[Arthroscopically assisted treatment for acute patellar dislocation].

Objective: To evaluate an improving operative procedure and the clinical results of arthroscopically assisted treatment for acute patellar dislocation.

Methods: Between April 2006 and March 2009, 22 patients (25 knees) with primary acute complete dislocation of the patella underwent an improving arthroscopic operation, release of lateral retinaculum and suture of medial capsule and retinaculum structure. There were 5 males and 17 females with an average age of 23.6 years (range, 14-34 years). Three patients had bilateral procedure. Eleven left knees and 14 right knees were involved. The disease duration was 1-10 days with an average of 5.9 days. All patients had lateral dislocation; of them, 14 patients showed reduction without treatment, and 8 patients showed dislocation at admission and were given close manipulative reduction. The results were positive for apprehension test in all patients with the limitation of passive motion and for Ballottable Patella Sign in 15 cases. Lysholm score, visual analogue scale (VAS) score, and Insall scale were adopted to evaluate the effect.

Results: All incisions healed by first intention. All the patients were followed up 12-36 months (17 months on average). During the first 3 months after operation, sunken skin in the puncture point medial to the patella was observed in 12 knees; 10 knees suffered pain of the soft tissue lateral to the patella; 15 knees felt tense in the soft tissue medial to the patella, however, all these problems disappeared or recovered gradually after rehabilitation and conservative treatment. No recurrence of dislocation was observed during the follow-up. Lysholm score was significantly improved from preoperative 67.3 +/- 5.7 to postoperative 96.6 +/- 4.5 (t = 3.241, P = 0.003) and VAS score from 6.5 +/- 0.5 to 1.8 +/- 0.4 (t = 2.154, P = 0.040). According to Insall scale, the results were excellent in 18 knees, good in 5 knees, and fair in 2 knees at 1 year after operation with an excellent and good rate of 92%.

Conclusion: The improving procedure of arthroscopically assisted treatment for acute patellar dislocation is a minimally invasive operation and has a number of benefits. Its short-term clinical outcome was satisfactory.