Question 1

Immobilization as a postoperative therapy for flexor tendon repair is recommended for:

Explanation

As children have difficulties in following the detailed flexor tendon rehabilitation program that is recommended for adults after flexor tendon repair, it is advisable to completely immobilize them to protect the repair and avoid inadvertent rupture.

Question 2

Optimization of early active motion protocols for flexor tendon rehabilitation includes:

Explanation

The use of 6- and 8-strand repair techniques allow the flexor tendon repair to withstand the force applied by early active motion protocols. The addition of epitendinous tendon repair also strengthens the repair.

Question 3

The splint for early active motion flexor tendon rehabilitation protocols includes:

Explanation

A hinge at the wrist, which provides a tenodesis effect, allows the patient to passively extend the wrist and flex the fingers in preparation for gentle muscle contraction of the fingers.

Question 4

A 13-year-old boy tears his anterior cruciate ligament (ACL) while playing flag football. What is the preferred graft material for his ACL reconstruction:

Explanation

Due to the patients age, autograft is the preferred option. Also, due to the patientâ s age, his growth plates are open and the surgeon is prohibited from using a graft with a bone construct due to the possible damage to the growth plate.

Question 5

What deformity can develop in a mistreated volar PIP joint dislocation?

Explanation

With volar PIP joint dislocations, there is almost always a disruption of the central slip of the extensor tendon. Because the central slip is involved, the PIP joint will hold a flexed position, and the lateral bands will fall volar to the axis of rotation of the PIP joint. The lateral bands will then exacerbate the flexion at the PIP joint, and due to their pull on the terminal tendon at the insertion on the distal phalanx, the DIP joint will hyperextend. This results in a boutonniere deformity.

Question 6

What percentage of the articular surface must be involved in a dorsal PIP joint fracture dislocation for disruption of the collateral ligaments to occur?

Explanation

The percentage of articular surface involved differentiates a stable dorsal PIP joint fracture dislocation from an unstable one. It is believed that when the involved fracture fragment is less than 40% of the articular surface, the insertion site of the collateral ligaments is not disrupted and the joint is stable. If more than 40% of the articular surface is fractured, then the insertion of the collateral ligaments is involved and the joint will subsequently be unstable.

Question 7

Which structures are disrupted in a lateral PIP joint dislocation?

Explanation

When a lateral PIP joint dislocation occurs, failure probably begins with disruption of the collateral ligament either from its origin on the head of the proximal phalanx or its insertion on the base of the middle phalanx. The injury then proceeds through the accessory collateral ligaments and terminates with disruption of the insertion of the volar plate on the middle phalangeal base.

Question 8

A 22-year old right-hand dominant male college student consumes a large amount of alcohol and falls asleep for eleven hours with his right arm over a chair. When he awakens, he is unable to feel the dorsum of his hand and cannot extend his elbow, wrist, or the metacarpalphalangeal joints of his affected arm. Initial management should consist of

Explanation

Saturday night palsy is the term used for external compression of the radial nerve, and commonly occurs following the clinical scenario described above. The accepted treatment is observation, as Sunderland et al, described complete relief in all seven patients with Saturday night palsy after a period of observation without any adjunctive treatments. Although NSAIDs can be used if pain is a symptom or there is significant edema, these are not necessarily needed. Electromyography may be indicated if there is no improvement in symptoms after a three to six month period of observation. Emergent nerve exploration is indicated only for open fractures with a known radial nerve injury. There is no role for angiography in treatment of Saturday night palsy.

Question 9

Flumazenil can be administered to reverse the effects of which of the following drugs:

Explanation

Midazolam is a benzodiazepine. Flumazenil is the only commercially available benzodiazepine antagonist. The recommended dose is 0.01 mg/kg every minute until reversed to a maximum dose of 1 mg. Fentanyl is an opioid and is reversible with naloxone. Flumazenil is a benzodiazepine antagonist and has no effects on the effects of opioids. Propofol, ketamine, and methohexital have no known antagonists.

Question 10

A 7-year-old boy fell off the jungle gym and landed on his outstretched right arm sustaining a forearm fracture in both bones. The fracture requires reduction. He was given a combination of fentanyl and midazolam for sedation. At his current level of sedation, he is protecting his own airway. His oxygen saturation has dropped slightly to 92% but is stable. He does not display any awareness or discomfort when the fracture is being manipulated. How would you define his current level of sedation:

Explanation

Deep sedation is the level where most fracture reductions are performed. Patients who are deeply sedated do not respond to verbal or noxious stimuli; they may display both a decreased ability to protect their airway and decreased respiratory drive. Analgesia is defined as affecting the sensation of pain, however, there is no change in overall awareness. Conscious sedation is defined as a lessening of awareness, with maintenance of protective reflexes. Patients will respond appropriately to commands and awaken to verbal stimuli. Patients do not respond to commands or noxious stimuli. With general anesthesia, patients will not respond to verbal or noxious stimuli. Additionally, they lose all of their respiratory drive and ability to protect their airway.

Question 11

A 14-year-old girl with a history of multiple food allergies and severe asthma was involved in a motor vehicle accident and sustained an isolated right femur fracture. Which of the following medications is the best choice to control her pain:

Explanation

The goal in this patient is to provide safe, effective, and long-acting analgesia. Meperidine is recommended in this circumstance. It is an opioid that provides intermediate and long-term analgesia. Additionally, it does not cause the associated histamine release and bronchospasm that can occur in patients with asthma and atopia. Ketamine would provide short-term analgesia, but would also alter the level of consciousness. Morphine is well known for precipitating bronchospasm in patients with atopia and asthma. Therefore, it would not be the best choice in the scenario presented. Methohexital (a barbiturate) and midazolam (a benzodiazepine) both cause decreased awareness and have no analgesic properties.

