Page 100 Guide to Pain Management in Low-Resource Settings

88 Richard Fisher

Do you think this pain pattern is typical which if continued, will lead to damage of the func-
for a fractured tibia, or should you look tional elements of the system—muscle, nerve, blood
for another cause? vessel, tendon, ligament, bone, and articular cartilage.
After examining him on rounds, so you suspect the Th e value of this feedback loop is better appreciated
problem is located: in situations where pain perception is impaired and a
• in the posterior deep compartment? rapid disintegration of musculoskeletal elements en-
• in the venous system, probably from a deep vein sues. Th is is seen in congenital syndromes, acquired
thrombosis? neuropathic conditions (diabetic neuropathy), and
• in the anterior compartment? situations of anesthetic use to enhance performance
• in the tibial nerve distribution? during athletic activities. Pain produced by musculosk-
eletal pathology, trauma, infection, or tumors must be
How do you reach a diagnosis? managed as a component of the treatment of those

Th e calf muscles are organized around four compart- conditions. The pain associated with certain chron-
ments, and the muscles are contained within substan- ic pain syndromes appears out of proportion to the
tial fascial sheaths. As the muscles become ischemic initial stimulus. The history and physical examina-
they swell, increasing the pressure within their com- tion provide the key to establishing a working differ-
partment. As the pressure increases, it eventually ex- ential diagnosis.
ceeds the capillary perfusion pressure, and no blood Pain is the most common symptom of patients
can fl ow to the muscles—and the cycle goes on. If seeking medical help for a musculoskeletal problem. It
the pressure is not released by dividing the surround- is often accompanied by other complaints such as swell-
ing fascia, the muscle will become permanently non- ing, discoloration, or the inability to perform certain
functional. A compartment syndrome is one of the tasks, such as walking up stairs, lifting the arm over
few surgical emergencies aff ecting the musculoskeletal one’s head, or gripping chopsticks, fork, or spoon, but
system. Th e compartment’s fascial sheath should be re- pain is commonly involved. Th us, pain is a useful tool
leased as soon as possible. for diagnosis and treatment and a way to measure prog-
Th e tissues manifesting the patient’s symptoms ress and healing as function is restored. In treating pa-
include artery, nerve, muscle, vein, ligament, and joint. tients we are always working on this edge of comfort
Th e symptoms are caused primarily by the ischemic versus function.
muscle. Th ey can be remembered by the “7 P’s”: Pain provides the starting point for the or-
Pallor—decreased blood fl ow, slow capillary refi ll thopedic examination; both the history and physical
Pain—from pressure on the muscle components. Where does it hurt? For how long? How
Paresthesia—from early nerve ischemia causing de- did it begin? What makes it worse? What makes it
creased or abnormal sensation feel better? The answers provide the clues we need to
Pressure—the compartment involved will feel tight, begin the physical examination. Fortunately the ba-
and the pressure will measure high sic orthopedic exam is not complex. It consists of a
Passive stretch—stretching the muscles of the in- rather limited set of maneuvers, coupled with some
volved compartment will cause extreme pain; in this knowledge of the anatomy involved. The goal is to
case, plantarfl exing the ankle and toes understand the abnormality and provide the advice
Palsy—the involved muscles will be weak or have or treatment necessary to restore pain-free or com-
no function. fortable function. This is an important concept, be-
Pulselessness—the pulse will not be palpable if the cause if you had continued to increase the pain
pressure is high enough, but this is a late sign and is not medication for the patient in the above case history
reliable for early diagnosis. without understanding the meaning of the physical
findings, the most likely outcome would have been
Why is musculoskeletal pain such loss of the extremity. After all, tibial fractures hurt.
an important medical problem? Why not just treat the pain? The physical examina-
tion is important and it is not difficult, but the ex-
Pain is an essential component of musculoskele- tremity examination maybe easier than the spine ex-
tal function. It is the signal we use to limit activities, amination, so let’s start there.