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Power tool attachment to cut an oval shape in bone

Inventors at the Leiden University Medical Center have developed a power tool attachment that cuts an oval shape.

In order to treat chondrosarcoma by curettage, an opening in bone is needed which is most often accomplished by drilling four holes and connecting them. Two disadvantages of this method are: a) the creation of sharp, squared corners which are weak points that promote breakage of the bone, and b) the loss of bone from cutting holes. This new saw creates an oval opening in the femur. This has several advantages over the conventional method. Importantly, the oval shape retains the advantage of creating a shape with a length similar to a rectangle, thus maximizing the area of the shape, but with round edges. Other advantages are that the width of the cut is 0.1 – 0.2 mm, much less than standard, thus the healing time is shortened when the bone is replaced. Furthermore less skill is needed to cut a shape in bone with an oval saw than by conventional methods.

The current length of the oval shape is approximately 3 cm but the mechanism can be developed to cut an oval shape of a different size.  A smaller cutout would allow access to tumors in smaller bones.

The bone saw may also be useful to create a bone flap for cranial surgery in which the bone will be replaced. Another application may be for harvesting bone. The attachment was designed to fit an existing hand-held power tool but can be adapted. The saw can cut multiple types of materials and therefore may be useful outside the medical device arena.

Key benefits

  • Oval shape reduces chance of bone fractures
  • Width of the cut is 0.1 to 0.2 mm, much less than standard, therefore less material is lost which allows for faster healing
  • Oval shape allows bone to be replaced in the exact position in which it was cut out which allows for faster healing
  • Less skill is needed to cut a shape in bone than with conventional method


  • Cutting bone to allow for curettage to treat chondrosarcoma
  • Harvesting bone
  • Cutting a bone flap in the skull

Development stage

A prototype has been made that cuts bone and other materials

Luris reference number


Patent status

A patent application has been filed

Further information

Vincent van der Mark Knowledge Broker (LUMC Div. 2/3) +31-71-527 2652 +31-6-1474 7912