The carpometacarpal (CMC) joint at the base of the thumb, also known as the basal joint, is highly mobile and allows the thumb its wide range of motion, which is crucial for pinching and grasping objects. When the cartilage in this joint wears away, typically due to osteoarthritis, it causes bone-on-bone friction that severely limits hand function and generates intense pain. Surgical intervention becomes necessary when conservative treatments fail to provide lasting relief from the pain and disability caused by this common form of arthritis.
Identifying the Need for Thumb Joint Surgery
The primary reason patients seek surgical treatment for the thumb is advanced osteoarthritis in the CMC joint, which leads to painful symptoms that interfere with nearly all daily activities. Pain is usually localized at the base of the thumb and often worsens with movements that involve pinching or gripping, such as opening jars, turning keys, or writing.
Patients commonly report tenderness, stiffness, and a reduced ability to pinch or grip objects with strength. Over time, the joint may also develop a noticeable bump or a square-shouldered appearance due to bone misalignment. Diagnosis is confirmed through a physical examination, noting tenderness over the joint and performing a painful grinding test, which is then confirmed with X-ray imaging showing the extent of joint deterioration.
Before surgery is considered, patients typically undergo non-surgical treatments to manage their symptoms. These conservative approaches include wearing a stabilizing splint, taking anti-inflammatory medications, and receiving corticosteroid injections. Surgery is generally reserved for individuals whose pain and functional limitations persist despite the failure of these non-operative treatments.
Surgical Options for Thumb Joint Reconstruction
While the term “thumb joint replacement” is often used broadly, surgeons frequently employ reconstruction techniques rather than a true prosthetic implant replacement. The most common procedure for basal joint arthritis is carpometacarpal arthroplasty, a reconstructive surgery that eliminates painful bone-on-bone contact by removing the damaged joint surface.
One component of this reconstruction is the Trapezial Excision, or trapeziectomy, where the surgeon removes the entire trapezium bone. Removing the trapezium creates a space that prevents the thumb metacarpal from grinding against the wrist bones. This excision alone can successfully relieve pain, but it is often combined with a technique to stabilize the remaining bones and prevent the thumb from collapsing into the empty space.
The most common combination technique is Ligament Reconstruction Tendon Interposition (LRTI), sometimes called suspension arthroplasty. After the trapeziectomy, the surgeon uses a piece of tendon, often from near the wrist, to fashion a sling to suspend the thumb metacarpal. The tendon is rolled up and placed into the defect, acting as a soft spacer to keep the bones separated. This method is highly effective for long-term pain relief, though it can involve a longer recovery period.
True Total Joint Replacement involves installing an artificial implant, similar to a hip or knee replacement. These prostheses, often made of metal or pyrocarbon, replace the damaged joint surfaces, sometimes without removing the trapezium. Joint replacement may offer a faster initial recovery and better preservation of thumb length and strength compared to LRTI, making it a good option for highly active or younger individuals. However, prosthetic implants can carry a higher risk of complications and failure with heavy use, meaning the choice depends heavily on the patient’s age, activity level, and the surgeon’s preference.
The Recovery Process
Recovery from thumb joint surgery, particularly the common LRTI procedure, is a phased process requiring patience and adherence to rehabilitation. Immediately following the operation, the hand is immobilized in a cast for approximately two to three weeks to protect the surgical site and allow initial healing. During this early phase, pain management and keeping the hand elevated above the heart are important to control swelling and discomfort.
After the initial immobilization period, the sutures are removed, and the cast is typically replaced with a custom-fitted, removable splint or brace that extends over the thumb and wrist. This removable splint is worn for several more weeks, only being taken off for showering and specific, gentle range-of-motion exercises directed by a hand therapist. The primary focus during this time is on reducing swelling and beginning to restore movement in the thumb.
Physical or occupational hand therapy is a necessary component of the recovery, beginning around four to six weeks post-surgery. The therapist guides the patient through exercises designed to improve range of motion, address stiffness, and gradually introduce strengthening activities. Light activities of daily living, such as eating, writing, or typing, may be resumed around the four-to-six-week mark, but heavy gripping, pulling, or pinching must be strictly avoided.
Full recovery of strength and function is a long-term process that can take six months to a full year. Strengthening exercises are typically introduced around three months after surgery, once the reconstructed tissues have had sufficient time to heal and stabilize. While significant pain relief is often achieved within the first three months, a return to heavy activities, like lifting or contact sports, will not occur until at least the six-month mark.