Dynamic assessment of scapholunate ligament status by real-time magnetic resonance imaging: an exploratory clinical study

OBJECTIVE

Clinical-standard MRI is the imaging modality of choice for the wrist, yet limited to static evaluation, thereby potentially missing dynamic instability patterns. We aimed to investigate the clinical benefit of (dynamic) real-time MRI, complemented by automatic analysis, in patients with complete or partial scapholunate ligament (SLL) tears.

MATERIAL AND METHODS

Both wrists of ten patients with unilateral SLL tears (six partial, four complete tears) as diagnosed by clinical-standard MRI were imaged during continuous active radioulnar motion using a 1.5-T MRI scanner in combination with a custom-made motion device. Following automatic segmentation of the wrist, the scapholunate and lunotriquetral joint widths were analyzed across the entire range of motion (ROM). Mixed-effects model analysis of variance (ANOVA) followed by Tukey's posthoc test and two-way ANOVA were used for statistical analysis.

RESULTS

With the increasing extent of SLL tear, the scapholunate joint widths in injured wrists were significantly larger over the entire ROM compared to those of the contralateral healthy wrists (p<0.001). Differences between partial and complete tears were most pronounced at 5°-15° ulnar abduction (p<0.001). Motion patterns and trajectories were altered. Complete SLL deficiency resulted in complex alterations of the lunotriquetral joint widths.

CONCLUSION

Real-time MRI may improve the functional diagnosis of SLL insufficiency and aid therapeutic decision-making by revealing dynamic forms of dissociative instability within the proximal carpus. Static MRI best differentiates SLL-injured wrists at 5°-15° of ulnar abduction.

Epidemiology of distal radius fractures in Germany - incidence rates and trends based on inpatient and outpatient data

We examined incidence rates (IR) for all distal radius fracture (DRF) events based on inpatient and outpatient data from a large statutory health insurance in Germany. Of all DRF, 56% were treated as inpatients, and thus, 44% treated as outpatients. IR were higher in women than in men.

PURPOSE

Although a distal radius fracture (DRF) is one of the most common fractures in the elderly population, epidemiological data are limited. Many studies examine only hospitalized patients, do not analyze time trends, or include only small populations. In this retrospective population-based observational study, routine data on inpatient and outpatient care of persons aged ≥ 60 years insured by a large statutory health insurance in Germany were analyzed from 2014 to 2018.

METHODS

DRF were identified by ICD-10 codes. All DRF events of an individual were considered with a corresponding individual washout period. Incidence rates (IR) and time trends were estimated assuming a Poisson distribution per 100,000 person-years, with 95% confidence intervals [95% CI] and age-sex standardization to the German population in 2018. Associations of calendar year, age, sex, and comorbidity with IR were examined using Poisson regression estimating incidence rate ratios (IRR) with CI.

RESULTS

The study population consists of 974,332 insured individuals, with 16,557 experiencing one or more DRF events during the observation period. A total of 17,705 DRF events occurred, of which 9961 (56.3%) were hospitalized. Standardized IR were 439 [424-453] (inpatient: 240 [230-251], outpatient: 199 [189-209]) in 2014 and 438 [423-452] (inpatient: 238 [227-249], outpatient: 200 [190-210]) in 2018. Female sex, older age, and comorbidity were associated with higher IR and adjusted Poisson regression showed no significant time trend (IRR overall 0.994 [0.983-1.006]).

CONCLUSION

A relevant proportion of DRF were treated in outpatient settings, so both inpatient and outpatient data are necessary for a valid estimate.

Possible effect of the early administration of tranexamic acid on myocardial injury in patients with severe trauma

Hemodynamic stabilization plays a crucial role in the treatment of patients suffering from severe trauma. Current guidelines recommend the early administration of tranexamic acid (TXA) for bleeding control. While less blood loss can result in less end-organ damage, including myocardial injury, TXA also exhibits prothrombotic effects with potentially adverse myocardial effects. The aim of this study was to investigate the association between the administration of TXA and myocardial injury in patients with severe trauma. We conducted a monocentric cohort study including severely injured patients ≥ 18 years [defined by Injury severity score (ISS) ≥ 16], who were admitted to a tertiary care hospital between 2016 and 2019. Primary outcome measure was myocardial injury according to the fourth Universal Definition (= high sensitive troponin T ≥ 14 ng/l). Secondary endpoints were in-hospital major adverse cardiovascular events (MACE) and mortality. Main exposure was defined as administration of TXA during prehospital period. We conducted multivariate logistic regression models including predefined covariables. A total of 368 patients were screened. Among the 297 included patients (72% male, age. 55?21 years), 119 (40%) presented myocardial injury at hospital arrival. TXA was administered to 20/297 (7%) patients in the prehospital setting, and in 96/297 (32%) patients during pre-or in-hospital period. MACE incidence was 9% (26/297) and in-hospital mortality was 26% (76/297). The adjusted odds ratios (OR) for prehospital TXA and myocardial injury, MACE and mortality were 0.75 [95% confidence interval (CI): 0.25-2.23], 0.51 [95%CI: 0.06-4.30] and 0.84 [0.21-3.33], respectively. In the present cohort of patients suffering from severe trauma, prehospital TXA did not affect the incidence of myocardial injury.

Is restoration of vertebral body height after vertebral body fractures and minimally-invasive dorsal stabilization with polyaxial pedicle screws just an illusion?

INTRODUCTION

Thoracolumbar spine fractures often require surgical treatment as they are associated with spinal instability. Optimal operative techniques and treatment are discussed controversially. Aim of our prospective cohort study was to investigate the sagittal alignment after reduction, the secondary loss of reduction and the subjective outcome as well as the causal correlation of these parameters after minimally invasive stabilization of thoracic and lumbar fractures with polyaxial pedicle screws.

MATERIALS AND METHODS

In a single-center study, a total of 78 patients with an average age of 61 ± 17 years who suffered a fracture of the thoracic or lumbar spine were included and subjected to a clinical and radiological follow-up examination after 8.5 ± 8 months. The kyphotic deformity was measured by determining the vertebral body angle, the mono- and bi-segmental wedge angle at three time points. The patients' subjective outcome was evaluated by the VAS spine score.

RESULTS

After surgical therapy, a significant reduction of the traumatic kyphotic deformity was shown with an improvement of all angles (vertebral body angle: 3.2° ± 4.4°, mono- and bi-segmental wedge angle: 3.1° ± 5.6°, 2.0° ± 6.3°). After follow-up, a significant loss of sagittal alignment was observed for all measured parameters with a loss of correction. However, no correlation between the loss of reduction and the subjective outcome regarding the VAS spine scale could be detected.

CONCLUSION

The minimally invasive dorsal stabilization of thoracic and lumbar spine fractures with polyaxial pedicle screws achieved a satisfactory reduction of the fracture-induced kyphotic deformity immediately postoperatively with a floss of reduction in the further course. However, maybe the main goal of this surgical procedure should be the prevention of a complete collapse of the vertebral body instead of a long-lasting restoration of anatomic sagittal alignment.

LEVEL OF EVIDENCE

II.

Dupuytren's Disease Is Mediated by Insufficient TGF-β1 Release and Degradation

Dupuytren's disease (DD) is a fibroproliferative disorder affecting the palmar fascia, causing functional restrictions of the hand and thereby limiting patients' daily lives. The disturbed and excessive myofibroblastogenesis, causing DD, is mainly induced by transforming growth factor (TGF)-β1. But, the extent to which impaired TGF-β1 release or TGF-β signal degradation is involved in pathologically altered myofibroblastogenesis in DD has been barely examined. Therefore, the complex in which TGF-β1 is secreted in the extracellular matrix to elicit its biological activity, and proteins such as plasmin, integrins, and matrix metalloproteinases (MMPs), which are involved in the TGF-β1 activation, were herein analyzed in DD-fibroblasts (DD-FBs). Additionally, TGF-β signal degradation via caveolin-1 was examined with 5-fluoruracil (5-FU) in detail. Gene expression analysis was performed via Western blot, PCR, and immunofluorescence analyses. As a surrogate parameter for disturbed myofibroblastogenesis, 𝛼-smooth-muscle-actin (𝛼-SMA) expression was evaluated. It was demonstrated that latency-associated peptide (LAP)-TGF-β and latent TGF-β-binding protein (LTBP)-1 involved in TGF-β-complex building were significantly upregulated in DD. Plasmin a serinprotease responsible for the TGF-β release was significantly downregulated. The application of exogenous plasmin was able to inhibit disturbed myofibroblastogenesis, as measured via 𝛼-SMA expression. Furthermore, a reduced TGF-β1 degradation was also involved in the pathological phenotype of DD, because caveolin-1 expression was significantly downregulated, and if rescued, myofibroblastogenesis was also inhibited. Therefore, our study demonstrates that a deficient release and degradation of TGF-β1 are important players in the pathological phenotype of DD and should be addressed in future research studies to improve DD therapy or other related fibrotic conditions.

