Misconceptions about the three point bony relationship of the elbow

The 3 bony point relationship of the elbow is an important surface evaluation done in all cases of elbow pathology; its importance is highlighted by the fact that significant emphasis is also laid on this during the specialty board examinations. Confusion about the exact inter relationship exists even in the standard orthopaedic books, with various authors labeling it as isosceles, equilateral or a different triangle, without any citation to back this statement.

The knowledge of the three bony points relationship in elbow was verified after a survey of orthopaedic surgeons undertaken by the senior author, produced disparate answers. Most (63%) classified this as an isosceles triangle. To clarify this further, 200 elbows were prospectively evaluated to measure the distances between these points and the angles were calculated.

Our observations indicate that this triangle is neither isosceles, nor equilateral, but a scalene triangle of unequal sides. There may even be a minimal difference in the 2 sides of the same individual, which has the potential to complicate routine comparison of the two elbows during examination.

The analysis of data revealed that all surgeons were aware of the three bony points relationship; however 21 of the 179 (mostly senior surgeons) did not give too much importance to this evaluation in daily clinical practice. Nine surgeons were not sure what type of triangle was formed, 17 thought it was an equilateral triangle, 40 thought it was some other type of triangle while 113 (63%) thought these points formed an isosceles triangle. This is a reflection of the disparity in the perception about this triangle in the orthopaedic community in general.