Pediatric Musculoskeletal Disorders

A 4-year-old boy presents with a 1-day history of right hip pain and refusal to bear weight. His temperature is 38.9°C (102.0°F). Examination shows a toxic-appearing child with the right hip held in flexion, abduction, and external rotation. Initial laboratory testing reveals a white blood cell count of 16,000/mm³, an erythrocyte sedimentation rate (ESR) of 65 mm/h, and a C-reactive protein (CRP) of 8.2 mg/dL. Radiographs of the pelvis are unremarkable. Based on the suspected diagnosis, arrange the following subsequent steps in the correct chronological sequence for the optimal management of this patient.

A 2-year-old girl is brought to the pediatric urgent care clinic by her mother due to sudden right arm pain. Approximately one hour ago, while walking in the park, the child stumbled. To prevent her from falling, the mother reflexively pulled the child up by the right hand. The child immediately began crying and has since refused to move her right arm. Vital signs are within normal limits. On physical examination, the patient is calm when undisturbed but holds her right arm adducted against her body, slightly flexed at the elbow, and pronated. There is no visible swelling, erythema, or deformity of the clavicle, shoulder, elbow, or wrist. Palpation of the radial head elicits mild tenderness. Which of the following is the most appropriate next step in management?

Match each classic clinical presentation with its most likely pediatric musculoskeletal diagnosis.

A 13-year-old boy is brought to the emergency department after experiencing a sudden, severe "pop" and excruciating pain in his left groin while playing basketball. He was unable to continue playing and had to be carried off the court. Over the preceding 8 weeks, he had been complaining of intermittent, mild aching in his left anterior thigh, which he attributed to a muscle strain. He is currently unable to bear any weight on the left leg. On physical examination, his body mass index is 31 kg/m². The left lower extremity is shortened and held in an externally rotated position. Passive range of motion of the left hip is exquisitely painful and globally restricted. Anteroposterior and frog-leg lateral radiographs of the pelvis demonstrate posterior and inferior displacement of the left proximal femoral epiphysis relative to the metaphysis. Compared to his clinical status yesterday, the acute event that occurred today has most significantly increased his risk for developing which of the following complications?

Carefully evaluate the following pediatric musculoskeletal case summaries. Pair each specific clinical profile with the most accurate underlying pathologic diagnosis.

Match each pediatric patient's clinical presentation with the most accurate description of the underlying pathophysiology or anatomic abnormality.

A 2-year-old girl is brought to the urgent care clinic by her father due to a sudden refusal to use her right arm. Thirty minutes ago, the father grabbed the child's right hand to prevent her from stepping into the street while they were walking. The child immediately cried and has since kept her arm close to her side. On physical examination, the child is calm while sitting on her father's lap but cries if her right arm is touched. Her right arm is held closely against her trunk with the elbow slightly flexed and the forearm pronated. There is no visible swelling, bruising, erythema, or obvious deformity of the clavicle, shoulder, elbow, or wrist. Which of the following is the most appropriate next step in management?

A 14-year-old adolescent boy presents to a primary care clinic reporting right anterior knee discomfort that has persisted for the past two months. The patient is an active participant in a competitive youth basketball league. He describes the discomfort as a dull ache that peaks during jumping drills and running, but notably subsides after a few hours of rest. He denies any systemic symptoms such as fever, chills, or weight loss, and reports no history of acute trauma. On physical evaluation, vital signs are within normal limits. Examination demonstrates localized swelling and marked point tenderness directly over the tibial tuberosity. The knee joint itself exhibits no effusion, and both varus and valgus stress testing reveal no laxity. Range of motion is fully preserved. Which of the following is the most appropriate management for this patient's condition?

A 12-year-old boy is brought to the outpatient clinic by his parents due to a 4-week history of dull, aching pain in his left knee. The pain worsens after physical activity and improves with rest. He denies any direct trauma, falls, or fevers. His medical history is unremarkable, and his BMI is 32 kg/m². Vital signs are within normal limits. On physical examination, the patient has an antalgic gait and walks with the left foot pointing slightly outward. Inspection and palpation of the left knee reveal no erythema, swelling, or focal point tenderness. Anterior drawer, posterior drawer, and McMurray tests of the knee are negative. When the patient is placed in the supine position and the left hip is passively flexed to 90 degrees, the thigh obligately rotates externally. Which of the following is the most appropriate next step in diagnosis?

A pediatric resident is reviewing the standard age-appropriate diagnostic and management strategies for Developmental Dysplasia of the Hip (DDH). Arrange the following clinical steps in the correct chronological order, starting from the earliest appropriate age of implementation (newborn) to the latest (> 6 months of age).

A 5-year-old boy is brought to the emergency department with an acute onset of right hip pain and a complete refusal to bear weight. His temperature is 39.2°C (102.6°F). Laboratory studies reveal a leukocyte count of 15,000/mm³ and an erythrocyte sedimentation rate (ESR) of 65 mm/h. Plain radiographs of the pelvis and bilateral lower extremities are unremarkable. Given the high probability of a severe bacterial joint infection based on these clinical and laboratory findings, the medical team proceeds with definitive evaluation and treatment.

Arrange the following interventions in the most appropriate chronological sequence for the management of this patient.

