Facet Osteoarthritis Research Articles

The lumbar facet joint: a review of current knowledge: part 1: anatomy, biomechanics, and grading

We present a two-part review article on the current state of knowledge of lumbar facet joint pathology. This first article discusses the functional anatomy, biomechanics, and radiological grading systems currently in use in clinical practice and academic medicine. Facet joint degeneration is presented within the larger context of degenerative disc disease to enable the reader to better understand the anatomical changes underlying facet-mediated lower back pain. Other less-common, but equally important etiologies of lumbar facet joint degeneration are reviewed. The existing grading systems are discussed with specific reference to the reliability of CT and MR imaging in the diagnosis of lumbar facet osteoarthritis. It is hoped that this discussion will stimulate debate on how best to improve the diagnostic reliability of these tests so as to improve both operative and non-operative treatment outcomes.

Characteristic Appearance of Facet Osteoarthritis of the Lower Lumbar Spine on Planar Bone Scintigraphy With a High Negative Predictive Value for Metastasis

The spine is a common site of various pathologic changes. On bone scans, differential diagnosis between metastasis and benign changes is not always easy. We describe a characteristic bone scan appearance of facet osteoarthritis most often seen at the fifth lumbar level. The lesion typically appears oval/elongated in shape, located along the lateral margin of the spine; its superior end is usually outside (lateral to) or just at the margin of the spine, and the inferior end is just at or inside (medial to) the margin, yielding a pattern of slightly oblique activity. Bone scans performed in 448 patients with known malignancy and interpreted as having some sort of spinal abnormalities were reviewed. Of these, the scans in 36 patients were judged to show the facet osteoarthritis sign (FOS). Follow-up was available in 28 of the 36 patients. The presence or absence of metastasis at the site of the FOS was determined by a minimum of 6-month follow-up by chart review and correlation with plain radiographs, computed tomography (CT), magnetic resonance imaging, and/or serial bone scans. None of the 28 patients had metastasis at the site of the FOS. CT and/or plain radiographs performed in 13 patients invariably showed facet disease. When planar bone scan images show the FOS, further evaluation of this region with SPECT imaging or other imaging, ie, plain radiography, CT, or magnetic resonance imaging, would be unnecessary because this sign has an extremely high negative predictive value for metastasis (100% in this series).

Sacralization of L5 in Radiological Studies of Degenerative Spondylolisthesis at L4-L5

Study DesignRadiological analysis.PurposeTo investigate sacralization of L5 on radiological studies of degenerative spondylolisthesis at L4-L5.Overview of LiteratureDegenerative spondylolisthesis commonly develops at L4-L5. Sacralization of L5 is thought to cause stress concentration at this level, which accentuates degenerative changes and promotes development of degenerative spondylolisthesis. However, there has been no study dedicated to determining whether the presence of sacralization at L5 influences the radiological findings in degenerative spondylolisthesis at L4-L5.MethodsSeventy-eight patients with degenerative spondylolisthesis at L4-L5 were classified into two groups according to the presence of L5 sacralization: with (n=54) and without (n=24). Four radiographic parameters were measured and compared between the two groups: anterior slippage of L4 on L5 (% slip), facet orientation of L4-L5 (degrees), facet osteoarthritis of L4-L5 by Fujiwara's criteria (1~4 grades), and disc degeneration of L4-L5 by Frymoyer's criteria (grades 1~5).ResultsThere was no significant difference in the degree of anterior slippage of L4 on L5 (17.02±6.21 versus 16.65±4.87, p=0.809), facet orientation (54.99±12.18 versus 56.23±4.35, p=0.642), facet osteoarthritis (3.43±0.59 versus 3.53±0.37, p=0.527), or disc degeneration (4.50±0.51 versus 4.35±0.61, p=0.340) between the two groups.ConclusionsOur study shows that the influence of sacralization of L5 on radiological findings in degenerative spondylolisthesis at L4-L5 may be less significant than previously expected. Further studies in large patient groups are needed to clarify the role of L5 sacralization on the development of degenerative spondylolisthesis at L4-L5.

