Robotic Knee Replacement in Bristol – Mako and CORI
The single most important decision in knee replacement surgery is choosing the right operation: partial or total, and which compartment to address. Get that wrong, and no amount of technology will save you. Get it right, and robotic assistance becomes a genuinely useful precision tool that helps me position implants accurately and consistently.
I use two robotic platforms – Mako and CORI – for both partial knee replacement (medial, lateral, or patellofemoral) and total knee replacement. This page explains what robotic assistance actually does, where it adds value, and where it doesn't.
What does the robot actually do?
The robot does not perform the operation. I do. What it provides is a planning and guidance system that helps me:
- Build a precise implant plan based on your individual knee anatomy
- Prepare bone accurately within the planned boundaries
- Fine-tune alignment and knee balance during the operation itself
Think of it as a precision instrument, not an autopilot. I use it most often for total knee replacement and patellofemoral replacement, where the ability to plan and balance the knee in real time makes a meaningful difference to how the implant performs.
Where robotic assistance adds real value
I find robotic assistance most useful for:
- Accuracy of component positioning – the system enforces the plan, so there is less variability between cases
- Knee balancing – I can check ligament tension and alignment through the full range of movement during the operation, and adjust in real time
- Bone preparation – the robot removes only what is planned, which matters for both total and partial replacement
- Complex anatomy – knees with unusual alignment or previous surgery benefit from the additional planning data
That said, it is still a tool. The outcome depends on the surgeon's decision-making before and during the operation, not the brand of robot in the room.
Robotic total knee replacement
Total knee replacement is where I use robotic assistance most frequently. When arthritis affects more than one compartment, the robot helps me plan and execute a replacement that is tailored to your specific anatomy rather than relying on generic sizing guides.
In total knee replacement, the robotic system helps me:
- Plan component positions matched to your specific anatomy
- Restore alignment and joint line position in a controlled way
- Balance the knee through flexion and extension – checking that it feels stable and tracks well before closing
This real-time balancing is where I find the robot adds the most value. I can assess ligament tension throughout the full arc of movement and make adjustments during the operation, rather than relying solely on pre-operative planning.
Robotic patellofemoral replacement
Patellofemoral replacement is the other procedure where I find robotic assistance particularly valuable. When arthritis is confined to the front of the knee – behind the kneecap and in the trochlear groove – kneecap tracking is very sensitive to component position. Robotic guidance helps me place the trochlear component precisely, which directly affects how the kneecap tracks and how the knee feels afterwards.
Robotic partial knee replacement (medial and lateral)
A partial knee replacement replaces only the worn compartment, preserving the healthy parts of the knee – bone, cartilage, and ligaments. Robotic assistance can be used for partial replacement, though I do not use it routinely for every case.
Medial (inner side)
Medial unicompartmental replacement is the most common partial replacement. When the arthritis is confined to the inner compartment, robotic guidance can help with implant positioning and preserving the rest of the knee.
Lateral (outer side)
Lateral unicompartmental replacement addresses arthritis on the outer side. The lateral compartment has more anatomical variability than the medial side, so robotic planning can be helpful for alignment and tracking.
The decision between partial and total replacement is far more important than whether a robot is used. A well-performed knee replacement without robotic assistance will outperform a robotically-assisted operation where the wrong procedure was chosen.
Who is robotic knee replacement right for?
If you need a knee replacement, robotic assistance is worth considering when:
- You are having a total knee replacement and would benefit from precision balancing and patient-specific planning
- You are having a patellofemoral replacement, where accurate component position directly affects kneecap tracking
- Your anatomy or alignment is unusual and would benefit from detailed pre-operative planning
- You want implant positioning guided by a data-driven surgical plan
It does not guarantee a better outcome, and it is not necessary for every case. The priority is always choosing the correct operation for your knee and getting rehabilitation right afterwards.
How I assess and plan robotic knee replacement
Every robotic knee replacement starts with a thorough pre-operative assessment. The most important question is not "should I have a robot?" but "which operation is right for my knee?"
I assess the pattern of your arthritis with weight-bearing X-rays (including alignment views), examine the knee for stability, movement, and kneecap tracking, and talk through what is actually limiting you day to day. If I am using the Mako system, a CT scan is also needed for pre-operative planning. The CORI system uses intra-operative mapping instead.
Once I am confident we have selected the right procedure, the robotic plan is built around your anatomy.
What happens during the operation?
The exact steps depend on the system and procedure, but the general sequence is:
- I create a surgical plan based on your anatomy (pre-operatively with Mako, intra-operatively with CORI)
- During surgery, I register landmarks and confirm the plan against your real anatomy
- The robotic arm guides bone preparation – I control the saw or burr, and the system constrains it to the planned boundaries
- I place the implants, then check stability, alignment, and range of movement before finishing
The operation itself takes roughly the same time as a conventional knee replacement. You will not feel any difference in terms of the anaesthetic or the incision.
Recovery and rehabilitation
Recovery after robotic knee replacement follows the same principles as conventional surgery. The main drivers are:
- Good pain control and swelling management in the first few weeks
- Early, safe mobilisation – most patients are up and walking the same day or the day after surgery
- Structured physiotherapy with progressive strengthening
- Time – the knee takes months to settle fully, and patience is important
Partial knee replacement generally recovers faster than total, regardless of whether a robot is used. Individual recovery also depends on pre-operative fitness, body weight, and how well the knee responds to rehabilitation.
Risks and limitations
The risks of robotic knee replacement are the same as conventional knee replacement:
- Infection
- Blood clots (DVT / pulmonary embolus)
- Stiffness or prolonged swelling
- Persistent pain or dissatisfaction
- Instability, loosening, or wear over time
- Fracture – very rarely, the pins used to register the robot can weaken the bone and cause a fracture (this is specific to robotic surgery)
Robotic assistance improves precision, but it does not eliminate the inherent risks of surgery. I discuss the realistic benefits and limitations with every patient before we decide whether to use it.
Frequently asked questions
Does the robot perform the operation?
No. I perform the operation. The robot is a guidance system that helps me plan implant positions and prepare bone accurately. I make all the surgical decisions.
Is robotic knee replacement better than standard?
It improves precision and consistency, but the most important factor is still the surgeon's experience and decision-making. Choosing the right operation and positioning the implant well matters more than the technology used to get there. Robotic assistance helps with the "how", but the surgeon determines the "what" and "why".
Can I have robotic patellofemoral replacement?
Yes – this is one of the procedures where I most often use robotic assistance. Kneecap tracking is very sensitive to the position of the trochlear component, and the precision the robot provides is a real advantage.
Does robotic surgery speed up recovery?
Not significantly. Recovery depends mainly on the type of operation (partial versus total), pain and swelling control, and rehabilitation. Some patients report a smoother early recovery, but this is not universal.
Which robotic systems do you use?
I use Mako and CORI – two established platforms for robotic knee replacement. Mako uses a pre-operative CT scan to build the plan; CORI maps the knee intra-operatively. Both support partial (medial, lateral, patellofemoral) and total knee replacement. The choice of system depends on the hospital and the procedure. The most important factor is always the surgeon's planning and execution, not the specific platform.
Can I be assessed for robotic knee replacement in Bristol?
Yes. I offer robotic partial and total knee replacement at my Bristol clinics. The first step is a consultation to work out whether you need a knee replacement, and if so, which type is right for your knee.
