Most people don't take time out of the day to consider the endless functional possibilities afforded by the range of motion of their thumbs. But for individuals who experience pain when opening a jar, turning a door knob or gripping a hammer, the hand's first digit can be a major issue.
Pain at the thumb carpometacarpal (CMC) joint, where the metacarpal bone of the thumb attaches to the trapezium bone of the wrist, is often a sign of wear and tear that has occurred over a long period of time. This pain typically signals the presence of osteoarthritis, otherwise known as degenerative arthritis, a disabling condition where the articular cartilage becomes worn and degraded.
Playing a crucial role in the normal function of the thumb, the CMC joint gives humans the ability to move the thumb into the palm. With the thumb being responsible for 50% to 60% of all hand function, pain and weakness in this joint can cause significant disability, according to Laurie Roundtree, OTR/L, CHT, co-owner of Hand Rehabilitation Specialists in Thousand Oaks, Calif.
Factors that may play a role in the development of degenerative arthritis include previous trauma or injury, repetitive use of the hand, history of heavy labor, genetics, joint hyperlaxity and hormonal changes. "Hand osteoarthritis develops independent of age and gender, but is more frequently seen in women over 50 years of age," said Roundtree.
Rehab for Functional Return
"How much you use your thumbs in activities such as gripping a coffee cup, texting on a smart phone or typing on a computer can be stressful to the joint," said Chris DeRosa, PT, OCS, owner of Davis & DeRosa Physical Therapy, Inc. in El Segundo, Calif. "The thumb is one of the main movers we use to perform many functions.
Degenerative arthritis of the thumb can be a painful condition that may prevent individuals from engaging in some activities of daily living. Patients often complain of pain during activities requiring forceful or repetitive thumb use, during weight-bearing activities such as Yoga or when grasping large objects. A proper rehabilitation program can address these limitations.
The long-term goals of a multi-faceted treatment approach for CMC osteoarthritis are to relieve pain and improve hand function, Roundtree told ADVANCE. "Our goal is to facilitate realistic expectations and to help patients manage their condition, not cure it," she said.
Roundtree believes that an assessment of the patient's history coupled with a thorough evaluation is the key to proper diagnosis of this condition. Prior history rules out other disorders or coexisting conditions such as carpal tunnel syndrome, deQuervain's tenosynovitis, flexor carpi radialis tendonitis, wrist synovitis, occult ganglion cysts, thenar muscle trigger points, trigger thumb and scaphotrapezial arthritis.
"The examiner needs to look for localized edema, tenderness, redness and pain with ligament stress," Roundtree shared. The evaluation may include a pinch strength test and a positive grind test for pain with or without crepitus. The patient's ROM, posturing and pinch patterns are considered.
According to Roundtree, although x-rays are commonly used to determine the extent or existence of osteoarthritis, many clinicians agree that there can be a poor correlation between radiological severity and clinical symptomology.
Therapists should also be aware of complications such as swan neck deformity. "CMC osteoarthritis results in laxity of this joint, often progressing to dorso-radial subluxaton and contracture into flexion and adduction," said Roundtree. "With limited ability to abduct the thumb functionally, the metacarpal joint gradually compensates by developing increased extension, thus the beginning of a 'zig-zag' deformity of CMC flexion, metacarpal hyperextension and interphalangeal flexion, sometimes called a swan neck."
DeRosa recently treated a 65-year-old female patient who was experiencing pain in her thumbs while taking care of her grandchildren. The pain would most often strike when feeding her grandson or picking up the baby seat.
On her first visit, the hand evaluation revealed acute arthritis. After calming the joint down, DeRosa performed laser therapy to reduce inflammation caused by the tendonitis present around the thumb.
"The patient did not participate in exercise the first day because she was pretty inflamed," DeRosa said. "I gave her a splint to sleep in to rest the joint. By the second treatment, she was able to do some gentle exercises and I sent her home with a home program."
The patient learned to modify many of the tasks she performs with her grandson such as lifting the baby seat with both hands.
Therapists who perform joint mobilization and soft tissue work on a regular basis are also susceptible to long-term damage. "Because our job is hands on, this is a common injury for us," DeRosa explained. "The repetitive motions can cause excessive wear and tear on the joint."
DeRosa tries to minimize the use of his thumbs during mobilization. He may use his elbows instead or supplement with tools and devices to lessen the use of his hands. "We often rely on thumbs during mobilization because they pick up so much stimulation."
Education on preventive measures is necessary for severe osteoarthritis. "Our patients may need to use modalities at home, obtain pain medications from the doctor or simply incorporate ways to not overuse the joint," DeRosa said.
