Abnormalities in and Around the Hip: MR Imaging Versus Sonography

Magnetic Resonance Imaging of Nonneoplastic Musculoskeletal Pathologies in the Pelvis

Musculoskeletal pathologies in the pelvis encompass a wide variety of lesions including femoroacetabular impingement, athletic pubalgia, ischiofemoral impingement, and apophyseal avulsion injuries. Magnetic resonance imaging is the noninvasive imaging modality of choice for the diagnosis and management of these lesions. In this article, the authors discuss the nonneoplastic musculoskeletal lesions in the pelvis, with illustrations and relevant case examples.

Musculoskeletal imaging: medicare use, costs, and potential for cost substitution

PURPOSE

The current study explores the substitution of ultrasound (US) for magnetic resonance imaging (MRI) of musculoskeletal (MSK) disorders by describing the recent use and costs of MSK imaging in the Medicare population, projecting these trends from 2006 to 2020, and estimating cost-savings involved in substituting MSK US for MSK MRI, when appropriate.

METHODS

The study used government-published data sets and de-identified Radiology Information System records exempt from institutional review board approval. From 1 year's MSK MRI records (n = 3,621), the proportion of cases in which US could be substituted for MRI was estimated. The use rates for 4 modalities of MSK imaging and average costs were determined from government Medicare data sets from 1996 to 2005. Regression analysis was used to project use rates from 2006 to 2020. The effect on costs of substitution was calculated.

RESULTS

For the Medicare population, although there has been a moderate overall increase (25.7%) in MSK imaging, MSK MRI has increased 353.5% from 1996 to 2005. Projected MSK imaging costs in 2020 are $3.6 billion, of which $2.0 billion will be for MRI. A study of 3,621 MSK MRI reports indicates that 45.4% of primary diagnoses and 30.6% of all diagnoses could have been made with MSK US. The substitution of MSK US for MSK MRI, when appropriate, would lead to savings of more than $6.9 billion in the period from 2006 to 2020.

CONCLUSION

MRI MSK use has grown substantially from 1996 to 2005. The substitution of MSK US, when appropriate, would lead to large cost-savings for Medicare.

Diagnostic procedures and surgical treatment of craniodorsal coxofemoral luxation in calves

OBJECTIVE

To report use of ultrasonographic examination of the coxofemoral joint, a surgical technique for repair of craniodorsal coxofemoral dislocation, and outcome.

STUDY DESIGN

Clinical case reports.

ANIMALS

Calves (n=4) with coxofemoral luxation.

METHODS

Craniodorsal coxofemoral luxation was diagnosed by physical examination, radiographic, and ultrasonographic findings. Open surgical reduction of the femoral head was performed using a modified caudal approach.

RESULTS

Craniodorsal luxation of the femoral head and the presence of an intact femoral neck were confirmed by ultrasonography. All luxations were successfully reduced and reluxation did not occur. At follow-up, 1 heifer had calved and 1 was 5 months pregnant. One calf died of bronchopneumonia 6 days after surgery. One calf had severe coxofemoral degenerative joint disease diagnosed (ultrasonography, radiography, and arthrocentesis) 3 months after surgery and confirmed by necropsy.

CONCLUSION

Ultrasonography proved to be a simple and effective non-invasive technique for diagnosis of coxofemoral luxation. Immediate surgical intervention in hip dislocation in calves is necessary to avoid unnecessary trauma to subchondral structures. In calves, open instead of closed surgical reduction appears preferable because it allows access to the acetabular cavity for removal of debris.

CLINICAL RELEVANCE

Ultrasonography should be considered a supplementary but not an alternative to radiographic examination for diagnosis of coxofemoral luxation and for follow-up examinations after reduction.

Hip pain in adults: MR imaging appearance of common causes

To determine the exact origin of hip pain can be challenging. Symptoms apparently originating from the hip may arise from the pelvis, the sacroiliac joint, the lumbar spine, periarticular structures such as muscles and bursae, or from unexpected sites such as the abdominal wall, the genitourinary tract, or the retroperitoneal space. This article reviews the differential diagnosis of hip pain arising from the hip and surrounding structures and the role of different imaging methods with emphasis on magnetic resonance imaging where most recent advances have occurred.