Assessment of clinical outcome of percutaneous needle quadriceps tenotomy in the treatment of congenital knee dislocation.

PURPOSE: Treatment of congenital knee dislocation (CDK) depends on the severity and flexibility of the deformity. Various modalities of treatment ranging from serial cast, open quadricepsplasty and minimally invasive quadricepsplasty have been described. We describe percutaneous needle quadriceps tenotomy for treatment of flexible CDK and present our result of retrospective case series.

METHODS: This was a retrospective study of 12 patients (20 knees) with flexible CDK. Eight patients with bilateral and four with unilateral deformities. The mean age of intervention was 14.5 days (range, 4-55 days). None of the patients were syndromic. All procedures were done within eight weeks of age. The outcome was measured using knee evaluation score and complications in view of extensor lag, instability and knee flexion deformity. Ultrasound was performed to check for integrity of quadriceps mechanism.

RESULTS: The mean pre-operative hyperextension was 50° (range, 30-70°). All patients were able to achieve >90° flexion intra-operatively. The mean knee flexion at walking age was 135° (range, 130-140°). Knee evaluation score showed good results in nine patients and fair result in three patients. There was no extensor lag, knee flexion deformity or infection. One patient of anterior instability had ACL aplasia which was documented on MRI. Ultrasound performed at walking age showed normal functioning of quadriceps mechanism.

CONCLUSIONS: Percutaneous needle tenotomy of quadriceps is a effective, simple and safe procedure for flexible, non syndromic CDK presenting early. It avoids complications associated with the open surgical procedure and causes less extensor scarring. However its effectiveness in stiff/hyperlax variants associated with syndromes is yet to be determined.