Lateral Disc Research Articles

182 Posterior Micro-Endoscopic Discectomy vs. ACDF for Single-level Radiculopathy

Abstract INTRODUCTION Cervical radiculopathy remains highly prevalent and costly in the U.S. healthcare system. While ACDF has remained the most popular surgical treatment modality, minimally invasive advancements such as posterior micro-endoscopic discectomy/foraminotomy (pMED) has emerged as a motion preserving and less invasive alternative. To date, the comparative effectiveness and cost-effectiveness of pMED vs. ACDF remains unclear. METHODS Patients undergoing surgery for single-level radiculopathy without myelopathy resulting from foraminal stenosis or foraminal disc herniation without instability over a one-year period were prospectively enrolled into an institutional database. Baseline, post -operative 3-months, and 12-months VAS-Arm and Neck, NDI, EQ −5D, and return to work(RTW) status were collected. Direct healthcare cost(payer perspective) and indirect cost (work-day losses multiplied by median gross-of-tax wage and benefits rate) was assessed. RESULTS >Total 20 ACDF and 28 pMED patients were identified. Baseline demographics, symptomatology, and co-morbidities were similar between the cohorts. For pMED vs. ACDF, mean length of surgery (48.1 ± 20.0 vs. 69.9 ± 11.6 minutes, P < 0.0001) and estimated blood loss (20.3 ± 9.3 vs. 31.8 ± 15.4 mL, P = 0.04) was reduced. There was no 90-day morbidity or re-admission for either cohort. One(3.6%) pMED patient required a subsequent ACDF; no patients in the ACDF cohort required re-operation by one-year. pMED and ACDF cohorts demonstrated similar improvement in arm-VAS(3.1 vs. 2.6, P = 0.66), neck-VAS(2.0 vs. 3.2, P = 0.24), NDI(9.0 vs. 6.8, P = 0.24), and EQ-5D(0.17 vs. 0.15, P = 0.82). Ability to RTW(93.8% vs. 94.1%, P = 1.0) and median time to RTW(3.7[0.9- 8.1] vs. 3.6[2.1-8.5] weeks, P = 0.85) were similar. pMED was associated with significantly reduced direct cost (p>0.001) but similar indirect cost (P = 0.43), resulting in an average total cost savings of $7689(P < 0.01) per case with similar QALY-gain (0.17 vs. 0.15, P = 0.82). CONCLUSION For single-level unilateral-radiculopathy resulting from foraminal stenosis or lateral disc herniation without segmental instability, pMED was equivalent to ACDF in safety and effectiveness. pMED represents a minimally invasive, motion preserving alternative to select patients with cervical radiculopathy without the need for implant costs with concomitant significant cost saving.

A more realistic disc herniation model incorporating compression, flexion and facet-constrained shear: a mechanical and microstructural analysis. Part II: high rate or 'surprise' loading.

Part I of this study explored mechanisms of disc failure in a complex posture incorporating physiological amounts of flexion and shear at a loading rate considerably lower than likely to occur in a typical in vivo manual handling situation. Given the strain-rate-dependent mechanical properties of the heavily hydrated disc, loading rate will likely influence the mechanisms of disc failure. Part II investigates the mechanisms of failure in healthy discs subjected to surprise-rate compression while held in the same complex posture. 37 motion segments from 13 healthy mature ovine lumbar spines were compressed in a complex posture intended to simulate the situation arising when bending and twisting while lifting a heavy object at a displacement rate of 400mm/min. Seven of the 37 samples reached the predetermined displacement prior to a reduction in load and were classified as early stage failures, providing insight to initial areas of disc disruption. Both groups of damaged discs were then analysed microstructurally using light microscopy. The average failure load under high rate complex loading was 6.96kN (STD 1.48kN), significantly lower statistically than for low rate complex loading [8.42kN (STD 1.22kN)]. Also, unlike simple flexion or low rate complex loading, direct radial ruptures and non-continuous mid-wall tearing in the posterior and posterolateral regions were commonly accompanied by disruption extending to the lateral and anterior disc. This study has again shown that multiple modes of damage are common when compressing a segment in a complex posture, and the load bearing ability, already less than in a neutral or flexed posture, is further compromised with high rate complex loading.

