This is a >1mth old infant with recurrent Grade III congenital dislocation of the knee (CDK) that has not responded to casting. VY quadricepsplasty (VYQ) is indicated.
Congenital knee dislocation is a rare disease. The etiology is thought to be quadriceps contracture. It is associated with developmental dysplasia of the hip (DDH) and clubfoot (CTEV). The dislocated knee should be treated first because good hip position cannot be maintained in DDH unless the knee can be flexed. It is also difficult to correct equinovarus caused by gastrocnemius tension (in CTEV) when the knee cannot be flexed.
Abdelaziz et al. reviewed a protocol for management of CDK based on the degree of knee flexion. They advocate treatment based on the Tarek grading system (see Illustration A): (1) Serial casting for GI (for 4 weeks). (2) For GII in neonates <1mth serial casting is started (up to 4 wks). If flexion to >90° is achieved, serial casting is continued; if range remains <90°, percutaneous quadriceps recession (PQR) is performed. (3) In babies >1 month when first seen; PQR is performed from the start. (4) VY quadricepsplasty is indicated in patients with GIII CDK or in recurrent cases.
Figures A and B show the range of motion of the knee (25deg hyperextension to 15deg flexion). Figure C is a radiograph showing congenital dislocation of the knee. Illustration A shows the Tarek grading system. Illustration B shows the different techniques of quadricepsplasty (upper row, structures divided and skin incisions used; lower row, how lengthening of the quadriceps mechanism is achieved). The most common PQR is the Roy-Crawford technique. The most common VYQ is the Curtis-Fisher technique.
Answer 1: Casting in extension is not indicated.
Answer 2: Serial casting in flexion has proven unsuccessful in attaining flexion >90°. Surgical intervention is indicated.
Answer 3: If both quadriceps tendon and ACL are divided, only fair results are seen. ACL division alone is not indicated.
Answer 4: Percutaneous quadriceps recession can be performed for infants at the first presentation. For older infants that have failed previous casting, this procedure is unlikely to be successful and a more extensive open release is necessary.
Schoenecker PL, Rich MM. The lower extremity. In: Morrissy RT, Weinstein SL, eds. Lovell and Winter’s Pediatric Orthopaedics, 6th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2006:1158-1211.
Abdelaziz TH, Samir S. Congenital dislocation of the knee: a protocol for management based on degree of knee flexion. J Child Orthop 2011 Apr;5(2):143-9.