[Compression osteosyntheses with the new AO universal nail. Functional principle and biomechanical prerequisites].

The new AO universal nail, with its special construction, allows extremely stable compression osteosynthesis in correctly selected fractures. Compression osteosynthesis with an intramedullary brace has definite advantages for fracture healing and biomechanics. The basic requirement, especially for the long-term maintenance of pressure, is truly stable anchorage of the locking bolts in the bone. Previous investigations by the author have shown that this is only possible in the shaft of the bone. Anchoring stability is not sufficient in the cancellous juxta-articular bone. Five years of clinical experience fully confirm the theoretical expectations.