Facet Joint Capsule Research Articles

20. Biomechanical effect of facet joint violation on adjacent segment motion and disc strain following single level lumbar fusion with transpedicular screw and rod instrumentation

<h3>BACKGROUND CONTEXT</h3> Facet joint violation (FV) is a complication occurring while placing pedicle screws at the upper-most level using an entry point and trajectory too close to the superior facet joint. The incidence of FV has been reported up to be as high as 50%. However, little is known about how FV affects superior adjacent level spinal stability and especially intervertebral disc (IVD) strain after lumbar fusion. <h3>PURPOSE</h3> To investigate the biomechanical effects of FV in terms of mobility and disc surface strains at the upper level adjacent to L4-5 pedicle screw-rod fixation (PSR) in cadaveric specimens. The disc strain was studied with a new optical technique of soft tissue strain analysis (3D digital image correlation [DIC] technique). <h3>STUDY DESIGN/SETTING</h3> Biomechanic testing in human cadaveric spine specimens. <h3>PATIENT SAMPLE</h3> A total of 14 human cadaveric L3-S1 specimens. <h3>OUTCOME MEASURES</h3> 1. Upper adjacent segment range of motion. 2. Disc surface strain/stress. <h3>METHODS</h3> A total of 14 human cadaveric L3-S1 specimens were divided into two equal groups. L4-5 pedicle-rod fixation was performed in a different fashion in each group ie, facet joint preservation (FP) and facet joint violation (FV). The violation of the facet joint was defined by denuding the facet joint capsule and removing of the external cortical surface of the superior articular process with a 3 mm Leksell-rongeur. The entry point of these pedicle screws was located at the junction between the inferolateral aspect of the facet joint. All specimens were tested multi-directionally under pure moment loading (7.5Nm). DIC was performed with cameras positioned laterally (left side) to capture the change in principal disc strains (Pmax and Pmin) at the upper adjacent level (L3-4) under peak load. Optical motion tracking was simultaneously performed on the right side. The IVD region was divided into four similar sized quarters and included upper and lower endplates. Analysis of variance of upper adjacent level range of motion (ROM) and disc strain, normalized to intact, was performed between the groups. Statistical significant was set at P≤0.05. <h3>RESULTS</h3> Normalized ROM was significantly greater with FV than FP at upper adjacent level (L3-4) during right axial rotation (1.22 vs 0.99, 23% difference, p=0.047). Normalized IVD Pmax strains at the upper adjacent level (L3-4) were significantly greater with FV than FP in the anterior quadrant during right axial rotation (1.80 vs 0.83 (ratio to intact), 97% difference, p=0.003). However, there were no significant differences in ROM and disc Pmax or Pmin strains during flexion, extension and lateral bending. <h3>CONCLUSIONS</h3> Facet violations at the uppermost level of fusion construct during pedicle screw-rod fixation were associated with adjacent level torsional instability and the increase of IVD strain. This study suggested that the preservation of uppermost facet joint of fusion segment was helpful for alleviating adjacent segment mobility and stress concentrations of the IVD above the fusion segment. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.

Is Preexisting Cervical Degeneration a Risk Factor for Poor Prognosis in Whiplash-Associated Disorder?

The term whiplash describes the acceleration-deceleration mechanism of injury to the cervical spine. Whiplash injuries present with a variety of clinical and psychological manifestations, collectively termed as whiplash-associated disorders (WADs). Although largely self-limiting, some patients may experience long-lasting symptoms. This review aimed to summarize the current literature regarding the predictive value of cervical degeneration in the prognosis of patients with WAD. A comprehensive search of the literature was performed. Nine studies were identified, including 894 patients, with an age range between 16 and 76 years. A statistically significant association was found between moderate facet joint degeneration and nonrecovery. Although no association was established between isolated disc degeneration and nonrecovery, total cervical degeneration (facet joint + disc degeneration) was shown to correlate with nonrecovery.All included studies demonstrated the lack of correlation between preexisting disc degeneration and clinical outcomes. Four studies showed a significant correlation between cervical degeneration and poor prognosis following whiplash injury. A significantly higher proportion of patients who remained symptomatic at 2 years following a whiplash injury had preexisting degenerative changes. This review highlights the presence of significant variability in the existing literature concerning WAD in terms of study methodology, definitions of cervical degeneration, and outcome measures. Degenerative changes of the facet joint lead to alterations in its biomechanics. Several cadaveric, biomechanical, and clinical studies have demonstrated facet joints as a source of pain in patients with chronic WAD. We present moderate evidence to suggest that preexisting facet joint degeneration is a negative prognostic indicator for long-lasting symptoms in WAD. Conversely, preexisting disc degeneration is not associated with chronicity of WAD symptoms. We propose facet joint instability due to facet joint capsule rupture as a potential mechanism for nonrecovery. Further studies are needed to inform our knowledge of the long-term sequelae of WAD among patients with preexisting cervicalspine degeneration.

