Osteoarthritis: Joint Pain, Causes and Treatment

Osteoarthritis (OA) is the most common joint disorder worldwide and the leading cause of disability in older adults. It results from the progressive breakdown of articular cartilage — the smooth, resilient tissue that covers the ends of bones within a joint — combined with changes in the underlying bone and surrounding joint structures.

OA affects an estimated 500 million people globally. It is not simply "wear and tear" in the traditional sense; it is a complex, dynamic process involving cartilage, bone, synovium (joint lining), ligaments, muscles and pain-signalling pathways.

Which Joints Are Affected?

OA most commonly involves:

• Knees — the most frequently affected weight-bearing joint; a leading cause of disability
• Hips — second most common weight-bearing joint affected
• Spine (lumbar and cervical) — degenerative disc disease and facet joint OA
• Hands — distal interphalangeal (DIP) joints (Heberden's nodes), proximal interphalangeal (PIP) joints (Bouchard's nodes), and the base of the thumb (first carpometacarpal joint)
• Feet — particularly the first metatarsophalangeal joint (base of the big toe)

Causes and Risk Factors

OA is classified as primary (idiopathic) when no specific cause is identified, or secondary when a known condition has damaged the joint.

Risk Factors for Primary OA

Factor	Mechanism
Age	Cartilage repair capacity declines; cumulative micro-damage accumulates
Female sex	Women develop OA at higher rates, particularly after menopause (oestrogen may be protective)
Obesity	Increases mechanical load on weight-bearing joints; adipose tissue also produces pro-inflammatory cytokines
Occupational repetitive joint loading	Farmers, miners, coal workers, construction workers — repeated joint stress
Genetics	Family history; specific gene variants affect cartilage composition
Prior joint injury	Anterior cruciate ligament (ACL) tear, meniscal injury, or fracture involving the joint surface raises future OA risk significantly
Muscle weakness	Weak quadriceps destabilise the knee; OA is both a cause and consequence

Causes of Secondary OA

• Previous infection of the joint (septic arthritis)
• Rheumatoid arthritis or other inflammatory arthritis causing cartilage damage
• Gout (urate crystal deposition damages cartilage)
• Haemochromatosis (iron deposits in cartilage)
• Wilson's disease (copper accumulation)
• Congenital joint abnormalities (dysplasia)

What Happens Inside the Joint

Healthy articular cartilage is 2–4 mm thick, smooth, and nearly frictionless. In OA, this balance is disrupted:

1. Cartilage softening and fibrillation — the cartilage surface develops fissures; fragments may break off into the joint space
2. Subchondral bone changes — bone beneath the cartilage scleroses (hardens) and develops cysts; osteophytes (bone spurs) form at joint margins
3. Synovial inflammation — mild to moderate inflammation of the joint lining; produces pain-mediating chemical signals
4. Joint space narrowing — visible on X-ray as the cartilage thins

Symptoms

OA develops gradually. Early disease may cause minimal symptoms; advanced disease can cause severe disability.

Pain:

• Deep, aching pain in or around the joint
• Initially worsens with activity and weight-bearing; relieved by rest
• In later stages, may occur at rest and at night
• Morning stiffness typically lasts less than 30 minutes (distinguishing OA from rheumatoid arthritis, where stiffness persists longer)

Stiffness:

• After periods of inactivity ("gelling") — brief stiffness that eases within minutes of movement

Swelling:

• From bony enlargement (osteophytes) and, in acute flares, from joint effusion (excess fluid)

Crepitus:

• Grinding, cracking or creaking sensation within the joint on movement

Reduced range of motion:

• Progressive loss of joint flexibility; difficulty fully bending or straightening the knee or hip

Instability:

• Particularly in the knee, as supporting ligaments and muscles weaken

Bony enlargement:

• Heberden's nodes (DIP joints) and Bouchard's nodes (PIP joints) in hand OA — hard, bony swellings visible and palpable

Functional limitations:

• Knee OA: difficulty climbing stairs, rising from a chair, walking distances
• Hip OA: difficulty putting on shoes and socks, getting in and out of cars, reduced walking tolerance
• Cervical OA: neck pain, arm numbness, headaches
• Lumbar OA: back pain, buttock pain, leg symptoms if nerve roots compressed

Diagnosis

Clinical Assessment

Diagnosis is primarily clinical — based on age, symptom pattern, joint distribution and examination findings. There is no blood test for OA (inflammatory markers like CRP and ESR are typically normal or mildly elevated).

X-Ray

Plain X-rays remain the standard imaging tool:

• Joint space narrowing — reflects cartilage loss
• Osteophytes — bone spurs at joint margins
• Subchondral sclerosis — increased bone density beneath worn cartilage
• Subchondral cysts — fluid-filled holes in bone beneath cartilage

X-ray severity does not always correlate with symptom severity — some patients have severe X-ray changes with minimal pain, and vice versa.

