In vivo standardization of bone ultrasonometry of the clavicle

OBJECTIVE: The assessment of fracture union includes physical examination and radiographic imaging, which depend on the examiner’s experience. The development of ancillary methods may avoid prolonged treatments and the improper removal of implants. Quantitative bone ultrasonometry has been studied for this purpose and will soon be included in clinical practice. The aims of the present study were to assess the feasibility of using this technique on the clavicle and to standardize its in vivo application. METHODS: Twenty adult volunteers, including 10 men and 10 women without medical conditions or a previous history of clavicle fracture, underwent axial quantitative ultrasonometric assessment using transducers in various positions (different distances between the transducers and different angulations relative to the clavicle). RESULTS: Similar values of wave propagation velocity were obtained in the different tested set-ups, which included distinct distances between the transducers and angular positions relative to the clavicle. There were significant differences only in the transducers positioned at 0° and at 5 or 7 cm apart. CONCLUSIONS: The use of bone ultrasonometry on the clavicle is feasible and the standardization of the technique proposed in this study (transducers placed at 45° and at 7 cm apart) will allow its future application in clinical trials to evaluate the healing process of diaphyseal fractures of the clavicle

Avaliação ultrassonométrica da osteossíntese de compressão axial: estudo experimental Ultrasonometric evaluation of axial compression osteosinthesis: experimental study

OBJETIVO: Medir a velocidade de propagação do ultrassom (VU) através de uma osteotomia transversal em tíbias de ovelha, antes e após a fixação com uma placa DCP. MÉTODOS: Foram utilizadas dez montagens de uma placa DCP com o segmento diafisário das tíbias, no qual era feita uma osteotomia transversal. Foi realizada a medida subaquática transversal, nos planos coronal e sagital, e axial da VU, no osso íntegro, nas montagens sem osteotomia e, depois, com osteotomia sem e com a compressão axial pela placa DCP; comparações estatísticas foram feitas ao nível de significância de 1% (pOBJECTIVE: To measure the ultrasound propagation velocity (UV) through a tibial transverse osteotomy in sheep, before and after the fixation with a DCP plate. MATERIAL AND METHODS: Ten assemblies of a DCP plate with the diaphyseal segment of tibiae, in which a transverse osteotomy was made, were used. Both coronal and sagittal transverse and the axial UV were measured, first with the intact bone assembled with the plate and then with the uncompressed and compressed osteotomy; statistical comparisons were made at the 1% (p<0.01) level of significance. RESULTS: Compared with the intact bone assembly, axial UV significantly decreased with the addition of the osteotomy and significantly increased with compression, presenting the same behavior for the other modalities, although not significantly. DISCUSSION AND CONCLUSION: In accordance with the literature data on the ultrasonometric evaluation of fracture healing, underwater UV measurement was able to demonstrate the efficiency of DCP plate fixation. The authors conclude that the method has a potential for clinical application in the postoperative follow-up of DCP plate osteosinthesis, with a capability to demonstrate when it becomes ineffective. Laboratory investigation