Mirko Aach

Risk factors for heterotopic ossification in patients with spinal cord injury: a case-control study of 264 patients.

Study Design. Case-control study. Objective. We designed a case-control study to analyze the risk factors associated with the development of heterotopic ossification (HO) in patients with traumatic spinal cord injury. Summary of Background Data. Patients with spinal cord injury have a high risk of developing HO, although the exact etiopathogenesis is still unknown. Several factors are known to be potential risk factors. However, we are not aware of any large clinical studies evaluating the risk factors for HO. Methods. Patients who were treated for a traumatic spinal cord injury in our hospital, and who subsequently developed HO, were identified by querying the electronic database at our hospital from 2002 to 2010. One hundred thirty-two patients and 132 controls were included. Our primary outcome measures were the risk of developing HO according to whether the patient had experienced a complete spinal cord lesion according to American Spinal Injury Association Impairment Scale; tetraplegia or paraplegia; cervical, thoracic, or lumbar injury; severe chest trauma; and the time interval between injury and surgery. Secondary risk factors explored were patient age; sex; presence and number of comorbidities; length of hospital and intensive care unit stay; associated traumatic injuries; presence of spasticity, pressure ulcers, deep venous thrombosis, and urinary tract infection; and pulmonary complications, such as pneumonia and necessity of tracheostomy. Results. Patients with associated spasticity and thoracic trauma, complete lesion, pneumonia, presence of tracheostomy, and urinary tract infection had a higher risk of developing HO. Conclusion. Adequate management of potential risk factors could help reduce the overall incidence of HO and outcome in patients with traumatic spinal cord injury.

Locomotion training using voluntary driven exoskeleton (HAL) in acute incomplete SCI

A 34-year-old man had a traumatic thoracic spinal cord injury, with vertebral fracture and a right acetabulum fracture. Dorsal spinal fusion of T6 through T9 was performed on admission. The initial American Spinal Injury Association (ASIA) Impairment Scale (C) showed incomplete motor T10 lesion.

The Effectiveness and Safety of Exoskeletons as Assistive and Rehabilitation Devices in the Treatment of Neurologic Gait Disorders in Patients with Spinal Cord Injury: A Systematic Review

Study Design Systematic review. Clinical Questions (1) When used as an assistive device, do wearable exoskeletons improve lower extremity function or gait compared with knee-ankle-foot orthoses (KAFOs) in patients with complete or incomplete spinal cord injury? (2) When used as a rehabilitation device, do wearable exoskeletons improve lower extremity function or gait compared with other rehabilitation strategies in patients with complete or incomplete spinal cord injury? (3) When used as an assistive or rehabilitation device, are wearable exoskeletons safe compared with KAFO for assistance or other rehabilitation strategies for rehabilitation in patients with complete or incomplete spinal cord injury? Methods PubMed, Cochrane, and Embase databases and reference lists of key articles were searched from database inception to May 2, 2016, to identify studies evaluating the effectiveness of wearable exoskeletons used as assistive or rehabilitative devices in patients with incomplete or complete spinal cord injury. Results No comparison studies were found evaluating exoskeletons as an assistive device. Nine comparison studies (11 publications) evaluated the use of exoskeletons as a rehabilitative device. The 10-meter walk test velocity and Spinal Cord Independence Measure scores showed no difference in change from baseline among patients undergoing exoskeleton training compared with various comparator therapies. The remaining primary outcome measures of 6-minute walk test distance and Walking Index for Spinal Cord Injury I and II and Functional Independence Measure–Locomotor scores showed mixed results, with some studies indicating no difference in change from baseline between exoskeleton training and comparator therapies, some indicating benefit of exoskeleton over comparator therapies, and some indicating benefit of comparator therapies over exoskeleton. Conclusion There is no data to compare locomotion assistance with exoskeleton versus conventional KAFOs. There is no consistent benefit from rehabilitation using an exoskeleton versus a variety of conventional methods in patients with chronic spinal cord injury. Trials comparing later-generation exoskeletons are needed.

