Arthritis and osteoblasts. Osteoclast activity can be directly induced by osteoblasts through the RANK/RANKL mechanism. Lupus is a common collagen vascular disorder that can be present with severe arthritis. Other features of lupus include a skin rash, extreme photosensitivity, hair loss, kidney problems, lung fibrosis and constant joint pain. Gout is caused by deposition of uric acid crystals in the joint, causing inflammation. There is also an uncommon form of gouty arthritis caused by the formation of rhomboid crystals of calcium pyrophosphate known as pseudogout. In the early stages, the gouty arthritis usually occurs in one joint, but with time, it
Toe joints, which form the toes. Since the toes are deformed further, these may press against a shoe and cause pain. Deformities of the foot can also be caused by rheumatoid arthritis and diabetes mellitus. Deformities may predispose to ulcers and pain, especially when shoe-wearing. A common problem involving the big toe is the formation of bunions. These are structural deformities of the bones and the joint between the foot and big toe, and may be painful. Similar deformity involving the fifth toe is described as tailor's bunion or bunionette. A favourable option for the reconstruction of missing adjacent fingers/multiple digit