The diagnosis and management of a vertebral artery loop causing cervical radiculopathy.

BACKGROUND: Cervical radiculopathies are rarely caused by vertebral artery loop formation, which is estimated to be present in less than 3% of patients. It is uncertain what causes the loop formation: some propose an association with spondylotic changes or trauma, whilst others suggest hypertension and atherosclerosis may be responsible. CASE REPORT 1: A 35-year-old male patient presented with signs and symptoms of cervical radiculopathy that was not improved with anterior cervical discectomy and fusion surgery performed 2 years beforehand. Vertebral artery loop was discovered at the level C5/6 on the MRI. Vertebral artery transposition surgery via a lateral approach was performed at the level of the left C5/6 for symptoms of left C6 radiculopathy. Deroofing of the transverse process was performed with post-surgical complete improvement in weakness and pain. CASE REPORT 2: A 48-year-old female patient presented with a 10-year history of left shoulder pain with occasional radiation into her middle three fingers accompanied by intermittent paraesthesia and weakness. Numerous shoulder surgeries, Botox injections and suprascapular nerve blocks had not provided any significant benefit. A vertebral artery loop was identified at the level of C3/4 and C4/5 on the left with cervical MRI. Transposition surgery of these two levels provided some post-surgical improvement in pain. CONCLUSION: Vertebral artery loop formations are a rare but potential cause for cervical radiculopathy. In two cases, the loop formations were not radiographically reported on MRI, thus clinicians should be aware of this as a differential diagnosis in the management of cervical radiculopathy. The presented surgical approach may be useful in managing future cases of vertebral artery loop formation causing cervical radiculopathy resistant to conservative measures.

Hollow modular anchorage (HMA) screws for anterior transvertebral fixation in high-grade spondylolisthesis cases requiring 360 degrees in-situ fusion.

OBJECTIVE: 360 degrees in-situ fusion for high-grade spondylolisthesis showed satisfying clinical long-term results. Combining anterior with posterior surgery increases fusion rates. Anteriorly inserted transvertebral HMA screws could be an alternative to strut graft constructs or cages, avoiding donor site complications. In addition, complete posterior muscle detachment is avoided and the injury risk of neural structures is minimized. This study investigates the use of HMA screws in this context. MATERIAL AND METHODS: Five consecutive patients requiring L4-S1 in-situ fusion for isthmic spondylolisthesis (four Grade 3 and one Grade 4) were included. The L5/S1 level was fused with an HMA screw filled with local bone and bone morphogenic protein (BMP2), inserted via the L4/5 disc space level. An L4/5 stand-alone interbody fusion with additional minimal invasive posterior screw fixation was added. RESULTS: Transvertebral insertion of the HMA device was accomplished via a retroperitoneal approach to L4/L5 in all cases without exposure of L5/S1. Blood loss ranged from 150 ml-350 ml. No intraoperative complication occurred. One patient developed posterior wound infection requiring debridement. Solid fusion was confirmed with a CT scan after 6 months in all patients. All patients improved to unrestricted activities of daily living with two being limited by occasional back pain. CONCLUSIONS: HMA screws allow for effective lumbosacral fusion via a limited anterior exposure. This is technically easier than posterior exposure of the lumbosacral junction in high-grade spondylolisthesis requiring 360 degrees fusion.

Comparison of in vitro biocompatibility of silicone and polymethyl methacrylate during the curing phase of polymerization.

Adverse events have been reported with acrylic bone cements. However, current test standards for acrylic materials fail to characterize the potentially harmful monomers released during the curing stage. In clinical applications, materials are implanted into the human body during this phase. Silicone may be a safer alternative to acrylic cements. Silicone is used in medical applications for its biocompatibility and stability characteristics. Previously, no study has been completed which compares silicone to acrylic cements. In this study, both materials were injected into the cell medium during the curing process which more accurately reflects clinical use of material. Initially, cell cultures followed ASTM standard F813-07 which fails to capture the effects of monomer released during curing. Subsequently, a modified cell culture method was employed which evaluated cytotoxicity while the materials cured. The objective of this study was to capture toxicity data during curing phase. Thus, the test method employed measured and excluded the impact of the exothermic reaction temperature of polymethyl methacrylate (PMMA) on cell growth. The concentration of PMMA monomer was measured at 1 and 24 h after injecting PMMA into culture plates in a manner consistent with established cell growth methodologies. Our results indicate current in vitro cytotoxicity assays recommended by ASTM standards are unable to reveal the real cytotoxic effect caused by methyl methacrylate monomers during polymerization. Our modified experiment can more accurately illustrate the true nature of the toxicity of materials and improve assay results. In these tests, silicone based elastomeric polymers showed excellent cytocompatibility. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2693-2699, 2018.