Question 12

Which of the following choices is the best for sedating an otherwise healthy child for a fracture reduction:

Explanation

The combination of fentanyl and midazolam is the closest we have to an ideal drug combination for conscious sedation. Both drugs have commercially available antagonists. Fentanyl and midazolam are both quick- onset and short-duration drugs. When using these two drugs together, there is a significant risk of respiratory depression. It is important to monitor patients closely.

Question 13

A 3-year-old child presents with an obvious right lower extremity abnormality. The left lower extremity has normal alignment and joint function. The right lower extremity displays a severely short thigh with a flexed hip. The right foot and leg are also abnormal. Radiographs reveal a right proximal femur with no femoral head or neck, as well as acetabular dysplasia. There is also fibular hemimelia and two missing lateral rays of the foot. The parents want treatment to preserve the function of the normal leg. The most appropriate treatment is:

Explanation

According to the Aitken classification, the patient has a type C proximal femoral focal deficiency (PFFD). In addition to a severe leg length discrepancy, a dysfunctional foot and ankle are also present. The patient would be best suited with an operative procedure to allow the development of ambulatory skills. The Syme's amputation with knee fusion is the standard procedure for severe PFFD and allows the patient to become proficient in the use of a prosthesis at an early age. In a child this young, a rotation-plasty may not be the best option due to a propensity to de-rotate and the weakness of the underdeveloped right ankle. For severe PFFD with unstable or dysplastic joints, lengthening is not the best option. If the leg length discrepancy were predicted to be <20 cm and a hip joint were present, then lengthening would be a better choice. If the child had a mild leg length discrepancy and was a candidate for lengthening, then an equinus prosthesis would be a reasonable choice until appropriate age for lengthening.

Question 14

The most common associated abnormality with proximal femoral focal deficiency (PFFD) is:

Explanation

Up to 45% of proximal femoral focal deficiency (PFFD) cases have coexisting fibular hemimelia. Tibial hemimelia may also have associated abnormalities of the distal femoral physis leading to a varus knee, but PFFD is more common. Absent radius is typically associated with thrombocytopenia agenesis radius (TAR) syndrome. Congenital scoliosis and cardiac defects are not commonly reported with PFFD.

Question 15

Osteogenesis imperfecta (OI) is caused by defects in:

Explanation

Both quantitative and qualitative defects in type I collagen lead to the various types of osteogenesis imperfecta (OI). Several hundred different collagen I mutations have been found in patients with OI. The less severe forms of OI are caused by mutations in which the defective gene product is not incorporated into collagen, so that formation of cells using the unimpaired strands can continue.

Question 16

Genetic transmission of osteogenesis imperfecta (OI) is best described as:

Explanation

Depending on the particular mutation involved, osteogenesis imperfecta can be either autosomal dominant or autosomal recessive. Osteogenesis imperfecta occurs because of a defect in type I collagen. The genes for type I collagen are found on chromosomes 7 and 17, and are therefore not sex- linked.

Question 17

The most common neurologic complications of osteogenesis imperfecta (OI) is:

Explanation

Basilar impression with brainstem compression is a neurologic sequela of the deforming types of osteogenesis imperfecta (OI). It can be identified by noting that the tip of the dens projects 7 mm or more above McGregor's line on plain film.

Question 18

Criteria for diagnosis of neurofibromatosis 1 (NF1) include all the signs below except:

Explanation

While neurologic deficit may be associated with some of the spinal deformities in neurofibromatosis 1 (NF1), it does not constitute one of the diagnostic criteria. The diagnostic criteria for NF1 were established by The C onsensus Development Conference on Neurofibromatosis at the National Institutes of Health in 1987: Six or more cafa-au-lait spots, at least 15 mm in diameter in adults and 5 mm in children. Two or more neurofibromas of any type or one plexiform neurofibroma. Freckling in the axillae or inguinal regions (Crowe sign). Two or more iris hamartomas (Lisch nodules). A distinctive osseous lesion, such as sphenoid dysplasia or thinning of long bone cortex, with or without pseudarthrosis. A first-degree relative with NF1 by the above criteria.

Question 19

The most common osseous abnormality in neurofibromatosis 1 (NF1) is:

Explanation

Of the many orthopedic manifestations of neurofibromatosis 1 (NF1), including kyphoscoliosis, lordoscoliosis, spondylolisthesis, congenital tibial dysplasia, segmental hypertrophy, cystic bone lesions, and subperiostial bone proliferation, scoliosis is the most common.

Question 20

The origin of "dumbbell lesions" found in radiographs of patients with neurofibromatosis 1 (NF1) is:

Explanation

Intraspinal lesions, such as neurofibromas and meningoceles, that protrude through the neural foramina give the radiologic appearance of a "dumbbell lesion." Flattening of the intervertebral disk with enlargement of the lateral borders is not a feature of neurofibromatosis 1 (NF1). Tibial dysplasia seen in patients with NF1 lead to anterolateral bowing and does not give the appearance of a dumbbell. While subperiostial bone proliferation is seen in NF1, it does not give the appearance of a dumbbell. Bone cysts are a recognized complication of NF1, but are not the origin of the dumbbell lesions seen on radiographs.

Question 21

Which of the following treatments is contraindicated as treatment for kyphoscoliosis in neurofibromatosis 1 (NF1):

Explanation

Laminectomy is contraindicated because the cord is usually compressed anteriorly and resection removes bone necessary for fusion.

