Differential Diagnosis


Differential Diagnosis


An important component of the Vision 2020 statement set forth by the American Physical Therapy Association (ATPA) is achieving direct access.1 With the majority of U.S. states now permitting direct access to physical therapists, many physical therapists now have the primary responsibility for being the gatekeepers of health care and for making medical referrals. In light of the APTA’s movement toward realizing “Vision 2020,” an operational definition of autonomous practice and the related term autonomous physical therapist practitioner is defined by the APTA’s Board as follows:

img “Autonomous physical therapist practice is practice characterized by independent, self-determined professional judgment and action.”

img “An autonomous physical therapist practitioner within the scope of practice defined by the ‘Guide to Physical Therapist Practice’ provides physical therapy services to patients who have direct and unrestricted access to their services, and may refer as appropriate to other healthcare providers and other professionals and for diagnostic tests.”2

Through the history and physical examination, physical therapists diagnose and classify different types of information for use in their clinical reasoning and intervention.3 The Guide clearly articulates the physical therapist’s responsibility to recognize when a consultation with, or referral to, another healthcare provider is necessary.4 This responsibility requires that the clinician have a high level of knowledge, including an understanding of the concepts of medical screening and differential diagnosis. The results of a number of studies have demonstrated that physical therapists can provide safe and effective care for patients with musculoskeletal conditions in a direct access setting.5–7 Indeed, in a study by Childs et al.,8 physical therapists demonstrated higher levels of knowledge in managing musculoskeletal conditions than medical students, physician interns and residents, and most physician specialists except for orthopaedists. In addition, physical therapist students enrolled in educational programs conferring the doctoral degree achieved higher scores than their peers enrolled in programs conferring the master’s degree.8 Furthermore, licensed physical therapists who were board certified achieved higher scores and pass rates than their colleagues who were not board certified.8

In an effort to aid the differential diagnosis of musculoskeletal conditions commonly encountered by physical therapists, screening tools have been designed to help recognize potential serious disorders (red or yellow flags).9

img Red-flag findings are symptoms or conditions that may require immediate attention and supersede physical therapy being the primary provider of service (Table 5-1), as they are typically indicative of nonmechanical (nonneuromusculoskeletal) conditions or pathologies of visceral origin.


Red-Flag Findings


Possible Condition

Constant and severe pain, especially at night

Neoplasm and acute neuromusculoskeletal injury

Unexplained weight loss


Loss of appetite


Unusual fatigue

Neoplasm and thyroid dysfunction

Visual disturbances (blurriness or loss of vision)

Neoplasm or neurologic dysfunction

Frequent or severe headaches

Neoplasm or neurologic dysfunction

Arm pain lasting > 2–3 mo

Neoplasm or neurologic dysfunction

Persistent root pain

Neoplasm or neurologic dysfunction

Radicular pain with coughing

Neoplasm or neurologic dysfunction

Pain worsening after 1 mo



Neoplasm or neurologic dysfunction

Trunk and limb paresthesia

Neoplasm or neurologic dysfunction

Bilateral nerve root signs and symptoms

Neoplasm, spinal cord compression, and vertebrobasilar ischemia

Signs worse than symptoms


Difficulty with balance and coordination

Spinal cord or CNS lesion

Fever or night sweats

Common findings in systemic infection and many diseases

Frequent nausea or vomiting

Common findings in many diseases, particularly of the gastrointestinal system


Upper cervical impairment, vertebrobasilar ischemia, craniovertebral ligament tear, inner ear dysfunction, CNS involvement, and cardiovascular dysfunction

Shortness of breath

Cardiovascular and/or pulmonary dysfunction and asthma

Quadrilateral paresthesia

Spinal cord compression (cervical myelopathy) and vertebrobasilar ischemia

CNS, central nervous system.

Data from Meadows J. A Rationale and Complete Approach to the Sub-Acute Post-MVA Cervical Patient. Calgary, AB: Swodeam Consulting; 1995.

img Yellow-flag findings are potential confounding variables that may be cautionary warnings regarding the patient’s condition, and that require further investigation. Examples include dizziness, abnormal sensation patterns, fainting, progressive weakness, and circulatory or skin changes.

Stith et al.10 describe the red-flag findings found within the patient’s history, which indicate a need for a referral to the physician. The presence of any of the following findings during the patient history, systems review, and/or scanning examination (see Chapters 3 and 4) may indicate serious pathology requiring medical referral:

img Fevers, chills, or night sweats. These signs and symptoms are almost always associated with a systemic disorder such as an infection.11

img Recent unexplained weight changes. An unexplained weight gain could be caused by congestive heart failure, hypothyroidism, or cancer.12 An unexplained weight loss could be the result of a gastrointestinal disorder, hyperthyroidism, cancer, or diabetes.12

img Malaise or fatigue. These complaints, which can help determine the general health of the patient, may be associated with a systemic disease.11

img Unexplained nausea or vomiting. This is never a good symptom or sign.11

img Unilateral, bilateral, or quadrilateral paresthesias. The distribution of neurologic symptoms can give the clinician clues as to the structures involved. Quadrilateral paresthesia always indicates the presence of central nervous system (CNS) involvement.

img Shortness of breath. Shortness of breath can indicate a myriad of conditions. These can range from anxiety and asthma to a serious cardiac or pulmonary dysfunction.11

img Dizziness. The differential diagnosis of dizziness can be quite challenging. Patients often use the word “dizziness” to refer to feelings of lightheadedness, various sensations of body orientation, blurry vision, or weakness in the legs.

img Nystagmus. Nystagmus is characterized by a rhythmic movement of the eyes, with an abnormal shifting away from fixation and rapid return.13 Failure of any one of the main control mechanisms for maintaining steady gaze fixation (the vestibuloocular reflex and a gaze-holding system) results in a disruption of steady fixation (see Chapter 3).

