Pediatric orthopedic emergencies — MCQs

10 questions

A 6-week-old boy is brought for routine examination at his pediatrician’s office. The patient was born at 39 weeks to a 26-year-old G1P1 mother by normal vaginal delivery. External cephalic version was performed successfully at 37 weeks for breech presentation. Pregnancy was complicated by gestational diabetes that was well-controlled with insulin. The patient’s maternal grandmother has early onset osteoporosis. On physical examination, the left hip dislocates posteriorly with adduction and depression of a flexed femur. An ultrasound is obtained that reveals left acetabular dysplasia and a dislocated left femur. Which of the following is the next best step in management?

A 17-year-old boy is brought to the physician because of progressive right knee pain for the past 3 months. He reports that the pain is worse at night and while doing sports at school. He has not had any trauma to the knee or any previous problems with his joints. His vital signs are within normal limits. Examination of the right knee shows mild swelling and tenderness without warmth or erythema; the range of motion is limited. He walks with an antalgic gait. Laboratory studies show an alkaline phosphatase of 180 U/L and an erythrocyte sedimentation rate of 80 mm/h. An x-ray of the right knee is shown. Which of the following is the most likely diagnosis?

A 6-year-old boy is brought to the physician because of right hip pain that started that afternoon. His mother reports that he has also been limping since the pain developed. He says that the pain worsens when he moves or walks. He participated in a dance recital yesterday, but his mother believes that he was not injured at the time. He was born at term and has been healthy except for an episode of nasal congestion and mild cough 10 days ago. His mother has rheumatoid arthritis and his grandmother has osteoporosis. He is at the 50th percentile for height and 50th percentile for weight. His temperature is 37.5°C (99.6°F), pulse is 105/min, respirations are 16/min, and blood pressure is 90/78 mm Hg. His right hip is slightly abducted and externally rotated. Examination shows no tenderness, warmth, or erythema. He is able to bear weight. The remainder of the examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 12.3 g/dL, a leukocyte count of 8,500/mm3, and an erythrocyte sedimentation rate of 12 mm/h. Ultrasound of the right hip shows increased fluid within the joint. X-ray of the hips shows no abnormalities. Which of the following is the most likely diagnosis?

A 7-year-old boy is brought to the physician by his mother because of a limp for the last 3 weeks. He has also had right hip pain during this period. The pain is aggravated when he runs. He had a runny nose and fever around a month ago that resolved with over-the-counter medications. He has no history of serious illness. His development is adequate for his age. His immunizations are up-to-date. He appears healthy. He is at the 60th percentile for height and at 65th percentile for weight. Vital signs are within normal limits. Examination shows an antalgic gait. The right groin is tender to palpation. Internal rotation and abduction of the right hip is limited by pain. The remainder of the examination shows no abnormalities. His hemoglobin concentration is 11.6 g/dL, leukocyte count is 8,900/mm3, and platelet count is 130,000/mm3. An x-ray of the pelvis is shown. Which of the following is the most likely underlying mechanism?

A patient presents to the emergency department with arm pain. The patient recently experienced an open fracture of his radius when he fell from a ladder while cleaning his house. Surgical reduction took place and the patient's forearm was put in a cast. Since then, the patient has experienced worsening pain in his arm. The patient has a past medical history of hypertension and asthma. His current medications include albuterol, fluticasone, loratadine, and lisinopril. His temperature is 99.5°F (37.5°C), blood pressure is 150/95 mmHg, pulse is 90/min, respirations are 19/min, and oxygen saturation is 99% on room air. The patient's cast is removed. On physical exam, the patient's left arm is tender to palpation. Passive motion of the patient's wrist and fingers elicits severe pain. The patient's left radial and ulnar pulse are both palpable and regular. The forearm is soft and does not demonstrate any bruising but is tender to palpation. Which of the following is the next best step in management?

