[Slipped vertebrae (Spondylolysis): the underestimated weak point of the (pre)professional football player-an algorithm]. / Der Gleitwirbel: unterschätzte Schwachstelle des (prä)professionellen Fußballspielers ­ ein Algorithmus.

BACKGROUND: Isthmic spondylolysis represents the most common cause of spinal pain in adolescent athletes. This article provides an overview of the classification, diagnosis, and treatment options for these conditions, including conservative and operative measures. It also provides a treatment pathway to how young athletes with spondylolysis should be treated. DIAGNOSTICS: Diagnostic imaging techniques are essential for an accurate diagnosis, with CT scans providing additional information for surgical planning. TREATMENT: Conservative treatment focuses on activity modification and physiotherapy, with a phased approach tailored to individual patient needs. Operative intervention may be considered if conservative measures fail, with minimally invasive techniques such as Buck's screw fixation showing promising results. The decision between conservative and operative management should consider factors of the patients' individual profile. In this paper, we present the first treatment algorithm for the treatment of isthmic spondylolysis. Long-term prognosis varies, with most athletes able to return to sport following treatment.

Lumbar Facet Joint Radiofrequency Denervation Therapy for Chronic Low Back Pain: Enhanced Outcome Compared With Chemical Neurolysis (Ethyl Alcohol 95% or Glycerol 20%).

BACKGROUND: It was hypothesized that radiofrequency denervation (RFD) of lumbar facet joints is associated with superior pain abolishment and less complications than chemical neurolysis (with ethyl alcohol or glycerol) in patients with chronic facet joint arthropathy. METHODS: For this prospective cohort study, adult patients with chronic lumbar facet joint arthropathy were prospectively enrolled between 2017 and 2019. The following groups were compared before the intervention and 6 weeks, 6 months, and 12 months after the intervention: RFD, chemical neurolysis with ethyl alcohol 95% (EA-95), or glycerol 20% (Gly-20). Outcome parameters included the Core Outcome Measures Index for the back (COMI-back), World Health Organization (WHO) pain ladder level, and visual analog scale (VAS). P values <0.05 were considered statistically significant. RESULTS: A total of 95 patients with a mean age of 63.7 years were included. Among them, 30 patients underwent RFD, 30 patients were treated with EA-95, and 35 individuals were treated with Gly-20. After 6 weeks, RFD patients had significantly lower VAS scores compared with the EA-95 group. After 6 months, both VAS and COMI were significantly lower in RFD patients than in the Gly-20 group. Twelve months after intervention, VAS scores were significantly lower in the RFD group compared with the Gly-20 group. CONCLUSIONS: This study reveals that RFD is associated with improved pain relief and quality of life compared with chemical neurolysis for facet joint-related chronic lower back pain and should be considered as the treatment of choice in patients with chronic low back pain due to facet joint arthropathy. CLINICAL RELEVANCE: The current study provides information that may improve clinical decision making in the treatment of chronic lumbar facet joint arthropathy and to appropriately counsel such patients about expected outcomes.

Biomechanical In Vitro and Finite Element Study on Different Sagittal Alignment Postures of the Lumbar Spine During Multiaxial Daily Motion.

Lumbar lordotic correction (LLC), the gold standard treatment for sagittal spinal malalignment (SMA), and its effect on sagittal balance have been critically discussed in recent studies. This paper assesses the biomechanical response of the spinal components to LLC as an additional factor for the evaluation of LLC. Human lumbar spines (L2L5) were loaded with combined bending moments in flexion (Flex)/extension (Ex) or lateral bending (LatBend) and axial rotation (AxRot) in a physiological environment. We examined the dependency of AxRot range of motion (RoM) on the applied bending moment. The results were used to validate a finite element (FE) model of the lumbar spine. With this model, the biomechanical response of the intervertebral discs (IVD) and facet joints under daily motion was studied for different sagittal alignment postures, simulated by a motion in Flex/Ex direction. Applied bending moments decreased AxRot RoM significantly (all P < 0.001). A stronger decline of AxRot RoM for Ex than for Flex direction was observed (all P < 0.0001). Our simulated results largely agreed with the experimental data (all R2 > 0.79). During the daily motion, the IVD was loaded higher with increasing lumbar lordosis (LL) for all evaluated values at L2L3 and L3L4 and posterior annulus stress (AS) at L4L5 (all P < 0.0476). The results of this study indicate that LLC with large extensions of LL may not always be advantageous regarding the biomechanical loading of the IVD. This finding may be used to improve the planning process of LLC treatments.

