Thumb Basal Joint Arthritis
- Type of osteoarthritis that most commonly affects the trapeziometacarpal (TM) joint of the thumb but can affect all five articulations of the thumb basal joint
- The TM joint is a biconcave saddle joint with minimal bony constraints.
- Ligamentous stability is very important for the TM joint.
- The anterior oblique ligament or “beak” ligament is a primary stabilizer of the TM joint, but recent studies suggest that the dorsoradial ligament may be more important.
- Degeneration and weakening of these ligaments result in laxity of the TM joint, which, in turn, results in abnormal translation of the metacarpal on the trapezium, which leads to excessive shear forces on the joint.
- Women have a greater predilection for the disease, with a female-to-male ratio of 10: 1.
- Commonly presents in fifth and sixth decades of life
- Because of adduction of the thumb, there may be compensatory hyperextension of the metacarpophalangeal joint and laxity of the volar plate.
- Left TM joint often exhibits symptoms related to osteoarthritis first possibly because stronger thenar muscles in right handed individuals may have a protective effect on the basilar joint.
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History
- Pain at the base of the thumb, particularly during pinch and grasp
- Difficulty turning keys in doors or other pinch and twist motions
- Pain and weakness with opening jars
- Occasionally pain that is not well localized and pain in entire thumb reported
- May report the appearance of the thumb “zigzag”
Physical Examination
- Observation of the thumb may reveal prominence of the base of the thumb metacarpal.
- Hyperextension of the metacarpophalangeal (MP) joint may be visible with motion or pinch.
- Tenderness at TM joint on palpation
- Grind test
- Axial load on the thumb combined with circumduction elicits pain and often crepitance in the joint.
- It is very sensitive (97%) but not very specific (30%).
- Traction-shift test
- The metacarpal is passively subluxed and then relocated, causing pain.
- This test is very specific.
Imaging
- Plain radiographs should be adequate to confirm the diagnosis
- Radiographic staging according to Eaton and Littler
- •Stage 1: normal joint with possible widening
- •Stage 2: joint space narrowing with debris and osteophytes less than 2 mm
- •Stage 3: joint space narrowing with debris and osteophytes greater than 2 mm
- •Stage 4: scaphotrapezial joint space narrowing in addition to TM joint involvement
- •Stage 5: pantrapezial arthritis
- Bone scan may be useful if diagnosis is in question
Additional Tests
- A local anesthetic agent can be injected into the TM joint and should alleviate most of the pain
Differential Diagnosis
Differential Diagnosis | Differentiating Feature | |
---|---|---|
de Quervain tenosynovitis | Pain and tenderness more proximal; positive Finkelstein test | |
Carpal tunnel syndrome | Often associated with numbness of the fingers; not acutely exacerbated with specific activities | |
Trigger thumb | Pain over A1 pulley and often associated with triggering | |
MCP joint osteoarthritis | Pain at MCP joint and tenderness on palpation of MCP joint; radiographs with arthritic changes at MCP joint | |
Sesamoiditis and subsesamoid arthritis | Pain typically volar over MCP joint |
MCP, Metacarpophalangeal.
Treatment
- At diagnosis
- First-line treatment for this disease involves nonsteroidal antiinflammatory drugs, topical diclophenac gel, intra-articular steroid injections, thenar cone strengthening therapy, and immobilization with a thumb spica or neoprene splint.
- These treatments, although not curative, may improve symptoms and delay the need for operative intervention.
- These therapies may be tried sequentially or may be done in combination.
- Later
- Once patients have failed nonoperative treatment, surgery should be considered.
- Many surgical procedures have been described for this disease process, which include TM arthrodesis, trapezium excision with or without ligament reconstruction and tendon interposition (LRTI) arthroplasty, implant arthroplasty, and arthroplasty with the Arthrex TightRope.
- TM arthrodesis is indicated when the arthropathy is limited to the TM joint and the patient has a high-demand hand (i.e., laborer).
- This procedure trades motion for retention of power and strength and long-term durability.
