Four-in-one Extensor Realignment for the Treatment of Obligatory or Fixed, Lateral Patellar Instability in Skeletally Immature Knee.

BACKGROUND: Congenital (fixed) and obligatory (habitual) patellar dislocations in children are a complex clinical and surgical challenge. Numerous individual surgical techniques have been described. This study aims to assess results, patient satisfaction, and complications after a combined Roux-Goldthwait procedure, vastus medialis obliquus advancement, Galeazzi procedure, and extensive, lateral release (4-in-1 extensor realignment) in the skeletally immature knee with obligatory, or fixed lateral patellar instability. METHODS: Records of children with congenital fixed or obligatory patellar instability, who underwent the 4-in-1 procedure at a single institution, were reviewed. Clinical results included ability and time for the return to activities of daily living (ADL) and sport, recurrent instability and/or dislocation, and necessity of long-term bracing. Continued pain was assessed by the Kujala Score. Complications including infection, recurrent instability, and the necessity for secondary procedures were recorded. RESULTS: A total of 34 patients (46 knees) mean age 10.3±2.4 years, underwent the 4-in-1 procedure with a mean postoperative follow-up of 51.6±31.5 (range, 12 to 146) months. Sixteen patients (22 knees) responded to a phone interview and questionnaire. All 16 patients returned to ADL in a mean time of 10.3±2.4 weeks. Ninety-one percent returned to sport in a mean time of 23.1±15.5 weeks. Long-term bracing was required for 6 knees after the surgery. The mean Kujala Score was 93.0±5.2 (range, 83 to 100). Complications included 6 of 34 patients (18%) with recurrent instability at the latest follow-up and 2 with superficial wound infection. CONCLUSIONS: Patients with obligatory or fixed lateral, patellar instability who undergo the 4-in-1 procedure have good short-term results with low complication rates. Return to ADL and sporting activity with minimal pain can be expected, usually without the need for long-term bracing. The 4-in-1 procedure is a viable option for skeletally immature patients with obligatory or fixed, lateral patellar instability. LEVEL OF EVIDENCE: Level IV-Therapeutic study.