Combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia.

ABSTRACT

BACKGROUND: To evaluate the clinical outcomes of combined medial and lateral patellar retinaculum plasty for skeletally immature patients with patellar dislocation and low-grade trochlear dysplasia. METHODS: From December 2014 to December 2016, we reviewed 19 skeletally immature patients who underwent medial and lateral patellar retinaculum plasty at our institution. Clinical evaluations were performed pre- and postoperatively, and included determination of the number of patellar re-dislocation patients, the Kujala and Tegner scores, the patellar tilt angle, lateral patellar shift, and congruence angle. The radiographic evaluation parameters were measured on computed tomography scans. RESULTS: No dislocation or subluxation occurred during the mean follow-up of 35.42 months (24-48 months). Postoperatively, the Kujala score improved from 57.6 ±â€¯4.2 to 86.9 ±â€¯8.1 (P < 0.05), and the Tegner activity score improved from 2.6 ±â€¯1.0 to 5.0 ±â€¯1.3 (P < 0.05). Radiographically, the patellar tilt angle decreased from 32.7 ±â€¯5.9° to 13.4 ±â€¯4.28° (P < 0.05), the lateral patellar shift decreased from 15.9 ±â€¯1.1 mm to 8.4 ±â€¯0.6 mm (P < 0.05), and the congruence angle decreased from 29.9 ±â€¯15.3° to -9.6 ±â€¯15.5° (P < 0.05). CONCLUSIONS: Medial and lateral patellar retinaculum plasty is a promising procedure that has the advantage of being a simple operation that induces little trauma. It is a good treatment option for skeletally immature patients with patellar dislocation who have low-grade trochlear dysplasia.