Remembering Prof Stephan M Perren

The AO community remembers an AO founding father, scientist, mentor and friend
With the death of Stephan Perren, we have lost one of the great pioneers of the AO. Stephan took over the leadership of the AO Research Institute in the late 1960s. Almost from day he took over, he began to advance our knowledge about the relationship between bone healing and bone surgery.

AO founding member Thomas P Rüedi knew Perren since 1965 when they both served on Allgöwer’s team at Kantonsspital Chur. Perren was a senior resident and Rüedi had just joined as a surgical trainee. Eight years later, after Perren had become head of the Laboratory for Experimental Surgery (now ARI), he was Rüedi’s PhD mentor and coach for six months, providing unlimited enthusiasm and support as Rüedi wrote his thesis. In 1982, Perren, Peter Matter, and Rüedi were privileged to join the AO fathers—as a second generation—in the creation of the AO Foundation.

 Stephan’s brilliant scientific research explained, step by step, all the mysteries surrounding the surgical manipulation of bone and its biological consequences. Without his research, the AO would not have had the solid scientific foundation that was necessary to refute its many opponents who ridiculed the idea that bone could heal under compression.

Each AO clinical advance was matched by an equally brilliant scientific explanation provided by Stephan and his colleagues in the AO Research Institute working under his leadership. He was also a brilliant teacher. During AO courses, we saw him lugging fully stuffed briefcases as he rushed from one lecture theater to another. His teaching was innovative; he enlivened his lectures with many simple teaching aids that he created to explain the concept he was attempting to demonstrate beyond any doubt. He had the gift to make the most complex biomechanical concept simple.

Under Stephan’s leadership, the scientific discoveries developed in the AO Research Institute Davos were matched by the arrival of new implants. First came the justification for compression plating, followed by the Dynamic Compression Plate (DCP), then the Limited Contact Dynamic Compression Plate (LC-DCP), then the Point Contact Fixator (PC-Fix), and finally the limited invasive stabilization system (LISS). Stephan understood research and researchers; he created an environment which attracted creative minds and allowed them to flourish.

“Under his leadership, the AO Research Institute Davos—ARI—evolved to one of the world’s best-known facilities in its field, attracting fellows from all continents,” Rüedi said. “Until his very last days Stephan was still full of ideas in the search for new facts and explanations of the biological and biomechanical secrets of bone healing. Besides his research, he was a great teacher and mentor, an exceptional personality and a wonderful friend. His passing away is an enormous loss for research, the AO community and, of course, for his family and many close friends.”

Not only a dedicated physician and an enthusiastic researcher, who never retired from working on innovative projects, Stephan was also a courageous pilot with many exploits to his credit. He was devoted to his family and a great friend to many. The AO community has lost one of its most distinguished members. He will be very much missed. I have lost a close friend and colleague, whom I admired for the past fifty years.