Introduction

The ESP prosthesis is a one-piece deformable but cohesive interbody spacer. it provides 6 full degrees of freedom about the 3 axes including shock absorption (fig1). The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion in this “silentblock” implant. It thus differs substantially from current prostheses.

Introduction

The viscoelastic lumbar disk prosthesis ESP is an innovative one-piece deformable but cohesive interbody spacer; it provides 6 full degrees of freedom about the 3 axes including shock absorption. The prosthesis geometry allows limited rotation and translation with resistance to motion (elastic return property) aimed at avoiding overload of the posterior facets. The rotation center can vary freely during motion. It thus differs substantially from current prostheses. This study reports the results of a prospective series of 120 patients who are representative of the current use of the ESP implant since 2006.

Introduction. Epidural steroid injection is an established treatment modality for intervertebral disc prolapse. It is a low-risk alternative to surgical intervention in some patients for whom noninvasive treatment has failed. Caudal epidural steroid injection is one of the most widely used methods for pain relief. The aim of this study was to determine the significance of same dose in different volume of caudal epidural steroid injection in the treatment of lumbar degenerative disc disease. Material/Methods. Prospective study was conducted during 2007 to 2009. 100 Patients were randomized in to two groups, of which 50 % (group A) received 4 ml of steroid with isotonic saline and remaining 50 % (group B) received 12 ml. Injection was given in prone position through a 22-G needle in to the epidural space through the sacral hiatus. The average follow-up was 18 months. Outcomes scores included the SF-36, Oswestry disability index and pain VAS and were recorded in the pre and post injection periods. Results. In group A, 18 patients had significant pain relief and 32 had no relief during the early period. Whereas in group B, 22 had significant pain relief and 28 had no relief. The quality of pain relief of 50% or greater was considered as significant. Follow up after 1 year does not show much difference. Group B had significant decrease in symptoms in the initial post injection period (P<0.05). Conclusions. The volume of steroid solution in the treatment of lumbar degenerative disc disease is significant in the early post injection period only

Repetitive manual handling caused 31% of all work related musculoskeletal disorders in 2015, with the back being the site of injury 38% of the time. Despite its high resilience, studies have shown that intervertebral discs can be damaged during repetitive loading at physiological motions, causing cumulative damage and disc herniation. To understand the mechanism of disc injury resulting from repetitive lifting, it is important to measure disc deformations/strains accompanied by MRI imaging to identify disc tissue damage. Therefore, the aim of this study was to examine associations between the magnitude of 3D internal strains, tissue damage and macroscopic evidence of disc injury after simulated repetitive lifting on normal human lumbar discs. Sixteen cadaver lumbar functional spinal units (FSUs) were subjected to pre-test MRI. Eight FSUs (control) underwent 20,000 cycles or until failure (5 mm displacement) of loading under compression (1.7 MPa – to simulate lifting a 20 kg weight) + flexion (13°) + right axial rotation (2°) using a novel Hexapod Robot. The remaining eight FSUs (experimental) had a grid of tantalum wires inserted, and stereoradiographs were taken to track internal disc displacements at increasing cyclic intervals. Maximum shear strains (MSS) were calculated from the displacements using radiostereometric analysis at cycle 1 and 20,000 cycles (or failure). Post-test MRI was conducted to determine the extent of tissue damage and associated with regions of highest MSS. A repeated measures ANOVA was performed on MSS with a within–subjects factor of cycle number (cycle 1 and failure cycle) and a between subjects-factor of disc region and failure type (p < 0 .05). Pfirrmann grading revealed mostly normal discs [I (N=2), II (N=13), and III (N=1)]. No significant difference in MSS between control and experimental groups was found for number of cycles to failure (p=0.279). Pre and post-test MRI analysis revealed that 13 specimens were injured after repetitive lifting with either an endplate failure (N=9) or disc bulge (N=4), and two specimens did not fail. Failure strain was significantly greater than cycle 1 in all regions except posterior, left/right posterolateral (p>0.109). Largest MSS at failure was seen in the anterior (60%), and left/right posterolateral regions (64% and 70%, respectively). MSS at failure for the endplate failure group was significantly larger than the no injury group in all regions except right lateral and nucleus (p>0.707). Disc bulge group MSS was significantly larger than the no injury group in the anterior, right anterolateral, and left/right posterolateral regions (p < 0 .027). Simulated repetitive lifting led to largest shear strains in the anterior, left and right posterolateral regions that corresponded to annular tears or annular protrusion. The no injury group shear strain was less than 50% in all regions, indicating there may be a threshold that could be associated with tissue damage linked with injuries such as disc bulge and endplate failure. There was no evidence of disc herniation in normal discs, agreeing with current clinical knowledge. These results may be indicative of the effects of repetitive manual handling on normal discs of younger patients