A 43-year-old man is brought to the emergency department 40 minutes after falling off a 10-foot ladder. He has severe pain and swelling of his right ankle and is unable to walk. He did not lose consciousness after the fall. He has no nausea. He appears uncomfortable. His temperature is 37°C (98.6°F), pulse is 98/min, respirations are 16/min, and blood pressure is 110/80 mm Hg. He is alert and oriented to person, place, and time. Examination shows multiple abrasions over both lower extremities. There is swelling and tenderness of the right ankle; range of motion is limited by pain. The remainder of the examination shows no abnormalities. An x-ray of the ankle shows an extra-articular calcaneal fracture. Intravenous analgesia is administered. Which of the following is the most appropriate next step in the management of this patient?

A 25-year-old man comes to the physician because of left-sided knee pain for 2 weeks. The pain started while playing basketball after suddenly hearing a popping sound. He has been unable to run since this incident. He has asthma, allergic rhinitis, and had a progressive bilateral sensorineural hearing impairment at birth treated with cochlear implants. His only medication is a salbutamol inhaler. The patient appears healthy and well-nourished. His temperature is 37°C (98.6°F), pulse is 67/min, and blood pressure is 120/80 mm Hg. Examination of the left knee shows medial joint line tenderness. Total knee extension is not possible and a clicking sound is heard when the knee is extended. An x-ray of the left knee shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?

A 17-year-old male presents to your office with right knee pain. He is the quarterback of his high school football team and developed the knee pain after being tackled in last night's game. He states he was running with the ball and was hit on the lateral aspect of his right knee while his right foot was planted. Now, he is tender to palpation over the medial knee and unable to bear full weight on the right lower extremity. A joint effusion is present and arthrocentesis yields 50 cc's of clear fluid. Which of the following exam maneuvers is most likely to demonstrate ligamentous laxity?

A 16-year-old man presents to the emergency department with a 2-hour history of sudden-onset abdominal pain. He was playing football when his symptoms started. The patient’s past medical history is notable only for asthma. Social history is notable for unprotected sex with 4 women in the past month. His temperature is 99.3°F (37.4°C), blood pressure is 120/88 mmHg, pulse is 117/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is noted for a non-tender abdomen. Testicular exam reveals a right testicle which is elevated with a horizontal lie and the scrotum is neither swollen nor discolored. Which of the following is the most likely diagnosis?

Q10

A 31-year-old man presents to the Emergency Department with severe left leg pain and paresthesias 4 hours after his leg got trapped by the closing door of a bus. Initially, he had a mild pain which gradually increased to unbearable levels. Past medical history is noncontributory. In the Emergency Department, his blood pressure is 130/80 mm Hg, heart rate is 87/min, respiratory rate is 14/min, and temperature is 36.8℃ (98.2℉). On physical exam, his left calf is firm and severely tender on palpation. The patient cannot actively dorsiflex his left foot, and passive dorsiflexion is limited. Posterior tibial and dorsalis pedis pulses are 2+ in the right leg and 1+ in the left leg. Axial load does not increase the pain. Which of the following is the best next step in the management of this patient?

Pediatric orthopedic emergencies US Medical PG Practice Questions and MCQs

Question 1: A 6-week-old boy is brought for routine examination at his pediatrician’s office. The patient was born at 39 weeks to a 26-year-old G1P1 mother by normal vaginal delivery. External cephalic version was performed successfully at 37 weeks for breech presentation. Pregnancy was complicated by gestational diabetes that was well-controlled with insulin. The patient’s maternal grandmother has early onset osteoporosis. On physical examination, the left hip dislocates posteriorly with adduction and depression of a flexed femur. An ultrasound is obtained that reveals left acetabular dysplasia and a dislocated left femur. Which of the following is the next best step in management?

