Transient Synovitis of the Hip Patient Profile: •Age: 5 years •Gender: Male •Medical History: Unremarkable; no prior significant illnesses or hospitalizations •Immunizations: Up-to-date •Family History: Non-contributory History of Present Illness: The patient presented with a 3-day history of right hip pain, which began without any known trauma. The pain was initially mild but progressively worsened, leading to a noticeable limp and refusal to bear weight on the right leg. Parents reported that the child had an upper respiratory infection (URI) approximately one week prior, characterized by a runny nose and cough, which resolved without intervention. There were no reports of fever, gastrointestinal symptoms, or recent vaccinations. Physical Examination: •General: Alert and cooperative; appears mildly uncomfortable •Vital Signs: •Temperature: 37.2°C (99°F) •Heart Rate: 100 bpm •Respiratory Rate: 20 breaths per minute •Blood Pressure: 100/60 mmHg •Right Hip Examination: •Inspection: No swelling, erythema, or deformity •Palpation: Tenderness over the anterior hip joint •Range of Motion: Limited internal rotation and abduction due to pain; other movements within normal limits •Gait: Antalgic limp favoring the right side; refuses to bear full weight on the right leg •Neurological Examination: Intact; no focal deficits Diagnostic Workup: •Laboratory Tests: •White Blood Cell Count (WBC): 9,000/µL •Erythrocyte Sedimentation Rate (ESR): 20 mm/hr •C-Reactive Protein (CRP): 1.0 mg/dL •Imaging: •X-ray of the Pelvis and Right Hip: No fractures or bony abnormalities; joint spaces preserved •Ultrasound of the Right Hip: Small effusion noted in the hip joint without synovial thickening Which condition is most likely based on the clinical presentation?