Development of a mapping function ("crosswalk") for the conversion of scores between the Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI).

INTRODUCTION: The Oswestry Disability Index (ODI) and the Core Outcome Measures Index (COMI) are two commonly used self-rating outcome instruments in patients with lumbar spinal disorders. No formal crosswalk between them exists that would otherwise allow the scores of one to be interpreted in terms of the other. We aimed to create such a mapping function. METHODS: We performed a secondary analysis of ODI and COMI data previously collected from 3324 patients (57 ± 17y; 60.3% female) at baseline and 1y after surgical or conservative treatment. Correlations between scores and Cohen's kappa for agreement (κ) regarding achievement of the minimal clinically important change (MCIC) score on each instrument (ODI, 12.8 points; COMI, 2.2 points) were calculated, and regression models were built. The latter were tested for accuracy in an independent set of registry data from 634 patients (60 ± 15y; 56.8% female). RESULTS: All pairs of measures were significantly positively correlated (baseline, 0.73; 1y follow-up (FU), 0.84; change-scores, 0.73). MCIC for COMI was achieved in 53.9% patients and for ODI, in 52.4%, with 78% agreement on an individual basis (κ = 0.56). Standard errors for the regression slopes and intercepts were low, indicating excellent prediction at the group level, but root mean square residuals (reflecting individual error) were relatively high. ODI was predicted as COMI × 7.13-4.20 (at baseline), COMI × 6.34 + 2.67 (at FU) and COMI × 5.18 + 1.92 (for change-score); COMI was predicted as ODI × 0.075 + 3.64 (baseline), ODI × 0.113 + 0.96 (FU), and ODI × 0.102 + 1.10 (change-score). ICCs were 0.63-0.87 for derived versus actual scores. CONCLUSION: Predictions at the group level were very good and met standards justifying the pooling of data. However, we caution against using individual values for treatment decisions, e.g. attempting to monitor patients over time, first with one instrument and then with the other, due to the lower statistical precision at the individual level. The ability to convert scores via the developed mapping function should open up more centres/registries for collaboration and facilitate the combining of data in meta-analyses.

Development of a machine-learning based model for predicting multidimensional outcome after surgery for degenerative disorders of the spine.

BACKGROUND: It is clear that individual outcomes of spine surgery can be quite heterogeneous. When consenting a patient for surgery, it is important to be able to offer an individualized prediction regarding the likely outcome. This study used a comprehensive set of data collected over 12 years in an in-house registry to develop a parsimonious model to predict the multidimensional outcome of patients undergoing surgery for degenerative pathologies of the thoracic, lumbar or cervical spine. METHODS: Data from 8374 patients (mean age 63.9 (14.9-96.3) y, 53.4% female) were used to develop a model to predict the 12-month scores for the Core Outcome Measures Index (COMI) and its subdomain scores. The data were split 80:20 into a training and test set. The top predictors were selected by applying recursive feature elimination based on LASSO cross validation models. Based on the 111 top predictors (contained within 20 variables), Ridge cross validation models were trained, validated, and tested for each of 9 outcome domains, for patients with either "Back" (thoracic/lumbar spine) or "Neck" (cervical spine) problems (total 18 models). RESULTS: Among the strongest outcome predictors in most models were: preoperative scores for almost all COMI items (especially axial pain (back or neck) and peripheral pain (leg/buttock or arm/shoulder)), catastrophizing, fear avoidance beliefs, comorbidity, age, BMI, nationality, previous spine surgery, type and spinal level of intervention, number of affected levels, and surgeon seniority. The R2 of the models on the validation/test sets averaged 0.16/0.13. A preliminary online tool was programmed to present the predicted outcomes for individual patients, based on their presenting characteristics. https://linkup.kws.ch/prognostictool . CONCLUSION: The models provided estimates to enable a bespoke prediction of the outcome of surgery for individual patients with varying degenerative pathologies and baseline characteristics. The models form the basis of a simple, freely-available online prognostic tool developed to improve access to and usability of prognostic information in clinical practice. It is hoped that, following confirmation of its validity and practical utility, the tool will ultimately serve to facilitate decision-making and the management of patients' expectations.

Vertebral osteomyelitis is characterised by increased RANK/OPG and RANKL/OPG expression ratios in vertebral bodies and intervertebral discs.