img Bowel or bladder dysfunction. Bowel and bladder dysfunction may indicate compromise of the cauda equina. Cauda equina syndrome is associated with compression of the spinal nerve roots that supply neurologic function to the bladder and bowel. A massive disk herniation may cause spinal cord or cauda equina compression. One of the early signs of cauda equina compromise is the inability to urinate while sitting down, because of the increased levels of pressure. The most common sensory deficit occurs over the buttocks, posterior–superior thighs, and perianal regions (the so-called saddle anesthesia), with a sensitivity of approximately 0.75.14 Anal sphincter tone is diminished in 60–80% of cases.14,15 Rapid diagnosis and surgical decompression of this abnormality is essential to prevent permanent neurologic dysfunction.

img Severe pain. An insidious onset of severe pain with no specific mechanism of injury.

img Pain at night that awakens the patient from a deep sleep, usually at the same time every night, and which is unrelated to a movement. This finding may indicate the presence of a tumor.

img Painful weakness. The presence of a painful weakness almost always indicates serious pathology, including but not limited to a complete rupture of contractile tissue or nerve palsy.

img A gradual increase in the intensity of the pain. This symptom typically indicates that the condition is worsening, especially if it continues during rest.

img Radiculopathy. Neurologic symptoms associated with more than two lumbar levels or more than one cervical level. With the exception of central protrusions or a disk lesion at L4 through L5, disk protrusions typically only affect one spinal nerve root. Multiple-level involvement could suggest the presence of a tumor or other growth, or it may indicate symptom magnification. The presence or absence of objective findings should help determine the cause.

Performing a medical screen is an inherent step in making a diagnosis for the purpose of deciding whether a patient referral is warranted, but the medical screen performed by the physical therapist is not synonymous with differential diagnosis. Differential diagnosis involves the ability to quickly differentiate problems of a serious nature from those that are not, using the history and physical examination. Problems of a serious nature include, but are not limited to, visceral diseases, cancer, infections, fractures, and vascular disorders. The purpose of the medical screen is to confirm (or rule out) the need for physical therapy intervention; the appropriateness of the referral; whether there are any red-flag findings, red-flag risk factors, or clusters of red-flag signs and/or symptoms; and whether the patient’s condition falls into one of the categories of conditions outlined in the Guide.16 Boissonnault and Bass17 noted that screening for medical disease includes communicating with a physician regarding a list or pattern of signs and symptoms that have caused concern but not to suggest the presence of a specific disease.3

In clinical practice, physical therapists commonly use a combination of red-flag findings, the scanning examination, and the systems review to detect medical diseases. The combined results provide the physical therapist with a method to gather and evaluate examination data, pose and solve problems, infer, hypothesize, and make clinical judgments, such as the need for a patient/client referral.16

Systemic dysfunction or disease can present with seemingly bizarre symptoms. These symptoms can prove to be very confusing to the inexperienced clinician. Complicating the scenario is that certain patients who are pursuing litigation can also present with equally bizarre symptoms. These patients may be subdivided into two groups:

  1. Those patients with a legitimate injury and cause for litigation who genuinely want to improve.
  2. Those patients who are merely motivated by the lure of the litigation settlement and who have no intention of showing signs of improvement until their case is settled. Termed malingerers, these patients are a frustrating group for clinicians to deal with, because, like the nonorganic patient type, they display exaggerated complaints of pain, tenderness, and suffering.

Malingering is defined as the intentional production of false symptoms or the exaggeration of symptoms that truly exist.18 These symptoms may be physical or psychological but have, in common, the intention of achieving a certain goal. Any individual involved in litigation, whether the result of a motor vehicle accident, work injury, or accident, has the potential for malingering.19 Malingering can be thought of as synonymous with faking, lying, or fraud, and it represents a frequently unrecognized and mismanaged medical diagnosis.18 Unfortunately, due to the similarity between malingerers and nonorganic patients, this deception often causes a significant, negative response from the clinician toward malingerers and nonorganic patients alike.

It is most important that the clinician addresses any suspected deception in a structured and unemotional manner and that interactions with the patient be performed in a problem-oriented, constructive, and helpful fashion.18

With very few exceptions, patients in significant pain look and feel miserable, move extremely slowly, and present with consistent findings during the examination. In contrast, malingerers present with severe symptoms and exaggerated responses during the examination, but can often be observed to be in no apparent distress at other times. This is particularly true if the malingering patient is observed in an environment outside of the clinic.

However, it cannot be stressed enough that all patients should be given the benefit of the doubt until the clinician, with a high degree of confidence, can rule out an organic cause for the pain.

A number of clinical signs and symptoms can alert the clinician to the possibility of a patient who is malingering. These include:

img subjective complaints of paresthesia with only stocking-glove anesthesia (conditions including diabetic neuropathy and the T4 syndrome must be ruled out);

img inappropriate scoring on the Oswestry Low Back Disability Questionnaire (Table 5-2), Neck Disability Index (Table 5-3), and McGill Pain Questionnaire (see Chapter 4);


Oswestry Low Back Disability Questionnaire

PLEASE READ: This questionnaire is designed to enable us to understand how much your low back pain has affected your ability to manage your everyday activities. Please answer each section by marking the ONE BOX that most applies to you. We realize that you feel that more than one statement may relate to your problem, but please just mark the one box that most closely describes your problem at this point in time.



