QT Pathologies (EN)
In a normal joint, cartilage covers the end of the bones and serves as a shock absorber to allow smooth, pain-free movement. In osteoarthritis (OA, or "degenerative arthritis") the cartilage layer wears out, resulting in direct contact between the bones and producing pain and deformity. One of the most common joints to develop OA in the hand is the base of the thumb.
The thumb basal joint, also called the trapeziometacarpal (TMC) joint, is a specialized saddle-shaped joint that is formed by a small bone of the wrist (trapezium) and the first bone of the thumb (metacarpal). The saddle shaped joint allows the thumb to have a wide range of motions, including up, down, across the palm, and the ability to pinch.
- Trapeziometacarpal joint or saddle joint of the thumb Anatomy images courtesy and copyright of Primal Pictures Ltd – www.primalpictures.com
- Rhizarthrosis or osteoarthritis of the thumb
Osteoarthritis can develop at any age, but usually appears after the age of 45 and the exact cause is unknown.
It may run in families, and it sometimes follows a fracture or dislocation involving the joint many years before.
Arthritis of the basal joint of the thumb is common in women and rather less common in men. Generalized joint laxity may predispose towards development of this type of arthritis.
X-rays show it is present in about 25% of women over the age of 55, but many people with arthritis of this joint have no significant pain.
- Pain at the base of the thumb, aggravated by thumb use.
- Tenderness if you press on the base of the thumb.
- Difficulty with tasks such as opening jars, turning a key in the lock etc.
- Stiffness of the thumb and some loss of ability to open the thumb away from the hand.
- In advanced cases, there is a bump at the base of the thumb and the middle thumb joint may hyperextend, giving a zigzag appearance.
Severity can also progress to pain at rest and pain at night.
- Z thumb deformation : clinical appearance
- Z thumb deformation : radiological appearance
The diagnosis is made by history and physical evaluation.
Pressure and movement such as twisting will produce pain at the joint. A grinding sensation may also be present at the joint.
X-rays are used to confirm the diagnosis, although symptom severity often does not correlate with x-ray findings.
- Severe bilateral rhizarthrosis: joint destruction, deformity and bone contact
Less severe thumb arthritis will usually respond to non-surgical care such as :
- Avoiding activities that cause pain, if possible.
- Arthritis medication (Analgesic and/or anti-inflammatory medication).
- Splinting (rigid and non-rigid splints).
- Limited steroid injection and viscosuplementation
- Surgery is a last resort, as the symptoms often stabilise over the long term and can be controlled by the non-surgical treatments above.
Patients with advanced disease or who fail non-surgical treatment may be candidates for surgical reconstruction. A variety of surgical techniques are available that can successfully reduce or eliminate pain.
Surgical procedures include removal of arthritic bone and joint reconstruction (joint replacement or ligament arthroplasty), joint fusion, bone realignment, and even arthroscopy in select cases.
During your consultation, Dr. D'Agostino will discuss the current treatment options and can help you choose the best treatment based on your particular case.
- « ball and socket » implant (thumb prosthesis) (left) and pyrocarbone interposition implant (right)