Exploring the influence of impact severity and posture on vertebral joint mechanics in an in-vitro porcine model

To date, no in vitro studies have been conducted to explore lumbar soft tissue injury potential and altered mechanical properties from exposure to impact forces. After a motor vehicle collision (MVC), the cause of reported acute onset low back pain is difficult to associate with potential soft tissue strain injury sites including the facet joint and innervated facet joint capsule ligament (FJC). Thus, the purpose of this investigation was to quantify intervertebral anterior-posterior (AP) translation and facet joint capsule strain under varying postures and impact severities. Seventy-two porcine spinal units were exposed to three levels of impact severity (4 g, 8 g, 11 g), and posture (Neutral, Flexion, Extension). Impacts were applied using a custom-built impact track that replicated parameters experienced in low to moderate speed rear-end MVCs. Flexion-extension and anterior-posterior shear neutral zone testing were completed prior to impact. AP intervertebral translation and the strain tensor of the facet capsule ligament were measured during impacts. A significant main effect of collision severity was observed for peak AP intervertebral translation (4 g—2.8 ±0.53 mm; 8 g—6.4 ±2.9 mm; 11 g—8.3 ±0.45 mm) and peak FJC shear strain (2.37% strain change from 4 g to 11 g impact severity). Despite observed main effects of impact severity, no influence of posture was observed. This lack of influence of posture and small FJC strain magnitudes suggest that the FJC does not appear to undergo injurious or permanent mechanical changes in response to low-to-moderate MVC impact scenarios.

Unintentional Fusion in Preserved Facet Joints without Bone Grafting after Percutaneous Endoscopic Transforaminal Lumbar Interbody Fusion.

Introduction A percutaneous endoscopic transforaminal lumbar interbody fusion (PETLIF) procedure has been previously developed. During postoperative follow-up, in some patients, bone fusion occurred between opened facet joints, despite not having bone grafting in the facet joints. Here, we investigated facet fusion's frequency and tendencies following PETLIF. Methods A retrospective analysis was conducted on a prospectively collected, nonrandomized series of patients. Forty-two patients (6 males and 36 females, average age: 69.9 years) who underwent single-level PETLIF at our hospital from February 2016 to March 2019 were included in this study. Patients were assessed with lumbar X-ray images and computed tomography (CT) prior to, immediately after, and 1 year after surgery. Results Pseudarthrosis was not observed in any patients, and facet fusion was observed in 26 of 42 post-PETLIF patients (61.9%) by CT 1 year postoperatively. The average interfacet distance increased from 1.3 mm preoperatively to 4.5 mm postoperatively, and facet fusion was observed under the opened conditions of 3.8 mm at 1 year. Segmental lordotic angle of the fusion segment in the lumbar X-ray images was significantly larger in the facet fusion subgroup prior to surgery, immediately following surgery, and 1 year after surgery compared to the facet non-fusion group (p=0.02, p<0.01, p=0.01, respectively). There were no significant differences in patient background, correction loss of segmental lordosis, interfacet distance, or clinical score between the facet fusion and facet non-fusion subgroups. Conclusions Facet fusion was achieved over time within the facet joints that were opened through indirect decompression after PETLIF. We hypothesized that the preserved facet joints potentially became the base bed for spontaneous bone fusion due to the preserved facet joint capsule and surrounding soft tissue, which maintained cranio-caudal facet traffic and blood circulation in the facet joints. The complete preservation of the facet joints was a key advantage of minimally invasive lumbar interbody fusion procedures. Level of evidence Level III

Development and Description of a New Multifidus-Sparing Radiofrequency Neurotomy Technique for Facet Joint Pain.