Quality of life and mortality after surgical treatment for vertebral osteomyelitis (VO): a prospective study.

PURPOSE: Vertebral osteomyelitis (VO) has a high mortality and leads to chronic pain and functional disability. Surgical treatment is often necessary. To date, little is known about the consequences of surgery on patient outcome. The aim of this study was to determine the quality of life (QoL) and mortality rates of surgically treated VO patients for a period of 2 years. METHODS: Patients with VO undergoing surgical treatment in a tertiary referral hospital from 2008 to 2015 were included prospectively. Data were collected before (T0) as well as 1 year (T1) and 2 years (T2) post-surgery. Within the European Spine Tango registry, prospective patient and QoL data were collected using validated outcome scores: Oswestry Disability Index, Short Form 36/EuroQol, Visual Analog Scale, and Core Outcome Measures Index. RESULTS: From 195 patients surgically treated for VO, QoL data were available from 136 patients at T0, 100 patients at T1, and 82 patients at T2, respectively. The 1- and 2-year mortality rates were 20% and 23%. Mainly all QoL outcome scores showed significant improvement at T1 and did not change significantly from T1 to T2. CONCLUSION: Surgical treatment of VO patients leads to significantly improved QoL. Nevertheless, QoL levels were below those of the general population. Our results underscore that spine disability questionnaires measuring QoL are mandatory to demonstrate comprehensively the severity of this entity. Our study confirms a high mortality and points out the role of VO as a potentially life-threatening condition.

Vertebral Osteomyelitis After Spine Surgery: A Disease With Distinct Characteristics.

STUDY DESIGN: Prospective cohort study. OBJECTIVE: We aimed to determine the 2-year survival and to identify clinical and microbiological characteristics of patients with native vertebral osteomyelitis (VO) as compared to postoperative VO to find further strategies for improvement of the management of VO. SUMMARY OF BACKGROUND DATA: A relevant subgroup (20%-30%) of patients with VO has a history of spine surgery. Infection in these patients might be clinically different from native VO. However, clinical, microbiological, and outcome characteristics of this disease entity have not been well studied as most trials either excluded these patients or are limited by a small cohort and short observation period. METHODS: Between 2008 and 2013, patients who presented at a tertiary care center with symptoms and imaging findings suggestive of VO were reviewed by specialists in infectious diseases, clinical microbiology, and orthopedics to confirm the diagnosis and followed prospectively for a period of 2 years. Statistical analysis for group comparisons, survival analysis, and uni- and multivariable Cox regression models were performed. RESULTS: Thirty percent of the patients with VO (56/189) reported a history of spine surgery in the same segment. Patients with postoperative infection had a lower ASA score (American Society of Anesthesiologists) (P = 0.01) and were less likely to suffer from comorbidities compared to native cases (P = 0.003). Infections caused by coagulase-negative staphylococci (33.3 vs. 6.5%, P < 0.001) and other bacteria of the skin flora (15.2 vs. 0%, P = 0.002) were more prevalent in postoperative patients. Suffering from native VO increased the 2-year mortality risk 3-fold, also when adjusted for the remaining risk factors ASA score and number of comorbidities (hazard ratio 2.916 [95% confidence interval 1.215 -6.999], P = 0.017). CONCLUSION: Beside clear microbiological differences, the significant better 2-year survival supports the concept of postoperative VO presenting a distinct disease entity. The subtle disease presentation of patients with postoperative VO should not attenuate clinical suspicion of physicians. LEVEL OF EVIDENCE: 3.

Biomechanical In Vitro Test of a Novel Dynamic Spinal Stabilization System Incorporating Polycarbonate Urethane Material Under Physiological Conditions.

