Question 1

The primary restraint to anterior translation of the abducted and externally rotated glenohumeral joint is the:

Explanation

The inferior glenohumeral ligament is the primary restraint to anterior translation of the abducted and externally rotated glenohumeral joint. The Bankart lesion is an avulsion of the inferior glenohumeral ligament and represents the primary pathoanatomy of traumatic anterior shoulder dislocation.

Question 2

The quadriceps angle or Q angle is defined as the angle formed by a line connecting the:

Explanation

The quadriceps angle, or Q angle, is used to evaluate patellofemoral alignment. It is defined as the angle formed by a line connecting the anterior superior iliac spine to the center of the patella and a line connecting the center of the patella to the center of the tibial tuberosity. A normal angle is up to 10° in men and up to 15° in women. Unfortunately, no standard technique exists for measuring the Q angle, and its reliability and usefulness have recently come under question.

Question 3

Innervation to the anterior cruciate ligament is provided by a branch of the:

Explanation

The posterior articular branch of the posterior tibial nerve provides pain fibers and mechanoreceptors to the anterior cruciate ligament.

Question 4

All of the following represent mechanisms of injury to the posterior cruciate ligament except:

Explanation

All of the above except application of valgus force to a flexed and externally rotated knee have been described in posterior cruciate ligament injuries. Application of a valgus force to a flexed and externally rotated knee would more likely result in an anterior cruciate ligament injury.

Question 5

Which of the following sets of compartment measurements confirms the diagnosis of exertional compartment syndrome:

Explanation

If pressures at preexercise are >15 mm Hg, 1-minute postexercise >30 mm Hg, 5-minute postexercise >20 mm Hg, it will confirm a diagnosis of exertional compartment syndrome. Exertional compartment syndrome is becoming increasingly recognized as a source of pain in runners and cyclists. The onset of pain is gradual during exercise and ultimately restricts performance. Activity modification usually is effective. Refractory cases may require fasciotomy.

Question 6

The most common adverse side effect of dietary supplementation with creatine in athletes is:

Explanation

Creatine has recently become a popular dietary supplement among athletes. The long-term effects of creatine are not known. However, it appears to cause muscle cramping and heat intolerance.

Question 7

When testing an elbow for insufficiency of the medial collateral ligament, valgus stress should be applied with the elbow positioned at:

Explanation

When testing the medial collateral ligament of the elbow, it is important to apply valgus stress with the elbow flexed approximately 20° to 30° to disengage the olecranon from the olecranon fossa. It is always important to examine and compare the injured and uninjured side.

Question 8

Internal impingement of the shoulder between the posterosuperior glenoid rim and the rotator cuff typically occurs with the arm in this position:

Explanation

Internal impingement of the shoulder occurs with the arm in the abducted, externally rotated, and extended position. This entity may be responsible for shoulder pain commonly occurring in overhead and throwing athletes. Initial treatment is focused on therapy that strengthens the anterior structures and scapular retractors and stretches the posterior structures. If nonoperative treatment fails, arthroscopic debridement, thermal capsular shrinkage, and humeral derotational osteotomy have all been used with varying degrees of success.

Question 9

The following structure is most responsible for anterior stability of the glenohumeral joint with the arm in 45° of abduction:

Explanation

The middle glenohumeral ligament, although absent in up to one third of shoulders, is the largest contributor to anterior stability of the shoulder with the arm abducted 45°. The inferior glenohumeral ligament is the primary restraint to anterior instability with the arm abducted to 90° and externally rotated.

Question 10

The following structure is most responsible for resisting inferior translation of the glenohumeral joint with the arm at the side:

Explanation

The coracohumeral ligament coupled with the superior glenohumeral ligament provides the primary restraint to inferior translation of the glenohumeral joint with the arm at the side. The coracohumeral ligament also provides restraint to external rotation with the arm at the side.

Question 11

Maximal external rotation of the shoulder occurs during which phase of pitching:

Explanation

The pitching motion can be divided into 6 phases: wind-up, early cocking, late cocking, acceleration, deceleration, and follow through. Maximal external rotation at the shoulder occurs during late cocking.

Question 12

A 35-year-old avid rock climber complains of persistent anterior elbow pain with climbing, particularly when pulling himself up with his arms. The following muscle would most likely show increased activity on an electromyogram:

Explanation

Brachialis tendonitis, or climberâ s elbow, causes pain in the anterior elbow with the forearm in the pronated and flexed position. An electromyogram typically shows increased activity in the brachialis muscle.

