Partial Knee Replacement: Procedure and Recovery

What is partial knee replacement?

Partial knee replacement, also known as unicompartmental knee arthroplasty, is a surgical procedure to replace damaged cartilage in the knee joint. This flexible connective tissue can get damaged by various types of arthritis, osteoarthritis, or external impacts.

Unlike total knee replacement, which replaces the entire knee joint, this procedure only replaces the damaged compartment, either the medial (inner), lateral (outer), or patellofemoral (front). 

This less invasive approach can result in a faster recovery time, less postoperative pain, and a more natural knee movement post-surgery.

When should you consider partial knee replacement? 

When someone has mild osteoarthritis or other knee pain condition, healthcare providers will usually suggest a non-surgical treatment. However, if the symptoms persist and the condition does not improve despite treatment, surgical intervention may be necessary.

Some symptoms that indicate the need for this procedure include:

• Persistent pain: 

  • Severe pain that lasts for more than a few weeks despite basic treatment, such as the RICE method or nonsteroidal anti-inflammatory drugs (NSAIDs).

• Swelling and inflammation: 

  • Significant swelling or inflammation in the damaged cartilage.

• Stiffness: 

  • Difficulty moving the knee, which gets tight and uncomfortable after a long period of sitting.

• Loss of function: 

  • Inability to stand up or walk without significant pain.

• Popping sounds: 

  • Popping sounds that come from the knee joint when moving can be a sign of joint degradation.

If you are experiencing these symptoms and need a thorough evaluation, don’t hesitate to request an appointment at Thomson Medical. Our orthopaedic specialists are ready to provide you with an accurate diagnosis and a personalised treatment plan, including surgery.

What to expect during the procedure

In the partial knee replacement  procedure, the damaged knee cartilage is removed and replaced with an artificial joint, known as a prosthesis. The primary goal of this surgery is to relieve pain and restore natural knee movement. 

Here’s a breakdown of the procedure:

Pre-surgery preparation

Before undergoing surgery, an orthopaedic surgeon will do several assessments to ensure you are a suitable candidate for the procedure 

• Pre-operative consultation: 

  • During this stage, your doctor will discuss your symptoms, enquire about any medications you are currently taking, and examine your medical history.

  • They will also verify that you do not have specific health conditions that could complicate your recovery, such as haemophilia, diabetes, or other autoimmune disorders like lupus.

  • The doctor will also go over the risk of complications based on your particular conditions.

• Physical examination:

  • Your doctor will conduct a thorough examination of your knee to determine the location of the pain. If it's located on the medial compartment or lateral compartment of the knee, you're eligible for this surgery.

  • However, if you experience persistent pain across the entire knee joint or specifically beneath the kneecap, a total knee replacement may be more suitable for you.

  • Additionally, your doctor will assess your knee's range of motion. If the knee is excessively stiff or if the ligaments feel weak or damaged, a unicompartmental knee replacement might not be the best option.

• Anaesthesia:

  • Before the surgery begins, your anaesthesiologist will discuss your anaesthesia options with you.

  • These options include general anaesthesia, which induces a deep sleep, and regional anaesthesia, where you remain awake while your lower body is numbed.

Surgical steps

Once the partial knee replacement surgery begins, patients will receive anaesthesia, allowing the procedure to commence. The surgery can last between one and two hours.

• Incision: 

  • An incision around 10-15 cm is made over the affected area.

• Joint exposure: 

  • The surgeon carefully exposes the damaged part of the knee.

• Bone preparation: 

  • Damaged bone and cartilage are removed from the damaged compartment.

• Implant placement: 

  • A prosthetic implant is carefully positioned, along with the insertion of a plastic spacer that mimics the smooth cushion provided by healthy cartilage.

• Closure: 

  • The incision is closed with stitches or staples, and a dressing is applied.

Immediate postoperative care

Following the unicompartmental knee replacement procedure, you will be closely monitored as you wake up from the anaesthesia. Depending on your recovery, you may either be discharged home the same day or moved to a hospital room for an overnight stay if needed.

Recovery

After the surgery is concluded, it's common to experience some postoperative pain and swelling. To effectively manage these symptoms and support your rehabilitation, your surgeon will provide you with a personalised recovery plan.

