Differential Diagnosis for Left Knee Pain
Single most likely diagnosis
- Osteoarthritis (OA): Given the long-standing nature of the pain (15+ years), the cramping character, and exacerbation with activity, OA is a highly likely diagnosis. OA is a common condition that affects the joints, causing pain, stiffness, and limited mobility, especially in older adults.
Other Likely diagnoses
- Meniscal tear: A meniscal tear could cause cramping pain in the knee, especially with activity. The long duration of symptoms could be due to a chronic tear.
- Ligament sprain: A ligament sprain, such as an MCL or LCL sprain, could cause chronic knee pain, especially with activity.
- Tendinitis: Tendinitis, such as patellar tendinitis or quadriceps tendinitis, could cause cramping pain in the knee, especially with activity.
Do Not Miss (ddxs that may not be likely, but would be deadly if missed.)
- Septic arthritis: Although less likely, septic arthritis is a medical emergency that requires prompt diagnosis and treatment. It can cause severe pain, swelling, and limited mobility in the affected joint.
- Osteonecrosis: Osteonecrosis, also known as avascular necrosis, can cause severe pain and limited mobility in the affected joint. It is a serious condition that requires prompt diagnosis and treatment.
- Tumor: A bone or soft tissue tumor, such as osteosarcoma or synovial sarcoma, can cause chronic pain and limited mobility in the affected joint.
Rare diagnoses
- Complex regional pain syndrome (CRPS): CRPS is a rare condition that can cause chronic pain, swelling, and limited mobility in the affected limb.
- Pseudogout: Pseudogout, also known as calcium pyrophosphate deposition disease (CPPD), is a rare condition that can cause sudden, severe pain and swelling in the affected joint.
- Hemophilic arthropathy: Hemophilic arthropathy is a rare condition that can cause chronic pain and limited mobility in the affected joint, especially in individuals with hemophilia.