Partial Knee Replacement - Procedure, Benefits and Recovery

Partial knee replacement surgery is also called unicompartmental knee replacement/partial knee resurfacing surgery/unicondylar knee replacement/unicondylar knee arthroplasty. This surgery is an alternative treatment to total knee replacement for individuals with knee osteoarthritis. In this surgery, the damaged compartment of the knee is replaced with an implant.

 

The benefits of partial knee replacement surgery are:

1. Faster recovery period
2. Shorter hospital stay
3. Gives more natural knee movement
4. Make the patient more active compared to total knee replacement
5. Improved mobility
6. Free from pain
7. Improved quality of life due to increased exercise and daily activity
8. Preservation of knee function and range of motion
9. Less blood loss
10. Lower risk of blood clots and infection 

Individuals with the following conditions need the procedure: 

1. Rheumatoid arthritis refers to an autoimmune disease affecting the joints.
2. Post-traumatic arthritis refers to arthritis that forms after a trauma.
3. Moderate deformity of the knee
4. Stable ligaments in the knee
5. Good range of motion of the knee
6. Medial knee osteoarthritis refers to osteoarthritis of the inner compartment of the joint, which is close to the opposite knee.
7. Lateral knee osteoarthritis refers to osteoarthritis of the outside compartment, which is far away from the opposite knee.

If the surgery is delayed, the osteoarthritis of the patient can worsen and cause symptoms like: 

1. Joint inflammation
2. Stiffness and pain in the joint
3. Limitation in the range of motion

The surgeon will: 

1. Make a cut over the knee to look at the knee thoroughly. 
2. Remove the damaged bone and tissue. 
3. Place a part made from metal or plastic into the knee. 
4. Attach the metal or plastic with bone cement. 
5. Stitch the cut.

The surgery takes around 60 to 90 minutes.

 

The surgeon will: 

1. Go through your complete medical history
2. Do your comprehensive physical examination
3. Explain the entire surgical procedure
4. Do blood tests and other diagnostic tests 
5. Ask if you are allergic to tape, latex, any medicines, and anaesthesia (general and local) 
6. Ask about the prescribed and over-the-counter medications, or herbal supplements
7. Ask about the history of a bleeding disorder or intake of any blood-thinning medication (aspirin) 
8. Tell you to stop taking blood-thinning medicine before the surgery
9. Ask whether you are pregnant or if there are chances of getting pregnant
10. Tell you to arrange for help for one or two weeks after the surgery
11. Suggest you consult the doctor for medical conditions like heart diseases, diabetes, or other conditions
12. Tell you to stop taking medication that weakens the immune system (methotrexate, enbrel) 
13. Ask you about your alcohol drinking habits
14. Tell you to stop smoking for faster recovery
15. Ask whether you have flu, cold, herpes, or other condition
16. Suggest you practise walking using a walker, cane, wheelchair, or crutches

The doctor will:

1. Ask you to fill out the consent form
2. Tell you when to arrive at the hospital
3. Tell you to take medicines with a sip of water

1. Position during surgery: You will be placed in a supine position (lying on the back with face upwards) with the knee flexed at 900.
2. Cleaning and Draping: Proper draping and cleaning will be done to prevent infection and protect your privacy and comfort.
3. Anaesthesia: You will be either given: 
   1. General anaesthesia: Puts you to sleep
   2. Regional anaesthesia (epidural or spinal): Numbs the region below the waist
4. Implant: An implant called a prosthesis might be placed after removing the damaged compartment of the knee. The implant is made of plastic and metal.

 

The recovery process in the hospital:

The doctor will inform the following things to you: 

1. To start moving the knee after the surgery 
2. Can go home the same day or after one day of the surgery 
3. Teach you physical therapy to strengthen the knee muscles and enhance the range of motion.
4. Prescribe pain-relieving medicines such as opioids, local anaesthetics and non-steroidal anti-inflammatory drugs (NSAIDs).

The recovery process after hospital discharge:

The doctor will inform the following things to you:

1. To walk without a walker or cane within three to four weeks after the surgery
2. Keep the surgical region dry and clean. 
3. Apply an ice pack to the knee and elevate the knee to lower the swelling.
4. To do physical therapy for three to four months
5. Can do physical exercises like swimming, walking, golf, tennis, and biking 
6. Avoid high-impact exercise like jogging.
7. You can resume work, depending on the job profile. If you have a desk job, you can continue work after six to eight weeks; on the other hand, if the job involves manual work or standing for a longer time, you can resume work after 10 to 12 weeks of the surgery.
8. You will mostly be able to resume all the daily activities after six weeks of the surgery.

First Follow-up Appointment

The first follow-up appointment will be around six weeks after the surgery to assess the recovery.

 

Possible side effects that can normally occur after the surgery are: 

1. Bleeding from the surgical site
2. Pain at the surgical site
3. Blood clot in the leg
4. Allergic reaction to medicines, equipment, or materials
5. Difficulty in urine passage
6. Scarring of skin
7. A build-up of fluid in the knee joint
8. Rarely, Reflex sympathetic dystrophy (severe burning pain in the extremities)
9. Chest infection
10. Stroke
11. Heart attack

Risk/complications of the surgery: 

1. Stiffness, severe pain, and loss of ability to use the knee
2. Blood vessels behind the knee might be damaged.
3. Nerves surrounding the knee might be damaged.
4. A bearing dislocation occurs when a plastic piece comes out of place in the middle of the knee replacement surgery.
5. Infection in the surgical area or knee