Arthritis of the Thumb     Normal Base of the thumb joint. Arthritic base of the thumb joint.     Arthritis of the thumb, as it joins the wrist, is caused by changes between the metacarpal bone of the thumb and the small square wrist bone with which it articulates. This is a very complicated joint because of the great mobility of the thumb that we have in our use of the hand. Arthritis changes often develop in this joint over the years. It can become disabling because of the degree of pain that it causes and also the fact that it severely limits strength in the hand, particularly pinching or grasping with the thumb. The pain is usually said to be aching in nature, but sometimes can be sharp and can even radiate upward into the forearm.     There have been many approaches used in orthopaedic surgery over the years to try to correct this condition.     Orthosphere       One of the new ways to treat this disabling arthritis at the base of the thumb is the surgical insertion of a small ceramic ball as a dynamic spacer in the arthritic joint. This is done by careful surgical preparation of the joint to accept the ceramic implant. The beauty of the procedure is that very little bone is removed to prepare for the insertion of the implant and it preserves the soft tissue structures around the joint. The results of this technique have been very promising and it certainly is important for anyone who has arthritis of the basal joint of the thumb to know about this procedure.     After the Orthosphere Zirconia Ceramic implant is inserted, there is a period of splinting for approximately four weeks. This gives time for the tissues to heal and for the implant to become stable in the thumb. Unrestricted activity is usually allowed with the operated hand in about eight weeks.     We at our office are very enthused about the possibilities of this implant and feel that it is a valuable addition to the treatment of arthritis of the thumb.     Orthosphere implant in place in base joint of thumb. Orthosphere Zirconia Ceramic prosthesis.