Abstract
Purpose: The purpose of this work was to analyse functional results in patients with objective patellar instability who underwent surgery between 1988 and 1999.
Material and methods: One hundred eighty knees, 140 patients, were included in this series. Minimum follow-up was two years, and the mean follow-up was five years (range 24 – 152 months). The IKDC 99 subjective knee chart was used for postoperative assessment. This chart has ten items for sports activities and functional status of the knee for everyday activities. Eighty-three percent of the patients (118 patients) responded to the questionnaire.
Results: Clinical assessment was available for 98 patients (63%) and phone interview data for 29 (20%). Subjectively, 111 (94.87%) patients were very satisfied, five (4.27%) were satisfied, and one was dissatisfied. We assessed results by pain level (37.6% mild or weather-related pain), residual oedema, sensation of blockage (15.8%), instability, daily activities (68% with difficulty in the kneeling position), sports activity and level.
Discussion: Certain authors (Insall) question the pertinence of operating objective patellar instability because of the risk of secondary femoropatellar degeneration. For us, surgical treatment is indicated when there has been at least one dislocation associated with morphological anomalies. We have not observed any cases of femoroatellar degeneration among our patients who were operated on more than ten years ago. The patients’ own subjective assessment shows that surgical treatment with medialisation and/or lowering of the tibial tuberosity has been effective with a very excellent rate of satisfaction. The quality of the results is directly related to correct treatment of the lesions (for patients without recurrent dislocation) and systematic analysis of the different factors contributing to patellar instability (trochlear dyplasia, patellar height, quadriceps dyplasia, length of the patellar tendon). Our rate of revision appears to be low but was directly related to the young age of this population and is close to or above the revision rates observed in series with follow-ups greater than two years.
Conclusion: Surgery for objective patellar instability gives good mid- and long-term results. The subjective IKDC score allows precise self-evaluation. We have not been able to find any correlation between subjective results and objective results.
The abstracts were prepared by Docteur Jean Barthas. Correspondence should be addressed to him at Secrétariat de la Société S.O.F.C.O.T., 56 rue Boissonade, 75014 Paris.
