A Unique Pattern of Peri-Prosthetic Fracture Following Total Knee Arthroplasty: The Insufficiency Fracture.

An isolated periprosthetic compression fracture following total knee arthroplasty has not been described in periprosthetic fracture classifications. Thus, the purpose is to describe this unique type of fracture based on clinical and radiographic analysis and identify the incidence and potential risk factors of this fracture. A retrospective chart review was performed from a database of 5864 primary total knee. A total of 56 (0.9%) periprosthetic fractures were identified with 15 (26.8%) of them demonstrating an isolated lateral compression fracture. Patients exhibiting this fracture pattern had a mean preoperative varus deformity of 176.3° and had poor bone quality (T score: -2.1). It is important to recognize that a compression fracture is not an infrequent finding and that further workup maybe warranted when clinical suspicion is high.