Original surgical technique for the treatment of patellofemoral instability after failure of conservative treatment

Introduction

Acute patellar dislocation is a common but serious injury that can significantly impact a patient's functional prognosis. The objective of this retrospective study is to evaluate the clinical outcomes of arthroscopic medial patellofemoral ligament (MPFL) reconstruction and plication of the medial patellar retinaculum using suture anchors in adolescent patients with first-time acute patellar dislocation (APD) and MPFL insertion injury.

Hypothesis

Tightening repair of the medial retinaculum complex can result in favorable clinical and functional outcomes in this patient population.

Materials and methods

A total of 84 adolescent patients with first-time APD and with an average age of 15.5 years (10-22) were included in the study. Of these patients, 61 (7 male and 54 female) underwent arthroscopic suture anchor plication for medial patellar retinaculum, while the other 23 were successfully treated non-operatively. Radiographic outcomes, including the congruence angle (CA), lateral patellofemoral angle (LPA), and patellar tilt angle (PTA), were evaluated preoperatively and at the last follow-up visit in the surgical group. Functional outcomes were assessed using the Lille Patello-Femoral Score, Lysholm Score, and Kujala Score at the same time points. In addition, the surgical and non-operative treatment success groups were compared in terms of both radiographic and functional outcomes.

Results

Mean follow-up was 40.9 months (24–60). Fifty-nine knees showed excellent or good results postoperatively, 2 patients had a recurrent patellar subluxation. The Lille Patello-Femoral Score was 96.9 ± 4.7 at the last follow-up. The subjective Lysholm Score and Kujala Score improved significantly, from 58.6 to 91.9 and from 60.4 to 88.9, respectively. The radiographic CA, LPA and PTA improved significantly, from 19.8 ± 2.1° to –6.7 ± 1.7°, from –7.4 ± 2.2° to 5.7 ± 1.8° and from 23.8 ± 2.9° to 12.3 ± 2.3°, respectively. There was no statistically significant difference in functional and radiographic assessments between the success with non-operative treatment group and the surgery group.

Conclusion

The results of this study suggest that arthroscopic MPFL insertion reconstruction and plication using suture anchors, which is less invasive and improves patella stability, can lead to favorable clinical and functional outcomes in adolescent patients with first-time acute patellar dislocation and insertion injury. This treatment approach should be considered as a viable option for this patient population.

Level of evidence

IV; monocentric retrospective descriptive study.