FREE Orthopedics MCQS 2022 1351 -1400

1351. (3926) Q3-7868:

Following ankle injury, which radiographic parameter is indicative of syndesmotic instability:

1) Medial clear space greater than 2 mm

3) Syndesmotic overlap of less than 1 mm measured 1 cm above the ankle joint on the mortise view

2) Syndesmotic clear space greater than 5 mm measured 2 cm above the ankle joint on the anteroposterior (AP) view

5) Syndesmotic overlap of less than 1 mm measured 1 cm above the ankle joint on the AP view

4) Syndesmotic clear space greater than 5 mm measured 1 cm above the ankle joint on the mortise view

The normal radiographic findings of the syndesmosis on plain radiographs of the ankle are: Medial clear space less than or equal to 4 mm

Syndesmotic clear space less than 5 mm measured 1 cm above the ankle joint on the AP view of the ankle

Syndesmotic overlap greater than 1 mm measured 1 cm above the ankle joint on the mortise view of the ankle

 

■Correct Answer:Syndesmotic overlap of less than 1 mm measured 1 cm above the ankle joint on the mortise view

1352. (3927) Q3-7870:

In children between ages 7 and 11 with bilateral flexible flatfeet and without any pathologic findings, the use of custom-made orthotics or off-the-shelf orthotics demonstrate:

1) Significant improvement in motor proficiency compared to controls treated without orthotics

3) Significant improvement in exercise efficiency compared to controls treated without orthotics

2) Significant improvement in visual analog pain scores compared to controls treated without orthotics

5) No significant difference compared to controls with regards to motor proficiency, pain, exercise efficiency, or self-perception

4) Significant negative effects on the childâs self-perception compared to controls treated without orthotics

In a randomized controlled trial comparing children with flatfeet treated with custom orthotics, off-the-shelf orthotics, and no treatment, there were no differences in the above parameters found. The study concluded that no significant difference was found with regard to motor proficiency, pain, exercise efficiency, or self-perception.

 

■Correct Answer:No significant difference compared to controls with regards to motor proficiency, pain, exercise efficiency, or self- perception

1353. (3928) Q3-7872:

Following open reduction and internal fixation of ankle fractures, early mobilization in a removable cast demonstrated:

1) Lower functional scores compared to non-weight bearing cast treatment at 9 and 12 weeks

3) Improved quality of life compared to non-weight bearing cast treatment at 6 months

2) Earlier return to work compared to non-weight bearing cast treatment

5) A lower postoperative rate of infection compared to non-weight bearing cast treatment

4) Lower costs in physical therapy following discontinuation of cast or boot

Patients treated with early mobilization in a removable custom fiberglass orthosis (non-weight bearing) had higher early functional scores, earlier return to work, but a higher rate of postoperative wound infection. There were no differences between the two groups with regard to the quality of life at 6 months or the costs of physical therapy.

 

■Correct Answer:Earlier return to work compared to non-weight bearing cast treatment

1354. (3929) Q3-7874:

In comparing the clinical efficacy of intra-articular sodium hyaluronate injections vs triamcinolone injections for the treatment of hallux rigidus, which factor showed significantly better improvement in the sodium hyaluronate group:

1) Gait pain

3) Pain with passive mobilization

2) Pain at rest

5) Pain with palpation

4) Use of analgesics

In a prospective randomized study comparing sodium hyaluronate vs cortisone injections for hallux rigidus, gait pain and AOFAS scores were significantly better in the sodium hyaluronate-treated group. There was no significant difference between the two treatment groups with regard to rest pain, pain with mobilization, pain with palpation, and use of analgesics.

 

■Correct Answer:Gait pain

1355. (3930) Q3-7875:

Which anatomical feature does not predispose patients to peroneal tendon dislocation:

1) Shallow peroneal groove

3) Peroneus quartus

2) Insufficient superior peroneal retinaculum

5) Varus heel alignment

4) Low-lying peroneus brevis muscle belly

A varus heel alignment would stabilize the peroneal tendons medially into the peroneal groove. Valgus heel alignment is associated with increased risk for peroneal tendon dislocation because this predisposes the tendons to move laterally out of the groove. The other anatomical features have all been implicated as risk factors for peroneal tendon dislocation.

 

■Correct Answer:Varus heel alignment

1356. (3931) Q3-7876:

A 39-year-old man has a forced dorsiflexion injury while skiing. Radiographs taken in the emergency department show a small avulsion flake off the lateral surface of the fibula distally on the mortise view. This patient most likely has:

1) A lateral process of the talus fracture

3) An anterior process of the calcaneus fracture

2) An osteochondral fracture of the talus

5) A syndesmotic sprain

4) A peroneal tendon dislocation

A forced dorsiflexion injury, especially with skiing, is a common mechanism described for peroneal tendon dislocation. All of the diagnoses listed are potential injuries that can initially be mistaken for an ankle sprain. The flake avulsion off of the lateral border of the distal fibula is almost pathognomonic of a peroneal tendon dislocation injury.

 

■Correct Answer:A peroneal tendon dislocation

1357. (3932) Q3-7877:

Which of the following is not considered to be a risk factor for peroneal tendon tears:

1) Shallow retromalleolar groove

3) Ligamentous laxity

2) Gastrocnemius-soleus  contracture

5) Recurrent lateral ankle ligament instability

4) Varus hindfoot alignment

A shallow retrofibular groove and ligamentous laxity predispose to subluxation of the peroneal tendons causing attritional tears over the posterolateral fibular ridge. Varus hindfoot alignment places patients at risk for inversion sprains, which may cause trauma to the peroneal tendons when they are put on stretch. Heel chord contracture has not been implicated in the development of peroneal tendon tears.

