PMR 2 - musculoskeletal Flashcards

Question

Writer's cramp; a. Is the least common type of dvstonia. b. Is a task-specific focal dystonia c. Improves after attempts to perform a specific task such as writing d. Has a poor prognosis

Answer 1

B)Writer's cramp is the most common type of dystonia. Patients with dystonia have simultaneous contraction of agonist and antagonist muscle groups. Initial complaints present as poor coordination, cramping, and aching of the hand with task-specific movements. Prognosis for recovery is good.

Answer 2

D) Steroid injection can be considered in patients diagnosed (by NCV/EMG) with mild to moderate CTS. Care is taken to avoid piercing the median nerve. The needle is directed at an angle of 30 degrees. Surgery is usually required in severe CTS, especially if abnormal spontaneous potentials are noted in the APB muscle.

Answer 3

C) Age, muscle imbalance (weakness), anatomic malalignment, and genetic predisposition are all intrinsic factors that contribute to the development of tendinitis. Extrinsic variables include training errors, environmental factors, and equipment.

Answer 4

D) Ice is used more frequently in the acute stages of inflammation, particularly during the first 72 hours. It is a very effective anti-inflammatory modality. Benefits of ice include vasoconstriction, decreased swelling, and relief of pain and muscle spasm.

Answer 5

C) Trigger points can develop due to a S variety of factors, including direct or indirect trauma, overuse, or stress. A trigger point is an area of tautness, which on compression can cause local or referred manifestations. Trigger points can refer symptoms to more remote regions. In contrast, palpation of a tender point causes local discomfort without referred pain.

Answer 6

D) Little League elbow is suspected in a throwing athlete between the ages of 9 and 12 with medial elbow pain and a recent history of throwing. There is tenderness over the medial epicondyle and pain with resisted flexion of the wrist and valgus stress testing of the elbow. There may also be a slight elbow flexion contracture. The pathology is irritation and inflammation of the growth plate on the medial epicondyle.

Answer 7

A) Synovial joints come in multiple types. Ball and socket joints (e.g., hip joint [multiaxial], provide the most ROM). The saddle joint is a biaxial joint that provides the second most ROM. Other types of synovial joints include the hinge (elbow-uniaxial), pivot (atlanto-axial joint uniaxial), condyloid joints (metacarpophalangeal joints-biaxial), and plain joints (acromioclavicular).

Answer 8

A) The scaphoid is the most commonly fractured carpal bone (70%). It is subject to osteonecrosis due to its poor blood supply. Clinical features of a scaphoid fracture include tenderness in the anatomical snuff box. Complications include collapse of carpal bones, especially scapholunate instability.

Answer 9

D) Clinical features of Kienböck's disease include pain over the dorsal aspect of the wrist, directly over the lunate. The mechanism is hypothesized to be an idiopathic loss of blood supply to the lunate, causing avascular necrosis. The disease is correlated with repetitive stress or fracture. Risk factors include short ulnar variance and poor vascular supply. In later stages, the collapse of the lunate results in multiple degenerative changes at the wrist.

Answer 10

D) Shoulder flexion involves the use of the anterior deltoid, pectoralis major, biceps brachii, and coracobrachialis.

Answer 11

D) Shoulder extension involves the use of the posterior deltoid, latissimus dorsi, teres major, long head of triceps, and sternocostal portion of the pectoralis major.

Answer 12

D) The biceps brachi is not involved in shoulder adduction. In addition to the pectoralis major, teres major and coracobrachialis, shoulder adduction involves the latissimus dorsi, infraspinatus, anterior and posterior deltoid, and the long head of the triceps.

Answer 13

B) Approximately 30% of the humeral head articulates directly with the glenoid fossa. A fibrocartilaginous complex called the labrum surrounds the glenoid fossa, effectively increasing the total contact of the humeral head with the glenoid to 70%. This allows for the stabilization of the glenohumeral joint and prevents anterior and posterior humeral head dislocation.

Answer 14

A) The supraspinatus is the primary muscle implicated in rotator cuff tears. The supraspinatus tendon has a poor blood supply and is susceptible to chronic subacromial impingement--a mechanism which is rarely seen in people younger than 40 years of age.

Answer 15

C) The proximal row of carpal bones (from a radial to ulnar direction) include the scaphoid, lunate, triquetrum, and pisiform. The distal row of carpal bones (from a radial to ulnar direction) include the trapezium, trapezoid, capitate, and hamate. A common acronm to remember these bones is "Some Lovers Try Positions That They Cannot Handle."

Answer 16

B) The flexor carpi ulnaris is innervated by the ulnar nerve. All of the other choices are muscles that are innervated by the median nerve. The median nerve also innervates the flexor digitorum superficialis. The flexor digitorum profundus is dually innervated by the median (second and third digit) and the ulnar nerve (fourth and fifth digit).

Answer 17

C) The extensor digiti minimi muscle is innervated by the ulnar nerve. All of the other choices are muscles that are innervated by the radial nerve. Other muscles innervated by the radial nerve include the extensor carpi ulnaris, the extensor digitorum communis, and the extensor pollicis longus.

