Congenital dislocation of the knee: a protocol for management based on degree of knee flexion.

PURPOSE: Congenital dislocation of the knee (CDK) is a relatively rare condition. It may occur as an isolated deformity, it may be associated with musculoskeletal anomalies such as developmental dysplasia of the hip and clubfoot, or it may occur as part of a syndrome such as arthrogryposis multiplex congenita or Larsen syndrome, or it may occur in paralytic conditions such as meningomyelocele. Treatment options include serial casting, percutaneous quadriceps recession (PQR) and V-Y quadricepsplasty (VYQ). The aim of this study is to evaluate the medium-term results of PQR and VYQ, and to set a protocol of management for CDK based on a modified grading system.

METHODS: Eleven infants with 21 CDK were treated at our unit. Five knees were treated with serial casting, 12 knees with PQR and four knees with VYQ. Follow up averaged 41 months.

RESULTS: Twelve knees achieved excellent results, seven knees achieved good results and two knees achieved fair results.

CONCLUSION: A modified grading system for CDK is introduced. Based on this, we recommend the following. Serial casting is performed in patients with GI CDK. In GII CDK in neonates (babies up to the age of 1 month) serial casting is started. A maximum of four weekly manipulations and castings are attempted. If a range of flexion >90° is achieved, serial casting is continued; if range of flexion remains <90° it is necessary to proceed to PQR. In babies older than 1 month when first seen; PQR is performed from the start. VYQ is indicated in patients with GIII CDK or in recurrent cases.