[120-day follow-up after proximal femoral fractures-first results from the Geriatric Trauma Registry DGU®]

BACKGROUND

Geriatric trauma centers which are certified to the status of a Geriatic Trauma Center DGU® based on the criteria catalogue as outlined by the German Trauma Society (DGU), are required to participate in the Geriatric Trauma Register (ATR-DGU) for quality management and outcome analyses. The evaluation is pseudoanonymous and includes data on all treated hip fracture patients over 70 years old. This has been in regular use since 2016. This study analyzed the postoperative evaluation of gait, mortality, quality of life, hospital readmission and treatment of osteoporosis after 120 days.

METHODS

A voluntary retrospective data evaluation of the ATR-DGU 120-day follow-up from 2017 was carried out. Written consent for the analysis and publication of the data was obtained from six clinics that already participated in the follow-up. The primary target parameters were mortality rate, readmission and revision rates, gait quality, osteoporosis treatment and quality of life according to EQ-5D-3L. The patient data were completely pseudonymized and a descriptive analysis was carried out.

RESULTS

In this study 957 patients from the 6 hospitals were included. The average age was 84.5 years (±6.8 years). The mortality rate during the acute treatment phase was 5%. The 120-day follow-up could be evaluated in 412 patients, 10% of these required hospital readmission due to complications oft he same fracture and of these 6% required revision surgery. The mortality rate at 120 days was 12%. In 54% of the patients the fracture led to deterioration of mobility and 49% of patients received osteoporosis treatment after 120 days. The results of the EQ-5D-3L at 120 days revealed improvement as compared to the values on postoperative day 7; however, the preoperative status with respect to mobility and quality of life could not be regained.

CONCLUSION

Despite the clear advantages of interdisciplinary treatment, the results are still limited concerning mobilization and quality of life. Further analysis of causative and influencing factors is necessary.

The Association Between Orthogeriatric Co-Management and Mortality Following Hip Fracture

BACKGROUND

To meet the special needs of older patients with fragility fractures, models for collaborative orthogeriatric care have been developed. The objective of our study was to analyze the association of orthogeriatric co-management with mortality following hip fracture in older patients in Germany.

METHODS

This observational study was based on health insurance claims data from 58 001 patients (79.4% women) aged ≥80 years admitted to the hospital with hip fracture between January 2014 and March 2016. They were treated in 828 German hospitals with or without orthogeriatric co-management. The outcome measure was cumulative mortality with adjustment of the regression analyses.

RESULTS

The crude 30-day mortality was 10.3% for patients from hospitals with orthogeriatric co-management and 13.4% for patients from hospitals without orthogeriatric co-management. The adjusted 30-day mortality was 22% lower for patients in hospitals with orthogeriatric co-management (rate ratio 0.78; 95% CI [0.74; 0.82]; adjusted absolute difference -2.48%; 95% CI [-2.98; -1.98]). The difference in 30-day mortality remained nearly unchanged over the first 6 months. The risk reduction with orthogeriatric co-management was consistently observed in both women and men, across age groups, and in patients with and without care needs. The mean length of the index stay was 19.8 days in hospitals with orthogeriatric co-management and 14.4 days in hospitals without orthogeriatric co-management.

CONCLUSION

A multidisciplinary orthogeriatric approach is associated with lower mortality and a longer index stay in hospital after hip fracture.

[Refresher Orthogeriatrics]

Fragility fractures are associated with a substantial mortality and morbidity. Because of the high prevalence of comorbidities and a high risk of complications the application of geriatric principles in the complex treatment of these patients is vital. The last years have seen a paradigm shift in the treatment of fragility fractures from an orthopedic disorder towards an orthogeriatric syndrome. This article reviews the orthogeriatric principles of treating fragility fractures.

[Results of the pilot phase of the Age Trauma Registry DGU®]

BACKGROUND

Since 2014, hospitals with ortho-geriatric fracture centres could be certified as AltersTraumaZentrum DGU® in Germany. To measure the quality of treatment in these centres, a geriatric trauma registry (AltersTraumaRegister DGU®) was established.

OBJECTIVES

The aim of this work was to report the results of the pilot phase of the AltersTraumaRegister DGU® from the year 2015.

MATERIALS AND METHODS

Included were 118 patients >70 years with hip fracture or implant-related femoral fractures. Apart from other parameters, the point of surgery, initiation of anti-osteoporotic treatment and the EQ-5D one week post-surgery was measured.

RESULTS

Surgery was performed in 87% of patients within 24 h. Specific osteoporotic therapy could be increased from 4 to 63 patients. The EQ-5D was strongly restricted to one week post-surgery.

CONCLUSION

Based on the timing of surgery and anti-osteoporotic therapy, the treatment seems to be successful in the ortho-geriatric fracture centres. For a better evaluation of treatment quality in the AltersTraumaZentren DGU®, implementation of follow-up examinations in the AltersTraumaRegister DGU® is essential.

[Geriatric trauma centers from the idea to implementation. What has been achieved?]

The geriatric trauma working party, a subgroup of the German Society of Trauma Surgery (Deutsche Gesellschaft für Unfallchirurgie, DGU), focuses on the challenges of geriatric fractures, which are steadily increasing due to demographic changes. Inherent comorbidities implicate perioperative complications leading to loss of mobility and endangered independence followed by an increased burden on the social services. An interdisciplinary approach is required. The geriatric trauma working party defined criteria for interdisciplinary treatment and comprehensive care as well as early rehabilitation in interdisciplinary geriatric fracture centers. By passing an independent audit process these centers can achieve certification as a geriatric trauma center DGU (AltersTraumaZentrum DGU). Certified centers can participate in a recently established geriatric fracture registry which includes an internationally consented data set. Audit and registry enable centers to acquire an international benchmark, ensure permanent improvement in quality and allow participation in health services research.

