Prophylactic pinning of the contralateral hip in unilateral Slipped Upper Femoral Epiphysis (SUFE) persists as a source of debate with the majority of surgeons selecting this option in a proportion of patients whom they regard as at increased risk of a subsequent slip.

Universal prophylactic pinning was introduced in our region in 2005 after an audit of ten years local practice identified 25% of unilateral cases presented with a subsequent slip. This study reports our experience between 2005 and 2020.

In this prospective study, 44 patients presented with 55 affected hips compared with 60 patients with 67 affected hips in the original study. Two patients were excluded as their initial slip had not been treated in our unit. Of the 42 hips seven were bilateral, 34 of the 35 unilateral hips underwent prophylactic pinning. The one exception subsequently underwent prophylactic pinning due to developing pain.

Consistent with our original series, at a minimum follow up of 13 months there have been no complications of infection, fracture, chondrolysis or avascular necrosis subsequent to prophylactic pinning.

Over 25 years 70 patients have undergone prophylactic pinning without complication. On the premise that 25% of our unpinned hips presented with subsequent slips before instituting our policy we estimate that we have prevented 17 subsequent slips over 25 years including the consequences which can be significant. We continue to advocate universal prophylactic pinning as an effective and safe practice in the management of SUFE.

Historically avoidance of avascular necrosis (AVN) has been the primary objective in the management of an acute unstable slipped upper femoral epiphysis (SUFE). When achieved through pinning in situ it was invariably associated with significant malunion. With increasing appreciation of the consequences of femoroacetabular impingement, modern techniques aim to correct deformity and avoid AVN.

Exactly what constitutes an acute unstable SUFE is a source of debate but should represent 5–10% of all cases.

This audit reviewed cases over the past 25 years treated in one region. Of 89 patients with 113 slips, 21 hips were recorded as unstable. During this period the management has evolved from closed reduction and stabilization through pinning in situ, to open reduction.

Radiographic outcomes following these three treatment methods were compared with record of any subsequent surgery in the form of osteotomy or total hip arthroplasty.

Currently the lowest reported incidence of AVN in patients with an acute unstable slip is associated with the Parsch technique which combines open arthrotomy, digital reduction and screw fixation. Early outcomes with this technique are in accordance with those reported in the literature and represents a significant improvement in outcome when compared to earlier techniques used in the management of the severe unstable SUFE.