Automated Machine Learning Predicts Necessary Upcoming Therapy Changes in Patients With Psoriasis Vulgaris et Arthritis And Uncovers New Influences On Disease Progression: Retrospective Study

BACKGROUND

Psoriasis vulgaris (PsV) and Psoriatic arthritis (PsA) are intertwined multifactorial diseases with significant impact on health and quality of life, which can be debilitating due to chronicity and treatment complexity. Predicting treatment response and disease progression in these conditions is challenging, but crucial for optimising therapeutic interventions. The advancing technology of automated machine learning (AutoML) holds great promise for rapidly building highly accurate predictive models based on patient features and treatment data.

OBJECTIVE

The study aimed to develop highly accurate ML models using AutoML to address key clinical questions in PsV and PsA patients, including predicting therapy changes and identifying reasons for therapy changes, factors influencing skin lesion progression or factors associated with an abnormal BASDAI score.

METHODS

After extensive dataset preparation of clinical study data from 309 PsV and PsA patients, a secondary dataset was created and ultimately analysed using AutoML to build a variety of predictive models and select the most accurate one for each variable of interest.

RESULTS

"Therapy change at 24 weeks follow-up" was modelled using the eXtreme Gradient Boosted Trees Classifier with Early Stopping model (AUC of 0.9078 and LogLoss of 0.3955 for the holdout partition) to gain insight into the factors influencing therapy change, such as the initial systemic therapeutic agent, the score achieved in the CASPAR classification criteria at baseline, and changes in quality of life. An AVG blender of 3 models (Gradient Boosted Trees Classifier, ExtraTrees Classifier, Eureqa Generalised Additive Model Classifier) with an AUC of 0.8750 and a LogLoss of 0.4603 was used to predict therapy changes on two hypothetical patients to highlight the importance of such influencing factors. Notably, treatments such as MTX or specific biologicals showed a lower propensity for change. A further AVG Blender of RandomForest Classifier, eXtreme Gradient Boosted Trees Classifier and Eureqa Classifier (AUC of 0.9241 and LogLoss of 0.4498) was then used to estimate "PASI change after 24 weeks" with the primary predictors being the initial PASI score, change in pruritus and change in therapy. A lower initial PASI score, and consistently low pruritus were associated with better outcomes. Finally, "BASDAI classification at baseline" was analysed using an AVG Blender of Eureqa Generalised Additive Model Classifier, eXtreme Gradient Boosted Trees Classifier with Early Stopping and Dropout Additive Regression Trees Classifier with an AUC of 0.8274 and LogLoss of 0.5037. Factors influencing BASDAI scores included initial pain, disease activity and HADS scores for depression and anxiety. Increased pain, disease activity and psychological distress were generally likely to lead to higher BASDAI scores.

CONCLUSIONS

The practical implications of these models for clinical decision making in PsV and PsA have the potential to guide early investigation and treatment, contributing to improved patient outcomes.

CLINICALTRIAL

[Benefits of participatory involvement of patients in the development of a dermatological treatment app-A report from the practice]

Approximately 2% of the German population suffer from psoriasis. HybridVITA has developed a mobile application (app) that enables psoriasis patients to independently document the progression of the disease and the current psychological stress at home. The HybridVITA app was created in close collaboration with user groups to ensure optimal adaptation to their needs. Two interactive workshops were held with the user groups and the technical developers of the app as a core element of the developmental process. The workshops identified the needs and suggestions for improvement of the various user groups and formulated user stories for the further development of the app using the Scrum method. The participatory approach of the workshop enabled the project team to gather valuable practical knowledge at an early stage of development. The team's awareness of potential obstacles during the early stages of the project enabled them to proactively identify and address these issues prior to implementing the app in dermatological care. We are confident that a patient-centered and participatory approach to health app development can provide valuable insights for developers.

The Effect of an Interdisciplinary Dermatological-Rheumatological Consultation on the Outcome of Patients with Psoriasis with Musculoskeletal Pain: A Prospective, Single-Center Cohort Study

INTRODUCTION

Psoriatic arthritis (PsA), a disease with complex inflammatory musculoskeletal manifestations, complicates psoriasis in up to 30% of patients. In this study, we aimed to determine the effect of an interdisciplinary dermatological-rheumatological consultation (IDRC) for patients with psoriasis with musculoskeletal symptoms.

METHODS

This prospective study enrolled 202 patients with psoriasis. Patients with musculoskeletal pain (MSP) (n = 115) participated in an IDRC 12 weeks after enrollment. The outcome was evaluated after 24 weeks.

RESULTS

In 12/79 (15.2%) patients seen in the IDRC, the prior diagnosis was changed: eight with a first diagnosis of PsA, four with a diagnosis of PsA rescinded. Treatment was modified in 28% of patients. Significant improvements in Psoriasis Area and Severity Index (PASI) (from 5.3 to 2.0; p < 0.001) and Dermatology Life Quality Index (DLQI) (from 6.7 to 4.5; p = 0.009) were observed. By comparing changes in PASI and DLQI over the study period, an improvement in PASI of 0.7 ± 1.4 points (p = 0.64) and in DLQI of 2.9 ± 1.5 points (p = 0.051) could be attributed to participation in the IDRC.

CONCLUSION

An IDRC of patients with psoriasis with MSP leads to a valid diagnosis of PsA and improvement in quality of life. Based on these results, an IDRC is a valuable and time efficient way for psoriasis patient with MSP to receive optimal care.

Automated Machine Learning Analysis of Patients With Chronic Skin Disease Using a Medical Smartphone App: Retrospective Study

BACKGROUND

Rapid digitalization in health care has led to the adoption of digital technologies; however, limited trust in internet-based health decisions and the need for technical personnel hinder the use of smartphones and machine learning applications. To address this, automated machine learning (AutoML) is a promising tool that can empower health care professionals to enhance the effectiveness of mobile health apps.

OBJECTIVE

We used AutoML to analyze data from clinical studies involving patients with chronic hand and/or foot eczema or psoriasis vulgaris who used a smartphone monitoring app. The analysis focused on itching, pain, Dermatology Life Quality Index (DLQI) development, and app use.