Vertebral osteomyelitis (VO) is an infection of the spine mainly caused by bacterial pathogens. The pathogenesis leading to destruction of intervertebral discs (IVDs) and adjacent vertebral bodies (VBs) is poorly described. The present study aimed at investigating the connection between infection and bone/disc metabolism in VO patients. 14 patients with VO (infection group) and 14 patients with burst fractures of the spine (fracture group; control) were included prospectively. Tissue biopsies from affected IVDs and adjacent VBs were analysed by RT-qPCR for mRNA-expression levels of 18 target genes including chemokines, adipokines and genes involved in bone metabolism. Most importantly, the receptor activator of NF-κB/osteoprotegerin (RANK/OPG) expression ratio was drastically elevated in both VBs and IVDs of the infection group. In parallel, expression of genes of the prostaglandin-E2-dependent prostanoid system was induced. Such genes regulate tissue degradation processes via the triad OPG/RANK/RANKL as well as via the chemokines IL-8 and CCL-20, whose expression was also found to be increased upon infection. The gene expression of the adipokine leptin, which promotes inflammatory tissue degradation, was higher in IVD tissue of the infection group, whereas the transcription of omentin and resistin genes, whose functions are largely unknown in the context of infectious diseases, was lower in infected VBs. In summary, similar expression patterns of pro-inflammatory cytokines and pro-osteoclastogenic factors were identified in VBs and IVDs of patients suffering from VO. This suggests that common immuno-metabolic pathways are involved in the mechanisms leading to tissue degradation in VBs and IVDs during VO.

Patient-rated outcome after atlantoaxial (C1-C2) fusion: more than a decade of evaluation of 2-year outcomes in 126 patients.

INTRODUCTION: Various surgical techniques have been introduced for atlantoaxial (C1-C2) fusion, the most common being Magerl's (transarticular) or the Harms/Goel screw fixation. Common indications include degenerative osteoarthritis (OA), trauma or rheumatoid arthritis (RA). Only few, small studies have evaluated patient-reported outcomes after C1-C2 fusion. We investigated 2-year outcomes in a large series of consecutive patients undergoing isolated C1-C2 fusion. METHODS: We analysed prospectively collected data (2005-2016) from our Spine outcomes database, collected within the framework of EUROSPINE's Spine Tango Registry. It included 126 patients (34 (27%) men, 92 (73%) women; mean (SD) age 67 ± 19 y) who had undergone first-time isolated C1-C2 fusion (61% Magerl, 39% Harms(-Goel)) at least 2 years ago for OA (83 (66%)), RA (20 (16%)), fracture (15 (12%)) or other (8 (6%)). Patients completed the multidimensional Core Outcome Measures Index (COMI; 0-10) and various single item outcomes. RESULTS: Questionnaires were returned by 118/126 (94%) patients, 2 years post-operative. Mean COMI scores showed a significant reduction from baseline: 6.9 ± 2.4 to 2.7 ± 2.5 (p < 0.0001). Overall, 75% patients achieved the MCIC of ≥ 2.2 points reduction in COMI and 88% reported a good global outcome. 91% patients were satisfied/very satisfied with their care. Self-reported complications were declared by 16% patients and further surgery at the same segment, by 2.5%. CONCLUSION: In this large series with almost complete follow-up, C1-C2 fusion showed extremely good results. Despite the complexity of the intervention, outcomes surpassed those typically reported for simple procedures such as ACDF and lumbar discectomy, suggesting reservations about the procedure should perhaps be reviewed.

What level of symptoms are patients with adult spinal deformity prepared to live with? A cross-sectional analysis of the 12-month follow-up data from 1043 patients.

