Root Impingement Research Articles

265. Lumbar vertebral body Hounsfield units are associated with cage subsidence after transforaminal lumbar interbody fusion

BACKGROUND CONTEXT Postoperative subsidence of transforaminal lumbar interbody fusion (TLIF) interbody cages can result in loss of lordosis and foraminal height, and in some cases recurrence of nerve root impingement and radicular symptoms. Hounsfield unit (HU) values as measured on computed tomography (CT) can be used in the assessment of bone quality and bone mineral density. PURPOSE Determine the association between HU measurement of the first lumbar vertebral body and cage subsidence after TLIF. We hypothesized that the HU measured in the vertebral body of L1 would be lower in patients with postoperative TLIF cage subsidence. STUDY DESIGN/SETTING Retrospective case-control study. PATIENT SAMPLE NA OUTCOME MEASURES NA METHODS We retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. Postoperative imaging studies (radiographs and CT) were evaluated for evidence of implant subsidence. Hounsfield unit values were obtained from the first lumbar vertebral body on postoperative CT scan. Primary outcomes of this study were presence of cage subsidence and measured HU value of first lumbar vertebral body. RESULTS We identified 89 patients with complete imaging who met our inclusion criteria, with a mean clinical follow up of 27 months. Forty-five patients (50.5%) had evidence of interbody cage subsidence. Average cage subsidence was 5.5mm, with a range of 2.2 to 10.8mm. We found implant height was significantly higher in the subsidence group (12.6mm) when compared to the nonsubsidence group (11.2mm). First lumbar vertebral body coronal (170.69±15.61 vs 138.64±14.21; P=0.003), sagittal (175.14±17.26 vs 140.16±13.71; P=0.002), axial (157.57±12.26 vs 134.35±12.30.83; P=0.009), and average HU (167.8±14.04 vs 137.71±12.83; P=0.002) were significantly higher in the non-subsided group vs subsided group (167.8±14.04 vs 137.71±12.83; P=0.002). The subsidence group had a fusion rate of 82% compared to 93% in the nonsubsidence group, although this finding did not reach statistical significance (p=0.08). CONCLUSIONS We found that HU measurements of the first lumbar vertebra are significantly higher in patients without evidence of TLIF cage subsidence when compared to patients with cage subsidence. We identified a trend toward a decreased fusion rate in the subsidence group, yet this finding was not statistically significant. Our findings suggest that HU measurements may function as a surrogate measurement for bone mineral density, and as a predictor for cage subsidence following TLIF. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.

Lumbar disc height and vertebral Hounsfield units: association with interbody cage subsidence.

Postoperative subsidence of transforaminal lumbar interbody fusion (TLIF) cages can result in loss of lordosis and foraminal height, and potential recurrence of nerve root impingement. The objectives of this study were to determine factors associated with TLIF cage subsidence. Specifically, the authors sought to determine if preoperative disc height compared to cage height could be used to predict TLIF interbody cage subsidence, and if decreased postoperative vertebral Hounsfield units (HUs) predisposed to cage subsidence. The authors retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. The preoperative disc height was measured for the operative and adjacent-level disc on MRI. The difference between cage and disc heights was measured and compared between the subsidence and nonsubsidence groups. The average HUs of the L1 vertebral body were measured on CT scans. Eighty-nine patients were identified with complete imaging and follow-up information. Forty-five patients (50.6%) had evidence of interbody cage subsidence on follow-up CT. The average cage subsidence was 5.5 mm (range 2.2-10.8 mm). The average implant height was significantly higher in the subsidence group compared to the nonsubsidence group (12.6 vs 11.2 mm). Additionally, the difference between cage height and preoperative adjacent-level disc height was also significantly larger in the subsidence group (3.8 vs 1.2 mm). First lumbar vertebral body (L1) HUs were significantly higher in the nonsubsidence versus the subsidence group (167.8 vs 137.71 HUs, p = 0.002). Multivariate logistic regression analysis identified suprajacent disc height and L1 HUs to be independent predictors of interbody cage subsidence. Receiver operating characteristic curves identified a suprajacent to cage height difference > 1.3 mm to have a 93.3% sensitivity for cage subsidence. This study is the first of its kind to demonstrate the association between vertebral body HUs and suprajacent disc height with the development of interbody cage subsidence after TLIF. The authors found that patients with lower HUs in the L1 vertebral body were more likely to experience subsidence, regardless of surgical level. Additionally, the study demonstrated that interbody cage height > 1.3 mm above the height of the suprajacent level is an independent risk factor for cage subsidence, with 93.3% sensitivity. These findings suggest that these factors may be utilized to create a template preoperatively for intraoperative cage selection.

