Abstract
Aim
(1) To determine whether any difference exists in AVN risk between surgical reduction [Fish] or pinning-in-situ [PIS] of severe slips. (2) To review the different classifications of SUFE in relation to AVN.
Materials and Methods
56 children presented with slipped upper femoral epiphysis (SUFE) from 1998 to 2008; 29 males, 27 females; mean age 12.8 years. The Loder & Southwick classifications were used. All slips were treated surgically. The mild and moderate groups were treated with a single pin-in-situ. The severe group had either surgical reduction [Fish femoral neck osteotomy], alternatively a single pin-in-situ, randomised by day of admission. Avascular necrosis of the femoral head (AVN) was the primary outcome measurement.
Results
There were seven cases of AVN (12.5%). 2/41 in the stable group developed AVN compared to 5/15 in the unstable group, statistically significant [Chi-Square P=0.001]. No patient in the mild group, one out of seven in the moderate group, and six out of 22 in the severe group developed AVN. In the severe slip group, the AVN rate in the PIS group was 40%, after Fish osteotomy it was 23.5%. This is not statistically significant, but the trend favours surgical reduction.
Conclusion and Significance
(1) Surgical reduction by Fish osteotomy is no riskier for AVN than pinning in situ for severe SUFE. Surgical reduction should therefore be performed to avoid gross deformity in these cases. (2) We have confirmed that the stability and the severity of the slip at presentation are the best indicators for predicting AVN.