- Short femur with apparent absence of continuity between neck & shaft
- Leg length discrepancy is 30-50%
- A pseudoarthrosis at the subtrochanteric level
Classification
| Type | Description |
|---|---|
| A | Radiographic defect in the upper femur that later ossifies, femoral head & acetabulum form, varus deformity & shaft may be higher than the head |
| B | Tuft at proximal end of femur, never get connection between head & shaft (pseudoarthrosis), acetabulum & head are present, femur short |
| C | Absent femoral head, flat-absent acetabulum, short femur |
| D | As in C but with very short femur represented by femoral condyles |
Clinical
- Short thigh
- Hip flexed, abducted & externally rotated
- Usually a flexion contracture of the knee
- 45% fibular hemimelia with short tibia & equinovalgus foot, commonly with absent lateral rays
- Children generally meet the normal motor milestone
- May be related to congenital short femur, anterolateral femoral bowing, AP laxity of the knee, ↓ SLR secondary to short hamstrings
T>Treatment
C>Considerations
- Length at maturity
- Proportionate shortening will continue
- > 20 cm should be thinking prosthesis or amputation
- What is present
- is there a normal hip
- Is there a normal knee
- Is there a normal foot
I>Indications for amputation
- If end length > 20 cm short
- Unstable hip
- Non functional foot
- Often young child will get an extension prosthesis
- Later Symes amputation with knee fusion versus a rotationplasty with knee fusion
- Get the limb to end slightly above the contralateral knee to accommodate a prosthetic knee joint
- Most of the hip configurations are stable requiring no intervention, an abductor lurch is inevitable
- Foot – amp, rotate or save
- Knee – fuse versus nothing
- Hip – fuse versus nothing
- most common approach is a Symes amputation with knee fusion