CORI: a technical system profile

In brief

• CORI is a portable Smith+Nephew system using a handheld burr and optical tracking.
• Its knee workflow needs no preoperative CT: the model is built from intraoperative data.
• The surgeon plans and moves the burr; software constrains its cutting function at the boundary.
• RI.HIP NAVIGATION is separate navigation software, not robotic hip bone preparation.

System architecture

CORI is a handheld robotics platform: the working tool remains in the clinician’s hands rather than on a positioning arm. The FDA describes computer-assisted navigation and surgical burring. A configuration includes a passive infrared camera, trackers, computer, software and robotic burr.

The current manufacturer page lists total, partial and revision knee applications. Functions depend on version, implant and market. FDA K201022 documents UKR/TKA and a specific 2020 compatibility set; newer cemented, cementless and revision uses require current application-specific instructions.

A model without preoperative CT

The surgeon maps bony surfaces and landmarks in theatre. A camera tracks references and tools while software creates a 3D representation. “Imageless” means no mandatory preoperative tomographic model, not an absence of measurements or digital anatomy.

The clinician plans resections and component position, assesses motion and gaps and may revise parameters in real time. CORI supplies measurements; the surgeon selects alignment strategy and acceptable balance.

Software boundary

After plan approval, the clinician guides the burr. Near the planned boundary, software manages exposure and/or speed of the cutting part, which may retract or stop effective cutting. This differs from MAKO’s haptic arm and ROSA’s cutting-guide positioning.

Direct control does not make every movement automatically safe. Exposure, tissue protection, stable tracking and registration verification remain team duties.

Typical sequence

1. Establish indication and strategy clinically.
2. Fix and verify optical references.
3. Capture surface points and landmarks.
4. Build the model and assess sizing and balance.
5. The surgeon revises and approves the plan.
6. Prepare bone with the constrained handheld burr.
7. Verify the result and complete the operation.

Evidence

What “imageless” means in practice

CORI does not rely on a pre-segmented CT model for the described knee workflow. Digital anatomy is instead built from points captured after the joint is exposed. This redistributes work rather than removing a model: data collection, landmark verification and planning take place in theatre.

That approach is not inherently better or worse than CT-based planning. It avoids separate CT acquisition and segmentation but depends on complete mapping and adds an intraoperative modelling step. CT-based systems provide a model in advance but require sound images and subsequent registration. A neutral comparison describes these trade-offs instead of declaring a winner.

Surgeon control

The clinician judges which captured points are valid, confirms size and orientation, interprets gap data and selects plan parameters. During burring, the clinician establishes tool position and direction. The software boundary manages cutting function but cannot determine exposure or recognise every clinical hazard.

If a reference moves, the camera loses line of sight or the display conflicts with anatomy, the team must pause and repeat the required checks. The platform requires trained users and a safe alternative workflow. A small physical footprint does not make the clinical decisions simpler.

Reading comparative results

A CORI report should identify the procedure, application, implant, operator experience, comparator and follow-up. Early perioperative findings cannot be presented as long-term effectiveness. Comparison with conventional instruments does not establish superiority over another robotic platform. Failure to find a statistically significant difference in a small sample does not prove equivalence.

A retrospective propensity-matched study compared 215 CORI TKAs with 215 conventional TKAs for early perioperative outcomes, complications, PROMs and revision endpoints. Two surgeons and short follow-up limit generalisability and do not establish long-term survival.

Another retrospective study compared 50 CORI with 50 Knee3 navigation TKAs. It is not a head-to-head comparison with MAKO, ROSA, CUVIS or VELYS and cannot support a platform ranking.

Limits and questions

Model quality depends on point capture and tracking stability. Avoiding CT moves modelling into theatre. Compatibility changes by version. Technical accuracy cannot guarantee less pain, fewer complications or revisions.

Is CORI truly image-free? It avoids preoperative CT but uses optical tracking and an intraoperative digital model.

Is it a robotic arm? No. The surgeon holds the burr while software constrains cutting.

Does it select ligament balance? No. It displays measurements; the clinician decides.

This is not treatment advice. Indications require individual assessment. Sources reviewed 8 August 2026; scheduled review August 2027. Author: RoboOrthoClub editorial team. Relevant conflicts must be disclosed.