Extraforaminal entrapment of the fifth lumbar spinal nerve by nearthrosis in patients with lumbosacral transitional vertebrae.

Lumbosacral transitional vertebrae (LSTV) often have nearthrosis between the L5 transverse processes and the sacral ala; this causes the formation of new bone and synovial-like tissue, which can entrap L5 nerve root. The present study aimed to examine the role of nearthrosis in L5 nerve root compression in patients with LSTV. From 2008 to 2018, 65 patients were surgically treated for severe leg pain/numbness caused by L5 extraforaminal stenosis. The patients were assessed regarding the presence of LSTV, radiographic features of nearthrosis, operative/radiological findings, and clinical outcomes. CT/MRI were used to classify the patients into three groups: group A had L5 nerve root compression that was not related to nearthrosis, group B had L5 nerve root impingement due to nearthrosis with new bone formation, and group C had L5 nerve root impingement due to nearthrosis with synovial-like tissue. The relationships between the type of LSTV (based on the Castellvi's classification) and these three groups were investigated. Although 26 of 65 patients had LSTV (40%), four were excluded because of less than 1-year follow-up. The 22 patients with LSTV were classified as type IA (n = 2), IIA (n = 13), and IIB (n = 7). In accordance with the radiological findings, there were eight patients in group A, six in group B, and eight in group C; the LSTV morphology did not significantly differ between groups. L5 nerve root was compressed by nearthrosis in 64% of symptomatic patients with LSTV; this region should be carefully assessed in all symptomatic patients with LSTV.

A Case Report on Mild Left Para-Central Bulge of Intervertebral Disc- C4/5 and C5/6 with Mild Narrowing of Left Intervertebral Foramen Inducing Severe Neck Pain and Ipsilateral Symptoms

Cervical disc bulge or other cervical spine diseases often results into neck and arm pain in patients formulating an etiology of direct impingement of nerve roots and associated inflammatory process. The clinical presentation also corresponds with the ipsilateral symptoms associated with the cervical disorder as depicted in the patient. A 33 year’s old South Indian male is diagnosed with Para-central bulge at the level of C4/5 and C5/C6-Intervertebral disc presented to the physical therapy with neck pain radiating into left sided upper and lower extremity pain. A magnetic resonance imaging revealed mild Para central bulge of C4/5 and C5/6-Intervertebral disc with mild narrowing of the left intervertebral foramen. Results from MRI scan show the alignment and the morphology of the vertebrae to be normal. Also, the CSF displays normal intensity in all sequences. The patient reported to physical therapy for cervical pain and Radiculopathy. After evaluation he was asked to continue with regular home exercise programme like cervical lateral flexion stretch, unilateral wall stretch which resulted to reduce the cervical pain and shows improvement in its subsequent symptoms. Key words: Cervical bulge, Intervertebral disc C4/5 and C5/6, Ipsilateral symptoms, Radiculopathy, Medical Respresntative, Severe Neck Pain.