The technique of radiofrequency neurotomy (RFN) of the facet joints has been used for decades to treat persistent low back pain to good effect in carefully selected patients. Traditionally, the target is the medial branches of the dorsal root supplying the facet joint. An alternative denervation target is the facet joint capsule. Capsule-targeting techniques may spare the multifidus muscle, a possible unintended target of traditional RFN that is thought to be important in recovering from low back pain, and have shown promising results. A modified RFN technique that targets the capsule and spares the multifidus (multifidus-sparing RFN) is described here, along with a brief report of its application in patients with symptomatic facet joint low back pain as compared to traditional medial branch RFN (MBRF). Over a 2-year period, a total of 401 initial multifidus-sparing RFN and 94 initial MBRF procedures were performed on patients attending a multidisciplinary pain clinic. The proportion of repeat procedures was similar: 28.4% of multifidus-sparing procedures and 23.4% of MBRF procedures. The median repeat interval was 12months for both groups and interquartile range was 10 months (8-18 months) for multifidus-sparing RFN and 4 months (11-15 months) for MBRF. Effectiveness and safety profiles appear to be similar, although limited, retrospective outcome information prevented robust analysis. Multifidus-sparing RFN represents an intriguing technique to denervate the facet joint pain generator while maintaining normal multifidus function. Further study is warranted, particularly in order to identify the appropriate patient criteria and long-term outcomes.

Clinical Outcomes of Interlaminar Percutaneous Endoscopic Decompression for Degenerative Lumbar Spondylolisthesis with Spinal Stenosis.

The use of traditional open decompression alone in degenerative spondylolisthesis can lead to the development of postoperative spinal instability, whereas percutaneous endoscopic decompression can preserve the attachment of intervertebral muscles, facet joint capsules, and ligaments that stabilize the spine. The study’s aim was to determine clinical as well as radiologic outcomes associated with interlaminar percutaneous endoscopic decompression in patients with stable degenerative spondylolisthesis. For this study, 28 patients with stable degenerative spondylolisthesis who underwent percutaneous endoscopic decompression were enrolled. The clinical outcomes in terms of the visual analogue scale (VAS) and Oswestry disability index (ODI) were evaluated. Radiologic outcomes were determined by measuring the ratio of disc height and the vertebral slippage percentage using lateral standing radiographs. The average follow-up period was 25.24 months. VAS and ODI were significantly improved at the final follow-up. In terms of ratio of disc height and vertebral slippage percentage found no significant difference between the preoperative and postoperative periods. One patient underwent further caudal epidural steroid injection. One patient underwent fusion because their radicular pain did not improve. Interlaminar percutaneous endoscopic decompression is an effective procedure with favorable outcomes in selected patients with stable degenerative spondylolisthesis.

The posterior surgical treatment and outcomes of cervical spondylotic myelopathy: Why not C5 nerve root palsy occur

Aim: Cervical spondylotic myelopathy is an age-related degenerative spinal pathology. Anterior or posterior approaches are preferredfor surgical treatment. C5 palsy is a common complication after the posterior approach. The aim of our study is to describe themodified laminectomy technique, evaluate short-time surgical outcomes and comment on the C5 nerve root palsy formation.Materials and Methods: 83 patients who had been treated by modified laminectomy for cervical spondylotic myelopathy between theyears 2012 and 2017 in our clinic were undertaken in our study. We evaluated the preoperative and postoperative neurologic statusof the patients with VAS and JOA scales, complications (C5 palsy) of surgical treatment. The posterior approach was not performedat patients with a >13 degree angle of cervical curvature.Results: 61 of 83 patients were male and 22 were female. The mean age at the time of surgery was 57.8±8.3. The average JOA scalescore was 9.4±0.9 preoperatively, 10.1±.0.9 early postoperatively and 15.1±1.0 during the late postoperative follow-up. The averageangle of the cervical curvature preoperatively-postoperatively was 17.1±2.6 and 15.8±2.4 respectively. There weren’t any symptomsfor C5 nerve root palsy which is a common postoperative complication.Conclusions: The cervical posterior laminectomy, which includes en-bloc laminectomy and preserving of the facet joint capsule,allows a sufficient and safe decompression of the neural structures for cervical spondylotic myelopathy.

