Knee Replacement Risks and Complications: Dr. Mayur Rabhadiya Explains

Understanding the Risks of Knee Replacement Surgery

Knee replacement can provide substantial improvement in pain, walking and daily function when it is performed for the correct clinical indication.

However, it remains a major operation.

Possible complications should be discussed before surgery so that the patient can make an informed decision and recognise warning signs during recovery.

Risks may relate to:

Anaesthesia
The surgical wound
Infection
Blood circulation
The heart or lungs
Knee movement
Ligament balance
Implant fixation
Individual medical conditions

The presence of a possible complication does not mean that it will occur.

Individual risk varies according to:

Age and frailty
Diabetes
Heart or lung disease
Kidney disease
Anaemia
Smoking
Body weight
Previous blood clots
Previous knee surgery
Infection history
Surgical complexity
Rehabilitation capacity

Dr. Mayur Rabhadiya is an Orthopedic & Joint Replacement Surgeon in Mumbai with a focused practice in total, partial, robotic-assisted, bilateral and revision knee replacement.

For the complete surgical overview, visit Knee Replacement Surgery in Mumbai.

How Safe Is Knee Replacement?

Most appropriately selected patients undergo knee replacement without a serious complication.

Risk should nevertheless be evaluated individually.

A medically fit patient undergoing a straightforward primary knee replacement may have a different risk profile from a patient undergoing:

Simultaneous replacement of both knees
Revision knee replacement
Surgery after a previous fracture
Surgery with severe deformity or bone loss
Surgery with uncontrolled medical conditions

The objective is not to describe knee replacement as completely safe or excessively dangerous.

The appropriate question is whether the expected improvement in pain and function reasonably outweighs the individual risk.

Infection After Knee Replacement

Infection may involve:

The skin and superficial wound
Deeper tissues
The artificial joint and implant

It may occur:

During early wound healing
Several weeks or months after surgery
Years after a previously successful replacement

Possible symptoms include:

Increasing pain
Increasing swelling
Redness
Wound drainage
Progressive stiffness
Persistent warmth
Fatigue or feeling unwell

Fever may occur, but its absence does not exclude implant infection.

Deep infection may require:

Blood tests
Joint-fluid aspiration
Antibiotics
Surgical cleaning
Exchange of the plastic bearing
Removal and revision of the implant in selected cases

Patients should not begin leftover antibiotics without assessment because this may interfere with infection testing.

How Infection Risk May Be Reduced

Risk-reduction measures may include:

Antibiotics around the time of surgery
Strict sterile technique
Skin preparation
Screening or treatment of active infections
Diabetes optimisation
Smoking cessation
Nutrition assessment
Treatment of skin wounds or rashes
Appropriate wound care
Avoiding unnecessary touching of the incision

Surgery may need to be delayed when there is:

Active skin infection
An open wound
Uncontrolled diabetes
Significant untreated infection elsewhere
Severe nutritional deficiency
Another medical concern affecting healing

Blood Clots and Pulmonary Embolism

A blood clot may form in a deep vein of the:

Calf
Thigh
Pelvis

This is called deep-vein thrombosis.

Possible warning signs include:

New calf pain
Calf tenderness
Increasing calf, ankle or foot swelling
Redness
Unequal swelling between the legs

A clot may occasionally travel to the lungs and cause pulmonary embolism.

Emergency symptoms include:

Sudden breathlessness
Sudden chest pain
Fainting
Coughing blood
Rapid unexplained deterioration

These symptoms require urgent emergency care.

Blood-Clot Prevention

Prevention may include:

Early walking
Ankle exercises
Prescribed blood-thinning medication
Compression devices
Compression stockings in selected protocols
Adequate hydration
Avoiding prolonged immobility
Individual assessment of previous clotting risk

Blood-thinning medication should be taken exactly as prescribed.

Taking too little may reduce protection, while taking too much may increase bleeding risk.

Bleeding and Anaemia

Some blood loss occurs during and after knee replacement.

