Changes in frailty among patients hospitalized for spine pathologies during the COVID-19 pandemic in Germany-a nationwide observational study.

PURPOSE: In spine care, frailty is associated with poor outcomes. The aim of this study was to describe changes in frailty in spine care during the coronavirus disease 2019 (COVID-19) pandemic and their relation to surgical management and outcomes. METHODS: Patients hospitalized for spine pathologies between January 1, 2019, and May 17, 2022, within a nationwide network of 76 hospitals in Germany were retrospectively included. Patient frailty, types of surgery, and in-hospital mortality rates were compared between pandemic and pre-pandemic periods. RESULTS: Of the 223,418 included patients with spine pathologies, 151,766 were admitted during the pandemic and 71,652 during corresponding pre-pandemic periods in 2019. During the pandemic, the proportion of high-frailty patients increased from a range of 5.1-6.1% to 6.5-8.8% (p < 0.01), while the proportion of low frailty patients decreased from a range of 70.5-71.4% to 65.5-70.1% (p < 0.01). In most phases of the pandemic, the Elixhauser comorbidity index (ECI) showed larger increases among high compared to low frailty patients (by 0.2-1.8 vs. 0.2-0.8 [p < 0.01]). Changes in rates of spine surgery were associated with frailty, most clearly in rates of spine fusion, showing consistent increases among low frailty patients (by 2.2-2.5%) versus decreases (by 0.3-0.8%) among high-frailty patients (p < 0.02). Changes in rates of in-hospital mortality were not associated with frailty. CONCLUSIONS: During the COVID-19 pandemic, the proportion of high-frailty patients increased among those hospitalized for spine pathologies in Germany. Low frailty was associated with a rise in rates of spine surgery and high frailty with comparably larger increases in rates of comorbidities.

Effects of the COVID-19 Pandemic on Spinal Fusion Procedures for Spinal Infections in a Nationwide Hospital Network in Germany.

BACKGROUND: The full impact of the COVID-19 pandemic on surgical spine care is difficult to assess due to a lack in nationwide evidence from more recent phases of the pandemic. We aimed to describe changes in in-hospital processes associated with spinal fusion procedures in the treatment of spinal infections (SI) during different phases of the pandemic. METHODS: In this retrospective observational study, we examined the in-hospital prevalence and outcomes of spinal fusion procedures for SI (along with patient characteristics, rates of transfer to intensive care units, and mortality rates) during the first four waves of the pandemic compared with the corresponding prepandemic periods in 2019. We used administrative data from a nationwide network of 76 hospitals managing 7% of all in-hospital cases in Germany. RESULTS: We observed no significant change in the prevalence of SI fusion procedures during the pandemic, neither in total numbers (349 vs. 373) nor for each wave separately. On a patient level, we found no differences in age, sex, and the prevalence of paresis, and no relevant differences in associated comorbidities. The rate of mechanical ventilation did not change during any of the examined pandemic waves: it ranged between 9.5 and 18.6% during the pandemic and 3.1 and 16.0% during the corresponding prepandemic control periods. The rate of transfer to intensive care changed only during wave 4 (from 70.4 to 54.8%; p = 0.046) but not in any other pandemic phases. We observed no changes in in-hospital mortality rates (range: 2.9-9.7% vs. 6.2-11.3%) or in duration of hospital stay (range: 26.2-30.8 days vs. 20.8-29.2 days). CONCLUSIONS: The main finding of our study is that within this nationwide network of spine care centers in Germany, the delivery of surgical treatment of SI by means of spinal fusion procedures was maintained throughout the first four waves of the pandemic. Furthermore, there were no relevant changes in patient demographics, in-hospital processes, and mortality rates.

Effect of different forearm positions on fragment rotation in extra-articular distal radius fractures: A cadaveric study.

