Anteromedial Gap Opening and Osteotomy Sufficiency Are Associated With Multiplanar Correction Errors in Open‐Wedge High Tibial Osteotomy: A Computed Tomography‐Based Study
Yugo Morita, Shinichi Kuriyama, Yusuke Yamawaki, Kohei Nishitani, Shinichiro Nakamura, Hiromu Ito, Shuichi MatsudaPurpose
To evaluate 3‐dimensional correction errors in the coronal, sagittal, and axial planes using computed tomography and identify surgical and anatomical factors associated with multiplanar correction errors after open‐wedge high tibial osteotomy.
Methods
This retrospective study included patients who underwent biplanar open‐wedge high tibial osteotomy between September 2014 and October 2022. The opening‐angle error, posterior tibial slope (PTS) change, and axial rotation were measured using preoperative and 1‐ to 2‐week postoperative computed tomography images; hinge angle and osteotomy sufficiency were evaluated. Analysis involved mixed‐effects models adjusted for age, sex, and body mass index.
Results
Of 110 included knees (94 patients), the mean opening‐angle error, PTS increase, and internal rotation were −0.1°, 2.6°, and 2.7°, respectively. Planned opening angle was associated with coronal undercorrection ( β = 0.230, P = .001) and internal rotation ( β = 0.321, P = .001); hinge angle with coronal undercorrection ( β = 0.023, P = .039) and PTS increase ( β = 0.045, P = .044); and osteotomy sufficiency was associated with a smaller PTS increase ( β = −0.039, P = .005) but greater internal rotation ( β = 0.046, P < .001). Sex‐stratified analyses identified factors associated with correction errors: planned opening angle in both sexes; hinge angle, biplanar and sagittal osteotomy angles, and osteotomy sufficiency in women; and entry height and osteotomy sufficiency in men. Each degree of internal rotation was associated with a 1.6‐point lower 1‐year Lysholm score ( β = −1.572, P = .018). Lateral hinge fractures occurred in 23.6% of knees. Type I fractures exhibited greater internal rotation, and type III fractures showed greater PTS increases and reduced postoperative flexion.
Conclusions
Anteromedial gap opening was associated with coronal undercorrection and increased PTS during open‐wedge high tibial osteotomy. Greater osteotomy sufficiency was associated with a reduced PTS increase but greater distal tibial internal rotation. Greater internal rotation was associated with lower 1‐year Lysholm scores.
Level of Evidence
Level III, retrospective case‐control study.