Association between hypotension and myocardial injury in patients with severe trauma

PURPOSE

During resuscitation of patients with severe trauma, guidelines recommend permissive hypotension prior to surgical bleeding control. However, hypotension may be associated with reduced organ perfusion and multiple organ dysfunction, e.g. myocardial injury. The association between hypotension and myocardial injury in trauma patients is underexplored. We hypothesized that hypotension is associated with myocardial injury in this population.

MATERIALS AND METHODS

This retrospective study included patients ≥ 18 years suffering from severe trauma [defined as Injury Severity Score (ISS) ≥ 16] that were treated in the emergency department resuscitation room between 2016 and 2019. Primary endpoint was the incidence of myocardial injury defined as high-sensitive troponin T > 14 ng/l. Main exposure was the duration of arterial hypotension during resuscitation period defined as mean arterial pressure < 65 mmHg.

RESULTS

Out of 368 patients screened, 343 were analyzed (73% male, age: 55 ± 21, ISS: 28 ± 12). Myocardial injury was detected in 143 (42%) patients. Overall in-hospital mortality was 26%. Multivariate binary logistic regression with forced entry of nine predefined covariables revealed an odds ratio of 1.29 [95% confidence interval 1.16-1.44]; p = 0.012) for the association between the duration of hypotension and myocardial injury.

CONCLUSION

The duration of hypotension during resuscitation period is independently associated with the incidence of myocardial injury in patients with severe trauma.

Myocardial Injury Is Associated with the Incidence of Major Adverse Cardiac Events in Patients with Severe Trauma

BACKGROUND

Severe trauma potentially results in end-organ damage such as myocardial injury. Data suggest that myocardial injury is associated with increased mortality in this cohort, but the association with the incidence of in-hospital major adverse cardiac events (MACE) remains undetermined.

METHODS

Retrospective cohort study including adult patients with severe trauma treated at the University Hospital Duesseldorf between January 2016 and December 2019. The main exposure was myocardial injury at presentation. Endpoints were in-hospital incidence of MACE and incidence of acute kidney injury (AKI) within 72 h. Discrimination of hsTnT for MACE and AKI was examined by the receiver operating characteristic curve (ROC) and the area under the curve (AUC). We conducted multivariate logistic regression analysis.

RESULTS

We included 353 patients in our final analysis (72.5% male (256/353), age: 55 ± 21 years). The AUC for hsTnT and MACE was 0.68 [95% confidence interval (CI): 0.59-0.78]. The AUC for hsTnT and AKI was 0.64 [95% (CI): 0.55-0.72]. The adjusted odds ratio (OR) for myocardial injury and MACE was 2.97 [95% (CI): 1.31-6.72], and it was 2.14 [95% (CI): 1.03-4.46] for myocardial injury and AKI.

CONCLUSION

Myocardial injury at presentation in patients with severe trauma is independently associated with the incidence of in-hospital MACE and AKI.

Evaluating the concept of gas‑based intraperitoneal hyperthermia beyond 43˚C in the treatment of peritoneal metastasis: A pilot study

While hyperthermic intraperitoneal applications have demonstrated high efficacy in treating peritoneal metastases (PM), these applications are limited to temperatures of 41-43˚C to prevent a harmful increase in core temperature. However, since gaseous substances display low specific heat capacities, gas-based hyperthermia could potentially increase surface temperatures without affecting the body's core temperature. To the best of our knowledge, the present study is the first to explore the in vivo feasibility of gas-based hyperthermia via spatial and time-based distribution. In the present study, a temperature-isolated, abdominal box model was created with fresh peritoneal tissue exposed to continuous high-volume airflow temperatures ranging between 47 and 69˚C. Heat conduction within the peritoneal tissues was measured using temperature microsensors. Temperature build-up at different time points during the procedure was calculated and the safest option to perform gas-based intraperitoneal hyperthermia beyond 43˚C was identified using an in vivo swine model. In subsequent experiments, viability and cytotoxicity of HT-29 colon cancer cells were measured following short-term hyperthermia. The present study demonstrated that the application of gas-based intraperitoneal hyperthermia with temperatures up to 50˚C is possible without increasing the core temperature to harmful levels. Gas-based intraperitoneal hyperthermia can induce a histological reaction on the peritoneal surface, and it can also result in decreased viability and increased cytotoxicity of HT-29 cells. The concept of extreme hyperthermia may be of great clinical importance as it could significantly increase local cytotoxicity in PM without increasing the body's core temperature. Further studies are required to investigate the benefits, as well as the restrictions, of this novel concept.

Safety, feasibility, and application of intraperitoneal gas-based hyperthermia beyond 43°C in the treatment of peritoneal metastasis: An in-vivo pilot study

BACKGROUND

43°Celsius (C) is currently the highest temperature used in the treatment of peritoneal metastasis (PM). Despite sufficient data on water- based hyperthermic solutions in PM treatment, there is currently no information on gas-based hyperthermia extending beyond 43°C. This study is the first to provide in-vivo data on different organ systems during and after intraperitoneal gas-based hyperthermia beyond 43°C. The aim of this study is to explore in-vivo feasibility, safety, and efficacy of this novel concept from a biological perspective.

METHODS

For this study, three swine were subjected to laparoscopy and subsequent gas-based intraperitoneal hyperthermia at 48°, 49° and 50°C under a high-flow air stream. Intraoperative data from multiple temperature sensors were analysed. Additionally, intraoperative anaesthesiologic and gasometrical data was analysed. Postoperatively, swine were monitored for one week and laboratory work-up was performed on postoperative days 1, 3 and 7.

RESULTS

During gas-based intraperitoneal hyperthermia, anesthesiologic parameters did not exhibit critical values. No intra- or postoperative complications were observed. Distinct temperature measurements on the skin, cystohepatic triangle and esophagus did not display any temperature increase. Postoperative laboratory workup did not show any changes in hemoglobin, white blood cell count, platelets, or kidney function.

DISCUSSION

Based on our data, there are no safety concerns for the application of gas-based hyperthermia between 48 - 50°C. In fact, no critical systemic temperature increase was observed. With respect to possible limitations, further in-vivo studies are required to evaluate whether gas-based intraperitoneal hyperthermia may be a therapeutic option for PM patients.

Screw fixation in the treatment of displaced intra-articular calcaneus fractures: a systematic review protocol

BACKGROUND

The Calcaneus is the largest bone of the foot and the most frequent tarsal bone to be fractured. Overall, it causes round about 10 cases per 100,000 residents per year mainly in men. Especially displaced intra-articular calcaneus fractures often have early and late complications and its associated disability. There are various strategies for the treatment of displaced intra-articular calcaneus fractures, but the gold standard is still subject of a long-standing controversy. Minimally invasive procedures became more common in an attempt to reduce the high rate of complications associated with open reduction and internal fixation. With the increase in minimally invasive techniques, screw fixation also gained in significance. The current literature does not sufficiently elucidate whether the screw fixation is superior to other treatment options especially in relation to adverse events, health-related quality of life and postoperative pain. This study aims to investigate benefits and harms of treating displaced intra-articular calcaneus fractures (types II, III and IV according to Sanders) with screw fixation in adults.

METHODS

A systematic review will be conducted based on the principles described in the Cochrane Handbook. We will include adults with displaced intra-articular calcaneus fractures of Sanders type II, III and IV. The surgical method of screw fixation shall be compared to other surgical interventions to stabilise calcaneus fractures. Primary outcomes are serious adverse events, health-related quality of life and postoperative pain level. MEDLINE, CENTRAL, CINAHL, Web of Science and bibnet.org, ClinicalTrial.gov and the World Health Organization International Clinical Trials Registry Platform (ICTR) will be searched. Screening and data extraction will be performed by two authors independently. A third author will arbitrate disputes. Risk of Bias will be assessed with the Cochrane tool. Meta-analysis will be performed if participants, interventions, comparisons and outcomes are sufficiently similar to ensure a result that is clinically meaningful.