Biomechanical Contributions of Spinal Structures with Different Degrees of Disc Degeneration.

Biomechanical cadaveric study. The aim of this study was to evaluate the effect of degeneration on biomechanical properties of the passive structures of the lumbar spine. Although the load apportionment among the passive structures in healthy spines follows well-defined contribution patterns, it remains unknown how this load distribution and sagittal preload changes by degenerative processes of the intervertebral disc (IVD). Fifty lumbar spinal segments were tested in a displacement-controlled stepwise reduction study in flexion, extension, axial rotation, lateral bending, anterior, posterior and lateral shear. The intertransverse ligaments (ITLs), supraspinous and interspinous ligaments (ISL&SSL), facet joint capsules (FJC), facet joints (FJ), ligamentum flavum (LF), posterior longitudinal ligament (PLL), anterior longitudinal ligament (ALL), and spondylophytes were subsequently reduced. The results were set in relation to IVD-degeneration, quantified with Pfirrmann classification. In flexion, a load redistribution from LF (-28% n.s.) and PLL (-13% n.s.) towards the IVD (+9%, n.s.) is observed comparing grade 2 to 5 IVD degeneration, whereas in all other loading directions, a reduction of IVD-contribution from -12% to -53% is recorded. In axial rotation, anterior and lateral shear, more load is shared by the FJ (+4% n.s., +23% ∗, +13% n.s.). The preload of the ALL, LF, PLL, and IVD is reduced ranging from -0.06 Nm to -0.37 Nm. IVD degeneration is related to notable load-redistributions between the passive spinal structures. With further degeneration, reduced contribution of the LF and PLL and higher loads on the IVD are observed in flexion. In the other tested loading directions, the relative load on the IVD is reduced, whereas higher FJ-exposure in axial rotation, anterior and lateral shear is observed. Furthermore, the preload of the spinal structures is reduced. These observations can further the understanding of the degenerative cascade in the spine.Level of Evidence: N/A.

Biomechanical contribution of spinal structures to stability of the lumbar spine—novel biomechanical insights

Background ContextThe contribution of anatomical structures to the stability of the spine is of great relevance for diagnostic, prognostic and therapeutic evaluation of spinal pathologies. Although a plethora of literature is available, the contribution of anatomical structures is still not well understood. PurposeWe aimed to quantify the biomechanical relevance of each of the passive spinal structure trough deliberate biomechanical test series using a stepwise reduction approach on cadavers. Study designBiomechanical cadaveric study. MethodsFifty lumbar spinal segments originating from 22 human lumbar cadavers were biomechanically tested in a displacement-controlled stepwise reduction study: the intertransverse ligaments, the supraspinous and interspinous ligaments, the facet joint capsules (FJC), the facet joints (FJ), the ligamentum flavum (LF), the posterior longitudinal ligament (PLL), and the anterior longitudinal ligament were subsequently reduced. In the intact state and after each transection step, the segments were physiologically loaded in flexion, extension, axial rotation (AR), lateral bending (LB) and with anterior (AS), posterior (PS) and lateral shear (LS). Thirty-two specimens with only minor degeneration, representing a reasonably healthy subpopulation, were selected for the here presented evaluation. Quantitative values for load and spinal level dependent contribution patterns for the anatomical structures were derived. ResultsSmall variability between of the contribution patterns are observed. The intervertebral disc (IVD) is exposed to about 67% of the applied load in LB and during shear loading, but less by load in flexion, extension and AR (less than 35%). The FJ&FJC are the main stabilizers in AR with 49%, but provide only 10% of the stability in extension. Beside the IVD, the LF and the PLL contribute mainly in flexion (22% and 16%, respectively), while the ALL plays a major role during extension (40%) and also contributes during LB (15%). The contribution of the intertransverse ligaments and the supraspinous and interspinous ligaments are very small in all loading directions (<2% and <6%, respectively). ConclusionThe IVD takes the main load in LB and absorbs shear loading, while the FJ&FJC stabilize AR. The ALL resists extension while LF and PLL stabilize flexion. With the small variability of contribution patterns, suggesting distinct adaptation of the structures to one another, the biomechanical characteristics of one structure have to be put in context of the whole spinal segment. CLINICAL SIGNIFICANCEThe novel information on load distribution helps predict the biomechanical consequences of surgical procedures in more detail.

