Thumb Arthritis Treatment: CMC Osteoarthritis Therapy

Evaluation Notes for Clinicians

Observations^1,4

• Shoulder sign-position/posture: This looks like an enlargement at the base of the thumb

• Narrowing of the first web space

• Dorsal radial subluxation of the CMC joint

• Zig-zag deformity

• General Posture → Note that rounded shoulders, head forward, and palms facing backwards at rest suggest proximal weakness. Please also note scapula position on ribcage.

• Does the patient report any abnormal sensation?

Range of Motion^1,4,9-10

• Norms available via the American Academy of Orthopaedic Surgeons. Please ensure measurements are obtained for both sides of the body to inform goal setting versus solely relying on norms. To facilitate inter-rater reliability, please refer to the standardized goniometric measurement techniques from the American Society of Hand Therapists (ASHT.org member cost $100, non-member $145).

  • Shoulder, elbow, wrist ROM all planes

  • Thumb IP joint flexion/extension

  • Thumb MP joint flexion

  • Thumb MP joint extension/hyperextension

  • Thumb CMC joint flexion/extension

  • Composite thumb flexion

  • Composite thumb extension

  • Opposition via Kapandji Scale

  • Palmar abduction

  • Radial abduction

    • Note: decreased thumb abduction may indicate changes in webspace contracture/thumb adduction contracture⁴

    • Inter-metacarpal distance (IMD): another reliable method for measuring palmar and radial abduction in CMC OA^9-10

Strength Testing^1,10-11

• Manual Muscle Testing (MMT)

  • Shoulder, elbow, and wrist in all planes to assess proximal stability

  • A brief review of the muscles of the hand found here

  • Dynamic stabilizers of the CMC joint:

Extrinsic Thumb Muscles

Intrinsic Thumb Muscles

• Pain-free grip strength, bilaterally

  • Grip Dynamometer costs approximately $300 on Amazon

  • Note: More advanced radiographic trapeziometacarpal OA is associated with lower grip strength and decreased self-reported functional outcomes, making grip strength an important measurement to assess¹¹

  • Read our full post on Grip Strength testing here

• Pain-free pinch strength, bilaterally

  • Note: Document deformities observed during testing

  • Pinch Gauge costs approximately $130 on Amazon

  • Palmar/Tripod/3-point pinch

  • 2-point pinch

  • Lateral pinch is generally avoided as it increases the mechanical load on the CMC joint.

Differential Diagnoses¹²

• C6 Radiculopathy

  • Characterized by pain radiating from neck, with paresthesias extending to thumb and index finger

• DeQuervains tenosynovitis

  • Finkelstein’s test → positive

• Scaphotrapeziotrapezoidal (STT) arthritis

  • Pain with palpation just proximal to TMC joint → positive

• Scaphoid nonunion/SNAC

  • Present in radiographs

• Radioscaphoid arthritis

  • Present in radiographs

• Carpal Tunnel Syndrome

  • Potential comorbid condition

  • Phalen’s test for carpal tunnel, Durkan’s/Carpal compression test, scratch-collapse test, Berger’s test

Goal Bank for Club Members

Each goal is intended as a starting point. The functional motivation behind each goal should be identified collaboratively with the client.

• The patient will demonstrate appropriate understanding of three joint protection techniques via teach back method to facilitate activity tolerance with [patient-specific ADL/IADL] within 3 weeks.

• The patient will demonstrate increased pain-free grip strength to *** to improve occupational performance in [patient-specific ADL/IADL] within 8 weeks.

  • Note: Right-handed individuals are typically 10% stronger on their dominant side, while left-handed individuals tend to have bilaterally identical grip strengths due to living in a right-handed world.

• The patient will report a decrease in (PRWHE / QuickDASH / COPM / PSFS / AUSCAN) outcome score to (at least MCD / MCID / AUC) demonstrating increased activity tolerance in affected functional tasks like *** without symptom increase within 4 weeks.

• The patient will demonstrate increased palmar abduction to *** mm by 4 weeks demonstrating decreased thumb adduction contracture and therefore optimizing occupational performance in functional tasks like [holding a cup of coffee, picking up their child, etc].

• The patient will demonstrate proper CMC joint positioning with activation of opponens pollicis while utilizing a 2 pt pinch to decrease symptoms and facilitate performance in functional tasks like [using tweezers, zipping jackets, etc] within 3 weeks.

• The patient will appropriately demonstrate one pain management technique in the clinic within 3 weeks to increase activity tolerance in [preferred I/ADL].

Treatment Interventions with Notes for Club Members

Aerobic Warm Up for endorphin release, and to assist synovial fluid excretion.

• Recommend low-impact exercises like swimming, Tai Chi, modified Yoga, UBE, LBE, elliptical.