Posterior dynamic stabilization systems (PDSS) were developed to provide stabilization to pathologic or hypermobile spinal segments while maintaining the healthy biomechanics of the spine. Numerous novel dynamic devices incorporate the temperature and moisture dependent material polycarbonate urethane (PCU) due to its mechanical properties and biocompatibility. In this study, standardized pure moment in vitro tests were carried out on human lumbar spines to evaluate the performance of a device containing PCU. An environmental chamber with controlled moisture and temperature was included in the setup to meet the requirements of testing under physiological conditions. Three test conditions were compared: (1) native spine, (2) dynamic instrumentation, and (3) dynamic instrumentation with decompression. The ranges of motion, centers of rotation, and relative pedicle screw motions were evaluated. The device displayed significant stiffening in flexion-extension, lateral bending, and axial rotation load directions. A reduction of the native range of motion diminished the stiffening effect along the spinal column and has the potential to reduce the risk of the onset of degeneration of an adjacent segment. In combination with decompression, the implant decreased the native range of motion for flexion-extension and skew bending, but not for lateral bending and axial rotation. Curve fittings using the sigmoid function were performed to parameterize all load-deflection curves in order to enhance accurate numerical model calibrations and comparisons. The device caused a shift of the center of rotation (COR) in the posterior and caudal direction during flexion-extension loading.

Intramedullary Stabilization of Pubic Ramus Fractures in Elderly Patients With a Photodynamic Bone Stabilization System (IlluminOss).

INTRODUCTION: A photodynamic bone stabilization system (PBSS) is a percutaneous operating method that provides intramedullary stabilization. The purpose of the study was to assess the clinical and radiological outcome after treatment of pubic ramus fractures with the PBSS. MATERIALS AND METHODS: In a retrospective study, patients with osteoporotic pubic ramus fractures were included. The patients were treated with the PBSS in a percutaneous method. In the routine follow-up examination, pain was measured with the visual analog scale (VAS) and the type of mobilization was verified. Computer tomography of the pelvis was carried out in the follow-up examination (mean of 7.5 months after surgery) to investigate bone healing. RESULTS: A total of 32 patients (25 females and 7 males) were included in the study. The average hospital stay was 16.5 ± 7.9 days (range: 5-37 days) and the mean operation time was 116.8 ± 47.1 minutes (range: 33-255 minutes). Two cases of wound infections and 1 case of misplacement of the PBSS implant with revision surgery have been documented. The mean VAS score for pelvic/hip pain at the day of inpatient discharge was 4.4 ± 1.4 (range: 2-7). A total of 25 patients could attend the follow-up examination 7.5 ± 1.7 months (range: 6-14) after the procedure, reporting a mean VAS for pelvic/hip pain of 3.0 ± 2.2 (range: 0-8). A total of 11 patients could walk without an orthopedic walking device, 7 patients needed underarm crutches, 6 patients used a walker-rollator, and 1 patient was immobilized. Consolidated pubis ramus fractures were described in 24 (96%) cases. DISCUSSION: The results of our study reveal adequate clinical and radiological outcomes after treatment of osteoporotic pubic ramus fractures with the PBSS. This is the first study investigating the outcome after treating pubic ramus fractures with the PBSS. CONCLUSION: Based on our findings, the PBSS is an alternative to known techniques for the stabilization of the pubic ramus.

Material failure in dynamic spine implants: are the standardized implant tests before market launch sufficient?

PURPOSE: International Standards Organization (ISO) 12189 and American Society for Testing and Materials F2624 are two standard material specification and test methods for spinal implant devices. The aim of this study was to assess whether the existing and required tests before market launch are sufficient. METHODS: In three prospective studies, patients were treated due to degenerative disease of the lumbar spine or spondylolisthesis with lumbar interbody fusion and dynamic stabilization of the cranial adjacent level. The CD HORIZON BalanC rod and S4 Dynamic rod were implanted in 45 and 11 patients, respectively. RESULTS: A fatigue fracture of the material of the topping off system has been found in five cases (11%) for the group fitted with the CD HORIZON BalanC rod. In the group using the S4 Dynamic rod group, a material failure of the dynamic part was demonstrated in seven patients (64%). All three studies were interrupted due to these results, and a report to the Federal Institute for Drugs and Medical Devices was generated. CONCLUSION: Spinal implants have to be checked by a notified body before market launch. The notified body verifies whether the implants fulfil the requirements of the current standards. These declared studies suggest that the current standards for the testing of load bearing capacity and stand ability of dynamic spine implants might be insufficient. Revised standards depicting sufficient deformation and load pattern have to be developed and counted as a requirement for the market launch of an implant. These slides can be retrieved under Electronic Supplementary Material.