The safe use of long screws in L5/S1 stand-alone anterior interbody fusion for olisthesis cases.

BACKGROUND: Stand-alone anterior interbody fusion (STALIF) with poly-ether-ether-ketone (PEEK) cages could offer a treatment option in olisthesis cases. The fixation of the PEEK-cage at the L5/S1 inferior endplate with long divergent screws however might endanger neural sacral structures, especially the S1 nerve root. If shorter screws are used, the achieved bony purchase might not be sufficient to resist the pull out and shear forces at the lumbosacral junction. The aim of the present investigation was to evaluate the use of long screws in PEEK-cages for olisthesis cases at the L5/S1 segment and its neurological complications. MATERIAL AND METHODS: 11 Patients (6 males) with a mean age of 47(± 15.1) years between 2013-2015 designated for an STALIF at the L5/S1 level were consecutively included in the present study. All patients had a Grade 1 or 2 slippage according to Meyerding. PEEK cages (SynFix-LR®, Depuy Synthes) were implanted with 30mm screws at the baseplate of L5/S1 in all patients. Perioperative and postoperative long-term complications were evaluated. Furthermore, radiological follow-up was performed (CT-scan at 6 months, X-ray at 6, 12 and 24 months). RESULTS: 6 patients suffered from an isthmic, 1 from a degenerative olisthesis. 4 patients with iatrogenic spondylolisthesis were included. Pre-operative radiculopathy was noted in 10 patients. 9 patients with pre-operative radiculopathy showed relief of symptoms until the last follow-up after 24 months. Fusion was achieved in all patients after 6 months. No screw-displacement, breakage or violation of the neural foramen was noted. Furthermore, no implant failure or pull-out fractures were seen. CONCLUSION: In this investigation, no complication due to the use of long divergent locking screws was noted. In addition, the majority of patients showed permanent relief of radiculopathy symptoms at the 2 years follow-up. This study demonstrates the safe usage of long divergent locking screws in the baseplate of L5/S1 in anterior interbody fusion at the L5/S1 level.

New method for correction of lumbo-sacral kyphosis deformity in patient with high pelvic incidence.

STUDY DESIGN: Technical note. OBJECTIVE: We describe a novel technique of bilateral longitudinal sacral osteotomy allowing direct reduction of high pelvic incidence (PI) and correction of sagittal imbalance. METHODS: A 25-year-old female patient presented with a disabling lumbo-sacral kyphosis fused in situ through previous operations with residual low-grade wound infection and grade IV L5/S1 spondylolisthesis with severity index (SI) of 65%. A two-stage correction was performed. First anterior in situ fixation of the L4-L5-S1 segments was performed using a hollow modular anchorages (HMA) screw and L3/L4 anterior interbody cage. The second stage consisted of instrumentation of the lower lumbar spine and pelvis; placement of an S1 transverse K-wire as pivot point and bilateral longitudinal sacral osteotomy which allowed for gradual retroversion of the central sacrum relative to the pelvis. RESULTS: Sacrum was derotated by 30° which allowed to restore spinal sagittal balance and decrease SI by 15%. Postoperative recovery was complicated by a flare up of the pre-existing deep wound infection. CONCLUSIONS: Bilateral longitudinal sacral osteotomy appears to be a safe and efficient way of correcting the sagittal imbalance caused by an extremely high PI. Although technically demanding, it achieves good radiological and functional outcomes and avoids entering the spinal canal.

The computed tomography-based fractal analysis of trabecular bone structure may help in detecting decreased quality of bone before urgent spinal procedures.

