congenital knee dislocation

CONGENITAL HYPEREXTENSION AND DISLOCATION OF THE KNEEBY: DR. MAHWISH KHAN

Introduction

Spectrum of disease including positional contractures rigid dislocation

Introduction Cont…

Associated conditions often associated with developmental

dysplasia of the hip, clubfoot, and metatarsus adductus

50% of patients with congenital knee dislocations will have hip dysplasia affect one or both hips

Structural Components

anterior capsule of the knee and quadriceps mechanism are contracted

intraarticular adhesions hypoplasia or absence of the patella fibrosis and loss of bulk of the vastus lateralis muscle suprapatellar pouch was obliterated by the adherent

quadriceps tendon Lateral displacement of patella

Clinical Presentation

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Presents with hyperextend knee at

birth

Grades of Congenital Hyperextension of the Knee

Congenital hyperextension of the knee is divided into three grades according to severity: Grade 1, congenital hyperextension Grade 2, congenital hyperextension with anterior

subluxation of the tibia on the femur and Grade 3, congenital hyperextension with anterior

dislocation of the tibia on the femur

A, Congenital hyperextension. B, Subluxation of knee. C, Dislocation of knee.

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Newborn with bilateral dislocations

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Note prominence of femoral condyles posterior to anteriorly dislocated tibia and fibula

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Anterior displacement of tibia and fibula is evident on lateral radiograph.

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Treatment

Depends upon Severity of subluxation or dislocation and The age of the patient

Non Operative Treatment

Reduction with manual manipulation and casting indications

most cases can be treated non-operatively if both knee and hip dislocated, then treat knee first

technique long leg casting on weekly basis

Excellent results at 5-Year Follow up

In non-responders------skeletal traction for correction is an option.

Newborn with mild-to-moderate hyperextension or subluxation

Operative Treatment

Surgical soft tissue releaseIndications

if failure to gain 30 degrees of flexion after 3 months of casting

Operative Treatment cont…

Goal Of Surgery : 90 degrees of flexion withquadriceps tendon lengthening (V-Y quadricepsplasty or Z

lengthening)anterior joint capsule releasehamstring tendon posterior transpositioncollateral ligaments mobilization

Curtis and Fisher technique

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Lines of incision to release anterior capsule medially and laterally and medial and lateral retinaculum of quadriceps mechanism

Curtis and Fisher technique

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Correction after soft-tissue release and lengthening of rectus femoris muscle

Operative Treatment cont…

Postoperativecast in 45 to 60 degrees of flexion for 3 to 4 weeks

Rare Cases osteotomy of the femur or tibia may be required in an older child.

After Treatment

cast changed at 2 weeks At 4 to 6 weeks,

the cast is removed active and passive exercises are begun

In Older Patients continuous passive motion can be used to regain motion during the

first 3 to 6 weeks after surgery long leg brace is worn for 6 to 12 months to prevent

hyperextension of the knee.