Functional significance of nonunion of the greater trochanter.

The effects of a trochanteric nonunion on four commonly measured criteria (pain, range of motion, walking, and a functional evaluation) used in evaluating the sucess of total hip arthroplasty were demontrated by statistical comparison of 557 hips with trochanteric union to 78 nonunions. Analyses performed at six months, one year, two years, and three years postoperation revealed no significant differences in the level of pain experienced by subjects with united fragments and those with trochanteric nonunion. However, nonunion subjects having had previous operations were found to have higher than usual levels of pain. Of the remaining criteria tested, only the walking evaluation showed significant differences between subjects with a united fragment and those with trochanteric nonunion. Patients with a united fragment demonstrated an improved ability to walk, significant at the p less than or equal to 0.05 level, at six months, one year, two years, and three years postoperatively. The size of the trochanteric gap (less than or equal to 1 cm) was not found to influence these results.