Anaemia may cause:

Fatigue
Dizziness
Weakness
Breathlessness on activity
Reduced rehabilitation tolerance

The medical team may monitor:

Haemoglobin
Blood pressure
Wound drainage
General symptoms

Blood transfusion is not required for every patient.

Its use depends on:

Blood count
Symptoms
Heart health
Ongoing bleeding
Clinical stability

Preoperative assessment and treatment of anaemia may reduce avoidable risk.

Wound-Healing Problems

Possible wound complications include:

Persistent drainage
Skin separation
Delayed healing
Increasing redness
Blistering
Skin-edge damage
Superficial infection

Risk may be increased by:

Diabetes
Smoking
Obesity
Poor circulation
Malnutrition
Previous scars
Steroid or immunosuppressive medication
Excessive swelling

Persistent drainage should be reviewed promptly because it may increase the risk of deeper infection.

Pain After Knee Replacement

Pain is expected during early recovery.

However, a small proportion of patients continue to experience significant pain after healing.

Possible causes include:

Infection
Stiffness
Instability
Implant loosening
Patellar problems
Nerve-related pain
Tendon irritation
Pain referred from the hip or spine
Complex pain mechanisms
No clearly identifiable cause

This is why surgery should be recommended only when the arthritic knee is clearly the principal source of symptoms.

Read Pain After Knee Replacement Surgery.

Stiffness and Reduced Movement

Scar tissue, swelling and muscle guarding may restrict knee movement.

Risk may be influenced by:

Severe stiffness before surgery
Previous operations
Pain
Delayed movement
Infection
Individual scar formation
Implant position
Prolonged swelling

Treatment may include:

Physiotherapy
Pain and swelling control
Manipulation under anaesthesia in selected patients
Investigation for infection or mechanical problems
Revision surgery when a correctable implant problem exists

Read Stiffness After Knee Replacement Surgery.

Knee Instability

A replaced knee may feel unstable or give way because of:

Quadriceps weakness
Ligament imbalance
Implant wear
Component position
Inappropriate bearing thickness
Trauma
Progressive soft-tissue damage

Early weakness may improve with rehabilitation.

Persistent mechanical instability may require:

Bracing
Targeted strengthening
Imaging
Revision surgery in selected cases

Repeated buckling or falls require orthopedic assessment.

Implant Wear and Loosening

Knee implants are designed to function for many years, but they are not permanent biological tissue.

Over time:

The plastic bearing may wear
Bone loss may develop
Components may loosen
Stability may deteriorate

Possible symptoms include:

Increasing pain while walking
Recurrent swelling
Reduced walking distance
Instability
Progressive X-ray changes

An older implant does not require revision solely because of its age.

Revision is considered when a defined problem causes symptoms or threatens the surrounding bone.

Read How Long Does a Knee Replacement Last?.

Fracture Around the Implant

A fracture may occur around a knee replacement after:

A fall
Significant trauma
Osteoporosis
Progressive bone loss

Treatment depends on:

Fracture location
Implant stability
Bone quality
Displacement
Patient health

Possible treatments include:

Restricted weight bearing
Fracture fixation
Revision knee replacement
A combination of fixation and revision

A fall followed by severe pain or inability to bear weight requires prompt imaging.

Nerve or Blood-Vessel Injury

Nerves and major blood vessels pass close to the knee.

Injury is uncommon but may cause:

Numbness
Weakness
Foot-drop
Severe nerve pain
Reduced circulation
A cold or pale foot

A small patch of numbness beside the scar is common and is usually related to small skin nerves.

This differs from:

New foot weakness
Widespread numbness
Loss of pulse
A cold or discoloured foot

These symptoms require urgent assessment.

Kneecap-Related Problems

Possible patellofemoral complications include:

Pain around the kneecap
Abnormal tracking
Clicking
Instability
Patellar fracture
Wear or loosening of a resurfaced patellar component

Mild painless clicking may occur normally because the artificial joint contains metal and plastic components.

Painful clicking, catching, swelling or instability should be assessed.

