Knee Arthritis in Both Knees

Knee arthritis commonly affects both knees, but the two sides are rarely identical. One knee may have greater pain, deformity or joint-space loss, while the other causes more instability, swelling or functional limitation. Each knee must therefore be assessed separately before a combined treatment plan is made.

Bilateral arthritis does not automatically mean both knees need injections or replacement at the same time. Treatment depends on symptoms, function, disease distribution, medical fitness, home support and rehabilitation capacity.

For the broader pathway, read Knee Arthritis Treatment in Mumbai.

Quick Answer: What Happens When Both Knees Have Arthritis?

Both knees may contribute to walking difficulty, slower chair rise, stair dependence and reduced balance. The more painful knee is not always the structurally worse knee. The plan may treat both non-surgically, operate on one side first or consider simultaneous bilateral replacement in a carefully selected patient.

Why Arthritis Often Affects Both Knees

• Age-related and genetic susceptibility

• Body weight and metabolic factors affecting both joints

• Similar lifelong alignment or loading patterns

• Compensation after pain or surgery in one knee

• Inflammatory or systemic joint disease in selected patients

Why One Knee Can Be Worse Than the Other

Previous fracture, ligament injury, meniscal loss, surgery, different alignment, muscle weakness or compartment pattern can make one side progress faster. A patient may also unconsciously load the less painful knee, increasing fatigue or symptoms on that side.

Research shows that advanced disease in one knee may be associated with greater risk of progression in the opposite knee, but it does not predict an exact individual timeline.

How Bilateral Knee Arthritis Affects Daily Function

• Shorter walking distance and slower pace

• Difficulty standing from chairs or toilets

• Greater reliance on railings or arm support

• Reduced balance because neither leg feels reliable

• Difficulty protecting one knee during a flare in the other

• Loss of confidence with outdoor travel and uneven ground

Each Knee Should Be Diagnosed Separately

The consultation records pain location, stiffness, swelling, locking, giving way, night pain, walking and stair limitation for each side. Examination compares alignment, movement, tenderness, strength, ligament stability and deformity. Hip, spine, nerve and vascular causes should be considered when symptoms do not match the knee findings.

Standing weight-bearing X-rays of both knees help compare compartment involvement and alignment. The side with worse imaging does not automatically need surgery first; symptoms and function remain central.

Non-Surgical Treatment for Both Knees

Exercise and rehabilitation

A bilateral programme usually includes quadriceps and hip strengthening, chair-rise practice, balance, walking or cycling and individual movement work for the stiffer side. Exercise dosage may differ between knees. Pool-based exercise can be useful when both sides are highly irritable, but it is not the only option.

Weight management

When relevant, sustainable weight reduction can reduce load across both knees and improve function. It should be combined with exercise and not used as a reason to postpone assessment when disability is substantial.

Medicines and aids

Topical or selected oral medicines may support activity after medical-risk review. A walking stick may help, but when both knees are severely affected a frame or rollator may provide better bilateral support. Fit and safe use should be checked.

Braces

A brace may help one compartment-specific knee more than the other. Wearing complex braces on both knees may be uncomfortable and is not routinely required. The decision should follow documented instability or abnormal loading and actual functional benefit.

Do Both Knees Need Injections?

No. Each knee should have a clear diagnosis and indication. One side may be suitable for an injection while the other is better managed with exercise, medication or surgery. Corticosteroid may offer short-term relief in selected cases. Evidence differs for hyaluronic acid, PRP, GFC and other injections; none can guarantee cartilage regeneration or avoidance of replacement.

Which Knee Should Be Treated First?

The first knee is usually the one causing greater pain, disability, deformity or instability, provided the diagnosis and surgical indication are clear. Occasionally the less painful knee is addressed first because it is structurally urgent, locked, rapidly deteriorating or strategically important for rehabilitation. The decision should be explicit rather than based only on the X-ray grade.

When Is Knee Replacement Considered?

Replacement is considered for each knee when confirmed arthritis substantially affects quality of life and suitable non-surgical care is ineffective or unsuitable. Bilateral X-ray arthritis alone is not an indication for bilateral surgery.

Read When Does Knee Arthritis Need Replacement?.

Staged Versus Simultaneous Bilateral Knee Replacement

Option A: Staged replacement

The knees are replaced in separate operations. This reduces the physiological burden of one surgical episode and allows recovery from the first side before the second. It requires two admissions, two anaesthetics and a longer total treatment period. The interval is individualised according to recovery, health and urgency of the second knee.

Option B: Simultaneous bilateral replacement

Both knees are replaced during one anaesthetic and one rehabilitation episode. This may suit carefully selected medically fit patients with severe bilateral symptoms and strong rehabilitation support. It creates a greater immediate physiological and rehabilitation demand and is not appropriate for every patient.