Minimally Invasive Sacroiliac Joint Fusion

Background:Minimally invasive sacroiliac (SI) joint fusion is indicated for low back pain from the SI joint that is due to degenerative sacroiliitis and/or sacroiliac joint disruption. This technique is safe and effective in relieving pain uncontrolled by nonoperative management1-4. There is some controversy, but there continues to be increasing evidence of effectiveness.Description:This procedure is performed, with the patient under general anesthesia and in the prone position, using fluoroscopy or 3-dimensional (3D) navigation such as cone-beam computed tomographic (CT) imaging. After navigation setup, a navigated probe is used to approximate the desired location of each implant and trajectory. These positions are marked on the skin, and the skin is incised. A 3 to 5-cm lateral incision is made. The gluteal fascia is bluntly dissected to the outer table of the ilium. A guide pin is passed across the SI joint and into the center of the sacrum lateral to the neural foramina, which is confirmed with imaging. This is then drilled and broached. Triangular titanium rods are placed. Typically, 3 implants are placed, 2 in S1 and 1 in S2. Multiplanar postplacement imaging of the pelvis is obtained. The wound is irrigated and closed in layers.Alternatives:Nonsurgical alternatives have been reported to include pharmacological therapies, such as nonsteroidal anti-inflammatory drugs, therapeutic SI joint blocks5, and physical therapy, such as core stabilization, orthotics (SI belts), and radiofrequency ablation1,2,6-8. The surgical alternative is an open anterior or posterior approach with SI joint arthrodesis. The anterior approach differs by the resection of the SI joint cartilage, the use of a plate or screws across the joint for stabilization, and the packing of bone graft to facilitate fusion9. These are more morbid and have a much longer recovery.Rationale:Conservative management for SI joint pain is inadequate for all patients. Having 3 of 5 positive physical examination maneuvers7, having confirmatory diagnostic block(s)10, and ruling out the hip or spine as the pain generator provide a success rate of >80%. These patients have early and sustained clinically important and significantly improved outcomes across varying measures compared with conservative treatment1-4,11,12.Expected Outcomes:Patients can expect to experience decreased pain, reduced disability, increased daily function, and improved quality of life soon after the procedure is performed. These patients typically have an improvement of ≥50% in the Oswestry Disability Index score and a clinically significant decrease in visual analog pain scores13. The procedure appears durable through at least 5 years14. Complete pain relief is rare, but clinically important improvement is typical.Important Tips:Proper setup of the navigation system or fluoroscopy is needed to ensure accurate starting points.For 3D navigation, use a reference pin in the contralateral posterior superior iliac spine.Although navigation is used, radiographic images are made periodically to confirm proper placement of guide pins and implants. Images provide the greatest benefit when establishing navigation, after guide-pin placement when an outlet view allows for evaluation of pin depth, and after implant placement to confirm proper placement.Blood loss is generally low, but care should be taken to avoid vascular injury. Although rare, improper placement has led to injury of the superior gluteal artery15 and iliac artery16. This can be avoided by staying in bone.Proper placement of the implant is imperative in this procedure. There is the potential for nerve injury with improper placement of the implant: an L5 nerve injury if the implant is too ventral or an S1 or S2 nerve injury if the implant is too deep and into the foramen. Revision surgery is commonly due to nerve root impingement and/or malpositioning.Preoperative 3D imaging is indicated when it is necessary to rule out differential diagnoses that mimic SI joint pain. This enables the surgeon to rule out intrapelvic pathology, assess sacral bone density17, and identify dysmorphic sacra or transitional vertebrae.

Coronal STIR sequence, a simple adjustment to routine MRI protocol for extra-spinal sciatica and sciatica-like symptoms

BackgroundThe value of adding coronal STIR images to MR imaging of sciatica aiming to detect extra-spinal abnormalities.ResultsAdditional coronal STIR images detected extra-spinal abnormalities in 20% of the patients, thereby downgraded the normal studies from 21 to 13%. The extra-spinal abnormalities included bone abnormalities (36.4%), soft tissue abnormalities (4.5%), neurological abnormalities (2.3%), gynecological abnormalities (50%), and miscellaneous (6.8%). In 6.9% of patients, the extra-spinal abnormalities explained the patients’ pain and influenced their management. Extra-spinal causes of pain significantly correlated to positive trauma and neoplasm history, normal routine protocol images, and absent nerve root impingement. Extra-spinal abnormalities were more prevalent in age groups (20–39 years).ConclusionCoronal STIR images (field of view: mid abdomen to the lesser trochanters) identify extra-spinal abnormalities that maybe overlooked on routine MRI protocol. It is of additional value in young adults, trauma, neoplasm, and negative routine images.

Association between MRI findings and clinical outcomes in a period of 5years after lumbar spine microdiscectomy.

To evaluate the associations between magnetic resonance imaging (MRI) findings and pain, disability and quality of life before surgery and up to 5 years after lumbar microdiscectomy. Sixty-one patients who underwent one-level lumbar microdiscectomy by the same surgeon participated in this analytic, observational, prospective study. Lumbar spine MRI was performed preoperatively and 5 years postoperatively. Pain, disability and quality of life were measured with VAS, ODI, Roland Morris and SF-36 pre- and up to 5 years postoperatively. Subsequently associations between radiological findings and clinical outcomes were recorded. Before surgery patients with disc extrusion or sequestration, with increased thecal sac compression (d > 2/3), with Modic changes (MC) 2 and 3 on the operated level and Pfirrmann grades IV and V on the operated and both adjacent discs presented the worst preoperative clinical outcomes. MC preoperatively were not related with postoperative results, in contrast with the type of disc herniation and thecal sac compression. Preoperative Pfirrmann grade IV and V on the operated and both adjacent discs and postoperative MC 2 and 3 on the operated level were related to poor clinical outcomes 36-60months post-discectomy. Extrusion or sequestration of the operated disc, increased compression of thecal sac, MC 2 and 3 on the operated level and Pfirrmann grades IV and V on the operated and adjacent discs were associated with the worst clinical outcomes. Nerve root impingement, facet joint arthritis, perineural fibrosis and disc granulation tissue had no effect on clinical scores.