Anaesthetic and Medical Complications

Possible medical complications include:

Nausea or vomiting
Low blood pressure
Urinary retention
Confusion in vulnerable patients
Lung complications
Heart rhythm problems
Heart attack
Stroke
Kidney problems
Medication reactions

Risk depends on:

Medical history
Age and frailty
Heart and lung function
Kidney function
Diabetes
Anaemia
Medication
Type and duration of surgery

Preoperative medical and anaesthetic assessment is therefore an important part of knee-replacement planning.

Falls During Recovery

Weakness, medication, poor balance and unfamiliar walking aids can increase fall risk.

A fall may cause:

Wound damage
Soft-tissue injury
Fracture
Implant-related injury
Loss of confidence

Risk reduction may include:

Using the prescribed walking aid
Removing loose rugs
Improving lighting
Using handrails
Avoiding wet floors
Wearing suitable footwear
Asking for assistance when necessary

A walking aid should not be discontinued merely to meet an arbitrary recovery target.

Can Robotic Surgery Eliminate Complications?

No.

Robotic assistance may support:

Planning
Bone preparation
Implant positioning
Alignment
Ligament-balance assessment

It cannot eliminate:

Infection
Blood clots
Medical complications
Scar formation
Falls
Individual pain responses
Implant wear
Rehabilitation-related problems

Robotic systems also introduce additional considerations such as tracking-pin pain, registration problems and equipment malfunction.

Read Robotic vs Conventional Knee Replacement.

Are Risks Greater When Both Knees Are Replaced?

Simultaneous bilateral knee replacement places greater immediate demands on:

Blood count
Heart and lungs
Pain management
Mobility
Rehabilitation
Home support

It may be appropriate only for carefully selected medically fit patients.

Other patients may be better suited to staged operations.

Read Bilateral Knee Replacement Surgery in Mumbai.

Risk Factors That May Require Optimisation

Risk may be influenced by:

Poorly controlled diabetes
Smoking
Significant obesity
Anaemia
Heart disease
Lung disease
Kidney disease
Malnutrition
Active infection
Previous blood clots
Poor skin condition
Immunosuppressive medication
Frailty
Severe muscle weakness

These factors do not automatically prohibit surgery.

They may require:

Medical treatment
Specialist review
Risk counselling
Procedure modification
Temporary delay
Additional hospital monitoring

Questions to Ask Before Surgery

Patients may ask:

What are my individual risks?
Which medical conditions need optimisation?
How will blood clots be prevented?
How will infection risk be reduced?
Which medicines should I stop or continue?
Is partial or total replacement appropriate?
Is robotic assistance relevant in my case?
What warning signs should I watch for?
Whom should I contact after discharge?
What happens if a complication develops?
Is simultaneous bilateral surgery appropriate?
What outcome cannot be guaranteed?

Clear risk counselling is part of informed consent.

Warning Signs After Surgery

Contact the treating team promptly for:

Increasing wound redness
Wound drainage
Persistent or increasing pain
Increasing swelling
Progressive stiffness
Fever or feeling unwell
New calf pain
New instability
New weakness or numbness
A fall followed by severe pain
Inability to bear weight

Seek emergency care for:

Sudden breathlessness
Chest pain
Fainting
Coughing blood
A cold, pale or blue foot
Sudden severe deterioration

Why Patients Consult Dr. Mayur Rabhadiya

Dr. Mayur Rabhadiya follows an evidence-based and patient-specific approach to knee-replacement risk assessment.

His evaluation emphasises:

Confirming that surgery is clinically justified
Balancing expected benefit against individual risk
Identifying medical conditions requiring optimisation
Selecting partial or total replacement appropriately
Assessing whether bilateral surgery is suitable
Discussing robotic and conventional options realistically
Planning infection and blood-clot prevention
Explaining expected recovery and limitations
Recognising complications early
Avoiding guarantees of risk-free surgery

Knee-Replacement Risk Assessment in Ghatkopar, Mumbai

Diabplus Clinic, Ghatkopar East

601, 6th Floor, Skyline Status, Mahatma Gandhi Road, opposite Pooja Hotel, Pant Nagar, Ghatkopar East, Mumbai, Maharashtra 400077.