Question 22

A 1-year-old girl presents with a right lower extremity abnormality. Her parents report that she has been attempting to stand, but she has not yet walked. C linically, she has a stiff, flexed, varus right knee with an obvious leg length discrepancy. Her ankle is also in a varus position. She does not spontaneously flex or extend the knee from its flexed position. Radiographs show that she has complete tibial hemimelia. The best choice of treatment at this time for the condition is:

Explanation

Knee disarticulation eliminates the malformed knee and ankle, allows the use of a prosthesis at an early age to promote ambulation development, and has good long-term results. Observation is a poor option due to the severity of the deformity and the need for treatment to develop ambulation. Syme's amputation does not address the deformity of the knee. In general, joint malformation or instability precludes lengthening procedures. The Brown procedure centralizes the fibula at the knee and includes a Syme's amputation for the abnormal ankle. However, a functioning quadriceps is a prerequisite and there is a high likelihood of flexion contracture postoperatively.

Question 23

All of the following are consistent with tibial hemimelia (TH) except:

Explanation

All of the answers are consistent with tibial hemimelia (TH) except for knee valgus. The knee is typically in varus due to a present fibula in TH. The foot is typically also in equinovarus, and the leg segment is shortened. Knee disarticulation is the best treatment for a complete TH.

Question 24

Fibular hemimelia (FH) can be associated with which of the following abnormalities:

Explanation

All of the stated abnormalities can be found with femoral hemimelia. It is estimated that 15% of cases have femoral deficiency. Commonly seen in the condition are tarsal coalition, anterior cruciate ligament deficiency, and an equinovalgus foot.

Question 25

A 7-year-old boy presents with bilateral high arches. His parents report that they are having difficulty finding shoes that comfortably fit him. The patient denies any foot pain. The father had similar problems with his feet and was diagnosed with a "mild" neurologic condition. On exam, the child has bilateral pes cavus with a supple hindfoot. Treatment of the feet at this time should consist of:

Explanation

The child has a supple deformity secondary to C harcot-Marie-Tooth disease that will progress if untreated. Soft tissue procedures, which may consist of claw toe correction, plantar release, and possibly tendon transfer, are recommended for children younger than 8 years old who have a supple hindfoot. The calcaneal osteotomy is reserved for patients with a rigid hindfoot. Triple arthrodesis is a salvage procedure reserved for a fixed, painful foot in older children. Bracing and observation are not preferred options due to the progressive nature of the disease, and the lack of ability to apply corrective forces to the foot in cavus.

Question 26

A 17-year-old man with C harcot-Marie-Tooth disease (C MT) presents with pain in his right foot. He has had no treatment for the foot in the past. On exam, he is noted to have a rigid pes cavus with hindfoot varus, as well as some weakness in the anterior tibialis and peroneal muscles. Radiographs display the above deformity with degenerative changes in the subtalar joint. Treatment of the foot should consist of:

Explanation

The patient has a rigid, painful deformity with radiographic signs of arthritis. A triple arthrodesis is his best chance at a pain-free, plantigrade foot. Observation will not solve his pain due to the deformity and degenerative changes in the foot. Nonsteroidal anti-inflammatory drugs (NSAIDs) may help with his pain, however, the degeneration in the foot will continue to progress. Because the patient has a rigid deformity, soft tissue procedures will not alleviate the pain.

Question 27

Which ancillary test is not helpful in the diagnosis of C harcot-Marie-Tooth disease (C MT):

Explanation

Charcot-Marie-Tooth disease (C MT) is a neuropathic process resulting in muscle atrophy, therefore, muscle enzyme studies will not be helpful. Electromyography (EMG) will confirm the diagnosis by displaying increased amplitude and duration of signals, both of which are indicative of a neuropathic process. Nerve conduction velocity (NC V) will also confirm the diagnosis by displaying decreased motor and sensory conduction velocities. Nerve biopsy can be helpful by showing loss of myelinated fibers and fibrosis. Muscle biopsy will show diffuse atrophy, fibrosis, and adipose tissue within muscle.

Question 28

Which of the following is not a feature of the foot deformity in C harcot- Marie-Tooth disease (C MT):

Explanation

Hindfoot varus develops to counter forefoot pronation due to weakness of evertors with preservation of inverter muscle strength. The first metatarsal plantarflexes relative to the other metatarsals, leading to pronation of the forefoot. Plantarflexion of the first metatarsal occurs as part of the windlass mechanism as the intrinsics and plantar fascia contract. As the intrinsics weaken, the toe extensors pull the metatarsophalangeal (MTP) joint into hyperextension as part of the claw toe deformity. When the MTP joint hyperextends, the strength of the long toe flexors pulls the interphalangeal joint into flexion contributing to the claw toe deformity.

Question 29

Which of the following etiologies is not thought to be associated with pseudarthrosis of the clavicle:

Explanation

Several theories have been proposed to explain the rare phenomenon of isolated pseudarthrosis of the clavicle. The most accepted theory is pressure from the higher riding right subclavian artery. Pseudarthrosis has also been described in patients with prominent cervical ribs. Finally, some believe that this condition is caused by failure of fusion of the medial and lateral ossification centers of the clavicle. C leidocranial dysplasia may be associated with pseudarthrosis of the clavicle. There is no evidence that they are related to stress.

Question 30

The most common presenting symptoms of congenital pseudarthrosis of the clavicle are:

Explanation

The most common presentation of pseudarthrosis of the clavicle is a painless mass in right the clavicle. There is no history of trauma, and the child uses the extremity normally, with minimal pain, and with no signs of instability. There is no history of pseudoparalysis involved with congenital pseudarthrosis. Arm use is nearly normal, except for aching with activity. There is minimal restriction of motion with the pseudarthrosis, which is one reason it is sometimes not diagnosed until later in childhood. There has not been neurologic impairment with this condition.

