Operative Treatment in Acute Patellar Dislocation

Lee, Beom Koo; Jo, Hyun Chul; Eom, Gi Serk; Kim, Shin Woong

Abstract

PURPOSE: To analyze factors related with patellar dislocation and evaluate clinical results after early surgical treatment in acute patellar dislocation.
MATERIALS AND METHODS
The study was done in 11 patients who underwent surgery due to acute patellar dislocation from February 1997 to January 2000. patients who had history of previous patella dislocation were excluded in this study. The average follow up period was 23 months. Radiographs were antero-posterior, lateral at 30 degree of flexion, and Merchant view. We looked for of patella alta, trochlear dysplasia, intraarticular loose body and measured sulcus angle, congruence angle, Q-angle. We checked the location of injured medial retinaculum and ostochondral lesions, and associated intraarticular lesions from MRI, arthrosopic and operative findings. We performed the 3 operative methods: Upon the completion of the arthroscopic evaluation, medial retinacular repair (5 cases), medial retinacular repair and lateral release(3 cases). augmented repair and plication of medial retinaculum ie, modified Madigan technique(3 cases).
RESULTS
patella alta was present in 7 cases(63.6%), trochlear dysplasia(crossing sign) in 5 cases(45.5%), and increased sulcus angle in 5 cases(45.5%). one or more predisposing factors contribut-ing to patella dislocation were seen in 9 of 11 cases(81.8 %). Medial retinacular tear was present in the adductor tubercle in 5 cases and midportion(parapatellar tear) in 4 cases, and relaxed without tear in 2 cases. The clinical results showed that the average Kujala score was 91 points. The congruence angle became normal in 10 cases and patella subluxation was seen in 1 case postoperatively.
CONCLUSIONS
Acute patellar dislocation was related in those cases with trochlear dysplasia and patella alta and increased sulcus angle . During the 23 months follow up preiods, Excellent clinical results were obtained with early surgical treatment.