The Journal of Bone and Joint Surgery (American). 2005;87:583-591.
doi:10.2106/JBJS.D.01966
© 2005 The Journal of Bone and Joint Surgery, Inc.
Thermal Tissue Damage Caused by Ultrasonic Cement Removal from the Humerus
Steven H. Goldberg, MD1,
Mark S. Cohen, MD1,
Michael Young, PHD, MSC2 and
Brian Bradnock, FRCS(ED), FRCS(ORTH)3
1 Department of Orthopaedic Surgery, Rush University Medical Center, 1653 W.
Congress Parkway, 1471 Jelke, Chicago, IL 60612. E-mail address for S.H.
Goldberg:
steven_h_goldberg{at}rush.edu
2 Orthosonics Ltd, Bremridge House, Ashburton, S. Devon TQ13 7JX, United
Kingdom
3 St. Albans and Hemel Hempstead NHS Trust, Waverly Road, St. Albans, Herts,
United Kingdom
Investigation performed at the Department of Orthopaedic Surgery, Rush
University Medical Center, Chicago, Illinois
One of the authors (M.Y.) is a full-time salaried employee of Orthosonics
Ltd. One of the authors (B.B.) is a part-time paid consultant to Orthosonics
Ltd. The other two authors (S.H.G. and M.S.C.) did not receive any payments or
benefits or a commitment or agreement to provide such benefits from a
commercial entity. No commercial entity paid or directed, or agreed to pay or
direct, any benefits to any research fund, foundation, educational
institution, or other charitable or nonprofit organization with which the
authors are affiliated or associated. The equipment used in this study was
provided by Orthosonics Ltd, Stryker Instruments, Howmedica, and Biomet. The
cadavera were provided by Anatomical Service, Inc.
Background: Ultrasound devices can selectively remove cement during
revision arthroplasty. These instruments initially were designed for the hip
and knee but also have been applied to the upper extremity. We describe a
patient in whom a radial nerve palsy and a pathologic humeral fracture
developed after ultrasonic cement removal was performed because of an
infection at the site of a total elbow arthroplasty. Biopsies of the humerus,
the triceps muscle, and the radial nerve showed widespread necrosis consistent
with thermal injury.
Methods: A study involving six human cadaveric specimens was
conducted to measure temperature elevations in bone and adjacent soft tissue
during cement removal with use of an ultrasound device with and without
irrigation.
Results: While temperature increased only minimally during cement
polymerization, ultrasonic melting and removal of cement with use of constant
energy delivery led to markedly elevated temperatures in the humeral cortex,
the triceps muscle, and the radial nerve. These temperatures were above the
known thresholds for thermal injury and necrosis. Subsequently, strategies
designed to allow for safe ultrasonic cement removal from the humerus were
applied, including intermittent delivery of energy and the use of cold
irrigation between probe passes. These strategies resulted in markedly lower
maximum temperatures in all tissues tested.
Conclusions: Temperatures in the humerus, triceps, and, most
importantly, the radial nerve can reach potentially dangerous levels when
ultrasound technology is used to remove cement from the humerus. We suggest
intermittent cold irrigation of the humeral canal, no tourniquet use,
education of surgeons with regard to proper techniques designed to limit heat
generation, and consideration of exposure and protection of the radial nerve
when ultrasound devices are used.

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