title: A comparative analysis between ultrasonometry and computer-aided tomography to evaluate bone healing.
abstract: An ultrasonometric and computed-tomographic study of bone healing was undertaken using a model of a transverse mid-shaft osteotomy of sheep tibiae fixed with a semi-flexible external fixator. Fourteen sheep were operated and divided into two groups of seven according to osteotomy type, either regular or by segmental resection. The animals were killed on the 90th postoperative day and the tibiae resected for the in vitro direct contact transverse and axial measurement of ultrasound propagation velocity (UV) followed by quantitative computer-aided tomography (callus density and volume) through the osteotomy site. The intact left tibiae were used for control, being examined in a symmetrical diaphyseal segment. Regular osteotomies healed with a smaller and more mature callus than resection osteotomies. Axial UV was consistently and significantly higher (p ≤ 0.01) than transverse UV and both transverse and axial UV were significantly higher for the regular than for the segmental resection osteotomy. Transverse UV did not differ significantly between the intact and operated tibiae (p=0.20 for regular osteotomy; p=0.02 for resection osteotomy), but axial UV was significantly higher for the intact tibiae. Tomographic callus density was significantly higher for the regular than for the resection osteotomy and higher than both for the intact tibiae, presenting a strong positive correlation with UV. Callus volume presented an opposite behavior, with a negative correlation with UV. We conclude that UV is at least as precise as quantitative tomography for providing information about the healing state of both regular and resection osteotomy.
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, Ribeirão Preto School of Medicine, São Paulo University. Campus Universitário, 14049-900 Ribeirão Preto, SP, Brazil.
authors.forename: Giuliano
authors.initials: G
authors.lastname: Barbieri
authors.forename: Nilton
authors.initials: N
authors.lastname: Mazzer
authors.forename: Eduardo Alvarez
authors.initials: EA
authors.lastname: Ribeiro
authors.forename: Marcello Henrique
authors.initials: MH
authors.lastname: Nogueira-Barbosa
authors.forename: Cláudio Henrique
authors.initials: CH
authors.lastname: Barbieri
mesh_terms: D000818:Animals; D018483:Diaphyses / Q000000981:diagnostic imaging / Q000502:physiology; D004195:Disease Models, Animal; D017102:Fracture Healing / Q000502:physiology*; D008954:Models, Biological; D010027:Osteotomy; D012756:Sheep; D013977:Tibia / Q000000981:diagnostic imaging / Q000502:physiology; D013978:Tibial Fractures / Q000000981:diagnostic imaging* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed / Q000379:methods*; D014463:Ultrasonography / Q000379:methods*