A rare case of bilateral medial femoral condylar cyst in OA knee managed with cruciate retaining TKA

Abstract

Introduction: We report an osteoarthritic patient with huge sub-chondral cyst-like lesions in the medial femoral condyle of distal femur. This large bone defects due to advanced osteoarthritis was successfully treated with Cruciate retaining implant in total knee replacement. Case Report: A 60yrs old obese Female presented in our institution diagnosed with bilateral tricompartmental Osteoarthritis. The x-rays showed bone on bone Tricompartment OA Knee with Varus Malalignment. The left knee was operated first. After exposure, Distal Femoral Cuts where taken wherein a huge bony defect of about 2cm*1 cm was found in medial femoral condyle, but as lateral border of medial femoral condyle was intact the contained defect was managed with bone grafting and Hebert’s screw and a Cruciate retaining implant was done in femur. The right knee was the mirror image of left and managed similarly with bone grafting and Hebert’s screw and implanted a CR femur. Conclusion: Any cystic /defect management in knee replacement traditionally always require extra armamentariumin form of augments, rods, wedges, but sometimes reverse thinking can also work if we understand the intraoperative scenario objectively and CR femur, the least constraint implant also, if used judiciously can bail us out from such a difficult situation. Usually one should keep rods, augments, wedges and constrain implants ready for difficult cases. Read your x ray carefully, if suspected a Preoperative MRI /CT scan should be done to exclude any sub-chondral cysts osteochondral defects and good planning of the cases, which will avoid any surprise during surgery. No benefits or funds were received in the support of this study. The authors reports no conflict of interest.