Background. Surgical site infection following spine surgery is associated with increased morbidity, mortality and increased cost for the health care system. The reported pooled incidence is 3%. Perioperative antibiotic prophylaxis is a key factor in lowering the risk of acquiring an infection. Previous studies have assessed perioperative cefuroxime concentrations in the anterior column of the cervical spine with an anterior surgical approach. However, the majority of surgeries are performed in the posterior column and often involve the lumbar spine. Accordingly, the objective was to compare the perioperative tissue concentrations of cefuroxime in the anterior and posterior column of the same lumbar vertebra using microdialysis in an experimental porcine model. Method. The lumbar vertebral column was exposed in 8 female pigs. Microdialysis catheters were placed for sampling in the anterior column (vertebral body) and posterior column (posterior arch) within the same vertebra (L5). Cefuroxime (1.5 g) was administered intravenously over 10 min. Microdialysates and plasma samples were continuously obtained over 8 hours. Cefuroxime concentrations were quantified by Ultra High Performance Liquid Chromatography Tandem Mass Spectrometry. Microdialysis is a catheter-based pharmacokinetic tool, that allows dynamic sampling of unbound and pharmacologic active fraction of drugs e.g., cefuroxime. The primary endpoint was the time with cefuroxime above the clinical breakpoint minimal inhibitory concentration (T>MIC) for Staphylococcus aureus of 4 µg/mL as this has been suggested as the best predictor of efficacy for cefuroxime. The secondary endpoint was tissue penetration (AUC. tissue. /AUC. plasma. ). Results. Mean T>MIC 4 µg/mL (95% confidence interval) was 123 min (105–141) in plasma, 97 min (79–115) in the anterior column and 93 min (75–111) in the posterior column. Tissue penetration (95% confidence interval) was incomplete for both the anterior column 0.48 (0.40–0.56) and posterior column 0.40 (0.33–0.48). Conclusions. Open lumbar spine surgery often involves extensive soft tissue dissection, stripping and retraction of the paraspinal muscles which may impair the local blood flow exposing the lumbar vertebra to postoperative infections. A single intravenous administration of 1.5 g cefuroxime resulted in comparable T>MIC between the anterior and posterior column of the lumbar spine. Mean cefuroxime concentrations decreased below the clinical breakpoint MIC for S. aureus of 4 µg/mL after 123 min (plasma), 97 min (anterior column) and 93 min (posterior column). This is shorter than the duration of most lumbar spine surgeries, and therefore alternative dosing regimens should be considered in posterior open lumbar spine surgeries lasting more than 1.5 hours

Mathematical modeling provides an efficient and easily reproducible method for the determination of joint forces under in vivo conditions. The need for these new modeling methodologies is needed in the lumbar spine, where an understanding of the loading environment is limited. Few studies using telemetry and pressure sensors have directly measured forces borne by the spine; however, only a very small number of subjects have been studied and experimental conditions were not ideal for giving total forces acting in the spine. As a result, alternative approaches for investigating the lumbar spine across different clinical pathologies are essential. Therefore, the objective of this study was to develop of an inverse dynamic mathematical model for theoretically deriving in-vivo contact forces as well as musculotendon forces in patients having healthy, symptomatic, pathological and post-operative conditions of the lumbar spine. Fluoroscopy and 3D-to-2D image registration were used to obtain kinematic data for patients performing flexion-extension of the lumbar spine. This data served as input into the multi-body, mathematical model. Other inputs included patient-specific bone geometries, recreated from CT, and ground reaction forces. Vertebral bones were represented as rigid bodies, while massless frames symbolized the lower body, torso and abdominal wall (Figure 1). In addition, ligaments were selected and modeled as linear spring elements, along with relevant muscle groups. The muscles were divided into individual fascicles and solved for using a pseudo-inverse algorithm which enabled for decoupling of the derived resultant torques defining the desired kinetic trajectory for the muscles. The largest average contact forces in the model for healthy, symptomatic, pathological, and post-operative lumbar spine conditions occurred at maximum flexion at L4L5 level and were predicted to be 2.47 BW, 2.33 BW, 3.08 BW, and 1.60 BW, respectively. The FE rotation associated with these theoretical force values was 43.0° in healthy, 40.5° in symptomatic, 44.4° in pathological, and 22.8° in post-operative patients. The smallest forces occurred as patients approached the upright, standing position, followed by slight increases in the contact force at full extension. The theoretically derived muscle forces exhibited similar contributory force profiles in the intact spine (healthy, symptomatic, and pathologic); however, surgically implanted spines experienced an increase in the contribution of the external oblique muscles accompanied with decreased slope gradients in the muscle force profiles (Figure 2). These altered force patterns may be associated with the decrease in the predicted contact forces in post-operative patients. In addition, the decreased slope gradients in surgically implanted patients corresponds with the observed difficulty of performing the prescribed motion, possibly due to improper muscle firing, thereby leading to slower motion cycles and less ranges-of-motion. On the contrary, patients having an intact spine performed the activity at a faster speed and to greater ranges-of-motion, which corresponds with the higher contact forces derived in the model. In conclusion, this research study presented the development of a mathematical modeling approach utilizing patient-specific data to generate theoretical in-vivo joint forces. This may serve to help progress the understanding for the kinetic characteristics of the native and surgically implanted lumbar spine

