Knee replacement surgery allows for recovery from osteoarthritis and is one of the most reliable medical procedures that has transformed the lives of many patients.
Knee replacement surgery is highly successful and is performed on thousands of patients worldwide.
It allows for recovery from knee osteoarthritis, eliminating pain and stiffness. It is now one of the most reliable and predictable medical procedures, transforming the lives of many patients and allowing them to return to an active, pain-free life.
The surgery enables recovery from chronic degenerative cartilage diseases such as osteoarthritis and it is also the definitive treatment for acute conditions like osteonecrosis.
In total knee replacement the cartilage and bone damaged by the disease are removed and replaced with the prosthesis.
In selected patients a partial prosthesis, also known as a unicompartmental prosthesis, can be used. This is the smallest implantable knee prosthesis: a minimally invasive device that respects the anatomy and allows for rapid recovery.
Types of procedures: conservative treatment or surgery?
In most cases knee replacement is recommended for advanced osteoarthritis, especially when conservative therapy fails (injections, physical therapy, medications, etc.) and is no longer effective.
Knee osteoarthritis, or gonarthrosis, is a chronic degenerative condition characterized by the progressive destruction of the articular cartilage, resulting in joint deformity, inflammation and pain.
The pain may be widespread throughout the knee or localized to the inner part (medial osteoarthritis), the outer part (isolated lateral osteoarthritis) or the front.
In the early stages osteoarthritis can benefit from:
- weight loss
- rehabilitation aimed at muscle strengthening and stretching
- use of cartilage supplements
- cryotherapy (ice packs)
- anti-inflammatory medications
- joint injections
As the disease progresses, it becomes impossible to play sports and walk or climb stairs without pain.
Some patients may even experience pain at night, making it difficult to rest and get up from a sitting position.
In advanced stages, unfortunately, conservative treatments are no longer effective and prosthetic surgery becomes necessary.
Prosthetic surgery
For patients, who have developed widespread knee osteoarthritis or who suffer from autoimmune diseases such as rheumatoid arthritis, total knee replacement is recommended.
Patients with osteoarthritis in only one part of the knee may benefit from a unicompartmental prosthesis, ensuring even faster recovery.
To identify candidates for prosthetic surgery the orthopedic specialist must examine the patient and review weight-bearing X-rays of the knee.
The outpatient visit with the orthopedic surgeon is the first step to evaluate the need for knee replacement. It’s important to note that not all patients require surgery and not all knee pain can be cured with a prosthesis.
Identifying a surgeon specialized in knee replacement surgery is the best guarantee of a good outcome.
The procedure is recommended when the X-ray shows severe osteoarthritis with bone-on-bone contact and the presence of any of the following symptoms:
- pain resistant to painkillers
- constant pain even at rest
- difficulty standing for long periods
- inability to perform daily activities such as walking or climbing stairs
- pain while walking
- significant difficulty getting up from a sitting position
- difficulty sleeping at night due to pain
- limited joint mobility that impairs daily activities
- no or limited benefit from physical therapy and conservative treatments.
Characteristics of knee prosthesis
As mentioned, conservative therapies help to feel a bit better, but the only way to definitively cure osteoarthritis is knee prosthetic surgery.
The total knee prosthesis consists of four components:
- the femoral shield is made of metal, usually titanium, coated with alloys that reduce friction and wear during movement (one of the most common is cobalt-chromium). Once positioned, it covers the articular part of the femur;
- the tibial component is made of titanium and usually has a small stem that enters the tibial bone for a few centimeters to increase stability;
- a polyethylene insert, a highly resistant plastic material with very low friction during prosthesis movement, is placed on the tibial component;
- the patellar component is a polyethylene button applied to the patella when this bone is also damaged by osteoarthritis or when the joint is affected by a rheumatologic disease.
In total knee replacement the entire knee surface is covered by the prosthesis; in compartmental replacement only the damaged part is covered, while the rest of the knee remains unchanged.
Moreover, each prosthesis is customized according to the patient’s needs.
There is no single prosthesis suitable for all patients; the treatment path must be personalized starting from the choice of the implant.
How does knee replacement surgery work?
The orthopedic surgeon’s effort is directed towards ensuring the patient’s safety and well-being during surgery.
The procedure begins with anesthesia administration: the safest and most commonly used is spinal anesthesia, a single injection in the lower part of the spine with a very thin needle, combined with a sedative if the patient wishes to sleep.
Spinal anesthesia is painless, reduces the risk of venous thrombosis and bleeding and improves postoperative pain control.
Once the patient is positioned on the operating table and the limb is disinfected, the damaged parts are replaced with the prosthetic components.
The surgery, which lasts about an hour, ends with the suturing of the incision and its dressing.
Finally, the wake-up phase can have a variable duration.
From the time the patient leaves the operating room to the moment they return to the ward, it takes about 2-3 hours: the return from the operating room occurs without a urinary catheter and without surgical drainage.
Once the anesthesia effect wears off, the patient can get up and walk with the physical therapists: the next day they can walk a longer distance and the day after even climb stairs.
Overall hospitalization lasts 3-4 days.
If necessary hospitalization can be extended for physical therapy; otherwise an outpatient or home physical therapy program can begin, even through the MyMobility app adopted by Dr. Vanni Strigelli.
Modern materials and advanced designs of modern prostheses allow for long implant survival.
Prostheses last more than 20 years in 90% of patients and more than 25 years in 80% of patients.
It is important to have an annual follow-up X-ray and orthopedic check-up.
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