DISCUSSION

Due to the increasing use of minimally invasive techniques and the increasing use of screw fixation instead of open reduction and plate fixation, it is important to analyse the benefits and harms of screw fixation for calcaneus fractures. Screw fixation could, in the future, help to operate in a less invasive and tissue preserving manner while still achieving an adequate functional result for the patient SYSTEMATIC REVIEW REGISTRATION: CRD42021244695.

The influence of fracture severity on postoperative outcome and quality of life after locking plate fixation of proximal humeral fractures

Objective:

For proximal humeral fractures open reduction und internal fixation (ORIF) with a fixed-angle plate is considered the gold standard for surgical management. However, it can lead to poor functional outcomes and is associated with postoperative complications. Therefore, the purpose of this study was to investigate the influence of fracture severity by applying a new classification (simple versus complex) on clinical outcome and quality of life after ORIF of proximal humerus fractures.

Methods:

We conducted a prospective clinical study with an average follow-up period of 12 (SD 1) months after ORIF of proximal humeral fractures with a fixed-angle plate. The postoperative function and quality of life was measured using the Oxford Shoulder Score (OSS) and the Constant Score. Data was tested for statistical significance with the Mann-Whitney test and Fisher's exact test. Based on the findings of this study a simplified fracture classification system has been developed.

Results:

Seventy-two patients with a mean age of 65 years (SD 12) with 69% being males were included. According to the Neer classification, 35% (n=25) non-displaced (“one-part fractures”), 19% (n=14) two-part fractures, 15% (n=11) three-part fractures and 31% (n=22) four-part fractures were detected. Regarding the AO/OTA classification, 18% (n=13) were type A fractures, 43% (n=31) type B and 39% (n=28) type C fractures. From these criteria we derived our own fracture classification, including 50% (n=36) simple and 50% (n=36) severe fractures. Patients with simple fracture types achieved significantly higher total values in the Constant Score as well as the OSS (p=0.008; p=0.013). The cumulative incidence of complications in the entire patient collective was 14% (n=10) with humeral head necrosis (n=5) occurring only in the severe fracture group.

Conclusions:

The postoperative clinical outcome as well as the incidence of humeral head necrosis after ORIF of proximal humeral fractures with a fixed-angle plate correlates with the fracture type and severity. The newly derived fracture classification into simple and severe fractures is suitable with regard to clinical results and complication rate. However, prospective studies comparing ORIF vs. conservative treatment of proximal humeral fractures of the same severity are required.

Level of Evidence:

III

[Differences in injury patterns in motorcycle accidents involving children and adolescents]

Hintergrund

Verkehrsunfälle und ihre Verletzungsfolgen stellen eine häufige traumatische Ursache für das Versterben und für das Auftreten von irreversiblen Schäden bei Kindern und Jugendlichen dar. Bei Motorradunfällen unterscheiden sich dabei Verletzungsmuster abhängig vom Patientenalter.

Ziel der Arbeit

Ziel dieser Studie ist es, die typischen Verletzungsmuster nach Motorradunfällen im Kindes- und Jugendalter vergleichend zu beschreiben, da diese einen ausschlaggebenden Einfluss auf die Prävention sowie die adäquate Behandlung der jeweiligen Patientengruppen bieten können.

Material und Methoden

In die Studie wurden innerhalb der Jahre 2002–2018 22.923 Patienten aus dem TraumaRegister der Deutschen Gesellschaft für Unfallchirurgie (DGU®) eingeschlossen. Die Auswertung erfolgte in 4 Altersgruppen: Gruppe 1 (4 bis 15 Jahre), Gruppe 2 (16 bis 17 Jahre), Gruppe 3 (18 bis 20 Jahre) sowie Gruppe 4 (21 bis 50 Jahre) als Kontrolle.

Ergebnisse

In Gruppe 2 stellten Extremitätenverletzungen das häufigste Verletzungsmuster dar und traten überwiegend im Bereich der unteren Extremität auf. Zudem ergab die Analyse, dass Gruppe 1 häufiger ein schweres Schädel-Hirn-Trauma erleidet, trotz initial schlechtem Zustand aber ein besseres Outcome aufweist. Thorakale, abdominelle sowie Wirbelsäulen- und Beckenverletzungen kommen bei den jüngeren Altersgruppen seltener vor. Insbesondere stellen Rippenfrakturen eine Rarität bei Kindern dar. In der Diagnostik werden Kinder im Vergleich zu Erwachsenen seltener einer Ganzkörper-CT-Diagnostik zugeführt.

Diskussion

Die Studie deckt altersabhängige Unterschiede in den Verletzungsmustern von Patienten auf, die als Beifahrer oder Fahrer eines Motorrades in einen Unfall involviert waren. Zudem konnten ebenso Unterschiede in der prä- und innerklinischen Versorgung herausgearbeitet werden.

Health care utilization and excess costs after pelvic fractures among older people in Germany

Our study demonstrates a strong increase in utilization of inpatient health care and clear excess costs in older people in the first year after pelvic fracture, the latter even after adjustment for several confounders. Excess costs were particularly high in the first few months and mainly attributable to inpatient treatment.

INTRODUCTION

We aimed to estimate health care utilization and excess costs in patients aged minimum 60 years up to 1 year after pelvic fracture compared to a population without pelvic fracture.

METHODS

In this retrospective population-based observational study, we used routine data from a large statutory health insurance (SHI) in Germany. Patients with a first pelvic fracture between 2008 and 2010 (n=5685, 82% female, mean age 80±9 years) were frequency matched with controls (n=193,159) by sex, age at index date, and index month. We estimated health care utilization and mean total direct costs (SHI perspective) with 95% confidence intervals (CIs) using BCA bootstrap procedures for 52 weeks before and after the index date. We calculated cost ratios (CRs) in 4-week intervals after the index date by fitting mixed two-part models including adjustment for possible confounders and repeated measurement. All analyses were further stratified for men/women, in-/outpatient-treated, and major/minor pelvic fractures.

RESULTS

Health care utilization and mean costs in the year after the index date were higher for cases than for controls, with inpatient treatment being particularly pronounced. CRs (95% CIs) decreased from 10.7 (10.2-11.1) within the first 4 weeks to 1.3 (1.2-1.4) within week 49-52. Excess costs were higher for inpatient than for outpatient-treated persons (CRs of 13.4 (12.9-13.9) and 2.3 (2.0-2.6) in week 1-4). In the first few months, high excess costs were detected for both persons with major and minor pelvic fracture.

CONCLUSION

Pelvic fractures come along with high excess costs and should be considered when planning and allocating health care resources.

Illuminating the effect of beneficial blue light and ROS-modulating enzymes in Dupuytren's disease

Dupuytren's disease (DD) is a fibroproliferative disorder of the palmar aponeurosis, which is characterized by a compound myofibrogenesis and evidenced by an increased expression of α-smooth muscle actin (α-SMA). In Dupuytren's tissue, higher levels of reactive oxygen species (ROS) are documented, stimulating the proliferation and differentiation of myofibroblasts. Our preliminary study demonstrates that α-SMA-expression is significantly inhibited by blue light irradiation in DD. The objective of this study was to investigate the beneficial effect of blue light irradiation and to elucidate the influence of ROS on myofibrogenesis in the pathogenesis of DD. Therefore, an in-vitro model of human DD fibroblasts was used. DD fibroblasts and control fibroblasts isolated from carpal tunnel syndrome (CTS) were daily irradiated with 40 J/cm2 (λ = 453 nm, 38 mW/cm2). Protein expression of ROS-modulating enzymes (Catalase, NOX4, SOD1, MnSOD) and α-SMA were determined, and additionally analysed after a pharmacological inhibition of the TGF-β1-signaling with SB431542. Furthermore, the protein expression of α-SMA as surrogate parameter for myofibrogenesis was evaluated after applying different concentrations of long-lasting ROS. It could be determined that the beneficial blue light irradiation, which inhibited myofibrogenesis, is mediated by a significant inhibition of catalase protein expression. This effect should be accompanied with an increased intracellular ROS level. Proof of evidence was an H2O2-application on DD fibroblasts, also leading to a decreased myofibrogenesis. Furthermore, it could be demonstrated that endogenous MnSOD was significantly downregulated in resting DD fibroblasts. If DD fibroblasts were treated with the pharmacological inhibitor SB431542, myofibrogenesis was inhibited, but MnSOD expression was simultaneously elevated, which ought to affect ROS level by raising intracellular H2O2 amount. Blue light irradiation as well as the pharmacological action of SB431542 in consequence mediates their beneficial effect on disturbed myofibrogenesis in DD by further increasing ROS level. The present study demonstrates the importance of intracellular ROS homeostasis in DD and illuminates the beneficial effect of blue light as a promising therapy option for DD.

