The Fixion Nail: New Kind of Intramedullary Nailing

The fixion nail is an expandable, inflatable nail which is inserted in a folded state via the typical accesses into the tibia, the femur and the humerus. Saline solution is driven with a pressure of up to 70 bar into the nail via a pressure control valve which is additionally placed in the driving-in instrument. This expands the nail in the bone and jams the entire nail in the medullar space. This prevents the nail from rotating in the entire shaft down to the metaphyses. Lateral locking is no longer required. Due to the various diameters available in the folded as well as expanded state, it is possible to offer an implant which is practically adaptable to every different medullar space diameter of the patient. In position and the optimum implant in hip and knee joint surgery, this nail system effectively contributes to individually adapted implant surgery in the field of traumatology. Currently, the system is available as a chrome-nickel-steel nail. Research is currently being conducted to equip the system with a titanium alloy.

Since July 2000, a total of 12 tibia and humerus shaft fractures have been treated with the Fixion Nail at the surgical clinic of the Johanniter-Krankenhaus (Hospital) in Duisburg-Rheinhausen. It was possible to treat not only classical fractures in the middle of the shaft but also fractures of the proximal and distal diaphyses bordering on the metaphyses of the tubular bones. By individually adapting the nail to the medullar space, a high exercise and load stability was generated, thus enabling the patients to exert a load of up to half the body weight on the bone within 4 weeks. Notably, intensive callus formation began very quickly and the patient reported hardly any pain.

During this period, we checked the patients clinically and radiologically after 6, 12 and 24 weeks and found that the implant for the tibia was well tolerated by the patient. The very brief periods of illness were particularly noticeable. Young patients between the ages of 25 and 35 years were able to take up their occupations again on average 3 to 5 months after the accident. We still do not have any long-term results after 3 months for the humerus. Small longitudinal groove jamming as well as a combination of longitudinal groove jamming and lateral locking can be applied for the humerus. We treated 2 patients with a sub-capital comminuted fracture of the humerus in this manner and were able to record a high exercise stability and low sensation of pain very shortly after surgery.

Compared to the lateral locking system, the operative screening time was reduced drastically. According to a corresponding learning curve the implantation time alone is approx. 30 minutes. Because the longitudinal skin incision above the patellar tendon is only approx. 4 cm hardly any scars are formed. Bored as well as non-bored insertion of the nail is possible. During the insufflation of the NaCl solution via the pressure control valve, the medullar nail should not be expanded in one go. Our experiences have shown that it is more effective to inflate the nail up to approx. 40 bar first and then to relieve the pressure to allow the nail to adapt to the anatomical conditions in the medullar space. This results in the typical phenomenon of hour-glass shaped tapering in narrow parts of the medullar space followed by club-shaped expansion in the wider parts of the medullar space. Nevertheless, the transversal stability remains the same. It is essential that pressure is built up slowly in the medullar nail so that the medullar nail can rest against the inner cortical membrane and not cause a dislocation of the individual fracture fragments.

Now after 8 months experience in surgery and postoperative treatment, we believe that the fixion nail is a very interesting alternative in the field of stabilizing implants in the medullar space. It is remarkable for its easy implantation and handling with low screening times during the operation. Special mention must be made of the early load capacity of the nail and excellent tolerance in the patients.