Diagnostic arthroscopy and longitudinal open lateral release

Abstract

The purpose of this study was as follows: 1) to review our previous findings regarding surgical outcome fol lowing open retinacular release but now at a mean followup of 4 years, 2) to test the validity of the correc tion of patellar "overhang" by Merchant views at 4 years and correlate this with outcome, 3) to correlate arthros copic findings of lateral overhang, patellofemoral carti lage disease, preoperative Q-angle measurements, and duration of symptoms with outcome at 4 years postre lease. The surgical technique of diagnostic arthroscopy and open longitudinal release has been described pre viously by the author, emphasizing the specific anatom ical structures to be divided. The synovium was never incised and the retinacular structures were freed to allow reduction of the patella medially. Sixty patients comprising 76 knees were reviewed at a mean followup of 4 years postrelease. Followup included evaluation of Merchant views and Q angles, physical examination, and determination of patient satisfaction. Eighty-five percent of the patients followed retained the good to excellent ratings they had at the 2 year followup. "Re duction" of the released patella on Merchant views correlated well with surgical outcome and patient sat isfaction in 95% of cases. Residual Merchant view patellar tilt or excessive lateral position correlated well with poor results. Hematoma formation was the leading cause of failure. A severe preoperative Q angle corre lated somewhat with results at 4 years but this was not statistically significant. The degree of articular cartilage disease at prerelease arthroscopy did not correlate at all with results at 4 years, nor did the duration of preoperative symptoms. "Good outcome" preoperative findings included biomechanical peripatellar pain, a pos itive patellar restriction/apprehension test, and a posi tive Merchant view. Intraoperative "good outcome" pre operative findings included a positive arthroscopic ov erhang sign, evidence of patellar maltracking, and an abnormal toughened lateral retinaculum. "Reduction" of the released patella on quadriceps films taken 6 weeks after surgery and rehabilitation remained un changed at 4 years, correlating exceedingly well with excellent clinical results.