Surgical Treatment of Congenital and Obligatory Dislocation of the Patella in Children.

BACKGROUND Congenital (fixed) dislocations and obligatory (habitual) patellar dislocations represent a complex clinical and surgical challenge. Numerous treatment options, offering different perspectives, and surgical solutions are reported in the literature.We implemented the surgical technique principles, originally described by Stanisavljevic, for congenital (fixed) and obligatory (habitual) patellar dislocations, with slight modifications. METHODS We retrospectively evaluated the results of group of 12 patients (15 knees), operated between the years 2002 and 2013. The procedure includes extensive subperiosteal quadriceps realignment and soft tissue medial plication, followed by distal realignment through patellar tendon splitting. The outcome measures were patellar stability, knee range of motion, Pedi-IKDC knee function score, and the PODCI global function score. RESULTS The study group included 12 patients, 9 females and 3 males (15 knees) whose mean age was 5 years 2 months at diagnosis and 7 years 5 months at surgery. Nine patients had an underlying diagnosed genetic background [Down syndrome (n=6), Larsen syndrome (n=2), nail-patella syndrome (n=1)]. The mean follow-up was 46.2 months. Eleven patients, gained stable patella with no recurrence of dislocation. Postoperative knee active extension was improved significantly (P<0.0001) for all patients. The average postoperative Pedi-IKDC and PODCI scores were significantly higher (P<0.001) among the idiopathic group. CONCLUSIONS These results suggest that the Stanisavljevic procedure principles with modifications, provides an efficient method for treatment of fixed and obligatory patellar dislocation. In our opinion, young age at surgery played an important role in the surgical outcome. LEVEL OF EVIDENCE Level IV-therapeutic.