Extensive spinal osteophytosis as a risk factor for heterotopic bone formation after total hip arthroplasty.

Observations on 54 patients present circumstantial evidence of a relationship between an underlying spinal ossifying diathesis and the heterotopic bone formation following total hip arthroplasty. This relationship should be investigated in a larger patient population to determine whether a spine-hip diathesis exists and could account for some patients with this complication. If it can be statistically substantiated, spinal roentgenograms may provide a preoperative screening procedure for the identification of "a population at risk" of heterotopic bone formation who might benefit from a prophylactic medical regimen.