Summary

In cases of recurrent objective patellar instability, reconstruction of the MPFL by soft tissue fixation is a safe, effective and uncomplicated procedure with a low failure rate when associated with an osseous procedure.

Abstract

Medial patellofemoral ligament (MPFL) reconstruction is known to be part of the treatment of patellar instability. The aim of this study was to evaluate clinical and functional results of MPFL reconstruction using a soft tissue fixation technique associated with a tibial tubercle osteotomy (TTO) in the adult population.
A retrospective analysis including patients with MPFL reconstruction with soft tissue fixation and TTO, with a 3 years minimum follow-up, was conducted. No trochleoplasty was performed. All preoperative and peroperative clinical and radiological data were collected. Kujala, Lysholm, IKDC, FJS scores, return to play and complications were evaluated at last follow-up. Failure was defined by a recurrence of patellar dislocation or a residual instability.
90 reconstructions were analyzed with a mean follow-up of 8.8 years. Mean age at surgery was 24.8 years and 64% of patient were females. Smilie test was positive in 96.7% patients and 65.6% of patients had a preoperative positive J-sign. 75.6% of patients had trochlear dysplasia (A, 51.5%; B, 32.3%; C, 10.3%; D, 5,9%) and 11.% had a patellar dysplasia. The mean preoperative Caton-Deschamps Index (CDI) was 1.26 (76.7% of patella alta) and the mean tibial tubercle-trochlear groove distance (TT-GT) was 16 mm. At last follow-up, Smilie test was positive in 3.3% patients, and no positive J-sign was found. The mean CDI was 0.99. Mean Kujala, Lysholm, IKDC and FJS scores were respectively 95, 94, 92 and 96. A number of 93.3% declared to be satisfied. 13 postoperative complications were found, including 4 infections, 3 tibial fractures, 1 tibial tubercle nonunion and a knee stiffness with no long-term functional consequence. 4 failures (failure rate of 4.4%) (2 recurrences and 2 residual instabilities) were observed. No specific complication of the MPFL reconstruction were found. The 3-years survival rate was 98.9% and the 10-year survival rate was 98.1%. Mean postoperative Tegner score (4.4) was comparable with preoperative Tegner score (4.4). 91.9% of patients practicing sports had return to play at a mean of 6.2 months.
In the case of recurrent patellar instability, MPFL reconstruction with a soft-tissue fixation is a safe and effective procedure with no specific complication and a low failure rate when associated with a concomitant TTO.