Early Detection of Foot-And-Mouth Disease Virus from Infected Cattle Using A Dry Filter Air Sampling System

Foot-and-mouth disease (FMD) is a highly contagious livestock disease of high economic impact. Early detection of FMD virus (FMDV) is fundamental for rapid outbreak control. Air sampling collection has been demonstrated as a useful technique for detection of FMDV RNA in infected animals, related to the aerogenous nature of the virus. In the current study, air from rooms housing individual (n = 17) or two groups (n = 4) of cattle experimentally infected with FDMV A24 Cruzeiro of different virulence levels was sampled to assess the feasibility of applying air sampling as a non-invasive, screening tool to identify sources of FMDV infection. Detection of FMDV RNA in air was compared with first detection of clinical signs and FMDV RNA levels in serum and oral fluid. FMDV RNA was detected in room air samples 1-3 days prior (seven animals) or on the same day (four animals) as the appearance of clinical signs in 11 of 12 individually housed cattle. Only in one case clinical signs preceded detection in air samples by one day. Overall, viral RNA in oral fluid or serum preceded detection in air samples by 1-2 days. Six individually housed animals inoculated with attenuated strains did not show clinical signs, but virus was detected in air in one of these cases 3 days prior to first detection in oral fluid. In groups of four cattle housed together, air detection always preceded appearance of clinical signs by 1-2 days and coincided more often with viral shedding in oral fluid than virus in blood. These data confirm that air sampling is an effective non-invasive screening method for detecting FMDV infection in confined to enclosed spaces (e.g. auction barns, milking parlours). This technology could be a useful tool as part of a surveillance strategy during FMD prevention, control or eradication efforts.

Molecular profiling of chordoma

The molecular basis of chordoma is still poorly understood, particularly with respect to differentially expressed genes involved in the primary origin of chordoma. In this study, therefore, we compared the transcriptional expression profile of one sacral chordoma recurrence, two chordoma cell lines (U-CH1 and U-CH2) and one chondrosarcoma cell line (U-CS2) with vertebral disc using a high-density oligonucleotide array. The expression of 65 genes whose mRNA levels differed significantly (p<0.001; ≥6-fold change) between chordoma and control (vertebral disc) was identified. Genes with increased expression in chordoma compared to control and chondrosarcoma were most frequently located on chromosomes 2 (11%), 5 (8%), 1 and 7 (each 6%), whereas interphase cytogenetics of 33 chordomas demonstrated gains of chromosomal material most prevalent on 7q (42%), 12q (21%), 17q (21%), 20q (27%) and 22q (21%). The microarray data were confirmed for selected genes by quantitative polymerase chain reaction analysis. As in other studies, we showed the expression of brachyury. We demonstrate the expression of new potential candidates for chordoma tumorigenesis, such as CD24, ECRG4, RARRES2, IGFBP2, RAP1, HAI2, RAB38, osteopontin, GalNAc-T3, VAMP8 and others. Thus, we identified and validated a set of interesting candidate genes whose differential expression likely plays a role in chordoma.

Early orthogeriatric treatment of trauma in the elderly: a systematic review and metaanalysis

BACKGROUND

More than 125,000 hip fractures occur in Germany every year, with a one-year mortality of about 25%. To improve treatment outcomes, models of cooperation between trauma surgery and geriatrics have been developed. Their benefit has not yet been unequivocally demonstrated.

METHODS

We systematically searched the Medline database and the Cochrane Library for prospective randomized controlled trials in which the treatment of elderly patients with fractures by the trauma surgery service alone was compared with preoperatively initiated collaborative treatment by the trauma surgery and geriatric services ("orthogeriatric" treatment). We investigated three treatment outcome variables--length of hospital stay, in-hospital mortality, and one-year mortality--in a metaanalysis.

RESULTS

The five trials of hip fracture treatment that met the selection criteria all had relatively small study populations and a high risk of bias. The outcomes with respect to hospital stay differed greatly among trials (I(2): 88.5%), and geriatric intervention was not found to have any statistically significant effect (0.06 days, 95% confidence interval [CI]: -3.74 to 3.62 days). The relative risk of dying in the hospital was 0.66 for orthogeriatric treatment (95% CI: 0.28-1.55, p = 0.34), and the hazard ratio for one-year mortality was 0.79 in favor of orthogeriatric treatment (95% CI: 0.57 to 1.10, p = 0.17). A metaanalysis of functional outcomes was not possible.

CONCLUSION

Only a few randomized controlled trials of early orthogeriatric treatment have been performed, and these trials are of limited quality. Due to low case numbers, a benefit from interdisciplinary orthogeriatric treatment could not clearly be demonstrated. Further trials are needed.

[Subsequent treatment following proximal femoral fracture - who, when, where? Assessment of the current situation in Germany]

BACKGROUND

Geriatric fractures are an increasing challenge for the German health-care system. While the acute care for patients with proximal femoral fractures is already standardised, differences remain in the further treatment and rehabilitation. A survey was conducted in cooperation with the section of geriatric trauma (AG Alterstraumatologie) of the German Association of Trauma Surgery (DGU) to point out existing problems in this group of patients.

MATERIAL AND METHODS

In October/November 2010 an electronic questionnaire, assessing the medical care for patients after proximal femoral fracture, was sent to 1080 medical directors of trauma and orthopaedic surgery departments in Germany.

RESULTS

339 (31.4 %) departments participated. The analysis revealed that 57 % of the hospitals had cooperation agreements with aftercare hospitals. 37 % of all hospitals had problems in finding a rehabilitation hospital. The initiation of a rehabilitation procedure is almost exclusively based on the doctors' decision. Influence of employees with other professions is marginal. Mobility and Barthel index before the release from the acute care hospital are major factors in the decision making.

CONCLUSION

The questionnaire confirms that there are problems in the aftercare service of geriatric patients all around Germany. A further improvement of collaboration between acute and aftercare hospitals is required.

Deceleration during 'real life' motor vehicle collisions - a sensitive predictor for the risk of sustaining a cervical spine injury?

Background

The predictive value of trauma impact for the severity of whiplash injuries has mainly been investigated in sled- and crash-test studies. However, very little data exist for real-life accidents. Therefore, the predictive value of the trauma impact as assessed by the change in velocity of the car due to the collision (ΔV) for the resulting cervical spine injuries were investigated in 57 cases after real-life car accidents.

Methods

ΔV was determined for every car and clinical findings related to the cervical spine were assessed and classified according to the Quebec Task Force (QTF).

Results

In our study, 32 (56%) subjects did not complain about symptoms and were therefore classified as QTF grade 0; 25 (44%) patients complained of neck pain: 8 (14%) were classified as QTF grade I, 6 (10%) as QTF grade II, and 11 (19%) as QTF grade IV. Only a slight correlation (r = 0.55) was found between the reported pain and ΔV. No relevant correlation was found between ΔV and the neck disability index (r = 0.46) and between ΔV and the QTF grade (r = 0.45) for any of the collision types. There was no ΔV threshold associated with acceptable sensitivity and specificity for the prognosis of a cervical spine injury.