MRI

MRI detects changes invisible on X-ray: cartilage defects, bone marrow lesions (areas of bone stress), synovial inflammation, meniscal tears (knee) and ligament status. Useful when diagnosis is uncertain, when surgical planning is needed, or when a meniscal or ligament problem may be treatable before OA advances.

Treatment

No treatment currently reverses established OA. Management aims to reduce pain, maintain function, slow progression, and time surgery appropriately.

Non-Pharmacological Treatments (First-Line for All Patients)

Exercise — the single most evidence-based non-surgical treatment. Strengthening the muscles around the joint reduces load on cartilage and pain signalling. Both aerobic exercise (walking, cycling, swimming) and targeted resistance training are beneficial. Exercise does not worsen OA.

Weight loss — for overweight patients with knee or hip OA; each kilogram of weight lost reduces knee joint load by approximately 4 kg across each step. A 10% body weight reduction significantly reduces OA symptoms.

Physiotherapy — targeted exercise programmes, manual therapy, walking aids, and bracing

Occupational therapy — joint protection strategies, assistive devices, home adaptations

Footwear and orthotics — lateral wedge insoles may redistribute load in medial compartment knee OA; appropriate footwear reduces foot and knee pain

Pharmacological Treatments

Treatment	Evidence	Notes
Topical NSAIDs (diclofenac gel)	Strong for knee OA	First-line pharmacological; minimal systemic absorption
Oral NSAIDs (naproxen, ibuprofen, celecoxib)	Effective; moderate risk profile	Use at lowest effective dose; caution in elderly, renal disease, cardiovascular disease
Paracetamol (acetaminophen)	Modest effect	Safer profile but limited efficacy
Intra-articular corticosteroid injection	Short-term pain relief (weeks to months)	Useful for flares; repeated injections may accelerate cartilage loss
Intra-articular hyaluronic acid injection	Modest effect; some guidelines do not recommend	May provide 3–6 months of benefit in some patients
Duloxetine	Moderate evidence for central sensitisation	Useful when pain is disproportionate to joint damage

Surgical Treatments

Arthroscopy (joint washout) — no longer recommended for OA; multiple trials show no benefit over placebo

Osteotomy — realigns the joint to redistribute load from the damaged compartment; used in younger patients with localised compartment OA to delay joint replacement

Total knee replacement (TKR) — highly effective for end-stage knee OA; removes damaged cartilage and bone surfaces and replaces them with metal and polyethylene implants. Over 90% of patients report significant pain relief and functional improvement. Implants typically last 15–20+ years.

Total hip replacement (THR) — among the most successful elective surgical procedures in medicine; reliably relieves hip OA pain and restores walking function. Modern implants (ceramic-on-ceramic or ceramic-on-polyethylene) carry excellent long-term durability.

Unicompartmental (partial) knee replacement — suitable when only one compartment of the knee is affected; smaller operation, faster recovery, bone-preserving; revision to total replacement possible if needed later.

Osteoarthritis and Joint Replacement in China

China's top orthopaedic hospitals deliver internationally benchmarked joint replacement services:

• Pre-surgical assessment: standing weight-bearing X-rays, MRI where indicated, anaesthetic review and full cardiopulmonary assessment
• High-volume surgeons: leading Chinese joint replacement surgeons perform 300–600 procedures annually, comparable to high-volume Western centres
• Computer-assisted and robotic-arm joint replacement: available at premium centres for improved implant alignment
• Implant choice: US, UK and German implant brands (Zimmer Biomet, DePuy, Stryker, Smith+Nephew) are available; implant cost in China is significantly lower than in private Western hospitals
• Enhanced recovery protocols: most patients walk on the day of surgery; typical hospital stay 3–5 days
• Cost: care in China is generally less expensive than UK private treatment, but the hospital prices each case individually — ask us for the written quote before you commit.
• Full English coordination and post-operative follow-up planning

Contact a ChinaMedicalTour care navigator to arrange an orthopaedic consultation or joint replacement assessment.

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Medical content based on MSD Manuals and international orthopaedic guidelines. Evidence reviewed 2025.

Frequently Asked Questions

Can international patients get a remote MRI review for joint or spinal conditions before traveling?

Yes. Overseas patients can submit DICOM MRI, CT, or X-ray imaging for remote pre-consultation coordination with Chinese orthopedics and spine specialists to assess surgical vs conservative indications.

What minimally invasive orthopedic procedures are commonly evaluated in China?

High-volume orthopedic departments evaluate arthroscopic joint repair, total joint replacement (hip and knee arthroplasty), percutaneous spinal endoscopy, and structured post-operative physical rehabilitation.

How is hospital admission and post-operative mobility coordinated?

Inpatient observation duration, surgical scheduling, and mobilization milestones are established directly by the hospital care team, supported by bilingual coordination throughout the hospital stay.