A $3$-year-old girl is brought to the emergency department by her parents due to a sudden refusal to walk since waking up this morning. She has been unusually fussy and had a fever for the past $24$ hours. Her temperature is $39.0^\circ C$ ($102.2^\circ F$). On physical examination, she is lying still on the examination table and keeps her right hip flexed, abducted, and externally rotated. Any passive movement of the right hip elicits severe crying and guarding. There is no history of recent trauma. Arrange the following steps in the most appropriate chronological sequence for the standard diagnostic workup and management of this patient's condition.

A 7-year-old girl is brought to the clinic by her parents due to a worsening "waddling" gait and a limp. The parents first noticed the gait abnormality 8 months ago, but it has become more pronounced recently. The patient does not complain of pain in her hips, knees, or back, and she has no history of trauma. Her parents note that she has been less energetic lately, frequently falling asleep after school, and her teacher reported a decline in her academic performance over the past two terms. She also has a history of chronic constipation requiring daily osmotic laxatives. Her height is at the 3rd percentile for her age, and her weight is at the 85th percentile. Vital signs are within normal limits. Physical examination reveals a wide-based gait. There is restricted internal rotation and abduction of both hips. Neurologic examination shows normal muscle bulk and tone, but deep tendon reflexes demonstrate delayed relaxation phases. Bilateral radiographs of the pelvis demonstrate symmetric fragmentation, flattening, and sclerosis of both capital femoral epiphyses. Which of the following is the most appropriate next step in evaluating the underlying cause of this patient's orthopedic findings?

A 16-month-old male toddler is carried into the acute care clinic by his father because he has been completely unwilling to stand or bear weight on his legs since yesterday evening. The father states that the child was previously healthy and recently started attending a new daycare center. Over the past 24 hours, the toddler has become increasingly irritable, refuses to eat, and feels very warm to the touch. Vital signs show a heart rate of 138/min, respiratory rate of 26/min, and a temperature of 39.3°C (102.7°F). On physical examination, the child cries inconsolably when the physician attempts passive range of motion of the right lower extremity. The right hip is held in a rigidly flexed, abducted, and externally rotated position. Laboratory testing reveals a leukocyte count of 17,200/mm³ and an erythrocyte sedimentation rate of 72 mm/hr. Which of the following represents the most appropriate immediate management for this patient?

A 13-year-old obese boy presents to the emergency department with a 3-week history of vague right thigh and knee pain. Today, the pain acutely worsened after he slipped and fell on a wet floor, and he is now completely unable to bear weight on his right leg. On physical examination, the right leg is held in external rotation. When the examiner passively flexes the right hip, the leg obligately externally rotates. Arrange the following steps in the optimal chronological sequence for the management of this patient.

An $11$-year-old girl is brought to the outpatient pediatric clinic by her father due to an $8$-week history of right-sided distal thigh and knee pain. The pain is described as a dull ache that worsens with physical activity, particularly after her dance classes, and improves with rest. She has not experienced any preceding trauma, fever, chills, or weight loss. Her past medical history is unremarkable, and she takes no medications. Vital signs show a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), heart rate of $78/\text{min}$, and blood pressure of $112/68 \text{ mm Hg}$. Her body mass index (BMI) is $28.5 \text{ kg/m}^2$ (above the $95^{\text{th}}$ percentile for age). Physical examination reveals a well-appearing girl walking with an antalgic gait. Inspection of the right knee shows no erythema, effusion, or localized tenderness over the tibial tuberosity or joint line. Ligamentous and meniscal testing of the knee is normal. When the patient is placed in the supine position and the right hip is passively flexed, the thigh deviates into obligatory external rotation. Internal rotation of the right hip is limited and elicits discomfort. Laboratory studies reveal a leukocyte count of $7,200/\text{mm}^3$, an erythrocyte sedimentation rate of $8 \text{ mm/h}$, and a C-reactive protein level of $0.3 \text{ mg/dL}$. Which of the following is the most appropriate next step in management?

A 6-month-old female infant is brought to the clinic for a routine well-child examination. The parents have no concerns and report that the infant is feeding well, babbling, and rolling over from front to back. She was born at 39 weeks gestation via uncomplicated spontaneous vaginal delivery to a 28-year-old primigravid woman. Family history is significant for a maternal aunt who required treatment for a hip condition during infancy. On physical examination, the infant's vital signs are within normal limits. She is alert, active, and interactive. Examination of the lower extremities reveals asymmetric thigh and gluteal skin folds. When the infant is placed in the supine position with both hips and knees flexed and feet resting flat on the examining table, the right knee rests visibly lower than the left knee. The Ortolani and Barlow maneuvers do not elicit any clunk or instability. Which of the following is the most appropriate next step in management?

Match the following pediatric clinical vignettes with the most likely diagnosis.

Match the following clinical presentations of pediatric limp and lower extremity pain with their most accurate underlying pathophysiologic description.

A 2-year-old boy is brought to the emergency department due to refusal to walk for the past 12 hours. His parents note he was well yesterday but awoke crying and pointing to his right leg. His current temperature is $39.5^{\circ}C$ ($103.1^{\circ}F$). On examination, the child is irritable, and the right hip is held rigidly in flexion, abduction, and external rotation. Any attempt to move the joint elicits severe distress. Arrange the following diagnostic and therapeutic steps in the most appropriate chronological sequence for managing this patient's condition.