METHODS

After extensive data set preparation, which consisted of combining 3 primary data sets by extracting common features and by computing new features, a new pseudonymized secondary data set with a total of 368 patients was created. Next, multiple machine learning classification models were built during AutoML processing, with the most accurate models ultimately selected for further data set analysis.

RESULTS

Itching development for 6 months was accurately modeled using the light gradient boosted trees classifier model (log loss: 0.9302 for validation, 1.0193 for cross-validation, and 0.9167 for holdout). Pain development for 6 months was assessed using the random forest classifier model (log loss: 1.1799 for validation, 1.1561 for cross-validation, and 1.0976 for holdout). Then, the random forest classifier model (log loss: 1.3670 for validation, 1.4354 for cross-validation, and 1.3974 for holdout) was used again to estimate the DLQI development for 6 months. Finally, app use was analyzed using an elastic net blender model (area under the curve: 0.6567 for validation, 0.6207 for cross-validation, and 0.7232 for holdout). Influential feature correlations were identified, including BMI, age, disease activity, DLQI, and Hospital Anxiety and Depression Scale-Anxiety scores at follow-up. App use increased with BMI >35, was less common in patients aged >47 years and those aged 23 to 31 years, and was more common in those with higher disease activity. A Hospital Anxiety and Depression Scale-Anxiety score >8 had a slightly positive effect on app use.

CONCLUSIONS

This study provides valuable insights into the relationship between data characteristics and targeted outcomes in patients with chronic eczema or psoriasis, highlighting the potential of smartphone and AutoML techniques in improving chronic disease management and patient care.

Prevalence of Physical Frailty: Results from the DO-HEALTH Study

BACKGROUND

Frailty is a geriatric syndrome associated with multiple negative health outcomes. However, its prevalence varies by population and instrument used. We investigated frailty and pre-frailty prevalence by 5 instruments in community-dwelling older adults enrolled to a randomized-controlled trial in 5 European countries.

METHODS

Cross-sectional baseline analysis in 2,144 DO-HEALTH participants recruited from Switzerland, Austria, France, Germany, and Portugal with complete data for frailty. Frailty status was assessed by the Physical Frailty Phenotype [PFP], SOF-Frailty Index [SOF-FI], FRAIL-Scale, SHARE-Frailty Instrument [SHARE-FI], and a modified SHARE-FI, and compared by country, age, and gender. Logistic regression was used to determine relevant factors associated with frailty and pre-frailty.

RESULTS

Mean age was 74.9 (±4.4) years, 61.6% were women. Based on the PFP, overall frailty and pre-frailty prevalence was 3.0% and 43.0%. By country, frailty prevalence was highest in Portugal (13.7%) and lowest in Austria (0%), and pre-frailty prevalence was highest in Portugal (57.3%) and lowest in Germany (37.1%). By instrument and overall, frailty and pre-frailty prevalence was highest based on SHARE-FI (7.0% / 43.7%) and lowest based on SOF-FI (1.0% / 25.9%). Frailty associated factors were residing in Coimbra (Portugal) [OR 12.0, CI 5.30-27.21], age above 75 years [OR 2.0, CI 1.17-3.45], and female gender [OR 2.8, CI 1.48-5.44]. The same three factors predicted pre-frailty.

CONCLUSIONS

Among relatively healthy adults age 70 and older enroled to DO-HEALTH, prevalence of frailty and pre-frailty differed significantly by instrument, country, gender, and age. Among instruments, the highest prevalence of frailty and pre-frailty was documented by the SHARE-FI and the lowest by the SOF-FI.

Coupling Single Photons from Discrete Quantum Emitters in WSe2 to Lithographically Defined Plasmonic Slot Waveguides

We report the observation of the generation and routing of single plasmons generated by localized excitons in a WSe₂ monolayer flake exfoliated onto lithographically defined Au-plasmonic waveguides. Statistical analysis of the position of different quantum emitters shows that they are (3.3 ± 0.7) times more likely to form close to the edges of the plasmonic waveguides. By characterizing individual emitters, we confirm their single-photon character via the observation of antibunching in the signal ( g⁽²⁾(0) = 0.42) and demonstrate that specific emitters couple to modes of the proximal plasmonic waveguide. Time-resolved measurements performed on emitters close to and far away from the plasmonic nanostructures indicate that Purcell factors up to 15 ± 3 occur, depending on the precise location of the quantum emitter relative to the tightly confined plasmonic mode. Measurement of the point spread function of five quantum emitters relative to the waveguide with <50 nm precision is compared with numerical simulations to demonstrate the potential for greater increases in the coupling efficiency for ideally positioned emitters. The integration of such strain-induced quantum emitters with deterministic plasmonic routing is a step toward deep-subwavelength on-chip single quantum light sources.

A few-emitter solid-state multi-exciton laser

We report on non-conventional lasing in a photonic-crystal nanocavity that operates with only four solid-state quantum-dot emitters. In a comparison between microscopic theory and experiment, we demonstrate that irrespective of emitter detuning, lasing with \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${g}^{\mathrm{(2)}}=1$$\end{document}g(2)=1 is facilitated by means of emission from dense-lying multi-exciton states. In the spontaneous-emission regime we find signatures for radiative coupling between the quantum dots. The realization of different multi-exciton states at different excitation powers and the presence of electronic inter-emitter correlations are reflected in a pump-rate dependence of the β-factor.

Extracellular matrix mimicking scaffold promotes osteogenic stem cell differentiation: A new approach in osteoporosis research

BACKGROUND

Osteoporosis is a common metabolic disease, with mesenchymal stem cells discussed to play an important role in its pathomechanism. For in vitro osteoporosis studies, selection of adequate culture conditions is mandatory so as to preserve cell properties as far as possible. A suitable cell culture surface would ideally provide reproducible experimental conditions by resembling those in-vivo.

OBJECTIVE

Generating an improved growth surface for osteogenic differentiation of human bone marrow derived mesenchymal stem cells (hBMSCs).