81 A Review of the Referrals to a Daily TIA Service and Subsequent Specialist Diagnosis

Abstract Background Current guidelines highlight the need for all patients experiencing transient ischaemic attacks (TIA) within the previous 7 days to be seen by a specialist service within 24 hours. (RCP National Clinical Guideline for Stroke 2016) Risk stratification tools are no longer recommended.(Lavallee 2007;Wardlaw, 2014) We reviewed the referrals to such a service to assess the proportion of patients who received a diagnosis of TIA and the time taken for assessment. Methods We used a retrospective review of 131 patients coded under the daily TIA clinic in 2018 and analysed the clinic letter from the attendance. We assessed the time taken from referral to clinic review and the percentage of patients diagnosed with TIA by the specialist service. Results Of 131 patients seen only 33.6% were diagnosed TIA by the stroke specialist team. Other frequently seen diagnoses were migraine (22.9%), presyncope (12.2%), transient global amnesia (4.6%). ‘Other’ diagnoses such as peripheral nerve palsy, cervical root impingement and delirium made up the remainder. Referrals from the emergency department only received TIA diagnosis in 25.3%, GP referrals (34.9%) and eye casualty (83.3%). The time from referral to review was a mean of 2.45 days. The patients diagnosed with TIA were seen with average of 2.14 days, non TIAs were 2.6 days. Conclusion Evidence shows that patients suffering TIA should be seen urgently within 24hrs. The degree of non TIA symptoms being reviewed risks these services being overrun. A review of our service has shown that the average time of referral to review is longer than desired, however only a third of patients seen were felt to have a TIA. Unless there is a change in the standard of referral it will continue to be difficult to see all true TIAs within 24hrs. This will require further education for our colleagues and a more robust triaging system.

Severe lumbar radiculopathy with epidural venous plexus engorgement in a morbidly obese pediatric patient

Introduction:Engorgement of the epidural venous plexus (EVP) is a rare cause of nerve root impingement. Dilated epidural veins cause compression of the thecal sac and spinal nerve roots, leading to lumbar radiculopathy.Patient concerns:Here we describe a case of severe lumbar radiculopathy in a 15-year-old morbidly obese boy.Diagnosis:Enhanced lumbar magnetic resonance imaging revealed left sided L1–L2 disc protrusion and engorgement of the lumbar EVP, resulting in narrowing of the thecal sac in the entire lumbar spine. There was no evidence of an intra-abdominal mass, thrombosis of the inferior vena cava, or vascular malformation.Interventions:A caudal epidural block was administered under fluoroscopic guidance. The patient reported a 30% reduction in pain intensity for just 1 day.Outcomes:The patient has been followed up for 2 years. He continues to take medication, including morphine sulfate 15 mg, gabapentin 300 mg, and oxycodone 20 mg per day. He is on a diet with exercise for weight reduction.Conclusion:An engorged EVP should be considered in the differential diagnosis of radiculopathy in morbidly obese patients.

Posterior Dural Shifts Following Spinous Process-Splitting Multi-Level Intervertebral Lumbar Laminectomies.

Study DesignRetrospective cohort study.PurposeThe aim of our study is to evaluate the extent of posterior spinal dural shift following spinous process splitting multi-level intervertebral lumbar laminectomies, and determine the relationship between posterior spinal dural shift and preoperative parameters.Overview of LiteratureThere are no existing studies on the posterior spinal dural shift after spinous process-splitting multi-leveled lumbar laminectomies.MethodsWe examined 37 patients who underwent spinous process-splitting laminectomies in at least two intervertebral levels, including at the L5/S level. We defined the distance between the vertebral bodies and the anterior edge of the dural sac in the magnetic resonance images at the L5 vertebral level as the anterior dural space (ADS) and detected the difference (d-ADS) between preoperative ADS (pre-ADS) and postoperative ADS (post-ADS). We assessed the relationship between ADS or d-ADS, and preoperative parameters, including age, sex, lumbar lordosis, focal lordosis (FL), and number of decompression levels.ResultsPost-ADS was significantly greater than pre-ADS (p<0.001). Pre-ADS was significantly correlated with FL (p=0.44, p<0.01) and also with post-ADS (p=0.43, p<0.01). d-ADS was negatively correlated with pre-ADS (p=−0.37, p<0.05). A single regression analysis revealed that the relationship between d-ADS and pre-ADS was described as d-ADS=3.67−0.46×pre-ADS. In one of three patients whose d-ADS was above the range of two standard errors, reoperation was performed because of impingement of the nerve root caused by the excessive posterior dural shift.ConclusionsPosterior dural shifts occur after spinous process-splitting multi-level lumbar laminectomies, including at the L5/S level. FL and pre-ADS are good predictive factors for posterior dural shift. Excessive posterior dural shift may lead to stretching and impingement of nerve roots and thus require attention.

