Hamidreza Yazdi1, Hossein Akbari Aghdam2,3, Paniz Motaghi2, Mehdi Mohammadpour2, Milad Bahari2, Sara Goodarziyan Ghahfarokhi3, Mohammad Taher Ghaderi4,5. 1. Bone and Joint Reconstruction Research Center, University of Medical Sciences, Firouzgar General Hospital, Tehran, Iran. 2. Bone and Joint Reconstruction Research Center, School of Medicine, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, IR, Iran. 3. Department of Orthopedics Surgery, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran. 4. Bone and Joint Reconstruction Research Center, School of Medicine, Shafa Orthopedic Hospital, Iran University of Medical Sciences, Tehran, IR, Iran. dr.ghaderim@gmail.com. 5. Shafa Hospital, Mojahedin-e-eslam St, Tehran, Iran. dr.ghaderim@gmail.com.
Abstract
BACKGROUND: A coherent measurement approach for sagittal alignment of the distal femur after fracture reduction or distal femur osteotomies is not available. The present study aims to introduce a new method using Blumensaat's line and tangent lines to the femoral cortexes to determine the sagittal alignment of the distal femur. METHODS: 113 patients who had true lateral knee radiographs were included. All of the radiographs were evaluated by one fellowship-trained knee surgeon and one radiologist using the PACS system. The Blumensaat's line was determined on the true lateral knee radiographs. Then, three long lines were drawn on the distal third of the femoral shaft. The first line is tangent to the anterior cortex of the femur, the second line is along with the anatomical axis of the femur, and the third line is tangent to the posterior cortex of the femur. The angles between Blumensaat's line and these lines were measured. Intraclass Correlation Coefficient (ICC) was used to measure the strength of inter-and intra-rater agreement. RESULTS: The mean angle between the Blumensaat's line and the anatomical axis of the femur was 35.4 ± 3°. The mean angle between the Blumensaat's line and the line tangent to the anterior femoral cortex and the line tangent to the posterior femoral cortex were 34.5 ± 3° and 35.2 ± 3°, respectively. Excellent inter-and intra-rater reliabilities were observed between the measurements (ICC = 0.96 and ICC = 0.98, respectively). The angle between the Blumensaat's line and the line tangent to the posterior femoral cortex was significantly higher in participants aged < 38 years (p = 0.049). No other significant association was found between the angles and demographic characteristics of the patients. CONCLUSIONS: The expected mean angles between the Blumensaat's line and the distal femur were 34.3 to 35.4 degrees. This finding could be useful to determine the normal sagittal alignment of the distal femur. LEVEL OF EVIDENCE: II.
BACKGROUND: A coherent measurement approach for sagittal alignment of the distal femur after fracture reduction or distal femur osteotomies is not available. The present study aims to introduce a new method using Blumensaat's line and tangent lines to the femoral cortexes to determine the sagittal alignment of the distal femur. METHODS: 113 patients who had true lateral knee radiographs were included. All of the radiographs were evaluated by one fellowship-trained knee surgeon and one radiologist using the PACS system. The Blumensaat's line was determined on the true lateral knee radiographs. Then, three long lines were drawn on the distal third of the femoral shaft. The first line is tangent to the anterior cortex of the femur, the second line is along with the anatomical axis of the femur, and the third line is tangent to the posterior cortex of the femur. The angles between Blumensaat's line and these lines were measured. Intraclass Correlation Coefficient (ICC) was used to measure the strength of inter-and intra-rater agreement. RESULTS: The mean angle between the Blumensaat's line and the anatomical axis of the femur was 35.4 ± 3°. The mean angle between the Blumensaat's line and the line tangent to the anterior femoral cortex and the line tangent to the posterior femoral cortex were 34.5 ± 3° and 35.2 ± 3°, respectively. Excellent inter-and intra-rater reliabilities were observed between the measurements (ICC = 0.96 and ICC = 0.98, respectively). The angle between the Blumensaat's line and the line tangent to the posterior femoral cortex was significantly higher in participants aged < 38 years (p = 0.049). No other significant association was found between the angles and demographic characteristics of the patients. CONCLUSIONS: The expected mean angles between the Blumensaat's line and the distal femur were 34.3 to 35.4 degrees. This finding could be useful to determine the normal sagittal alignment of the distal femur. LEVEL OF EVIDENCE: II.
Authors: Sander Koëter; Ernie M H F Bongers; Jacky de Rooij; Albert van Kampen Journal: Knee Surg Sports Traumatol Arthrosc Date: 2006-01-05 Impact factor: 4.342
Authors: Patrick W Joyner; Frederic Baker Mills; Scott Brotherton; Jeremy Bruce; Travis Roth; Ryan Hess; C Luke Wilcox; Charles E Leddon; Benjamin Davis; Christopher O'Grady; James R Andrews; Charles A Roth Journal: Orthop J Sports Med Date: 2020-08-06