Tag Archive | ultrasound

Polytrauma Patients Face Cancer Risk from Imaging Radiation

Orthopaedic surgeons work with radiation in some capacity almost every day. We would struggle to provide quality patient care if it were not for the many benefits that radiographic images provide us. But the more we are exposed to something, the less we tend to think about it. For example, how often do we discuss the risks of radiation exposure with our patients—especially those who are exposed to a large amount of it after an acute traumatic injury?

The article by Howard et al. in the August 7, 2019  issue of JBJS strongly suggests that polytrauma patients need to better understand the risks associated with radiation exposure as they progress through treatment of their injuries. The authors evaluated the cumulative 12-month postinjury radiation exposure received by almost 2,400 trauma patients who had an Injury Severity Score of 16+ upon admission. Those patients received a median radiation dose (not counting fluoroscopy) of 18.46 mSv, and their mean radiation exposure was 30.45 mSv. These median-versus-mean data indicate that a small subset of patients received substantially more radiation than others, and in fact, 4.8% of the cohort was exposed to ≥100 mSv of radiation. To put these amounts in context, the average human in the UK (where this study was performed) is exposed to about 2 mSv of background radiation per year, and there is good evidence suggesting that carcinogenesis risk increases with acute radiation doses exceeding 50 mSv.

Based on mathematical models (actual occurrences of cancer were not tracked), the authors conclude that for these patients, the median risk of fatal carcinogenesis as a result of medical radiation following injury was 3.4%. In other terms, 85 of these patients would be expected to develop cancer as a result of medical imaging—which struck me as a startling estimate.

So what are we to do? In a Commentary accompanying this study, David A. Rubin, MD, FACR offers some practical suggestions for reducing unnecessary radiation exposure. I personally feel that because the radiation associated with CT scans and radiographs can be, quite literally, life-saving for patients who have sustained traumatic injuries, increasing the chance that patients develop cancer later in life in order to save their life now is a good risk-benefit proposition. But the findings from this study should make us think twice about which imaging tests we order, and they should encourage us to help patients better understand the risks involved.

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

Assessing Fatty Infiltration in Rotator Cuff Tears: MRI vs Ultrasound

In the setting of rotator cuff injuries, higher degrees of fatty infiltration into cuff muscles are positively correlated with higher repair failure rates and worse clinical outcomes. MRI continues to be the gold standard imaging modality for evaluating fatty infiltration of the rotator cuff, but ultrasound represents another viable modality for that assessment—at considerably lower cost. Such is the conclusion of Tenbrunsel et al. in a recent issue of JBJS Reviews.

The authors reviewed 32 studies that investigated imaging modalities used to assess fatty infiltration and fatty atrophy. They found that grading fatty infiltration using ultrasound correlated well with grading using MRI. However, the authors identified difficulties distinguishing severe from moderate fatty infiltration on ultrasound, but they added that discerning mild from moderate fatty infiltration is more important clinically. Tenbrunsel et al. also mention sonoelastography, which measures tissue elasticity and can also be used to help determine the severity of fatty atrophy of the rotator cuff.

Overall, the trade-off between MRI and ultrasound comes down to higher precision with the former and lower cost with the latter.

For more information about JBJS Reviewswatch this video featuring JBJS Editor-in-Chief Dr. Marc Swiontkowski.

Faster Relief for Patients with Painful Bone Metastases

MR Guided Ultrasound for OBuzz2A technique that combines magnetic resonance (MR) imaging with high-intensity focused ultrasound hyperthermia provides faster pain relief than conventional radiation therapy (RT) for patients with a painful bone metastasis.

In the September 20, 2017 issue of JBJS, Lee et al. report on a matched-pair study of 63 patients with a painful bone metastasis who received either magnetic resonance-guided focused ultrasound (MRgFUS) or RT as first-line treatment. Both modalities were effective overall, yielding response rates of >70% at the three-month follow-up evaluation. However, MRgFUS was more efficient, providing a 71% response rate at 1 week after treatment, compared with 26% for RT at that same time point.

The total treatment time and cost of the two modalities were similar, and neither was associated with adverse events above grade 2. Among MRgFUS patients, there was a 14% rate of positioning-related pain and a 33% rate of sonication-related pain, which typically resolved within 1 day after treatment.

Lee et al. report that the median overall survival of patients in the study was 12.7 months in the MRgFUS group and 9.8 months in the RT group, a statistically nonsignificant difference. But the authors emphasize that the study was more about pain relief than extending life. “Reduc[ing] pain, restor[ing] function, and maintain[ing] quality of life is imperative” for those with bone metastasis, the authors conclude. They also caution that MRgFUS is not appropriate for bone metastases of the skull or most of the spine, or for any lesion that is not at least 1 cm away from “tissues at risk.”