 

■Correct Answer:Gastrocnemius-soleus  contracture

1358. (458) Q4-633:

The thoracic outlet syndrome is characterized by:

1) The invariable presence of abnormal congenital structures such as cervical ribs or costovertebral synestosis

3) A high incidence of vascular symptoms and a low incidence of neurological symptoms

2) Proximal compression of upper extremity neurologic and vascular structures at one of multiple

5) A frequently identifiable traumatic precipitant.

4) C ompression of the subclavian vein between the anterior and middle scalene muscles

The thoracic outlet syndrome is a compressive neurovascular disorder of the upper extremity with many possible sites of entrapment. Abnormal congenital structures, macro-, and micro-trauma have all been implicated as possible mechanisms for the process, though none of these factors is an absolute requisite for the disorder. Neurologic symptoms are more common than vascular complaints. The subclavian vein passes anterior to the interscalene interval which contains the subclavian artery and the brachial plexus.

■Correct Answer:Proximal compression of upper extremity neurologic and vascular structures at one of multiple

1359. (459) Q4-635:

A typical presentation of thoracic outlet syndrome is likely to include:

1) An upper plexus constellation involving median nerve innervated muscles being the most common.

3) Venous obstruction presenting as edema and cyanosis progress to subclavian or axillary vein thrombosis.

2) Sensory loss and diminished strength at initial evaluation

5) Normal somatosensory evoked potentials in the affected extremity

4) Symptoms that are present at rest and alleviated by upper extremity acitivity

A lower plexus symptom constellation involving muscles supplied by the ulnar nerve is most typical of thoracic outlet syndrome. Objective signs of sensory loss and diminished strength are often not found. Somatosensory evoked potential abnormalities are common (74%), but are non-specific and may be seen in asymptomatic individuals. Although venous obstruction is rare, it may lead to subclavian or axillary vein thrombosis necessitating fibrinolytic treatment. Symptoms are usually exacerbated by upper extremity activities.

■Correct Answer:Venous obstruction presenting as edema and cyanosis progress to subclavian or axillary vein thrombosis.

1360. (460) Q4-636:

Primary treatment of thoracic outlet syndrome should include:

1) First rib resection with scalenectomy

3) Psychiatric evaluation

2) C laviculectomy

5) First rib resection without scalenectomy

4) Activity modification and shoulder girdle strengthening

Initial treatment of thoracic outlet syndrome is non-operative. Aggravating activities are modified and shoulder girdle strengthening is initiated. Surgery is considered for patients who have failed conservative therapy and suffer intractable pain, and for those who have significant neurologic or vascular deficits. Operative procedures must be tailored to the presumed pathological anatomy; there is no single best procedure.

■Correct Answer:Activity modification and shoulder girdle strengthening

1361. (461) Q4-637:

The term acrosyndactyly describes digits that are:

1) Joined by bone only

3) Joined proximally but separated distally

2) Joined by soft tissue only

5) Joined at the tips but separated proximally

4) Joined along the entire length of the web space

Acrosyndactyly describes digits that are joined distally but remain separated by a proximal cleft. Acrosyndactylized digits initially develop normal web spaces, but are subsequently joined by secondary events, such as the formation of constriction bands. In contrast to syndactylized fingers, which remain joined due to failure of formation of the web space between contiguous digits, acrosyndactyly may form between non-contiguous digits. C omplex syndactyly involves a confluence of distal osseous and nail elements in addition to soft-tissue bridging. Simple syndactyly describes digits that are joined by soft tissue only. Finally, complete syndactyly refers to digits that are joined along their entire lengths, while incomplete syndactyly describes a web that extends more distally than usual, but not all the way to the finger tips.

■Correct Answer:Joined at the tips but separated proximally

1362. (462) Q4-638:

In normal development, the differentiation of the interdigital web space is influenced by which of the following factors:

1) Bone morphogenetic protein (BMP)

3) Interleukin-1 (IL-1)

2) Fibroblast growth factor-3 (FGF-3)

5) Thalidomide

4) Apical ectodermal ridge maintenance factor (AERMF)

The distal phalanges are composed of two germ cell layers. Ectodermal cells produce the tuft of the distal phalanx and the nail elements, while mesodermal cells form the epiphysis, physis, and metaphysis. Apical ectodermal ridge maintenance factor (AERMF) is a substance elaborated by the mesenchymal condensations between digits. When AERMF ceases to be produced, the apical ectodermal ridge begins to break apart. This in turn triggers the release of lysosomes which dissolve the mesenchymal connections between the developing digits, completing web space formation.

