What is a Thumb Joint Implant?
A thumb joint implant is an artificial joint made of metal or pyrocarbon components that are used to replace a severely arthritic or injured joint located at the base of the thumb. Thumb implant surgery is a motion-preserving alternative to thumb joint fusion surgery.
Anatomy
Most activities of the hand that involve grasping objects are made possible due to the high level of dexterity of the thumb. However, the wide range of motion increases the risk of wear and tear of the joint at the base of the thumb, the carpometacarpal (CMC) joint, which is formed by the trapezium bone of the wrist and the metacarpal bone of the thumb.
Indications for Thumb Joint Implant
A thumb joint implant may be indicated if the thumb is painful, unstable, and has a limited range of motion due to arthritis, injury, or post-fracture deformation.
Preparation for Thumb Joint Implant
Your doctor will assess your symptoms and perform an examination. Imaging tests such as X-ray, MRI, or CT-scanning may be ordered. Inform your doctor about the medicines you are taking prior to the procedure, and if you are allergic to any medicines or anesthesia. Arrange for someone to drive you home after the surgery.
- Either general or regional anesthesia can be used for the surgery.
- A surgical incision is made on the skin over the base of the thumb.
- The underlying soft tissues are separated using a retractor.
- The joint capsule is incised to expose the CMC joint
- The ends of the bones forming the joint surfaces are excised.
- A cutting tool is used to reshape the bones to receive the implant.
- The thumb joint implant is fitted in place.
- A strip of the tendon may be used to wrap the joint for additional stability.
- The incision is closed in layers.
- The thumb is placed in a splint and bandaged with a padded dressing.
Recovery after Thumb Joint Implant Surgery
Prescription pain medicines or NSAIDs (non-steroidal anti-inflammatory drugs) are used to manage pain. The splint will hold the thumb in the correct position while healing. Keep the hand elevated as much as possible for the first few weeks. Stitches will be removed after 10-14 days. You will be recommended to work with an occupational therapist to regain mobility and strengthen in the thumb. With the newer implants, patients can expect to return to normal activities within 3-5 weeks.
Risks of Thumb Joint Implant Surgery
As with any surgery, there are associated risks and complications that may occur. Those related to thumb joint implant surgery may include:
- Anesthetic complications
- Infection
- Loss of sensation
- Stiffness
- Delayed healing or failure to heal.
Benefits of Thumb Joint Implant Surgery
Most patients that have undergone thumb joint implant surgery report significant relief of painful symptoms and improvement in thumb function.
