Gender-Specific Differences in Presentation and Management of Spinal Infection: A Single-Center Retrospective Study of 159 Cases.

STUDY DESIGN: A retrospective single-center analysis of 159 cases. OBJECTIVE: To investigate differences between male and female patients, as spinal infection (SI) represents a life-threatening condition and numerous factors may facilitate the course and outcome of SI, including patients' age and comorbidities, as well as gender. To date, no comparative data investigating sex differences in SI is available. Thus, the purpose of the present retrospective trial was to investigate differences between male and female patients. METHODS: A total of 159 patients who were treated for a spinal infection between 2010 and 2016 at our department were included in the analysis. The patients were categorized into 2 groups based on gender. Evaluation included magnetic resonance imaging, laboratory values, clinical outcome, and conservative/operative management. RESULTS: Male patients suffered from SI significantly more often than female patients (n = 101, 63.5% vs n = 58, 36.5%, P = .001). However, female patients were initially affected more severely, as infection parameters were significantly higher (P = .032) and vertebral destruction was more serious (P = .018). Furthermore, women suffered from intraoperative complications more often (P = .024) and received erythrocyte concentrates more frequently (P = .01). Nevertheless, mortality rates and outcome were comparable. Pain scales were significantly higher in female patients at 12-month follow-up (P = .042). CONCLUSION: Although male patients show a higher incidence for SI, the course of disease and the management is more challenging in female patients. Nevertheless, outcome after 12 months is comparably good. Underlying mechanisms may include a better immune response and dissimilar effects of antibiotic treatment in women. Pain management in female patients is still unsatisfactory after 12 months.

The impact of obesity and smoking on young individuals suffering from lumbar disc herniation: a retrospective analysis of 97 cases.

The negative impact on spinal diseases may apply not only to obesity but also to smoking. To investigate the influence of obesity and smoking on the development and recovery of lumbar disc herniation in young adults. Retrospective analysis of 97 patients who presented with lumbar disc herniation at the authors' department between 2010 and 2017. Data were collected using the patients' digital health records including demographics, clinical and neurological characteristics, treatment details, and outcomes. Ninety-seven patients between 17 and 25 years were included in this retrospective analysis. Patients were categorized into two groups according to their body mass index: obese (O, ≥ 30 kg/m2) and non-obese (NO, < 30 kg/m2). The proportion of obese patients in our cohort vs. in the overall population differed significantly (19.4% vs. 3.8-7.1%, RR 3.17; p < 0.01). Group NO showed a trend toward faster recovery of motor deficits (p = 0.067) and pain (p = 0.074). Also, the proportion of regular smokers differed significantly from the numbers of known smokers of the same age (62.4% vs. 30.2%, RR 2.0; p = 0.01). Obesity plus smoking showed a significantly negative impact on motor deficits postoperatively (p = 0.015) and at discharge (p = 0.025), as well as on pain values (p = 0.037) and on analgesic consumption (p = 0.034) at 6 weeks follow-up. The negative impact of obesity and smoking on the occurrence of lumbar disc herniation could be demonstrated for individuals aged 25 or younger. Furthermore, a trend to earlier recovery of motor deficits and significantly lower pain scales for non-obese and non-smoking patients could be shown.

Navigation for Tubular Decompression of the L5 Nerve Root Ganglion after Cement Leakage via a Wiltse Approach.

Osteoporotic vertebral fractures are a widespread problem in the elderly population. In experienced hands, treatment procedures are safe and can be done in a minimally invasive fashion. Nevertheless, in rare cases, severe complications may occur. We present a case report of cement leakage after vertebroplasty of L5 compressing the nerve root with neurological signs and radiculopathy. An 86-year-old female patient was introduced to our department with severe L5 nerve root radiculopathy and a foot flexion paresis after vertebroplasty of L5. Computed tomography (CT) of the lumbar spine revealed extraforaminal extravasation of cement around the nerve root causing significant compression. The patient underwent surgical revision using spinal navigation for skin incision, retractor placing, and verification of the cement extravasation. The cement plombage was removed, and the patient improved immediately. Sufficient decompression of the nerve root after cement leakage can be achieved using a spinal navigation setup in combination with intraoperative CT.

Extraforaminal Lumbar Disk Herniations Lead To Neuroplastic Changes: a Study Using Quantitative Sensory Testing.

