Orthopedic Surgery Mock Exam - Set 674211

A 34-year-old male presents after a high-speed motorcycle collision. Radiographs demonstrate a displaced scapular body fracture.

Which of the following associated injuries is statistically most common in this clinical setting?

A 62-year-old female who underwent a metal-on-metal total hip arthroplasty 5 years ago presents with new-onset groin pain and a palpable mass. Aspiration yields sterile, cloudy fluid. Histopathological analysis of the periprosthetic tissue is most likely to demonstrate which of the following?

A 6-year-old boy falls from monkey bars and sustains a completely displaced extension-type supracondylar humerus fracture. Radiographs show the distal fragment is displaced posterolaterally. Based on this displacement pattern, which neurovascular structure is at the greatest risk of injury?

A 45-year-old male presents with right arm pain and weakness. Physical examination reveals weakness in wrist flexion and finger extension, diminished sensation over the dorsal middle finger, and an absent triceps reflex. Which cervical nerve root is most likely compressed?

Which of the following Bone Morphogenetic Proteins (BMPs) is an FDA-approved osteoinductive agent for the treatment of acute, open tibial shaft fractures?

A 28-year-old professional cyclist presents with intrinsic muscle weakness in his right hand but normal sensation over the volar and dorsal aspects of the small finger. He is diagnosed with ulnar nerve compression at Guyon's canal. This clinical presentation most likely correlates with compression at which specific zone of Guyon's canal?

During arthroscopic evaluation of a 22-year-old athlete's knee, a longitudinal tear is identified in the peripheral red-red zone of the medial meniscus. Which of the following blood vessels provides the primary vascular supply to this region of the medial meniscus?

A 30-year-old man falls from a height and sustains a talar neck fracture. Six weeks postoperatively, an AP radiograph of the ankle reveals a subchondral radiolucent band extending across the dome of the talus. What is the clinical significance of this radiographic finding?

A 35-year-old female presents with knee pain. Radiographs reveal an eccentric, lytic epiphyseal lesion extending to the subchondral bone of the distal femur. Biopsy confirms a Giant Cell Tumor (GCT) of bone.

Which cellular component of this tumor expresses RANKL, serving as the target for medical therapy?

A 55-year-old male who underwent a ceramic-on-ceramic total hip arthroplasty 3 years ago reports a new 'squeaking' noise from his hip during specific movements. He denies pain, and radiographs show no gross loosening. Which of the following component position factors is most strongly associated with the development of squeaking in ceramic-on-ceramic bearings?

A 42-year-old male is brought to the trauma bay after a crush injury. Pelvic radiographs show widening of the pubic symphysis of 3.5 cm and disruption of the anterior sacroiliac ligaments, but intact posterior sacroiliac ligaments. According to the Young-Burgess classification, which type of pelvic ring injury does this represent?

A 65-year-old female presents with neurogenic claudication and lower back pain. Radiographs reveal a grade I L4-L5 degenerative spondylolisthesis. Which of the following anatomical features is most characteristic of degenerative spondylolisthesis compared to isthmic spondylolisthesis?

Following a flexor tendon repair in Zone 2, a patient experiences bowstringing of the flexor tendons. During the surgical approach, the surgeon aggressively vented the pulley system. Which two annular pulleys are most critical to preserve to prevent bowstringing and loss of mechanical advantage in the finger?

A 6-week-old female infant is diagnosed with developmental dysplasia of the hip (DDH) and placed in a Pavlik harness. During a follow-up visit, the parents report that the infant is no longer actively kicking her left leg, though she cries when the leg is manipulated. Examination shows absent active knee extension on the left. The harness strap positioning is likely causing compression of which structure?

A 24-year-old football player sustains a twisting injury to the knee. On examination, there is a normal posterior sag sign. The dial test demonstrates 15 degrees of increased external rotation compared to the contralateral side at 30 degrees of knee flexion, but symmetrical external rotation at 90 degrees of flexion. What is the most likely diagnosis?