The Safety Profile of Percutaneous Minimally Invasive Sacroiliac Joint Fusion.

Study Design:Literature review.Objectives:Systematic review of the existing literature to determine the safety of minimally invasive (MI) sacroiliac (SI) joint fusion through the determination of the rate of procedural and device-related intraoperative and postoperative complications.Methods:All original studies with reported complication rates were included for analysis. Complications were defined as procedural if secondary to the MI surgery and device related if caused by placement of the implant. Complication rates are reported using descriptive statistics. Random-effects meta-analysis was performed for preoperative and postoperative Visual Analog Score (VAS) pain ratings and Oswestry Disability Index (ODI) scores.Results:Fourteen studies of 720 patients (499 females/221 males) with a mean follow-up of 22 months were included. Ninety-nine patients (13.75%) underwent bilateral SI joint arthrodesis resulting in a total of 819 SI joints fused. There were 91 reported procedural-related complications (11.11%) with the most common adverse event being surgical wound infection/drainage (n = 17). Twenty-five adverse events were attributed to be secondary to placement of the implant (3.05%) with nerve root impingement (n = 13) being the most common. The revision rate was 2.56%. MI SI joint fusion reduced VAS scores from 82.42 (95% confidence interval [CI] 79.34-85.51) to 29.03 (95% CI 25.05-33.01) and ODI scores from 57.44 (95% CI 54.73-60.14) to 29.42 (95% CI 20.62-38.21).Conclusions:MI SI joint fusion is a relatively safe procedure but is not without certain risks. Further work must be done to optimize the procedure’s complication profile. Possible areas of improvement include preoperative patient optimization, operative technique, and use of intraoperative real-time imaging.

Virtual Noncalcium Dual-Energy CT: Detection of Lumbar Disk Herniation in Comparison with Standard Gray-scale CT.

Purpose To assess the diagnostic performance of dual-energy CT with reconstruction of virtual noncalcium (VNCa) images for the detection of lumbar disk herniation compared with standard CT image reconstruction. Materials and Methods For this retrospective study, 41 patients (243 intervertebral disks; overall mean age, 68 years; 24 women [mean age, 68 years] and 17 men [mean age, 68 years]) underwent clinically indicated third-generation, dual-source, dual-energy CT and 3.0-T MRI within 2 weeks between March 2017 and January 2018. Six radiologists, blinded to clinical and MRI information, independently evaluated conventional gray-scale dual-energy CT series for the presence and degree of lumbar disk herniation and spinal nerve root impingement. After 8 weeks, readers reevaluated examinations by using color-coded VNCa reconstructions. MRI evaluated by two separate experienced readers, blinded to clinical and dual-energy CT information, served as the standard of reference. Sensitivity and specificity were the primary metrics of diagnostic performance. Results A total of 112 herniated lumbar disks were depicted at MRI. VNCa showed higher overall sensitivity (612 of 672 [91%] vs 534 of 672 [80%]) and specificity (723 of 786 [92%] vs 665 of 786 [85%]) for detecting lumbar disk herniation compared with standard CT (all comparisons, P < .001). Interreader agreement was excellent for VNCa and substantial for standard CT (κ = 0.82 vs 0.67; P < .001). VNCa achieved superior diagnostic confidence, image quality, and noise scores compared with standard CT (all comparisons, P < .001). Conclusion Color-coded dual-energy CT virtual noncalcium reconstructions show substantially higher diagnostic performance and confidence for depicting lumbar disk herniation compared with standard CT. © RSNA, 2018.

Postoperative MRI findings 5years after lumbar microdiscectomy.