Exoskeletal Neuro-Rehabilitation in Chronic Paraplegic Patients – Initial Results

Treadmill training after traumatic spinal cord injury is established as a therapy to improve walking capabilities in incomplete injured patients. In this study we investigate walking capabilities after a three month period of HAL® exoskeleton supported treadmill training in patients with chronic (>6 month) complete/incomplete (ASIA A – ASIA C) spinal cord injury. We monitored walking distance, walking speed and walking time with additional analysis of functional improvement by using the 10-m-walk test, the timed-up-and-go test and the WISCI II score in combination with the ASIA classification.

Against the odds: what to expect in rehabilitation of chronic spinal cord injury with a neurologically controlled Hybrid Assistive Limb exoskeleton. A subgroup analysis of 55 patients according to age and lesion level

Objective Age and lesion level are believed to represent outcome predictors in rehabilitation of patients with chronic spinal cord injury (SCI). The Hybrid Assistive Limb (HAL) exoskeleton enables patients to perform a voluntary controlled gait pattern via an electromyography-triggered neuromuscular feedback system, and has been introduced as a temporary gait training tool in patients with SCI. The aim of this prospective pre- and postintervention study was to examine functional outcomes as a function of age and lesion level in patients with chronic incomplete SCI (iSCI) or chronic complete SCI (cSCI) with zones of partial preservation (ZPP) by using the HAL as a temporary training tool. Methods Fifty-five participants with chronic iSCI or cSCI (mean time since injury 6.85 ± 5.12 years) were classified according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS) and divided by age (< 50 or ≥ 50 years), independent of lesion level, and also into 4 homogeneous groups according to lesion level. The subgroups were as follows: Subgroup 1, tetraplegic iSCI (n = 13) (C2-8, AIS C [n = 8] and AIS D [n = 5]); Subgroup 2, paraplegic iSCI with spastic motor behavior (n = 15) (T2-12, AIS C [n = 8] and AIS D [n = 7]); Subgroup 3, paraplegic cSCI with complete motor paraplegia and absence of spastic motor behavior (n = 18) (T11-L4 [AIS A], and ZPP from L-3 to S-1); and Subgroup 4, paraplegic iSCI with absence of spastic motor behavior (n = 9) (T12-L3, AIS C [n = 8] and AIS D [n = 1]). The training paradigm consisted of 12 weeks of HAL-assisted treadmill training (5 times/week). Baseline status was documented prior to intervention by using the AIS grade, Walking Index for SCI II (WISCI II) score, the 10-meter walk test (10MWT), and the 6-minute walk test (6MinWT). Training effects were assessed after 6 and 12 weeks of therapy, without HAL assistance. Results Overall, a time reduction of 47% in the 10MWT, self-selected speed (10MWTsss) (< 50 years = 56% vs ≥ 50 years = 37%) and an increase of 50% in the 6MinWT were documented. The WISCI II scores showed a mean gain of 1.69 levels. At the end of the study, 24 of 55 patients (43.6%) were less dependent on walking aids. Age had a nonsignificant negative influence on the 10MWTsss. Despite a few nonsignificant subgroup differences, participants improved across all tests. Namely, patients with iSCI who had spastic motor behavior improved to a nonsignificant, lesser extent in the 6MinWT. Conclusions The HAL-assisted treadmill training leads to functional improvements in chronic iSCI or cSCI, both in and out of the exoskeleton. An improvement of approximately 50% in the 10MWTsss and in gait endurance (6MinWT) can be expected from such training. The influences of SCI lesion level and age on functional outcome were nonsignificant in the present study. Older age (≥ 50 years) may be associated with smaller improvements in the 10MWTsss. An iSCI in paraplegic patients with spastic motor behavior may be a nonsignificant negative predictor in gait endurance improvements. Clinical trial registration no.: DRKS00010250 ( https://drks-neu.uniklinik-freiburg.de/drks_web/setLocale_DE.do ).

Neurorehabilitation in Chronic Paraplegic Patients with the HAL ® Exoskeleton – Preliminary Electrophysiological and fMRI Data of a Pilot Study

Training leads to increased neuronal excitability, decreased inhibition and different types of neuronal plasticity. Most studies focus on cortical plastic changes after cerebral lesions or in healthy humans. In this study, we investigate cortical excitability and plastic changes after a three month period of HAL® exoskeleton supported treadmill training in patients with chronic incomplete spinal cord injury by means of electrophysiological measurements and functional magnetic resonance imaging. Here we report preliminary results of four patients.