■Correct Answer:Apical ectodermal ridge maintenance factor (AERMF)

1363. (463) Q4-639:

Syndactyly may be isolated, it may be bilateral, or it may occur as part of a broader genetic syndrome. Which of the following syndromes are commonly associated with syndactyly:

1) Down syndrome (trisomy-21)

3) Marfan syndrome

2) Polandâs anomaly

5) Hunter syndrome

4) VATER association

Individuals afflected by Polandâs anomaly exhibit unilateral symbrachydactyly (simple syndactyly with short or absent middle phalanges), absent sternocostal head of the pectoralis major, and hypoplasia of the ipsilateral breast and nipple. Apertâs syndrome, the other syndrome most commonly associated with syndactyly, is characterized by complex acrosyndactyly of the hands and feet associated with premature closure of the cranial sutures. The features of the VATER association include Verterbral anomalies and or Ventricular septal defect, Anal atresia, T-E fistula, and Renal anomalies and or Radial dysplasia (pre-axial syndactyly is a possible but inconsistent feature). Individuals with Marfan syndrome exhibit arachnodactyly in addition to retinal detachments, lens subluxations, aortic dilatations/aneurysms, and tall stature with long, thin limbs. Hand manifestations of Down syndrome include short metacarpals and phalanges, clinodactyly, and abnormal crease patterns, but not syndactyly. Hunter syndrome (mucopolysaccharidosis  II) is marked by stiffened joints and the development of a clawhand, but not by syndactyly.

■Correct Answer:Polandâs anomaly

1364. (464) Q4-640:

Surgical separation of syndactylized fingers produces two separate digits with an increase in total surface area. How are the gaps in coverage left by eliminating the common side between the two fingers best addressed:

1) Full-thickness skin graft

3) Fascio-cutaneous graft

2) Split-thickness skin graft

5) No graft is necessary; the defects will heal by secondary intention

4) Rotation flap

If syndactyly release is to be successful, contractures must be avoided at all costs. Tension-free closures are imperative to this effort. The surface area of two complete fingers is substantially greater than that of two fingers that share a common side, so primary closure of the skin on both sides of the new web is not possible without tension except in very proximal, incomplete syndactylies. For this reason, a strategy other than primary closure is necessary. Healing by secondary intention and split- thickness grafting are both prone to produce contracture. Fascio-cutaneous grafting and rotation flaps are unnecessary, since the defect is confined to the dermal layer. Full-thickness skin graft is least likely to contract, and thus is the material of choice for closing the separated digits.

■Correct Answer:Full-thickness skin graft

1365. (473) Q4-651:

The           of the brachial plexus emerge between the anterior middle scalane muscles:

1) Roots

3) Divisions

2) Trunks

5) Branches

4) C ords

After the roots emerge between the anterior scalene muscles, they merge to form trunks. The trunks branch into divisions and then merge into cords in the axilla. The cords branch into nerves.

■Correct Answer:Roots

1366. (474) Q4-653:

Dupuytren contracture is a progressive disease involving:

1) Proliferative fibrodysplasia of the flexor tendons in the palm.

3) A chronic inflammatory response with an increase in type 2 collagen in the flexor tendon sheath.

2) Pretendinous bands of the palmar aponeurosis which form nodules and cords causing metacarpophalangeal joint contracture.

5) A predilection for young women between the ages of 20 and 40 with exacerbation of symptoms during pregnancy.

4) C ontracture beginning distally at the level of the distal interphalangeal joint and extending proximally as the disease progresses.

Dupuytren contracture involves proliferative fibrodysplasia of the subcutaneous palmar connective tissue. The flexor tendons are not involved. Pretendinous bands of the palmer aponeurosis form nodules and cords causing metacarpophalangeal joint contracture. The interphalangeal joint can be affected but only rarely is the distal interphalangeal joint involved. There is no inflammatory response but a proliferation of myofibroblasts with an increase in Type 3 collagen. The disease is most often seen in men between the ages of 40 and 60 years old and is associated with epilespy, alcoholism and diabetes. C arpal tunnel syndrome is often seen in young women and can be exacerbated by pregnancy.

■Correct Answer:Pretendinous bands of the palmar

aponeurosis which form nodules and cords causing metacarpophalangeal joint contracture.

1367. (475) Q4-654:

Which of the following statements is true:

1) Spinnerâs sign is an early sign of anterior interosseous nerve compression.

3) The ligament of Strutherâs and the arcade of Strutherâs refer to the same structure.

2) Electromyography/nerve  conduction velocity is usually normal in pronator syndrome.

5) The pain of pronator syndrome is dull aching in the proximal forearm that is worse with activity and awakens patients at night.

4) Forearm pronation is usually weak with anterior interosseous nerve syndrome.

Electromyography/nerve  conduction velocity is usually normal in pronator syndrome, but abnormal in anterior interosseous nerve syndrome. The arcade of Struthers describes a possible point of compression of the ulnar nerve. The ligament of Struthers describes a possible point of compression of the median nerve. In AIN syndrome, forearm pronation may be weak due to weakness of the pronator quadratus, but the pronator teres is unaffected. There is no strict correlation between the pain of pronator syndrome and sleeplessness.

■Correct Answer:Spinnerâs sign is an early sign of anterior interosseous nerve compression.

1368. (476) Q4-655:

Initial treatment for De Quervain disease involves:

1) Occupational therapy with active range of motion and strengthening of the wrist extensors.

3) Steroid injection of the second dorsal compartment followed by range of motion exercises.

2) Surgical release of the extensor pollicis longus tendon as it wraps around Listerâs tubercle.

5) Surgical release of the first dorsal compartment.

4) Activity modification, steroid injection of the first dorsal compartment, followed by splinting full time for 3 to 4 weeks.

