High-resolution ultrasound of the supra- and infraclavicular levels of the brachial plexus including the axillary nerve: imaging anatomy based on multiplanar reconstructions and technical guide.

PURPOSE: The diagnosis of peripheral nerve injuries remains challenging. Electromyography and nerve conduction studies do not allow precise localization of the lesion and differentiation between lesions in continuity and non-continuity in cases with complete axonotmesis. Improved ultrasound technology allows the examination of almost the entire peripheral nervous system. The complex sono-anatomy of the brachial plexus outside of the standard scanning planes makes it difficult to access this region. METHODS: On the basis of the Visible Human Project of the National Institutes of Health (NIH), multiplanar reconstructions were created with the 3D Slicer open-source software in the various planes of the ultrasound cross-sections. The ultrasound examination itself and the guidance of the ultrasound probe in relation to the patient were recorded as video files and were synchronized through the audio channel. Subsequently, image matching was performed. RESULTS: Multiplanar reconstructions facilitate visualization of anatomical regions which are challenging to access thereby enabling physicians to evaluate the course of the peripheral nerve of interest in dynamic conditions. Sonographically visible structures could be reproducibly identified in single-frame analysis. CONCLUSION: With precise knowledge of the ultrasound anatomy, the nerve structures of the brachial plexus can also be dynamically assessed almost in their entire course. An instructional video on ultrasound of the brachial plexus supplements this manuscript and has been published on Vimeo.com.

Joint-preserving treatment for type 3 sequelae following fracture of the proximal humerus with small head fragments.

BACKGROUND: Although nonunions of the proximal humerus are rare, they cause significant disability to patients. Surgical reconstruction is challenging, especially with small and excavated head fragments. A promising surgical option is open reduction and stabilization using the Humerusblock device along with tension wires. The aim of this retrospective investigation was to evaluate the clinical and radiological results of this procedure. MATERIALS AND METHODS: Fifteen patients with symptomatic surgical neck nonunions were treated with open reduction and internal fixation using the Humerusblock device without bone grafting. All patients showed a loss of bone stock, leading to excavated head fragments. The mean interval from injury to the described treatment was 6.2 months (range, 3.4-10.7). At a mean follow-up of 40.5 months, the Constant-Murley score was documented, pain and patient satisfaction were evaluated using a visual analogue scale, and x-rays were taken in two planes. RESULTS: The patients' mean age was 69.7 years (range, 52-83). The mean Constant-Murley score improved from 24 points before surgery to 62 points at follow-up, which was an average of 80.8% of the score obtained for the contralateral arm. Radiological examination confirmed bony healing in 14 patients. All but one patient felt satisfied with the results. Three patients required revision surgery because of a hematoma, and early metal removal was performed in one patient because of infection. CONCLUSION: Nonunions of humeral surgical neck fractures can be successfully treated by fixation using the Humerusblock device along with tension wires without the need for additional bone grafting. Especially in patients with flat, concave head fragments, this procedure remains a promising reconstructive option to arthroplasty. LEVEL OF EVIDENCE: Level IV; Therapeutic retrospective case series.

Trajectory of Serum Levels of Glial Fibrillary Acidic Protein Within Four Weeks Post-Injury Is Related to Neurological Recovery During the Transition from Acute to Chronic Spinal Cord Injury.

