4 THE CLASSIC The Lithotriptor and Its Potential Use in the Revision of Total Hip Arthroplasty Robert R. Karpman, MD; Frank P. Magee, BSc; Thomas W. S. Gruen, MS; and Theodore Mobley, MD A native of Philadelphia, Robert Karpman (Fig 1) was educated at LaSalle College (BA, 1973), and the University of Pennsylvania (MD, 1977). He then moved to the Uni- versity of Arizona in Tucson where he received his orthopaedic training. Karpman fin- ished his training in 1981. After this, Karpman moved to Phoenix where he entered pri- vate practice. In addition to his practice, Karpman has held numerous important positions in the teacing programs of the Maricopa Medical Center including Director of Academic Affairs (1991–1996), Chief of Orthopaedics (1986–1998), and Medical Di- rector of Physical Medicine and Rehabilitation (1988–1996). His academic appoint- ments include Clinical Professor, Department of Orthopedics, University of Arizona; Associate Professor, Mayo Medical School, Scottsdale, Arizona; and Adjunct Profes- sor, Department of Chemical and Bioengineering, Arizona State University. In addition to these activities, Karpman obtained an MBA from the University of Phoenix in 1991. His interest in research and teaching is reflected in a substantial bibliography, which in- cludes the following classic article on the use of focused shock waves in orthopaedic surgery. Interest in focused shock waves began during World War II when observers at the Dormier factory in Germany became interested in patterns of injuries in tank crews when the turrets were struck by shells, and when pitting of metal surfaces was observed asso- ciated with supersonic flight. The wife of one of the engineers suggested the possible ap- plication of this knowledge to the fragmentation of kidney stones, which lead to the de- velopment of lithotripsy. Perfection of this technique led to the thought that a similar application to the loosening of cement in the revision of total hip arthroplasty might be feasible. The following article is one of the first to explore this possibility. Leonard F. Peltier, MD, PhD ABSTRACT Revision total hip arthroplasty, particularly femoral component replacement, has proved extremely difficult and has met with frequent complications. Despite a variety of devices and techniques that have been developed to fa- cilitate removal of the femoral stem, the pro- cedure remains difficult. Extracorporeal shock wave lithotripsy (ESWL) is a new technique