The revised zone of partial preservation (ZPP) in the 2019 International Standards for Neurological Classification of Spinal Cord Injury: ZPP applicability in incomplete injuries

STUDY DESIGN

Consensus process.

OBJECTIVES

To provide a reference for the Zone(s) of Partial Preservation (ZPP) in the 2019 International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) and analyze the initial impact of applicability of the revised ZPPs. Revisions include the use of ZPPs in selected incomplete injuries (in addition to prior use in sensorimotor complete injuries). Specifically, the revised motor ZPPs are applicable bilaterally in injuries with absent voluntary anal contraction (VAC) and the revised sensory ZPP for a given side is applicable if deep anal pressure (DAP), light touch and pin prick sensation in S4-5 are absent on that side.

SETTING

Committee with 16 ISNCSCI experts and datasets from the European Multicenter Study about Spinal Cord Injury (EMSCI).

METHODS

Occurrence frequencies of applicable ZPPs were determined in an EMSCI cohort consisting of two ISNCSCI examinations from 665 individuals with traumatic SCI.

RESULTS

Motor ZPPs were derived in 35.2% of all datasets of incomplete injuries, while sensory ZPPs are much less frequent (1.0%). Motor ZPPs are applicable in all American Spinal Injury Association Impairment Scale (AIS) B datasets (mean ZPP length: 0.9 ± 1.0 segments), in 55.4% of all AIS C datasets (ZPP length: 11.8 ± 8.2 segments) and in 9.9% of the AIS D datasets (ZPP length: 15.4 ± 7.9 segments).

CONCLUSIONS

The revised ZPP allows for determining motor ZPPs in approximately 1/3 of all incomplete injuries. The broadened applicability enables the use of ZPPs beyond complete injuries for complementary description of residual functions in more individuals.

SPONSORSHIP

N/A.

Lower motoneuron dysfunction impacts spontaneous motor recovery in acute cervical spinal cord injury

Paresis after spinal cord injury is caused by damage to upper and lower motoneurons and may differentially impact neurological recovery. This prospective monocentric longitudinal observational study investigated the extent and severity of lower motoneuron dysfunction and its impact on upper extremity motor recovery after acute cervical spinal cord injury. Pathological spontaneous activity at rest and/or increased discharge rates of motor unit action potentials recorded by needle electromyography (EMG) were taken as parameters for lower motoneuron dysfunction and its relation to the extent of myelopathy in the first available spine MRI was determined. Motor recovery was assessed by standardized neurological examination within the first 4 weeks (acute stage) and up to 1 year (chronic stage) after injury. Eighty-five muscles of 17 individuals with cervical spinal cord injury (neurological level of injury from C1 to C7) and a median age of 54 (28-59) were examined. The results showed that muscles with signs of lower motoneuron dysfunction peaked at the lesion center (Χ²[2,n=85]=6.6, p=0.04) and that the severity of lower motoneuron dysfunction correlated with T2-weighted hyperintense MRI signal changes in routine spine MRI at the lesion site (spearman ρ=0.31, p=0.01). Muscles exhibiting signs of lower motoneuron dysfunction, as indicated by pathological spontaneous activity at rest and/or increased discharge rates of motor unit action potentials, were associated with more severe paresis in both the acute and chronic stages after spinal cord injury (spearman ρ acute=-0.22, p=0.04 and chronic=-0.31, p=0.004). Moreover, the severity of lower motoneuron dysfunction in the acute stage was also associated with a greater degree of paresis (spearman ρ acute=-0.24, p=0.03 and chronic=-0.35, p=0.001). While both muscles with and without signs of lower motoneuron dysfunction were capable of regaining strength over time, those without lower motoneuron dysfunctions had a higher potential to reach full strength. Muscles with signs of lower motoneuron dysfunction in the acute stage displayed increased amplitudes of motor unit action potentials with chronic-stage needle EMG, indicating reinnervation through peripheral collateral sprouting as compensatory mechanism (Χ²[1,n=72]=4.3, p=0.04). Thus, lower motoneuron dysfunction represents a relevant factor contributing to motor impairment and recovery in acute cervical spinal cord injury. Defined recovery mechanisms (peripheral reinnervation) may at least partially underlie spontaneous recovery in respective muscles. Therefore, assessment of lower motoneuron dysfunction could help refine prediction of motor recovery following spinal cord injury.

Metadata Definition in Registries: What Is a Data Element?

Observational research benefits from a rich methodological foundation of registry development and operation published in international and national guidelines. Metadata management is an essential part of registry implementation based on concepts of data elements and value sets. The metadata from six German registries revealed vastly divergent interpretations of the concept of data elements. The different perspectives of research questions, data acquisition and data storage were all represented in the registries' catalogs of data elements. Consequently, the whole life cycle of a registry needs to be accompanied by a catalog of data elements, which has to be continuously adapted to the changing perspectives. A standard for the representation of those metadata is still missing. The FAIR Guiding Principles introduce important methodological requirements, but the tools for their fulfillment in respect to the management of metadata are still in its infancy.

Impact of Heterotopic Ossification on Functional Recovery in Acute Spinal Cord Injury

Objective: In spinal cord injury (SCI), heterotopic ossification is a frequent secondary complication, commonly associated with limited range of motion of affected joints, which could lead to secondary disability in activities of daily living. Additionally, heterotopic ossifications might challenge the effect of regeneration-promoting therapies on neurological and functional recovery. This study evaluated the impact of heterotopic ossification on clinical recovery within the first year after SCI.

