Doctors perform tens of thousands of back and spinal surgeries every year. These types of surgeries the most complicated, because every one of them is different. Surgeons sometimes have to place support systems into the spine to support a person’s back and/or repair injuries. Specially designed systems are inserted into the patient’s spine to repair back problems. These systems often include the following:

1. Screws to be inserted into the spine as seen above in picture “C” below right.
2. Self positioning movable swivels connected to the top of the screw for the rod to be placed in as seen in picture “B” below center.
3. Individual short rods are placed in-between each swivel and screw. This allows the back to move freely and flex/bend at each connection point as seen in picture “A” below left.
4. Cap to lock and hold each rod into place as seen be in picture “B” below center.

Picture A Picture B
Picture C

Par3 Technology has helped develop medical tools, implants, and devices for several years. Vice President Earl Dunlap was watching a back surgery one day to observe a monitoring apparatus his company had developed. During the surgery, Dunlap noticed that the doctor was struggling with a tool that is used to insert the screws and position the rods and pins. After the surgery, Dunlap got the opportunity to ask the doctor why he was having such difficulty. After hearing about the multiple problems, Dunlap asked if he could watch a few more surgeries to see if Par3 could offer some suggestions to develop a better design. After watching a few more surgeries that used the same tools, it was clear that the same problems were arising for the doctors. The main problems with the current design were the necessity of multiple tools to complete the surgery, tool slipping in the doctors’ hands causing positioning and function problems, and tools being dropped, breaking the sterile field and stopping or delaying the surgery. Below is a chart comparing current design problems versus new design enhancements.

Spine Chart

The new design used to complete the surgery is named the Positioner Assembly Tool. The single tool design assembly includes details within the assembly which work with individual tools to complete all the necessary functions. During the product development process, Par3’s Analysis Driven Design Process was used to create features and functions to enhance and optimize the product. This process uses computer aided analysis software to optimize the design of a product and reduce the need for costly sample building and speed up the development cycle. 

The Positioner Assembly Tool, disassembled

Finite Element Analysis (FEA) was used to dial in the scissoring/clamping function of the tool assembly to hold onto swivel, so that the doctor would not have to reposition it while using another part of the tool. Computation Fluid Dynamics (CFD analysis) was used to simulate blood and body fluids on the surfaces of tools to drive the design features and material choices for gripping and leverage functions. Both FEA and CFD Analysis helped optimize the overall product development.

The Positioner Assembly Tool, assembled

 This Positioner Assembly Tool is lightweight, easy-to-use, and comes apart to ensure proper sterilization before the next surgery.