Tibial Tubercle Osteotomy With Distalization Is a Safe and Effective Procedure for Patients With Patella Alta and Patellar Instability.

BACKGROUND: Tibial tubercle osteotomy with concomitant distalization for the treatment of patellar instability remains controversial, as it may cause anterior knee pain and chondral degeneration. PURPOSE: To evaluate radiographic, clinical, and functional outcomes in patients who had patellar instability with patella alta and underwent tibial tubercle osteotomy with distalization (TTO-d) as well as medial patellofemoral ligament reconstruction. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: Included in this study were 25 patients (31 cases) (mean age at surgery, 28.7 years; range, 14-33 years) with patellar instability and patella alta who underwent TTO-d with minimum 1-year follow-up. The Caton-Deschamps index (CDI), tibial tubercle-trochlear groove (TT-TG) distance, and amount of distalization were assessed. Clinical and functional variables included J-sign, anterior knee pain, apprehension test, Tegner activity level, and Kujala score. RESULTS: The mean follow-up period was 2.62 years. The mean TT-TG was 16.15 mm (range, 7-24 mm); the mean CDI changed from 1.37 (1.25-1.7) preoperatively to 1.02 (0.9-1.12) postoperatively (P = .001); and the mean amount of tibial tubercle distalization was 8.80 mm (range, 4-16 mm). Lateral release (22 cases; 71.0%), medialization of tibial tubercle (17 cases; 54.8%), and autologous chondrocyte implantation (4 cases; 12.9%) were other associated procedures. The J-sign improved in 30 cases (96.8%; P = .001), and there was a complete resolution of anterior knee pain in 22 cases (71.0%; P = .001). An exploratory analysis showed that patellar cartilage defect severity was correlated with persistent pain (P = .005). The apprehension test became negative in all cases (P = .001). The median Kujala score increased from 52 to 77 (P = .001), and the median Tegner activity level improved from 3 to 4 (P = .001). No cases of osteotomy nonunion were reported. One case (3.2%) of patellar instability recurrence and 3 cases (6.5%) with painful hardware were observed. CONCLUSION: TTO-d resulted in good radiographic, clinical, and functional outcomes providing proper patellar stability to patients with patella alta. TTO-d appears to be a safe and efficient procedure with low complication rates, providing an additional tool for the personalized treatment of patellar instability.