Introduction and Aims: Practice standards vary considerably for prophylactic pinning the contralateral hip opposite a scfe. This work provides a data-driven framework with which to analyse the risks, benefits, and costs of two modes of treatment: prophylactic pinning the normal side contralateral to a scfe versus observation; and pinning of subsequent slips.
Method: A decision analysis model was constructed using the English language literature to estimate SCFE incidence and severity. The model framework assumes that if a hip is pinned prophylactically it will not slip. The benefits of prophylactic pinning are therefore determined by identifying the percentage of contralateral hips that will subsequently slip and then develop early osteoarthritis requiring total hip arthroplasty at a young age. In our cost analysis model, the cost of diagnosis, treatment, and follow-up was developed for the two treatment modes using actual hospital costs and standardised medicare reimbursement schedules for professional fees.
Results: If a hip is not pinned prophylactically, there is a 7% risk of requiring a total hip arthroplasty in the contralateral hip at an early age due to osteoarthritis. This 7% is a combination of patients whose contralateral femoral epiphysis slipped moderately or severely and was pinned in a non-anatomic position (1.5% of the initial population) and patients whose substantial slip was not detected (5.5%). The risk of prophylactic pinning appears to be associated with a 0.3% chance of developing avascular necrosis. Other risks would include chances of infection or chondrolysis, although these have not been reported to date.
If every patient is managed by the prophylactic pinning protocol, the total cost per patient, not including lost time at work or school, for pinning a slipped capital femoral epiphysis, prophylactically pinning the contra lateral side, and post-operative follow-up is $6266. Conversely, the total cost per patient for the second mode, pinning a slipped capital femoral epiphysis, post-operative follow-up and pinning of subsequent contralateral slips that are detected is $6864. Costs of later hip arthroplasty were not included. This analysis suggests that costs to a national health care system for treatment of SCFE would not increase by prophylactic contralateral pinning.
Conclusions: Prophylactic pinning of the contralateral side is merited on the basis of both risk/benefit and cost-effectiveness analyses. Ultimately, the decision must incorporate the physician’s assessment of patient risk factors including: age, weight, co-morbidities, sports activities, the likelihood and feasibility of regular follow-up, and the patient’s and parents’ acceptance of prophylactic surgery.
