OrthoNet

DDH/Adult
Approach to DDH in Adults

History:
- usu young female with hip pain
- childhood hip problems; risks for DDH; PSHx
- risk factors for AVN- EtOH, steroids, diving
- other joint involvement - generalized inflammatory process
- SHx - occupation, degree of disability

Physical Exam:
- gait & alignment
- trendelenberg sign; pelvic obliquity; LLD; previous incisions
- ROM both hips, knees, ankles, lumbar spine
- NV exam

Xrays:
- location of dislocation - high, intermediate, low
- presence of arthritis
- femoral deformity - short, straight, small, anteverted, coxa valga

Classification: (Athens)
- divide pelvis into thirds
- high - articulates with iliac crest; very poor bone stock
- intermediate
- low
Treatment:
- 1st decide if patient is a candidate for a redirectional osteotomy (acetabulum/femur) à presence of arthritis
- if not a candidate, then conservative treatment 1st à meds, physio, walking aids, modify activity
- if candidate for THA, remember to council about risks of infection, blood loss, nerve injury, LLD, repeat surgery because of young age
** as a rule, should refer to recon surgeon **

Approach:
- need wide exposure of acetabulum
- can use trochanteric osteotomy or vastus slide
- with vastus slide à anterior approach to hip but versatile
- be sure to identify sciatic nerve.

Pitfalls of THA in DDH:
1. femur - short, straight, small, coxa valga, excessive anteversion & ? deformity
2. acetabulum
- location - high, intermediate, low (always bring down a high dislocation)
- bone stock - usu require structural graft (own head or allograft) at superior margin
3. soft tissue
- iliopsoas - usu needs to be released
- abductors - usu need to be retensioned & can be done with trochanteric osteotomy or vastus slide
- sciatic nerve - usu short & determines how much the leg can be safely lengthened (usu 2-3 cm)