The Effect of Hinge Position on Posterior Tibial Slope in Medial Open-Wedge High Tibial Osteotomy

• Published in: Arthroscopy Vol. 31; no. 6; pp. 1128 - 1133
• Main Authors: Moon, Sang Won, M.D, Park, Sin Hyung, M.D, Lee, Byung Hoon, M.D, Oh, Minkyung, Ph.D, Chang, Minho, Ph.D, Ahn, Jin Hwan, M.D., Ph.D, Wang, Joon Ho, M.D., Ph.D
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2015
• Subjects: Adult; Aged; Female; Humans; Imaging, Three-Dimensional; Joint Diseases - diagnostic imaging; Joint Diseases - surgery; Knee Joint - diagnostic imaging; Knee Joint - surgery; Male; Middle Aged; Orthopedics; Osteoarthritis, Knee - surgery; Osteotomy - methods; Prostheses and Implants; Retrospective Studies; Tibia - diagnostic imaging; Tibia - surgery; Tomography, X-Ray Computed; Young Adult
• ISSN: 0749-8063; 1526-3231
• DOI: 10.1016/j.arthro.2015.01.009

Purpose To evaluate whether hinge position affects the change in posterior tibial slope in medial open-wedge high tibial osteotomy (HTO). Methods We retrospectively evaluated 19 knees from 17 patients who underwent medial open-wedge HTO by 3-dimensional computed tomography scan before and after surgery. A 3-dimensional image model was constructed by applying reverse-engineering software to the computed tomography DICOM (Digital Imaging and Communications in Medicine) files. The hinge axis (i.e., the position of the hinge compared with the anteroposterior axis on an axial view), posterior tibial slope, medial-proximal tibial angle, and gap ratio (i.e., the ratio of anterior gap to posterior gap in the opened wedge) were measured. Results The mean hinge axis was 4.92° ± 3.86°. Posterior tibial slope increased from 7.29° ± 2.56° preoperatively to 10.48° ± 3.01° postoperatively ( P  = .001). The mean medial-proximal tibial angle was 85.96° ± 1.97° preoperatively and 93.13° ± 3.17° postoperatively ( P  = .001). The mean gap ratio was 62.48% ± 7.26%. Linear regression analysis determined that the hinge axis ( P  = .0001) was a significant factor changing posterior tibial slope. Conclusions Hinge position affected the change in posterior tibial slope in medial open-wedge HTO; in particular, a posterolateral hinge position led to an increase in posterior tibial slope. Level of Evidence Level IV, therapeutic study.