Partial knee replacement, also called unicompartmental knee arthroplasty, replaces only the damaged section of the knee joint while preserving the rest of your natural bone, cartilage and ligaments. Dr. Juilee Mhatre Nair assesses whether this joint-preserving approach is right for you, based on exactly where and how much of your knee is affected.
What partial knee replacement is
The knee joint has three compartments: the medial (inner), lateral (outer), and patellofemoral (behind the kneecap). When arthritis or damage is confined to just one of these — most commonly the medial compartment — a partial knee replacement replaces only that section with an implant, leaving the healthy parts of the joint untouched. This differs from /total-knee-replacement/, which replaces the entire joint surface.
Who this suits
Partial knee replacement is generally suitable for patients with localised osteoarthritis confined to one compartment, intact ligaments (particularly the ACL), a stable knee with reasonable range of motion, and no significant inflammatory arthritis such as rheumatoid arthritis. It is not right for everyone with knee pain — assessment is needed to confirm the damage is genuinely isolated before this option is offered.
Symptoms and indications
- Pain concentrated on one side of the knee, rather than throughout the joint.
- Imaging showing cartilage loss confined to a single compartment.
- A stable knee with intact ligaments on clinical examination.
- Persistent symptoms despite conservative treatment for localised /osteoarthritis/.
Patients sometimes assume that one-sided knee pain automatically means they are a candidate for partial knee replacement, but the only reliable way to confirm this is through clinical examination combined with imaging. Pain location alone can be misleading, since pain from other structures, including the hip or lower back, can sometimes be felt around the knee.
Non-surgical management first
As with any joint replacement decision, conservative measures are tried first: weight management, targeted physiotherapy, activity modification, and medication or injections for pain and inflammation. Partial knee replacement is considered once these measures no longer adequately control symptoms and imaging confirms the damage remains genuinely localised to one compartment.
The surgical option and what it involves
Partial knee replacement typically uses a smaller incision than total knee replacement, since only one compartment needs to be accessed. The damaged cartilage and a thin layer of underlying bone are removed from the affected compartment, and a prosthetic component is fitted and aligned to work smoothly with the rest of the knee's healthy structures. Because less tissue is disturbed, many patients experience less immediate post-operative pain than with a full joint replacement, though individual experience varies.
What robotic or minimally invasive assistance changes
Some partial knee replacements are performed using robotic-assisted planning, similar in principle to /robotic-knee-replacement-surgery/ for total knee cases — using imaging-based planning to guide precise alignment of the smaller implant within the single compartment. Because a partial knee replacement implant sits within a narrower space than a total knee implant, small differences in positioning can matter more, which is one reason some surgeons find imaging-guided planning particularly useful here. This remains a precision aid for planning and positioning, not a guarantee of outcome, and whether it is used depends on your anatomy and the facility where surgery is performed.
How partial knee replacement compares with continuing conservative care
Patients sometimes ask whether it is better to delay surgery and continue with physiotherapy, weight management and medication for as long as possible, or to proceed once damage is confirmed to be isolated to one compartment. There is no universally correct answer — some patients manage well on conservative measures for a long period, while others find that persistent pain in one compartment limits daily life enough that surgery becomes the more sensible choice. Dr. Juilee Mhatre Nair will talk through your specific pain levels, imaging findings, and how the joint is affecting your day-to-day function before making a recommendation either way, rather than defaulting to surgery simply because you meet the technical criteria.
Recovery phases
Recovery generally involves an initial period of pain control and early mobilisation, often with patients going home the same day or the day after surgery, followed by a structured physiotherapy programme to restore strength and joint mobility, and a longer-term phase of gradually resuming normal activity. Because less tissue is disrupted than in total knee replacement, some patients return to daily activities sooner, though the exact pace depends on your baseline fitness and how the joint responds.
Risks, discussed honestly
Risks include progression of arthritis in the other compartments over time (which may eventually require conversion to total knee replacement), implant loosening or wear, infection, and stiffness. These risks, and how they might apply to you specifically, are discussed openly before you decide to proceed.
What influences the cost
The cost of partial knee replacement is shaped by the implant used, whether robotic-assisted planning is involved, the hospital setting, length of stay, and the physiotherapy plan afterward, along with your insurance or cashless coverage. We do not quote a fixed figure — call or WhatsApp NAIR Spine & Knee Clinic for a personalised estimate once your case has been reviewed.
What determines the right candidate
Being a suitable candidate for partial knee replacement depends on a combination of factors visible on examination and imaging: the pattern of cartilage loss, the health of your ligaments, the alignment of your leg, and the absence of significant inflammatory arthritis affecting the whole joint. Age and activity level are considered too, but they are not disqualifying on their own — the anatomical picture is what ultimately determines whether a partial or total replacement is the more appropriate procedure.
What a consultation involves
A consultation includes a detailed examination of knee stability and range of motion, and a review of X-rays or MRI to confirm whether your damage is genuinely confined to one compartment. Dr. Juilee Mhatre Nair consults at /spine-and-knee-clinic-kharghar/ and at Kokilaben Dhirubhai Ambani Hospital via /spine-and-knee-specialist-kopar-khairane/. Learn more about her focus areas on the /dr-juilee-mhatre-nair/ page.
Frequently asked questions
This depends on how much of your knee joint is damaged. Partial knee replacement is only appropriate when wear is confined to one compartment of the knee — usually the inner (medial) side — and your ligaments, including the ACL, are healthy and intact. If damage extends across the whole joint, total knee replacement is generally the more suitable option. Dr. Juilee Mhatre Nair confirms this with a clinical examination and imaging before recommending either procedure.
Partial knee replacement typically involves a smaller incision and less disruption to surrounding tissue than total knee replacement, because only the damaged compartment is addressed and healthy bone, cartilage and ligaments elsewhere in the joint are preserved. It is often grouped with minimally invasive knee surgery approaches for this reason, though the exact technique and incision size depend on your individual anatomy.
It is possible. Because partial knee replacement leaves the rest of the joint in place, arthritis can develop in a previously unaffected compartment over time, and some patients eventually need conversion to a total knee replacement. This is discussed as a genuine long-term consideration during your consultation, rather than something to be surprised by later.
Age and activity level are considered alongside the pattern of joint damage, not in isolation. Some younger, active patients with damage confined to one compartment and healthy ligaments are reasonable candidates, while others may be better served by continuing conservative management for longer. Dr. Juilee Mhatre Nair will discuss what is realistic for your specific joint and activity goals.
If assessment shows that more than one compartment of the knee is significantly affected, or the ligaments are not intact, partial knee replacement is unlikely to be suitable and total knee replacement is usually the more appropriate option. This is one of the key things your surgeon checks for before recommending a partial procedure.
Talk to a spine and joint specialist
Share your symptoms, reports or scans and our team will help you book a consultation with Dr. Vishnu Vikraman Nair or Dr. Juilee Mhatre Nair at the Navi Mumbai location most convenient for you.