Lateral retinacular release in patellofemoral subluxation

A consecutive series of patients who have undergone arthroscopy and lateral retinacular release for patello femoral subluxation was evaluated so that the results could be compared to an earlier series of open patel lofemoral reconstructions. Of 96 patients, 4 had bilat eral releases; therefore, 100 knees were evaluated. The average age was 28 years. Specific symptoms and signs were reviewed.

All patients were initially treated conservatively with specific exercises. Failure of the exercise program to improve symptoms significantly, the patient's inability to perform normal daily activities, or expected associ ated pathology were indications for surgery.

The surgical technique consisted of arthroscopy with treatment of associated pathology and lateral reti nacular release using the Smillie meniscotome through the inferior lateral portal. The patella could be tilted approximately 90° medially when the release was ac complished.

Pain, function, and patellar instability were evaluated preoperatively and postoperatively by signs of tender ness on the retinaculum or bone, patellar mobility, effusion, muscle atrophy, and tone. Range of motion was also evaluated. Average followup was 36 months.

When evaluated subjectively by the patients, pain improved from a mean preoperative grade of 3.4 to 1.7 postoperatively, function improved from 3.4 to 1.7, and instability from 3.4 to 1.6.

Objective evaluation found that tenderness on the patella improved from a mean preoperative grade of 3.3 to 1.7 postoperatively. Tenderness on the retinac ulum improved from 3.2 to 1.7. Patellar mobility im proved from 3.3 to 1.7. Effusion dropped from 3.2 preoperatively to 1.5 postoperatively; quadriceps atro phy from a mean preoperative grade of 3.2 to 1.5, and quadriceps tone from 3.2 to 1.6.

Lateral retinacular release compared favorably to a similar series of patellofemoral reconstructions. The average mean difference in preoperative and postop erative ratings improved 1.6 in lateral retinacular release compared to 1.9 in open patellofemoral reconstruc tions.

The authors believe that a lateral retinacular release involves less surgery than a formal patellofemoral re construction. The patients do improve significantly from lateral retinacular release, and the degree of improve ment parallels that of patellofemoral reconstruction. If the lateral retinacular release patient does not improve, then patellofemoral reconstruction should be consid ered.