Screw placement in slipped upper femoral epiphysis: Is good the enemy of better?

Abstract

Introduction and aims A single hip screw is the recommended method of fixation for slipped upper femoral epiphysis (SUFE). Current practice favours the placement of the screw in the centre of the femoral head on both anteroposterior and lateral planes to avoid the risks of chondrolysis and avascular necrosis (AVN). We investigated the correlation between different positions of the screw in the femoral head and the prevalence of AVN, chondrolysis, late slippage and the time to epiphyseal closure.Methods The clinical notes and radiographs of 38 consecutive patients (61 hips) who underwent single screw fixation for SUFE were evaluated retrospectively with a mean follow-up of 36 months. Two-way ANOVA and the post hoc test was performed to analyse the correlation between the different variables and the outcome at the 5% level of significance.Results There were 16 acute slips, 18 chronic slips and ten acute-on-chronic slips. Seventeen slips were treated prophylactically. Mild slip was encountered in 39 hips, moderate slip in four and severe slip in one. The centralcentral position was only achieved in 51% of cases. The most significant results of the study were as follows: (1) no significant difference between the time to epiphyseal closure and the position of the screw, and (2) no late slippage or chondrolysis was observed in our series.Conclusion Our results showed that the positioning of the screw other than in the centre of the femoral head has the ability to provide physeal stability and has no correlation with the timing to closure of the epiphysis and the risk of avascular necrosis or chondrolysis. We therefore recommend that other positions be considered if the ''optimal central-central position'' is not initially achieved -specifically for the treatment of mild slip -as the potential hazards from several attempts to achieve the optimum position outweigh the benefits.

Continued growth of the hip after fixation of slipped capital femoral epiphysis using a single cannulated screw with a proximal threading

“…Screw fixation seems to be associated with a lower complication rate [2,4,10,17,18]. Therefore, single-screw fixation is, at present, the most common [19].…”

“…The type of implant used to fix the epiphysis remains controversial. Screw fixation seems to be associated with a lower complication rate [2, 4, 10, 17, 18]. Therefore, single-screw fixation is, at present, the most common treatment for SCFE [19].…”

“…Depending on the surgeon's preference, screws [2, 4, 5, 10] or Kirschner wires [11, 12] are used for stabilizing the slipped upper femoral epiphysis. Most authors agree to support the observation that single cannulated screw fixation is associated with a lower complication rate [2, 4] but generates premature growth arrest.…”

Static Plantar Pressure under Different Conditions in Children with Surgically Treated Unilateral Slipped Capital Femoral Epiphysis

“…The goals of screw fixation for the treatment of SCFE are stabilizing the physis, preventing further slippage, avoiding avascular necrosis or chondrolysis, and promoting physeal closure. A technique that utilizes a single hip screw has shown to provide a good outcome in the short and intermediate term [26,30]. A study by Jamil et al [30] showed that screw positioning other than in the center of the femoral head can also provide physeal stability and has no correlation with the timing of epiphyseal closure and the risks of avascular necrosis and chondrolysis in mild cases.…”

Factors Affecting Slip Progression After In Situ Screw Fixation of Stable Slipped Capital Femoral Epiphysis

“…Regarding screw tip position in the epiphysis, Jamil compared the center-center position with placements outside of this location 20. They found no late slippage or chondrolysis in either group and screw position did not influence time to physeal closure, concluding that positions outside of the “ideal” center-center location are adequate to provide physeal stability.…”