Answer 18

A) Paired contraction of the flexor carpi' ulnaris and extensor carpi ulnaris causes ulnar deviation of the wrist.

Answer 19

D) The palmaris longus muscle is primarily a wrist flexor. Although it is absent in about 14% of the population, its absence does not have any known effects on grip strength. All the other choices are finger flexors, including the flexor digitorum profundus (not listed).

Answer 20

A) All of the above muscles are digit 2 to 4 extensors, except the extensor pollicis longus, which is a thumb extensor.

Answer 21

B) Overall, there is 2° of glenohumeral motion for every 1° of scapulothoracic motion during shoulder abduction (120° of glenohumeral motion to 60 ° of scapulothoracic motion). However, in a normal shoulder, the majority of the initial ROM occurs at the glenohumeral joint when the arm is supinated.

Answer 22

C) Although there is considerable overlap between adjacent dermatomes, the C7 dermatome supplies sensation to the area of skin over the index finger. The C6 dermatome supplies sensation to the first digit, whereas the C8 dermatome supplies the fifth digit. The C5 dermatome supplies sensation to the lateral aspect of arm.

Answer 23

B) The celiac ganglion is part of the sympathetic (thoracolumbar) division of the ANS. The cranial parasympathetic outflow is via cranial III, VII, and IX involving ciliary, pterygopalatine, otic, and submandibular ganglia. Cranial nerve X provides parasympathetic outflow to multiple visceral organs (heart, lungs, upper gastrointestinal system). Additionally, sacral parasympathetic outfl ow supplies the lower gastrointestinal and genitouri nary system via pelvic splanchnic nerves arising from S2, 3, 4 segments.

Answer 24

A) The ciliary ganglion is part of the parasympathetic (craniosacral) division of the ANS.

Answer 25

D) Congenital torticollis occurs in 1 per 250 live births, with 75% involving the right side. The most common cause is fi brosis of the sternocleidomastoid. The presence of a cervical hemivertebra is less common. On physical examination, a nontender enlargement in the sternocleidomastoid is noted.

Answer 26

A) The posterior longitudinal ligament attaches to the posterior rim of vertebral bodies and disc from C2 to the sacrum.

Answer 27

D) The thyroid cartilage is located at the level of C4, C5 anteriorly.

Answer 28

D) L4 is at the level of the iliac crests.

Answer 29

A) Compression of the C5 nerve root will result in weakness of the biceps brachii. Compression of C6 and C7 nerve roots would result in weakness of the extensor carpi L radialis and triceps, respectively. Compression of C8 and T1 nerve roots would result in weakness of flexor digitorum profundus and abductor digiti minimi (ADM/interossei, respectively.

Answer 30

A) Compression of the T1 nerve root would result in weakness of the ADM/interossei. Compression of C6 and C7 nerve roots would result in weakness of the extensor carpi radialis and triceps, respectively. Compression of the C8 nerve roots would result in weakness of the flexor digitorum profundus.

Answer 31

B) L2 nerve root compression would result in cremasteric reflex abnormalities. The cremaster muscle receives innervation via the genitofemoral nerve (L1 and L2). Patellar tendon and Achilles tendon reflexes would be present in L3/L4 and S1 nerve root compressions, respectively. Cross adductor reflex is a withdrawal reflex on one side, with an inhibitory response on the contralateral side to maintain balance-for example, stepping on a nail would result in flexion of the affected limb and extension of the contralateral limb.

Answer 32

D) The internal intercostals are accessory muscles used during expiration. In addition to the other choices above, the external intercostals and scalene muscles serve as accessory muscles during inspiration. Diaphragmatic muscle contraction (innervated by the phrenic nerve) serves as the primary muscle of respiration during inspiration.

Answer 33

B) Structural scoliosis is not reversible. Subtypes include idiopathic, congenital, or acquired. Idiopathic scoliosis accounts for 80% of structural scoliosis.

Answer 34

C) Senile changes in a person's spine result in the acquired type of structural scoliosis and is not reversible. All other answer choices are characteristic of functional scoliosis and are reversible.

Answer 35

B) If the Cobb angle exceeds 50° to 60°, abnormalities in pulmonary function tests may appear. Treatments are based on the degree of curvature: 1°to 20° observation; 20 to 40° bracing; greater than 40 ° evaluation for surgery.

Answer 36

B) The dorsal root ganglion contains cell bodies of the afferent spinal nerves responsible for relaying sensory information. A motor unit contains the following components from proximal to distal: anterior horn cell, motor nerve axons, peripheral nerve, the neuromuscular junction, muscle fibers.

Answer 37

A) All of the answer choices except the motor nerve cell body are components of the neuromuscular junction. The motor nerve cell body gives rise to motor nerve axons.

Answer 38

A) Endoneurium is the connective tissue that surrounds each individual axon and its myelin sheath. The myelin sheath itself improves conductance of the electrical signal down an axon.

