Development and testing of a new self-locking intramedullary nail system: testing of handling aspects and mechanical properties.

A distal interlocking system has been developed which is easy to use, carries out an aligning effect on the distal fracture fragment, reduces the exposure to radiation for the surgeon and the patient, and allows for a decrease in operating time. The goal of this study was to develop and test the handling and mechanical properties of two prototype nails in comparison to a conventional interlocking nail concept (Unreamed Femoral Nail system). It was shown that the prototype designs represent an improvement over this system. Both designs were easy to use. The prototype with the asymmetrically offset interlocking bolts exhibited an exemplary aligning effect on the distal fracture fragment. Both designs showed mechanical stability comparable or superior to that of the standard contralateral control in four-point-bending and axial compression. Given the handling advantages afforded by the new self-locking intramedullary implant system, it would be expected that use of this system would reduce exposure to radiation for the surgeon as well as the patient and allow for a decrease in operating time. This new development may be of particular interest for clinics without access to fluoroscopes in the operating theatre (e.g. in the Third World).