INTRODUCTION: Previous studies suggest that a meaningful and easily understood measure of treatment outcome may be the proportion of patients who are in a "patient acceptable symptom state" (PASS). We sought to quantify the score equivalent to PASS for different outcome instruments, in patients with adult spinal deformity (ASD). METHODS: We analysed the following 12-month questionnaire data from the European Spine Study Group (ESSG): Oswestry Disability Index (ODI; 0-100); Numeric Rating Scales (NRS; 0-10) for back/leg pain; Scoliosis Research Society (SRS) questionnaire; and an item "if you had to spend the rest of your life with the symptoms you have now, how would you feel about it?" (5-point scale, dichotomised with top 2 responses "somewhat satisfied/very satisfied" being considered PASS+, everything else PASS-). Receiver operating characteristics (ROC) analyses indicated the cut-off scores equivalent to PASS+. RESULTS: Out of 1043 patients (599 operative, 444 non-operative; 51 ± 19 years; 84% women), 42% reported being PASS+ at 12 months' follow-up. The ROC areas under the curve were 0.71-0.84 (highest for SRS subscore), suggesting the questionnaire scores discriminated well between PASS+ and PASS-. The scores corresponding to PASS+ were > 3.5 for the SRS subscore (> 3.3-3.8 for SRS subdomains); ≤ 18 for ODI; and ≤ 3 for NRS pain. There were slight differences in cut-offs for subgroups of age, treatment type, aetiology, baseline symptoms, and sex. CONCLUSION: Most interventions for ASD improve patients' complaints but do not totally eliminate them. Reporting the percentage achieving a score equivalent to an "acceptable state" may represent a more stringent and discerning target for denoting treatment success in ASD. These slides can be retrieved under Electronic Supplementary Material.

How does patient-rated outcome change over time following the surgical treatment of degenerative disorders of the thoracolumbar spine?

PURPOSE: Patient-rated measures are considered the gold standard for assessing the outcome of spine surgery, but there is no consensus on the appropriate timing of follow-up. Journals often demand a minimum 2-year follow-up, but the indiscriminate application of this principle may not be warranted. We examined the course of change in patient outcomes up to 5 years after surgery for degenerative spinal disorders. METHODS: The data were evaluated from 4287 consecutive patients (2287 women, 2000 men; aged 62 ± 15 years) with degenerative disorders of the thoracolumbar spine, undergoing first-time surgery at the given level between 01/01/2005 and 31/12/2011. The Core Outcome Measures Index (COMI; scored 0-10) was completed by 4012 (94%) patients preoperatively, 4008 (93%) at 3-month follow-up, 3897 (91%) at 1-year follow-up, 3736 (87%) at 2-year follow-up, and 3387 (79%) at 5-year follow-up. 2959 (69%) completed the COMI at all five time-points. RESULTS: The individual COMI change scores from preoperatively to the various follow-up time-points showed significant correlations ranging from r = 0.50 (for change scores at the earliest vs the latest follow-up) to r = 0.75 (for change scores after 12- vs 24-month follow-up). Concordance with respect to whether the minimum clinically important change score was achieved at consecutive time-points was also good (70-82%). COMI decreased significantly (p < 0.05) from preop to 3 months (by 3.6 ± 2.8 points) and from 3 to 12 months (by 0.3 ± 2.4 points), then levelled off up to 5 years (0.04-0.05 point change; p > 0.05). The course of change up to 12 months differed slightly (p < 0.05) depending on pathology/whether fusion was carried out. For patients undergoing simple decompression, 3-month follow-up was sufficient; those undergoing fusion continued to show further slight but significant change up to 12 months. CONCLUSIONS: Stable group mean COMI scores were observed for all patients from 12 months postoperatively onwards. The early postoperative results appeared to herald the longer term outcome. As such, a 'wait and see policy' in patients with a poor initial outcome at 3 months is not advocated. The insistence on a 2-year follow-up could result in a failure to intervene early to achieve better long-term outcomes.

Posterolateral fusion in acute traumatic thoracolumbar fractures: a comparison of demineralized bone matrix and autologous bone graft.

