CORRInsights®: Iatrogenic Hip Instability Is a Devastating Complication After the Modified Dunn Procedure for Severe Slipped Capital Femoral Epiphysis
How did we get here? The modern definition of a SCFE is either stable or unstable , with the vast majority being stable. The risk for AVN in the unstable SCFE is extremely low, probably less than 1%. The risk of AVN in the unstable SCFE by contrast is high, perhaps in the neighborhood of up to 50%. The concern for the stable SCFE, especially the severe SCFE, is the long-term risk of degenerative hip disease resulting in the need for hip arthroplasty. Both outcomes (AVN or degenerative hip disease) are ones that all orthopaedic surgeons wish to avoid.
Out of these adverse outcomes came the “hip-preservation movement” . In the last decade, the movement, with its altruistic motives, has spread across the orthopaedic community like a flood. It is in this context that the modified Dunn procedure for SCFE became popular. It was the hope that such a procedure would markedly reduce the incidence of AVN in the unstable SCFE, as well as minimize the long-term risk of degenerative hip disease in the severe stable SCFE.
The initial results of such procedures from Switzerland were promising [8, 12], yet more recent studies outside of Europe have noted a higher risk of complications . Iatrogenic hip instability received little attention in hip-preservation studies from Europe.
High AVN and complication rates have now been brought to our attention thanks to remarkably honest reporting.