Robotic Partial Knee Replacement & Patellofemoral Joint Replacement

Restoring mobility and comfort through careful planning and precision surgery

Robotic Partial Knee Replacement & Patellofemoral Joint Replacement

Understanding compartmental knee arthritis

Knee arthritis does not always affect the entire knee equally. In many patients, wear may be isolated to a specific part of the joint rather than involving all three compartments.

The knee is divided into:

  • Medial compartment (inner side)

  • Lateral compartment (outer side)

  • Patellofemoral compartment (behind the kneecap)

When arthritis is limited to one compartment, a partial knee replacement (unicompartmental knee replacement) or patellofemoral joint replacement may provide effective pain relief while preserving more of the natural knee.

Symptoms may include:

  • Localised knee pain

  • Swelling

  • Difficulty with stairs or inclines

  • Mechanical symptoms such as catching or grinding

  • Reduced mobility and confidence

Non-surgical treatment may include physiotherapy, weight management, injections, medications, and activity modification. When these measures no longer provide adequate relief, surgery may be considered.

View All Knee Conditions

What is a partial knee replacement?

Partial knee replacement (unicompartmental knee arthroplasty) involves resurfacing only the damaged compartment of the knee while preserving:

  • Healthy cartilage in unaffected compartments

  • Cruciate ligaments where appropriate

  • More natural bone structure

  • Normal knee kinematics where possible

This can allow for:

  • Smaller incisions

  • Faster recovery

  • More natural-feeling knee movement

  • Reduced pain compared with total knee replacement in selected patients

Partial knee replacement is most suitable when arthritis is isolated and ligaments remain functional.

What is patellofemoral joint replacement?

Patellofemoral joint replacement specifically addresses arthritis affecting the joint between the kneecap (patella) and the femur (trochlea).

This procedure resurfaces:

  • The worn groove at the front of the femur

  • The damaged undersurface of the kneecap

It is designed for patients with:

  • Isolated patellofemoral arthritis

  • Severe anterior knee pain

  • Difficulty with stairs, squatting, or rising from chairs

  • Preserved tibiofemoral compartments

Patellofemoral replacement preserves the remainder of the knee and can offer improved function with less invasive surgery than total knee replacement.

Why consider robotic-assisted surgery?

Robotic-assisted surgery using the MAKO system enhances surgical planning and precision for both partial knee and patellofemoral replacement.

Robotic assistance allows the surgeon to:

  • Create a personalised 3D CT-based model of the knee

  • Plan implant size, position, and alignment precisely

  • Preserve healthy bone and soft tissues

  • Improve implant positioning accuracy

  • Fine-tune ligament balance in real time

  • Optimise knee mechanics for each individual patient

The surgeon performs the operation. The robotic system is a precision-guidance tool that supports accurate execution.

Techniques used in compartmental knee replacement

  • Uses standard guides based on anatomical landmarks.

  • Provides real-time alignment guidance.

  • Uses imaging-based cutting guides tailored to anatomy.

  • Uses CT-based pre-operative planning with haptic robotic arm guidance to improve precision and consistency.

How robotic partial or patellofemoral replacement works

  • A CT scan creates a 3D model of your knee, allowing detailed planning.

  • Your anatomy is verified during surgery to match the digital plan.

  • Only the diseased portion of the joint is resurfaced within defined boundaries.

  • Joint movement and stability are assessed dynamically.

  • Components are inserted according to the surgical plan for precise restoration.

Advantages of robotic-assisted partial and patellofemoral replacement

Potential benefits include:

  • Greater precision in implant positioning

  • Preservation of healthy bone and ligaments

  • More natural knee function

  • Smaller surgery compared with total knee replacement

  • Reduced soft tissue disruption

  • Faster recovery and rehabilitation

  • Lower early revision rates for robotic partial knee replacement in registry studies

  • Easier future conversion to total knee replacement if needed

Considerations & limitations

Not all patients are suitable candidates.

Factors influencing suitability include:

  • Extent of arthritis

  • Ligament stability

  • Knee deformity

  • Body weight

  • Activity level

  • Previous surgery

Other considerations:

  • Requires specialised equipment

  • Long-term outcomes continue to evolve

  • Disease progression in other compartments may eventually require further treatment

How surgery is performed

    • Damaged cartilage and bone are removed from the affected compartment only

    • Metal and polyethylene implants resurface the area

    • Healthy structures are preserved where possible

    • The trochlear groove is resurfaced

    • The patella may be resurfaced

    • Alignment and tracking are optimised

    • Range of motion

    • Stability

    • Implant positioning

    • Patellar tracking

Recovery & Rehabilitation

Recovery is generally faster than total knee replacement but varies between individuals.

Typical recovery milestones:

  • Day 0–1: Walking with physiotherapy support

  • 1–2 weeks: Reduced swelling, improving mobility

  • 4–6 weeks: Return to most daily activities

  • 6–12 weeks: Strengthening and low-impact exercise

  • 3–6 months: Continued functional improvement

Rehabilitation focuses on:

  • Strength

  • Motion

  • Balance

  • Gait retraining

Key points to remember

  • Partial and patellofemoral replacement preserve more of the natural knee

  • Robotic assistance supports precision and personalised surgery

  • Appropriate patient selection is critical

  • Rehabilitation is essential for optimal outcomes

  • Surgery aims to restore comfort, confidence, and mobility

Frequently asked questions

  • Suitability depends on arthritis location, ligament integrity, symptoms, and imaging findings.

  • In many cases, yes. Patients often experience less pain and quicker return to function.

  • Most patients stay 1–2 nights depending on mobility and support.

  • Usually on the day of surgery or the next day.

  • Most patients stay 1–3 nights, depending on mobility, pain control, and home support.

    • Right knee: often 2–4 weeks

    • Left knee (automatic): often 1–2 weeks

    • Desk work: 2–4 weeks

    • Manual work: 6–12 weeks or longer

  • Modern implants are designed for long-term durability, often 10–20 years or more depending on patient factors.

  • Yes. Some patients may later require conversion to total knee replacement.

  • Risks include:

    • Infection

    • Blood clots

    • Stiffness

    • Implant loosening

    • Progression of arthritis

    • Persistent pain

    These risks are discussed thoroughly during consultation.

Key takeaway

Robotic partial knee replacement and patellofemoral joint replacement are highly specialised procedures designed for selected patients with isolated compartment arthritis.

By combining careful patient selection, advanced robotic precision, and tailored rehabilitation, these procedures can provide excellent pain relief, improved mobility, and preservation of natural knee function.

Have a question or want to book an appointment?

Request a Consultation