Section 1—Pain Intensity

img The pain comes and goes and is very mild

img The pain is mild and does not vary much

img The pain comes and goes and is moderate

img The pain is moderate and does not vary much

img The pain comes and goes and is severe

img The pain is severe and does not vary much

Section 2—Personal Care

img I have no pain when I wash or dress

img I do not normally change my way of washing and dressing even though it causes some pain

img I have had to change the way I wash and dress because these activities increase my pain

img Because of pain I am unable to do some washing and dressing without help

img Because of pain I am unable to do most washing and dressing without help

img Because of pain I am unable to do any washing and dressing without help

Section 3—Lifting (Skip if you have not attempted lifting since the onset of your back pain.)

img Can lift heavy weights without increasing my pain

img Can lift heavy weights but it increases my pain

img Pain prevents me from lifting heavy weights off the floor

img Pain prevents me from lifting heavy weights off the floor but I can manage if they are conveniently positioned, e.g., on a table

img Pain prevents me from lifting heavy weights but I can manage light to medium weights if they are conveniently positioned

img I can only lift very light weight at the most

Section 4—Walking

img I have no pain when I walk

img I have some pain when I walk but it does not prevent me from walking normal distances

img Pain prevents me from walking long distances

img Pain prevents me from walking intermediate distances

img Pain prevents me from walking short distances

img Pain prevents me from walking at all

Section 5–Sitting

img Sitting does not cause me any pain

img I can sit as long as I need to, provided I have my choice of chair

img Pain prevents me from sitting more than 1 h

img Pain prevents me from sitting more than ½ h

img Pain prevents me from sitting more than 10 min

img Pain prevents me from sitting at all

Section 6—Standing

img Standing does not cause me any pain

img I have some pain when I stand but it does not increase with time

img Pain prevents me from standing more than 1 h

img Pain prevents me from standing more than ½ h

img Pain prevents me from standing more than 10 min

img Pain prevents me from standing at all

Section 7—Sleeping

img I have no pain when I lie in bed

img I have some pain when I lie in bed but it does not prevent me from sleeping well

img Because of pain my sleep is reduced by 25%

img Because of pain my sleep is reduced by 50%

img Because of pain my sleep is reduced by 75%

img Pain prevents me from sleeping at all

Section 8—Sex Life (if applicable)

img My sex life is normal and causes no pain

img My sex life is normal but increases my pain

img My sex life is nearly normal but is very painful

img My sex life is severely restricted

img My sex life is nearly absent because of pain

img Pain prevents any sex life at all

Section 9—Social Life

img My social life is normal and causes no pain

img My social life is normal but increases my pain

img Pain has no significant effect on my social life, apart from limiting my more energetic interests (sports, etc.)

img Pain has restricted my social life and I do not go out often

img Pain has restricted social life to my home

img I have no social life because of pain

Section 10—Traveling

img I have no pain when I travel

img I have some pain when I travel but none of my usual forms of travel make it worse

img Traveling increases my pain but has not required that I seek alternative forms of travel

img I have had to change the way I travel because my usual form of travel increases my pain

img Pain has restricted all forms of travel

img I can only travel while lying down


Neck Disability Index

This questionnaire has been designed to give the doctor information as to how your neck pain has affected your ability to manage in everyday life. Please answer every section and mark in each section only the ONE BOX that applies to you. We realize you may consider that two of the statements in any one section relate to you, but please just mark the box that most closely describes your problem.

Section 1—Pain Intensity

img I have no pain at the moment

img The pain is very mild at the moment

img The pain is moderate at the moment

img The pain is fairly severe at the moment

img The pain is the worst imaginable at the moment

Section 2—Personal Care (Washing, Dressing, etc.)

img I can look after myself normally without causing extra pain

img I can look after myself normally but it causes extra pain

img It is painful to look after myself and I am slow and careful

img I need some help but manage most of my personal care

img I need help every day in most aspects of self-care

img I do not get dressed, I wash with difficulty and stay in bed

Section 3—Lifting

img I can lift heavy weights without extra pain

img I can lift heavy weights but it gives extra pain

img Pain prevents me from lifting heavy weights off the floor, but I can manage if they are conveniently positioned, for example, on a table

img Pain prevents me from lifting heavy weights, but I can manage light to medium weights if they are conveniently positioned

img I can lift very light weights

img I cannot lift or carry anything at all

Section 4—Reading

img I can read as much as I want to with no pain in my neck

img I can read as much as I want to with slight pain in my neck

img I can read as much as I want with moderate pain in my neck

img I can’t read as much as I want because of moderate pain in my neck

img I can hardly read at all because of severe pain in my neck

img I cannot read at all

Section 5–Headaches

img I have no headaches at all

img I have slight headaches which come infrequently

img I have moderate headaches which come infrequently

img I have moderate headaches which come frequently

img I have severe headaches which come frequently

img I have headaches almost all the time

Section 6—Concentration

img I can concentrate fully when I want to with no difficulty

img I can concentrate fully when I want to with slight difficulty

img I have a fair degree of difficulty in concentrating when I want to

img I have a lot of difficulty in concentrating when I want to

img I have a great deal of difficulty in concentrating when I want to

img I cannot concentrate at all

Section 7—Work

img I can do as much work as I want to

img I can only do my usual work, but no more

img I can do most of my usual work, but no more

img I cannot do my usual work

img I can hardly do any work at all

img I can’t do any work at all

Section 8—Driving

img I can drive my car without any neck pain

img I can drive my car as long as I want with slight pain in my neck

img I can drive my car as long as I want because of moderate pain in my neck

img I can’t drive my car as long as I want because of moderate pain in my neck

img I can hardly drive at all because of severe pain in my neck

img I can’t drive my car at all

Section 9—Sleeping

img I have no trouble sleeping

img My sleep is slightly disturbed (less than 1 h sleepless)

img My sleep is mildly disturbed (1–2 h sleepless)

img My sleep is moderately disturbed (2–3 h sleepless)

img My sleep is greatly disturbed (3–5 h sleepless)

img My sleep is completely disturbed (5–7 h sleepless)

Section 10—Recreation

img I am able to engage in all my recreation activities with no neck pain at all

img I am able to engage in all my recreation activities, with some pain in my neck

img I am able to engage in most, but not all of my usual recreation activities because of pain in my neck

img I am able to engage in a few of my usual recreation activities because of pain in my neck

img I can hardly do any recreation activities because of pain in my neck

img I can’t do any recreation activities at all

Note: For the Oswestry Low Back Disability and the Neck Disability Index each of the 10 items is scored from 0-5. The maximum score is therefore 50. The obtained score can be multiplied by 2 to produce a percentage score. Occasionally, a respondent will not complete one question or another. The average of all other items is then added to the completed items. The amount of disability can be determined using the following:

0–4 = no disability; 5–14 = mild; 15–24 = moderate; 25–34 = severe; above 34 = complete.

img muscle stretch reflexes inconsistent with the presenting problem or symptoms;

img cogwheel motion of muscles during strength testing for weakness; and

img the ability of the patient to complete a straight-leg raise in a supine position, but demonstrating difficulty in performing the equivalent range (knee extension) in a seated position.

