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1. General Principles & Basic Science MCQs

Practice Set 57 of 789

This practice set contains high-yield board review questions covering key concepts in 1. General Principles & Basic Science. Each clinical scenario is designed to test your diagnostic and management skills relevant to this subspecialty.

Question 1121

Topic: 1. General Principles & Basic Science

Which of the following tests is most specific for the diagnosis of Lyme disease:

. Elevated erythrocyte sedimentation rate (ESR)
. Elevated C -reactive protein (C RP)
. Negative antinuclear antibody (ANA)
. Negative rheumatoid factor
. Elevated antibody titer to Borrelia burgdorferi

Correct Answer & Explanation

. Elevated antibody titer to Borrelia burgdorferi

Explanation

The most specific laboratory finding is an elevated antibody titer to Borrelia burgdorferi. This test is commonly referred to as a Lyme titer. All of the mentioned tests are generally seen in Lyme disease, however, elevated erythrocyte sedimentation rate, elevated C - reactive protein, negative antinuclear antibody, and negative rheumatoid factor are all nonspecific.

Question 1122

Topic: 1. General Principles & Basic Science

Lyme disease is caused by which of the following organisms or mechanisms:

. Group A Streptococcus
. Borrelia burgdorferi
. Vibrio vulnificus
. Group B Streptococcus
. Autoimmune disorder of unknown etiology

Correct Answer & Explanation

. Borrelia burgdorferi

Explanation

Lyme disease was initially thought to be an idiopathic autoimmune disorder; however, in the 1970s, researchers at Yale University identified Borrelia burgdorferi as the cause of the disease. The disease is transmitted by a deer tick known as Ixodes ricinusi. Group A streptococcal pharyngitis may be followed by rheumatic fever, but not Lyme disease. Vibrio vulnificus is the organism responsible for severe soft tissue infections in patients who are exposed to fresh-water shellfish. Group B Streptococcus is a common etiologic agent for necrotizing fasciitis.

Question 1123

Topic: 1. General Principles & Basic Science

The most serious long-term sequela of rheumatic fever is:

. Skin disfiguration from migratory rash
. Disabling arthritis in affected joints
. Rheumatic valvular heart disease
. Need for long-term prophylaxis for the prevention of relapses
. Decreased lung capacity secondary to fibrosis

Correct Answer & Explanation

. Rheumatic valvular heart disease

Explanation

The most serious potential long-term sequela of rheumatic fever is rheumatic valvular heart disease. Patients do not develop any permanent skin lesions or joint disability from the disease. Some patients require long-term prophylaxis to prevent recurrences, however, this is an inconvenience and not a sequela. The lungs are not affected in the acute fever or subsequent relapses.

Question 1124

Topic: 1. General Principles & Basic Science

Joint pain in rheumatic fever:

. Affects 2 to 4 large joints over several months
. Responds to aspirin therapy
. Results in long-term disability with joint destruction
. Is best treated with penicillin G
. Is a major criterion for diagnosis

Correct Answer & Explanation

. Responds to aspirin therapy

Explanation

Joint pain is common in rheumatic fever. It is an intensely painful arthralgia that migrates from joint to joint within hours. The pain responds to aspirin therapy, as well as rest. Although oral penicillin G is used for treatment of the disease, it will not produce rapid resolution of the joint pain. In untreated cases, it can affect up to 16 joints. Most patients are left with no long-term sequelae or disability of the musculoskeletal system from rheumatic fever. Joint arthralgias are minor criteria for diagnosis.

Question 1125

Topic: 1. General Principles & Basic Science

Following a Zone II flexor digitorum profundus (FDP) repair, what is the primary biomechanical advantage of adding a peripheral epitendinous suture to a robust 4-strand core suture?

. Increases gliding resistance within the sheath
. Decreases gap formation and increases construct strength
. Prevents tendon adhesion to the adjacent pulley
. Eliminates the need for postoperative splinting
. Promotes intrinsic tendon healing over extrinsic healing

Correct Answer & Explanation

. Decreases gap formation and increases construct strength

Explanation

The addition of a peripheral epitendinous suture significantly increases the ultimate tensile strength of the repair construct. It also smooths the repair site and decreases the risk of gap formation during early active motion protocols.

Question 1126

Topic: Biomechanics & Biomaterials
In total joint arthroplasty, early ultra-high-molecular-weight polyethylene (UHMWPE) components failed due to rapid oxidative degradation. Which historical sterilization method was primarily responsible for introducing the free radicals causing this issue?
. Ethylene oxide gas
. Gamma irradiation in air
. Hydrogen peroxide gas plasma
. Autoclaving
. Electron beam irradiation in a vacuum

Correct Answer & Explanation

. Gamma irradiation in air

Explanation

Gamma irradiation in the presence of oxygen (air) creates free radicals that react with oxygen over time, leading to oxidative degradation, embrittlement, and accelerated wear of the polyethylene component.