Exoskeletons for rehabilitation of patients with spinal cord injuries. Options and limitations

BACKGROUND Mobile exoskeletons are increasingly being applied in the course of rehabilitation and provision of medical aids to patients with spinal cord injuries. OBJECTIVES AND METHODS This article gives a description of the currently available exoskeletal systems and the clinical application including scientific and medical evidence, to derive recommendations regarding clinical practice of the various exoskeletons in the rehabilitation of patients with spinal cord injuries. RESULTS The different systems represent a useful adjunct to the therapeutic regimen depending on the medical objectives. Posture-controlled exoskeletons in particular enable mobilization of patients with neurological gait disorders via direct motion support. In addition the neurologically controlled exoskeleton HAL® leads to functional improvements in patients with residual muscular functions in the chronic phase of spinal cord injury in terms of improved walking abilities subsequent to training. However, beneficial effects on bone density, bladder function and perfusion are conceivable but not yet adequately supported by evidence. Positive effects on spasticity and neuropathic pain are currently based only on case series or small clinical trials. CONCLUSION Although exoskeletons are not yet an established tool in the treatment of spinal cord injuries, the systems will play a more important role in rehabilitation of patients with spinal cord injuries in the future. Neurologically controlled exoskeletons show beneficial effects in the treatment of acute and chronic spinal cord injuries and might therefore evolve to be a useful alternative to conventional locomotion training.ZusammenfassungHintergrundIm Rahmen des Lokomotiontrainings bei der Behandlung querschnittgelähmter Patienten kommen zunehmend mobile Exoskelette in der Rehabilitation und Hilfsmittelversorgung zum Einsatz.Fragestellung und MethodikDie derzeit auf dem Markt verfügbaren exoskelettalen Systeme werden beschrieben, ihre Möglichkeiten in der klinischen Anwendung und die dafür zurzeit vorhandene Evidenz dargestellt. Daraus werden Empfehlungen zur klinischen Anwendung der verschiedenen Exoskelette in der Rehabilitation querschnittgelähmter Patienten abgeleitet.ErgebnisseDie Anwendbarkeit unterschiedlicher Exoskelette als Therapiegerät ist mit jeweils unterschiedlicher Zielsetzung möglich. Elektromechanisch kontrollierte Exoskelette zeigen ihre Einsetzbarkeit insbesondere in der Mobilisation bei neurogenen Gangstörungen durch direkte Gangunterstützung. Der Einsatz des neuronal gesteuerten HAL®-Exoskeletts verspricht zusätzlich funktionelle Verbesserungen auch in der chronischen Phase einer Querschnittlähmung bei Patienten mit motorischen Restfunktionen, wenn sie nach dem Training ohne Exoskelett gehen. Ergebnisse, die positive Einflüsse auf Knochendichte, Blasen-Mastdarm-Funktion und Durchblutung zeigen, sind denkbar, aber noch nicht hinreichend belegt. Effekte hinsichtlich Spastikreduktion und Linderung neuropathischer Schmerzen sind bisher lediglich in Fallserien oder im Rahmen kleiner Studien berichtet worden.SchlussfolgerungExoskelette werden zunehmend bei querschnittgelähmten Patienten als „High-tech-Hilfsmittel“ zum Einsatz kommen, sind aber zurzeit im routinemäßigen Einsatz nicht etabliert. Neurologisch-kontrollierte Exoskelette versprechen einen positiven Einfluss auf die Behandlung akuter und chronischer Querschnittlähmungen und können damit eine zukünftige Alternative zum etablierten Lokomotiontraining darstellen.AbstractBackgroundMobile exoskeletons are increasingly being applied in the course of rehabilitation and provision of medical aids to patients with spinal cord injuries.Objectives and methodsThis article gives a description of the currently available exoskeletal systems and the clinical application including scientific and medical evidence, to derive recommendations regarding clinical practice of the various exoskeletons in the rehabilitation of patients with spinal cord injuries.ResultsThe different systems represent a useful adjunct to the therapeutic regimen depending on the medical objectives. Posture-controlled exoskeletons in particular enable mobilization of patients with neurological gait disorders via direct motion support. In addition the neurologically controlled exoskeleton HAL® leads to functional improvements in patients with residual muscular functions in the chronic phase of spinal cord injury in terms of improved walking abilities subsequent to training. However, beneficial effects on bone density, bladder function and perfusion are conceivable but not yet adequately supported by evidence. Positive effects on spasticity and neuropathic pain are currently based only on case series or small clinical trials.ConclusionAlthough exoskeletons are not yet an established tool in the treatment of spinal cord injuries, the systems will play a more important role in rehabilitation of patients with spinal cord injuries in the future. Neurologically controlled exoskeletons show beneficial effects in the treatment of acute and chronic spinal cord injuries and might therefore evolve to be a useful alternative to conventional locomotion training.

