What Is Rhizarthrosis?

Rhizarthrosis is osteoarthritis of the carpometacarpal (CMC) joint of the thumb — the saddle-shaped joint at the base of the thumb that allows opposition, pinch, and grasp movements. It is the second most common form of hand osteoarthritis, affecting 15 to 25% of postmenopausal women and causing disabling pain in the most basic activities of daily living.

Opening a bottle cap, turning a key, writing, holding a cup — everything depends on the CMC joint. When the cartilage of this joint deteriorates, every pinch movement generates pain, synovial inflammation, and progressive loss of strength. The Eaton-Littler classification divides rhizarthrosis into 4 stages, from mild joint narrowing (stage I) to complete destruction with pantrapezial arthrosis (stage IV).

Medical acupuncture works on rhizarthrosis by reducing periarticular inflammation, modulating local nociception, and relaxing the hypertonic thenar musculature — offering significant relief especially in stages I to III, where conservative treatment is the priority.

RHIZARTHROSIS IN NUMBERS

15–25%
POSTMENOPAUSAL WOMEN
Radiographic prevalence of rhizarthrosis after age 50
3:1
FEMALE:MALE RATIO
Strong female predominance — hormonal and ligamentous influence
−28%
PINCH STRENGTH
Average reduction in fine pinch grip strength in symptomatic rhizarthrosis
72%
RESPONSE TO ACUPUNCTURE
Patients with clinically significant improvement in stages I-III in specific RCTs — individual response may vary
01

Saddle Joint

The CMC of the thumb is the most complex joint of the hand — it allows opposition, abduction, and rotation — and is therefore the most vulnerable to osteoarthritis.

02

Devastating Functional Impact

Rhizarthrosis compromises up to 60% of activities of daily living that depend on pinch and grasp — far beyond what the radiographic image suggests.

03

Conservative Treatment First

In stages I-III, conservative treatment (orthosis + acupuncture + exercises) can postpone or avoid surgery in a considerable share of cases, according to specific case series; response is individual.

Conventional Treatments and Their Limitations

Conservative management of rhizarthrosis includes immobilization orthoses, anti-inflammatories, and corticosteroid injections. The orthosis stabilizes the CMC joint and reduces mechanical pain, but limits hand function. NSAIDs offer temporary relief; however, chronic use — common in this progressive disease — exposes the patient to gastrointestinal, renal, and cardiovascular risks.

Corticosteroid injection provides relief for 4 to 12 weeks, but recent studies show that repeated injections may accelerate cartilage degeneration. Surgery (trapeziectomy with or without tendon interposition) is reserved for cases refractory to conservative treatment — stages III-IV with failure of at least 6 months of treatment.

COMPARISON: CONVENTIONAL TREATMENT VS. ACUPUNCTURE

ASPECTCONVENTIONALMEDICAL ACUPUNCTURE
Pain reliefNSAIDs: hours; injection: weeksCumulative: weeks to months after a series
Hand functionOrthosis reduces pain but limits functionImproves pinch strength by up to 28%
Joint inflammationSystemic NSAIDs, local corticosteroidLocal reduction of periarticular IL-1β and TNF-α
Thenar musculatureNot directly addressedRelaxation of hypertonic opponens and adductor
Adverse effectsGastropathy, chondrodegenerationMinimal — mild transient hematoma
Chronic useCumulative riskSafe long-term

How Does Medical Acupuncture Work in Rhizarthrosis?

Medical acupuncture for rhizarthrosis combines a local (periarticular) approach with segmental neuromodulation of the C6-C7 dermatomes that innervate the CMC joint. Treatment targets three simultaneous goals: synovial inflammation, hypertonia of the thenar musculature, and peripheral and central nociceptive sensitization.

Mechanism of Action in Rhizarthrosis

  1. Periarticular Needling of the CMC

    Insertion of needles into the capsular recesses of the carpometacarpal joint — local reduction of pro-inflammatory cytokines (IL-1β, TNF-α, IL-6) in the synovial fluid and improvement of periarticular microcirculation.

  2. Relaxation of the Thenar Musculature

    Deactivation of trigger points in the opponens pollicis, adductor pollicis, and first dorsal interosseous — muscles that contract protectively and amplify joint pain.

  3. C6-C7 Segmental Neuromodulation

    Stimulation of the C6 and C7 roots (which innervate the CMC joint via the median and radial nerves) activates the segmental inhibitory system: release of enkephalins in the corresponding dorsal horn.

