DynaFix プレートと気孔率60% β-TCP を用いた Opening wedge HTO（高位脛骨外反骨切り術）の経験と問題点

抄録

We performed opening-wedge HTO with the use of a DynaFix Plate and 60% β-TCP Graft in 21 patients between 2008 and April 2011. The mean age of the patients was 64.4 years (range 58-72 yr). The medial osteotomy site was fixed with a DynaFix VS osteotomy plate, followed by grafting with porous 60% β-tricalcium phosphate (TCP). The limb was not immobilized with a knee brace postoperatively, and full weight-bearing was allowed from the fourth week in principle. Rigid fixation allows early full weight-bearing and discharge within four to five weeks after surgery.
The mean preoperative and postoperative femorotibial angles were 182.9 degrees and 172.3 degrees, respectively, and the mean JOA score improved from 58.6 to 85.5 points.
The complications during surgery included fissures of the tibial lateral cortex in one knee, tibial lateral plateau in four knees, and tibial medial plateau in one knee. There was no pseudoarthrosis.
The correction can be adapted intraoperatively based on an X-ray image of the whole lower extremity, but the femorotibial angle in three patients exceeded 175 degrees. The mean correction angle was 10.6 degrees. We recommend open wedge osteotomy for patients with a femorotibial angle of less than 185 degrees.