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Background: Artificial Cervical Disc Replacement (ACDR) is an effective treatment for cervical degenerative disc diseases. However, clinical information regarding the facet joint alterations after ACDR was limited. Facet tropism is common in the sub-axial cervical spine. Our previous research indicated that facet tropism could lead to increased pressure on the cervical facet joints. This study aimed to assess the impact of facet tropism on the facet contact force and facet capsule stress after ACDR., Methods: A C2-T1 cervical finite element model was constructed from computed tomography (CT) scans of a 28-year-old male volunteer. Symmetrical, moderate asymmetrical (7 degrees tropism), and severe asymmetrical (14 degrees tropism) models were created at the C5/C6 level by altering the facet orientation at the C5-C6 level. The C5/C6 ACDR was simulated in the intact, moderate asymmetrical and severe asymmetrical models. A 75-N follower load with 1.0-Nm moments was applied to the top of C2 vertebra in the models to simulate flexion, extension, lateral bending, and axial rotation with the T1 vertebra fixed. The range of motions (ROMs) under all moments, facet contact forces (FCFs) and facet capsule strains were tested., Results: In the asymmetrical model, the right FCFs considerably increased under flexion, extension, right bending, left rotation, especially under right bending the right sided FCF of the severe asymmetrical model was about 5.44 times of the neutral position, and 3.14 times of the symmetrical model. and concentrated on the cephalad part of the facets. The facet capsule stresses on both sides remarkably increased under extension, lateral bending and right rotation. In the moderate and severe asymmetrical models, the capsule strain was greater on both sides of each position than in the symmetric model., Conclusions: The face tropism increased facet contact force and facet capsule strain after ACDR, especially under extension, lateral bending, and rotation, and also could result in abnormal stress distribution on the facet joint surface and facet joint capsule. The results suggest that face tropism might be a risk factor for post-operative facet joint degeneration progression after ACDR. Facet tropism may be noteworthy when ACDR is considered as a surgical option., (© 2024. The Author(s).)

Objective: To compare the clinical and radiographic outcomes of single-segment posterior decompression combined with two different non-fusion dynamic stabilization systems, Isobar EVO and Isobar TTL, in the context of facet joint degeneration and segmental mobility., Method: A retrospective study was conducted on 47 patients who underwent single-segment surgery at the L4/5 level using either the Isobar EVO (n = 23) or Isobar TTL (n = 24) systems. We assessed facet joint degeneration on both sides of the fixed (L3/4, L4/5) and superior adjacent (L2/3) segments using the Fujiwara MRI grading system. Clinical outcomes were evaluated using the Oswestry Disability Index (ODI) and visual analog scale (VAS) for back and leg pain at baseline, 12 months, and 24 months postoperatively., Result: Both groups exhibited significant facet joint degeneration at the fixed segments (L3/4 and L4/5) at 24 months. The TTL group also showed significant degeneration at the superior adjacent segment (L2/3), whereas the EVO group did not. Restoration of lumbar lordosis was significantly better in the EVO group. Pain and disability scores improved more in the EVO group than in the TTL group at both 12 and 24 months postoperatively., Conclusion: The Isobar EVO system, with its enhanced mobility, may delay facet joint degeneration in the superior adjacent segment compared to the Isobar TTL system. However, both systems result in degeneration at the fixed segment, indicating a need for further improvements to mimic the natural biomechanics of the spine more closely., (© 2024. The Author(s).)

BACKGROUND Cervical spondylosis (CS) is a degenerative disease of the cervical spine characterized by persistent neck pain. Cervical facet joint mobilization (CM) and the osteopathic muscle energy technique (MET) are effective manual procedures for the treatment of neck pain. In this study, we compared the efficacy of the MET and CM techniques on pain, disability, and proprioception in 76 patients with CS. MATERIAL AND METHODS A total of 96 participants with a diagnosis of CS were randomized into an electro-thermal therapy (ET) group (control group, n=32), ET+MET group (experiment I, n=32), and ET+CM group (experiment II, n=32). All patients received 3 treatment sessions per week for 4 consecutive weeks. Pain intensity, functional disability and cervical position sense were measured using the visual analog scale (VAS), Copenhagen Neck Functional Disability Scale (CNFDS), and cervical range of motion (CROM) device. RESULTS The study was completed by 76 participants. VAS and CNFDS scores decreased significantly after treatment in all 3 groups (P<0.001); however, there was no significant difference between the groups (P>0.05). Between-group analysis showed a significant difference in extension joint position error in favor of MET (P<0.001), while there was no significant difference between the groups in other movement directions (P>0.05). CONCLUSIONS MET and CM have similar effects on improving pain and disability in individuals with CS and chronic neck pain. However, the results of this study show that MET combined with ET is a more effective method for improving cervical position sense.

Objective: To investigate the association between spinal damage and functional capacity in patients with axial spondyloarthritis (axSpA) and to compare the performance of 2 radiographic scores (modified Stoke Ankylosing Spondylitis Spine Score [mSASSS] and Combined Ankylosing Spondylitis Spine Score [CASSS])., Methods: Radiographs from 101 patients with axSpA were scored for cervical facet joints (CFJ) and mSASSS for vertebral bodies. CASSS was calculated as the sum of both scores. Physical function was assessed by Bath Ankylosing Spondylitis Functional Index (BASFI); disease activity by Bath Ankylosing Spondylitis Disease Activity Index (BASDAI) and Ankylosing Spondylitis Disease Activity Score (ASDAS); mobility by Bath Ankylosing Spondylitis Metrology Index (BASMI); and quality of life by Ankylosing Spondylitis Quality of Life (ASQOL). Univariate and multivariate analyses were performed to investigate the association between possible explanatory variables and outcomes., Results: BASFI correlated strongly with ASQOL (Spearman ρ 0.66) and BASDAI (ρ 0.70), moderately with BASMI (ρ 0.46) and ASDAS (ρ 0.59), and weakly with mSASSS (ρ 0.29) and CASSS (ρ 0.28). A best-fit multivariate model for BASFI, adjusted for symptom duration, age, sex, and smoking status, included BASDAI ( B 0.76, P < 0.001), BASMI ( B 0.62, P < 0.001), and history of total hip arthroplasty ( B 1.22, P = 0.05). Radiographic scores were predictors of BASFI only when BASMI was removed from the model (mSASSS: B 0.03, P = 0.01; CASSS: B 0.02, P = 0.01)., Conclusion: Spinal damage was independently associated with physical function in axSpA, but to a lesser extent than disease activity and mobility. Moreover, incorporating CFJ assessment in the mSASSS did not improve the ability to predict function., (Copyright © 2024 by the Journal of Rheumatology.)

Study Design: A cross-sectional and observational study., Objective: To investigate the incidence of bidirectional lumbar facet tropism and its relationship with lumbar spine disease in adolescents., Summary of Background Data: There is limited information on facet joint asymmetry in the sagittal plane in adolescents., Materials and Methods: The orientation of all lumbar facet joints was measured in the bidirectional planes on computed tomographic images for 191 patients with low back pain. The patients were divided into 4 groups according to age (<15 or ≥15 yr) and sex. The facet joint angle and tropism rate were compared among the groups. Facet tropism was defined as a difference in bilateral angle of >10° in the axial plane and >5° in the sagittal plane. Facet joint orientation was compared among groups using a one-way analysis of variance and Tukey honestly significant difference test or Games-Howell post hoc test and the incidence of facet tropism using the Kruskal-Wallis test with Bonferroni correction. The association of facet tropism with disease was investigated further by analyzing facet joint orientation and the incidence of facet tropism in 116 patients with single-level lumbar disease., Results: Facet tropism was observed in 8.7% of axial views and 7.5% of sagittal views. The incidence of axial facet tropism was significantly higher in male patients aged ≥15 years, especially at L4/5. Facet joint morphology in the axial plane was more coronal at L3/4 and L4/5 in male patients ≥15 years than in those <15 years. Facet joint morphology in the sagittal plane was unchanged at around 15 years of age in both sexes. Axial facet tropism was found at L4/5 in 55.6% of patients with herniated nucleus pulposus. There was a significant difference in sagittal facet orientation in patients with spondylolysis at L5. The facet angle was significantly larger in patients with L5 spondylolysis at L3/4 and L4/5., Conclusions: Facet tropism in adolescents is similar in the axial and sagittal planes. Facet tropism and specific morphology may be related to lumbar disk herniation and spondylolysis in this age group., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Most ball-in-socket artificial lumbar disc implanted in the spine result in increased hypermobility of the operative level and overloading of the facet joint., Methods: A finite element model was established and validated for the lumbar spine (L1-L5). The structure of the Mobidisc prosthesis was modified, resulting in the development of two new intervertebral disc prostheses, Movcore and Mcopro. The prostheses were implanted into the L3/L4 level to simulate total disc replacement, and the biomechanical properties of the lumbar spine model were analyzed after the operation., Findings: Following the implantation of the prostheses, the mobility of operative level, peak stress of lumbar spine models, and peak stress of facet joint increased. The performance of mobility was found to be more similar between Movcore and Mobidisc. The mobility and facet joint peak stress of the Mcopro model decreased progressively with an increase in the Young's modulus of the artificial annulus during flexion, extension, and lateral bending. Among all the models, the Mcopro50 model had the mobility closest to the intact model. It showed a 3% decrease in flexion, equal range of motion in extension, a 9% increase in left lateral bending, a 7% increase in right lateral bending, and a 3% decrease in axial rotation., Interpretation: The feasibility of the new intervertebral disc prostheses, Movcore and Mcopro, has been established. The Mcopro prosthesis, which features an artificial annular structure, offers significant advantages in terms of reduced mobility of the operative level and peak stress of facet joint., Competing Interests: Declaration of competing interest All authors disclosed no relevant relationships., (Copyright © 2023. Published by Elsevier Ltd.)