Detection of missed fractures of hand and forearm in whole-body CT in a blinded reassessment

BACKGROUND

We examined the visibility of fractures of hand and forearm in whole-body CT and its influence on delayed diagnosis. This study is based on a prior study on delayed diagnosis of fractures of hand and forearm in patients with suspected polytrauma.

METHODS

Two blinded radiologists examined CT-scans of patients with fractures of hand or forearm that were diagnosed later than 24 h after admission and control cases with unremarkable imaging of those areas. They were provided with clinical information that was documented in the admission report and were asked to examine forearm and hands. After unblinding, the visibility of fractures was determined. We examined if time of admission or slice thickness was a factor for late or missed diagnoses.

RESULTS

We included 72 known fractures in 36 cases. Of those 65 were visible. Sixteen visible fractures were diagnosed late during hospital stay. Eight more fractures were detected on revision by the radiologists. Both radiologists missed known fractures and found new fractures that were not reported by the other. Missed and late diagnoses of fractures occurred more often around 5 pm and 1 am. Slice thickness was not significantly different between fractures and cases with fractures found within 24 h and those found later.

CONCLUSIONS

The number of late diagnosis or completely missed fractures of the hand and forearm may be reduced by a repeated survey of WBCT with focus on the extremities in patients with suspected polytrauma who are not conscious.

LEVEL OF EVIDENCE

III.

[Septic Arthritis of the Hand and Wrist]

This review article addresses the epidemiology, ethology, clinic, diagnostics and therapy of infections of the wrist and small joints of the hand.

Possible risk factors for acute and chronic deep periprosthetic joint infections in primary total knee arthroplasty. Do BMI, smoking, urinary tract infections, gender, and ASA classification have an impact?

Purpose

Aim of this retrospective study was to evaluate the impact of the patient related factors body mass index (BMI), urinary tract infection, current smoking, gender, and American Society of Anesthesiologists (ASA) classification on the incidence of acute and chronic deep periprosthetic joint infections (PJI) in total knee arthroplasty (TKA).

Methods

All patients undergoing revision surgery for a deep PJI of primary TKA between July 2012 and December 2016 were included in this study. All relevant data was collected from the medical records. Acute deep PJI was defined when PJI was diagnosed within the first 6 weeks after primary TKA, chronic PJI was defined when patients demonstrated PJI later than 6 weeks after primary TKA.

Results

A total of 57 patients was included in this study with 13 cases of acute PJI and 44 of chronic PJI. Overweight patients (BMI > 25 kg/m²) represent a significantly larger proportion in both PJI groups (p < 0.05). Current smokers had an significantly increased risk for acute and chronic PJI (p < 0.05). In the acute PJI group 46.2% patients had an postoperative urinary tract infection.

Conclusion

An elevated BMI (>25 kg/m²), current smoking and urinary tract infection are possible risk factors for acute and chronic deep PJI. After primary TKA screening for urinary tract infection is recommendable to prevent predominantly acute deep PJI.

Neutral or Natural? Functional Impact of the Coronal Alignment in Total Knee Arthroplasty

Total knee arthroplasty (TKA) is a very successful procedure. The alignment in TKA has been identified as being of importance to prevent early implant failure and patient dissatisfaction. Our hypothesis was that patients with a preoperative varus deformation remaining in a slight varus alignment as their natural alignment after TKA will have superior clinical results compared with patients who are restored in neutral alignment. A total of 115 patients were corrected from varus to neutral (varus-neutral) and in 33 patients a preoperative varus alignment was kept in varus (varus). Standardized preoperative and postoperative full-length hip-knee-ankle radiographs under full weight-bearing conditions were performed in all patients. The patients' knees were categorized preoperatively and postoperatively based on the angle between mechanical femoral axis and mechanical tibial axis. Knees with alignment between ± 3 degrees were categorized as neutrally aligned, whereas alignment within ≤ -3 degrees was categorized as varus. The Knee Injury Osteoarthritis Outcome Score (KOOS) and Oxford Knee Score were determined retrospectively. The varus group scored significantly better in total KOOS (p < 0.05) compared with the varus-neutral group. Also, a trend was visible in the Oxford Knee Score but this was not significant (p > 0.05). This trend was even more evident in varus knees which were slightly undercorrected. The results support the assumption that leaving a residual varus alignment after TKA leads to better functional outcomes in TKA for patients with preoperative varus osteoarthritis.

Healthcare provision, functional ability and quality of life after proximal femoral fracture - 'ProFem': Study protocol of a population-based, prospective study based on individually linked survey and statutory health insurance data

INTRODUCTION

Proximal femoral fractures (PFF) are among the most frequent fractures in older people. However, the situation of people with a PFF after hospital discharge is poorly understood. Our aim is to (1) analyse healthcare provision, (2) examine clinical and patient-reported outcomes (PROs), (3) describe clinical and sociodemographic predictors of these and (4) develop an algorithm to identify subgroups with poor outcomes and a potential need for more intensive healthcare.

METHODS AND ANALYSIS

This is a population-based prospective study based on individually linked survey and statutory health insurance (SHI) data. All people aged minimum 60 years who have been continuously insured with the AOK Rheinland/Hamburg and experience a PFF within 1 year will be consecutively included (SHI data analysis). Additionally, 700 people selected randomly from the study population will be consecutively invited to participate in the survey. Questionnaire data will be collected in the participants' private surroundings at 3, 6 and 12 months after hospital discharge. If the insured person considers themselves to be only partially or not at all able to take part in the survey, a proxy person will be interviewed where possible. SHI variables include healthcare provision, healthcare costs and clinical outcomes. Questionnaire variables include information on PROs, lifestyle characteristics and socioeconomic status. We will use multiple regression models to estimate healthcare processes and outcomes including mortality and cost, investigate predictors, perform non-responder analysis and develop an algorithm to identify vulnerable subgroups.

ETHICS AND DISSEMINATION

The study was approved by the ethics committee of the Faculty of Medicine, Heinrich-Heine-University Düsseldorf (approval reference 6128R). All participants including proxies providing written and informed consent can withdraw from the study at any time. The study findings will be disseminated through scientific journals and public information.

TRIAL REGISTRATION NUMBER

DRKS00012554.

Normal CRP and WBC values in total hip arthroplasty (THA) with signs of loosening. Do we need a joint aspiration?

PURPOSE

Overall Total hip arthroplasty (THA) is a very successful procedure. However, in case of complication dedicated management is required. Two major complications of THA failures are aseptic loosening (AL) and periprosthetic joint infection (PJI). The primary hypothesis of this study was that joint aspirations in patients with signs of loosening after THA are capable to detect PJI in suspected AL with negative serologic testing.

METHODS

In this study a total of 108 symptomatic patients with radiographic signs of prosthetic loosening and hip pain in THA were included. Based on a standardized algorithm all patients underwent serological testing followed by joint aspiration preoperatively. Intraoperatively harvested samples were subjected to microbiological testing and served as the gold standard in differential diagnosis. Demographics, as well as the results of serologic and microbiological testing were collected from the medical records.

RESULTS

Of the included patients 85 were finally diagnosed with an AL and 23 with PJI. Within the patients with PJI 13 (56%) patients demonstrated elevated CRP and WBC counts, as well as positive synovial cultures after joint aspiration. In ten patients (44%) diagnosed with PJI neither CRP nor WBC were abnormal.

CONCLUSION

The diagnosis of PJI can be difficult in THA with radiographic signs of loosening. Clinical features including pain, fever, and local sings of infection are uncommon especially a long period after index operation. First-line screening testing relies on serological evaluation of CRP and WBC. However, normal CRP and WBC values cannot rule out a PJI. These cases can be detected by joint aspiration and synovial cultures reliably.

[Distal radius fractures : Current treatment concepts and controversies]

Distal radius fractures represent the most frequent bone fractures in humans. Although the treatment was dominated for decades by conservative measures or closed surgical procedures, such as percutaneous wire osteosynthesis, a paradigm shift was instigated by the introduction and rapid dissemination of volar locking plate osteosynthesis (VLP). The novel procedure was soon proclaimed to be the gold standard and applied for practically all forms of fractures of the distal radius. In addition to clinical mishaps, e.g. failure to address dorsal edge fragments or the occurrence of extensor and flexor tendon irritation, the publication of various prospective randomized studies and meta-analyses led to a certain degree of disillusionment. In comparison to percutaneous wire osteosynthesis, no differences in the clinical result could be established for VLP 1 year postoperatively. It was therefore obvious that not all problems of the distal radius could be solved using the innovative instrument of volar locking plates. This article gives an overview on the current insights and reflects the current expert opinion on the present concepts for the treatment of distal radius fractures. This is illustrated by comprehensive case presentations.