In contrast to the malingering patient, is the patient that presents with psychogenic symptoms. This type of patient tends to exhibit an exaggeration of the symptoms in the absence of objective findings. Psychogenic symptoms are common in patients with anxiety, depression, or hysteria, making it important for the clinician to determine the level of psychological stress in a patient who demonstrates symptom magnification. Waddell et al.20 have proposed a number of characteristics of this illness behavior (Table 5-4).


Waddell Test for Nonorganic Physical Signs


Inappropriate Response


Superficial, nonanatomic to light touch


Axial loading

Axial loading on standing patient’s skull produces low back pain


Passive, simultaneous rotation of shoulders and pelvis produces low back pain


Discrepancy between findings on supine and seated straight leg raising

Regional disturbances


Giving way (Cogwheel) weakness


Nondermatomal sensory loss


Disproportionate facial expression, verbalization, or tremor during examination

Data from Waddell G, McCulloch JA, Kummel E, et al. Nonorganic physical signs in low-back pain. Spine. 1980;5:117–125.


Ehlers–Danlos Syndrome

Ehlers–Danlos syndrome (EDS) is an inherited heterogeneous connective tissue disorder characterized by varying degrees of skin hyperextensibility, joint hypomobility, joint dislocations, musculoskeletal pain, and vascular fragility.21 Inheritance is autosomal dominant, autosomal recessive, or X-linked. There are six major types:21,22

img Classical. This type is characterized by the presence of skin hyperextensibility with atrophic scars in individuals with joint hypomobility.

img Hypermobility. This type is characterized by hypermobile joints and some degree of skin hyperextensibility. This type is associated with the most debilitating musculoskeletal manifestations, and joint pain is reported by 100% of patients.

img Vascular. This type is characterized by fragile viscera and, therefore, has the most serious consequences.

img Kyphoscoliosis. This type is characterized by severe hypotonia and scoliosis.

img Arthrochalasia. This type is characterized by severe hypermobility and joint dislocations.

img Dermatosparaxis. This type is characterized by fragile, sagging, and redundant skin.

The diagnosis of this condition begins with a complete history. The typical history with EDS includes reports of joint dislocations, subluxations, pain, easy bruising, easy bleeding, or poor wound healing.21 The physical examination includes an evaluation of range of motion. Joint hypermobility is assessed using the Beighton criteria scale (Table 5-5), where a maximum score of 9 points is possible, and a score of >4 defines hypermobility.23 The skin is assessed for its consistency, the presence of dystrophic scars, striae, brown discoloration (secondary to hemosiderin deposition at areas of repetitive trauma and bruising), and hyperextensibility.21


Beighton Criteria for Generalized Joint Hypermobility


Score (Points)

Forward flexion of the trunk with knees fully extended so that the palms of the hand rest flat on the floor—one point

1 point

Hyperextension of the elbows beyond 10 degrees

1 point for each elbow

Hyperextension of the knees beyond 10 degrees

1 point for each knee

Passive apposition of the thumbs to the flexor aspect of the forearm

1 point for each hand

Passive dorsiflexion of the little fingers beyond 90 degrees

1 point for each hand

Data from Beighton P, Solomon L, Soskolne CL. ‘Articular Mobility in an African Population’. Ann Rheum Dis. 1973;32413–418.

Physical therapy can be used to enhance musculotendinous strength, neuromuscular coordination, and joint proprioception to maximize function, minimize symptoms, and improve joint stability.21



Osteomyelitis is an acute or chronic inflammatory process of the bone and its marrow secondary to infection with pyogenic organisms or other sources of infection, such as tuberculosis, or specific fungal infections (mycotic osteomyelitis), parasitic infections (Hydatid disease), viral infections, or syphilitic infections (Charcot arthropathy). The following are the two primary categories of acute osteomyelitis:

img Hematogenous osteomyelitis. It is an infection caused by bacterial seeding from the blood. The most common site is the rapidly growing and highly vascular metaphysis of growing bones.

img Direct or contiguous inoculation. This type of osteomyelitis is caused by direct contact with the tissue and bacteria during surgery, a penetrating wound, or as a result of poor dental hygiene.

Disease states known to predispose patients to osteomyelitis include diabetes mellitus, sickle-cell disease, acquired immune deficiency syndrome, IV drug abuse, alcoholism, chronic steroid use, immunosuppression, and chronic joint disease. Clinical signs and symptoms associated with osteomyelitis include fever (approximately 50% of cases), fatigue, edema, erythema, tenderness, and reduction in the use of the extremity.


Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS), commonly referred to as Lou Gehrig’s disease, is a neurodegenerative progressive disorder that causes rapid loss of motor neurons in the brain and spinal cord, leading to paralysis and death. Diagnosis is based solely on clinical data. The diagnosis of ALS depends upon the recognition of a characteristic constellation of symptoms and signs and supportive electrophysiological findings. For clinically definite ALS diagnosis, UMN and LMN signs in bulbar and two spinal regions or in three spinal regions are required. The LMN weakness and muscle atrophy involves both peripheral nerve and myotomal distributions. The clinical hallmark of ALS is the coexistence of muscle atrophy, weakness, fasciculations, and cramps (caused by LMN degeneration), together with hyperactive or inappropriately brisk muscle stretch reflexes, pyramidal tract signs, and increased muscle tone (due to corticospinal tract involvement).24 Muscle cramps are often already present before other symptoms develop. Most patients present with asymmetrical, distal weakness of the arm or leg. The symptoms usually progress first in the affected extremity and then gradually spread to adjacent muscle groups and remote ipsilateral or contralateral regions. Although disability is usually limited in the early stages, ALS progresses relentlessly. Most patients are ultimately unable to walk, care for themselves, speak, and swallow.24 However, there is usually no clinical involvement of parts of the CNS other than the motor pathways.24

Respiratory weakness due to high cervical (phrenic nerve, C4) and thoracic spinal cord involvement is the most common cause of death in ALS, often in conjunction with aspiration pneumonia.24

Guillain–Barré Syndrome

Guillain–Barré syndrome (GBS) is challenging to identify because of its multitude of presentations and manifestations. GBS may be defined as a postinfectious, acute, paralytic peripheral neuropathy. It can affect any age group although there is a peak incidence in young adults. GBS appears to be an inflammatory or immune-mediated condition.