UNLABELLED: INTRODUCTION Alternative fusion expanders are in clinical use for instrumented posterolateral fusion (PLF) to avoid donor site morbidity in autologous bone graft (ABG) harvesting. Purpose of this study was to evaluate demineralized bone matrix (DBM) in PLF as alternative to the gold standard of ABG in acute traumatic vertebral body fractures of the thoracolumbar spine. MATERIAL AND METHODS We retrospectively identified 101 patients with acute traumatic vertebral body fractures of the thoracic and lumbar spine who were treated with instrumented PLF in our level one trauma center between 2005 and 2011. Patients with a primary paraplegia, osteodepriving disease or loss to follow-up had been excluded. Until August 2008, autologous bone graft harvested from the posterior iliac crest was used in PLF (control group n = 46). Starting September 2008, DBM was used as fusion expander in PLF (study group n = 16). Clinical and radiological evaluation was performed with a minimum followup of 18 months to assess the clinical and radiological outcome. RESULTS We found a fusion rate of 94% in patients undergoing PLF with the use of DBM and 100% with the use of ABG. There was one major complication of deep infection in the DBM group and two cases of superficial wound infection in the ABG group. We discovered a trend of reduced operating time with the use of DBM. CONCLUSIONS DBM leads to a similar fusion rate as the use of ABG in patients undergoing PLF for acute traumatic vertebral body fractures of the thoracic and lumbar spine. DBM is associated with reduced operating time. LEVEL OF EVIDENCE III: case-control study Key words: demineralized bone matrix instrumented posterolateral fusion, acute traumatic vertebral body fracture, thoracolumbar spine, autologous bone graft.

Evidence based postoperative treatment of distal radius fractures following internal locking plate fixation.

Originally, the treatment method of choice for distal radial fractures (DRF) has been a non-operative approach with six to eight weeks of plaster casting. The introduction of volar locking plate systems at the beginning of the 21 st century has pushed trends towards open reduction and internal fixation (ORIF). While the introduction of fixed angle locking plates together with the increasing knowledge on wrist function and related variable outcomes has led to consensus that operative fixation in instable DRF is the treatment method of choice, there is no agreement on a postoperative care of these injuries. The authors will discuss the available evidence for current concepts of postoperative treatment of DRFs following fixed angle fixation under socioeconomical, biomechanical and burden of disease aspects. Further, relevant randomized controlled trials are evaluated with regard to applied postoperative treatment regimes and related risks for complications.

Association of high volumes of hydroxyethyl starch with acute kidney injury in elderly trauma patients.

INTRODUCTION: Initial fluid resuscitation in trauma is still controversial. Hydroxyethyl starch (HES), a commonly used fluid for resuscitation in trauma patients, has potential nephrotoxic effects. Advancing age is a known risk factor for acute kidney injury (AKI) in trauma patients. Therefore, the objective of this study was to evaluate the impact of large volumes of HES 130/0.4 on renal function in trauma patients, with a particular focus on the significance of age. METHODS: A retrospective review of all patients admitted to the Trauma Centre of the University Hospital Regensburg from September 1, 2007 to December 31, 2012 was performed. This investigation used data from the TraumaRegister of the German Trauma Society (DGU®), including preclinical data from the prehospital emergency physician's protocol, the patient data management system of the intensive care units and the anaesthesia protocols of the emergency room and the operating room. AKI was evaluated according to the risk, injury, failure, loss, or end-stage kidney disease (RIFLE) criteria. The rate of AKI and the rate of renal replacement therapy (RRT) were compared between patients who received<2000ml HES 130/0.4 during the first 24h (L-HES) after trauma and patients who received≥2000ml HES 130/0.4 during the first 24h (H-HES) after trauma. An additional sub analysis of patients older than 59 years of age was performed. RESULTS: A total of 260 patients were included. Although patients in the H-HES group showed a higher injury severity score, the incidence of AKI and RRT were comparable. Furthermore, the sub analysis of patients older than 59 years of age also demonstrated similar results regarding incidence of AKI and the rate of RRT. CONCLUSIONS: Fluid resuscitation with more than 2000ml HES (130kD/0.4) during the first twenty four hours after trauma was not associated with an increased incidence of AKI or need for RRT in trauma patients compared to patients who were administered<2000ml HES (130kD/0.4). The analysis of patients older than 59 years of age did not demonstrate any difference in the incidence of AKI or the need for RRT.

Pressure monitoring during lipofilling procedures.