Excess Mortality After Pelvic Fractures Among Older People

The study aimed to estimate excess mortality in patients aged 60 years or older up to 1 year after pelvic fracture compared with a population without pelvic fracture. In this retrospective population-based observational study, we use routine data from a large health insurance in Germany. For each patient with a first pelvic fracture between 2008 and 2010 (n = 5685 cases, 82% female, mean age 80 ± 9 years), about 34 individuals without pelvic fracture (n = 193,159 controls) were frequency matched by sex, age at index date, and index month. We estimated survival probabilities in the first year after the index date separated for cases (further stratified into inpatient/outpatient treated or minor/major pelvic fractures) and controls using Kaplan-Meier curves. Additionally, time-dependent hazard ratios (HRs) measuring excess mortality in 4-week intervals up to 52 weeks were estimated by fitting Cox regression models including adjustment for relevant confounders. Twenty-one percent of cases and 11% of controls died within 1 year. HRs (95% confidence intervals) decreased from 3.9 (3.5-4.5) within the first 4 weeks to 1.4 (1.1-1.9) within weeks 49 to 52 after the index date. After full adjustment, HRs lowered substantially (3.0 [2.6-3.4] and 1.0 [0.8-1.4]) but were still significantly increased up to week 32. Adjusted HRs in women were lower than in men: 2.8 (2.4-3.2) and 1.0 (0.7-1.4) versus 3.8 (2.9-5.0) and 1.2 (0.6-2.3). We found a clear excess mortality among older people in the first 8 months after pelvic fracture even after full adjustment. Excess mortality was higher among men in the beginning as well as for inpatient-treated persons. Absence of excess mortality was noticed for outpatient-treated persons within the first 3 months. When broken down into site-specific data, excess mortality was no longer significant for most pelvic fractures classified as minor. The only exception was fracture of pubis within the first 4 weeks. © 2017 American Society for Bone and Mineral Research.

Hyperbaric oxygen therapy improves angiogenesis and bone formation in critical sized diaphyseal defects

Besides the use of autologous bone grafting several osteoconductive and osteoinductive methods have been reported to improve bone healing. However, persistent non-union occurs in a considerable number of cases and compromised angiogenesis is suspected to impede bone regeneration. Hyperbaric oxygen therapy (HBO) improves angiogenesis. This study evaluates the effects of HBO on bone defects treated with autologous bone grafting in a bone defect model in rabbits. Twenty-four New-Zealand White Rabbits were subjected to a unilateral critical sized diaphyseal radius bone defect and treated with autologous cancellous bone transplantation. The study groups were exposed to an additional HBO treatment regimen. Bone regeneration was evaluated radiologically and histologically at 3 and 6 weeks, angiogenesis was assessed by immunohistochemistry at three and six weeks. The additional administration of HBO resulted in a significantly increased new bone formation and angiogenesis compared to the sole treatment with autologous bone grafting. These results were apparent after three and six weeks of treatment. The addition of HBO therapy to autologous bone grafts leads to significantly improved bone regeneration. The increase in angiogenesis observed could play a crucial role for the results observed.

Concentration of platelets and growth factors in platelet-rich plasma from Goettingen minipigs

In minipigs little is known about the concentration of growth factors in plasma, despite their major role in several patho-physiological processes such as healing of fractures. This prompted us to study the concentration of platelets and selected growth factors in plasma and platelet-rich plasma (PRP) preparation of sixteen Goettingen minipigs.

Platelet concentrations increased significantly in PRP in comparison to native blood plasma. Generally, significant increase in the concentration of all growth factors tested was observed in the PRP in comparison to the corresponding plasma or serum. Five of the plasma samples examined contained detectable levels of bone morphogenic protein 2 (BMP-2) whereas eleven of the plasma or serum samples contained minimal amounts of vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF-bb) respectively. On the other hand variable concentrations of bone morphogenic protein 7 (BMP-7) and transforming growth factor β1 (TGF-β1) were measured in all plasma samples. In contrast, all PRP samples contained significantly increased amounts of growth factors. The level of BMP-2, BMP-7, TGF-β1, VEGF and PDGF-bb increased by 17.6, 1.5, 7.1, 7.2 and 103.3 fold, in comparison to the corresponding non-enriched preparations. Moreover significant positive correlations were found between platelet count and the concentrations of BMP-2 (r=0.62, p<0.001), TGF-β1 (r=0.85, p<0.001), VEGF (r=0.46, p<0.01) and PDGF-bb (r=0.9, p<0.001). Our results demonstrate that selected growth factors are present in the platelet-rich plasma of minipigs which might thus serve as a source of autologous growth factors.

The role of erythropoietin and bone marrow concentrate in the treatment of osteochondral defects in mini-pigs

Background

All available treatment options for osteochondral and chondral defects do not restore hyaline cartilage and are limited to decreasing associated pain, and maintaining or improving joint function. The purpose of this study was to evaluate the potential of erythropoietin (EPO) in combination with bone marrow aspiration concentrate (BMAC) in the treatment of osteochondral defects of mini-pigs.

Methods

14 Goettinger mini-pigs, in which a 6×10 mm osteochondral defect in the medial femoral condyle of both knee joints was created, were randomized into four groups: biphasic scaffold alone, scaffold with EPO, scaffold with BMAC and scaffold in combination with EPO and BMAC. After 26 weeks all animals were euthanized and histological slides were evaluated using a modified ÓDriscoll Score.

Results

In the therapy groups, areas of chondrogenic tissue that contained collagen II were present. Adding EPO (p = 0.245) or BMAC (p = 0.099) alone to the scaffold led to a non-significant increase in the score compared to the control group. However, the combination of EPO and BMAC in the implanted scaffold showed a significant improvement (p = 0.02) in the histological score.

Conclusion

The results of our study show that in mini-pigs, the combination of EPO and BMAC leads to an enhanced osteochondral healing. However, additional research is necessary to further improve the repair tissue and to define the role of MSCs and EPO in cartilage repair.

Employment of telemedicine in emergency medicine. Clinical requirement analysis, system development and first test results

OBJECTIVES

Demographic change, rising co-morbidity and an increasing number of emergencies are the main challenges that emergency medical services (EMS) in several countries worldwide are facing. In order to improve quality in EMS, highly trained personnel and well-equipped ambulances are essential. However several studies have shown a deficiency in qualified EMS physicians. Telemedicine emerges as a complementary system in EMS that may provide expertise and improve quality of medical treatment on the scene. Hence our aim is to develop and test a specific teleconsultation system.

METHODS

During the development process several use cases were defined and technically specified by medical experts and engineers in the areas of: system administration, start-up of EMS assistance systems, audio communication, data transfer, routine tele-EMS physician activities and research capabilities. Upon completion, technical field tests were performed under realistic conditions to test system properties such as robustness, feasibility and usability, providing end-to-end measurements.

RESULTS

Six ambulances were equipped with telemedical facilities based on the results of the requirement analysis and 55 scenarios were tested under realistic conditions in one month. The results indicate that the developed system performed well in terms of usability and robustness. The major challenges were, as expected, mobile communication and data network availability. Third generation networks were only available in 76.4% of the cases. Although 3G (third generation), such as Universal Mobile Telecommunications System (UMTS), provides beneficial conditions for higher bandwidth, system performance for most features was also acceptable under adequate 2G (second generation) test conditions.

CONCLUSIONS

An innovative concept for the use of telemedicine for medical consultations in EMS was developed. Organisational and technical aspects were considered and practical requirements specified. Since technical feasibility was demonstrated in these technical field tests, the next step would be to prove medical usefulness and technical robustness under real conditions in a clinical trial.