- Soft-tissue arthroplasties have gained increasing popularity, and of these procedures the LRTI described by Burton and Pellegrini is probably the most common surgery performed.
- This involves excision of the trapezium followed by harvest of the flexor carpi radialis tendon
- The tendon is used to reconstruct the beak ligament and then formed into an “anchovy” and used as a soft-tissue spacer between the base of the metacarpal and the scaphoid.
- Examination of the scaphotrapezoid joint is essential, and if arthritis is present at this location, it must be addressed simultaneously.
- Simple trapeziectomy has also gained more favor recently and has been shown to be as beneficial as the LRTI, with fewer complications.
When to Refer
- Referral to a hand specialist for this condition, like many conditions in the hand, depends on the practitioner’s comfort with diagnosing TM arthritis and executing nonoperative therapy.
- Certainly once the nonoperative therapies have been instituted and the patient still has significant functional impairment from the disease, the patient should be referred to the hand surgeon for consideration for surgical treatment.
Prognosis
- TM arthritis is a progressive disease and only definitively treated with surgery.
- Nonoperative modalities often alleviate symptoms but only temporarily.
- The prognosis for pain relief and good function is very good after surgical treatment. Approximately 80% of patients have significant improvement in pain and retain good functional range of motion.
Troubleshooting
- The degree of arthritis on radiographs and the severity of symptoms may not correlate.
- Patients with little change on radiographs may have significant symptoms, and, conversely, patients with severe disease radiographically may have surprisingly mild symptoms.
- Patients who do not respond to nonsteroidal antiinflammatory drugs, splinting, and therapy should have a corticosteroid injection in the TM joint, if indicated.
- No response or partial response to the steroid injection may indicate scaphotrapezoid trapezium or pantrapezial involvement.
- Continued pain after surgical treatment may indicate unrecognized scaphotrapezoid joint involvement.
Patient Instructions
- Patients should be instructed about the progressive nature of the process once the diagnosis is made.
- Hand therapists are often an excellent source for patient information and instruction; this is one of the reasons that referral to the therapist for splinting and thenar cone strengthening is helpful.
- For patients undergoing surgery, the entire postoperative course needs to be explained to the patient.
- In addition, it needs to be stressed to patients undergoing surgery that complete pain relief may not be accomplished until 3 to 6 months postoperatively.
- It also needs to be explained that patients will have some loss of strength compared with the precondition strength.
- Patients typically have loss of strength with basilar joint arthritis and are grateful for the return of power after surgery.
Considerations in Special Populations
- Young patients with high-demand hands should be considered for TM arthrodesis.
- Patients undergoing surgical treatment who have developed more than 30 degrees of hyperextension of the MP joint should have either a capsulodesis or an arthrodesis of this joint.
- Patients with concomitant carpal tunnel syndrome should have carpal tunnel release if the basilar joint arthritis is treated surgically.
References
- Baker RH, Al-Shukri J, David TR: Evidence based medicine: thumb basal joint arthritis . Plast Recontr Surg 2017; 139: pp. 256e-266e.
- Burton R, Pellegrini VD: Surgical management of basal joint arthritis of the thumb: part II. Ligament reconstruction with tendon interposition arthroplasty . J Hand Surg Am 1986; 11: pp. 325-332.
- Damen A, van der Lei B, Robinson PH: Carpometacarpal arthritis of the thumb . J Hand Surg Am 1996; 21: pp. 807-812.
- Luria S, Waitayawinya T, Nemechek N, et al.: Biomechanical analysis of trapeziectomy, ligament reconstruction with tendon interposition, and tie-in trapezium implant arthroplasty for thumb carpometacarpal arthritis: A cadaver study . J Hand Surg Am 2007; 32: pp. 697-706.
- Tomaino MM, King J, Leit M: Thumb basal joint arthritis . In Green DP, Hotchkiss RN, Pederson WC, Wolfe SW (eds): Operative Hand Surgery ., 5th ed 2005. Churchill Livingstone , Philadelphia pp. 461-485.