Computer algorithms for three-dimensional measurement of humeral anatomy: analysis of 140 paired humeri

A Novel Method for the Approximation of Humeral Head Retrotorsion Based on Three-Dimensional Registration of the Bicipital Groove

“…As a reference, we also assessed the LBR error. The mean LBR error was 6.4°, which corresponds to the intra-individual bilateral differences in humeral head retrotorsion 14,15 . While the LBR error was <5°in almost half of the cases, in 26% of the individuals, the LBR error was between 5°and 10°, and in an additional 26% of the cases, it was >10°.…”

“…We measured the retrotorsion of each humerus between the articular margin plane and the elbow tangent plane, as previously described (Fig. 4) 15 . Consequently, the LBR error is the absolute difference in the retrotorsion angles of both sides of an individual.…”

“…The average height was 172.4 ± 8.7 cm (range, 154 to 187 cm), and the average weight was 68.4 ± 16.9 kg (range, 37 to 108 kg). The specimens were also used in previous studies 5,15,16 . Exclusion criteria were the presence of osteoarthritis or previous trauma.…”

“…However, and especially if there are underlying side-toside differences in the twist about the humeral axis (humeral torsion) in a given individual 14, 15 , these template-based approaches using the contralateral anatomy might introduce an error into the quantification of the deformity. A recent study by our group demonstrated that, for the 3D assessment of distal humeral deformities, a proper segment selection of a healthy part of the humerus yields a deformity assessment of the distal part of the humerus that is less prone to bias arising from inherent bilateral differences 16 .…”

A Novel Registration-Based Approach for 3D Assessment of Posttraumatic Distal Humeral Deformities

“…The current state-of-the-art method in 3D deformity assessment relies on comparison of the pathological bone with a reconstruction template representing the normal anatomy. Currently, the contralateral anatomy most commonly serves as the basis of such reconstruction templates 1,4-8 because most geometric measurements are similar between both sides of an individual [7][8][9] . A surface registration method is applied to superimpose the model of the pathological side onto the mirrored model of the contralateral side 1,3,5,10 .…”