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Management of bone defects in revision total knee arthroplasty.

Managing substantial bone loss is a challenge in revision total knee arthroplasty. The etiology of bone loss is usually multifactorial and can range from subsidence of loose implants, stress shielding, and periprosthetic osteolysis to osteonecrosis and even infection1. Goals of revision total knee arthroplasty include preservation of host bone, correction of sagittal and coronal alignment, restoration of flexion-extension balance, optimization of ligamentous stability, and establishment of a stable bone-implant interface. Selection of reconstructive methods such as bone cement and screws, block augments, impaction or bulk allografts, or metaphyseal sleeves and cones is determined by the location and quantity of osseous defects in the femur and tibia. This article reviews the different operative methods for dealing with bone loss in revision total knee arthroplasty.

The goal of preoperative assessment is to precisely determine the mechanism of failure and thereby decrease the risk of repeating mistakes that may have led to the initial failure of the total knee replacement. Because the results of revision total knee arthroplasty in patients with unexplained pain are often unsatisfactory2, it is mandatory to determine the mechanism of failure, what is deficient, and what is necessary to reconstruct in terms of both bone and soft-tissue deficits. The surgeon must determine whether the patient’s symptoms are consistent with a failed total knee replacement and are not related to extrinsic causes of knee pain such as spine or hip pathology. He or she must also rule out conditions in which revision total knee arthroplasty may be contraindicated such as infection, Charcot arthropathy, neuromuscular disease, or adverse medical conditions.

The preoperative evaluation of the patient begins with a detailed history and clinical examination. Operative reports should be reviewed to assess the previous surgical approach used, soft-tissue releases performed, and size and type of present prosthetic components. …