Medial patellotibial ligament (MPTL) reconstruction for patellar instability

Abstract

Purpose: To evaluate mid-term clinical and radiographic outcomes after an original medial patellotibial ligament reconstruction in patients with patellar dislocation.

Methods: Twenty-nine knees (27 patients, 8 males and 19 females) treated for patellar dislocation with medialization of the patellar tendon medial third combined with medial and lateral release were evaluated clinically and radiographically at a mean follow-up of 6.1±2.5 years. Trochleoplasty was performed in case of severe flat trochlea (6 knees, 21%). Aetiology of patellofemoral instability was traumatic in 6 (21%) and atraumatic in 23 (79%) knees. The mean age at first dislocation was 19.2±10.1 years. WOMAC, subjective and objective IKDC, Kujala, VAS for pain, Tegner activity and EQ-5D scores were used. Anteroposterior, lateral and 30° axial views were performed for radiographic monitoring.

Results: There was a significant improvement of all clinical scores and significant reduction in knee pain. Twenty-four knees (83%) were normal or nearly normal by objective IKDC score at final follow-up. Radiographs showed a higher incidence of patella alta and flat trochlea in the atraumatic group. Severe signs of patellar osteoarthritis were found in 1 knee (3%). A higher body mass index (BMI) was correlated with worse pre-operative scores. Four knees (14%) were considered failures (2 further dislocations, 2 revision surgeries). The overall survival rate at 6 years was 0.811.

Conclusions: The presented techniques produced good clinical and radiographic results at mean 6.1 years follow-up, with 14 % failures. Signs of patellofemoral dysplasia were found in patients with atraumatic patellar dislocation. BMI was related to worse pre-operative clinical status.

Level of evidence: Retrospective study, Level IV.