A systematic review of the surgical outcomes of interprosthetic femur fractures.

Background: Interprosthetic femur fractures (IFFs) are rare, but the treatment is challenging. Currently, there are many treatment methods used in practice, but an updated systematic review of comparison of common different surgical outcomes has not been thoroughly inspected. Methods: A systematic review of retrospective studies was conducted. The resource databases of PubMed, Cochrane, and Embase were searched using a combination of the keywords involving IFFs and surgical outcomes from inception through June 2021. Data collected included patient demographics, intraoperative data, and postoperative outcomes. Outcomes were measured based on healing time, revision rate, complication rate, and functional scores. Results: Forty studies were included for review with a total of 508 patients. Average reported age of patients was 78.7 years old and 403 (79.3%) were females. Overall union rate was 74.0% with 376 of 508 patients achieving fracture union after primary treatment of IFF. Only 271 patients had reported healing times of fractures with a mean of 5.15 months. The plate, prosthetic revision, nail/rod, and external fixator groups had mean healing times of 4.69, 8.73, 6.5, and 5.1 months, respectively. Revision rates were highest in the femur replacement treatment group with 9 (32.1%) patients needing at least one reoperation surgery for any reason. Overall, hardware failure and non-unions were the most reported complications in treatment of IFFs. Postoperative functional outcome scores were available for 242 patients. Harris Hip Scores for the plate, revision, replacement, nail/rod, and plate + revision groups were 76.84, 77.14, 69.9, 77, and 78.4, respectively. Conclusion: Each treatment method should be carefully considered by the surgeon depending on the patient. Locking plate was the most common method for the treatment of the patients with IFFs. Half of them combined with cerclage wires/cables. Around two thirds' patients could achieve union with the fastest mean healing time around 4.69 months. Other less common methods included prosthetic revision, femur replacement, nail/rod, external fixator, etc. A small number of patients treated with Ilizarov external fixator, and it has proven to be a viable option with few complications and high union rates.