Differential Diagnosis for 12 yo Male with Pain at the Insertion of the Medial Collateral Ligament Knee

• Single Most Likely Diagnosis
  • Medial Tibial Stress Syndrome (Shin Splints): This condition is common in adolescents, especially those involved in sports, and typically presents with pain in the medial aspect of the tibia, which could radiate to the area of the medial collateral ligament insertion.
• Other Likely Diagnoses
  • Medial Collateral Ligament (MCL) Sprain: Direct trauma or valgus stress to the knee can cause an MCL sprain, leading to pain at its insertion site.
  • Osgood-Schlatter Disease: Although it typically affects the tibial tuberosity, the pain can sometimes be referred to the medial aspect of the knee, especially if there's associated medial collateral ligament strain.
  • Medial Meniscal Tear: Tears in the medial meniscus can cause pain in the medial knee, which might be perceived at the MCL insertion, especially with activities that increase pressure on the meniscus.
• Do Not Miss Diagnoses
  • Osteosarcoma: Although rare, osteosarcoma is a malignant bone tumor that can present with pain in the knee area, including the medial aspect. It's crucial to consider this diagnosis to ensure timely treatment if present.
  • Septic Arthritis: Infection within the knee joint can cause severe pain, swelling, and decreased range of motion. Prompt diagnosis and treatment are essential to prevent long-term damage.
  • Fracture: Stress fractures or acute fractures in the medial tibia or femur could present with pain at the MCL insertion site and must be ruled out, especially with a history of trauma.
• Rare Diagnoses
  • Medial Plica Syndrome: This condition involves irritation of the synovial folds within the knee, which can cause medial knee pain.
  • Sinding-Larsen-Johansson Syndrome: Similar to Osgood-Schlatter disease but affects the patellar tendon at its inferior pole, potentially causing referred pain to the medial knee.
  • Popliteal Cyst (Baker's Cyst): Although more commonly associated with posterior knee pain, a large Baker's cyst could potentially cause medial knee pain due to its location and potential to compress adjacent structures.