PROPHYLACTIC CONTRALATERAL FIXATION IN SLIPPED CAPITAL FEMORAL EPIPHYSIS - IS IT SAFE?

Abstract

Prophylactic stabilisation with internal fixation of the asymptomatic hip in unilateral slipped capital femoral epiphysis is controversial.

The incidence of bilaterality varies from 20–80% depending on the length of follow-up. The opposite hip has 2335 times higher incidence of developing a slip in cases of a unilateral slip at presentation and there is no chemical, anatomic or radiological feature which can predict a slip.

The arguments regarding prophylactic fixation are based on risks of AVN, chondrolysis, and problems with implant removal and joint penetration

We present a retrospective analysis of sixty-five patients who had prophylactic fixation of the uninvolved hip at the same time as their opposite slipped femoral physis. None had an underlying systemic or endocrine disorder and the average age was 12.5 years (range 11–15 years).A single 7.0 mm cannulated screw was used in all cases. The average time to fusion was 18 months (range 6 to 36 months) and duration of follow up ranged from 3–8 years (mean 4.5 years).

None of the patients had implant removal and at latest review did not show any evidence of chondrolysis, avascular necrosis, premature physeal arrest or secondary arthrosis in the prophylactically fixed hip. There were a couple of cases of inadvertent wire penetration into joint, which were recognised and rectified immediately, and a correct length screw inserted. Both these patients had an uneventful post-operative course with no problems of chondrolysis etc at latest follow-up (5 years). One patient (1.5%) developed a superficial wound infection, which cleared up with antibiotics.

Conclusion: This study demonstrates the safety of prophylactic fixation using a single cannulated cancellous screw and is recommended for prevention of delayed slip and hence secondary osteoarthrosis.