Partial knee replacement, also called unicompartmental knee replacement, resurfaces one damaged compartment of the knee while preserving healthy cartilage, bone, and ligaments elsewhere.
A partial knee replacement replaces only the diseased compartment of the knee. It may be considered when arthritis is limited to one area and the ligaments, motion, and remaining joint surfaces are suitable.
It is not simply a smaller version of total knee replacement. The key question is whether the knee arthritis is truly isolated enough for a partial replacement to make sense.
Partial knee replacement works best when damage is isolated to one compartment, not spread throughout the knee.
Ligament stability matters because the preserved knee structures continue guiding the replacement.
If arthritis, stiffness, deformity, or instability is too extensive, total knee replacement may be the better operation.
For the right patient, partial knee replacement may mean less surgical disruption and a knee that feels more natural. For the wrong patient, it may leave untreated arthritis behind. That is why evaluation by a knee replacement specialist matters.
Partial knee replacement is usually considered when arthritis is isolated to one compartment of the knee and the remaining compartments, ligaments, and motion are suitable. It is a selection-sensitive operation, which means the diagnosis matters as much as the technique.
Patients with inflammatory arthritis, substantial stiffness, arthritis in multiple compartments, poor ligament stability, or deformity that cannot be corrected safely may be better served by total knee replacement.
Preserves suitable healthy compartments and may feel more natural for the right patient, but it can fail if arthritis progresses elsewhere.
Treats arthritis across the knee and may be safer when disease is more widespread, ligaments are not reliable, or deformity is more complex.
The surgeon should be able to explain the tradeoff between preserving anatomy now and reducing the risk of needing another operation later.
Many appropriate candidates recover faster than after total knee replacement, but recovery varies by health, pain control, and surgical findings.
Yes. If arthritis progresses or the implant fails, partial knee replacement can sometimes be converted to total knee replacement.
It can, because more native knee tissue is preserved, but the result depends on patient selection and surgical execution.
Patients with inflammatory arthritis, major stiffness, ligament damage, or arthritis in multiple compartments may not be candidates.
Procedure pages help patients understand the option. Scheduling helps turn that into a visit with the right TJS specialist, office, and appointment type based on symptoms, imaging, prior treatment, and recovery goals.
This page was reviewed by Total Joint Specialists clinical leadership on May 11, 2026. It is reviewed at least annually and whenever major clinical guidance, source references, or practice facts change.
The content is educational, cites orthopedic society or peer-reviewed sources where relevant, and is not a substitute for an evaluation with an orthopedic surgeon who has reviewed your individual case.
Patient education references used for this page: AAOS Unicompartmental Knee Replacement, AAHKS Full vs. Partial Knee Replacement, and AAHKS Surgical Options for Knee Arthritis.
A TJS knee replacement specialist can review whether the arthritis pattern is limited enough for a partial replacement.
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