Surgical treatment results of chronic patellar instabilities through anterior tibial tuberosity transfer: A descriptive retrospective study involving 13 patients at the hospital Centre of the order of Malta (CHOM) in Dakar, Senegal

Abstract

Introduction:The therapeutic management of chronic patellar instabilities involves surgical procedures aimed at alleviating symptoms and addressing etiological factors. The Roux-Elmslie-Trillat technique, enhanced by the concept of proximal or distal transfer of the anterior tibial tuberosity (TTA) by J. Caton, provides a promising therapeutic alternative that is effective in addressing both patellar tracking and etiological factors. The aim of this study, focusing on the surgical treatment of chronic patellar instabilities through TTA transfer, is to assess the anatomical, clinical, and functional outcomes of knees after TTA transfer. Patients and Methods: This is a descriptive retrospective study spanning 72 months (6 years) with an average follow-up of 33.32 months. A series of 13 knees from 13 patients, all operated using this technique, were included. There were 3 males and 10 females, with an average age of 28.31 years. Eleven knees (84.62%) had recurrent dislocations, and 2 knees (15.38%) had permanent patellar dislocation. Smillie's apprehension was found in all 11 knees in the recurrent dislocation group. Nine trochleae were dysplastic according to Dejour, with one classified as type D. Clinical evaluation of the knees was conducted using the Lille score and the Kujala score, and femoro-patellar arthritic lesions were classified according to Iwano. Data were analyzed using SPSS 20.0 software. Results: Surgery was performed on 10 left knees (76.92%) and 3 right knees (23.08%). Procedures associated with the Roux-Elmslie-Trillat osteotomy included lateral release (13 cases), lowering of the TTA (5 cases), medial patellar retinaculum plication (3 cases), and trochleoplasty for deepening according to Masse (1 case). We noted 1 case of surgical site infection and 1 case of TTA pseudarthrosis. At follow-up, no recurrences were reported, and subjective results were rated as 'excellent' in 69.27% of cases and 'good' in 30.77% of cases. The Lille Score improved from 34.53 points preoperatively to 92.61 points at follow-up, and the Kujala score increased from 41.61 points to 93.79 points. The Caton-Deschamps index was 1.02 vs. 1.17; patellar tilt and TT-TG measurements in the 9 patients with followup CT scans were 15° vs. 30.4° and 12.32 mm vs. 22.75 mm, respectively. Additionally, at follow-up, there were 3 cases of stage II osteoarthritis and 1 case of stage I osteoarthritis.