A 40-year-old male sustains a distal femur fracture. CT imaging reveals a coronal plane fracture of the lateral femoral condyle. This specific fracture pattern (Hoffa fracture) is best stabilized with which of the following internal fixation constructs to resist the primary deforming forces?

Within articular cartilage, which structural landmark separates the deep uncalcified zone from the calcified cartilage zone and serves as the physical barrier to the transport of nutrients from the subchondral bone?

A 58-year-old male with poorly controlled type 2 diabetes presents with a swollen, erythematous, and warm left foot. Radiographs reveal fragmentation of the tarsometatarsal joints, periarticular debris, and joint subluxation, but no skin ulceration. According to the Eichenholtz classification, what is the most appropriate initial management for this patient?

A 14-year-old boy presents with pain and swelling in the mid-shaft of his femur. Radiographs display a permeative, diaphyseal lytic lesion with an 'onion-skin' periosteal reaction. Biopsy reveals small, round, blue cells. Which chromosomal translocation is most characteristically associated with this malignancy?

A 2-week-old male infant presents with idiopathic congenital talipes equinovarus (clubfoot).

The pediatric orthopedist plans to initiate Ponseti serial casting. According to the Ponseti method, what is the correct sequential order of deformity correction?

An 11-year-old male with a body mass index (BMI) in the 99th percentile presents with left hip pain and an obligatory external rotation during hip flexion. He is diagnosed with a slipped capital femoral epiphysis (SCFE). Which of the following is considered an absolute indication for prophylactic pinning of the contralateral, asymptomatic hip?

A 35-year-old male is brought to the trauma bay following a high-speed motorcycle collision. A pelvic binder was placed in the field. Anteroposterior (AP) pelvis radiograph reveals an anterior-posterior compression (APC) injury.

His pubic symphysis is widened by 3.5 cm, but the posterior pelvic ring appears grossly intact on initial imaging. In an APC-II pelvic ring injury, which of the following ligamentous structures remains intact?

A 14-year-old boy presents with progressive pain and swelling in his mid-thigh over the last two months. Radiographs reveal a permeative, diaphyseal lytic lesion with an 'onion skin' periosteal reaction.

Biopsy demonstrates uniform, small round blue cells. What is the most common chromosomal translocation associated with this patient's diagnosis?

A 55-year-old carpenter presents with a long history of dominant wrist pain. Radiographs demonstrate advanced scapholunate advanced collapse (SLAC).

The surgeon is deciding between a four-corner fusion and a proximal row carpectomy (PRC). Which of the following radiographic findings represents an absolute contraindication to performing a proximal row carpectomy?

A 65-year-old female complains of progressive clumsiness in her hands, difficulty buttoning her shirts, and a feeling of unsteadiness when walking.

Physical examination reveals hyperreflexia and a positive Hoffmann sign. How is the Hoffmann sign elicited on physical examination?

A 22-year-old male rugby player is evaluated for recurrent anterior shoulder instability. He has had 5 dislocations over the past year. A CT scan of his shoulder indicates 28% anterior glenoid bone loss. What is the most appropriate surgical treatment to minimize his risk of recurrent dislocation?

A 60-year-old male who underwent an uncomplicated total hip arthroplasty (THA) 3 years ago presents to the clinic complaining of a high-pitched squeaking noise coming from his hip when he walks or bends over. He denies any pain, instability, or trauma. Based on this presentation, what bearing surface combination was most likely utilized in his THA?

A 55-year-old male with poorly controlled type 2 diabetes presents with a unilaterally swollen, red, and warm right foot. He denies any ulceration or systemic signs of infection. Radiographs demonstrate fragmentation of the midfoot bones, subchondral debris, and joint subluxation. According to the Eichenholtz classification, the patient is currently in Stage I (Developmental). What is the gold standard initial management?

According to Perren's strain theory of bone healing, the process of primary bone healing (direct remodeling by osteonal cutting cones without callus formation) depends heavily on the mechanical environment. For primary bone healing to occur, the interfragmentary strain must remain below which of the following thresholds?

