Basal Joint Arthritis of the Thumb
Basal joint arthritis of the thumb is the most common site of osteoarthritis of the hand. It involves the erosion of articular cartilage between the thumb metacarpal, trapezium bone, and often the trapezium-scaphoid joint area. The patient complains of symptoms consisting of chronic swelling and pain within the thumb. Often, there is a subluxation of the joint with a shifting of the thumb metacarpal out of position giving a prominence and deformity to the base of the thumb.
Diagnosis is made both on physical examination and x-ray evaluation. Gradation of this type of arthritis is based on the amount of damage to the level of the articular surface as well as subluxation of the joint. Initial treatment often includes that of anti-inflammatories, injection of cortisone and/or splinting including the thumb, wrist and hand. If this is not successful, then surgical intervention offers a reliable option for treatment. The basis of the surgery is to remove the offending arthritic bone, i.e., the trapezium, and reconstruct the ligaments between the thumb and second metacarpal using a slip of one of the muscles in the area, the abductor pollicis longus tendon. Postoperatively, the patient is splinted for approximately 6 weeks and must refrain from heavy lifting with regard to the thumb and hand. At approximately 6 weeks' time, the splint is removed and a 6 week period of therapy is warranted for regaining range of motion and strength within the thumb.
The surgery is performed on an outpatient basis under regional anesthesia which involves anesthesia for the entire arm as well intravenous sedation. During the surgical procedure, a pin is placed to keep the alignment of the thumb and allow the ligament reconstruction to heal. This is usually removed in the office under a local anesthetic at approximately 6 weeks as the pin is buried underneath the skin. This is a reliable procedure for relief of pain because one of the trapezium bone is removed; there is no longer the grinding sensation between the offending damaged articular cartilages.