METHODS

We modified electrospun gelatine meshes with hydroxyapatite nanopowder. The potential beneficial impact of the ensuing culture conditions were evaluated by cultivating and comparing the growth of cells from osteoporotic and non-osteoporotic donors on either hydroxyapatite-gelatine (HA) meshes, pure gelatine meshes, or 2D standard tissue culture surfaces.

RESULTS

After 21 days of differentiation, cells grown on pure or HA-gelatine meshes showed significantly higher mineralization levels compared to cells cultured in standard conditions. The amount of mineralization varied considerably in hBMSC cultures of individual patients but showed no significant difference between stem cells obtained from osteoporotic or non-osteoporotic donors.

CONCLUSIONS

Overall, these results indicate that the use of HA-gelatine meshes as growth surfaces may serve as a valuable tool for cultivation and differentiation of mesenchymal stem cells along the osteogenic lineage, facilitating future research on osteoporosis and related issues.

Do we still need autopsy in times of modern multislice computed tomography?-Missed diagnoses in the emergency room

INTRODUCTION

In spite of increasing quality of emergency room (ER) assessment in trauma patients and improved accuracy of modern multislice computed tomography (MSCT), the number of potentially missed diagnoses is still controversial. The aim of this study was to compare the initial findings of ER assessment and MSCT to the findings during autopsy in trauma patients not surviving the first 48 h after admission. We hypothesized that autopsy was more accurate than MSCT in diagnosing potentially fatal diagnoses.

PATIENTS AND METHODS

Between January 2004 and September 2007, all trauma patients undergoing ER treatment in our institution who deceased within 48 h after admission were analyzed regarding diagnoses from initial ER assessment, including MSCT, and diagnoses from autopsy. Data were prospectively collected and retrospectively analyzed. Autopsy reports were compared to diagnoses of ER assessment and MSCT. Missed diagnoses (MD) and missed potentially fatal diagnoses (MPFD) were analyzed.

RESULTS

Seventy-three patients with a mean age of 53.2 years were included into the study. Sixty-three percent were male. Autopsy revealed at least one missed diagnosis in 25% of the patients, with the thoracic area accounting for 67% of these. At least one MPFD was found in 4.1% of the patients, all of them being located in the thorax. Total numbers of MD and MPFD were significantly lower for the newer CT generation (64 MSCT, N = 11), compared to older one (4 MSCT, N = 26).

CONCLUSIONS

As determined by autopsy, modern multislice computed tomography is an accurate method to diagnose injuries. However, 25% of all diagnoses, and 4.1% of potentially fatal diagnoses are still missed in trauma patients, who deceased within the first 48 h after admission. Therefore, autopsy seems to be necessary to determine potentially missed diagnoses for both academic and medicolegal reasons as well as for quality control.

EULAR/EFORT recommendations for management of patients older than 50 years with a fragility fracture and prevention of subsequent fractures

The European League Against Rheumatism (EULAR) and the European Federation of National Associations of Orthopaedics and Traumatology (EFORT) have recognised the importance of optimal acute care for the patients aged 50 years and over with a recent fragility fracture and the prevention of subsequent fractures in high-risk patients, which can be facilitated by close collaboration between orthopaedic surgeons and rheumatologists or other metabolic bone experts. Therefore, the aim was to establish for the first time collaborative recommendations for these patients. According to the EULAR standard operating procedures for the elaboration and implementation of evidence-based recommendations, 7 rheumatologists, a geriatrician and 10 orthopaedic surgeons met twice under the leadership of 2 convenors, a senior advisor, a clinical epidemiologist and 3 research fellows. After defining the content and procedures of the task force, 10 research questions were formulated, a comprehensive and systematic literature search was performed and the results were presented to the entire committee. 10 recommendations were formulated based on evidence from the literature and after discussion and consensus building in the group. The recommendations included appropriate medical and surgical perioperative care, which requires, especially in the elderly, a multidisciplinary approach including orthogeriatric care. A coordinator should setup a process for the systematic investigations for future fracture risk in all elderly patients with a recent fracture. High-risk patients should have appropriate non-pharmacological and pharmacological treatment to decrease the risk of subsequent fracture.

[Augmentation techniques on the proximal femur]

BACKGROUND

Due to the demographic change fractures of the proximal femur are an increasing major healthcare problem and are associated with the highest mortality among frailty fractures.

OBJECTIVES

These mainly osteoporosis-associated fractures of the hip often represent a surgical challenge and the outcome has a decisive influence on the preservation of function and independency of orthogeriatric patients. Augmentation techniques could improve the stability of osteosynthesis in proximal femoral fractures.

METHODS

Cement augmentation of proximal femoral nailing (PFNA) for the treatment of pertrochanteric femoral fractures is the most commonly used and standardized method of augmentation for these fractures by which a safer condition for immediate full weight bearing and mobilization can be achieved.

RESULTS

In biomechanical and clinical studies good fracture healing was shown and there was no evidence of cement-associated complications in augmented PFNA nailing. In the majority of patients the mobility level prior to trauma could be achieved.

CONCLUSION

In addition to the optimal surgical treatment, secondary prevention such as osteoporosis management to avoid further fractures is crucial in the treatment of these patients. This article is based on the current literature and provides an overview of the possible applications of cement augmentation for the treatment of proximal femoral fractures. In addition the surgical approach as well as previous scientific data on an established osteosynthesis using cement-augmented PFNA for the treatment of pertrochanteric frailty fractures are presented.

Allograft augmentation in proximal humerus fractures

OBJECTIVE

Achieve stable fixation to initially start full range of motion (ROM) and to prevent secondary displacement in unstable fracture patterns and/or weak and osteoporotic bone.

INDICATIONS

(Secondarily) displaced proximal humerus fractures (PHF) with an unstable medial hinge and substantial bony deficiency, weak/osteoporotic bone, pre-existing psychiatric illnesses or patient incompliance to obey instructions.

CONTRAINDICATIONS

Open/contaminated fractures, systemic immunodeficiency, prior graft-versus-host reaction.

