Objective To investigate the effectiveness of arthroscopic medial retinaculum plication (MRP) for acute patellar dislocation (APD) in adolescents. Methods 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. Results 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 lt; 0.05), and the scores at 12 months were significantly higher than those at 3 months (P lt; 0.05). Conclusion 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.
Objective To explore the effectiveness of arthroscopic medial retinaculum pl ication (MRP) for recurrent patellar dislocation in adolescents. Methods Between March 2000 and October 2007, 30 adolescent patients with recurrent patellar dislocation underwent arthroscopic MRP, and 28 of them (12 left knees and 16 right knees) completed thefinal follow-up and were enrolled. There were 5 males and 23 females with an average age of 14.7 years (range, 12-19 years). The dislocation duration was 4 to 39 months with an average of 18.8 months. All patients experienced 2-4 episodes of dislocation. Before operation, all the patients showed positive apprehension test; the degree of lateral patellar translation was (2.9 ± 0.7)° and there was no hardness termination in lateral translation. The International Knee Documentation Committee (IKDC), Lysholm, Kujala, and Tegner scores were 47.7 ± 3.7, 52.6 ± 4.9, 66.7 ± 5.9, and 3.1 ± 1.3, respectively. All patients underwent arthroscopic MRP procedure. Results All incisions healed by first intention without compl ication. All the patients were followed up 2-7 years (4.8 years on average). During the follow-up, more and more patients showed positive apprehension test, and at 24 months of follow-up, 12 patients showed positive apprehension test; less and less patients had hardness termination in lateral translation, only 3 patients at 24 months of follow-up; the degree of lateral patellar translation increased, (2.3 ± 1.1)° at 24 months of follow-up. There were significant differences in positive apprehension test and hardness termination between preoperation and 24 months of follow-up (P lt; 0.05). Moreover, 6 patients suffered from redislocation, and 23 patients experienced patella instabil ity. The IKDC, Lysholm, Kujala, and Tegner scores at 24 months of follow-up were 62.5 ± 6.2, 70.7 ± 5.1, 76.6 ± 4.8, and 3.9 ± 0.7, respectively, showing significant differences when compared with preoperative scores (P lt; 0.05). CT examination showed that the congruence angle, lateral patellar angle, and patellar tilt angle were recovered to normal level after operation immediately, however, the final patellar position at 24 months of follow-up was not significantly betterthan that before surgery (P gt; 0.05). There was significant difference in the lateral patellar displacement between preoperation and 24 months of follow-up (P lt; 0.05). Conclusion Arthroscopic MRP is not rel iable for maintaining the corrected position of the patella for recurrent patellar dislocation in adolescents, though functional improvements are significant.