Question 13

A 16-year-old baseball pitcher complains of dominant-sided elbow pain when pitching. He has recently been removed from the pitching rotation because of "control" problems. Physical examination reveals pain when a supinated, flexed, and valgus stressed elbow is brought into progressive extension. The most likely diagnosis is:

Explanation

The process described is posteromedial impingement syndrome of the elbow. It typically presents as vague elbow pain with loss of control in pitchers. The valgus extension overload test typically elicits pain and sometimes crepitus. The pathological changes in posteromedial impingement syndrome start with chondromalacia on the medial aspect of the trochlear groove and may progress to osteophyte formation and loose bodies necessitating arthroscopic debridement.

Question 14

This slide is a computed tomogram of the shoulder of a 22-year-old rugby player. The most likely diagnosis is:

Orthopedic Prometric Exam Chapter 3 Image

Explanation

The computed tomogram shows a posterior avulsion of the glenoid rim and an impaction fracture of the anterior aspect of the humeral head consisted with a prior posterior dislocation.

Question 15

This slide is a computed tomogram of the dominant shoulder of a 45-year- old male tennis player. The most likely diagnosis is:

Orthopedic Prometric Exam Chapter 3 Image

Explanation

Synovial osteochondromatosis is a rare condition typically affecting middle- aged men. The computed tomogram demonstrates the osteocartilaginous nodules. Early in the disease, arthroscopic removal of loose bodies and synovectomy usually results in an acceptable outcome. In cases of progressive disease resulting in secondary shoulder arthrosis, shoulder arthroplasty may be required.

Question 16

Weight training that employs constant resistance throughout the arc of motion is referred to as:

Explanation

Isotonic training employs a constant resistance throughout the arc of joint motion

Question 17

Weight training that employs a constant velocity and variable resistance is referred to as:

Explanation

Isokinetic training employs constant velocity and variable resistance. Special equipment, such as a C ybex device (C ybex, Medway, Mass), is required for isokinetic training.

Question 18

During arthroscopic repair of a medial meniscal tear, the following structure is at greatest risk for damage:

Explanation

No matter what technique for arthroscopic medial meniscal repair is used, the saphenous nerve must be protected to avoid a painful neuroma postoperatively.

Question 19

During arthroscopic repair of a lateral meniscal tear, the following structure is at greatest risk for damage:

Explanation

When performing arthroscopic lateral meniscal repair, the peroneal nerve must be protected from insult.

Question 20

A 15-year-old male football player is discovered to have a reproducible painless pop with meniscal testing during a routine preparticipation physical examination. The patient states that he has never experienced any knee problems other than an occasional audible pop. His family physician orders a magnetic resonance image. It shows a discoid lateral meniscus without evidence of tearing. Recommended management should include:

Explanation

A discoid lateral meniscus can be complete, incomplete, or a Wrisberg variant. If asymptomatic, the patient can simply be observed without restriction. In patients with symptoms, the preferred treatment is excision of the central portion of the meniscus. In individuals with a discoid meniscus and a peripheral tear, repair of the tear is performed with excision of the central portion of the meniscus.

Question 21

With the arm resting at the side in 0 degrees of abduction, what is the primary static restraint to inferior translation of the glenohumeral joint?

Explanation

In the adducted shoulder (0 degrees of abduction), the superior glenohumeral ligament (SGHL) and the coracohumeral ligament (CHL) are the primary static restraints to inferior translation. The inferior glenohumeral ligament becomes the primary restraint at 90 degrees of abduction.

Question 22

Which of the following statements correctly describes the functional biomechanics of the anterior cruciate ligament (ACL) bundles?

Explanation

The ACL is composed of two main bundles: the anteromedial (AM) and posterolateral (PL). The AM bundle tightens in flexion and is the primary anterior restraint at 90 degrees, while the PL bundle tightens in extension and resists rotatory loads.

Question 23

A 24-year-old male presents with a locked knee after a twisting injury during a soccer match. An MRI is obtained as shown below.

What is the most likely diagnosis?

Explanation

The clinical presentation of a locked knee following a twisting injury is classic for a bucket-handle meniscus tear. On sagittal MRI, a displaced meniscal fragment lying anterior to the posterior cruciate ligament creates the classic "double PCL" sign.

Question 24

During open kinetic chain knee extension, the "screw-home" mechanism ensures maximal joint congruency in terminal extension. This mechanism is primarily characterized by which of the following coupled kinematic motions?