Clinical experiences with a PEEK-based dynamic instrumentation device in lumbar spinal surgery: 2 years and no more.

BACKGROUND: Dynamic spine implants were developed to prevent adjacent segment degeneration (ASD) and adjacent segment disease (ASDi). Purpose of this study was to investigate the clinical and radiological outcomes of "topping off" devices following lumbar spinal fusion procedure using a PEEK-based dynamic rod system. Moreover, this study focused on the hypothesis that "topping off" devices can prevent ASD. METHODS: This prospective nonrandomized study included patients with indication for single-level lumbar fusion and radiological signs of ASD without instability. The exclusion criteria were previous lumbar spine surgery and no sign of disc degeneration in the adjacent segment according to magnetic resonance imaging. All patients were treated with single-level lumbar interbody fusion and dynamic stabilization of the cranial adjacent segment. Patients underwent a clinical examination and radiographs preoperatively and at 1 and 2 years after surgery. Analyses were performed on clinical data collected with the German Spine Registry using the core outcome measure index (COMI) and visual analogue scale (VAS) scores for back and leg pain. RESULTS: A total of 22 patients (6 male and 16 female) with an average age of 57.6 years were included in the study; 20 patients completed the follow-up (FU). The average COMI score was 9.0 preoperatively, 4.2 at the 1-year FU, and 4.7 at the 2-year FU. The average preoperative VAS scores for back and leg pain were 7.7 and 7.1, respectively. At the 1-year FU, the scores were 4.25 for back pain and 2.2 for leg pain, and at the 2-year FU, the scores were 4.7 for back pain and 2.3 for leg pain. At FU, failure of the dynamic topping off implant material was verified in four cases, and ASD of the segment cranial to the topping off was confirmed in three cases. CONCLUSIONS: These results demonstrate significant improvements in clinical outcomes and pain reduction after lumbar spinal fusion with topping off at 2 years after surgery. However, the implant failed due to the high rate of implant failure and the development of ASD in the segment cranial to the dynamic stabilized segment.

The use of the DTO™ hybrid dynamic device: a clinical outcome- and radiological-based prospective clinical trial.

BACKGROUND: The purpose of this study was to assess the radiological and clinical outcome parameters following lumbar hybrid dynamic instrumentation with the focus on the adjacent segment degeneration (ASD) and adjacent segment disease (ASDi). METHODS: In this prospective trial all patients presenting with degenerative changes to the lumbar spine have been included. Precondition was a stable adjacent level with/without degenerative alteration. The elected patients underwent a standardised fusion procedure with hybrid instrumentation (DTO™, Zimmer Spine Inc., Denver, USA). Patients' demographics have been documented and the follow-up visits were conducted after 6 weeks, and then stepwise after 6 up to 48 months. Each follow-up visit included assessment of quality of life and pain using specific questionnaires (COMI, SF-36, ODI) and the radiological evaluation with focus on the adjacent level alterations. RESULTS: At a mean follow up of 24 months an incidence of ASD with 10.91% and for ASDi with 18.18% has been observed. In 9% a conversion to standardised fusion was needed. There was a high rate of mechanical complication: (1) screw loosening (52.73%), (2) pedicle screw breakage (10.91%), and (3) rod breakage (3.64%) after a follow up of a maximum of 60 months. There were no significant difference of COMI, ODI and SF-36(v2) in comparison to all groups but all 55 patients showed a clinical improvement over the time. CONCLUSION: The dynamic hybrid DTO™ device is comparable to the long-term results after standardised fusion procedure, while a high rate of mechanical complication decreased the initial benefit. TRIAL REGISTRATION: This trial was registered at the ClinicalTrials Register ( #NCT03404232 , 2018/01/18, registered retrospectively).

