Intraoperative fracture during primary total knee arthroplasty.

UNLABELLED: While the occurrence of periprosthetic fractures around total knee arthroplasties (TKAs) is well know, little is known about intraoperative fractures that occur during TKA. We describe the incidence, location, and outcomes of iatrogenic intraoperative fracture during primary TKA. We reviewed 17,389 primary TKAs performed between 1985 and 2005 and identified 66 patients with 67 intraoperative fractures including 49 femur fractures, 18 tibia fractures, and no patella fractures. There were 12 men and 54 women with a mean age of 65.2 +/- 16 years. Of the 49 femur fractures, locations included medial condyle (20), lateral condyle (11), supracondylar femur (eight), medial epicondyle (seven), lateral epicondyle (two), and posterior cortex (one). Tibia fractures (18) included lateral plateau (six), anterior cortex (four), medial plateau (three), lateral cortex (three), medial cortex (one), and posterior cortex (one). Twenty-six fractures occurred during exposure and preparation, 22 while trialing, 13 during cementation, and three while inserting the polyethylene spacer. The minimum followup was 0.15 years (mean, 5.1 years; range, 0.15-15.4 years). All fractures healed clinically and radiographically. Knee Society scores and function scores improved from 46.4 and 34.6 to 79.5 and 61, respectively. Fourteen of the 66 (21%) patients were revised at an average of 2.8 years. Intraoperative fracture is an uncommon complication of primary TKA with a prevalence of 0.39%. Intraoperative fracture occurred more commonly in women (80.6%) and in the femur (73.1%). The majority of fractures occurred during exposure and bone preparation and trialing of the components. LEVEL OF EVIDENCE: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.