A 2-year-old girl is brought to the pediatric orthopedic clinic by her parents due to worsening bilateral 'bowlegs.' Radiographs reveal a metaphyseal-diaphyseal angle of 18 degrees on the right and 19 degrees on the left, along with medial physeal beaking.

She is diagnosed with infantile Blount disease (tibia vara). What is the most appropriate initial management?

A 45-year-old female presents to the emergency department after falling on an outstretched hand. Radiographs show a fracture of the distal radius involving the volar rim, with the carpus subluxated volarly along with the fracture fragment. Which eponymous term correctly describes this injury pattern?

A 30-year-old female presents with a painful lytic epiphyseal lesion of the distal femur. Biopsy confirms the diagnosis of Giant Cell Tumor of bone. Due to the proximity to the joint space and the large size of the defect, the multidisciplinary tumor board recommends neoadjuvant treatment with Denosumab to downstage the tumor prior to intralesional curettage. What is the precise mechanism of action of Denosumab?

A 25-year-old male rugby player attempts to tackle an opponent by grabbing his jersey. He feels a sudden 'pop' in his right ring finger and presents unable to actively flex the distal interphalangeal (DIP) joint. Radiographs demonstrate a large bony avulsion fragment located volar to the proximal interphalangeal (PIP) joint, failing to retract completely into the palm. According to the Leddy-Packer classification, what type of flexor digitorum profundus (FDP) avulsion injury is this?

A 68-year-old female presents with recurrent posterior dislocations following a primary total hip arthroplasty performed 6 months ago.

A recent CT scan evaluating component positioning reveals an acetabular component inclination of 45 degrees and an anteversion of 0 degrees. The femoral stem has 15 degrees of anteversion. What is the most likely underlying cause of her recurrent instability?

A 21-year-old collegiate soccer player is undergoing anterior cruciate ligament (ACL) reconstruction. The surgeon discusses various graft options and their respective morbidity profiles. Which of the following complications is most specifically associated with the use of a bone-patellar tendon-bone (BTB) autograft compared to a multi-strand hamstring autograft?

Articular cartilage depends on a highly organized extracellular matrix to resist compressive loads. Which of the following is the most abundant proteoglycan found in articular cartilage, functioning to provide compressive stiffness through its massive water-binding capacity when complexed with hyaluronic acid?

A 40-year-old male sustains an acute, complete rupture of the Achilles tendon while playing tennis. He opts for non-operative management utilizing functional rehabilitation with early range of motion. Compared to traditional open surgical repair, which of the following best describes the expected outcome of his non-operative approach based on recent prospective trials?

A 72-year-old male complains of an insidious onset of bilateral buttock and posterior thigh pain that worsens after walking two blocks or standing for 15 minutes.

He notices immediate relief when he sits down on a bench or leans forward onto his grocery shopping cart. What physical examination finding is most characteristic of this patient's underlying condition?

A 28-year-old male is admitted after suffering a closed, highly comminuted tibia fracture from a motor vehicle accident. Twelve hours post-admission, he develops severe, unrelenting leg pain out of proportion to the injury. His systemic blood pressure is 115/70 mmHg. Intracompartmental pressure monitoring of the anterior compartment yields a pressure of 45 mmHg. What is the patient's delta P (ΔP), and what is the most appropriate next step in management?

A 6-year-old boy presents with a 3-month history of a painless limp.

Radiographs demonstrate fragmentation and increased sclerosis of the capital femoral epiphysis, consistent with Legg-Calvé-Perthes disease. The lateral pillar classification (Herring) is widely utilized to determine the prognosis of this condition. This classification system relies on evaluating the height of which specific portion of the capital femoral epiphysis on an anteroposterior (AP) radiograph?

Which Bone Morphogenetic Protein (BMP) is most closely associated with the FDA-approved indication for use in acute, open tibial shaft fractures?

A 45-year-old female presents with sudden onset medial knee pain while squatting. MRI shows a medial meniscus posterior root tear. Biomechanically, what is the consequence of this specific injury on the knee joint?

