Rhizarthrosis: Surgical Techniques, Recovery, and Considerations

What is the Surgical Technique for Rhizarthrosis?

Surgical intervention for rhizarthrosis, or thumb basal joint arthritis, primarily involves procedures aimed at alleviating pain and restoring function when conservative treatments fail, with common techniques including trapeziectomy (often with ligament reconstruction), arthrodesis (fusion), and various forms of arthroplasty (joint replacement).

Understanding Rhizarthrosis

Rhizarthrosis refers to osteoarthritis affecting the carpometacarpal (CMC) joint at the base of the thumb. This crucial joint, formed by the trapezium carpal bone and the first metacarpal bone, is highly mobile, allowing for a wide range of motion essential for gripping, pinching, and fine motor skills. Over time, the smooth articular cartilage cushioning these bones can wear away, leading to bone-on-bone friction, inflammation, pain, stiffness, and a progressive loss of strength and function in the thumb.

When is Surgery Indicated?

Surgical intervention for rhizarthrosis is typically considered when conservative management strategies have proven ineffective. These non-surgical approaches include:

• Activity modification
• Splinting or bracing
• Anti-inflammatory medications
• Corticosteroid injections
• Physical or occupational therapy

Surgery becomes an option when persistent pain significantly impairs daily activities, thumb strength is severely compromised, or joint deformity progresses despite comprehensive conservative care. The decision to proceed with surgery is a shared one between the patient and surgeon, weighing the potential benefits against the risks.

Primary Surgical Techniques for Rhizarthrosis

Several surgical techniques are employed to address rhizarthrosis, each with its own indications, advantages, and disadvantages. The choice of procedure depends on factors such as the severity of the arthritis, the patient's age, activity level, functional demands, and the surgeon's experience.

Trapeziectomy

This is one of the most common surgical procedures for advanced rhizarthrosis.

• Procedure: The trapezium bone, which is the primary source of the arthritic pain, is completely removed. This creates a space where the arthritic surfaces previously articulated, thereby eliminating the painful bone-on-bone contact.
• Variations:
  • Simple Trapeziectomy: The trapezium is removed, and the space is left empty.
  • Trapeziectomy with Ligament Reconstruction and Tendon Interposition (LRTI): After removing the trapezium, a portion of a nearby tendon (often the flexor carpi radialis or abductor pollicis longus) is harvested. This tendon is then used to reconstruct the thumb's stabilizing ligaments and/or coiled into the space where the trapezium once was, acting as a cushion or "spacer" to prevent the thumb metacarpal from sinking into the wrist bones. This aims to maintain thumb length and stability.
• Benefits: Excellent pain relief, good range of motion, and high patient satisfaction rates.
• Considerations: Potential for some loss of pinch strength, and a longer recovery period if LRTI is performed due to tendon healing.

Arthrodesis (Fusion)

Arthrodesis involves surgically fusing the CMC joint, permanently eliminating motion at the joint.

• Procedure: The damaged cartilage is removed, and the bones of the thumb metacarpal and trapezium are fixed together, typically with screws, plates, or pins, until they grow into a single, solid bone.
• Indications: Primarily considered for younger, active individuals who require high stability and strength for manual labor or specific activities, or in cases where other procedures have failed.
• Benefits: Complete pain relief and excellent stability and strength.
• Considerations: Permanent loss of motion at the thumb CMC joint, which can impact some activities requiring fine dexterity. This loss of motion is compensated for by increased motion at other thumb joints (metacarpophalangeal and interphalangeal joints).

Arthroplasty (Joint Replacement)

This involves replacing the damaged joint surfaces with an artificial implant.

• Procedure: Similar to hip or knee replacement, the arthritic bone and cartilage are removed, and the joint is reconstructed with an implant.
• Types:
  • Total Joint Arthroplasty: Both the metacarpal and trapezium surfaces are replaced with prosthetic components, often made of metal and polyethylene.
  • Hemiarthroplasty: Only one side of the joint (typically the metacarpal base) is replaced, often with a silicone, pyrocarbon, or metallic implant, articulating against the remaining trapezium or a reconstructed surface.
• Indications: Often preferred for older patients with lower functional demands, or those who desire to maintain more motion than fusion allows.
• Benefits: Excellent pain relief and preservation of joint motion.
• Considerations: Potential for implant wear, loosening, or dislocation over time, and generally less strength compared to fusion.

Osteotomy

While less common as a primary treatment for advanced rhizarthrosis, osteotomy may be considered in early stages or for specific deformities.

• Procedure: A small wedge of bone is removed from either the metacarpal or the trapezium to realign the joint surfaces, thereby reducing abnormal stress on the arthritic cartilage.
• Indications: Used when there is only mild or moderate arthritis and specific biomechanical alignment issues contribute to symptoms.
• Benefits: Preserves the native joint.
• Considerations: Not suitable for advanced arthritis, and may not provide as complete pain relief as other methods.

Surgical Considerations and Post-Operative Care

Regardless of the technique chosen, several general considerations apply to rhizarthrosis surgery:

• Anesthesia: Procedures are typically performed under regional anesthesia (e.g., an arm block) or general anesthesia.
• Duration: Surgery usually takes 1-2 hours.
• Hospital Stay: Most procedures are outpatient or require a short overnight stay.
• Immobilization: Post-operatively, the thumb and wrist are typically immobilized in a cast or splint for 4-6 weeks to allow for initial healing.
• Rehabilitation: A crucial component of recovery is hand therapy. This often begins shortly after surgery once the initial immobilization period is over, focusing on:
  • Pain and swelling management
  • Gradual restoration of range of motion
  • Strengthening exercises for the thumb and hand
  • Scar management
  • Return to functional activities
• Recovery Timeline: Full recovery can take several months (3-6 months), with continued improvement possible for up to a year.
• Potential Complications: As with any surgery, risks include infection, nerve damage (numbness or weakness), stiffness, persistent pain, non-union (if fusion is attempted), or implant-related issues (for arthroplasty).

Choosing the Right Surgical Approach

The decision regarding the most appropriate surgical technique is highly individualized. It involves a thorough discussion with your orthopedic surgeon, who will consider:

• The severity and extent of your arthritis as seen on X-rays.
• Your age, occupation, and activity level.
• Your functional goals and expectations post-surgery.
• Your overall health.
• The surgeon's expertise and preference for specific techniques.

A comprehensive evaluation, including physical examination and imaging, is essential to determine the best course of action to alleviate pain and restore optimal thumb function.

Conclusion

Surgical intervention for rhizarthrosis offers several effective techniques to manage chronic pain and improve functional limitations when conservative measures fail. From the widely practiced trapeziectomy to joint fusion and replacement options, each procedure targets the specific anatomical and functional challenges posed by thumb basal joint arthritis. Understanding these approaches, coupled with a detailed discussion with an orthopedic specialist, empowers patients to make informed decisions for their long-term hand health and quality of life.