The diagnosis of arthritis is based on clinical and radiological findings. Typically, a patient either feels well in the morning, or complains of stiffness lasting about 15 minutes.10 Pain develops during the day, and worsens with use of the affected joints.³ Resting the joint usually provides relief.

X-rays will initially show widening of the joint space, suggesting effusion. As the arthritis progresses, the joint space narrows asymmetrically, reflecting loss of cartilage.^4,9,15 Osteophytes, spurs,⁹ and subchondral bone sclerosis, manifested as increased bone density,¹⁰ are present in the advanced stages.^4,9

Osteophytes may be a response to the degeneration of the cartilage and the remodeling of subchondral bone. The spurs may be the body’s attempt to increase the surface area available for loading.¹⁰

OA of the first CMC joint

Pain, especially when pinching, and weak grip⁹ are usually what prompts a patient to seek medical attention. Patients report difficulty holding objects, squeezing toothpaste tubes or bearing weight on the heel of the hand. In more advanced stages, the patient is unable to place the palm flat on a table or to fully spread the thumb away from the index finger.6 It is important to rule out wrist ganglions, carpal tunnel syndrome, DeQuervain’s tenosynovitis or trigger thumb,^6,9 which can coexist with arthritis.

Clinical findings are consistent when examining the arthritic CMC joint. The beak ligament is attenuated due to environmental stressors, hormonal changes, or genetics. The joint capsule and adjacent ligaments are excessively lax and inefficient.^4,6,9 Abnormal shear forces are borne on the joint’s surfaces as a result of the joint instability.

These factors eventually lead to progressive wear of the joint’s cartilage.^9,10 Hypermobility at the MP joint can also contribute to the development and progression of CMC arthritis. When the MP joint hyperextends, forces become more concentrated on the volar aspect of the CMC joint surface, where joint changes generally occur.⁹ Hyperextension of the MP also encourages reciprocal flexion of the metacarpal shaft, and resultant dorsal subluxation.¹²

The CMC joint is unloaded when the MP joint is flexed 30 degrees. With compromised ligamentous stability and abnormal joint forces, as well as the strong deforming pull from the adductor pollicis, the first metacarpal eventually translates dorsally on the trapezium with lateral pinch. This “shoulder sign” presents as a prominence at the radial base of the thumb.9 Palpable tenderness over the volar surface of the joint,¹⁵ which can be inflamed,⁹ is notable. Palpation of the phalanges is pain-free, and15 crepitus is felt with movement.⁹

In the later stages, there is atrophy of the thenar muscles, and possibly a contracture of the first web space.^9,15 The grind and crank tests are used to confirm the presence of CMC OA. The crank test is performed by applying an axial load of the thumb with passive flexion-extension of the metacarpal.⁹ The grind test is a combination of axial loading and rotation of the first metacarpal.^6,9 Force is then applied into the trapezium. The tests are considered positive if pain is reproduced.

“Make it feel better!”

Osteoarthritis can be managed medically using both prescription and over-the- counter medications. Since there is no cure for OA, objectives of treatments are to decrease pain, reduce inflammation, and improve function. An abundance of traditional and non-traditional treatments is available, including copper bracelets and various homeopathic remedies. Frequently when a plethora of treatment options exist, none works completely.

More traditional treatments include oral analgesics such as acetaminophen, topical capsaicin derived from chili peppers, methyl salicylate creams, superficial and deep heat, and cold treatments.⁴ Some believe glucosamine and chondroitin sulfate to be helpful,¹⁷ yet others believe glucosamine is no more effective than a placebo.¹⁸

Nonsteroidal anti-inflammatory drugs (NSAIDs) and corticosteroids decrease inflammation, but each has its own potential risks. NSAIDs can lead to gastrointestinal disturbances,^4,9 and repeated use of corticosteroid injections can lead to hypo-pigmentation and tissue destruction.⁹ Additionally, there is controversy whether steroids might actually accelerate the degeneration of articular cartilage.⁴

There are several strategies a physical therapist can utilize to help patients manage their arthritis. A joint protection program, an essential component of care, emphasizes how ADLs and avocations are accomplished with as little stress on the joints as possible. By reducing stress, deformity and pain may be held at bay.

A key concept emphasized to patients is the need to distribute forces over larger surface areas. Using two hands instead of one, breaking tasks into smaller components, and avoiding tight grip or pinch often helps the patient complete an activity with less discomfort by decreasing the loading on the joints.⁶

For example, instead of wringing out a washcloth, it should be suspended over a faucet and the water clapped out using the palms of both hands. Wearing oven mitts instead of pot holders allows the pot to rest on the palms instead of being gripped by the small joints of the hand. Often larger handles make it easier to perform a task. However, if there is a contracture of the first web space, the handle size will need to be reduced. Patients are encouraged to take rest periods and to avoid static positions to prevent muscle fatigue and joint strain.⁶

Avoiding lateral pinch is especially important. Some experts contend that one of the causes of subluxation of the first joint is a thin lateral pinch resulting from a muscle imbalance between the adductor pollicis and the abductor pollicis longus. Pinching a wider object prevents this tendency to sublux.⁷ This is in addition to the deforming forces of supination and adduction of the thumb in lateral pinch, which should also be avoided.⁹

