Patellar height and the inclination of the tibial plateau after high tibial osteotomy. The open versus the closed-wedge technique.
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.
Brouwer
R W
RW
Erasmus Medical Centre, Rotterdam, The Netherlands. r.w.brouwer@mzh.nl
Bierma-Zeinstra
S M A
SM
van Koeveringe
A J
AJ
Verhaar
J A N
JA
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000473:pathology / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D010329:Patella / Q000000981:diagnostic imaging / Q000473:pathology*; D011446:Prospective Studies; D011859:Radiography; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery