Partial Knee Replacement (Unicompartmental Knee Replacement) in Bristol & Bath

A partial knee replacement (also called a unicompartmental knee replacement or UKR) is an operation that replaces only the damaged part of the knee, rather than the whole joint. It is most commonly used when arthritis mainly affects one compartment of the knee (often the inner/medial side).

Mr Simon Abram, Consultant Specialist Knee Surgeon, provides assessment and treatment for partial knee replacement in Bristol and Bath. For the right person, a partial knee replacement can provide excellent pain relief with a more “natural-feeling” knee and, in many cases, a faster recovery than a total knee replacement. The key is careful assessment and choosing the option that best matches your knee pattern, lifestyle and goals.

What is a partial knee replacement?

Your knee has three main “compartments”:

Medial compartment (inner side)
Lateral compartment (outer side)
Patellofemoral compartment (behind the kneecap)

In a partial knee replacement, only the worn compartment is resurfaced with metal and plastic components. The rest of the knee (including much of the bone, cartilage and ligaments) is preserved.

Why people consider a partial knee replacement

Most people consider surgery because knee pain is limiting daily life despite good non-surgical treatment. Typical goals include:

Reducing pain from arthritis
Improving walking distance and confidence
Getting back to activities such as hiking, cycling, gym work or golf
Reducing reliance on painkillers

Assessment with Mr Simon Abram (Bristol & Bath)

Choosing the right treatment starts with a clear diagnosis and an accurate understanding of which part of the knee is causing symptoms. Mr Simon Abram offers specialist assessment for knee arthritis and suitability for partial knee replacement in Bristol and Bath.

Assessment usually includes:

History: where the pain is, what triggers it, and what you’ve tried already
Examination: alignment, stability, range of motion, tenderness and kneecap tracking
X-rays: typically weight-bearing views to show the pattern and severity of arthritis
MRI scan (sometimes): helpful if the pattern is unclear or to assess cartilage/meniscus/ligaments

The main aim is to confirm whether your arthritis is predominantly in one compartment and whether a partial knee replacement is the best option for your knee and your goals.

Who is (and isn’t) suitable?

A partial knee replacement works best when arthritis is mainly confined to one compartment and the rest of the knee is in good condition.

You may be a good candidate if:

Your pain is mainly from one side of the knee (often the inner side)
Imaging suggests arthritis is predominantly in one compartment
Your knee is reasonably stable and the deformity is correctable
You have a functional range of movement (your knee bends and straightens reasonably well)
Ligaments (especially the ACL) are functioning well for your knee pattern

A total knee replacement may be more appropriate if:

Arthritis is significant in more than one compartment
There is marked stiffness, major deformity that is not correctable, or significant instability
There is widespread inflammatory arthritis affecting the whole knee

Suitability is assessed on your symptoms, examination findings and imaging, not just age.

Non-surgical options (often tried first)

Many people benefit from a structured plan before considering surgery. Depending on your situation, this can include:

Targeted physiotherapy (strength, balance, movement control)
Weight management and activity modification
Simple pain relief and anti-inflammatory medication (if appropriate for you)
Injections (such as corticosteroid; other options may be considered case-by-case)
Knee brace for compartment unloading (in selected cases)

If symptoms remain limiting despite good non-surgical care, Mr Simon Abram can advise whether surgery is appropriate and which option is most likely to give you a reliable outcome.

Partial vs total knee replacement

Potential advantages of a partial knee replacement

Smaller operation with less disruption to the knee
Often faster recovery and earlier return to function
Many patients report a more natural-feeling knee
Preserves healthy bone and ligaments

Potential limitations

It is only suitable for specific arthritis patterns
Arthritis can progress in the other compartments over time
Some patients may eventually need a revision (conversion to a total knee replacement)

The best choice is the one that fits your knee and your goals–not simply “partial is better” or “total is better”.

What happens during the operation?

While the exact approach varies, a typical partial knee replacement involves:

Removing the worn cartilage and a small amount of underlying bone in the affected compartment
Placing a metal component on the femur and tibia
Inserting a plastic bearing to create a smooth, low-friction surface

In selected cases, additional planning tools or computer/robotic assistance may be used to support accurate positioning and balance of the knee. Mr Simon Abram will discuss what is appropriate for your situation during your consultation in Bristol or Bath.

Anaesthetic and hospital stay

Usually performed with a spinal or general anaesthetic, often with additional pain-control techniques
Many patients go home the same day or after an overnight stay, depending on comfort, mobility and support at home

Recovery and rehabilitation

Recovery is individual, but most people follow a staged plan focusing on swelling control, regaining movement and rebuilding strength. Mr Simon Abram will outline what to expect and how rehabilitation is typically structured after surgery.

Typical milestones (guide only)

First 1–2 weeks: walking little and often, swelling control, gentle exercises, short outdoor walks as tolerated
Weeks 2–6: improving walking distance, stair confidence, strengthening and restoring normal gait
Weeks 6–12: building endurance and function; returning to many day-to-day activities comfortably
3–6 months: continued gains in strength and confidence for higher-level activities (often with ongoing rehab)

Driving and work

Driving: depends on which leg was operated on, your control and reaction times, and insurance requirements
Work: desk-based roles may return earlier; physically demanding jobs often need longer

Your rehabilitation plan should be tailored to you, including clear goals and progression criteria.

Risks and complications

All operations carry risk. Your surgical team should discuss your individual risk profile. Potential risks include:

Infection
Blood clots (DVT / pulmonary embolus)
Stiffness or prolonged swelling
Persistent pain (rarely, pain may not improve as expected)
Progression of arthritis in other compartments
Loosening, wear, or need for further surgery over time

When to seek urgent advice after surgery

Increasing redness, heat, wound leakage, fever or feeling unwell
New calf pain/swelling, chest pain or shortness of breath
Sudden inability to weight-bear or a dramatic change in knee function

How long does a partial knee replacement last?

Longevity varies between individuals. Implant survival depends on factors such as your arthritis pattern, activity level, body weight, bone quality, alignment and surgical technique. Many people do very well for years, but some may need further surgery later–most commonly conversion to a total knee replacement if arthritis progresses elsewhere or if components wear/loosen.

Frequently asked questions

Is a partial knee replacement less painful than a total knee replacement?

Many patients find the early recovery more manageable because less of the knee is resurfaced. Pain control still matters, and rehabilitation is still essential.

Will it feel more “natural” than a total knee replacement?

Because more of your own knee structures are preserved, many people report a more natural-feeling knee. Outcomes vary, and the best predictor is whether the operation matches your arthritis pattern.

Can I kneel after a partial knee replacement?

Some people can kneel, but it can remain uncomfortable. Technique, soft tissue sensitivity and confidence all play a role. Your physiotherapist can help you practise safely.

Can I return to sport?

Many people return to low-impact sports such as cycling, swimming, hiking and gym work. Higher-impact or pivoting sports can be possible for some, but should be discussed individually based on your knee, fitness and goals.

What if my arthritis is on the inner side but I also have kneecap pain?

This is common. The key question is whether the kneecap joint has significant arthritis or whether the pain is mainly from the worn compartment. Careful assessment and imaging help guide the best option.

Can Mr Simon Abram assess me for a partial knee replacement in Bristol or Bath?

Yes. Mr Simon Abram is a specialist in the assessment and treatment planning for partial knee replacement in Bristol and Bath, including advice on non-surgical options, suitability for UKR, and surgical planning where appropriate.