OBJECTIVE: The aim of the study was to investigate the effect of different arm positions (hand pronation/supination and elbow flexion/extension) on fragment rotation in extra-articular distal radius fractures in a cadaveric model. METHODS: In this study, ten fresh-frozen cadaveric upper extremities from five donors with a mean age of 69 ± 12 years were used. Two cortical pins were inserted in the radius and the ulna. In a custom-made device, different forearm (30°, 60°, and 90° of pronation and supination) and elbow positions (full extension) were tested, using a fluoroscopic analysis. The degree of malrotation between the two pins was measured in these positions. At the last test sequence, the tendon of the brachioradialis muscle was released. RESULTS: A significant difference was found in concerns of the rotational angle between the distal fragment and the radial shaft at different degrees of pronation and supination if the elbow joint was in an extended and flexed position. The release of the brachioradialis tendon did not show any effect. CONCLUSION: The results of this study supported that rotational malpositions in distal radius fractures can be decreased if the forearm is in a neutral position. Accordingly, the forearm should be in a neutral position while initially immobilization in a plaster splint is performed.

Subaxial Cervical Spine Injury in the Elderly and Treatment-Related Mortality - Anterior or Posterior Approach. / Subaxiale Halswirbelsäulenverletzungen des alten Menschen und therapiebedingte Mortalität ­ sind ventrale oder dorsale Operationsverfahren besser?

BACKGROUND: Subaxial cervical spine injury especially in the elderly can be associated to severe complications and disability. Until today there is no consensus concerning the best operative treatment. A potential superiority of anterior or posterior fixation is the subject of controversial discussions. OBJECTIVES: The aim of this study was to compare the outcome of anterior and posterior fixation after subaxial cervical spine trauma in the elderly focussing on the postoperative mortality. MATERIAL AND METHODS: A retrospective cohort analysis was performed to analyse the data of 43 patients. Especially mortality data were collected. RESULTS: A total of 43 patients was identified. Anterior fixation was performed in 21 patients, posterior fixation was performed in 22 patients. There were no significant differences between these groups. Although statistical significance was not reached, a slightly higher mortality was found among patients undergoing anterior fixation (52,4 vs. 31,8%). Furthermore the male sex, a higher age, translation injuries, long duration of operation and hospitalisation as well as postoperative complications were slightly associated to a higher mortality. CONCLUSIONS: Subaxial cervical spine trauma is associated to a high mortality in the elderly. Although neither anterior nor posterior fixation could show a significant superiority, every surgical decision making should be performed individually for each patient balancing the advantages and disadvantages of each method.

Early Spinal Injury Stabilization in Multiple-Injured Patients: Do All Patients Benefit?

BACKGROUND: Thoracolumbar spine fractures in multiple-injured patients are a common injury pattern. The appropriate timing for the surgical stabilization of vertebral fractures is still controversial. The purpose of this study was to analyse the impact of the timing of spinal surgery in multiple-injured patients both in general and in respect to spinal injury severity. METHODS: A retrospective analysis of multiple-injured patients with an associated spinal trauma within the thoracic or lumbar spine (injury severity score (ISS) >16, age >16 years) was performed from January 2012 to December 2016 in two Level I trauma centres. Demographic data, circumstances of the accident, and ISS, as well as time to spinal surgery were documented. The evaluated outcome parameters were length of stay in the intensive care unit (ICU) (iLOS) and length of stay (LOS) in the hospital, duration of mechanical ventilation, onset of sepsis, and multiple organ dysfunction syndrome (MODS), as well as mortality. Statistical analysis was performed using SPSS. RESULTS: A total of 113 multiple-injured patients with spinal stabilization and a complete dataset were included in the study. Of these, 71 multiple-injured patients (63%) presented with an AOSpine A-type spinal injury, whereas 42 (37%) had an AOSpine B-/C-type spinal injury. Forty-nine multiple-injured patients (43.4%) were surgically treated for their spinal injury within 24 h after trauma, and showed a significantly reduced length of stay in the ICU (7.31 vs. 14.56 days; p < 0.001) and hospital stay (23.85 vs. 33.95 days; p = 0.048), as well as a significantly reduced prevalence of sepsis compared to those surgically treated later than 24 h (3 vs. 7; p = 0.023). These adverse effects were even more pronounced in the case where cutoffs were increased to either 72 h or 96 h. Independent risk factors for a delay in spinal surgery were a higher ISS (p = 0.036), a thoracic spine injury (p = 0.001), an AOSpine A-type spinal injury (p = 0.048), and an intact neurological status (p < 0.001). In multiple-injured patients with AOSpine A-type spinal injuries, an increased time to spinal surgery was only an independent risk factor for an increased LOS; however, in multiple-injured patients with B-/C-type spinal injuries, an increased time to spinal surgery was an independent risk factor for increased iLOS, LOS, and the development of sepsis. CONCLUSION: Our data support the concept of early spinal stabilization in multiple-injured patients with AOSpine B-/C-type injuries, especially of the thoracic spine. However, in multiple-injured patients with AOSpine A-type injuries, the beneficial impact of early spinal stabilization has been overemphasized in former studies, and the benefit should be weighed out against the risk of patients' deterioration during early spinal stabilization.