Answer 39

C) Choices A and B are paired with the incorrect nerves. Choice D is responsible for lateral winging of the scapula.

Answer 40

D) The dorsal portion of the annulus fibrosis is innervated by the medial branch of the segmental spinal nerves.

Answer 41

D) The brachioradialis muscle is innervated by the radial nerve.

Answer 42

B) Homonymous hemianopsia would result from injury to the optic tract. Cortical blindness results from bilateral lesions of the primary visual cortex, as seen in Anton syndrome. Monocular blindness would be a result of injury to the optic nerve.

Answer 43

D) The superior oblique muscle is innervated by cranial nerve IV. The lateral rectus is innervated by cranial nerve VI. Rest of the ocular muscles are innervated by cranial nerve Ill

Answer 44

A) The lesser and the greater occipital nerves arise from C2 and C3, respectively. The rest of the choices are the three main branches of the trigeminal nerve.

Answer 45

C) The mandibular nerve is a branch of the trigeminal nerve- cranial nerve V.

Answer 46

A) The genitofemoral nerve is part of the lumbar plexus (L1-4). The sacral plexus also includes the posterior cutaneous nerve of the thigh.

Answer 47

D) The posterior cutaneous nerve of the thigh (S1-3) is part of the sacral plexus.

Answer 48

B) The suprascapular nerve innervates the supraspinatus and infraspinatus muscles.

Answer 49

A) The axillary nerve innervates the teres minor and the deltoid muscles.

Answer 50

C) The subscapular nerve innervates the subscapularis and the teres major muscles.

Answer 51

C) The dorsal scapular nerve innervates both levator scapulae and the rhomboids.

Answer 52

D) The semispinalis muscle is one of the deep layers of intrinsic back muscles and arises from approximately half of the spine-hence its name. It is divided into three parts: semispinalis capitis, semispinalis thoracis, and semispinalis cervices. The other muscles in the deep layer of intrinsic back muscles are the multifidus and the rotators. Collectively, the deep layer of the intrinsic back muscles is known as the transversospinal muscle group.

Answer 53

B) Splenius capitis and splenius cervicis are part of superficial layer of the intrinsic back muscles.

Answer 54

C) The distal end of humerus is in direct contact with the median nerve.

Answer 55

B) The other choices refer to the pectoralis minor (a), levator scapulae (c), and subscapularis (d).

Answer 56

B) The shoulder joint is a ball-and-socket type joint. An example of a hinge joint is the elbow. Joints between bones of the skull are called sutures, and the base of the carpometacarpal ioint of the thumb is an example of a saddle joint.

Answer 57

C) The Rockwood classification system is used to describe AC joint injuries. Type I is mild injury with intact AC and CC ligaments. Type Il is a complete tear of the AC ligament and intact CC ligament. Type III-VI each describe complete disruption of both AC and CC ligaments with varying degrees of dislocation of the clavicle. In type Ill injuries, the clavicle is displaced superiorly, whereas in type IV the clavicle is displaced superiorly and posteriorly into the trapezius. In type V injuries, the clavicle is displaced superiorly with > 100% increase in the coracoclavicular interspace. In type VI, the clavicle is displaced inferiorly below the acromion or coracoid process.

Answer 58

B) Clavicle fractures are one of the most common bony injuries. The most common location is the middle third (80%). 15% occur in the distal third and 5% occur in the proximal third.

Answer 59

D) Four muscles (infraspinatus, supraspinatus, subscapularis, and teres minor) form the rotator cuff. The insertion point of these four muscles is subiect to repetitive microtrauma and impingement between the acromion and greater tuberosity of the humerus. Impingement syndrome, supraspinatus syndrome, and bursitis are terms commonly used. Neer's test will be positive in the setting of impingement. Hawkins' test can also be performed to further confirm impingement. Drop arm test is used to detect rotator cuff tears. O'Brien test can be used to detect SLAP lesions or AC joint abnormalities. Apley scarf test is also used to detect AC joint pathology.

Answer 60

A) When there is shoulder instability, there are recurrent episodes of subluxation where the humeral head partially comes out of the socket. Anterior instability is more commonly seen than posterior instability, hence dislocations also more commonly occur anteriorly. With recurrent anterior dislocations (where the humeral head remains fully out of socket), the anterior glenoid labrum may become torn or even avulsed off of the glenoid rim (called a Bankart lesion). Choice B describes a Hill-Sachs lesion. Choice C is a SLAP lesion, and choice D describes the setting of thoracic outlet syndrome.

Answer 61

D) Adhesive capsulitis is usually an idiopathic condition resulting in the loss of both active and passive ROM of the shoulder. It most commonly affects middle-aged adults (40-60 years). Associated risk factors include female gender, diabetes (most common risk factor) and hypothyroidism, among other conditions. None of the aforementioned risk factors have been determined to be primary causes of this condition. Adhesive capsulitis is divided into three stages (freezing stage, frozen stage, and thawing stage).

