Quantification of fracture healing with three-dimensional computed tomography.
Quantitative methods are necessary for an objective evaluation of fracture healing. Three-dimensional computed tomography (CT) for the measurement of callus volume and density could be such a method and was investigated in an animal model. In 23 goats a closed tibial fracture was created and stabilized with a cast. The animals were killed at 2, 4 and 6 weeks for radiographical, CT and biomechanical analysis. From the CT scans a three-dimensional reconstruction of the callus was made to measure its volume and mean density. At 2 weeks the callus volume had already reached its maximum. In contrast, callus density, torsional strength and torsional stiffness increased over time (P < 0.0001, analysis of variance, ANOVA). Multiple regression analysis showed that the callus volume was not related to the torsional properties. However, callus density was a significant explanatory variable for both torsional strength (R2 = 0.72, P < 0.0001) and torsional stiffness (R2 = 0.82, P < 0.0001). Therefore, callus density as measured by three-dimensional CT is a predictor of the extent of fracture consolidation. CT with three-dimensional reconstruction of the callus seems a valid technique for the quantification of fracture healing.
den Boer
F C
FC
Department of Surgery, Free University Hospital, Amsterdam, The Netherlands.
Bramer
J A
JA
Patka
P
P
Bakker
F C
FC
Barentsen
R H
RH
Feilzer
A J
AJ
de Lange
E S
ES
Haarman
H J
HJ
D000704:Analysis of Variance; D000818:Animals; D001696:Biomechanical Phenomena; D015519:Bone Density; D002146:Bony Callus / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002370:Casts, Surgical; D004195:Disease Models, Animal; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D006041:Goats; D011856:Radiographic Image Enhancement / Q000379:methods*; D012044:Regression Analysis; D012680:Sensitivity and Specificity; D013978:Tibial Fractures / Q000000981:diagnostic imaging* / Q000628:therapy; D014057:Tomography, X-Ray Computed / Q000379:methods*