%0 Journal Article
%T Lumbar Facet Joint Arthritis Is Associated with More Coronal Orientation of the Facet Joints at the Upper Lumbar Spine
%A Thorsten Jentzsch
%A James Geiger
%A Stefan M. Zimmermann
%A Ksenija Slankamenac
%A Thi Dan Linh Nguyen-Kim
%A Cl¨¦ment M. L. Werner
%J Radiology Research and Practice
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/693971
%X We retrospectively analyzed CT scans of 620 individuals, who presented to our traumatology department between 2008 and 2010. Facet joint (FJ) arthritis was present in 308 (49.7%) individuals with a mean grade of 1. It was seen in 27% of individuals ¡Ü40 years and in 75% of individuals ¡Ý41 years ( ) as well as in 52% of females and 49% of males ( ). Mean FJ orientation was 30.4¡ã at L2/3, 38.7¡ã at L3/4, 47¡ã at L4/5, and 47.3¡ã at L5/S1. FJ arthritis was significantly associated with more coronal (increased degree) FJ orientation at L2/3 ( ) with a cutoff point at ¡Ý32¡ã. FJs were more coronally oriented (48.8¡ã) in individuals ¡Ü40 years and more sagittally oriented (45.6¡ã) in individuals ¡Ý41 years at L5/S1 ( ). Mean FJ asymmetry was 4.89¡ã at L2/3, 6.01¡ã at L3/4, 6.67¡ã at L4/5, and 7.27¡ã at L5/S1, without a significant difference for FJ arthritis. FJ arthritis is common, increases with age, and affects both genders equally. More coronally oriented FJs (¡Ý32¡ã) in the upper lumbar spine may be an individual risk factor for development of FJ arthritis. 1. Introduction A functional spinal unit consists of anteriorly located adjacent vertebrae separated by an intervertebral disc and posteriorly located facet (zygapophyseal) joints (FJ) [1]. FJs are composed of an inferior articular process, facing anteriorly, and a superior articular process, facing posteriorly, of two adjacent vertebrae [2]. Being synovial-lined, diarthrodial, and freely moveable functional units, they transmit shear forces and help the intervertebral discs in carrying about 16% of the vertical load [3, 4]. FJ orientation planes differ at various levels, with a more sagittal and curved orientation for resistance against axial rotation in the upper compared to a more coronal and flat orientation for resistance against flexion and shearing forces in the lower lumbar segments [5, 6]. FJ asymmetry or tropism describes the asymmetry of the left and right FJ angle [7, 8]. Low back pain is one of the most common health problems [9]. It affects up to 85% of people at least once during their lifetime and up to 5% chronically [10]. Even though etiologies of low back pain are multifactorial [11], FJ arthritis is common and affects at least 50% of the population [12]. After Ghormley [13] first described a facet syndrome in 1933, there has been an ongoing debate [14, 15] about the possible association low back pain and FJ pathology [16]. FJs are synovial covered joints with hyaline cartilage [17] and innervated by the medial branches of the dorsal rami from two levels [18, 19]. Recently, it has been shown that
%U http://www.hindawi.com/journals/rrp/2013/693971/