Explanation

The screw-home mechanism is an obligatory 10 degrees of external rotation of the tibia on the femur during the final 30 degrees of open-chain terminal knee extension. It occurs due to the asymmetry of the femoral condyles and the tension of the cruciate ligaments.

Question 25

A 22-year-old collegiate baseball pitcher presents with medial elbow pain during the acceleration phase of throwing. Physical examination reveals valgus instability at 90 degrees of elbow flexion. Which structure is most likely injured?

Explanation

The anterior bundle of the medial ulnar collateral ligament (MUCL) is the primary static restraint to valgus stress at the elbow between 30 and 120 degrees of flexion. It is most commonly injured in overhead throwing athletes.

Question 26

During a pectoralis major tendon repair, a surgeon must restore normal anatomical footprints. How does the sternal head of the pectoralis major muscle normally insert on the humerus relative to the clavicular head?

Explanation

The pectoralis major tendon undergoes a 180-degree twist before its insertion. As a result, the sternal (lower) head crosses deep to the clavicular head and inserts posterior and superior to the clavicular (upper) head.

Question 27

In the setting of an acromioclavicular (AC) joint injury, which ligament functions as the primary static restraint to superior translation of the distal clavicle?

Explanation

The coracoclavicular (CC) ligaments consist of the conoid and trapezoid. The conoid ligament is posteromedial and acts as the primary restraint to superior translation, while the trapezoid is anterolateral and primarily resists axial compression.

Question 28

A 25-year-old overhead athlete complains of posterior shoulder pain and a subjective feeling of a "dead arm" during the late cocking phase of throwing. Based on the provided MRI finding,

which pathophysiologic mechanism best explains the development of this specific capsulolabral pathology?

Explanation

The clinical scenario and late cocking phase pain are characteristic of a Type II SLAP lesion. In overhead throwers, this is most commonly caused by a "peel-back" mechanism where abduction and external rotation create torsional forces at the biceps anchor.

Question 29

The posterolateral corner (PLC) of the knee, consisting primarily of the fibular collateral ligament, popliteus tendon, and popliteofibular ligament, functions as the primary restraint to which of the following combined forces?

Explanation

The posterolateral corner (PLC) structures work together to resist varus gapping, external tibial rotation, and posterior tibial translation. Injury to the PLC is best assessed clinically with the dial test at 30 and 90 degrees.

Question 30

A physical therapist is designing a rehabilitation protocol for a patient with severe patellofemoral osteoarthritis. To minimize patellofemoral joint reaction forces during open kinetic chain (OKC) knee extension exercises, the patient should avoid which arc of motion?

Explanation

In open kinetic chain (OKC) knee extension, patellofemoral joint reaction forces are highest in terminal extension (30 to 0 degrees of flexion). Conversely, in closed kinetic chain exercises (e.g., squats), these forces are highest in deep flexion.

Question 31

A professional volleyball player presents with insidious onset of shoulder weakness. Examination reveals marked atrophy of the infraspinatus with isolated weakness in external rotation, but normal supraspinatus bulk and strength. Where is the most likely site of nerve compression?

Explanation

Compression of the suprascapular nerve at the spinoglenoid notch results in isolated infraspinatus denervation, as the motor branch to the supraspinatus has already branched off. Compression at the suprascapular notch would affect both the supraspinatus and infraspinatus.

Question 32

Which of the following closely approximates the anticipated increase in contact stresses within the medial compartment of the knee following a complete medial meniscectomy?

Explanation

The meniscus dramatically increases joint contact area. A complete medial meniscectomy reduces contact area by approximately 50% to 70%, which leads to a corresponding 100% (or roughly double) increase in medial compartment peak contact stresses.

Question 33

During reconstruction of the medial patellofemoral ligament (MPFL), identifying the correct femoral origin is critical to ensure appropriate graft isometry. Radiographically, the anatomic femoral attachment (Schöttle's point) is located where?

Explanation

The anatomic femoral origin of the MPFL lies in a saddle-shaped sulcus between the adductor tubercle proximally and the medial epicondyle distally. Radiographically, Schöttle's point represents this location slightly anterior to the posterior femoral cortex line.

Question 34

A 21-year-old dancer suffers an acute inversion ankle sprain while "en pointe" (maximally plantarflexed). Which ligament serves as the primary restraint to inversion in this foot position and is most likely to be injured?

