Operative versus closed treatment of primary dislocation of the patella. Similar 2-year results in 125 randomized patients.

To assess whether initial surgery is beneficial for patients with primary dislocation of the patella, we carried out a prospective randomized study. Knee stability was examined under anesthesia, and associated injuries were excluded by diagnostic arthroscopy. 55 patients then had closed treatment and 70 patients were operated on with individually adjusted proximal realignment procedures. Surgery gave no benefit based on 2 years of follow-up. The subjective result was better in the non-operative group in respect of mean Houghston VAS knee score (closed 90, operative 87), but similar in terms of the patient's own overall opinion and mean Lysholm II knee score. Recurrent instability episodes (redislocation or recurrent subluxation) occurred in 20 nonoperated and in 18 operated patients. Of these, 15 and 12, respectively, then suffered redislocations. Function was better after closed treatment. Serious complications occurred after surgery in 4 patients. In conclusion, the recurrence of patellar dislocation may be more frequent than reported, whatever the form of treatment. Routine operative management cannot be recommended for primary dislocation of the patella.