Differential Diagnosis for Knee Pain in a 14-Year-Old
Single Most Likely Diagnosis
- Osgood-Schlatter Disease: This is a common cause of knee pain in adolescents, particularly during growth spurts. It is characterized by inflammation of the patellar tendon at its insertion on the tibial tubercle, leading to pain, swelling, and tenderness below the knee.
Other Likely Diagnoses
- Patellofemoral Pain Syndrome: This condition is characterized by pain around or behind the patella, often related to activities that put stress on the knee, such as jumping, running, or climbing stairs. It is common in adolescents and young adults.
- Medial Collateral Ligament (MCL) Sprain: An MCL sprain can occur from a direct blow to the knee or a sudden twisting motion, leading to pain, swelling, and instability on the medial aspect of the knee.
- Meniscal Tear: A meniscal tear can result from a twisting injury, leading to pain, swelling, and mechanical symptoms such as locking or catching of the knee.
Do Not Miss Diagnoses
- Septic Arthritis: Although less common, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. It presents with severe pain, swelling, redness, and warmth of the knee, often with systemic symptoms such as fever and chills.
- Osteosarcoma: This is the most common primary malignant bone tumor in adolescents, often presenting with pain, swelling, and limited range of motion in the affected limb.
- Slipped Capital Femoral Epiphysis (SCFE): SCFE is a hip condition that can refer pain to the knee. It is characterized by a slip of the femoral head off the femoral neck, leading to pain, limp, and limited range of motion.
Rare Diagnoses
- Juvenile Rheumatoid Arthritis (JRA): Now known as Juvenile Idiopathic Arthritis (JIA), this is a chronic autoimmune disease that can present with knee pain, swelling, and stiffness, often with systemic symptoms.
- Kohler's Disease: A rare condition characterized by avascular necrosis of the tibial tubercle, leading to pain and swelling below the knee.
- Discoid Meniscus: A rare congenital anomaly of the meniscus that can lead to knee pain, snapping, or locking symptoms.