The influence of the operation technique and implant used in the treatment of periprosthetic hip and interprosthetic femur fractures: a systematic literature review of 1571 cases.

INTRODUCTION: A systematic literature review on periprosthetic/interprosthetic fracture fixation after hip arthroplasties was performed to summarize available clinical data. Operation techniques and implants used were evaluated as possible risk factors for outcomes.

MATERIALS AND METHODS: MEDLINE and Cochrane databases were searched. Articles describing patients with postoperative periprosthetic femur fractures sustained around a hip arthroplasty and with interprosthetic fractures treated with plates, nails, screws and/or cerclage were included. Considered articles were from 2000 or newer. Eligible abstracts were screened by two independent persons and discrepancies were resolved by consensus. Absolute numbers of complications and/or reoperation events along with their corresponding rates were calculated according to operation technique and type of implant. Relative risks of having a complication and/or a reoperation according to the operation technique and the type of implant used were estimated.

RESULTS: Available data from 49 prospective and retrospective studies were analyzed. Of 1574 fractures, 81.7 % were treated with plating. For 83.0 % of all fractures, an open approach was applied. The overall complication rate was 14.3 %. Fixation failure and nonunion were most often reported (fixation failure: 4.4 %; nonunion: 3.9 %). Nonunion and refracture occurred more often after open approaches than after minimal invasive osteosynthesis (nonunion: 4.5 vs. 0.0 %, p = 0.001; refracture: 3.8 vs. 0.6 %. p = 0.024). The relative risk for nonunion was 11.9 (95 % CI 4.5-31.5) times higher (p < 0.0001) for non-locking plates (13.0 %) than for locking plates (1.1 %).

CONCLUSIONS: The clinical evidence of published studies dealing with periprosthetic/interprosthetic fractures after hip arthroplasty is generally low. This literature search suggested higher rates of nonunion and refracture after an open approach and a higher risk of nonunion for non-locking plates compared to locking plates. Based on the available clinical evidence, no treatment recommendations can be given.