Question 31

Which of the following statements regarding congenital pseudarthrosis of the clavicle is not true:

Explanation

Pseudarthrosis of the clavicle occurs primarily on the right side. The right predominance has been attributed to pressure on the right clavicle from the subclavian artery and occasionally cervical ribs. Treatment is straightforward with intercalary bone grafting with plate and screws fixation. There is no association with neurofibromatosis and/or pseudarthrosis of the tibia. Unlike pseudarthrosis of the tibia, congenital pseudarthrosis of the clavicle is rarely, if ever, associated with neurofibromatosis Pressure from the subclavian artery or prominent cervical ribs have been used to explain the observation that the pseudarthrosis is almost always located on the right, and if bilateral, it is associated with bilateral cervical ribs Bone graft with plate fixation is the usual treatment for these cases, although there have been reports of success in younger children from simply suturing the periosteum of the two ends together Brachial plexus impairment rarely develops in the untreated pseudarthrosis.

Question 32

Which of the following laboratory findings are consistent with ankylosing spondylitis:

Explanation

Diagnostic work-up for an inflammatory autoimmune condition should include an erythrocyte sedimentation rate (ESR), antinuclear antibody (ANA), rheumatoid factor (RF), haplotype, and Lyme titer. The laboratory results most consistent with ankylosing spondylitis are an elevated ESR at the time of an acute exacerbation, negative ANA and RF, and a haplotype of HLAB27.

Question 33

Which of the following clinical features distinguishes homocystinuria from Marfan syndrome:

Explanation

Patients with Marfan syndrome do not typically have defects in intellectual functioning, while patients with homocystinuria typically do show signs of delayed intellectual development. Patients with Marfan syndrome and homocystinuria both develop lens dislocations, scoliosis, chest wall abnormalities, and tall stature.

Question 34

Patients with homocystinuria undergoing lower extremity and spinal surgery must be warned of an increased risk of which complication:

Explanation

Arterial and venous thromboembolic disease is common in patients with homocystinuria. Patients are at increased risk for this major complication when undergoing any surgical procedure. Unlike patients with Marfan syndrome, patients with homocystinuria do not develop aortic root dilation, aneurysms, mitral valve prolapse with high output heart failure, or spontaneous pneumothoraces. Underlying lung pathology is not a feature of homocystinuria, therefore, these patients are not at an increased risk for prolonged ventilatory support.

Question 35

What is the molecular disturbance responsible for the development of homocystinuria:

Explanation

The metabolic disturbance responsible for homocystinuria is a deficiency of cystathionine ß-synthase. A translocation of chromosome 11 and 22 is a feature of some patients with Ewingâ s tumor. Accumulation of cerebrosides in the reticuloendothelial system is found in Gaucherâ s disease. Methionine is present in excessive quantities in homocystinuria because it cannot be converted to cysteine due to the deficiency of cystathionine ß- synthase. Pyridoxine deficiency is a secondary feature of the disorder, but it is not the primary cause.

Question 36

Which form of chronic inflammatory arthritis is more common in boys than in girls?

Explanation

Overall, juvenile rheumatoid arthritis (JRA) is much more common in girls. In pauciarticular JRA, the ratio is 4:1 female. In polyarticular JTA, it is 3:1 female, and in systemic JRA the ratio is 1:1. Seronegative spondylarthropathy is more common in males. The incidence of polyarticular JRA is 3 times higher in girls than in boys. The incidence of pauciarticular JRA occurs 4 times more often in girls than in boys. Girls and boys are equally affected by systemic onset JRA.

Question 37

Which of the following subtypes of juvenile rheumatoid arthritis (JRA) results in the highest risk of developing iritis:

Explanation

Patients with pauciarticular juvenile rheumatoid arthritis (JRA) have the highest risk of developing iritis, cataracts, and blindness. Polyarticular JRA has the second highest risk. Patients with systemic JRA rarely develop iritis. All newly diagnosed JRA patients should be acutely evaluated and closely followed by an ophthalmologist. Systemic-onset JRA has the lowest risk of uveitis There is a distinct difference among the types of JRA in terms of risk of eye involvement. Eye involvement is one of the problems physicians should be alert for in order to make an early diagnosis and prevent cataracts and blindness.

Question 38

In the evaluation of a child with possible inflammatory arthritis, which tests should be ordered for possible juvenile rheumatoid arthritis:

Explanation

Juvenile rheumatoid arthritis (JRA) is primarily a clinical diagnosis; however, routine screening tests should be ordered as part of a routine work- up. All patients should have a C BC , RF, ANA, ESR, C RP, and ophthalmology consult to look for eye involvement. An echocardiogram is not necessary unless a pericardial rub or other cardiac symptoms are present. HLA associations have been made with the different sub-types of the disease; however, this test is not necessary or diagnostic. The CBC helps to rule out hematologic malignancy and assess the patientâ s general health. The ANA looks at the possibility of systemic lupus erythematosus and, if positive at low titer, heralds an increased risk of uveitis. A positive RF helps rule in JRA and makes the risk of later erosive disease more likely. ESR and C RP are helpful for monitoring disease activity. Ophthalmology consultation will help to rule out or detect uveitis at an early stage. HLA typing is not indicated in the typical patient with JRA; it may be useful in the older male with axial symptoms. Synovial fluid analysis yields inflammatory fluid in this condition, but no information specific for the diagnosis.

Question 39

A 7-year-old child sustained a type 3 closed supracondylar fracture of the humerus 2 hours ago. Neurologic function is intact, but a pulse cannot be found by palpation or doppler. The hand is slightly cool. Your next step is to perform:

Explanation

Closed reduction should be carefully attempted at first, and often a tethered artery will be freed. If no pulse returns, open exploration is indicated if the hand remains cool. An arteriogram is rarely indicated because it is unlikely to yield additional information. Lidocaine may be instilled if there is spasm at the time of open reduction. Open reduction of the fracture is indicated only if closed reduction fails, or if the fracture is open. Vascular repair is not the first step; exploration and repair should be carried out only if the pulse does not return after an attempt at closed reduction.