BACKGROUND: Grafting of autologous lipoaspirate for various clinical applications has become a common procedure in clinical practice. With an estimated mortality rate of 10-15 percent, fat embolism is among the most severe complications to be expected after lipofilling therapies. OBJECTIVE: The aim of this study was to determine the level of interstitial pressure after the injection of defined volumes of lipoaspirate into the subcutaneous tissue of female breasts. It was hypothesized, that interstitial pressure levels exceed the physiologic capillary pressure during lipofilling procedures and hence increase the potential risk for fat embolism. Further it was investigated if external tissue expansion has the potential to significantly reduce interstitial tissue pressure. METHODS: Interstitial pressure was monitored in 36 female patients, that underwent autologous fat injections into the breast. Measurements were conducted with a sensor needle connected to a pressure transducer (LogiCal Pressure Monitoring Kit, Smiths medical int. Ltd., UK). Patients were divided into 4 subcohorts differing in their pre-treatment regimen or local tissue conditions. Pre-treatment consisted of tissue expansion, achieved with the Brava™ (Brava LLC Miami, Fla., USA) vacuum-chamber. RESULTS: The increase in interstitial pressure after injection volumes of 100 ml (p = 0.006), 200 ml (p = 0.000) and between 100 ml and 200 ml (p = 0.004) respectively, were significant in non-mastectomized patients without pre-treatment. Patients pre-treated with Brava™ did not show such statistically significant differences in interstitial pressures before and after the injection of 100 ml and 200 ml of lipoaspirate (p = 0.178). The difference in interstitial pressure in mastectomized patients between 0 ml and 100 ml (p = 0.003), as well as 0 ml and 200 ml (p = 0.028) was significant. The difference in pressures between pre-treated patients and patients without pre-treatment did not differ significantly in the mastectomized patient cohort. CONCLUSION: During lipofilling procedures interstitial pressures are reached that exceed pressure limits defined as hazardous for fat embolism. To date it is unknown what pressure levels need to be considered critical for complications in soft tissue interventions. Further the results indicate higher interstitial pressures for patients that had undergone mastectomy, whereas pre-treatment with external tissue expansion seemed to diminish pressure values.

Outcome-related co-factors in 105 cases of vertebral osteomyelitis in a tertiary care hospital.

PURPOSE: Vertebral osteomyelitis (VO) is an infection of the vertebral body and the adjacent disc space. The aim of our study was to identify outcome-related co-factors of patients with VO treated in the last decade. METHODS AND RESULTS: We retrospectively identified 105 patients with VO (mean age 66.1 years) who had been treated at our institution from 2004 to 2011. The median time of hospitalization at our institution was 31.5 days, and 44 patients required intensive medical care. Back pain and fever were documented in 66.7 and 33.3 % of cases, respectively. The radiologic diagnosis of VO was made in 94.8 % of all obtained magnetic resonance imaging scans and in 66.2 % of all computed tomography (CT) scans. Biopsies were taken in 71 patients, and the causative organisms were identified in 56.2 % of patients, with Staphylococcus aureus being the predominant pathogen. Fifty-six patients underwent surgical treatment. During hospitalization, infectious complications were observed in 63 patients (60.0 %). The most common complications were psoas, paravertebral and epidural abscesses. Patients with S. aureus infections had a significantly higher rate of infectious complications than those without (76.5 vs. 40.3 %, respectively), and were more frequently treated in intensive care units (58.8 vs. 34.7 %, respectively). Overall in-hospital mortality rate was 12.4 %. Elevated C-reactive protein levels at admission, advanced age and a Charlson Comorbidity Index of ≥2 were associated with higher mortality. CONCLUSIONS: Magnetic resonance imaging currently is the imaging procedure of choice for the radiologic diagnosis of VO. Mortality is attributable in part to co-morbidities. However, infections with S. aureus are frequent in this patient population and are associated with a higher rate of complications and a trend towards higher mortality.

3D scaffolds co-seeded with human endothelial progenitor and mesenchymal stem cells: evidence of prevascularisation within 7 days.

Blood supply is a critical issue in most tissue engineering approaches for large defect healing. As vessel ingrowth from surrounding tissues is proven to be insufficient, current strategies are focusing on the neo-vascularisation process. In the present study, we developed an in vitro pre-vascularised construct using 3D polyurethane (PU) scaffolds, based on the association of human Endothelial Progenitor Cells (EPC, CD34+ and CD133+) with human Mesenchymal Stem Cells (MSC). We showed the formation of luminal tubular structures in the co-seeded scaffolds as early as day 7 in culture. These tubular structures were proven positive for endothelial markers von Willebrand Factor and PECAM-1. Of special significance in our constructs is the presence of CD146-positive cells, as a part of the neovasculature scaffolding. These cells, coming from the mesenchymal stem cells population (MSC or EPC-depleted MSC), also expressed other markers of pericyte cells (NG2 and αSMA) that are known to play a pivotal function in the stabilisation of newly formed pre-vascular networks. In parallel, in co-cultures, osteogenic differentiation of MSCs occurred earlier when compared to MSCs monocultures, suggesting the close cooperation between the two cell populations. The presence of angiogenic factors (from autologous platelet lysates) in association with osteogenic factors seems to be crucial for both cell populations' cooperation. These results are promising for future clinical applications, as all components (cells, growth factors) can be prepared in an autologous way.