Poster 208: Treatment of Thoracic Facet Osteoarthritis With a 5% Lidocaine Patch: A Case Report

Setting: Tertiary care academic medical center. Patient: A 74-year-old man with thoracic facet joint osteoarthritis. Case Description: The patient presented with chronic mid thoracic anterior radiating back pain, quality described as burning, aggravated by physical activity including walking, and relieved by heat, ice, and massage therapy. Physical examination revealed intact strength and sensation in all upper and lower myotomes; reflexes that were +2 and symmetric at biceps, triceps, and brachioradialis; and negative Hoffman and Spurling signs. Palpation revealed right rhomboid major and latissimus dorsi tenderness, with focal tenderness over T5-6 facet joints. Radiographs revealed facet osteoarthritis on T5-6 and T6-7 and magnetic resonance imaging showed T6-7 disk protrusion without foraminal narrowing. The patient’s initial treatments included nonsteroidal anti-inflammatory drugs, physical therapy, and thoracic facet steroid injections without any relief of the mid back pain. The patient was prescribed 5% lidocaine patches (Lidoderm), with instructions to apply them to the affected area for 12 hours on and 12 hours off. Assessment/Results: At 4 weeks, the patient reported significant pain relief with numeric pain scores before and after lidocaine patch of 7/10 and 0/10, respectively. The patient reported no unfavorable side effects and further conveyed improved function in daily activities and movement. Discussion: The U.S. Food and Drug Administration approved Lidoderm for postherpetic neuralgia. No published studies exist for thoracic facet osteoarthritis treatment with the lidocaine patch. The lidocaine patch provided more pain relief for thoracic joint osteoarthritis than analgesics and other physical interventions. Conclusions: Conservative medical management for thoracic joint osteoarthritis is limited to oral medications, physical therapy, and thoracic facet steroid injections. Lidocaine patch may provide a safe alternative for pain relief as monotherapy or in combination with other treatments.

Orientation and Osteoarthritis of the Lumbar Facet Joint

Several studies have shown an association between sagittal orientation of the facet joint and degenerative spondylolisthesis. There is currently no information available on the association between orientation of the facet joint and osteoarthritis. This study examined the association between orientation and osteoarthritis of the lumbar facet joints. One hundred eleven consecutive patients underwent plain radiography and magnetic resonance imaging. These patients were divided into two groups: No Degenerative Spondylolisthesis Group (98 patients) and Degenerative Spondylolisthesis Group (13 patients). In the No Degenerative Spondylolisthesis Group, segments with higher grades of osteoarthritis showed more sagittal orientation of the facetjoints at the L3-L4 and L4-L5 levels. The facet joint was oriented significantly more sagittally in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L4-L5 and L5-S1 levels. The severity of facet joint osteoarthritis was significantly higher in the Degenerative Spondylolisthesis Group than in the No Degenerative Spondylolisthesis Group at the L3-L4, L4-L5, and L5-S1 levels. A significant association was found between sagittal orientation and osteoarthritis of the lumbar facet joints, even in patients without degenerative spondylolisthesis. Facet joint osteoarthritis, rather than spondylolisthesis, is the pathoanatomic feature that is associated with sagittal orientation of the facet joints in patients with degenerative spondylolisthesis.

The effect of disc degeneration and facet joint osteoarthritis on the segmental flexibility of the lumbar spine.