SURGICAL TECHNIQUE

Deltopectoral approach. Identification of the rotator cuff. Disimpaction and reduction of the fracture, preparation of the situs. Graft preparation. Allografting. Fracture closure. Plate attachment. Definitive plate fixation. Radiological documentation. Postoperative shoulder fixation (sling).

POSTOPERATIVE MANAGEMENT

Cryotherapy, anti-inflammatory medication on demand. Shoulder sling for comfort. Full active physical therapy as tolerated without pain. Postoperative radiographs (anteroposterior, outlet, and axial [as tolerated] views) and clinical follow-up after 6 weeks and 3, 6, and 12 months.

RESULTS

Bony union and allograft incorporation in 9 of 10 noncompliant, high-risk patients (median age 63 years) after a mean follow-up of 28.5 months. The median Constant-Murley Score was 72.0 (range 45-86). Compared to the uninjured contralateral side, flexion was impaired by 13 %, abduction by 14 %, and external rotation by 15 %. Mean correction of the initial varus displacement was 38° (51° preoperatively to 13° postoperatively).

Does MIPO of fractures of the distal femur result in more rotational malalignment than ORIF? A retrospective study

PURPOSE

Intraoperative control of rotational malalignment poses a big challenge for surgeons when using modern MIPO (minimally invasive plate osteosynthesis) techniques. We hypothesized that distal femoral fractures treated with MIPO technique are more often fixed in malrotation than those treated with open reduction internal fixation (ORIF).

METHODS

In this retrospective study, we identified 20 patients who met the inclusion criteria and agreed to take part in the study. In ten patients MIPO was applied, in the other ten ORIF was used. Mean age was 44.8 (19-71 years). Functional status was assessed using clinical scores (Harris Hip Score, WOMAC Hip, KS Score, WOMAC Knee, Kujala Score). Rotational alignment was assessed with magnetic resonance imaging and compared to the opposite leg.

RESULTS

We discovered a significant difference in the mean rotational difference between the MIPO group (14.3°) and the ORIF group (5.2°). Functionally, patients in the ORIF group outperformed patients in the MIPO group in all clinical scoring systems although no one proved to be statistically significant. MIPO technique was associated with significantly more rotational malalignment compared to ORIF in distal femur fracture fixation. However, implant failure and nonunion was more common in the ORIF group, with a revision rate of 3 versus 1 in the ORIF group. Clinical scoring did not significantly different between both groups.

CONCLUSION

Taking into account the undisputable advantages of minimally invasive surgery, improved teaching of methods to avoid malrotation as well as regular postoperative investigations to detect any malrotation should be advocated.

[Proximal femoral fractures in the elderly]

Proximal femoral fractures represent an increasing major healthcare problem due to the demographic changes in this aging population and are associated with the highest mortality among fractures in elderly patients after suffering insufficiency injuries (so-called fragility fractures). The main aim in the treatment of orthogeriatric patients who suffered from a proximal femoral fracture is the preservation of function and independency. Given the high prevalence of comorbidities in these patients, interdisciplinary and interprofessional approaches are required. The use of modern osteosynthesis procedures can provide an improved, individualized surgical treatment with early full weight bearing of the affected extremity. Another aspect is the accompanying geriatric treatment which is associated with a significant reduction of perioperative and postoperative complications. In addition to acute treatment, the organization of secondary fracture prevention is a crucial pillar of treatment. This article provides an overview of the essential elements of orthogeriatric trauma surgery in elderly patients following proximal femoral fractures.

[Factors Associated with the Use of Protective Gear among Adults during Recreational Sledging]

BACKGROUND

Recreational sledging (tobogganing) is a very popular winter sport in the Alps. Therefore, injury prevention through the usage of protective gear seems important. Therefore, the aim of this study was to evaluate factors associated with the use of protective gear among adults during recreational sledging.

METHODS

Adult recreational sledgers were interviewed during the winter seasons 2012/13 and 2013/14 at six sledging tracks in Austria on demographics, skill level, sledging frequency, risk taking behaviour, sitting alone or with another person on the sledge, previous sledging-related injuries, and use of protective gear, respectively. Interviews were conducted on all days of the week.

RESULTS

A total of 1968 adult sledgers (49.4 % females) with a mean age of 37.1 ± 14.4 years participated in this study. A (ski) helmet, sun or snow goggles, a back protector, and wrist guards were used by 42.3 %, 71.0 %, 5.9 %, 2.6 % of sledgers, respectively. Helmet use was significantly higher with increasing age and increasing skill level as well as when sitting alone compared to sitting together with another person. Females, Austrians, persons sitting alone on the sledge, a higher frequency of sledging and a higher skill level were significantly associated with an increasing use of goggles. A back protector was significantly more often worn by younger people, more risky sledgers, and persons with a previous sledging-related injury. Wrist guards were significantly more often used by persons with a previous sledging-related injury.

CONCLUSION

During recreational sledging, the factors age, sex, nationality, skill level, sitting alone compared to sitting together with another person on the sledge, sledging frequency, and injury experience were associated with the frequencies of usage of different types of protective gear. These factors should be considered when implementing preventive measures for recreational sledging.

Fragility non-hip fracture patients are at risk

INTRODUCTION

Fragility fractures are a growing worldwide health care problem. Hip fractures have been clearly associated with poor outcomes. Fragility fractures of other bones are common reasons for hospital admission and short-term disability, but specific long-term outcome studies of non-hip fragility fractures are rare. The aim of our trial was to evaluate the 1-year outcomes of non-hip fragility fracture patients.

METHODS

This study is a retrospective cohort review of 307 consecutive older inpatient non-hip fracture patients. Patient data for analysis included fracture location, comorbidity prevalence, pre-fracture functional status, osteoporosis treatments and sociodemographic characteristics. The main outcomes evaluated were 1-year mortality and post-fracture functional status.

