Primary Focus
Conservative Path
Symptom management, quad strength, offloading
Interventional Path
Structural correction, joint resurfacing or repair
Treatments
Partial Knee Replacement
Surgical replacement of a single worn compartment of the knee joint, preserving healthy ligaments and bone.
On this page
Overview
Partial knee replacement (unicompartmental replacement) is considered for localized arthritis. This page covers patient selection, advantages, and recovery.
Partial knee replacement is a surgical procedure where only the damaged compartment of the knee (medial, lateral, or patellofemoral) is replaced with metal and plastic implants, leaving the healthy compartments and ligaments (including the ACL and PCL) intact. Wording is cautious: suitability depends on localized arthritis and ligament integrity.
This information is for general patient education and does not replace an individual clinical assessment. Suitability and outcomes depend on joint condition and physical health.
Clinical Overview Illustration
What does this treatment involve?
Typical clinical stages of this treatment pathway include:
1Preoperative assessment, anaesthetic, and surgical preparation
2Making an incision over the front of the knee to expose the worn compartment
3Removing the damaged cartilage and a thin layer of bone from the femur and tibia
4Cementing the metal implants to the bone ends and inserting a plastic spacer
5Checking joint alignment, range of motion, and stability
6Closing the incision in layers and applying dressings and compression
Suitability
Suitability depends entirely on an individual clinical examination, diagnostic imaging, medical history, and personal activity goals.
Who may benefit?
- Patients with advanced osteoarthritis strictly localized to one compartment of the knee
- Patients with intact, functional cruciate ligaments (ACL and PCL)
- Individuals experiencing severe pain that restricts daily mobility and sleep
When might it not be suitable?
- Widespread, multi-compartment knee osteoarthritis (total replacement preferred)
- Inflammatory arthritis (e.g. rheumatoid arthritis) which affects the whole joint
- Severe knee stiffness or fixed deformities prior to surgery
- Ligament-deficient knees (unstable joints)
Alternatives
Alternative treatment pathways that may be considered depending on clinical severity:
Physiotherapy, weight management, and activity modificationExplore Option >
Knee bracing (compartment offloader braces)Explore Option >
Clinical joint injections (steroid, hyaluronic acid, hydrogel)Explore Option >
Total knee replacement (if wear is more widespread than expected)Explore Option >
Risks
As with any clinical intervention, risks and complications differ between patients. Suitability and risk profiles are discussed in detail during consultation. General risks associated with this procedure include:
Progression of arthritis in the unreplaced compartments of the knee
Loosening or wear of the implants over time, requiring revision
Deep vein thrombosis (DVT) or pulmonary embolism
Joint infection requiring implant removal or antibiotics
Nerve or blood vessel damage around the incision
Recovery & Rehabilitation
Post-treatment rehabilitation and timelines are key to restoring joint health. We do not provide guaranteed recovery times.
Immediate Recovery
- Mobilisation begins on day 0 or 1, often with crutches for support
- Hospital stay is typically 1 to 2 days
- Return to desk work in 2-4 weeks; driving in 3-4 weeks once muscle control allows an emergency stop
- Significant improvement is observed by 3 months, with full recovery taking 6-12 months
Rehabilitation Pathway
- Early focus on swelling management, knee straightening, and active quad exercises
- Progression to walking distance increases and bending mobility
- Long-term low-impact strengthening to maintain joint health
Rehabilitation Milestones
Partial Knee Replacement Recovery Timeline
Typical phase-based progression and return to functional activity guidelines.
1
Phase 1 (Weeks 1-2)
Initial Mobility & Healing
Primary Focus:Control swelling, achieve full extension, activate key stabilizing muscles.
- Use crutches or support frame for safety
- Perform gentle range of motion exercises (0-90° flexion)
- Regular elevation and icing to manage inflammatory response
Weight BearingWeight-bearing as tolerated with aids
Driving StatusNot permitted
2
Phase 2 (Weeks 3-6)
Gait Normalisation & Range
Primary Focus:Restore normal walking gait, progress knee bending beyond 90°, and increase standing load.
- Gradually wean off walking aids as gait stabilizes
- Introduce closed-chain exercises (squats, calf raises)
- Increase active movement and daily walking distances
Weight BearingFull weight-bearing
Driving StatusPermitted once emergency stop is safe (approx. 6 weeks)
3
Phase 3 (Weeks 6-12+)
Strengthening & Functional Return
Primary Focus:Restore leg strength, balance, and return to light work/recreation.
- Progress resistance training (leg press, cycling)
- Incorporate balance and coordination drills
- Gradual return to work, driving, and low-impact activity
Weight BearingUnrestricted
Driving StatusPermitted
Important Clinical AdviceRecovery timelines are indicative. Individual rehabilitation progression depends on surgical findings, tissue quality, and the specific guidance of your consultant orthopaedic surgeon and physiotherapist.
Surgical Recovery Resources
As this is a surgical procedure, you may find our recovery resources helpful. These explain how to prepare and what to expect:
Clinical Pathway Map
Staged treatment and recovery journey.
Staged Clinical Pathway
Phased Rehabilitation & Recovery Pathway
Patient Education Pathway: This pathway diagram is for patient educational purposes only. It is not a diagnostic, triage, or clinical decision-making tool. Individual care options are determined dynamically following consultation.
Anatomy Comparison
Management Strategy Comparison
Comparing conservative treatment with active intervention options.
Conservative Path
Conservative PathClinical Reference
Conservative PathClinical ReferenceInterventional Path (Intervention Options)
Interventional PathClinical Reference
Interventional PathClinical ReferenceTimeframe
Conservative Path
Gradual ongoing adaptation over 3-6 months
Interventional Path
Structured acute healing followed by targeted rehab
Expected Outcome
Conservative Path
Improved function and pain control, preserved anatomy
Interventional Path
Restored mechanical stability, reconstructed tissue
| Anatomical Feature | Conservative Path | Interventional Path |
|---|---|---|
| Primary Focus | Symptom management, quad strength, offloading | Structural correction, joint resurfacing or repair |
| Timeframe | Gradual ongoing adaptation over 3-6 months | Structured acute healing followed by targeted rehab |
| Expected Outcome | Improved function and pain control, preserved anatomy | Restored mechanical stability, reconstructed tissue |
Frequently Asked Questions
Partial replacements preserve healthy ligaments (like the ACL), leading to a knee that often feels more natural, has better bending, recovers faster, and has lower surgical risks.
Most modern partial knee replacements last 15 years or more in the majority of patients, depending on activity levels and joint loading.
Awaiting Clinical Review
This page is in draft and has not yet been formally reviewed by our clinical team. Content may change following clinical review.
Would you like to discuss your treatment options?
A consultation can help clarify the cause of your symptoms and discuss appropriate treatment options.
Face-to-face appointments are arranged through the reception team at the chosen clinic. Video consultations use Google Calendar where available.
Continue Your Knee Journey
Explore Recovery→Next Step: Recovery & Rehabilitation
Understand recovery milestones, physical therapy timelines, and guidelines for returning to daily activities, driving, work, or sports safely.
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Medical Disclaimer
This website provides educational and general information about knee symptoms, conditions, and treatments. The content is for informational purposes only and does not constitute medical advice, diagnosis, or a treatment plan. It should not be used as a substitute for a professional consultation, examination, or clinical decision-making by a qualified orthopaedic specialist.
If you are experiencing symptoms or are concerned about a knee problem, please arrange a clinical consultation. If you have urgent symptoms, severe pain, or are unable to put weight on your leg, please read our urgent advice guidance or contact emergency services immediately (dial 999 or NHS 111).