Is it time for a partial knee replacement?
When arthritis in just one part of the knee starts stealing your sleep, your walks and your independence, a partial knee replacement can give them back – often with a smaller operation and quicker recovery than a full knee replacement. Mr Ashwin Unnithan is a Consultant Orthopaedic Surgeon with a specific clinical interest in unicompartmental knee replacement, and at your consultation he reviews your imaging with you and discusses every option, including non-surgical measures, so surgery is only recommended when it is genuinely the right choice.
Mr Unnithan offers both conventional and robotic-assisted partial knee replacement, using implants with excellent long-term performance data recorded on the National Joint Registry, and plans surgery around your own anatomy and activity level rather than a standard template.
You might recognise these signs
- Knee pain confined mainly to one side of the joint
- Night pain that disturbs your sleep
- Walking distance shrinking month by month
- Painkillers no longer working
If your knee pain sits predominantly on one side rather than throughout the whole joint, you may be a good candidate for a partial rather than total knee replacement – worth discussing at consultation.
What is a partial knee replacement?
A partial, or unicompartmental, knee replacement resurfaces only the damaged section of the knee – commonly the inner (medial) compartment – leaving the healthy cartilage, ligaments and bone elsewhere in the joint untouched. Because less of the knee is altered, many patients experience a more natural-feeling knee, a shorter hospital stay and a faster return to activity compared with a total knee replacement.
Not every patient with knee arthritis is suitable for this approach – it depends on which parts of the knee are affected and the health of your ligaments – which is why careful assessment and imaging at consultation are essential before recommending it.
Why choose Mr Ashwin Unnithan for partial knee replacement in Wimbledon?
- Specific clinical interest
unicompartmental knee replacement is one of Mr Unnithan’s named areas of clinical focus, not a peripheral offering.
- Minimally invasive technique
as a minimally invasive hip and knee replacement surgeon, the aim is less soft-tissue disruption and a smoother recovery.
- Robotic precision where appropriate
robotic-assisted planning can help fine-tune implant positioning and knee balance in suitable patients.
- Knee pain but not sure it's arthritis?
If your symptoms involve catching or locking rather than steady wear, knee arthroscopy may be the more relevant first step.
- High-volume, senior surgeon
over ten years’ experience as a Consultant Orthopaedic Surgeon managing both straightforward and complex knee cases.
- Careful patient selection
an honest assessment of whether a partial or total knee replacement – or an osteotomy – genuinely suits your knee.
- Local accessibility
based in Walton-on-Thames, Surrey, easily reached from Wimbledon and South-West London, with appointments usually available within days and no GP referral needed for an initial consultation.
- Recognised standing
Fellow of the Royal College of Surgeons, member of the British Orthopaedic Association and American Academy of Orthopaedic Surgeons.
At a glance
Your treatment journey
Consultation & imaging
X-rays, a thorough examination and an honest discussion of whether a partial or total knee replacement suits your knee.
Planning
A personalised surgical plan is built, with 3D robotic planning where suitable, to protect your healthy compartments and ligaments.
Surgery & recovery
Because only part of the knee is treated, most patients stay just one night and are walking the same day, supported by an enhanced recovery programme.
Rehab & follow-up
Structured physiotherapy and scheduled reviews help you regain strength and confidence, with many patients returning to activity faster than after a total knee replacement.
- COMMON QUESTIONS
Frequently asked questions about total hip replacement
What is the difference between a partial and total knee replacement?
A partial knee replacement resurfaces only the damaged compartment of the knee, leaving healthy bone, cartilage and ligaments in place, whereas a total knee replacement resurfaces the whole joint. Partial replacement is only suitable when arthritis is confined to one area.
What is a partial knee replacement, in simple terms?
It is an operation that resurfaces only the worn part of the knee, leaving healthy bone, cartilage and ligaments untouched elsewhere in the joint.
How do I know if I need a partial or total knee replacement?
This is determined through examination and imaging at consultation, assessing which compartments of the knee are affected and the condition of your ligaments, in line with current NICE guidance on osteoarthritis referral.
Is recovery faster after a partial knee replacement?
Generally, yes. Because less tissue is disturbed, many patients experience less pain, a shorter hospital stay of around one night, and a quicker return to walking and daily activities compared with a total knee replacement.
Does a partial knee replacement feel more natural than a total knee replacement?
Many patients report their knee feels more like their own natural joint, since the anterior and posterior cruciate ligaments and healthy compartments are preserved.
Will I eventually need a total knee replacement after a partial one?
Some patients do progress to a total knee replacement years later if arthritis develops elsewhere in the joint, but for well-selected patients, partial knee replacements can last well, and this is discussed openly at consultation.
Can I have a partial knee replacement with robotic assistance?
Yes, robotic-assisted planning is available where suitable, helping to fine-tune implant positioning and soft-tissue balance for your individual anatomy.
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