Fixation of multifragmentary patella fractures using a bilateral fixed-angle plate

This biomechanical study is the first to compare 3 fixation methods-bilateral fixed-angle plate, modified anterior tension wiring, and cannulated lag screws with anterior tension wiring-in multifragmentary distal patella fractures. A T-shaped 3-part fracture simulating a multifragmentary articular distal patella fracture (AO/OTA 34-C2.2) was created in 18 human cadaver knee specimens. Three groups were created using homogenous ages and bone mineral densities based on the fixation method received. Repetitive testing over 100 cycles was performed by moving the knee against gravity from 90° flexion to full extension. Failure was defined as fracture displacement greater than 2 mm. In all patellae using fixed-angle plates, an anatomical fracture reduction could be maintained throughout cyclic testing, whereas anterior tension wiring and lag screws with tension wiring showed significant fracture displacement after 100 cycles, with mean fracture gaps of 2.0±1.3 and 1.9±1.6 mm, respectively. The differences in fracture gaps between the fixed-angle plate group and the other 2 groups were statistically significant. In both groups using tension wiring, half of the constructs (3 of 6 in each group) failed due to a fracture displacement greater than 2 mm. The bilateral fixed-angle plate was the only fixation method that sustainably stabilized a multifragmentary articular distal patella fracture during cyclic loading when compared with modified anterior tension wiring and cannulated lag screws with anterior tension wiring.

The early phase influence of bone marrow concentrate on metaphyseal bone healing

Bone marrow concentrate (BMC) contains high densities of progenitor cells. Therefore, in critical size defects BMC may have the potency to support bone healing. The aim of this study was to investigate the effect of BMC in combination with calcium phosphate granules (CPG) on bone defect healing in a metaphyseal long bone defect in mini-pigs. A metaphyseal critical-size bone defect at the proximal tibia of 24 mini-pigs was filled with CPG combined with BMC, CPG solely (control group) or with an autograft. Radiological and histomorphometrical evaluations after 6 weeks (42 days) showed significantly more bone formation in the BMC group in the central area of the defect zone and the cortical defect zone compared to the CPG group. At the same time the resorption rate of CPG increased significantly in the BMC group. Nevertheless, compared to the BMC group the autograft group showed a significantly higher new bone formation radiologically and histomorphometrically. In BMC the count of mononuclear cells was significantly higher compared to the bone marrow aspirate (3.5-fold). The mesenchymal progenitor cell characteristics of the cells in BMC were confirmed by flow cytometry. Cells from BMC created significantly larger colonies of alkaline phosphatase-positive colony forming units (CFU-ALP) (4.4-fold) compared to cells from bone marrow aspirate. Nevertheless, even in the BMC group complete osseous bridging was only detectable in isolated instances of the bone defects. Within the limitations of this study the BMC+CPG composite promotes bone regeneration in the early phase of bone healing significantly better than the isolated application of CPG. However, the addition of BMC does not lead to a solid fusion of the defect in the early phase of bone healing an still does not represent an equal alternative to autologous bone.

Determination of the amount of leg length inequality that alters spinal posture in healthy subjects using rasterstereography

PURPOSE

Leg length inequalities (LLIs) can result in an increased energy consumption, abnormal gait or osteoarthritis of the hip. In a previous study we simulated different LLIs of up to 15 mm and evaluated their effects on the pelvic position and spinal posture. We found a correlation between LLIs and resulting changes of the pelvic position. Despite suggestions in the literature we were not able to detect significant changes of the spinal posture. Therefore, the purpose of this study was to determine the amount of LLI that would in fact alter the spinal posture.

METHODS

The subjects were placed on a simulation platform, whose height could be precisely controlled by the measuring device, to simulate different LLIs of up to 20 mm. For LLIs >20 mm, additional precision-cut wooden blocks were used under one foot. After an adaptation period the resulting changes of the pelvis and spine were measured with a rasterstereographic device.

RESULTS

We found a significant correlation between platform height changes and changes of the pelvic position. The frontal spinal parameters surface rotation and lateral deviation changed significantly when simulating differences greater than 20 mm. No changes of the sagittal spinal curvature were measured, however, a trend to decreasing kyphotic angles was noted.

CONCLUSIONS

Our study has shown for the first time that LLIs >20 mm will lead to significant changes in the spinal posture of healthy test subjects. However, these changes were only found in frontal (surface rotation and lateral flexion) spinal parameters, but not in sagittal parameters. Here for the kyphotic angle only a tendency to decreasing angles was noted. We have also found a significant correlation between different leg lengths and changes of the pelvic position. Further, females and males seem to react in the same way to LLIs.

Cyclic long-term loading of a bilateral fixed-angle plate in comparison with tension band wiring with K-wires or cannulated screws in transverse patella fractures

PURPOSE

A bilateral fixed-angle plate was biomechanically compared to the two currently preferred methods of osteosynthesis for transverse patella fractures. It was hypothesized that the new angle-stable implant would provide a secure and sustainable fracture fixation, superior to the established standard techniques.

METHODS

Twenty-one identical patellae made of polyurethane foam (Sawbones(®)), osteotomized to create a transverse two-part fracture, were fixed with modified anterior tension wiring, cannulated lag screws with anterior tension wiring or bilateral polyaxial 2.7-mm fixed-angle plates. The testing protocol consisted of 10,000 repetitive cycles using a non-destructive physiological load between 100 and 300 N at a simulated knee flexion of 60°.

RESULTS

All 21 Sawbone(®)-patellae sustained repetitive loading up to 10,000 cycles without failing. The anterior tension wire group displayed significant displacement of the fracture gap (0.7 ± 0.2 mm) during cyclic loading, while both lag screws with tension wiring and bilateral fixed-angle plates showed no fracture gap widening at all (p < 0.01).

CONCLUSION

The bilateral fixed-angle plate and cannulated lag screws with anterior tension wiring preserved a constantly reduced fracture gap over 10,000 tensile cycles in contrast to modified anterior tension wiring, which exhibited significant widening of the gap after initial loading. Results of in vitro testing indicate that bilateral fixed-angle plates provide sustainable fixation stability offering a promising new option in the treatment for transverse patella fractures.

Biomechanical stability of different suture fixation techniques for tibial eminence fractures

PURPOSE

Displaced tibial eminence fractures require surgical fixation in order to obtain a stable knee joint. Suture fixation with FiberWire(®) seems to be the most favorable therapeutic option. Biomechanical studies show failure of this technique most commonly due to a suture cutout with subsequent fracture of the tibial eminence fragment. The goal of this study is to compare the biomechanical properties of three different techniques of suture fixation using FiberWire(®).

METHODS

Bone mineral density was evaluated in 18 human knee specimens by pqCT, and three similar groups were formed. A standardized anterior tibial eminence fracture was created, and suture fixation was performed using one of three different techniques in 6 specimens each. Cyclic and destructive testing was conducted.

RESULTS

Significant differences between the three techniques could be shown neither in the cycles needed to achieve a steady state nor in a failure load or initial stiffness. Almost all specimens failed by suture cutout.

CONCLUSION

The presented modification of the existing technique for suture fixation of tibial eminence fractures did not lead to an increased initial stability nor did it lower the rate of suture cutout. All tested suture techniques showed comparable initial stiffness and failure load.

Biomechanical cadaver testing of a fixed-angle plate in comparison to tension wiring and screw fixation in transverse patella fractures

INTRODUCTION

Operative treatment of patella fractures is frequently associated with implant failure and secondary dislocation which can be attributed to the employed hardware. Therefore, a 2.7 mm fixed-angle plate designed for the treatment of patella fractures was tested biomechanically against the currently preferred methods of fixation. It was hypothesized that under simulated cyclic loading fixed-angle plating would be superior to modified anterior tension wiring or cannulated lag screws with anterior tension wiring.

MATERIALS AND METHODS

Eighteen human cadaver knees, matched by bone mineral density and age, were divided into three groups of six. After setting a transverse patella fracture each group received one of the osteosyntheses mentioned above. Repetitive testing over 100 cycles was performed at non-destructive loads by simulating knee motion from 90° flexion to full extension.

RESULTS

Anterior tension wiring as well as lag screws with tension wiring showed significant fracture displacement after the initial cycle already. Both constructs, lag screws plus wiring (3.7 ± 2.7 mm) as well as tension wiring alone (7.1 ± 2.2 mm) displayed fracture displacement of >2 mm which is clinically regarded as failure. Those patellae stabilized with fixed-angle plates showed no significant fracture gap widening after completion of 100 cycles (0.7 ± 0.5 mm). The differences between the fixed-angle plate group and the other two groups were statistically significant (p<0.05).

CONCLUSION

In contrast to modified anterior tension wiring and cannulated lag screws with anterior tension wiring the bilateral fixed-angle plate was the only fixation device to stabilize transverse patella fractures securely and sustainably.

Initial stability of two different adhesives compared to suture repair for acute Achilles tendon rupture--a biomechanical evaluation

PURPOSE

Treatment of acute subcutaneous Achilles tendon rupture remains challenging. Whereas the results of conservative and operative treatment are inconsistent, early mobilisation treatment seems to be beneficial. Besides suture repair, operative treatment using adhesives reveals promising results. Our hypothesis was that a gluing technique provides initial stability comparable to sutures.

