Intraoperative rotational measuring device: a new device to achieve accuracy in corrective osteotomy of malrotated femur.

A new derotation device for corrective femoral osteotomy is reported. This device helps eliminate errors of undercorrection and overcorrection in derotational osteotomies of femurs with torsional deformities. A prototype of the intraoperative rotational measuring device was tested on 16 cadaver femurs.