Introduction. Numerous studies have been conducted to investigate the kinematics of the lumbar spine, and while many have documented its intricacies, few have analyzed the complex coupled out-of-plane rotations inherent in the low back. Some studies have suggested a possible relationship between patients having low back pain (LBP) or degenerative conditions in the lumbar region and various degrees of restricted, excessive, or poorly-controlled lumbar motion. Conversely, others in the orthopedic community maintain there has been no distinct correlation found between spinal mobility and clinical symptoms. The objective of this study was to evaluate both the in-plane and coupled out-of-plane rotational magnitudes about all three motion axes in both symptomatic and asymptomatic patients. Methods. Ten healthy, 10 LBP, and 10 degenerative patients were CT scanned and evaluated under fluoroscopic surveillance while performing flexion/extension of the lumbar spine. Three-dimensional, patient-specific bone models were created and registered to fluoroscopic images using a 3D-to-2D model fitting algorithm. In vivo kinematics were derived at specified increments and the overall in-plane flexion/extension and coupled out-of-plane rotations were analyzed using two techniques. The first method derived the maximal absolute rotational magnitude (MARM) at each level by subtracting the rotational motion in the increment exhibiting the most negative or least amount of rotation from the increment having the greatest amount of rotation. The second method was designed to isolate the path of rotation (POR) of the vertebrae at each level while performing the prescribed flexion/extension activity. By tracking the rotational path of the cephaled vertebrae as it articulated upon the more caudal vertebrae and summing the absolute rotation between each increment about each axis the POR was calculated over the entire flexion/extension activity. Results. Using both the MARM and POR methods, the average overall in-plane rotations between L1 and L5 were not significantly different among any of the groups, although the degenerative group did exhibit less in-plane range-of-motion compared to the healthy and LBP patients. At the L4–L5 level, patients in the healthy and LBP groups achieved 13.1° and 14.4° of rotation, respectively, compared to only 10.7° in the degenerative group. In addition, both of the symptomatic patient groups experienced less rotation during the extension phase of the activity. The coupled out-of-plane motions in both the LBP and degenerative subjects were significantly greater than those observed in healthy subjects (p=0.0199 and p<0.001, respectively). On average, LBP and degenerative patients achieved 5.5° and 7.1° more out-of plane rotational motion per level, respectively, compared to healthy subjects. Conclusions. These findings correlate with previous studies documenting paradoxical motions in the lumbar spine during an overall gross motion and support the idea of pain being a biological response to tissue injury which may result from excessive kinetic energy introduced into the biological system. Identification of these aberrant motion path magnitudes may aid in recognizing possible causes of pain in patients suffering from non-specific low back problems. Increased magnitudes of out-of-plane rotational paths observed in symptomatic patients may also be an indicator for progressive pathologies requiring surgical intervention in the lumbar spine region