Methods: The study was conducted as a monocentric longitudinal paired cohort study. Recruitment was based on consecutive sampling in the framework of the European Multicenter about Spinal Cord Injury (EMSCI). Recovery profiles were determined using standardized neurological and functional clinical assessments within the 1st year following SCI. All study participants underwent at least two comprehensive standardized neurological and functional clinical examinations according to the International Standards for Neurological Classification of SCI and the Spinal Cord Independence Measure, respectively. Data regarding the diagnosis and treatment of heterotopic ossification were obtained by reviewing the patient medical records. The most similar “digital twin” from the entire EMSCI database were matched in terms of age, acute neurological and functional status to each individual with SCI, and heterotopic ossification.

Results: Out of 25 participants diagnosed with heterotopic ossification, 13 individuals were enrolled and matched to control individuals. Most individuals presented with motor complete injury (75%). Ossifications were most frequently located at the hip joints (92%) and mainly occurred within the first 3 months after SCI. Individuals with heterotopic ossification achieved around 40% less functional improvement over time compared to their matched counterparts, whereas neurological recovery was not altered in individuals with SCI and heterotopic ossification.

Conclusion: Heterotopic ossification—a common complication of SCI—unfavorably affects functional recovery, which in the end is most relevant for the best possible degree of independence in activities of daily living. Upon presentation with heterotopic ossification, neurological improvement achieved through potential restorative therapies might not translate into clinically meaningful functional improvement. Diagnostic algorithms and effective early prevention/treatment options for heterotopic ossification need to be established to ensure the best possible functional outcome.

Clinical Trial Registration: NCT01571531 (https://clinicaltrials.gov).

[Germany-wide, Web-based ParaReg Registry for Lifelong Monitoring of People with Spinal Cord Injury: Data Model, Ethico-legal Prerequisites and Technical Implementation]

OBJECTIVE

In Germany, treatment paths for patients with acute spinal cord injury (SCI) differ considerably depending on intrinsic, disease-specific and extrinsic factors. Which of these factors are associated with improved outcome with fewer subsequent complications and inpatient re-admissions is not clear. The German-wide, patient-centered, web-based ParaReg registry will be implemented to improve the long-term quality of patient care and the planning of treatment paths with increased cost-effectiveness.

METHODS

In the 2017-18 conceptualization phase, the data model of the registry was developed in an iterative process of the ParaReg steering committee together with the extended DMGP board and patient representatives. In ParaReg, routine social and medical data as well as internationally established neurological, functional and participation scores will be documented. The assignment of a unique patient ID allows a lifelong, cross-center documentation of inpatient stays in one of the 27 SCI centers organized in the German-speaking Medical Society for SCI (DMGP). The ParaReg data protection concept and patient information/consent are based on the Open Source Registry for Rare Diseases (OSSE) which were extended by GDPR-relevant aspects.

RESULTS

In the realization phase, which started in 2019, the information technology infrastructure was implemented according to the clinical ID management module of the Technology and Methods Platform for Networked Medical Research (TMF). In parallel, the legal and ethical prerequisites for registry operation under the patronage of the DMGP were created. Recommendations of the working group data protection of the TMF were integrated into ParaReg's data protection concept. Based on the feedback from the alpha test phase with documentation of the hospitalization data of 40 patients, the ergonomics of the electronic case report forms were improved in particular for data entry on mobile devices.

CONCLUSION

After completion of the monocentric alpha test phase, the multicenter data acquisition was started in 5 DMGP-SCI centers. The sustainability of ParaReg is ensured by the structural and financial support of the DMGP after expiry of the funding by the German Federal Ministry of Education and Research (BMBF).

Revisiting the Examination of Sharp/Dull Discrimination as Clinical Measure of Spinothalamic Tract Integrity

Objective: Revisiting the sharp/dull discrimination as clinical measure of spinothalamic tract function considering the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Three clinically relevant factors were evaluated as to their impact on reliability: (1) the localization of dermatomes in relation to the sensory level, (2) the examination tool, and (3) the threshold of correct answers for grading of a preserved sharp/dull discrimination.

Design: Prospective monocentric psychometric study.

Setting: Spinal Cord Injury Center, Heidelberg University Hospital, Germany.

Participants: Convenient sample of 21 individuals with subacute spinal cord injury (age: 31–82 years) and 20 individuals without spinal cord injury (age: 24–63 years).

Assessment: All participants underwent three assessments for sharp/dull discrimination, applying five commonly used examination tools in seven dermatomes, performed by three trained examiners under conditions in accordance with ISNCSCI.

Main Outcome Measures: Assessment of interrater reliability by determining both the Fleiss kappa (κ) coefficient and the percentage agreement between raters. Data were dichotomized regarding the ISNCSCI threshold.

Results: Interrater reliability in individuals with SCI was overall substantial (κ = 0.68; CI 0.679–0.681) and moderate (κ = 0.54; CI 0.539–0.543) in dermatomes below the sensory level. All applied tools led to at least moderate reliability below the sensory level (lowest κ = 0.44; CI 0.432–0.440), with the officially endorsed safety pin achieving the highest (substantial) reliability (κ = 0.64; CI 0.638–0.646). Percentage agreement differed between non-SCI (97.3%) and formally intact above level dermatomes in SCI (89.2%).

