Femoral Episiotomy as a Tool for the Extraction of Well-Fixed Cemented Stems During Revision Surgery for Expandable Tumor Prosthesis

Introduction: Expandable endoprosthesis are increasingly being used for limb reconstruction in pediatric malignant bone tumors. Follow-up studies reported high rates of revision surgeries during which the extraction of a well-fixed stem may be necessary. In this case series, the episiotomy technique was used for that purpose. Methods: A total of 11 patients were included. All had a primary diagnosis of an Osteosarcoma of the distal femur. The mean age at the time of revision was 14.5±2.7 years. The stem fixation was cemented in all patients. The reason for revision was implant breakage in 6, and exchange of expandable tumor prosthesis into an adult tumor prosthesis in 5 patients. A longitudinal cortical slit was done along the stem to be removed, followed by back hammering using vise grip. Barack grading of cement mantle was used to assess the quality of cement around newly implanted stems. Results: All stems were successfully extracted followed by insertion of a new cemented stem without internal fixation at the episiotomy site. Barrack grading of cement mantle was grade A in 8, B in 2 and C in 1 patient. The mean time to full weight bearing was 50±7.08 days. The mean follow-up duration was 41.6±8.5 months (24 to 50 m). Stem loosening and extensive stress shielding developed in 2 patients at 39 and 21 months from surgery, respectively. Conclusion: Femoral episiotomy is a simple technique which facilitates the extraction of well-fixed cemented stems of tumor prosthesis. Larger studies comparing outcomes with versus without fixation at the osteotomy site and assessing the success rate in noncemented stems are still needed. Level of evidence: Level IV—retrospective therapeutic study.