A. Pavlik harness (Correct Answer)
B. Closed reduction and spica casting
C. Observation
D. Physiotherapy
E. Open reduction and femoral osteotomy

Explanation: ***Pavlik harness*** - A Pavlik harness is the **gold standard treatment** for **developmental dysplasia of the hip (DDH)** in infants younger than 6 months. It maintains the hips in a **flexed and abducted position**, promoting proper acetabular development and hip reduction. - The patient's age (6 weeks), clear diagnosis of **acetabular dysplasia**, and a dislocated hip on ultrasound make the Pavlik harness the **most appropriate and least invasive initial treatment**. *Closed reduction and spica casting* - This treatment is typically reserved for children older than 6 months or those who **fail Pavlik harness treatment**. - It involves a more aggressive reduction technique, often requiring **anesthesia**, and is followed by prolonged immobilization in a **spica cast**. *Observation* - **Observation is not appropriate** for a 6-week-old infant with a **diagnosed dislocated hip** and **acetabular dysplasia**. - Untreated DDH can lead to **permanent hip instability**, pain, and early arthritis. *Physiotherapy* - While physiotherapy may play a role in rehabilitation after other interventions, it is **not sufficient as a primary treatment** for a dislocated hip in an infant. - It cannot achieve or maintain the necessary **reduction and stabilization** required for proper hip development. *Open reduction and femoral osteotomy* - This is an **invasive surgical procedure** typically reserved for older children (older than 18-24 months) or in cases of **failed non-operative management** and closed reduction, especially in irreducible or severely dysplastic hips. - It involves directly opening the joint to reduce the hip and may include reshaping bone (osteotomy) to improve hip stability. This is **premature** for a 6-week-old.

Question 2: A 17-year-old boy is brought to the physician because of progressive right knee pain for the past 3 months. He reports that the pain is worse at night and while doing sports at school. He has not had any trauma to the knee or any previous problems with his joints. His vital signs are within normal limits. Examination of the right knee shows mild swelling and tenderness without warmth or erythema; the range of motion is limited. He walks with an antalgic gait. Laboratory studies show an alkaline phosphatase of 180 U/L and an erythrocyte sedimentation rate of 80 mm/h. An x-ray of the right knee is shown. Which of the following is the most likely diagnosis?

A. Chordoma
B. Chondrosarcoma
C. Osteosarcoma (Correct Answer)
D. Osteochondroma
E. Ewing sarcoma

Explanation: ***Osteosarcoma*** - This diagnosis is supported by the **progressive knee pain** worsening at night and with activity, **elevated alkaline phosphatase** and **ESR**, and the X-ray findings typical of an osteosarcoma (e.g., **Codman's triangle**, **sunburst appearance**, or **periosteal elevation**). - It commonly presents in adolescents, typically in the **metaphysis of long bones** (like the distal femur or proximal tibia), and the presence of mild swelling, tenderness, and limited range of motion align with a rapidly growing bone tumor. *Chordoma* - This is a rare, malignant tumor typically arising from notochord remnants, usually seen in the **sacrococcygeal region** or **skull base**, not the knee. - It usually presents in older adults (30-60 years) and would not have the characteristic X-ray findings seen in this case. *Chondrosarcoma* - Characterized by the formation of **cartilage-producing tumors**, typically affecting older adults (40-70 years) and often the **pelvis and proximal long bones**, rather than the knee in an adolescent. - While it causes pain and swelling, the radiographic features generally show **calcified cartilaginous matrix** (arc and ring pattern) rather than the aggressive periosteal reaction associated with osteosarcoma. *Osteochondroma* - This is a **benign cartilaginous tumor** that usually presents as a **painless, solitary mass** near a joint, only causing pain if it irritates surrounding structures or fractures. - The X-ray image would show a **bony outgrowth covered by cartilage** pointing away from the joint, which is distinctly different from the lytic and blastic changes of an osteosarcoma, and it would not typically cause elevated inflammatory markers. *Ewing sarcoma* - While Ewing sarcoma can occur in the knee and presents with pain, swelling, and systemic symptoms, it typically has an **"onion-skin" periosteal reaction** on X-ray, which is distinct from the aggressive sunburst pattern or Codman's triangle seen in osteosarcoma. - It is more commonly associated with a **diaphyseal location** in long bones and can sometimes show a large soft tissue mass.