Answer 62

B) In the Stimson technique, the patient with an anterior shoulder dislocation is placed prone on the stretcher with the dislocated arm hanging off the edge of the bed. A 5 to 15 lb weight is attached to the distal arm so that it is not touching the floor. The physician places their thumb on the patient's acromion and using fingers of the same hand places them over the humeral head. As the patient's muscles gradually relax, the provider gently pushes the humeral head caudally until it reduces. Choice C describes another type of technique different from Stimson's.

Answer 63

D) Long thoracic nerve injury or palsy will result in serratus anterior weakness. The long thoracic nerve originates from the C5-C7 nerve roots, travels below the brachial plexus and clavicle before ultimately innervating the serratus anterior muscle. The serratus anterior muscle works to protract the scapula and cause its upward rotation, pulling it forward against the rib cage. In medial scapular winging, the scapula comes away from the chest wall medially. Forward flexion of the shoulder is often weaker and limited to 90 degrees relative to the unaffected side. Injury to the spinal accessory nerve results in lateral scapular winging.

Answer 64

A) The surgical neck is called so because of frequent fractures which occur here. This area lies below the head and tubercle and is narrow. The anatomical neck is located at the junction point of the head with the shaft, and is between the head and tubercles.

Answer 65

C) Speed's test is performed by asking the patient to anteriorly flex the shoulder against resistance while the elbow is extended. Hawkins' and Neer's both test for rotator cuff impingement. Empty can test is used to detect supraspinatus tendinopathy.

Answer 66

B) Rheumatoid arthritis is the most common cause of elbow joint destruction and occurs in most patients who have polyarticular involvement.

Answer 67

C) The most commonly dislocated joint in children is the elbow. The elbow is the second most common dislocated joint in adults.

Answer 68

A) The posterior interosseous nerve (PIN) is a deep branch of the radial nerve which if compressed may present with lateral el bow pain. The PIN usually gets compressed by a fibrous band located between two heads of the supinator muscle (the radial tunnel). Patients may present with symptoms similar to lateral epicondylitis, but remain refractory to treatment. In such situations, an EMG/NCS should be sought to evaluate for PIN compression.

Answer 69

D) Cozen's test is performed with the examiner stabilizing the patient's elbow and his or her thumb over the extensor tendon origin along the lateral epicondyle. With the opposite hand, the examiner provides resistance as the patient tries to extend and radially deviate the wrist. Pain over the lateral epicondyle indicates a positive test.

Answer 70

D) The phases of throwing in order are: wind up, early cocking, late cocking, acceleration, and follow-through. During late cocking there is significant vagus stress on the elbow joint, with maximal stress on the medial collateral ligament (MCL). The elbow also experiences a significant degree of valgus stress during acceleration, but not as much as late cocking.

Answer 71

A) Up to 18% of humeral shaft fractures are associated with radial nerve injury, particularly if the fracture occurs at the junction between the middle and distal third of the shaft. The axillary nerve is the most commonly injured nerve with more proximal humerus fractures (i.e., surgical neck fractures).

Answer 72

C) The most powerful forearm supinator is the biceps brachii. This muscle has two proximal attachments. The short head attaches L/to the coracoid process, whereas the long head attaches to the supraglenoid tubercle of the scapula. The distal attachment is at the radial tuberosity and bicipital aponeurosis into fascia of the forearm. The biceps brachii is innervated by the musculocutaneous nerve, and this muscle is best tested when the forearm is placed in flexion and supination.

Answer 73

D) The anconeus muscle originates at the lateral epicondle of the humerus and inserts along the lateral side of the ulna. This muscle functions in forearm extension as well as stabilization of the elbow joint against flexion or pronation-supination. The anconeus muscle is innervated by the radial nerve.

Answer 74

C) The brachialis muscle is supplied mainly by the musculocutaneous nerve. A small branch of the radial nerve may sometimes innervate the lateral portion of this muscle. The brachialis muscle originates at the lower half of the anterior humerus and inserts at the ulnar tuberosity.

Answer 75

A) Osteochondritis dissecans is characterized by fragmentation of the bone and cartilage overlying the capitellum in the elbow. This condition often occurs in teenage boys involved with throwing sports due to valgus stress on the elbow. It is often mistakenly confused with Panner's disease, which has more to do with a circulatory problem affecting the bone in the elbow and occurs in children 5 to 12 years of age.

Answer 76

A) There are six compartments in the dorsum of the hand. The contents of each compartment are as follows: -extensor pollicis brevis, abductor pollicis longus; 11-extensor carpi radialis brevis, extensor carpi radialis longus; III-extensor pollicis longus; IV-extensor digitorum; V-extensor digiti minimi; VI-extensor carpi ulnaris.

Answer 77

C) The carpal tunnel contains the four tendons of FDS, four tendons of FDP, FPL tendon and median nerve. The roof of the carpal tunnel is formed by the transverse carpal ligament; the floor is formed by the central carpal bones. The medial wall is formed by the hamate and the pisiform bones. The lateral wall is formed by the trapezius and scaphoid bones.

