Arthroscopic lateral retinacular release, medial retinacular plication and partial medial tibial tubercle transfer for recurrent patellar dislocation

Objective: To assess the efficacy of a therapeutic protocol composed of arthroscopic lateral retinacular release, medial retinacular plication, and partial medial tibial tuberosity transfer for patients with recurrent patellar dislocation. Method: 71 patients, 11 males and 60 females and a total of 77 knees, with recurrent dislocation of the patella were enrolled between 1998 and 2012. The average age of the patients was 19.5 years and 67 of them had previous knee trauma history. Tibial tubercle avulsion fractures were all surgically treated without complications like dysplasia in the femoral trochlear groove or valgus deformity. The Q angle, sulcus angle, patella-femoral trochlear congruence angle and lateral patellofemoral angle were measured on X-ray, while tibial tubercle-trochlear groove (TT-TG) distance was measure on CT scans, before the arthroscopic operation. Result: 69 patients were followed-up for 2-16 years (average of 7.2 years), while 2 patients were lost during follow-up. Among the patients with follow-up, one patient had recurrent patella dislocation two months after the operation. Q angle decreased from 13.2 degrees to 9.2 degrees in male patients (P < 0.05) and from 21.0 degrees to 15.4 degrees in female patients (P < 0.05). On average, the patella-femoral trochlear congruence angle decreased from 24.2 +/- 6.8 degrees to -2.1 +/- 5.8 degrees (P < 0.05) and the lateral patellofemoral angle increased from -2.0 +/- 5.2 degrees to 10.9 +/- 4.0 degrees (P < 0.05). TT-TG distance decreased from 19.8 +/- 2.1 mm to 13.6 +/- 1.8 mm (P < 0.01). Mean Lysholm score increased from 45.6 +/- 4.8 to 92.3 +/- 10.8 (P < 0.05) and, IKDC score increased from 48.3 +/- 6.8 to 94.3 +/- 8.4 (P < 0.05). Conclusion: As evidenced by minimal trauma and markedly improved knee joint function, the proposed therapeutic protocol demonstrated clear benefits for patients with recurrent patella dislocation. (C) 2017 Published by Elsevier Ltd on behalf of IJS Publishing Group Ltd.