Conclusions: Sharp/dull discrimination as a common clinical examination technique for spinothalamic tract function is a reliable assessment. Independent from the used examination tools, reliability was substantial, with the medium-sized safety pin delivering the most favorable results. Notwithstanding this, all other tools could be considered if a safety pin is not available. Regarding interrater reliability and guessing probability, a threshold of 80% correct responses for preserved sharp/dull discrimination appears to be most suitable, which is in line with current clinical approaches and ISNCSCI. The causal attribution of the identified differences in sharp/dull discrimination between clinically intact dermatomes of individuals with SCI and unaffected dermatomes of individuals without SCI requires future work.

Clinical Trial Registration Number (German Clinical Trials Register): DRKS00015334 (https://www.drks.de).

Influence of patient isolation due to colonization with multidrug-resistant organisms on functional recovery after spinal cord injury

STUDY DESIGN

Chart reviews were combined with neurological and functional outcome data obtained from the prospective European Multicenter Study on Spinal Cord Injury (EMSCI, www.emsci.org).

OBJECTIVES

To determine if strict physical isolation of multidrug-resistant organisms (MDRO)-positive patients negatively affects neurological recovery and functional outcome in the first year after acute spinal cord injury (SCI).

SETTING

SCI Center Heidelberg University Hospital.

METHODS

Individuals with acute (< 6 weeks) traumatic or ischemic SCI were included. During primary comprehensive care, isolated MDRO-positive patients (n = 13) were compared with a MDRO-negative control group (n = 13) matched for functional (Spinal Cord Independence Measure-SCIM) and neurological impairment (motor scores based on the International Standards for Neurological Classification of Spinal Cord Injury-ISNCSCI) at an early stage up to 40 days after SCI. SCIM scores and motor scores were obtained at 12 weeks (intermediate stage) and 24 or 48 weeks (late stage) after SCI.

RESULTS

Isolated MDRO-positive (median duration of hospitalization: 175 days, 39% of inpatient stay under isolation measures) and non-isolated MDRO-negative (median duration of hospitalization: 161 days) patients showed functional and neurological improvements, which were not statistically different between groups at the intermediate and late stage.

CONCLUSION

Prolonged isolation due to MDRO colonization for over a third of the inpatient comprehensive care period does not appear to impair neurological recovery and functional outcome within the first year after SCI.

Theoretical and practical training improves knowledge of the examination guidelines of the International Standards for Neurological Classification of Spinal Cord Injury

Study design

Prospective pre–post study.

Objectives

International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) represents the most frequently used assessment to determine the level and severity of a spinal cord injury (SCI). The guidelines for ISNCSCI are complex and challenging. Knowledge of its correct execution needs to be imparted precisely. The aim of this study was to investigate whether hands-on instructional courses can increase the knowledge of the ISNCSCI examination guidelines.

Setting

European Multicenter Study about SCI.

Methods

Before and after the instructional courses, participants were asked to complete questionnaires. The set of questions covered the most important aspects of the examination guidelines. Attendees were asked to self-rate their occupation and experience in ISNCSCI.

Results

The comparison of pretest and posttest results of 164 attendees from 2014 to 2018 revealed an improvement of knowledge reflected by an increase of correct answers from 66 ± 17% before to 89 ± 11% after the course (p < 0.01). The improvement was not associated with occupation (p > 0.1). However, the correctness of pretest results differed concerning both the period of experience with ISNCSCI (p < 0.05) and the course language (p < 0.01), while the frequency of execution resulted in differences in the posttest (p = 0.01).

Conclusions

Instructional courses substantially improve knowledge of the ISNCSCI examination guidelines. Differences in knowledge present before the course leveled off after the course. Comprehensive theoretical training is strongly recommended to ensure reliability and validity of ISNCSCI examinations in clinical routine and research. Albeit being practiced in the instructional courses, the benefit of hands-on training still needs to be systematically evaluated in future studies.

Differences in Characteristics of Error-Related Potentials Between Individuals With Spinal Cord Injury and Age- and Sex-Matched Able-Bodied Controls

Background: Non-invasive brain-computer interfaces (BCI) represent an emerging technology for enabling persons with impaired or lost grasping and reaching functions due to high spinal cord injury (SCI) to control assistive devices. A major drawback of BCIs is a high rate of false classifications. The robustness and performance of BCIs might be improved using cerebral electrophysiological correlates of error recognition (error-related potentials, ErrPs). As ErrPs have never been systematically examined in subjects with SCI, this study compares the characteristics of ErrPs in individuals with SCI with those of able-bodied control subjects. Methods: ErrPs at FCz and Cz were analyzed in 11 subjects with SCI (9 male, median age 28 y) and in 11 sex- and age-matched controls. Moving a shoulder joystick according to a visual cue, subjects received feedback about the match/mismatch of the performed movement. ErrPs occurring after "error"-feedback were evaluated by comparing means of voltage values within three consecutive time windows after feedback (wP1, wN1, wP2 containing peak voltages P1, N1, P2) using repeated-measurement analysis of variance. Results: In the control group, mean voltage values for the "error" and "correct" feedback condition differed significantly around N1 (FCz: 254 ms, Cz: 252 ms) and P2 (FCz: 347 ms, Cz: 345 ms), but not around P1 (FCz: 181 ms, Cz: 179 ms). ErrPs of the control and the SCI group showed similar morphology, however mean amplitudes of ErrPs were significantly smaller in individuals with SCI compared to controls for wN1 (FCz: control = -1.55 μV, SCI = -0.27 μV, p = 0.02; Cz: control = -1.03 μV, SCI = 0.11 μV, p = 0.04) and wP2 (FCz: control = 2.79 μV, SCI = 1.29 μV, p = 0.011; Cz: control = 2.12 μV, SCI = 0.81 μV, p = 0.003). Mean voltage values in wP1, wN1, and wP2 did not correlate significantly with either chronicity after or level of injury. Conclusion: The morphology of ErrPs in subjects with and without SCI is comparable, however, with reduced mean amplitude in wN1 and wP2 in the SCI group. Further studies should evaluate whether ErrP-classification can be used for online correction of false BCI-commands in individuals with SCI.