RESULTS

As compared to the expected mortality, the observed 1-year mortality was increased in the study group (17.6 vs. 12.2 %, P = 0.005). After logistic regression, three variables remained as independent risk factors for 1-year mortality among non-hip fracture patients: malnutrition (OR 3.3, CI 1.5-7.1), Charlson comorbidity index (CCI) (OR 1.3, CI 1.1-1.5) and the Parker Mobility Score (PMS) (OR 0.85, CI 0.74-0.98). CCI and PMS were independent risk factors for a high grade of dependency after 1 year. Management of osteoporosis did not significantly improve after hospitalization due to a non-hip fragility fracture.

CONCLUSION

The outcomes of older non-hip fracture patients are comparable to the poor outcomes of older hip fracture patients, and appear to be primarily related to comorbidities, pre-fracture function and nutritional status. The low rate of patients on osteoporosis medications likely reflects the insufficient recognition of the importance of osteoporosis assessment and treatment in non-hip fracture patients. Increased clinical and academic attention to non-hip fracture patients is needed.

Osteoanabolic effect of alendronate and zoledronate on bone marrow stromal cells (BMSCs) isolated from aged female osteoporotic patients and its implications for their mode of action in the treatment of age-related bone loss

SUMMARY

In the present study, we evaluated the potential for aminobisphosphonates to enhance the development of bone-forming osteoblasts from progenitor cells isolated from aged female osteoporotic patients. The aminobisphosphonates tested significantly enhanced osteoblast formation and thus lend further insights into their possible mode of action in the treatment of osteoporosis.

INTRODUCTION

The primary aim of this study was to evaluate the influence of aminobisphosphonates on the osteogenesis of human bone marrow stromal cells (hBMSCs) and mineralization of differentiating bone-forming cells isolated from osteoporotic patients.

METHODS

The influence of aminobisphosphonate treatment on hBMSC osteogenesis was assessed by the quantitative measurement of alkaline phosphatase (ALP) activity, in addition to quantitative reverse transcription polymerase chain reaction and Western blot analysis of known osteogenic markers. Mineralized matrix formation by hBMSC-derived osteoblasts was visualized and quantified using Alizarin red staining.

RESULTS

hBMSC cultures treated with osteogenic medium supplemented with zoledronate demonstrated a significant increase in Alizarin red staining after 3 weeks as compared to cells cultured in osteogenic medium alone. Similarly, cultures of differentiating hBMSCs isolated from patients receiving alendronate treatment also demonstrated an increased propensity for mineralization, even in the absence of further in vitro stimulation by zoledronate. The stimulatory effects of aminobisphosphonate treatment on hBMSC-derived osteoblast-mediated mineralization were independent of any alterations in ALP activity, although significant decreases in the expression levels of osteopontin (SPP1) were evident in hBMSCs following exposure to aminobisphosphonates. Further analysis including Western blotting and loss-of-function studies revealed osteopontin as having a negative influence on the mineralization of differentiating osteoporotic bone-forming cells.

CONCLUSIONS

The results presented here demonstrate for the first time that aminobisphosphonate treatment of osteoporotic hBMSCs enhances their capacity for osteoblast formation and subsequent mineral deposition, thus supporting the concept of aminobisphosphonates as having an osteoanabolic effect in osteoporosis.

Long-term results of the augmented PFNA: a prospective multicenter trial

BACKGROUND

Pertrochanteric fractures are increasing and their operative treatment remains under discussion. Failures needing reoperations such as a cut-out are reported to be high and are associated with multiple factors including poor bone quality, poor fracture reduction and improper implant placement. The PFNA(®) with perforated blade offers an option for standardized cement augmentation with a PMMA cement to provide more stability to the fracture fixation. It remains unclear if the augmentation of this implant does any harm in a longer time span. This prospective multicenter study shows clinical and radiological results with this implant with a mean follow-up time of 15 months.

METHODS

In 5 European clinics, 62 patients (79 % female, mean age 85.3 years) suffering from an osteoporotic pertrochanteric fracture (AO 31) were treated with the augmented PFNA(®). The primary objectives were assessment of activities of daily living, pain and mobility. Furthermore, the X-rays were analyzed for the cortical thickness index, changes of the trabecular structure around the cement and the hip joint space.

RESULTS

The mean follow-up time was 15.3 months. We observed callus healing in all cases. The surgical complication rate was 3.2 % with no complication related to the cement augmentation. A mean volume of 3.8 ml of cement was injected and no complication was reported due to this procedure. 59.9 % reached their prefracture mobility level until follow-up. The mean hip joint space did not change significantly until follow-up and there were no signs of osteonecrosis in the follow-up X-rays. Furthermore, no blade migration was assessed.

CONCLUSION

This study makes us believe that the standardized augmentation of the PFNA with a perforated blade is a safe method to treat pertrochanteric femoral fractures. It leads to good functional results and is not associated with cartilage or bone necrosis.

The influence of distal locking on the need for fibular plating in intramedullary nailing of distal metaphyseal tibiofibular fractures

Using human cadaver specimens, we investigated the role of supplementary fibular plating in the treatment of distal tibial fractures using an intramedullary nail. Fibular plating is thought to improve stability in these situations, but has been reported to have increased soft-tissue complications and to impair union of the fracture. We proposed that multidirectional locking screws provide adequate stability, making additional fibular plating unnecessary. A distal tibiofibular osteotomy model performed on matched fresh-frozen lower limb specimens was stabilised with reamed nails using conventional biplanar distal locking (CDL) or multidirectional distal locking (MDL) options with and without fibular plating. Rotational stiffness was assessed under a constant axial force of 150 N and a superimposed torque of ± 5 Nm. Total movement, and neutral zone and fracture gap movement were analysed.

In the CDL group, fibular plating improved stiffness at the tibial fracture site, albeit to a small degree (p = 0.013). In the MDL group additional fibular plating did not increase the stiffness. The MDL nail without fibular plating was significantly more stable than the CDL nail with an additional fibular plate (p = 0.008).

These findings suggest that additional fibular plating does not improve stability if a multidirectional distal locking intramedullary nail is used, and is therefore unnecessary if not needed to aid reduction.

Cite this article: Bone Joint J 2014;96-B:385–9.

