MusculoSkeletal Exam

Please refer to Chapter 2 for an overview of the sequence of a physical examination. For purposes of length and to avoid having to repeat anatomy more than once, the palpation section appears directly after the section on subjective examination and before any section on testing, rather than at the end of each chapter. The order in which the examination is performed should be based on your experience and personal preference as well as the presentation of the patient.

Functional Anatomy

The elbow is a complex hinged joint whose function is to facilitate the placement of the hand in space. It allows flexion–extension and pronation–supination of the forearm. It is composed of three bonesathe humerus, radius, and ulnaaand three articulationsa humero-ulnar, humero-radial, and the less important proximal radio-ulnar.

The humero-ulnar joint is the largest and most stable of the elbow articulations. It is a simple hinge. Its stability is dependent on the medial collateral ligament. Dislocation at the elbow is pathognomonic of medial collateral ligament compromise. Therefore, after reduction of dislocation, the reduced elbow must be recognized as being potentially unstable until medial collateral ligament integrity has been restored by healing or surgical repair, or both.

The humero-radial joint lies lateral to the humeroulnar articulation. It is composed of a shallow disc (radial head) articulating on the spherical humeral capitellum. As such, proximal migration of the radius is prevented throughout the entire arc of elbow flexion and extension (Figure 9.1). Pronation and supination are accomplished by rotation of the radius along its long axis about the ulna (Figure 9.2A). Rotation toward the palm down is pronation, whereas rotation toward the palm up is supination. At full supination, the radius and ulna lie parallel within the forearm. At full pronation, the radius crosses the ulna at its mid-shaft. Although it rotates during pronation and supination, the radial head remains otherwise in a fixed position relative to the ulna. The relative position and movement of the radius about the elbow is crucial to the diagnosis and treatment of injuries to the elbow– arm–wrist complex. A common mechanism of injury

of the upper extremity is falling onto the outstretched hand (Figure 9.2B). In this position, the elbow is extended and the forearm is usually pronated by the rotation of the body on the fixed hand. During pronation with the radial head fixed proximally to the ulna by the annular ligament, the shaft of the radius rotates about the long axis of the ulna. Terminal pronation is limited by the contact of the shaft of the radius on the ulna. At maximum pronation, the contact point of the crossed radius (increased pronation) places enormous stress on the bones and articulations of the elbow and forearm. The consequences of forcibly pronating the forearm beyond this point will result in the following spectrum of possible injuries:

1tear of the annular ligament with dislocation of the radial head;

2fracture of the radial shaft;

3fracture of the ulnar shaft;

4fracture of both bones of the midforearm; or

5combination or permutation of the above (i.e., Monteggia fractureafracture of the ulna with dislocation of the radial head).

Understanding this analysis of the mechanism of

injury provides insight into the treatment of such injuries. It is crucial to their resolution. For example, treatment of fractures and dislocations usually requires a maneuver that reverses the mechanism of injury. Therefore, for injuries resulting from hyperpronation of the forearm, an integral part of the manipulative movements performed for treatment involves supination of the forearm.

In addition to bony and articular injuries, the soft tissue about the elbow can also be injured, for example, from excessive movements. As a consequence of the enormous range of motion the elbow must perform during the course of daily activities, the large excursions of bony prominences beneath the overlying soft tissues can create irritations. To permit the elbow its large range of excursion (0–150 degrees of flexion), the skin overlying the posterior aspect of the elbow is very redundant and loosely attached to the underlying hard and soft tissues. Interposed between the skin and underlying tissues is the olecranon bursa. This bursa ensures that the skin will not become adherent to the underlying tissues restricting terminal flexion of the elbow. This function is similar to that which exists on the anterior aspect of the knee and the dorsum of the metacarpophalangeal and interphalangeal joints of the digits of the hand. Like these areas, as a consequence of its location, the posterior elbow bursa (olecranon bursa) is very vulnerable to blunt trauma, the result of which may be hemorrhage,

swelling, pain, and inflammation characteristic of traumatic injuries. The lining of a bursal sac is similar to the synovial lining that exists in synovial articulations. As a result, when traumatized and inflamed, it becomes thickened, produces excessive fluid exudates, and is characterized by localized swelling and warmth (bursitis) (Figure 9.2C).