Instrumented gait analysis in patients with medial osteoarthritis of the knee after mobile-bearing unicompartmental knee arthroplasty

BACKGROUND

Unicompartmental knee arthroplasty (UKA) is an effective treatment for patients with medial osteoarthritis of the knee joint. Instrumented gait analysis provides an objective measure to quantify and qualify postoperative changes of gait. The purpose of this study was to evaluate standardized instrumented gait analysis for functional recovery and gait as an outcome of mobile-bearing UKA in patients with medial osteoarthritis of the knee.

METHODS

Twenty-one patients with isolated medial osteoarthritis of the knee joint received mobile-bearing UKA. They were examined by a gait analysis before surgery and after an average follow-up time of seven months. Gait analysis was performed on a treadmill with six infrared-cameras to identify changes of gait characteristics (e.g., velocity, stride time, stride length, knee adduction and hip abduction).

RESULTS

Mean velocity (chosen by individuals) increased from 0.61 to 0.76m/s and further significant advancements, particularly in the knee adduction and the hip abduction were detected. Time and length of strides improved significantly as well as the clinical scores American Knee Society Score (AKSS), Oxford-12, Hannover Functional Ability Questionnaire for Osteoarthritis (FFbH-OA) Score and Devane Score.

CONCLUSION

Mobile-bearing UKA can restore physiological axis of the leg and improve gait and function of the knee joint. The combination of instrumented gait analysis with clinical scores constitutes an eligible measuring instrument to quantify and qualify changes in patients' gait patterns.

Trainer in a pocket - proof-of-concept of mobile, real-time, foot kinematics feedback for gait pattern normalization in individuals after stroke, incomplete spinal cord injury and elderly patients

BACKGROUND

Walking disabilities negatively affect inclusion in society and quality of life and increase the risk for secondary complications. It has been shown that external feedback applied by therapists and/or robotic training devices enables individuals with gait abnormalities to consciously normalize their gait pattern. However, little is known about the effects of a technically-assisted over ground feedback therapy. The aim of this study was to assess whether automatic real-time feedback provided by a shoe-mounted inertial-sensor-based gait therapy system is feasible in individuals with gait impairments after incomplete spinal cord injury (iSCI), stroke and in the elderly.

METHODS

In a non-controlled proof-of-concept study, feedback by tablet computer-generated verbalized instructions was given to individuals with iSCI, stroke and old age for normalization of an individually selected gait parameter (stride length, stance or swing duration, or foot-to-ground angle). The training phase consisted of 3 consecutive visits. Four weeks post training a follow-up visit was performed. Visits started with an initial gait analysis (iGA) without feedback, followed by 5 feedback training sessions of 2-3 min and a gait analysis at the end. A universal evaluation and FB scheme based on equidistant levels of deviations from the mean normal value (1 level = 1 standard deviation (SD) of the physiological reference for the feedback parameter) was used for assessment of gait quality as well as for automated adaptation of training difficulty. Overall changes in level over iGAs were detected using a Friedman's Test. Post-hoc testing was achieved with paired Wilcoxon Tests. The users' satisfaction was assessed by a customized questionnaire.

RESULTS

Fifteen individuals with iSCI, 11 after stroke and 15 elderly completed the training. The average level at iGA significantly decreased over the visits in all groups (Friedman's test, p < 0.0001), with the biggest decrease between the first and second training visit (4.78 ± 2.84 to 3.02 ± 2.43, p < 0.0001, paired Wilcoxon test). Overall, users rated the system's usability and its therapeutic effect as positive.

CONCLUSIONS

Mobile, real-time, verbalized feedback is feasible and results in a normalization of the feedback gait parameter. The results form a first basis for using real-time feedback in task-specific motor rehabilitation programs.

TRIAL REGISTRATION

DRKS00011853 , retrospectively registered on 2017/03/23.

Early Administration of Gabapentinoids Improves Motor Recovery after Human Spinal Cord Injury

The anticonvulsant pregabalin promotes neural regeneration in a mouse model of spinal cord injury (SCI). We have also previously observed that anticonvulsants improve motor outcomes following human SCI. The present study examined the optimal timing and type of anticonvulsants administered in a large, prospective, multi-center, cohort study in acute SCI. Mixed-effects regression techniques were used to model total motor scores at 1, 3, 6, and 12 months post injury. We found that early (not late) administration of anticonvulsants significantly improved motor recovery (6.25 points over 1 year). The beneficial effect of anticonvulsants remained significant after adjustment for differences in 1-month motor scores and injury characteristics. A review of a subset of patients revealed that gabapentinoids were the most frequently administrated anticonvulsant. Together with preclinical findings, intervention with anticonvulsants represents a potential pharmacological strategy to improve motor function after SCI.