Anatomic investigation of lumbar transforaminal fenestration approach and its clinical application in far lateral disc herniation.

Treating lumbar disease at the intervertebal foramina is controversial because we lack an approach providing sufficient exposure and preserving spinal stability. The primary objective of this study was to investigate the feasibility of the transforaminal fenestration (TFF) approach for treating lumbar disease involving the intervertebal foramina.In the anatomic study of 30 adult cadaveric lumbar spine specimens, the TFF approach was used from L1 to S1. The scope of resection was measured manually and on 3D CT images. 3D CT images of the lumbar spine of 31 adult patients were collected, and the scope of resection needed during the TFF approach was defined and measured from L1 to S1. In total, 30 patients (14 men) with lumbar FLDH underwent microendoscopic discectomy (MED) via the TFF approach. The results were evaluated with visual analog scale (VAS), Oswestry Disability Index (ODI), Short Form-36 survey (SF-36), and the MacNab scale.In cadavers, the TFF approach provided sufficient exposure to the posterolateral aspect of the disc and the exiting nerve root at all segments. At L1 to L4, a relatively small part of the isthmus and facet joint was resected; at L4 to S1, a relatively large part of the isthmus and facet joint was resected, so luniform fenestration was needed to preserve a more inferior articular process and continuity of the isthmus. Treatment with MED via the TFF approach was successful in the 30 patients with significantly relieved of symptom after operation. In total, 24 patients were followed for a mean of 24 months. The VAS, ODI, SF-36 physical component, and mental component summary scores at the final follow-up improved significantly compared with preoperative data (P < .05), and excellent results were obtained in 19 patients and good results in 6 according to the Macnab scale.The TFF approach can provide sufficient exposure to the lumbar intervertebal foramina with preservation of stability and can be used effectively with MED to treat lumbar FLDH.

Disc Herniation and Cyst Gas: A Rare Association Causing Radicular Compression

Introduction Intraspinal gas is a common clinical finding, but an epidural gas pseudocyst in association with lateral disc herniation compressing a nerve root is an exceptional observation. Case Report A 49-year-old man was admitted to our department presenting with sciatica. The neurological examination demonstrated moderate lumbar pain without neurological deficit. A lumbosacral computed tomography showed the presence of degenerated disc herniation and epidural gas collection. Discussion The pathological association between the cyst and the hernia is probably due to the migration of gas pumped from the intervertebral space through a breaking point or lower in the annulus fibrosis, involving its contiguity with the herniated disc. Conclusion An association between a disc herniation and a gas pseudocyst can be a cause of sciatica.

The Extraforaminal Approach for the Management of Far Lateral Lumbar Disc Herniation

Background Data: Far lateral lumbar disc herniation accounts for 1-12% of all lumbar disc herniations. Every aspect of management of this unique type of lumbar disc herniation is challenging for spine surgeons, and no consensus has been reached for the best surgical approach and technique to use.Purpose: The purpose of this study is to evaluate the extraforaminal approach, which is a less invasive approach, for the treatment of far lateral lumbar disc herniation.Study Design: A prospective case series.Patients and Methods: Of 501 lumbar disc prolapse patients treated surgically in our department between September 2013 and August 2015, 15 patients presented with far lateral lumbar disc herniation. These 15 patients (11 males and 4 females, mean age 46.80 ± 8.08 years) were treated surgically using the extraforaminal approach and were prospectively followed for 1 year. The study was approved by the Institution Ethical Committee, and all patients signed an informed consent form. Clinical and functional outcomes were assessed using VAS and ODI scores and MacNab’s criteria. Follow-up MRI was performed at 1 year. Results: Far lateral lumbar disc herniation accounted for 3% of all lumbar disc herniation patients treated surgically in our department. The mean back pain VAS score improved from 6.46 preoperatively to 1.06 at the 1-year follow-up evaluation (P=0.001). The mean leg pain VAS score improved from 7.40 preoperatively to 1.06 at the 1-year follow-up evaluation (P=0.001). The mean ODI score improved from 30.20 preoperatively to 2.80 at the 1-year follow-up evaluation (P=0.001). According to MacNab’s criteria, 12 patients (80%) had excellent outcomes, 3 (20%) had good outcomes, and no patients showed fair or poor outcomes at the final follow-up evaluation at 1 year.Conclusion: The extraforaminal approach seems to be a safe, less traumatic and less destabilizing approach for managing far lateral lumbar disc herniation and can lead to a better outcome than traditional approaches. (2017ESJ129)