Conclusion

The results of this study indicate that ΔV is not a conclusive predictor for cervical spine injury in real-life motor vehicle accidents. This is of importance for surgeons involved in medicolegal expertise jobs as well as patients who suffer from whiplash-associated disorders (WADs) after motor vehicle accidents.

Trial registration

The study complied with applicable German law and with the principles of the Helsinki Declaration and was approved by the institutional ethics commission.

Comparison of the relative benefits of 2 versus 10 days of soft collar cervical immobilization after acute whiplash injury

OBJECTIVE

To investigate the effects of 2-day and 10-day immobilization of the cervical spine on pain, range of motion (ROM), and disability of patients with Quebec Task Force (QTF) grade II whiplash injuries.

DESIGN

Randomized controlled trial.

SETTING

University hospital emergency department.

PARTICIPANTS

Seventy patients with acute QTF grade II whiplash injuries.

INTERVENTIONS

At the intake examination within 24 hours after the whiplash trauma, the patients were randomized to 2 therapy groups (2-d or 10-d immobilization with a soft cervical collar). All patients received pain drugs (nonsteroidal anti-inflammatory drugs) and after 7 days, all patients started a standardized physiotherapy program 2 to 3 times a week.

MAIN OUTCOME MEASURES

Patients' pain and disability scores were assessed using visual analog scales and ROM was assessed using a goniometer. All parameters were measured within 24 hours after injury and after 2 and 6 months.

RESULTS

After 2 months, the different periods of immobilization (2d or 10d) were associated with comparable improvements in pain symptoms (median, 4.60 vs 4.65), ROM (median, 100.0 degrees vs 117.5 degrees ), and disability score (median, 4.90 vs 5.15). No statistically significant differences could be identified between the 2 treatment groups. After 6 months, persistent pain was reported by 4 patients in each group (12.5%).

CONCLUSIONS

In patients with QTF grade II whiplash injuries, there is no short- or long-term difference between 2-day and 10-day immobilization with a cervical collar in terms of pain, ROM, or disability.

Injuries of the cervical spine in patients with ankylosing spondylitis: experience at two trauma centers

Object

The cervical spine in a patient with ankylosing spondylitis (AS) (Bechterew disease) is exposed to maximal risk due to physical load. Even minor trauma can cause fractures because of the spine’s poor elasticity (so-called bamboo spine). The authors conducted a study to determine the characteristics of cervical fractures in patients with AS to describe the standard procedures in the treatment of this condition at two trauma centers and to discuss complications of and outcomes after treatment.

Methods

Between 1990 and 2006, 37 patients were surgically treated at two institutions. All patients were examined preoperatively and when being discharged from the hospital for rehabilitation. Single-session (11 cases) and two-session anterior–posterior (13 cases), anterior (11 cases), posterior (two cases), and laminectomy (one case) procedures were performed. The injury pattern, segments involved, the pre- and postoperative neurological status, and complications were analyzed.

Preoperative neurological deficits were present in 36 patients. All patients experienced improvement postoperatively, and there was no case of surgery-related neurological deterioration. In patients in whom treatment was delayed because of late diagnosis, preoperative neurological deficits were more severe and improvement worse than those treated earlier. The causes of three deaths were respiratory distress syndrome due to a rigid thorax and cerebral ischemia due to rupture of the vertebral arteries. There were 12 perioperative complications (32%), three infections, one deep venous thrombosis, five early implant failures, and the three aforementioned fatalities. There were no cases of epidural hematoma. In all five cases in which early implant failure required revision surgery, the initial stabilization procedure had been anterior only. A comparison of complications and the outcomes at the two centers revealed no significant differences.

Conclusions

The standard intervention for these injuries is open reduction, anterior decompression and fusion, and anterior–posterior stabilization; these procedures may be conducted in one or two stages. Based on the early implant failures that occurred exclusively after single-session anterior stabilizations (five of 10—a failure rate of 50%), the authors have performed only posterior and anterior procedures since 1997 at both centers. Diagnostic investigations include computed tomography scanning or magnetic resonance imaging of the whole spine, because additional injuries are common. The causative trauma may be very slight, and diagnosis may be delayed because plain radiographs can be initially misinterpreted. In cases in which diagnosis is delayed, patients present with more severe neurological deficits, and postoperative improvement is less pronounced than that in patients in whom a prompt diagnosis is established. Because of postoperative pulmonary and ischemic complications, the mortality rate is high. In the present series the mortality rate was lower than the mean rate reported in the literature.

Sonographic findings of hibernoma. A report of two cases

We present 2 cases of hibernoma, a rare lipomatous tumor arising from brown fat tissue. In each case, a hyperechoic mass in comparison to surrounding musculature combined with elevated vascularization was highly suggestive of a liposarcoma. As a rule, malignancy cannot be excluded safely by imaging modalities, and a preoperative biopsy should be performed. Although rare, hibernomas should be considered in the differential diagnosis of lipomatous soft-tissue tumors.

Device-assisted muscle strengthening in the rehabilitation of patients after surgically stabilized vertebral fractures

OBJECTIVES

To investigate the effects of a device-assisted muscle strengthening exercise program on the surgically traumatized multifidus musculature and on the intact longissimus and iliocostal muscles and to assess the possible relationship between patients' reported pain symptoms and changes in muscle strength or changes in cross-sectional area (CSA) of the musculature.

DESIGN

Open, prospective noncontrolled prepost intervention study.

SETTING

University-affiliated center for ambulant physiotherapy.

PARTICIPANTS

Fifteen patients who had undergone dorsal osteosynthesis for treatment of thoracolumbar vertebral fracture and who complained of persistent back pain.

INTERVENTION

Twelve-week device-assisted training exercise program.

MAIN OUTCOME MEASURES

Patients' pain score, muscle strength, and the CSA of the paravertebral musculature determined by magnetic resonance imaging (MRI) were assessed before and after the exercise program.

RESULTS

MRI findings revealed no increase in the CSA of the multifidus muscle in any patient (median change, -.27 cm 2 ). All patients, however, exhibited hypertrophy of both the longissimus and iliocostal muscles (median change, 1.39 cm 2 ). Significant increase in muscle strength was observed in 14 of 16 patients (median increase, 56%; range, 0.7%-126.4%). The median overall pain score improved from 19 (range, 7-24) to 16 (range, 5-27). The change in muscle strength and muscle CSA, however, showed no correlation. There was also no correlation between increase in muscle strength and changes in pain scores.