The primary stability of pelvic reconstruction after partial supraacetabular pelvic resection due to malignant tumours of the human pelvis: A biomechanical in vitro study

BACKGROUND Up until now, reconstructions after partial supraacetabular pelvic resection have been done with the use of megaprostheses or allo-/autografs, including screws. The literature states complications in up to 100%. Therefore, the university hospital of Muenster has successfully established a reconstruction using poly-axial screws and titanium rods in combination with a Palacos(®) shroud. The aim of this study was to gather data on primary stability of five different types of reconstruction. METHODS Using a biomechanical model Load (N), displacement (mm) and stiffness (N/mm) were recorded in load cycles from 100N up to 1050N. FINDINGS The data shows that reconstructions with poly-axial screws, titanium rods and Palacos(®) can bear a load of up to 1050N without structural damages. The same is valid with an additional bone graft and for a full metal prosthesis. Referring to reconstructions with just bone graft or without graft and Palacos(®) the load-bearing capacity is significantly worse. Additionally, structural damages were recorded in those reconstructions from 700N onwards. INTERPRETATION Due to the biomechanical results and the save and easy handling, reconstructions with poly-axial screws, titanium rods and Palacos(®) (and, if necessary, bone graft) can be recommended achieving high primary stability for pelvic ring reconstruction after partial supraacetabular pelvic resection.

