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
Hallux rigidus Hallux rigidus Hallux rigidus or stiff big toe is degenerative arthritis and stiffness due to bone spurs that affects the MTP joint at the base of the hallux (big toe). Hallux flexus was initially described by Davies-Colley in 1887 as a plantar flexed posture of phalanx relative to the metatarsal head. About the same time, Cotterill first used the term "hallux rigidus". Although the condition is degenerative, it can occur in patients who are relatively young, particularly active sports people who have at some time suffered trauma to the joint (turf toe). A notable example is NBA star Shaquille O'Neal