Open lateral patellar retinacular lengthening versus open retinacular release in lateral patellar hypercompression syndrome: A prospective double-blinded comparative study on complications and outcome

摘要

Purpose: To compare complication rates and outcome of open lateral retinacular (LR) lengthening and open LR release in the treatment of lateral patellar hypercompression syndrome (LPHS). Methods: In a prospective double-blinded study, 28 patients (mean age, 48 years; 21 women and 7 men) received either LR release (14 patients) or LR lengthening (14 patients) in alternating fashion over the same lateral parapatellar skin incision for LPHS (blinding of patients to surgical procedure [i.e., single blinding]). Strict inclusion criteria (retinacular pain, tight retinaculum, decreased patellar mobility) were used to exclude other reasons for anterior knee pain (patellar instability, leg malalignment or maltorsion, trochlear dysplasia, patella alta). The surgeon and postsurgical rehabilitation were the same. Preoperatively and at 3, 6, 12, and 24 months postoperatively, complications, muscle atrophy, and Kujala patellofemoral outcome score were documented by examiners blinded to the surgical procedure (double blinding). All patients completed 2 years of follow-up. Results: The results of 2 years of follow-up showed that recurrence of LPHS, as indicated by the patellar tilt test and decreased medial patellar glide test, developed in 2 cases after LR release and 1 case after LR lengthening (P >.999). Medial patellar subluxation, as indicated by the gravitation-subluxation test and increased medial patellar glide test, developed in 5 cases after LR release and no case after LR lengthening (P =.041). Quadriceps atrophy, as indicated by the mean circumference difference compared with the healthy contralateral side, was significantly higher (P =.001) in the LR release group (1.8 cm) than in the LR lengthening group (0.2 cm). The mean Kujala score was significantly lower (P =.035) in the LR release group (77.2 points) than in the LR lengthening group (88.4 points). Conclusions: In this prospective double-blinded study, retinacular lengthening showed less medial instability, less quadriceps atrophy, and a better clinical outcome at 2 years compared with retinacular release. We believe that this may be explained by the controlled preservation of the lateral patellar muscle-capsuloligamentous continuity after retinacular lengthening. Level of Evidence: Level II, prospective double-blinded comparative study.