Posterior Lumbar Interbody Fusion versus Dynamic Hybrid Instrumentation: A Prospective Randomized Clinical Trial.

OBJECTIVE: The purpose of this study was to assess the radiologic and clinical outcomes after lumbar fusion intervention and to compare the established posterior lumbar interbody fusion (PLIF) technique and dynamic hybrid instrumentation (topping off). METHODS: In this prospective randomized trial, all patients who presented with degenerative changes to the lumbar spine (L2-S1) were included and randomized in 2 groups: patients who underwent the 360°-fusion procedure in PLIF (group 1: control group) and those patients who underwent fusion surgery with additional hybrid instrumentation (Dynesys-Transition-Optima [Zimmer Spine Inc., Denver, Colorado, USA]) cranial to the rigid fixed segment (group 2: intervention group). Patients' demographics were documented and follow-up visits were conducted after 6 weeks and then stepwise after 6 up to 36 months. Each follow-up visit included assessment of quality of life and pain using specific questionnaires (Core Outcome Measurements Index, Short-Form 36, and Oswestry Disability Index) as well as radiologic evaluation with the focus on the adjacent level alteration. RESULTS: Fifteen patients per group met the inclusion criteria, and after 36 months, the loss to follow-up was 20%. At the maximum follow-up time, the overall risk for adjacent segment degeneration was substantial (i.e., 24.14%), independent of the surgical procedure. Material failure was observed in 17.24%. Although no significant difference was observed between both groups, all patients presented with postoperative improvement regarding the clinical scores. CONCLUSIONS: The present study cannot support the safety of dynamic hybrid devices in those cases if the reduction of adjacent segment degeneration is the main target, especially regarding the reported implant failure rates and the similar clinical outcomes between the both groups.

A new in vitro spine test rig to track multiple vertebral motions under physiological conditions.

In vitro pure moment spine tests are commonly used to analyse surgical implants in cadaveric models. Most of the tests are performed at room temperature. However, some new dynamic instrumentation devices and soft tissues show temperature-dependent material properties. Therefore, the aim of this study is to develop a new test rig, which allows applying pure moments on lumbar spine specimens in a vapour-filled chamber at body temperature. As no direct sight is given in the vapour-filled closed chamber, a magnetic tracking (MT) system with implantable receivers was used. Four human cadaveric lumbar spines (L2-L5) were tested in a vapour atmosphere at body temperature with a native and rigid instrumented group. In conclusion, the experimental set-up allows vertebral motion tracking of multiple functional spinal units (FSUs) in a moisture environment at body temperature.

Incidental durotomy in decompression for lumbar spinal stenosis: incidence, risk factors and effect on outcomes in the Spine Tango registry.

PURPOSE: The three aims of this Spine Tango registry study of patients undergoing decompression for spinal stenosis were to: report the rate of dural tear (DT) stratified by treatment centre; find factors associated with an increased likelihood of incurring a DT; and compare treatment outcomes in relation to DT (none vs. repaired vs. unrepaired DT). METHODS: Multivariate logistic regression was used to assess the association between DT and patient and treatment characteristics. Patient-rated and surgical outcomes were compared in patients with no DT, repaired DT, and unrepaired DT, while adjusting for case-mix. RESULTS: DT occurred in 328/3254 (10.1%) of included patients. The rate for all 29 contributing hospitals was within 95% confidence intervals of the average. The likelihood of DT increased by 2% per year of age, 1.78 times with previous spine surgery, 1.67 for a minimally/less invasive surgery, 1.58 times with laminectomy, and 1.40, and 2.12 times for BMI 31-35, and >35 in comparison with BMI 26-30, respectively. The majority of DTs (272/328; 82.9%) were repaired. Repairing the DT was associated with a longer duration of surgery (p < 0.001). More patients with repaired than with unrepaired DTs were satisfied with treatment, but the difference was not statistically significant. There was no association between DT and patient-reported outcomes. CONCLUSION: The unadjusted rate of incidental DT during decompression for LSS was homogeneous across the participating centres and was associated with age, BMI, previous surgery at the same spinal level, minimally/less invasive surgery, and laminectomy. Non-repair of DTs had no negative association with treatment outcome; however, the unrepaired DTs may have been those that were smaller in size.