To evaluate the impact of the preoperative severity of facet joint arthropathy on long-term functional outcomes and spinopelvic parameters in patients undergoing lumbar-stability-preserving decompression and Dynesys fixation. In this retrospective study, 88 patients undergoing combined surgery at our hospital from 2008 to 2015 were included. The patients were divided into two groups, the less and more than mean degeneration groups, based on preoperative facet joint arthropathy of the index level(s). The clinical outcomes were the Visual Analogue Scale (VAS) score, the Oswestry Disability Index (ODI) score and spinopelvic parameters. The mean follow-up durations for the less and more than mean degeneration groups were 84.83 ± 27.58 and 92.83 ± 20.45 months, respectively. The combined surgery significantly improved VAS and ODI scores, and increased sacral slope (SS) regardless of preoperative arthropathy severity. In addition, facet joint arthropathy at adjacent levels continued to worsen after surgery in both arthropathy severity groups. Preoperative facet joint arthropathy did not influence most long-term clinical outcomes in patients undergoing lumbar-stability-preserving decompression and Dynesys fixation. This combined surgery may be suitable for patients with facet joint arthropathy regardless of disease severity.

Background: Facet tropism (FT) refers to the difference in the orientation of facet joints with respect to each other in the sagittal plane. FT leads to unequal biomechanical forces on facet joint and intervertebral disc during rotation and other physiologic movements. Most of the studies have reported the incidence of FT in the lumbar spine to vary between 40% and 70%, with L4-5 level being the most commonly afflicted level. The objective of this study was to find the association between FT and various lumbar and cervical degenerative disorders., Methods: A systematic search of PubMed was performed with the keywords "facet tropism" and "facet asymmetry." Data for meta-analysis were extracted from the studies to obtain pooled impact of FT on lumbar disc herniation (LDH) and lumbar degenerative spondylolisthesis (LDS)., Results: Eighty-two articles were included in the systematic review and 18 studies had the required data to be included in the meta-analysis. The pooled standard mean difference between FT angles in patients with or without LDH was 0.31 with (P = 0.04). The pooled odds ratio for FT in patients with LDH was 3.27 with (P = 0.02). Subgroup analysis showed that there is no significant difference in the L3/4, L4/5, and L5S1 subgroups. The pooled standard mean difference between FT angles in patients with or without LDS was 0.54 (P = 0.009)., Conclusions: FT is significantly associated with LDH and LDS along with various other lumbar and cervical degenerative diseases., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Study Design: A retrospective case-control study., Objective: Investigating the correlation between the facet tropism (FT) and subaxial cervical disc herniation (CDH)., Summary of Background Data: Although debatable, it was widely reported that FT was associated with lumbar disc herniation. However, the exact correlation between FT and subaxial CDH is still unclear., Methods: Two-hundred patients with any disc herniation at C3/4, C4/5, C5/6, or C6/7 and 50 normal participants without CDH (normal control group) were included in this study. For patients, the cervical levels with CDH and the levels without herniation were classified into the "herniation group" and "patient control group," respectively. Bilateral facet joint angles at C3/4, C4/5, C5/6, and C6/7 on sagittal, axial, and coronal planes were measured on computed tomography (CT). The disc degeneration at each level was assessed on magnetic resonance imaging (MRI)., Results: Both the mean difference between left and right facet angles and tropism incidence in herniation group were significantly greater than those in two control groups whenever at C3/4, C4/5, C5/6, or C6/7 level and whenever on sagittal, axial, or coronal plane. The mean differences of angles and tropism incidences in most patient control groups were not significantly greater than those of corresponding normal control groups. The incidence of greater facet angle at the left or right side was not significantly different among the left, central, and right herniation groups. The mean disc degeneration grades in both herniation and patient control groups were significantly higher than those in normal control groups while no difference between herniation and patient control groups., Conclusion: The FT on the sagittal, axial, and coronal planes are all associated with CDH in the subaxial cervical spine. The greater facet angle at the left or right side does not affect the side of herniation. The severity of cervical disc degeneration is not associated with FT.Level of Evidence: 3., (Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.)

Objective: This report analyzes the significance of osteophytes in the overall pathologic scheme in patients with single-level or multilevel cervical spinal degeneration., Methods: From January 2010 to December 2018, 249 patients with cervical spondylosis were surgically treated. The alterations in ventral compression caused by disc bulges, osteophytes, and ligament buckling (disc-osteophye-ligament [DOL] complex) at single or multiple levels were evaluated after surgical treatment that involved only spinal fixation and did not involve any kind of bone or soft tissue decompression. Delayed (≥1 year after surgery) postoperative imaging was available in 165 patients and these patients formed the study group. Forty-five patients underwent facet distraction arthrodesis (group A), 106 patients underwent only-fixation involving transarticular screw insertion (group B), and 14 patients underwent hybrid fixation that involved both intra-articular spacers and transarticular fixation techniques (group C) as the surgical treatment., Results: The size of the DOL complex at the segments that underwent fixation was reduced in 136 patients. The size of the DOL complex or its related dural or neural compression did not increase in any of the cases evaluated. Reduction in the size of DOL was more pronounced in patients in group A in both immediate postoperative and delayed images and in patients in group C at spinal levels at which facet distraction was performed using facet distraction spacers., Conclusions: Spinal stabilization reduces the size of osteophytes. Facet distraction spacers are more effective in reduction of the size of DOL in both immediate and delayed postoperative periods., (Copyright © 2020 Elsevier Inc. All rights reserved.)

The aim of the study was to evaluate the biomechanical properties of a novel nonfused artificial vertebral body in treating lumbar diseases and to compare with those of the fusion artificial vertebral body. An intact finite element model of the L1-L5 lumbar spine was constructed and validated. Then, the finite element models of the fusion group and nonfusion group were constructed by replacing the L3 vertebral body and adjacent intervertebral discs with prostheses. For all finite element models, an axial preload of 500 N and another 10 N m imposed on the superior surface of L1. The range of motion and stress peaks in the adjacent discs, endplates, and facet joints were compared among the three groups. The ranges of motion of the L1-2 and L4-5 discs in flexion, extension, left lateral bending, right lateral bending, left rotation and right rotation were greater in the fusion group than those in the intact group and nonfusion group. The fusion group induced the greatest stress peaks in the adjacent discs and adjacent facet joints compared to the intact group and nonfusion group. The nonfused artificial vertebral body could better retain mobility of the surgical site after implantation (3.6°-8.7°), avoid increased mobility and stress of the adjacent discs and facet joints.