Visit Dr. Mayur Rabhadiya in Ghatkopar East.

Savla Clinic, Ghatkopar West

2/3, Dharmodaya Building, next to Raj Medical, near NULife Hospital, Jivdaya Lane, Ghatkopar West, Mumbai, Maharashtra 400086.

Visit Dr. Mayur Rabhadiya in Ghatkopar West.

Frequently Asked Questions

Is knee replacement a high-risk operation?

Most appropriately selected patients do not develop a serious complication, but risk varies according to medical health and procedure complexity.

What is the most serious complication?

Deep infection and pulmonary embolism are among the most serious complications, although both are uncommon.

How common is infection?

Deep joint infection is uncommon, but individual risk varies and infection can be difficult to treat.

Can infection occur years later?

Yes. Bacteria may reach a joint replacement months or years after the original surgery.

How are blood clots prevented?

Prevention may include early walking, ankle exercises, compression devices and prescribed blood-thinning medication.

What are the warning signs of a blood clot?

New calf pain, tenderness, redness and increasing calf, ankle or foot swelling require assessment.

What are the signs of pulmonary embolism?

Sudden breathlessness, chest pain, fainting or coughing blood requires emergency care.

Can knee replacement cause permanent pain?

Most patients improve, but a small proportion may continue to have significant pain.

Can stiffness be treated?

Treatment may include physiotherapy, manipulation under anaesthesia or further surgery when a correctable cause is found.

Can the implant become loose?

Yes. Wear, bone loss, infection or mechanical factors may lead to loosening over time.

Can a nerve be injured?

Nerve injury is uncommon but may cause weakness, numbness or nerve-related pain.

Does robotic surgery remove surgical risk?

No. Robotic assistance does not eliminate infection, clots, medical complications or implant-related problems.

Are risks higher with both knees replaced together?

The immediate medical and rehabilitation demands may be greater, so simultaneous bilateral surgery requires careful selection.

Does diabetes increase risk?

Poorly controlled diabetes may increase infection and wound-healing risk. Optimisation is important.

Does smoking increase risk?

Smoking may impair wound healing and increase infection and lung-related risk.

Can overweight patients undergo surgery?

Yes, but body weight may affect wound, infection, clotting, technical and rehabilitation risks.

Should I seek a second opinion?

A second opinion is appropriate when individual risks, alternatives or the need for surgery have not been clearly explained.

About the Author

Dr. Mayur Rabhadiya
Orthopedic & Joint Replacement Surgeon

Qualifications

MBBS
D’Ortho
DNB Orthopedics
MNAMS Orthopedics
Fellowship in Robotic & Computer-Navigated Joint Replacement

Clinical focus

Knee-replacement risk assessment
Total and partial knee replacement
Robotic-assisted knee replacement
Bilateral knee replacement
Painful and stiff knee-replacement assessment
Knee-replacement infection evaluation
Revision knee replacement
Complex joint reconstruction

Written and medically reviewed by: Dr. Mayur Rabhadiya
Last medically reviewed: June 2026

Clinical References

Book a Knee-Replacement Risk Assessment

Consultation may be useful if:

Knee replacement has been advised
You have diabetes, cardiac disease or kidney disease
You have a history of blood clots
Both knees have been advised replacement
Previous surgery makes the knee complex
You want to understand robotic and conventional risks
You require medical optimisation before surgery
You are uncertain whether the expected benefit outweighs the risks
You require a second opinion

Book an orthopedic consultation with Dr. Mayur Rabhadiya in Ghatkopar, Mumbai

Call or WhatsApp

+91 84249 03913
+91 96113 30063

Medical Disclaimer

This page provides general patient education and does not replace individual orthopedic, medical or anaesthetic assessment. The likelihood and importance of each complication depend on the patient’s health, operation, implant, medical optimisation and rehabilitation. Seek prompt medical advice for wound drainage, increasing redness, worsening pain, progressive swelling, fever, calf pain or inability to bear weight. Sudden chest pain, breathlessness, fainting, coughing blood or a cold and pale foot requires emergency care.