“Autologous cruciate ligament reconstruction can offer a long-term solution”

Since 2008, Dr. med. Adalbert Missalla, Orthopedics Specialist and Sports Physician, specializing in shoulder and knee surgery, has successfully performed about 3,000 anterior cruciate ligament reconstructions without the use of screws. In his interview, he reports how he developed the patented solution with certified engineer Helmut Reinhard from BIOMEDIX®, developer and manufacturer of the instrument for the All-Press-Fit technique.

life: In the All-Press-Fit technique, a tendon implant is used for the reconstruction of the cruciate ligament and secured on the femoral side of the implant by locking it in position with a bone cylinder. What convinced you of Felmet’s procedure?

Dr. Missalla: The possibility of only working with the body’s own material and of being able to secure the tendon with a bone block which is harvested when creating the tunnel for the implant. Autologous cruciate ligament reconstruction like this can offer a long-term solution. It is based on natural biological processes and has a much lower re-rupture risk. Foreign material poses a higher infection rate and always causes a reaction. When screws are inserted, they often damage the bony parts of the joint, the tissue and sometimes the implant. Bioabsorbable screws sometimes do not dissolve completely and can result in inflammation or cysts, which impairs in-growth and healing as well as treatment. Plus, foreign materials sometimes break and cannot withstand the load. The practical implementation of the original technique didn’t always have the ideal outcome during the fixation process. I had many problems, such as collisions during the drilling process or uneven bone blocks on removal.

How did the further development of the technique come about with BIOMEDIX®, the manufacturer of the associated instrument ACL 1.0?

Dr. Missalla: I see problems as a challenge and try to solve them. This approach resulted in close cooperation with Helmut Reinhard, the company’s Managing Partner. He accompanied me into the operating theater. We realized quickly that, in order to create a biomechanically lasting Press-Fit fixation, we had to redefine the term ‘Press Fit’. The reason being that the securing process of a thigh’s semitendinosus tendon with almost structurally viscous behavior is different from a Press-Fit fixation used for patellar tendons. Based on lab test results, we developed a mathematical model in order to describe the correlations of the tendon’s primary stability and its ability to compress using a Press-Fit factor. It also provided us with the basics for asymmetric dilation which is based on the tendon’s diameter determined during surgery.

Cruciate ligament reconstruction using the Press-Fit-Hybrid® technique

The new instrument ACL 2.0 is also part of the Press-Fit-Hybrid® technique you described. What sort of problems have you addressed with it?

Dr. Missalla: We developed stop technology to prevent lateral femoral rupture and to prevent artifacts caused by the collision of the rotating AlphaLock®-Turbo-Cutter with the tibial target device. We also developed a special reamer to prevent fractures in the area of the tibial plateau, an extractor with a centering zone for extracting circular cylinders, and a special preparation board to visualize reproducible transplants. The AlphaLock®-Turbo-Cutter is very important for this technique. It is used to simultaneously create the drilling channel and the bone cylinder within just a few seconds without causing trauma – both free from necrosis, which would otherwise pose a risk of complications.

Which achievements do you associate with the technique developed by Helmut Reinhard?

Dr. Missalla: Secure fixation of the implant near the joint and quick in-growth of the bone cylinder after four to six weeks. In addition to reduced susceptibility to infection, patients benefit from improved mobility and accelerated recovery overall. The revision rate is extremely low, and the scans obtained during long-term follow-up show that the bone cylinder has fully grown in. Sometimes, arteries can even be seen in the implant.

Bauerfeind AG bears no legal or sales-related relation to BIOMEDIX® or the products mentioned by Dr. Adalbert Missalla regarding the surgical techniques in this interview. The statements about the products in this text were reviewed and approved by certified engineer Helmut Reinhard, Managing Partner at REINHARD Feinmechanik GmbH & BIOMEDIX®.

Images: Udo Schönewald, Dr. A. Missalla