Background:  The long-term outcome of facet joint replacement (FJR) still is to be proven., Methods:  We present a prospective case series of 26 (male-to-female ratio of 1:1; mean age: 61 years) patients undergoing FJR with a follow-up of at least 1 year (range: 12-112; mean: 67 months). Visual analog scale (VAS) for back and leg pain, Oswestry Disability Index (ODI), and the 12-Item Short Form Health Survey (SF-12) were applied pre- and postoperatively (after 3, 6, and 12 months) as well as at the last follow-up ( N  = 24). Using X-rays of the lumbar spine ( N  = 20), the range of motion (ROM) and disk height in the indicator and adjacent levels were assessed., Results:  FJR was performed at L3/L4 ( N  = 7), L4/L5 ( N  = 17), and L5/S1 ( N  = 2). Mean VAS (mm) for back pain decreased from 71 to 18, mean VAS for right leg pain from 61 to 7, and from 51 to 3 for the left leg. Mean ODI dropped from 51 to 22% (for all p  < 0.01). Eighty seven percent of patients were satisfied and pretreatment activities were completely regained in 78.3% of patients. Disk height at the indicator and adjacent levels and ROM at the indicator segment and the entire lumbar spine were preserved. No loosening of implants was observed. Explantation of FJR and subsequent fusion had to be performed in four cases (15.4%)., Conclusions:  In selected cases, long-term results of FJR show good outcome concerning pain, quality of life, preservation of lumbar spine motion, and protection of adjacent level., Competing Interests: None declared., (Thieme. All rights reserved.)

Aim: To evaluate the clinical results of patients who underwent unilateral dynamic rod stabilization after unilateral facet joint excision during spinal surgery., Material and Methods: Twenty patients who were diagnosed with degenerative spinal disease or spinal tumor, who were operated on using a unilateral approach, who underwent facet joint resection, and who were stabilized with a unilateral dynamic rod were examined. Visual analog scale (VAS) and Oswestry disability index (ODI) scores were used to clinically evaluate the cases during the preoperative and postoperative periods. Radiological examinations for sagittal alignment, segmental angle, and bone fusion were also conducted., Results: The mean preoperative VAS and ODI scores were 7.6 and 71.7, respectively, and the 12 < sup > th < /sup > postoperative month scores were 1.1 and 12.8, respectively. The mean segmental angle measurements were 22.1° in the preoperative period and 21.6° at the postoperative 12 < sup > th < /sup > month. No deterioration in sagittal alignment and no bone fusion were observed., Conclusion: We can protect segmental movements and provide sufficient stability by applying unilateral dynamic rod stabilization after unilateral facetectomy. In addition, applying screws to one side can reduce operation time and cost as well as the possibility of complications.

Background: Low back pain is a very common musculoskeletal complaint that impacts patients' quality of life in numerous ways. Facet joint injection is a widely used spinal intervention to relieve back pain. Effects of facet joint injection on spinopelvic parameters and the relationship between injection levels and spinopelvic parameter changes have not been evaluated before., Objective: To compare spinopelvic parameters before and after injections at different levels, and to evaluate the correlation between these changes and functional outcome., Methods: 144 patients were included in the study and retrospectively grouped by injection level: Group 1 (n= 72), L4-L5 and L5-S1, and group 2 (n= 72), L1-L2, L2-L3, L3-L4, L4-L5 and L5-S1. Pre- and post-injection Oswestry Disability Index (ODI), sacral slope, pelvic tilt, pelvic incidence, and intervertebral angles between T12 and S1 were compared. The correlation between ODI and radiographic parameter changes was evaluated., Results: The pre- to post-injection ODI change was significantly lower in group 2 (p= 0.010). There was no significant difference between the groups in terms of pre- and post-injection spinopelvic parameters before and after injection (p> 0.05) except pelvic tilt (p= 0.001 and p= 0.007, respectively). There was a significant moderate positive correlation between the change in the ODI value and the change in pelvic tilt (P= 0.012, r= 0.581)., Conclusions: Multilevel lumbar facet injections are clinically more effective than only two-level lower level lumbar injections. Pelvic tilt changes positively correlate with the ODI score changes.

Background: Thoracic facet joint disorder is a common thoracic disorder in clinic, inducing pain and discomfort at the dislocated thoracic vertebrae, radiating to pain of the neck and back. The incidence of thoracic facet joint disorder is higher than the facet disorder of the cervical and lumbar vertebrae. Therefore, an ideal strategy to relieve thoracic facet joint disorder is urgently needed. In recent years, massage therapy has been increasingly accepted by thoracic facet joint disorder patients due to its lower costs, fewer unwanted side effects and safety for clinical use. In this systematic review, we aim to evaluate the effectiveness and safety of massage therapy for patients with thoracic facet joint disorder., Methods: We will search the following electronic databases for randomized controlled trials to evaluate the effectiveness of massage therapy in treating thoracic facet joint disorder: Wanfang and PubMed Database, CNKI, CENTRAL, CINAHL and EMBASE. Each database will be searched from inception to October 2020. The entire process will include study selection, data extraction, risk of bias assessment and meta-analyses., Results: This proposed study will evaluate the effectiveness of massage therapy for patients with thoracic facet joint disorder., Conclusions: This proposed systematic review will evaluate the existing evidence on the effectiveness and safety of massage therapy for patients with thoracic facet joint disorder., Dissemination and Ethics: The results of this review will be disseminated through peer-reviewed publication. Because all of the data used in this systematic review and meta-analysis has been published, this review does not require ethical approval. Furthermore, all data will be analyzed anonymously during the review process., Osf Registration Number: DOI 10.17605/OSF.IO/XMEJD.

Background: The subchondral bone parallels with the progression of osteoarthritis (OA). However, the biomechanical properties and histopathological changes of subchondral bone changes in the lumbar facet joint (LFJ) after long-term axial loading on the spine have not been explored. In this study, we aimed to investigate the subchondral bone histopathological changes that occur in the LFJ and pain behaviors in a novel bipedal standing mouse model., Methods: Sixteen 8-week-old male C57BL/6 mice were randomly assigned into bipedal standing and control groups. A finite element stimulate model based on the micro-CT data was generated to simulate the von Mises stress distribution on the LFJ during different positions. The spine pain behaviors tests were analysis. In addition, the change in the subchondral bone of the LFJ was assessed by histological and immunohistochemistry staining., Results: The computerized simulation of the von Mises stress distribution in the superior articular process of LFJ at the spine level 5 in the lying position increased and reached a maximum value at the bipedal standing posture. The spine pain behavior test revealed that the threshold of pressure tolerance decreased significantly in bipedal groups relative to control groups, whereas the mechanical hyperalgesia of the hind paw increased significantly in bipedal groups relative to control groups. The axial load accelerates LFJ degeneration with increased histological scores in bipedal groups. The expression of type II collagen and aggrecan (ACAN) was significantly decreased in the bipedal groups compared with the control groups, whereas the expression of MMP13 was increased. Compared with the control groups, the osteoclast activity was activated with higher TRAP-positive staining and associated with increased CD-31-positive vessels and GCRP-positive nerve ending expression in the subchondral bone of LFJ., Conclusion: Collectively, long-term axial loading induces the development of spine hyperalgesia in mice associate with increased osteoclast activity and aberrant angiogenesis and nerve invasion into the subchondral bone of LFJ that stimulates the natural pathological change in human LFJ OA. These results indicate that aberrant bone remodeling associate with aberrant nerve innervation in the subchondral bone has a potential as a therapeutic target in LFJ OA pain., Competing Interests: The authors have no conflicts of interest to declare., (Copyright © 2020 Miao Li et al.)

A commonly disputed medicolegal issue is the documentation of the location, degree, and anatomical source of an injured plaintiff's ongoing pain, particularly when the painful region is in or near the spine, and when the symptoms have arisen as result of a relatively low speed traffic crash. The purpose of our paper is to provide health and legal practitioners with strategies to identify the source of cervical pain and to aid triers of fact (decision makers) in reaching better informed conclusions. We review the medical evidence for the applications and reliability of cervical medial branch nerve blocks as an indication of painful spinal facets. We also present legal precedents for the legal admissibility of the results of such diagnostic testing as evidence of chronic spine pain after a traffic crash. Part of the reason for the dispute is the subjective nature of pain, and the fact that medical documentation of pain complaints relies primarily on the history given by the patient. A condition that can be documented objectively is chronic cervical spine facet joint pain, as demonstrated by medial branch block (injection). The diagnostic accuracy of medial branch blocks has been extensively described in the scientific medical literature, and evidence of facet blocks to objectively document chronic post-traumatic neck pain has been accepted as scientifically reliable in courts and tribunals in the USA, Canada and the United Kingdom. We conclude that there is convincing scientific medical evidence that the results of cervical facet blocks provide reliable objective evidence of chronic post-traumatic spine pain, suitable for presentation to an adjudicative decision maker.