Literature review of outcome parameters used in studies of Geriatric Fracture Centers

INTRODUCTION

A variety of multidisciplinary treatment models have been described to improve outcome after osteoporotic hip fractures. There is a tendency toward better outcomes after implementation of the most sophisticated model with a shared leadership for orthopedic surgeons and geriatricians; the Geriatric Fracture Center. The purpose of this review is to evaluate the use of outcome parameters in published literature on the Geriatric Fracture Center evaluation studies.

MATERIALS AND METHODS

A literature search was performed using Medline and the Cochrane Library to identify Geriatric Fracture Center evaluation studies. The outcome parameters used in the included studies were evaluated.

RESULTS

A total of 16 outcome parameters were used in 11 studies to evaluate patient outcome in 8 different Geriatric Fracture Centers. Two of these outcome parameters are patient-reported outcome measures and 14 outcome parameters were objective measures.

CONCLUSION

In-hospital mortality, length of stay, time to surgery, place of residence and complication rate are the most frequently used outcome parameters. The patient-reported outcomes included activities of daily living and mobility scores. There is a need for generally agreed upon outcome measures to facilitate comparison of different care models.

Identifying a standard set of outcome parameters for the evaluation of orthogeriatric co-management for hip fractures

BACKGROUND AND PURPOSE

Osteoporotic fractures are an increasing problem in the world due to the ageing of the population. Different models of orthogeriatric co-management are currently in use worldwide. These models differ for instance by the health-care professional who has the responsibility for care in the acute and early rehabilitation phases. There is no international consensus regarding the best model of care and which outcome parameters should be used to evaluate these models. The goal of this project was to identify which outcome parameters and assessment tools should be used to measure and compare outcome changes that can be made by the implementation of orthogeriatric co-management models and to develop recommendations about how and when these outcome parameters should be measured. It was not the purpose of this study to describe items that might have an impact on the outcome but cannot be influenced such as age, co-morbidities and cognitive impairment at admission.

METHODS

Based on a review of the literature on existing orthogeriatric co-management evaluation studies, 14 outcome parameters were evaluated and discussed in a 2-day meeting with panellists. These panellists were selected based on research and/or clinical expertise in hip fracture management and a common interest in measuring outcome in hip fracture care.

RESULTS

We defined 12 objective and subjective outcome parameters and how they should be measured: mortality, length of stay, time to surgery, complications, re-admission rate, mobility, quality of life, pain, activities of daily living, medication use, place of residence and costs. We could not recommend an appropriate tool to measure patients' satisfaction and falls. We defined the time points at which these outcome parameters should be collected to be at admission and discharge, 30 days, 90 days and 1 year after admission.

CONCLUSION

Twelve objective and patient-reported outcome parameters were selected to form a standard set for the measurement of influenceable outcome of patients treated in different models of orthogeriatric co-managed care.

Surgeons save bones: an algorithm for orthopedic surgeons managing secondary fracture prevention

Postmenopausal osteoporosis has a big impact on health care budget worldwide, which are expected to double by 2050. In spite of severe medical and socioeconomic consequences from fragility fractures, there are insufficient efforts in optimizing osteoporotic treatment and prevention. Undertreatment of osteoporosis is a well known phenomenon, particularly in elderly patients. Treatment rates remain low across virtually all patient, provider, and hospital-level characteristics, even after fragility fractures. In-hospital initiation is one of the options to increase treatment rates and improve osteoporosis management. However, multiple factors contribute to the failure of initiating appropriate treatment of osteoporosis in patients with fragility fractures. These include a lack of knowledge in osteoporosis and an absence of a comprehensive treatment guideline among family physicians and orthopedic surgeons. Furthermore, orthopedic surgeons are hardly willing to accept their responsibility for osteoporosis treatment due to the fact that they are usually not familiar with the initiation of specific drug treatments. The presented algorithm offers trauma surgeons and orthopedic surgeons a safe and simple guided pathway of treating osteoporosis in postmenopausal women appropriately after fragility fractures based on the current literature. From our point of view, this algorithm is useful for almost all cases and the user can expect treatment recommendations in more than 90 % of all cases. Nevertheless, some patients may require specialized review by an endocrinologist. The proposed algorithm may help to increase the rate of appropriate osteoporosis treatment hence reducing the rates of fragility fractures.

[Intramedullary nailing of the distal tibia illustrated with the Expert(TM) tibia nail]

OBJECTIVE

Restoration of axis, length, and rotation of the lower leg. Sufficient primary stability of the osteosynthesis for functional aftercare and to maintain joint mobility. Good bony healing in closed and open fractures.

INDICATIONS

Closed and open fractures of the tibia and complete lower leg fractures distal to the isthmus (AO 42), extraarticular fractures of the distal tibia (AO 43 A1/A2/A3), segmental fractures of the tibia with a fracture in the distal tibia, and certain intraarticular fractures of the distal tibia without impression of the joint line with the use of additional implants (AO 43 C1)

CONTRAINDICATIONS

Patient in reduced general condition (e.g., bed ridden), flexion of the knee of less than 90°, patients with knee arthroplasty of the affected leg, infection in the area of the nail's insertion, infection of the tibial cavity, complex articular fractures of the proximal or distal tibia with joint depression.

SURGICAL TECHNIQUE

Closed reduction of the fracture preferably on a fracture table or using a distractor or an external fixation frame. If necessary, use pointed reduction clamps or sterile drapery. In some cases, additional implants like percutaneous small fragment screws, poller screws or k-wires are helpful. Open reduction is rarely necessary and must be avoided. Opening of the proximal tibia in line with the medullary canal. Canulated insertion of the Expert(TM) tibia nail (ETN; Synthes GmbH, Oberdorf, Switzerland) with reaming of the medullary canal. Control of axis, length, and rotation. Distal interlocking with the radiolucent drill and proximal interlocking with the targeting device.

POSTOPERATIVE MANAGEMENT

Immediate mobilization of ankle and knee joint. Mobilization with 20 kg weight-bearing with crutches. X-ray control 6 weeks postoperatively and increased weight-bearing depending on the fracture status. In cases with simple fractures, good bony contact, or transverse fracture pattern, full weight-bearing at the end of week 6 is targeted.

