Absence or compromise of the medial collateral ligament (MCL) in conjunction with osseous defects of the medial femoral condyle in total knee arthroplasty (TKA) is a challenging reconstructive problem. Treatment usually requires a highly constrained TKA with or without ligamentous reconstruction. To restore the medial femoral condylar bone and to provide ligamentous stability on the medial side of the knee, the authors present a technique for reconstruction of the medial femoral condyle and MCL using a tendoachilles allograft with a calcaneal bone block. The construct also can be augmented with a semitendinosus tendon autograft. Two illustrative cases and a review of the literature are presented.