By Arthritis Deformans * is understood nowadays any affection of a joint which side by side with retrogressive changes leads to real hypertrophy of bone and cartilage, i.e., to rounded knob-like formations, often to atrophy and attrition of other bony parts, and to the destruction of the porous character of the bone, which may lead to an ivory-like hardness. This disease may begin in the cartilage, bones, or soft parts of a joint, and may be mon- or polyarticular. Similar changes may also take place in the cartilage, e.g., in the fibrous rings of the intervertebral discs in cases of spondylarthritis of the spine.

* The term "arthritis deformans" does not apply to "stalactites," osteophytes, and the small projections formed as a result of any osteitis.

Malum senile (Coxae) is only distinguished from arthritis deformans in that the attrition of cartilage and bone is more marked than that which goes on side by side with the processes of hypertrophy in the latter disease.

Arthritis deformans may occur after a trauma as a monarthritis in the larger joints - hip, elbow, shoulder, and others. It may also be the end of a progressive chronic polyarthritis, and is then found in the small joints, e.g., in the fingers in "arthritis nodosa "; it may occur in joints affected with chronic rheumatism and even in a joint which has once been the seat of tuberculosis. The term expresses a pathological anatomical stage of development rather than an actual disease.

The pull exercised by the capsule, ligaments, and muscles on the diseased bones, the force of gravity, and functional influences result in changes of position, with subluxations, deformities, and altered (not merely limited) movement. The muscles are often found to atrophy through inactivity.

It is easily understood that neither massage nor gymnastics can do much good in these cases, although both may well be used to prevent muscle atrophy. Various forms of hot bath may be tried, and Bier's bandage and fibrolysin are sometimes employed. Surgical treatment, especially resection, often has good results, and the same can be said of treatment of the lower extremities by means of irons to take the weight of the body off the affected joint.

It is important to encourage the patient to use the joints as much as possible in all cases of chronic progressive diseases, chronic rheumatism of joints, and arthritis deformans.