Literature describes different patterns of calcaneal facets for the talus in terms of whether some calcaneal facets are connected or separated from each other or completely absent. The aim of this study was to establish the patterns of calcaneal facets for the talus, to calculate their total area, and to analyse the data with respect to gender. The study involved 59 calcanei which were photographed. The patterns of calcaneal facets noted in this study were compared with the patterns from the literature. ImageJ program was used to measure different parameters on calcanei. The pattern 1 was the most commonly found in the study sample (45.76%), then the pattern 2 (40.68%), and finally the pattern 3 (13.56%). That order of frequencies is the same in both sexes. The patterns 1 and 2 have a larger contact surface for the talus in comparison to the pattern 3. Male bones have a larger contact surface for the talus than female bones. The sum of the pattern 1 and pattern 3 frequencies was high. Knowing the frequency of different patterns of calcaneal facets for the talus in a certain population is important for orthopaedic surgeons when performing foot osteotomy., Competing Interests: The authors have declared that no competing interests exist.

Objective: This research studied the in vivo motion characteristics of the L3-S1 lumbar spine with facet-joint degeneration during functional activities., Methods: Thirteen male and 21 female patients with facet-joint degeneration at the L3-S1 spinal region were included in the study. The L3-S1 lumbar segments of all the patients were divided into 3 groups according to the degree of facet-joints degeneration (mild, moderate, or severe). The ranges of motion (ROM) of the vertebrae were analyzed using a combination of computed tomography and dual fluoroscopic imaging techniques. During functional postures, the ROMs were compared between the 3 groups at each spinal level (L3-L4, L4-L5, and L5-S1)., Results: At L3-L4 level, the primary rotations between the mild and moderate groups during left-right twisting activity were significantly different. At L4-L5 level, the primary rotation of the moderate group was significantly higher than the other groups during flexion-extension. During left-right bending activities, a significant difference was observed only between the moderate and severe groups. At L5-S1 level, the rotation of the moderate group was significantly higher than the mild group during left-right bending activity., Conclusions: Degeneration of the facet joint alters the ROMs of the lumbar spine. As the degree of facet-joint degeneration increased, the ROMs of the lumbar vertebra that had initially increased declined. However, when there was severe facet-joint degeneration, the ROMs of the lumbar spine declined to levels comparative to the moderate group. The relationship between the stability of the lumbar vertebra and the degree of facet-joint degeneration requires further study.

Objective: The composition of cervical-spine meniscoids may have clinical significance in neck-pain conditions, but the accuracy of assessment of meniscoid composition in vivo using magnetic resonance imaging has not been established. The aim of this study was to compare cervical-spine meniscoid composition by magnetic resonance imaging with histologic composition., Methods: Four embalmed cadaveric cervical spines (mean [standard deviation] age, 79.5 [3.7] years; 1 female, 3 male) underwent magnetic resonance imaging, allowing radiologic classification of lateral atlantoaxial- and zygapophyseal-joint (C2-3 to C6-7) meniscoids as either mostly fatty, mixed tissue, or mostly connective tissue. Subsequently, each joint was dissected and disarticulated to allow excision of meniscoids for histologic processing. Each meniscoid was sectioned sagittally, stained with hematoxylin and eosin, examined using light microscopy, and classified as adipose, fibroadipose, or fibrous in composition. Data were analyzed using the kappa statistic with linear weighting., Results: From dissection, 62 meniscoids were identified, excised, and processed; 46 of these 62 were visualized with magnetic resonance imaging. For single-rater identifying structures, agreement between assessment of meniscoid composition by magnetic resonance imaging and by microscopy was fair (κ = 0.24; 95% confidence interval, 0.02-0.46; P = .02)., Conclusion: Findings suggest that the accuracy of this method of magnetic resonance imaging assessment of cervical-spine meniscoid composition may be limited. This should be considered when planning or interpreting research investigating meniscoid composition using magnetic resonance imaging., (Copyright © 2020. Published by Elsevier Inc.)

The aim of this study is to establish whether facet tropism (FT) and orientation (FO) are associated with degenerative lumbar spinal stenosis (DLSS). A retrospective computerized tomography (CT) study including 274 individuals was divided into two groups: control (82 males and 81 females) and stenosis (59 males and 52 females). All participants have undergone high-resolution CT scan of the lumbar spine in the same position. FT and FO were measured at L1-2 to L5-S1. Significant sagittal FO was noted in the stenosis males (L2-3 to L4-5) and females (L2-3 to L5-S1) compared to the controls. The prevalence of FT was remarkably greater in the stenosis males (L4-5, L5-S1) and females (L3-4, L5-S1) compared to their counterparts in the control group. Our results also showed that FT (L3-4 to L5-S1) increases approximately 2.9 times the likelihood for DLSS development. This study indicates that FO and FT in the lower lumbar spine are significantly associated with DLSS., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2020 Janan Abbas et al.)

Background: An autologous bone-cage made from the spinous process and laminae might provide a stability in posterior lumbar interbody fusion (PLIF) close that of the traditional-cage made of polyetheretherketone (PEEK) or titanium. The biomechanical effect of autologous bone-cages on cage stability, stress, and strains, and on the facet contact force has not been fully described. This study aimed to verify whether autologous bone-cages can achieve similar performance as that of PEEK cages in PLIF by using a finite element analysis., Methods: The finite element models of PLIF with an autologous bone-cage, a titanium cage, and a PEEK cage were constructed. The autologous bone-cage was compared with the titanium and PEEK cages. The mechanical properties of the autologous bone-cage were obtained through mechanical tests. The four motion modes were simulated. The range of motion (ROM), the stress in the cage-end plate interface, and the facet joint force (FJF) were compared., Results: The ROM was increased at adjacent levels but decreased over 97% at the treated levels, and the intradiscal pressure at adjacent levels was increased under all conditions in all models. The FJF disappeared at treated levels and increased under extension, lateral bending, and lateral rotation in all models. The maximum stress of the cage-endplate interface was much lower in the autologous bone-cage model than those in the PEEK and titanium cage models., Conclusions: In a finite model of PLIF, the autologous bone-cage model could achieve stability close that of traditional titanium or PEEK cages, reducing the risk of subsidence.

Objective: The present study aimed to investigate whether experimentally induced lumbar facet-joint OA lead to degenerative changes and enhanced SP expression within the ipsilateral neurosegmentally linked tibiofemoral cartilage., Methods: Adult male Sprague-Dawley rats were assigned to left side L5-L6 facet mechanical compression injury (surgery) ( n = 6), L5-L6 facet exposure with no compression (sham) ( n = 5), or naïve (no surgery) ( n = 4) groups. The morphology of the tibiofemoral articular cartilage was assessed using a modified Mankin scoring system. Immunohistochemistry was used to examine the density of chondrocytes stained positive for SP (cells/cm 2 ) in the ipsilateral tibiofemoral cartilage at 28 days postintervention., Results: Tibiofemoral cartilage in the surgery group showed consistent loss of superficial zone chondrocytes, mild roughening of the articular surface and occasional chondrocyte clusters as well as a greater density of SP mainly in the superficial cartilage zone compared with sham and naïve groups, although they also had a basic SP-expression., Conclusion: Our results support the hypothesis that neurogenic mechanisms may mediate the spread of SP to neurosegmentally linked heterologous joints affecting the distal cartilage homeostasis. These findings contribute additional insight into the potential role of neurogenic inflammation with implications in the pathophysiology of chronic inflammatory joint disease and OA.

Objective: To report in vivo measurements of lumbar facet joint subchondral bone mineral density used in the description of facet joint loading patterns and to interrogate if low back pain is associated with changes in subchondral bone mineral density., Materials and Methods: In vivo measurements of lumbar facet joint subchondral bone mineral density (L1/2 to L5/S1) in Hounsfield units were performed on 89 volunteers (56 controls and 33 with low back pain) by computed tomography osteoabsorptiometry at subchondral regions between 1.5 mm and 2.5 mm below the joint surface. The facet surface was divided into five topographic zones: cranial, lateral, caudal, medial, and central., Results: We analyzed 1780 facet joint surfaces. Facets were denser (p < 0.0001) both in superior facets and in low back pain subjects (p < 0.0001). For the entire cohort, the facet center zone subchondral bone mineral density was higher (p < 0.0001) than that of the peripheral zones. The analyses indicate that subchondral bone mineral density is highest in patients with low back pain, the superior facets, and the center zone of the facets., Conclusions: Subchondral bone mineral density is thought to reflect cumulative, long-term distribution of stress acting on a joint. This work shows that higher subchondral bone mineral density values in the center zone indicate predominant stress transmission through the center of the facet joints. Finally, the greater subchondral bone mineral density in patients with low back pain may reflect both increased load bearing by the facets secondary to disc degeneration and misdistribution of loading within the joint.