Introduction. Hip-Spine syndrome has various clinical aspects. For example, schoolchild with severe congenital dislocation of the hip have unfavorable standing posture and disadvantageous motions in ADL. Hip-Spine syndrome is closely related closely as the adjacent lumbar vertebrae and the hip joint. Furthermore, not only the pelvis and the lumbar spine, but also the neck position might influence on the maximum hip flexion angle. In this study, we examined the maximum hip flexion angle and pelvic movement angle by observing the lumbar spine, the pelvis and the neck in three different positions. Subjects and Methods. The participants were five healthy volunteers (three males and two females) and ranged in age from 16 to 49 years. We measured the hip flexion angle (=∠X) and the pelvic tilt angle (=∠Y), using Zebris WinData and putting the six markers on skin. The positions of the marker are Femur lateral condyle (M1), Greater trochanter (M2), Lateral margin of 10th rib (M3), Anterior superior iliac spine (M4), Superior lateral margin of Iliac (M5), and Acromion (M6). We performed maximum hip flexion three times in three positions and measured ∠X (=∠M1,2,3) and ∠Y (=∠M4,5,6) and calculated the mean and SD of each position. The first position (P1) that we investigated is the regular position specified by the Japanese Orthopedics Association and Rehabilitation Medical Association. The second position (P2) is performed in the limited position of the posterior pelvic tilt and lumbar movement, by placing the tube under the subject's lower back. The third position (P3) is the altered limited position of P2 added by placing the 500ml PET bottle filled water under the back of the subject's neck. Analysis. A two way factorial analysis of variance was used for statistical analysis to examine the difference among three different positions (P1, P2 and P3) in ∠X and ∠Y. A significance level was set at P < 0.05. We also calculated Spearman rank correlation coefficients to determine the correlation between ∠X and ∠Y. Results. There was a statistically significant difference among three different positions (P1, P2 and P3) in both ∠X and ∠Y (p < 0.01). Slight strong correlations were found between ∠X and ∠Y in three different positions. (r =0.5178571). The smallest values of ∠X and ∠Y were obtained in P1. The values of ∠X and ∠Y in P3 were all smaller than those in P2. Conclusions. The limited movement of pelvic and lumbar spine, and neck different positions give the limit to a maximum hip joint flexion angle

INTRODUCTION. Standing spinal alignment has been the center of focus recently, particularly in the setting of adult spinal deformity. Humans spend approximately half of their waking life in a seated position. While lumbopelvic sagittal alignment has been shown to adapt from standing to sitting posture, segmental vertebral alignment of the entire spine is not yet fully understood, nor are the effects of DEGEN or DEFORMITY. Segmental spinal alignment between sitting and standing, and the effects of degeneration and deformity were analyzed. METHODS. Segmental spinal alignment and lumbopelvic alignment (pelvic tilt (PT), pelvic incidence (PI), lumbar lordosis (LL), PI-LL, sacral slope) were analyzed. Lumbar spines were classified as NORMAL, DEGEN (at least one level of disc height loss >50%, facet arthropathy, or spondylolisthesis), or DEFORMITY (PI-LL mismatch>10°). Exclusion criteria included lumbar fusion/ankylosis, hip arthroplasty, and transitional lumbosacral anatomy. Independent samples t-tests analyzed lumbopelvic and segmental alignment between sitting and standing within groups. ANOVA assessed these differences between spine pathology groups. RESULTS. There were 183 NORMAL, 216 DEGEN and 92 DEFORMITY patients with significant differences in age, gender, and hip OA grades. After propensity matching for these factors, there were 56 patients in each group (age 63±14, 58% female) [Fig. 1]. Significant differences were noted between spinal pathology groups with regard to changes from standing to sitting alignment with regard to NORMAL vs DEGEN vs DEFORMITY groups in PT (13.93° vs −11.98° vs − 7.95°; p=0.024), LL (21.91° vs 17.45° vs 13.23°; p=0.002), PI-LL (−22.32° vs −17.28° vs −13.18°; p<0.001), SVA (−48.99° vs −29.98° vs −32.12°; p=0.002), and TPA(−16.35° vs −12.69° vs −9.64; p=0.001). TK (−2.08° vs −2.78° vs −2.00°, p=0.943) and CL (−3.84° vs −4.14° vs −3.57°, p=0.621) were not significantly different across spinal pathology groups [Fig. 2]. NORMAL patients had overall greater mobility in the lower lumbar spine from standing to sitting compared to DEGEN and DEFORMITY patients. L4-L5 (7.50° vs 5.23° vs 4.74°, p=0.012) and L5-S1 (6.96° vs 5.28° and 3.69°, p=0.027). There were no significant differences in change in alignment from standing to sitting at the upper lumbar levels or lower thoracic levels between the three groups [Fig. 3]. CONCLUSION. The lower lumbar spine provides the greatest sitting to standing change in lumbopelvic alignment in normal patients. Degeneration and deformity of the spine significantly reduces the mobility of the lower lumbar spine and PT. With lumbar spine degeneration and flatback deformity, relatively more alignment change occurs at the upper lumbar spine and thoracolumbar junction

