[Treatment of acute patellar dislocation with arthroscopic medial retinaculum plication in adolescents]

To investigate the effectiveness of arthroscopic medial retinaculum plication (MRP) for acute patellar dislocation (APD) in adolescents.

Between March 2007 and June 2011, 24 adolescent patients suffering from APD were treated by arthroscopic MRP. There were 14 males and 10 females, aged 8-18 years (mean, 12.7 years). The location was the left knee in 16 cases and the right knee in 8 cases. Injury was caused by sports in 19 cases, by traffic accident in 4 cases, and by heavy bruising in 1 case. The duration from injury to operation was 3 to 21 days with an average of 7.8 days. The results of floating patella test and dislocation apprehension test were both positive. MRI examination showed the arthroedema in all cases; associated injuries included medial retinaculum injury in 20 cases, medial patellar injury in 8 cases, and meniscus tear in 5 cases.

All incisions healed by first intention without complication of infection or neurovascular injury. All the patients were followed up 12-36 months (mean, 14.6 months). Only 2 patients suffered from patellar re-dislocation at 4 months and 6 months after operation respectively. The knee joint activity returned to normal at 12 months. The Lysholm, Kujala, and International Knee Documentation Committee (IKDC) scores at 3 and 12 months after operation were significantly higher than those before operation (P < 0.05), and the scores at 12 months were significantly higher than those at 3 months (P < 0.05).

Treatment of APD with arthroscopic MRP has the advantages of minor trauma and good knee functional improvement. The technique can decrease incidence of patellar re-dislocation in adolescent.