CASE 105

BY: Dr. NIZAR AL-NAKSHABANDI MD, FRCPC

HISTORY: 34-year-old female complaining of right hip pain.

What are your findings?

What is the differential diagnosis?

What are the causes?

FINDINGS:

Coronal T1 weighted images of the hips [A] demonstrate diffuse low signal intensity changes in the left hip epiphysis and metaphysis and sparing the diaphysis with no evidence of subchondral fracture or collapse.

Axial T1 fat saturated posy gad sequence through the hips [B] demonstrate these similar changes of high signal intensity involving the left femur/neck with no evidence of subchondral fracture or collapse. Reactive synovial effusion is incidentally detected.

Coronal T1 fat saturated sequences with infusion of gadolinium [C] demonstrate avid enhancement of the left hip region with evidence of enhancement of the effusion.

DIFFERENTIAL DIAGNOSIS:

Transient osteoporosis of the hip/idiopathic transient osteoporosis of hip.

Avascular necrosis of the hips.

Subchondral insufficiency stress fracture.

Osteomyelitis/septic arthritis.

Infiltrative neoplastic process.

DIAGNOSIS:

Transient osteoporosis of the hip/idiopathic transient osteoporosis of hip.

PEARLS AND DISCUSSION:

Transient osteoporosis of the hips was initially described in pregnant females. However, it can affect middle aged men. If a woman is affected, she is usually in the third trimester of her pregnancy.

Rarely similar changes can involve the contralateral hip. In those cases, it is termed regional migratory osteoporosis.

The etiology is thought to be on a vascular basis and possibly due to hyperstimulation of the sympathetic system.

It is a diagnosis of exclusion, and other serious conditions must be excluded such as infection and malignancy. It is confirmed by a follow-up MRI which usually shows resolution of the bone marrow edema in 6 months.

These cases are best treated by weight protected weight bearing and symptomatic relief.

FURTHER READING:

1.       Bin Abdulhak AA, Ba-Mougadam FA, Al-Nakshabandi NA, Al-Tannir MA. Transient osteoporosis of the hip/bone marrow edema syndrome with soft tissue involvement: a case report. Oman Med J. 2011 Sep;26(5):353-5

2.    Kaplan P. Musculoskeletal MRI. W B Saunders Co. (2001) ISBN:0721690270. 

3.      Stoller D, Tirman P, Bredella M et-al. Diagnostic imaging. AMIRSYS. (2004)