The knee is one of the most complex and hardworking joints in the body. It supports movement, balance, and weight with every step you take. Over time, or after injury, the structures within the knee can become damaged—leading to pain, stiffness, and loss of function. When these symptoms persist despite other treatments, knee replacement surgery may be recommended.
Why Knee Replacement May Be Needed
Knee replacement, also known as knee arthroplasty, is typically considered when the joint has been severely damaged and conservative treatments—such as medications, injections, physical therapy, or bracing—no longer provide relief.
Common Causes Leading to Knee Replacement
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Advanced Arthritis:
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Osteoarthritis: The most common reason for knee replacement. It occurs when the protective cartilage that cushions the bones in the knee wears away, causing pain, stiffness, and swelling.
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Rheumatoid Arthritis: An autoimmune condition that inflames the joint lining, damages cartilage, and erodes bone over time.
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Post-Traumatic Arthritis: Arthritis that develops after a serious knee injury, such as a fracture or ligament tear, which disrupts the normal alignment and surface of the joint.
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Severe Joint Deformity or Instability:
Chronic misalignment—like bowlegs or knock knees—can place uneven stress on the knee, eventually leading to degeneration that may require surgical correction. -
Trauma or Bone Damage:
Fractures or repeated impact injuries can permanently alter the structure of the knee joint, leading to instability, chronic pain, and limited movement. -
Failed Previous Surgery:
In some cases, a prior procedure to repair cartilage or ligaments may not provide lasting relief, resulting in continued pain that may only be resolved with joint replacement.
When pain persists despite treatment and affects everyday activities—such as walking, climbing stairs, or sleeping comfortably—knee replacement may be the best solution to restore mobility and improve quality of life.
The Steps of a Knee Replacement Surgery
Knee replacement surgery involves removing the damaged surfaces of the joint and replacing them with artificial components that mimic natural movement. The procedure is usually performed under general or spinal anesthesia and takes about one to two hours.
Step 1: Preparing the Knee
The surgeon makes an incision at the front of the knee and gently moves the kneecap aside to access the joint. The damaged bone and cartilage from the femur (thigh bone) and tibia (shin bone) are carefully removed.
Step 2: Reshaping and Balancing the Joint
Precise measurements are taken to ensure that the new components will align properly. The bone ends are shaped to fit the implants perfectly, maintaining proper motion and balance.
Step 3: Placing the Implants
Metal components are attached to the ends of the femur and tibia using special bone cement or a press-fit technique. A smooth plastic spacer is inserted between them, allowing the joint to move easily and without friction.
Step 4: Testing and Closing the Incision
Before closing the incision, the surgeon tests the new joint to ensure smooth movement and stability. Once satisfied with alignment and function, the tissues and skin are sutured, and the knee is bandaged.
Recovery and Outlook
Most patients begin gentle movement within 24 hours of surgery. Physical therapy starts early to rebuild strength, improve flexibility, and train proper walking mechanics. Recovery time varies, but most individuals resume normal daily activities within three to six months, with full recovery taking up to a year.
Knee replacement surgery is one of the most successful procedures in modern orthopedics, with the vast majority of patients experiencing significant pain relief and improved mobility. However, it is still a major operation that involves risk, rehabilitation, and a recovery period that requires patience and consistency.
Avoiding Surgery with ONSTIM
Not every patient with chronic knee pain or arthritis needs knee replacement surgery. If the bone structure and joint alignment are still good, an advanced treatment called ONSTIM may offer a way to relieve pain without undergoing major surgery.
ONSTIM uses a small, implantable device that delivers gentle electrical stimulation to the nerves responsible for sending pain signals from the knee to the brain. By disrupting these signals, ONSTIM can reduce or even eliminate knee pain—helping patients stay active and regain comfort without replacing the joint.
The treatment is minimally invasive, preserves the natural anatomy of the knee, and is typically performed as an outpatient procedure. For individuals who want to avoid or delay knee replacement surgery, ONSTIM may be a promising alternative to restore quality of life while maintaining joint integrity.
The Bottom Line
Knee replacement surgery can be life-changing for patients suffering from advanced arthritis or severe joint damage. However, not every painful knee requires replacement. For those whose bones and joint structures remain healthy, ONSTIM offers a new pathway to pain relief—without the long recovery or risks of major surgery.
If you suffer from chronic knee pain and are exploring alternatives to knee replacement, talk to your orthopedic or pain management specialist about whether ONSTIM may be right for you.
