Charcot’s arthropathy is one of the most debilitating orthopedic sequelae of diabetes. Regarding its pathogenesis, the current theory suggests a role of diabetic peripheral and autonomic neuropathy (1).
Kidney-pancreas transplantation is an accepted therapeutic approach in uremic type 1 diabetic patients, providing normalization of glycometabolic control and improvement of secondary diabetic complications, including neuropathy (2,3,4).
We report a case of a diabetic uremic patient who developed acute Charcot’s arthropathy despite 11 years of tight metabolic control after successful kidney and pancreas transplantation. A 41-year-old type 1 diabetic uremic male patient underwent kidney and pancreas transplantation. His immunosuppression regimen consisted of steroids, cyclosporin, and azathioprine. During the entire follow-up period, the patient was insulin-free, in good metabolic control (HbA1c 5.2 ± 0.6%), and had good renal function (creatinine 1.3 ± 0.1 mg/dl). At baseline, neurological examination and electromiography documented symmetrical sensory loss in the distal lower extremities and motor deficits mostly on the right side, with footdrop. A test of autonomic function showed a near normal blood pressure response to standing. During deep breathing, the heart rate was compromised, whereas the response to standing was normal.
After transplantation, an improvement of motor and sensory nerve conduction velocity was observed during the follow-up period, and the median nerve reached normal values at 5 years, whereas sural and peroneal nerves remained severely impaired. Bone mineral density by dual-energy X-ray absorptiometry with Hologic was evaluated regularly, and the results showed stable osteopenia.
Eleven years after transplantation, the patient showed a painless profound swelling of the right ankle joint with locally increased skin temperature, joint effusion, and erythema. X-ray, computerized tomography, magnetic resonance, and Technetium-99 bone scan showed an erosive area at the third distal segment of the tibia, fibula, and astragalus, with involvement of the surrounding soft tissue and joint effusion. The patient was submitted to surgical tibiotalar fusion. During surgery, samples were collected for histological test and microbiological evaluation. Histological examination showed broken detached osteocartilagineus connection without evidence of phlogistic infiltration, and cultures were negative.
This patient, despite long-term functioning kidney and pancreas transplantation, developed Charcot’s arthropathy. The clinical diagnosis was confirmed by histological analysis via bone and synovial biopsy—negative cultures ruled out the hypothesis of an infective arthropathy. The development of Charcot’s arthropathy in this patient was probably multifactorial. Among the factors that could have influenced the development of this artropathy, steroids did not seem to have played a fundamental role because they were administered for a short period after transplantation and because a progression of osteopenia was not observed. Cyclosporin was described to induce peripheral neuropathy (5). This could counterbalance the positive effects of tight metabolic control on diabetic neuropathy, thus leading to impairment of nerve function. In fact, in this patient, diabetic neuropathy was partially reversed.
We can conclude that in patients already affected by severe diabetic complications, tight metabolic control achieved with pancreas transplantation does not prevent the development of Charcot’s arthropathy.
References
Address correspondence to Antonio Secchi, Associate Professor of Medicine, University of Milan, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy. E-mail: [email protected].