The role of facet tropism in lumbar intervertebral disc prolapse

Aim: To evaluate the role of facet tropism as an etiological factor in lumbar intervertebral disc prolapse. Setting: Medical college teaching hospital from South India Design: Case series analysis Methods: The study included MRI scans of 120 patients which were studied by Heithoff’s technique. The facet angles of each segment were measured by Cyron and Hutton’s method. The association of asymmetry of lumbar facets and low back pain was studied. Results: In 80 patients with MRI showing disc prolapse, there was more asymmetry of lumbar facets compared to 40 patients with low back pain but MRI showing no disc prolapse. Although facet tropism was observed in subjects with MRI showing no disc prolapse, it was encountered far more frequently in patients with disc prolapse. It was seen that lateral disc prolapse occurred more frequently in patients with facet tropism and the prolapse tended to occur more frequently on the side where facet angle was lower. The results showed no significant association between facet tropism and lumbar disc prolapse. Conclusion: Facet tropism may be one of the causes of back pain because altered mechanism of the spinal motion segment. The association of facet tropism and lateral disc herniation needs to be investigated further before attributing a causal relationship.

Temporomandibular joint lower compartment surgery

The temporomandibular joint is divided into upper and lower joint compartments by the intraarticular cartilage. Significant pathology occurs in the lower joint compartment and therefore the arthroscopic procedure is incomplete without the ability to operate in both upper and lower joint compartments. Pathology found in the lower joint compartment is as follows: synovitis, effusion, adhesions, osteoarthritic bone changes, stuck disc Essential to this technique is that the joint be suitably distracted. Steinman pins and special distractor is used for this purpose. Three portal surgery is necessary: An anterior portal, a posterior portal and an intermediate portal to enable manipulation of the disc with a fine probe. The procedures that can be carried out in the lower joint compartment are as follows: Investigation of lower joint compartment pathology lysis and lavage in the lower joint compartment high condylar shave. An anterior release incision made in combination with the lateral disc access incision enables the disc to be reduced and stabilised with the Prolene endaural plication suture and cauterisation. Injection of Marcaine and steroid can be done into the lower joint compartment and posterior attachment by direct vision. In severely arthritic joints where a thorough lysis and lavage of adhesions in the lower joint compartment is carried out, with postoperative physiotherapy and occlusal splint management the joints can be rendered functional and comfortable for the patient without undergoing major arthroplasty procedures.

Early experience with lateral lumbar total disc replacement: Utility, complications and revision strategies

Lumbar total disc replacement (TDR) is an alternative to interbody fusion for the treatment of symptomatic degenerative disc disease. Traditionally, lumbar TDR is performed via an anterior retroperitoneal approach with regional risks of vascular and visceral injury. The direct lateral retroperitoneal, transpsoas approach avoids mobilisation of the great vessels and preserves the anterior longitudinal ligament, thereby maintaining physiological limits on motion. This study aimed to (i) report one site’s early experience with lateral lumbar TDR and (ii) provide case examples illustrating the utility, complications and revision strategies of the XL-TDR device. Data were collected prospectively on the first 12 consecutive patients treated with XL-TDR. Patient outcomes included pain (VAS), disability (ODI), and quality of life (SF-36 PCS and MCS). Mean follow-up was 27.5months (range 18–48months). Patients had significant improvements in back (74%) and leg (50%) pain, ODI (69%), PCS (50%) and MCS (39%) (P<0.05). Two patients had early prosthesis dislocation due to prosthesis undersizing. The same skin incision was used to retrieve the XL-TDR and perform salvage lateral lumber interbody fusion, with solid fusion by 12months. Lumbar TDR using the XL-TDR via a lateral transpsoas muscle-splitting approach is a minimally invasive alternative to anterior retroperitoneal exposures for motion preservation. Correct sizing of the XL-TDR and complete contralateral annulectomy with annulus box cutters mitigates the risk of lateral dislocation. Revision surgery for lateral dislocation of the XL-TDR is more straightforward compared to anterior TDR dislocation.

