LAB 2: OBSERVATION OF THE BACK AND

VERTEBRAL COLUMN

Dr. James S. Wilson

Clinical Scenario

The student should study and observe the back keeping the following problem in mind:

• • On May 26, Christopher Reeves was involved in equestrian competition in Culpeper, VA. While approaching a jump, his horse suddenly stopped, throwing Mr. Reeve high into the air. Although he was wearing a helmet, his upper cervical vertebrae were crushed when he landed on the ground on his head. He was knocked unconscious and not breathing. An emergency medical team was at the competition and revived him with mouth-to-mouth resuscitation in the ambulance on the way to the hospital, where he was placed on a respirator.

Osteology and X-Rays

• • • • A. Review the features of a typical vertebra

        B. Identify the anatomical features that are used to distinguish vertebrae of one region from another

        C. Study the 'atypical' vertebrae of each region including: atlas, axis, and T11-T12.

        D. Examine the articulated vertebral column. Identify any major curvatures - How do they develop? Where is the vertebral column most prone to injury and why?

        E. Examine and classify the clinical condition(s) of specimens with abnormal curvatures of the spine. Discuss the mechanisms by which kyphosis, lordosis and scoliosis may develop.

        F. Identify and classify the joints formed between adjacent vertebrae. What movements are possible at these joints? What range of movements is the vertebral column capable? Where do dislocations most frequently occur and why? What are the clinical consequences of vertebral fracture and/or dislocation at different levels? Where did Mr. Reeves most likely injure his vertebral column?

        G. What is a herniated disc? A disc most often herniates in which direction and why? Which structures can be functionally compromised by a herniated disc and why? How does a patient with a herniated disc present? Identify a herniated disc on an MRI. Clinically, how is a herniated disc treated?

        H. What is the clinical significance of the sacral hiatus?

Surface Anatomy

Identify the following bony landmarks on yourself and/or on a consenting lab partner using palpation. (Work to develop a professional attitude).

• • A. Inion

    B. Transverse process of Atlas

    C. The spine of C7

    D. Superior and inferior angles of the scapula and the base of the spine of the scapula- At what vertebral levels are these landmarks located?

    E. Iliac crest - A line connecting the crests crosses which vertebra?

    F. Posterior superior iliac spine - The dimple formed by this structure is found at what vertebral level?

    G. Natal cleft

    H. Sacral hiatus

    I. Ischial tuberosity

Dissection (Grant's Dissector, pages: 81 - 86)

I. Salient features

• • A. Appreciate that the different functional groups of back muscles are organized in layers.

    B. Surgical Undermining: This type of blunt and sharp dissection is used surgically to free skin up from superficial fascia, thereby allowing easier closure of a wound with less tension on the sutures and resulting in better healing and less scar formation. You will be developing this skill as the skill is removed to reveal the first layer of back muscles.

II. Questions

• • A. How many anatomical layers of muscles are found on the back? List the muscles found in each layer. Explain the embryonic basis of their innervation.

    B. Define the triangle of auscultation and lumbar triangle? What are their clinical significance?

    C. After completing the laminectomy, identify the following ligaments: posterior longitudinal, anterior longitudinal, supraspinous, interspinous, ligamentum nuchae, and ligamentum flavum. Which ligaments are damaged in "whip lash" and why?

    D. Describe the relationships of the spinal cord, spinal nerves, meninges and vertebral column at different levels.

    E. Where is a spinal tape performed on a child and on an adult? Why are these locations used? How are these locations identified on the patient? List sequentially all the structures pierced by the needle during spinal tap. What clinical procedures can be carried out after completing a spinal tap?

    F. What is caudal anesthesia? How and when is it produced? List the structures pierced by the needle during caudal anesthesia.