INTRODUCTION: Extraforaminal lumbar disk herniations are characterized by distinct clinical features in comparison to paramedian lumbar disk herniations. METHODS: We applied the quantitative sensory testing (QST) protocol of the German Research Network on Neuropathic Pain in 63 patients with a single lumbar disk herniation. They were categorized in 2 groups: (I) an intraspinal (group I; n = 47, 75%) and an extraforaminal (group E; n = 16, 25%). RESULTS: The wind-up ratio for assessing endogenous pain-modulating pathways was higher in group E (2.9 ± 2) than in group I (1.4 ± 1; P = 0.021). After a subsequent series of pinprick stimuli, an increase in pain assessed by the numeric rating scale could be shown in group E (2.1 ± 2 vs 1.1 ± 1; P = 0.032). DISCUSSION: Extraforaminal compression is associated with chronic as well as neuropathic pain, presumably caused by direct compression of the dorsal root ganglion, which may preferentially promote specific chronic pain mechanisms. Muscle Nerve 58: 676-680, 2018.

Clinical and radiological effect of medialized cortical bone trajectory for lumbar pedicle screw fixation in patients with degenerative lumbar spondylolisthesis: study protocol for a randomized controlled trial (mPACT).

BACKGROUND: Spinal fusion with pedicle screw fixation represents the gold standard for lumbar degenerative disc disease with instability. Although it is an established technique, it is nevertheless an invasive intervention with high complication rates. Therefore, minimally invasive approaches have been developed, the medialized bilateral screw pedicel fixation (mPACT) being one of them. The study objective is to evaluate prospectively the efficacy and safety of the mPACT technique compared with the traditional trajectory for degenerative lumbar spondylolisthesis. METHODS/DESIGN: This is a single-center, randomized, controlled, parallel group, superiority trial. A total of 154 adult patients are allocated in a ratio of 1:1. Sample size and power calculation were performed to detect the minimal clinically important difference of 10%, with an expected standard deviation of 20% in the primary outcome parameter, the Oswestry Disability Index, with power of 80%, based on an assumed maximal dropout rate of 20%. Secondary outcome parameters include the EuroQoL 5-Dimension questionnaire, the Beck Depression Inventory, the painDETECT questionnaire and the "timed up and go" test. Furthermore, radiological and health economic outcomes will be evaluated. Follow up is performed until 5 years after surgery. Major inclusion criteria are lumbar degenerative spondylolisthesis with Meyerding grade I or II, which qualifies for decompression and fusion by medialised posterior screw placement with cortical trajectory (mPACT) or by a traditional trajectory for lumbar pedicle screw placement. DISCUSSION: This trial will contribute to the understanding of the short-term and long-term clinical and radiological postoperative course in patients with lumbar degenerative disc disease, in which the mPACT technique is used. TRIAL REGISTRATION: ISRCTN registry, ISRCTN99263604 . Registered on 3 November 2016.

Management of spinal infection: a review of the literature.

Spinal infection (SI) is defined as an infectious disease affecting the vertebral body, the intervertebral disc, and/or adjacent paraspinal tissue and represents 2-7% of all musculoskeletal infections. There are numerous factors, which may facilitate the development of SI including not only advanced patient age and comorbidities but also spinal surgery. Due to the low specificity of signs, the delay in diagnosis of SI remains an important issue and poor outcome is frequently seen. Diagnosis should always be supported by clinical, laboratory, and imaging findings, magnetic resonance imaging (MRI) remaining the most reliable method. Management of SI depends on the location of the infection (i.e., intraspinal, intervertebral, paraspinal), on the disease progression, and of course on the patient's general condition, considering age and comorbidities. Conservative treatment mostly is reasonable in early stages with no or minor neurologic deficits and in case of severe comorbidities, which limit surgical options. Nevertheless, solely medical treatment often fails. Therefore, in case of doubt, surgical treatment should be considered. The final result in conservative as well as in surgical treatment always is bony fusion. Furthermore, both options require a concomitant antimicrobial therapy, initially applied intravenously and administered orally thereafter. The optimal duration of antibiotic therapy remains controversial, but should never undercut 6 weeks. Due to a heterogeneous and often comorbid patient population and the wide variety of treatment options, no generally applicable guidelines for SI exist and management remains a challenge. Thus, future prospective randomized trials are necessary to substantiate treatment strategies.