Traumatic Atlantoaxial and Fracture-Related Dislocation.

Traumatic atlantoaxial dislocation due to ligamentous and combined osseous injuries rarely occurs in adults. There are only few cases published in the literature. In this level 4 study, a cohort of nine consecutive patients suffering from traumatic atlantoaxial dislocation has been analyzed regarding morphology of injury, trauma mechanism, and outcome since 2007. Three types of those injuries have been found regarding direction of dislocation indicating the underlying ligamentous injuries as well as the accompanying grade of instability. Firstly, there was rotatory dislocation, if the alar ligaments were injured. Secondly, there occurred horizontal dislocation, when transverse atlantal ligament was damaged additionally. Thirdly, excessive ligamentous injury led to distraction of the atlantoaxial complex resulting in dissociation of the atlas against the axis. Additionally fractures of the atlas as well as of the odontoid process (type II or III according to Anderson/D'Alonzo) were diagnosed frequently. Atlantoaxial dislocation injuries, especially distraction injuries, offer a high risk for accompanied neurovascular disorders deserving reduction followed by surgical fixation. Only rotatory injuries leading to ligamentous damage solitarily can safely be successfully treated conservatively. Understanding of the injuries' morphology is essential, in order to set the correct diagnosis and to implicate the most advantageous treatment regime.

Treatment of Injuries to the Subaxial Cervical Spine: Recommendations of the Spine Section of the German Society for Orthopaedics and Trauma (DGOU).

STUDY DESIGN: Expert consensus. OBJECTIVES: To establish treatment recommendations for subaxial cervical spine injuries based on current literature and the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. METHODS: This recommendation summarizes the knowledge of the Spine Section of the German Society for Orthopaedics and Trauma. RESULTS: Therapeutic goals are a stable, painless cervical spine and protection against secondary neurologic damage while retaining maximum possible motion and spinal profile. The AOSpine classification for subaxial cervical injuries is recommended. The Canadian C-Spine Rule is recommended to decide on the need for imaging. Computed tomography is the favoured modality. Conventional x-ray is preserved for cases lacking a "dangerous mechanism of injury." Magnetic resonance imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and to exclude disco-ligamentous injuries. Computed tomography angiography is recommended in high-grade facet joint injuries or in the presence of vertebra-basilar symptoms. A0-, A1- and A2-injuries are treated conservatively, but have to be monitored for progressive kyphosis. A3 injuries are operated in the majority of cases. A4- and B- and C-type injuries are treated surgically. Most injuries can be treated with anterior plate stabilization and interbody support; A4 fractures need vertebral body replacement. In certain cases, additive or pure posterior instrumentation is needed. Usually, lateral mass screws suffice. A navigation system is advised for pedicle screws from C3 to C6. CONCLUSIONS: These recommendations provide a framework for the treatment of subaxial cervical spine Injuries. They give advice about diagnostic measures and the therapeutic strategy.

The effect of myelotomy following low thoracic spinal cord compression injury in rats.