Biomechanical testing of a PEEK-based dynamic instrumentation device in a lumbar spine model.

BACKGROUND: The purpose of this study was to investigate the range-of-motion after posterior polyetheretherketone-based rod stabilisation combined with a dynamic silicone hinge in order to compare it with titanium rigid stabilisation. METHODS: Five human cadaveric lumbar spines with four vertebra each (L2 to L5) were tested in a temperature adjustable spine-testing set-up in four trials: (1) native measurement; (2) kinematics after rigid monosegmental titanium rod instrumentation with anterior intervertebral bracing of the segment L4/5; (3) kinematics after hybrid posterior polyetheretherketone rod instrumentation combined with a silicone hinge within the adjacent level (L3/4) and (4) kinematics after additional decompression with laminectomy of L4 and bilateral resection of the inferior articular processes (L3). During all steps, the specimens were loaded quasi-statically with 1°/s with pure moment up to 7.5Nm in flexion/extension, lateral bending and axial rotation. FINDINGS: In comparison to the native cadaveric spine, both the titanium device and polyetheretherketone-based device reduce the range-of-motion within the level L4/5 significantly (flexion/extension: reduction of 77%, p<0.001; lateral bending: reduction of 62%, p<0.001; axial rotation: reduction of 71%, p<0.001). There was a clear stabilisation effect after hybrid-instrumentation within the level L3/4, especially in flexion/extension (64%, p<0.001) and lateral bending (62%, p<0.001) but without any effect on the axial rotation. Any temperature dependency has not been observed. INTERPRETATION: Surprisingly, the hybrid device compensates for laminectomy L4 and destabilising procedure within the level L3/4 in comparison to other implants. Further studies must be performed to show its effectiveness regarding the adjacent segment instability.

Predictors of improvement in quality of life and pain relief in lumbar spinal stenosis relative to patient age: a study based on the Spine Tango registry.

BACKGROUND: An open decompression is the most common treatment for lumbar spinal canal stenosis (LSS), even in the elderly. However, it is not clear whether the treatment outcome is age dependent. The main purpose of this study was to evaluate the improvement in quality of life (QoL) and pain relief, after open decompression for LSS in relation to patient age. METHODS: The study was performed on the basis of Spine Tango registry data. The database query resulted in 4768 patients from 40 international Spine Tango centres. The patients were subdivided into three age groups: (1) 20-64, (2) 65-74, and (3) ≥75 years. In multivariate logistic regression models, predictors for improvement in QoL and achievement of the minimum clinically relevant change in pain of two points were analysed. RESULTS: All groups benefited from significant improvement in QoL and back and leg pain relief. Age group had no significant influence on the outcomes. The preoperative status of each outcome was a predictor for its own postoperative outcome. Fewer previous surgeries, rigid or dynamic stabilization, and lower patient comorbidity also had a partially predictive influence for one or the other outcome. CONCLUSIONS: Our results confirm that all age groups significantly benefit from the open decompressive treatment of LSS. Age group had no significant influence on any outcome.

Spondylodiscitis: Diagnosis and Treatment Options.

BACKGROUND: A recent population-based study from Denmark showed that the incidence of spondylodiscitis rose from 2.2 to 5.8 per 100 000 persons per year over the period 1995-2008; the age-standardized incidence in Germany has been estimated at 30 per 250 000 per year on the basis of data from the Federal Statistical Office (2015). The early diagnosis and treatment of this condition are essential to give the patient the best chance of a good outcome, but these are often delayed because it tends to present with nonspecific manifestations, and fever is often absent. METHODS: This article is based on a systematic search of Medline and the Cochrane Library for the period January 2009 to March 2017. Of the 788 articles identified, 30 publications were considered. RESULTS: The goals of treatment for spondylodiscitis are to eliminate infection, restore functionality of the spine, and relieve pain. Magnetic resonance imaging (MRI) remains the gold standard for the radiological demonstration of this condition, with 92% sensitivity and 96% specificity. It also enables visualization of the spatial extent of the infection and of abscess formation (if present). The most common bacterial cause of spondylodiscitis in Europe is Staphylococcus aureus, but tuberculous spondylodiscitis is the most common type worldwide. Antibiotic therapy is a pillar of treatment for spondylodiscitis and should be a part of the treatment in all cases. Neurologic deficits, sepsis, an intraspinal empyema, the failure of conservative treatment, and spinal instability are all indications for surgical treatment. CONCLUSION: The quality of life of patients who have been appropriately treated for spondylodiscitis has been found to be highly satisfactory in general, although back pain often persists. The risk of recurrence increases in the presence of accompanying illnesses such as diabetes mellitus, renal failure, or undrained epidural abscesses.