Primary acquired spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery: a single-center retrospective study of 159 cases.

Spondylodiscitis may arise primarily via hematogenous spread or direct inoculation of virulent organisms during spine surgery. To date, no comparative data investigating the differences between primary and postoperative spondylodiscitis is available. Thus, the purpose of this retrospective study was to investigate differences between these two etiologies. One hundred fifty-nine patients that were treated at our department were included in the retrospective analysis. The patients were categorized into two groups based on the etiology of spondylodiscitis: group NS, primary spondylodiscitis without prior spinal surgery; group S, spondylodiscitis following spinal surgery. Evaluation included magnetic resonance imaging (MRI), laboratory values, clinical outcome, and operative or conservative management. Preoperative MRI showed higher rates of epidural and paraspinal abscess in patients with primary spondylodiscitis (p < 0.005). Vertebral bone destruction was more severe in group NS (p < 0.05). Survival rate in group S (98.2%) was higher than in group NS (87.5%, p = 0.024). The extent of the operative procedure in patients who were surgically treated (n = 116) differed between the two groups (p < 0.005). In conclusion, spondylodiscitis is a life-threatening and serious disease and requires long-term treatment. Primary spondylodiscitis is frequently associated with epidural and paraspinal abscess, vertebral bone destruction and has a higher mortality rate than postoperative spondylodiscitis. Therefore, primary spondylodiscitis shows a more severe course than spondylodiscitis following spine surgery.

Thoracic corpectomy for neoplastic vertebral bodies using a navigated lateral extracavitary approach-a single-center consecutive case series: technique and analysis.

Thoracic myelopathy is often caused by vertebral body fractures resulting from neoplastic conditions, traumatic events, or infectious diseases. One of the preferred procedures for treating it is the lateral extracavitary approach (LECA) with single-level or multilevel decompressive corpectomy and reconstruction. The aim of this retrospective study was to analyze the thoracic lateral extracavitary approach with corpectomy using vertebral body replacement systems (VBR-S) and dorsal reconstruction. Twenty-four patients with metastatic or primary lesions of thoracic vertebrae T2-T12 underwent spinal decompression and ventral column reconstruction with correction of spinal deformity via a LECA. One-level to four-level corpectomies were performed with additional navigated dorsal pedicle screw fixation at an average of two levels above and below the corpectomy lesion. None of the patients received preoperative spinal embolization, and the majority of the patients were admitted to radiotherapy postoperatively. Their mean age was 56 years (± 15), with a female-to-male sex ratio of 8 to 16. Patients with a minimum follow-up period of 16 months were included. The Karnofsky index, preoperative and postoperative numeric rating scale (NRS), and Frankel scale were measured. In addition, intraoperative loss of blood (LOB), units of packed red blood cell (PRBC) transfusions, the duration of the operation, and the hospitalization period were evaluated and correlated with preoperative and postoperative values. The majority of the patients were suffering from metastatic lesions and were treated with a 1 level corpectomy (median 1 level, range 1 to 4). The mean duration of surgery was 288 min (± 121) and the mean LOB was 1626 mL (± 1486 mL), with approximately two PRBC units per patient used. All patients were transferred to the intensive care unit (ICU) postoperatively, with a mean ICU stay of 2.0 days (± 1 day). The mean hospitalization period was 13 days (± 7 days). No implant-related failures or procedure-related deaths were observed. Significant differences were noted between the preoperative and postoperative Karnofsky index (74 vs. 84%) and NRS (4 vs. 2). One patient required revision surgery due to a superficial wound infection, and another needed revision surgery due to a dural tear. In another patient, an iatrogenic dural tear was repaired during the same surgical procedure and did not lead to postoperative complications. Four pleural effusions and one pneumothorax were observed, so that the overall complication rate was approximately 33%. Four of the patients died within 2 years of the operation due to progression of the primary disease. Lateral corpectomy and sagittal reconstruction of the thoracic spine using VBR-S conducted via a navigated LECA approach yields favorable results, despite the burden of neoplastic disease. These challenging procedures are accompanied by increased LOB and hospitalization periods, with moderate transfusion requirements. Surgery-related complications are low and local tumor control is satisfactory, despite the progression of the underlying neoplastic disease. However, optimal surgical therapy does not ensure long-term survival.Study design Retrospective analysis of thoracic corpectomiesLevel of evidence 4.

