Is the fracture pattern in periprosthetic fractures around the knee related with the anterior femoral notch?

Introduction: Periprosthetic fractures around the knee (PPF) are a devastating complication of total knee arthroplasty (TKA). Anterior femoral notching during TKA is considered a risk factor for PPF. The aim of this paper is to determine if an anterior femoral notch after total knee arthroplasty may affect the fracture pattern when a PPF appears postoperatively.

Material and methods: 50 patients diagnosed in our centre of a PPF from January 2010 to December 2013 were retrospectively enrolled. 100 patients who underwent a total knee arthroplasty without fracture were randomly obtained as a control group. Evidence of the notch was searched in both groups in postoperative X-rays. In the PPF group, distance from the shield of the femoral component to the most distal (d) and proximal (D) point of the fracture were measured.

Results: Two different groups were obtained: 1) d = 0 (33 out of 50 patients); the fracture is supposed to be related with the notch as it's a theoretically weaker area. 2) d > 0 (17 out of 50 patients); the fracture pattern has no relationship with the notch. Prevalence of patients suffering a fracture in the shield of the prosthesis (d = 0), was similar in both patients with notch (66,7%) and without it (68%).

Conclusions: In conclusion, fracture pattern is not related with the existence of a femoral notch in the clinical setting.