Comparison of double bundle semitendinosus technique and pedicled quadriceps technique in patellar instability

To compare clinical and functional outcomes of medial patellofemoral ligament (MPFL) reconstruction using a minimally invasive pedicled quadriceps tendon (QT) or patella double tunnel technique with semitendinosus tendon (ST) graft in patients with recurrent patella dislocation.

A retrospective analysis was conducted on 51 patients who underwent MPFL reconstruction between 2014 and 2022, with a minimum 2-year post-operative follow-up. Patients were grouped as QT (n = 24) and ST (n = 27), alongside a control group of 24 healthy individuals. Kujala, Lysholm and Visual Analogue Scale (VAS) scores were evaluated. Isokinetic tests at 60° angular velocity were performed to calculate the limb symmetry index (LSI) and hamstring/quadriceps (H/Q) ratio.

No significant differences were found between groups regarding age, sex, body mass index, time to surgery, or number of dislocations (n.s). Mean Kujala (QT: 89.2 ± 8.9, ST: 85.4 ± 11.4), Lysholm (QT: 90.6 ± 9.4, ST: 87.9 ± 10.7), and VAS (QT: 0.83 ± 1.3, ST: 0.9 ± 1.1) scores showed no statistically significant differences between the groups (n.s). Extension LSI was significantly higher in QT (92.2 ± 10.0%) than ST (81.4 ± 16.4%, p = 0.024), as was flexion LSI (QT: 94.2 ± 10.9%, ST: 83.3 ± 17.5%, p < 0.01). H/Q ratios showed no significant differences between operated and non-operated sides (n.s). No redislocations or patellar fractures occurred. Apprehension signs were positive in two patients (7.4%) in ST and one patient (4.1%) in QT.

MPFL reconstruction with both ST and pedicled QT grafts yields successful results in well-selected patient groups. Unlike ST, reconstruction with QT results in extension and flexion strength in the operated extremity that is closer to the non-operated side and to the healthy control group.

Level III, retrospective case-control study.