Initial treatment for De Quervain tenosynovitis involves rest and splinting with steroid injection into the first dorsal compartment. The splint should be worn as much as possible for 3 to 4 weeks. The extensor carpi radialis brevis has been implicated in lateral epicondulitis. The extensor pollicis longus can be a source of pain as it wraps over the wrist extensor giving the classic symptoms of intersection syndrome between the second and third dorsal compartments. Surgical release is only indicated in persistent cases that have failed conservative management. In 20% to 30% of cases, the first compartment is divided by longitudinal septations into two distinct tunnels. C are must be taken to identify and release both of these tunnels, as well as any multiple tendinous slips, when performing a surgical release.

■Correct Answer:Activity modification, steroid injection of the first dorsal compartment, followed by splinting full time for 3 to 4 weeks.

1369. (477) Q4-656:

The ulnar nerve arises from:

1) The lateral cord of the brachial plexus containing fibers from the C 6 and C 7 nerve roots.

3) The posterior cord of the brachial plexus containing fibers of the C 5 and C 6 nerve roots.

2) The medial cord of the brachial plexus containing fibers from the C 8 and T1 nerve roots.

5) The C 5 through C 7 nerve roots immediately before the upper trunk.

4) The lateral trunk of the brachial plexus containing fibers from C 7 through T1.

The ulnar nerve is the continuation of the medial cord of the brachial plexus containing fibers of the C 8 and T1 nerve roots. Radiculopathy at the C 8-T1 level may mimic a more distal compression of the nerve in the cubital tunnel. The axillary and radial nerves come off the posterior cord. There is no lateral trunk of the brachial plexus. The nerve to the rhomboids comes directly off of the C 5 nerve root and its presence is often helpful in differentiating pre-ganglionic from post-ganglionic lesions of the brachial plexus.

The lateral cord forms the musculocutaneous nerve. The medial cord forms the ulnar nerve. The medial and lateral cords form the median nerve. The radial nerve arises from the posterior cord.

■Correct Answer:The medial cord of the brachial plexus containing fibers from the C 8 and T1 nerve roots.

1370. (478) Q4-658:

Which of the following statements is true:

1) Posterior interosseous nerve syndrome and radial tunnel syndrome describe the same clinical syndrome with separate causes.

3) The posterior interosseous nerve contains both motor and sensory fibers.

2) The radial nerve spirals around the humeral shaft with the radial artery.

5) The most common site of proximal radial nerve compression is the leash of Henry.

4) Wartenberg's sign and Wartenberg's syndrome are both related to radial nerve compression.

The PIN contains motor fibers to the EDC , EDQP, EC U, APL, EPB, EPL, and EIP. Occasionally it gives motor fibers to the EC RB. It terminates with a sensory branch to the carpus and wrist capsule. There is, however, no cutaneous sensation.

In radial tunnel syndrome, the entire radial nerve is compressed, including a sensory component. The radial nerve passes posteriorly and laterally next to the humerus, but not with the radial artery. Wartenberg's sign is an isolated ulnar nerve palsy. This syndrome relates to the compression of the superficial branch of the radial nerve. The most common site of radial nerve compression is the arcade of Frohse.

■Correct Answer:The posterior interosseous nerve contains both motor and sensory fibers.

1371. (479) Q4-659:

The treatment of stenosing tenosynovitis should include all of the following except:

1) Release of the A1 pulley.

3) Splinting and nonsteroidal anti-inflammatory drugs (NSAIDs).

2) Release of the A1 pulley and flexor tendon tenosynovectomy.

5) Release of the A1 and A2 pulleys.

4) Steroid injections between the flexor tendon and the A1 pulley.

The A2 pulley should not be released as part of the treatment for trigger finger. Its presence, along with the A4 pulley, is important in maintaining efficient flexor tendon function. The pathology usually involves the A1 pulley and its release is usually all that is necessary.

Other modalities include NSAIDs, splinting, tenosynovectomy, and steroid injections. 

■Correct Answer:Release of the A1 and A2 pulleys.

1372. (480) Q4-660:

Swan-neck deformity can be caused by which of the following:

1) C entral slip rupture

3) Acute extensor tendon avulsion fracture

2) Flexor digitorum profundus avulsion fracture (Jersey finger)

5) Metaphalangeal (MP) arthroplasty

4) Dorsal proximal interphalangeal joint dislocation (middle phalanx dorsal to proximal phalanx)

A chronic mallet finger results in proximal retraction of the extensor mechanism and overpull of the central slip. Isolated central slip rupture does not cause this deformity. Rupture of the flexor digitorum sublimis can cause Swan-neck deformity. MP arthroplasty is not associated with this deformity. The sequalae of dorsal proximal interphalangeal joint dislocation (e.g., volar plate laxity or deficiency) leads to Swan-neck deformity.

■Correct Answer:Dorsal proximal interphalangeal joint dislocation (middle phalanx dorsal to proximal phalanx)

1373. (481) Q4-664:

Which of the following identifies the clinical finding of inadvertent hyperextension of the thumb metaphalangeal joint during attempted thumb-index finger pinch?

1) Froment's sign

3) Duchenne's sign

2) Jeanne's sign

5) Wartenberg's sign

4) Pollock's sign

Jeanne's sign identifies thumb metaphalangeal joint hyperextension of 10° to 15° with key pinch or gross grip.

Froment's sign refers to the exaggeration of thumb interphalangeal joint flexion during key punch by the flexor pollicis longus in ulnar nerve palsies.