Sonoelastography can be used to monitor the restoration of Achilles tendon elasticity after injury.

PURPOSE: The aim of the current study was to evaluate an ultrasound approach for depicting elastic recovery after stem cell application on injured Achilles tendons. MATERIALS AND METHODS: A rabbit Achilles tendon injury model was used and randomized hind limbs received an extracellular matrix either with autologous mesenchymal stem cells (group 2, n = 6) or without (group 3, n = 6). The cells were harvested from the rabbits' nuchal fat body. Untreated Achilles tendons (group 1, n = 6) served as controls. Specimens were harvested after 8 weeks and analyzed longitudinally for elasticity using a high resolution 6-15 MHz matrix linear probe. For each tendon, real-time color-coded sonoelastography sequences were recorded for 20 seconds and 10 color histogram frames were obtained. Defined regions of interest (ROIs) were placed on the injury (n = 3) and on the adjacent uninjured tendon tissue (n = 3). In total, 180 measurements were obtained for semi-quantitative analysis. RESULTS: Repeated measures ANOVA demonstrated a higher elasticity for the stem cell-seeded matrix (group 2) in comparison to the unseeded matrix (group 3) (p < 0.001). No significant difference was found between the injured tendon tissue treated with stem cell-seeded matrix (group 2) and the uninjured Achilles tendons (group 1) (p > 0.05). Moreover, no differences were found between the measurements at different points in time (p > 0.05). CONCLUSION: Our results indicate that autologous mesenchymal stem cell application successfully restores the mechanical properties of injured tendon tissue. Furthermore, sonoelastography makes it possible to monitor the elasticity of injured Achilles tendons.

Non-effective increase of fMRI-activation for motor performance in elder individuals.

Motor performance declines with increasing age and it has been proposed that elder people might compensate for these deficits with increased cerebral activation. However, it is not known, whether increased activation - especially in motor areas of the contralateral and the ipsilateral cerebral hemisphere - might effectively contribute to motor performance or whether it is an ineffective way to counteract age related deficits in the motor system. We tested this question by mapping brain activation during performance of differentially demanding motor tasks in 18 young (mean 25.39 years) and 17 elderly (mean 66.65 years) healthy individuals. We tested a wide range of hand motor tasks from passive wrist movements, fist clenching at different frequencies, to a somatosensory-guided finger pinch task. In the elderly group functional activation was generally increased for all tasks with comparable motor performance for ipsilateral primary and secondary motor areas. The young group showed increased contralateral primary motor cortex activation for the more difficult somatosensory guided precision grip task. We correlated motor performance of the task with high difficulty and comparable performance with fMRI-activation. Elder participants showed a negative correlation for the ipsilateral supplementary motor area (SMA) and for the ipsilateral sensorimotor cortex (SM1). Young participants showed a positive correlation for contralateral SMA and SM1. Our data suggest an increased cerebral recruitment reflects an inefficient response to an age-related higher difficulty of task and is not an effective way to counteract age-related deficits in the motor system.

[A penetrating volar foreign body: a wooden splinter beneath the flexor tendons]. / Fremdkörper in der Hohlhand - Holzsplitter unter den Beugesehnen.

Hand injuries are among the most common injuries seen in general practitioner (GP) consultation hours and emergency departments and are most often affecting the dominant hand. We report on a case of unsuccessful primary exploration of the volar hand for a foreign body by the GP. In regard to detailed history of the injury mechanism, we performed the clinical examination and an additional ultrasound evaluation of the hand, suggesting evidence for a foreign body and a laceration of one of the flexor tendons. Figures are illustrating the mechanism of the injury and emphasize the need for determining the kinematics and course of the injury. The suspicion of a foreign body within the hand requires the consultation of a trained hand surgeon to adequately treat the injury and provide the after-care.