Which option is better?

Neither is universally better. Age alone does not decide suitability. Cardiac, respiratory, kidney, anaemia, clotting, diabetes, frailty, home support, rehabilitation capacity, severity and patient preference must be considered.

Rehabilitation When the Other Knee Is Still Arthritic

After one knee is replaced, the unreplaced knee may limit walking, stairs and exercise. Preoperative strengthening, suitable aids, realistic home planning and treatment of the opposite knee are important. The first knee should not be labelled a failed replacement simply because the other side continues to restrict overall function.

Robotic Assistance and the Mini-Subvastus Approach

Robotic assistance can support planning and execution for each knee after replacement has been selected. The anatomy, alignment and implant plan are assessed separately for the two sides. The robot does not decide whether both knees should be operated together.

The mini-subvastus approach concerns surgical access while respecting the quadriceps mechanism when clinically suitable. Dr. Mayur Rabhadiya combines robotic planning with a minimally invasive mini-subvastus, muscle-sparing approach in suitable patients. Suitability may differ between the two knees and cannot be guaranteed.

Warning Signs Requiring Prompt Assessment

• A hot, red and rapidly swollen knee, especially with fever

• Sudden inability to bear weight on either side

• True locking, repeated falls or rapidly worsening deformity

• Sudden calf swelling, chest pain or breathlessness

• New numbness, weakness or foot drop

Questions Patients Commonly Ask

Is bilateral knee arthritis common?

Yes. Osteoarthritis frequently affects both knees, although severity and symptoms may differ.

Why does one knee hurt more if both X-rays look similar?

Inflammation, strength, alignment, bone stress, sensitisation and activity can differ between sides.

Can both knees improve with exercise?

Yes. The programme can treat both knees while using different loads or exercises for the more irritable side.

Should both knees be injected together?

Not automatically. Each knee needs a diagnosis and indication, and medical factors must be considered.

Which knee should be replaced first?

Usually the knee causing greater disability, provided the clinical indication is clear. The decision can differ when one side is rapidly deteriorating or mechanically urgent.

How long should I wait between staged operations?

There is no universal interval. The first knee’s recovery, medical fitness, anaemia, support and second-knee disability guide timing.

Is simultaneous bilateral surgery more painful?

It creates a more demanding early rehabilitation because neither knee is unoperated. Pain experience varies and should not be reduced to one guarantee.

Is simultaneous surgery safer because there is only one anaesthetic?

One anaesthetic is an advantage, but the operation is longer and the immediate physiological demand is greater. Overall suitability requires medical risk assessment.

Can I have partial replacement in one knee and total replacement in the other?

Yes, when disease distribution and ligament condition differ. Each knee receives the procedure appropriate to its anatomy and symptoms.

Can one knee replacement improve pain in the other knee?

Walking mechanics and overall function may improve, but established arthritis in the opposite knee remains and may still need treatment.

Do both knees need the same implant or alignment plan?

Not necessarily. Anatomy, deformity, bone and ligament balance are assessed separately.

Does bilateral arthritis mean I should avoid walking?

Usually no. Walking volume and support may need adjustment, while strength and aerobic activity remain important.

Clinical References and Further Reading

NICE NG226: Osteoarthritis in over 16s—diagnosis and management

Contralateral advanced knee osteoarthritis and progression of the opposite knee

NICE NG157: Joint replacement—primary hip, knee and shoulder

About Dr. Mayur Rabhadiya

Dr. Mayur Rabhadiya is an Orthopedic and Joint Replacement Surgeon in Mumbai. His focused knee practice includes diagnosis-first assessment, stage-wise arthritis care, bilateral decision-making and minimally invasive mini-subvastus robotic knee replacement when clinically indicated. His qualifications are MBBS, D’Ortho, DNB (Orthopedics), MNAMS (Orthopedics) and FIJR (Robotic & Navigation).

Last medically reviewed: 24 July 2026. Medical reviewer: Dr. Mayur Rabhadiya.

Book a Bilateral Knee-Arthritis Consultation in Mumbai

Patients with arthritis in both knees or uncertainty about which knee to treat first can consult Dr. Mayur Rabhadiya in Ghatkopar East or Ghatkopar West, Mumbai. Call or WhatsApp +91 84249 03913 or +91 96113 30063, or use the orthopedic appointment page.

Medical Disclaimer

This guide is for general education and does not replace an individual clinical assessment. Seek urgent care for a hot swollen knee with fever, inability to bear weight, true locking, sudden calf swelling, chest pain, breathlessness or progressive neurological weakness.