Question 3: A 6-year-old boy is brought to the physician because of right hip pain that started that afternoon. His mother reports that he has also been limping since the pain developed. He says that the pain worsens when he moves or walks. He participated in a dance recital yesterday, but his mother believes that he was not injured at the time. He was born at term and has been healthy except for an episode of nasal congestion and mild cough 10 days ago. His mother has rheumatoid arthritis and his grandmother has osteoporosis. He is at the 50th percentile for height and 50th percentile for weight. His temperature is 37.5°C (99.6°F), pulse is 105/min, respirations are 16/min, and blood pressure is 90/78 mm Hg. His right hip is slightly abducted and externally rotated. Examination shows no tenderness, warmth, or erythema. He is able to bear weight. The remainder of the examination shows no abnormalities. Laboratory studies show a hemoglobin concentration of 12.3 g/dL, a leukocyte count of 8,500/mm3, and an erythrocyte sedimentation rate of 12 mm/h. Ultrasound of the right hip shows increased fluid within the joint. X-ray of the hips shows no abnormalities. Which of the following is the most likely diagnosis?

A. Transient synovitis (Correct Answer)
B. Osteomyelitis
C. Slipped capital femoral epiphysis
D. Developmental dysplasia of the hip
E. Legg-Calve-Perthes disease

Explanation: ***Transient synovitis*** - This is the most likely diagnosis given the **recent viral illness**, acute onset of hip pain and limp, and **normal inflammatory markers** (WBC, ESR). Ultrasound showing **increased joint fluid** further supports this benign, self-limiting condition. - The hip being held in **abduction and external rotation** is a common compensatory posture to maximize joint space and minimize pain in transient synovitis. *Osteomyelitis* - This would typically present with **fever**, significant systemic symptoms, and **elevated inflammatory markers** (ESR, CRP), which are absent here. - Imaging might show bone changes, and the child would likely be **unable to bear weight** due to severe pain. *Slipped capital femoral epiphysis* - SCFE typically affects **adolescents** (obese males) and presents with chronic, progressive pain. - X-rays would show a **displacement of the femoral head** from the femoral neck, which is not noted in this case. *Developmental dysplasia of the hip* - This is a condition usually diagnosed in **infancy or early childhood** through screening and clinical examination (e.g., Ortolani and Barlow maneuvers), often requiring early intervention. - It would not typically present acutely in a 6-year-old with a recent viral prodrome and normal X-rays. *Legg-Calve-Perthes disease* - This condition involves **avascular necrosis of the femoral head** and typically presents in children between **4 and 8 years old** with a **chronic limp** and hip pain, often worsening over weeks to months. - X-rays would show characteristic changes in the femoral head (e.g., fragmentation, flattening), which are absent in this case.

Question 4: A 7-year-old boy is brought to the physician by his mother because of a limp for the last 3 weeks. He has also had right hip pain during this period. The pain is aggravated when he runs. He had a runny nose and fever around a month ago that resolved with over-the-counter medications. He has no history of serious illness. His development is adequate for his age. His immunizations are up-to-date. He appears healthy. He is at the 60th percentile for height and at 65th percentile for weight. Vital signs are within normal limits. Examination shows an antalgic gait. The right groin is tender to palpation. Internal rotation and abduction of the right hip is limited by pain. The remainder of the examination shows no abnormalities. His hemoglobin concentration is 11.6 g/dL, leukocyte count is 8,900/mm3, and platelet count is 130,000/mm3. An x-ray of the pelvis is shown. Which of the following is the most likely underlying mechanism?

