Differential Diagnosis for Swelling near Medial Knee into Shin

• Single most likely diagnosis
  • Medial meniscal tear: This is a common injury that can cause swelling and pain in the medial aspect of the knee, potentially radiating down into the shin.
• Other Likely diagnoses
  • Medial ligament sprain: A sprain to the medial collateral ligament can cause swelling and pain in the medial knee area.
  • Prepatellar or pes anserine bursitis: Inflammation of the bursae around the knee can cause localized swelling and may extend down towards the shin.
  • Shin splints (medial tibial stress syndrome): While more commonly associated with the lower shin, shin splints can sometimes cause swelling that extends up towards the knee.
• Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
  • Deep vein thrombosis (DVT): Although less common, DVT can cause swelling in the leg and must be considered due to its potential for severe complications, such as pulmonary embolism.
  • Osteosarcoma or other bone tumors: While rare, bone tumors can cause swelling and must be ruled out, especially in the context of unexplained or persistent swelling.
  • Infection (cellulitis, abscess): Infections can cause significant swelling and require prompt treatment to prevent serious complications.
• Rare diagnoses
  • Popliteal cyst (Baker's cyst) rupture: A ruptured Baker's cyst can cause swelling down the medial aspect of the leg into the shin.
  • Nerve tumors (e.g., schwannoma): Rarely, tumors of the nerves can cause localized swelling and should be considered in the differential diagnosis of unexplained swelling.
  • Vascular malformations: Abnormalities in blood vessels can sometimes cause swelling in specific areas, including the medial knee and shin.