Question 40

The nerve most commonly injured at the time of a supracondylar fracture is:

Explanation

The anterior interosseous nerve is the most commonly injured nerve. The anterior interosseous nerve can be tested by asking the patient to make an "O" with the thumb and index fingers, and watching for active flexion of the distal interphalangeal joints. The radial nerve is the second most commonly injured, after the anterior interosseous nerve. The ulnar nerve is not the most commonly injured at time of fracture but is the most commonly injured at time of treatment. The posterior interosseous nerve is rarely injured.

Question 41

A 9-year-old child presents one year after a supracondylar humerus fracture is healed. The elbow is in 15° more varus than the other side. Which of the following statements to the family is true:

Explanation

Fracture malalignment is the most common cause of cubitus varus. Physeal damage is rare after supracondylar fractures. Angular malalignment corrects slowly and incompletely in the distal humerus, especially in the coronal plane. There is no reason for selective hyperemia of the capitellum in this fracture. There is no evidence of predisposition to degenerative joint disease in cubitus varus.

Question 42

Positioning of the humeral stem at the time of total shoulder arthroplasty should allow congruent articulation with the glenoid component. C ongruent articulation occurs in most shoulders with a humeral stem positioned in:

Explanation

It is important to place the humeral stem in appropriate version to "mate" with the glenoid component. This is most often represented by 20° to 30° of humeral retroversion.

Question 43

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

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 44

Which of the following statements is true regarding Lyme disease:

Explanation

Approximately 60% of patients develop arthritic symptoms that primarily affect large joints. The prognosis for most patients is good after treatment with antibiotics. Cardiac and neurologic symptoms occur in a minority of patients, however, they can be the most serious symptoms. Erythema chronicum migrans is the characteristic skin rash. The rash tends to remit with antibiotic treatment and permanent disfigurement is not typically a problem. Only 1%-2% of pediatric patients develop chronic arthritis. Lyme disease may be difficult to diagnose because of the numerous possible presentations.

Question 45

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

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 46

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

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 47

Joint pain in rheumatic fever:

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 48

Patients with homocystinuria phenotypically resemble patients with:

Explanation

Patients with homocystinuria may phenotypically resemble patients with Marfan syndrome. Patients with homocystinuria and Marfan syndrome are tall with long limbs, arachnodactyly, scoliosis, chest wall deformities, and lens dislocations. Achondroplasia is characterized by short stature, frontal bossing, and rhizomelic shortening of the limbs. Larsen's syndrome is a disorder characterized by short stature and multiple joint dislocations. Gaucher's disease is a lysosomal storage disease characterized by accumulation of cerebroside in cells of the reticuloendothelial system. As in patients with homocystinuria, patients with Gaucher's disease have osteoporosis, however, they do not develop any of the other phenotypic features seen in homocystinuria. Noonan's syndrome effects boys and clinical features include short stature, a webbed neck, and cubitus valgus deformities.

Question 49

A genetic defect found in some types of Ehlers-Danlos syndrome (EDS) is:

Explanation

Ehlers-Danlos syndrome (EDS) was once described as a single gene disorder affecting type I collagen, but it has since been discovered that EDS is a family of heterogeneous disorders with many described mutations. Type I collagen is defective in EDS type VII and collagen type III is defective in EDS type IV and VIII. Fibrillin and fibroblast growth factor (FGF) receptor 3 are defective in Marfan syndrome and achondroplasia, respectively. Dystrophin is deficient in muscular dystrophy. Hypoxanthine-guanine phosphoribosyl transferase is defective in Lesch- Nyhan syndrome.

Question 50

Which of the following features differentiates Marfan syndrome from Ehlers-Danlos syndrome (EDS):

Explanation

Patients with Ehlers-Danlos syndrome (EDS) and Marfan syndrome may have joint hypermobility, scoliosis, vascular problems, and recurrent joint instability. Patients with Marfan syndrome also develop lens dislocations, and while some patients with EDS exhibit eye problems, it is related to ocular globe fragility. Lens dislocation is not a feature of EDS.

Question 51

A 28-year-old carpenter suffers a laceration over the dorsal aspect of the proximal interphalangeal (PIP) joint, resulting in a Zone III extensor tendon disruption. If left untreated, this injury will classically lead to which of the following deformities?

Explanation

A Zone III extensor tendon injury disrupts the central slip attachment at the base of the middle phalanx. This leads to volar subluxation of the lateral bands, causing PIP flexion and DIP hyperextension, known as a Boutonniere deformity.

Question 52

During flexor tendon repair in Zone II of the hand, meticulous management of the tendon sheath and pulley system is essential. Which two pulleys are biomechanically most critical to preserve in order to prevent bowstringing of the flexor tendons?

Explanation

The A2 and A4 pulleys are the major mechanical contributors to the flexor tendon pulley system. Their preservation is essential to prevent flexor tendon bowstringing and subsequent loss of active digital flexion.

Question 53

A 35-year-old male sustains a severe open tibia fracture with massive soft tissue stripping and exposed bone lacking periosteal coverage. What is the most appropriate Gustilo-Anderson classification and indicated soft tissue management?

Explanation

A Gustilo-Anderson Type IIIB fracture is characterized by extensive soft tissue loss with periosteal stripping and exposed bone. This requires complex soft tissue reconstruction, such as a rotational or free muscle flap.

Question 54

A 22-year-old athlete undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) autograft. Compared to hamstring autografts, what is the most common complication specifically associated with the BPTB graft type?

Explanation

Bone-patellar tendon-bone (BPTB) autografts provide excellent initial fixation and bone-to-bone healing. However, they are most frequently associated with donor site morbidity, particularly anterior knee pain and kneeling pain.