Neck is one of the most common site of musculoskeletal symptom manifestations. An impaired spinal curvature is a common finding in patients with mechanical neck pain. A pre-post quasi experimental pilot study was conducted at Fauji Foundation Hospital from January- March 2017,in which 12 patients with mechanical neck pain and straightening of the cervical spine were included and treated for 7 consecutive sessions consisting of muscle energy techniques (MET) in combination with facet joint mobilization. The objective of this study was to determine the effects of MET and facet joint mobilization on spinal curvature and functional outcomes in patients with neck pain. Outcome measurement tools that were included comprised of pain severity, neck disability index (NDI), cervical lordosis which was measured via x-ray based posterior tangential method, goniometry for cervical range of motion (ROM) and modified sphygmomanometer dynamometry (MSD) for isometric muscle strength. A significant difference was observed in pre and post treatment scores for all outcomes (p<0.05); demonstrating an effective combination therapy in terms of improved spinal curvature, pain, disability, ROM and isometric muscle strength.

The aim of this study was to determine the effect of the posterior ligaments and facet joints on the shear stiffness of lower cervical functional spinal units in anterior, posterior, and lateral shear. Five functional spinal units were loaded in anterior, posterior, and right lateral shear up to 100 N using a custom-designed apparatus in a materials testing machine. Specimens were tested in three conditions: intact, with the posterior ligaments severed, and with the facet joints removed. There was a significant decrease in anterior stiffness in the 20-100 N load range from 186 (range: 98-327) N/mm in the intact condition to 105 (range: 78-142) N/mm in the disc-only condition (p = 0.03). Posterior stiffness between these condition decreased significantly from 134 (range: 92-182) N/mm to 119 (range: 83-181) N/mm (p = 0.03). There was no significant effect of posterior ligament removal on shear stiffness. No significant differences were found in the lateral direction or in the 0-20 N range for any direction. Under a 100-N shear load, the facet joints played a significant role in the stiffness of the cervical spine in the anterior-posterior direction, but not in the lateral direction.

Objectives: This study aims to evaluate whether ultrasound (US)-guided facet joint injection reduces pain and improves mobility in patients with failed back surgery syndrome (FBSS)., Patients and Methods: This retrospective study included 27 patients (8 males, 19 females; mean age 43.6±11.5 years; range, 31 to 54 years) who underwent US-guided facet injections for FBSS between January 2017 and January 2019. Patients' medial records were assessed. Pain rating scores were evaluated with the Numeric Rating Scale (NRS). Functional status was assessed with Oswestry Disability Index (ODI) version 2.0. Lumbar flexion degree was noted. After injection (lidocaine-betamethasone mixture), patients were reevaluated at first and sixth months. The study data were analyzed with Wilcoxon signed-rank test., Results: Successful facet joint injections were achieved without any complications in all patients. The median duration of time after surgery was 7.8±1.3 months. Mean duration of pain was 6.7±5.7 months. There was a significant decrease in NRS values between baseline and sixth month comparison (7.0 at baseline and 6.0 at sixth month, p=0.006). Baseline-first month and first-sixth months comparisons were not significant (p=0.165 and p=0.106, respectively). For ODI, no significant change was observed between baseline-first month, first-sixth months, and baseline-sixth month comparisons (p=0.109, p=0.857, and p=0.095, respectively). For lumbar flexion, all comparisons resulted in significant increase (50.0° for baseline, 60.0° at first month, and 70.0° at sixth month; p<0.001 for baseline-first month comparison, p<0.001 for baseline-sixth month comparison, and p<0.001 for first-sixth months comparison)., Conclusion: Our results show that pain is reduced and mobility is improved with US-guided facet joint injections in patients with FBSS.

Background: The purpose in this study is to investigate the T2 value of lumbar facet joint (FJ) in subjects without lumbar spinal disorders, age from 20s to 70s, using T2 mapping, and to evaluate the correlation between age and T2 value. And also, we investigated the T2 value of lumbar intervertebral disc (IVD) in the same way as FJ, and evaluated the correlation between the T2 value of FJ and that of IVD., Methods: We investigated 60 volunteers (30 male, 30 female), who were recruited from six age groups, 20s-70s (10 subjects in each decade; 5 male, 5 female). We measured the T2 values of FJ at the L4/5 level in axial image and those of IVD (nucleus pulposus; NP, anterior and posterior annulus fibrosus; AAF and PAF) at the L4/5 level in midline sagittal image. We investigated the correlation between age and T2 value of FJ, and the correlation between the T2 value of FJ and that of IVD., Results: There was a strong positive correlation between age and T2 value of FJ (r = 0.717). Age and T2 values of IVD were negatively correlated (NP; r = -0.728, AAF; r = -0.696, PAF; r = -0.580). There was a negative correlation between T2 value of FJ and that of IVD (NP; r = -0.575, AAF; r = -0.617, PAF; r = -0.492)., Conclusions: T2 value of FJ was significantly increased as age rose. Our results suggest that T2 mapping could detect the degenerative changes of FJ related to aging even in subjects without lumbar spinal disorders. The results of this study will be the reference data of FJ T2 value in order to evaluate the relationship between low back pain and FJ using T2 mapping., (Copyright © 2019 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.)

Background: To investigate the biomechanical changes in the development of scoliosis due to intervertebral disc and facet joint degeneration., Methods: We enrolled 39 cases of fresh-frozen lumbar spine specimens and underwent CT scanning and 3D reconstruction. An Osirix Dicom imaging system was to assess the degeneration of the intervertebral disc and facet joints, and mechanical loading was conducted using a spine mechanical instrument with the frequency set at plus/minus 7.5 NM, 0.005 Hz. Range of motion (ROM) and neutral zone (NZ) of 39 cadaveric lumbar spines were tested., Findings: Degeneration existed in all 39 cases of the lumbar specimens: the Cobb angle >10° in 5 cases (degenerative scoliosis (DS) group), between 3° and 10° in 9 cases (pre-degenerative scoliosis (PS) group) and <3° in 25 cases (no scoliosis (NS) group). The axial torsion (AT) range of motion (ROM AT ) and the NZ of the DS and PS groups was greater than in the NS group and increased with increasing Cobb angle. A significant correlation was found between the degeneration of the intervertebral disc and the AT and the AT correlated with the Cobb angle and facet joint degeneration., Interpretation: The AT correlated with intervertebral disc and facet joint degeneration, which might be a mechanic factor in the occurrence and development of degenerative scoliosis., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Objective: We aimed to define the potential complications of intra-articular steroid injections into the lateral C1-2 articulations and safety margins to the relevant structures., Methods: A total of 488 contrast-enhanced computed tomography angiogram (CTA) "arch to vertex" studies were retrospectively reviewed for theoretical intersection of the vertebral artery or thecal sac and distance of the named structures from the anticipated/theoretical trajectory of injection into the lateral C1-C2 joint., Results: Patients were 60.4±15.8 years old and 55.5% male. In total, seven vertebral arteries and 11 thecal sac theoretical intersections were found. In cases without a direct intersection, the distance from the trajectory (range) was 0.71±0.18 (0.22-1.44) cm to the vertebral artery and 0.6±0.22 (0.14-1.8) cm to the thecal sac., Conclusions: Although injection of steroid into the lateral C1-C2 articulation for pain management has historically been reported to carry risk of severe complications due to close proximity and location variability of surrounding structures, our study quantifies the potential risk of such injections. Further, our analysis suggests that preprocedural imaging should be considered., (© Crown copyright 2019.)