Interventions and Modalities
Treatment for thumb osteoarthritis is usually conservative or non-surgical, at least initially. Splint treatment at night, during flare ups and to stabilize the thumb during activity can be effective at decreasing the pain associated with thumb arthritis. Oral non-steroidal anti-inflammatory medications and cortisone injections may also be helpful.
Interventions used at Hand Rehabilitation Specialists include splinting and modalities such as light/laser, paraffin and iontophoresis with dexamethasone, as needed, to reduce pain and inflammation.
"Both custom and pre-fabricated splints are very important in the treatment of this condition," stated Roundtree. "The specific orthosis is determined by the hand therapist after the physical exam and patient interview."
Taking into consideration the intensity of pain and the patient's activities, the therapist determines the optimal design and either fabricates an orthosis - usually hand-based and with the metacarpal free if there is absence of metacarpal hyperextension - or fits a prefabricated support that supports and abducts the CMC joint.
"Any splint should be as minimalistic and comfortable as necessary to accomplish the goals, in order to assure patient wear," said Roundtree.
According to DeRosa, patients may wear a larger splint at night to stop from rolling over on the thumb and a smaller tri-point splint during the day to accomplish daily tasks more easily.
Once pain is under control, patients perform a set of individualized exercises to strengthen the thumb, with close supervision of their therapists.
Stabilization exercises, according to Roundtree, are generally instituted once there is no pain at rest. Exercises may include pain-free isometric strengthening of the abductor pollicis brevis and abductor pollicis longus and isotonic or isometric strengthening of the first dorsal interosseus.
Roundtree believes that it's best to avoid lateral pinch strengthening which requires an unstable position contributing to CMC subluxation. She will, however, perform 3-point pinch strengthening once the client demonstrates the ability to maintain CMC abduction and metacarpal flexion with resistive pinch through prior training.
In addition to manual therapy techniques, modalities are often used to supplement the rehab program. The therapists at Davis & DeRosa Physical Therapy, Inc. use cold laser, electrical stimulation, ice and ultrasound to reduce pain and inflammation of the joint.
"When evaluating our patients, we check range of motion and to see if the joint is red hot and swollen," De Rosa said. "If the joint appears aggravated, we may do laser treatment to reduce inflammation and perform gentle joint mobilizations to release pressure at the joint."
One approach that DeRosa is particularly fond of is the use of therapeutic tape. "The tape takes the pressure off the muscles, allowing them to work more efficiently," he explained. "Plus it's so light that you barely feel it when it's on except to serve as a reminder."
"CMC arthroplasty is the surgical treatment of choice when all other options have failed," Roundtree said.
Once non-surgical treatment has been exhausted, excellent surgical treatments exists for the treatment of thumb arthritis.
Although fusion or arthrodesis is an option for younger patients who use their hands for heavy labor, the procedure called first CMC arthroplasty is the most commonly performed.
"Unlike joint arthroplasty in the hip and knee, where the arthritic joint is replaced or resurfaced, thumb arthroplasty does not implant a prosthesis or artificial joint," said Roundtree. Thumb arthroplasty involves removing the small arthritic bone called the trapezium and sometimes reconstructing a stabilizing ligament or rerouting tendons to act as a spacer or cushion between the arthritic thumb bone and the rest of the wrist bones.
"CMC arthroplasty results in excellent pain relief, and usually restoration of lost range of motion," Roundtree shared. "Patients often return to activities that they thought they might never be able to participate in again."
If one does decide on surgery, a course of therapy is generally necessary post-op to fabricate a protective splint, improve wrist and thumb mobility, desensitize and mobilize the scar and eventually progress to safe strengthening, reported Roundtree.
Prevention and Education
The keys to managing this disorder long-term, according to Roundtree, are education in joint protection and activity modification. "We provide our patients with a 5-page handout with scores of tips on modifying activities, including specific adaptive equipment ideas with ordering information," she said.
A few solutions Roundtree has identified to address common areas of difficulty for this patient population include an electric jar and can opener, nonslip gripers to open prescription bottles and having scissors and needle nose pliers handy in various locations for opening bags, boxes and containers.
"We educate our patients on abnormal pinch biomechanics, use of splints, muscle rebalancing and ROM exercises, training in joint protection techniques and adaptive equipment, and availability of community resources," Roundtree said.
DeRosa suggests solutions such as using the voice feature rather than texting on a smart phone. "The CMC joint needs to be properly protected to limit the amount of stress," DeRosa observed. "Therapists need to find accommodation for patients who have limitations."
DeRosa's clinic has developed resources for patients including an online component based on various diagnoses. "If patients can physically see what is happening and why, then they learn how to properly manage the joint to prevent the condition from getting worse," he said.
Rebecca Mayer Knutsen is on staff at ADVANCE.