The majority of patients describe an antecedent febrile illness. Upper respiratory infections are seen in 50% of cases and are caused by a variety of viruses. The illness is usually an acute respiratory or gastrointestinal condition that lasts for several days and then resolves. This is followed in 1–2 weeks by the development of a progressive ascending weakness or paralysis, which is usually symmetric. The progression of the weakness or paralysis can be gradual (1–3 weeks) or rapid (1–2 days). The patient reports difficulty or instability with walking, arising from a chair, and ascending or descending stairs. Associated signs and symptoms include cranial nerve involvement (facial weakness), paresthesias, sensory deficits, difficulty in breathing, diminished muscle stretch reflexes, autonomic dysfunction (tachycardia and vasomotor symptoms), oropharyngeal weakness, and ocular involvement.25

The differential diagnosis of GBS is quite large and includes the spectrum of illnesses causing acute or subacute paralysis. These include spinal cord compression (myelopathy), UMN disorders, poliomyelitis, transverse myelitis, polyneuropathy, SLE, polyarteritis nodosa, myasthenia gravis, and sarcoidosis.25

All patients with suspected GBS should be hospitalized for vigilant monitoring because of the high risk of respiratory failure, which occurs in approximately one-third of patients.25


Syringomyelia is a disease that produces fluid-containing cysts (syrinx) within the spinal cord, often associated with stenosis of the foramen magnum. The syrinx can occur within the spinal cord (syringomyelia) or brain stem (syringobulbia). Syringomyelia has been found in association with various disorders, including spinal column or brain stem abnormalities (scoliosis, Klippel–Feil syndrome, Chiari I malformation), intramedullary tumors, and traumatic degeneration of the spinal cord. Chiari I malformation is the most common condition in patients with syringomyelia.

Painful dysesthesias, which have been described variously as burning pain, pins-and-needles sensations, and stretching or pressure of the skin, occur in up to 40% of patients with syringomyelia.26 The pain tends to arise in a dermatomal pattern and is accompanied, in most cases, by hyperesthesia.

Radiologic features that suggest syringomyelia include an increase in the width and depth of the cervical canal, bony abnormalities at the craniovertebral junction, diastematomyelia, and occipitalization of the atlas.


Perhaps, the most common inflammatory disorders of the musculoskeletal system are the rheumatoid diseases.

Rheumatoid Arthritis

Rheumatoid arthritis (RA) can be defined as a chronic, progressive, systemic, inflammatory disease of connective tissue, characterized by spontaneous remissions and exacerbations (flare-ups). It is the second most common rheumatic disease after osteoarthritis (OA), but it is the most destructive to synovial joints. Unlike OA, RA involves primary tissue inflammation rather than joint degeneration. Although most individuals who develop RA do so in their early-to-middle adulthood, some experience it either earlier (Juvenile RA—see Chapter 30) or later.

Although the exact etiology of RA is unclear, it is considered one of many autoimmune disorders. Abnormal immunoglobulin (Ig) G and IgM antibodies develop in response to IgG antigens, to form circulating immune complexes. These complexes lodge in connective tissue, especially synovium, and create an inflammatory response. Inflammatory mediators, including cytokines (e.g., tumor necrosis factor), chemokines, and proteases, activate and attract neutrophils and other inflammatory cells. The synovium thickens, fluid accumulates in the joint space, and a pannus forms, eroding joint cartilage and bone. Bony ankylosis, calcifications, and loss of bone density follow.

RA typically begins in the joints of the arm or hand. The individual complains of joint stiffness lasting longer than 30 minutes on awakening, pain, swelling, and heat (synovitis). Unlike with OA, the distal interphalangeal joints of the fingers usually are not involved in RA.

The signs and symptoms of RA vary among individuals, depending on the rate of progress of the disease. A complete musculoskeletal examination helps diagnose the disease. Clinical manifestations include both joint involvement and systemic problems; some are associated with the early stages of RA, whereas others are seen later in advanced disease.

Complaints of fatigue, anorexia, low-grade fever, and mild weight loss are commonly associated with RA. As the disease worsens, joints become deformed, and secondary osteoporosis (see “Metabolic Disease”) can result in fractures, especially in older adults. Hand and finger deformities are typical in the advanced stages of the disease. Palpable subcutaneous nodules, often appearing on the ulnar surface of the arm, are associated with a severe, destructive disease pattern. As the disease progresses over years, systemic manifestations increase and potentially life-threatening organ involvement begins. Cardiac problems, such as pericarditis and myocarditis, and respiratory complications, such as pleurisy, pulmonary fibrosis, and pneumonitis, are common. RA can affect body image, self-esteem, and sexuality in older adults. The person with RA loses control over body changes, is chronically fatigued, and eventually may lose independence in activities of daily living (ADLs). As a reaction to these losses, individuals may display the phases of the grieving process, such as anger or denial. Some people become depressed, feeling helpless and hopeless because no cure presently exists for the condition. Chronic pain and suffering interfere with quality of life.

The physical therapy examination of the patient with RA involves:

img measurement of independence with functional activities;

img measurement of joint inflammation;

img measurement of joint range of motion; and

img determination of limiting factors including pain, weakness, and fatigue.

Because RA affects multiple body systems, lessens the quality of life, and affects functional ability, the approach to managing the patient with this condition must be interdisciplinary. Management typically includes drug therapy, physical and/or occupational therapy, and recreational therapy. Some clients also need psychologic counseling to help cope with the disease.

