If you have elderly people at home who are facing problems with osteoarthritis, chronic knee pain, or are deciding whether to undergo knee replacement surgery, we have answers to your questions about osteoarthritis and knee replacement surgery.
Q: What are the characteristics of ‘osteoarthritis’?
A: It is important to understand that our knee joint resembles a hinge, with the rounded end of the femur and the flat, shallow concave top of the tibia connected by four strong ligaments on the sides and in the middle (anterior and posterior cruciate ligaments). The upper edge of the patella is attached firmly by the quadriceps muscle, and the lower end of the patella is connected to the upper part of the tibia by the patellar tendon. The patella plays a crucial role in transmitting force through the knee, especially when extending the knee.
Our knee joint consists of three main parts:
- The end of the femur (Femur)
- The top of the tibia (Tibia)
- The patella (Patella)
The knee joint is formed by the connection of the tibia and femur ends. Both ends are covered with cartilage to help absorb shock. The front of the knee has the patella, which acts as a lever to facilitate knee extension and flexion. Around the joint, there is an inner synovial membrane and outer ligaments to provide strength to the knee.
Osteoarthritis is the degeneration of the cartilage covering the ends of the femur, tibia, and patella. Sometimes, inflammation of the synovial membrane causes increased fluid production, leading to more pain, limited knee bending, and swelling compared to the normal side. If left untreated, cartilage damage worsens, increasing pain. When standing or walking, weight is transferred to the thigh muscles and then to the knee. Strong thigh muscles can bear more weight, reducing the load on the knee. Weak thigh muscles bear less weight, increasing the load on the knee.
Q: What are the factors that cause osteoarthritis?
A: There are several factors that contribute to osteoarthritis, including:
- Age – Older age increases the risk of osteoarthritis due to prolonged use of the knee joint.
- Gender – Women have twice the rate of osteoarthritis compared to men because women generally live longer and thus use their knees longer. Additionally, women tend to gain weight more easily, which increases knee wear.
- Weight – Being overweight accelerates knee degeneration.
- Lifestyle habits – People who frequently squat, sit cross-legged, or sit on their heels for long periods are more likely to develop osteoarthritis earlier.
- Knee injuries – Accidents causing fractures or ligament tears in the knee can lead to faster osteoarthritis development.
- Muscle and bone strength – People who do not exercise regularly are at higher risk of osteoarthritis compared to those who exercise consistently, as regular exercise strengthens muscles and bones.
Q: How do you know when it’s time for ‘knee replacement surgery’?
A: Knee replacement surgery involves removing the damaged joint surface and replacing it with synthetic metal components, usually made of titanium, cobalt-chromium, ceramic, and special plastic. Surgery is indicated when it can reduce knee pain, correct deformities, prevent further joint degeneration, and when conservative treatments (physical therapy, massage, bone adjustment, acupuncture, anti-inflammatory medication, herbal remedies, steroid injections, joint lubrication injections) have not yielded satisfactory results.
Q: How should patients prepare before surgery?
A: 1. Preoperative physical examination: Patients will undergo a physical exam and meet with an internist to prepare their body for surgery. Tests include blood tests, urine tests, chest X-rays, electrocardiograms, and other special tests as needed.
2. Preoperative patient instructions:
- Stop smoking to prevent complications during anesthesia, respiratory infections, and circulatory system complications.
- Maintain good hygiene of the body, mouth, teeth, and reproductive organs. For example, treat tooth decay, ingrown nails, or bladder infections before surgery.
- Avoid shaving hair on both legs for 5 days before surgery to prevent postoperative infections.
- Control diet to maintain appropriate body weight.
- Relax and get enough rest.
3. Medications patients should take before surgery:
- Patients taking heart or blood pressure medications should continue taking them regularly until the day of hospital admission.
- Patients taking oral or injectable diabetes medications should continue regularly but stop taking or injecting them on the morning of fasting before hospital admission.
- Patients taking anti-inflammatory drugs for conditions like rheumatoid arthritis should consult their doctor about stopping medication 2 weeks before surgery.
- Patients taking non-steroidal anti-inflammatory drugs (NSAIDs) such as Ibuprofen, Naproxen, Diclofenac, etc., should consult their doctor about stopping these medications before surgery.
4. Prepare the recovery area at home:
- Arrange a suitable living space for post-surgery life, such as setting up a bedroom on the ground floor for the first 1-2 weeks after surgery.
- Keep the home tidy and free of obstacles in walkways.
- Install grab bars in the bathroom and replace squat toilets with Western-style toilets.
- Ensure adequate lighting to prevent accidents at night.
- Prepare a chair for sitting after surgery that is not too low and has armrests for ease of sitting and standing.
Q: What items should be brought to the hospital?
A: Recent physical exam results, blood test results, and knee X-ray films from other hospitals (within 3 months, if available). Bring regular medications with the name and dosage labeled on the packaging (if any). Glasses, dentures (if any). Walking aids (walker) if convenient, for use after surgery. Cold gel packs for knee icing after surgery. Items not recommended to bring include jewelry, valuables, or items that may be lost.
Q: What is the nature of the surgery?
A: During surgery, the doctor will make an 8-10 cm incision over the knee to remove the damaged cartilage surfaces of the femur (up to 9-10 mm thick), tibia (up to 10 mm thick), and patella (up to 8 mm thick, only if necessary to replace the patellar surface). These removed parts are the worn joint surfaces.
The surgery is not just about removing the damaged bone. The doctor will also adjust the tension of the tissues around the knee to restore normal leg shape, prevent deformity, and ensure correct placement of the prosthetic surfaces. Proper positioning helps the patient walk well and extends the lifespan of the prosthesis. The doctor will also test the joint’s movement to achieve the best outcome for the patient.
The Muscle, Bone, and Joint Center at Phyathai 3 Hospital provides systematic care for all patients with a team equipped with specialized knowledge, understanding, and extensive experience. Our team includes orthopedic surgeons specializing in joint replacement, nurses, physical therapists, nutritionists, and pharmacists who are ready to care for patients before and after surgery to enhance treatment effectiveness and help patients regain healthy joints.
Muscle, Bone, and Joint Center, Phyathai 3 Hospital, 1st Floor
For appointments or inquiries, contact Phyathai Call Center 1772 or
Tel. 0-2467-1111 ext. 3100 and 3112 Hotline 084-0258915