Prolonged length of stay (LOS) is a significant contributor to the variation in surgical health care costs and resource utilization after elective spine surgery. The primary goal of this study was to identify patient, surgical and institutional variables that influence LOS. The secondary objective is to examine variability in institutional practices among participating centers. This is a retrospective study of a prospectively multicentric followed cohort of patients enrolled in the CSORN between January 2015 and October 2020. A logistic regression model and bootstrapping method was used. A survey was sent to participating centers to assessed institutional level interventions in place to decrease LOS. Centers with LOS shorter than the median were compared to centers with LOS longer than the median. A total of 3734 patients were included (979 discectomies, 1102 laminectomies, 1653 fusions). The median LOS for discectomy, laminectomy and fusion were respectively 0.0 day (IQR 1.0), 1.0 day (IQR 2.0) and 4.0 days (IQR 2.0). Laminectomy group had the largest variability (SD=4.4, Range 0-133 days). For discectomy, predictors of LOS longer than 0 days were having less leg pain, higher ODI, symptoms duration over 2 years, open procedure, and AE (p< 0.05). Predictors of longer LOS than median of 1 day for laminectomy were increasing age, living alone, higher ODI, open procedures, longer operative time, and AEs (p< 0.05). For posterior instrumented fusion, predictors of longer LOS than median of 4 days were older age, living alone, more comorbidities, less back pain, higher ODI, using narcotics, longer operative time, open procedures, and AEs (p< 0.05). Ten centers (53%) had either ERAS or a standardized protocol aimed at reducing LOS. In this study stratifying individual patient and institutional level factors across Canada, several independent predictors were identified to enhance the understanding of LOS variability in common elective lumbar spine surgery. The current study provides an updated detailed analysis of the ongoing Canadian efforts in the implementation of multimodal ERAS care pathways. Future studies should explore multivariate analysis in institutional factors and the influence of preoperative patient education on LOS

Aim. To evaluate morbidity and outcome associated with lumbar spine decompression for central spinal stenosis in the elderly compared with younger age groups. Patients & methods. Case notes review of patients with symptomatic and MRI proven central lumber canal stenosis, under the care of a single surgeon. The study population was 3 age groups: patients < 60 year of age (Group 1, n=21), patients between 60 and 79 years (Group 2, n=54), and > age of 80 years (Group 3, n=15). Data with regard to intra- and post-operative complications and subjective outcome variables were collected. These included pain (VAS), walking distance, Oswestry Disability score (ODI) and patient satisfaction scores. Results. There was a statistically significant improvement in VAS score for leg pain (p<0.05) and back pain (p<0.05) after surgery for each group. All three groups reported improvement in their walking distance. The average walking distance improved by factor 5 in groups 1 and 2 and by factor 2.5 in group 3 (p< 0.05). However the improvement in group 3 was not statistically significant. There was a statistically significant improvement in ODI for all three groups (mean ODI improvement in Group 1, 16 points, Group 2, 23 points and Group 3, 15 points). Overall 96% of patients were satisfied and would consider the same treatment again under similar circumstances. The overall complication was 19% in group 1, 18% in group 2, and 33% in group 3. Conclusions. Surgery for neurogenic claudication in the octogenarian is associated with a higher complication rate. The outcomes however in this patient group are comparable to younger patients. Lumbar decompression surgery in octogenarians is a worthwhile procedure