A taxonomic review of the genus Astrohelix Döderlein, 1930 including thesynonymy of the subgenus Asteroporpa (Astromoana) Baker, 1980 to Astrohelix.

The holotypes of Astrohelix bellator bellator and Astrohelix bellator paucidens (Echinodermata: Ophiuroidea: Euryalida: Gorgonocephalidae) are redescribed. Based on these observations Asteroporpa (Astromoana) with Astrohelix is proposed. With the elevation of two subspecies of Asteroporpa (Astrohelix) bellator bellator and A. (Astrohelix) bellator paucidens to species level, A. (Astrohelix) comprises six species, A. (Astrohelix) bellator, A. (Astrohelix) indicus, A. (Astrohelix) koyoae, A. (Astrohelix) muricatopatella, A. (Astrohelix) paucidens and A. (Astrohelix) reticulata. These species can be distinguished by the shape of the ossicles on the aboral disc, on the oral plates, and length of terminal projection of cone-shaped epidermal ossicles around the lateral interradial disc. A taxonomic key to all six species of the subgenus A. (Astrohelix) is provided.

Atypical anatomy associated with a lumbar far lateral disc herniation

Abstract Far lateral disc herniation is an uncommon but potentially significant cause of intractable leg pain associated with compression of the exiting nerve root and associated dorsal root ganglion. Since far lateral disc herniations are located outside the spinal canal, several minimally invasive paraspinal muscle-splitting techniques have been developed that allow for neural decompression with reduced soft tissue and bony trauma compared with conventional midline approaches. However, minimally invasive approaches require familiarity with the microsurgical anatomy of the extra-foraminal compartment because of the limited exposure. We report a case of an atypical anatomic relationship identified during far lateral discectomy involving a disc fragment located in a superolateral location relative to the exiting nerve root rather than the more common inferomedial location. This report highlights that familiarity with atypical locations of an extra-foraminal disc herniation and careful exploration of all quadrants in the surgical field is important during minimally invasive far lateral discectomy.

High lumbar noninstrumented fusion rates using lamina autograft and Nanoss/bone marrow aspirate.

Background:Patients with marked osteoporosis and/or obesity/morbid obesity and severe multilevel lumbar stenosis and other pathology often undergo multilevel laminectomies with non instrumented posterolateral fusions (PLF). The other pathology may include combinations of degenerative spondylolisthesis/lysis, foraminal/far lateral discs, and/or synovial cysts requiring more extensive facet resections. Presently, spine surgeons often use bone graft expanders to supplement the lamina autograft harvested in the course of laminectomy/decompressions for the PLF mass.Methods:In 59 patients, we prospectively analyzed the fusion rates following multilevel laminectomies/noninstrumented fusions using lamina autograft and the bone graft expander Nanoss (RTI Surgical Alachua, FL, and USA) with autogenous bone marrow aspirate (BMA). Patients averaged 66.1 years of age; many exhibited marked osteoporosis (48 patients) and obesity (13 of 27 morbidly obese). Magnetic resonance (MR) and computed tomography (CT) studies documented stenosis/ossified yellow ligament (OYL) and degenerative spondylolisthesis (51 patients)/lysis (2 patients), synovial cysts (32 patients), and disc herniations (10 of 21 far lateral). Patients were followed remove up for an average of 3.12 years.Results:Average 4.0 level laminectomies/1.2 level noninstrumented fusions utilized lamina autograft and Nanoss/BMA. Both X-ray/CT studies performed an average of 4.9 months postoperatively documented a 97% fusion rate (57 of 59 patients). Two patients with severe osteoporosis, morbid obesity, and smoking histories exhibited pseudarthroses; neither was sufficiently symptomatic to require secondary surgery.Conclusions:Fifty-nine patients with multilevel lumbar stenosis/OYL and other pathology underwent multilevel lumbar laminectomies/noninstrumented fusions using lamina autograft and Nanoss/BMA. Both dynamic X-ray/CT studies confirmed a 97% fusion rate an average of 4.9 months postoperatively. Nanoss/BMA contributed to a high posterolateral lumbar non instrumented fusion rate without complciations.