CONCLUSIONS

The device-assisted training program resulted in hypertrophy of the iliocostal and longissimus muscles and an increase in muscle strength in patients with surgically stabilized vertebral fractures. About half of the patients reported relief of pain. No correlation was found between hypertrophy, increase in muscle strength, and relief of pain. The surgically damaged multifidus musculature, however, did not show any change in CSA and was not accessible to rehabilitative measures.

[Accident analytics for structural traumas of the cervical spine]

The differentiation between degenerative syndromes of the cervical spine and post-traumatic symptoms requires accident analysis. Experiments with human subjects yield data only in the low-energy range, and there are still no accident analyses of structural traumas of the cervical spine. From 1 January 2000 to 30 April 2002, 15 patients with structural injuries to the cervical spine due to car accidents were treated in the Department of Trauma Surgery of the University of Ulm. In 11 of these cases, the DEKRA Ulm completed an appraisal of the accident process.With lateral impacts, structural injuries to the cervical spine can occur even at speeds of only ca 10 km/h. Injuries to the alar ligaments are produced by frontal collisions with substantial differences in speed. Data from accident analysis of structural injuries to the cervical spine must be taken into consideration in causality examinations of distortions of the cervical spine.

Intramuscular pressure, tissue oxygenation and EMG fatigue measured during isometric fatigue-inducing contraction of the multifidus muscle

Simultaneous measurement of intramuscular pressure (IMP), tissue oxygen partial pressure (pO(2)) and EMG fatigue parameters in the multifidus muscle during a fatigue-inducing sustained muscular contraction. The study investigated the following hypotheses: (1) Increases in IMP result in tissue hypoxia; (2) Tissue hypoxia is responsible for loss of function in the musculature. The nutrient supply to muscle during muscle contraction is still not fully understood. It is assumed that muscle contraction causes increased tissue pressure resulting in compromised perfusion and tissue hypoxia. This tissue hypoxia, in turn, leads to muscle fatigue and therefore to loss of function. To the authors' knowledge, no study has addressed IMP, pO(2) and EMG fatigue parameters in the same muscle to gain a deeper sight into muscle perfusion during contraction. As back muscles need to have a constant muscular tension to maintain trunk stability during stance and locomotion, muscle fatigue due to prolonged contraction-induced hypoxia could be an explanation for low back pain. Sixteen healthy subjects performed an isometric muscular contraction exercise at 60% of maximum force until the point of localized muscular fatigue. During this exercise, the individual changes of IMP, pO(2) and the median frequency (MF) of the surface EMG signal of the multifidus muscle were recorded simultaneously. In 12 subjects with a documented increase in intramuscular pressure, only five showed a decrease in tissue oxygen partial pressure, while this parameter remained unchanged in six other subjects and even increased in one. A fall in tissue pO(2) was associated with a drop in MF in only five subjects, while there was no correlation between these parameters in the other 11 subjects. To summarize, an increase in IMP correlated with a decrease in pO(2) and a drop in MF in only five out of 16 subjects. High intramuscular pressure values are not always associated with a hypoxia in muscle tissue. Tissue hypoxia is not automatically associated with a median frequency shift in the EMG signal's power spectrum.

Biomechanical in vitro comparison of different mono- and bisegmental anterior procedures with regard to the strategy for fracture stabilisation using minimally invasive techniques

Endoscopic minimally invasive techniques have become an established method of fracture stabilisation in the spine. In view of this fact, anterior stabilisation strategies must be reconsidered, as monosegmental A 3.1 compression fractures are increasingly being stabilised endoscopically from the anterior aspect using minimally invasive techniques. This study investigated the biomechanical necessity of anterior two-point or four-point stabilisation in the instrumentation of mono- and bisegmental fractures. In three biomechanical in vitro studies, burst fracture stabilisation was simulated, and anterior short fixation devices were tested under load with pure moments up to 3.75 Nm to evaluate the biomechanical stabilising characteristics of different kinds of instrumentations in flexion/extension, lateral bending, and axial rotation. Only anterior four-point stabilisation resulted in sufficient primary stability both in mono- and bisegmental instrumentation and therefore represents the standard procedure in open as well as in minimally invasive spinal surgery.

Surface electromyography of the paravertebral muscles in patients with chronic low back pain

OBJECTIVE

To investigate the differences in the electromyographic signals of patients with chronic low back pain (CLBP) and healthy subjects.

DESIGN

Cross-sectional study with a matched-pair design.

SETTING

University hospital.

PARTICIPANTS

Thirty-one patients with CLBP and 31 healthy, matched-pair controls.

INTERVENTIONS

The mean rectified surface electromyographic amplitude and muscle strength were measured during maximal voluntary contraction (MVC). During an endurance test at 60% of MVC, the electromyographic parameters of the 2 groups were compared.Main outcome measure Electromyographic measuring of local fatigue, which can be described with changes in the median frequency or by a different parameter of the power spectrum called frequency banding.

RESULTS

The strength measurement revealed a deficiency of 40% in the patients and a deficit in the electromyographic amplitude of approximately 60%, compared with the control group. By pairwise comparison, the decrease in the median frequency during the endurance test was greater in the control group. In the frequency banding of the power spectrum, local fatigue was less pronounced in the CLBP patients in pairwise comparison.

CONCLUSIONS

The back muscles of CLBP patients appear to be less fatigable than those of controls. The results can be explained by morphologic changes, but influences such as pain, avoidance of pain, and deconditioning, need to be considered when the results are assessed.

Influence of screw-cement enhancement on the stability of anterior thoracolumbar fracture stabilization with circumferential instability

The influence of additional dorsal structure damage on anterior stabilization of a thoracolumbar fracture is still unknown. Screw-cement enhancement can be used to reinforce the stability of anterior instrumentation. We have developed a new anchorage system for fixation of anterior stabilization devices, adapted through geometric optimization and the additional option of cementation after screw insertion. This study examines the question of whether this enhancement is strong enough to enable a single anterior procedure and still compensate for dorsal instability. Various spinal reconstruction procedures were evaluated biomechanically in an increasing ventrodorsal instability model for thoracolumbar fracture stabilization. A biomechanical in vitro study, simulating stabilized defect situations (corporectomy/vertebrectomy) with strut grafting and overbridging instrumentation, was performed on six human T10-L2 cadaveric specimens. The primary stability parameters, range of motion and neutral zone, were evaluated with or without anterior screw-cement enhancement. This was compared with a single conventional anterior stabilization without a dorsal defect (corporectomy). It was also compared with a single anterior, posterior or combined procedure in the presence of additional dorsal structure damage (vertebrectomy). The use of an additional cementable screw dowel enhanced the primary stability of the anterior instrumentation, compensating for dorsal instability. These results are warranted for the clinical use of minimally open or endoscopic techniques, creating the highest possible primary stability while performing a single anterior enhanced instrumentation with a tissue-preserving approach.

In vitro low-speed side collisions cause injury to the lower cervical spine but do not damage alar ligaments

Whether injuries to the alar ligaments could be responsible for complaints of patients having whiplash injury in the upper cervical spine is still controversially discussed. It is known that these ligaments protect the upper cervical spine against excessive lateral bending and axial rotation movements. The objective of the present in vitro study was therefore to examine whether the alar ligaments or any other structures of the cervical spine are damaged in side collisions. In a specially designed acceleration apparatus, six human osteoligamentous cervical spine specimens were subjected to incremental 90 degrees side collisions from the right (1 g, 2 g, 3 g, etc.) until structural failure occurred. A damped pivot table accounted for the passive movements of the trunk during collision, and a dummy head (4.5 kg) ensured almost physiological loading of the specimens. For quantification of functional injuries, the three-dimensional flexibility of the specimens was tested in a spine tester before and after each acceleration. In all six specimens, structural failure always occurred in the lower cervical spine and always affected the facet joint capsules and the intervertebral discs. In four specimens, this damage occurred during the 2 g collision, while in the other two it occurred during the 3 g and 4 g collision, respectively. The flexibility mainly increased in the lower cervical spine (especially in lateral bending to both sides) and, to a minor extent, in axial rotation. In vitro low-speed side collisions caused functional and structural injury to discoligamentous structures of the lower cervical spine, but did not damage the alar ligaments. Since the effects of muscle forces were not taken into account, the present in vitro study reflects a worst-case scenario. Injury thresholds should therefore not be transferred to reality.

Correlation between neck injury risk and impact severity parameters in low-speed side collisions

STUDY DESIGN

In vitro acceleration study on human cadaveric cervical spine specimens.

OBJECTIVES

To investigate the correlation between the risk to sustain a structural cervical spine injury and vehicle-related impact severity parameters.

SUMMARY OF BACKGROUND DATA

Impact severity parameters, such as the peak acceleration of the vehicle, its mean acceleration, and its velocity change, are often used to predict the whiplash injury risk or to objectify the patient's symptoms even though their correlation to injury is still not well understood.

METHODS

In a series of three in vitro experiments, a total of 18 human cadaveric cervical spine specimens were subjected to incremental side accelerations until structural injury occurred. While the duration of the acceleration pulse was kept constant throughout all three experiments, its shape was varied: In Experiment I, the acceleration pulse had a fast increase up to the maximum value and a fast decrease down to zero (fast-fast). Experiment II was characterized by a slow increase and fast decrease (slow-fast), and Experiment III was characterized by a fast increase and a slow decrease (fast-slow).

RESULTS

The specimens of Experiment II (slow-fast) sustained structural injury at a significantly higher peak acceleration of the sled (4.6 g on average) than those of Experiments I (fast-fast) (2.6 g) and III (fast-slow) (3.1 g). In contrast, mean acceleration and velocity change of the injuring impacts were almost the same in all three experiments.

CONCLUSION

The injury risk to the cervical spine was predictable by the mean acceleration of the sled and since the duration of the crash pulses was constant also by its velocity change but not by its peak acceleration.

Simultaneous measurement of intramuscular pressure and surface electromyography of the multifidus muscle

The anatomic proof of a spinal compartment and the clinical symptoms of compartment syndrome in patients with chronic back pain are inconsistent with the rarely met measuring criteria of intramuscular pressure (IMP). Previous studies assume a dependence of the IMP on spinal alignment (degree of lumbar spine flexion) and the degree of muscle activation. The significance of these disturbance variables in the interpretation of IMP could explain the above discrepancy. This study therefore investigates the influence of both a 30% increase in trunk flexion and alterations in muscle contraction from 100% to 60%. Sixteen healthy subjects participated in the study. The IMP and mean rectified amplitude of the multifidus surface EMG signal were determined at rest and 0 degrees and approximately 30 degrees of lumbar spine flexion, and they were compared. Subsequently, both parameters were measured during both 100% and 60% maximal voluntary contraction (MVC) of the muscle and then correlated. During rest and 0 degrees flexion, the median IMP was 9.3 mmHg (range 0.0-22.5) while the median mean rectified amplitude (MRA) of the EMG signal was 1.98 microV (range 1.32-7.38). In 30 degrees flexion, the median IMP went up to 24.3 mmHg (range 1.4-97.3) with hardly any increase in the median MRA of 2.32 microV (range 1.20-9.72). Under 60% MVC, the median IMP rose to 186.6 mmHg (range 15.4-375.4) and the median MRA to 21.02 microV (range 4.63-43.63). During 100% MVC, the median MRA increased to 34.38 microV (range 12.99-102.54) while the median IMP rose to 273.4 mmHg (range 90.4-395.1). Spearman's rank correlation coefficient for the IMP and MRA quotients of the 100/60% MVC values was r= -0.21. To sum up, it can be said that IMP was subject to great interindividual variation in all the experiments. This parameter is highly dependent on spinal alignment and muscular activity. Further studies are needed so that the IMP can be interpreted properly when diagnosing a chronic compartment of the erector spinae muscles.

A new acceleration apparatus for the study of whiplash with human cadaveric cervical spine specimens

The biomechanics of whiplash is often studied using cadaveric cervical spine specimens. One of the most important points in this kind of study is to create realistic loading conditions. The aim of the present project therefore was to develop an acceleration apparatus, which allows the study of whiplash with human cadaveric cervical spine specimens under as realistic loading conditions as possible. The new acceleration apparatus mainly consisted of a sled, a pneumatic acceleration unit and a railtrack and offered several unique features to create more realistic loading conditions. Among these features, the possibility to simulate the passive movements of the trunk is of capital importance. In this new apparatus, first, the general feasibility of whiplash experiments was studied, second, the reproducibility of the impacts was quantified and third, the effect of simulated movements of the trunk on accelerations and loads was examined. In the new acceleration apparatus various types of collisions could reproducibly be simulated. Simulated passive movements of the trunk strongly influenced the loading pattern of the neck. Without pivoting a steep increase of all loading parameters could be observed. This increase was less pronounced if pivoting was allowed. In conclusion, biomechanical aspects of whiplash could reproducibly be examined in the new acceleration apparatus. Due to its significant effects on the loading of the neck, pivoting of the trunk should always be taken into account in future experiments on the biomechanics of whiplash in which isolated cervical spine specimens are used.

[Navigation of tumors and metastases in the area of the thoraco-lumbar spine]

In this clinical feasibility study, CT-based verification of the efficacy of navigated decompression and pedicle screw placement in patients who had tumor-related posterior surgery was demonstrated. Eighty-six percent of the pedicle screws were positioned centrally in the bone without perforation; in all patients accurate decompression was seen. The accuracy of transpedicle screw implantation postoperatively was investigated with CT. In contrast to other published studies, no postoperative neurologic deterioration was seen in the patients as a result of using computer-aided surgical procedures. At the same time we were able to achieve complete decompression of the neural structures for radiologic and neurologic findings. Because of inaccurate registration, it was not possible to use computer-aided implantation surgery for 15% of the pedicles and, therefore, a conventional fluoroscopic approach was used. Our initial results indicate that computer-aided frameless navigation of tumor surgery of the spine is a safe technique which improves surgical performance during posterior decompression and transpedicle stabilization. In addition, CAS surgery improved the intraoperative information about the tumor and the current surgical intervention during decompression. Nevertheless the technique should be used only by experienced surgeons who can, if required, continue the operation using conventional techniques. Furthermore, the surgeon should have a complete theoretical understanding of the navigation system to minimize possible misinterpretation of computer guidance information.

[Cost effectiveness of intraoperative three-dimensional imaging with a mobile surgical C-arm]

DRGs lead to a new definition of refunding medical treatment. The calculated DRG covers all costs of the individual hospital stay of each patient. Any revision surgery is not refunded separately. Especially in spine surgery and in articular fractures, postoperative X-ray control sometime reveals malposition of implants that later require operative revision. The latter causes additional costs that can be in the range of 50% of the whole refund as shown here for tibia plateau and calcaneus fractures. New intraoperative 3D fluoro techniques provide CT-like images of bones and joints that enable the surgeon to optimize implant positions immediately. Despite higher initial costs as compared to conventional imaging devices, these technologies help to increase process quality in the OR and clearly save costs.

Solvent-preserved, bovine cancellous bone blocks used for reconstruction of thoracolumbar fractures in minimally invasive spinal surgery-first clinical results

We investigated the osseointegration of solvent-preserved, xenogenous cancellous bone blocks in the treatment of unstable fractures of the thoracolumbar junction. In 22 patients, the anterior repair procedure was performed by thoracoscopy or minimally invasive retroperitoneal surgery. Twenty-two patients had undergone monosegmental anterior fusion and were surveyed prospectively. Solvent-preserved, bovine cancellous bone blocks were used in 11 patients; iliac crest bone graft was used in the others. Follow-up after 12 months included CT scans, which revealed successful osseointegration in eight out of 11 patients who had received autogenous iliac crest bone grafts, while three patients showed a partial integration. There were no graft fragmentations. In patients who had received solvent-preserved, xenogenous cancellous bone blocks, complete osseointegration was achieved at the graft-bone interface in only two out of 11 cases, after 1 year. Partial integration was found in three patients. In view of these results, autogenous iliac crest bone grafts are still the unrivalled standard for defect repair in spinal surgery.

[Complications of malignant tumors--pathological fractures]

Advances in the treatment of tumors have improved the life expectancy of cancer patients appreciably. As a consequence the incidence of bone metastases has also increased. Surgical interventions must achieve a maximal palliative effect with minimal morbidity and mortality. Major objectives are reduction of pain while preserving stability and function. Surgical treatment of primary and secondary bone tumors is complicated and thus also burdened with complications. However, interdisciplinary therapy comprising surgical resection and stabilization, radiotherapy and/or chemotherapy improves life expectancy and the quality of life of the cancer patient.

Thoracolumbar fracture stabilization: comparative biomechanical evaluation of a new video-assisted implantable system

Minimally invasive techniques for spinal surgery are becoming more widespread as improved technologies are developed. Stabilization plays an important role in fracture treatment, but appropriate instrumentation systems for endoscopic circumstances are lacking. Therefore a new thoracoscopically implantable stabilization system for thoracolumbar fracture treatment was developed and its biomechanical in vitro properties were compared. In a biomechanical in vitro study, burst fracture stabilization was simulated and anterior short fixation devices were tested under load with pure moments to evaluate the biomechanical stabilizing characteristics of the new system in comparison with a currently available system. With interbody graft and fixation the new system demonstrated higher stabilizing effects in flexion/extension and lateral bending and restored axial stability beyond the intact spine, as well as having comparable or improved effects compared with the current system. Because of this biomechanical characterization a clinical trial is warranted; the usefulness of the new system has already been demonstrated in 45 patients in our department and more than 300 cases in a multicenter study which is currently under way.

Metachronous and multiple aneurysmal bone cysts: a rare variant of primary aneurysmal bone cysts

In 1942, Jaffe and Lichtenstein introduced the term aneurysmal bone cyst (ABC). Primary ABC is characterized by the presence of spongy or multi-cameral cystic tissue filled with blood. The process is benign, but it is locally destructive and has a high propensity for recurrence. In this paper, we present the third case of multiple metachronous primary ABCs as a rare variant of ABC. We describe the 10-year history of a 12-year-old boy with metachronous multiple primary ABCs at five different sites (right proximal humerus, right ulna, bilateral distal radius and right lateral clavicle). Furthermore, our patient suffered from vascular malformations, such as aortic isthmus stenosis, hypoplastic thoraco-abdominal aorta and bilateral renal artery stenosis. To date, in contrast to solitary ABC, the multiple lesions have been found more frequently in male individuals. Using interphase cytogenetics, we analyzed three of five of the patient's ABCs and one of these was also analyzed by GTG-banding. No chromosomal abnormalities were found. Significantly, we excluded the missense mutation of codon 201 in guanine nucleotide-binding protein 1 gene consistently found in McCune-Albright syndrome (MAS) and in non-MAS cases of polyostotic fibrous dysplasia of bone with or without secondary ABC.