BACKGROUND CONTEXT: To date, no reliable method is available to determine the parameters of bone density based on the routine spinal computed tomography (CT) in the emergency setup. We propose the use of fractal analysis to detect patients with poor quality of bone before urgent or semi-urgent spinal procedures. PURPOSE: This study aimed to validate the hypothesis that the CT-based fractal analysis of the trabecular bone structure may help in detecting patients with poor quality of bone before urgent spinal procedures. STUDY DESIGN: This is a retrospective analysis of prospectively collected data. METHODS: Patients in whom the dual-energy x-ray absorptiometry (DEXA) scan and lumbar spine CT were performed at an interval of no more than 3 months were randomly selected from a prospectively collected database. Diagnostic axial CT scans of L2, L3, and L4 vertebrae were processed to determine the fractal dimension (FD) of the trabecular structure of each spinal level. Box-count method and ImageJ 1.49 software were used. The FD was compared with the results of the DEXA scan: bone mineral density (BMD) and T-score by mean of correlation coefficients. Receiver operating characteristic curve analysis was later performed to determine the cutoff value of FD. RESULTS: A total of 102 vertebral levels obtained from 35 patients (mean age 60±18 years; 29 female) were analyzed. The FD was significantly higher in the group of patients with decreased bone density (DBD) (T-score<-1.0) (1.67 vs. 1.43; p<.0001) and negatively correlated with BMD (R Spearman, -0.53; p<.0001) and T-score (-0.49; p<.0001). Receiver operating characteristic curve analysis revealed that a cutoff value of FD>1.53 indicates DBD (p<.0001; area under the ROC curve [AUC], 0.84; 95% confidence interval [CI], 0.76-0.91). CONCLUSIONS: This study shows that fractal analysis of the lumbar spine CT images may be used to determine bone density before spinal instrumentation (eg, metastatic or traumatic cord compression). Further prospective studies comparing results of the fractal analysis of CT scans with quantitative CT (qCT) are warranted.

Development of a new assessment tool for cervical myelopathy using hand-tracking sensor: Part 1: validity and reliability.

PURPOSE: To assess the reliability and validity of a hand motion sensor, Leap Motion Controller (LMC), in the 15-s hand grip-and-release test, as compared against human inspection of an external digital camera recording. METHODS: Fifty healthy participants were asked to fully grip-and-release their dominant hand as rapidly as possible for two trials with a 10-min rest in-between, while wearing a non-metal wrist splint. Each test lasted for 15 s, and a digital camera was used to film the anterolateral side of the hand on the first test. Three assessors counted the frequency of grip-and-release (G-R) cycles independently and in a blinded fashion. The average mean of the three was compared with that measured by LMC using the Bland-Altman method. Test-retest reliability was examined by comparing the two 15-s tests. RESULTS: The mean number of G-R cycles recorded was: 47.8 ± 6.4 (test 1, video observer); 47.7 ± 6.5 (test 1, LMC); and 50.2 ± 6.5 (test 2, LMC). Bland-Altman indicated good agreement, with a low bias (0.15 cycles) and narrow limits of agreement. The ICC showed high inter-rater agreement and the coefficient of repeatability for the number of cycles was ±5.393, with a mean bias of 3.63. CONCLUSIONS: LMC appears to be valid and reliable in the 15-s grip-and-release test. This serves as a first step towards the development of an objective myelopathy assessment device and platform for the assessment of neuromotor hand function in general. Further assessment in a clinical setting and to gauge healthy benchmark values is warranted.

Development of a new assessment tool for cervical myelopathy using hand-tracking sensor: Part 2: normative values.

PURPOSE: To set a baseline measurement of the number of hand flexion-extension cycles and analyse the degree of motion in young healthy individuals, measured by leap motion controller (LMC), besides describing gender and dominant hand differences. METHODS: Fifty healthy participants were asked to fully grip-and-release their dominant hand as rapidly as possible for a maximum of 3 min or until subjects fatigued, while wearing a non-metal wrist splint. Participants also performed a 15-s grip-and-release test. An assessor blindly counted the frequency of grip-and-release cycles and magnitude of motion from the LMC data. RESULTS: The mean number of the 15-s G-R cycles recorded by LMC was: 47.7 ± 6.5 (test 1, LMC); and 50.2 ± 6.5 (test 2, LMC). In the 3-min test, the total number of hand flexion-extension cycles and the degree of motion decreased as the person fatigued. However, the decline in frequency preceded that of motion's magnitude. The mean frequency of cycles per 10-s interval decreased from 35.4 to 26.6 over the 3 min. Participants reached fatigue from 59.38 s; 43 participants were able to complete the 3-min test. CONCLUSIONS: Normative values of the frequency of cycles and extent of motion for young healthy individuals, aged 18-35 years, are provided. Future work is needed to establish values in a wider age range and in a clinical setting.

Intracardiac bone cement embolism as a complication of vertebroplasty: management strategy.

