RESUMO
Introduction: Osteotomy around proximal femur provides excellent exposure and helps in revision of both cemented and uncemented femoral stem. Hereby, describing our case report on wedge episiotomy, a new surgical technique for removal of distal fitting cemented or uncemented femoral stem in conditions were extended trochanteric osteotomy (ETO) becomes inappropriate and episiotomy becomes inadequate. Case Report: A 35-year-old lady presented with painful right hip and difficulty in walking. Her X-rays showed a dissociated bipolar head and long cemented femoral stem prosthesis. She gave history of proximal femur giant cell tumor operated with cemented bipolar which failed in 4 months (Figs. 1, 2, 3). There were no signs of active infection such as discharging sinus and elevated blood infection markers. Hence, she was planned for one-stage revision of the femoral stem and conversion into total hip arthroplasty. Surgical Technique: A small trochanter fragment, along with the abductor and vastus lateralis continuity, was preserved and mobilized away augmenting hip exposure. The long femoral stem was found well fixed with a cement mantle all around in an unacceptable retroversion. There was metallosis with no macroscopic signs of infection. Taking in consideration of her young age and the long femoral prosthesis with cement mantle, the idea of ETO was considered inappropriate and more iatrogenic.Initially, an episiotomy was done along the lateral border of femur with an oscillating saw to interrupt the radio compressive force of the bone along the cement mantle and stem. However, the lateral episiotomy was not sufficient to loosen up the tight fit between bone and cement interface. Hence, a small wedge episiotomy was done along the full length lateral border of the femur (Figs. 5 and 6). A lateral wedge of 5 mm bone was removed increasing the exposure of bone cement interface with intact 3/4th cortical rim. This exposure allowed 2 mm K-wire, drill bit, flexible osteotome, and micro saw to go in between the bone and cement mantle to dissociate it. A 240 x 14 mm long uncemented femoral stem was fixed using bone cement extending along the entire femur length, With utmost care, all the cement mantle and implant were removed. The wound was soaked with three minutes of hydrogen peroxide and betadine solution and washed with high jet pulse lavage. A long 305 × 18 mm Wagner-SL revision uncemented stem was placed with adequate axial and rotational stability (Fig. 7). The long straight stem of 4 mm wider than the extracted was passed along the anterior femoral bowing augmenting the axial fit and the wagner fins helped in getting the much need rotational stability (Fig. 8). The acetabular socket was prepared with uncemented cup size of 46 mm with a posterior lip liner poly and 32 mm metal head was used. The wedge of bone was kept back along the lateral border and help with 5-ethibond sutures. Intraoperative histopathology sampling did not show any evidence of giant cell tumor recurrence, ALVAL score of 5 and microbiology culture grew negative. The physiotherapy protocol included non-weight-bearing walking for 3 months, later then partial loading was started and complete loading was done by end of fourth month. The patient had no complication such as tumor recurrence, periprosthetic joint infection (PJI) and implant failure at end of 2 years(Fig. 9).
