In Situ Bending Instruments for Pelvic Plates

Keith Mayo, Robin Peter

A specific instrument set of bending instruments has been developed to enable in situ plate contouring of 3.5 mm reconstruction plates in their older and newer designs:

  • 3.5 mm low-profile reconstruction plates (straight, curved, and J-shaped)
  • 3.5 mm wide-angle reconstruction plates
  • 3.5 mm DCP reconstruction plates, straight and curved

The contouring or pre-bending of plates used for open reduction and internal fixation of pelvic and acetabular fractures can be a difficult and time-consuming task due to the complex three-dimensional anatomy of the pelvic skeleton. Once these plates are positioned on the bone, a final in situ adaptation of their contour is frequently required especially when using longer plates. This is particularly true for ilioinguinal or other extended approaches. The current state-of-the-art procedure of plate contouring to match the pelvic anatomy includes the use of bending presses and pliers which may only be used outside the body. The precise contouring of plates may therefore require repeated cycles of plate removal, bending and reinsertion. To date, no specific instruments have been available for the intra-operative in-situ bending of plates. Some surgeons use a pair of large screwdrivers inserted into two of the plate's holes to achieve flexion-extension bending and twisting, although the screwdrivers are not designed or intended for this usage. Furthermore, no dedicated tools are available to increase or decrease the plate curvature (in-plane bending) in situ.

These newly designed in situ bending tools are specifically intended for use only with 3.5 mm reconstruction plates. They are not suitable for bending or twisting of 3.5 mm reconstruction plates with locking or coaxial screw holes, regular plates (non-reconstruction plates), nor are they suitable for larger (4.5 mm) reconstruction plates.

The instrument set consists of one special in situ bending plier, which provides in-plane bending through a powerful three-point grip (Fig 1). This plier will prove particularly helpful when a reconstruction plate is already partially fixed to the bone and requires additional bending. Several special in situ bending and twisting handles, designed to be inserted into the plate's holes, are also provided. These levers are designed for plate twisting and flexion-extension bending. They are fitted with silicone handles, and come with three different tip designs (straight, 90, 120) (Fig 2) to allow for their use in various anatomical locations (Fig 3). The instruments are provided in a modular tray (Fig 4) which can be customized for different instrument combinations.

The challenge of in situ pelvic plate contouring is well known to surgeons performing pelvic or acetabular open reduction and internal fixation procedures. This new instrument set should prove helpful in this respect, while also improving the quality of reduction. The tools provided in this new set are easy to use and should save time, while avoiding the need for repeated, and sometimes frustrating, plate contouring outside the surgical wound.

Hazards and labeling

Due to varying countries’ legal and regulatory approval requirements, consult the appropriate local product labeling for approved intended use of the products described on this website. All devices on this website are approved by the AO Technical Commission. For logistical reasons, these devices may not be available in all countries worldwide at the date of publication. 

Legal restrictions

This work was produced by AO Foundation, Switzerland. All rights reserved by AO Foundation. This publication, including all parts thereof, is legally protected by copyright.

Any use, exploitation or commercialization outside the narrow limits set forth by copyright legislation and the restrictions on use laid out below, without the publisher‘s consent, is illegal and liable to prosecution. This applies in particular to photostat reproduction, copying, scanning or duplication of any kind, translation, preparation of microfilms, electronic data processing, and storage such as making this publication available on Intranet or Internet.

Some of the products, names, instruments, treatments, logos, designs, etc referred to in this publication are also protected by patents, trademarks or by other intellectual property protection laws (eg, “AO” and the AO logo are subject to trademark applications/registrations) even though specific reference to this fact is not always made in the text. Therefore, the appearance of a name, instrument, etc without designation as proprietary is not to be construed as a representation by the publisher that it is in the public domain.

Restrictions on use: The rightful owner of an authorized copy of this work may use it for educational and research purposes only. Single images or illustrations may be copied for research or educational purposes only. The images or illustrations may not be altered in any way and need to carry the following statement of origin “Copyright by AO Foundation, Switzerland”.

Check for more information.


If you have any comments or questions on the articles or the new devices, please do not hesitate to contact us

“approved by AO Technical Commission” and “approved by AO Foundation”
The brands and labels “approved by AO Technical Commission” and “approved by AO Foundation”, particularly "AO" and the AO logo, are AO Foundation's intellectual property and subject to trademark applications and registrations, respectively. The use of these brands and labels is regulated by licensing agreements between AO Foundation and the producers of innovation products obliged to use such labels to declare the products as AO Technical Commission or AO Foundation approved solutions. Any unauthorized or inadequate use of these trademarks may be subject to legal action.

AO ITC Innovations Magazine

Find all issues of the AO ITC Innovations Magazine for download here.

Meet the Experts

Directly learn about AO Approved Solutions from the Experts themselves.

Innovation Awards

Recognizing outstanding achievements in development and fostering excellence in surgical innovation.