Purpose: Abnormal stress in the lumbar vertebra, also known as bony stress, can be a precursor to degenerative changes which may manifest as low back pain (LBP). However, the prevalence of bony stress in the lumbar spine and its relationship with degenerative changes and LBP is unclear. The purpose of this study was to evaluate the prevalence of bony stress in the lumbar spine and its relationship with intervertebral disc (IVD) degeneration, facet osteoarthritis and LBP in patients under 25 years of age., Methods: A retrospective case-control study of 130 patients under 25 years of age was conducted from a population of 493 patients who had lumbar MRI across three imaging centres over three years. A cohort of 55 consecutive patients with bony stress was identified. A control group of consecutive patients (n = 75) without bony stress was also selected from the population., Results: Bony stress was prevalent in 11% (95% CI [8.4-14.5%]) of patients and was not diagnosed in 36% (95% CI [22-55%]) of these cases. Patients with bony stress had over twofold (OR 2.3, 95% CI [1.1-4.8]) and fivefold (OR 5.3, 95% CI [2.11-13.3]) higher likelihood of having IVD degeneration and LBP, respectively, when compared with the control group. Bony stress was not found to be associated with facet osteoarthritis., Conclusion: Bony stress in the lumbar spine was prevalent in 11% of patients under 25 years of age. It was commonly undiagnosed in radiology reports (not reported in 36% of the cases). Being significantly associated and with an increased likelihood of IVD degeneration and LBP, we posit that bony stress is likely a symptomatic and clinically meaningful diagnostic entity in the assessment of LBP. These slides can be retrieved under Electronic Supplementary Material.

Posterior pedicle fixation technique is a common method for treating thoracolumbar burst fractures, but the effect of different fixation techniques on the postoperative spinal mechanical properties has not been clearly defined, especially on adjacent segments. A finite element model of T10-L2 with moderate T12 vertebra burst fracture was constructed to investigate biomechanical behavior of three posterior pedicle screw fixation techniques. Compared with traditional short-segment 4 pedicle screw fixation (TS-4) and intermediate long-segment 6 pedicle screw fixation (IL-6), mono-segment 4 pedicle screw fixation (MS-4) provides a safer surgical selection to prevent the secondary degeneration of adjacent segments in the long-term.

Facet arthrosis at surgical level was identified as major complication after total disc replacement (TDR). One of the reasons for facet arthrosis after TDR has been speculated to be the hypermobility of artificial discs. Accordingly, the artificial disc that can constrain the hypermobility of ball-and-socket type artificial discs and reduce loading on facet joints is demanded. The proposed artificial disc, which is named as NewPro, was constructed based on the FDA-approved ProDisc but contained an interlocking system consisting of additional bars and grooves to control the range of motion (ROM) of lumbar spine in all anatomical planes. The three-dimensional finite element model of L1 to L5 was developed first, and the biomechanical effects were compared between ProDisc and NewPro. The ROM and facet contact force of NewPro were significantly decreased by 42.7% and 14% in bending and by 45.6% and 34.4% in torsion, respectively, compared with the values of ProDisc, thanks to the interlocking system. In addition, the ROM and facet contact force could be selectively constrained by modifying the location of the bars. The proposed artificial disc with the interlocking system was able to constrain the intersegmental rotation effectively and reduce excessive loading on facet joints, although wear and strength tests would be needed prior to clinical applications., (© 2019 John Wiley & Sons, Ltd.)

Purpose: The endplate defects (EDs), Modic changes (MCs), disc degeneration (DD), facet orientation (FO), and facet tropism (FT) were demonstrated to be related to the low back pain (LBP). The aim of this study was to investigate possible correlations between them., Methods: 75 patients were reviewed to evaluate the degenerative change in vertebral bodies (EDs and MCs), intervertebral discs (DD), and facet joint degeneration (FO and FT). All patients were categorized into four groups based on the grade of EDs. Clinical outcomes were evaluated with the visual analog scale (VAS) and Oswestry disability index (ODI) before and after surgery., Results: There was no difference between the four groups in baseline characteristics except for gender and weight. FT is positively correlated with FO. The same rule exists between EDs, the size of MCs II, FO (left) and FO (right), and VAS and ODI. The grade of EDs is positively correlated with the grade of DD. L4-L5 can bear more load than other levels; thus, the grade of EDs is higher than that of other lumbar levels. The preoperative LBP was relieved in all groups in varying degrees. The change of pain and dysfunction is inversely proportional to the grade of EDs in the general trend., Conclusion: The relationship between weight, gender, and disc degeneration provided a mechanism by which increasing weight can predispose to DD. Different grades of EDs had different effects on patients with LBP. There was a significant correlation between EDs, MCs II, DD, FT, and FO.

Purpose: This retrospective study determined the rate of osteoarthritis and spontaneous facet joint fusion and analyzed risk factors related to patient characteristics, fracture type or surgical technique on pre- and postoperative CT after percutaneous instrumentation in thoracolumbar fractures., Methods: 1050 facet joints adjacent to screws in 148 patients (15-85 years) with thoracolumbar fractures were analyzed with an average time between CTs of 12.3 months. Screw diameters, lengths and cement augmentation were recorded. Facet joint violation by screw trajectory and by insertion depth was classified in three grades. Pre- and postoperative osteoarthritis was graded as absent, minor or severe and postoperative facet joint fusion as absent, partial or complete., Results: The facet violation rate was moderate in 15.4% and severe in 0.6% according to screw trajectory, and 11.0 and 0.6%, respectively, according to insertion depth. Osteoarthritis was preoperatively rated moderate in 9.6% and severe in 1.2%. A progression was evidenced in 79 facet joints (7.5%). Screw cement augmentation was the main predictive factor (p < 0.0001). Partial fusion was evidenced in 2.6% and complete fusion in 1% of facet joints. Risk factors were: BMI (p = 0.0002), age (p = 0.0013), preoperative osteoarthritis (p = 0.0005), time between 2 CTs (p = 0.0001), B-type fractures (p = 0.0005), concomitant anterior fusion (p = 0.0034)., Conclusions: Occurrence or worsening of osteoarthritis was mainly observed in elderly patients with cement-augmented screws and spontaneous facet fusion in elderly patients with high BMI and preoperative osteoarthritis, or in anteriorly fused B-type injuries. Thus, percutaneous instrumentation can safely be removed after fracture consolidation in younger patients while preserving facet joints.

Background: Although the cervical interspinous ligament is a potential source of neck pain, the effects on cervical joint motion and pressure pain sensitivity has never been investigated. The understanding of the relationship will broaden our understanding of cervical biomechanics and improve diagnosis and treatment of neck pain., Methods: Fluoroscopy videos of cervical flexion and extension movements and pressure pain thresholds over bilateral C2/C3 and C5/C6 facet joints were collected in fifteen healthy subjects before and after injections of hypertonic and isotonic saline in C4/C5 ISL. The videos were divided into 10 even epochs and the motion of individual joints during each epoch was extracted. Joint motion parameters including anti-directional motion, pro-directional motion, total joint motion and joint motion variability were extracted across epochs. Joint motion parameters and PPTs were compared before and after injection of hypertonic and isotonic saline separately., Findings: Compared with baselines: hypertonic saline injection 1) decreased anti-directional motion and joint motion variability at C4/C5 (P < 0.05) and increased at C2/C3 (P < 0.05) during extension; 2) increased total joint motion of C0/C1 during first half range (P < 0.05) and decreased during second half range of extension, and total joint motion of C2/C3 increased during second half range of extension (P < 0.05) and; 3) increased pressure pain thresholds over left C2/C3 facet joint (P < 0.01)., Interpretation: The cervical interspinous ligament pain redistributed anti-directional motion between C4/C5 and C2/C3 during dynamic extension and decreased pressure pain sensitivity over the left C2/C3 facet joint., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Neck pain from cervical facet loading is common and induces inflammation and upregulation of nerve growth factor (NGF) that can sensitize the joint afferents. Yet, the mechanisms by which these occur and whether afferents can be pre-conditioned by certain nonpainful stimuli are unknown. This study tested the hypothesis that a nonpainful mechanical or chemical insult predisposes a facet joint to generate pain after a later exposure to typically nonpainful distraction., Methods: Rats were exposed to either a nonpainful distraction or an intra-articular subthreshold dose of NGF followed by a nonpainful distraction two days later. Mechanical hyperalgesia was measured daily and C6 dorsal root ganglia (DRG) tissue was assayed for NGF and matrix metalloproteinase-3 (MMP-3) expression on day 7., Findings: The second distraction increased joint displacement and strains compared to its first application (p = 0.0011). None of the initial exposures altered behavioral sensitivity in either of the groups being pre-conditioned or in controls; but, sensitivity was established in both groups receiving a second distraction within one day that lasted until day 7 (p < 0.024). NGF expression in the DRG was increased in both groups undergoing a pre-conditioning exposure (p < 0.0232). Similar findings were observed for MMP-3 expression, with a pre-conditioning exposure increasing levels after an otherwise nonpainful facet distraction., Interpretation: These findings suggest that nonpainful insults to the facet joint, when combined, can generate painful outcomes, possibly mediated by upregulation of MMP-3 and mature NGF., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objectives: To determine whether individualised manual therapy plus guideline-based advice results in superior outcomes to advice alone in participants with clinical features potentially indicative of lumbar zygapophyseal joint pain., Design: Multi centre parallel group randomised controlled trial., Setting: 14 physiotherapy clinics in Melbourne, Australia., Participants: Sixty-four participants with clinical features potentially indicative of lumbar zygapophyseal joint pain., Interventions: 10-weeks of physiotherapy comprising individualised manual therapy based on pathoanatomical, psychosocial and neurophysiological barriers to recovery plus guideline-based advice (10 sessions) or advice alone (two sessions)., Main Outcome Measures: Primary outcomes were activity limitation (Oswestry Disability Index), and separate 0 to 10 numerical rating scales for leg pain and back pain. Measures were taken at baseline and 5, 10, 26 and 52-week., Results: Between-group differences for back pain favoured individualised manual therapy over advice for back pain at 5 (1.0; 95% CI 0.6 to 2.0), 10 (1.5; 95% CI 0.5 to 2.4) and 26-weeks (1.4; 95% CI 0.4 to 2.3) as well as for activity limitation at 26 (8.3; 95% CI 2.6 to 14.2) and 52-weeks (8.2; 95% CI 2.3 to 14.2). There were no significant between-group differences for leg pain. Secondary outcomes and responder analyses also favoured individualised manual therapy at almost all time-points., Conclusions: In participants with clinical features potentially indicative of lumbar zygapophyseal joint pain, individualised manual therapy led to greater reduction in back pain at 5, 10 and 26-week follow-up as well as activity limitation at 26 and 52-weeks. Between-group differences were likely to be clinically important., Trial Registration: ACTRN12609000334202., (Copyright © 2018 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.)