A 35-year-old male sustains a distal femur fracture. CT scan reveals a coronal plane fracture of the lateral femoral condyle.

Which surgical approach is most appropriate for direct visualization and reduction of this specific intra-articular fragment?

During a total knee arthroplasty, the surgeon evaluates the gaps after initial bony resections. The extension gap is symmetric and perfectly balanced, but the flexion gap is tight medially and loose laterally. What is the most appropriate next step to balance the knee?

A 42-year-old male presents with severe lower back pain, bilateral sciatica, and new-onset urinary retention (post-void residual greater than 500 mL). MRI confirms a massive L4-L5 central disc herniation. Current literature suggests that surgical decompression is ideally performed within what timeframe to maximize the chance of urologic recovery?

A 30-year-old female presents with knee pain. Radiographs show an eccentric, lytic epiphyseal lesion of the proximal tibia.

Biopsy reveals multinucleated giant cells in a background of mononuclear stromal cells. What is the primary molecular target of the systemic therapy commonly used to treat unresectable cases of this tumor?

A 13-year-old obese boy presents with left thigh pain and an obligatory external rotation of the left hip during flexion.

He is diagnosed with a Slipped Capital Femoral Epiphysis (SCFE). Which of the following is considered an absolute indication for prophylactic pinning of the contralateral asymptomatic hip?

Which of the following best defines 'stress relaxation' in the context of orthopedic biomechanics and viscoelastic materials?

A 28-year-old carpenter sustains a laceration to his volar index finger at the level of the proximal phalanx, transecting both the FDS and FDP tendons. This injury corresponds to which flexor tendon zone?

A 45-year-old male is brought to the ED after a motorcycle crash. His pelvis is unstable. Radiographs show symphyseal diastasis of 3.5 cm and widening of the anterior sacroiliac joints, but the posterior SI ligaments remain intact.

According to the Young-Burgess classification, what type of injury is this?

A 55-year-old diabetic male presents with a swollen, erythematous, and warm left foot. Radiographs demonstrate periarticular debris, fragmentation, and joint subluxation at the tarsometatarsal joints. According to the Eichenholtz classification of Charcot arthropathy, what stage does this represent?

You are treating an infant with idiopathic congenital talipes equinovarus using the Ponseti method.

What is the correct sequence of deformity correction?

A 25-year-old male undergoes an isolated posterior cruciate ligament (PCL) reconstruction using an anterolateral bundle (ALB) single-bundle technique. At what degree of knee flexion should the ALB graft be tensioned and fixed to best replicate native biomechanics?

Which bearing surface combination in Total Hip Arthroplasty (THA) is associated with the lowest volumetric wear rate in laboratory simulator studies?

Articular cartilage has specialized zones with varying structure and function. Which of the following best describes the collagen fiber orientation and primary collagen type in the superficial zone of articular cartilage?

A 32-year-old female falls from a height and sustains a talar neck fracture with subtalar and tibiotalar joint dislocation, but the talonavicular joint remains intact.

What is the Hawkins classification of this fracture and the approximate associated risk of avascular necrosis (AVN)?

A 60-year-old male presents with dorsal midfoot pain and limited dorsiflexion of the great toe. Radiographs demonstrate dorsal osteophytes and joint space narrowing at the first metatarsophalangeal (MTP) joint, consistent with Coughlin and Shurnas Grade 3 hallux rigidus. Conservative management has failed. What is the most reliable surgical treatment for long-term pain relief?

A 72-year-old male with known cervical spondylosis is involved in a hyperextension motor vehicle accident. He presents with bilateral upper extremity weakness (hands worse than arms) and relative sparing of lower extremity strength. What is the classic anatomic explanation for this specific pattern of weakness?

De Quervain's tenosynovitis involves inflammation of the first dorsal compartment of the wrist. Which tendons are located within this compartment?

