Femoral Bow Predicts Postoperative Malalignment in Revision Total Knee Arthroplasty

• Published in: The Journal of arthroplasty Vol. 29; no. 8; pp. 1605 - 1609
• Main Authors: Sebastian, Arjun S., MD, Wilke, Benjamin K., MD, Taunton, Michael J., MD, Trousdale, Robert T., MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2014
• Subjects: Ankle Joint - diagnostic imaging; Arthroplasty, Replacement, Knee - adverse effects; axial alignment in revision total knee arthroplasty; Bone Malalignment - diagnostic imaging; Bone Malalignment - etiology; Bone Malalignment - surgery; coronal bowing; Coxa Valga - diagnostic imaging; Coxa Valga - etiology; Coxa Valga - surgery; Diaphyses - diagnostic imaging; femoral bow; Femur - diagnostic imaging; Femur - surgery; Hip Joint - diagnostic imaging; Humans; Knee Joint - diagnostic imaging; Knee Joint - surgery; malalignment; Orthopedics; Postoperative Period; Predictive Value of Tests; Radiography; Reoperation - methods; Reproducibility of Results; revision total knee arthroplasty; Tibia - diagnostic imaging; Tibia - surgery; femoral bow; revision total knee arthroplasty; coronal bowing; axial alignment in revision total knee arthroplasty; malalignment
• ISSN: 0883-5403; 1532-8406
• DOI: 10.1016/j.arth.2014.03.002

Abstract Diaphyseal bowing may compromise axial alignment in revision total knee arthroplasty (TKA). 277 patients undergoing revision TKA were evaluated for coronal bowing and hip–knee–ankle (HKA) axis. The mean femoral bow was 1.52° ± 0.18° varus (− 10.1° to + 8.4°). The mean tibial bow was 1.25° ± 0.13° valgus (− 5.9° to + 10°). HKA axis averaged 3.08° ± 0.35° varus preoperatively compared to 0.86° ± 0.25° varus postoperatively. Inter-rater and intra-rater reliability was high. Femoral bow greater than 4° significantly correlated with postoperative HKA axis malalignment (r = 0.402, P = 0.008). 39.7% of patients deviated 3° or greater from a neutral mechanical axis with a significant difference in femoral bow (0.94° ± 0.31°, P = 0.003). Diaphyseal bowing clearly has an important effect on postoperative limb alignment in revision TKA.