Question 55

A 12-year-old male presents with a stable slipped capital femoral epiphysis (SCFE) of the left hip. Which of the following is the strongest clinical indication for prophylactic in situ pinning of the asymptomatic contralateral right hip?

Explanation

Endocrine disorders (such as hypothyroidism, panhypopituitarism, or renal osteodystrophy) significantly increase the risk of bilateral SCFE. Prophylactic pinning of the contralateral hip is strongly recommended in these patients.

Question 56

A 14-year-old male presents with a diaphyseal femur lesion showing a permeative pattern and "onion-skin" periosteal reaction on radiographs. Which chromosomal translocation is most characteristic of this suspected malignant bone tumor?

Explanation

The clinical and radiographic presentation is classic for Ewing Sarcoma. The hallmark genetic mutation is the t(11;22)(q24;q12) translocation, which forms the EWS-FLI1 fusion protein.

Question 57

During a standard posterior approach to the hip for total hip arthroplasty, the surgeon meticulously detaches the short external rotators. Which specific muscle is typically left intact to protect the medial femoral circumflex artery (MFCA)?

Explanation

The quadratus femoris is typically preserved or only partially released during a posterior approach to protect the medial femoral circumflex artery. The MFCA courses highly predictably just deep to the proximal border of this muscle.

Question 58

A 65-year-old male with cervical spondylosis complains of deteriorating handwriting and frequent tripping. Examination shows a positive Hoffmann's sign. MRI reveals critical stenosis at C5-C6. What is the primary pathological mechanism driving his upper motor neuron signs?

Explanation

A positive Hoffmann's sign and gait disturbances indicate cervical myelopathy with upper motor neuron involvement. This is primarily caused by compression of the descending corticospinal tracts in the spinal cord.

Question 59

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?

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 60

A 28-year-old male sustains a closed comminuted tibial shaft fracture and complains of pain out of proportion to the injury. Which intra-compartmental pressure measurement is the most reliable threshold for diagnosing acute compartment syndrome?

Explanation

The delta P (diastolic blood pressure minus intra-compartmental pressure) is the most reliable indicator of compartment syndrome. A delta P of less than 30 mmHg is the widely accepted threshold indicating the need for immediate fasciotomy.

Question 61

A 30-year-old athlete sustains a hyperplantarflexion injury to his midfoot. Radiographs show a widening between the first and second metatarsal bases. Anatomically, the critical Lisfranc ligament connects which two osseous structures?

Explanation

The Lisfranc ligament is a strong interosseous ligament bridging the plantar-lateral aspect of the medial cuneiform to the plantar-medial aspect of the second metatarsal base. Its disruption causes midfoot instability.

Question 62

A 20-year-old swimmer presents with recurrent anterior shoulder instability. An MRI arthrogram demonstrates an anterior labroligamentous avulsion where the anterior scapular periosteum remains intact but is stripped medially. Which lesion does this describe?

Explanation

An ALPSA (Anterior Labroligamentous Periosteal Sleeve Avulsion) lesion occurs when the labrum is avulsed but the anterior scapular periosteum remains intact, allowing the labrum to heal in a displaced, medialized position.

Question 63

A 6-year-old boy falls on an outstretched hand, sustaining a Gartland Type III extension-type supracondylar humerus fracture. Which nerve is most commonly injured in this specific fracture pattern?

Explanation

The anterior interosseous nerve (AIN), a branch of the median nerve, is the most frequently injured nerve in extension-type supracondylar humerus fractures. Clinically, this presents as an inability to make the "OK" sign.

Question 64

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?

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 65

A 24-year-old male sustains a displaced fracture of the proximal pole of the scaphoid. This injury is at high risk for avascular necrosis due to the retrograde blood supply primarily derived from which vessel?

Explanation

The major blood supply to the scaphoid enters distally via the dorsal carpal branch of the radial artery and flows retrograde to the proximal pole. Proximal pole fractures often disrupt this supply, leading to avascular necrosis.

Question 66

A 70-year-old woman presents with bilateral leg pain and cramping that worsens with standing but improves when pushing a shopping cart. Which physical examination finding best differentiates neurogenic claudication from vascular claudication?

Explanation

Neurogenic claudication is highly responsive to changes in spinal posture; lumbar flexion (e.g., sitting or leaning on a shopping cart) increases the canal volume and relieves symptoms. Vascular claudication is relieved simply by resting, regardless of spinal posture.

Question 67

During a primary total knee arthroplasty (TKA), the surgeon balances the knee but finds it is extremely tight in flexion while remaining perfectly balanced in extension. Which intraoperative adjustment is most appropriate to resolve this issue?

Explanation

When the flexion gap is tight but the extension gap is balanced, downsizing the femoral component reduces the posterior condylar offset. This increases the flexion gap space without altering the extension gap.

Question 68

A 4-month-old female infant is diagnosed with developmental dysplasia of the hip (DDH). Dynamic ultrasound confirms a dislocated but reducible left hip. What is the most appropriate initial management for this patient?

Explanation

For infants under 6 months of age with a reducible dislocated hip, a Pavlik harness is the gold standard initial treatment. It maintains the hip in flexion and abduction to promote concentric reduction and acetabular remodeling.

Question 69

A 19-year-old male complains of severe night pain in his right tibial diaphysis that is consistently and completely relieved by NSAIDs. Radiographs demonstrate a 1 cm radiolucent nidus surrounded by reactive sclerosis. If conservative management fails, what is the treatment of choice?

Explanation

The clinical and radiographic presentation is classic for an osteoid osteoma. If medical management with NSAIDs fails or is poorly tolerated, percutaneous Radiofrequency Ablation (RFA) is the definitive, minimally invasive treatment of choice.

Question 70

A 60-year-old patient undergoes an arthroscopic rotator cuff repair for a massive crescent-shaped tear. Biomechanically, what is the primary advantage of utilizing a double-row repair construct compared to a single-row repair?