Is the duration of pre-operative conservative treatment associated with the clinical outcome following surgical decompression for lumbar spinal stenosis? A study based on the Spine Tango Registry.

BACKGROUND: The incidence of lumbar spinal stenosis (LSS) continues to rise, with both conservative and surgical management representing options for its treatment. The timing of surgery for LSS varies from shortly after the onset of symptoms to several months or years after conservative treatment. The aim of this study was to investigate the association between the duration of pre-operative conservative treatment and the ultimate outcome following surgical interventions for LSS. METHODS: The study was based on prospective multicentre registry data (Spine Tango). Cases of LSS with a documented duration of conservative treatment, undergoing spinal decompression with at least one post-operative patient assessment between 3 and 30 months, were included in the study. Cases of LSS with spondylolisthesis, additional spinal pathology or previous spinal surgery were excluded. Interrogation of the Spine Tango Registry listed 3478 patients meeting the prescribed inclusion criteria. This cohort was stratified into four groups: (1) no previous treatment (n = 497; 14.3%), (2) conservative treatment <6 months (n = 965; 27.8%), (3) conservative treatment between 6 and 12 months (n = 758; 21.8%), and (4) conservative treatment >12 months (n = 1258; 36.1%). Group 4 reference group in regression analysis. The inverse probability of treatment weighting (IPTW) was applied using the propensity score to balance the groups for their characteristics. Outcome measures included achievement of the minimum clinically important change (MCIC) score of 2 points for (a) back pain, (b) leg pain and (c) Core Outcome Measures Index (COMI), and (d) surgical complications, (e) general complications and (f) operation time >2 h. RESULTS: Patient group ("duration of conservative therapy") was not associated with achievement of the MCIC for post-operative relief of leg pain (p = 0.22), achievement of MCIC for the COMI score (p = 0.054), surgical complications (p = 0.11) or general complications (p = 0.14). Only MCIC for post-operative relief of back pain (p = 0.021) and operation time were significantly associated with patient group (p = 0.038). However, compared with the reference group of >12 months of conservative treatment there was no significant difference in the likelihood of achieving the MCIC for those with none, <6 or 6-12 months of conservative treatment. CONCLUSIONS: The duration of pre-operative conservative treatment was not associated with the ultimate outcome of decompression surgery. Further research is required to investigate optimal thresholds/indications for surgery and its appropriate timing in individual patients.

Plasmacytoid dendritic cells and memory T cells infiltrate true sequestrations stronger than subligamentous sequestrations: evidence from flow cytometric analysis of disc infiltrates.

PURPOSE: Herniated nucleus pulposus has been considered to induce an adaptive immune response. Antigen recognition by antigen-presenting-cells (APCs) represents an important step within manifestation of an adaptive immune response. Macrophages have been assumed to function as APC, while importance of plasmacytoid dendritic cells for initiation of an immune response directed towards herniated nucleus pulposus has never been examined. The aim of the present study was to assess importance of plasmacytoid dendritic cells for initiation of immune response directed towards herniated discs. METHODS: Fifteen patients with true sequestrations and three patients with subligamentous sequestrations underwent surgery after their neurological examinations. Disc material was harvested, weighted and digested for 90 min. Separated single cells were counted, stained for plasmacytoid dendritic cells (CD123(+)CD4(+)), macrophages (CD14(+)CD11c(+)) and memory T cells (CD4(+)CD45RO(+)) and analysed by flow cytometry. Both patient groups were compared in cell proportions. Furthermore, patients with true sequestrations (TRUE patients) were subdivided into subgroups based on severity of muscle weakness and results in straight leg raising (SLR) test. Subgroups were compared in cell proportions. RESULTS: Plasmacytoid dendritic cells and memory T cells infiltrated true sequestrations stronger than the subligamentous sequestration and plasmacytoid dendritic cells predominated over macrophages in true sequestrations. Highest proportions of plasmacytoid dendritic cells were detected in infiltrates of patients having true sequestrations, severe muscle weakness and negative result in SLR test. CONCLUSIONS: The findings of the present study indicate that plasmacytoid dendritic cells are involved in initiation of an immune response directed towards herniated nucleus pulposus, while macrophages may reinforce the manifested immune response and mediate disc resorption.