The use of biomarkers in spinal cord injury (SCI) research has evolved rapidly in recent years whereby most studies focused on the acute post-injury phase. Since SCI is characterized by persisting neurological impairments, the question arises whether blood biomarkers remain altered during the subacute post-injury time. Sample collection in the subacute phase might provide a better insight in the ongoing SCI specific molecular mechanism with fewer confounding factors compared with the acute phase where, amongst other complications, individuals receive a substantial amount of medication. This study aimed to determine if the temporal dynamics of serum biomarkers of neurodegeneration differ between individuals depending on their extent of neurological recovery in the transition phase between acute and chronic SCI. We performed a secondary analysis of biomarkers in patients with SCI (n = 41) who were treated at a level I trauma center in Germany. Patients with cervical or thoracic SCI regardless of injury severity were included. Blood samples were collected in the acute phase (1-4 days post-injury), and after 30 and 120 days post-injury. Serum protein levels of glial fibrillary acidic protein (GFAP) and neurofilament light protein (NfL) were determined for each time-point of sample collection using R-Plex Assays (Meso Scale Discovery). Linear mixed models were used to evaluate the trajectory of GFAP and NfL over time. Fixed effects of time, neurological recovery, and injury severity, along with the recovery-by-time interaction, were included in models with random slopes and intercepts. GFAP levels increase during the first days after SCI and decrease in subacute to chronic stages. Notably, the trajectory of GFAP over time is significantly associated with the extent of neurological recovery during the transition from acute to chronic SCI with a steeper decline in individuals who recovered better. Serum levels of NfL continue to rise significantly until Day 30 followed by a decrease afterwards, independent of neurological recovery. The trajectory of serum GFAP levels qualifies as a prognostic biomarker for neurological recovery, and facilitates monitoring of disease progression in the sub-acute post-injury phase.

A New Score Based on the International Standards for Neurological Classification of Spinal Cord Injury for Integrative Evaluation of Changes in Sensorimotor Functions.

Sensorimotor function of patients with spinal cord injury (SCI) is commonly assessed according to the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). From the ISNCSCI segmental motor and sensory assessments, upper and lower extremity motor scores (UEMS and LEMS), sum scores of pinprick (PP) and light touch (LT) sensation, the neurological level of injury (NLI) and the classification of lesion severity according to the American Spinal Injury Association Impairment Scale (AIS) grade are derived. Changes of these parameters over time are used widely to evaluate neurological recovery. Evaluating recovery based on a single ISNCSCI scoring or classification variable, however, may misestimate overall recovery. Here, we propose an Integrated Neurological Change Score (INCS) based on the combination of normalized changes between two time points of UEMS, LEMS, and total PP and LT scores. To assess the agreement of INCS with clinical judgment of meaningfulness of neurological changes, changes of ISNCSCI variables between two time points of 88 patients from an independent cohort were rated by 20 clinical experts according to a five-categories Likert Scale. As for individual ISNCSCI variables, neurological change measured by INCS is associated with severity (AIS grade), age, and time since injury, but INCS better reflects clinical judgment about meaningfulness of neurological changes than individual ISNCSCI variables. In addition, INCS is related to changes in functional independence measured by the Spinal Cord Independence Measure (SCIM) in patients with tetraplegia. The INCS may be a useful measure of overall neurological change in clinical studies.

Serum Levels of Glial Fibrillary Acidic Protein and Neurofilament Light Protein Are Related to the Neurological Impairment and Spinal Edema after Traumatic Spinal Cord Injury.

Neurological examination in the acute phase after spinal cord injury (SCI) is often impossible and severely confounded by pharmacological sedation or concomitant injuries. Therefore, diagnostic biomarkers that objectively characterize severity or the presence of SCI are urgently needed to facilitate clinical decision-making. This study aimed to determine if serum markers of neural origin are related to: 1) presence and severity of SCI, and 2) magnetic resonance imaging (MRI) parameters in the very acute post-injury phase. We performed a secondary analysis of serological parameters, as well as MRI findings in patients with acute SCI (n = 38). Blood samples were collected between Days 1-4 post-injury. Serum protein levels of glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE), and neurofilament light protein (NfL) were determined. A group of 41 age- and sex-matched healthy individuals served as control group. In the group of individuals with SCI, pre-operative sagittal and axial T2-weighted and sagittal T1-weighted MRI scans were available for 21 patients. Serum markers of neural origin are different among individuals who sustained traumatic SCI depending on injury severity, and the extent of the lesion according to MRI in the acute injury phase. Unbiased Recursive Partitioning regression with Conditional Inference Trees (URP-CTREE) produced preliminary cut-off values for NfL (75.217 pg/mL) and GFAP (73.121 pg/mL), allowing a differentiation between individuals with SCI and healthy controls within the first 4 days after SCI. Serum proteins NfL and GFAP qualify as diagnostic biomarkers for the presence and severity of SCI in the acute post-injury phase, where the reliability of clinical exams is limited.