In vitro analysis of thoracic spinal motion segment flexibility during stepwise reduction of all functional structures.

The aim of this study was to quantify the stabilizing effect of the passive structures in thoracic spinal motion segments by stepwise resections. These data can be used to calibrate finite element models of the thoracic spine, which are needed to explore novel surgical treatments of spinal deformities, fractures, and tumours. Six human thoracic spinal motion segments from three segmental levels (T2-T3, T6-T7, and T10-T11) were loaded with pure moments of 1 and 2.5Nm in flexion/extension, lateral bending, and axial rotation. After each loading step, the ligaments, facet capsules, and the nucleus pulposus were stepwise resected from posterior to anterior direction, while the segmental relative motions were measured using an optical motion tracking system. Significant increases (p < 0.05) in the range of motion were detected after resecting the anterior spinal structures depending on loading magnitude, motion direction, and segmental level. The highest relative increases in the range of motion were observed after nucleotomy in all motion directions. The vertebral arch mostly stabilized the thoracic spinal motion segments in flexion and extension, while the facet joint capsules mainly affected the segmental stability in axial rotation. Coupled motions were not observed. The anulus fibrosus defines the motion characteristics qualitatively, while the ligaments and the presence of the nucleus pulposus restrict the mobility of a thoracic spinal motion segment solely in a quantitative manner. The posterior ligaments do not predominantly serve for primary stability but for the prevention of hyperflexion. These slides can be retrieved under Electronic Supplementary Material.

Strain of the facet joint capsule during rotation and translation range-of-motion tests: an in vitro porcine model as a human surrogate

BACKGROUND CONTEXTPrior data about the modulating effects of lumbar spine posture on facet capsule strains are limited to small joint deviations. Knowledge of facet capsule strain during rotational and translational intervertebral joint motion (ie, large joint deviations) under physiological loading could be useful as it may help explain why visually normal lumbar spinal joints become painful. PURPOSEThis study quantified the strain tensor of the facet capsule during rotation and translation range-of-motion tests. STUDY DESIGN/SETTINGStrain was calculated in isolated porcine functional spinal units. Following a preload, each specimen underwent a flexion/extension rotation (F/E) followed by an anterior/posterior translation (A/P) range-of-motion test while under a 300 N compression load. METHODSTwenty porcine spinal units (10 C3–C4, 10 C5–C6) were tested. Joint flexion/extension was imposed by applying a ±8 Nm moment at a rate of 0.5°/s, and translation was facilitated by loading the caudal vertebra with a ±400 N shear force at a rate of 0.2 mm/s. Points were drawn on the exposed capsule surface and their coordinates were optically tracked throughout each test. Strain was calculated as the displacement of the point configuration with respect to the configuration in a neutral joint position. RESULTSCompared to a neutral posture, superior-inferior strain increased and decreased systematically during flexion and extension, respectively. Posterior displacement of the caudal vertebra by more than 1.3 mm was associated with negative strains, which was significantly lower than the +4.6% strain observed during anterior displacement (p≥.199). The shear strain associated with anterior translation was, on average, −1.1% compared to a neutral joint posture. CONCLUSIONSThese results demonstrate that there is a combination of strain types within the facet capsule when spinal units are rotated and translated. The strains documented in this study did not reach the thresholds associated with nociception. CLINICAL RELEVANCEThe magnitude of flexion-extension rotation and anterior-translation may glean insight into the facet capsule deformation response under low compression (300 N) loading scenarios. Further, intervertebral joint motion alone, even under low compression loading, does not appear to initiate a clinically relevant pain response in the lumbar facet capsule of a nondegenerated spinal joint.

