In the late 1940s, the biology of bone healing had not been scientifically investigated and knowledge was sparse. Industrial accidents were the most common cause of fractures. Hospital treatment for leg fractures usually consisted of several weeks in wire traction with attached plaster casts. Once discharged from a hospital, patients were mostly left to their own devices, and joint stiffness, permanent muscle atrophy, or postthrombotic oedema were common consequences. In 1945, the Swiss Accident Insurance (SUVA) was paying lifetime invalidity pensions to 40 percent of patients who had suffered a tibial fracture. For patients who had suffered a femoral fracture, the number was significantly higher, at 70 percent.
In March 1950, Maurice Müller, a young, innovative Swiss surgeon who was travelling Europe to learn more about internal fixation, visited the then 70 years old Robert Danis in Brussels. Danis had been practicing osteosynthesis as a “lone wolf” for 25 years and had published a book, “Théorie et Pratique de l’Ostéosynthèse”, in 1949. Müller was with Danis for just one day but later admitted that his book was one of the most important works he had ever read. In the following years, Müller started to apply the techniques of osteosynthesis at various hospitals in Switzerland and gathered a circle of like-minded young surgeons around him.
On November 6, 1958, a group of 13 Swiss surgeons—among them founding fathers Maurice Müller, Robert Schneider, Hans Willenegger, Martin Allgöwer, and Walter Bandi—convened at the Hotel Elite in Biel, Switzerland, to establish the “Arbeitsgemeinschaft für Osteosynthesefragen”, dedicated to the techniques of internal fracture fixation.
All members of the newly founded AO were to adhere to its foundational principles:
Even before the AO’s founding, Martin Allgöwer had found an adequate location to carry out the group’s intended research. The former Institute of Pathological Anatomy at Villa Fontana in Davos, Switzerland, had recently been abandoned and appeared adequate for the installation of laboratories. The building, however, still had to be structurally modified and equipped to fit its new purpose. Each of the AO’s founders made a significant financial contribution towards the start-up costs for their first research facility, and the “Laboratorium für experimentelle Chirurgie” (Laboratory for Experimental Surgery) was officially established on June 18, 1959. Allgöwer became its first director.
All surgeon members of the newly founded AO were obliged to document every single case of osteosynthesis they performed. Maurice Müller designed colored code sheets to document the operation and its check-ups at four and twelve months. Each sheet, including a set of x-rays, had to be sent to the AO Documentation Center in Davos, where the information was used to produce two punch cards, one of which remained in Davos while the other was sent back to the submitting surgeon. Within its first year, the center registered 1000 cases and made 10’000 x-ray copies available for analysis.
The first implant designs by Maurice Müller and manufacturer Robert Mathys reflected the aim to achieve absolute stability and combine it with pressure on the bone to maximize healing. The first plate they developed was the standard compression plate (CP) with round holes and screws, and the initial standard “AO Instrumentarium” was used in the first AO course in 1960, primarily for long bone fractures to the upper and lower leg.
Led by AO founding fathers Maurice Müller and Martin Allgöwer, 69 surgeons attended the first AO course in Davos, held at the Laboratory for Experimental Surgery, to learn the latest techniques in osteosynthesis. After completing the course, surgeons were entitled to purchase their own set of AO instruments.
The AO Technical Commission was established as the organization’s body for the development and approval of surgical techniques, implants, and instruments. The AO TK controlled all the catalogues and commercial material and made sure that the products were identical to those described in the AO manuals and textbooks. Only instruments and implants that were approved by the AO TK were allowed to be sold.
In their 1963 manual «Technik der operativen Frakturenbehandlung» (Technique of Surgical Fracture Treatment), the AO’s founders postulated the following principles:
