[Risk factors for the development of rotator cuff tears in individuals with paraplegia : A cross-sectional study]. / Risikofaktoren für Rotatorenmanschettenrupturen bei Paraplegikern : Eine Querschnittstudie.

QUESTION: Shoulder pain and rotator cuff tears are highly prevalent among wheelchair dependent individuals with paraplegia. The purpose of this study was to identify potential risk factors associated with the development of rotator cuff tears in this population. METHODS: A total of 217 wheelchair dependent individuals with paraplegia were included in this cross-sectional study (level of evidence III). The mean age of this population was 47.9 years and the mean duration of wheelchair dependence was 24.1 years. Each individual was asked to complete a questionnaire designed to identify risk factors for rotator cuff tears and underwent a standardized clinical examination with the documentation of the Constant-Murley shoulder outcome score and magnetic resonance imaging (MRI) of both shoulder joints. RESULTS: MRI analysis revealed at least one rotator cuff tear in 93 patients (43%). Multiple logistic regression analysis identified the following factors to be associated with the presence of rotator cuff tear: patient age, duration of spinal cord injury/wheelchair dependence, gender, and wheelchair athletic activity. Neither BMI nor the level of spinal cord injury was found to pose a risk factor in the population studied. With respect to patient age, the risk of developing a rotator cuff tear increased by 11% per annum. In terms of duration of spinal cord injury, the analysis revealed a 6% increased risk per year of wheelchair dependence (OR = 1.06). Females had a 2.6-fold higher risk of developing rotator cuff tears than males and wheelchair sport activity increased the risk 2.3-fold. DISCUSSION: There is a high prevalence of rotator cuff tears in wheel-chair dependent persons with paraplegia. Risk factors such as age, gender, duration of paraplegia, and wheel chair sport activity seem to play an important role in the development of rotator cuff tears.

Exploratory study to suggest the possibility of MMP-8 and MMP-9 serum levels as early markers for remission after traumatic spinal cord injury.

STUDY DESIGN: A prospective observational study reporting the correlation between matrix metalloprotein serum levels and remission after traumatic spinal cord injury (SCI). OBJECTIVES: To investigate serum cytokine levels as predictive markers. SETTING: Germany, Rhineland-Palatinate (Rheinland-Pfalz). METHODS: Between 2010 and 2015, data sets from 115 patients (33 female, 82 male) after traumatic SCI were recorded at the BG Trauma Centre Ludwigshafen. We examined the serum levels of Matix metallopraoteinases (MMPs) MMP-2, MMP-8, MMP-9, MMP-10 and MMP-12 over a 12-week period, that is, at admission and 4, 9, 12 h, 1 and 3 days and 1, 2, 4, 8 and 12 weeks after trauma. Following the same match-pair procedure as in our previous studies, we selected 10 patients with SCI and neurological remission (Group 1) and 10 patients with an initial American Spinal Injury Association (ASIA) A grade and no neurological remission (Group 0). Ten patients with an isolated vertebral fracture without neurological deficits served as a control group (Group C). Our analysis was performed using a Luminex Performance Human High Sensitivity Cytokine Panel. Multivariate logistic regression models were used to examine the predictive value of MMPs with respect to neurological remission vs no neurological remission. RESULTS: MMP-8 and MMP-9 provided significantly different values. The favoured predictive model allows to differentiate between neurological remission and no neurological remission in 97% of cases. CONCLUSIONS: The results indicate that further studies with an enlarged collective are warranted in order to investigate current monitoring, prognostic and tracking techniques as well as scoring systems.

sCD95L in serum after spinal cord injury.