A 14-year-old boy presents with a permeative lytic lesion in the diaphysis of the femur with an 'onion skin' periosteal reaction. A biopsy confirms small blue round cells. Which chromosomal translocation is pathognomonic for this tumor?

A 55-year-old poorly controlled diabetic male presents with a massively swollen, warm, and erythematous right foot. He denies any recent trauma or open wounds. Laboratory studies reveal a normal white blood cell count and normal inflammatory markers. Radiographs demonstrate fragmentation and subluxation at the tarsometatarsal joints. What is the most appropriate initial management for this condition?

A 30-year-old male is involved in a motor vehicle collision. A cervical spine CT reveals bilateral pars interarticularis fractures of C2 with 4 mm of anterior translation and slight angulation of C2 on C3. The presumed mechanism is hyperextension and axial loading followed by severe flexion. According to the Levine-Edwards classification, what type of fracture does this represent?

A 13-year-old female undergoes in situ percutaneous pinning for a stable slipped capital femoral epiphysis (SCFE). Six months postoperatively, she presents with progressive hip stiffness, pain, and a severely restricted range of motion. Anteroposterior radiographs of the pelvis demonstrate concentric joint space narrowing of the affected hip to less than 3 mm. What is the most likely diagnosis?

A 30-year-old female presents with knee pain. Radiographs reveal an eccentric, lytic, epiphyseal lesion in the distal femur that extends to the subchondral bone without a sclerotic margin. Biopsy reveals numerous multinucleated giant cells interspersed in a background of mononuclear stromal cells. Which cell type represents the true neoplastic component of this tumor?

A 25-year-old male manual laborer complains of persistent dorsal, central wrist pain. Radiographs show sclerosis of the lunate with preservation of its height and architecture. Ulnar variance is determined to be negative 2 mm. What is the most appropriate surgical intervention to halt disease progression?

A 60-year-old male who underwent a metal-on-metal total hip arthroplasty 8 years ago presents with groin pain and a palpable anterior mass. Serum cobalt and chromium levels are significantly elevated. A MARS MRI shows a thick-walled, cystic mass communicating with the joint. What is the characteristic histological finding associated with this condition?

A 22-year-old collegiate athlete undergoes an anterior cruciate ligament (ACL) reconstruction using a bone-patellar tendon-bone autograft. During the biological process of 'ligamentization', at approximately what postoperative time frame does the graft reach its nadir of mechanical strength, placing the patient at highest risk for traumatic rupture?

A 28-year-old female is involved in a high-speed collision. She sustains a talar neck fracture with complete subluxation of the subtalar joint; however, the tibiotalar (ankle) joint remains congruous. Based on the Hawkins classification, what is the approximate risk of avascular necrosis (AVN) of the talar body?

An adult tibia shaft fracture is treated with a statically locked intramedullary nail, creating a biomechanical environment that allows for micromotion at the fracture site. This environment promotes secondary bone healing. What is the correct physiological sequence of secondary bone healing?

A 25-year-old running back sustains a forceful plantarflexion injury to his foot. A weight-bearing AP radiograph reveals a 3 mm diastasis between the base of the first and second metatarsals. He is diagnosed with a Lisfranc injury. Which ligament represents the primary structural stabilizer of this joint complex?

A 45-year-old male presents to the emergency department with acute onset of severe bilateral sciatica, saddle anesthesia, and urinary retention with overflow incontinence following heavy lifting. An urgent MRI reveals a massive L4-L5 disc extrusion causing central canal stenosis and compression of the cauda equina. Surgical decompression should ideally be performed within what time frame to maximize the probability of neurological recovery, particularly bladder and bowel function?

When applying the Ponseti casting method for the conservative management of congenital talipes equinovarus (clubfoot), the deformity is corrected in a specific sequential order. Which component of the deformity is corrected LAST?

A 65-year-old male complains of severe mechanical back pain and profound fatigue. Laboratory tests show anemia, hypercalcemia, and an elevated M-spike on serum protein electrophoresis. Plain radiographs demonstrate multiple 'punched-out' lytic lesions in the skull and spine. What is the current imaging modality of choice to accurately assess the extent of skeletal burden in this disease?

