Differential Diagnosis for Pain Radiating to a Hip

When considering pain that radiates to a hip, it's crucial to approach the diagnosis systematically, considering various potential causes based on the anatomy and common pathological conditions affecting the region. Here's a structured differential diagnosis:

• Single Most Likely Diagnosis

  • Lumbar Radiculopathy: This condition, often due to a herniated disc, can cause pain that radiates from the lower back down to the hip and even further down the leg, following the distribution of the affected nerve root. The proximity of the lumbar spine to the hip and the common referral patterns of pain make this a leading consideration.

• Other Likely Diagnoses

  • Trochanteric Bursitis: Inflammation of the bursa over the greater trochanter of the femur can cause pain on the outer aspect of the hip, which may radiate down the thigh. This condition is common and can be caused by repetitive friction or direct trauma.
  • Osteoarthritis of the Hip: Degenerative joint disease can lead to pain in the hip that may radiate to the groin or down the thigh. The pain typically worsens with weight-bearing activities.
  • Piriformis Syndrome: The piriformis muscle, which runs from the base of the spine to the thighbone, can irritate the sciatic nerve, causing pain that radiates from the hip down the back of the leg.

• Do Not Miss Diagnoses

  • Avascular Necrosis of the Femoral Head: A condition where the blood supply to the head of the femur is interrupted, leading to necrosis of the bone tissue. It can cause severe hip pain and is a medical emergency if not promptly treated.
  • Septic Arthritis of the Hip: A bacterial infection within the hip joint, which is a medical emergency requiring immediate attention to prevent destruction of the joint and potential systemic infection.
  • Fracture: Especially in older adults or those with osteoporosis, a fracture of the hip or pelvis can cause radiating pain and requires urgent medical evaluation.

• Rare Diagnoses

  • Sacroiliitis: Inflammation of the sacroiliac joints, which can be due to various causes including inflammatory arthritis (e.g., ankylosing spondylitis), infection, or trauma. It can cause pain in the lower back and hips.
  • Neoplastic Processes: Tumors, either benign or malignant, affecting the bones, muscles, or nerves around the hip can cause radiating pain. These are less common but important to consider, especially with persistent or worsening symptoms.