Answer 78

B) De Quervain's tenosynovitis is a condition in which inflammation causes thickening and stenosis of the synovial sheath surrounding the first dorsal compartment of the wrist. This produces pain with tendon movement. On examination, there may be appreciable thickening of the fibrous sheath and Finkelstein's test will be positive. Nonoperative management is indicated in most cases. Splinting with a thumb spica splint is applied such that pinching is possible. Steroid injection can help for symptomatic relief, and surgery may be indicated for decompression in refractory cases.

Answer 79

C) Typical radiographic features of osteoarthritis include joint space narrowing, osteophyte formation, and subchondral cysts. Periarticular osteopenia/osteoporosis and soft tissue swelling are typically seen in rheumatoid arthritis. Pencil-in-cup deformity is a finding in psoriatic arthritis.

Answer 80

A) The FDP muscle's origin is at the anterior ulna and interosseous membrane. The insertion is the distal phalanx of the index, middle, ring, and small fingers. Its main action is flexion of the DIP joint of the fingers. The FDP is innervated by the anterior interosseous nerve from the median nerve (index and middle fingers) as well as the ulnar nerve (ring and small finger).

Answer 81

D) The dorsal interosseous (DIO) muscles are part of the intrinsic group of muscles in the hand. The DIO proximally attach at adjacent metacarpals and distally attach to proximal phalanges. Their main function is to abduct the digits and for MCP flexion.

Answer 82

A) Individual flexor tendons for each digit of the hand are housed within a flexor tendon sheath. The tendon sheath has areas of thickening called annular and cruciate pulleys that function to stabilize the tendon. In stenosing tenosynovitis (trigger finger), the proximal pulley becomes inflamed and thickened with concurrent nodular enlargement of the tendon itself. As the inflamed tendon passes through the thickened pulley, it occasionally becomes stuck, locking the finger in flexion. This condition usually affects the middle or ring fingers. Therapy includes local steroid injection or surgery.

Answer 83

C) Heberden's nodes are swellings of the distal interphalangel joints seen in osteoarthritis. Contents of these swellings are gelatinous hyaluronic acid. These growths arise in the chronic phase of osteoarthritis.

Answer 84

B) Kienbock's disease is a consequence of traumatic or repetitive microtrauma to the lunate leading to osteonecrosis. Patients present with pain, stiffness, and wrist dysfunction. Physical examination reveals local tenderness over the lunate, limited ROM, and decreased grip strength. Radiographs may show lunate sclerosis and degeneration of adjacent joints in later stages. In later stages, wrist fusion may be indicated.

Answer 85

D) Boutonniere deformity is seen in patients with rheumatoid arthritis and is a consequence of disruption of the central slip of the extensor tendons with volar migration of the lateral bands. This results in hyperflexion of the PIP joint. Treatment in early stages includes splinting of the PIP joint in extension.

Answer 86

B) The distal humerus has two surfaces of articulation- the capitellum and the trochlea. The radial head articulates with the capitellum and the ulna articulates with the trochlea.

Answer 87

C) The elbow joint is comprised of three articulations: ulnoumeral, radiocapitellar, and proximal radioulnar.

Answer 88

A) Gamekeeper's thumb is an injury to the ulnar collateral ligament of the thumb MCP joint resulting in joint instability. Usually, the mechanism of injury is a forced radial deviation of the thumb or from a ski pole injury. Patients may describe pain and decreased grip strength at this location. There may be appreciable laxity of the MCP. A palpable mass at the location of the ulnar collateral ligament is called a Stener lesion, where the adductor pollicis aponeurosis falls under the torn collateral ligament.

Answer 89

C) Froment's sign is performed by asking the patient to pinch a piece of paper between his or her index finger and thumb while the examiner tries to pull the paper away. If the patient flexes the first interphalangeal joint, suggesting adductor pollicis weakness, the test is considered a positive Froment's sign and indicates possible ulnar nerve palsy.

Answer 90

D) Allen's test is used to check for patent ulnar and/or radial artery circulation to the hand. To perform the test, the examiner manually occludes the patient's ulnar and radial arteries while the patient makes a fist. As the examiner releases pressure one by one, visible reperfusion of the palm indicates patency of the arteries. This test is usually performed prior to doing a radial artery arterial blood gas to ensure that collateral circulation will be possible should the radial artery become occluded.

Answer 91

C) Guyon's canal is also known as the ulnar tunnel. The floor of Guyon's canal is formed by the transverse carpal ligament, the roof is the volar carpal ligament, and the medial and lateral walls are formed by the pisiform and hook of hamate. The canal houses both the ulnar nerve and the ulnar artery. Fractures or masses (e.g., ganglion cyst) can compress the nerve or artery at this location.

Answer 92

A) There are six dorsal compartments to the wrist. The first compartment houses the abductor pollicis longus and the extensor pollicis brevis tendons. This is the location where De Quervain's tenosynovitis can occur.