A 30-year-old carpenter sustains a volar laceration over the proximal phalanx of his index finger, severing both the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons (Zone II). Following primary surgical repair, the hand therapist initiates a rehabilitation protocol that uses a dorsal blocking splint, allowing for active extension and utilizing rubber band traction attached to the fingernail to achieve passive flexion. Which protocol is being utilized?

During a primary total knee arthroplasty (TKA), the surgeon determines the rotational alignment of the femoral component. If the surgeon chooses to use the surgical epicondylar axis (SEA) to establish rotation, what specific anatomical landmarks must be connected?

A 25-year-old collegiate baseball pitcher presents with vague, deep shoulder pain and mechanical symptoms (clicking) during the late cocking phase of throwing. A magnetic resonance arthrogram demonstrates a tear of the superior labrum with complete detachment of the biceps tendon anchor from the superior glenoid rim. According to the Snyder classification, this represents which type of SLAP lesion?

A 40-year-old pedestrian is struck by a motor vehicle, sustaining a severe valgus force to the knee. Computed tomography reveals a pure central depression fracture of the lateral tibial plateau, with the lateral cortical rim remaining intact. According to the Schatzker classification system, how is this fracture pattern classified?

Parathyroid hormone (PTH) plays a central role in maintaining systemic calcium homeostasis by acting on bone, kidneys, and the intestines. What is the direct mechanism by which continuously elevated PTH levels stimulate bone resorption?

A 35-year-old recreational athlete sustains an acute tear of his Achilles tendon during a tennis match. After discussing the risks and benefits, he chooses non-operative management utilizing a modern early functional rehabilitation protocol. Historically, compared to primary open surgical repair, non-operative management carries a significantly higher risk of which of the following complications?

A 65-year-old male presents with bilateral hand clumsiness, gait instability, and frequent falls. Physical examination reveals hyperreflexia in all four extremities, a positive Hoffman sign bilaterally, and an unsteady, broad-based gait. He requires the use of a cane at all times to ambulate safely, but he is not restricted to a wheelchair. What is his Nurick classification grade for cervical spondylotic myelopathy?

A 35-year-old male presents with a progressive, dull ache in his proximal femur. Radiographs reveal a lytic lesion in the femoral head epiphysis with a sclerotic margin. Biopsy shows tumor cells with abundant clear cytoplasm and central nuclei, interspersed with coarse woven bone and osteoclast-like giant cells. What is the most appropriate treatment?

A 28-year-old male is involved in a high-speed MVC and sustains a neck injury. CT scan shows a fracture through the pars interarticularis of C2 bilaterally. There is 4 mm of anterior translation of C2 on C3, and 12 degrees of severe kyphotic angulation.

According to the Levine-Edwards classification, what is the injury type and the recommended initial treatment?

A 24-year-old football player falls forward over his plantar-flexed foot. He complains of severe midfoot pain. Radiographs demonstrate a small avulsion fracture at the base of the second metatarsal.

The ligament primarily injured in this pathology originates from which structure and inserts onto which structure?

A 65-year-old female presents with severe base of thumb pain. Radiographs reveal advanced thumb carpometacarpal (CMC) joint arthritis with complete loss of joint space, significant subluxation, and cystic changes. Additionally, there is complete loss of joint space and osteophyte formation at the scaphotrapezial trapezoid (STT) joint. According to the Eaton-Littler classification, what stage is this disease?

A 9-year-old boy with panhypopituitarism and a BMI of 32 presents with right knee pain and a limp. He is diagnosed with a right slipped capital femoral epiphysis (SCFE).

Which of the following is the strongest indication for prophylactic in situ pinning of his contralateral asymptomatic left hip?

Bone Morphogenetic Proteins (BMPs) are used as osteoinductive agents in spine fusions and nonunion surgery. Which of the following BMPs is an FDA-approved recombinant protein utilized in anterior lumbar interbody fusion (ALIF) within a specific carrier?