Biomechanical effects of sequential resection of the posterior ligamentous complex on intradiscal pressure and resistance to compression forces

ObjectiveThe aim of this biomechanical experimental study was to evaluate the resistance of each posterior ligamentous complex structure of the thoracic and lumbar spine to compression forces and to measure the shifting load to the intervertebral disc when each PLC structure was interrupted. MethodThe study was conducted on 4 groups for thoracic and lumbar region as intact, supraspinous ligament interrupted, interspinous ligament/ligamentum flavum combination interrupted and facet joint capsule interrupted. Pre and post anterior vertebral body height, the highest compression force and pressure changes in the intervertebral disc during 40 N loading were measured. ResultsA significantly different degree of resistance to compression force was determined in each posterior ligamentous complex structure in the thoracic and lumbar spine samples. The combination of interspinous ligament and ligamentum flavum was found to be the most effective structure to resist compression forces (p = 0.001 in both groups). The effect of the supraspinous ligament in thoracic and lumbar segments was found to be similar to that of the interspinous ligament and ligamentum flavum combination (p = 0.008 and p = 0.006, respectively). The least effective structure was observed to be the facet joint capsule. Compression forces were significantly increased in the intervertebral disc as a result of the disruption of supraspinous ligament (p = 0.0032 and p = 0.0029, respectively in thoracic and lumbar segments) and combination of interspinous ligament/ligamentum flavum (p = 0.0019 and p = 0.0021, respectively in thoracic and lumbar segments). ConclusionThe interspinous ligament/ligamentum flavum combination and supraspinous ligament are the largest contributor to resisting applied compression moments in the sheep thoracic and lumbar spine. As a result of the loss of resistance to compression forces, there will be a shift of a great proportion of this force onto the intervertebral disc. Level of evidenceLevel V.

Is Cervical Stabilization for All Cases of Chiari-I Malformation an Overkill? Evidence Speaks Louder Than Words!

Chiari I malformation is characterized by the downward displacement of cerebellar tonsils through the foramen magnum. While discussing the treatment options for Chiari I malformation, the points of focus include: (1) Has the well-established procedure of posterior fossa decompression become outdated and has been replaced by posterior C1–2 stabilization in every case? (2) In case posterior stabilization is required, should a C1–2 stabilization, rather than an occipitocervical fusion, be the only procedure recommended? The review of literature revealed that when there is bony instability like atlantoaxial dislocation (AAD), occipito-atlanto-axial facet joint asymmetry or basilar invagination (BI) associated with Chiari I malformation, one should address the anterior bony compression as well as perform stabilization. This takes care of the compromised canal at the foramen magnum and re-establishes the cerebrospinal fluid flow along the craniospinal axis; and also provides treatment for CVJ instability. In the cases with a pure Chiari I malformation without AAD or BI and with completely symmetrical C1–2 joints, however, posterior fossa decompression with or without duroplasty is sufficient to bring about neurological improvement. The latter subset of cases with pure Chiari I malformation have, thus, shown significant (>70%) rates of neurological improvement with posterior fossa decompression alone. A C1–2 posterior stabilization is a more stable construct due to the strong bony purchase provided by the C1–2 lateral masses and the short lever arm of the construct. However, in the cases with significant bleeding from paravertebral venous plexus; a very high BI, condylar hypoplasia and occipitalized atlas; gross C1–2 rotation or vertical C1–2 joints with unilateral C1 or C2 facet hypoplasia, as well as the presence of subaxial scoliosis; maldevelopment of the lateral masses and facet joints (as in very young patients); or, the artery lying just posterior to the C1–2 facet joint capsule (being endangered by the C1–2 stabilization procedure), it may be safer to perform an occipitocervical rather than a C1–2 fusion.