Explanation

Double-row rotator cuff repairs biomechanically provide a significantly larger and more pressurized contact area between the tendon and the tuberosity footprint. This promotes superior biologic healing rates compared to single-row constructs.

Question 71

A 9-month-old non-ambulatory infant presents to the emergency department with a spiral fracture of the right femoral shaft. The parents state the child caught his leg in the crib slats. What is the most appropriate next step in management?

Explanation

In a non-ambulatory infant under 1 year of age, a femur fracture is highly suspicious for non-accidental trauma regardless of the fracture pattern. A complete skeletal survey and involvement of Child Protective Services are critical first steps.

Question 72

A 35-year-old male arrives in the trauma bay following a high-speed motorcycle collision. He has an anteroposterior compression type III (APC-III) pelvic ring injury. Despite application of a pelvic binder and massive transfusion protocols, he remains hemodynamically unstable. What is the most appropriate emergent intervention?

Explanation

In a hemodynamically unstable patient with a mechanically stabilized pelvic fracture who fails to respond to fluid resuscitation, retroperitoneal arterial or venous hemorrhage is likely. Preperitoneal pelvic packing or angioembolization is the emergent treatment of choice.

Question 73

In total hip arthroplasty, the use of highly cross-linked polyethylene (HXLPE) liners compared to conventional ultra-high-molecular-weight polyethylene (UHMWPE) is associated with which of the following biomechanical tradeoffs?

Explanation

Highly cross-linked polyethylene significantly reduces volumetric wear and subsequent osteolysis. However, the cross-linking and subsequent thermal remelting processes decrease its yield and fatigue strength, slightly increasing the risk of mechanical failure or rim fracture.

Question 74

A 45-year-old male presents with acute severe lower back pain and bilateral radiculopathy. Which of the following clinical findings is the most sensitive for the diagnosis of cauda equina syndrome?

Explanation

Urinary retention is considered the most sensitive symptom of cauda equina syndrome. A post-void residual volume of less than 100 to 200 mL makes the diagnosis of cauda equina syndrome highly unlikely.

Question 75

Which of the following anatomic and biomechanical factors is most strongly associated with an increased risk of primary anterior cruciate ligament (ACL) injury and subsequent graft failure after reconstruction?

Explanation

An increased posterior tibial slope (typically greater than 12 degrees) is a significant biomechanical risk factor for native ACL injury and reconstruction failure. It increases anterior tibial translation and places higher stress on the ACL graft under axial loading.

Question 76

A 16-year-old male is undergoing treatment for osteosarcoma of the distal femur. Following preoperative neoadjuvant chemotherapy, surgical resection is performed. Which of the following factors provides the most significant prognostic value for his overall survival?

Explanation

The degree of tumor necrosis following neoadjuvant chemotherapy is the most reliable prognostic indicator for survival in osteosarcoma. A good response is defined as greater than 90% tumor necrosis in the resected specimen.

Question 77

Six weeks after non-operative management of a non-displaced distal radius fracture, a 60-year-old female presents with a sudden inability to actively extend the interphalangeal joint of her thumb. What is the most appropriate surgical treatment?

Explanation

Extensor pollicis longus (EPL) rupture is a known complication of non-displaced distal radius fractures due to attrition and localized ischemia. Primary repair is usually impossible due to tendon retraction and fraying, making EIP to EPL transfer the treatment of choice.

Question 78

A 24-year-old male sustains a midfoot injury during a football game. Radiographs reveal a small bony avulsion fragment in the space between the base of the first and second metatarsals (the "fleck sign"). This fragment typically originates from which of the following structures?

Explanation

The "fleck sign" is pathognomonic for a Lisfranc injury. It represents a bony avulsion of the Lisfranc ligament, which connects the medial cuneiform to the base of the second metatarsal.

Question 79

A 12-year-old boy diagnosed with slipped capital femoral epiphysis (SCFE) of the left hip undergoes in situ single-screw fixation. Prophylactic pinning of the asymptomatic contralateral right hip is most strongly indicated if the patient has which of the following?

Explanation

Prophylactic pinning of the contralateral hip in SCFE is highly recommended for patients with underlying endocrine disorders (e.g., hypothyroidism) or renal failure. These patients have a significantly higher risk of bilateral involvement compared to idiopathic cases.

Question 80

A 22-year-old male sustains a fracture of the proximal pole of the scaphoid. The high risk of avascular necrosis (AVN) in this specific fracture pattern is primarily due to the retrograde blood supply originating from which of the following vessels?

Explanation

The major blood supply to the scaphoid enters the dorsal ridge distally via the dorsal carpal branch of the radial artery. It flows in a retrograde fashion to supply the proximal pole, predisposing proximal pole fractures to ischemia and AVN.

Question 81

During a physical examination of a 68-year-old male with progressive clumsiness in his hands, the examiner flicks the distal phalanx of the patient's middle finger, causing sudden flexion of the thumb and index finger. This physical sign indicates pathology in which of the following locations?

Explanation

The described maneuver elicits a positive Hoffmann sign, which is indicative of an upper motor neuron lesion, such as cervical spondylotic myelopathy. It typically points to spinal cord compression above the C5 or C6 level.

Question 82

A 40-year-old male sustains a Schatzker II tibial plateau fracture. During surgical fixation, the surgeon decides to evaluate the articular reduction directly. Which of the following surgical approaches and techniques is most appropriate for this specific fracture pattern?

Explanation

A Schatzker II fracture is a split-depression fracture of the lateral tibial plateau. It is best managed via an anterolateral approach, often incorporating a submeniscal arthrotomy to directly visualize and elevate the depressed articular segments.