BACKGROUND: Vertebroplasty carries multiple complications due to the leakage of polymethylmethacrylate (PMMA) into the venous system through the iliolumbar or epidural veins. The rate of venous cement complications may vary from 1 to 10 %, with cement extravasation into the venous system in 24 % of patients. Emboli may further migrate into the right heart chambers and pulmonary arteries. Patients may vary in presentation from asymptomatic or symptoms such as syncope to life-threatening complications. CASE REPORT: We present a case of a 57-year-old lady diagnosed with osteoporosis who underwent a staged antero-posterior fixation with PMMA vertebroplasty of progressive thoraco-lumbar kyphosis caused by osteoporotic fractures to T12, L1 and L2 vertebral bodies. Four weeks after the operation, the patient developed symptoms of left-sided chest pain, tachycardia and tachypnea. CT pulmonary angiogram (CTPA) found a high-density material within the right atrium, whilst ECHO demonstrated normal systolic function. The patient was commenced on enoxaparin at therapeutic dose of 1.5 mg/kg for 3 months and remained asymptomatic. Follow-up ECHO found no change to the heart function and no blood clot on the PMMA embolus. CONCLUSIONS: Factors influencing the decision about conservative treatment included symptoms, localisation of the embolus, as well as time lapse between vertebroplasty and clinical manifestation. Patients that are commonly asymptomatic can be treated conservatively. The management of choice is anticoagulation with low-molecular-weight heparin or warfarin until the foreign body epithelialises and ceases in becoming potentially thrombogenic. Symptomatic patients with thrombi in the right atrium are commonly managed via percutaneous retrieval, whilst those with RV involvement or perforation are commonly managed with surgical retrieval. Management of individual patients should be based on individual clinical circumstances. Patients presenting with intracardiac bone cement embolism related to spinal procedures require thorough clinical assessment, cardiology input, and if required, surgical intervention.

The management of high-grade spondylolisthesis and co-existent late-onset idiopathic scoliosis.

INTRODUCTION: It is relatively common for a scoliosis deformity to be associated with a lumbar spondylolisthesis in adolescents (up to 48 % of spondylolistheses). In the literature two types of curve have been described: 'sciatic' or 'olisthetic'. However, there is no consensus in the literature on how best to treat these deformities. Some authors advocate a single surgical intervention, where both deformities are corrected; whereas, others advocate treating them as separate entities. In this situation, it has been shown that the scoliosis will correct with treatment of the spondylolisthesis. MATERIALS AND METHODS: We present a 12-year-old girl who had a concomitant high-grade spondylolisthesis and scoliosis. Her main complaints were those of low back pain and an L5 radiculopathy. We took the decision to treat the spondylolisthesis surgically, but observe the scoliosis, rather than correcting them both surgically at the same sitting. RESULTS: Although the immediately post-operative radiographs showed persistence of the scoliosis, 1-year follow-up demonstrated full resolution of the deformity. This young lady also had relief of her low back pain and leg pain following the surgery. CONCLUSION: There are no standard guidelines and therefore, we discuss the management of this difficult problem, exemplifying a case of a young girl who had high-grade spondylolisthesis along with a clinically non-flexible scoliosis treated at our institution. We demonstrate that it is safe to observe the scoliosis, even in high-grade spondylolistheses.

Anatomical considerations for percutaneous trans ilio-sacroiliac S1 and S2 screw placement.

OBJECTIVE: To determine the presence of a consistent osseous corridor through S1 and S2 and fluoroscopic landmarks thereof, which could be used for safe trans ilio-sacroiliac screw fixation of posterior pelvic ring disorders. STUDY DESIGN: Computed tomography (CT) based anatomical investigation utilising multiplanar image and trajectory reconstruction (Agfa-IMPAX Version 5.2 software). Determination of the presence and dimension of a continuous osseous corridor in the coronal plane of the sacrum at the S1 and S2 vertebral levels. OUTCOME MEASURES: Determination of: (a) the presence of an osseous corridor in the coronal plane through S1 and S2 in males and females; (b) the dimension of the corridor with regard to diameter and length; (c) the fluoroscopic landmarks of the corridor. RESULTS: The mean cross-sectional area for S1 corridors in males and females was 2.13 and 1.47 cm(2) , respectively. The mean cross-sectional area for the S2 corridor in males and females was 1.46 and 1.13 cm(2), respectively. The limiting anatomical factor is the sagittal diameter of the sacral ala at the junction to the vertebral body. The centre of the S1 and S2 corridor is located in close proximity to the centre of the S1 and S2 vertebrae on the lateral fluoroscopic view as determined by the adjacent endplates and anterior and posterior vertebral cortices. CONCLUSION: Two-thirds of males and females have a complete osseous corridor to pass a trans-sacroiliac S1 screw of 8 mm diameter. The S2 corridor was present in all males but only in 87 % of females. Preoperative review of the axial CT slices at the midpoint of the S1 or S2 vertebral body allows the presence of a trans-sacroiliac osseous corridor to be determined by assessing the passage at the narrowest point of the corridor at the junction of the sacral ala to the vertebral body.