Supporting the arthritic joint in a splint can decrease pain and inflammation^3,9,15 during activities. In the early stages of the disease, it can help prevent contracture of the first web space.⁹ There are two basic styles of splints: a long opponens that immobilizes the wrist, first CMC and MP joints; and a short opponens that immobilizes just the CMC ^9,15, or the CMC and MP joints.^6,9

The interphalangeal joint of the thumb is not included in any of these splints.¹⁵ If the MP joint is not splinted, it should be stable.6 If it is splinted, it should be flexed 30 degrees to help decrease the load on the CMC joint.⁹ Custom fabricated splints enable the therapist to reduce the subluxation in the earlier stages osteoarthritis.^6,15 This is accomplished by applying a gentle extension force to the volar-ulnar aspect of the distal metacarpal with counter pressure to the dorsoradial aspect of the metacarpal base.9 Prefabricated splints, which are readily available, are sometimes adequate, particularly with early joint changes.

Unfortunately, they cannot be modified for fit and comfort, nor can they reduce a mildly subluxing joint. A splint is typically worn during activities that would cause pain, and during the night. Wearing a splint while sleeping allows the joint to rest more completely, and avoids the discomfort caused by adjusting the covers while in bed.

If the joint is not acutely inflamed and painful, pain-free gentle active range of motion (AROM) exercises emphasizing the stable joint positions of palmar and radial abduction are performed. These will help nourish the joint and maintain mobility. In the early stages, strengthening the abductors may improve dynamic stability to the basal joint. Pain-free manual resistance⁹ is usually sufficient.

When conservative management is not enough

The primary reason to surgically address the first CMC joint, the most common site for reconstruction, is to relieve pain.⁹ Two categories of surgical options are arthrodesis and arthroplasty. Arthrodesis, or joint fusion, is traditionally used as a salvage procedure when a failed implant is removed,^3,6,9 as described below, or for the younger population,^3,6,9,19 who place large demands on their joints and tend not to have arthritis in other wrist joints.20
There is an average of 13% non- union rate,²¹ and about a 60% loss of range of motion.⁶ Despite its limitations, 75 to 100% of patients have reported satisfaction with the procedure.³

Because of the high satisfaction rate, some surgeons are performing this procedure in older adults successfully. Postoperatively, the thumb and wrist are immobilized for six to eight weeks. When the postoperative cast is removed, gentle AROM exercises and gentle strengthening exercises are initiated as pain allows.²¹ Most patients do not require a formal therapy program.

Arthroplasties allow movement and relieve pain at the CMC joint. Silicone implants had been used to replace an excised trapezium. This has fallen out of favor due to fragmentation of the prosthesis with resultant silicone synovitis. The problems developed when the mechanical demands exceeded the work threshold of the implant.^6,9,22 When the silicone implant failed and disintegrated, the joint structures became irritated. Eventually, bony erosions developed and the bone and cartilage were destroyed. The clinical presentation included soft-tissue swelling, severe pain, and loss of range of motion.²²

Currently, the most common surgical techniques involve using native soft tissue interpositions.⁹ With interpositional arthroplasty, the first metacarpal’s arthritic base is minimally resected, and the trapezium is excised. A strip of the flexor carpi radialis (FCR) tendon is rolled up and replaces the trapezium. This prevents the first metacarpal from impinging on the adjacent scaphoid.

The procedure is coined the “anchovy technique,” perhaps because the rolled tendon resembles an anchovy. An advancement of this technique is ligament reconstruction and tendon interposition, LRTI, in which the FCR is also used to reinforce the attenuated beak ligament to provide stability to the joint.^7,9,19,23 Postoperatively, the wrist and thumb are immobilized in a cast^7,9,23 and the patient is instructed to control swelling with ice and elevation. AROM exercises for the unaffected joints are performed to prevent stiffness.

Around the fourth postsurgical week, the cast is replaced with a custom fabricated splint that immobilizes the wrist, CMC and MP. The thumb is splinted in a functional position for pinch, but can be removed to bathe and perform gentle AROM exercises of the thumb and wrist.^6,9 Lateral pinch, with the thumb adducted and flexed, is avoided, as this can stress the reconstructed joint in this early phase of healing.⁹

Soft tissue mobilization is initiated to control scarring and edema. Gradual strengthening, especially into abduction and opposition, begins in the sixth postoperative week. Strong grasp and pinch is contraindicated. The patient begins to use the hand for light activities and gradually weans out of the splint.

Typically, the splint is discontinued around the third month.^6,7,9 As each situation is unique, this timeline is a general guide. Complications can include a painful scar, superficial radial nerve
neuroma and dysesthesia.²⁴ Follow-up studies have shown that over time, the arthroplasty space diminishes.^9,24,25

There was a further reduction in joint space with lateral pinch.²⁵ Interestingly, this joint change did not seem to interfere with patient satisfaction or function.^24,25

In fact, pinch and grip strength were stronger post-operatively regardless of the degree of metacarpal slipping. Long-term follow up showed improvements in function and strength^9,25 and up to 95% satisfaction with the results.³