Orthosis

• For conservative management of CMC OA, orthoses have been found to improve function, contribute to improved grip and pinch strength, and reduce pain. However, the research does not indicate one design that is superior to another, which is likely due to the wide variety of anatomy and function present in the human population requiring varied orthoses needs.⁴

Orthosis Type:

• Custom orthoses should be used to provide additional stability as needed^1,4

  • When fabricating a custom rigid orthosis → place MP joint in 30° of flexion to help offload pressures at the volar CMC joint⁴

  • Long thermoplastic orthoses are the best option for pain relief, while short thermoplastic CMC orthoses are the best option for increasing function, and more common.¹⁴

• Pre-fabricated orthoses: A wide range of prefabricated thumb orthoses exists, including completely soft and rigid options. Many commercially available pre‑fabricated options place the CMC joint in suboptimal alignment, which may limit their effectiveness, so please select with caution. The orthoses listed below have demonstrated success when matched appropriately to patient needs.

  • One prefabricated option for approximately $30: Comfort Cool Thumb CMC Restriction Splint¹⁵

  • One prefabrication option for approximately $30: Hely & Weber CMC Controller Plus¹⁶

  • One prefabricated option for approximately $126: PUSH Metagrip CMC Thumb Brace

Orthosis Wear Schedule:

• During activities that increase pain

  • It is important that the patient does not “fight” their orthosis during functional tasks. If the task is limited by their orthosis, modifications to the task or modifications to the wear schedule should be considered.

• During sleep, particularly if the patient reports pain when trying to fall asleep or upon waking.

• Expert consensus recommends wearing orthosis until patient can use affected hand outside of orthosis without pain¹

  • Note: This may include indefinite use as needed

• No significant differences found between daytime and nighttime use of hand-based orthotics¹³→ Make sure to work with the patient to determine which orthosis type and wear schedule best supports their participation in meaningful activities.

Manual Therapy

• Joint mobilization → Effective for relieving pain and facilitating proper joint alignment.⁴ Do not perform techniques over Maitland’s Grade II on hypermobile joints. Mobilization levels I and II are typically used to reduce pain and irritability.

  • Passively take CMC joint through full mobility of joint capsule

  • Gentle traction at CMC joint

  • Oscillatory techniques

  • Posterior/anterior joint gliding with distraction

  • Instruction in self-thumb CMC joint traction/mobilization

  • Other methods of self-thumb CMC joint mobilization:^17-18

    • Grasp the affected thumb with the other hand on top of the head. Gently roll the CMC joint on top of head while distracting the joint.

    • With the affected hand resting on the patient’s chest (palm facing the chest), grasp thenar eminence with other hand and gently pull away from the chest.

    • Grasp the affected thumb with the other hand behind the back. Let gravity help to distract the joint.

• Manual ischemic compression to adductor pollicis

  • Apply pressure to the webspace → facilitates muscle relaxation in preparation for active/passive webspace stretching⁴

    • Self-massage with opposite thumb.^17-18

    • Gently massage webspace with downward pressure on a small ball.¹⁷

    • Place chip clip in webspace of thumb.^17-18 Please take note of the strength of the spring on the clip you trial.

    • Hold webspaces together and gently stretch fingers away → hold 30s and repeat.^17-18

    • Table method: Palm facing down and thumb even with table edge (avoid hyperextension at any joint), gently move fingers away from thumb and hold.¹⁷

  • Manual compression of FDI may also help decrease pain in CMC OA¹⁹

• Additional manual therapy tools:

  • Instrument Assisted Soft Tissue Mobilization Tools (IASTM) along dynamic stabilizers and in thenar webspace to improve blood flow, decrease pain.

  • Myofascial Decompression therapy (cupping) to improve blood flow, decrease pain.

Neuromuscular Re-education

• Dynamic stabilization exercises to reduce/prevent subluxation, stabilize the joint, mitigate pain, and improve function^4,18,20-21

Dynamic Stability Exercises

• Utilize joint position sense test to facilitate functional proprioception at the thumb CMC joint^{1, 23}

• Proximal strengthening including scapular stabilization, posture correction, and core strength improve stability and function down the entire UE chain

  • Balance training may also be appropriate if a patient is relying heavily on hand gripping external objects in the environment for mobility support - like hand railings on stairs, walkers/canes, or “furniture surfing”

Self-Care Home Management^1,4,15,24

• Joint protection education

  • Frequent rest breaks, respect pain, avoid positions of deformity (such as MP joint or IP joint hyperextension), exercise in a pain-free range, use larger and stronger joints when able, reduce force and effort placed on joint

• Activity modifications and adaptive equipment

  • Built up foam for handles, pens

  • Use “C” position pinch to unscrew toothpaste lids, write, etc

  • Add zipper pulls to clothing items

  • Hold cell phone in your palm and scroll with your index finger

  • Use bags with handles that can rest on your forearms instead of gripping with your hands

  • Jar openers like this one to open any container with a twist off top

Incorporate Functional Tasks and Occupation-Based Interventions

• Use stable EPB/ “C” posture during daily activities and functional tasks^17,15,24

  • Daily activities with appropriate modifications: Crocheting, writing, knitting, musical instrument practice

    • PenAgain is a fantastic (and surprisingly natural feeling) option for writing support that removes stress from the thumb. Available on Amazon starting at $7.