METHODS

In a biomechanical study, 18 fresh frozen sheep Achilles tendons were used to compare the biomechanical properties of suture repair using PDS® II and Bunnell's technique to tendon gluing using BioGlue® and Tissucol®. Load to failure testing was performed.

RESULTS

Ultimate failure loads of sutures (146.2 ± 30.8 N) are significantly superior to the techniques using BioGlue® (38.4 ± 18.3 N; p <0.0001) or Tissucol® (4.7 ± 2.5 N; p <0.0001). Interestingly, no significant differences in stiffness were found between the application of BioGlue® and PDS® II.

CONCLUSIONS

Suture repair provides significantly superior biomechanical properties compared to the use of both tested adhesives BioGlue® and Tissucol®. Based on the presented data we recommend the use of suture material for open Achilles tendon repair.

Fixed-angle plates in patella fractures - a pilot cadaver study

Objective

Modified anterior tension wiring with K-wires and cannulated lag screws with anterior tension wiring are currently the fixation of choice for patellar fractures. Failure of fixation, migration of the wires, postoperative pain and resulting revision surgery, however, are not uncommon. After preliminary biomechanical testing of a new fixed-angle plate system especially designed for fixation of patella fractures the aim of this study was to evaluate the surgical and anatomical feasibility of implanting such a plate-device at the human patella.

Methods

In six fresh unfixed female cadavers without history of previous fractures around the knee (average age 88.8 years) a bilateral fixed-angle plate fixation of the patella was carried out after previous placement of a transverse central osteotomy. Operative time, intra-operative problems, degree of retropatellar arthritis (following Outerbridge), quality of reduction and existence of any intraarticular screw placement have been raised. In addition, lateral and anteroposterior radiographs of all specimens were made.

Results

Due to the high average age of 88.8 years no patella showed an unimpaired retropatellar articular surface and all were severely osteoporotic, which made a secure fixation of the reduction forceps during surgery difficult. The operation time averaged 49 minutes (range: 36-65). Although in postoperative X-rays the fracture gap between the fragments was still visible, the analysis of the retropatellar surface showed no residual articular step or dehiscence > 0.5 mm. Also in a total of 24 inserted screws not one intraarticular malposition was found. No intraoperative complications were noticed.

Conclusions

Osteosynthesis of a medial third patella fracture with a bilateral fixed-angle plate-device is surgically and anatomically feasible without difficulties. Further studies have to depict whether the bilateral fixed-angle plate-osteosynthesis of the patella displays advantages over the established operative procedures.

Quantitative modeling of biochemical networks

Today different database systems for molecular structures (genes and proteins) and metabolic pathways are available. All these systems are characterized by the static data representation. For progress in biotechnology, the dynamic representation of this data is important. The metabolism can be characterized as a complex biochemical network. Different models for the quantitative simulation of biochemical networks are discussed, but no useful formalization is available. This paper shows that the theory of Petrinets is useful for the quantitative modeling of biochemical networks.

Treatment strategies for intramedullary nailing of femoral shaft fractures

Intramedullary nailing has become the gold standard to treat femoral shaft fractures. It is unknown which nailing technique orthopedic surgeons prefer. The goal of this study was to determine current techniques and perioperative complications of intramedullary nailing of diaphyseal femoral fractures. Fifty-one institutions in 26 countries participated in an international survey to assess detailed descriptions of preferred operative strategies and perioperative complications. Altogether, 517 cases of diaphyseal femoral fractures were collected. The Internet-based survey incorporated information about fracture classification, time to operation, Injury Severity Score, type of nail, and operative technique, as well as perioperative complications such as infection, femoral neck fracture, and hardware failure. The preferred position for implantation was supine (91.1%). Most surgeons used a traction table (57.1%) and an antegrade implantation technique (84.5%). Intraoperative fractures of the femoral neck occurred in 1.2% of cases when a traction table was used and in 0.2% if no traction table was used, but without statistical significance (P>.16). In 59.2% of the cases, an isolated femur fracture was present, while the rest sustained multiple injuries. In polytrauma patients and patients with severe thorax injuries, most surgeons chose a delayed treatment with intramedullary femoral nails. Interestingly, 38.0% of the patients with severe thorax injuries were treated on the first day with intramedullary femoral nails. The total rate of complications for intramedullary femoral nailing was low (4.9%), but a high rate of intraoperative femoral neck fractures was observed (1.4%).

The dynamics of proximal femoral nails: a clinical comparison between PFNA and Targon PF

The objective of this study comparing the proximal femoral nails Targon PF (Aesculap, Tuttlingen, Germany) and Proximal Femoral Nail Antirotation (PFNA; Synthes. Oberdorf, Switzerland) was to observe the complications and postoperative results following pertrochanteric femoral fracture fixation, with special attention devoted to the dynamic properties of both implants under physiological load in vivo. The survey was designed as a randomized, prospective study of 80 patients who had sustained a pertrochanteric femoral fracture (AO type 31.A2). Postoperative radiological and clinical examinations were conducted over a period of 12 months on 40 respective patients treated with a PFNA or a Targon PF nail. Average operative time was 66.2 minutes and average fluoroscopy time was 103.6 seconds in the PFNA group, which was significantly lower than in the Targon PF group (84.7 minutes and 164.5 seconds, respectively). No significant difference was found between the 2 groups in terms of range of motion (P=.26) or Harris Hip Score (P=.83). The femoral neck components of the Targon PF showed a significantly higher sliding ability (14.5 mm; P=.04) than the PFNA (11.1 mm).Both implants are suited to treat pertrochanteric femoral fractures and display comparable clinical results. The Targon PF demonstrates better dynamic properties than the PFNA under physiological load in vivo. A disadvantage of the Targon PF, however, is the more complicated surgical technique and the longer operative time.

[Radial nerve palsy associated with humeral shaft fractures - early exploration or expectant procedure? An analysis concerning current strategies of treatment]

BACKGROUND

With a prevalence from 11.8 to 18% no fracture is as often associated with nerve damage as the humeral shaft fracture. Whether the radial nerve should be surgically explored in association with a palsy in humeral shaft fractures in order to exclude an interposition or discontinuity is being discussed controversially. The aim of this study was to assess the strategies for primary care of radial nerve palsies associated with humeral shaft fractures in Germany.

MATERIAL AND METHODS

In a standardised survey 495 traumatological and 134 neurosurgical clinics were interviewed regarding the treatment of primary radial nerve palsies after humeral shaft fractures. The distribution of the survey included all level-one trauma centres. Statistics were based on the supply strategies, the number of observed contusions, discontinuities and inter-position of the N. radialis in the fracture gap. Moreover, the results were recorded after primary neurorrhaphy.

RESULTS

The evaluable response rate to the questionnaire was 56% (university hospitals 77%, level-one trauma centres 63%, level-two trauma centres 70%, level-three trauma centres 44%). 6097 humeral shaft fractures have been treated per year, the incidence of primary radial nerve palsy was 8.6%. Regarding the management strategies, 59% of the hospitals advocated exploration of the nerve, while 25% reported that the decision depends on the individual case. 16% reject the exploration in case of a primary nerve palsy. In the case of an exploration, contusions (74%) of the nerve were largely seen, followed by nerve interpositions in the fracture gap (19%) and discontinuity (7%). In the case of neurorrhaphy, a partial or complete remission was found in 87% of cases.

DISCUSSION

Although a primary expectant procedure is recommended in the literature due to the high spontaneous remission rate of 90%, an early exploration of the nerve is often preferred in clinical practice. In these cases, the use of an interlocking intramedullary nail as a minimally invasive treatment option does not appear useful due to the direct exposure of the fracture zone and the radial nerve. Interestingly, the feared discontinuity occurs rarely. The impact of nerve interposition in the fracture gap without surgical exploration remains unclear due to the lack of visibility.

CONCLUSION

There is no consensus concerning the treatment of radial nerve palsies after humeral shaft fractures in Germany. Discontinuities are rare, the rate of spontaneous recoveries is high. Whether and when an exploration of the radial nerve is obligatory in primary radial palsy remains unclear and should be clarified by prospective randomised trials.

