A 43-year-old man with a history of alcohol abuse, pancreatitis, and chronic liver disease presented with left hip pain.


Avascular necrosis of femoral head


• Patients may be asymptomatic early in the disease process but ultimately present with pain and limitation of motion.

• Pain is most commonly in the groin area but may also manifest in the ipsilateral buttock, knee, or greater trochanteric region.

• Pain is usually exacerbated with weight bearing and relieved with rest.

• Predisposing factors include corticosteroids, alcohol abuse, chronic liver disease, pancreatitis, coagulopathy, and hemoglobinopathies; traumatic etiologies include femoral neck fracture, hip dislocation, and slipped capital femoral epiphysis.

Key Diagnostic Features (MRI)

• MRI is the most sensitive modality and demonstrates changes well before plain film changes are visible.

• Diffuse edema

• Serpiginous low T1 signal line

• Double line sign: inner high T2 signal line representing granulation tissue and outer low signal line representing sclerotic bone at the periphery of osteonecrotic region

Differential Diagnosis

• Femoral neck stress fracture

• Synovitis

• Idiopathic transient osteoporosis of the hip

• Chondroblastoma

• Metastatic disease


Treatment varies with location and stages of osteonecrosis: conservative (anti-inflammatory, analgesia, non-weight bearing), core decompression, and joint replacement for end-stage disease.

— Waikeong P. Wong, MD, PhD, is a radiology resident at Saint Barnabas Medical Center in Livingston, New Jersey.



  1. Zurlo JV. The double-line sign. Radiology. 1999; 212:541-542.
  2. Manaster BJ, May DA, Disler DG. Musculoskeletal Imaging. Philadelphia, PA: Mosby Elsevier; 2007.

Submission Instructions

Submit cases directly to Rahul V. Pawar, MD, DABR (section editor for “On the Case”) at rvp325@yahoo.com. Cases submitted should be relevant and interesting. All modalities and subspecialties within radiology are equally considered.

Case submission entails two PowerPoint slides:

a. History (one-line phrase)
b. Two to five high-quality images in JPEG format without annotations
c. Name(s) of the author(s) (three maximum) and respective institutions

a. Diagnosis
b. Concise bulleted discussion (one to two lines each), including the following: pertinent clinical history, diagnostic imaging findings, differential diagnoses, treatment (if applicable)
c. Two to three relevant and current references, preferably citing peer-reviewed radiology literature

Section Editor: Rahul V. Pawar, MD, DABR
Department of Radiology, Division of Neuroradiology
Saint Barnabas Medical Center/Barnabas Ambulatory Care Center