Early Decompression (<8 Hours) Improves Functional Bladder Outcome and Mobility After Traumatic Thoracic Spinal Cord Injury.

BACKGROUND: There is accumulating evidence of a potential beneficial effect of early surgical intervention after acute cervical spinal cord injury (SCI). However, around one third of all SCIs affect the thoracic spine. This cohort has not been extensively investigated, mainly because of less sensitive clinical readout measures. Apart from regaining full sensorimotor function, improvements in bladder and bowel management remain of the highest priority for patients with chronic paraplegia. Therefore, this study investigates the effect of early decompression (here defined as <8 hours) versus delayed management on neurologic and functional outcome. METHODS: We retrospectively analyzed data from the institutional database, in which follow-up data were collected prospectively according to the European Multicenter Study about Spinal Cord Injury standards. Within a 13-year period, we identified 43 patients who met inclusion and exclusion criteria. Of these, 32 (74%) were managed surgically within the first 8 hours. There was a trend toward a higher rate of patients with clinically complete SCI in the early group at baseline. RESULTS: After 1 year, we did not observe a benefit on the neurologic outcome as assessed via the American Spinal Injury Association Impairment Scale grade. Functional outcome was evaluated using the Spinal Cord Independence Measure (SCIM). The early decompressed group demonstrated significantly improved SCIM 6 (i.e., bladder management) (P < 0.045) and SCIM 9-11 subitems (i.e., mobility, transfer) (P < 0.019). CONCLUSIONS: Early decompression was an independent predictor for improved functional bladder outcome and mobility after 1 year. This effect needs to be studied in future prospective, multicenter studies.

Earlier Decompression (< 8 Hours) Results in Better Neurological and Functional Outcome after Traumatic Thoracolumbar Spinal Cord Injury.

The optimal timing of surgical intervention following spinal cord injury (SCI) remains under debate. Recent studies indicate a potential neurological and functional benefit of early surgery (< 8 h) after cervical SCI. For thoracolumbar SCI syndromes, fewer studies exist. Bladder and bowel dysfunction are highly relevant for these patients and impair their quality of life. Hence, we performed a retrospective study on patients with thoracolumbar SCI who were operated on at our institution and who met inclusion as well as exclusion criteria (n = 58 patients). Follow-up data were collected prospectively within a fixed time schedule over 1 year according to the European Multicenter Study about Spinal Cord Injury protocol. Early decompression was defined as within the first 8 h after injury and was performed in 35 patients. After the follow-up period, the early decompression group showed improved American Spinal Injury Association Impairment Scale (AIS) grades (p < 0.040) and a higher AIS conversion (p < 0.021). Further, these patients demonstrated a higher total Spinal Cord Independence Measure (SCIM) difference (p < 0.005). Special emphasis was placed on the functional bladder and bowel outcome. Here, we observed improved bladder outcome (i.e., SCIM-6 sub-item; p < 0.021) and a trend towards better functional bowel management (i.e., SCIM-7; p < 0.090). Linear regression models showed that early surgery was an independent predictor for higher AIS shifts and improved total SCIM difference. Our data suggests that prompt surgical management after thoracolumbar SCI might have a positive impact on the functional and neurological outcome.

Influence of Preoperative Magnetic Resonance Imaging on Surgical Decision Making for Patients with Acute Traumatic Cervical Spinal Cord Injury: A Survey Among Experienced Spine Surgeons.

