For many people with arthritic knees, a surgical procedure known as a high-tibial osteotomy (HTO) often brings relief. Thanks to 3D printing technology, however, it could soon be even more effective – and also safer to perform.
HTO surgery involves making a cut to the patient's tibia (shin bone) just below the knee, then using that cut to open a small gap in the bone, and finally keeping the bone in that position by fastening a stabilizing steel plate onto the cut side of the tibia. Doing so realigns the knee, so that the load is now being placed on a less-worn part of the joint.
Currently, doctors utilize "off-the-shelf" plates that aren't an exact match to the contours of the patient's tibia. This means that some time needs to be taken in selecting a plate, then positioning it on the bone and screwing it into place. Even then, the resulting knee realignment may not be precisely what was required.
In the experimental new Tailored Osteotomy for Knee Alignment (TOKA) procedure, developed at Britain's University of Bath, physicians begin by performing a 3D CT scan of the patient's tibia and knee. Using that data, they then 3D print a titanium alloy plate that is shaped exactly to that individual patient's tibia. They also print a patient-specific jig, which is used to guide the placement of the plate.
According to the university, TOKA should result in better knee alignments, increased stability of the joint, and less discomfort for the patient. Additionally, by having everything ready to go beforehand, the time of the surgery itself should be decreased from two hours to approximately 30 minutes.
In an ongoing trial being performed at Italy's Rizzoli Institute, 25 patients have undergone the procedure so far. Plans call for a UK trial to begin later this year, involving hospitals in Bath, Bristol, Exeter and Cardiff.
A paper on the research, which is being led by Prof. Richie Gill, was recently published in the journal Communications Medicine.
Source: University of Bath