Is Hydronephrosis a Complication after Anterior Lumbar Surgery?

Study Design Prospective follow-up design. Objective Ureteral injury is a recognized complication following gynecologic surgery and can result in hydronephrosis. Anterior lumbar surgery includes procedures like anterior lumbar interbody fusion (ALIF) and total disk replacement (TDR). Anterior approaches to the spine require mobilization of the great vessels and visceral organs. The vascular supply to the ureter arising from the iliac arteries may be compromised during midline retraction of the ureter, which could theoretically lead to ureter ischemia and stricture with subsequent hydronephrosis formation. Methods Potential candidates with previous ALIF or TDR via anterior retroperitoneal access between January 2008 and March 2012 were chosen from those operated on by a single surgeon in a university hospital setting (n = 85). Renal ultrasound evaluation of hydronephrosis was performed on all participants. Simple descriptive and inferential statistics were used to generate results. Results A total of 37 voluntary participants were recruited (23 male, 14 female subjects; average age 51.8 years). The prevalence of hydronephrosis in our population was 0.0% (95% confidence interval 0 to 8.1%). Conclusions Retraction of the ureter across the midline in ALIF and TDR does not result in an increase in hydronephrosis and appears to be a safe surgical technique.

Chest wall reconstruction after en bloc Pancoast tumour resection with the use of MatrixRib and SILC fixation systems: technical note.

STUDY DESIGN: Technical note. OBJECTIVE: In cases in which partial resection of the rib cage is accomplished with vertebrectomy, reconstruction of the chest wall may be challenging. That is because of lack of the anchor point which normally would be a proximal end of a rib or transverse process. We report a straightforward technique for chest wall reconstruction with the novel use of two systems of fixation commonly applied in spinal practice. METHODS: The operation of a squamous cell carcinoma (Pancoast tumour) of the right lung infiltrating T2, T3 and T4 vertebrae was performed though T4 lateral thoracotomy. Posterior instrumentation with transpedicular screws T1-3-5 on the left and T1-5 on the right side was followed with the right upper lobectomy and hemivertebrectomy. The laminae and facet joints of T2-T4 vertebrae were removed on the side of the tumour. An osteotomy was performed medial to the pedicle at the lateral aspect of the dural sac on the side of the tumour. Proximal parts of four adjacent ribs were removed allowing radical en bloc resection with tumour-free margins. The distal end of each of four rib plates used (MatrixRib Precontoured Plate system) was attached to the proximal end of the rib. The proximal end of the plate was then attached to the rod of posterior fixation construct with the use of a flexible polyethylene terephthalate (PeT) band of the SILC™ fixation system. The other end of the PeT band was then passed through the top-loading clamp subsequently attached to the rod of the posterior fixation. RESULTS: The patient did not require additional procedures for chest wall reconstruction. On the 7-month follow-up, in chest CT he was found with satisfactory expansion of the remaining lung tissue with proper spinal alignment and anatomical shape of the rib cage. CONCLUSIONS: The reported technique can be applied for chest wall reconstruction in cases of total or subtotal vertebrectomy accomplished with the resection extending towards rib cage. It appears to be straightforward, safe and effective allowing good cosmetic and functional outcome.

Posterior lumbar fixation in a kidney transplant recipient: logistics and perioperative challenges.

BACKGROUND: Kidney transplantation has become the ideal and successful treatment for medically suitable patients with established kidney disease. This results in increased likelihood of these patients developing unrelated conditions requiring surgery, including spinal surgery. There are only a few publications available regarding spinal patients with renal transplants. CASE REPORT: A 67-year-old patient presented with recurrent sciatica. Four years prior to this, he received a living donor kidney transplant. He was diagnosed with right L4 radiculopathy due to recurrent foraminal stenosis as a result of the grade I L4/5 spondylolisthesis. He was offered a reoperation including microdecompression and postero-lateral fixation and fusion. The renal transplant necessitated specific pre- and intraoperative considerations. The knee-chest position with extra padding was used to maintain the region of the renal transplant free from any pressure. The renal care was planned in detail by the transplant surgeons and nephrologists and shared with the ward doctors and on-call teams. The procedure was uneventful; there were no signs of intraoperative or postoperative acute renal injury. The patient was discharged 5 days postoperatively; all renal parameters remained within normal ranges and the postoperative plain films demonstrated satisfactory surgical results. CONCLUSIONS: The key to success was a multidisciplinary approach and detailed planning regarding pre-, intra- and postoperative care. The presented scheme of care might be useful when considering the posterior approach and prone positioning in kidney transplant recipients with spinal pathologies requiring surgical treatment.

