Arthroscopic riveting with line versus lateral retinacular release plus medial patellofemoral ligament re-construction for habitual patellar dislocation

Objective To compare the clinical efficacy between arthroscopic riveting with line and lateral retinacular release plus medial patellofemoral ligament reconstruction in the treatment of habitual patellar dislocation. Methods A retrospective study was conducted of the 40 children with habitual patellar dislocation who had been treated at Department of Pediatric Orthopaedics, Foshan Hospital of Traditional Chinese Medicine from January 2016 to December 2016. They were divided evenly into an observation group and a control group according to the treatment methods (n=20). In the observation group which was treated by lateral retinacular release plus medial patellofemoral ligament reconstruction, there were 14 boys and 6 girls, with an age of 14.2±1.2 years and an average number of dislocations of 5.3±1.1 times. In the control group which was treated by arthroscopic riveting with line, there were 13 boys and 7 girls, with an age of 13.8±1.3 years and an average number of dislocations of 5.5±1.2 times. The 2 groups were compared in terms of visual analogue score (VAS), Q-angle, knee motion, Lysholm score and Kujala score of the knee at the last follow-ups. Results The 2 groups were comparable due to insignificant differences in preoperative general data between them (P>0.05). The observation and control groups were followed up for 13.3±1.2 months and 12.9±1.2 months, respectively, showing no significant difference between them(P>0.05). At the last follow-ups, the observation group had a significantly lower VAS score (2.2±0.8 pints), a significantly smaller Q-angle (14.5°±1.2°), significantly larger knee motion (30.3°±3.8°), and significantly higher Lysholm (91.6±5.3 points) and Kujala scores (93.2±2.8 points) than the control group (4.3±1.1 points, 17.8°±1.6°, 23.4°±3.4°, 81.4±4.4 points and 82.0±5.4 points, respectively) (all P<0.05). Conclusion In the treatment of habitual patellar dislocation, lateral retinacular release plus medial patellofemoral ligament reconstruction can lead to improvements in knee function and clinical symptoms and better clinical outcomes than arthroscopic riveting with line. Key words: Patellar dislocation; Arthroscopy; Bone nails; Lateral retinaculum; Medial patellofemoral ligament