Treatment of back pain due to facet joint syndrome has been a challenge for physicians since its recognition ∼80 years ago. Intra-articular injections of steroids, local anesthetics, and phenol have been widely adopted despite their known shortcomings. Recently, intra-articular injection of amniotic membrane-umbilical cord (AMUC) has been utilized in various orthopedic indications, including those involving synovial joints, due to its reported anti-inflammatory properties. Herein, use of AMUC for facet joint syndrome was evaluated.A single-center case series was conducted on patients presenting with pain caused by facet joint syndrome, confirmed by single blocking anesthetic injection and treated using a single intra-articular injection of 50 mg particulate AMUC (CLARIX FLO) suspended in preservative-free saline. Patient reported back pain severity (numerical scale 0-10) and opioid use were compared between baseline and 6 months following treatment.A total of 9 patients (7 males, 2 females), average age 52.1 ± 15.9 years, were included. Five patients with cervical pain had a history of trauma, 1 patient had suffered lumbar facet injury and 3 had degenerative lumbar facet osteoarthritis. All patients had severe pain prior to injection (8.2 ± 0.8) and 4 (44%) were taking opioids (>100 morphine milligram equivalents). Six-month post-treatment, average pain had decreased to 0.4 ± 0.7 (P <.05). All patients had ceased use of prescription pain medications, including opioids. No adverse events, repeat procedures, or complications were reported.Intra-articular injection of AMUC appears to be promising for managing facet pain and mitigating opioid use. Further investigation with larger sample size is warranted.

Background Context: Degenerative disc disease (DDD) is a common, widespread socioeconomic problem. Appropriate large animal models of DDD are required for improved understanding and to serve as preclinical test beds for therapeutic strategies., Purpose: To evaluate the effects of short and medium duration immobilization on the sheep lumbar intervertebral disc (IVD) and facet joints (FJs), and to establish a large animal model for DDD research., Study Design: An in vivo sheep model evaluating the effect of short- and medium-term immobilization on disc degeneration., Methods: Eighteen sheep were equally randomized into three groups: short-term (6-week) immobilization (n=6), medium-term (26-week) immobilization (n=6), and control (no surgery) (n=6). Immobilization of L3-L4 was achieved with pedicle screw and rod implantation, the IVD was kept intact, and the annulus and end plates were not disrupted. The IVD and FJs were assessed with planar radiography, computerized tomography (CT), magnetic resonance imaging (MRI), pure moment biomechanical testing, and histologic analysis., Results: Disc height was reduced for 6- and 26-week immobilization groups. The MRI and histologic analysis demonstrated significant disc degeneration for both immobilized groups compared with control, but no statistical difference was detected between short- and medium-term duration. Progressive degenerative changes in FJs were observed with micro-CT and histologic end points. Immobilization significantly reduced lateral bending and flexion-extension range of motion., Conclusions: The mechanical environment set up by immobilization alone is capable of inducing lumbar disc degeneration at both 6 and 26 weeks in sheep. Longer duration immobilization did not advance disc degeneration process beyond of that found with short duration. The present model produces a degenerative disc with intact annulus and without acute injury, more closely representing the scenario common in human disc degeneration. This provides a suitable large animal in vivo model for the evaluation of the new therapies for disc degeneration. Further studies would do well to examine the effect of remobilization after immobilization in this model., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Interspinous spacers used stand-alone preserve joint movement but provide little protection for diseased segments of the spine. Used as adjuncts with fusion, interspinous spacers offer rigid stability but may accelerate degeneration on adjacent levels. Our new device is intended to balance the stability and preserves motion provided by the implant. A new interspinous spacer was devised according to the results of topology optimization studies. Four finite element (FE) spine models were created that consisted of an intact spine without an implant, implantation of the novel, the device for intervertebral assisted motion (DIAM system), and the Dynesys system. All models were loaded with moments, and their range of motions (ROMs), peak disc stresses, and facet contact forces were analyzed. The limited motion segment ROMs, shielded disc stresses, and unloaded facet contact forces of the new devices were greater than those of the DIAM and Dynesys system at L3-L4 in almost all directions of movements. The ROMs, disc stresses, and facet contact forces of the new devices at L2-L3 were slightly greater than those in the DIAM system, but much lower than those in the Dynesys system in most directions. This study demonstrated that the new device provided more stability at the instrumented level than the DIAM system did, especially in lateral rotation and the bending direction. The device caused fewer adjacent ROMs, lower disc stresses, and lower facet contact forces than the Dynesys system did. Additionally, this study conducted topology optimization to design the new device and created a smaller implant for minimal invasive surgery.

The zygapophysial joint, a diarthrodial joint commonly referred to as the facet joint, plays a pivotal role in back pain, a condition that has been a leading cause of global disability since 1990. Along with the intervertebral disc, the facet joint supports spinal motion and aids in spinal stability. Highly susceptible to early development of osteoarthritis, the facet is responsible for a significant amount of pain in the low-back, mid-back, and neck regions. Current noninvasive treatments cannot offer long-term pain relief, while invasive treatments can relieve pain but fail to preserve joint functionality. This review presents an overview of the facet in terms of its anatomy, functional properties, problems, and current management strategies. Furthermore, this review introduces the potential for regeneration of the facet and particular engineering strategies that could be employed as a long-term treatment.