Observation

The examination should begin in the waiting room before the patient is aware of the examiner’s observation. Information regarding the degree of the patient’s disability, level of functioning, posture, and gait can be observed. The clinician should pay careful attention to the patient’s facial expressions with regard to the degree of discomfort the patient is experiencing. The information gathered in this short period can be very useful in creating a total picture of the patient’s condition

Note the manner in which the patient is sitting in the waiting room. Notice how the patient is posturing

the upper extremity. Is the arm relaxed at the side or is the patient cradling it for protection? If the elbow is swollen, the patient may posture it at 70 degrees of flexion (the resting position), which allows for the most space for the fluid. Swelling may be easily noticed at the triangular space bordered by the lateral epicondyle, radial head, and the olecranon. How willing is the patient to use the upper extremity? Will he or she extend their arm to you to shake your hand? Pain may be altered by changes in position so watch the patient’s facial expression to give you insight into their pain level.

Observe the patient as he or she assumes the standing position. Observe the patient’s posture. Pay particular attention to the position of the head, cervical spine, and the thoracic kyphosis. Note the height of the shoulders and their relative positions. Once the patient starts to ambulate, observe whether he or she is willing to swing the arms, which can be limited by either loss of motion or pain.

Once the patient is in the examination room, ask the patient to disrobe. Observe the ease with which the patient uses the upper extremities and the rhythm of the movements. Observe for symmetry of bony structures. Note the carrying angle with the upper

Subjective Examination

The elbow is a stable joint. Since it is non-weight- bearing, problems are most commonly related to overuse syndromes, inflammatory processes, and trauma. You should inquire about the nature and location of the patient’s complaints as well as their duration and intensity. Note whether the pain travels either above or below the elbow. Inquire about the behavior of the pain during the day and night to give you better insight into the pain pattern secondary to changes in position, activity level, and swelling.

You want to determine the patient’s functional limitations. Question the patient regarding use of their upper extremity. Is the patient able to comb his hair, fasten her bra, bring his arm to his mouth to eat, or remove her jacket? Does the patient regularly participate in any vigorous sports activity that would stress the elbow? What is the patient’s occupation?

If the patient reports a history of trauma, it is important to note the mechanism of injury. The direction of the force and the activity in which the patient was participating at the time of the injury contribute to your understanding of the resulting problem and help you to better direct the examination. The degree of pain, swelling, and disability noted at the time of the trauma and within the initial 24 hours should be noted. Does the patient have a previous history of the same injury? Does the patient report any clicking or locking? This may be due to a loose body in the joint. Is any grating present? This may be due to osteoarthritis.

The patient’s disorder may be related to age, gender, ethnic background, body type, static and dynamic posture, occupation, leisure activities, hobbies, and general activity level. Therefore, it is important to inquire about any change in daily routine and any unusual activities in which the patient has participated.

The location of the symptoms may give you some insight into the etiology of the complaints. The cervical spine and the shoulder can refer pain to the elbow.

Ulna

Pronation

Radius

A

Figure 9.2 (A) Pronation is the medial rotation of the radius anterior to the ulna; this results in a palm-down position of the hand. Supination is the reverse movement, palm-up rotation of the hand.

The most common nerve roots that refer pain are C6 and C7. (Please refer to Box 2.1, p. 18 for typical questions for the subjective examination.)

Gentle Palpation

The palpatory examination is started with the patient in either the supine or sitting positions. You should first search for areas of localized effusion, discoloration, birthmarks, open sinuses or drainage, incisional areas, bony contours, muscle girth and symmetry, and skinfolds. You should not have to use deep pressure to determine areas of tenderness or malalignment. It is important to use a firm but gentle pressure, which will enhance your palpatory skills. By having a sound basis

Radius

Pronation

B

Ulna

Ulna

Fulcrum

Humerus

Triceps

Radius

Skin

Olecranon bursa

Paradigm for inflammatory disease involving the elbow

A 25-year-old woman presents with complaints of swelling, pain and limited motion in her right elbow. She reports no history of recent or prior trauma. She is employed as a secretary and has recently joined a health club. A year ago her symptoms were initially episodic, but now have become a daily problem. Upon arising each morning, she notices stiffness in the elbows, wrists and finger joints of both upper extremities. She has had no recent infections but reports having a low grade temperature and her face to be “flushed.” Her weight has decreased by 10 pounds and she has noticed an increase in the frequency of her urination. She has no significant prior medical history; but does remember an aunt who became an early invalid because of “arthritis.”

Her physical exam demonstrates the patient to be a slender young woman in no acute distress. Her right elbow is slightly swollen, minimally tender and lacking the terminal 30 degrees of flexion and extension. Her left elbow seems unremarkable but the metacarpophalangeal (MP) and proximal interphalangeal (PIP) joints of many digits on each hand are moderately enlarged and lack full extension. Her cheeks have a slightly erythematous rash. Laboratory tests report a mild anemia, an increase in the white cell count, increased protein in the urine and an elevated sedimentation rate (ESR). X-rays of the elbows and hands show only soft tissue enlargement with no bony lesions. Aspiration of the elbow produces a cloudy yellowish viscous fluid which on analysis shows a large number of inflammatory cells but no organisms.

