Differential Diagnosis for Medial Knee Pain
- Single most likely diagnosis
- Medial meniscus tear: The patient's symptoms of medial knee pain that worsens with stair climbing, along with physical examination findings of swelling and point tenderness inferior and medial to the patella, are consistent with a medial meniscus tear. The meniscus is a common source of knee pain, especially in older adults, and stair climbing can exacerbate the pain due to increased stress on the meniscus.
- Other Likely diagnoses
- Medial collateral ligament (MCL) sprain: The location of the pain and tenderness could also suggest an MCL sprain, which is a common injury in older adults. However, the absence of a reported traumatic event or valgus stress makes this diagnosis less likely.
- Pes anserine bursitis: This condition, characterized by inflammation of the bursa located on the medial aspect of the knee, can cause pain and swelling in the same region. The patient's age and symptoms are consistent with this diagnosis, but the specific location of the tenderness and the worsening of pain with stair climbing make it less likely than a medial meniscus tear.
- Osteoarthritis (OA) of the knee: OA is a common condition in older adults and can cause medial knee pain, especially with activities like stair climbing. However, the presence of point tenderness and swelling suggests a more localized lesion, such as a meniscus tear, rather than the diffuse pain and stiffness typically seen in OA.
- Do Not Miss diagnoses
- Septic arthritis: Although less likely, septic arthritis is a serious condition that requires prompt diagnosis and treatment. The presence of swelling, pain, and point tenderness could be indicative of septic arthritis, especially if the patient has a fever, redness, or warmth around the knee.
- Osteonecrosis: Osteonecrosis of the medial tibial plateau or femoral condyle could cause medial knee pain and should be considered, especially if the patient has a history of steroid use or other risk factors.
- Rare diagnoses
- Medial plica syndrome: This condition, characterized by inflammation of the medial plica (a fold of synovial tissue), can cause medial knee pain and is more common in younger adults. However, it could be considered in this patient if other diagnoses are ruled out.
- Tumor or cyst: A tumor or cyst in the medial aspect of the knee could cause pain and swelling, but this would be a rare cause of the patient's symptoms and would likely require additional imaging or diagnostic tests to confirm.