STUDY DESIGN: A prospective observational study reporting correlation between sCD95L (serum cluster of differentiation 95 ligand) serum levels and remission after traumatic spinal cord injury (SCI). OBJECTIVES: To describe the correlation between sCD95L serum levels and remission after traumatic SCI in a human protocol compared with animal studies. SETTING: Rhineland-Palatinate (Rheinland-Pfalz), Germany. METHODS: We included 45 patients with traumatic SCI. According to their neurological outcome, patients were divided into two groups, patients with (G1, n=26) and without (G2, n=19) remission. Blood was collected on post-admission and according to a fixed scheme, that is, after 4, 9, 12 h, 1, 3 days and 1, 2, 4, 8, 12 weeks. RESULTS: By comparing G1 with G2, we found a correlation between neurological remission and sCD95L serum concentrations. Consistently elevated levels of sCD95L in G1 between 9 h and 1 month after injury show significantly differing values 7 days after injury. This indicates a correlation between patients with clinically documented neurological remission and elevated sCD95L serum concentrations. CONCLUSIONS: In opposite to animal studies, our patients with neurological remission show on average higher levels of sCD95L compared with patients without. Therefore, spinal cord-injured patients would probably not profit from neutralizing CD95L. Our results present that the transfer of findings from animal studies to humans must always be considered critically. We were able to show that peripheral serum cytokine expression is suitable to state processes after SCI in humans.

Preoperative scoring and limits of prognostication: functional outcome after surgical decompression in metastatic spinal cord compression.

OBJECTIVE: To determine whether preoperative parameters correlate with the postoperative functional outcome in para- and tetraplegic patients with lung, kidney, breast and prostate cancer and metastatic spinal cord compression (MSCC). METHODS: Information on 43 patients undergoing decompressive surgery and rehabilitation for MSCC was reviewed, including primary tumor, age, pre- and postoperative ambulation status, mobility subcategory of the Spinal Cord Injury Measure (mSCIM) and the Tokuhashi score. Differences between groups were analyzed by the nonparametric χ(2) test, and correlation coefficients (Spearman's rho) were computed. RESULTS: Preoperative ambulation (p < 0.001), the American Spinal Injury Association Impairment Scale (p < 0.001) and the type of operation (p = 0.02) influenced the postoperative functional outcome. Any positive change in the mSCIM was influenced by preoperative ambulation (p < 0.001). Patients with breast carcinoma showed significantly more positive changes in the mSCIM compared with other tumors (p = 0.002). No correlation was found between the treatment categories of the Tokuhashi score and the preoperative ambulatory status (p = 0.13) or the change in ambulation status (p = 0.29). CONCLUSION: The postoperative functional outcome of MSCC patients shows a linear association between the categories of the Tokuhashi score and the change in ambulation status. We recommend surgical decompression even in a palliative situation (Tokuhashi score 0-8) with the aim of optimizing the short-term rehabilitation outcome.

A retrospective study on flap complications after pressure ulcer surgery in spinal cord-injured patients.

STUDY DESIGN: A retrospective study reporting specific complications of certain skin flaps for treating pressure ulcers. OBJECTIVES: To describe the rate and type of complications after pressure ulcer surgery in patients with spinal cord injury. SETTING: Germany, Rheinland Pfalz. METHODS: We collected data from 352 patients treated with 421 skin flaps to determine the rate and type of complications of each skin flap used. RESULTS: In this study, we analyzed the results of 421 skin flaps in 352 patients with a total of 657 pressure ulcers from January 2006 to December 2010. Our patients had ischial, pelvic, sacral, trochanteric and lower extremity ulcers. Ischial ulcers were most common, followed by sacral and trochanteric ulcers. There were 87 complications in 421 flaps, which was an overall rate of 21%. Suture line dehiscence was the most common complication with 27 cases (31%), followed by 22 cases of infection (25.2%), 17 cases of hematoma (19.5%), 12 cases of partial necrosis (13.7%) and 9 cases of total flap necrosis (10.3%). CONCLUSION: Pressure ulcers in spinal cord-injured patients are very common and difficult and expensive to treat. The high rate of complications and the associated costs suggest the importance of evaluating the efficacy of treatment options. Conservative procedures have been standardized, but there still has been limited success in establishing guidelines on how to manage complications arising from flap surgery. Our extensive documentation of flap plastics will be useful managing complications after the surgical treatment of pressure ulcers in spinal cord-injured patients.

