PURPOSE: Tibial osteotomy is used to treat a variety of orthopedic conditions, including reduction in pain and improvement of deformity and function. In templating for surgery, accurate radiographic measurement aids in planning for correction. The purpose of our study was to examine the effect of internal rotation and external rotation on measurement of tibial sawbone models with 5 closing wedge varus deformities at 10-degree increments between 10 and 50 degrees. One sawbone without deformity served as the control. STUDY DESIGN: A total of 66 radiographs were measured by 5 individuals. Measurement deviations from the control in each of the 10 positions of rotation were assessed. RESULTS: In the analysis of variance models, increased rotation and varus angulation were associated with increased deviation compared with the control. In external rotation for every 10 degrees of varus angulation, the degree deviation increased 0.69 degrees. In IR for every 10 degrees of angulation, the degree deviation increased by 0.84 degrees. Internal rotation had the greatest impact. Mean differences between different rater's measurements were small (1.1+/-1.2 degrees) and correlations suggested high interrater reliability. CONCLUSIONS: As the degree of rotation from neutral increased and varus angulation increased, deviation from neutral increased. CLINICAL RELEVANCE: Clinically, the results of this study support the importance of proper alignment of the tibia during radiography to more precisely template surgery.
PURPOSE: Tibial osteotomy is used to treat a variety of orthopedic conditions, including reduction in pain and improvement of deformity and function. In templating for surgery, accurate radiographic measurement aids in planning for correction. The purpose of our study was to examine the effect of internal rotation and external rotation on measurement of tibial sawbone models with 5 closing wedge varus deformities at 10-degree increments between 10 and 50 degrees. One sawbone without deformity served as the control. STUDY DESIGN: A total of 66 radiographs were measured by 5 individuals. Measurement deviations from the control in each of the 10 positions of rotation were assessed. RESULTS: In the analysis of variance models, increased rotation and varus angulation were associated with increased deviation compared with the control. In external rotation for every 10 degrees of varus angulation, the degree deviation increased 0.69 degrees. In IR for every 10 degrees of angulation, the degree deviation increased by 0.84 degrees. Internal rotation had the greatest impact. Mean differences between different rater's measurements were small (1.1+/-1.2 degrees) and correlations suggested high interrater reliability. CONCLUSIONS: As the degree of rotation from neutral increased and varus angulation increased, deviation from neutral increased. CLINICAL RELEVANCE: Clinically, the results of this study support the importance of proper alignment of the tibia during radiography to more precisely template surgery.