Introduction. Given the rising incidence of obesity in the adult population, it is more than likely that orthopaedic surgeons will be treating more obese patients with lumbar disc pathologies. The relationship between obesity and recurrent herniated nucleus pulposus (HNP) following microdiscectomy remains unclear. Objectives. To investigate the relationship between obesity and recurrent HNP following lumbar microdiscectomy. Methods. A retrospective review of case notes from 2008–2011 was conducted for all patients that underwent one level lumbar microdiscectomy, performed by a single surgeon. The standard criteria for microdiscectomy were used. Patient demographics, including Body Mass Index (BMI), collected from notes. Obese patients classified as BMI >/= 30. The primary clinical outcome measure was evidence of recurrent HNP on post operative MRI scan requiring further surgery. Results. A total of 283 patients were available for analysis: 190(67%) were in the non-obese group and 93 (32.9%) in the obese group. The average BMI was 28.1 and the average length of stay was 1.3days. Dural leak was seen in 11 patients(3.9%) out of which 8(4.2%) occurred in the non-obese group and 3(3.2%) in the obese group [p=0.04]. Recurrent symptomatic HNP was seen in 27(9.5%) patients confirmed by MRI scan. 19(10%) were in the non-obese group and 8(8.6%) in the obese group [p>0.8]. Conclusion. Obesity was not a predictor of recurrent HNP after lumbar microdiscectomy and did not have increased complication rates compared to the non-obese group

Background and Objective. In industrialized societies, the prevalence of radicular low back pain has exploded in recent years. Lumbar disc prolaps, protrusion, or extrusion account for less than 5% of all low back problems, but are the most common causes of nerve root pain and surgical interventions. The primary rationale for any form of surgery for disc prolaps is to relieve nerve root irritation or compression due to herniated disc material. The primary modality of surgical treatment continues to be either open or microdiscectomy, but several alternative techniques including. Nucleoplasty. It provokes ablation of the nucleus of the disk by a controlled thermal effect produced by radiofrequency. Nucleoplasty is minimally invasive treatment aimed at removing nuclear material and lowering intradiscal pressure and decompressing through coblation needle inserted percutaneously into the nucleus of intervertebral discs. This paper will show a 3 years experience with 110 cases with lumbar radicular pain secondary to a disc protrusion that underwent Nucleoplasty as their secondary therapy. Methods. Included in this series were 110 patients with significant lumbar radicular pain, resistant to interventional therapy done before hand like fluoroscopically guided spinal transforaminal epidural injections or sacral injections with steroids. These cases were done under local anaesthesia with short analgesia and stand by monitoring. Results. In the overall cohort, the average Visual Analogue Scale (VAS) pain score decreased. Conclusions. We conclude that with use of the present selection criteria, Nucleoplasty is very effective long-term treatment for lumbar radicular pain. We recommend modifying the criteria to include only those cases with lumbar radicular pain due to protrusion whose annular integrity is confirmed via MRI and by either selective nerve root blocks and to exclude cases with axial pain