Increase in soluble CD95L during subacute phases after human spinal cord injury: a potential therapeutic target.

STUDY DESIGN: A pilot study measuring the levels of serum-soluble CD95 ligand (CD95L) in eight spinal cord-injured patients. OBJECTIVES: To determine the soluble concentration of CD95L in spinal cord injury (SCI) patients after trauma. METHODS: We collected blood samples from eight patients with acute traumatic SCI. Soluble CD95L serum levels were determined using an enzyme-linked immunosorbent assay. American Spinal Injury Association (ASIA) was determined according to ASIA classification. The patients were monitored, and venous blood was drawn after arrival at the hospital on the 1st and 3rd day and during the 1st, 2nd, 4th, 8th and 12th weeks after trauma. RESULTS: The average patient age was 48.1 years (18-86 years). Three patients were paraplegic (two incomplete, one complete), five were quadriplegic (one complete, four incomplete). The serum concentration of soluble CD95L (sCD95L) decreased during the 1st week (41 ng(- l)) and increased after the 2nd week in all eight patients. It peaked during the 4th week (68.5 ng (- l)) and reached a plateau during the 12th week (76.2 ng (- l)). There are many possible explanations for not being able to detect a statistical significance, one of course being the small sample size. CONCLUSION: Promising results for anti-CD95L therapy have already been documented in lab studies with rodents. Anti-CD95L blocks the pro-apoptotic and proinflammatory activity of membrane-bound CD95L during the acute phase of SCI. We observed that sCD95L levels are elevated during the subacute and intermediate phases of SCI. It would be of great interest to study a larger group of patients to determine whether higher sCD95 levels are correlated with improved or impaired neurological outcome or with increasing levels of autoimmune components in peripheral blood.

Use of Medihoney as a non-surgical therapy for chronic pressure ulcers in patients with spinal cord injury.

STUDY DESIGN: Prospective, observational study of 20 spinal cord-injured (SCI) patients with chronic pressure ulcers (PUs) using Medihoney. OBJECTIVES: To determine the effects of Medihoney by bacterial growth, wound size and stage of healing in PUs. METHODS: We treated 20 SCI adult patients with chronic PUs using Medihoney. In all, 7 patients (35%) were female, and 13 (65%) were male. The average patient age was 48.7 years (30-79). In all, 6 patients (30%) were tetraplegic and 14 (70%) were paraplegic. Also, 5 patients (25%) had grade IV ulcers and 15 patients (75%) had grade III ulcers according to the National Pressure Ulcer Advisory Panel. RESULTS: After 1 week of treatment with Medihoney, all swabs were void of bacterial growth. Overall 18 patients (90%) showed complete wound healing after a period of 4 weeks, and the resulting scars were soft and elastic. No negative effects were noted from the treatment using Medihoney. No blood sugar level derailment was documented. CONCLUSION: The medical-honey approach to wound care must be part of a comprehensive conservative surgical wound-care concept. Our study indicates the highly valuable efficacy of honey in wound management and infection control as measured by bacterial growth, wound size and healing stage.

The effect of polytrauma as a possible confounder in the outcome of monotraumatic vs polytraumatic paraplegic patients: a clinical cohort study.

STUDY DESIGN: Clinical cohort study. OBJECTIVE: To evaluate if the impact of the severity of the trauma as a possible confounding factor influences the neurological and functional recovery in paraplegia during the course of a 6-month follow-up period after injury. SETTING: Spinal Cord Injury Center, Heidelberg University Hospital, Germany. METHODS: A retrospective monocentric analysis, from 2002 to 2008, of the Heidelberg European Multicenter Study about spinal cord injury database was performed. We included 31 paraplegic patients (neurological level T1-T12) who were assigned either to a monotrauma (polytraumaschluessel (PTS) 1) or to a polytrauma (PTS≥2) group. The American Spinal Injury Association Impairment Scale, lower extremity motor score, pin prick, light touch and the spinal cord independence measure (SCIM) were obtained at five distinct time points after trauma. Data were analyzed using Mann-Whitney U-test (α<0.05). RESULTS: The changes in lower extremity motor score, pin prick and light touch showed no significant differences in both groups over the whole evaluation period. Polytraumatic paraplegics showed a significantly delayed increase of SCIM between 2 and 6 weeks compared with monotraumatic patients, followed by a quantitative increase in the subitems bladder management, bowel management, use of toilet and prevention of pressure sores between 3 and 6 months (P=0.031). The mean length of primary rehabilitation in the polytrauma group was 5.5 vs 3.6 months in monotrauma. CONCLUSIONS: The prognosis of polytraumatic paraplegics in terms of neurological recovery is not inferior to those with monotrauma. Multiple-injured patients need a prolonged hospital stay to reach the functional outcome of monotraumatic patients.

Clinical presentation of spondylodiscitis as a long-term complication in incomplete paraplegia: a report of three cases.

STUDY DESIGN: Case report. OBJECTIVE: Complications in spinal cord injury (SCI) are a challenging problem for the patients and often difficult to manage. Three cases of spondylodiscitis, localized at the lumbosacral junction in long-term paraplegic patients are presented. SETTING: Spinal Cord Injury Center, Orthopaedic University Hospital Heidelberg, Heidelberg, Germany. CLINICAL PRESENTATION: In all three cases, neurological deterioration (ASIA A) was caused by a secondary compression of the spinal cord at the lumbosacral spine. Increase of spasticity and pain, atonic bladder and sphincter function accompanied by vegetative symptoms were present in all patients. Microbiological analysis of the sacral area showed coagulase negative staphylococcus in two cases, whereas in one case no microorganism was found. The diagnosis was made by MRI of the whole spine and surgical treatment was required. At follow-up (6 months), patients showed no AIS (ASIA Impairment Scale) changes. CONCLUSION: If neurological deterioration occurs, spondylodiscitis should be ruled out in paraplegic individuals. The therapeutic goal is to achieve emergent decompression of the spinal cord and to administrate adequate antibiotic therapy to avoid a neurologically complete situation.

Progressive spastic paraplegia: the combination of Scheuermann's disease, a short-segmented kyphosis and dysplastic thoracic spinous processes.

STUDY DESIGN: Case report. OBJECTIVE: To describe a rare case of paraplegia in a patient with Scheuermann's disease and dysplastic thoracic spinous processes. SETTING: Spinal Cord Injury Center, Orthopaedic University Hospital Heidelberg, Heidelberg, Germany. CLINICAL PRESENTATION: The authors report on a 15-year-old boy with progressive incomplete spastic paraplegia presenting segmental dysplastic thoracic spinous processes and Scheuermann's disease. The magnetic resonance imaging showed a kyphotic angulation at T 5/6 and signs of myelopathy. Hypoplastic thoracic processes and hypoplastic paraspinal muscles in the upper thoracic spine were observed intraoperatively. In this case, dorsoventral stabilization from T 4-7 was performed and the neurological outcome improved at follow-up (6 months). CONCLUSION: Paraplegia can be accelerated in patients with Scheuermann's disease, severe kyphotic angulation and dysplastic posterior elements. After operative treatment, neurological recovery and a normal walking pattern were shown.

Neuroprosthetics of the upper extremity--clinical application in spinal cord injury and challenges for the future.

The complete restoration of movements lost due to a spinal cord injury (SCI) is the greatest hope of physicians, therapists and certainly of the patients themselves. Particularly, in patients with lesions of the cervical spinal cord every little improvement of missing or weak grasp function will result in a large gain in quality of life. Despite the fact that novel drugs for axonal regeneration in the spinal cord are in the phase of imminent human application, up to now, the only possibility of restoration of basic movements in SCI persons consists in the use of functional electrical stimulation (FES). While FES systems in the lower extremities for standing or walking have not reached widespread clinical acceptance yet, devices are available for demonstrable improvement of the grasp function. This applies to tetraplegic patients with stable, active shoulder function, but missing control of hand and fingers. Particularly, with the use of implantable systems a long-term stable, user-friendly application is possible. Most recent work aims at the development of minimally invasive, subminiature systems for individual functional support. The possibility of direct brain control of FES systems will extend the application of grasp neuroprostheses to patients with injuries of the highest cervical spinal cord.