Purpose:. The purpose of the study was to evaluate the safety and efficacy of fixation of the lumbar spine, without fusion, using the Cosmic Pedicle Fixation System. Method:. Prospective study of 107 patients selected to have either a completely non fused fixation (40 patients), and 67 who underwent a hybrid fusion. During the same period 299 standard fusions were performed at same institution. Enrolment was from January 2006 to August 2008. Appropriate consent was obtained, but the choice of which levels to fuse and which levels to fix only was the surgeon's choice. Pre-operative ODI and VAS scores were obtained as well as parameters of sitting, standing and walking potential. Regular follow-up visits were done, and these parameters were controlled together with regular x-rays at each visit at 6 weeks, 6 months and 12 months and annually thereafter. Intra-operative blood loss, hospital stay and any adverse reaction or complications were documented. Results:. The average follow up was more than 3 years. Average age at surgery was 62 years. Most were treated for spinal stenosis (79/107). Average VAS score improved from 8 to 2.2. ODI score improved from 50 to 14 (at 12 months), but there was a slight deterioration with time and aging. All improved dramatically on walking distances and sitting time. Revision surgery was required in 10 patients, of which only 5 had fusions performed at the previously non fused segment. Screw breakage occurred in a number of patients but was not correlated to poor outcomes. Average blood loss was 336 ml while hospital stay was only 3 days. Conclusion:. Cosmic fixation without fusion is safe, giving comparable results to fusion with less complications, shorter hospital stay and very modest blood loss. Although not measured as such, pain control and use of opioids were deemed much less than conventional fusion surgery

Resident involvement in the operating room is a vital component of their medical education. Conflicting and limited research exists regarding the effects of surgical resident participation on spine surgery patient outcomes. Our objective was to determine the effect of resident involvement on surgery duration, length of hospital stay and 30-day post-operative complication rates.

This study was a multicenter retrospective analysis of the prospectively collected American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database. All anterior cervical or posterior lumbar fusion surgery patients were identified. Patients who had missing trainee involvement information, surgery for cancer, preoperative infection or dirty wound classification, spine fractures, traumatic spinal cord injury, intradural surgery, thoracic surgery and emergency surgery were excluded. Propensity score for risk of any complication was calculated to account for baseline characteristic differences between the attending alone and trainee present group. Multivariate logistic regression was used to investigate the impact of resident involvement on surgery duration, length of hospital stay and 30 day post-operative complication rates.

1441 patients met the inclusion criteria: 1142 patients had surgeries with an attending physician alone and 299 patients had surgeries with trainee involvement. After adjusting using the calculated propensity score, the multivariate analysis demonstrated that there was no significant difference in any complication rates between surgeries involving trainees compared to surgeries with attending surgeons alone. Surgery times were found to be significantly longer for surgeries involving trainees. To further explore this relationship, separate analyses were performed for tertile of predicted surgery duration, cervical or lumbar surgery, instrumentation, inpatient or outpatient surgery. The effect of trainee involvement on increasing surgery time remained significant for medium predicted surgery duration, longer predicted surgery duration, cervical surgery, lumbar surgery, lumbar fusion surgery and inpatient surgery. There were no significant differences reported for any other factors.

After adjusting for confounding, we demonstrated in a national database that resident involvement in surgeries did not increase complication rates, length of hospital stay or surgical duration of more routine surgical cases. We found that resident involvement in surgical cases that were generally more complexed resulted in increased surgery time. Further study is required to determine the relationship between surgery complexity and the effect of resident involvement on surgery duration.

Purpose of study. This RCT is to determine whether or not there is a clinical benefit from inserting a dynamic stabilising implant such as the Wallis ligament on the functional recovery of patients who have undergone lumbar decompression surgery. This Interspinous implant was developed as an anatomically conserving procedure without recourse to lumbar spinal fusion surgery. The biomechanical studies have shown that unloading the disc and facet joints reduces intradiscal pressures at same and adjacent levels. The aim of this study was to identify a patential Wallis affect. Methods. Ethicallly approved. Patients were randomized into 2 groups, decompression alone or decompression with wallis interspinous ligament stabilisation. Patients were assessed pre operatively and post operatively every 6 months by VAS pain score and Oswestry Disability Index. Summary of findings. A total of 60 patients were recriuted the study from October 2005. Equal number had been randomized into two groups. The mean age of 54 (24–85) and the average follow is 36 months (6–48). The results were significantly better in decompression plus Wallis group compared to decompression alone, showing a minimal clinical difference compared to the control group. Relationship between findings and existing knowledge: Our results deomonstrate that clincial outcomes are significantly better when a Wallis implant was used in lumbar deompression. Patients experienced less back pain. Overall significance of findings: The Wallis implant represents a successful non fusion stabilisation device in the treatment of degenerative lumbar spine disease with canal stenosis. Minimal soft tissue dissection, quick rehabilitation, low morbidity. The Wallis ligament sucessfully treats spinal stenosis by reducing pain score, preserving mobility, and function

Up to one-third of patients experience limited benefit following surgical intervention for LS-OA. Thus, identifying contributing factors to this is important. People with OA often have multijoint involvement, yet this has received limited attention in this population. We documented the occurrence and evaluated the influence of multijoint symptoms on outcome following surgery for LS-OA.

