Bone and articular involvement in Systemic Sclerosis
Bone involvement is usually demonstrated by resorption of bone. Acrosclerosis with osteolysis is common. Resorption of ribs, mandible, acromion, radius, and ulna has been reported. Arthralgias and morning stiffness are relatively common, but erosive arthritis is rare. Hand deformities and ankylosis are seen, but these are usually attributed to the tethering effects of skin thickening instead of joint involvement. Tendon sheaths can become inflamed and fibrinous, mimicking arthritis. Tendon friction rubs can be palpated typically over the wrists, ankles, and knees and are found primarily in patients with diffuse SSc (50%–65%). Friction rubs are due to fibrin deposition in the tenosynovial sheath and/or increased thickness of the tendon retinacula.