Nonunion after periprosthetic femoral fracture associated with total hip arthroplasty

Background: Nonunion after a periprosthetic femoral fracture associated wit h total hip arthroplasty occurs rarely. There is little information, to our knowledge, regarding the prevalence of this complication, its treatment, a nd the functional outcomes of treatment, The purpose of this study was to i dentify the patterns and frequency of nonunions of femoral fractures around total hip prostheses and to evaluate the results and problems associated w ith treatment of this complication in a consecutive series of patients. Methods: The study included twenty-three nonunions of periprosthetic femora l fractures in twenty-three patients with an average age of fifty-five year s (range, twenty-two to eighty-five years) at the time of the initiation of treatment of the nonunion. Thirteen of the fractures occurred during or af ter a primary total hip arthroplasty, and ten occurred during or after a re vision total hip arthroplasty, According to the classification system of Du ncan and Masri, there were six B-1 fractures (associated with a well fixed prosthesis), seven B-2 fractures (associated with a loose stem), and ten B- 1 fractures (associated with very poor proximal bone). Ten patients were managed with revision to a longstem prosthesis. Six patie nts had revision to a proximal femoral replacement prosthesis, A two-stage technique consisting of removal of the prosthesis and open reduction and in ternal fixation of the nonunion followed by reimplantation of the prosthesi s was used in two patients. Two patients were managed initially with bone-g rafting alone, and two patients were managed nonoperatively. One patient wh o had an infection at the site of the nonunion was managed definitively wit h resection arthroplasty, Results: The duration of clinical follow-up averaged 8.3 years (range, thre e months to twenty-three years), and that of radiographic surveillance aver aged 7.0 years (range, eight months to seventeen years). Of the thirteen pa tients in whom an attempt to achieve union was made and for whom radiograph s were available, nine eventually had bone-healing, Five of the twenty-thre e femora became infected and were treated with resection arthroplasty, Of t he seventeen patients who had not had a resection arthroplasty for infectio n and for whom radiographs were available at the time of the most recent fo llow-up, eleven had a stable and well fixed implant and six had a loose imp lant as seen radiographically or had had a revision because of aseptic loos ening. Seventeen patients had no or mild pain at the time of the most recen t follow-up, but ten required two-handed support to walk. The overall compl ication rate was 52 percent (twelve of twenty-three patients). Conclusions: Nonunion of a femoral fracture associated with a total hip pro sthesis is an infrequent problem, Treatment is difficult, with a high rate of complications and relatively poor functional outcomes. The data from thi s series must be interpreted with caution, as patients were managed over a period of three decades and many did not have the advantage of modern techn iques of revision hip arthroplasty, Prevention of nonunion by optimum treat ment of the initial fracture is most important. Treatment of a femoral nonu nion about a total hip implant should be implemented on the basis of the st atus of the fixation of the prosthesis and the quality of the surrounding b one.