[Intra-operative periprosthetic fractures during THA in the period 1995-2009]

The aim of this prospective study was to investigate whether female gender and revision surgery were significant risk factors for intra-operative periprosthetic fractures during total hip arthroplasty (THA).

The group investigated comprised the patients who, in the period 1995-2009, sustained an intra-operative periprosthetic fracture during primary or revision THA. The patients were treated by a therapeutic procedure based on the Vancouver system. The results were related to the total number of patients undergoing THA in that period, Statistical analysis was performed using Pearson's x2 test at the 5% significance level.

Intra-operative periprosthetic fractures occurred in 110 patients (89 women, 21 men). The average age of the patients was 69 years (70 in women and 62 in men). The women significantly outnumbered the men (p < 0.001). In the period under study, 2936 primary and 791 revision THAs were performed; the incidence of all intra-operative fractures was 3%. Intra-operative fractures during primary THA were recorded in 95 patients (3.2%; range in individual years, 0.4 to 5.9%); fractures during revision THA were found in 15 patients (1.9%; range, 0 to 8.0%). This difference was slightly above the set significance level (p = 0.057). The majority of intra-operative fractures were minimal Vancouver type-A fractures in the greater trochanter region. They were recorded in 95 of the 110 patients (86%) with either primary or revision THA. Of the 15 type-B fractures, eight were shown by a detailed evaluation to occur during revision THA. An independent analysis of type-B fractures in relation to all replacements showed that their occurrence was significantly higher in revision than in primary THA (p = 0.006). DISCUSSION Intra-operative periprosthetic fractures have primarily been studied in terms of their frequency and the cause of their occurrence. Revision surgery and female gender are regarded as risk and predisposing factors. Our results, in accordance with other relevant data, confirmed that serious intra-operative type-B fracture occurred more frequently during revision THA than during primary surgery. It further showed a significantly higher number of periprosthetic fractures in women than in men. However, this finding is affected by the fact that women in general undergo more THAs than men and that the female median life span is longer. The authors consider a careful pre-operative planning and thorough evaluation of all risk factors related to surgery as basic preventive measures. CONCLUSIONS This continuous 15-year study on patients with intra-operative periprosthetic fractures of the hip has allowed us to conclude that these fractures occur more frequently in women than in men, and that more serious fractures (Vancouver type-B) are significantly more frequent during revision than primary THA. The higher incidence in women is, to a great part, accounted for by osteoporosis of the skeleton in elderly people. In revision THA, poor bone quality plays a role as well as osteolysis due to polyethylene granuloma which may be present.