This is a paradigm of inflammatory disease (rheumatoid arthritis or systemic lupus erythematosis) rather than soft-tissue injury of the elbow because of:

No history of trauma

Age and sex of the patient

Pattern of symptom onset and progression

Symmetrical distribution of signs and symptoms to both upper extremities

Anterior Aspect

Soft-Tissue Structures

Cubital (Antecubital) Fossa

The anterior surface of the crook of the elbow is referred to as the cubital fossa. This has been described as a triangular structure. The base of the triangle is formed by a line between the medial and lateral epicondyles of the humerus. The medial side is formed by the pronator teres and the lateral side by the brachioradialis. The floor is composed of the brachialis and the supinator. The fossa contains the following structures: biceps tendon, distal part of the brachial artery and veins, the origins of the radial and ulnar arteries, and parts of the median and radial nerves (Figure 9.3).

Trauma in the cubital fossa can lead to compression of the brachial artery, leading to Volkmann’s ischemic contracture.

Biceps

Median N.

Brachioradialis

Brachial artery

of cross-sectional anatomy, you will not need to physically penetrate through several layers of tissue to have a good sense of the underlying structures. Remember that if you increase the patient’s pain at this point in the examination, the patient will be very reluctant to allow you to continue and may become more limited in his or her ability to move.

Palpation is most easily performed with the patient in a relaxed position. Although palpation may be performed with the patient standing, the sitting position is preferred for ease of examination of the elbow. While locating the bony landmarks, it is also useful to pay attention to areas of increased or decreased temperature and moisture. This will help you identify areas of acute and chronic inflammation.

Pronator teres

Figure 9.3 Palpation of the cubital fossa and contents.

Biceps tendon

Figure 9.4 Palpation of the biceps muscle and tendon.

Biceps Muscle and Tendon

The anterior surface of the middle two-thirds of the humerus is composed of the biceps muscle belly. Follow the fibers distally and you will feel the tapered ropelike structure, which is the biceps tendon just proximal to its distal attachment on the radial tuberosity (Figure 9.4). The tendon becomes more prominent if you resist elbow flexion with the forearm in the supinated position.

The distal tendon or muscle belly can be ruptured following forceful flexion of the elbow. The patient will demonstrate weakness in elbow flexion and supination, pain on passive pronation, and tenderness in the cubital fossa. Rupture of the long head is often asymptomatic and may not be evident clinically, except for a concavity in the upper arm or a bulbous swelling in the anterior lower half of the arm, which is the retracted muscle belly.

Brachial Artery

The brachial artery is located in the cubital fossa medial to the biceps tendon (see Figure 9.3). The brachial pulse can be readily assessed at this point.

Median Nerve

The median nerve crosses in front of the brachial artery and travels medial to it in the cubital fossa. Locate the brachial artery and allow your finger to move

slightly medially and you will feel a ropelike structure, which is the median nerve (see Figure 9.3). It travels between the bicipital aponeurosis and the brachialis before it enters the forearm between the heads of the pronator teres.

Medial Aspect

Bony Palpation

Medial Epicondyle and Supracondylar Ridge

Stand next to the patient and make sure the upper extremity is in the anatomical position. Place your fingers along the medial aspect of the humerus and allow them to move distally along the medial supracondylar ridge of the humerus until you reach a very prominent pointed structure. This is the medial epicondyle of the humerus (Figure 9.5). Tenderness in this area can be due to inflammation of the common aponeurosis of the flexor and pronator tendons of the forearm and wrist and is commonly referred to as golfer’s elbow (medial epicondylitis).

Soft-Tissue Structures

Medial (Ulnar) Collateral Ligament

The medial collateral ligament consists of anterior and posterior sections that are connected by an intermediate section. The anterior portion attaches from the medial epicondyle of the humerus to the coronoid process. The posterior section attaches from the medial epicondyle to the olecranon. It has been described as a fan-shaped structure (Figure 9.6). The ligament is responsible for the medial stability of the elbow and its integrity can be tested with a valgus stress test (described on p. 213). The ligament is not distinctly palpable but the medial joint line should be examined for areas of tenderness secondary to sprains.

Ulnar Nerve

Ask the patient to flex the elbow to 90 degrees. Palpate the medial epicondyle and continue to move posteriorly and laterally until you feel a groove between the medial epicondyle and the olecranon. Gently palpate in the groove and you will feel a round cordlike structure under your fingers. This is the ulnar nerve (Figure 9.7). Because the nerve is so superficial, be careful not to press too hard; you may cause parasthesias radiating down the forearm and into the hand. It is often referred to as the funny bone since when it is accidentally hit, the person experiences tingling.