A. Viral infection
B. Bacterial infection of the joint
C. Unstable proximal femoral growth plate
D. Avascular necrosis of the femoral head (Correct Answer)
E. Immune-mediated synovial inflammation

Explanation: ***Avascular necrosis of the femoral head*** - The patient's age (7 years), chronic hip pain and limp, and absence of acute systemic symptoms, along with the **classic X-ray findings of fragmentation and increased density of the femoral epiphysis** (as seen in Legg-Calvé-Perthes disease), strongly indicate avascular necrosis of the femoral head. - This condition is characterized by **interruption of the blood supply to the femoral head**, leading to collapse and deformity. *Viral infection* - While a recent viral infection could cause **transient synovitis**, its symptoms are typically acute and resolve much quicker, usually within 1-2 weeks, unlike the 3-week history here. - Furthermore, **transient synovitis** does not lead to the distinct X-ray changes of avascular necrosis. *Bacterial infection of the joint* - A bacterial infection (septic arthritis) would present with more acute and severe symptoms, including **high fever, significant pain, inability to bear weight**, and elevated inflammatory markers (ESR, CRP). - The X-ray findings would typically show **joint effusion and potentially bone destruction** in later stages, not the specific changes seen in avascular necrosis. *Unstable proximal femoral growth plate* - An unstable proximal femoral growth plate is characteristic of **slipped capital femoral epiphysis (SCFE)**, which typically occurs in adolescent, often obese, children (10-16 years old), **not in a 7-year-old child**. - The X-ray would show **posterior and inferior displacement of the femoral epiphysis**, which is different from the fragmentation and increased density seen here. *Immune-mediated synovial inflammation* - Immune-mediated synovial inflammation, such as **juvenile idiopathic arthritis**, typically presents with **morning stiffness, chronic joint swelling**, and can affect multiple joints. - While it can cause a limp and pain, the **distinctive X-ray findings of avascular necrosis** are not characteristic of this condition.

Question 5: A patient presents to the emergency department with arm pain. The patient recently experienced an open fracture of his radius when he fell from a ladder while cleaning his house. Surgical reduction took place and the patient's forearm was put in a cast. Since then, the patient has experienced worsening pain in his arm. The patient has a past medical history of hypertension and asthma. His current medications include albuterol, fluticasone, loratadine, and lisinopril. His temperature is 99.5°F (37.5°C), blood pressure is 150/95 mmHg, pulse is 90/min, respirations are 19/min, and oxygen saturation is 99% on room air. The patient's cast is removed. On physical exam, the patient's left arm is tender to palpation. Passive motion of the patient's wrist and fingers elicits severe pain. The patient's left radial and ulnar pulse are both palpable and regular. The forearm is soft and does not demonstrate any bruising but is tender to palpation. Which of the following is the next best step in management?

A. Replace the cast with a sling
B. Measurement of compartment pressure (Correct Answer)
C. Ibuprofen and reassurance
D. Emergency fasciotomy
E. Radiography

Explanation: ***Measurement of compartment pressure*** - The patient exhibits classic signs of **compartment syndrome**, including severe pain out of proportion to injury, pain with passive stretching, and a history of trauma followed by casting. Measuring compartment pressure is crucial for diagnosis despite palpable pulses. - Early measurement of compartment pressures can confirm the diagnosis and guide the decision for an **emergency fasciotomy** to prevent irreversible tissue damage. *Replace the cast with a sling* - This action would likely worsen the patient's condition by delaying the diagnosis and treatment of potential **compartment syndrome**. - A sling does not address the underlying issue of increased pressure within the muscle compartments. *Ibuprofen and reassurance* - Administering **Ibuprofen (NSAID)** might mask the pain but will not resolve the increased pressure within the compartment, which is a surgical emergency. - Reassurance without proper assessment of compartment syndrome could lead to irreversible muscle and nerve damage. *Emergency fasciotomy* - While a fasciotomy is the definitive treatment for confirmed compartment syndrome, it should only be performed **after compartment pressures have been measured** and the diagnosis confirmed, unless the clinical suspicion is extremely high and pressures cannot be obtained. - Performing a fasciotomy without objective confirmation is generally not the immediate next step, as it is an invasive procedure with its own risks. *Radiography* - **Radiography** would be useful to assess the healing of the fracture or rule out new fractures, but it will not provide information about the soft tissue pressure changes characteristic of compartment syndrome. - The patient's symptoms are more indicative of a circulatory or soft tissue issue rather than a new bony problem.