Purpose of the study. In a recent study, O'Leary et al. [2005] reported their observations on the patterns of Charité disc prosthesis motion under physiologic loads. The purpose of this study was to investigate whether the motion patterns observed in the in vitro model are replicated in clinical practice. Methods. 55 patients with implanted SB Charité 111 artificial lumbar discs were subjected to flexion extension x-rays. Two consultant spinal surgeons and a neuro-radiological consultant were asked to classify the pattern of motion in the clinical subjects based on the patterns observed in the in vitro model. The results were recorded independently then collated. Following this first round of observations an algorithm was devised and the method of measurement was standardised. Summary of findings: There was modest correlation amongst the three observers in distinguishing motion from nonmotion (Kappa 5.6). There was less agreement on what type of motion was present. On both counts using the algorithm there was no correlation. The clinical study based on patients' flexion-extension radiographs identified the following patterns of prosthesis motion:. angular motion between both the upper and lower endplates and core, with visual evidence of core motion;. angular motion predominantly between the upper endplate and core, with little visual evidence of core motion;. lift-off of upper prosthesis endplate from core or of core from lower endplate;. core entrapment and deformation; and. no motion. There are difficulties associated with the interprtation of these using only flexion extension views. Conclusions. In devising artificial discs the requirement would be to replicate spinal motion as closely as possible. O'Leary et al have found non-physiological motions in in vitro models. These have been found in this clinical study but interobserver correlations were far from conclusive. Demonstrating non physiological patterns may have important implications for outcome

Hypothesis. Athletes significantly alter their lumbar spinal motion when performing squat lifting at heavy weights. This altered motion effects a change in pressure in the posterior annulus of lumbar discs. Methods. 48 athletes performed 6 lifts at 40% maximum, 4 lifts at 60% maximum and 2 lifts at 80% maximum. Zebris 3-D motion analysis system used to measure lumbar spine motion. Exercise then repeated with weight lifting support belt. 4 cadaveric sheep spinal motion segments fixed to tension/compression loading frame, allowing compression replicating the forces seen in in vivo study. Pressure measurement achieved using a Flexiforce single element force sensor strip, positioned at posterior annulus. Posterior annulus pressure measured during axial compression and on compression with specimen fixed at 3° of extension. Results. Significant decrease (p<0.05) seen in flexion in all groups studied when lifting at 40% maximum was compared with lifting at 60% and 80% of maximum lift. Extension from a calibrated zero point ranged in groups studied from -1.5° (40% group), to -20.3° (80% group). No statistically significant difference found between motion seen when performing exercise as ‘free’ squat or when lifting using support belt in any group. Comparing axially loaded specimens with specimens loaded in extension, there was an average increase in pressure of 36.4% in the posterior annulus, when the spine was loaded in 3° of extension at a pressure equivalent to the 80% lift in the in vivo motion study, in comparison to axial loading. Conclusions. Squat weight lifting at heavier weights, causes athletes to lift at a progressively greater degree of extension. The use of a weight lifting support belt does not significantly alter spinal motion during lifting. The increased extension at heavier weights results in a stress concentration in the posterior annulus

Nowadays many new minimally invasive techniques are experienced to perform lower lumbar interbody fusion in attempt to decrease the complications related to open anterior approach. AxiaLIF (axial lumbar interbody fusion) system is a percutaneous transacral approach that exploits the virtual presacral retroperitoneal space to perform annulus-sparing discectomy and interbody instrumented fusion of lower lumbar disc spaces. Additioning posterior percutaneous instrumentation, a robust axial construct is placed which restores disc height, sagittal balance and lordosis with minimal muscle dissection, blood loss and postoperative pain. Via fluoroscopically-guided approach, AxiaLIF procedure creates a presacral retroperitoneal corridor in the midline through a paracoccigeal skin incision of 2-3 cm. This space is void of neuro-vascular major elements. A safe working cannula is put in and docked in the S1-S1 entry level and a transacral channel is realized gaining the central space of the disc. A 360° annulus-sparing radial discectomy is performed with special cutters even in case of collapsed disc space and the bone graft is inserted. The following screwing of AxiaLIF rod restores disc height via distraction if necessary, decompresses the neural foramen indirectly and undertakes instantaneous rigid fixation of adjacent vertebral bodies. Using the same incision point and trajectory through the presacral space as AxiaLIF, it is possible to realized a similar procedure L4-S1 vertebral fusions called AxiaLIF 2L. Between february 2009 and may 2010 25 patients (16F:9M) affected by degenerative disc disease (17) and grade 1 or 2 spondylolisthesis (8) were included in this study. Evaluated outcomes were the amount of bleeding, the presence of presacral hematoma, the functional recovery time, the surgery time rate, the x-ray time rate, the complication rate (infection, pelvic visceral injury, postoperative pain). 21 of 25 patients underwent AxiaLIF L5-S1 procedures, 4 of these with a stand alone implant and 17 followed by posterior instrumentation. In the remaining 4 patients, a AxiaLIF 2L L4-S1 procedures is performed. 4 of 25 patients had a perioperative suction drenage. Mean operative time for L5-S1 AxiaLIF procedure was 49 minutes. A 2. nd. p.o.d. CT pelvic scan of undrained and drained groups showed a mean presacral hematoma of 45 cc and 17 cc respectively reduced one month later to a mean value of 19 cc and 3 cc. Hemoglobin rate mainly reduced of 1,7 g/dL between pre and postoperative time. At one month all patients improved their quality of life significantly but one had a gluteal pain. No patient had perioperative infections or pelvic visceral injuries or required blood transfusions. This study seems to assess that AxiaLIF procedure is a minimally invasive lower spine techique actually. The presacral hematoma presence seems to have no side effect and it may be prevented by perioperative drainage. More large studies are needed to confirm our results