A 42-year-old male sustains a high-energy distal tibia pilon fracture.

An anterolateral surgical approach is planned for open reduction and internal fixation. During this approach, which nerve is at greatest risk of iatrogenic injury as it crosses the operative field?

A 28-year-old athlete undergoes evaluation for a knee injury. MRI confirms an isolated tear of the posterior cruciate ligament (PCL). Which of the following statements regarding the biomechanics of the PCL is correct?

A 55-year-old male who underwent a metal-on-metal total hip arthroplasty 6 years ago presents with new-onset groin pain and a palpable mass. Workup reveals an aseptic lymphocyte-dominated vasculitis-associated lesion (ALVAL). Which type of hypersensitivity reaction is the primary driver of this pathology?

A 19-year-old male presents with severe night pain in his right mid-tibia that is predictably relieved by ibuprofen.

Imaging shows a 0.8 cm radiolucent nidus surrounded by dense reactive sclerosis. The pain associated with this lesion is mediated by the overproduction of which of the following?

A 32-year-old female falls from a height. CT of the lumbar spine reveals an L1 burst fracture. There is splaying of the spinous processes on the AP radiograph. MRI confirms disruption of the posterior ligamentous complex (PLC). Neurological examination is completely normal. According to the Thoracolumbar Injury Classification and Severity (TLICS) score, what is her total score and the recommended management?

A 40-year-old manual laborer presents with central dorsal wrist pain.

Radiographs show sclerosis and early collapse of the lunate, without fixed scaphoid rotation or pan-carpal arthritis. Ulnar variance is -3mm. According to the Lichtman classification, this represents Stage IIIa Kienbock's disease. Which of the following is the most appropriate surgical intervention?

A 58-year-old patient with poorly controlled diabetes mellitus presents with a swollen, erythematous, and warm right foot.

Radiographs reveal extensive periarticular debris, fragmentation of the tarsal bones, and early subluxation at the midfoot. According to the Eichenholtz classification, what stage of Charcot arthropathy is this, and what is the most appropriate initial treatment?

In a 7-year-old boy diagnosed with Legg-Calve-Perthes disease (LCPD), AP pelvis radiographs are obtained during the fragmentation phase.

The lateral pillar of the femoral head maintains exactly 40% of its normal height. According to the Herring lateral pillar classification, what group does this patient fall into, and what is the general prognosis?

Articular cartilage is highly specialized to withstand compressive and shear forces. Within the deep (basal) zone of articular cartilage, how is the type II collagen network primarily oriented relative to the articular surface?

A 38-year-old skier falls and twists her knee. Radiographs and CT show a fracture of the lateral tibial plateau characterized by a split wedge fragment with central articular depression.

According to the Schatzker classification, what type of fracture is this?

During a primary total knee arthroplasty (TKA), after making all bone cuts and placing trial components, the surgeon assesses the gaps. The knee is noted to be perfectly balanced and appropriately tensioned in full extension but is excessively tight in 90 degrees of flexion. Which of the following component adjustments is the most appropriate to correct this mismatch?

A 29-year-old female presents with knee pain. Radiographs show an eccentric, lytic lesion in the distal femoral epiphysis extending into the metaphysis.

Biopsy confirms a Giant Cell Tumor of bone. Neoadjuvant therapy with denosumab is considered. What is the mechanism of action of this medication?

A 45-year-old man presents with chronic wrist pain and a history of a scaphoid fracture 10 years ago. Radiographs demonstrate a scaphoid nonunion. There is radioscaphoid arthritis and narrowing of the scaphocapitate joint, but the lunocapitate and radiolunate joints are completely preserved. According to the Scaphoid Nonunion Advanced Collapse (SNAC) classification, what is the stage of his arthritis?

A 45-year-old male feels a 'pop' in his posterior knee while squatting. MRI reveals a radial tear at the attachment site of the posterior horn of the medial meniscus.

Biomechanical studies indicate that a complete posterior root tear of the medial meniscus leads to which of the following?