However, you can do these steps to achieve shorter recovery time, such as:

• Ice pack: 

  • Apply an ice pack to the injured area to reduce swelling and pain post-surgery. Do this for 15-20 minutes at a time, several times a day.

• Elevate your knee: 

  • Keep your knee raised above the level of your heart to reduce swelling and promote proper blood flow. You can use pillows or a cushion to prop up your leg while sitting or lying down. 

• Medications:

  • Non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen or naproxen help reduce pain levels and inflammation.

• Keep your incision clean and covered:

  • Follow your surgeon's guidelines for incision care, such as when to change the dressing and when it's safe to shower, to ensure faster recovery time.

• Home exercises: 

  • Exercises are necessary for strengthening the muscles surrounding your knee, preventing stiffness, improving quality of life, and enhancing your range of motion.

• Follow-up appointments:

  • Schedule regular check-ups with your orthopaedic surgeon to monitor your health conditions and ensure that the knee implants fit properly to do normal activities.

• Physical therapy: 

  • For several weeks after your surgery, a physical therapist will give you exercises to help maintain your range of motion and restore your strength.

  • These exercises focus on regaining balance, adapting to the new knee, and strengthening the muscles surrounding the knee joint.

By adhering to these recovery steps, most patients can return to daily activities within six weeks post-surgery. More vigorous activities may be possible within three to six months, depending on individual progress. 

Here's a video of a 73-year-old patient who was able to complete full squats following knee replacement surgery conducted by Dr. Jerry Chen, an orthopaedic specialist at Thomson Medical.

Cost of partial knee replacement in singapore

The cost of partial knee replacement surgery can vary depending on factors such as the hospital, the surgeon's experience, and the type of implant used. 

In general, here are the costs of this procedure in Singapore:

• Estimated cost: 

  • In Singapore, the cost ranges from SGD 20,000 to SGD 35,000. Which already includes hospital fees, surgical procedures, anaesthesia services, and postoperative care.

• Available payment options:

  • MediSave

  • Health insurance coverage

  • MediShield Life

  • Integrated shield plans

However, there are several important things you should keep in mind:

• Actual costs may vary based on individual medical conditions

• Additional charges may apply for complications or extended care

• Pre-surgical consultations and follow-up visits may incur separate fees

• Fees are subject to change

The information provided above is intended for general reference only. For detailed fee information and payment options, please consult with healthcare providers and insurers directly.

Potential post-surgery complications

As with any surgical procedure, there is a risk of complications associated with this surgery. However, your surgeon will carefully review these risks with you and take proactive measures to reduce the chance of potential risks beforehand.

Here are complications that might happen post-surgery, including:

• Bleeding

• Blood clots

• Infection at the surgery site

• Nerve damage

• Blood vessel damage

• Problems with the prosthetic implants, including the device wearing down too soon or loosening

• Scar tissue inside your knee

• Reduced range of motion and stiffness

• A total knee replacement in the future, if arthritis starts affecting healthy knee compartments

FAQ

What is the downside of a partial knee replacement?

Although this procedure can help you return to normal activities, after 10 to 15 years, the partial knee implants will gradually wear out. Factors such as age, activity level, and body weight can impact their durability.

How long does it take to fully recover from partial knee replacement?

Full recovery usually took around six weeks, with an additional three to six months needed for more vigorous activities. However, you can begin moving and walking with the help of physical therapists immediately after the procedure.

What's the difference between partial and full knee replacement?

Unlike total knee replacement, which replaces the entire knee joint, this procedure only replaces the damaged compartment, either the medial (inner), lateral (outer), or patellofemoral (front) of the knee.

Is a partial knee replacement done as an outpatient surgery or an overnight stay?

Depending on the assessment by a healthcare professional, you may either be discharged home the same day or may require an overnight stay in a hospital room for further observation if necessary.

Can I run with a partial knee replacement?

After the surgery, patients usually can begin walking almost immediately. But returning to running or other high-impact activities may take longer, often requiring at least six months of recovery.

How to strengthen the knee after partial knee replacement?

To help strengthen your knee after partial knee replacement, a physical therapist will create a personalised exercise program. These exercises are aimed to improve balance, help your body adapt to the new knee, and strengthen the muscles surrounding it.

The information provided is intended for general guidance only and should not be considered medical advice. For personalised recommendations and tailored advice, please consult a specialist at Thomson Medical. Book an appointment with Thomson Medical today.