Evaluation of Short-Term Clinical Results Following Isolated MPFL Reconstruction with Superficial Quadriceps or Hamstring Tendon in Patellar Dislocation: MPFL Reconstruction Using Quadriceps Versus Semitendinosus Autograft

Objectives: While hamstring autografts are widely used in medial patellofemoral ligament reconstruction (MPFLR), concerns have arisen regarding complications associated with the patella bone tunnel and fixation hardware, such as endobutton. As an alternative, the superficial quadriceps tendon (SQ) has also been used presently. The purpose of the present study is to compare the short-term clinical outcomes of MPFLR using superficial quadriceps tendon and using hamstring tendon. Methods: All patients who had undergone MPFLR for patella instability from 2013 to 2020 and were able to follow up for more than two years were retrospectively evaluated. For autograft of MPFLR, hamstring was inserted to the patellar bone tunnel formed at superomedial corner of the patella or through the whole patella (ST group), while the center third of the superficial layer of the quadriceps tendon graft was harvested and turned medially leaving its attachment to the patella intact (SQ group). Both grafts were fixed at Schottle’s point with an initial tension of 10-20 N and 30 degrees of knee flexion. Preoperative assessment included the range of knee motion (ROM), and radiographic features such as tibial tubercle–trochlear groove (TT-TG) distance, patellar tilt, and sulcus angle. The Kujala score, Tegner activity score, Lysholm score, ROM, and patellar tilt were assessed at one year postoperatively. Failure was defined by a postoperative patellar dislocation, surgical revision for recurrent patellar instability or any complication. Paired t-test and two-way repeated measure ANOVA followed by multiple comparison using Bonferroni test was carried out for statistical analysis, and statistical differences were considered significant for values of p < 0.05. Results: Among 69 patients (72 knees) who underwent MPFL reconstruction, 65 patients 70 knees (97.2%, 24 males and 41 females) were able to follow-up. The mean follow-up period was 33.4 ± 26.1 months. There were 43 patients (46 knees) in the SQ group and 22 patients (24 knees) in the ST group. There was no difference in preoperative TT-TG distance (SQ group: 14.5 ± 4.2 mm, ST group: 16.3 ± 3.1 mm) and sulcus angle (SQ group: 139.5 ± 8.8 degrees, ST group: 140.5 ± 11.1 degrees). Significant difference between groups in clinical scoring only appeared in Lysholm score at both pre and postoperatively (p < 0.01). ROM improved postoperatively, but there was no significance between the two groups. The Tilting angle (preoperative; SQ group: 20.4 ± 8.3 degrees, ST group: 24.9 ± 11.8 degrees) improved significantly (postoperatively; SQ group: 11.5 ± 4.5 degrees, ST group: 10.9 ± 4.8 degrees) (p < 0.01). There were two failures (8.3%) in the ST group with one patellar fracture and one postoperative patellar dislocation requiring additional surgery. Conclusion: Both groups had good short-term results, but postoperative Lysholm score and Kujala score were higher in the SQ group. Postoperative improvement in tilting angle reveals that both grafts contribute to restoring MPFL function. However, concerning failures that occurred in the ST group, SQ autograft may be safe and considerable for MPFLR.