Background
Interprosthetic femur fractures (IFFs) are a rare injury that projects to increase as more ipsilateral total hip and knee arthroplasties are performed. Treatment of this fracture type can be challenging and there are many treatment methods used in practice including external fixation and internal fixation surgical methods. This study analyzes the existing literature on IFFs in conjunction with a retrospective study.
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. A non-published retrospective study conducted at a level 2 trauma center was also included in this review.
Results
Forty-one studies were included for review with a total of 526 patients. Average reported age of patients was 78.7 years old and 420 (79.8%) were females. Overall union rate was 74.0% with 389 of 526 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 for fixation of IFFs should be carefully considered by the orthopaedic surgeon depending on the patient and fracture classification. While locking plate was the most common method of fixation, nail/rod and prosthetic revisions also yielded favorable union rates. Half of the locking plate cases utilized cerclage wires/cables. Nearly three fourths of these patients achieved union with the fastest mean healing time around 4.69 months. Other methods included femur replacement, external fixator, and combined treatment modalities. Although a small number of patients were treated with Ilizarov external fixator and achieved high union rates, much more research needs to be conducted on this treatment method.