141 patients undergoing decompression surgery+/−fusion for LS-OA completed the Oswestry Disability Index (ODI) pre- and 12-months post-surgery. Also captured pre-surgery: age, sex, education, BMI, smoking, depressive symptoms and comorbidities. Any joints with “pain/stiffness/swelling most days of the month” were indicated on a homunculus. A symptomatic joint site count (e.g. one/both knees= one site), excluding the back, was derived (range zero to nine) and considered as a predictor of magnitude of ODI change, and likelihood of achieving minimally clinically important improvement in ODI (MCID=12.8) using multivariable adjusted linear and log-Poisson regression analyses.

Mean age: 66 years (range:42–90), 46% female. 76% reported one+ joint site other than the back, 43% reported three+, and nearly 10% reported six+. (< MCID) for those with three sites, and four units for those with six+ sites. Associated with a greater likelihood of not achieving MCID were increasing joint count (11% increase per site (p=0.012)), higher BMI, current/former smoker, and worse baseline ODI tertile.

Results suggest there is more than just the back to consider to understand patient-reported back outcomes. Multijoint symptoms directly contribute to disability, but there is potential they may contribute to systemic, largely inflammatory, effects in OA as well.

We reported the first single surgeon series comparing outcome of microscopic and open primary single level unilateral lumbar decompression or discectomy. We aimed to determine any difference in outcomes between the two techniques.

Forty-six decompressions were performed with use of an operating microscope (microscopic), and forty without (open) at two different hospitals. All procedures were performed by the senior author. Information was obtained by analysis of the patients' notes. The average age of the patients in both groups was comparable. Operating time was shorter in the microscopic group (68min, range 30-130) compared to the open group (83 mins, range 30-180). Dural tear rate was 4.3% with use of a microscope (0% symptomatic dural tear rate) and 7.5% without (2.5% symptomatic dural tear rate). Nerve damage incidence was 0% with use of a microscope and 5% (two patients) without. One of these was a neurapraxia and the patient made a full recovery. Wound infection rates, diagnosed on grounds of clinical suspicion, were 4.3% and 2.5% for microscopic and open respectively. There were no incidences of deep infection or post-operative discitis. Average inpatient stay was under 48 hours in both groups.

Using the modified Macnab criteria, results using the microscope were 0% poor, 14% fair, 32% good, and 55% excellent. The results for the open group were 0% poor, 10% fair, 37% good and 53% excellent. Average follow-up was six months (1-19) for the microscope group, and seven months (2-16) for the open group.

We conclude that primary single level unilateral lumbar decompressive surgery, performed without the use of a microscope, has a higher dural tear rate than the same surgery performed with the benefit of an operating microscope. Surgical time and incidence of nerve damage are also reduced by use of the microscope.

The purpose of this study is to determine whether the mode of anaesthesia chosen for patients undergoing lumbar microdiscectomy surgery has any significant influence on the immediate outcome in terms of safety, efficacy or patient satisfaction.

This prospective randomised study compared safety, efficacy and satisfaction levels in patients having spinal versus general anaesthesia for single level lumbar microdiscectomy.

Fifty consecutive healthy and cooperative patients were recruited and prospectively randomised into two equal groups; half the patients received a spinal anaesthetic (SA), the remainder a general anaesthetic (GA). Each specific mode of anaesthesia was standardised.

Comprehensive post-operative evaluation concentrated on documenting any complications specific to the particular mode of anaesthesia, recording the pace at which the various milestones of physiological and functional recovery were reached, and the level of patient satisfaction with the type of anaesthesia used.

The results showed no serious complication specific to their particular mode of anaesthesia in either group. Thirteen out of 25 SA patients required temporary urinary catheterisation (9 males, 4 females) while among the GA group 4 patients required urinary catheterisation (4 males and 1 female). Post-operative pain perception was significantly lower in the SA group. The SA patients achieved the milestones of physiological and functional recovery more rapidly. While both groups were satisfied with their procedure, the level of satisfaction was significantly higher in the SA group.