Lumbar microdiscectomy is a common procedure with satisfactory results; however, postoperative events like progressive adjacent level degeneration and perineural fibrosis can contribute to long-term pain. The purpose of the study was to evaluate MRI changes 5years after lumbar microdiscectomy and assess their association with clinical parameters. A prospective study enrolling 61 patients who underwent microdiscectomy. Changes between preoperative and postoperative MRI findings were recorded, and these findings were tested for associations with demographic, clinical and perioperative parameters. The measured imaging parameters were degeneration of the operated and adjacent discs and endplates, morphology of the disc herniation, facet joints arthritis and the presence of postoperative perineural fibrosis. Statistically significant differences were found between preoperative and postoperative morphology of the operated disc, facet joints arthritis and degeneration of the operated and caudal adjacent disc. There were no differences between preoperative and postoperative disc degeneration of the superior adjacent disc and in degeneration of the operated and adjacent endplates. Postoperatively perineural fibrosis was common; however, thecal sac compression and nerve root impingement were reduced. Age at the time of surgery was the only parameter associated with postoperative changes. Five years after microdiscectomy, several postoperative MRI changes including operated disc's morphology, facet joints arthritis and degeneration of the operated and caudal adjacent disc were shown. Taking into consideration that participants were on average middle-aged, these changes could be attributed not only to the impact of the surgery but also to the natural history of lumbar spine degeneration.

Friday, September 28, 2018 1:00 PM–2:30 PM abstracts: achieving lumbar interbody fusion: 196. Preoperative disc height predicts TLIF cage subsidence

BACKGROUND CONTEXT Postoperative subsidence of the transforaminal lumbar interbody fusion (TLIF) cages can result in loss of lordosis and foraminal height, and in some cases recurrence of nerve root impingement and radicular symptoms. PURPOSE The purpose of this study is to determine factors associated with TLIF cage subsidence. Specifically, we sought to determine if preoperative disc height compared to cage height could be used to predict TLIF interbody cage subsidence. STUDY DESIGN/SETTING Retrospective case-control study. PATIENT SAMPLE We identified 127 patients with complete imaging who met our inclusion criteria, with a mean clinical follow up of 27 months. OUTCOME MEASURES The primary outcome of this study was presence of cage subsidence identified with radiograph or CT. METHODS We retrospectively reviewed all patients undergoing instrumented TLIF from two institutions between July 2004 and June 2014. Postoperative imaging studies (radiographs and CT) were evaluated for evidence of implant subsidence. Preoperative disc height was measured for the operative and adjacent level disc heights. The delta between cage height and disc heights were measured and compared between groups. RESULTS Fifty four patients (44.3%) had evidence of interbody cage subsidence. Average cage subsidence was 5.5mm, with a range of 2.2–10.8mm. We found implant height was significantly higher in the subsidence group (12.6mm) when compared to the nonsubsidence group (11.2mm). Additionally, the delta between cage height and preoperative disc height was significantly larger in the subsidence group delta (5.5mm vs. 3.9mm). Similarly, the delta between cage height and preoperative adjacent level disc height was also significantly larger (1.2mm vs. 3.8mm). CONCLUSIONS This study demonstrates that preoperative disc height and preoperative adjacent level disc height can be used to template TLIF cage height to potentially decrease rates of subsidence. Larger cages subsided more frequently than smaller cages. Patients with evidence of subsidence had larger deltas between cage height and preoperative disc height. Similarly, a significant difference existed if preoperative adjacent level disc height was compared to cage height. This demonstrates that preoperative imaging should be used for TLIF cage height templating to avoid subsidence.

Posterior longitudinal ligament resection in anterior cervical discectomy

BackgroundThe concept of generous decompression, including resection of the posterior longitudinal ligament (PLL) and even partial bilateral uncovertebral joint resection, has been adopted by some authors. This was justified by the need to remove compressive structures hidden underneath and to prevent nerve root impingement during extreme flexion/extension or rotation. This study was designed to assess the benefits of PLL resection as a routine step in anterior cervical discectomy and fusion (ACDF) surgeries and to find out if there is any added risk of such a procedure that overweighs its benefits.MethodsThis is a retrospective study conducted on 50 patients who underwent ACDF for treatment of degenerative cervical intervertebral disc disease with microscopic resection of the posterior longitudinal ligament.ResultsThere were 31 (62%) males and 19 (38%) females. Age ranged from 22 to 69 years with a mean age of 47.32 years. A total of 83 disc levels were operated upon with a mean of 1.66 levels per patient. Analysis of the obtained data showed a statistically significant difference between the preoperative and both early and late postoperative VAS (p value < 0.001 for both). Moreover, there was a statistically significant difference between early and late postoperative VAS with a p value < 0.001. For axial neck pain, similar results could be demonstrated. Regarding motor function of related nerve roots, there was a statistically significant improvement in preoperative motor power grade values that can be demonstrated when compared with both the early and late postoperative grade values (3.96 ± 0.638, 4.34 ± 0.557, and 4.88 ± 0.328 respectively).ConclusionsDespite being an additional step in ACDF surgery, resection of the PLL does not seem to add significant surgical risk. On the other hand, it had a positive impact on outcome regarding axial and radicular pain. So, it may be advisable to attempt resection of the PLL as a routine step in ACDF surgery.

