effects is essential for improving rehabilitation strategies and patient outcomes following ACLR.
Methods
The study group (QTA-quadriceps tendon autograft) included 38 patients (22 males and 16 females), while the control group (BPTB) was expanded to 96 patients (55 males and 41 females) who received a patellar tendon graft. MRI measurements for the QTA group were performed at five intervals: pre-surgery and 12, 24, 36, and 48 weeks post-operation. For the BPTB group, assessments occurred at 2, 6, 12, 24, 36, 48, 72, and 96 weeks. Key measurements, including patellar tendon length (PTL), craniocaudal patella distance (CPD), craniocaudal patella face (CPF), patella-tibia distance (PTD), and patellofemoral contacting surface (PCS), were marked on sagittal and axial sections of the MRI. Subsequently, parameters such as ISI, CDI, BPI, PTI, FA, and PTA were determined and subjected to statistical analysis.Functional assessment included evaluating patellar position at a 15-degree flexion angle and subjective patient well-being using the Kujala scale and the Patellofemoral Pain Scale (PFPS).
Results
Analysis of patellar position in the transverse plane revealed significantly lower PTA values at 12 and 24 weeks post-surgery for the QTA group, and at 12 weeks for the BPTB group. In the sagittal plane, the QTA group displayed a significantly lower Canton-Deschamps index (CDI) at 12, 24, and 36 weeks compared to baseline (p<0.03), while differences in the Blackbourne-Peel index were noted at 12 weeks. No significant changes were observed in ISI, BPI, or PTI during the 12-month follow-up. Comparative analysis between QTA and BPTB groups showed significantly lower ISI values up to 12 months in the BPTB group (p<0.01), as well as significantly lower CDI values in the QTA group at 12 weeks. Additionally, the BPTB group exhibited significantly lower BPI values at 24 and 48 weeks (p<0.05). There were no significant differences in PTI values between the groups. Functional analysis did not reveal any significant differences in patellar positioning (p>0.05) or in subjective assessment of knee function concerning the patellofemoral joint. More than 90% of patients reported no pain in the anterior compartment of the knee at 6 months post-surgery.
Conclusion
Normalization of patella position, as well as functional assessment concerning the patellofemoral joint, takes at least 6 months, which may be important in the context of overload protection in the patellofemoral joint, especially when training loads are intensified.