The role of the ossific nucleus in the treatment of established hip dislocation

Abstract

Timing the reduction of a delayed presenting dislocated hip is controversial if the ossific nucleus of the proximal femoral epiphysis is absent. We formulated a decision model for management of 6- to 13-month-old infants based on two strategies: waiting for the ossific nucleus to appear before reducing the hip or immediate reduction. The model included the occurrence of long-term physical disability within a period of 20 years. A literature synthesis provided outcome probabilities. Outcome was measured by utilities derived by content experts. Waiting for the ossific nucleus was the preferred strategy with an expected value of 0.95 as opposed to 0.86 in the immediate reduction strategy. Sensitivity analyses showed the model was robust. Based on the results of decision analysis, reducing a dislocated hip in the presence of the ossific nucleus is likely to be the better strategy if avascular necrosis and long-term disability are considered. The difference between the two strategies is equivalent to one quality-adjusted life year, which is substantial.

Level of evidence: Economic and Decision Analyses, Level II-1. See the Guidelines for Authors for a complete description of levels of evidence.