Terry R. Yochum, D.C, D.A.C.B.R., Fellow, A.C.C.R., and Chad J. Maola, D.C. History This young adult male patient complains of wrist pain after physical activity. Plain film radiographs showed no abnormalities of any of the bones of the wrist, nor was there any joint disease in the carpal bones. Because of persistent pain, an MRI scan was performed. Diagnosis: Kienbock's Disease Osleonecrosis may occur at any carpal bone as a result of traumatic disruption of the blood supply. The scaphoid and the lunate are the most frequently affected carpal bones (Kienbock's disease).1 Osteone- crosis of the scaphoid is usually the sequela of a traumatic injury to the waist or proximal pole and occurs in 10-15% of all scaphoid fractures.1 MR1 demonstrates the extent of the necrotic process more accurately than does conventional radiography and is equal in sensitivity to nuclear scintigra-phy. When only Tl-weighted sequences are used, the MR] sensitivity in diagnosing necrosis is about 87.5%; with the addition of the T2-weighted sequences, the specificity is 100%.' Therefore Tl- and T2-weighted coronal and axial images should be used to best display the characteristics of the lesion. In the early stages, T2-weighted sequences demonstrate regions of increased signal intensity. This area can be surrounded by hypointense signal, which is believed to represent the interface between non-viable (dead) bone and reparative granulation tissue. In advanced cases the necrotic zone has a homogeneous, hypointense signal on both Tl- and T2-weighted images. Dr. Terry R. Yochum is a second generation chiropnidor and a Cum Lcmde Graduate of National College of Chiropractic, where he subsequently completed his radiology1 residency. He is currently Director of the Rock}- Mountain Chiropractic Radiological Center in Denver, Colorado, and Adjunct Professorof Radiology at the Southern California University of Health Sciences, as well as an instructor of skeletal radiology at the University of Colorado Schoolof Medicine, Denver, CO. Dr. Yochum can be reached at I-S03-940-9400 or bv e-mail at dcradO99(ci aol.com. Dr. Chad Maola is a 1990 Magna Cum Laude Graduate of National College oj Chiropractic. Dr. Maola is available for post-graduate seminars. He may he reached at 1-727-433-0153 or by email at dc OICam.sn.com. References 1. Yochum TR, Rowe LJ: Essentials of Skeletal Radiology. 3'J ed., Williams & Wilkins, Baltimore, Maryland, 2005.| Figure 1. T1-weighted MRI scan, coronal wrist. Note the homogeneous low signal intensity of the carpal lunate suggesting osteonecrosis.