Non-operative treatment of lumbar spinal stenosis.

BACKGROUND AND OBJECTIVE: Non-operative treatment is widely accepted for early stages of lumbar spinal stenosis. In general, a trial of conservative treatment is recommended prior to surgery. However, there is an ongoing debate regarding benefits from non-operative treatment and their duration. METHODS: Thirty-eight patients were included in this prospective study. All patients received repeated epidural injections and facet joint injections as well as physiotherapy during a one week hospitalization. Patient characteristics, VAS scores, COMI and ODI scores and SF-36 were assessed prior to and immediately after treatment as well as after six, twelve, and 26 weeks. For six weeks after treatment, patients were asked to record a pain diary. RESULTS: Back and leg pain scores improved significantly on VAS up to three months follow-up. COMI score improved significantly over the entire follow-up. Regarding quality of life, mental sub-scores showed no improvement. Physical component summary scores improved for the first three months. CONCLUSIONS: Non-operative treatment offers pain relief and improves physical function for three months. COMI scores improve up to six months follow-up. Spine Tango registry offers standardized instruments for outcome evaluation of non-operative treatment.

Indications and contraindications: interspinous process decompression devices in lumbar spine surgery.

BACKGROUND: Interspinous process decompression devices (IPD) allow a minimally invasive treatment of lumbar spinal stenosis (LSS), but their use is discussed highly controversial. Several level I studies suggest that IPD implantation is a viable alternative for both conservative treatment and decompression, but clear indications and contraindications are still missing. This study was designed to explore the perspectives and limitations of IPDs and to evaluate the role of these devices in general. MATERIAL AND METHODS: The study is based on a questionnaire sent to all hospitals registered in the German Hospital Address Register 2010 with an orthopedic, neurosurgerical, or spine surgery department (n = 1,321). The questionnaire was reviewed by experienced spine surgeons and statisticians, and included both single-response, close-ended, and multiple-response open-ended questions. RESULTS: We received 329 (24.9%) entirely analyzable questionnaires. A total of 164 respondents (49.8%) stated that IPDs are a treatment option for LSS, and 135 of the 164 respondents (82.3%) use them. Poor clinical experience (60%) and lack of evidence (53.9%) are the main reasons cited for not using IPDs. We detected a high negative correlation between the size of the hospital, the number of outpatients and inpatients treated for LSS and other spine pathologies, and the use of IPDs (p = 0.001). Most respondents prefer the combination of open decompression and IPD (64.4%; n = 87). A total of 9.6% (n = 13) of the users favor IPD implantation as a stand-alone procedure. Overall, 25.9%  n = 35 use both options. Most surgeons aim to relieve the facet joints (87.7%) and to stabilize a preexisting instability (75.4%). They recommend IPDs in the segments L2-L3 (77%), L3-L4 (98.5%), and L4-l5 (99.3%) and consider that IPD implanation also could be done at the L5-S1 segment (40.1%). Overall, 64.4% (n = 87) of the users recommend limiting IPD implantation to two segments. Infection (96.3%), fracture (94.8%), isthmic spondylolisthesis (77%), degenerative spondylolisthesis (higher than Meyerding I [57%]), lumbar spine scoliosis (48.1%), and osteoporosis (50.4%) are seen as contraindications for IPD. CONCLUSION: No clear consensus exists among spine surgeons concerning the use of IPD for LSS treatment. The study showed that hospital-related parameters also influence decision making for or against the use of IPDs. However, despite the lack of evidence, the indications and contraindications which had been identified in the present study might contribute to improved outcomes after IPD implantation or at least prevent harm to patients.