Differential Diagnosis for Left Knee Pain and Swelling
Single Most Likely Diagnosis
- Osteoarthritis (OA): The presence of severe medial compartment joint space loss, tricompartmental osteophytes, and quadriceps insertion enthesophyte on the left knee X-ray are classic findings for osteoarthritis. The patient's complaint of left knee pain and swelling also supports this diagnosis.
Other Likely Diagnoses
- Meniscal Tear: Although the X-ray does not directly show a meniscal tear, the joint space loss and osteophytes could be associated with a meniscal tear, which is a common cause of knee pain and swelling.
- Ligamentous Sprain: The absence of an acute fracture and the presence of joint space loss could suggest a ligamentous sprain, particularly if the patient has a history of trauma or injury.
- Bursitis: The swelling and pain in the left knee could be due to bursitis, especially if the patient has a history of repetitive knee movements or direct trauma to the knee.
Do Not Miss Diagnoses
- Deep Vein Thrombosis (DVT): Although the Venus duplex is negative, it is essential to consider DVT in the differential diagnosis, especially if the patient has risk factors such as recent surgery (total knee arthroplasty on the right knee), immobility, or cancer. A negative D-dimer does not entirely rule out DVT.
- Septic Arthritis: The presence of pain, swelling, and joint space loss could suggest septic arthritis, which is a medical emergency. Although the patient does not have a fever or elevated white blood cell count mentioned, it is crucial to consider this diagnosis, especially if the patient has a history of recent joint injection or surgery.
- Osteonecrosis: The patient's history of total knee arthroplasty on the right knee and the presence of joint space loss on the left knee could suggest osteonecrosis, which can be a cause of knee pain and swelling.
Rare Diagnoses
- Hemochromatosis: This rare genetic disorder can cause osteoarthritis-like symptoms, including joint space loss and osteophytes.
- Wilson's Disease: This rare genetic disorder can cause osteoarthritis-like symptoms, including joint space loss and osteophytes, as well as neurological symptoms.
- Charcot Arthropathy: This rare condition can cause joint destruction and deformity, particularly in patients with diabetes or other neuropathic conditions.