Dr. Alon Covo
Thumb arthritis is the most common condition of degenerative disease of a joint in the human palm.
Cause of Thumb Arthritis
Thumb arthritis is caused by grinding of the cartilage coating the bone edges composing the joint.
Frequency of Thumb Arthritis
The reasons for appearance of thumb arthritis are many. In many cases thumb arthritis appears in women (at a 10:1 proportion compared to men) above the age of 40. Genetics affect the appearance of arthritis, for example the general flexibility of ligaments and joint diseases such as Rheumatoid arthritis.
Injury of the cartilage of the thumb base joint, which could be a high-energy injury, such as a fall, injury to the hand holding the steering wheel during a car accident and so on.
Micro-trauma – repeated motion while straining the joint as in jobs require the holding of small objects between the fingers and the thumb (diamond grinders, jewelers, dental technicians and so on).
Changes to the thumb base joint are created as a result of the injury with the grinding of cartilage from the bone edges on both sides of the joint and the formation of bone spikes. All of this causes the grinding of bone on bone with an accompanying inflammatory response and deterioration of the joint damage.
Characteristics of Thumb Arthritis
A pain appearing initially when grabbing objects between the thumb and other fingers develops into a chronic pain even when not using the thumb. Swelling and edema around the joint. Outward protruding of the joint causing the appearance of a "square palm". A reduction in motion ranges of the thumb with a difficulty in conducting daily activities such as opening bottles, lifting plates or books and so on.
Diagnosing Thumb Arthritis
Feeling by hand – checking of the source of pain.
Movement – moving the joint might lead to a feeling of "screeching" predicting the grinding of cartilage.
Imaging tests – X-Ray Radiographies of the palm base joint show: a reduction in joint distance, the appearance of bone spikes on both sides of the joint, sub-sprain of the thumb base joint as an expression of joint injury.
Treating Thumb Arthritis
Conservative treatment - including changes in work/sport/hobby patterns.
Thumb support splint - allows the thumb to rest and reduces the pain. Keeps the joint in a correct position.
Pharmaceutical treatment - pain killers and anti-inflammatory medications,
If the situation does not improve, an injection of cortisone - a strong anti-inflammatory medication which usually brings about a pause in the inflammatory process lasting for a longer period of time than oral treatment.
Surgical treatment -
If the conservative treatment does not ameliorate the condition and if the pain lead to a significant reduction of movement ranges and thus harm the quality of life, it is possible to consider a surgical treatment to solve the problem:
Arthrodesis - binding together the two bones forming the damaged joint. After the binding there is no more movement so the pain stops.
Osteotomy - cutting the bone in order to achieve a different axis and reduce the stress on damaged areas of the joint.
Trapezictomy - removal of one of the two bones forming the thumb base joint and thus stopping friction and the accompanying pain. This is the most common operation for solving this proble,.
Joint replacement (arthroplasty) - removal of the damaged joint planes of the thumb base joint and implantation of an artificial joint made of silicone, metal or plastic.
After these operations there is need for treatment with a cast for several weeks and then rehabilitation, physical therapy and occupational therapy. Normally the rehabilitation lasts approximately 6 months until the thumb returns to normal function.
In case of a fracture without risk of damage to the joint's stability it is possible to treat it using a splint as described above. In this case the splint has to be set for 4-6 weeks and follow-up uses X-Ray Radiography.