SIMPLIFIED CALCULATION FOR CORRECTIVE OSTEOTOMIES OF LONG BONES.

OBJECTIVES: To present a simplified calculation for the measurement of osteotomy wedges used for the correction of angular uniplanar deformities of long bones and to compare the simplified calculation proposed (circumferential calculation) with the classical trigonometric calculations, as well as with the exact calculation performed by computer software AutoCADtm.

METHODS: The software AutoCADtm was used to calculate the bone wedges, for mathematical comparison of the three main groups, each one of them containing 18 hypothetical bone deformities which angles ranging from 5 to 90 degrees, with 5 degrees intervals between them.

RESULTS: In the analysis of 18 deformities, the hypothetical angular bone, the average lengths of the corrective wedges obtained by the trigonometric, circumferential and the exact metods were, respectively, 32.21 ± 16.81 mm, 33.16 ± 18.63 mm and 35.22 ± 23.52 mm. There was no statistically significant difference between the three calculation methods (p>0.05).

CONCLUSION: The circumferential calculation proposed in this study is useful for being accurate and simple, not requiring any trigonometric knowledge. Level of Evidence II, Experimental Study.