Because of its close proximity to the bony prominences, the nerve can be injured secondary to fractures of the medial epicondyle and the supracondylar ridge. The ulnar nerve can be entrapped in the cubital tunnel formed by the medial collateral ligament and flexor carpi ulnaris. This can cause a tardy ulnar palsy (see Neurological Examination section in this chapter).

Wrist Flexor-Pronator

The common origin of the flexor-pronator muscle group is found at the medial epicondyle of the humerus.

From lateral to medial this group is composed of the pronator teres, flexor carpi radialis, palmaris longus, and flexor carpi ulnaris (Figure 9.8). The individual muscles are difficult to differentiate by palpation. You can get a sense of their location by resisting the individual muscle’s function. Resist pronation of the forearm and you will feel the pronator teres contract under your fingers. Provide resistance while the patient flexes the wrist in radial deviation and you get a sense of the location of the flexor carpi radialis. Provide resistance while the patient flexes the wrist in ulnar deviation and you get a sense of the location

of the flexor carpi ulnaris. The tendons are easily distinguishable at the wrist (described on pp. 237–240 in Chapter 9).

The muscle mass should be examined for tenderness and swelling, which can occur after overuse or strain. Inflammation of this area is commonly involved in golfer’s elbow. The specific test is described later on p. 229.

Lateral Aspect

Bony Structures

Lateral Epicondyle and Supracondylar Ridge

Stand next to the patient and make sure the upper extremity is in the anatomical position. Place your fingers along the lateral aspect of the humerus and allow them to move distally along the lateral supracondylar ridge of the humerus until you reach a small rounded structure. This is the lateral epicondyle of the humerus (Figure 9.9). Tenderness in this area can be due to inflammation of the common aponeurosis of the extensor tendons of the wrist and is commonly referred to as tennis elbow (lateral epicondylitis).

Medial collateral ligament

Figure 9.6 Palpation of the medial collateral ligament.

Ulnar

nerve

Figure 9.7 Palpation of the ulnar nerve.

Figure 9.8 Palpation of the wrist flexor-pronator muscles.

Supracondylar ridge

Lateral

Epicondyle

Figure 9.9 Palpation of the lateral epicondyle and supracondylar ridge.

Figure 9.10 Palpation of the radial head.

Radial Head

Ask the patient to flex the elbow to 90 degrees. Place your fingers on the lateral epicondyle and move them distally. You will first palpate a small indentation and then come to the rounded surface of the radial head (Figure 9.10). If you place your fingers more laterally, the radial head is more difficult to locate because it is covered by the thick bulk of the extensor mass. To confirm your hand placement, ask the patient to supinate and pronate the forearm and you will feel the radial head turning under your fingers.

Soft-Tissue Structures

Lateral (Radial) Collateral Ligament

The lateral collateral ligament attaches from the lateral epicondyle to the annular ligament. It is a cordlike structure (Figure 9.11). The ligament is responsible for the lateral stability of the elbow and its integrity can be tested with a varus stress test (described on p. 213). The ligament is not distinctly palpable but the lateral joint line should be examined for areas of tenderness secondary to sprains.

Annular Ligament

The annular ligament surrounds the radial head and serves to keep it in contact with the ulna. The lateral collateral ligament blends with the superficial fibers. The ligament is not palpable (Figure 9.12).

Humeroradial Bursa

The humeroradial bursa is located over the radial head and under the common aponeurosis of the extensor tendons. It is not normally palpable. It can be inflamed secondary to direct trauma or overuse and should not be confused with lateral epicondylitis. Calcification can be visualized in a radiograph.

Wrist Extensor-Supinator

The common origin of the extensor-supinator muscle group is found at the lateral epicondyle and the supracondylar ridge of the humerus. This group is composed of the brachioradialis, extensor carpi radialis longus, extensor carpi radialis brevis, and extensor digitorum (Figure 9.13). The individual muscles are difficult to differentiate by palpation at the muscle belly. You can get a sense of their location by resisting the muscle function. Provide resistance while the patient flexes the elbow with the forearm in the neutral position and you will see the contour of the brachioradialis on the anterolateral surface of the forearm lateral to the biceps tendon. It forms the lateral border of the cubital fossa. Provide resistance while the patient extends the wrist in radial deviation and you get a sense of the location of the extensor carpi radialis longus and brevis. Resist finger extension and you will feel the extensor digitorum contract under your fingers. The tendons are easily distinguishable at the wrist (described in the wrist and hand chapter).