The influence of surface EMG-triggered multichannel electrical stimulation on sensomotoric recovery in patients with lumbar disc herniation: study protocol for a randomized controlled trial (RECO).

BACKGROUND: Intervertebral disc degeneration is one of the most common reasons for chronic low back pain and sensomotoric deficits, often treated by lumbar sequestrectomy. Nevertheless, the prognostic factors relevant for time and quality of recovery, of the surgical procedure, relative to conservative treatment, remain controversial and require further investigation. Surface electrical stimulation (SES) may be an influential intervention, already showing positive impact on motor and sensory recovery in different patient groups. Since mechanisms of SES still remain unclear, further inquiry is needed. METHODS/DESIGN: This is a prospective, monocentric, randomized, controlled clinical trial. A total of 80 adult patients suffering from a lumbar disc herniation (LDH; 40 treated surgically, 40 conservatively) are allocated in a ratio of 1:1. Patients in the treatment group will receive surface electromyography (EMG)-triggered electrical stimulation for eight weeks, whereas patients in the control group will not obtain any additional treatment. The primary outcome parameter is defined as the cold detection threshold (CDT), determined by quantitative sensory testing (QST), 24 months after intervention. Secondary outcome parameters include the inquiry of sensory nerve function by two-point discrimination and QST, the assessment of motor nerve function by manual muscle testing, and validated scales and scores. These include: the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) assessing the domains pain, back-specific function, work disability, and patient satisfaction; the EQ-5D investigating the patient's generic health status; the painDETECT questionnaire (PD-Q) to identify neuropathic pain components; and the Beck Depression Inventory (BDI) to assess severity of depression. Moreover, neurological status, pain medication usage, and blood samples (CRP, TNFα, IL-1ß, IL-6) will be evaluated. Study data generation (study site) and data storage, processing, and statistical analysis are clearly separated. DISCUSSION: The results of the RECO study will detect the effect of EMG-triggered multichannel SES on the improvement of mechanical and thermal sensitivity and the effect on motor recovery and pain, associated with clinical and laboratory parameters. Furthermore, data comparing surgical and conservative treatment can be collected. This will hopefully allow treatment recommendations for patients with LDH accompanied by a sensomotoric deficit. TRIAL REGISTRATION: ISRCTN, ISRCTN12741173 . Registered on 15 January 2017.

Analysis of the Literature on Cervical Spine Fractures in Ankylosing Spinal Disorders.

STUDY DESIGN: Narrative literature review. OBJECTIVE: The numbers of low-energy cervical fractures seen in patients suffering from ankylosing spondylitis (also known as Bechterew disease) or diffuse idiopathic skeletal hyperostosis (also known as Forestier disease) have greatly increased over recent decades. These fractures tend to be particularly overlooked, leading to delayed diagnosis and secondary neurological deterioration. The aim of the present evaluation was to summarize current knowledge on cervical fractures in patients with ankylosing spinal disorders (ASDs). METHODS: The literature was analyzed through an extensive PubMed search focusing on cervical fractures, especially with delayed diagnosis. RESULTS: In ASDs, it was mainly the cervical spine that was found to be affected by fractures. Fifty percent of ASD patients had neurological deficits at admission, with a high probability of secondary deterioration due to an initially missed diagnosis. Multislice high-resolution imaging techniques should be the radiological standard of care if a vertebral fracture is suspected. Nevertheless, many of these spinal fractures are overlooked, leading to feared secondary deterioration of existing unstable fractures. Long posterior instrumentations were found to be the treatment of choice, followed by anterior and combined anterior-posterior instrumentations. CONCLUSIONS: Delayed diagnosis of cervical fractures in ASDs contributes to initially misinterpreted clinical symptoms, inadequate imaging techniques, and a lack of knowledge about this disease entity due to its peculiarities. Thorough assessment of the patients' neurological morbidity at admission might reduce the occurrence of the associated fractures. The biomechanical behavior of ASD fractures is completely different from that of non-ASD fractures, so that the treatment strategy for these patients should be at least surgical, in combination with long dorsal instrumentations or combined anterior-posterior approaches.

Minimally invasive spine surgery in lumbar spondylodiscitis: a retrospective single-center analysis of 67 cases.

