Development

The MicroHip technique, a minimally invasive and relatively gentile surgical method to replace the hip joint, was developed by Dr. Markus C. Michel and Dr. Pierre Witschger of the Orthopaedic Center in Münsingen, Switzerland.

We are often asked how such a development was possible, and why it was not discovered earlier.

"The history of MicroHip begins with an anecdote", says Dr. Markus C. Michel: My first mentor was the world-renowned surgeon Dr. Maurice E. Müller, one of the key pioneers in the development of modern hip surgery. One day, he showed us his new approach to the hip joint for hip surgery—the transgluteal approach. This novel approach required the cutting of much fewer tendons than all other approaches used at that time.

„Super“, I said then as a young assistant, "But wouldn't it be much better if you didn't have to cut any muscles and tendons at all? That always causes permanent damage".

The great mentor smiled at me patiently and answered: "Better, yes, but unfortunately impossible!“

This thought never really left my mind. After I finished my initial Orthopaedic Specialist training and had gained more experience in performing hip surgery, I soon realised that most postoperative complications were not related to the hip implant itself, but rather to problems with the tendons and muscles. The fire within me was rekindled!

If you look into the history of hip replacement surgery, you will soon discover that hip implants were not developed primarily to restore the function of the hip joint, but rather, to alleviate pain.

Anyone who suffers from the pain of hip arthritis knows what I'm talking about:

Hip pain can sometimes be so terrible that nothing else matters! Since hip joint function was secondary to the developers of hip replacement surgery, the tendons and muscles were also secondary.

If only the pain would go away, then it would certainly be nice to be able to do a bit of walking ..." Back in those days, no one dreamed of doing sports or strenuous work after hip replacement surgery.

Development

  1. First hypotheses 1985
  2. Literature studies- 1998
  3. Anatomical studies - 2003
  4. First clinical use - 2005
  5. The first presentation of the standardized MicroHip technique, March 17, 2005 in Interlaken, Switzerland.
  6. 2006 – The first international peer-reviewed publication

My first mentors Prof. Maurice E. Müller (left) with Sir Charnley

The situation today is completely different. Now, patients expect that a good hip implant will allow them to do EVERYTHING they could do before. Because of this, the preservation of tendons and muscles is extremely important. You could say: What good is the most beautiful Ferrari without an engine? One of our patients even made a film showing that people who undergo hip replacement surgery today can return to sports or even climb the North Face of the Eiger (Patient: Johan).

Our project to develop the most tissue-sparing hip replacement procedure possible, meaning, to develop a procedure using a truly minimally invasive approach to the hip joint, was launched in 1998. As is always the case in such a research project, our first task was to study the international literature on hip implant surgery. In this regard, we Swiss had a great linguistic advantage: We could not only read all the literature in English, but also has no problem understanding the articles in German and French. This was a tremendous advantage for our research. Our research soon revealed that from all of the more recent publications available on the Internet, hardly any contained a stimulus for new surgical approaches. We had to resort to the original literature, some of which dates back to the beginning of the 20th century and, of course, was not available in English. We had to order copies of the original articles from large international libraries.

After reading several hundred articles, what we learned was astonishing. The standard surgical approaches used in German and English-speaking countries entered on the side of the hip (lateral approach) or back of the hip (posterior approach).

The problem with all posterior approaches is that the gluteus maximus (largest muscle of the buttocks) must be cut and that at least some fibres of the lesser rotator muscles, important for fine control of hip movement, must be detached. In addition, all posterior approaches have a high risk of hip dislocation.

Equally as problematic was that all of the lateral approaches go through the muscles that stabilize the pelvis (the abductor muscles). When these approaches are used, there is a significant risk of damaging muscles and tendons, which could result in variably severe and permanent limping.

Specifically, we our research revealed that a posterior approach results in a 20% loss of muscle strength for outward rotation, and the lateral approach results in a significant and often painful loss of abductor muscle strength in more than 80% of cases.

Things got interesting in the French literature, where several references were made to anterior (front) approaches to the hip joint. Details are described under "MicroHip – Technique".