Microendoscopic anterior cervical foraminotomy: A preliminary series of 76 cases

Anterior cervical foraminotomy represents a relatively recent minimally invasive approach that can potentially preserve the intervertebral disc and thus the functional motion segment. This study aims to evaluate the clinical outcome of microendoscopic anterior cervical foraminotomy (MACF) for patients with cervical unilateral radiculopathy due to single level soft disc herniation or hard disc-osteophyte complex (DOC). In the period between August 2009 and March 2015, 76 consecutive patients with symptomatic unilateral cervical radiculopathy were included in this study. There were 40 left-sided cervical radiculopathy cases and 36 right-sided; of those, 42 had soft disc fragment herniation, 18 had DOC, 12 had a migrated disc fragment whether cranial or caudal, and four had far lateral (foraminal) disc herniation. In all cases, MACF with root decompression was performed. Cervical magnetic resonance imaging (MRI), computed tomography (CT) scan, and plain X-rays were performed for all patients and then repeated postoperatively. All patients were followed-up for at least a year. Clinical and functional outcomes were assessed using visual analogue scale (VAS) and Odom’s criteria. According to VAS score, there was an improvement in neck pain from 6.4 (range 5–10) to 1.5 (1–5) and in arm pain from 7.2 (range 6–10) to 1.2 (0–4) at final follow-up (P < 0.05). Functional outcomes according to Odom’s criteria were excellent in 59 (78%) cases, good in ten (13%), fair in six (8%), and poor in one (1%) case. Success of surgery was considered to be achieved in 91% (excellent + good) of cases. Mean operating time was 81 min, and mean intraoperative blood loss was 21 ml. Most significant complications included a dural tear in one case, transient postoperative dysesthesia in six cases, excess bony work resulting in unintended uncinectomy in three cases, fracture of transverse process in one case, unintended near total discectomy in two cases, infective discitis in one case, and persistent radicular pain due to incomplete osteophyte removal in one case. This preliminary report suggests that MACF yields overall excellent results in selected patients with unilateral cervical radiculopathy. The technique potentially can preserve the functional motion segment, thus patients typically experience immediate postoperative neck mobility and do not need to wear a cervical collar.

Relative Risk of Operation between Lumbar Far Lateral Disc Herniation and Posterolateral Disc Herniation: A Retrospective Cohort Study

Relative Risk of Operation between Lumbar Far Lateral Disc Herniation and Posterolateral Disc Herniation: A Retrospective Cohort Study

Thorns and dermal denticles of skates Atlantoraja cyclophora and A. castelnaui: Microscopic features and functional implications.

Some batoid species are covered with dermal denticles (or placoid scales) that occasionally develop into thorns. In sexually mature males, sharp teeth and alar thorns found on the apex of the lateral disc are used to hold the female during copulation. This study set out to analyze microscopic features of modified dermal denticles and thorns and to investigate sexual dimorphism in Atlantoraja cyclophora and A. castelnaui species. Skin samples collected from areas covered with thorns were fixed in 10% formaldehyde, processed and analyzed using scanning electron microscopy. Alar thorn morphology varied within species, while caudal thorn, rostral and caudal dermal denticle morphology varied within and between species. These structures play an important role in the protection and reproduction of the species studied and constitute important taxonomic information, given they are often the only elements preserved in archaeological sites and fossil records.

Transforaminal lumbar interbody fusion using one diagonal fusion cage with unilateral pedicle screw fixation for treatment of massive lumbar disc herniation.

