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Case study: Pedicle Screws and Cages 2017-05-19T11:11:43+00:00

Case study: Pedicle Screws and Cages

Pedicle screws and cages are commonly used in spinal surgery.  Tendency is to provide more and more specialized techniques to the surgeons, resulting in larger instrument sets and complex screw design. Our customer, in cooperation with a group of surgeons wanted to return “back to the basic” and develop a simple and reliable system with only the basic features. We have developed such system, comprising of pedicle screws (mono-poly and reduction) and cages.


Stage 1: Explore

The aim was to provide a robust and simple system and the first step was to find out what is meant by simple and robust. For the cage system it was decided to have one system that is suitable for a PLIF, TLIF, XLIF and even an ALIF approach. Sizing was very basic, just 9 sizes would fit the complete range.

For the screw is was important for the user to be able to manipulate the screw  against high tissue reaction forces during the surgery. Especially the interface between screw head and the reduction instrument/ screw drive needed special attention. Another need was to provide a screw system with a very tight fit of the set screw to avoid loosening.

Stage 2: Design

During the design phase test models where developed to address the main issues. These issues where: Slipping of the rod and the poly head. Strength of the fit of the screw on the screw driver during insertion and ease of use of the cages while introducing them via the various approaches. We built special test set ups to find out the behavior of the screws and cages. Using sawbone, we compared the new system with others, available on the market.  Beside the implant we also designed the key instrument for insertion of the implant.

Stage 3: Engineer

Once the key issues where solved, the design was finalized into detail. Sizes of the implant where defined and the set of instruments was completed. This phase did not only contain product development activities. Also setting up the production process, was completed. Finally we have tested the complete procedure during saw bones sessions.

Stage 4: Validate

In this phase we validated the design. All mechanical tests according to the applicable standards where performed. Moreover, cleaning and sterilization was carried out. CE mark was obtained by following the clinical literature route.

Stage 5: Transfer

Once the CE mark was obtained, the actual delivery of the product started. Our main role was to monitor the production of the first batches. We checked whether the quality procedures as developed in the previous phase were indeed effective and all trace ability data was stored properly. Because when more surgeons started using the implant it was unavoidable that some issues appeared during use. During this project we had to solve issues with the screw driver and reduction instrument. In that phase we addressed those issues and solved them appropriately. Although the product is already CE marked we decided to conduct, together with a team of surgeons, a post market clinical follow up study in order to address the residual risk topics.

Once the production batches run smoothly the customer took over the CE mark by means of an own brand labeling contract.Both cage as screw system are on the market for a couple of years now. For specific information, don’t hesitate to contact us: 0031-88-5656600 or mail us at info@baatmedical.com.