BACKGROUND: Minimally invasive surgical techniques have been developed to minimize tissue damage, reduce narcotic requirements, decrease blood loss, and, therefore, potentially avoid prolonged immobilization. Thus, the purpose of the present retrospective study was to assess the safety and efficacy of a minimally invasive posterior approach with transforaminal lumbar interbody debridement and fusion plus pedicle screw fixation in lumbar spondylodiscitis in comparison to an open surgical approach. Furthermore, treatment decisions based on the patient´s preoperative condition were analyzed. METHODS: 67 patients with lumbar spondylodiscitis treated at our department were included in this retrospective analysis. The patients were categorized into two groups based on the surgical procedure: group (MIS) minimally invasive lumbar spinal fusion (n = 19); group (OPEN) open lumbar spinal fusion (n = 48). Evaluation included radiological parameters on magnetic resonance imaging (MRI), laboratory values, and clinical outcome. RESULTS: Preoperative MRI showed higher rates of paraspinal abscess (35.5 vs. 5.6%; p = 0.016) and multilocular location in the OPEN group (20 vs. 0%, p = 0.014). Overall pain at discharge was less in the MIS group: NRS 2.4 ± 1 vs. NRS 1.6 ± 1 (p = 0.036). The duration of hospital stay was longer in the OPEN than the MIS group (19.1 ± 12 days vs. 13.7 ± 5 days, p = 0.018). CONCLUSION: The open technique is effective in all varieties of spondylodiscitis inclusive in epidural abscess formation. MIS can be applied safely and effectively as well in selected cases, even with epidural abscess.

Self-complementary adeno-associated virus serotype 6 mediated knockdown of ADAMTS4 induces long-term and effective enhancement of aggrecan in degenerative human nucleus pulposus cells: A new therapeutic approach for intervertebral disc disorders.

Inhibition of intervertebral disc (IVD) degeneration, which is often accompanied by painful inflammatory and immunopathological processes, is challenging. Current IVD gene therapeutic approaches are based on adenoviral gene delivery systems, which are limited by immune reactions to their viral proteins. Their applications in IVDs near to sensitive neural structure could provoke toxicity and immunological side-effects with neurological deficits. Self-complementary adeno-associated virus (scAAV) vectors, which do not express any viral gene and are not linked with any known disease in humans, are attractive therapeutic gene delivery vectors in degenerative IVDs. However, scAAV-based silencing of catabolic or inflammatory factor has not yet been investigated in human IVD cells. Therefore, we used scAAV6, the most suitable serotype for transduction of human nucleus pulposus (NP) cells, to knockdown the major catabolic gene (ADAMTS4) of IVD degeneration. IVD degeneration grades were determined by preoperative magnetic resonance imaging. Lumbar NP tissues of degeneration grade III were removed from 12 patients by nucleotomy. NP cells were isolated and cultured with low-glucose. Titre of recombinant scAAV6 vectors targeting ADAMTS4, transduction efficiencies, transduction units, cell viabilities and expression levels of target genes were analysed using quantitative PCR, fluorescence microscopy, fluorescence-activated cell sorting, 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assays, quantitative reverse transcription PCR, western blot and enzyme-linked immunosorbent assays during 48 days of post-transduction. Transduction efficiencies between 98.2% and 37.4% and transduction units between 611 and 245 TU/cell were verified during 48 days of post-transduction (p<0.001). scAAV6-mediated knockdown of ADAMTS4 with maximum 87.7% and minimum 40.1% was confirmed on day 8 and 48 with enhanced the level of aggrecan 48.5% and 30.2% respectively (p<0.001). scAAV6-mediated knockdown of ADAMTS4 showed no impact on cell viability and expression levels of other inflammatory catabolic proteins. Thus, our results are promising and may help to design long-term and less immunogenic gene therapeutic approaches in IVD disorders, which usually need prolonged therapeutic period between weeks and months.

Cement-augmented screws in a cervical two-level corpectomy with anterior titanium mesh cage reconstruction: a biomechanical study.