In conclusion, lumbar spinal microdiscectomy can be carried out with equal safety, employing either spinal or general anaesthesia. While they require more temporary urinary catheterisation associated with the previous use of intrathecal morphine, patients undergoing SA suffer less pain in association with their procedure and recover more rapidly. Blinded to an extent by not having experienced the alternative, both groups appeared satisfied with their anaesthetic. However, the level of satisfaction was significantly higher in the SA group.

Introduction

Limb-length discrepancy (LLD) is a common postoperative complication after total hip arthroplasty (THA). This study focuses on the correlation between patients’ perception of LLD after THA and the anatomical and functional leg length, pelvic and knee alignments and foot height. Previous publications have explored this topic in patients without significant spinal pathology or previous spine or lower extremity surgery. The objective of this work is to verify if the results are the same in case of stiff or fused spine.

Pedicle screw (PS) insertion has been critised for its risk of serious injury to neurovascular structures. Although computed tomography (CT)-based navigation has been developed to avoid such complications, perforation remains an issue, even with the aid of additional guidance. We clarify screw perforation rate and direction in 359 consecutive patients treated using CT-based PS insertion and present important considerations for more accurate screw placement.

The medical records of 359 consecutive patients who underwent PS insertion involving C2-L5 using a CT-based navigation system were reviewed. Postoperative CT images were analysed to evaluate the accuracy of screw placement. We investigated both rate and direction of screw perforation according to vertebral level.

Of the 3413 PS that were inserted, 3.0% (104/3413) were judged as Grade 3 (more than 4mm) perforations. Allover perforation rates by vertebral level were shown in Table 1. The rate of these perforations was 5.0% for C2, 7.8% for C3–5, 3.9% for C6–7, 3.4% for T1–4, 3.5% for T5–8, 1.4% for T9–12, and 1.7% for L1–5. We also analysed the odds ratio (OR) for screw perforation in vertebrae accounting for the effects of age and disease. Multivariate analysis identified that PS insertions at C3–5 (OR 4.9, 95% CI 2.2–10.9; p<0.001) were significantly associated with Grade 3 screw perforation as compared with that of L1–5.

Even with CT-based navigation, careful insertion of PS is needed in the middle cervical spine because of a significantly higher perforation rate as compared with the lumbar region.

For figures and tables, please contact authors directly.

Military personnel operating on high speed marine craft are exposed to Whole-Body Vibration (WBV). Additionally planing craft operate at speeds with minimal contact of the hull with warer making the crew vulnerable to mechanical shock. An association between Low Back Pain (LBP) and exposure to WBV has been extensively reported in civilian literature. LBP is reported by military personnel operating on planing craft leading to downgrades and potential discharge. There is a clear need to understand the impact prolonged exposure has on our population operating these craft. We performed a bibliographical search of the PubMed database for records using a combination of keywords. Abstracts were screened for relevance and references cited in retrieved papers reviewed. There is no consensus in the literature on the potentially pivotal pathological process behind the association. Evidence from professional driving suggests current safe operating exposure levels require review to protect against long-term damage however with little evidence concerning the unique environment in which boats crews operate, the parity of these environments require investigation to allow direct comparison. Due to the prevalence of LBP in this population a need exists to establish the pathological process and add to the evidence base driving safe operating exposure levels.

Introduction

Pedicle screw fixation is considered gold standard as it provides stable and adequate fixation of all the three columns of spine. Mal-placement of screws in dorso-lumbar region, using fluoroscopic control only, varies from 15% to 30 %. The aim of this study was to determine whether accuracy of pedicle screw placement can be improved using CT based navigation technique.

