Abstract
We report our early experience with distracting external fixation used to offload the hip after avascular necrosis (AVN) of the femoral head secondary to severe slipped upper femoral epiphysis (SUFE).
A case series of five patients treated in a tertiary centre is reported. Electronic case records and radiographs were reviewed. Data recorded included demographics, initial presentation, timing of head collapse, timing and duration of distraction and outcome including referral to adult arthoplasty services.
Mean age at presentation was 12 years (range 12–15). 4 were females. Initial treatment in 4 cases was a delayed cuneiform osteotomy and pinning, one patient underwent serendipitous reduction and percutaneous pinning. Mean duration to initial surgery was 10 days (range 5–16). All patients had femoral head collapse at a mean of 148 days from time of presentation. 2 patients required backing out of screws due to intra-articular protrusion. All patients underwent distraction at a mean 193 days from presentation. Average distraction achieved was 10 mm and duration of application was 125 days (range 91–139)
All patients experienced improvement or resolution of pain but persistence of poor function, characterised by fixed adduction and limb length discrepancy. 3 patients were referred to adult arthroplasty services.
This may be an effective treatment option for pain associated with AVN post SUFE. However, in our experience normal anatomy and function of the hip is not restored if performed after collapse of the femoral head. Consideration should be given to application of the distractor either at the time of initial fixation or prior to femoral head collapse. Authors believe that timing of the application of the distractor is critical for a successful outcome and recommend a prospective study with large numbers.