Sensory Feedback Interferes with Mu Rhythm Based Detection of Motor Commands from Electroencephalographic Signals

Background: Electroencephalogram (EEG)-based brain-computer interfaces (BCI) represent a promising component of restorative motor therapies in individuals with partial paralysis. However, in those patients, sensory functions such as proprioception are at least partly preserved. The aim of this study was to investigate whether afferent feedback interferes with the BCI-based detection of efferent motor commands during execution of movements. Methods: Brain activity of 13 able-bodied subjects (age: 29.1 ± 4.8 years; 11 males) was compared between a motor task (MT) consisting of an isometric, isotonic grip and a somatosensory electrical stimulation (SS) of the fingertips. Modulation of the mu rhythm (8-13 Hz) was investigated to identify changes specifically related to the generation of efferent commands. A linear discriminant analysis (LDA) was used to investigate the activation pattern on a single-trial basis. Classifiers were trained with MT vs. REST (periods without MT/SS) and tested with SS and vice versa to quantify the impact of afferent feedback on the classification results. Results: Few differences in the spatial pattern between MT and SS were found in the modulation of the mu rhythm. All were characterized by event-related desynchronization (ERD) peaks at electrodes C3, C4, and CP3. Execution of the MT was associated with a significantly stronger ERD in the majority of sensorimotor electrodes [C3 (p < 0.01); CP3 (p < 0.05); C4 (p < 0.01)]. Classification accuracy of MT vs. REST was significantly higher than SS vs. REST (77% and 63%; p < 10^-8). Classifiers trained on MT vs. REST were able to classify SS trials significantly above chance even though no motor commands were present during SS. Classifiers trained on SS performed better in classifying MT instead of SS. Conclusion: Our results challenge the notion that the modulation of the mu rhythm is a robust phenomenon for detecting efferent commands when afferent feedback is present. Instead, they indicate that the mu ERD caused by the processing of afferent feedback generates ERD patterns in the sensorimotor cortex that are masking the ERD patterns caused by the generation of efferent commands. Thus, processing of afferent feedback represents a considerable source of false positives when the mu rhythm is used for the detection of efferent commands.

Motor levels in high cervical spinal cord injuries: Implications for the International Standards for Neurological Classification of Spinal Cord Injury

CONTEXT/OBJECTIVE

To verify the hypothesis that motor levels (ML) inferred from sensory levels in the upper cervical segments C2-C4 according to the current version of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) are counterintuitive in cases where the most rostral myotomes C5 and C6 are graded as intact.

DESIGN

Prospective cohort study of ISNCSCI instructional course participants completing a post-test after the workshop to determine the MLs in two variants of a complete, high cervical spinal cord injury (SCI) case scenario. Both variants were based on the same ISNCSCI sensory and MLs of C2. In the first variant myotomes C5 and C6 were bilaterally graded as intact, while in variant 2 only active movements against gravity were possible (grade 3).

SETTING

Eight ISNCSCI instructional courses conducted during the study period from November 2012 until March 2015 in the framework of the European Multicenter Study on Human Spinal Cord Injury (EMSCI- http//emsci.org ).

PARTICIPANTS

Ninety-two clinicians from twenty-two SCI centers. Most of the attendees were physicians (58.7%) or physical therapists (33.7%) and had less than one year (44.6%) experience in SCI medicine.

INTERVENTIONS

Not applicable.

OUTCOME MEASURE

The classification performance described as percentage of correctly determined MLs by the clinicians.

RESULTS

Variant 2 (89.13%) was significantly (P < 0.0001) better classified than variant 1 (65.76%). In variant 1 with intact myotomes at C5 and C6, C6 was incorrectly classified as the ML by the clinicians in 33.15% of all cases, whereas in variant 2 with non-intact C5 / C6 myotomes, C6 was rarely chosen (2.17%).

CONCLUSIONS

Sensory level deferred MLs in the high cervical region of C2-C4 are counterintuitive whenever the most rostral cervical myotomes are intact. An adjustment of the ML definition in ISNCSCI may be needed.

International standards for neurological classification of spinal cord injury: impact of the revised worksheet (revision 02/13) on classification performance

STUDY DESIGN

Prospective cohort study.

OBJECTIVES

Comparison of the classification performance between the worksheet revisions of 2011 and 2013 of the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI).

SETTINGS

Ongoing ISNCSCI instructional courses of the European Multicenter Study on Human Spinal Cord Injury (EMSCI). For quality control all participants were requested to classify five ISNCSCI cases directly before (pre-test) and after (post-test) the workshop.

PARTICIPANTS

One hundred twenty-five clinicians working in 22 SCI centers attended the instructional course between November 2011 and March 2015. Seventy-two clinicians completed the post-test with the 2011 revision of the worksheet and 53 with the 2013 revision.

INTERVENTIONS

Not applicable.

OUTCOME MEASURES

The clinicians' classification performance assessed by the percentage of correctly determined motor levels (ML) and sensory levels, neurological levels of injury (NLI), ASIA Impairment Scales and zones of partial preservations.

RESULTS

While no group differences were found in the pre-tests, the overall performance (rev2011: 92.2% ± 6.7%, rev2013: 94.3% ± 7.7%; P = 0.010), the percentage of correct MLs (83.2% ± 14.5% vs. 88.1% ± 15.3%; P = 0.046) and NLIs (86.1% ± 16.7% vs. 90.9% ± 18.6%; P = 0.043) improved significantly in the post-tests. Detailed ML analysis revealed the largest benefit of the 2013 revision (50.0% vs. 67.0%) in a case with a high cervical injury (NLI C2).