Explanation

The anterior talofibular ligament (ATFL) is the primary restraint to inversion when the ankle is plantarflexed. The calcaneofibular ligament (CFL) becomes the primary restraint to inversion when the ankle is dorsiflexed.

Question 35

Posterolateral rotatory instability (PLRI) of the elbow typically follows a traumatic dislocation or iatrogenic injury. This condition is primarily characterized by insufficiency of which of the following ligamentous structures?

Explanation

PLRI is the most common pattern of chronic elbow instability and is caused by an injury or deficiency of the lateral ulnar collateral ligament (LUCL). The LUCL serves as the primary restraint to posterolateral rotatory subluxation of the radius relative to the humerus.

Question 36

Which of the following ligamentous structures is the strongest in the human body and serves as the primary static restraint to hyperextension and external rotation of the hip joint?

Explanation

The iliofemoral ligament (also known as the Y ligament of Bigelow) is the thickest and strongest ligament in the body. It plays a critical role in hip biomechanics by checking hyperextension and external rotation.

Question 37

In the assessment of anterior glenohumeral instability, the concept of the "glenoid track" is utilized to evaluate bone loss. An "engaging" Hill-Sachs lesion is best defined clinically and radiographically as a defect that:

Explanation

An engaging Hill-Sachs lesion is an "off-track" defect. During the extremes of abduction and external rotation, the defect drops over the anterior glenoid rim, causing the joint to lever out and dislocate.

Question 38

The posterior cruciate ligament (PCL) provides the primary restraint to posterior tibial translation and is composed of two functional bundles. Which statement accurately describes the tension pattern of the anterolateral (AL) bundle?

Explanation

The PCL has a larger anterolateral (AL) bundle and a smaller posteromedial (PM) bundle. The AL bundle is tight in flexion and lax in extension, whereas the PM bundle is tight in extension.

Question 39

Unlike the medial collateral ligament (MCL), the anterior cruciate ligament (ACL) possesses a notoriously poor intrinsic healing capacity following complete rupture. Which biological factor is a primary driver of this clinical observation?

Explanation

The ACL has an inadequate healing response because synovial fluid continuously bathes the torn ends. The upregulation of plasminogen activators converts plasminogen to plasmin, which prematurely dissolves the provisional fibrin clot necessary for organized healing.

Question 40

To permit full active elevation of the arm overhead, the clavicle must undergo complex, coupled movements at the sternoclavicular and acromioclavicular joints. During this full elevation, the clavicle normally undergoes which essential motion?

Explanation

During full shoulder elevation, the clavicle must rotate posteriorly approximately 40 to 50 degrees along its longitudinal axis. This motion is dictated by the tensioning of the coracoclavicular ligaments as the scapula upwardly rotates.

Question 41

The primary restraint to varus stress at 30 degrees of knee flexion is the:

Explanation

The fibular collateral ligament (LCL) is the primary restraint to varus stress at 30 degrees of knee flexion. The popliteus complex provides secondary varus stability but is the primary restraint to external rotation.

Question 42

During an acromioclavicular joint reconstruction, the surgeon reconstructs the conoid and trapezoid ligaments. The conoid ligament inserts onto the clavicle at what distance from the distal end of the clavicle?

Explanation

The conoid ligament inserts approximately 4.5 cm medial to the distal clavicle. The trapezoid ligament inserts more laterally, about 3.0 cm medial to the distal clavicle.

Question 43

Peak patellofemoral joint reaction forces during normal gait occur at which phase?

Explanation

Peak patellofemoral joint reaction forces occur during the early mid-stance phase of gait. This correlates with the point of maximum knee flexion (around 15-20 degrees) during the weight-bearing phase.

Question 44

The anterolateral bundle of the posterior cruciate ligament (PCL) is most taut in which position?

Explanation

The anterolateral bundle of the PCL is the larger of the two bundles and is most taut in flexion (around 80-90 degrees). Conversely, the posteromedial bundle is tightest in full extension.

Question 45

Which of the following arteries is considered the principal blood supply to the articular segment of the humeral head?

Explanation

Recent microvascular studies demonstrate that the posterior humeral circumflex artery provides approximately 64% of the blood supply to the humeral head. This contradicts older literature that primarily credited the anterior humeral circumflex artery.

Question 46

Which of the following structures is NOT considered part of the boundaries or contents of the rotator cuff interval?