STUDY DESIGN: Biomechanical investigation. PURPOSE: Cervical two-level corpectomies with anterior-only instrumentation are associated with a high rate of implant-related complications. These procedures, therefore, often require an additional dorsal instrumentation to prevent screw loosening. Cement augmentation of the anterior screws in two-level corpectomies might stabilize the construct, so that a second dorsal procedure could be avoided. To evaluate the screw anchorage in cervical anterior-only procedures, an ex vivo evaluation of the range of motion (ROM) in two-level corpectomies (C4 and C5), with and without cement augmentation of the anterior screws, was carried out in this study. METHODS: Twelve human cervical cadaveric spines (C2-T1) were divided into two groups of six specimens each. Corpectomies were performed in C4 and C5, with grafting and anterior instrumentation with and without cement augmentation of the anterior screw-and-plate system (0.3-0.5 mL cement/screw). Flexibility tests with pure moments (1.5 Nm) were carried out before and after three cyclic loading periods of 5000 cycles with increasing eccentric forces (100, 200, and 300 N). RESULTS: After corpectomy and instrumentation, the control group and the augmented group showed a significant reduction in ROM in comparison with the native states with average ROMs of 49% (±17%) and 24% (±10%), respectively (P = 0.006). The ROM in the control group increased significantly in all motion directions in the course of cyclic loading and approached native values after the third cyclic loading period, with an overall ROM of 78% (±22%). In contrast, the augmented group maintained a significantly decreased ROM in all motion directions during cyclic loading, with a final ROM of 32% (±14%) after the third period of cyclic testing. Inter-group comparison demonstrated a significant difference between the two groups in the course of cyclic loading. The cement-augmented group outperformed the control group in all motion directions, with a significantly lower ROM after all three cyclic loading periods. CONCLUSIONS: A two-level corpectomy with cement-augmentation results in a significantly reduced ROM. In comparison with the conventional anterior screw-and-plate fixation, it represents a significantly stabilized two-level anterior construct. This might be a treatment option for patients with a two-level corpectomy associated with reduced bone mineral density, to avoid an additional dorsal instrumentation.

Preoperative sport improves the outcome of lumbar disc surgery: a prospective monocentric cohort study.

A lumbar disc herniation resulting in surgery may be an incisive event in a patient's everyday life. The patient's recovery after sequestrectomy may be influenced by several factors. There is evidence that regular physical activity can lower pain perception and improve the outcome after surgery. For this purpose, we hypothesized that patients performing regular sports prior to lumbar disc surgery might have less pain perception and disability thereafter. Fifty-two participants with a single lumbar disc herniation confirmed on MRI treated by a lumbar sequestrectomy were included in the trial. They were categorized into two groups based on their self-reported level of physical activity prior to surgery: group NS, no regular physical activity and group S, with regular physical activity. Further evaluation included a detailed medical history, a physical examination, and various questionnaires: Visual Analog Scale (VAS), Beck-Depression-Inventory (BDI), Oswestry Disability Index (ODI), Core Outcome Measure Index (COMI), and the EuroQoL-5Dimension (EQ- 5D). Surgery had an excellent overall improvement of pain and disability (p < 0.005). The ODI, COMI, and EQ-5D differed 6 months after intervention (p < 0.05) favoring the sports group. Leg and back pain on VAS was also significantly less in group B than in group A, 12 months after surgery (p < 0.05). Preoperative regular physical activity is an important influencing factor for the overall satisfaction and disability after lumbar disc surgery. The importance of sports may have been underestimated for surgical outcomes.

A prospective randomized multicenter phase I/II clinical trial to evaluate safety and efficacy of NOVOCART disk plus autologous disk chondrocyte transplantation in the treatment of nucleotomized and degenerative lumbar disks to avoid secondary disease: safety results of Phase I-a short report.

NOVOCART® Disk plus, an autologous cell compound for autologous disk chondrocyte transplantation, was developed to reduce the degenerative sequel after lumbar disk surgery or to prophylactically avoid degeneration in adjacent disks, if present. The NDisc trial is an ongoing multi-center, randomized study with a sequential phase I study within the combined phase I/II trial with close monitoring of tolerability and safety. Twenty-four adult patients were randomized and treated with the investigational medicinal product NDisc plus or the carrier material only. Rates of adverse events in Phase I of this trial were comparable with those expected in the early time course after elective disk surgery. There was one reherniation 7 months after transplantation, which corresponds to an expected reherniation rate. Immunological markers like CRP and IL-6 were not significantly elevated and there were no imaging abnormalities. No indications of harmful material extrusion or immunological consequences due to the investigational medicinal product NDplus were observed. Therefore, the study appears to be safe and feasible. Safety analyses of Phase I of this trial indicate a relatively low risk considering the benefits that patients with debilitating degenerative disk disease may gain.