Myelotomy is a surgical procedure allowing removal of extravasated blood and necrotic tissue that is thought to attenuate secondary injury as well as promote recovery in experimental spinal cord injury (SCI) models and humans. Here we examined in rat whether myelotomy at 48 h after low-thoracic compressive SCI provided any benefit over a 12 week period. Compared to animals receiving SCI alone, myelotomy worsened BBB scores (p < 0.05) and also did not improve plantar stepping, ladder climbing, urinary bladder voiding or sensory function (thermal latency) during the 12-week period. Quantitative analyses of tissue sections at 12 weeks showed that myelotomy also did not reduce lesion volume nor alter immunohistochemical markers of axons in spared white matter bridges, microglia, astrocytes or serotinergic fibres. However, myelotomy reduced synaptophysin expression, a marker of synaptic plasticity. We conclude that further studies are required to evaluate myelotomy after SCI. (142 words).

Constitutively reduced sensory capacity promotes better recovery after spinal cord-injury (SCI) in blind rats of the dystrophic RCS strain.

BACKGROUND: We compared functional, electrophysiological and morphological parameters after SCI in two groups of rats Sprague Dawley (SD) rats with normal vision and blind rats from a SD-substrain "Royal College of Surgeons" (SD/RCS) who lose their photoreceptor cells after birth due to a genetic defect in the retinal pigment epithelium. For these animals skin-, intramuscular-, and tendon receptors are major available means to resolve spatial information. OBJECTIVE: The purpose of this study was to check whether increased sensitivity in SD/RCS rats would promote an improved recovery after SCI. METHODS: All rats were subjected to severe compression of the spinal cord at vertebra Th8, spinal cord segment Th10. Recovery of locomotion was analyzed at 1, 3, 6, 9, and 12 weeks after SCI using video recordings of beam walking and inclined ladder climbing. Five functional parameters were studied: foot-stepping angle (FSA), rump-height index (RHI) estimating paw placement and body weight support, respectively, number of correct ladder steps (CLS) assessing skilled hindlimb movements, the BBB-locomotor score and an established urinary bladder score (BS). Sensitivity tests were followed by electrophysiological measurement of M- and H-wave amplitudes from contractions of the plantar musculature after stimulation of the tibial nerve. The closing morphological measurements included lesion volume and expression of astro- and microglia below the lesion. RESULTS: Numerical assessments of BBB, FSA, BS, lesion volume and GFAP-expression revealed no significant differences between both strains. However, compared to SD-rats, the blind SD/RCS animals significantly improved RHI and CLS by 6 - 12 weeks after SCI. To our surprise the withdrawal latencies in the blind SD/RCS rats were longer and the amplitudes of M- and H-waves lower. The expression of IBA1-immunoreactivity in the lumbar enlargement was lower than in the SD-animals. CONCLUSION: The longer withdrawal latencies suggest a decreased sensitivity in the blind SD/RCS rats, which promotes better recovery after SCI. In this way our results provide indirect support to earlier work showing, that hypersensitivity and chronic pain after contusive SCI impair the recovery of locomotor function.

[Analysis of the accuracy of fit of five anatomically precontoured clavicle plate systems]. / Analyse der Passgenauigkeit fünf anatomisch vorgeformter Klavikulaplattensysteme.

BACKGROUND: A common method in surgical treatment of midshaft clavicular fractures is the clavicle plating system. In addition to traditional osteosynthetic devices, anatomically preformed plate systems also exist. Advantages are described in greater accuracy of fit and less irritation of surrounding soft tissues. The purpose of this study was to compare the anatomical fit of five different precontoured clavicle plating systems. MATERIAL AND METHODS: The anatomical fit of five different types of anatomical precontoured clavicle plates, 3 times VariaxSystem® (Stryker, Kalamazoo, MI), Meves® Plate (Ulrich medical Ulm, Germany) and LCP clavicle plate (Synthes, Bettlach, Switzerland) were investigated in 20 embalmed human cadaveric clavicles. An imprint of the space between the well-positioned plate and the clavicle was obtained using a silicone mass and the silicone imprint was digitally measured. Additionally, the anatomical fit was evaluated by three investigators following a standardized protocol (+2 to -2 points at lateral, midshaft and medial clavicle portions). RESULTS: The first three ranks went to the Stryker Variax-plates. They showed the least distance (Stryker 628027: 7­hole 1.44 mm, low curvature 0.93 mm-2.36 mm, 2. Stryker 628028: 8­hole low curvature 1.68 mm, 1.03 mm-2.4 mm and 3. Stryker 628128: 8­hole high curvature 1.87 mm, range 1.09 mm-3.1 mm) The evaluation of the anatomical fit by the investigators was in agreement with the measurement results. CONCLUSION: Although there was no complete congruency between the plates and the clavicle, all clavicle plates investigated in this study presented a reasonable anatomical shape. The 7­hole VariAx Stryker plate with slight curvature showed the best anatomical fit. A low profile and optimized anatomical precontouring can minimize irritation of the surrounding soft tissues and should be considered in plate design and implant choice.