[Do organizational structures and factors influence the outcome of physiotherapy--a questionnaire survey related to whiplash-associated disorders]

BACKGROUND

The effectiveness of physiotherapy in patients with whiplash injuries of the cervical spine is a subject of critical discussion. Besides the inadequate situation with regard to the medical data available and the financial cuts in drug prescription, organizational factors and structures are assumed to be factors that have an influence on the effectiveness of physiotherapy.

AIM

The aim of this study was to evaluate data on training, patient population, communication, prescription activity and therapies of physiotherapists.

METHODS

In a survey of 213 physiotherapists in the City of Ulm, data were collected with the aid of questionnaires related to "therapy of whiplash-associated disorders".

RESULTS

The results show deficits in the theoretical knowledge of physiotherapists, in the exchange of information and in therapy management. The survey further revealed that 22% of the patients decide themselves which therapy they will undergo. One can assume that these factors have a detrimental effect on the effectiveness of conservative therapy.

CONCLUSION

An optimization of the organizational structures is thus urgently required and constitutes the only possibility, in the short to medium term, of improving the effectiveness of physiotherapy in patients with whiplash injuries of the cervical spine.

Minimally invasive ventral spondylodesis for thoracolumbar fracture treatment: surgical technique and first clinical outcome

A new instrumentation system for ventral stabilization of the spine that can be used for an endoscopic and minimally invasive approach was developed. We describe the implantation technique and report on the first clinical results. This prospective study covers the first 45 patients to undergo this new technique since it was introduced in 1999. In all patients the operation was successfully performed in a completely minimally invasive procedure. Mono- and bisegmental stabilization was performed mainly at the thoracolumbar junction after initial posterior instrumentation in most cases. Lesions varied from fresh/old fractures to metastases (T5-L3). Pre- and postoperative follow-up included clinical examination and radiological visualization via X-ray and computed tomographic scan. Our experience with this minimally invasive procedure demonstrated the feasibility of the method.

Axial compression force measurement acting across the strut graft in thoracolumbar instrumentation testing

OBJECTIVE

Current recommendations for spinal implant testing do not consider the determination of axial compression forces of the overbridging implant on the strut graft. No direct data exist on the influence of load transfer through the strut graft and of the kind of instrumentation, especially in thoracolumbar corpectomy models.

DESIGN

Therefore in this biomechanical in vitro study a method for measurement of the axial compression force acting across the strut graft in different thoracolumbar instrumentations was developed.

METHODS

In this in vitro study, a corpectomy model was simulated and anterior, posterior and combined short fixation devices currently available were tested under pure moments to evaluate their biomechanical stabilizing characteristics. Range of motion, neutral zone and the axial compressive force acting on the strut graft were measured continuously in the three primary directions.

RESULTS

Without loads, the combined stabilization and followed by anterior instrumentation created a higher axial compression force than the dorsal instrumentation on the strut graft. Especially during maximal extension there was no axial compression of the dorsal instrumentation on the strut graft, which resulted in an increase of the range of motion.

CONCLUSION

The feasibility of the new method was demonstrated in this study. For the purpose of standardization and comparison it should be considered in spinal implant testing.

Guidelines for the intramuscular positioning of EMG electrodes in the semispinalis capitis and cervicis muscles

The objective of the study was to establish guidelines for the application of fine-wire or needle electrodes in the semispinalis cervicis and semispinalis capitis muscles. First of all, measured data for the puncture angle and puncture depth of each muscle were determined in CT scans. Using a regression approach, a model relation of these data with the neck circumference was established. This made it possible to accurately determine the puncture angle and puncture depth on the basis of the known neck circumference. In a further step, the neck muscles of seven human cadavers were punctured with wires in order to check the workability of these guidelines. At the same time, the wires' positions in relation to important structures (nerves, vessels) were studied. Both muscles can be punctured with a high degree of reliability. However, when puncturing the semispinalis cervicis muscle, one has to pass through a layer that contains vessels, nevertheless the risk of injury is regarded as very small. The technique enables intramuscular EMG measurements of the two muscles in manifold clinical problems.

[OR-manager: surgeon or anaesthetist?]

The heart of any surgical department is the operating room (OR) area. Any disturbances in the daily routine will affect the work flow of the whole hospital. On account of its central function, with numerous connections to other departments, the OR is the crystallisation point for deficiencies in various events and processes. As an example, the major complaints made by a surgical department regarding workflow and communication are outlined. To solve these problems, an "OR organization" team was established, which worked on the basis of a newly developed OR statute. Within 1 year the employees were more contentment and the workflow had improved. However, even in the second year of central OR management there is still the need to further stabilize the system as mismanagement still occurs.

[Occupational disease 2108. Degenerative changes of the cervical spine as a causality criterion in the assessment of discogenic diseases according to BeKV 2108]

With the second amendment to the Ordinance on Occupational Diseases (BeKV) of 18 December 1992, discogenic diseases of the spine are included in the disease register of occupational diseases for the first time. If occupations that impose stress on the spine have been practised for many years, the possibility exists of recognizing degenerative diseases as an occupational disease. In assessment practice, the radiological data on the spine exposed to stress is compared with that of regions which are remote from the stress (cervical/thoracic spine). This pattern of the distribution of degenerative disease is then used as the basis for determining a causal relationship between the occupation causing the stress and disease of the axial skeleton. The pattern of degeneration of the cervical spine was investigated in two groups, one with ( n =153) and one without ( n =333) occupations that impose stress on the lumbar spine. A cumulative score of degenerative changes was elaborated and presented as a new classification. No differences were found between the groups with regard to either the frequency of occurrence, segmental distribution or severity of disease. In both groups, degenerative changes correlated with age. The prevailing assessment practice is discussed on the basis of these data.

