Total knee replacement surgery is one of the most effective and successful orthopedic procedures performed worldwide. It helps relieve severe knee pain, improves mobility, corrects deformity, and allows patients to return to a more active and independent life. For many people suffering from advanced arthritis, knee damage, and chronic pain, knee replacement becomes a life-changing solution when medicines, injections, and physiotherapy no longer work. Although total knee replacement surgery has a very high success rate, it is still important to understand that, like any major surgery, it carries certain risks.
Knowing what are the risks of total knee replacement surgery helps patients make informed decisions. Understanding potential complications does not mean discouraging surgery, but rather preparing mentally, asking the right questions, choosing the right surgeon, and following medical advice carefully to minimize risks.
Understanding That All Surgeries Have Some Risk
Before discussing specific risks, it is important to realize that every major surgery, whether heart surgery, abdominal surgery, or orthopedic surgery, carries certain risks. However, total knee replacement is considered one of the safest orthopedic surgeries globally, with success rates often reported above 95% when performed by experienced surgeons with proper care and modern technology.
Most patients recover successfully without any major complications. However, knowing the risks helps patients stay alert, follow instructions correctly, and handle recovery responsibly.
Risk 1: Infection After Total Knee Replacement Surgery
One of the most serious but rare risks of knee replacement surgery is infection. Infection can occur:
on the skin around the incision (superficial infection)
deep inside the knee joint (deep infection)
in the implant area (prosthetic joint infection)
Why Can Infection Occur?
Infection may develop due to bacteria entering the wound during or after surgery. Even with sterile techniques, advanced operation theatres, and strict hygiene protocols, a very small percentage of patients may experience infection.
Symptoms of Infection
Patients may experience:
redness and warmth around the knee
severe pain or increasing pain instead of improvement
swelling and pus discharge
fever and chills
difficulty moving the knee
How Doctors Reduce Infection Risk
To prevent infection, hospitals use:
advanced sterilization systems
antibiotic-coated implants in some cases
antibiotics before and after surgery
sterile operating rooms
controlled surgical environments
Patients are also advised to keep the wound clean, avoid contamination, and attend follow-up visits regularly.
Risk 2: Blood Clots (Deep Vein Thrombosis and Pulmonary Embolism)
Blood clots are another potential risk after total knee replacement surgery. After surgery, blood may sometimes clot in the deep veins of the leg — a condition called Deep Vein Thrombosis (DVT). If a part of this clot travels to the lungs, it can cause Pulmonary Embolism, which is a medical emergency.
Why Blood Clots Happen
Blood clot risk increases due to:
reduced movement immediately after surgery
decreased blood flow in the leg veins
pre-existing clotting disorders
obesity, age, smoking, or other health conditions
Symptoms of Blood Clots
Patients may experience:
severe leg pain
swelling in the calf
warmth and redness
difficulty walking
sudden breathlessness (in severe cases)
chest pain (emergency)
How Doctors Prevent Clots
Doctors take strong preventive measures such as:
blood thinning medications
encouraging early movement
compression stockings
leg exercises
pneumatic compression devices
With proper care, clot risk is significantly reduced.
Risk 3: Implant Loosening or Wear Over Time
Knee replacement involves inserting artificial implants made of strong metal and plastic. Over time, due to repeated movement, weight bearing, and lifestyle factors, implants may loosen or wear down.
Why Implant Loosening Happens
It may occur due to:
high physical activity
excessive weight
age-related bone weakening
poor implant bonding
rare manufacturing defects
infection
Symptoms of Implant Loosening
Patients may feel:
pain in the knee after years of surgery
instability
grinding sensation
swelling
reduced mobility
Can It Be Fixed?
Yes. If implant loosening is severe, revision knee replacement surgery may be required. However, modern implants are highly durable and designed to last 15–25 years or more, especially when patients follow doctor advice.
Risk 4: Joint Stiffness and Reduced Mobility
Some patients may experience stiffness after surgery. This may happen if scar tissue formation restricts movement or if physiotherapy and rehabilitation are not followed properly.
Why Stiffness Occurs
inadequate physiotherapy
excessive scar formation
delayed mobilization
poor compliance with exercises
Prevention
Early movement, guided physiotherapy, and regular exercises are essential to prevent stiffness.
Risk 5: Damage to Nerves or Blood Vessels
Although rare, there is a possibility of damage to nerves or blood vessels around the knee during surgery.
Symptoms
numbness
weakness
tingling sensation
circulation problems (rare)
Most minor nerve damages may heal over time, but severe injury is extremely rare in experienced surgical hands.
Risk 6: Persistent Pain After Surgery
While the goal of total knee replacement is pain relief, a small number of patients may continue to experience pain even after surgery.
Reasons for Persistent Pain
unresolved muscular issues
infection
implant loosening
scar tissue formation
improper physiotherapy
rare complications
Proper evaluation helps identify the cause and treat it.
Risk 7: Fractures During or After Surgery
In rare cases, bones around the knee joint may fracture during surgery, especially in patients with weak bones or osteoporosis. Falls after surgery can also cause fractures.
Doctors use careful surgical techniques and supportive implants to reduce risk.
Risk 8: Allergic Reaction to Implant Materials
Extremely rarely, some patients may have sensitivity to metal components in implants. Doctors may perform tests if such allergies are suspected and may choose hypoallergenic implants.