OBJECTIVE: Early decompression after acute spinal cord injury (SCI) is recommended. Acute care is crucial, but optimal management is unclear. The aim of this study was to investigate the role of preoperative magnetic resonance imaging (MRI) in addition to computed tomography (CT) in surgical decision making for acute cervical SCI. METHODS: All patients with cervical SCI between 2008 and 2016 who had preoperative CT and MRI (n = 63) at the Trauma Center Murnau, Germany, were included. We administered a survey to 10 experienced spine surgeons (5 neurosurgeons, 5 trauma surgeons) regarding the surgical management. First, the surgeons were shown clinical information and CT scans. Two months later, the survey was repeated with additional MRI. Corresponding percentages of change and agreement were obtained for each rater and survey item. Finally, results from both parts of the survey were compared with the definitive treatment option (i.e., real-world decision). RESULTS: MRI modified surgical timing in a median of 41% of patients (interquartile range 38%-56%). In almost every fifth patient (17%), no surgery would have been indicated with CT alone. The advocated surgical approach was changed in almost half of patients (median 48%, interquartile range 33%-49%). Surgically addressed levels were changed in a median of 57% of patients (interquartile range 56%-60%). MRI led to higher agreement with the real-world decision concerning addressed levels (median 35% vs. 73%), timing (median 51% vs. 57%), and approach (median 44% vs. 65%). CONCLUSIONS: Preoperative MRI influenced surgical decision making substantially in our cohort and has become a new standard for patients with cervical SCI in our institution if medically possible.

Minimally Invasive Treatment of Displaced Proximal Humeral Fractures in Patients Older Than 70 Years Using the Humerusblock.

Background. Surgical treatment of proximal humeral fractures (PHF) in osteoporotic bone of elderly patients is challenging. The aim of this retrospective study was to evaluate the clinical and radiological outcome after percutaneous reduction and internal fixation of osteoporotic PHF in geriatric patients using the semirigid Humerusblock device. Methods. In the study period from 2005 to 2010, 129 patients older than 70 years were enrolled in the study. After a mean follow-up of 23 months, a physical examination, using the Constant-Murley score and the VAS pain scale, was performed. Furthermore radiographs were taken to detect signs of malunion, nonunion, and avascular necrosis. Results. The recorded Constant-Murley score was 67.7 points (87.7% of the noninjured arm) for two-part fractures, 67.9 points (90.8%) for three-part fractures, and 43.0 points (56.7%) for four-part fractures. In ten shoulders (7.8%) loss of reduction and in four shoulders (3.1%) nonunion were the reason for revision surgery. Avascular humeral head necrosis developed in eight patients (6.2%). Conclusions. In two- and three-part fractures postoperative results are promising. Sufficient ability for the activities of daily living was achieved. In four-part fractures the functional results were less satisfying regarding function and pain with a high postoperative complication rate. In those patients other treatment strategies should be considered. Study design. Therapeutic retrospective case series (evidence-based medicine (EBM) level IV).

Early Decompression (< 8 h) after Traumatic Cervical Spinal Cord Injury Improves Functional Outcome as Assessed by Spinal Cord Independence Measure after One Year.

There is an ongoing controversy about the optimal timing for surgical decompression after acute traumatic cervical spinal cord injury (SCI). For this reason, we performed a retrospective study of patients who were operated on after traumatic cervical SCI at the Trauma Center Murnau, Germany, and who met inclusion as well as exclusion criteria (n = 70 patients). Follow-up data were collected prospectively according to the European Multicenter Study about Spinal Cord Injury (EMSCI) protocol over a period of 1 year. Early decompression was defined as within the first 8 h after the insult (n = 35 patients). Primary outcome was the difference in the SCIM (Spinal Cord Independence Measure) 1 year after the trauma. After the follow-up period, patients who were decompressed earlier had a significantly higher SCIM difference (45.8 vs. 27.1, p < 0.005). A regression analysis showed that timing of decompression, age, as well as basal AIS (American Spinal Injury Association Impairment Scale) and basal SCIM scores were independent predictors for a better functional outcome (SCIM). Further, patients from the early decompression group had better AIS grades (p < 0.006) and a higher AIS conversion rate (p < 0.029). Additionally, this cohort also had a better total motor performance as well as upper extremity motor function after 1 year (p < 0.025 and p < 0.002). The motor and neurological levels of patients who were operated on within 8 h were significantly more caudal (p < 0.003 and p < 0.014) after 1 year. The present study suggests that early decompression after traumatic cervical SCI might have a positive impact on the functional and neurological outcome of affected individuals.

Evaluation of risk for secondary fracture after removal of a new femoral neck plate for intracapsular hip fractures.