Wartenberg's sign is the inability to adduct the extended small finger due to an ulnar nerve palsy. Duchenne's sign refers to clawing of the ring and small fingers.

Pollock's sign is the inability to flex the distal interphalangeal joints of the ring and small fingers in high palsies.

■Correct Answer:Jeanne's sign

1374. (482) Q4-665:

The Bunnell procedure to provide index finger abduction in ulnar nerve palsies refers to:

1) Transfer extensor indicis proprius (EIP) to the first dorsal interosseous

3) Transfer extensor pollicis brevis (EPB) to the first dorsal interosseous

2) Split and transfer EIP to the first dorsal interosseous and the adductor pollicis

5) Transfer flexor digitorum sublimis to the proximal phalanx of the thumb

4) Transfer EPB with EIP to the adductor pollicis

The Bunnell procedure transfers the EIP to the first dorsal interosseous. Answers B through E refer to the Omer technique, Bruner technique, Abreu technique, and Graham procedure or Riordan procedure, respectively.

■Correct Answer:Transfer extensor indicis proprius (EIP) to the first dorsal interosseous

1375. (565) Q4-784:

Ganglions most commonly arise from the:

1) Scapholunate interosseous ligament

3) Pisotriquetral joint

2) Scaphotrapezial joint

5) Flexor tendon sheath

4) Dorsal distal interphalangeal joint

Sixty percent to 70% of all ganglion cysts occur on the dorsum of the wrist. A majority of ganglions emanate from the scapholunate interosseous ligament. Volar wrist ganglions are prevalent in 16% to 20% of cases, followed by volar retinacular ganglions occurring at the metacarpophalangeal joints and proximal interphalangeal joints (7% to 12%), and mucous cysts presenting dorsally at the level of the joint.

■Correct Answer:Scapholunate interosseous ligament

1376. (566) Q4-785:

Pain from a dorsal carpal ganglion is caused by:

1) Tendinitis

3) Median nerve impingement

2) Posterior interosseous nerve impingement

5) Mass effect

4) Premalignant synovial degeneration

Dorsal carpal ganglions arising from the scapholunate interosseous ligament may expand to a large size without causing significant pain. Alternatively, small ganglions that compress the sensory terminus of the posterior interosseous nerve may be painful. The median nerve, on the volar side of the wrist, is not affected by dorsal ganglions. Dorsal carpal ganglions are benign. They have no potential for malignant degeneration and are not a significant cause of tendinitis.

■Correct Answer:Posterior interosseous nerve impingement

1377. (567) Q4-786:

Optimal treatment for a symptomatic ganglion is:

1) Observation

3) Aspiration

2) C losed rupture

5) C orticosteroid injection

4) Surgical excision

Surgical excision of a symptomatic ganglion, with removal of the entire ganglion stalk and a portion of the joint capsule at its base, reliably relieves pain and has a low recurrence rate (approximately 5%). C losed rupture, while potentially effective, has a recurrence rate of approximately 50%. Ganglions are prone to recur after aspiration, although 3 serial aspirations of a ganglion have been shown to reduce the recurrence rate to about 15%. The addition of corticosteroids to aspiration treatment has not been shown to provide any additional benefit. While observation of painless ganglions is certainly acceptable treatment given their benign prognosis, it is not considered the optimal course for a symptomatic lesion.

■Correct Answer:Surgical excision

1378. (568) Q4-787:

The following pair of tendons is affected in De Quervain disease:

1) Extensor pollicis longus and extensor pollicis brevis

3) Abductor pollicis brevis and extensor pollicis longus

2) Abductor pollicis longus and extensor pollicis longus

5) Abductor pollicis longus and extensor pollicis brevis

4) Opponens pollicis and abductor pollicis brevis

De Quervain disease affects the tendons in the first dorsal compartment, the extensor pollicis brevis and the abductor pollicis longus (consisting of 2 to 7 individual tendon slips). The extensor pollicis longus traverses the third dorsal compartment. The abductor pollicis brevis and the opponens pollicis are thenar muscles and do not lie within any of the dorsal compartments.

■Correct Answer:Abductor pollicis longus and extensor pollicis brevis

1379. (569) Q4-789:

Poor or incomplete resolution of symptoms following first dorsal compartment release for De Quervain disease would most likely occur as a result of:

1) Early return to activity

3) Abductor pollicis longus laceration

2) Superficial radial sensory nerve injury

5) Pseudoaneurysm in the radial artery

4) Incomplete release

The most common reason for recurrent or persistent symptoms of first dorsal compartment stenosis is failure to recognize and release a separate extensor pollicis brevis subsheath. The superficial radial sensory nerve may be injured in surgery for De Quervain disease, but the resulting neuroma is often more painful than the original symptoms and is of a different character. Abductor pollicis longus laceration would result in loss of radial abduction of the thumb. Early motion of the thumb is recommended following release of the first dorsal compartment.

■Correct Answer:Incomplete release

1380. (660) Q4-912:

When performing a tendon transfer to restore thumb index finger lateral pinch in an ulnar nerve palsy, which tendon, when transferred to the 1st dorsal interosseous provides the greatest power?

