Reconstruction of the medial patellofemoral ligament using a double-bundle semitendinosus tendon graft and a single suture anchor

BACKGROUND: The double bundle medial patellofemoral ligament reconstruction (MPFL-R) is a well-established surgical technique for the management of patellar instability. While double anchor screw fixation on the patellar side is currently favored by many surgeons, this article presents a modified surgical approach involving minor technical modifications that may decrease dependence on internal implants. METHODS: From July 2016 to August 2023, the same surgeon performed two distinct MPFL-R procedures on patients with recurrent patellar dislocation. The novel single-anchor MPFL-R technique involves fixing the inferior graft bundle into a surgically created medial bony groove of the patella using a single suture anchor, while the superior bundle is passed through the junction of the vastus medialis obliquus (VMO) tendon and the patella. The double-anchor MPFL-R technique utilizes two suture anchors placed on the patella to separately secure the inferior and superior graft bundles, following the established surgical approach. Functional outcomes were assessed preoperatively and at follow-up using the Kujala, Lysholm, and Tegner scores. Radiological outcomes, including the Insall-Salvati index, tibial tubercle-trochlear groove (TT-TG) distance, and patellar tilt angle (PTA), were also evaluated preoperatively and during follow-up. RESULTS: A total of 40 patients (42 knees) in the single-anchor (SA) group and 72 patients (76 knees) in the double-anchor (DA) group were included. Patient characteristics were comparable between the two groups. Preoperative clinical scores were as follows: Kujala (SA: 59.0 ± 9.2, DA: 60.1 ± 8.1), Lysholm (SA: 62.7 ± 9.1, DA: 61.6 ± 8.3), and Tegner (SA: 2.8 ± 1.0, DA: 3.1 ± 1.3). Postoperative scores improved to Kujala (SA: 88.3 ± 4.7, DA: 90.6 ± 4.8), Lysholm (SA: 90.8 ± 4.2, DA: 91.0 ± 4.9), and Tegner (SA: 4.6 ± 1.2, DA: 4.8 ± 1.5). Radiologically, preoperative patella trochlear angle (PTA) values were SA: 31.8 ± 9.0 and DA: 29.3 ± 10.2, which improved postoperatively to SA: 14.7 ± 8.6 and DA: 12.6 ± 6.3. All postoperative outcomes demonstrated significant improvement compared to preoperative values (P < 0.001). However, no significant differences were observed between the SA and DA groups in any outcome measure (P > 0.05). CONCLUSION: Single-anchor MPFL-R is a reliable technique for managing recurrent patellar dislocation, demonstrating comparable clinical and radiographic outcomes to the double-anchor approach. This method provides a feasible surgical alternative for surgeons already proficient in the double-anchor technique.