Answer 93

B) Scaphoid fractures are the most common carpal bone fractures. The usual mechanism of injury (as is the case with most carpal fractures) is a fall on outstretched hands. Patients will have tenderness in the anatomical "snuffbox" area and decreased ROM. Fracture of the middle third of the scaphoid bone (known as the waist) is most common. This bone has retrograde blood supply, making this bone particularly susceptible to malunion or vascular necrosis following a fracture. It is for this reason that a low threshold of suspicion is maintained for scaphoid fractures, and immobilization is usually initially prescribed if there is high clinical suspicion (despite negative x-rays).

Answer 94

C) Recurrent anterior shoulder dislocations can lead to a compression fracture of the posterolateral humeral head known as a Hill-Sachs deformity. Radiographic evaluation with anterior-posterior views and Stryker notch view are used. In the Stryker notch view, the patient is supine with a cassette placed under the involved shoulder. The palm of the affected arm is placed on top of the head with the fingers pointing posteriorly, and the elbow pointing upward toward the ceiling. The x-ray beam is centered over the coracoid process with the beam directed 10 degrees towards the head.

Answer 95

B) Static and dynamic stabilizers contribute to shoulder joint stability. Static stabilizers are glenoid, labrum, articular congruity, glenohumeral ligaments and capsule, and negative intraarticular pressure. The dynamic stabilizers are rotator cuff muscles/tendons, biceps tendon, and periscapular muscles.

Answer 96

A) Adson's test is performed by locating the radial pulse of the affected arm and asking the patient to turn their head toward the affected shoulder. The arm may be abducted and externally rotated as part of the maneuver. If the radial pulse diminishes on the affected side, this is positive for possible thoracic outlet syndrome. Thoracic outlet syndrome is the compression of the neurovascular structures in the neck, usually by a cervical rib or first rib and scalene muscles.

Answer 97

D) The quadrangular space of the shoulder is bordered by the teres minor, teres major, long head of the triceps muscle, and medial border of the humerus. It is an area of potential compression of the posterior humeral circumflex artery or axillary nerve, especially in athletes who engage in overhead activities (throwing athletes, tennis players, swimmers). Patients will present with pain and paresthesias of the posterior lateral shoulder.

Answer 98

B) The most common "mass" to occur in the wrist is a ganglion cyst. It is essentially a "ballooning-out" of the joint lining and the fluid inside is synovial fluid. Ganglion cysts most commonly occur on the dorsal aspect of the wrist (usually from the scapholunate joint). On physical examination, the cyst may transilluminate. They can be evaluated by MRI, while x-rays will often be normal. Observational management is indicated for asymptomatic cases. If the cysts interfere with activity, aspiration may be warranted. Ganglion cysts tend to recur at a rate of 20%, while recurrence rate drops to <10% following excision.

Answer 99

D) The radial nerve originates from the C5-1 nerve roots and the posterior cord (originates from upper, middle, and lower trunks).

Answer 100

A) Saturday night palsy, honeymooner's palsy, or radial nerve mononeuropathy usually presents with wrist and finger drop. It may present with numbness and paresthesias of the forearm and wrist as well. Acute compression of the radial nerve typically occurs at the spiral groove.

Answer 101

D) The spinal accessory nerve is most commonly injured in the posterior cervical triangle. This will result in isolated trapezius muscle weakness. The mechanism of injury may be stretch or external compression or after surgical procedure (i.e., cervical lymph node biopsy). A lesion in this region will spare the sternocleidomastoid of the affected side. Mild scapular winging may also be observed with shoulder abduction (lateral winging).

Answer 102

C) Thé suprascapular nerve is commonly compressed at the level of the suprascapular notch, resulting in deep, boring shoulder pain along the superior scapula and weakness of shoulder abduction and external rotation. If nerve entrapment occurs at the level of the spinoglenoid notch, then the only appreciable finding may be isolated atrophy and weakness of the infraspinatus muscle. Pain is not so prominent at this level because the sensory fibers have already exited.

Answer 103

C) The main flexor of the forearm is the brachialis muscle. The anconeus is a relatively insignificant muscle that helps the triceps extend the forearm and it also resists ulnar abduction during pronation. The biceps brachii muscle is the major supinator of the forearm, while the brachioradialis is a forearm flexor (but not the main flexor).

Answer 104

D) In Erb's palsy, the upper trunk of the brachial plexus is affected (C5-C6) resulting in shoulder abduction, elbow flexion, and forearm supination weakness. It is the most common brachial plexopathy seen in newborns.

Answer 105

C) The infraspinatus muscle's proximal attachment is in the infraspinous fossa, while its distal attachment is at the greater tuberosity of the humerus. The primary action of the infraspinatus muscle is to externally rotate the arm as well as to provide stability to the rotator cuff.

Answer 106

B) CRPS is a condition characterized as a chronic pain syndrome due to dysfunction in the central and peripheral nervous systems. It presents with changes in skin color and temperature and is accompanied by intense burning pain symptoms and sensitivity. The stellate ganglion block is a sympathetic block used primarily to diagnose and treat symptoms of CRPS. Such blocks are usually performed by a pain specialist and may result in complete or partial pain relief. An adequate block may result in a temporary Horner's syndrome. Sympathetic blocks performed for the lower extremities are called lumbar sympathetic blocks.

