An inquiry into the causation, diagnosis, and treatment of fracture of the internal table of the skull / by William Frederic Teevan.

  • Teevan, W. F. (William Frederic), 1834-1887.
Date:
1865
Catalogue details

Licence: Public Domain Mark

Credit: An inquiry into the causation, diagnosis, and treatment of fracture of the internal table of the skull / by William Frederic Teevan. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    Let A B (Fig, 1) be a section of the skull. Draw two vertical lines, C E and D F, parallel to one another. Now, if pressure be applied at G, temporary depression takes place, and the bone assumes the shape of H K (Fig. 2), and the lines C E and D F, are no longer parallel to each other, but converge towards each other at the upper surface, I L, J M, so that the distance from I to J is less than that from C to D, but the distance from L to M is greater than that from E to F, signifying that the atoms of bone in the upper surface from I to J have been brought nearer to each other, or compressed, whilst the atoms of bone in the lower surface from L to M have been extended or separated from each other; therefore, if any fracture take place, it is clear it must do so in the line of extension L M, and at that point in the line where the greatest extension is going on, which is at N, exactly opposite the spot O, where the pressure was applied. Proof: Take a cane, slightly bent, say A B (Fig. 1), and insert two pins or wires, C E, D F, vertically, and parallel to each other: the more the pins project at each sirrface, the more manifest will be the result. Exert pressure at G till the cane is made flatter, H K. It will now be found that the wires are no longer parallel to each other, but converge along the upper surface, so that the distance between them from I to J, is less than that from C to D ; but the distance from L to M is greater than that from E to F, showing cleai’ly that the atoms along the lines I J have been com- pressed and brought nearer to eacli other, whilst those :dong the hne L M have been extended; consequently, if any fracture take place, it must commence at N. If the pressure on the cane be continued till it breaks, it will be found that it commences to break at the point N. A familiar instance of a fracture accidentally occurring in nature, similar to fracture of the internal table only, is when the ice cracks imder pressure. It will often be seen that there are cracks in the under surface of the ice and none in the upper, and it will always be found that when a crack takes place it commences in the under surface, thus illustrating the fact that the fracture commences in the distal side, which is the line of extension.