Explanation

The rotator cuff interval is bounded by the supraspinatus superiorly, subscapularis inferiorly, and the coracoid base medially. It contains the long head of the biceps tendon, the superior glenohumeral ligament, and the coracohumeral ligament; the teres minor is posterior.

Question 47

What is the primary difference in the vascularity of the medial and lateral menisci in an adult?

Explanation

In adults, only the peripheral 10% to 30% of both menisci (the red-red zone) receives vascularity. This supply comes from the perimeniscal capillary plexus derived from the medial and lateral genicular arteries.

Question 48

The spring ligament (plantar calcaneonavicular ligament) primarily supports the head of the talus. Which of the following tendons provides dynamic support directly inferior to this ligament?

Explanation

The tibialis posterior tendon courses directly inferior and medial to the spring ligament. It provides crucial dynamic support to the medial longitudinal arch and the talar head.

Question 49

The artery of the ligamentum teres is a branch of which of the following arteries?

Explanation

The artery of the ligamentum teres is typically a branch of the posterior division of the obturator artery. Its contribution to the femoral head blood supply is minimal in adults but can be important in children.

Question 50

Which annular pulleys are most critical to preserve during flexor tendon surgery to prevent bowstringing?

Explanation

The A2 and A4 pulleys arise directly from the periosteum of the proximal and middle phalanges, respectively. They are the most biomechanically crucial pulleys for preventing flexor tendon bowstringing.

Question 51

Which of the following positions represents the close-packed position of the glenohumeral joint?

Explanation

The close-packed position for the glenohumeral joint is maximum abduction and external rotation. In this position, the capsuloligamentous structures (specifically the inferior glenohumeral ligament complex) are maximally taut.

Question 52

Evaluate the following image of a knee stress radiograph.

In an isolated posterior cruciate ligament (PCL) injury, the maximum posterior tibial translation observed at 90 degrees of flexion is typically:

Explanation

An isolated PCL injury typically results in 10-12 mm of posterior translation on stress radiographs. Translation significantly greater than 12 mm suggests a combined injury, usually involving the posterolateral corner.

Question 53

During a classic deltopectoral approach to the shoulder, the cephalic vein is typically retracted in which direction to preserve its primary draining tributaries?

Explanation

The cephalic vein is usually retracted laterally with the deltoid muscle during the deltopectoral approach. This is because its primary draining tributaries arise from the deltoid, and lateral retraction prevents their avulsion.

Question 54

Consider the biomechanical principles shown in the diagram.

In the setting of a reverse total shoulder arthroplasty, lateralization of the glenosphere primarily achieves which of the following?

Explanation

Lateralization of the glenosphere in reverse total shoulder arthroplasty provides better clearance and significantly decreases inferior scapular notching. However, it can increase shear forces at the baseplate-bone interface.

Question 55

The primary stabilizer of the distal radioulnar joint (DRUJ) during forearm supination is the:

Explanation

During supination, the volar radioulnar ligament becomes taut and serves as the primary stabilizer of the DRUJ. In contrast, the dorsal radioulnar ligament is the primary restraint during pronation.

Question 56

In the subaxial cervical spine, the greatest amount of flexion-extension occurs at which of the following segmental levels?

Explanation

The C5-C6 level exhibits the greatest range of flexion-extension in the subaxial cervical spine. Because of this high mobility, it is also the most common level for degenerative cervical spondylosis and disc herniation.

Question 57

According to static biomechanical models of the hip during single-leg stance, the ratio of the force generated by the hip abductors to body weight is approximately:

Explanation

During single-leg stance, the hip abductors must generate a force approximately 2.5 times body weight to balance the pelvis. This results in a total joint reaction force across the hip of about 3 to 4 times body weight.

Question 58

Tendons are primarily composed of type I collagen. Which of the following proteoglycans is most abundant in the tensile-bearing regions of normal tendons?

Explanation

Decorin is the predominant small leucine-rich proteoglycan (SLRP) found in the tensile-bearing regions of normal tendons. It plays a key role in regulating collagen fibrillogenesis and directly binds to type I collagen.

Question 59

The medial plantar nerve provides motor innervation to all of the following muscles EXCEPT the:

Explanation

The adductor hallucis is innervated by the deep branch of the lateral plantar nerve. The medial plantar nerve reliably innervates the abductor hallucis, flexor digitorum brevis, flexor hallucis brevis, and the first lumbrical.

Question 60

Following a diaphyseal fracture treated with rigid plate fixation (absolute stability), healing primarily occurs via which of the following mechanisms?

