J Knee Surg 2018; 31(04): 302-305
DOI: 10.1055/s-0037-1603638
Original Article
Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Reliability of Roentgenographic Knee Alignment Measurements in Gonarthrosis

Teng-Le Huang
1  Department of Orthopedics, Tai-An Hospital Shuang Shi Branch, Taichung, Taiwan
2  Department of Biomedical Imaging and Radiological Science, College of Medicine, China Medical University, Taichung, Taiwan
Chen-Chie Wang
3  Department of Orthopedic Surgery, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan
4  Department of Orthopedics, School of Medicine, Tzu Chi University, Hualien, Taiwan
Kai-Chiang Yang
3  Department of Orthopedic Surgery, Taipei Tzu Chi Hospital, The Buddhist Tzu Chi Medical Foundation, New Taipei City, Taiwan
5  School of Dental Technology, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
Chang-Chin Wu
6  Department of Orthopedics, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei, Taiwan
7  Department of Biomedical Engineering, Yuanpei University of Medical Technology, Hsinchu, Taiwan
8  Department of Orthopedics, En Chu Kong Hospital, New Taipei City, Taiwan
› Author Affiliations
Further Information

Publication History

18 July 2016

21 April 2017

Publication Date:
09 June 2017 (eFirst)


A reliable method of measuring knee alignment is critical in the preoperative planning of high tibial osteotomy (HTO). This radiological study, based on the measurements of the mechanical and anatomical axes of the lower limb, aimed to determine which method would be more reliable and reproducible. From 2004 to 2013, 50 consecutive patients (50 knees) with medial gonarthrosis were treated with valgus-producing HTO. Four independent investigators assessed preoperative standing lower limb radiography (including hip, knee, and ankle joints) to measure both anatomical and mechanical axes. We defined a response as a difference in the angle measured by the same investigator using the same method. The covariates were the investigators and methods. To account for both inter- and intraobserver variabilities, all data were evaluated using a generalized estimating equation model. The results revealed that the effect of the investigators was not statistically significant; however, the effect of the measurement method was highly significant (p < 0.0001). The estimated coefficient of the anatomical axis method was negative, indicating that the reproducibility of the anatomical axis method was better than that of the mechanical axis.