The Evaluation of Digital Rectal Examination for Assessment of Anal Tone in Suspected Cauda Equina Syndrome.

STUDY DESIGN: Seventy-five doctors completed a questionnaire documenting their grade, specialty, and experience in performing digital rectal examination (DRE). A model anus, using a pressure transducer surrounding an artificial canal, was assembled and calibrated. Participants performed 4 DREs on the model (with a break between attempts) and predicted tone as "reduced" or "normal" (35 and 60 mm Hg, respectively), followed by a "squeeze" test. Thirty health care assistants partook as a control group with no training in DRE. OBJECTIVE: Our main objective was to investigate the validity of digital rectal examination (DRE) for assessment of anal tone. SUMMARY OF BACKGROUND DATA: Cauda equina syndrome represents the constellation of symptoms and signs resulting from compression of lumbrosacral nerve routes. Combined with subjective neurological findings, a reduction in anal tone is an important sign, deeming further imaging necessary. DRE is an invasive procedure used to assess anal tone despite debated accuracy. METHODS: A total of 75 doctors from various specialties were asked to fill in a questionnaire detailing their grade, age, and area of expertise. In addition, information was gathered with regard to prior training in performing DRE to assess anal tone and the importance placed on any findings. Thirty hospital health care assistants (HCAs) were used as a control group. HCAs were selected as a control group because they receive no training on the technique and would never be required to perform it in their clinical practice. A model anus was assembled using a modified pediatric sphygmomanometer cuff to act as a sphincter. The cuff could be inflated to simulate a full range of anal tone. The cuff was incorporated into an artificial anal canal, which was, in turn, placed into a model buttock created from plaster of Paris. The apparatus was calibrated across a range of pressures. RESULTS: In each attempt, 60%, 61%, 63%, and 67% of doctors correctly identified the anal tone, respectively (average accuracy: 64%). HCAs had an identical average accuracy of 64%. All participants (100%) were able to correctly identify the squeeze test. For doctors, no correlation was found between confidence in assessing anal tone using DRE and a correct result. Seventy-one percent had received previous training in DRE, with 64% of these taught how to assess anal tone. Forty-three percent of doctors thought that further training would be beneficial. CONCLUSION: The results demonstrate that accuracy in assessing anal tone using DRE is limited, with overall correctness of 64%. Poor correlation exists between perceived level of skill and study result. Doctors were not significantly more able than HCAs to detect correct tone. Therefore, DRE for the assessment of anal tone is not a wholly accurate tool. A squeeze test may be of greater value if interpreted correctly. LEVEL OF EVIDENCE: 4.

The surgical management of metastatic spinal tumors based on an Epidural Spinal Cord Compression (ESCC) scale.

BACKGROUND CONTEXT: There have been no previous studies looking at the outcome of surgical decompression (+/-stabilization) for various grades of epidural spinal cord compression (ESCC) due to spinal metastases. PURPOSE: The aim of this study was to determine the outcome of surgical treatment in patients with ESCC using the Bilsky six-point scale. STUDY DESIGN/SETTING: This was a retrospective cohort review of prospectively collected data. PATIENT SAMPLE: A consecutive series of 101 patients managed over the period of 3 years for ESCC due to spinal metastases in a tertiary spine surgery referral unit were included. METHODS: Data on age, gender, revised Tokuhashi score, preoperative Frankel grade, tumor histology, magnetic resonance imaging scan-based Bilsky cord compression grade, postoperative Frankel grade at last follow-up, complications, and survivorship were collected. OUTCOME MEASURES: Frankel grading system for function was used to evaluate the patient's preoperative and postoperative neurologic status. Patient survival and postoperative complications were also collected. RESULTS: Average patient age was 64.7 years (13-88 years): 62 males and 39 females. Mean follow-up was 7.3 months (3-23.3 months). Most primary tumors were in prostate, breast, renal, lung, and the blood dyscrasias. Within the lower grade of compression (Group 1; Bilsky Grades 0,1a, 1b, and 1c; n=40), 29 patients (72.5%) had no improvement in Frankel grade, seven patients (17.5%) improved, whereas four patients (10%) deteriorated neurologically after surgery. Within the higher compression grade (Group 2; Bilsky Grades 2 and 3; n=61), 37 patients (60%) did not experience neurologic change, 20 (33%) improved, whereas neurology worsened in four patients (7%). When compared with Group 2 patients, Group 1 patients had better preoperative Frankel scores but a greater number of patients in Group 2 improved their Frankel scores significantly postoperatively. The mean revised Tokuhashi score for Groups 1 and 2 was 10 and 9.1, respectively (p=.1). The complication rate for Groups 1 and 2 was 25% and 42.6%, respectively (p=.052). Survival analysis showed no difference between the groups (Group 1: median 376 days [12-1052]; Group 2: median 326 days [12-979]; p=.62). CONCLUSIONS: Surgery can achieve improvements in neurology even in higher grades of cord compression. There is a trend toward more complications and worse survival with spinal surgery in patients with higher grades of compression.