Explanation

Rigid plate fixation provides absolute stability, minimizing interfragmentary strain to near zero. This leads to primary bone healing via direct Haversian remodeling (cutting cones) without an intermediate cartilage phase or visible callus.

Question 61

The primary restraint to inferior translation of the glenohumeral joint with the arm in 0 degrees of abduction is the:

Explanation

At 0 degrees of abduction, the superior glenohumeral ligament and coracohumeral ligament are the primary restraints to inferior translation. The inferior glenohumeral ligament becomes the primary restraint at 90 degrees of abduction.

Question 62

During anterior cruciate ligament (ACL) reconstruction, non-anatomic anterior placement of the femoral tunnel will most likely result in a graft that is:

Explanation

A femoral tunnel placed too anteriorly (high in the notch) will result in a graft that is overly tight in flexion and loose in extension. This can lead to a loss of knee flexion and stretching or failure of the graft over time.

Question 63

A 24-year-old baseball pitcher presents with medial elbow pain. Clinical evaluation demonstrates valgus instability of the elbow. The anterior bundle of the ulnar collateral ligament (UCL), which is the primary restraint to this stress, inserts onto which of the following structures?

Explanation

The anterior bundle of the UCL is the primary restraint to valgus stress at the elbow from 30 to 120 degrees of flexion. It originates from the medial epicondyle and inserts onto the sublime tubercle of the proximal ulna.

Question 64

Which of the following components of the posterolateral corner (PLC) of the knee is the primary restraint to external tibial rotation at 30 degrees of knee flexion?

Explanation

The popliteofibular ligament and the popliteus tendon are the primary restraints to external rotation of the tibia. The FCL is the primary restraint to varus stress, not external rotation.

Question 65

A 28-year-old volleyball player has weakness in external rotation but normal abduction strength. An MRI shows isolated atrophy of the infraspinatus. Entrapment of the suprascapular nerve is most likely occurring at which location?

Explanation

The suprascapular nerve passes through the spinoglenoid notch to innervate the infraspinatus after having already supplied the supraspinatus. Compression at this notch (often by a paralabral cyst) results in isolated infraspinatus weakness.

Question 66

Which of the following structures forms the superior border of the quadrangular space, through which the axillary nerve and posterior circumflex humeral artery pass?

Explanation

The quadrangular space is bordered superiorly by the teres minor, inferiorly by the teres major, medially by the long head of the triceps, and laterally by the surgical neck of the humerus.

Question 67

The anteromedial (AM) bundle of the anterior cruciate ligament (ACL) can be biomechanically differentiated from the posterolateral (PL) bundle by which of the following characteristics?

Explanation

The ACL is composed of the AM and PL bundles. The AM bundle is tightest in flexion and primarily restricts anterior translation, whereas the PL bundle is tightest in extension and provides rotational stability.

Question 68

A 32-year-old male presents with recurrent patellar instability. The primary ligamentous restraint to lateral patellar translation at 0 to 30 degrees of knee flexion originates from a point strictly defined by radiographic landmarks. Where is this femoral origin located?

Explanation

The medial patellofemoral ligament (MPFL) originates between the medial epicondyle and the adductor tubercle (often termed Schöttle's point). This point is consistently located proximal and posterior to the medial epicondyle.

Question 69

Regarding the menisci of the knee, which of the following statements most accurately describes their vascular supply and intrinsic healing potential?

Explanation

The peripheral 10-30% of the menisci (red-red zone) is vascularized by the perimeniscal capillary plexus originating from the medial and lateral genicular arteries. This zone has the greatest potential for healing following a meniscal repair.

Question 70

A 21-year-old football player sustains a high-energy knee injury. Clinical examination reveals a positive dial test at 30 degrees of knee flexion but symmetric external rotation at 90 degrees. This pattern is pathognomonic for an isolated injury to which structure?

Explanation

An increase in external rotation of more than 10 degrees compared to the contralateral side at 30 degrees of flexion, but not at 90 degrees, indicates an isolated posterolateral corner (PLC) injury. Combined PLC and PCL injuries demonstrate increased rotation at both 30 and 90 degrees.

Question 71

A 19-year-old athlete undergoes evaluation for shoulder instability.

Which of the following physical examination findings is most specific for a superior labrum anterior and posterior (SLAP) tear?

