Proximal tibia reconstruction with a porous tantalum cone in a patient with Charcot arthropathy.

Neuropathic arthritis, or Charcot arthropathy, is a rapidly destructive process associated with nerve damage and periarticular insensitivity. Most commonly it is associated with diabetes mellitus, tabes dorsalis, syringomyelia, or other peripheral nerve disorders. Clinical manifestations of this disorder classically include gross deformity, crepitus, lack of proprioception, joint effusion, calor, and decreased awareness of pain in the affected joint. Often the clinical picture is difficult to distinguish from septic arthritis. Radiographic findings are typically worse than portrayed during clinical examination. Rapid destruction of the articular surface with bony fragmentation is commonly found. The incidence of neuropathic arthritis among all diabetic patients is relatively small, ranging between 0.15% and 0.4%. Historically, there have been conflicting reports as to the efficacy of total knee arthroplasty (TKA) in patients with neuropathic arthritis. However, recent literature on the use of modern implants has been more optimistic as to the success of TKA. Difficulties associated with severe bone loss, poor bone quality, and ligamentous laxity may necessitate the use of structural allografts/augments, as well as stemmed and/or constrained TKA components. This article presents a case of a patient with Charcot arthropathy of the knee secondary to diabetes mellitus (type 2) treated successfully with a minimally constrained TKA and a porous tantalum cone (Zimmer, Warsaw, Indiana) as an "internal plate," for reconstruction of a combined segmental/cavitary defect of the proximal tibia. At 2-year follow-up, radiographs revealed stable TKA components with reconstitution of the fragmented proximal tibia around an osseointegrated porous cone.