Question 1127

Topic: Biology, Genetics & Bone Healing

Which of the following best describes the histologic process of primary bone healing?

. It requires a robust cartilaginous intermediate before ossification.
. It occurs exclusively under conditions of absolute stability via direct Haversian remodeling.
. It depends heavily on the formation of a bridging external soft tissue callus.
. It is primarily mediated by osteoclasts without subsequent osteoblast activity.
. It is the typical mechanism of healing following closed reduction and casting.

Correct Answer & Explanation

. It occurs exclusively under conditions of absolute stability via direct Haversian remodeling.

Explanation

Primary bone healing (intramembranous ossification without callus formation) occurs only under conditions of absolute stability, such as with rigid internal compression plating. It proceeds via direct Haversian remodeling across the fracture gap.

Question 1128

Topic: Infection, Pharmacology & VTE

When comparing the outcomes of operative versus non-operative treatment with early functional rehabilitation for acute Achilles tendon ruptures, the current literature indicates that operative treatment is associated with:

. A significantly lower re-rupture rate but higher deep vein thrombosis (DVT) risk
. A significantly higher re-rupture rate and decreased plantar flexion strength
. A similar re-rupture rate but a significantly higher risk of soft-tissue and wound complications
. A faster return to work but a significantly higher rate of sural nerve neuroma exclusively
. Inferior functional outcomes at one year compared to casting in gravity equinus

Correct Answer & Explanation

. A similar re-rupture rate but a significantly higher risk of soft-tissue and wound complications

Explanation

Recent high-level evidence demonstrates that non-operative management utilizing an early functional rehabilitation protocol has re-rupture rates comparable to operative management. However, surgical treatment carries a significantly higher risk of wound infections and soft-tissue complications.

Question 1129

Topic: Surgical Anatomy & Approaches
During the anterior approach to the pelvic ring for symphyseal plating of an APC-III injury, significant hemorrhage is suddenly encountered over the superior pubic ramus. Which vascular anastomosis (the corona mortis) is most likely injured in this location?
. Internal pudendal artery and inferior gluteal artery
. Superior gluteal artery and iliolumbar artery
. Inferior epigastric artery and obturator artery
. External pudendal artery and obturator artery
. Deep circumflex iliac artery and femoral artery

Correct Answer & Explanation

. Inferior epigastric artery and obturator artery

Explanation

The corona mortis is a vascular anastomosis between the external iliac or inferior epigastric vessels and the obturator vessels. It is located on the posterior aspect of the superior pubic ramus and is at high risk of injury during anterior pelvic approaches.

Question 1130

Topic: Biology, Genetics & Bone Healing

A 40-year-old patient sustains a transverse femur fracture treated with a rigid reamed intramedullary nail. Which type of bone healing is predominantly expected in this biomechanical environment?

. Primary bone healing via cutting cones
. Secondary bone healing via callus formation
. Endochondral ossification solely without intramembranous ossification
. Appositional bone growth exclusively
. Creeping substitution

Correct Answer & Explanation

. Secondary bone healing via callus formation

Explanation

Intramedullary nailing provides relative stability, which allows for micromotion at the fracture site. This mechanical environment promotes secondary bone healing characterized by the formation of a soft and hard callus.

Question 1131

Topic: 1. General Principles & Basic Science

Arthroscopic resection/debridement posterior to the midline of the radio- capitellar joint can result in damage to __ ligament, resulting in ______ instability.

. Lateral collateral; valgus
. Ulnar collateral; valgus
. Ulnar collateral; posterolateral rotatory
. Annular; posterolateral rotatory
. Lateral collateral; posterolateral rotatory

Correct Answer & Explanation

. Lateral collateral; posterolateral rotatory

Explanation

Resection posterior to the midpoint of the radiocapitellar joint can result in damage to the lateral collateral ligament and subsequent development of posterolateral rotator instability.

Question 1132

Topic: 1. General Principles & Basic Science

Which of the following is a concerning risk factor for a dorsal open approach to the scaphoid:

. Damage to tenous blood supply of the scaphoid
. Difficulty of central screw placement
. Damage to scapho-trapezial-trapezoid joint during the approach
. Damage to the lunatotriquetral (LT) ligament
. njury to the higher rate of infection

Correct Answer & Explanation

. Damage to tenous blood supply of the scaphoid

Explanation

The dorsal approach is advantageous in obtaining central screw placement. The scapho-trapezial-trapezoid joint is at risk during a volar approach, not a dorsal approach, and infection has not been shown to occur more frequently in one approach over the other. The LT ligament is not seen in either approach. The risk of the open dorsal approach is compromise of the main blood supply to the scaphoid, entering through the dorsal ridge.

