Download 7 The Back Injury Claim

7
The Back Injury Claim
lion Americans suffer from low back pain each year,
and 50% of those who experience an episode of
low back pain will have a repeat occurrence within
one year.
These statistics are staggering and demonstrate
the great care that must be exercised in handling
a back injury claim to ascertain the real cause of
the problem. This chapter examines the anatomy
of the spine and includes a discussion of the bones
that make up this structure, the cushions that allow
the spine to bend, and the soft tissues that hold the
vertebral column together. Information about spinal injuries and surgical repair techniques is also
presented, as well as litigation tips in order to assist
the practitioner in presenting or defending a back
injury claim.
WHAT DOES 80% of the population have during their lifetime and is the second leading cause
of missed time from work? Back pain is a major
health problem that extracts an enormous emotional and financial toll. Musculoskeletal problems
cost the economy more than $215 billion annually,
and each year, 14% of the population suffers a back
impairment that will limit activities of daily living.
(47 Am. Acad. Orthopaedic Surgeons Bull. (Oct. 1999).)
Back symptoms are the second leading reason for
visits to physicians, and the most frequent cause for
orthopaedic and neurosurgical consultations. (Taylor, Deyo, Cherkin, and Kreuter, “Low Back Pain
Hospitalization—Recent United States Trends and
Regional Variations,” 19 Spine 1207 (1994).) It is
also the most common reason for disability in individuals under the age of 45. (Linda S. Cunningham
and Jennifer L. Kelsey, “Epidemiology of Musculoskeletal Impairments and Associated Disability,” 74
Am. J. Pub. Health 574 (1984).) In excess of 65 mil-
ANATOMY OF THE SPINE • The spine extends
from the base of the skull to near the bottom of the
pelvis and consists of a number of bones, the verte95
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brae, each of which is separated by soft cushion-like
pads, known as discs (see Fig. 7-1). Vertebrae are not
uniform in size and generally become larger in a
descending order because of their weight-bearing
responsibilities (see Fig. 7-2).
Figure 7-3
Figure 7-1
C1 is the atlas and is named after the Greek
character that carried the weight of the world on his
shoulders (see Fig. 7-4). In the human body, the atlas
carries the weight of the head. In turn, the atlas is
attached to the second vertebrae, which is called the
axis. The axis is different in shape from the other
spinal structures in that it has a bony projection that
arises straight up from the posterior part of the vertebra. This stub is called the dens and allows the
head to rotate.
Figure 7-2
Major Regions Of The Spine
There are five regions of the spine consisting
of 26 bones. At birth, however, these bones number
33, but some fuse together with time. The cervical
vertebrae consist of seven small and tightly grouped
bones, which support the head and provide a great
deal of flexibility (see Fig. 7-3).
The first bone starts at the base of the skull,
and the last one terminates at the first prominent
nodule, which can be palpated on the back of the
neck. The neck is able to engage in two types of
movements: rotation and flexion/extension. Sideto-side movement is the function of the first two
vertebrae, or the C1 and C2 bones.
Figure 7-4
Up-and-down motion occurs in the lower portion of the cervical spine, which flexibility makes the
discs between the C5-6 and C6-7 levels vulnerable
to injury (see Fig. 7-5).
Although the cervical region is mobile, it is
very much at risk from a strong, sudden jerk such
as that which occurs with a whiplash type of movement. This risk occurs because the neck has a limited muscle support system. Nevertheless, it must
still support the weight of the head, which is about
Back Injury | 97
6.2% of a person’s body weight or 10 pounds in a
person who weighs 160 pounds. (“Anatomy of the
Spine,” All About Back and Neck Pain, www.allaboutbackandneckpain.com/html/spinesub.asp?id=45.)
Therefore, these muscles can be abused in a car accident.
port the majority of the body’s weight (see Fig. 7-7).
The first lumbar bone is located directly under the
last thoracic vertebra, and the end of the lumbar
spine is located at the waist. This area of the back
has great flexibility and is the subject of the highest
number of back injuries.
Figure 7-5
Figure 7-7
The thoracic spine is the largest area of the
back and is made up of the next 12 vertebrae (see
Fig. 7-6). These bones attach to the ribs and form
a fairly rigid unit. Therefore, very little movement
occurs in this region, and it is not a common location for nerve root compression or herniated discs.
The first thoracic vertebra starts at a location parallel to the collarbone, and the 12th bone ends at the
last rib, which is known as a floating rib. Because of
their anatomical positioning, the thoracic vertebrae
and rib cage protect many of the vital organs, such
as the lungs, liver, spleen, and heart.
The next level is the sacrum, a single fused unit
consisting of five bones that resemble an upsidedown triangle (see Fig. 7-8). The sacrum sits inside
the pelvis and forms part of that unit. The coccyx,
or tailbone, is the termination point of the spine and
is made up of several small pieces of bone. Coccydynia is the term used to identify pain in this area.
Figure 7-8
Figure 7-6
The lumbar region has the five largest vertebrae because their increased size is needed to sup-
Spinal Part
Cervical
Thoracic
Lumbar
Sacrum
Coccyx
PARTS OF THE SPINE
Number of Seven bones
Twelve bones
Five bones
Five fused bones
Four fused bones
Abbreviation
C1 to C7
T1 to T12
L1 to L5
S1 to S5
None
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Ligaments That Hold The Spine Together
The spine has two sets of ligaments that hold
the bones together. The first is the longitudinal ligament, so-named because it runs the length of the
vertebral column and holds the bones in place. The
ligament in the front is the anterior longitudinal
ligament, and the one in the back is the posterior
longitudinal ligament (see Fig. 7-9).
Curves Of The Spine
When the spine is viewed anteriorly, it seems
perfectly straight. A lateral examination, however,
reveals that the column has several gentle curves
(see Fig. 7-11). These bends are present to allow the
vertebral column to act as a spring or shock absorber for the impacts of daily life. Some of the curves
are normal, whereas others are not.
Figure 7-9
Figure 7-11
The construction of the posterior longitudinal
ligament makes the discs in the lower part of the
lumbar spine susceptible to herniation because the
ligament narrows in this region and only covers a
small portion of the disc (see Fig. 7-10). Therefore,
there is very little covering holding the discs in place
at the L4-5 and L5-S1 levels.
The cervical and lumbar spines both have a
lordotic curve, which represents a gentle bending
of this portion of the spine in an inward direction.
When the cervical curve is exaggerated, the person
is said to have a swayback. The thoracic spine and
sacrum complete the spring by having bends in the
opposite direction. These curves are called kyphosis and represent gentle outward bends. When this
curve is exaggerated, the person is said to have a
humpback (see Fig. 7-12).
Figure 7-10
The ligamentum flavum is the second ligament
of the back that holds the vertebrae in place. This
term means “yellow ligament,” and it attaches to
the anterior portion of each lamina to help secure
the bones of the back.
Figure 7-12
A bend of the spine to the lateral side represents a condition called scoliosis. This problem gives