Influence of rupture patterns of the medial patellofemoral ligament (MPFL) on the outcome after operative treatment of traumatic patellar dislocation

• Published in: Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA sports traumatology, arthroscopy : official journal of the ESSKA, 2013-03, Vol.21 (3), p.683-689
• Main Authors: Petri, M., von Falck, C., Broese, M., Liodakis, E., Balcarek, P., Niemeyer, P., Hofmeister, M., Krettek, C., Voigt, C., Haasper, C., Zeichen, J., Frosch, K. H., Lill, H., Jagodzinski, M.
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Asymmetry; Child; Dislocations; Female; Gerontology; Hernia; Humans; Injuries; Joint Instability - etiology; Joint Instability - physiopathology; Knee; Knees; Laterality; Ligaments; Ligaments, Articular - injuries; Ligaments, Articular - physiopathology; Ligaments, Articular - surgery; Magnetic Resonance Imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Orthopedics; Patellar Dislocation - complications; Patellar Dislocation - diagnosis; Patellar Dislocation - physiopathology; Patellar Dislocation - surgery; Patellofemoral Joint; Patients; Retrospective Studies; Rupture; Satisfaction; Surgery; Trauma; Young Adult
• ISSN: 0942-2056; 1433-7347
• DOI: 10.1007/s00167-012-2037-z

Purpose Patellar dislocation usually occurs to the lateral side, leading to ruptures of the medial patellofemoral ligament (MPFL) in about 90 % of all cases. Reliable prognostic factors for the stability of the patellofemoral joint after MPFL surgery and satisfaction of the patient have not been established as yet. Methods This multicentric study retrospectively included 40 patients with a mean age of 22.4 ± 8.1 years (range 9–48) from 5 German Trauma Departments with first-time traumatic patellar dislocation and operative treatment. Surgery was limited to soft tissue repairs, and a preoperative magnetic resonance imaging (MRI) was performed in all cases. Evaluation of the MRI included sulcus angle, dysplasia of the trochlea, depth and facet asymmetry of the trochlea, Insall-Salvati index, Tibial tuberosity to trochlear groove (TTTG) distance, and rupture patterns of the MPFL. Patients were interrogated after 2 years about recurrent dislocation, satisfaction, and the Kujala score. Results Trochlea facet asymmetry was significantly lower in patients with redislocation (23.5 ± 18.8) than in patients without redislocation (43.1 ± 16.5, p  = 0.03). Patients with a patellar-based rupture were significantly younger (19.5 ± 7.2 years) than patients without patellar-based rupture (25.4 ± 8.1 years, p