  4. Electroacupuncture for Sustained Analgesia

    Electrical stimulation at 2-4 Hz between periarticular points activates the descending PAG-RVM pathway with release of β-endorphins — analgesia that persists for days after each session.

Scientific Evidence

The evidence base for acupuncture in hand osteoarthritis — including rhizarthrosis — is growing, with controlled trials and systematic reviews demonstrating consistent efficacy in pain reduction and functional improvement.

CLINICAL OUTCOMES IN RHIZARTHROSIS

−3.1 pts
VAS (PAIN SCALE)
Reduction on the visual analog scale after an 8-week series
+28%
PINCH STRENGTH
Objective improvement in fine pinch grip — pinch dynamometer
−14 pts
DASH SCORE
Functional improvement on the Disabilities of the Arm, Shoulder, and Hand questionnaire
3 months
MAINTENANCE OF EFFECT
Persistence of benefits without additional treatment at follow-up

Modern Approach and Clinical Protocol

The modern protocol for rhizarthrosis integrates periarticular medical acupuncture with electroacupuncture, a supervised exercise program, and rational orthosis use. Treatment is staged according to the Eaton-Littler stage and individual clinical response.

Phased Treatment Protocol

  1. Evaluation (session 1)

    Eaton-Littler classification by radiograph, pinch strength assessment (dynamometer), DASH score, examination of thenar eminence trigger points, screening for concurrent De Quervain.

  2. Intensive Phase (weeks 1-4)

    Periarticular CMC acupuncture 2×/week: 4-6 needles in the joint capsule + trigger points of the opponens and adductor. 2 Hz electroacupuncture for 20 min. Nighttime orthosis. Daily isometric exercises.

  3. Consolidation Phase (weeks 5-8)

    Weekly sessions. Progression of exercises to isotonic strengthening with therapeutic putty. Adjustment of the orthosis according to improvement. Reassessment of pinch strength.

  4. Maintenance (monthly)

    Monthly or on-demand sessions. Home exercise program maintained. Orthosis only for high-demand activities. Annual radiographic monitoring in stages II-III.

When to See a Medical Acupuncturist

Rhizarthrosis is a progressive condition that benefits from early treatment. The earlier conservative treatment is started, the greater the likelihood of preserving hand function and avoiding surgery.

Profiles with the Best Response to Acupuncture

  • Stage I-II rhizarthrosis with pain on pinch and grasp — broader window for conservative treatment
  • Perimenopausal women with bilateral pain at the base of the thumb — responsive hormonal component
  • Patients with concurrent De Quervain — simultaneous treatment of both conditions
  • Pain that limits occupational manual activities (dentists, hairdressers, seamstresses)
  • Patients who wish to avoid or postpone surgery while preserving hand function

Frequently Asked Questions

FREQUENTLY ASKED QUESTIONS · 05

Frequently Asked Questions

In stages I to III, conservative treatment (acupuncture + orthosis + exercises) is the first line according to hand surgery guidelines, and may postpone or avoid surgery in a significant share of patients according to specific case series — response is individual. In stage IV with fixed deformity and failure of conservative treatment, trapeziectomy is often necessary. The medical acupuncturist evaluates case by case and refers to a hand surgeon when indicated.

The standard protocol includes 8-12 sessions over 8 weeks (2×/week for the first 4 weeks, then weekly). Most patients perceive significant improvement between the 3rd and 5th session. After the initial series, monthly maintenance sessions preserve the result long term.

The periarticular region of the CMC is sensitive, and the patient may feel a brief stabbing sensation on insertion. Once the needle is positioned, the sensation is one of mild pressure. Electroacupuncture produces a gentle, controllable tingling. The vast majority of patients tolerate it very well — the pain of the session is incomparably less than the daily pain of rhizarthrosis.

Yes, and you should! Active mobilization of the hand is part of treatment. We recommend activity modification in the first few days (avoiding maximum pinch effort), but normal functional use is maintained. Isometric exercises and exercises with therapeutic putty are progressively intensified over the weeks.

Yes. Acupuncture works through completely different mechanisms from injection (neuromodulation and muscle relaxation vs. pharmacologic suppression of inflammation). Many patients start acupuncture precisely when injections lose efficacy. The two approaches can coexist, provided they are coordinated by the physician.