Rest and energy conservation are crucial for managing RA (Table 5-6). Pacing activities, obtaining assistance, and allowing rest periods help conserve energy. Positioning joints in their optimal functional position help to prevent deformities. Ambulatory and adaptive devices can help individuals maintain independence in ADLs. For example, a long-handled shoehorn may help in putting on shoes. Velcro attachments on shoes often are a better option than laces. Styrofoam or paper cups may collapse or bend, whereas a hard plastic or china cup may be easier to handle. The clinician should also review principles of joint protection with the patient and family and provide adaptive equipment as needed to perform ADLs independently.


Intervention Strategies for Rheumatoid Arthritis




Pain control

Therapeutic heat to decrease rigidity of joints, increase the flexibility of fibrous tissue, and decrease pain and muscle spasm

Massage, usually applied with heat treatment and before stretching, can be used to relieve pain and prevent adhesions

Therapeutic cold can be used for analgesic and vasoconstriction purposes in inflamed joints during the acute period. Care must be taken to avoid adverse effects

Heat applications:

Aquatic therapy

Instructions on the wearing of warm pajamas, sleeping bag, and electric blanket

Paraffin for hands


Heating pads—moist heat better than dry heat

Minimizing the effects of inflammation

Joint protection strategies


Rest from abuse

Body mechanics education

As needed—balance rest with activity by using splinting (articular resting)

Resting splints are used to rest the joint in the appropriate position in the acute period

Dynamic splints are used to exert adequate force that the tissue can tolerate and provide sufficient joint volume

Functional splints are used to protect the joint in the course of activity

Stabilizer splints are used in cases of permanent contractures. Gradual casting can be used to apply a stretch to the contracture

Preventing limitation and restoring ROM in affected joints

Range-of-motion and stretching exercises

Acute stage: passive and active assisted to avoid joint compression

Subacute/chronic stage: active exercises, passive stretching or contract–relax techniques

Maintaining and improving strength

Resistive exercises

Endurance exercises

Electrical stimulation

Acute and subacute stages: isometric exercises progressing cautiously to resistive

Subacute/chronic stages: strengthening exercises that avoid substitutions and minimize instability, atrophy, deformity, pain, and injury

Chronic stage: judicious use of concentric exercise

Provision of encouragement to exercise—fun and recreational activities of moderate intensity and 30 min duration per day


Tai Chi

Short-term electrical stimulation is useful in cases of excessive muscle atrophy and in those who cannot exercise

Ensuring normal growth and development

Posture and positioning

Mobility and assistive devices

To maintain joint range of motion, patients should spend 20 min/d in prone to stretch the hip flexors and quadriceps; assess leg length discrepancy in standing and avoid scoliosis

Extended comb handles, thicker spoons, shoehorns

Clothes with easy openings and/or Velcro

Strengthening exercises and other pain-relief measures, such as the use of ice and heat, can be prescribed. Ice application is used for hot, inflamed joints. Heat is used for painful joints that are not acutely inflamed. Showers, hot packs (not too heavy), and paraffin dips are ideal for heat application.

Some RA patients have associated syndromes. Two such syndromes are Sjogren and Felty syndromes. Sjogren syndrome is characterized by dryness of the eyes (keratoconjunctivitis), mouth (xerostomia), and other mucous membranes. Felty syndrome is characterized by leukopenia and hepatosplenomegaly, often leading to recurrent infections. It encompasses a diverse group of pathogenic mechanisms in RA, all of which result in decreased levels of circulating neutrophils.

No single test or group of laboratory tests can confirm a diagnosis of RA, but they can support the findings from the patient’s history and the physical findings. A number of immunologic tests, such as the rheumatoid factor and antinuclear antibody titer, are available to aid diagnosis. Normal values differ, depending on the precise laboratory technique used.


Gout is the most common form of inflammatory arthritis in men older than 40 years and appears to be on the increase.27 In the United States, the self-reported prevalence of gout almost trebled in men aged 45–64 years between 1969 and 1981.28 The rising prevalence of gout is thought to stem from dietary changes (high-purine diet and habitual alcohol ingestion), obesity, environmental factors, increasing longevity, subclinical renal impairment, and the increased use of drugs causing hyperuricemia, particularly diuretics.29 High blood levels of uric acid lead to inflammation, joint swelling, and severe pain. Symptoms are caused by deposits of sodium urate or calcium pyrophosphate crystals in joints and periarticular tissues.

Onset is usually sudden, often during the night or early morning. The classic finding of gouty arthritis (gout) is warmth, swelling, cutaneous erythema, and severe pain of the first metatarsophalangeal (MTP) joint (podagra). However, other joints may also be involved. These include the shoulder, knee, wrist, ankle, elbow, or fingers. Fever, chills, and malaise accompany an episode of gout. As the condition becomes chronic, the patient may report morning stiffness and joint deformity, progressive loss of function, or disability. Chronic gouty nephropathy may occur.

Differential diagnosis includes cellulitis, septic arthritis, RA, bursitis related to a bunion, sarcoidosis, multiple myeloma, and hyperparathyroidism.

Treatment is geared toward pharmacologic control of serum uric acid levels.

Ankylosing Spondylitis

Ankylosing spondylitis (AS, also known as Bekhterev or Marie–Strümpell disease) is a chronic rheumatoid disorder that affects 1–3 per 1,000 people. The patient is usually between 15 and 40 years. There is a 10–20% risk that offspring of patients with the disease will later develop it.30 Although males are affected more frequently than females, mild courses of AS are more common in the latter.31

A human leukocyte antigen (HLA) haplotype association (HLA-B27) has been found with AS and remains one of the strongest known associations of disease with HLA-B27, but other diseases are also associated with the antigen. C-reactive protein has only 53% sensitivity and 70% specificity in spondyloarthropathies (X20).32 Thoracic involvement in AS occurs almost universally. The disease includes involvement of the anterior longitudinal ligament and ossification of the intervertebral disk, thoracic zygapophyseal joints, costovertebral joints, and manubriosternal joint. This multijoint involvement of the thoracic spine makes the checking of chest expansion measurements a required test in this region.