  • Functional tasks: Paper tearing, line tracing on ball, palmar translation tasks (like pill management), dressing closure practice (buttons, zippers, hooks, shoe laces).

• Engage in occupation-based interventions to practice joint protection techniques in the clinic

  • Washing, rinsing, and drying a dish

  • Moving a pot and pan

  • Filling, carrying, and emptying a laundry basket

  • Pouring a pitcher of water^1,25

Pain Management Tools

• Kinesiotape⁴ → One of several methods to apply kinesiotape at the CMC joint

• Modalities: moist heat, paraffin, fluidotherapy^1,4

• Over-the-counter topicals including Arnica Gel, BioFreeze, Stopain, and/or Salonpas

• Pain Neuroscience Education (PNE)

  • Improves pain and disability in individuals with persistent musculoskeletal pain in combination with other interventions such as therapeutic exercise and manual therapy.²⁶ One RCT reported a 50% improvement in pain among participants following an intervention that combined pain neuroscience education with cognition-targeted motor control training.²⁷

  • It can be helpful to describe the central nervous system as the body’s alarm system. When you experience an injury, the part of the body that is injured sends signals to the brain. The brain sends pain signals back to the body to tell you to protect that body part. When a person experiences chronic pain, the alarm system becomes more sensitive over time. This means that the brain requires less intense signals from the body to trigger the pain sensation.²⁸

Home Program

• Prioritize 1-3 exercises to enhance patient adherence to the home program.

Patient Education on Disease Pathology

• When educating patients about OA, it is important to be clear that this is a degenerative condition, meaning there is unfortunately no cure. However, they can learn new habits and techniques to help them manage the pain and prevent their condition from worsening.

• Here are some key points to hit on to help a patient understand what OA is:

  • Our joints lubricate themselves with synovial fluid that is ONLY excreted in response to motion. Physical activity is the best non-drug treatment to improve motion and function. Recommend the phrase “Motion is Lotion” for ease of recall.

  • A joint is where two bones meet to allow movement at that part of the body

  • A protective layer of tissue, called cartilage, provides cushioning at the ends of each bone to allow them to glide smoothly across each other

  • Due to factors such as aging or injury, the cartilage can wear down. When the cartilage wears down, the bones cannot glide smoothly across each other anymore. They eventually become damaged, which can cause pain.

  • It is important to note that the presence of arthritis does not guarantee the presence of pain.

Red Flags²⁹

• If the patient does not report pain reduction in response to conservative management after 6 weeks, a referral to orthopedics for corticosteroid injections or surgical intervention may be warranted⁴

• Recommend taking blood pressure and pulse with every patient

• Symptoms of any kind that present bilaterally

• Fever

• Unexplained sweating

• Nausea

• Fatigue

• Weight loss

• Dizziness/fainting

• Pain that is constant and unchanging regardless of position/loading

• Pain at night

• Hand and Upper Extremity Rehabilitation: A Practical Guide 4th Edition is a useful reference text for treating the upper extremity.

  • Starting at $79.55 on Amazon

• American Society for Hand Therapists (ASHT.org)

  • Annual Membership is $275

• The American Society of Hand Therapists outlined several novice hand therapist resources, including content related to anatomy, orthotic fabrication, how-to video series, and more.

• Hand Therapy Academy

• Article for review of anatomy: Komatsu, I., & Lubahn, J. D. (2018). Anatomy and biomechanics of the thumb carpometacarpal joint. Operative Techniques in Orthopaedics, 28(1), 1-5. Redirecting

• Reference the Indiana Hand to Shoulder Center’s Diagnosis and Treatment Manual for Physicians & Therapists, 5th Edition for post-operative protocols

  • Here is an example of a CMC joint arthroplasty post-op protocol

Pain Neuroscience Education resources:

• If you or your patient wants to learn more about pain neuroscience education, you can read the book, Explain Pain, by David Butler and G. Lorimer Moseley. You can find it on Amazon starting at approximately $90, or on Kindle for $34.99.

• The Meg Foundation has a free pain education handout based on the biopsychosocial model. This handout was made for providers, kids, teens, caregivers, and parents.

• Northwest Pain Guidance provides a pain education toolkit, complete with handouts, videos, and additional resources.

• Therapy Insights has an occupational therapy-based PNE handout made for adults with chronic pain. This handout is not free, and a subscription to their membership platform costs $15 per month.

• Alpine Physical Therapy put together an exhaustive list of pain education resources for both clinicians and individuals with pain. These include websites, resources, educational videos, podcasts, books, Ted Talks, continuing education, meditation and pain apps, continuing education, and goal-setting resources, among others.