Differential Diagnosis for Lower Back Pain Radiating Down Right Thigh Worsening with External Rotation of the Hip
- Single Most Likely Diagnosis
- Lumbar Radiculopathy (L4-L5 or L5-S1 Disc Herniation): This condition is the most likely diagnosis due to the radiation of pain down the thigh, which is a common presentation of nerve root compression. The worsening of pain with external rotation of the hip suggests irritation of the sciatic nerve or its roots, which is consistent with a herniated disc at the L4-L5 or L5-S1 level.
- Other Likely Diagnoses
- Piriformis Syndrome: This condition involves the piriformis muscle compressing the sciatic nerve, leading to pain in the buttock and thigh. Activities that involve external rotation of the hip can exacerbate the symptoms, making it a plausible diagnosis.
- Trochanteric Bursitis: Inflammation of the bursa over the greater trochanter can cause pain in the lateral thigh and hip, which may worsen with movements like external rotation.
- Osteoarthritis of the Hip: While more commonly associated with groin pain, hip osteoarthritis can also cause pain in the thigh, especially with certain movements.
- Do Not Miss Diagnoses
- Cauda Equina Syndrome: A serious condition where the nerves in the spinal canal are compressed, leading to severe pain, numbness, and potentially bladder and bowel dysfunction. It is crucial to identify this condition early due to its potential for permanent neurological damage.
- Spinal Infection (Abscess or Osteomyelitis): Infections in the spine can cause severe back pain and neurological symptoms. Early diagnosis is critical to prevent serious complications.
- Spinal Tumor: Tumors in the spine can compress nerves, leading to pain and neurological deficits. Although rare, missing this diagnosis could have severe consequences.
- Rare Diagnoses
- Sacroiliac Joint Dysfunction: While this can cause lower back and thigh pain, it is less commonly associated with the specific exacerbation by external rotation of the hip.
- Neurogenic Claudication: Associated with spinal stenosis, this condition causes pain in the legs and buttocks when walking or standing, relieved by bending forward or sitting. It's less likely given the specific worsening with external rotation of the hip.