Our aim was to compare the degree of patellar descent and alteration in angle of the inclination of the tibial plateau in lateral closing-wedge and medial opening-wedge high tibial osteotomy (HTO) in 51 consecutive patients with osteoarthritis of the medial compartment and varus malalignment. Patellar height was measured by the Insall-Salvati (IS) and the Blackburne-Peel (BP) ratios. The tibial inclination was determined by the Moore-Harvey (MH) method. Multivariate linear regression analysis was used to determine the influence of the type of HTO (closing vs opening wedge) on the post-operative patellar height or tibial inclination. The intra- and interobserver variability of these methods was determined before operation and at follow-up at one year. After an opening-wedge HTO the patellar height was significantly more decreased (mean post-operative difference: IS = 0.15; 95% confidence interval (CI) 0.06 to 0.23; BP = 0.11; 95% CI 0.05 to 0.18) compared with a closing-wedge HTO. The angle of tibial inclination differed significantly (mean post-operative difference MH = -6.40 degrees; 95% CI -8.74 to -4.02) between the two HTO techniques, increasing after opening-wedge HTO and decreasing after closing-wedge HTO. There was no clinically-relevant difference in the intra- and interobserver variability of measurements of patellar height either before or after HTO.

Adult, Aged, Female, Humans, Knee Joint/pathology/radiography, Male, Middle Aged, Osteoarthritis, Knee/pathology/*surgery, Osteotomy/*methods, Patella/*pathology/radiography, Prospective Studies, Tibia/*pathology/radiography/surgery
dx.doi.org/10.1302/0301-620X.87B9.15972, hdl.handle.net/1765/15675
Journal of Bone and Joint Surgery: British Volume
Erasmus MC: University Medical Center Rotterdam

Brouwer, R.W, Bierma-Zeinstra, S.M, van Koeveringe, A.J, & Verhaar, J.A.N. (2005). Patellar height and the inclination of the tibial plateau after high tibial osteotomy. The open versus the closed-wedge technique. Journal of Bone and Joint Surgery: British Volume, 87(9), 1227–1232. doi:10.1302/0301-620X.87B9.15972