Enhanced primary stability through additional cementable cannulated rescue screw for anterior thoracolumbar plate application

OBJECT

The authors conducted a study to investigate the biomechanical in vitro influence of a new anchorage system for fixation of anterior stabilization devices and the possibility of using additional cement after screw insertion to compensate for poor bone quality. The incidence of osteoporosis-related fractures has increased nearly twofold in the last decade. Because of problems associated with anterior screw fixation such as loosening, mechanical failure, and the weakness of osteoporotic bone, current surgical treatments of vertebral body (VB) fractures are problematic. This is due to poor fixation strength of anterior screws in the adjacent segments. The aim of this study was to determine whether a new cemented and uncemented VB screw provides improved primary stability following placement of anterior instrumentation in cases of fracture.

METHODS

The primary stability-related parameters of a new uncemented/cemented screw were compared with those of conventional monocortical screw fixation in a burst fracture model in which strut graft and anterior overbridging instrumentation were used. The use of the new uncemented screw improved the range of motion (ROM) of the stabilized spine in flexion-extension by approximately 22%, in rotation by 20%, and in lateral bending by 15%. Additional cementation improved the ROM by approximately 41% in flexion-extension, 32% in rotation, and 30% in lateral bending compared with conventional monocortical screw fixation.

CONCLUSIONS

The new cannulated screw improves fixation strength and primary stability parameters. It is useful in the initial treatment of fractures in cases of poor bone quality and as a rescue device if previously inserted screws do not remain securely in place.

[Flat rate reimbursement system for minimally invasive management of unstable vertebral fractures. An analysis of costs and benefits]

Some 30% of unstable vertebral fractures of the thoracic and lumbar spine involve a destruction of the ventral column and thus of the supporting structures of the spine. This requires extensive surgical reconstruction procedures, which are carried out using minimally invasive techniques. The disadvantages of the minimally invasive methods are the high cost, the technical equipment and the expenditure of time required in the initial phase for the performance of the surgical procedure. With the structural reform of the health care system in the year 2000, the private-sector regulatory bodies were called upon to introduce a flat-rate compensation system for hospital services according to section 17b of the Hospital Law (KHG). The previous financing system which involved per-diem operating cost rates has thus been abolished. Calculations of individual entities are now required. Considering the case values to date, a contribution margin deficit of EUR 4628.45 has been calculated for our patients with fractures of the thoracic and lumbar spine without neurological defunctionalization symptoms. An economically efficient medical care is thus no longer possible. Consequently, an adjustment of the German relative weights must urgently be demanded in order to guarantee a high-quality medical care of patients.

Spinal navigation in tumor surgery of the thoracic spine: first clinical results

In this clinical study, the accuracy of computed tomography-based and computer-guided decompression and insertion of pedicle screws in patients who have had tumor-related posterior surgery of the thoracic spine was evaluated. Eight patients with advanced metastatic disease were treated surgically using a posterior approach with the assistance of an optoelectronic navigation system. Postoperative computed tomography scans were obtained for all patients and provided information regarding decompression and transpedicle implant localization. In all eight patients accurate decompression of the spinal canal was seen. Using the navigation system, 22 of 26 scheduled transpedicle screws were inserted using computer guidance. Eighty-six percent (19 of 22) of the navigated pedicle screws were positioned centrally in the bone. Initial results indicate that computer-aided frameless navigation in tumor surgery of the thoracic spine is a safe system to improve surgical performance during posterior decompression and transpedicle stabilization. Although computed tomography-based computer-assisted spinal navigation is important, the system is not 100% accurate. Therefore, application of the navigation system should be restricted to experienced surgeons who can continue the operation using a conventional approach. Finally, detailed knowledge of the principles of the tracking systems is necessary to prevent possible misinterpretation of information provided by the computer.

[Combined posterior and anterior endoscopic supported instrumentation of the thoracic and lumbar spine. Arguments, concepts and first clinical results]

The operative therapeutic principles of thoracic and lumbar spine injuries are based on reposition, decompression and stabilization of the unstable area. Secondary loss of correction and consecutive deformation have negative impact on the long-term results after defect fractures of vertebral bodies and will be minimized only by the reconstruction of all involved spinal columns. With dissemination of thoracoscopic techniques at the thoracic spine and minimal invasive retroperitoneal approaches at the lumbar spine a decrease of the morbidity was achieved with equal effectivity for recalibration and fusion. Our experiences with the first consecutive 42 patients, treated minimal invasive are presented. Indications for anterior thoracoscopic and minimal invasive instrumentations after posterior transfixation are remaining osseous defects of the end plates of more than a quarter of the volume of the involved vertebra in case of migration of the vertebral disc, wedging of the vertebral body after posterior reposition of more than 10 degrees and persisting anterior encroachment of the spinal canal of more than 30 %. The decision is based on radiographs and CT-scans, performed after posterior stabilization.

[MACS-TL polyaxial screw XL. A new concept for increasing stability of ventral spondylodesis in the presence of dorsal injuries]

The influence of additional dorsal structure damage on anterior stabilization of thoracolumbar fracture is still unknown. Screw cement enhancement is a possibility to reinforce the stability of anterior instrumentation. A new anchorage system has been developed for fixation of anterior stabilization devices, adapted through geometric optimization and the possibility of optional additional cementation after screw insertion in cases of poor bone quality. Is this enhancement strong enough to support a single anterior procedure such as the thoracoscopic technique and still compensate for dorsal instability? A biomechanical in vitro study simulating an anterior corpectomy, strut grafting, and overbridging stabilization with a dorsal laminectomy as dorsal structure damage was performed, and the primary stability parameters were evaluated with and without screw cement enhancement. The additional cementation enhanced the primary stability of the anterior instrumentation and compensated for dorsal instability.

[MAC-TL twin screw. A new thoracoscopic implantable stabilization system for treatment of vertebral fractures--implant design, implantation technique and in vitro testing]

Due to the lack of an appropriate instrumentation system for minimally invasive procedures to treat spinal fracture, a new thoracoscopically implantable stabilization system was developed. This report describes the new implant design and implantation technique. In a biomechanical in vitro study, an anterior corpectomy model representing the worst case of burst fracture instability was simulated, and the primary stability parameters of the new system were evaluated in comparison to a dorsal stabilization system. With the interbody graft and fixation, the new system demonstrated higher stabilizing effects in flexion/extension and lateral bending and restored axial stability beyond the intact spine and the dorsal stabilization system. Considering all the advantages of the endoscopic procedure and this biomechanical characterization, the clinical trial is warranted; its usefulness has been demonstrated in more than 150 cases in a multicenter study to date.