NEUROPATHIC ARTHROPATHY DUE TO TABES-DORS ALIS AND CHONDROCALCINOSIS - REPORT OF 2 CASES

Neuropathic arthropathy due to tabes dorsalis and chondrocalcinosis is a rarely reported combination of which two new cases are reported her ein. Case 1 was a 60-year-old woman with severe arthropathy of the kne es, thoracolumbar kyphoscoliosis, and arthropathy of the right shoulde r. She had evidence of dysfunction of the nerve roots and spinal cord dorsal columns, and she felt virtually no pain in her affected joints. Tests for syphilis were positive on blood and cerebrospinal fluid sam ples. Calcium pyrophosphate dihydrate crystals were found in joint flu id samples. Initial radiographs showed changes suggestive of neuropath ic arthropathy in the knees and lumbar spine, as well as subchondral c ysts in the right shoulder. On followup radiographs obtained six years later, linear calcium deposits were seen in the knees and hands. Case 2 was a 67-year-old man who reported a history of primary syphilis 40 years earlier and presented with a severe painless arthropathy affect ing both knees. He had ataxia with loss of vibratory sense and absent deep tendon reflexes. Serologic tests for syphilis were positive. Radi ographs of the knees showed evidence of neuropathic arthropathy and ca lcium deposits in the lateral meniscus of the right knee. Joint trauma due to microprecipitation of calcium pyrophosphate dihydrate crystals may increase the risk of arthropathy in patients with tabes dorsalis. Case 1 also suggests that chondrocalcinosis may promote the developme nt of neuropathic arthropathy in joints rarely affected by tabes dorsa lis, such as the shoulder.