[Management and outcome of type II fractures of the odontoid process]. / Therapiekonzept und Outcome bei Typ-II-Frakturen des Dens axis.

BACKGROUND: The most effective treatment of type II dens fractures according to Anderson and D'Alonzo remains controversial as there is no guidance on the choice of conservative or surgical therapy and if the anterior or the posterior approach is more advantageous. In 1993 Eysel and Roosen showed that the consolidation rate of type II odontoid fractures mostly depends on the morphology of the fracture and established a classification with corresponding treatment recommendations. OBJECTIVE: The investigation aimed at clarifying the outcome of type II dens fractures treated according to the recommendations of Eysel and Roosen. MATERIAL AND METHODS: Data of dens fractures from 72 patients were analyzed and categorized according to the Eysel and Roosen classification. Furthermore, the treatment was analyzed and the outcome was evaluated retrospectively using radiographs acquired during follow-up. RESULTS: The mean age of the 72 patients was 70.7 years. Of the patients 19.4% suffered from type A, 75% from type B and 5.6% from type C fractures according to Eysel and Roosen. Out of the 72 patients 45 were assessed by computed tomography (CT) scan during follow-up. According to the recommendations of the authors 34 of the 41 patients with type A or type B fractures underwent anterior screw fixation of the dens and 3 out of the 4 patients with a type C fracture underwent a dorsal C1 and C2 fusion. After a mean follow-up of 7 months non-union was observed in 15.6% of the patients whereby 6 of the these patients were treated by surgery and 1 patient was managed conservatively. All of the patients who developed a non-union had a type B fracture. CONCLUSION: The simple clinical applicability together with the low rate of non-union development shows that the Eysel and Roosen classification appears to be a suitable guide for clinical use when deciding on the appropriate treatment regimen.

Rheumatoid Arthritis Affecting the Upper Cervical Spine: Biomechanical Assessment of the Stabilizing Ligaments.

Diameters of anterior and posterior atlantodental intervals (AADI and PADI) are diagnostically conclusive regarding ongoing neurological disorders in rheumatoid arthritis. MRI and X-ray are mostly used for patients' follow-up. This investigation aimed at analyzing these intervals during motion of cervical spine, when transverse and alar ligaments are damaged. AADI and PADI of 10 native, human cervical spines were measured using lateral fluoroscopy, while the spines were assessed in neutral position first, in maximal inclination second, and in maximal extension at last. First, specimens were evaluated under intact conditions, followed by analysis after transverse and alar ligaments were destroyed. Damage of the transverse ligament leads to an increase of the AADI's diameter about 0.65 mm in flexion and damage of alar ligaments results in significant enhancement of 3.59 mm at mean. In extension, the AADI rises 0.60 mm after the transverse ligament was cut and 0.90 mm when the alar ligaments are damaged. After all ligaments are destroyed, AADI assessed in extension closely resembles AADI at neutral position. Ligamentous damage showed an average significant decrease of the PADI of 1.37 mm in the first step and of 3.57 mm in the second step in flexion, while it is reduced about 1.61 mm and 0.41 mm in the extended and similarly in the neutrally positioned spine. Alar and transverse ligaments are both of obvious importance in order to prevent AAS and movement-related spinal cord compression. Functional imaging is necessary at follow-up in order to identify patients having an advanced risk of neurological disorders.

Astrocytic expression of the CXCL12 receptor, CXCR7/ACKR3 is a hallmark of the diseased, but not developing CNS.

