|
https://upload.orthobullets.com/topic/4058/images/Clinical photo - courtesy Miller_moved.png
https://upload.orthobullets.com/topic/4058/images/tib hemimelia_moved.jpg
https://upload.orthobullets.com/topic/4058/images/tibia hemi_moved.jpg
Introduction
  • A longitudinal deficiency of the tibia with varying degrees of tibial absence
    • previously known as tibial hemimelia
  • Genetics
    • autosomal dominant inheritance pattern
      • obtain genetic counseling
  • Associated conditions
    • musculoskeletal conditions present in 75% of patients   
      • ectrodactyly
      • preaxial polydactyly
      • ulnar aplasia
Classification
  • Jones classification: types I- IV

1a: No proximal tibia visible on radiograph.  Extensor mech absent. Hypoplastic distal femoral epiphysis

1b- Proximal tibia eventually ossifies and extensor mechanism will function.  Distal femoral epiphysis appears normal

2- Proximal tibia present at birth but short tibia

3- diaphyseal and distal tibia present but proximal tibia absent

4- short tibia, fibula migrated proximal, diastasis of distal tib-fib joint

  • Alternate system is Kalamachi and Dawe  (types 1-3)
Presentation
  • Physical exam
    • deformity
      • shortening of the affected extremity
      • anterolateral bowing of the tibia
      • prominent fibular head
    • ROM & stability
      • the knee is usually flexed with an associated knee flexion contracture 
        • it is important to evaluate for active knee extension
      • check stability of the knee joint in all planes
        • treatment is based primarily on the stability of the knee joint
    • foot deformity
      • there is often a rigid equinovarus and supination deformity of the foot
      • sole of foot faces perineum
Imaging
  • Radiographs
    • recommended
      • AP and lateral tibia/fibula 
    • findings
      • show deficiency of the tibia  
      • early radiographs may show small and minimally ossified distal femoral epiphysis
Treatment
  • Operative
    • knee disarticulation followed by prosthestic fitting
      • indications
        • complete  absence of the tibia
        • no active knee extension present (most cases)
    • tibiofibular synostosis with modified Syme amputation
      • indications
        • proximal tibia present with intact extensor mechanism and minimal flexion contracture 
    • Syme/Boyd amputation
      • indications
        • ankle diastasis
    • Brown Procedure (centralization of fibula under femur)
      • no longer recommended due to high failure rate
 

Please rate topic.

Average 3.9 of 27 Ratings

Questions (1)

(OBQ06.90) A 13-month-old boy has shortening and deformity of the right leg. A clinical photograph and radiograph are provided in Figures A and B. Which of the following findings most predictive of a good outcome with a Syme amputation? Review Topic

QID: 201
FIGURES:
1

35 degree flexion contracture

1%

(19/2035)

2

Absence of tibiofibular synostosis

10%

(202/2035)

3

Bilateral involvement

0%

(9/2035)

4

Full functional quadriceps strength

88%

(1783/2035)

5

Family history of tibial hemimelia

1%

(13/2035)

Select Answer to see Preferred Response

PREFERRED RESPONSE 4
ARTICLES (5)
CASES (1)
GROUPS (1)
Topic COMMENTS (21)
Private Note