Softening of the nail bed leads to a rocking sensation on palpation. Increased convexity of the nail and widening of the fingertips are also present. In most cases of hypertrophic osteoarthropathy, clubbing is the only external manifestation. 2 Abnormal deposition of periosteal bone is first noted as subperiosteal edema with resultant periosteal elevation. Later, subperiosteal new bone forms along the long bone shafts primarily at the distal ends.
Progression is symmetric and proximal.
Periostosis most commonly occurs near the metacarpophalangeal, metatarsophalangeal, wrist, ankle and knee joints. It can be asymptomatic, but more commonly patients complain of a deep-seated burning or aching pain, particularly incapacitating in the lower extremities. The pain is aggravated by recumbency and generally relieved by elevation of the affected extremity. In the areas of new bone formation, tenderness on palpation is usually noted. On the radiograph, periosteal thickening is seen and periosteal elevation appears as a continuous, thin, sclerotic line of new bone along the long bone shaft.