Based on our previous demonstration of CXCR7 as the major mediator of CXCL12 signaling in cultured astrocytes, we have now compared astrocytic expression of the CXCL12 receptors, CXCR7 and CXCR4, during CNS development and disease. In addition, we asked whether disease-associated conditions/factors affect expression of CXCL12 receptors in astrocytes. In the late embryonic rat brain, CXCR7+/GFAP+ cells were restricted to the ventricular/subventricular zone while CXCR4 was widely absent from GFAP-positive cells. In the early postnatal and adult brain, CXCR7 and CXCR4 were almost exclusively expressed by GFAP-immunoreactive astrocytes forming the superficial glia limitans. Contrasting the situation in the intact CNS, a striking increase in astrocytic CXCR7 expression was detectable in the cortex of rats with experimental brain infarcts, in the spinal cord of rats with experimental autoimmune encephalomyelitis (EAE) and after mechanical compression, as well as in the in infarcted human cerebral cortex and in the hippocampus of Alzheimer's disease patients. None of these pathologies was associated with substantial increases in astrocytic CXCR4 expression. Screening of various disease-associated factors/conditions further revealed that CXCR7 expression of cultured cortical astrocytes increases with IFNγ as well as under hypoxic conditions whereas CXCR7 expression is attenuated following treatment with IFNß. Again, none of the treatments affected CXCR4 expression in cultured astrocytes. Together, these findings support the hypothesis of a crucial role of astrocytic CXCR7 in the progression of various CNS pathologies.

[Influence of Osseous and Ligamentous Injuries on the Stability of the Atlantoaxial Complex]. / Einfluss osteoligamentärer Verletzungen auf die Stabilität des atlantoaxialen Komplexes.

Background The odontoid process and the transverse ligament are the most important structures stabilising the atlantoaxial complex. It has not been fully elucidated how injuries of these structures contribute towards instability and a potential narrowing of the spinal canal. Therefore, our investigation aimed to perform a biomechanical analysis of spinal width and dislocation of the odontoid process depending on injuries of the aforementioned structures. Methods In 10 fresh human cadaveric specimens, physiologic flexion and extension were simulated under fluoroscopy in intact specimens and after application of an odontoid process fracture and transverse ligament rupture in a crossover design. The width of the spinal canal and the dislocation of fragments were measured. Results In the intact condition, values of 19.8/19.5/19.8 mm (neutral/flexion/extension) were observed regarding spinal width. After an isolated fracture, values were 18.5/18.9/17.9 mm. With additional ligamentous injury, values changed to 20.3/19.4/22.6 mm. In the second group, values after initial ligament injury were 18.6/16.2/17.3 mm and 16.6/14.1/18.7 mm after fracture. Dislocation of fragments after an isolated fracture averaged 2.2/2.5/2.5 mm; an additional ligamentous injury led to 2.6/2.2/2.2 mm. In the second group, where a ligamentous injury preceded the fracture, a dislocation of 1.5/1.9/3.5 mm was detected after the fracture. Conclusion Neurological disorders have been observed starting at a spinal canal constriction of 2.0 mm. Our results demonstrate that a relevant constriction of the spinal canal may be due to isolated or combined injuries of the bone and the transverse ligament. Furthermore, our results show the importance of posttraumatic immobilisation of the spine with a view to the role of the transverse ligament for stabilisation of the atlantoaxial complex.

[Subaxial Cervical Spine Injuries: Treatment Recommendations of the German Orthopedic and Trauma Society]. / Therapieempfehlungen zur Versorgung von Verletzungen der subaxialen Halswirbelsäule.