Selection of Tubular and Endoscopic Transforaminal Disc Procedures Based on Disc Size, Location, and Characteristics.

The clinical effectiveness of percutaneous and transforaminal endoscopic discectomy procedures has been evaluated by the system used or compared to open laminectomy or micro-discectomy but are not evaluated based on the location and characteristics of the abnormal disc. This review proposes that outcomes are primarily related to disc size, biomechanics, location, and associated segmental fibrotic and bone changes as well as the surgeon's skill in using various systems rather than the specific system used. In these cases, the surgeon needs to decide if the goal of the procedure is simply internal decompression of an abnormal but contained herniated disc or release of the entrapped nerve root by a large contained disc, extruded and migrated disc fragment, or coexistent foraminal stenosis. Percutaneous and tubular transforaminal procedures are quite different, technically ranging from simple discectomy aspirating probes to larger endoscopic systems, providing the capability to remove large extruded free disc fragments, with or without foraminotomy. Recently, the ability to perform interbody fusion has been added to the range of procedures able to be performed endoscopically. At the same time, biologic solutions to disc degeneration are rapidly evolving and may have a place in combination with these procedures. This article reviews the interrelationship between clinical signs and symptoms, radiologic findings, and the biochemistry and biomechanics of the affected disc segment. Understanding the role played by all these factors enables the surgeon to evaluate both the disc and surrounding bone structures pre-operatively to determine if the clinical signs and symptoms are related to enlargement and displacement of a contained disc or compression or impingement of the nerve root. Based on this, the surgeon can choose different surgical systems, allowing simple decompression of a contained disc, possibly adding biologics, with a 'small' system, while a large herniated disc, or extruded fragment, causing root impingement, would require a ‘larger’ system that provides direct endoscopic visualization within the epidural space, foraminal decompression with drills, and direct surgical manipulation and freeing of the nerve root. By choosing the surgical system based on characteristics such as disc size, location, and associated inflammatory and fibrotic changes, the effectiveness of minimally invasive procedures will be more consistent and improve as the surgeon's diagnostic and operative skills improve.

Pedicle distraction increases intervertebral and spinal canal area in a cadaver and bone model.

Introduction: Lumbar spinal stenosis is degenerative narrowing of the spinal canal and/or intervertebral foramen causing compression of the spinal cord and nerve roots. Traditional decompression techniques can often cause significant trauma and vertebral instability. This paper evaluates a method of increasing pedicle length to decompress the spinal and intervertebral foramen, which could be done minimally invasive.Methods: Three Sawbone (Sawbones Europe, Sweden) and 1 cadaveric lumbar spine underwent bilateral pedicle distraction at L4. A pedicle channel was drilled between the superior articular process and transverse process into the vertebral body. The pedicles underwent osteotomy at the midpoint. Screws were inserted bilaterally and fixated distraction of 0 mm, 2 mm, 4 mm and 6 mm. CT images were taken at each level of distraction. Foramen area was measured in the sagittal plane at L3/4. Spinal canal area was measured at L4 in the axial images. The cadaver was used to evaluate safety of osteotomy and soft tissue interactions preventing distraction. Statistical analysis was by student paired t-test and Pearson rank test.Results: Increasing distraction led to greater Spinal canal area. From 4.27 cm2 to 5.72 cm2 (p = 0.002) with 6 mm distraction. A Maximal increase of 34.1%. Vertebral foramen area also increased with increasing pedicle distraction. From 2.43 cm2 to 3.22 cm2 (p = 0.022) with 6 mm distraction. A maximal increase of 32.3%. The cadaver spinal canal increased in area by 21.7%. The vertebral foramen increased in area by 36.2% (left) and 22.6% (right).Discussion: For each increase in pedicle distraction the area of the spinal and vertebral foramen increases. Pedicle distraction could potentially be used to alleviate spinal stenosis and root impingement. A potential osteotomy plane could be at the midpoint of the pedicle with minimal risk to nerve roots and soft tissue restrictions to prevent distraction.