CONCLUSION

The results from the EMSCI ISNCSCI post-tests show a significantly better classification performance using the revised 2013 worksheet presumably due to the body-side based grouping of myotomes and dermatomes and their correct horizontal alignment. Even with these proven advantages of the new layout, the correct determination of MLs in the segments C2-C4 remains difficult.

Effects of Pain and Pain Management on Motor Recovery of Spinal Cord–Injured Patients

Background. Approximately 60% of patients suffering from acute spinal cord injury (SCI) develop pain within days to weeks after injury, which ultimately persists into chronic stages. To date, the consequences of pain after SCI have been largely examined in terms of interfering with quality of life. Objective. The objective of this study was to examine the effects of pain and pain management on neurological recovery after SCI. Methods. We analyzed clinical data in a prospective multicenter observational cohort study in patients with SCI. Using mixed effects regression techniques, total motor and sensory scores were modelled at 1, 3, 6, and 12 months postinjury. Results. A total of 225 individuals were included in the study (mean age: 45.8 ± 18 years, 80% male). At 1 month postinjury, 28% of individuals with SCI reported at- or below-level neuropathic pain. While pain classification showed no effect on neurological outcomes, individuals administered anticonvulsant medications at 1 month postinjury showed significant reductions in pain intensity (2 points over 1 year; P < .05) and greater recovery in total motor scores (7.3 points over 1 year; P < .05). This drug effect on motor recovery remained significant after adjustment for injury level and injury severity, pain classification, and pain intensity. Conclusion. While initial pain classification and intensity did not reveal an effect on motor recovery following acute SCI, anticonvulsants conferred a significant beneficial effect on motor outcomes. Early intervention with anticonvulsants may have effects beyond pain management and warrant further studies to evaluate the therapeutic effectiveness in human SCI.

Validity and reliability of a locomotor stage-based functional rating scale in spinal cord injury

STUDY DESIGN

This is a prospective observational cohort study.

OBJECTIVES

The objectives of this study were to apply and adapt a rating scale based on locomotor stages (LSs) derived from cerebral palsy (CP) to spinal cord injury (SCI) and to quantify its inter-rater reliability and construct validity.

METHODS

The inter-rater reliability of LSs originally developed for children with CP was tested in a chronic SCI cohort. On the basis of the distribution of the LSs for CP, Locomotor Stages in Spinal Cord Injury (LOSSCI) were defined. Their validity was then tested with the Spinal Cord Independence Measure (SCIM) in another acute SCI cohort.

RESULTS

The 10-point LSs for CP were assessed by two raters in 65 chronic patients. Weighted Cohen's kappa (WCk) was 0.985 (P<0.0001). Only four mismatches were found, resulting in an accuracy of 93.4%. On the basis of the distribution of the LSs for CP in SCI, the five-point LOSSCI grading scale was developed. WCk of LOSSCI was 0.976 (P<0.0001). Only three mismatches between raters were found, resulting in an overall accuracy of 95.1%. The validity data sets consisted of 448 SCIM records from 161 patients obtained within the first year after injury. Spearman's correlation coefficients were the highest between LOSSCI and SCIM indoor mobility (room and toilet; R=0.82) and the lowest between LOSSCI and SCIM respiration and sphincter management (R=0.68).

CONCLUSION

LOSSCI provides a reliable and valid clinical tool to assess locomotor function in SCI. LOSSCI not only reflects bipedal walking but also covers a wide range of key motor skills.

Change of gait in patients with lateral osteoarthritis of the knee after mobile-bearing unicompartmental knee arthroplasty

PURPOSE

Patients with lateral osteoarthritis of the knee suffer not only from pain but also impaired gait and limited mobility. Common treatment options are total knee replacement and lateral unicompartmental knee arthroplasty (UKA). The domed lateral mobile-bearing Oxford Uni is a new treatment option for patients with isolated osteoarthritis of the lateral compartment of the knee joint. We used instrumented gait analysis and clinical scores to study patients before and after lateral UKA.

METHODS

Nineteen patients suffering from lateral osteoarthritis underwent implantation of a mobile-bearing lateral UKA. They were examined in a gait analysis before the operation and after an average follow-up time of 7 months. Gait analysis was performed on a treadmill with six infrared cameras to identify gait characteristics (e.g. velocity, stride time, stride length, knee abduction or hip adduction).

RESULTS

Mean velocity changed from 0.58 to 0.73 m/s. Significant advancements were also found in knee abduction and hip adduction. Time and length of strides improved significantly as well as the clinical scores American Knee Society Score, Oxford-12, FFb-H-OA and Devane Score.

CONCLUSION

Patients with lateral osteoarthritis of the knee showed an impaired gait with an increased knee abduction and hip adduction angle. Implantation of a lateral mobile UKA can restore normal axis of the leg and improve gait and function of the knee. Instrumented gait analysis is a suitable measuring instrument to quantify and qualify the post-operative change of gait.

LEVEL OF EVIDENCE

II.

Feasibility of visual instrumented movement feedback therapy in individuals with motor incomplete spinal cord injury walking on a treadmill

Background: Incomplete spinal cord injury (iSCI) leads to motor and sensory deficits. Even in ambulatory persons with good motor function an impaired proprioception may result in an insecure gait. Limited internal afferent feedback (FB) can be compensated by provision of external FB by therapists or technical systems. Progress in computational power of motion analysis systems allows for implementation of instrumented real-time FB. The aim of this study was to test if individuals with iSCI can normalize their gait kinematics during FB and more importantly maintain an improvement after therapy.