Exoskelette in der Rehabilitation Querschnittgelähmter

BACKGROUND Mobile exoskeletons are increasingly being applied in the course of rehabilitation and provision of medical aids to patients with spinal cord injuries. OBJECTIVES AND METHODS This article gives a description of the currently available exoskeletal systems and the clinical application including scientific and medical evidence, to derive recommendations regarding clinical practice of the various exoskeletons in the rehabilitation of patients with spinal cord injuries. RESULTS The different systems represent a useful adjunct to the therapeutic regimen depending on the medical objectives. Posture-controlled exoskeletons in particular enable mobilization of patients with neurological gait disorders via direct motion support. In addition the neurologically controlled exoskeleton HAL® leads to functional improvements in patients with residual muscular functions in the chronic phase of spinal cord injury in terms of improved walking abilities subsequent to training. However, beneficial effects on bone density, bladder function and perfusion are conceivable but not yet adequately supported by evidence. Positive effects on spasticity and neuropathic pain are currently based only on case series or small clinical trials. CONCLUSION Although exoskeletons are not yet an established tool in the treatment of spinal cord injuries, the systems will play a more important role in rehabilitation of patients with spinal cord injuries in the future. Neurologically controlled exoskeletons show beneficial effects in the treatment of acute and chronic spinal cord injuries and might therefore evolve to be a useful alternative to conventional locomotion training.ZusammenfassungHintergrundIm Rahmen des Lokomotiontrainings bei der Behandlung querschnittgelähmter Patienten kommen zunehmend mobile Exoskelette in der Rehabilitation und Hilfsmittelversorgung zum Einsatz.Fragestellung und MethodikDie derzeit auf dem Markt verfügbaren exoskelettalen Systeme werden beschrieben, ihre Möglichkeiten in der klinischen Anwendung und die dafür zurzeit vorhandene Evidenz dargestellt. Daraus werden Empfehlungen zur klinischen Anwendung der verschiedenen Exoskelette in der Rehabilitation querschnittgelähmter Patienten abgeleitet.ErgebnisseDie Anwendbarkeit unterschiedlicher Exoskelette als Therapiegerät ist mit jeweils unterschiedlicher Zielsetzung möglich. Elektromechanisch kontrollierte Exoskelette zeigen ihre Einsetzbarkeit insbesondere in der Mobilisation bei neurogenen Gangstörungen durch direkte Gangunterstützung. Der Einsatz des neuronal gesteuerten HAL®-Exoskeletts verspricht zusätzlich funktionelle Verbesserungen auch in der chronischen Phase einer Querschnittlähmung bei Patienten mit motorischen Restfunktionen, wenn sie nach dem Training ohne Exoskelett gehen. Ergebnisse, die positive Einflüsse auf Knochendichte, Blasen-Mastdarm-Funktion und Durchblutung zeigen, sind denkbar, aber noch nicht hinreichend belegt. Effekte hinsichtlich Spastikreduktion und Linderung neuropathischer Schmerzen sind bisher lediglich in Fallserien oder im Rahmen kleiner Studien berichtet worden.SchlussfolgerungExoskelette werden zunehmend bei querschnittgelähmten Patienten als „High-tech-Hilfsmittel“ zum Einsatz kommen, sind aber zurzeit im routinemäßigen Einsatz nicht etabliert. Neurologisch-kontrollierte Exoskelette versprechen einen positiven Einfluss auf die Behandlung akuter und chronischer Querschnittlähmungen und können damit eine zukünftige Alternative zum etablierten Lokomotiontraining darstellen.AbstractBackgroundMobile exoskeletons are increasingly being applied in the course of rehabilitation and provision of medical aids to patients with spinal cord injuries.Objectives and methodsThis article gives a description of the currently available exoskeletal systems and the clinical application including scientific and medical evidence, to derive recommendations regarding clinical practice of the various exoskeletons in the rehabilitation of patients with spinal cord injuries.ResultsThe different systems represent a useful adjunct to the therapeutic regimen depending on the medical objectives. Posture-controlled exoskeletons in particular enable mobilization of patients with neurological gait disorders via direct motion support. In addition the neurologically controlled exoskeleton HAL® leads to functional improvements in patients with residual muscular functions in the chronic phase of spinal cord injury in terms of improved walking abilities subsequent to training. However, beneficial effects on bone density, bladder function and perfusion are conceivable but not yet adequately supported by evidence. Positive effects on spasticity and neuropathic pain are currently based only on case series or small clinical trials.ConclusionAlthough exoskeletons are not yet an established tool in the treatment of spinal cord injuries, the systems will play a more important role in rehabilitation of patients with spinal cord injuries in the future. Neurologically controlled exoskeletons show beneficial effects in the treatment of acute and chronic spinal cord injuries and might therefore evolve to be a useful alternative to conventional locomotion training.

Treadmill Training with HAL Exoskeleton—A Novel Approach for Symptomatic Therapy in Patients with Limb-Girdle Muscular Dystrophy—Preliminary Study

Purpose: Exoskeletons have been developed for rehabilitation of patients with walking impairment due to neurological disorders. Recent studies have shown that the voluntary-driven exoskeleton HAL® (hybrid assistive limb) can improve walking functions in spinal cord injury and stroke. The aim of this study was to assess safety and effects on walking function of HAL® supported treadmill therapy in patients with limb-girdle muscular dystrophy (LGMD). Materials and Methods: Three LGMD patients received 8 weeks of treadmill training with HAL® 3 times a week. Outcome parameters were 10-meter walk test (10 MWT), 6-minute walk test, and timed-up-and-go test (TUG). Parameters were assessed pre and post training and 6 weeks later (follow-up). Results: All patients completed the therapy without adverse reactions and reported about improvement in endurance. Improvements in outcome parameters after 8 weeks could be demonstrated. Persisting effects were observed after 6 weeks for the 10 MWT and TUG test (follow-up). Conclusions: HAL® treadmill training in LGMD patients can be performed safely and enables an intensive highly repetitive locomotor training. All patients benefitted from this innovative method. Upcoming controlled studies with larger cohorts should prove its effects in different types of LGMD and other myopathies.