A stiff spine leads to increased demand on the hip, creating an increased risk of total hip arthroplasty (THA) dislocation. Several authors propose that a change in sacral slope of ≤10° between the standing and relaxed-seated positions (ΔSSstanding→relaxed-seated) identifies a patient with a stiff lumbar spine and have suggested use of dual-mobility bearings for such patients. However, such assessment may not adequately test the lumbar spine to draw such conclusions. The aim of this study was to assess how accurately ΔSSstanding→relaxed-seated can identify patients with a stiff spine. This is a prospective, multi-centre, consecutive cohort series. Two-hundred and twenty-four patients, pre-THA, had standing, relaxed-seated and flexed-seated lateral radiographs. Sacral slope and lumbar lordosis were measured on each functional X-ray. ΔSSstanding→relaxed-seated seated was determined by the change in sacral slope between the standing and relaxed-seated positions. Lumbar flexion (LF) was defined as the difference in lumbar lordotic angle between standing and flexed-seated. LF≤20° was considered a stiff spine. The predictive value of ΔSSstanding→relaxed-seated for characterising a stiff spine was assessed. A weak correlation between ΔSSstanding→relaxed-seated and LF was identified (r2= 0.15). Fifty-four patients (24%) had ΔSSstanding→relaxed-seated ≤10° and 16 patients (7%) had a stiff spine. Of the 54 patients with ΔSSstanding→relaxed-seated ≤10°, 9 had a stiff spine. The positive predictive value of ΔSSstanding→relaxed-seated ≤10° for identifying a stiff spine was 17%. ΔSSstanding→relaxed-seated ≤10° was not correlated with a stiff spine in this cohort. Utilising this simplified approach could lead to a six-fold overprediction of patients with a stiff lumbar spine. This, in turn, could lead to an overprediction of patients with abnormal spinopelvic mobility, unnecessary use of dual mobility bearings and incorrect targets for component alignment. Referring to patients ΔSSstanding→relaxed-seated ≤10° as being stiff can be misleading; we thus recommend use of the flexed-seated position to effectively assess pre-operative spinopelvic mobility

Low back pain is the single most common cause for disability in individuals aged 45 years or younger, it carries tremendous weight in socioeconomic considerations. Degenerative aging of the structural components of the spine can be associated with genetic aspects, lifetime of tissue exposure to mechanical stress & loads and environmental factors. Mechanical consequences of the disc degenerative include loss of disc height, segment instability and increase the load on facets joints. All these can lead to degenerative changes and osteophytes that can narrow the spinal canal. Surgery is indicated in patients with spinal stenosis who have intractable pain, altered quality of life, substantially diminished functional capacity, failed non-surgical treatment and are not candidates for non-surgical treatment. The aim was to determine the reasons for refusal of surgery in patients with established degenerative lumber spine pathology eligible for surgery. All patients meeting the study criteria, patients older than 18 years, patients with both clinical and radiological established symptomatic degenerative lumbar spine pathology and patients eligible for surgery but refusing it were recruited. Questionnaire used to investigate reasons why they are refusing surgery. Results 59 were recruited, fifty-one (86.4 %) females and eight (13.6 %) males. Twenty (33.8 %) were between the age of 51 and 60 years, followed by nineteen (32.2 %) between 61 and 70 years, and fourteen (23.7 %) between 71 and 80 years. 43 (72 %) patients had lumber spondylosis complicated by lumber spine stenosis, followed by nine (15.2 %) with lumbar spine spondylolisthesis and four (6.7 %) had adjacent level disease. 28 (47.4 %) were scared of surgery, fifteen (25.4 %) claimed that they are too old for surgery and nine (15.2 %) were not ready. Findings from this study outlined that patients lack information about the spinal surgery. Patients education about spine surgery is needed

Abstract. Objective. Flexible stabilisation has been utilised to maintain spinal mobility in patients with early-stage lumbar spinal stenosis (LSS). Previous literature has not yet established any non-fusion solution as a viable treatment option for patients with severe posterior degeneration of the lumbar spine. This feasibility study evaluates the mean five-year outcomes of patients treated with the TOPS (Total Posterior Spine System) facet replacement system in the surgical management of lumbar spinal stenosis and degenerative spondylolisthesis. Methods. Ten patients (2 males, 8 females, mean age 59.6) were enrolled into a non-randomised prospective clinical study. Patients were evaluated with standing AP, lateral, flexion and extension radiographs and MRI scans, back and leg pain visual analog scale (VAS) scores, Oswestry Disability Index (ODI), Zurich Claudication Questionnaire (ZCQ) and the SF-36 questionnaires, preoperatively, 6 months, one year, two years and latest follow-up at a mean of five years postoperatively (range 55–74 months). Flexion and extension standing lumbar spine radiographs were obtained at 2 years to assess range of motion (ROM) at the stabilised segment. Results. The clinical outcome scores for the cohort improved significantly across all scoring systems. Radiographs at 2 years did not reveal any loss of position or loosening of metal work. There were two incidental durotomies and no failures at 5 years with no patient requiring revision surgery. Conclusions. The TOPS implant maintains clinical improvement and motion in the surgical management of LSS and spondylolisthesis, indicating it can be considered an option for these indications