1) Flexor digitorum profundus (FDP)

3) Extensor digitorum communis (EDC )

2) Extensor indicis proprius (EIP)

5) Extensor carpi radialis lingus (EC RL)

4) Extensor carpi radialis brevis (EC RB)

The EC RB transfer gives the greatest return of power pinch due to the strength of this wrist motor. This transfer should be coupled with a thumb MP arthrodesis to provide the best results. The ideal pinch transfer is an extensor pollicis brevis to first dorsal interosseous with a metaphalangeal (MP) arthrodesis at the thumb. The FDP and EDC tendons are not good choices because they are not independent tendons. The EIP provides power, but the vector of the transfer is not ideal. Transfer of the EC RL would unbalance the wrist.

■Correct Answer:Extensor carpi radialis brevis (EC RB)

1381. (661) Q4-913:

In the diagnosis of a boutonniere deformity, a patient will not present with:

1) Laxity in the intrinsic system leading to passive hyperflexion of the distal interphalangeal joint, with the proximal interphalangeal joint held in extension.

3) Full extension at the proximal interphalangeal joint, with the wrist and metacarpophalangeal joint fully flexed but inability to extend the distal interphalangeal joint with the hand in this position.

2) Ecchymosis at the base of the middle phalanx, with a dorsal avulsion fragment from the middle phalanx base on the x-ray.

5) Pain and swelling over the metacarpophalangeal joint, with full flexion and extension over the proximal interphalangeal joint and distal interphalangeal joint.

4) Active hyperextension at the proximal interphalangeal joint, with full flexion at the distal interphalangeal joint, but no active flexion at the proximal interphalangeal joint.

A boutonniere deformity refers to a finger in which the PIP joint is in a flexed position and the DIP joint is in a hyperextended position. These deformities may be acute or chronic. With the exception of answer choice D, all of the other answers describe possible presentations of a patient with boutonniere deformity. A patient with active hyperextension at the PIP joint with full flexion at the DIP joint, but no active flexion at the PIP joint has a swan-neck deformity.

■Correct Answer:Active hyperextension at the proximal interphalangeal joint, with full flexion at the distal interphalangeal joint, but no active flexion at the proximal interphalangeal joint.

1382. (671) Q4-924:

In the diagnosis of a boutonniere deformity, a patient may present with:

1) Laxity in the intrinsic system leading to passive hyperflexion of the distal interphalangeal joint, with the proximal interphalangeal joint held in extension.

3) Full extension at the proximal interphalangeal joint, with the wrist and metacarpophalangeal joint fully flexed but inability to extend the distal interphalangeal joint with the hand in this position.

2) Flexion deformity of the PIP joint with ecchymosis at the base of the middle phalanx, with a dorsal avulsion fragment at the middle phalanx base on radiograph, as well as inability to actively extend the PIP joint.

5) Pain and swelling over the metacarpophalangeal joint, with full flexion and extension over the proximal interphalangeal joint and distal interphalangeal joint.

4) Active hyperextension at the proximal interphalangeal joint, with full flexion at the distal interphalangeal joint, but no active flexion at the proximal interphalangeal joint.

A bony boutonniere injury is a fracture of the base of middle phalanx with the central slip of the extensor mechanism attached. With this injury, the patient is unable to actively extend the PIP joint from its flexed position.

■Correct Answer:Flexion deformity of the PIP joint with ecchymosis at the base of the middle phalanx, with a dorsal avulsion fragment at the middle phalanx base on radiograph, as well as inability to actively extend the PIP joint.

1383. (1157) Q4-1521:

Horner syndrome includes all of the following except:

1) Miosis

3) Enophthalmos

2) Anhidrosis

4) Exophthalmos

Horner syndrome is due to disruption of sympathetic innervation and is characterized by enophthalmos not exophthalmos. 

■Correct Answer:Exophthalmos

1384. (1158) Q4-1522:

Axonotmesis involves injury to which of the following structure:

1) Epineurium

3) Perineurium

2) Endoneurium

4) Axon

Axonotmesis as described in Seddon classification implies injury to the axon and myelin sheath. It is neurotmesis that involves injury to all the three layers.

 

■Correct Answer:Axon

1385. (1159) Q4-1523:

All of the following may be seen with preganglionic lesion EXC EPT:

1) Horner syndrome

3) Positive Histamine test

2) Hemi-diaphragmatic palsy

4) Tinel sign

Tinel sign is seen with postganglionic lesions. 

■Correct Answer:Tinel sign

1386. (1160) Q4-1524:

Weakness of which of the following muscles is not seen with root avulsion:

1) Rhomboids

3) Supraspinatus

2) Serratus anterior

4) Trapezius

Trapezius is innervated by spinal accessory nerve and thus will not be involved in a brachial plexus lesion. In the case of a preganglionic lesion, ALL muscles innervated by the nerve roots will be affected.

 

■Correct Answer:Trapezius

1387. (1161) Q4-1525:

In obstetric brachial plexus injury, return of which of the following muscle by 3 months is considered an indicator of plexus recovery:

1) Biceps

3) Brachioradialis

2) Triceps

4) Latissimus

Biceps recovery at 3 months is considered the single most important indicator of recovery in obstetric plexus palsy. 