RESULTS

Between July 2004 and May 2005, 180 patients were included in a multicenter study. The follow-up rate was 81% after 1 year. Of these, 91 fractures (50.6%) were located in the distal third of the tibia. In this segment, the rate of delayed union was 10.6%. Malalignment of > 5° was observed in 5.4%. A secondary malalignment after initial good reduction was detected in only 1.1% of all cases. The implant-specific risk for screw breakage was 3.2%. One patient sustained a deep infection. If additional fibula plating was performed an 8-fold higher risk for delayed bone healing was observed (95%CI: 2.9-21.2, p< 0.001). If the fracture of the fibula was at the same height as on the tibia, the risk for delayed healing was even 14-fold (95% CI: 3.4-62.5, p< 0.001). Biomechanically plating of the fibula does not increase stability in suprasyndesmal distal tibia-fibular fractures treated with an intramedullary nail. Using the ETN with its optimized locking options, fibula plating is not recommended, thus, avoiding soft tissue problems and potentially delayed bone healing.

The Tyrolean Geriatric Fracture Center: an orthogeriatric co-management model

BACKGROUND

The aging population is growing rapidly and this change results in an increase in the number of fragility fracture patients. Several reports describe their poor outcome. Integrated models of care have been published in order to improve quality of patient care. We established an orthogeriatric model of care at the Department of Trauma Surgery in Innsbruck in cooperation with the Department of Geriatric Medicine (Hochzirl) and the Department for Anesthesiology. This report describes our concept as well as initial experience.

PATIENTS AND METHODS

We included all geriatric patients according to the definition of the German Geriatric Society. In all patients, basic demographic data, Charlson Comorbidity Index, and type of fracture were recorded. Main principles of the newly implemented system are the integration of a geriatrician in our team of trauma surgeons and anesthesiologists, prioritization of patients, development of our own clinical treatment guidelines, regular interdisciplinary and interprofessional meetings, a special outpatient clinic for these patients, and the better cooperation with the nearby Department of Geriatric Medicine.

RESULTS

A total of 529 patients met our inclusion criteria during 2010; 77.4% were female and the mean age was 84.1 years. The overall medical complication rate was 20.4%. Of the patients, 36.1% had hip fractures and 70.5% could be operated mainly using spinal anesthesia within 24 h and their mean length of stay was significantly shorter than operations performed 5 years previously. At 3 months, 86.7% of the patients had returned home and, thus, had reached their prefracture residency.

CONCLUSION

A coordinated, multidisciplinary model for the treatment of fragility fractures has the potential to improve the quality of patient care. Several international studies report superior outcome and our own findings are promising as well. We could show that our major goals, e.g., reduction of complications, shortening the length of stay, and restoration of the prefracture residency, can be improved by implementing such a model.

Standardised cement augmentation of the PFNA using a perforated blade: A new technique and preliminary clinical results. A prospective multicentre trial

Pertrochanteric fractures are a rising major health-care problem in the elderly and their operative stabilisation techniques are still under discussion. Furthermore, complications like cut-out are reported to be high and implant failure often is associated with poor bone quality. The PFNA(®) with perforated blade offers a possibility for standardised cement augmentation using a polymethylmethacrylate (PMMA) cement which is injected through the perforated blade to enlarge the load-bearing surface and to diminish the stresses on the trabecular bone. The current prospective multicentre study was undertaken to evaluate the technical performance and the early clinical results of this new device. In nine European clinics, 59 patients (45 female, mean age 84.5 years) suffering from an osteoporotic pertrochanteric fracture (Arbeitsgemeinschaft für Osteosynthesefragen, AO-31) were treated with the augmented PFNA(®). Primary objectives were assessment of operative and postoperative complications, whereas activities of daily living, pain, mobility and radiologic parameters, such as cement distribution around the blade and the cortical thickness index, were secondary objectives. The mean follow-up time was 4 months where we observed callus healing in all cases. The surgical complication rate was 3.4% with no complication related to the cement augmentation. More than one-half of the patients reached their prefracture mobility level within the study period. A mean volume of 4.2ml of cement was injected. We did not find any cut-out, cut through, unexpected blade migration, implant loosening or implant breakage within the study period. Our findings lead us to conclude that the standardised cement augmentation using the perforated blade for pertrochanteric fracture fixation enhances the implant anchorage within the head-neck fragment and leads to good functional results.

Biomechanical effect of bone cement augmentation on rotational stability and pull-out strength of the Proximal Femur Nail Antirotation™

INTRODUCTION

After surgical treatment of osteoporotic hip fractures, complications such as implant cut-out are reported to be high and implant failure often is associated with poor bone quality. As augmentation is reported to enhance implant anchorage, the aim of our study was to investigate the effect of bone cement augmentation on the rotational stability and the pull-out resistance of the Proximal Femur Nail Antirotation™ (PFNa) blade.

MATERIALS AND METHODS

A total of 18 fresh-frozen femoral heads (mean age 68 years, standard deviation (SD) 8.2) were scanned with quantitative computed tomography (qCT) for bone mineral density (BMD) measurements and instrumented with a PFNa blade. Nine specimens were augmented with a mean volume of 4.4 ml Traumacem V+. After cement consolidation, the blade was rotated for 60° for the rotational test. Subsequently, the blade was extracted from the specimens. Force, torque, displacement and angle were recorded constantly.

RESULTS

In the rotational test, the mean maximum torque in the augmented group (17.2 Nm, SD 5.0) was significantly higher (p=0.017) than in the non-augmented group (11.7 Nm, SD 3.5). The pull-out test also yielded a significant difference (p=0.047) between the augmented (maximum pullout force: 2315.2N, SD 1060.6) and the non-augmented group (1180.4N, SD 1171.4).

DISCUSSION

Augmentation of femoral heads yielded a significantly superior rotational stability, as well as an enhanced pull-out resistance, compared to the non-augmented state. However, the higher the BMD of the specimens, the lower was the effect of augmentation on the rotational stability. Therefore, augmentation can be a good clinical tool to enhance implant anchorage in osteoporotic bone.