Question 6: A 43-year-old man is brought to the emergency department 40 minutes after falling off a 10-foot ladder. He has severe pain and swelling of his right ankle and is unable to walk. He did not lose consciousness after the fall. He has no nausea. He appears uncomfortable. His temperature is 37°C (98.6°F), pulse is 98/min, respirations are 16/min, and blood pressure is 110/80 mm Hg. He is alert and oriented to person, place, and time. Examination shows multiple abrasions over both lower extremities. There is swelling and tenderness of the right ankle; range of motion is limited by pain. The remainder of the examination shows no abnormalities. An x-ray of the ankle shows an extra-articular calcaneal fracture. Intravenous analgesia is administered. Which of the following is the most appropriate next step in the management of this patient?

A. Short leg splint and orthopedic consultation
B. Broad-spectrum antibiotic therapy
C. MRI of the right ankle
D. Open reduction and internal fixation
E. X-ray of the spine (Correct Answer)

Explanation: ***X-ray of the spine*** - A **high-energy calcaneal fracture** (especially from a fall from height) is often associated with other injuries, particularly to the **spine**, due to axial loading. - Approximately **10% of calcaneal fractures** are associated with **lumbar spine compression fractures**, making imaging of the spine an essential next step to rule out this potentially serious concomitant injury. *Short leg splint and orthopedic consultation* - While a **short leg splint** is appropriate for initial immobilization and pain control of the ankle fracture, and **orthopedic consultation** is necessary, these steps do not address the immediate need to exclude other critical injuries like spinal fractures in high-impact trauma. - This option represents definitive management of the ankle rather than comprehensive early trauma assessment in a high-risk patient. *Broad-spectrum antibiotic therapy* - **Antibiotic therapy** is primarily indicated for **open fractures** to prevent infection, or in cases of significant soft tissue injury with high contamination risk; the provided information describes an extra-articular fracture with abrasions, but not explicitly an open fracture requiring immediate broad-spectrum antibiotics. - The focus should first be on skeletal integrity elsewhere and definitive fracture management rather than presumptive infection prevention unless an open fracture is confirmed. *MRI of the right ankle* - While an **MRI** can provide detailed imaging of soft tissues, ligaments, and cartilage, and may be useful later for surgical planning or to assess subtle injuries, a plain **X-ray has already confirmed a calcaneal fracture**. - The immediate priority after a high-energy trauma is to rule out other significant, potentially disabling or life-threatening bony injuries, particularly to the spine, rather than further detailed imaging of the already-identified ankle fracture. *Open reduction and internal fixation* - **Open reduction and internal fixation (ORIF)** is a surgical procedure for definitive management of certain fractures; however, it is not the **immediate next step** in the emergency department for initial patient assessment following trauma. - Before surgical intervention, a comprehensive assessment to rule out other injuries (especially spinal fractures) and to thoroughly plan the specific surgical approach is required.

Question 7: A 25-year-old man comes to the physician because of left-sided knee pain for 2 weeks. The pain started while playing basketball after suddenly hearing a popping sound. He has been unable to run since this incident. He has asthma, allergic rhinitis, and had a progressive bilateral sensorineural hearing impairment at birth treated with cochlear implants. His only medication is a salbutamol inhaler. The patient appears healthy and well-nourished. His temperature is 37°C (98.6°F), pulse is 67/min, and blood pressure is 120/80 mm Hg. Examination of the left knee shows medial joint line tenderness. Total knee extension is not possible and a clicking sound is heard when the knee is extended. An x-ray of the left knee shows no abnormalities. Which of the following is the most appropriate next step in the management of this patient?