In time, AS progresses to involve the whole spine and results in spinal deformities, including flattening of the lumbar lordosis, kyphosis of the thoracic spine, and hyperextension of the cervical spine. These changes, in turn, result in flexion contractures of the hips and knees, with significant morbidity and disability.31

The most characteristic feature of the back pain associated with AS is pain at night.33 Patients often awaken in the early morning (between 2 and 5 AM) with back pain and stiffness and usually either take a shower or exercise before returning to sleep.31 Back ache during the day is typically intermittent, irrespective of exertion or rest.31

Calin et al.34 describe five screening questions for AS:

  1. Is there morning stiffness?
  2. Is there an improvement in discomfort with exercise?
  3. Was the onset of back pain before age 40 years?
  4. Did the problem begin slowly?
  5. Has the pain persisted for at least 3 months?

Using at least four positive answers to define a “positive” result, the sensitivity of these questions was 0.95, and specificity was 0.85.34

Peripheral arthritis is uncommon in AS, but when it occurs, it is usually late in the course of the condition.35 Peripheral arthritis developing early in the course of the disease is a predictor of disease progression.36 The arthritis usually occurs in the lower extremities in an asymmetric distribution, with the involvement of the “axial” joints, including shoulders and hips, more common than involvement of more distal joints.31,37

The inspection usually reveals a flat lumbar spine and gross limitation of extension, and side bending in both directions (capsular pattern). In addition, the glides of the costotransverse joints and distraction of the sternoclavicular joints are decreased. Mobility loss tends to be bilateral and symmetric. There is loss of spinal elongation on flexion in the McRae’s modification of the Schober test,38,39 although this can occur in patients with chronic low back pain (LBP), or spinal tumors, and is thus not specific for inflammatory spondylopathies.40 The McRae’s modified Schober test is performed with the patient standing upright. The clinician marks the spinous process of L5 with a pen, and then creates a mark 10 cm above the L5 and 5 cm below L5 in the midline. The patient is then asked to bend forward maximally, and the distance between the upper and lower marks is measured. Patients with normal mobility of the spine have an increase of at least 5 cm in the measured distance from upright (15 cm) to maximal flexion (should be >20 cm).38,39 The patient may relate a history of costochondritis, and, upon examination, rib springing may give a hard end-feel. Basal rib expansion often is decreased with the chest expansion test. The chest expansion test is performed with the patient’s hands elevated and folded behind the head. The clinician takes a circumferential measurement of the patient’s chest at the level of the fourth intercostal space, or just below the breast in females. Chest circumference is measured after a maximal forced expiration and again after a maximal inspiration. The expansion should be >5 cm. Expansion of <2.5 cm is abnormal.38,39

As the disease progresses, the pain and stiffness can spread up the entire spine, pulling it into forward flexion, so that the patient adopts the typical stooped-over position. The patient gazes downward, the entire back is rounded, the hips and knees are semiflexed, and the arms cannot be raised beyond a limited amount at the shoulders.41

Longitudinal studies in patients with AS have revealed that deformities and disability occur within the first 10 years of disease.36 Most of the loss of function occurs during the first 10 years and correlates significantly with the occurrence of peripheral arthritis, radiographic changes of AS in the spine, and the development of the so-called bamboo spine.

An exercise program is particularly important for these patients to maintain functional spinal outcomes.42 The goal of exercise therapy is to maintain the mobility of the spine and involved joints for as long as possible and to prevent the spine from stiffening in an unacceptable kyphotic position. A strict regimen of daily exercises, which include positioning, spinal extension exercises, breathing exercises, and exercises for the peripheral joints, must be followed. Several times a day, patients should lie prone for 5 minutes, and they should be encouraged to sleep prone or supine on a hard mattress and avoid the side-lying position. Swimming is the best routine sport.

Psoriatic Arthritis

Psoriatic arthritis, which is an inflammatory form of arthritis associated with a chronic skin condition called psoriasis, affects men and women with equal frequency, with its peak onset in the fourth decade of life, although it may occur in children and in older adults.37 Psoriatic arthritis can manifest in one of a number of patterns, including distal joint disease (affecting the distal interphalangeal joints of the hands and feet), asymmetric oligoarthritis, polyarthritis (which tends to be asymmetric in half the cases), and arthritis mutilans (a severe destructive form of arthritis and a spondyloarthropathy that occurs in 40% of patients, but most commonly in the presence of one of the peripheral patterns).37 Patients with psoriatic arthritis have less tenderness over both affected joints and tender points than patients with the classic RA.43

The spondyloarthropathy of psoriatic arthritis may be distinguished from AS by the pattern of the sacroiliitis.44 Whereas sacroiliitis in AS tends to be symmetric, affecting both sacroiliac joints to the same degree, it tends to be asymmetric in psoriatic arthritis,37 and patients with psoriatic arthritis do not have as severe a spondyloarthropathy as patients with AS.30

Another articular feature of psoriatic arthritis is the presence of dactylitis, tenosynovitis (often digital, in flexor and extensor tendons and in the Achilles tendon), and enthesitis.44 The presence of erosive disease in the distal interphalangeal joints is typical.44

Nail lesions occur in more than 80% of the patients with psoriatic arthritis and have been found to be the only clinical feature distinguishing patients with psoriatic arthritis from patients with uncomplicated psoriasis.45 Other extra-articular features include iritis, urethritis, and cardiac impairments similar to those seen in AS, although less frequently.44

Treatment for psoriatic arthritis is directed at reducing and controlling inflammation, with milder cases of psoriatic arthritis often being treated with NSAIDs alone. More severe cases are treated using disease-modifying antirheumatic drugs or biological response modifiers to help prevent irreversible joint destruction and disability.