Total disc replacement (TDR) is the gold standard for lumbar degenerative disc disease in selected patient groups. Traditional TDR designs benefit from a wealth of literature and use a polyethylene inlay pseudo-disc between two metal endplates. There is scarce literature for novel monomodular implants that form an artificial construct of woven annulus and central nucleus, providing physiological motion preservation. The aim was to compare the evolving changes to radiological position between monomodular and traditional implants and assess the relationship of migration with bone densitometry. This retrospective series of consecutive patients undergoing TDR under a single surgeon recorded demographics, co-morbidities, previous surgery and clinical outcomes. Measurements of endplate subsidence, lordosis and spondylolisthesis taken from weight-bearing erect x-rays at 0, 3, 6 and 12 months. Radiological outcomes were compared against CT bone densitometry. 33 monomodular and 13 traditional implants. Mean age 40 years. All patients had degenerative disc disease. Monomodular and traditional implants were as likely to develop lordosis (p=0.32), endplate subsidence (p=0.78) or spondylolisthesis (p=0.98). Comparison between endplate subsidence and low bone densitometry were insignificant (p=0.47). Developing lordosis in the monomodular implant was related to low bone density; mean 134vs.184mg/cm. 3. (p=0.018). Three monomodular implants developed a posterior hinge after migrating into lordosis. One traditional implant dislocated, requiring emergency fusion. Radiological outcomes are comparable between traditional and monomodular implants. The larger endplate-footprint of the monomodular implant did reduce subsidence. Monomodular implants pivoting on a posterior hinge may fail early. Bone densitometry may identify patients who will drift into lordosis

This study was undertaken to evaluate the safety and efficacy of retrievable inferior vena cava filters in high-risk orthopaedic patients. A total of 58 patients had a retrievable inferior vena cava filter placed as an adjunct to chemical and mechanical prophylaxis, most commonly for a history of previous deep-vein thrombosis or pulmonary embolism, polytrauma, or expected prolonged immobilisation. In total 56 patients (96.6%) had an uncomplicated post-operative course. Two patients (3.4%) died in the peri-operative period for unrelated reasons.

Of the 56 surviving patients, 50 (89%) were available for follow-up. A total of 32 filters (64%) were removed without complication at a mean of 37.8 days (4 to 238) after placement. There were four filters (8%) which were retained because of thrombosis at the filter site, and four (8%) were retained because of incorporation of the filter into the wall of the inferior vena cava. In ten cases (20%) the retrievable filter was left in place to continue as primary prophylaxis. No patient had post-removal thromboembolic complications.

A retrievable inferior vena cava filter, as an adjunct to chemical and mechanical prophylaxis, was a safe and effective means of reducing the acute risk of pulmonary embolism in this high-risk group of patients. Although most filters were removed without complications, thereby avoiding the long-term complications that have plagued permanent indwelling filters, a relatively high percentage of filters had to be left in situ.