Neurogenic bladder dysfunction in patients with neoplastic spinal cord compression: adaptation of the bladder management strategy to the underlying disease.

OBJECTIVES: To study the outcome of different bladder management strategies in patients with neoplastic spinal cord compression. METHODS: 22 patients with neoplastic spinal cord compression underwent urodynamic examination. According to the urodynamic data and the underlying disease different bladder management strategies were recommended. In patients with curatively treated disease a full bladder rehabilitation program was arranged. In patients with metastatic malignant disease, voluntary voiding was continued if possible or a suprapubic catheter was placed. RESULTS: Eight patients were treated with curative intention. Of those, 2 patients were able to void during urodynamics continued normal voluntary voiding. Six patients were taught intermittent catheterisation, with three additionally received oral anticholinergic treatment because of UMN lesion. At follow-up, all patients had successfully finished bladder rehabilitation program and at follow up, all patients were continuing their previously recommended bladder rehabilitation program. Fourteen patients had malignant disease and were treated palliatively. In 2 patients with UMN lesion, voluntary control of micturition was maintained and both continued voluntary voiding. In 12 patients a suprapubic catheter was inserted. At follow-up, 9 out of 14 had died (mean 8 month after primary visit), the remaining 5 continued treatment with suprapubic catheters. CONCLUSION: Underlying disease and life expectancy should be considered for the selection of bladder management in patients with neoplastic spinal cord compression. In patients with curatively treated disease, a full bladder rehabilitation program is recommended while in patients with malignant disease and palliative care, a suprapubic catheter might be the treatment of choice.

Event-related beta EEG changes during wrist movements induced by functional electrical stimulation of forearm muscles in man.

Event-related beta electroencephalographic (EEG) changes were studied during wrist movements induced by functional electrical stimulation (FES) of the appropriate forearm muscles in healthy volunteers. Active and passive hand movements were investigated as control conditions. Significant EEG changes with respect to a pre-movement period were analyzed by calculating time-frequency maps of event-related (de-)synchronization (ERD/ERS) for 32 EEG channels recorded from sensorimotor and premotor areas. Immediately after the beginning of the FES movement, a prominent ERD was found, followed by a beta ERS similar to that observed after active or passive wrist movements. Both changes were maximal over the contralateral primary hand area. The main difference between active and stimulation-induced movements was that in the latter case no ERD was detectable prior to movement-onset. These findings suggest that the sensorimotor processing during FES involves some of the processes which are also involved in voluntary hand movements.

Tissue and serum concentrations of levofloxacin in orthopaedic patients.

The level of levofloxacin was determined in serum, bone and several tissues after a single dose of 500 mg i.v. Twenty-one patients (mean age: 56.8 years) undergoing bone surgery (nine patients) or surgical debridement of a decubitus ulcer (12 patients) who received levofloxacin as perioperative prophylaxis were included in the study. During surgery, blood and tissue samples were obtained approximately 1.5 h (range 40-210 min) postdosing. Levofloxacin concentrations in 87 specimens including 21 serum samples were determined using high-performance liquid chromatography (HPLC). The mean serum concentration at 1.5 h was 8.6+/-2.3 microg/ml. Concentrations above the MIC of common pathogens were reached in all tissues during the collection period with a maximum in skin samples (19.9+/-9.9 microg/g) followed by wound tissue and granulation tissue with 17.3+/-6.5 and 13.7+/-6.4 microg/g respectively. In muscle and fatty tissue mean levofloxacin concentrations of 8.0+/-0.9 and 4.0+/-2.2 microg/g were attained. Mean levels in cancellous bone were 6.6+/-3.6 microg/g, lowest levels were measured in cortical bone (2.8+/-1.1 microg/g). Twenty-two different pathogens were cultivated from the lesions of 11 of 12 patients with pressure ulcers. MIC values for levofloxacin were determined and compared with the corresponding tissue concentrations. Levofloxacin may be useful for perioperative prophylaxis and treatment in orthopaedic patients due to its good tissue penetration.