Lumbar facet joint disease : Classification, clinical diagnostics, and minimally invasive treatment

The degeneration of the lumbar facet joint is amulti-factorial process that is closely linked to degeneration of the intervertebral discs and has been implicated as one of the causes of low-back pain of elderly patients in about 15 up to 40% of cases. Moreover, emerging data suggest that increased inflammatory features play an important role in the progression of lumbar facet joint disease and may serve as alink to the afferent pain nerve fibers. Since the first description in 1975 of minimally invasive treatment of lumbar facet joint disease, different techniques have been developed and used with varying results. Today, the major techniques are thermorhizotomy, cryorhizotomy, and endoscopic or percutaneous facet debridement with different anatomical targets, such as the medial branch of the dorsal ramus or facet joint capsule.

The effect of facet joint injection on lumbar spinal stenosis with radiculopathy

Objectives:Facet Joint Injection (FJI) is known to be effective in axial back pain, but the purpose of this study was to assess the effects of FJI on patients treated with it among those with Lumbar Spinal Stenosis (LSS).Methods:We conducted a retrospective database analysis and investigated electronic medical records of 125 LSS patients treated with FJI in the pain clinic of Chungbuk National University Hospital from November 2, 2016 to July 31, 2017. Sex, age, histories of low back surgery, complaining of neurogenic claudication, symptomatic sites of patients, FJI sites, number of sites of FJI, triamcinolone dosage, Numeric Rating Scale (NRS) before and after treatment, facet joint capsule rupture during treatment, and improvement of neurogenic claudication after treatment, were examined.Results:Among 125 patients, we investigated 91 patients who met the criteria. There was significant difference in NRS before and after treatment (p<0.000). Forty one patients with reduction of NRS more than 30% after FJI were allocated to effect group. FJI was more effective in patients who did not have the surgery (p=0.044), as well as those who showed an improved neurogenic claudication after treatment (p=0.001). Other measured values did not show statistical significances.Conclusions:FJI has relatively a lower risk and is simpler in terms of techniques than other interventional treatments performed within the spinal canal. Therefore, FJI may be another interventional treatment option in patients with pain by LSS. In the future, studies for FJI indication in LSS patients should be additionally required.

The Consequence of the Relationship between Shoulder and Cervical Multifiduc Muscles Contractions

Cervical multifidus muscles (MM) are small and strong spinal muscles which are well suited to keep the posture of cervical vertebras [1]. They are located in the deepest layers of posterior neck area attaching directly to the facet joint capsules and cervical bones. The function of this muscle may be disturbed in people who work for a long period of time while their head and neck are kept in a static bended posture

Evaluation and Treatment of Lumbar Facet Cysts.

Lumbar facet cysts are a rare but increasingly common cause of symptomatic nerve root compression and can lead to radiculopathy, neurogenic claudication, and cauda equina syndrome. The cysts arise from the zygapophyseal joints of the lumbar spine and commonly demonstrate synovial herniation with mucinous degeneration of the facet joint capsule. Lumbar facet cysts are most common at the L4-L5 level and often are associated with spondylosis and degenerative spondylolisthesis. Advanced imaging studies have increased diagnosis of the cysts; however, optimal treatment of the cysts remains controversial. First-line treatment is nonsurgical management consisting of oral NSAIDs, physical therapy, bracing, epidural steroid injections, and/or cyst aspiration. Given the high rate of recurrence and the relatively low satisfaction with nonsurgical management, surgical options, including hemilaminectomy or laminotomy to excise the cyst and decompress the neural elements, are typically performed. Recent studies suggest that segmental fusion of the involved levels may decrease the risks of cyst recurrence and radiculopathy.