■Correct Answer:Biceps

1388. (1162) Q4-1526:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

The diagnosis of the boyâs condition is:

1) Brachial plexus neuropraxia

3) Brachial plexus neuritis

2) Erbâs palsy

4) C 5, C 6 disk herniations

The muscles involved have C 5, C 6 root innervations. There are multiple findings that rule out a preganglionic lesion: positive Tinel sign, functioning rhomboids and serratus anterior, absent Horner syndrome. The electromyogram finding confirms the clinical finding (it does not show subclinical involvement of any other muscle). Neuropraxia usually resolves in 6 weeks and EMG shows fibrillation, both of which are inconsistent with neuropraxia. Brachial plexus neuritis (Parsonage-Turner syndrome) has an acute presentation following a painful episode involving the whole arm. There is significant history of fall from an all terrain vehicle in

this case.

 

■Correct Answer:Erbâs palsy

1389. (1163) Q4-1527:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

What is the level of lesion:

1) Postganglionic C 5, C 6

3) Posterior cord injury

2) Preganglionic C 5, C 6

4) Middle trunk

The muscles involved have C 5, C 6 root innervations. There are multiple findings that rule out a preganglionic lesion: positive Tinel sign, functioning rhomboids and serratus anterior, absent Horner syndrome. The electromyogram finding confirms the clinical finding (it does not show subclinical involvement of any other muscle). Neuropraxia usually resolves in 6 weeks and EMG shows fibrillation, which is inconsistent with neuropraxia. Brachial plexus neuritis (Parsonage-Turner syndrome) has an acute

presentation following a painful episode involving the whole arm. There is significant history of fall from an all terrain vehicle in this case.

 

■Correct Answer:Postganglionic C 5, C 6

1390. (1164) Q4-1528:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

What is the least helpful test in further management of this patient:

1) Magnetic resonance imaging

3) Repeat electromyogram after 4 weeks

2) C omputer tomography scan of the neck

4) Somatosensory evoked potential (SSEP)

C omputer tomography scan of the cervical spine will not be of any use as it will neither show the pseudomeningoceles nor provide any information on brachial plexus. C T scan may be needed in case of a suspected neck injury but does not form part of a

brachial plexus work up.

 

■Correct Answer:C omputer tomography scan of the neck

1391. (1165) Q4-1529:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

The plan of management in this boy 5 months after injury with no clinical improvement should be:

1) Neurotization

3) C ontinued observation

2) Exploration and nerve grafting

4) Tendon transfers

Neurotization is appropriate in preganglionic lesions. Around 6 months with no evidence of recovery is ideal time for plexus exploration. Further observation will not change the picture and tendon transfers are reconstructive procedures, which are done at a later stage.

 

■Correct Answer:Exploration and nerve grafting

1392. (1166) Q4-1530:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

What will be the most important indication for an early exploration in this case:

1) Absence of biceps function at 3 months

3) Presence of âtrickâ movements

2) Absence of biceps function with return of extensor carpi radialis longus (EC RL) power at 4 months

4) Subluxation of humeral head on x-ray

An important indication for early exploration is recovery of a distally supplied muscle (EC RL â C 6) in the absence of a proximally supplied muscle (biceps â C 5). Trick movements are adaptive movements employed by the patient by recruiting other muscles (use of flexor-pronator as elbow flexors in this patient). Bony deformity is a late sequela and biceps recovery at 3 months is important in obstetric brachial palsy.

 

■Correct Answer:Absence of biceps function with return of extensor carpi radialis longus (EC RL) power at 4 months

1393. (1167) Q4-1531:

A 15-year-old white boy presents to your office with inability to elevate his right shoulder and flex his elbow. He sustained a fall from an all-terrain vehicle 8 weeks ago. He landed on the right shoulder and says his neck was twisted away at the time of fall. He was seen at the local emergency department; skull, chest, cervical and thoracic spine, and shoulder x-rays showed no damage. There was no loss of consciousness and he has no chest pain or breathing difficulties. He was observed in the hospital until stable and was referred to follow up in the hand clinic at 4 weeks and scheduled for an electromyogram.

C linical examination reveals weakness of deltoid, supraspinatus, infraspinatus, teres minor, biceps, brachialis, brachioradialis, and extensor carpi radialis longus. The remainder of his forearm musculature is preserved and he can grasp and release and pinch. Sensations are decreased along the distribution of axillary nerve. There is 3 cm wasting of his arm and 2 cm of his forearm. Tinel sign is positive around the clavicle. Horner signs are absent and his arm lies against the body. The EMG report shows fibrillation potentials in the weak muscles. The parents are concerned and say they have not seen any improvement. The boy reports that he is now able to flex his elbow. When asked to demonstrate you notice that he flexes his wrist and pronates his forearm to âswingâ his elbow into flexion.

The most important function that needs to be restored in this boy is:

1) Shoulder abduction

3) Elbow flexion

2) Shoulder elevation

4) Wrist extension

Elbow flexion is central to management of brachial plexus management because it serves the most important function of feeding. 

■Correct Answer:Elbow flexion

1394. (1168) Q4-1532:

An 18-month-old boy is brought to your office for a clawing deformity of his right hand. The parents inform you that he was born full term after a difficult delivery complicated by shoulder dystocia. The boy weighed 9½ lbs at birth. The child had a brief episode of apnea with an APGAR score of 5 at birth and needed resuscitation and admission to the natal intensive care unit. Parents recall having noted a bump on his right clavicle, which was tender and was diagnosed as clavicle fracture. They also noticed a week later that the child did not flex the fingers of his right hand. The neonatologist had informed them that the

fracture is managed conservatively and the absence of finger flexion is due to the fracture and shall recover. They were warned that the recovery can be prolonged and can take up to 2 years. The boy has grown well and has achieved his milestones on time. His immunization is complete for his age.