Explanation

O'Brien's test (active compression test) is considered positive for a SLAP tear when pain is elicited with the arm internally rotated and is relieved when the arm is externally rotated. Deep glenohumeral joint pain is specifically indicative of labral pathology.

Question 72

The medial collateral ligament (MCL) of the knee consists of superficial and deep layers. The superficial MCL is the primary restraint to valgus stress. Where is its primary tibial insertion?

Explanation

The superficial MCL has a broad tibial insertion located approximately 4.5 cm distal to the joint line. It sits deep to the pes anserinus tendons, separated from them by a bursa.

Question 73

A 35-year-old male presents with posterolateral rotatory instability (PLRI) of the elbow after a traumatic dislocation. The primary ligamentous restraint deficient in this condition is the lateral ulnar collateral ligament (LUCL). What is the normal insertion site of the LUCL?

Explanation

The lateral ulnar collateral ligament (LUCL) originates on the lateral epicondyle and blends with the annular ligament before inserting onto the supinator crest of the proximal ulna. It acts as the primary restraint against PLRI.

Question 74

Which of the following combinations of structures accurately defines the contents of the rotator interval of the shoulder?

Explanation

The rotator interval is the triangular anatomical space between the supraspinatus and subscapularis tendons. It contains the long head of the biceps tendon, the superior glenohumeral ligament (SGHL), and the coracohumeral ligament (CHL).

Question 75

The posterior cruciate ligament (PCL) is the primary restraint to posterior translation of the tibia relative to the femur. At what degree of knee flexion does it provide the maximum percentage of this restraining force?

Explanation

The PCL provides up to 95% of the total restraining force to posterior translation of the tibia. Its effectiveness as a primary restraint is greatest at 90 degrees of knee flexion.

Question 76

The medial patellofemoral ligament (MPFL) is recognized as the primary soft tissue restraint against lateral patellar translation. At what angle of knee flexion does it provide the greatest percentage of this restraining force?

Explanation

The MPFL provides 50-60% of the restraining force against lateral patellar displacement, functioning primarily from 0 to 30 degrees of flexion before the patella fully engages the bony stability of the trochlear groove.

Question 77

The superior glenohumeral ligament (SGHL) provides the primary restraint to inferior translation of the humeral head in which of the following shoulder positions?

Explanation

The SGHL works synergistically with the coracohumeral ligament to prevent inferior translation of the humeral head when the arm is adducted at the side. At 90 degrees of abduction, the inferior glenohumeral ligament (IGHL) complex takes over as the primary restraint.

Question 78

Which ligament acts as the primary restraint to anterior translation of the talus within the ankle mortise when the foot is positioned in plantar flexion?

Explanation

The anterior talofibular ligament (ATFL) is tightest in plantar flexion, making it the primary restraint to anterior translation of the talus. Due to this biomechanical role, it is the most commonly injured ligament in lateral ankle sprains.

Question 79

During the late cocking phase of throwing, which elbow structure serves as the primary restraint against valgus stress?

Explanation

The anterior bundle of the medial ulnar collateral ligament (MUCL) is the primary restraint to valgus stress of the elbow between 30 and 120 degrees of flexion. It experiences maximal stress during the late cocking and early acceleration phases of throwing.

Question 80

The lateral meniscus differs from the medial meniscus in both morphology and mobility. Which of the following statements accurately describes the lateral meniscus?

Explanation

The lateral meniscus is more circular (O-shaped) and covers a larger portion of the tibial plateau compared to the medial meniscus. It is highly mobile and is physically separated from the lateral collateral ligament by the popliteus tendon.

Question 81

The primary blood supply to the anterior cruciate ligament (ACL) is derived from which of the following vascular structures?

Explanation

Both the anterior and posterior cruciate ligaments receive their primary blood supply from the middle genicular artery. This artery branches from the popliteal artery and pierces the posterior capsule to supply the intracapsular structures.

Question 82

The scapholunate interosseous ligament is a C-shaped structure essential for proximal carpal row stability. Which portion of this ligament is the strongest and acts as the primary restraint to dorsal translation and diastasis?

Explanation

The scapholunate ligament is anatomically divided into volar, dorsal, and proximal membranous regions. The dorsal portion is the thickest and strongest component, acting as the primary restraint against scapholunate diastasis.

Question 83

In the setting of a massive rotator cuff tear involving the supraspinatus and infraspinatus, which intact anatomical structure limits superior translation (escape) of the humeral head?