Background:Large lumbar or lumbosacral (LS) disc herniations usually expand from the paramedian space to the neuroforamen and compress both the transversing (lower) and the exiting (upper) nerve roots, thus leading to bi-radicular symptoms. Bi-radicular involvement is a statistically significant risk factor for poor outcome in patients presenting with far lateral or foraminal disc herniation after facet preserving microdecompression. There is evidence showing that patients suffering from large lumbar disc herniations treated with interbody fusion have significant superior results in comparison with those who received a simple discectomy. We report our experiences on managing large LS disc herniation with bi-radicular symptoms by transforaminal lumbar interbody fusion (TLIF) using one diagonal fusion cage with unilateral pedicle screw/rod fixation.Materials and Methods:Twenty-three patients who suffered from single level lumbar or LS disc herniation with bi-radicular symptoms treated with unilateral decompression and TLIF using one diagonal fusion cage with ipsilateral pedicle screw/rod fixation operated between January 2005 and December 2009, were included in this study. Operation time and blood loss were recorded. The pain and disability status were pre- and postoperatively evaluated by the visual analog score (VAS) and Oswestry Disability Index (ODI). Interbody bony fusion was detected by routine radiographs and computed tomography scan. Adjacent segment degeneration was detected by routine radiographs and magnetic resonance imaging examination. Overall outcomes were categorized according to modified Macnab classification.Results:The patients were followed up for an average of 44.7 months. Pain relief in the VAS and improvement of the ODI were significant after surgery and at final followup. No severe complications occurred during hospital stay. Interbody bony fusion was achieved in every case. No cage retropulsion was observed, while 3 cases experienced cage subsidence. Adjacent segment degeneration occurred at 3 discs cephalic to the fusion segment at followup. No patients underwent revised surgery. Overall outcome was excellent in 5 patients (21.7%), good in 13 (56.5%), fine in 4 (17.5%), and poor in 1 (4.3%).Conclusions:TLIF using one cage with ipsilateral pedicle screw/rod fixation is an effective treatment option for massive lumbar or LS disc herniation with bi-radicular involvement.

In vitro analysis of circumferential joint replacement, including bilateral facet joint replacement with lateral lumber disc prosthesis: a parametric investigation of disc sizing.

Lateral lumbar disc prosthesis (LLDP) is an innovative device used to restore motion in select patients through a lateral retroperitoneal approach. No in vitro biomechanical studies have been published. Further, the potential for in toto circumferential joint restoration when use of this anterior disc is combined with facet replacement remains unqualified but signifies a potentially interesting clinical direction. Researchers conducted a biomechanical feasibility study of an LLDP designed to investigate parameters of disc sizing used with bilateral facet joint replacement in a cadaveric model. Tested constructs at L4-L5 included (1) intact, (2) LLDP, (3) LLDP+ wide discectomy, (4) LLDP+ bilateral facetectomy, and (5) LLDP+ bilateral facet joint replacement (BFJR). Investigators tested instrumented constructs (2-5) with an LLDP at compact-fit and lax-fit heights and used raw data to perform statistical analysis by repeated measures analysis of variance (ANOVA), along with Student-Newman-Keuls post hoc analysis (p≤0.05). Increased height of the LLDP resulted in significantly less motion compared with intact. Widening the discectomy while using lax-fit sizing led to motion similar to intact in flexion-extension. As expected, motion was greater with lax-fit height than with compact-fit height in all loading modes and constructs, as is noted with a widened discectomy. The L4-L5 center of rotation was maintained regardless of placement of the LLDP. After bilateral facetectomy, reconstruction of the three-joint complex achieved by combining the LLDP with BFJR may provide a viable alternative to current clinical treatment regimens.

Correlation between the lateral pterygoid muscle attachment type and temporomandibular joint disc position in magnetic resonance imaging.

The aim of this study was to investigate the correlation between the lateral pterygoid muscle (LPM) attachment type and temporomandibular joint (TMJ) disc position on sagittal and coronal MR scans. 191 patients (148 females, 43 males), aged 14-60 years, underwent MR investigations of the TMJs in the intercuspal position (IP) and open-mouth position (OMP). The disc position was evaluated on oblique sagittal and coronal images in the IP and OMP on many MRI sections showing all portions of the joint. Relationships between the LPM attachment patterns and articular disc positions were evaluated by z and χ2 tests. Three types of the LPM attachment were found. There was a statistically significant correlation between the LPM attachment type and the disc position in IP (χ2 = 24.29; p < 0.01). The type of muscle attachment did not determine the prevalence of normal, lateral and medial disc positions. There were differences between the muscle attachment types in the anterior, anteromedial and anterolateral disc positions. There was a statistically significant association between TMJ disc position in OMP and particular attachment types in the sagittal plane (χ2 = 9.702; p < 0.01). Certain types of the LPM insertion are correlated with TMJ disc position.

Is There an Association Between Temporomandibular Joint Effusion and Arthralgia?