Benign Tumors: Osteoblastoma and Osteoid Osteoma

Osteoblastoma and osteoid osteoma are benign bone-forming tumors with similar clinical findings.

img Osteoblastoma is a solitary bone neoplasm. It is most common in the vertebrae of children and young adults. Short and flat bones are more commonly affected than the long bones (76.5% vs. 23.5%).46 In the vertebrae, the body is only rarely affected primarily; usually, it is involved only secondarily by tumors extending from other segments of the same or the nearest vertebra.46

img Osteoid osteoma is a benign osteoblastic tumor of unknown etiology. It occurs most often in the long bones, although the spine is the location of 10% of all osteoid osteomas.47

img Painful scoliosis is a well-recognized presentation of spinal osteoid osteoma and osteoblastoma and is thought to be caused by pain-provoked muscle spasm on the side of the lesion.46

Malignant Tumors

Metastatic disease of the spine is the most frequent neoplastic disorder of the axial skeleton. Malignant tumors can be primary or secondary.

  1. Primary. Primary tumors include the following:

    1. Multiple myeloma. Myeloma is a plasma cell tumor. It is the most common malignant primary bone tumor. Early in its course, it can easily be overlooked as the cause of back pain. Common presentations of myeloma include bone pain, recurrent or persistent infection, anemia, renal impairment, or a combination of these. Some patients are asymptomatic. Presenting features, which require urgent specialist referral, include:

      (1) persistent, unexplained backache associated with loss of height and osteoporosis;

      (2) symptoms suggestive of spinal cord or nerve root compression.

    2. Chordoma. Chordomas are rare tumors of notochordal origin, representing approximately 5% of all malignant tumors of bone.48 They typically are slow-growing, locally aggressive tumors. Chordomas usually are diagnosed in patients with pain or symptoms caused by compression of the surrounding structures. The clinical presentation initially may be mild in nature, leading to considerable delay in seeking medical attention. Vertebral chordomas involve the spinal cord and nerve roots progressively, resulting in pain, numbness, motor weakness, and, eventually, paralysis.
    3. Osteosarcoma. Osteosarcoma is a relatively uncommon malignancy. The peak incidence of osteosarcoma occurs in the second decade, with an additional smaller peak after the age of 50 years.49 These tumors typically arise in the metaphyseal regions of long bones, with the rib, distal femur, proximal tibia, and proximal humerus representing the four most common sites. The metaphysis of the vertebra is also predilected.46 Osteosarcomas frequently penetrate and destroy the cortex of the bone and extend into the surrounding soft tissues.

      The initial clinical symptom of a malignant tumor is frequently pain in the affected area, which may also be associated with localized soft-tissue swelling or limitation of motion in the adjacent joint.50

  2. Secondary. Metastases to the spine most commonly arise from breast and lung cancer and from lymphoma.51,52 Lesions associated with the metastasis of primary tumors from the breast, prostate, kidney, and thyroid and lesions associated with lymphoma and myeloma account for 75% of all spinal metastases.51,52 When lung cancer is included, the percentage is greater than 90%.53 The clinical findings for a secondary spinal tumor are similar to those of a primary tumor.



More than 10 million adults in the United States have osteoporosis, 80% of which are women, but almost 3 million males are affected as well.54 Osteoporosis or osteopenia can result from an insufficient bone formation (low bone mass), excessive bone resorption, or a combination of these two phenomena (see Chapter 1). The result is decreased bone mineral density (BMD) and a progressive loss of trabecular connectivity that is irreversible and diminishes the bone quality in terms of its mechanical resistance to deformity underloading.55 In addition to the loss of bone mass, there is also narrowing of the bone shaft and widening of the medullary canal. Osteoporosis causes pathological (fragility) fractures of the vertebrae and fractures of other bones such as the ribs, proximal humerus, distal forearm, proximal femur (hip), and pelvis. However, with appropriate care, osteoporosis, fractures, and resultant disability can be prevented.

Osteoporosis has been classified into two broad general types: type 1 (postmenopausal) and type 2 (involutional).56 Type 2 osteoporosis generally is seen in the older age population and has been referred to as senile osteoporosis.56

It has been estimated that 15% of postmenopausal Caucasian women in the United States and 35% of women older than 65 years have osteoporosis.56 Further, 50% of women older than 50 years have osteopenia of the femoral neck, and 20% have osteoporosis at this site.57 The incidence of hip fracture rises dramatically with age to 3.4 per 100 in the 65–74-year-old age group and 9.4 per 100 in those older than 85 years.55 The presence of a significant vertebral fracture (see “Vertebral Fracture”) is associated with increased mortality.58 Patients with these fragility fractures have a relative risk of death that is nine times greater than healthy counterparts.59 Approximately 20% of women with vertebral fractures have another fracture of a different bone within a year.58

Numerous risk factors have been identified as contributing to the likelihood that an individual will develop bone loss. Genetics plays a major role, and female gender, positive family history, and racial characteristics associated with Caucasian, Asian, or Hispanic background increase the risk of osteoporosis.60 Low body weight (less than 85% ideal body weight, or less than 127 lb) has also been correlated with the development of osteoporosis.56

Modifiable risk factors associated with osteoporosis include early or iatrogenic menopause, pregnancy at an early age, smoking, sedentary lifestyle, alcoholism, low body fat, low calcium intake, high caffeine intake, prolonged bed rest, and anorexia.56,61,62 Medications such as corticosteroids, some diuretics, and thyroid hormone preparations can also increase bone loss and the risk of osteoporosis significantly.63,64

The populations most vulnerable to developing osteoporosis include the following:65

img Women aged 65 years and older.

img Postmenopausal women younger than 65 years with the risk factors for fracture, such as low body weight, prior fracture, or high-risk medication use.

img Women during the menopausal transition with clinical risk factors for fracture.

img Men aged 70 years and older.

img Men younger than 70 years with clinical risk factors for fracture.

img Adults with a fragility fracture.

img Adults with the disease or condition, or who are taking medications associated with low bone mass or bone loss.

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Dec 27, 2016 | Posted by in ORTHOPEDIC | Comments Off on Differential Diagnosis

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