Differential Diagnosis for Pain on Flexion over Medially Below Part of Knee and Incomplete Extension of Knee
- Single Most Likely Diagnosis
- Medial Meniscus Tear: This is the most likely diagnosis due to the location of the pain (medially below the knee) and the symptom of incomplete extension of the knee, which can occur due to mechanical obstruction or pain from a meniscus tear.
- Other Likely Diagnoses
- Medial Ligament Sprain: Pain on the medial aspect of the knee and issues with knee extension could be related to a sprain of the medial ligament, especially if there was a traumatic event or overuse.
- Pes Anserine Bursitis: This condition causes pain on the medial aspect of the knee, below the joint line, and can be exacerbated by flexion, making it a plausible diagnosis.
- Osteoarthritis of the Knee: While more common in older populations, osteoarthritis can cause pain with flexion and issues with full extension of the knee, particularly if the disease is advanced.
- Do Not Miss Diagnoses
- Septic Arthritis: Although less likely, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. It can cause severe pain, limited range of motion, and systemic symptoms like fever.
- Tumor (e.g., Osteosarcoma): While rare, a tumor in the knee region could cause pain and mechanical symptoms, including limited extension. Missing this diagnosis could have severe consequences.
- Rare Diagnoses
- Osgood-Schlatter Disease: Typically seen in adolescents, this condition causes pain below the knee due to inflammation of the patellar tendon at its insertion on the tibia. It's less likely in adults but could be considered in younger patients.
- Sinding-Larsen-Johansson Syndrome: Another condition more common in adolescents, it involves inflammation of the patellar tendon at its origin, leading to knee pain, especially with activity.