Explanation

The coracoacromial ligament forms the critical "roof" of the coracoacromial arch over the humeral head. In massive rotator cuff tears, it provides a crucial static restraint against superior humeral head escape and should generally be preserved during surgery.

Question 84

The Achilles tendon is most susceptible to rupture in its distinct hypovascular "watershed" zone. This region is typically located what distance proximal to its insertion on the calcaneal tuberosity?

Explanation

The Achilles tendon has a relative hypovascular watershed zone located approximately 2 to 6 cm proximal to its calcaneal insertion. Due to diminished blood supply, this specific region is the most common site for degenerative tendinosis and acute ruptures.

Question 85

A 28-year-old overhead throwing athlete presents with deep posterior shoulder pain during the late cocking phase of throwing.

What is the primary stabilizing role of the superior labrum anterior to posterior (SLAP) complex during this motion?

Explanation

The SLAP complex serves as the critical anchor point for the long head of the biceps tendon. During the late cocking and deceleration phases of throwing, it primarily acts to resist superior/anterior translation and glenohumeral distraction.

Question 86

The coracoclavicular (CC) ligaments provide the primary vertical stability to the acromioclavicular joint. Which of the following accurately describes the anatomic relationship between the two distinct ligaments comprising this complex?

Explanation

The coracoclavicular ligament complex consists of the conoid and trapezoid ligaments. The conoid ligament is distinctly located posteromedial to the trapezoid ligament and inserts onto the conoid tubercle of the distal clavicle.

Question 87

The "screw-home" mechanism of the knee provides terminal extension stability, locking the joint. This mechanism is primarily driven by which inherent anatomical feature?

Explanation

The screw-home mechanism involves obligatory external rotation of the tibia during terminal knee extension. It is dictated mechanically by the larger articular surface area and geometric asymmetry of the medial femoral condyle compared to the lateral condyle.

Question 88

A 22-year-old female sustains a non-contact pivoting injury to her knee, reporting a loud pop.

Assuming an acute anterior cruciate ligament (ACL) rupture occurred, which associated meniscal injury is most commonly encountered in this acute setting?

Explanation

In the setting of acute ACL ruptures, lateral meniscus tears (especially posterior horn longitudinal tears) are significantly more common due to the characteristic pivoting and subluxation mechanism. Conversely, medial meniscus tears are more frequently associated with chronic ACL-deficient knees.

Question 89

Which of the following capsular ligaments is considered the thickest and strongest in the human body, serving as the primary restraint against hyperextension of the hip joint?

Explanation

The iliofemoral ligament, also known as the Y ligament of Bigelow, is the strongest ligament in the human body. It spans the anterior aspect of the hip joint capsule and tightly winds during extension to potently resist hip hyperextension.

Question 90

The anterolateral ligament (ALL) of the knee has been identified as a secondary restraint to internal tibial rotation. What is the typical anatomic insertion site of this ligament?

Explanation

The anterolateral ligament (ALL) originates near the lateral femoral epicondyle and takes an oblique course to insert on the anterolateral tibia, approximately midway between Gerdy's tubercle and the fibular head.

Question 91

During a closed kinetic chain lower extremity exercise, such as a deep squat, patellofemoral joint reaction forces reach their peak at approximately which range of knee flexion?

Explanation

Patellofemoral joint reaction forces increase substantially with deeper flexion during closed kinetic chain activities. These forces typically peak around 90 to 120 degrees of knee flexion due to the increased quadriceps force required and the smaller contact area.

Question 92

During an arthroscopic inside-out repair of a posterior horn tear of the medial meniscus, aberrant suture passage poses the greatest iatrogenic risk to which of the following nerves?

Explanation

Inside-out meniscal repair of the medial meniscus places the saphenous nerve and its infrapatellar branches at significant risk during suture passage. By contrast, the common peroneal nerve is at risk during lateral inside-out meniscal repairs.

Question 93

In an adult patient, the intrinsic blood supply to the menisci of the knee is physiologically restricted to which anatomical zone?

Explanation

The vascular supply to the menisci originates from the perimeniscal capillary plexus supplied by the genicular arteries. In adults, this vascularity recedes and is strictly limited to the peripheral 10% to 30% (the "red-red" zone), severely limiting the healing potential of central tears.

Orthopedic Prometric MCQs - Chapter 3 Part 1

Orthopedic Prometric MCQs - Chapter 3 Part 40

Orthopedic Prometric MCQs - Chapter 3 Part 40

Chapter Index