A. Reassurance and follow-up
B. Arthrocentesis of the left knee
C. Open meniscal repair
D. Arthroscopy of the left knee
E. MRI scan of the left knee (Correct Answer)

Explanation: ***MRI scan of the left knee*** - The patient's presentation with a **popping sound**, inability to run, **medial joint line tenderness**, limited extension, and a clicking sound suggests a **meniscal tear**, which is not visible on X-ray. - An **MRI scan** is the *most appropriate* next step as it is the **gold standard** for diagnosing meniscal tears and other soft tissue injuries of the knee. *Reassurance and follow-up* - This option is *inappropriate* given the clear signs and symptoms of a **significant knee injury** that warrants further investigation. - Delaying diagnosis and treatment could lead to **worsening of the injury** and chronic pain. *Arthrocentesis of the left knee* - Arthrocentesis involves aspirating joint fluid, which is primarily indicated for diagnosing **septic arthritis** or **gout**, neither of which is suggested by this patient's acute trauma history. - While a meniscal tear can cause an effusion, the primary diagnostic goal here is imaging the soft tissue injury, not analyzing synovial fluid. *Open meniscal repair* - **Open meniscal repair** is a surgical intervention, and it is *premature* to consider surgery before a definitive diagnosis is established. - The *most appropriate* initial step after physical exam and X-ray is often an MRI to confirm the pathology. *Arthroscopy of the left knee* - **Arthroscopy** is both a **diagnostic and therapeutic procedure**, but it is generally reserved after non-invasive imaging like MRI has been performed. - Although it can confirm a meniscal tear, an MRI is less invasive and can provide comparable if not superior detail for surgical planning.

Question 8: A 17-year-old male presents to your office with right knee pain. He is the quarterback of his high school football team and developed the knee pain after being tackled in last night's game. He states he was running with the ball and was hit on the lateral aspect of his right knee while his right foot was planted. Now, he is tender to palpation over the medial knee and unable to bear full weight on the right lower extremity. A joint effusion is present and arthrocentesis yields 50 cc's of clear fluid. Which of the following exam maneuvers is most likely to demonstrate ligamentous laxity?

A. Pivot shift test
B. Varus stress test
C. Anterior drawer test
D. Valgus stress test (Correct Answer)
E. Lachman's test

Explanation: ***Valgus stress test*** - The patient's presentation with a lateral blow to the knee while the foot was planted, tenderness over the **medial knee**, and an effusion strongly suggests an injury to the **medial collateral ligament (MCL)**. - The **valgus stress test** assesses the integrity of the MCL by applying an outward (valgus) force to the knee, checking for excessive gapping on the medial side. *Pivot shift test* - The **pivot shift test** primarily assesses for **anterior cruciate ligament (ACL)** instability, particularly rotational laxity of the tibia on the femur. - While an ACL injury is possible with this mechanism, the specific tenderness to palpation medially points more directly to an MCL injury. *Varus stress test* - The **varus stress test** evaluates the integrity of the **lateral collateral ligament (LCL)** by applying an inward (varus) force to the knee. - This patient's mechanism of injury (lateral blow) and medial tenderness are inconsistent with an isolated LCL injury. *Anterior drawer test* - The **anterior drawer test** assesses the integrity of the **anterior cruciate ligament (ACL)** by pulling the tibia forward on the femur. - While ACL injury is a concern with knee trauma, the focal tenderness on the medial side is not directly evaluated by this test. *Lachman's test* - **Lachman's test** is considered the most reliable clinical test for evaluating the integrity of the **anterior cruciate ligament (ACL)**, even in the acute setting with an effusion. - However, the primary findings of medial tenderness after a lateral blow specifically point to an MCL injury, which is best assessed by the valgus stress test.

Question 9: A 16-year-old man presents to the emergency department with a 2-hour history of sudden-onset abdominal pain. He was playing football when his symptoms started. The patient’s past medical history is notable only for asthma. Social history is notable for unprotected sex with 4 women in the past month. His temperature is 99.3°F (37.4°C), blood pressure is 120/88 mmHg, pulse is 117/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is noted for a non-tender abdomen. Testicular exam reveals a right testicle which is elevated with a horizontal lie and the scrotum is neither swollen nor discolored. Which of the following is the most likely diagnosis?

