Differential Diagnosis for Knee Pain in a 12-year-old Boy
- Single most likely diagnosis
- D) Repetitive quadriceps contraction: This is the most likely cause of the findings, as the patient's symptoms and examination results are consistent with Osgood-Schlatter disease, a condition characterized by inflammation of the patellar tendon at its insertion on the tibial tuberosity, often due to repetitive quadriceps contraction in active adolescents.
- Other Likely diagnoses
- B) Increased growth velocity at the start of puberty: This could contribute to the development of Osgood-Schlatter disease, as rapid growth during puberty can lead to inflammation and pain at the sites of tendon insertion.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- A) Bacterial infection of the bone: Although less likely, bacterial infection (osteomyelitis) could present with similar symptoms, including pain and swelling over the affected area, and would require prompt diagnosis and treatment to prevent serious complications.
- E) Trauma causing subperiosteal hemorrhage: While the patient denies a history of trauma, it is essential to consider this possibility, as a subperiosteal hemorrhage could lead to significant morbidity if not recognized and treated appropriately.
- Rare diagnoses
- C) Loss of intraarticular cartilage: This would be an unusual finding in a 12-year-old boy without a history of trauma or systemic disease, and the patient's symptoms and examination results do not suggest intraarticular pathology.
- Other rare diagnoses, such as tumors or systemic diseases, are not suggested by the patient's presentation and would require additional symptoms or findings to be considered.