Methods: Individuals with chronic iSCI had to complete 6 days (1 day per week) of treadmill-based FB training with a 2 weeks pause after 3 days of training. Each day consists of an initial gait analysis followed by 2 blocks with FB/no-FB. During FB the deviation of the mean knee angle during swing from a speed matched reference (norm distance, ND) is visualized as a number. The task consists of lowering the ND, which was updated after every stride. Prior to the tests in patients the in-house developed FB implementation was tested in healthy subjects with an artificial movement task.

Results: Four of five study participants benefited from FB in the short and medium term. Decrease of mean ND was highest during the first 3 sessions (from 3.93 ± 1.54 to 2.18 ± 1.04). After the pause mean ND stayed in the same range than before. In the last 3 sessions the mean ND decreased slower (2.40 ± 1.18 to 2.20 ± 0.90). Direct influences of FB ranged from 60 to 15% of reduction in mean ND compared to initial gait analysis and from 20 to 1% compared to no-FB sessions.

Conclusions: Instrumented kinematic real-time FB may serve as an effective adjunct to established gait therapies in normalizing the gait pattern after incomplete spinal cord injury. Further studies with larger patient groups need to prove long term learning and the successful transfer of newly acquired skills to activities of daily living.

Tibial cementing in UKA: a three-dimensional analysis of the bone cement implant interface and the effect of bone lavage

Loosening is a common cause for revision in cemented UKA. In a cadaver study, we analyzed the three-dimensional cement distribution under the tibial implant and the effect of bone lavage (pulsed lavage, syringe lavage) on maximum cement penetration and penetration volume. Analyses were determined by performing bone cuts in medio-lateral direction and converting this data into a 3D model. Pulsed lavage led to an increased mean maximum cement penetration 5.79 ± 2.63 mm and penetration volume 6471.34 ± 1156.43 mm(3) compared to syringe lavage 4.62 ± 2.61 mm, 5069.81 ± 1177.09 mm(3) (P<0.001; P<0.001). Our results show a complete cement mantle for both investigated lavage techniques. Cleansing the cancellous tibial bone bed using pulsed lavage is more effective than conventional syringe lavage and leads to a deeper cement penetration and lager cement penetration volume under the tibial component.

Effect of formal training in scaling, scoring and classification of the International Standards for Neurological Classification of Spinal Cord Injury

STUDY DESIGN

Prospective, longitudinal cohort study.

OBJECTIVES

To quantify the effect of formal training in the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) on the classification accuracy and to identify the most difficult ISNCSCI rules.

SETTINGS

European Multicenter Study on Human Spinal Cord Injury (EMSCI).

METHODS

EMSCI participants rated five challenging cases of full sensory, motor and anorectal examinations before (pre-test) and after (post-test) an ISNCSCI instructional course. Classification variables included sensory and motor levels (ML), completeness, ASIA Impairment Scale (AIS) and the zones of partial preservation.

RESULTS

106 attendees were trained in 10 ISNCSCI workshops since 2006. The number of correct classifications increased significantly (P<0.00001) from 49.6% (2628 of 5300) in pre-testing to 91.5% (4849 of 5300) in post-testing. Every attendee improved, 12 (11.3%) achieved 100% correctness. Sensory levels (96.8%) and completeness (96.2%) are easiest to rate in post-testing, while ML (81.9%) and AIS (88.1%) are more difficult to determine. Most of the errors in ML determination arise from sensory levels in the high cervical region (C2-C4), where by convention the ML is presumed to be the same as the sensory level. The most difficult step in AIS classification is the determination of motor incompleteness.

CONCLUSION

ISNCSCI training significantly improves the classification skills regardless of the experience in spinal cord injury medicine. These findings need to be considered for the appropriate preparation and interpretation of clinical trials in spinal cord injury.

The influence of the femoral force application point on tibial cementing pressure in cemented UKA: an experimental study

BACKGROUND

Aseptic loosening is the major cause for implant failure in cemented unicompartmental knee arthroplasty (UKA). Central positioning of the femoral pressure during the tibial cementation process is recommended to achieve equal pressure and a good cementation result. The aim of this study was to verify the central position of the femoral force application point (FFAP) at 45° flexion of the knee and to investigate the influence of ligament tension and cement penetration pressure (CPP) for UKA.

MATERIALS AND METHODS

Cemented Oxford UKAs were performed in 24 human legs. CPP and ligament tension forces (LTF) were measured. The FFAP was measured in a standardised manner in relation to the tibial implant length on lateral digital X-rays.

RESULTS

The FFAP at 45° of knee flexion is located at 53.5 % and is not significantly different from the FFAP at 0° (p = 0.768). The CPP shows mean values at the anterior portion of 13.97 kPa (SD 16.11), at the implant keel of 24.34 kPa (SD 25.21) and at the posterior portion of 36.58 kPa (SD 26.51). The LTF shows a mean value of 194.35 N (SD 83.77).

CONCLUSION

The central position of the FFAP for the investigated cemented UKA with single radius femoral component at 45° flexion of the knee could be confirmed. A flexion angle of <45° does not influence the position of the FFAP significantly. More than 45° of flexion should be avoided because the FFAP shifts backwards significantly and may cause increased pressures posteriorly and therefore tilting of the component occurs during the cementation process.

