Periprosthetic Fracture in Unicompartmental Knee Arthroplasty

Although rare, periprosthetic fractures following unicompartmental knee arthroplasty (UKA) present a treatment dilemma for the orthopedic surgeon. These fractures are most commonly seen of the medial tibial plateau with femoral fractures occurring much less frequently. Patient-related factors such as disorders, which lead to poor bone quality, may predispose to this complication, while stress risers such as those created by the pinholes used to affix the tibial cutting guide, the vertical tibial cut itself, and tibial component sizing and positioning have been proposed as possible mechanisms. Assessing component stability is the key to management of these injuries. Well-fixed components associated with nondisplaced fractures may be managed nonoperatively with a period of protected weight bearing and/or bracing. Displaced fractures with a stable component should be treated with open reduction and internal fixation using a buttress plate for fixation. If the component is loose, revision to a total knee arthroplasty is required and can be technically challenging.