Question 1133

Topic: 1. General Principles & Basic Science
Which type of flexor digitorum profundus (FDP) avulsion is considered the most severe?
. Type I
. Type II
. Type III
. Type IV
. Type V

Correct Answer & Explanation

. Type I

Explanation

Type I is the most threatening scenario because the FDP tendon retracts into the palm, and vincular and diffusional blood supply is lost. The sheath may be noncompliant after a few days and may not allow passage of the FDP tendon through the sheath in an attempt to repair the stump to its insertion. Additionally, proximal muscle contracture prevents tendon stump advancement.

Question 1134

Topic: 1. General Principles & Basic Science
When performing pollicization to correct a hypoplastic thumb, the surgeon should rotate the index finger:
. 120°
. 135°
. 150°
. 165°
. 180°

Correct Answer & Explanation

. 150°

Explanation

After the index finger is rotated 150°, the index finger will be in the ideal location as it mimics the position of where the thumb would have naturally been. This position allows for the greatest amount of grip and pinch strength possible.

Question 1135

Topic: 1. General Principles & Basic Science
For which types of thumb hypoplasia is pollicization the best option?
. Type I
. Type II
. Type IIIA
. Type IIIB
. Type I, type II, and type IIIA

Correct Answer & Explanation

. Type I, type II, and type IIIA

Explanation

Reconstruction is possible and is therefore the best option for thumb hypoplasia in patients with type I, type II, and type IIIA. These three types of hypoplasia can be corrected because the thumb still has most of the bones and muscles intact. Corrective surgery is necessary to correct weak muscles or a tight web space between the thumb and index finger. When a type IIIB exists, reconstruction is not possible and pollicization must be performed.

Question 1136

Topic: 1. General Principles & Basic Science

Which of the following is not considered a part of the triangular fibrocartilage complex:

. Ulnolunate ligament
. Palmar radioulnar ligament
. Dorsal radioulnar ligament
. Radiolunate ligament
. Ulnotriquetral ligament

Correct Answer & Explanation

. Radiolunate ligament

Explanation

The triangular fibrocartilage complex is made up of the dorsal and palmar radioulnar ligaments, the meniscal homologue, the articular disk, the ulnolunate, and the ulnotriquetral ligaments. The radiolunate ligament is not part of the complex.

Question 1137

Topic: 1. General Principles & Basic Science

Which of the following arterial branches does not supply the peripheral 25% of the triangular fibrocartilage complex:

. Dorsal branch of the anterior interosseous artery
. Palmar branch of the anterior interosseous artery
. Dorsal branch of the radial artery
. Dorsal branch of the ulnar artery
. Palmar branch of the ulnar artery

Correct Answer & Explanation

. Dorsal branch of the radial artery

Explanation

The triangular fibrocartilage complex is supplied by both branches of the anterior interosseous artery and the ulnar artery; it is not supplied by the dorsal branch of the radial artery.

Question 1138

Topic: 1. General Principles & Basic Science

Which of the following parameters is not a determinant of the Palmer classification of triangular fibrocartilaginous complex injuries:

. Location of the lesion
. Presence of ulnar head chondromalacia
. Presence of lunatotriquetral ligament injury
. Size of the lesion
. Presence of ulnocarpal arthritis

Correct Answer & Explanation

. Size of the lesion

Explanation

The Palmer classification divides triangular fibrocartilage complex lesions into traumatic and degenerative. Traumatic subclassifications are based on the location of the ligament tear. In the degenerative tear, subclassifications are based on the degree of injury to the triangular fibrocartilage complex and associated chondral and ligamentous injury. Thus, the size of the lesion is not a parameter in the Palmer classification.

Question 1139

Topic: 1. General Principles & Basic Science
Care of an amputated part prior to replantation includes:
. Painting the amputated part with povidone-iodine
. Immersing the amputated part in water
. Placing the amputated part in a warm saline bath
. Wrapping the amputated part with saline-soaked gauze and placing it in a plastic bag on ice
. Putting the amputated part next to the patient's body to keep it warm

Correct Answer & Explanation

. Wrapping the amputated part with saline-soaked gauze and placing it in a plastic bag on ice

Explanation

The appropriate care of an amputated part includes wrapping it in saline-dampened gauze and placing it on ice in a watertight bag. These actions preserve the tissues and slow cellular death until replantation is attempted. The part should not be immersed, painted with povidone-iodine, or kept next to the body.

Question 1140

Topic: 1. General Principles & Basic Science

Replants are monitored by:

. C olor
. Turgor
. Doppler probes
. Temperature measurements
. All of the above

Correct Answer & Explanation

. All of the above

Explanation

Monitoring of replanted parts postoperatively is accomplished by clinical checks of color or turgor to indicate blood flow. Additional objective monitoring is performed by using Doppler probes to check flow or by measuring temperature differences between the replanted part as compared to other digits.

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