Congenital Femoral Deficiency

COurtesy: William Mackenzie, Jefferson Medical College, USA

OVERVIEW

• Congenital femoral deficiency is a spectrum of congenital anomalies involving deficiency, deformity, and instability of the femur.

• Severity ranges from mild femoral shortening to near-complete absence of the femur.

• Limb length discrepancy, joint instability, and associated deformities are common.

• Management is individualized and depends on predicted limb length discrepancy and joint stability.

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CLASSIFICATIONS

Several classification systems have been described:

• Aitken classification (1968)

• Hamanishi classification (1980)

• Pappas classification (1983)

• Gillespie classification (1998)

• Paley classification (reconstruction-oriented)

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GILLESPIE TYPE A / PALEY TYPE 1A (MILD FORM)

Etiology

• Etiology is unknown.

• No established genetic predisposition.

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Clinical Features

• Limb length discrepancy approximately 20 to 30 percent.

• Foot level at mid tibia or below.

• Short thigh segment.

• Anterolateral bowing of the femur.

• Hip flexion contracture.

• Femoral retroversion.

• Genu valgum.

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Associated Findings

• Acetabular dysplasia.

• Coxa vara, usually non-progressive.

• Cruciate ligament deficiency.

• Lateral patellar instability.

• Fibular hemimelia.

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Management

Management depends on predicted limb length discrepancy at skeletal maturity:

• Shoe lift for mild discrepancy.

• Epiphysiodesis for moderate discrepancy.

• Reconstruction for discrepancy greater than 4 to 5 centimeters:

  • Periacetabular osteotomy.

  • Proximal femoral osteotomy.

  • Femoral lengthening.

  • Distal femoral realignment.

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Principles of Femoral Lengthening

• Femoral lengthening is technically demanding.

• Avoid excessive lengthening in a single stage.

• Soft tissue releases should be considered.

• High risk of posterolateral knee subluxation.

• Fractures are common.

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Prevention of Joint Instability

• Structured physical therapy.

• Maintenance of knee extension.

• Primary and secondary soft tissue releases.

• Extension of external fixation across the joint when required.

• Joint reconstruction when indicated.

• Lengthening of adjacent stable segments.

• Avoid over-lengthening.

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GILLESPIE TYPE B AND C / PALEY TYPE 1B OR 2A

Etiology

• Unknown etiology.

• No genetic predisposition.

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Clinical Features

• Limb length discrepancy approximately 30 to 50 percent.

• Foot positioned above the level of the proximal tibia.

• Short and broad thigh segment.

• Hip and knee flexion contractures.

• External rotation deformity of the limb.

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Associated Findings

• Fibular hemimelia (50 to 80 percent).

• Cruciate ligament deficient knee.

• Foot deformities.

• Congenital spinal anomalies.

• Congenital heart disease.

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Management Considerations

Decision-making depends on:

• Predicted limb length discrepancy at maturity.

• Hip stability.

• Adequacy of musculature.

• Presence of hip dysplasia.

• Limb malrotation.

• Foot and ankle function.

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Treatment Options

Predicted Limb Length Discrepancy Less Than 50 Percent of the Opposite Femur

With a stable hip and functional foot (more than 3 rays):

• Staged limb lengthening and realignment.

• Epiphysiodesis as an adjunct.

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Predicted Limb Length Discrepancy Greater Than 15 to 20 Centimeters

Or unstable hip or non-functional foot (less than 2 rays):

• Limb lengthening is contraindicated.

• Management options include:

  • Prosthetic fitting.

  • Amputation (Boyd or Syme procedure), with or without knee arthrodesis.

  • Rotationplasty.

  • Iliofemoral fusion.

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Bilateral Congenital Femoral Deficiency

• Avoid procedures that compromise overall function.

• Emphasis is on symmetry and functional mobility rather than length equalization.

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PALEY CLASSIFICATION OF CONGENITAL FEMORAL DEFICIENCY

Children with congenital femoral deficiency demonstrate a spectrum of femoral deficiency, deformity, and joint instability. Earlier classifications were oriented toward amputation and prosthetic management. Dror Paley introduced a classification system focused on reconstructive limb lengthening strategies.

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Type 1: Intact Femur With Mobile Hip and Knee

• Type 1A: Normal ossification of proximal femur.

• Type 1B: Delayed ossification of proximal femur:

  • Neck

  • Subtrochanteric

  • Combined neck and subtrochanteric.

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Type 2: Mobile Pseudoarthrosis

Greater trochanteric apophysis present; knee usually mobile.

• Type 2A: Femoral head mobile within acetabulum.

• Type 2B: Femoral head partially fused to acetabulum.

• Type 2C: Femoral head and acetabulum completely fused or absent.

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Type 3: Diaphyseal Deficiency of Femur

Greater trochanteric apophysis absent.

• Type 3A: Distal physis present, knee motion greater than 45 degrees.

• Type 3B: Distal physis present, knee motion less than 45 degrees.

• Type 3C: Complete distal femoral deficiency or fusion of distal femur to tibia.

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Type 4: Distal Femoral Deficiency

• Proximal femur is relatively normal.

• Distal femur is deficient.

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SUPERHIP PROCEDURE

The SUPERhip procedure was developed by Dror Paley in 1997.
SUPER stands for Systematic Utilitarian Procedure for Extremity Reconstruction.

• Designed to address severe hip deformities in congenital femoral deficiency.

• Can be performed as early as 2 years of age.

• Ideally performed between 2 and 3 years.

• Can also be performed in older children and adults.

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Components of SUPERhip

1. Soft Tissue Releases

• Correct hip flexion, abduction, and external rotation contractures.

• Restores functional hip motion.

2. Femoral Osteotomy

• Corrects proximal femoral varus, flexion, and external rotation deformities.

• Restores mechanical alignment.

3. Pelvic Osteotomy

• Improves femoral head coverage.

• Corrects acetabular dysplasia.

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SUPERKNEE PROCEDURE

The SUPERknee procedure, developed in 1994, addresses knee instability associated with congenital femoral deficiency.

Objectives

1. Reconstruction of anterior cruciate ligament and posterior cruciate ligament.

2. Realignment of the patella.

3. Correction of knee flexion contracture.

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Surgical Principles

• Fascia lata is used to reconstruct both cruciate ligaments.

• Fascia lata is divided into two components:

  • FL1 for anterior cruciate ligament reconstruction.

  • FL2 for posterior cruciate ligament reconstruction.

• FL1 is passed beneath the lateral collateral ligament and through the intercondylar notch.

• FL2 is passed through the intermuscular septum and sutured to itself.

• Both ligaments are interconnected for reinforcement.

• The reconstructed posterior cruciate ligament is often referred to as Paley ligament.

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Customization

• Each SUPERknee procedure is individualized.

• Components are performed based on the patient’s specific instability and deformity pattern.

• May be performed independently or in combination with SUPERhip.

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KEY PRINCIPLES

• Accurate classification guides treatment.

• Joint stability is more important than limb length alone.

• Over-lengthening increases complications.

• Reconstruction requires staged planning and long-term follow-up.

• Functional outcome takes precedence over cosmetic symmetry.