The rasterstereographic-dynamic analysis of posture in adolescents using a modified Matthiass test

The Matthiass posture test is a clinical test to detect posture changes in children and adolescents. Aim of this study was to objectify this test using a dynamic rasterstereographic measuring device. We examined 31 healthy athletes during a modified Matthiass test with a dynamic rasterstereographic measuring system. Hereby the trunk inclination, kyphosis and lordosis angle were measured. The trunk inclination decreased by about 50% of the basic value just by raising the arms. Additional weight loads of only 5% body weight (bw) resulted in significant changes of the posture (lordosis and kyphosis angle) during this test. With this rasterstereographic measuring device it seems to be possible to determine spinal posture changes under dynamic conditions. The results suggest that additional weights of 5% bw during the Matthias-test are enough to create significant deviations in posture parameters, even in healthy subjects.

The influence of talonavicular versus double arthrodesis on load dependent motion of the midtarsal joint

BACKGROUND

Today the most frequently used operative procedures in advanced arthritis of the hindfoot joints are isolated talonavicular arthrodesis and double arthrodesis (involving the talonavicular and calcaneocuboid joints, i.e. the Chopart joint). This in vitro study investigates whether the fusion of the talonavicular joint alone can provide the hindfoot, as well as a midfoot, with comparable biomechanical stability as the double arthrodesis does. Hence with the less-invasive intervention the same benefit in terms of pain reduction and better functionality could be achieved.

METHODS

In a series of ten fresh cadaver feet without any radiological pathologies, we measured the range of motion of different tarsal bones in three planes under axial stress. Every foot was loaded without arthrodesis, after talonavicular and after double arthrodesis, by charging tibia and fibula with a force of 350 N using a calibrated Instron® load frame. Each tarsal bone was marked with a K-wire and its motion was measured by registering the movement of the wire’s shade that was projected onto the surrounding walls of the trial box.

RESULTS

Both operative procedures led to a considerable reduction of the motion of every marked bone to a mean of 18% of the preoperative value. In direct comparison of the two simulated arthrodeses we found for every bone and in every plane only minimal differences of the mean excursions of 1.0 mm on average. Both fusions lead to equal residual tarsal bone motion postoperatively, and provide the midtarsal joint as well as the subtalar joint with comparable biomechanical stability.

CONCLUSIONS

Isolated talonavicular arthrodesis is a useful and effective alternative to double arthrodesis. It is the less complicated, less-invasive and functionally equivalent operative option for arthritic alterations of the hindfoot and transverse tarsal joint.

Diagnostic accuracy of neutrophil-derived circulating free DNA (cf-DNA/NETs) for septic arthritis

The release of "neutrophil extracellular traps" (NETs) has been identified as a novel immune response in innate immunity. NETs are composed of neutrophil-derived circulating free DNA (cf-DNA) and neutrophil cytoplasm-derived proteins such as proteases. In this study, we analyzed the putative diagnostic value of synovial cf-DNA/NETs for identification of septic arthritis. Forty-two patients with a joint effusion who had undergone arthrocentesis were included. From synovial fluid, cf-DNA/NETs (j-cf-DNA) levels were directly quantified. Diagnostic value of j-cf-DNA was compared with white blood cells (WBC), synovial white blood cells (j-WBC), C-reactive protein (CRP), j-IL-6, j-TNF alpha, j-IL-1 beta, and myeloperoxidase (j-MPO). Sensitivity, specificity, positive and negative predictive value, as well as ROC-curves for each parameter were calculated. Synovial fluid cf-DNA/NETs values from patients with septic arthritis (3,286 +/- 386 ng/ml, n = 9) were significantly increased compared to patients with noninfectious joint inflammation (1,040 +/- 208 ng/ml, n = 17) or osteoarthritis (278 +/- 34 ng/ml, n = 16, p < 0.01). In conjunction with j-cf-DNA, j-IL-6 and j-IL-1 beta were significantly elevated (p < 0.01), but WBC, CRP, and j-WBC were not. At a cut-off of 300 ng/ml, j-cf-DNA had a sensitivity of 0.89, a specificity of 1.0, a positive predictive value of 1.0, and a negative predictive value of 0.97. Receiver operation curves revealed largest areas under the curve for cf-DNA/NETs (0.933) and j-IL-6 (0.951). cf-DNA/NETs seem to be a valuable additional marker for the diagnosis of septic arthritis or periprosthetic infections. However, this result should be confirmed in a large clinical trial.

[Functional and subjective results following subtalar dislocations]

BACKGROUND

The objective of our study is to evaluate the functional and subjective results following subtalar dislocations without any associated bone injuries and to examine whether the direction of dislocation has any effect on the post-traumatic results.

METHODS

Over the period from February 1998 to May 2006, 56 patients with a subtalar dislocation were enrolled in the study. A subtalar dislocation without any associated bone injuries was only present in 13 patients. Follow-up examination after an average of 39.8 months was performed using the AOFAS Ankle-Hindfoot scale. The adapted classification developed by Altman was used to assess the post-traumatic degree of arthrosis radiologically.

RESULTS

The average AOFAS score was 81, with good results in 11 patients and satisfactory results in 2 patients. The range of motion (ROM) for the ankle-hindfoot joint was 39.2 degrees .

CONCLUSION

Despite the severity of the injury, the functional and subjective results of subtalar dislocations without any bone injuries are good. Generally, no early post-traumatic arthrosis occurs if there are no associated bone injuries. No differences were established between medial and lateral subtalar dislocations.

Influence of the pulse duration of an Er:YAG laser system on the ablation threshold of dental enamel

The present study examines the dependence of the ablation threshold on the duration of the applied laser pulses in the dental enamel of human wisdom teeth. To this end, 600 treatments with the Er:YAG laser (lambda=2940 nm) were carried out on a total of 50 extracted teeth. The laser light was coupled into a fluoride glass light guide for this purpose, in order to ensure almost gaussian distribution of the light in a radially symmetrical beam. The beam diameter on the specimen was 610 micro m. The radiant exposure on the tooth surface was varied between 2 and 20 J/cm(2), while the duration of the pulses applied was changed in four steps from 100 micro s to 700 micro s. The irradiated tooth surfaces were examined for visible signs of ablation under a reflected-light microscope. The experiments revealed that, when pulses of shorter duration are used, the limit at which ablation sets in is reduced by up to approx. 3 J/cm(2). This expands the ablation threshold range of Er:YAG laser radiation to between 6 and 10 J/cm(2). In this context, both the pulse duration and the radiant exposure have a statistically significant influence on the ablation threshold (logistic regression, p<0.0001). Although the ablation threshold of the dental enamel can be changed by varying the pulse duration of the Er:YAG laser, no clinical consequences can be expected, as the shift is only slight.

Quantitative modeling of biochemical networks

Today different database systems for molecular structures (genes and proteins) and metabolic pathways are available. All these systems are characterized by the static data representation. For progress in biotechnology the dynamic representation of this data is important. The metabolism can be characterized as a complex biochemical network. Different models for the quantitative simulation of biochemical networks are discussed, but no useful formalization is available. This paper shows that the theory of Petrinets is useful for the quantitative modeling of biochemical networks.

Constitutive expression of stromal derived factor-1 by mucosal epithelia and its role in HIV transmission and propagation

HIV particles that use the chemokine receptor CXCR4 as a coreceptor for entry into cells (X4-HIV) inefficiently transmit infection across mucosal surfaces [1], despite their presence in seminal fluid and mucosal secretions from infected individuals [2] [3] [4]. In addition, although intestinal lymphocytes are susceptible to infection with either X4-HIV particles or particles that use the chemokine receptor CCR5 for viral entry (R5-HIV) during ex vivo culture [5], only systemic inoculation of R5-chimeric simian-HIV (S-HIV) results in a rapid loss of CD4(+) intestinal lymphocytes in macaques [6]. The mechanisms underlying the inefficient capacity of X4-HIV to transmit infection across mucosal surfaces and to infect intestinal lymphocytes in vivo have remained elusive. The CCR5 ligands RANTES, MIP-1alpha and MIP-1beta suppress infection by R5-HIV-1 particles via induction of CCR5 internalization, and individuals whose peripheral blood lymphocytes produce high levels of these chemokines are relatively resistant to infection [7] [8] [9]. Here, we show that the CXCR4 ligand stromal derived factor-1 (SDF-1) is constitutively expressed by mucosal epithelial cells at sites of HIV transmission and propagation. Furthermore, CXCR4 is selectively downmodulated on intestinal lymphocytes within the setting of prominent SDF-1 expression. We postulate that mucosally derived SDF-1 continuously downmodulates CXCR4 on resident HIV target cells, thereby reducing the transmission and propagation of X4-HIV at mucosal sites. Moreover, such a mechanism could contribute to the delayed emergence of X4 isolates, which predominantly occurs during the later stages of the HIV infection.