Joint deformity refers to a permanent alteration of the normal anatomical alignment of a joint, which may involve the alignment of the bones forming the joint, the shape of the articular surfaces, or the overall morphology of the affected area.
It may result from various causes, including advanced osteoarthritis with asymmetric cartilage wear, chronic inflammatory diseases such as rheumatoid arthritis, malunion after a fracture, congenital abnormalities, as well as prolonged uneven loading of the joint.
Typical examples of joint deformity include varus knee deformity (bow-legged alignment) and valgus knee deformity (knock-knee alignment), as well as finger deformities occurring in rheumatoid arthritis.
Such deformity disrupts the normal biomechanics of the joint by altering the distribution of loads across the articular surfaces. This may further accelerate the degenerative process and worsen pain and functional impairment.
Assessment includes clinical examination of joint alignment and mobility, as well as imaging evaluation, usually with weight-bearing radiographs, to accurately determine the degree and type of deformity.
Treatment depends on the severity and underlying cause of the deformity, ranging from conservative measures, such as orthotic devices and physiotherapy, to surgical correction, including osteotomy or joint arthroplasty, in more advanced cases.