[Measurement of CSF flow in the spinal canal using MRI with an optimized MRI protocol: experimental and clinical studies]. / MR-tomographische Liquorflussmessungen am Spinalkanal mit einem optimierten MRT-Protokoll: Experimentelle und klinische Untersuchungen.

PURPOSE: Measurement of the oscillating CSF flow in the spinal canal (SC) of healthy volunteers and in patients with post-traumatic syringomyelia (PTS) using an optimized MRI protocol as well as to determine whether stenosis induced velocity changes are detectable using MRI. METHODS: In 68 healthy volunteers quantitative studies of CSF flow in the cervical, thoracic, and lumbar regions were performed. First, an optimized sequence was developed and tested in 19 volunteers using four different flow-encoding velocities (4, 8, 12, 16 cm/s). Secondly, the optimized sequence was employed in 49 volunteers to measure the different CSF patterns in the cervical, thoracic, and lumbar spinal canals (CSC, TSC, LSC). Part three of the study, in which patients with PTS are being examined is still underway. We measured the maximum velocity (cm/s), the pixel area (mm2), and the stroke volume (ml/s). Using a flow model the velocities prior to and after compression with 5 different power levels were measured at the stenosis and at a distance of 70 cm. RESULTS: A total of 226 dynamic measurements have been performed--so far 76 in the first part (62 = 81.5% evaluable) and 150 in the second part--using the optimized sequence and optimal flow velocities. A flow-encoding sequence of 12 cm/s was found best in the CSC and one of 6 cm/s in the TSC and LSC. The maximum velocity in the CSC was 0.95 cm/s with the flow being directed caudal and 0.38 cm/s with the flow being directed cranial. In the TSC the values were 4.7 cm/s and 1.65 cm/s and in the LSC 0.96 cm/s and 0.59 cm/s. The highest velocities were found at the TSC, which has the smallest diameter compared to the CSC and LSC. In the 4 patients with PTS, the maximum velocities were between 0.09 cm/s and 0.97 cm/s with the flow being directed cranial and between 0.04 cm/s and 1.03 cm/s with the flow being directed caudal. The stroke volumina in the CSC were between 0.1 and 1.23 ml/s (mean: 0.48 ml/s) and 0.2 and 2.45 ml/s (mean: 0.66 ml/s) in the TSC and in the LSC 0.08 ml/s and 0.67 ml/s (mean: 0.29 ml/s). The results of the flow model studies showed an increase of velocity between 2.06 and 4.94 cm/s (mean: 3.31 cm/s) at the stenosis and 1.1 and 1.33 cm/s (mean: 1.23 cm/s) at a distance of 70 cm. CONCLUSION: Quantitative measurement of the oscillating CSF flow in the entire spinal canal (SC) is possible using an optimized MRI protocol as well as to detect stenosis induced velocity changes. Due to the high interindividual variability in the data of spinal CSF dynamics, further studies are necessary to collect normal data. The detection of movement of CSF in a post-traumatic spinal cord lesion may alter the therapeutic management.

[Urodynamic findings in patients with infantile cerebral palsy]. / Videourodynamische Erstbefunde bei infantiler Zerebralparese.

