Open-wedge high tibial osteotomy using intraoperative control of joint line convergence angle with reference to preoperative supine radiograph

• Published in: Archives of orthopaedic and trauma surgery Vol. 141; no. 4; pp. 645 - 653
• Main Authors: Akamatsu, Yasushi, Nejima, Shuntaro, Tsuji, Masaki, Kobayashi, Hideo, Muramatsu, Shuntaro
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.04.2021; Springer Nature B.V
• Subjects: Arthritis; Arthroscopy and Sports Medicine; Clinical outcomes; Hospitals; Knee; Medicine; Medicine & Public Health; Orthopedics; Osteoarthritis; Patients; Planning; Surgery; Trauma; Soft tissue correction; Coronal alignment; Supine radiograph; Open-wedge high tibial osteotomy; Joint line convergence angle
• ISSN: 0936-8051; 1434-3916
• DOI: 10.1007/s00402-020-03738-3

Introduction Preoperative supine joint line convergence angle (JLCA) correlates with postoperative standing JLCA. Here, we compared the radiographic and clinical outcomes of knees with preoperative JLCAs of ≥ 4° and < 4° in open-wedge high tibial osteotomy (OWHTO). We hypothesized that the postoperative coronal alignment in both groups would not be affected by a change in JLCA if this change could predict before surgery. Materials and methods Eighty-four patients with medial knee osteoarthritis who underwent OWHTO were enrolled retrospectively. A weight-bearing line (WBL) ratio of 62% and a JCLA equivalent to the preoperative supine JLCA were anticipated in preoperative planning. These were intraoperatively set using an alignment rod and a radiolucent protractor under fluoroscopy. Soft tissue correction was defined as correction angle minus bone correction. The participants with preoperative JLCAs of < 4° (low-JLCA group) and ≥ 4° (high-JLCA group) were compared. Results No significant difference in the coronal alignment was found between the groups after OWHTO. No significant differences in correction angle or bone correction were found between the groups, but the soft tissue correction in the high-JLCA group was higher than that in the low-JLCA group after OWHTO ( p  = 0.013). Conclusions When we controlled intraoperative JLCA, the postoperative coronal alignment was not affected by the change in JLCA and the differences in soft tissue correction between the low-JLCA and high-JLCA groups. However, overcorrection compared with the target coronal alignment remained in both groups. Level of evidence Level III, retrospective comparative study.