The value of quantitative sensory testing in spine research.

The improvement of pain and functionality is the major goal of a surgical intervention. Thus, the purpose of the present prospective study was to evaluate whether subjective sensory deficits in patients with lumbar radiculopathy caused by a lumbar disc herniation are related to clinical status, using several outcome scores and the quantitative sensory testing (QST) pre- and 12 months postoperatively. We applied the QST in 52 patients with a single lumbar disc herniation treated by lumbar sequestrectomy pre- and 12 months postoperatively. Further evaluation included numeric rating scale (NRS) for leg, EuroQoL-5D (EQ-5D), Core Outcome Measure Index (COMI), Oswestry Disability Index (ODI), Beck Depression Inventory (BDI) and PaindDetect questionnaire (PD-Q). Patients were then categorized into two groups based on their subjective recovery of sensory function. The patients' self-assessment and QST were correlated with each other for the pre- and postoperative visit after 12 months. The two groups showed postoperative differences in mechanical and vibration detection threshold as well as in the postoperative PD-Q (p < 0.005). Multidimensional scores did not consistently match the QST parameters in patients with a lumbar disc herniation. Commonly used clinical scores in spine research show low or no correlation with QST. Nevertheless, mechanical thresholds seem to play an important role to detect and follow up a sensory deficit investigated by QST.

Gender differences after lumbar sequestrectomy: a prospective clinical trial using quantitative sensory testing.

BACKGROUND: Quantitative sensory testing (QST) gained popularity to evaluate the time course of recovery in sensory dysfunction and the results of different treatment options. Concerning sex differences in lumbar spine surgery, female gender seems to play a major role as a negative prognostic factor in different spinal disorders. For this purpose, we hypothesised that there are also comparable differences in pain patterns in men and women after lumbar sequestrectomy using QST. METHODS: We applied the QST protocol of the German Research Network on Neuropathic Pain in 53 patients (21 women and 32 men) with a single lumbar disc herniation confirmed on MRI treated by a lumbar sequestrectomy. Further evaluation included a detailed medical history, a physical examination, and various questionnaires: Beck-Depression-Inventory, Oswestry Disability Index, Core Outcome Measure Index, painDETECT-Questionnaire and EQ-5D thermometer. RESULTS: Our analyses showed lower heat thresholds in females preoperatively, that adjusted to that of males 1 week postoperatively. Pressure pain thresholds were lower in women as well, but differed between genders throughout the study. Vibration perception deficits resolve earlier in female than in male patients. Both, women and men, had an excellent overall improvement, postoperatively. CONCLUSION: Our results clearly revealed pre- and postoperative differences in pain perception between genders. These differences have to be taken into account in the evaluation of outcome between genders. Therefore, QST seems to be a good method to evaluate the time course of recovery after surgery.

Improvement of sensory function after sequestrectomy for lumbar disc herniation: a prospective clinical study using quantitative sensory testing.

BACKGROUND: Previous studies have investigated sensory recovery in patients with lumbar disc herniation using rather subjective methods. There have been no reports on changes of sensory function in patients suffering from a preoperative sensory deficit using quantitative sensory testing (QST). The aims of this prospective study were (1) to assess the recovery of preoperative sensory dysfunction after lumbar sequestrectomy and (2) to quantify the strength of relationship between a sensory deficit and the patient's quality of life. METHODS: We applied the QST protocol of the German Research Network on Neuropathic Pain (DFNS) in fifty-two patients with a single lumbar disc herniation confirmed on MRI treated by lumbar sequestrectomy. Further evaluation included a detailed medical history, a physical examination, numeric rating scale for leg, EQ-5D questionnaire, and thermometer. RESULTS: Disc surgery resulted in a significant reduction of leg pain and a significant gain of quality of life. Thermal, mechanical, and vibration perception thresholds showed an obvious side-to-side difference preoperatively (p < 0.005). An early recovery of mechanical and vibration perception thresholds was detected, whereas cold perception needed more than 6 months to recover (p < 0.05). Quality of life was independent from perception thresholds, but correlated significantly with pain reduction. CONCLUSION: Our data clearly show that there is a subjective and quantifiable improvement in sensory dysfunction postoperatively. The current data suggest that a sensory dysfunction does not influence a patient's quality of life.