Percutaneous radiofrequency facet capsule denervation as an alternative target in lumbar facet syndrome

ObjectivesPercutaneous radiofrequency denervation of the medial dorsal branch is often used in chronic low back pain of intervertebral facet etiology, which is sometimes difficult to perform and recurrence of pain often ensues. We theorized that shifting the target of RF coagulation to the facet joint capsule would provide an easier target and a longer-lived pain relieving response. Patients and methodsA prospective randomized controlled trial where 120 patients diagnosed with CLBP of a confirmed facet origin were randomly divided into three equal groups, the first was submitted to percutaneous radiofrequency coagulation of the facet joint capsule, the second underwent percuataneous denervation of the medial dorsal branch and the third did not receive radiofrequency lesioning. All the three groups received local injection of a mixture of local anesthetic and steroid. Cases were followed for up to 3 years. Results87(72.5%) patients were females. By 3 months’ post procedure, improvement in VAS was significantly better than pretreatment levels in all groups (p<0.05). The control group lost improvement by 1-year follow-up (p=0.017). At 2 years’ follow-up, the joint capsule denervation group maintained significant improvement (p=0.033) whereas the medial branch denervation group lost its significant effect (p=0.479). By the end of follow-up period, only joint capsule denervation group kept significant improvement (p=0.026). ConclusionIn CLBP of facet origin, shifting the target of percutaneous radiofrequency to the facet joint capsule provides an easier technique with an extended period of pain relief compared to the medial dorsal branch of the facet joint.

Computer simulation of lumbar flexion shows shear of the facet capsular ligament

Background ContextThe lumbar facet capsular ligament (FCL) is a posterior spinal ligament with a complex structure and kinematic profile. The FCL has a curved geometry, multiple attachment sites, and preferentially aligned collagen fiber bundles on the posterior surface that are innervated with mechanoreceptive nerve endings. Spinal flexion induces three-dimensional (3D) deformations, requiring the FCL to maintain significant tensile and shear loads. Previous works aimed to study 3D facet joint kinematics during flexion, but to our knowledge none have reported localized FCL surface deformations likely created by this complex structure. PurposeThe purpose of this study was to elucidate local deformations of both the posterior and anterior surfaces of the lumbar FCL to understand the distribution and magnitude of in-plane and through-plane deformations, including the prevalence of shear. Study Design/SettingThe FCL anterior and posterior surface deformations were quantified through creation of a finite element model simulating facet joint flexion using a realistic geometry, physiological kinematics, and fitted constitutive material. MethodsGeometry was obtained from the micro-CT data of a healthy L3–L4 facet joint capsule (n=1); kinematics were extracted from sagittal plane fluoroscopic data of healthy volunteers (n=10) performing flexion; and average material properties were determined from planar biaxial extension tests of L4–L5 FCLs (n=6). All analyses were performed with the non-linear finite element solver, FEBio. A grid of equally spaced 3×3 nodes on the posterior surface identified regional differences within the strain fields and was used to create comparisons against previously published experimental data. This study was funded by the National Institutes of Health and the authors have no disclosures. ResultsInhomogeneous in-plane and through-plane shear deformations were prominent through the middle body of the FCL on both surfaces. Anterior surface deformations were more pronounced because of the small width of the joint space, whereas posterior surface deformations were more diffuse because the larger area increased deformability. We speculate these areas of large deformation may provide this proprioceptive system with an excellent measure of spinal motion. ConclusionsWe found that in-plane and through-plane shear deformations are widely present in finite element simulations of a lumbar FCL during flexion. Importantly, we conclude that future studies of the FCL must consider the effects of both shear and tensile deformations.

Emerging Techniques for Posterior Fixation of the Lumbar Spine.

Pedicle screw fixation is the preferred method of posterior fusion in lumbar spinal surgery. The technique provides three-column support of the vertebrae, contributing to the biomechanical strength of the construct. However, open pedicle screw fixation often necessitates wide posterior exposure and dissection with soft-tissue disruption of the facet joint. Alternative posterior fixation techniques have been developed to reduce surgical time, soft-tissue dissection, disruption of the adjacent facet joint capsule, neurologic risk, and implant cost. Results of these techniques are comparable to those of standard pedicle screw fixation systems. Certain patients, especially those at a lower risk of nonunion or those who require posterior fixation only as an adjunct to anterior column support, may benefit from the shorter surgical time and limited posterior exposure of the alternative techniques. However, the decreased rigidity of these alternative constructs can result in excessive motion, which can lead to nonunion and early hardware failure.