Pedicle

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A Moment in History

William S. Halsted, MD
(1852 – 1922)

American anatomist, teacher, and surgeon, William Stewart Halsted was born in New York City, USA to a wealthy family of English origin. His father was involved in charitable work and Governor and trustee to a city hospital. Not a brilliant student initially, Halsted took an undergraduate in Liberal Arts in Yale, CT., after which he entered the Medical College of Physicians at the Columbia College, where he excelled.

As a second-year medical student Halsted applied and obtained a position in surgery at a local hospital. In here he learned about Lister’s antiseptic technique and became an adamant proponent of it to reduce infection. In 1877 Halsted obtained his MD. After a short time as House Physician at the New York Hospital, Halsted traveled to Europe to further his education studying for two years at the Universities of Vienna, Leipzig, and W?rzburg.

Besides being at the forefront of surgical and antiseptic techniques (introducing the use of rubber gloves in surgery), Halsted was extremely concerned with the way medical students were taught in the US. He pioneered bedside clinical round discussions with the medical students after two years of basic sciences studies. Halsted developed the idea of a patient chart; he also developed the residency program for medical students in use today.

Halsted is probably the most influential researcher and surgeon at the turn of the century. He dedicated time to the study of intestinal anastomoses and the use of silk as a suture material. His experimental work in 1887 proved that the inclusion of the submucosa layer in an anastomosis was mandatory, as well that a single layered anastomosis was enough to attain closure. Perhaps Halsted’s most important contribution was the application and use of the scientific method to surgical questions. Halsted’s principles, also known as "Halsted's Rules of Surgery", set the standards used today in surgical suturing and surgical stapling.

He also pioneered the development and surgical techniques for radical mastectomy as a treatment for breast cancer.

As a side effect of this studied in anesthesia and the use of cocaine for anesthesia, Halsted became addicted to this substance, a problem that followed him through the years. Without impairing his capacity as a researcher and a surgeon, Halsted eventually recovered. He died in Baltimore in 1922 as a complication to surgery.

Sources:
1. Dubay, A. D., & Franz, G. M. (2003). Acute Wound Healing: The Biology of Acute Wound Failure. Surg Clin NA, 83, 463-481.
2. Halsted, W. S. (1887). Circular Suture of the Intestine - An Experimental Study. Am J Med Sci, 436-461.
3. “William Stewart Halsted: his life and contributions to surgery” Osborne, P. Lancet Oncol 2007; 8: 256–65
4. “William Stewart Halsted: Surgical pioneer” Burress, P Endoc Today (2010), 8: (2) 22
5. “William Stewart Halsted (1852–1922) Neurological stamp” Haas, LF J Neurol Neurosurg Psych 2000;69:641
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Details: Published: July 30, 2015

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[UPDATED] The word [pedicle] is a derivative from the Latin [pediculus] meaning “a small foot”, a “stem”, or a “stalk”. The Latin term [pediculus] is itself a derivative of [pes/pedis] meaning “foot”.

[Pedicle] is also used to denote structures that lie at the root of “foot” of an organ, as in the “renal pedicle” (an older anatomical term) or in the pedicle of a sessile tumor. It is also used in surgery, to denote the vascular pedicle or “stalk” of a free tissue graft.

Since a pedicle is also the “foot” of an arch, the term has also been used to denote the base of the vertebral arch. Thus explained, each vertebra has bilateral bony bridges between the vertebral body anteriorly and the laminae posteriorly. These are the vertebral pedicles, which form the lateral walls of the vertebral canal.

The vertebral pedicles have different characteristics (width, length, angulation) depending on their vertebral level. This is important for spine surgery where pedicle screws are used:

• Lumbar vertebra: has a thicker, wider pedicle that tends to angulate posterolaterally
• Thoracic vertebra: has a thinner pedicle that looks almost anteroposteriorly
• Cervical vertebra: the pedicle is very small and thin, angles quite laterally, and forms the medial border of the transverse foramina.

The accompanying image is an inferior view of a thoracic vertebra showing the location of the vertebral pedicles. Click on the image for a larger version.

Additional information: “Vertebral pedicle anatomy in relation to pedicle screw fixation: a cadaver study” Chaynes et al. Surg Rad Anat (2001) 23:2, 85-90
Image property of: CAA.Inc.. Photographer: D.M. Klein.

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