MotionTherapy@Home - First results of a clinical study with a novel robotic device for automated locomotion therapy at home

In incomplete spinal cord injured subjects, task-oriented training regimes are applied for enhancement of neuroplasticity to improve gait capacity. However, a sufficient training intensity can only be achieved during the inpatient phase, which is getting shorter and shorter due to economic restrictions. In the clinical environment, complex and expensive robotic devices have been introduced to maintain the duration and the intensity of the training, but up to now only a few exist for continuation of automated locomotion training at home. For continuation of the automated locomotion training at home prototypes of the compact, pneumatically driven orthosis MoreGait have been realized, which generate the key afferent stimuli for activation of the spinal gait pattern generator. Artificial pneumatic muscles with excellent weight-to-force ratio and safety characteristics have been integrated as joint actuators. Additionally, a Stimulative Shoe for generation of the appropriate foot loading pattern has been developed without the need for verticalization of the user. The first results of the pilot study in eight chronic incomplete spinal cord injured subjects indicate that the home-based therapy is safe and feasible. The therapy related improvements of the walking capacity are in the range of locomotion robots used in clinical settings.

[Significance of bone mineral density and modern cementing technique for in vitro cement penetration in total shoulder arthroplasty]

AIM

Loosening of the glenoid component is one of the major causes of failure in total shoulder arthroplasty. Possible risk factors for loosening of cemented components include an eccentric loading, poor bone quality, inadequate cementing technique and insufficient cement penetration. The application of a modern cementing technique has become an established procedure in total hip arthroplasty. The goal of modern cementing techniques in general is to improve the cement-penetration into the cancellous bone. Modern cementing techniques include the cement vacuum-mixing technique, retrograde filling of the cement under pressurisation and the use of a pulsatile lavage system. The main purpose of this study was to analyse cement penetration into the glenoid bone by using modern cement techniques and to investigate the relationship between the bone mineral density (BMD) and the cement penetration. Furthermore we measured the temperature at the glenoid surface before and after jet-lavage of different patients during total shoulder arthroplasty. It is known that the surrounding temperature of the bone has an effect on the polymerisation of the cement. Data from this experiment provide the temperature setting for the in-vitro study.

METHOD

The glenoid surface temperature was measured in 10 patients with a hand-held non-contact temperature measurement device. The bone mineral density was measured by DEXA. Eight paired cadaver scapulae were allocated (n = 16). Each pair comprised two scapulae from one donor (matched-pair design). Two different glenoid components were used, one with pegs and the other with a keel. The glenoids for the in-vitro study were prepared with the bone compaction technique by the same surgeon in all cases. Pulsatile lavage was used to clean the glenoid of blood and bone fragments. Low viscosity bone cement was applied retrogradely into the glenoid by using a syringe. A constant pressure was applied with a modified force sensor impactor. Micro-computed tomography scans were applied to analyse the cement penetration into the cancellous bone.

RESULTS

The mean temperature during the in-vivo arthroplasty of the glenoid was 29.4 °C (27.2-31 °C) before and 26.2 °C (25-27.5 °C) after jet-lavage. The overall peak BMD was 0.59 (range 0.33-0.99) g/cm (2). Mean cement penetration was 107.9 (range 67.6-142.3) mm (2) in the peg group and 128.3 (range 102.6-170.8) mm (2) in the keel group. The thickness of the cement layer varied from 0 to 2.1 mm in the pegged group and from 0 to 2.4 mm in the keeled group. A strong negative correlation between BMD and mean cement penetration was found for the peg group (r (2) = -0.834; p < 0.01) and for the keel group (r (2) = -0.727; p < 0.041). Micro-CT shows an inhomogenous dispersion of the cement into the cancellous bone.

CONCLUSIONS

Data from the in-vivo temperature measurement indicate that the temperature at the glenohumeral surface under operation differs from the body core temperature and should be considered in further in-vitro studies with human specimens. Bone mineral density is negatively correlated to cement penetration in the glenoid. The application of a modern cementing technique in the glenoid provides sufficient cementing penetration although there is an inhomogenous dispersion of the cement. The findings of this study should be considered in further discussions about cementing technique and cement penetration into the cancellous bone of the glenoid.

Conversion in ASIA impairment scale during the first year after traumatic spinal cord injury

The neurological severity of a spinal cord injury (SCI) is commonly classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS). The aim of this study was to assess the course of the AIS following SCI, and to discern the nature of any changes in the classification that occur. Assessments were performed in a European cohort of SCI patients within 2 weeks and at 1, 3, 6, and 12 months after the initial injury. Overall, about 70% of the patients initially diagnosed as AIS A did not convert, as did 90% of the AIS D patients. When only evaluating patients with complete datasets, 68% did not convert, while the AIS category improved in 30% of patients and deteriorated in 2%. A change in the last sacral segments (40%), motor improvement (31%), sensory improvement (19%), and a change in the neurological level of the SCI (10%) contributed to or accompanied the AIS conversion. When the AIS remained unchanged between successive assessment points, there was no change in the number of muscles graded three or more (NMG3(+)) in 73% of the transitions. An improvement in AIS was associated with a gain in NMG3(+) in 49% of the transitions, while an aggravation in AIS was accompanied by a loss in NMG3(+) in 10% of the transitions. These results, documenting a substantial amount of spontaneous AIS conversions, should be taken into consideration when designing clinical trials to assess the effects of potential new treatments for SCI.