Short-term outcomes of periprosthetic compared to native distal femur fractures, a national database study

Distal femur fractures (DFFx) are highly morbid injuries with a complication rate comparable to hip fractures. Rising rates of total knee arthroplasty (TKA) have led to increasing rates of periprosthetic DFFx (pDFFx). We sought to determine how pDFFx complication rates differed from native DFFx (nDFFx).

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) was used to identify patients who sustained pDFFx or nDFFx between 2012 and 2018. Patients were further stratified by operative treatment: open reduction internal fixation (ORIF) or distal femur replacement (DFR). Multivariate logistic regression was used to compare 30-day complication rates between pDFFx versus nDFFx and, among pDFFx patients, ORIF versus DFR or revision TKA (rTKA).

563 patients with pDFFx and 2259 patients with nDFFx were identified between 2012 and 2018. pDFFx patients had significantly lower rates of ORIF than nDFFx patients (36.4 vs 95.4%, p < 0.001). On multivariate analysis, pDFFx were associated with a higher rate of surgical site complications (OR 2.48, p = 0.009) compared to nDFFx. There were no differences in mortality, reoperations, major complications, rate of blood transfusion, venous thromboembolism and disposition. In patients with pDFFx, patients undergoing DFR/rTKA were more likely to be discharged home versus a rehab facility, compared to those undergoing ORIF (OR 2.62, p < 0.001).

In this first large registry study comparing pDFFx and nDFFx, we find similar outcomes between these groups in the first 30 days after surgery. Patients with pDFFx did have higher rates of surgical site complications, including infection and dehiscence. In pDFFx patients, those undergoing DFR were more likely to return home post-operatively.