OBJECTIVE: To determine whether a new femoral neck plate has a higher risk for secondary fracture after implant removal than the current standard treatment for intracapsular hip fractures. METHODS: Six pairs of human cadaver femora (age, 56 ± 5.6 years; range, 48-64 years; two female and four male donors) were instrumented with the femoral neck plate (FNP) or the compression hip screw combined with an antirotation screw (CHS) in a paired study design. After removal of the implants, axial compression tests to failure of the bones were conducted. Maximum force to failure of the bones after implant removal was determined. Axial stiffness of the bones before surgery and after implant removal was determined. RESULTS: The FNP resulted in a mean failure load of 4687 ± 1743 N (mean ± standard deviation) and the CHS resulted in a mean failure load of 4892 ± 1608 N with no significant difference between the two implant groups (P = 0.405). There was no significant difference in stiffness (P = 0.214) between the FNP (1240 ± 362 N/mm) and the CHS (1293 ± 304 N/mm). The cavities left by the surgery had no effect on the bone stiffness (P > 0.05). The mean failure load of all specimens correlated with the bone mineral density in the proximal part of the femurs by R² = 0.715 (P = 0.001). CONCLUSION: The FNP demonstrated a similar failure load after implant removal compared with the CHS, although the FNP left a 39% larger cavity in the bone.

Should extramedullary fixations for hip fractures be removed after bone union?

BACKGROUND: Osteosynthesis implants, which remain in the patient after fracture union to save additional surgery, may affect the strain distribution within the bone. A reduction of strain within the bone is known to result in localized bone loss ("stress shielding") and increased fracture risk. The purpose of this study was to examine whether extramedullary fixations for femoral neck fractures have to be removed after fracture union to prevent reductions in cortex strains. METHODS: In a biomechanical experiment, six pairs of human cadaver femora (mean age 56 years, range 48 to 64) were supplied with five strain gauges per bone. The bones were equally supplied with a compression hip screw or a femoral neck plate. Before surgery, after surgery and after removal of the implants, axial compression tests were conducted to measure surface strains during loading. FINDINGS: The compression hip screw reduced the amount of strain at the superior neck by 88% (P=0.015) and at the lesser trochanter by 51% (P=0.038). The femoral neck plate reduced the amount of strain at the superior neck by 89% (P=0.001), and increased the amount of strain at the inferior neck by 58% (P=0.02) and at the lesser trochanter by 63% (P=0.005). After implant removal, there was no significant difference in strain compared to pre-fracture levels, except for the compression hip screw with 21% less strain (P=0.047) at the superior neck. INTERPRETATION: Removal of osteosynthesis implants after bone union reverts bone strains to pre-fracture levels, and might prevent further bone loss induced by stress shielding.

Patient-specific finite element analysis of the human femur--a double-blinded biomechanical validation.

Patient-specific finite element (PSFE) models based on quantitative computer tomography (qCT) are generally used to "predict" the biomechanical response of human bones with the future goal to be applied in clinical decision-making. However, clinical applications require a well validated tool that is free of numerical errors and furthermore match closely experimental findings. In previous studies, not all measurable data (strains and displacements) were considered for validation. Furthermore, the same research group performed both the experiments and PSFE analyses; thus, the validation may have been biased. The aim of the present study was therefore to validate PSFE models with biomechanical experiments, and to address the above-mentioned issues of measurable data and validation bias. A PSFE model (p-method) of each cadaver femur (n = 12) was generated based on qCT scans of the specimens. The models were validated by biomechanical in-vitro experiments, which determined strains and local displacements on the bone surface and the axial stiffness of the specimens. The validation was performed in a double-blinded manner by two different research institutes to avoid any bias. Inspecting all measurements (155 values), the numerical results correlated well with the experimental results (R(2) = 0.93, slope 1.0093, mean of absolute deviations 22%). In conclusion, a method to generate PSFE models from qCT scans was used in this study on a sample size not yet considered in the past, and compared to experiments in a douple-blinded manner. The results demonstrate that the presented method is in an advanced stage, and can be used in clinical computer-aided decision-making.