Reoperation rates in the surgical treatment of spinal metastases.

BACKGROUND CONTEXT: The surgical treatment in spinal metastases has been shown to improve function and neurologic outcome. Unplanned hospital readmissions can be costly and cause unnecessary harm. PURPOSE: Our aim was to first analyze the reoperation rate and indications for this revision surgery in spinal metastases from an academic tertiary spinal institute and, second, to make comparisons on outcome (neurology and survival) against patients who underwent single surgery only. STUDY DESIGN/SETTING: This was an ambispective review of all patients treated surgically over an 8-year period considering their neurologic and survival outcome data. Statistical analysis was performed using IBM SPSS 20. Because all scale values did not follow the normal distribution and significant outlier values existed, all descriptive statistics and comparisons were made using median values and the median test. Crosstabs and Pearson correlation were used to calculate differences between percentages and ordinal/nominal values. For two population proportions, the z test was used to calculate differences. The log-rank Mantel-Cox analysis was used to compare survival. PATIENT SAMPLE: During the 8 years' study period, there were 384 patients who underwent urgent surgery for spinal metastasis. Of these, 289 patients were included who had sufficient information available. There were 31 reoperations performed (10.7%; mean age, 60 years; 13 male, 18 female). Exclusion criteria included patients treated solely by radiotherapy, patients who had undergone surgery for spinal metastasis before the study period, and those who had other causes for neurologic dysfunction such as stroke. OUTCOME MEASURES: The outcomes considered in this study were revised Tokuhashi score, preoperative/postoperative Frankel scores, and survival. METHODS: We performed an ambispective review of all patients treated surgically from our comprehensive database during the study period (October 2004 to October 2012). We reviewed all patient records on the database, including patient demographics and reoperation rates. RESULTS: Reoperations were performed in the same admission in the majority of patients (n=20), whereas 11 patients had their second procedure in subsequent hospitalization. The reasons for their revision surgery were as follows: surgical site infection (SSI; 13 of 31 [42%]), failure of instrumentation (9 of 31 [29%]), local recurrence (5 of 31 [16%]), hematoma evacuation (2 of 31 [6%]), and others (2 of 31 [6%]).When comparing the "single surgery" and "revision surgery" groups, we found that the median preoperative and postoperative Frankel scores were similar at Grade 4 (range, 1-5) for both groups (preoperative, p=.92; postoperative, p=.87). However, 20 patients (8%) from the single surgery group and 7 (23%) from the revision group had a worse postoperative score, and this was significantly different (p=.01). No significant difference was found (p=.66) in the revised Tokuhashi score. The median number of survival days was similar (p=.719)-single surgery group: 250 days (range, 5-2,597 days) and revision group: 215 days (range, 9-1,352 days). CONCLUSION: There was a modest reoperation rate (10.7%) in our patients treated surgically for spinal metastases over an 8-year period. Most of these were for SSI (42%), failure of instrumentation (26%), and local recurrence (16%). Patients with metastatic disease could benefit from revision surgery with comparable median survival rates but relatively poorer neurologic outcomes. This study may help to assist with informed decision making for this vulnerable patient group.

Major neurological deficit following anterior cervical decompression and fusion: what is the next step?

