Anteromedialisation tibial tubercle osteotomy for recurrent patellar instability in young active patients: A retrospective case series

Recurrent patellar instability can be a source of continued pain and functional limitation in the young, active patient population. Instability in the setting of an elevated tibial tubercle-trochlear groove (TT-TG) distance can be effectively managed with a tibial tubercle osteotomy. At the present time, clinical outcome data are limited with respect to this surgical approach to patellar instability.

A retrospective chart review was performed to identify all cases of tibial tubercle osteotomy for the management of patellar instability performed at our institution with at least 1 year of post-operative follow-up. Patient demographic information was collected along with relevant operative data. Each patient was evaluated post-operatively with their outcomes assessed utilising a visual analogue score of pain, patient satisfaction, Tegner Activity Scale and Kujala score.

31 patients (23 females and 8 males) with mean age of 27 years (17-43 years) and a mean BMI of 26.3kg/m(2) (19.6-35.8) at time of surgery who underwent a tibial tubercle osteotomy as treatment for recurrent patellar instability were identified. The cohort had a mean follow up of 4.4 years (1.5-11.8 years). The mean pre-operative TT-TG distance was 18mm (10-22mm). The mean VAS pain score demonstrated a significant improvement from 6.8 (95% CI 6.1-7.5) at baseline to 2.8 (95% CI 1.9-3.7) post-operatively (p<0.001). The Tegner score improved from 4.1 (95% CI 3.4-4.8) pre-operatively to 5.2 (95% CI 4.5-5.9) at the time of final follow up (p<0.04). The Kujala score for anterior knee pain improved postoperatively from 62 (95% CI 55.4-68.7) to 76.5 (95% CI 69.5-83.5) at final follow up (p<0.001). 26 of the 31 patients (83.8%) had good to excellent Kujala scores. 27 of 31 patients (87.1%) reported that they would undergo the procedure again if necessary.

For the management of recurrent patellar instability in the setting of an increased tibial tubercle-trochlear groove distance, a corrective tibial tubercle osteotomy is an effective treatment modality to reliably prevent patellar instability while reducing pain and improving function in this cohort of young, active patients.