Purpose: Nonunion of the trochanter after total hip arthroplasty using the transtrochanteric approach is a serious complication. Incidence is estimated at 3%. Failure after simple cerclage reaches 40%. A plate was therefore designed specifically for fixation of trochanteric fractures. The purpose of this retrospective analysis was to assess outcome in a continuous series of trochanteric fractures treated with this plate.

Material and methods: The series included 72 nonunions in 71 patients treated between 1986 and 1999. Mean age was 66 years. Most of the arthroplasties had been performed for primary degenerative joint disease or for hip dysplasia. The time interval between artrhoplasty and treatment of the nonunion was eight months on the average. The trochanter was fixed with a plate alone in 47 hips and in combination with a frontal wire in 25. The primary outcome criterion was trochanter healing scored as: union (pain free hip, radiological fusion and stability), nonunion (lack of radiological fusion and/or presence of an instability), and doubtful union (moderate pain, no instability, radiological fusion difficult to affirm).

Results: Mean follow-up was 47 months (range 12 – 14). Mean functional score at last follow-up was 15/9 compared with 13.5 preoperatively (paired test, p < 10–4) with 51 unions, 12 nonunions and 9 doubtful unions. Among the factors studied, trochanter fixation technique was the only factor predictive of outcome. Results were as follows for plate fixation alone: union 62%, doubtful union 13% and failure 25%. For hips with wire and plate fixation, the results were union 87.5%, doubtful union 12/5%, failure 0%. The difference was highly significant (chi-square, p = 0.006) in favour of wire-plate fixation of trochanteric fractures.

Discussion and conclusion: This study leads to the conclusion that the treatment of choice for trochanteric nonunion is wire-plate fixation which provides more than 90% good and very good results.