INTRODUCTION: Major neurological deficit following anterior cervical decompression and fusion (ACDF) is a rare event, with incidences of up to 0.2 % now reported. Post-operative MRI is mandatory to assess for ongoing compression of the cord. In the past, the deficit has often been attributed to oedema or overzealous intra-operative manipulation of the cord. Reperfusion injury is a more recent concept. We describe a case of acute cervical disc prolapse with progressive neurology, and the difficult decision making one is faced with when the neurological deficit continues to deteriorate post ACDF. MATERIALS AND METHODS: A 30-year-old male was referred from the Emergency Department with acute left arm paraesthesia and left leg weakness. A cerebrovascular accident was ruled-out with a CT of the brain, and later an MRI of the cervical spine revealed a large C6/7 disc prolapse with significant compression of the spinal cord. A C6/7 ACDF was performed, but post-operatively the patient could no longer move his lower limbs. An urgent MRI was obtained which showed removal of the disc fragment, cord signal changes and the suggestion of ongoing cord compression. In part, this was due to his narrow cervical canal. The decision was made to proceed to posterior decompression and stabilisation, although cord reperfusion injury was one of the differential diagnoses considered at this stage. RESULTS: Post-operatively the patient's neurology started to improve over the next 48 h. He was discharged from in-patient rehabilitation at 2 months post-surgery and by 3 months he had returned to work. Latest follow-up revealed normal function with only mild paraesthesia in the T1 dermatome of his left arm. CONCLUSION: The management of patients in whom a neurological deficit has increased post-operatively is difficult. Urgent MRI scan is mandatory to assess for epidural haematoma which may need further decompression. Cord reperfusion injury is a diagnosis of exclusion. The difficulty the clinician faces is in interpreting the MRI for 'acceptable' decompression, and therefore excluding the need for further surgery.

The molecular composition of the extracellular matrix of the human iliolumbar ligament.

BACKGROUND CONTEXT: The human iliolumbar ligament connects the transverse process of L5 to the iliac crest and contributes to lumbosacral stability and has been associated with low back pain. However, different opinions exist regarding the functional relevance of the ligament. PURPOSE: In the present study, we analyze the regional molecular composition of the ligament extracellular matrix. STUDY DESIGN: Special attention is given to the attachment sites, to determine whether the ligament is subjected to a certain mechanical environment. METHODS: Iliolumbar ligament samples, extending from one enthesis to the other, were removed from 11 cadavers and fixed in methanol. Cryosections were immunolabeled with a panel of antibodies directed against collagens, glycosaminoglycans, proteoglycans, matrix proteins, and neurofilament. RESULTS: The mid-substance of the ligament labeled for all the molecules normally found in dense fibrous connective tissue including types I, III, and VI collagen, versican, dermatan -, chondroitin 4 -, and keratan sulfate. However, both entheses were fibrocartilaginous and labeled for type II collagen, aggrecan, and chondroitin 6- sulfate. A common feature was fat between the fiber bundles near the entheses. Occasionally this fat contained nerve fibers. CONCLUSIONS: The existence of fibrocartilaginous entheses suggests that the insertion sites of the ligament are subject to both tensile and compressive loading-probably because of insertional angle changes between ligament and bone during loading. Our findings support the suggestion that the iliolumbar ligament might play an important role in the stabilization of the lumbosacral junction.

Effects of adding resorbable phosphate glass fibres and PLA to calcium phosphate bone cements.

BACKGROUND: Calcium phosphate cements (CPCs), due to their biocompatibility and degradation properties, are being widely investigated as a replacement to more commonly used polymethylmethacrylate (PMMA) for vertebroplasty. CPCs have shown the potential to be replaced by host bone tissue during the healing/remodelling process. However, brittleness and comparatively low strength restrict the use of CPC in load-bearing applications. Although porous CPC can integrate with bone over time, slow degradation profiles and poor interconnectivity between pores restricts osseointegration to the top layer of CPC only. METHODS: Polylactic acid (PLA) and phosphate glass fibres (PGFs) were incorporated in a CPC matrix to overcome the problem of inherent brittleness and limited osseointegration. RESULTS: Incorporation of PLA and PGFs within CPC was successful in achieving a much less brittle CPC matrix without affecting the mechanical properties of CPC. The area under the stress-strain curve showed that the total energy to failure of the CPC hybrid was significantly greater than that of the CPC control. CONCLUSIONS: The methodology adopted here to add PLA within the CPC matrix may also allow for incorporation of PLA cross-linked biochemicals. Micrographic studies revealed that it was possible to confer control over pore size, shape and interconnectivity without negatively affecting the mechanical properties of the cement. This tailorable porosity could potentially lead to better osseointegration within CPC.