Radiological analysis of closed-wedge high tibial osteotomy

Objectives: in this study,we aimed to evaluate changes in frontal plane (anatomical axis) and sagittal plane (tibial slope,patellar height) parameters following closed-wedge high tibial osteotomy (hto) and possible correlations between them. patients and methods: between june 2003 and may 2007,15 knees of the 13 female patients (mean age 52.6 years; range 45 to 64 years) who were followed on a regular basis in our outpatient clinic and underwent closed-wedge hto were included. the mean follow-up was 49 months (range 29-75 months). radiologic analysis was performed using pre- and postoperative anatomical axis,tibial slope,and patellar height measurements [caton index (ci) and insall-salvati index (isi)]. the findings were analyzed by using wilcoxon matched pairs test and pearson's correlation test. results: preoperative varus deformity was 6.3°±2.7°,while it was measured as 7.2°±2.5° valgus in the last visit (p=0.0004). the pre- and postoperative ci were 0.97±0.1 and 0.96±0.1,respectively (p=0.85). the isi decreased from 1.23±0.15 to 1.14±0.15 (p=0.012). patella baja was observed in only one patient (isi=0.77). preoperatively tibial slope was 6.5°±2.4°,while it was measured as 0.06°±3.4° in the last visit (p=0.0001). there was no correlation between frontal plane angle change and tibial slope,also between patellar height and tibial slope. conclusion: closed-wedge hto does not result in significant changes in patellar height. the risk of patella baja can be decreased through minimal dissection around patellar tendon. however,closed-wedge hto reduces tibial slope significantly. optimal resection from posterior tibia is necessary to prevent this condition. a possible loss of tibial slope should be considered in the further reconstructive procedures.