Answer 107

A) Ipsilateral Horner's syndrome (dropping eye, pupillary constriction, and increased skin temperature or flushing) indicates that the block was adequate.

Answer 108

D) Panner's disease is usually seen in young boys aged 5 to 12 years. It is felt to be due to an interruption in the blood supply to the epiphysis resulting in initial resorption followed by eventual remodeling of the epiphysis. This condition most commonly occurs in the dominant arm and is found to be due to chronic repetitive trauma, hereditary factors, and certain endocrine disorders.

Answer 109

C) Smith's fracture is when the distal radius becomes fractured and the distal fragment is displaced toward the palm (volar). It is also called a "reverse Colle's fracture" because in a Colle's fracture the distal radial fragment is displaced dorsally.

Answer 110

A) The FDS inserts at the middle phalanx of the index, middle, ring, and small fingers. The FDS muscle's origins are the medial humeral epicondyle, the coronoid process of the ulna, and the upper anterior surface of the radius. Its main action is to flex the fingers at the PIP joints. However, it also acts to flex the hand and wrist.

Answer 111

C) MRI has replaced arthrography as the gold standard test for rotator cuff injuries. MRI offers high sensitivity and specificity that can be used to identify size, location, and quality of injury. MRI is relatively expensive and requires lack of motion by the patient in order to avoid artifact.

Answer 112

C) Dupuytren's contracture most commonly involves the ring finger. This condition appears in the fourth to sixth decade of life and is more severe in males of northern European descent. The pathophysiology results in collagen type III hyperproliferation affecting the palmar fascia. Treatment includes serial triamcinolone injections in early stages, collagenase injections, and surgery.

Answer 113

D) Swan neck deformity is characteristic of rheumatoid arthritis. The deformity may start at the MCP, PIP, or DIP joint. If the flexor tendon at the MCP joint tightens, this may result in hyperextension at the PIP joint. Alternatively, if the PIP volar capsule becomes lax secondary to tenosy novitis, the PIP joint will hyperextend causing swan necking of the remaining joints. More commonly, however, stretching or disruption of the distal extensor mechanism results in a mallet finger deformity, which leads to eventual PIP hyperextension.

Answer 114

B) No differences have been found in knee ROM, pain scores, or analgesic use in patients who used CPM following TKA. One study did reveal some evidence suggesting PM can shorten the length of hospital stay and improve knee flexion at early time points, but does not affect other functional outcomes. The postoperative use of a continuous passive motion machine does not improve outcomes after anterior cruciate ligament tear surgical repair either.

Answer 115

C) An avulsion fracture of the ASIS, especially in an adolescent athlete, often occurs from forceful eccentric contraction of the sartorius or tensa facia lata muscle with hip extension and knee flexion, as in sprinting or swinging a baseball bat. Surgery may be needed for a displaced apophysis. The rectus femoris muscle is involved in an anterior inferior iliac spine avulsion fracture.

Answer 116

A) The proximal tibiofi bular joint is located between the lateral tibial condyle and the fibular head and has been construed as the "fourth compartment" of the knee joint. It is a synovial joint and communicates with the knee joint in approximately 10% of adults. It is a source of lateral knee pain that is often overlooked.

Answer 117

B) The cruciate ligaments lie outside the synovial cavity but within the fibrous joint capsule.

Answer 118

C) During the last 20 degrees of extension of the knee, the femur slightly internally rotates on the tibia to lock the knee joint in place in the closed chain, or the tibia slightly externally rotates on femur in the open chain, which is also called the screw-home mechanism. In the closed chain, the popliteus can externally rotate the femur to unlock the knee for flexion.

Answer 119

D) Patrick's test is a provocative maneuver to assess for sacroiliac joint dysfunction as well as hip joint pathology by flexion, abduction, external rotation, and extension of the hip joint (hence it is also called the FABERE test). FAIR test (flexion, adduction, and internal rotation) is a provocative test for priformis syndrome.

Answer 120

B) Thomas' test is used to assess for a hip flexion contracture. With the patient supine, flex one hip to obliterate the lumbar lordosis. The angle between the affected thigh and the table reveals the fixed flexion contracture of the hip. Ober's test is used to assess for an iliotibial band contracture.

Answer 121

C) The true leg length should be measured from anterior superior iliac spine to medial malleolus. Apparent leg length discrepancy should be assessed if no true leg length discrepancy exists by measuring from a nonfixed point (e.g., umbilicus) to a fixed point (e.g., medial malleolus), which may be associated with pelvic obliquity.

Answer 122

D) Internal snapping hip syndrome is caused by a tight iliopsoas tendon snapping over the iliopectineal prominence of the pelvis, or less commonly, acetabular labral tear or loose body in the hip joint. A tight iliotibial band or glutes maximus snapping over the greater trochanter causes external snapping hip syndrome.