A biomechanical and imaging study of human cadaveric spinal motion segments. To investigate the effect of both disc degeneration and facet joint osteoarthritis on lumbar segmental motion. Spinal degeneration includes the osteoarthritic changes of the facet joint as well as disc degeneration. Disc degeneration has been reported to be associated with spinal motion. The association of facet joint osteoarthritis with lumbar segmental motion characteristics and the combined influence of disc degeneration and facet osteoarthritis has not yet been investigated. A total of 110 lumbar motion segments (52 female, 58 male) from 44 human lumbar spines were studied (mean age = 69 years). Magnetic resonance images were used to assess the disc degeneration from Grade I (normal) to Grade V (advanced) and the osteoarthritic changes in the facet joints in terms of cartilage degeneration, subchondral sclerosis, and osteophytes. Disc height, endplate size, and facet joint orientation and width also were measured from the computed tomographic images. Rotational movements of the motion segment in response to the flexion, extension, lateral bending, and axial rotational moments were measured using a three-dimensional motion analysis system. Female motion segments showed significantly greater motion (lateral bending: P < 0. 001, flexion: P < 0.01, extension: P < 0.05) and smaller endplate size (P < 0.001) than male ones. The segmental motion increased with increasing severity of disc degeneration up to Grade IV, but decreased in both genders when the disc degeneration advanced to Grade V. In male segments, the disc degeneration-related motion changes were significant in axial rotation (P < 0.001), lateral bending (P < 0.05), and flexion (P < 0.05), whereas female segments showed significant changes only in axial rotation (P < 0.001). With cartilage degeneration of the facet joints, the axial rotational motion increased, whereas the lateral bending and flexion motion decreased in female segments. In male segments, however, motion in all directions increased with Grade 3 cartilage degeneration and decreased with Grade 4 cartilage degeneration. Subchondral sclerosis significantly decreased the motion (female: axial rotation, P < 0. 05; extension, P < 0.05 vs.- male:flexion,P < 0.05). Severity of osteophytes had no significant association with the segmental motion. Axial rotational motion was most affected by disc degeneration, and the effects of disc degeneration on the motion were similar between genders. Facet joint osteoarthritis also affected segmental motion, and the influence differed for male and female spines. Further studies are needed to clarify whether the degenerative process of facet joint osteoarthritis differs between genders and how facet joint osteoarthritis affects the stability of the spinal motion segment.

Role of ligaments and facets in lumbar spinal stability.

The issue of segmental stability using finite element analysis was studied. Effect of ligament and facet (total and partial) removal and their geometry on segment response were studied from the viewpoint of stability. To predict factors that may be linked to the cause of rotational instabilities, spondylolisthesis, retrospondylolisthesis, and stenosis. The study provides a comprehensive study on the role of facets and ligaments and their geometry in preserving segmental stability. No previous biomechanical study has explored these issues in detail. Three-dimensional nonlinear finite element analysis was performed on L3-L4 motion segments, with and without posterior elements (ligaments and facets), subjected to sagittal moments. Effects of ligament and facet (partial and total) removal and their orientations on segment response are examined from the viewpoint of stability. Ligaments play an important role in resisting flexion rotation and posterior shear whereas facets are mainly responsible for preventing large extension rotation and anterior displacement. Facet loads and stresses are high under large extension and anterior shear loading. Unlike total facetectomy, selective removal of facets does not compromise segmental stability. Facet loads are dependent on spatial orientation. Rotational instability in flexion or posterior displacement (retrospondylolisthesis) is unlikely without prior damage of ligaments, whereas instability in extension rotation or forward displacement (spondylolisthesis) is unlikely before facet degeneration or removal. The facet stress and displacement distribution predicts that facet osteoarthritis or hypertrophy leading to spinal stenosis is most likely under flexion-anterior shear loading. Selective facetectomy may restore spinal canal size without compromising the stability of the segment. A facet that is more sagittally oriented may be linked to the cause of spondylolisthesis, whereas a less transversely oriented facet joint may be linked to rotational instabilities in extension.

Discs Degenerate Before Facets

The purpose of this study was to determine the relationship between facet joint osteoarthritis and disc degeneration in subjects in whom both MRI and CT scans had been obtained. The MRI scans were used to determine disc degeneration, the CT scans to determine facet joint osteoarthritis. It was hypothesized that disc degeneration would sometimes occur without the presence of facet joint osteoarthritis, but that facet joint osteoarthritis would only occur in the presence of disc degeneration. Sixty-eight sets of scans were included and 330 discs and 390 facet joints were evaluated. There were 144 degenerated discs and 41 levels with facet osteoarthritis. Disc degeneration without facet osteoarthritis was found at 108 levels, while all but one of 41 levels with facet degeneration also had disc degeneration. That one exception occurred in a patient with advanced Paget's disease. Disc degeneration and facet osteoarthritis both were found to increase with increasing age. There was no difference between women and men. Degeneration at the L4-5 and L5-S1 levels was significantly more prevalent than at the L3-4 levels, while degeneration at the L3-4 level was significantly more common than at the L1-2 and L2-3 levels. We conclude that disc degeneration occurs before facet joint osteoarthritis, which may be secondary to mechanical changes in the loading of the facet joints.