You find a healthy, playful boy who tends to use his left hand to reach for objects. His right hand has extension at all the metacarpophalangeal (MC P) joints of the fingers while his proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints are flexed. His thumb is an adducted position and it is difficult to passively bring it to full abduction. There is obvious wasting of the hand and forearm. The child is able to move the arm well with no abnormalities noticed at the shoulder, elbow, and the wrist. The x-ray of his chest shows a healed clavicle fracture with no evidence of diaphragmatic paralysis. There is no evidence of Horner Syndrome and the grasp reflex is absent.

The diagnosis of this boyâs condition is:

1) Erbâs palsy

3) C erebrovascular accident

2) Klumpkeâs palsy

4) Ulnar and median combined nerve injury

This is a case of obstetric brachial plexus injury involving the C 8, T1 roots (Klumpke Palsy). Erbâs palsy involves upper roots only. C ombined nerve injuries can present in a similar fashion; however, low ulnar and median nerve lesions will not have weakness of flexor digitorum profundus (FDP) and flexor digitorum superficialis (FDS).

History of large baby, shoulder dystocia and clavicle fracture point to a difficult labor. The most common type of brachial plexus injury related to birth is Erbâs palsy, which is usually associated with a breech presentation. Isolated Klumpkeâs palsy is rare, and involvement of C 8, T1 usually occurs as part of global plexus injury.

 

■Correct Answer:Klumpkeâs palsy

1395. (1169) Q4-1533:

An 18-month-old boy is brought to your office for a clawing deformity of his right hand. The parents inform you that he was born full term after a difficult delivery complicated by shoulder dystocia. The boy weighed 9½ lbs at birth. The child had a brief episode of apnea with an APGAR score of 5 at birth and needed resuscitation and admission to the natal intensive care unit. Parents recall having noted a bump on his right clavicle, which was tender and was diagnosed as clavicle fracture. They also noticed a week later that the child did not flex the fingers of his right hand. The neonatologist had informed them that the

fracture is managed conservatively and the absence of finger flexion is due to the fracture and shall recover. They were warned that the recovery can be prolonged and can take up to 2 years. The boy has grown well and has achieved his milestones on time. His immunization is complete for his age.

You find a healthy, playful boy who tends to use his left hand to reach for objects. His right hand has extension at all the metacarpophalangeal (MC P) joints of the fingers while his proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints are flexed. His thumb is an adducted position and it is difficult to passively bring it to full abduction. There is obvious wasting of the hand and forearm. The child is able to move the arm well with no abnormalities noticed at the shoulder, elbow, and the wrist. The x-ray of his chest shows a healed clavicle fracture with no evidence of diaphragmatic paralysis. There is no evidence of Horner Syndrome and the grasp reflex is absent.

The level of the lesion in this boyâs case is:

1) preganglionic lesion

3) lateral cord

2) postganglionic lesion

4) posterior cord

It is difficult to clinically differentiate between a pre- and post ganglionic lesion of C 8, T1 in a child. Absence of Hornerâs syndrome and hemi-diaphragmatic palsy in this case indicates that this is not a preganglionic lesion. Also, the ability of the child to hold his head suggests that the paravertebral muscles are functional as is true in postganglionic lesions.

 

■Correct Answer:postganglionic lesion

1396. (1170) Q4-1534:

An 18-month-old boy is brought to your office for a clawing deformity of his right hand. The parents inform you that he was born full term after a difficult delivery complicated by shoulder dystocia. The boy weighed 9½ lbs at birth. The child had a brief episode of apnea with an APGAR score of 5 at birth and needed resuscitation and admission to the natal intensive care unit. Parents recall having noted a bump on his right clavicle, which was tender and was diagnosed as clavicle fracture. They also noticed a week later that the child did not flex the fingers of his right hand. The neonatologist had informed them that the

fracture is managed conservatively and the absence of finger flexion is due to the fracture and shall recover. They were warned that the recovery can be prolonged and can take up to 2 years. The boy has grown well and has achieved his milestones on time. His immunization is complete for his age.

You find a healthy, playful boy who tends to use his left hand to reach for objects. His right hand has extension at all the metacarpophalangeal (MC P) joints of the fingers while his proximal interphalangeal (PIP) and distal interphalangeal (DIP) joints are flexed. His thumb is an adducted position and it is difficult to passively bring it to full abduction. There is obvious wasting of the hand and forearm. The child is able to move the arm well with no abnormalities noticed at the shoulder, elbow, and the wrist. The x-ray of his chest shows a healed clavicle fracture with no evidence of diaphragmatic paralysis. There is no evidence of Horner Syndrome and the grasp reflex is absent.

Appropriate surgical management in this case should be:

1) Neurotization

3) Tendon transfers

2) Exploration and nerve grafting

4) Neurolysis

Neurotization has not been shown to produce successful results for lower root involvement and is performed for preganglionic lesions. At 18 months, exploration and nerve grafting must still be carried out. Neurolysis is reserved for cases in which the recovery is partial or plateaus. Tendon transfers in children younger than 3 years of age do not work as well. Younger children do not cooperate well in their rehabilitation and it is also difficult to decide upon the functioning motors for transfer.

 

■Correct Answer:Exploration and nerve grafting