Answer 123

B) MRI of both hips is indicated to assess for a diagnosis of AVN of the femoral head. MRI is most sensitive to early changes with a low signal intensity noted on T1 imaging.

Answer 124

A) My ositis ossifiCans is the formation of heterotopic ossification within muscle. Prevention of contractures is a priority and can be accomplished by gentle ROM. Surgery may be needed if the myositis ossifi cans causes nerve entrapment, decreased ROM, or loss of function. However, surgery should be delayed until heterotopic ossification matures at 10 to 12 months.

Answer 125

A) The ACL originates at the lateral femoral condyle, travels through the intercondylar notch, and attaches to the medial tibial eminence. Its primary function is to limit anterior tibial translation, or prevent backward sliding of the femur. It limits internal rotation of the femur when the foot is fixed. The A CL loosens in flexion and tightens in full extension. ACL pathology leads to increased pressures on the posterior menisci.

Answer 126

D) Q' angle is the angle formed by a line drawn from the ASIS to the central patella, and a second line drawn from the central patella to the tibial tubercle. Normally, Q angle is 14 degrees for males and 17 degrees for females. An increased Q angle is a risk factor for patellar subluxation. The Q angle is increased by genu valgum, increased femoral anteversion, external tibial torsion, a laterally positioned tibial tuberosity or a tight lateral retinaculum.

Answer 127

D) The menisci appear to transmit approximately 50% of the compressive load through ROM of 0 to 90 degrees. The contact area is increased, protecting articular cartilage from high concentrations of stress. The circumferential continuity of the peripheral rim of the meniscus is integral to meniscal function. Partial meniscectomy, or bucket-handle tearing, will still preserve meniscal function as long as the peripheral rim is intact. Conversely, if a radial tear extends to the periphery and interrupts the continuity of the meniscus, the load-transmitting properties of the meniscus are lost. The tibial femoral contact area is decreased by up to 75% in postmeniscectomy knees. This decrease results in a 235% increase in contact stresses after total meniscectomy. The peripheral outer 1/3 of a meniscus is well vascularized, and the inner 2/3 poorly vascularized. Therefore, no surgical repair is needed for the inner 2/3 of a meniscus tear. The meniscus also plays an important role in proprioception of the knee joint.

Answer 128

A) The pivot shift test is the most specific test to diagnose an ACL tear. Under anesthesia, the specificity approaches 100%. Lachman test is usually considered the most sensitive test for an A CL tear. Ege's test is used for diagnosis of a meniscal injury.

Answer 129

A) The most common site of compartment syndrome is the lower leg. The anterior compartment is the most frequently affected, followed by the lateral compartment and the deep posterior compartment.

Answer 130

D) MTSS, also known as shin splints, is a common type of overuse injury that results from chronic traction on the periosteum at the periosteal-fascial junction along the posteromedial border of the tibia. The main predisposing factor is hyperpronation. Pain may improve with exercise but worsens afterward. Rest is the first priority in management of MTSS. Return to activity should be gradual.

Answer 131

B) The patellofemoral joint is under high levels of compression during stair climbing due to significantly increased quadriceps activity.

Answer 132

D) Sudden impact to the front of the tibia with the knee flexed (as in a motor vehicle accident) is the most frequent cause of PCL injury. Hyperflexion is the most common cause of PCL injury in athletes.

Answer 133

A) The anterior hip dislocation precautions are different from the posterior hip dislocation precautions: no hip extension, bridging, prone lying, or hip external rotation beyond neutral. When the patient is supine, keep the hip flexed to approximately 30 ° by placing a pillow under the patients knees or by raising the head of the bed.

Answer 134

B) In lateral ankle sprains, the ligaments within in lateral ligament complex are injured in a predictable sequence as forces increase: anterior talofibular ligament, calcaneofibular ligament, then posterior talofibular ligament.

Answer 135

D) The knee plica is considered a vestigial structure due to remnant embryological tissue that compartmentalizes the knee during fetal development. This horses hoe shaped structure can become irritated or inflamed, which causes anterior knee pain and weakness known as the plica syndrome.

Answer 136

D) Plantar fasciitis is caused by inflammation of the plantar fascia. Increased tension on the plantar fascia, such as pes cavus, pes plans, obesity, tight Achilles tendon, or bone spurs can lead to chronic inflammation. Treatment options are mostly conservative, including modalities, NSAIDs, orthotics or shoe modification (heel pads, cushion, and lift), as well as Achilles tendon and plantar fascia stretching. Anesthetic/corticosteroid injection is effective. Injection from the medial side of the heel helps avoid injection into subcutaneous tissue or fascial layer, which may cause fat pad atrophy/necrosis and fascia rupture. Nighttime dorsiflexion splints may be used if other conservative measures fail.

Answer 137

C) Morton's neuroma is a benign neuroma of an intermetatars al plantar nerve, and most commonly affects the third intermetatarsal space (between the third and fourth metatarsal bones).