Osteoarthritis in a relatively young person should always raise the suspicion of a secondary cause. Clues to a possible etiology are found in the medical history and in the distribution of joint involvement. Primary osteoarthritis is generalized in distribution but causes decreased range of motion. Ehlers-Danlos syndrome, type III (also known as benign hypermobility syndrome) causes hyperlaxity of the joints, but the laxity tends to decrease after adolescence, and digital tufting is not found on radiography. Wilsons disease and ochronosis are deposition diseases that result in the accumulation of copper and homogentisic acid, respectively, in cartilage. As a result, the compressibility of cartilage is compromised, which increases mechanical stress and accelerates degenerative changes. Patients with Wilsons disease may have mild hypermobility, but the distribution in the hand tends to be proximal, with marked osteophyte formation. In ochronosis, joint stiffness and decreased mobility are more prominent than joint pain. Acromegalic arthropathy results from the effects of growth hormone on bone and cartilage. Early in the disease, the cartilage hypertrophies and widened joint spaces appear on radiography. The cartilage is friable, however, and degenerates prematurely. Both diabetes mellitus and acromegaly are associated with carpal tunnel syndrome; however, the musculoskeletal findings and symptoms in this patient are most indicative of acromegaly.
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Seminars in Medical Practice
Hospital Physician Board Review Manuals
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