In a consensus process during four sessions in 2016, the working group "lower cervical spine" of the German Society for Orthopedic and Trauma Surgery (DGOU), formulated "Therapeutic Recommendations for the Lower Cervical Spine", taking into consideration the current literature. Therapeutic goals are a permanently stable, painless cervical spine and the protection against secondary neurologic damage while retaining the greatest possible amount of motion and spinal profile. Due to its ease of use and its proven good reliability, the AOSpine classification for subaxial cervical injuries should be used. The Canadian C-Spine Rule is recommended as a clinical decision rule whether to perform imaging or not. If a structural or unstable injury is suspected by patient history or clinical findings, a spiral CT scan of the cervical spine is the favoured diagnostic modality. Conventional X-ray is reserved for patients in whom there is no "dangerous mechanism of injury". MR imaging is recommended in case of unexplained neurologic deficit, prior to closed reduction and open posterior surgery and to exclude disco-ligamentous injuries. Urgency of MR imaging depends on the specific findings. CT angiography is recommended in higher-grade facet joint injuries or in the presence of vertebra-basilar symptoms. Flexion-extension imaging is recommended only as a physician-guided dynamic fluoroscopy, when an unstable lesion is still suspected. The therapeutic strategy is mainly dependent on morphologic criteria, which are described using the AOSpine classification. A0-injuries are treated conservatively. A1- and A2-injuries are treated conservatively in the majority of cases, and in single cases a gross kyphotic deformity might indicate surgical stabilisation. A3-injuries do indicate a surgical therapy in the majority of cases, but certain cases might be treated conservatively. A4-fractures as well as B- and C-type injuries are to be treated surgically. Most injuries can be treated by anterior plate stabilisation with interbody support; when a complete burst fracture is present, corpectomy and vertebral body replacement is necessary. In certain cases, an additive posterior or pure posterior instrumentation might be possible or even mandatory. In most of these cases, lateral mass screws are sufficient; when pedicle screws are applied in C3 to C6, a 3D-navigation system is recommended. Injuries in an ankylosing spine (M3-modifier) should be treated preferably from posterior with long-segment instrumentation.

Whole body vibration (WBV) following spinal cord injury (SCI) in rats: Timing of intervention.

BACKGROUND: Following spinal cord injury (SCI), exercise training provides a wide range of benefits and promotes activity-dependent synaptic plasticity. Whole body vibration (WBV) in SCI patients improves walking and spasticity as well as bone and muscle mass. However, little is known about the effects of timing or frequency of intervention. OBJECTIVE: To determine which WBV-onset improves locomotor and bladder functions and influences synaptic plasticity beneficially. METHODS: SCI was followed by WBV starting 1, 7, 14, 28 days after injury (WBV1, WBV7, etc.) and continued for 12 weeks. Intact animals and those receiving SCI but no WBV (No WBV), SCI plus WBV twice daily (2×WBV) and SCI followed by passive hindlimb flexion-extension (PFE) served as controls. Locomotor [BBB rating, foot stepping angle (FSA) and rump-height index (RHI)] as well as bladder function were determined at 1, 3, 6, 9, and 12 weeks. Following perfusion fixation at 12 weeks, lesion volume and immunofluorescence for astrogliosis (GFAP), microglia (IBA1) and synaptic vesicles (synaptophysin, SYN) were determined. RESULTS: Compared to the No WBV group, the WB7 and WBV14 groups showed significantly faster speeds of BBB score recovery though this effect was temporary. Considering RHI we detected a sustained improvement in the WBV14 and PFE groups. Bladder function was better in the WBV14, WBV28, 2×WBV and PFE groups. Synaptophysin levels improved in response to WBV7 and WBV14, but worsened after WBV28 in parallel to an increased IBA1 expression. Correlation- and principal components analysis revealed complex relationships between behavioural (BBB, FSA, RHI) and morphological (GFAP, IBA1, SYN) measurements. CONCLUSIONS: WBV started 14 days after SCI provides the most benefit (RHI, bladder); starting at 1day after SCI provides no benefit and starting at 28 days may be detrimental. Increasing the intensity of WBV to twice daily did not provide additional benefit.

Accuracy of 3D fluoroscopy-navigated anterior transpedicular screw insertion in the cervical spine: an experimental study.

