[Initial clinical experience with osteosynthesis of femoral shaft fractures with a newly developed intramedullary implant (claw interlocking nail)].
The implantation of distal interlocking screws in interlocking nailing can be difficult and time-consuming. With the AO Universal Femoral Nail as the basis, an implant was designed with which distal interlocking is accomplished from the inside of the nail by means of a simple claw mechanism. Instrumentation and interlocking are possible from the proximal standard approach, so that an additional operation adjacent to the knee (which is necessary when interlocking bolts are used) is superfluous; neither for the insertion nor for the removal of the interlocking mechanism is an image intensifier necessary. We stabilized 24 femoral shaft fractures with this new interlocking nailing device [20 fresh fractures, 3 refractures and 1 pathologic fracture caused by tumor metastasis from chronic myeloid leukemia (CML)]. The mean age of the patients concerned was 34.8 years (18-57 years). Fractures were classified according to the Müller classification with 11 type-A fractures (45.8%), 9 type-B fractures (37.5%) and 4 type-C fractures (16.7%). There were only 2 cases (8.3%) with open fractures. In 11 cases (45.8%) the fracture was located in the midshaft region, in 6 cases (25.0%) in the proximal shaft, and in 7 cases (29.2%) in the distal femoral shaft. Multiple trauma was present in 11 patients (45.8%), while in 8 patients (33.2%) the femoral shaft fracture was the only major injury. Full weight-bearing was allowed after a mean of 4.4 weeks (0.7-8.2 weeks). In 1 case we saw a deep venous thrombosis with pulmonary embolism obvious on clinical examination and scintigraphy. Two patients died of their multiple trauma, and of cachexia the patient with the CML metastasis died 6 weeks after stabilization.(ABSTRACT TRUNCATED AT 250 WORDS)