The role magnetic resonance imaging and myelogram in the cervical spondylitis radiculopathy (prospective study)

objective:The objective of this study was to prospectively evaluate the accuracy of MRI and myelogram for the demonstration of foramina nerve root impingement in cervical spondylitis radiculopathyPatients And MethodsBetween January 2012 and May 2014. Eighty five patients referred to the department of Hilla teaching hospital with. cervical spondylitis radiculopathy were imaged with conventional MM and with MR myelogram . The diagnostic accuracy of these imaging strategies for the demonstration of exit foraminal stenosis was calculated relative to a gold standard of the combination of conventional MRI and MR myelogramResults:Conventional MRI had a sensitivity of 88.9%, specificity of 99.1%, and diagnostic accuracy of 94.5% for the demonstration of exit foraniinal disease. MR myelography alone had a sensitivity of 84.4%, a specificity of 90.1%, and diagnostic accuracy of 88%.Conclusion:However, the addition of MR myelography increased the diagnostic yield of the MR examination for the detection of forantinal stenotic disease. MR myelography is a useful adjunct to conventional MN in the investigation of cervical spondylotic radiculopathy.

Minimally invasive posterior cervical foraminotomy for treatment of radiculopathy : An effective, time-tested, and cost-efficient motion-preservation technique.

To relieve foraminal root impingement due to lateral soft disc fragments, bony spurs, or other rarer causes. Soft disc fragment whose bulk is>2/3lateral to the lateral border of the thecal sac. Intraforaminal dorsal bony narrowing of the root canal. Intraforaminal synovial cyst, extra/intradural tumor. Paramedian and median soft/hard disc protrusions. Kyphosis of the index level. Patient prone in reverse Trendelenburg position with the head fixed in aMayfield clamp. Cervical spine horizontal and approximately 10 cm above the heart. Microscope from skin to skin. Skin incision: 25 mm, about 10 mm off the midline. Microsurgical blunt splitting of the muscle layers along the fiber direction. An expandable tubular retractor or aminiaturized speculum counter retractor, table anchored, is centered on the target lamino-facet junction as confirmed by fluoroscopy. Drilling of the keyhole. The axilla of the root is exposed while preserving most of the facet complex. Epidural exploration until an extruded or subligamentous disc fragment(s) is removed. If needed, removal of the dorsal bone overlying the root exiting in the foramen. The adequacy of decompression is assessed by palpating the root along its course with asmall nerve hook. Closure by layers. No drain. Same day mobilization. No external brace. Minimally invasive posterior cervical foraminotomy (MI-PCF) was used to treat 103patients for unilateral cervical radiculopathy. Mean follow-up was 32months. Despite 1cerebrospinal fluid leak, 1wound hematoma, and 1radiculitis during the early postoperative period, no patients required revision surgery. Visual analog scale (VAS) scores for neck/shoulder and arm improved significantly in the early postoperative period (3months) and were maintained with time (p< 0.001). Neck Disability Index (NDI) improved significantly postoperatively but worsened slightly during follow-up (p< 0.001). Anterior decompression and fusion (ACDF) was required at the index level by 3patients (mean: 55months later) and at the adjacent level by 4patients (mean: 27months later).

Novel Technique of Percutaneous Fat Graft for Repair of Persistent Large Pseudomeningocele

Pseudomeningocele is an uncommon but problematic complication in lumbar spine surgery. Initial conservative measures frequently are successful, but persistence requires additional management. The current surgical approach can involve a range of techniques, including blood patches, hydrogel/fibrin sealants, drains, open surgical repair of the dura, or a combination of the all techniques if symptoms persist. This report demonstrates a novel technique for repair via a percutaneous approach to deliver an autologous fat graft into the pseudomeningocele. A 64-year-old woman with a history of multiple complex lumbar spinal surgeries with previous durotomy had persistent positional headaches from an unresolved pseudomeningocele from L3 to L5. The defect and symptoms remained after all available surgical options were exhausted, including blood patches, hydrogel sealants (Duraseal), and open surgical repair with muscle and Gelfoam grafts. After autologous fat harvest, the patient underwent percutaneous repair of the pseudomeningocele with simultaneous aspiration of cerebrospinal fluid and injection of fat into the defect space. At 3 months postoperatively, the patient's symptoms were resolved with no clinical or radiographic findings of nerve root or thecal sac impingement and complete obliteration of the pseudomeningocele. This less-invasive approach offers the option of open surgical repair for persistent pseudomeningocele with the use of autologous graft material.