The literature on joint effusion (JE) and its association with clinical and radiologic variables in patients with temporomandibular disorders (TMDs) is inconsistent and is characterized by multiple methodologic limitations. The primary aim of this investigation was to evaluate the association between magnetic resonance imaging (MRI) identified JE and temporomandibular joint (TMJ) arthralgia. The secondary aim of this investigation was to determine the association between JE and other clinical and MRI-identified soft tissue characteristics. A retrospective cohort study was conducted. Clinical and soft tissue imaging assessments were carried out according to the Diagnostic Criteria for Temporomandibular Disorders guidelines. The dependent variable was JE and the primary independent variable was arthralgia. The secondary independent variables were TMJ pain-associated characteristics and MRI-identified variables. When applicable, Pearson χ2 or t test was used to determine the statistical associations between JE and clinical characteristics and between JE and MRI-identified variables. Furthermore, generalized estimating equation (GEE) modeling was conducted to determine which of the independent clinical and MRI-identified variables were associated with JE. Data for 158 participants, representing 312 joints, were extracted. The mean age of the female sample (59.4%) was 31 ± 11.1years and that of the male sample (40.6%) was 29.8 ± 9.7years. No association was found between JE and arthralgia. However, statistically significant associations were found between JE and lateral disc rotation (P= .001) and between JE and disc position in the coronal and sagittal planes (P= .001). The GEE model suggested that disc displacement with reduction (odds ratio= 2.5) was a statistically relevant contributing factor for JE in the absence of degenerative joint disease. Results associated JE with the position of the disc in the sagittal plane. No association was found between JE and arthralgia or TMJ pain-associated clinical characteristics in patients with TMDs.

Improvement of Soft Soil Performance using Stone Columns Improved with Circular Geogrid Discs

Objective: To study the load carrying capacity and settlement behavior of the soft soils improved with lateral reinforced stone columns. Methods/Analysis: In this study, the soft soil is reinforced with stone columns by providing lateral circular geogrid discs within the column. The tests were conducted on plain clay bed, plain stone column and stone column with geogrid by placing reinforcement at two different spacing i.e., at D and D/2 over full column length and investigated the effect of reinforcement to improve the properties of the clay bed. Findings: By improving the soft soil with stone column, the ultimate load of the soil has been increased by about 117% and is increased by 16% and 41% by placing the circular geogrid reinforcement at D spacing and D/2 spacing respectively as compared with stone column alone. This results shows that the spacing of the reinforcement is influencing the ultimate load of the stone column. The settlement of the soil has been decreased by providing the stone column and further decreased by providing the geogrid reinforcement. Novelty/Improvement: Lateral Reinforcement with geogrid discs increases the load carrying capacity of the soft soil and also it varies with varying the spacing of the reinforcement.

Microscopic tubular discectomy for far lateral lumbar disc herniation

Microscopic tubular discectomy (MTD) reduces muscle trauma associated with treatment of far lateral lumbar disc herniation (FLDH), but data from randomised controlled studies concerning its efficacy on posterolateral disc herniation, has failed to demonstrate its superiority over standard open techniques. Importantly concerns have been raised that it may be inferior in terms of relief of leg and back pain. Although several FLDH series show that MTD can deliver excellent outcomes, the volume of literature in this field has remained small and evidence based on health-related quality of life (HRQOL) measures, scarce. In this study we therefore evaluated the role of MTD for FLDH through analysing multiple HRQOL scores collected in a prospective database. We identified 24 patients who underwent MTD through a caudal approach, targeting directly the disc space to minimise traction on the dorsal root ganglion implicated in causing iatrogenic neuralgia. With a mean follow-up of 9.2months, the improvement in Oswestry Disability Index and Short Form 36 physical functioning and bodily pain scores was 32, (95% confidence interval [CI]: 21–43), 40 (95% CI: 30–51) and 35 (95% CI: 26–43) respectively. The improvement on the Visual Analogue Scale was 38mm (95% CI: 23–54) and 35mm (95% CI: 21–48) for leg pain and back pain respectively. There was no postoperative neuralgia noted and no reoperation required. Our data demonstrated clinically meaningful treatment effects and compare favourably with HRQOL surgical outcomes established for posterolateral disc herniation, supporting MTD as a valid treatment option for FLDH.