A. Traumatic urethral injury
B. Seminoma
C. Appendicitis
D. Epididymitis
E. Testicular torsion (Correct Answer)

Explanation: ***Testicular torsion*** - The sudden onset of **unilateral scrotal pain** in an adolescent, accompanied by an **elevated testicle** with a **horizontal lie**, is highly suggestive of testicular torsion. The absence of scrotal swelling or discoloration in the early stages is also consistent. - Testicular torsion is a **surgical emergency** requiring prompt intervention to preserve testicular viability. *Traumatic urethral injury* - This would typically present with **dysuria**, **hematuria**, inability to void, and potentially **blood at the urethral meatus**, none of which are described. - A traumatic urethral injury often results from falls, straddle injuries, or pelvic fractures, not typically from playing football without direct trauma to the perineum. *Seminoma* - Seminoma is a type of **testicular cancer** that typically presents as a **painless testicular mass**. - It would not cause sudden, acute abdominal pain and would not manifest with an acutely elevated testicle and horizontal lie. *Appendicitis* - Although appendicitis can cause abdominal pain, the **non-tender abdomen** on examination and the specific findings on **testicular examination** (elevated testicle, horizontal lie) make appendicitis unlikely. - Appendicitis pain typically localizes to the right lower quadrant, often associated with fever, nausea, and vomiting. *Epididymitis* - Epididymitis causes **scrotal pain** and **swelling**, often with fever and **dysuria**, usually developing over days, not hours. - It is often associated with the **Prehn's sign** (pain relief with elevation of the testicle), which is usually absent or negative in torsion. The patient's sexual history might suggest an STI, but the acute presentation and examination findings point away from epididymitis.

Question 10: A 31-year-old man presents to the Emergency Department with severe left leg pain and paresthesias 4 hours after his leg got trapped by the closing door of a bus. Initially, he had a mild pain which gradually increased to unbearable levels. Past medical history is noncontributory. In the Emergency Department, his blood pressure is 130/80 mm Hg, heart rate is 87/min, respiratory rate is 14/min, and temperature is 36.8℃ (98.2℉). On physical exam, his left calf is firm and severely tender on palpation. The patient cannot actively dorsiflex his left foot, and passive dorsiflexion is limited. Posterior tibial and dorsalis pedis pulses are 2+ in the right leg and 1+ in the left leg. Axial load does not increase the pain. Which of the following is the best next step in the management of this patient?

A. Lower limb CT scan
B. Lower limb ultrasound
C. Splinting and limb rest
D. Fasciotomy (Correct Answer)
E. Lower limb X-ray in two projections

Explanation: ***Fasciotomy*** - The patient presents with classic signs and symptoms of **acute compartment syndrome**, including unrelieved pain by analgesics, paresthesias, pain with passive stretching, and a tense compartment due to the bus door trauma. - **Fasciotomy** is the definitive and urgent treatment to relieve pressure within the muscle compartments, prevent muscle ischemia, and avoid permanent nerve damage or limb loss. *Lower limb CT scan* - A **CT scan** is primarily used to evaluate bony structures and soft tissue injuries but is not the most immediate or definitive diagnostic tool for acute compartment syndrome. - Delaying **fasciotomy** for imaging in a clear case of compartment syndrome can lead to irreversible damage. *Lower limb ultrasound* - **Ultrasound** can assess vascular flow and some soft tissue aspects but is not accurate or rapid enough for diagnosing compartment syndrome. - It would not provide the necessary information to guide urgent surgical intervention. *Splinting and limb rest* - This approach is appropriate for fractures or soft tissue injuries without compartment syndrome; however, in acute compartment syndrome, **splinting or limb rest** will worsen the condition. - **Immobilization** and elevation are contraindicated as they can further decrease blood flow and increase compartment pressure. *Lower limb X-ray in two projections* - An **X-ray** is useful for ruling out fractures but will not provide information about compartment pressure or muscle viability. - While a fracture can sometimes cause compartment syndrome, the immediate concern here is the compartment syndrome itself, for which **X-rays** are not diagnostic.

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