Make robotic knee replacement affordable and implant-neutral. Today's knee robots are big, costly and locked to one company's implants; a small open robot could bring precise bone cuts to more hospitals and surgery centres.
ScalingStage 5 of 5
5,000+ knee replacements; compatible with ~70% of US knee implants; cases up fivefold in a year.
Updated 14 Jul 2026·Checked 11 Oct·0 updates this week
Milestones
Next · Commercial expansion in the US
FDA 510(k) clearance for TMINI30 May 2023Complete.
First clinical use (Washington Hospital)Sep 2023Complete.
Distribution agreement with Zimmer Biomet12 Jun 2024Complete.
TMINI 1.1 cleared; implants from more makers added23 Jul 2024Complete.
1,000th procedure15 May 2025Complete.
First cases with Stryker's Triathlon knee27 Feb 2026Complete.
5,000th procedure27 May 2026Complete.
Up to $65M growth capital to expand sales14 Jul 2026Complete.
Commercial expansion in the USTarget 2026Current milestone.
Competing with Mako and VELYSStryker's Mako and J&J's VELYS bundle robots with their own implants; THINK relies on partners like Zimmer Biomet to reach surgeons.
Scan step adds costNeeding a CT before surgery adds radiation, cost and scheduling that image-free systems avoid.
Physics limits
Bone cuts versus soft tissueA robot can make cuts accurate to about a millimetre, but how a new knee feels also depends on ligament balance, which the plan from bone images cannot fully capture.
Saw blades flexEven on a perfect guide, an oscillating saw bends and skives on hard bone, so the final cut can stray from the plane the pins defined.
How it works
4 parts
Plan
3D plan from a CT scan
Before surgery the knee is CT-scanned and the implant is fitted virtually, fixing where each bone cut should go.
Handpiece
Robot cancels hand wobble
In surgery the wireless handpiece moves to offset the surgeon's natural hand motion, so pins go in exactly on the planned planes.
Cutting
Guides on the pins
Standard cutting guides slide onto the pins and the surgeon saws along them, replacing many of the usual alignment instruments.
Implant data
One module per implant
Each manufacturer's implant geometry is loaded from THINK's implant data hub, which is how one robot serves many brands.
TMINI handheld knee-replacement robot, open implants
Fremont, California maker of TMINI, a handheld robot for total knee replacement that works with implants from many manufacturers, unlike rivals tied to one company's knees. Privately held.
TMINI is an open platform: surgeons choose the implant; it covers about 70% of US knee implants by volume, including Stryker's Triathlon.
5,000th procedure in May 2026, five times the volume of a year earlier.
Zimmer Biomet distributes TMINI with its Persona knee; up to $65M debt facility from Symbiotic Capital (July 2026).
