Abstract
Purpose of the study: Congenital dislocation of the patella is a very rare condition. The pathology is inconsistent and treatment modalities are unclear. The aim of the study was to show the results of operative treatment of congenital dislocation of the patella.
Material and methods: 9 knee joints in 7 patients with congenital dislocation of the patella have been treated between 1989 and 1999. Additional diagnoses were Rubinstein-Taybe syndrome, Larsen syndrome, pteryg-ium syndrome and cerebral palsy in 1 patient each. The age at the time of surgery was 8.9 years on average (between 4.3 and 14.8 years). In 6 knees primary treatment was a medial shifting of the quadriceps muscle according to Stanisavljevic, in the other 3 a combination of lateral release according to Green, proximal quadriceps realignment according to Insall and either medial displacement of the tibial tuberosity according to Elmslie or a duplication of the patellar tendon according to Goldthwait had been done.
Results: The follow-up time was 6.4 years on average (between 2 and 12.5 years). 4 of 9 patellae remained stable after 1 operation, 3 remained stable after 2 operations and 2 remained unstable. 4 of the 9 knees were symptomatic at the time of follow-up. All patients were able to walk and to run and all had full extension. Apart from recurrence there were no major complications.
Conclusions: Permanent dislocation of the patella reduces the extension force of the quadriceps muscle significantly. Medial shifting of the quadriceps muscle according to Stanisavljevic gives the best chance to reduce the patella permanently. Postoperative taping, splinting and muscle-exercises are often necessary to get a stable situation.
Local Host: British Society for Children’s Orthopaedic Surgery. Conference Theme: Congenital Deficiencies of the Lower Limb. These abstracts were prepared by A.Catterall.
