Partial Knee Replacement Surgery

Disadvantages over total knee replacement surgery

Survivorship: The average survivorship of partial knee replacement is in the range of 8–10 years. Generally, after this period, either the rest of the knee joint develops progressive arthritis or components loosen or wear out, necessitating total knee replacement surgery

Ongoing pain/lack of full function: Some patients complain of ongoing pain or lack of full function after partial knee replacement due to some pre-existing arthritis in the other two native compartments of the knee joint.

Patient Selection

I choose my patients very carefully for partial knee replacement in order to achieve a successful outcome. This is done by careful history taking, focused clinical examination, and appropriate investigations. Investigations can include X-rays and occasionally MRI scans. In some cases, knee arthroscopy procedure may need to be carried out to assess the degree of arthritis in the joint and determine the suitability for partial knee replacement.

Physiologically young patients are best suited for this type of procedure; however, age is not the absolute criterion for partial knee replacement surgery.

Types of Partial Knee Replacement Surgery

The most commonly performed partial knee replacement involves replacing the medial compartment (inner part of the knee). Due to the biomechanics of the knee joint, the medial compartment of the knee develops progressive arthritis ahead of the other two compartments in the vast majority of the patients. Very occasionally, partial knee replacement of either the lateral compartment (outer part of the knee) or of the patellofemoral compartment (behind the knee cap) can be considered.

Based on how the bearing surface is fixed on to the components, partial knee replacement can be mobile-bearing or fixed bearing. However, studies have not shown any significant difference in clinical outcomes between the two types of knee replacement. In my practice, I use fixed bearing partial knee replacement.

Risks and Benefits

Overall, partial knee replacement is a very successful operation in modern-day surgery. In my practice, the success rate of a partial knee replacement is around 85-90%. Pain relief and improvement in the quality of life is substantial in the vast majority of patients. Partial knee replacement helps patients maintain an active life including sporting activities.

Risks of partial knee replacement include infection (around 1%), bleeding, DVT (clots in your leg), PE (clots in your lung), stiffness, loosening, wear, persistent pain (around 2-3%), need for further surgery, medical and anesthetic complications. Precautions are taken in order to minimize all the above risks e.g. use of antibiotic prophylaxis and specialized laminar airflow theatres to minimize the risk of infection, use of blood-thinning medications, and mechanical methods to reduce the risk of clots, etc. Post-operative exercises are extremely important to gain/maintain a good range of flexion after the surgery.

Rehabilitation and Recovery

You are generally admitted to the hospital on the day of surgery. The average length of stay in the hospital is 2-3 days. During the hospital stay, a multi-disciplinary team including an orthopaedic team, ward doctor, nursing staff, physiotherapist, and occupational therapist, treats you. Once you and the team are happy with the progress, you are discharged from the hospital.

Post-operative mobilization includes the use of walking aids like walkers or crutches, to begin with. You can subsequently use the walking stick/s until independent mobility can be achieved. Most patients can hope to regain independent mobility after 3-4 weeks.

You can expect some swelling and redness around the wound and of the lower leg for a few weeks. Generally, by 6 to 12 weeks, nearly full recovery can be expected in most patients. Most patients can expect to drive around 3-4 weeks mark.

Implants of My Choice

Currently, my preferred implants are PFC Sigma Higher-Performance Partial Knee System (manufactured by Depuy Synthes).

• Unicompartmental Knee Replacement

Frequently Asked Questions

Q1. Is it worth doing a partial knee replacement?
Yes, for suitable candidates, a partial knee replacement can be worth it, offering a faster recovery, less pain, and a more natural feel than a total knee replacement, with fewer serious complications.

Q2. What is the recovery time for a partial knee replacement?
A partial knee replacement has a quicker recovery than a total knee replacement, with most patients being comfortable walking without aids within 6 to 8 weeks, and returning to work within 6 to 12 weeks, depending on their job’s physical demands. Full recovery and achieving the highest level of activity can take 6 to 12 months, although improvements can continue for up to two years.

Q3. What is the success rate of partial knee replacement?
Partial knee replacement success rates are high, with many studies showing 90% or higher survival rates at 10 years. Patients often experience excellent outcomes and high satisfaction, though a common cause for failure is the progression of arthritis in the unoperated part of the knee.

Q4. How long does a hospital stay for knee replacement surgery take?
A hospital stay after knee replacement surgery varies, with many people going home the same day or the day after, while others may stay for 1 to 3 days, or even longer depending on their individual needs and recovery progress.

Q5. What is the best age to have a partial knee replacement?
There isn’t a single “best” age for a partial knee replacement, as it depends on individual factors like overall health, arthritis severity, and lifestyle, rather than a specific age.

Q6. What is the cost of partial knee replacement in UK?
In the UK, private partial knee replacements generally cost between £9,000 and £18,000, with average prices typically around £11,500 to £12,500, though costs vary based on the hospital, surgeon’s expertise, location, and type of implant used.

Q7. How soon can you drive after a partial knee replacement?
You can typically resume driving after a partial knee replacement in about three to six weeks, but the exact timeline depends on your individual recovery and ability to perform an emergency stop comfortably and safely.

Q8. Who is not a candidate for partial knee replacement?
A patient is not a candidate for partial knee replacement if their arthritis is spread across multiple knee compartments, they have significant ligament damage, significant knee stiffness, inflammatory arthritis like rheumatoid arthritis, or a significant knee deformity.

Q9. Which is better, a partial or full knee replacement?
Neither a partial nor a full knee replacement is inherently “better”; the superior choice depends on individual factors like the extent of arthritis, knee ligament health, and activity level, but generally, a partial replacement offers a more natural feel, faster recovery, and better function for suitable candidates.

Q10. Who is the best knee replacement surgeon in UK?
One of the best knee replacement surgeons in the UK is Professor Kuntal Patel, a highly experienced consultant specialising in hip and knee replacements with excellent patient satisfaction and results.

Q11. Who should avoid knee replacement surgery?
People should avoid knee replacement surgery if they have an active infection, severe systemic health issues like advanced heart or lung disease, or if they have not yet experienced significant pain and disability from knee damage.

Q12. What is the biggest complaint after knee replacement?
The most common complaint after knee replacement surgery is ongoing pain and stiffness, often linked to limited bending and difficulty with daily activities, though most patients are satisfied with the outcome and improvement in their lives.

Q13. What is the newest alternative to knee replacement?
The newest alternatives to knee replacement include Genicular Artery Embolization (GAE), Arthrosamid® hydrogel injections, and cartilage regeneration treatments like MACI or stem cell therapy. These methods reduce pain, improve movement, and may delay or avoid full knee replacement.

Q14. What percentage of people are happy with their knee replacements?
Approximately 87% to 90% of people are satisfied with their knee replacement results, considering them “excellent, very good, or good,” while 75-90% feel their problems are better after the operation.

Q15. What is the fastest way to recover from a knee replacement?
The fastest way to recover from a knee replacement is by actively participating in your recovery, which involves early movement and physiotherapy, effective pain management, maintaining a healthy lifestyle including a nutritious diet and sufficient rest, and following your surgeon’s instructions closely, such as using walking aids and elevating your leg.