Objective: Artificial cervical disc replacement is expected to maintain normal cervical biomechanics. At present, the effect of the Prestige LP prosthesis height on cervical biomechanics has not been thoroughly studied. This finite element study of the cervical biomechanics aims to predict how the parameters, like range of motion (ROM), adjacent intradiscal pressure, facet joint force, and bone-implant interface stress, are affected by different heights of Prestige LP prostheses., Methods: The finite element model of intact cervical spine (C3-C7) was obtained from our previous study, and the model was altered to implant Prestige LP prostheses at the C5-C6 level. The effects of the height of 5, 6, and 7 mm prosthesis replacement on ROM, adjacent intradiscal pressure, facet joint force, as well as the distribution of bone-implant interface stress were examined., Results: ROM, adjacent intradiscal pressure, and facet joint force increased with the prosthesis height, whereas ROM and facet joint force decreased at C5-C6. The maximal stress on the inferior surface of the prostheses was greater than that on the superior surface, and the stresses increased with the prosthesis height. The biomechanical changes were slightly affected by the height of 5 and 6 mm prostheses, but were strongly affected by the 7-mm prosthesis., Conclusions: An appropriate height of the Prestige LP prosthesis can preserve normal ROM, adjacent intradiscal pressure, and facet joint force. Prostheses with a height of ≥2 mm than normal can lead to marked changes in the cervical biomechanics and bone-implant interface stress., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Objective: To describe a practical approach for the diagnosis and treatment of thoracic zygapophyseal joint pain and to present preliminary clinical data on the effects of this treatment approach on health-related quality of life., Design: An observational study., Setting: Specialist outpatient pain clinic in northern Sweden., Subjects: Patients with long-term thoracic pain., Methods: We describe a method of radiofrequency denervation of thoracic zygapophyseal joints. We compared health-related quality of life between patients who underwent radiofrequency denervation of thoracic zygapophyseal joints and patients who underwent radiofrequency denervation for lumbar and cervical zygapophyseal joint pain., Results: Treatment according to the Spine Intervention Society Guidelines was performed on the lumbar region in 178 patients and in the cervical region in 55 patients. Another 82 patients were treated in the thoracic region with our proposed technique. A survival plot of improvements in health-related quality of life revealed that all three treatments were effective in 65% or more of patients. The improvement in health-related quality of life was maintained for 12 or more months after treatment in 47% to 51% of patients., Conclusions: Our results suggest that radiofrequency denervation of thoracic zygapophyseal joint pain is as effective as radiofrequency denervation, the standard treatment, for lumbar and cervical zygapophyseal joint pain. If these results can be confirmed by other centers, radiofrequency denervation is likely to become more widely available for the treatment of thoracic zygapophyseal joint pain.

Background: Skeletal and soft tissue damage are often associated with unilateral facet dislocations, which undoubtedly lead to instability of the spine and further increase difficulties in cervical reduction. This type of irreducible facet dislocation is usually accompanied with potential catastrophic consequences including neurological deficit and severe disability. Therefore, a consistent and evidence-based treatment plan is imperative., Case Presentation: The literature regarding the management of traumatic unilateral locked cervical facet dislocations was reviewed. Two patient cases (a 30-year-old Asian man and a 25-year-old Asian woman) who suffered irreducible cervical facet dislocations were presented. These two patients received surgical treatments including posterior reduction by poking facet joints, adjacent spinous process fixation by wire rope banding, anterior plate fixation, and intervertebral fusion after the failure of skull traction and closed reduction. At the postoperative 24-month follow-up, intervertebral fusion was achieved and our patients' neurological status improved based on the American Spinal Injury Association scale, compared with their preoperative status., Conclusions: Unilateral facet joint dislocations of subaxial cervical spine are difficult to reduce when complicated with posterior facet fractures or ligamentous injury. Magnetic resonance imaging can be beneficial for identifying ventral and dorsal compressive lesions, as well as ligamentous or capsule rupture. The combination of posterior reduction and anterior fixation with fusion has advantages in terms of clinical safety, ease of operation, and less iatrogenic damage.

Background: A porous additive manufactured (AM) cage may provide stability similar to that of traditional solid cages and may be beneficial to bone ingrowth. The biomechanical influence of various porous cages on stability, subsidence, stresses in cage, and facet contact force has not been fully described. The purpose of this study was to verify biomechanical effects of porous AM cages., Methods: The surgical finite element models with various cages were constructed. The partially porous titanium (PPT) cages and fully porous titanium (FPT) cages were applied. The mechanical parameters of porous materials were obtained by mechanical test. Then the porous AM cages were compared with solid titanium (TI) cage and solid polyetheretherketone (PEEK) cage. The 4 motion modes were simulated. Range of motion (ROM), cage stress, end plate stress, and facet joint force (FJF) were compared., Results: For all the surgical models, ROM decreased by >90%. Compared with TI and PPT cages, PEEK and FPT cages substantially reduced the maximum stresses in cage and end plate in all motion modes. Compared with PEEK cages, the stresses in cage and end plate for FPT cages decreased, whereas the ROM increased. Comparing FPT cages, the stresses in cage and end plate decreased with increasing porosity, whereas ROM increased with increasing porosity. After interbody fusion, FJF was substantially reduced in all motion modes except for flexion., Conclusions: Fully porous cages may offer an alternative to solid PEEK cages in lateral lumbar interbody fusion. However, it may be prudent to further increase the porosity of the cage., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The facet capsular ligaments encapsulate the bilateral spinal facet joints and are common sources of painful injury due to afferent innervation. These ligaments exhibit architectural complexity, which is suspected to contribute to the experimentally observed lack of co-localization between macroscopic strain and microstructural tissue damage. The heterogeneous and multiscale nature of this ligament, combined with challenges in experimentally measuring its microscale mechanics, hinders the ability to understand sensory mechanisms under normal or injurious loading. Therefore, image-based, subject-specific, multiscale finite-element models were constructed to predict the mechanical responses of the human cervical facet capsular ligament under uniaxial tensile stretch. The models precisely simulated the force-displacement responses for all samples ([Formula: see text]) and showed promise in predicting the magnitude and location of peak regional strains at two different displacements. Yet, there was a loss of agreement between the model and experiment in terms of fiber organization at large tissue stretch, possibly due to a lack of accounting for tissue failure. The mean fiber stretch ratio predicted by the models was found to be significantly higher in regions that exhibited anomalous fiber realignment experimentally than in regions with normal realignment ([Formula: see text]). The development of microstructural abnormalities was associated with the predicted fiber-level stretch ([Formula: see text]), but not with the elemental maximum principal stress or maximum principal strain by logistic regression. The multiscale models elucidate a potential mechanical basis for predicting injury-prone tissue domains and for defining the relationships between macroscopic ligament stretch and microscale pathophysiology in the subfailure regime.

Integrins modulate chemically-induced nociception in a variety of inflammatory and neuropathic pain models. Yet, the role of integrins in mechanically-induced pain remains undefined, despite its well-known involvement in cell adhesion and mechanotransduction. Excessive spinal facet capsular ligament stretch is a common injury that induces morphological and functional changes in its innervating afferent neurons and can lead to pain. However, the local mechanisms underlying the translation from tissue deformation to pain signaling are unclear, impeding effective treatment. Therefore, the involvement of the integrin subunit β1 in pain signaling from facet injury was investigated in complementary in vivo and in vitro studies. An anatomical study in the rat identified expression of the integrin subunit β1 in dorsal root ganglion (DRG) neurons innervating the facet, with greater expression in peptidergic than non-peptidergic DRG neurons. Painful facet capsule stretch in the rat upregulated the integrin subunit β1 in small- and medium-diameter DRG neurons at day 7. Inhibiting the α2β1 integrin in a DRG-collagen culture prior to its stretch injury prevented strain-induced increases in axonal substance P (SP) in a dose-dependent manner. Together, these findings suggest that integrin subunit β1-dependent pathways may contribute to SP-mediated pain from mechanical injury of the facet capsular ligament.

Objective: The purpose of this study was to evaluate the immediate effects of upper cervical translatoric spinal mobilization (UC-TSM) on cervical mobility and pressure pain threshold in subjects with cervicogenic headache (CEH)., Methods: Eighty-two volunteers (41.54 ± 15.29 years, 20 male and 62 female) with CEH participated in the study and were randomly divided into the control and treatment groups. The treatment group received UC-TSM and the control group remained in the same position for the same time as the UC-TSM group, but received no treatment. Cervical mobility (active cervical mobility and flexion-rotation test), pressure pain thresholds over upper trapezius muscles, C2-3 zygapophyseal joints and suboccipital muscles, and current headache intensity (visual analog scale) were measured before and immediately after the intervention by 2 blinded investigators., Results: After the intervention, UC-TSM group exhibited significant increases in total cervical mobility (P = .002, d = 0.16) and the flexion-rotation test (P < .001, d = 0.81-0.85). No significant difference in cervical pressure pain thresholds were observed between groups (P > .05). Nevertheless, there was a significantly lower intensity of headache in the UC-TSM group (P = .039, d = 0.57)., Conclusions: Upper cervical translatoric spinal mobilization intervention increased upper, and exhibited a tendency to improve general, cervical range of motion and induce immediate headache relief in subjects with CEH., (Copyright © 2017. Published by Elsevier Inc.)