The Common Vein Copyright 2011
Definition
Fractures of the are usually caused by a fall onto the outstretched hand.
There are five types of acute lunate fractures; frontal palmar pole, osteochondral, frontal dostal pole, transverse body, and transarticular frontal fractures of the lunate body.
Kienbock’s disease or lunatomalacia is a result of avascular necrosis of the lunate that results in collapse of the bone. It is a chronic condition.
Lunate fractures sometimes are complicated in the subacute and chronic stages by nonunion, malunion, neurovascular injury, osteonecrosis, and stiffness. Lunate fractures may not not diagnosed until they osteonecrosis ensues. DJD is a late complication.
Diagnosis is by physical exam and x-ray imaging.
Imaging includes the use of x-rays, CT-scans, and occasionally MRI. Early Kienbock’s disease can be picked up by MRI before there are x-ray findings.
Nondisplaced fractures are treated with a short or long arm cast or splint. Displaced fractures are treated with surgical repair.
Kienbock’s disease is treated with casting or a wide variety of surgical interventions aimed at decreasing the pressure on the lunate bone, known as “off-loading the lunate”.
The Normal Lunate |
| Courtesy Ashley Davidoff MD 2011 45738c01 |
References
Davis MF, Davis PF, Ross DS. Expert Guide to Sports Medicine. ACP Series, 2005.
Elstrom J, Virkus W, Pankovich (eds), Handbook of Fractures (3rd edition), McGraw Hill, New York, NY, 2006.
Koval K, Zuckerman J (eds), Handbook of Fractures (3rd edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Lieberman J (ed), AAOS Comprehensive Orthopaedic Review, American Academy of Orthopaedic Surgeons, 2008.
Moore K, Dalley A (eds), Clinically Oriented Anatomy (5th edition), Lippincott Williams & Wilkins, Philadelphia, PA, 2006.
Wheeless’s Textbook of Orthopaedics: Kienbock’s disease/ Lunatomalacia (http://www.wheelessonline.com/ortho/kienbocks_disease_lunatomalacia)