PURPOSE: The technique of pedicle screw stabilization is finding increasing popularity for use in the cervical spine. Implementing anterior transpedicular screws (ATPS) in cervical spine offers theoretical advantages compared to posterior stabilization. The goal of the current study was the development of a new setting for navigated insertion of ATPS, combining the advantage of reduced invasiveness of an anterior approach with the technical advantages of navigation. METHODS: 20 screws were implanted in levels C3 to C6 of four cervical spine models (SAWBONES(®) Cervical Vertebrae with Anterior Ligament) with the use of 3D fluoroscopy navigation system [Arcadis Orbic 3D, Siemens and VectorVision fluoro 3D trauma software (BrainLAB)]. The accuracy of inserted screws was analyzed according to postoperative CT scans and following the modified Gertzbein and Robbins classification. RESULTS: 20 anterior pedicle screws were placed in four human cervical spine models. Of these, eight screws were placed in C3, two screws in C4, six screws in C5, and four screws in C6. 16 of 20 screws (80 %) reached a grade 1 level of accuracy according to the modified Gertzbein and Robbins Classification. Three screws (15 %) were grade 2, and one screw (5 %) was grade 3. Grade 4 and 5 positions were not evident. Summing grades 1 and 2 together as "good" positions, 95 % of the screws achieved this level. Only a single screw did not fulfill these criteria. CONCLUSION: The setting introduced in this study for navigated insertion of ATPS into cervical spine bone models is well implemented and shows excellent results, with an accuracy of 95 % (Gertzbein and Robbins grade 2 or better). Thus, this preliminary study represents a prelude to larger studies with larger case numbers on human specimens.

Anatomical fit of seven different palmar distal radius plates.

INTRODUCTION: The purpose of this study was to compare the anatomical fit of different, precontoured palmar distal radius plates. METHODS: The anatomical fit of seven different types of palmar distal radius plates [Königsee variable fixed-angle radius plate 7/3-hole, Königsee variable fixed-angle radius plate 5/3-hole (Allendorf, Germany), Medartis 2.5 Adaptive TriLock, Medartis 2.5 TriLock, Medartis 2.5 TriLock extraarticular, (Basel, Switzerland), Synthes VA-LCP distal two-column-radius, Synthes LCP extraarticular (Bettlach, Switzerland)] were investigated in 25 embalmed human cadaveric radii. An imprint of the space between the well-positioned plate and the distal radius was attained using a silicone mass and the maximum height of the silicone imprint was digitally measured. The mean maximum imprint height was compared between the seven plates using an analysis of variance with repeated measures and Bonferroni correction for multiple comparisons. RESULTS: The mean maximum distance between the plates and the radial cortex was <2 mm for all plates. The greatest difference was found with the Medartis Adaptive (1.99 ± 0.45 mm) and the least difference with the Synthes two-column (1.56 ± 0.76 mm), this difference being statistically significant (p = 0.005). CONCLUSION: Although there was no complete congruency between the plates and the radial cortex, all distal palmar radius plates investigated in this study presented a reasonable anatomical shape. The Synthes VA-LCP distal two-column-radius plate palmar showed the best anatomical fit. A low profile and optimized anatomical precontouring minimizes irritation of the surrounding soft tissues and should be considered with plate design and implant choice.

Ten year survivorship after cemented and uncemented medial Uniglide® unicompartmental knee arthroplasties.

BACKGROUND: Results of knee replacement registries have shown that unicompartmental knee arthroplasty (UKA) has a significantly higher revision and failure rate than current state-of-the-art TKA. The aim of this prospective study is to evaluate the long-term outcomes and to calculate the 10 year survival of knees with medial osteoarthritis treated with Uniglide® UKA. METHODS: Two hundred thirty-four patients were assessed by an independent clinical observer using the American Knee Society Clinical Rating System, a validated outcome measure. Kaplan-Meier analysis was used to calculate the 10 year survival rates using revision surgery for any cause as the end point. RESULTS: There were no revisions due to progression of lateral osteoarthritis or polyethylene failure. There were one traumatic and three non-traumatic bearing dislocations and two revisions due to aseptic loosening of the tibial component. One joint was revised for traumatic ligament rupture, one for synovitis from bearing impingement, one due to femoral component mal-positioning and one for infection. A total of 10 cases were revised due to failures for any cause in the 61 patients withdrawn because they had died, thus giving a cumulative survival rate at 10 years of 95.57%. The knee (function) score showed an increase from 33.4 (54.7) pre-operatively to 94 (83.4) points post-operatively. The average range of motion increased from 107 to 122° (p<0.01). CONCLUSION: Based on our findings we believe that the Uniglide® unicompartmental knee prosthesis offers a safe and effective solution for the treatment of medial compartment osteoarthritis.