Arthritis – CMC-1 (Basal Joint)
Basal joint arthritis is a debilitating, painful, condition affecting the joint where the thumb joins the wrist. Many types of arthritis can affect this joint but the most common is “degenerative osteoarthritis” sometimes called “Degenerative Joint Disease” (DJD). This occurs when the smooth thin cartilage, which covers the joint providing a “slick” gliding surface, becomes softened due to age or disease. Gradually the cartilage wears away, usually starting at the edges of the joint. Pinch or grip becomes painful and weaker as the body tries to protect the remaining joint surface. Bone spurs, or “osteophytes” form around the outer edges of the joint and a “catch” or “click” can occur with grip.
Early treatment can include rest, splinting or use of a special support, and anti-inflammatory medications. Persistent pain should be evaluated by a Hand Surgeon.
Trigger thumb is one of the most common thumb afflictions. The tendon that flexes the thumb runs through a tight “sleeve” or sheath starting at the first flexion crease (where the skin folds) and continuing in this sleeve for about an inch. At the point where it enters the sleeve, a thickening of the wall of the sheath can occur. This usually causes pain around the skin crease and, if the constriction worsens, can cause a “pinching” of the tendon. The tendon swells and forms a “bump” at the point of constriction. At this point the smooth flexion of the end joint closest to the thumbnail can start to “catch” or “trigger”. This can become severe enough so that the end joint “sticks” in a flexed or extended position requiring assistance with the other hand to move it. Eventually the joint can become “stuck” making active motion impossible.
Early treatment includes resting the thumb, splinting, and anti-inflammatory medication. If these measures are ineffective for more than two weeks evaluation by a Hand Surgeon is advisable.
Ligaments are the supporting tissues that provide support to the three joints of the thumb along with the muscles and tendons. Together they work in concert to provide the support and mobility essential for proper thumb function. The thumb ligaments are arranged around each of the three joints in a unique fashion allowing flexion-extension at the end joint, flexion-extension plus a bit of side-to-side motion at the middle joint, and a complex of flexion-extension, rotation, and motion into the plane of the palm and away from it at the basal joint. These important structures can be affected by various processes including chronic strains, arthritis, hereditary traits (excessive tightness or laxity), and injury. Injury can produce swelling, bruising, dislocation of the joint, and chronic pain. Mild injuries (sprains) can respond to icing (first 24-36hrs), splinting, and rest. More severe injuries (usually but not always associated with bruising) should be evaluated by a Hand Surgeon as these may involve a boney fracture or a complete ligament tear requiring more complex treatment.