COMPARISON OF KNEE MOTION AND CALLUS FORMATION IN FEMORAL LENGTHENINGWITH THE WAGNER OR MONOLATERAL-RING DEVICE

Twenty-three patients who underwent femoral lengthening had proximal f ixation with two Shanz screws; however, the type of distal fixation an d site of the osteotomy differed. One group had distal fixation with t wo Shanz screws attached to a Wagner device and had a midshaft osteoto my; the other group had distal fixation with an Ilizarov ring attached to a modified Wagner device and underwent metaphyseal osteotomy. Pati ents were compared with regard to callus formation, presence of knee s ubluxation, and range of motion (ROM) at the knee. The average lengthe ning achieved was 9.9 cm. The type of bone healing was superior when t he osteotomy was performed in the metaphysis rather than to the diaphy sis. Knee ROM was poorer in the group with the distal fixation by the Ilizarov wires than the group with the Shanz pins. Multiple adhesions caused by Ilizarov wire impalement of muscles appeared to have caused the excessive stiffness. In instances of simultaneous ipsilateral leng thening of the femur and tibia, interconnection of the Ilizarov ring b y means of hinges was successful in reducing the incidence of knee sub luxation.