Tibial hemimelia

 

tibial hemimeliaTibial hemimelia

 

Definition

 

Deficiency of tibia resulting in short leg and associated knee and ankle deformity

 

Epidemiology

 

Extremely rare: 1/1,000,000

Autosomal dominant - only skeletal deficiency with a documented familial occurrence 

Bilateral 30%

 

Clinical

 

Anterolateral bowing

Significant leg length discrepancy - short tibia +/- short femur

Ankle equinovarus

Knee - unstable, deficient quadriceps

Hypoplastic great toe / reduplication of toes

 

Jones classification

 

Type 1 Type 2 Type 3 Type 4
Complete absence of tibia Proximal tibia present Distal tibial present Short tibia

Knee unstable

Distal femur hypoplastic

Foot abnormalities

Knee unstable

Ankle equinovarus

  Distal tibia-fibula diastatsis

 

Tibial Hemimelia CompleteTibial Hemimelia Partial

 

Management

 

Options

 

Amputation

Reconstruction

 

Type 1: Complete absence of tibia

 

Brown procedure

- fibula transfer + centralization 

- Syme amputation of foot

- poor outcomes due to knee stiffness / instability

 

Fibula lengthening + fusion knee / ankle

 

Yadav et al JBJS Open 2019

- 10 cases of fibula lengthening and knee and ankle fusion

- no amputations or fusions

 

Amputation / knee disarticulaation

 

Type 2: Proximal tibia present

 

Knee: tibia - fibular synostosis

Tibial lengthening

Below knee amputation

 

Type 3:  Distal tibia present

 

Amputation / knee disarticulation

 

Type 4:  Short tibia with ankle diastasis

 

tibial hemimeliaTibial hemimelia

 

Distal tibia - fibular stabilization

Tibial osteotomy / lengthening

Foot centralization / ankle releases / amputation

 

Tibial hemimeliatibial hemimelia