Differential Diagnosis for 16 Year Old Male with Knee Pain, Buckling, and Lower Extremity Weakness
- Single Most Likely Diagnosis
- Osgood-Schlatter disease: This condition is a common cause of knee pain in adolescents, especially during periods of rapid growth. It is characterized by inflammation of the patellar tendon at its insertion on the tibial tubercle, which can cause pain, swelling, and sometimes buckling of the knee.
- Other Likely Diagnoses
- Patellofemoral pain syndrome: This condition is characterized by pain around or behind the patella, often associated with activities that put stress on the knee, such as climbing stairs, squatting, or jumping. It can also cause instability or a feeling of the knee giving way.
- Meniscal injuries: Tears in the menisci, which are cartilage structures in the knee joint, can cause pain, locking, or buckling of the knee. These injuries are common in adolescents who participate in sports.
- Quadriceps or patellar tendonitis: Inflammation of the quadriceps or patellar tendons can cause knee pain and weakness, especially with activities that involve running, jumping, or quick changes of direction.
- Do Not Miss Diagnoses
- Osteosarcoma: Although rare, osteosarcoma is a type of bone cancer that can present with pain, swelling, and weakness in the affected limb. It is crucial to consider this diagnosis to ensure prompt treatment if present.
- Neuromuscular disorders (e.g., muscular dystrophy): Certain neuromuscular conditions can cause progressive muscle weakness, which may initially present as lower extremity weakness and knee instability.
- Infections (e.g., osteomyelitis, septic arthritis): Infections of the bone or joint can cause severe pain, swelling, and systemic symptoms. Prompt diagnosis and treatment are essential to prevent long-term damage.
- Rare Diagnoses
- Legg-Calve-Perthes disease: This condition involves avascular necrosis of the femoral head and can cause hip pain that may be referred to the knee, as well as weakness and instability.
- Slipped capital femoral epiphysis: This condition involves displacement of the femoral head from the femoral neck and can cause hip pain, weakness, and instability that may be referred to the knee.
- Tumors (e.g., giant cell tumor, chondroblastoma): Although rare, various types of tumors can affect the bones around the knee, causing pain, swelling, and weakness.