Therapeutic case series, Level IV.

No abstract

This study examined the changes in knee alignment after an open wedge high tibial osteotomy before and after weight-bearing. From 2004 to 2006, 36 high tibial osteotomies were performed to treat unicompartmental arthritis with a varus deformity. Thirteen patients without instability and with an accurate radiographic evaluation were included. The changes in the deviation of the mechanical axis and femorotibial angle were evaluated retrospectively using whole extremity radiographs immediately after surgery (supine position) and 4 months after surgery (weight-bearing position). In the nonweight-bearing radiograph obtained immediately after surgery, the mean deviation of the mechanical axis was 22% laterally and the mean femorotibial angle was valgus 8.9 degrees . The weight-bearing radiograph at 4 months after surgery showed that the former shifted laterally 34% and the latter shifted valgus 10.6 degrees . The changes in the mechanical axis and femorotibial angle were significant (P < 0.001). During open wedge high tibial osteotomy, the surgeon should consider the increase in deviation of the mechanical axis and femorotibial angle after weight-bearing.

Case series, Level IV.

No abstract

BackgroundDuring ligament balancing for severe medial contracture in varus knee total knee arthroplasty (TKA), complete distal release of the medial collateral ligament (MCL) or a medial epicondylar osteotomy can be necessary if a large amount of correction is needed.MethodsThis study retrospectively reviewed 9 cases of complete distal release of the MCL and 11 cases of medial epicondylar osteotomy which were used to correct severe medial contracture. The mean follow-up periods were 46.5 months (range, 36 to 78 months) and 39.8 months (range, 32 to 65 months), respectively.ResultsThere were no significant differences in the clinical results between the two groups. However, the valgus stress radiograph revealed significant differences in medial instability. In complete distal release of the MCL, some stability was obtained by repair and bracing but the medial instability could not be removed completely.ConclusionsMedial epicondylar osteotomy for a varus deformity in TKA could provide constant medial stability and be a useful ligament balancing technique.

BackgroundThis study evaluated the preoperative distractive stress radiographs in order to quantify and predict the extent of medial release according to the degree of varus deformity in primary total knee arthroplasty.MethodsWe evaluated 120 varus, osteoarthritic knee joints (75 patients). The association of the angle on the distractive stress radiograph with extent of medial release was analyzed. The extent of medial release was classified into the following 4 groups according to the stage: release of the deep medial collateral ligament (group 1), release of the posterior oblique ligament and/or semimembranous tendon (group 2), release of the posterior capsule (group 3) and release of the superficial medial collateral ligament (group 4).ResultsThe mean femorotibial angle on the preoperative distractive stress radiograph was valgus 2.4° (group 1), valgus 0.8° (group 2), varus 2.1° (group 3) and varus 2.7° (group 4). The extent of medial release increased with increasing degree of varus deformity seen on the preoperative distractive stress radiograph.ConclusionsThe preoperative distractive stress radiograph was useful for predicting the extent of medial release when performing primary total knee arthroplaty.

V.