Pediatric Musculoskeletal Disorders

During a health maintenance visit, a $13$-year-old adolescent male reports a $4$-week history of a constant, dull ache in his left anterior thigh and knee. He has no history of recent trauma, fever, or prior medical conditions. His body mass index is $32 \text{ kg/m}^2$. Vital signs are within normal limits, with a temperature of $36.8^\circ\text{C}$ ($98.2^\circ\text{F}$), heart rate of $78/\text{min}$, and blood pressure of $112/72 \text{ mm Hg}$. On physical examination, the left knee has no effusion, erythema, or joint line tenderness, and range of motion is full and painless. However, his gait is noticeably antalgic, and his left foot rests in an externally rotated position while standing. Passive internal rotation of the left hip is restricted and elicits pain. Laboratory evaluation reveals an erythrocyte sedimentation rate of $9 \text{ mm/h}$, a C-reactive protein level of $0.4 \text{ mg/dL}$, and a leukocyte count of $7,100/\text{mm}^3$. Which of the following is the most appropriate next step in management?

A full-term female infant is delivered vaginally from a breech presentation. The mother has a positive family history of developmental dysplasia of the hip (DDH). The pediatrician is discussing the long-term evaluation and potential treatment plan for this condition with the parents. Assuming the patient will require the complete spectrum of standard medical intervention due to progressive or refractory disease, arrange the following steps in the chronological sequence they would be appropriately performed, starting from birth and progressing through late infancy.

A worried father brings his $4$-year-old son to the pediatric clinic due to acute-onset refusal to walk over the past $24$ hours. The child was previously healthy except for a mild rhinovirus infection that resolved $10$ days ago. Current vital signs reveal a temperature of $38.9^{\circ}\text{C}$ ($102.0^{\circ}\text{F}$), pulse of $118/\text{min}$, and respirations of $22/\text{min}$. On physical examination, the child is irritable and resists any passive range of motion of the right hip, which is held in a flexed, abducted, and externally rotated position. Laboratory analysis demonstrates a leukocyte count of $14,500/\mu\text{L}$, an erythrocyte sedimentation rate (ESR) of $55 \text{ mm/h}$, and a C-reactive protein (CRP) level of $32 \text{ mg/L}$. Which of the following is the most appropriate next step in the management of this patient?

A variety of pediatric musculoskeletal conditions present with distinct physical examination signs or characteristic resting postures. Match each specific clinical examination finding with the most appropriate underlying diagnosis.

A $15$-month-old boy is brought to the pediatric clinic by his paternal grandmother for a routine evaluation. She expresses significant concern regarding the child's "curved legs" and insists that he requires immediate corrective casting to prevent permanent deformity. The patient's mother, who has sole legal custody and is accessible via phone, previously discussed this finding with the physician and stated she is comfortable with conservative observation. The child began walking independently at $12$ months of age and is currently acquiring new vocabulary. His diet is well-balanced and includes fortified whole milk and a daily multivitamin. Vital signs are within normal limits. Physical examination reveals a happy, well-appearing toddler with symmetric bilateral genu varum (bowlegs). There is no localized tenderness, erythema, or leg-length discrepancy. His gait is steady without limping. A basic metabolic panel, serum calcium, phosphorus, thyroid-stimulating hormone (TSH), and free T4 are all within normal limits. Which of the following is the most appropriate next step in management?

A 3-year-old girl is brought to the emergency department by her mother due to refusal to use her left arm. The mother reports that an hour ago, they were walking on a slippery sidewalk when the child lost her balance. To prevent her from falling to the ground, the mother instinctively pulled up firmly on the child's left hand. Following this, the child immediately began crying and has since refused to bend her elbow or reach for toys. Vital signs include a temperature of $37.0^\circ\text{C}$ ($98.6^\circ\text{F}$), pulse of $105/\text{min}$, and blood pressure of $90/60\text{ mm Hg}$. On physical examination, the child is calm when left undisturbed but holds her left arm adducted against her side with the elbow slightly flexed and the forearm pronated. There is no erythema, ecchymosis, or focal point tenderness upon palpation of the clavicle, shoulder, humerus, elbow, or wrist. As part of the initial triage protocol, point-of-care laboratory studies are obtained and reveal a leukocyte count of $7,200/\text{mm}^3$, an erythrocyte sedimentation rate of $6\text{ mm/hr}$, and a C-reactive protein of $0.3\text{ mg/dL}$. Which of the following is the most appropriate next step in management?

A 2-week-old male infant is evaluated in the pediatric orthopedic clinic for bilateral foot deformities present since birth. Physical examination reveals marked plantar flexion of the ankles, inversion of the heels, and medial deviation of the forefeet. The deformities are rigid and cannot be passively corrected to a neutral, anatomic position. Neurological examination of the lower extremities is unremarkable, and the spine is normal. A diagnosis of idiopathic congenital talipes equinovarus (clubfoot) is made, and the parents agree to proceed with the gold-standard conservative management approach. Arrange the following steps of this treatment protocol (the Ponseti method) in the most appropriate chronological order, from initial intervention to long-term maintenance.