Risk 9: Anesthesia-Related Risks
Total knee replacement surgery is performed under anesthesia, either spinal or general. Like any major surgery, anesthesia carries certain risks, including breathing difficulty, allergic reaction, or heart stress. However, modern anesthesia techniques and advanced monitoring greatly reduce these risks.
Risk 10: Delayed Wound Healing
Some patients, especially those with diabetes, vascular disease, or poor immunity, may experience slower wound healing. Proper wound care and monitoring help manage this risk.
Risk 11: Knee Instability or Movement Problems
Very rarely, the artificial knee may feel unstable if ligaments are weak or alignment is incorrect. This may require medical evaluation and rarely further surgery.
Risk 12: Rare Complication – Failure of Surgery
Though extremely uncommon, a knee replacement may fail due to infection, loosening, repeated trauma, or severe complications. Revision surgery may be needed in such cases.
Who Is More Likely to Experience Risks?
Risk may be slightly higher in:
elderly patients
obese patients
diabetic patients
smokers
those with heart or lung disease
patients with weak immunity
those with poor bone health
However, with proper medical evaluation and pre-surgery preparation, most risks can be controlled.
How Doctors Reduce the Risks of Knee Replacement Surgery
Modern orthopedic care uses several safety strategies:
advanced sterilization and infection control
skilled surgical teams
high-quality implants
antibiotic support
blood clot prevention programs
pre-surgery health optimization
advanced operation theatres
robotic and computer-assisted surgery in some centers
These significantly improve outcomes and reduce risk.
How Patients Can Help Reduce Risk
Patients also play an important role in ensuring safe recovery. You can help minimize risks by:
controlling diabetes and blood pressure
maintaining healthy weight
quitting smoking before surgery
following pre-surgery instructions
completing physiotherapy regularly
maintaining wound hygiene
attending follow-up visits
reporting unusual symptoms immediately
Teamwork between doctor and patient ensures the best results.
Is Total Knee Replacement Still Safe Despite These Risks?
Yes. Despite these risks, total knee replacement remains one of the most successful surgeries in medical history. Millions of people worldwide benefit every year and regain comfortable movement, independence, and quality of life. Most risks are rare and can be minimized with good medical care and responsible patient behavior.
Table of Contents
Introduction
The Introduction gives a brief overview of total knee replacement and why it is done.
Candidates
The Candidates section explains who may need total knee replacement and when it is recommended.
Consultation
The Consultation section describes what happens during a knee replacement consultation and evaluation.
Questions
The Questions section covers important doubts patients should clarify before surgery.
Cost
The cost of total knee replacement surgery varies based on implant type, hospital facilities, surgical approach, and postoperative care needs.
Preparation
Preparation includes medical evaluation, medication review, prehabilitation exercises, home planning, and understanding the recovery plan.
Steps
The procedure involves removing damaged joint surfaces, positioning artificial components, restoring alignment, and completing surgical closure with postoperative care. Steps
Recovery
Recovery includes pain management, early mobilization, structured physiotherapy, gradual strength gains, and scheduled follow-up visits.
Results
Most patients experience significant pain relief, improved knee stability, better mobility, and enhanced daily function. Results
Before-and-after
Before-and-after results commonly show reduced pain, improved alignment, increased walking ability, and better overall knee movement.
Choosing the right surgeon
Choosing the right surgeon involves assessing experience in joint replacement, patient outcomes, communication clarity, and access to comprehensive rehabilitation.
Frequently Asked Questions
1. What are the common risks of total knee replacement surgery?
Common risks include infection, blood clots, implant loosening, stiffness, anesthesia-related complications, and delayed wound healing.
2. Is infection a risk after total knee replacement surgery?
Yes, infection is a possible complication, but hospitals follow strict sterilization, antibiotics, and hygiene protocols to minimize the risk.
3. Can blood clots occur after knee replacement surgery?
Yes, blood clots such as Deep Vein Thrombosis may occur, which is why doctors prescribe blood thinners, encourage movement, and use compression stockings.
4. Can the implant loosen or wear out after surgery?
Over many years, implants may loosen or wear out, especially with heavy activity or obesity, but modern implants are highly durable and long-lasting.
5. Is stiffness a possible risk after total knee replacement?
Yes, some patients may experience stiffness if exercises are not followed. Proper physiotherapy and early movement help prevent stiffness.
6. Are there anesthesia risks in knee replacement surgery?
Like any major surgery, anesthesia carries small risks, but modern medical technology and expert monitoring make it very safe.
7. Can nerves or blood vessels be damaged during knee replacement?
This is extremely rare, but possible. Minor nerve effects usually improve over time with proper care.
8. Can pain continue even after total knee replacement surgery?
A small number of patients may continue to feel discomfort due to stiffness, scar tissue, or implant-related problems, but most patients experience major relief.
9. Who is at higher risk of complications after knee replacement?
Higher risk is seen in elderly patients, diabetics, obese individuals, smokers, and those with heart or lung diseases.
10. Is total knee replacement surgery still safe despite these risks?
Yes, total knee replacement is considered highly safe and successful worldwide, with most patients enjoying excellent pain relief and improved mobility.