Abstract
Introduction
Prophylactic pinning of the contralateral hip in the treatment of slipped upper femoral epiphysis (SUFE) has been shown to be safer than continued observation of the contralateral hip. This treatment remains controversial due to the potential for harm caused to an apparently unaffected hip.
There is evidence that pinning of an already slipped epiphysis causes growth disturbance of the proximal femur, however this has been questioned in that the slip occurs at the hypertrophic layer of the growth plate with no damage to the germative layer.
Aim
To determine whether prophylactic pinning affects subsequent growth of the unaffected hip in cases of unilateral SUFE.
Method
In order to determine the effect of prophylactic pinning we compared radiographs of skeletally mature patients who had either undergone prophylactic pinning (group 1), pinning of the affected side only (group 2), and adults with no history of SUFE (group 3). We measured the articulo-trochanteric distance (ATD) and calculated the ratio of the trochanteric-trochanteric distance to articulo-trochanteric distance. These measures have been used in previous studies and have been shown to be reliable indicators of disturbed proximal femoral growth. As this was a pilot study we recruited 8 to each group.
Results
The absolute sum of the ATDs were 219mm (average 27.3mm) Group 1, 213mm (average 26.6mm) Group2 and 258mm (average 32.5mm). The average trochanter-trochanter: ATD ratio in group 1 was 2.7 (1.9–3.8) compared to 2.7 (2.3–3.2) and 2.3 (1.9–2.7) in groups 2 and 3 respectively.
Conclusion
Our results suggest no difference in subsequent growth between hips that are prophylactically pinned and those that are not. Abnormal growth was observed in unpinned hips suggesting undiagnosed SUFE in some cases. In this series pinning had no effect on proximal femoral growth in patients with SUFE.
