History of the AO



 AO Foundation Timeline


 We recommend viewing this timeline in fullscreen​


 More about us


Participants on an AOSpine course 
AO Foundation – Celebrating 60 years of transforming surgery and changing lives

On November 6, 2018 the AO Foundation celebrated 60 years of the transforming surgery and changing lives. Take a look at some of the milestones that what we've achieved so far.  

Faculty Education Program ​ 
AO Facts & Figures

Find out more about the AO, its origins and current global reach. 

The AO has a presence across the world, and is the recognized leader in research, innovation, and education for health care professionals specializing in trauma and musculoskeletal disorders. 



Participants on an AOSpine course 
The AO Science Path

In 2018 the AO Science Path was unveiled; a series of five signs erected near the AO Center in Davos that describe the AO's origins and achievements.

Each of the signs cover a different key area of the AO's activity: Education, Innovation, Patient Outcomes, the AO Center, and AO in Davos. 

Click the image to view a preview video of the AO Science Path. We invite you all to come walk the AO Science Path with us.

AO origins

The late 1940s saw the culmination of the random development of fracture fixation devices starting in the mid 19th century, an eclectic mix of implants from a great variety of surgical "authors", none designed to complement the others. The biology of bone healing had not been investigated scientifically and knowledge was sparse.

In 1949, a Belgian surgeon, Robert Danis, published a book entitled Théorie et Pratique de l'Ostéosynthèse. This, his second book on fracture fixation, documented his concepts of early functional rehabilitation following rigid fracture fixation.

Danis' observation that, with anatomical reduction and rigid fixation, diaphyseal bone healed without external callus attracted the attention of a young, innovative Swiss surgeon, Maurice E Müller, who visited Robert Danis in March 1950. This auspicious meeting fired the mind of Dr. Müller and he gathered about him a small group of Swiss surgeons who shared his interests, namely Robert Schneider, Hans Willenegger, and Martin Allgöwer.

The decision was reached to form a study group, Arbeitsgemeinschaft für Osteosynthesefragen, or AO, to conduct research in bone healing, with particular reference to the influence of the mechanical environment of the fracture upon its healing pattern. Along with a group of surgeons, who first met together in March 1958 at Chur, this embryonic AO took a number of initiatives.

Listen to the SRF broadcast celebrating 100 years since the birth of Martin Allgöwer.

Read the new biography Maurice Edmond Müller—In His Own Words published to mark the AO's 60-year anniversary and the 100th anniversary of Müller's birth.

In the AO's 60th anniversary year, an in-house team of broadcast professionals, filmmakers, educators, and surgeons, combined forces to create an animated video about the AO's founders and key milestones in its development since 1958. Watch the videos below to find out more about the AO's history, in an engaging and entertaining format.


 AO Foundation 60th Anniversary Animations


AO Foundation History

Explore the highlights of the first 60 years of the AO



The Clinical Divisions

Learn about the establishment of AOVET, AOCMF, AOSpine, and AOTrauma 


The Institutes

Learn about the AO Education Institute, AO Research Institute Davos, AO Clinical Evaluation and Documentation, and AO Technical Commission



The Future

A glimpse into what the future holds for the AO



Establishment of a Laboratory for Experimental Surgery

Laboratory for Experimental Surgery at the Obere Strasse in DavosLaboratory for Experimental Surgery
at the Obere Strasse in Davos

The first undertaking was the establishment of a Laboratory for Experimental Surgery (Forschungsinstitut) in Davos by Martin Allgöwer. Herbert Fleisch was appointed its director in 1963, and Stephan Perren in 1967. The early work that was conducted, together with that of Drs Schenk and Willenegger, laid the foundation for the current knowledge of the direct and indirect healing of fractures, as well as the influence of rigid fixation upon the healing of non unions. Their classical landmark experiments are known to fracture surgeons throughout the world.

Secondly, the early AO pioneers forged a strategic alliance with the Swiss precision engineering discipline and worked closely with Robert Mathys to develop an integrated system of implants and instruments. Some time afterwards Fritz Straumann, a metallurgical specialist, was included. These instruments and implants would enable surgical fracture fixations to fulfill the biomechanical priniciples which were the consequence of the experimental work. This fruitful collaboration led to the evolution of the AO instrumentarium and of the surgical techniques for its use.

The third arm of this endeavor followed the decision to document carefully their surgical cases so that lessons could be learned from the clinical application of the emerging technology; hence the Documentation Center.

All these elements of the original AO grew on a parallel basis and this led to the need to restructure the whole organization. In December 1984 the AO Foundation was constituted, which took on the responsibility of the various commissions for research, development, education, documentation and international affairs.

Constitution of AO Foundation at Davos in December 1984
Constitution of AO Foundation at Davos in December 1984

Aims of the AO pioneers

The AO Center in Davos, SwitzerlandThe AO Center in Davos, Switzerland

The aims of the AO pioneers were not to popularize the indiscriminate use of surgical fixation, but rather to evaluate scientifically its place in the care of the injured and, where appropriate, to refine surgical practice so that the outcome for the victim of injury could be optimized. The entire laboratory, as well as the Foundation, moved to a custom built AO Center on the outskirts of Davos in 1992.

Increased growth in certain regions of the world led to the setting up of AO Regions in order to provide more localized support. Increased growth in certain regions of the world led to the setting up of AO Regions in order to provide more localized support. There are now five AO Regions: Asia Pacific, Europe and Southern Africa, Latin America, Middle East and Northern Africa, and North America.  These regions are forging ahead with making the AO more relevant in their regions. This is all done with specialized support from the AO Center in Switzerland. Today the AO has a membership of over 20,000 surgeons, operating room personnel, and scientists, and an extensive network of more than 170,000 health care professionals in 124 countries and builds on its legacy every day.

The AO broadens its scope

Participants on an AOSpine courseParticipants on an AOSpine course

By the 1990s the world of surgery was changing and in response the AO broadened its scope. By 1996 the AO was involved in Computer Aided Surgery. The year 2003 saw the founding of AOSpine, a unit dedicated to improving the quality of medical service provided to spine patients through education, research, documentation, and communication. The opportunities provided by the changing medical world led to a shift into the field of biotechnology with the setting up of the AO Biotechnology Advisory Board in 2003. In 2004 the Academic Council approved the launch of four Clinical Priority Programs, an initiative to focus research and development on issues relevant for the surgeon.

The engagement in new media eventually led to strategic cooperation with BrainLAB in the field of computer-assisted surgery, resulting in the introduction of the first CAS/MIS trauma modules in 2005.

AO Surgery Reference being used in the operating roomAO Surgery Reference being used in the
operating room

AO Surgery Reference, a unique online reference tool designed for everyday clinical life was introduced in 2006. It was launched with 6 anatomical modules which are continually being added to, making AO Surgery Reference a dynamic reference tool.

Perhaps the greatest change of recent times came in 2006 when the AO and Synthes agreed to new contracts under which Synthes will acquire existing “Synthes” trademarks, brands, and intellectual property from the AO. Further cooperation also forms part of the agreement.

In 2018 the AO Foundation celebrates 60 years of transforming surgery and changing lives.