Question 83

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

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 84

During a total knee arthroplasty (TKA), the popliteal artery is at the greatest risk for iatrogenic injury during which of the following steps?

Explanation

The popliteal artery lies immediately posterior to the posterior joint capsule of the knee. It is at highest risk of injury during posterior capsular releases, resection of the PCL, or when making the posterior tibial bone cut if retractors are not appropriately placed.

Question 85

A 28-year-old male with recurrent anterior shoulder instability is found to have a Hill-Sachs lesion on MRI. Which of the following best describes the anatomic nature of this lesion?

Explanation

A Hill-Sachs lesion is an impaction fracture of the posterolateral humeral head. It is created when the humeral head strikes the sharp anterior glenoid rim during an anterior glenohumeral dislocation.

Question 86

When evaluating an infant with suspected developmental dysplasia of the hip (DDH) using coronal ultrasound, the alpha angle is measured. What does the alpha angle represent, and what is its normal value?

Explanation

In the Graf method of neonatal hip ultrasound, the alpha angle quantifies the bony concavity of the acetabulum (bony roof). An alpha angle of greater than 60 degrees is considered normal (Graf Type I).

Question 87

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:

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 88

A 30-year-old male basketball player presents with an acute, closed mallet finger of the right ring finger without volar subluxation of the distal phalanx. What is the most appropriate initial management?

Explanation

The gold standard treatment for an acute, closed mallet finger injury without joint subluxation is strict, continuous extension splinting of the distal interphalangeal (DIP) joint for 6 to 8 weeks. The PIP joint is left free to move.

Question 89

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?

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 90

A 12-year-old obese boy presents with a 3-week history of groin pain and a limp. Examination reveals obligatory external rotation with hip flexion. Radiographs confirm a stable slipped capital femoral epiphysis (SCFE). What is the most appropriate standard surgical management?

Explanation

The gold standard treatment for a stable SCFE is in situ percutaneous pinning using a single partially threaded cannulated screw. This prevents further slippage while minimizing the risk of avascular necrosis and chondrolysis.

Question 91

A 25-year-old female undergoes anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone (BPTB) autograft. Which of the following is the most commonly reported complication associated with this specific graft choice when compared to hamstring autograft?

Explanation

BPTB autografts are historically associated with a higher incidence of donor-site morbidity, specifically anterior knee pain and pain with kneeling, compared to hamstring autografts. Rates of graft rupture and stability are generally comparable or slightly favor BPTB.

Question 92

A 28-year-old man falls on an outstretched hand and sustains a displaced proximal pole scaphoid fracture. Given the retrograde blood supply to the scaphoid, which surgical approach and fixation method is generally preferred for isolated proximal pole fractures?

Explanation

A dorsal approach is preferred for proximal pole scaphoid fractures because it provides direct access to the proximal fragment, avoids injury to the volar radiocarpal ligaments, and allows for central screw placement in the small proximal pole.

Question 93

A 68-year-old man is 10 years post-THA. Radiographs show eccentric wear of the femoral head within the acetabular cup and focal osteolysis in the proximal femur. Which of the following particulate debris is the primary mediator of this osteolytic response?

Explanation

UHMWPE wear particles are the most common cause of macrophage-induced aseptic loosening and periprosthetic osteolysis in total hip arthroplasty. The macrophages phagocytose the particles and release cytokines like TNF-alpha and IL-1, stimulating osteoclast activity.

Question 94

A 14-year-old boy presents with knee pain and a palpable mass in the distal femur. Biopsy confirms conventional high-grade intramedullary osteosarcoma. What is the most appropriate, evidence-based treatment sequence?

Explanation

The standard of care for conventional high-grade osteosarcoma is neoadjuvant (preoperative) chemotherapy, followed by wide surgical resection, and concluding with adjuvant (postoperative) chemotherapy. Osteosarcoma is highly radioresistant, making radiation therapy generally ineffective for primary local control.

Question 95

A 65-year-old man presents with progressive hand clumsiness and gait instability. Examination demonstrates a positive Hoffmann sign and lower extremity hyperreflexia. MRI shows severe cervical stenosis at C4-C5 with a T2 hyperintense signal in the spinal cord. What is the primary pathophysiologic mechanism corresponding to this T2 signal change?

Explanation

In cervical spondylotic myelopathy, T2 hyperintensity in the spinal cord typically represents edema, inflammation, or irreversible myelomalacia secondary to chronic compression and ischemia. This finding often correlates with disease severity and potentially poorer post-surgical outcomes.

Question 96

A 32-year-old man sustains a closed midshaft tibia fracture. Twelve hours post-admission, he develops severe leg pain out of proportion to the injury. Intracompartmental pressure testing reveals an absolute pressure of 45 mmHg, and his diastolic blood pressure is 60 mmHg. What is the most appropriate next step in management?

Explanation

Acute compartment syndrome is diagnosed when the Delta P (Diastolic BP minus Compartment Pressure) is less than 30 mmHg. In this patient, the Delta P is 15 mmHg (60 - 45), mandating an emergent four-compartment fasciotomy.

Question 97

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?

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 98

A 6-year-old boy falls off monkey bars and sustains a significantly displaced supracondylar humerus fracture (Gartland Type III). He has an absent radial pulse but a well-perfused, "pink, and warm" hand. What is the most appropriate initial management in the operating room?

Explanation

For a "pink, pulseless" hand in the setting of a displaced supracondylar humerus fracture, the initial step is urgent closed reduction and percutaneous pinning. The pulse frequently returns after fracture realignment; vascular exploration is reserved for cases where the hand remains dysvascular (white and pulseless) after reduction.

Orthopedic Prometric Exam Preparation MCQs - Part 1

Orthopedic Prometric Exam Preparation MCQs - Part 14

Orthopedic Prometric Exam Preparation MCQs - Part 14

Chapter Index