OBJECTIVE: Aim of study was to evaluate the urodynamic findings in patients with infantile cerebral palsy. MATERIAL AND METHODS: In 29 patients (aged 3-53), a videourodynamic investigation was performed after evaluation of urological anamnesis, clinical assessment and sonographic determination of residual urine. The patients were divided into group 1 (23 symptomatic patients aged 5 years and older with recurrent urinary tract infection, pollakiuria or urinary incontinence) and group 2 (6 asymptomatic patients). RESULTS: In group 1, 21/23 patients (91%) had reduced compliance (0.6 - 16.4 ml/cmH(2)O) and 16/23 patients (70%) increased leak point pressure (> 40 cmH(2)O). In all 23 patients, detrusor instability and detrusor sphincter dyssynergia (during voiding) was found. Fluoroscopy showed bladder trabeculation or diverticula in 14 patients (61%) and 2nd-3rd degree vesicoureterorenal reflux in 2 patients (9%). In group 2, 2/6 patients (33%) had reduced compliance (0.7 and 5.8 ml/cmH(2)O) and 4/6 (67%) increased leak point pressure (> 40 cmH(2)O). In 5/6 patients (83%), detrusor instability and detrusor sphincter dyssynergia was seen. Fluoroscopy showed bladder trabeculation in 3 patients (50%), whereas no reflux was observed. Only one of the 29 patients (3 %) showed no pathological videourodynamic or anamnestic findings. CONCLUSIONS: We conclude that videourodynamic assessment should be performed in all patients with infantile cerebral palsy. The decision should not be based on clinical symptoms such as pollakiuria, recurrent urinary tract infection or urinary incontinence.

[The Freehand System: an implantable neuroprosthesis for functional electrostimulation of the upper extremity]. / Das Freehand-System: Eine implantierbare Neuroprothese zur funktionellen Elektrostimulation der oberen Extremität.

We report on the first experience with the Freehand system in German-speaking countries, an implantable neuroprosthesis developed for the functional electrical stimulation of the upper extremity. Indications for its use are neurological deficits of the cervical spinal cord with active mobility of the shoulder and elbow flexion in tetraplegics, ideally in C5/6 tetraplegics. A further precondition for the implantation of this system is an intact reflex arc of the muscles that are to be stimulated, i.e. of the forearm and hand. Central defects such as hemiparesis, cerebral palsies or athetoid disorders or peripheral nerve palsies (e.g. brachial plexus lesions) are no good indications for the implantation of the Freehand system. We report on patient selection criteria, preoperative percutaneous electrical stimulation, the surgical procedure itself with optional active tendon transpositions, the intensive postoperative rehabilitation program until the patient is able to use the system independently and the life-long after-care.

Neuroprosthetics of the upper extremity--clinical application in spinal cord injury and future perspectives.

Within the last couple of years, partial restoration of lost motor functions in a larger number of spinal cord injured patients has become possible by the introduction of neuroprostheses into the clinical environment. The Freehand system in particular is the first implantable neuroprosthesis from which a certain group of tetraplegic patients with stable shoulder function, but missing or weak grasp and hold function of the hand do benefit. The system is based on the combination of electrical stimulation and operative tendon transfers and thus represents a multicomponent concept for long-term restoration of the grasp function. The crucial prerequisites for successful use of an implantable neuroprosthesis are the right indication, careful preoperative muscle stimulation, differentiated planning of the surgery and functional training adopted to the individual residual functions. After successful completion of an extensive rehabilitation program, patients are able to use the system for activities of daily living without the need for special additional aids, which enhances their quality of life and independency. In order to extend the group of potential users of neuroprostheses in the future, new technological developments will have to take into account that nowadays the majority of spinal cord injured patients suffer from an incomplete lesion of the spinal cord. For these particular patients who still possess residual functions, modular, "naturally" controllable systems for supporting these functions are needed rather than complex systems to substitute them.

[Bipolar , active electrode for 4-channel recording of dynamic surface EMG during electric stimulation]. / Eine bipolare, aktive Elektrode zur Vielkanalableitung des dynamischen EMGS während Elektrostimulation.

In this paper we present an electrode for measuring the surface electromyogram (EMG) that combines high quality of signal recording with the ease of use in clinical routine. Additional requirements have been the use of the electrode in combination with electrical stimulation and under dynamic conditions like walking. Special focus was put on the minimization of movement artifacts by integration of a dual impedance transformer (active electrode) and by a self-adjusting fixation of the two contacts of the electrode via proprietary springs. An elaborate preparation of the skin is not necessary due to a very high input impedance of the amplifier. A special circuit for overvoltage protection makes the electrode suitable for use in the presence of high voltage stimulation pulses without the risk of destroying the FET-input stages.