Outcome in geriatric fracture patients and how it can be improved

Geriatric fractures are an increasing medical problem worldwide. This article wants to give an overview on the literature concerning the outcome to be expected in geriatric fracture patients and what can be done to improve it. In literature, excess mortality rates vary from 12% to 35% in the first year after a hip fracture, and also, other geriatric fractures seem to reduce the patient's remaining lifetime. Geriatric fractures and, in particular, hip fractures constitute a major source of disability and diminished quality of life in the elderly. Age, gender, comorbid conditions, prefracture functional abilities, and fracture type have an impact on the outcome regarding ambulation, activities of daily living, and quality of life. Comprehensive orthogeriatric comanagement might improve the outcome of geriatric fracture patients. For the future, well designed, large prospective randomized controlled trials with clear outcome variables are needed to finally prove the effectiveness of existing concepts.

Ortho-geriatric service--a literature review comparing different models

In the fast-growing geriatric population, we are confronted with both osteoporosis, which makes fixation of fractures more and more challenging, and several comorbidities, which are most likely to cause postoperative complications. Several models of shared care for these patients are described, and the goal of our systematic literature research was to point out the differences of the individual models. A systematic electronic database search was performed, identifying articles that evaluate in a multidisciplinary approach the elderly hip fracture patients, including at least a geriatrician and an orthopedic surgeon focused on in-hospital treatment. The different investigations were categorized into four groups defined by the type of intervention. The main outcome parameters were pooled across the studies and weighted by sample size. Out of 656 potentially relevant citations, 21 could be extracted and categorized into four groups. Regarding the main outcome parameters, the group with integrated care could show the lowest in-hospital mortality rate (1.14%), the lowest length of stay (7.39 days), and the lowest mean time to surgery (1.43 days). No clear statement could be found for the medical complication rates and the activities of daily living due to their inhomogeneity when comparing the models. The review of these investigations cannot tell us the best model, but there is a trend toward more recent models using an integrated approach. Integrated care summarizes all the positive features reported in the various investigations like integration of a Geriatrician in the trauma unit, having a multidisciplinary team, prioritizing the geriatric fracture patients, and developing guidelines for the patients' treatment. Each hospital implementing a special model for geriatric hip fracture patients should collect detailed data about the patients, process of care, and outcomes to be able to participate in audit processes and avoid peerlessness.

Operative treatment of 733 patients with acute thoracolumbar spinal injuries: comprehensive results from the second, prospective, Internet-based multicenter study of the Spine Study Group of the German Association of Trauma Surgery

The second, internet-based multicenter study (MCSII) of the Spine Study Group of the German Association of Trauma Surgery (Deutsche Gesellschaft für Unfallchirurgie) is a representative patient collection of acute traumatic thoracolumbar (T1-L5) injuries. The MCSII results are an update of those obtained with the first multicenter study (MCSI) more than a decade ago. The aim of the study was to assess and bring into focus: the (1) epidemiologic data, (2) surgical and radiological outcome, and (3) 2-year follow-up (FU) results of these injuries. According to the Magerl/AO classification, there were 424 (57.8%) compression fractures (A type), 178 (24.3%) distractions injuries (B type), and 131 (17.9%) rotational injuries (C type). B and C type injuries carried a higher risk for neurological deficits, concomitant injuries, and multiple vertebral fractures. The level of injury was located at the thoracolumbar junction (T11-L2) in 67.0% of the case. 380 (51.8%) patients were operated on by posterior stabilization and instrumentation alone (POSTERIOR), 34 (4.6%) had an anterior procedure (ANTERIOR), and 319 (43.5%) patients were treated with combined posteroanterior surgery (COMBINED). 65% of patients with thoracic (T1-T10) and 57% with lumbar spinal (L3-L5) injuries were treated with a single posterior approach (POSTERIOR). 47% of the patients with thoracolumbar junction (T11-L2) injuries were either operated from posterior or with a combined posterior-anterior surgery (COMBINED) each. Short angular stable implant systems have replaced conventional non-angular stable instrumentation systems to a large extent. The posttraumatic deformity was restored best with COMBINED surgery. T-spine injuries were accompanied by a higher number and more severe neurologic deficits than TL junction or L-spine injuries. At the same time T-spine injuries showed less potential for neurologic recovery especially in paraplegic (Frankel/AISA A) patients. 5% of all patients required revision surgery for perioperative complications. Follow-up data of 558 (76.1%) patients were available and collected during a 30-month period from 1 January 2004 until 31 May 2006. On average, a posterior implant removal was carried out in a total of 382 COMBINED and POSTERIOR patients 12 months after the initial surgery. On average, the rehabilitation process required 3-4 weeks of inpatient treatment, followed by another 4 months of outpatient therapy and was significantly shorter when compared with MCSI in the mid-1990s. From the time of injury until FU, 80 (60.6%) of 132 patients with initial neurological deficits improved at least one grade on the Frankel/ASIA Scale; 8 (1.3%) patients deteriorated. A higher recovery rate was observed for incomplete neurological injuries (73%) than complete neurological injuries (44%). Different surgical approaches did not have a significant influence on the neurologic recovery until FU. Nevertheless, neurological deficits are the most important factors for the functional outcome and prognosis of TL spinal injuries. POSTERIOR patients had a better functional and subjective outcome at FU than COMBINED patients. However, the posttraumatic radiological deformity was best corrected in COMBINED patients and showed significantly less residual kyphotic deformity (biseg GDW -3.8° COMBINED vs. -6.1° POSTERIOR) at FU (p = 0.005). The sagittal spinal alignment was better maintained when using vertebral body replacement implants (cages) in comparison to iliac strut grafts. Additional anterior plate systems did not have a significant influence on the radiological FU results. In conclusion, comprehensive data of a large patient population with acute thoracolumbar spinal injuries has been obtained and analyzed with this prospective internet-based multicenter study. Thus, updated results and the clinical outcome of the current operative treatment strategies in participating German and Austrian trauma centers have been presented. Nevertheless, it was not possible to answer all remaining questions to contradictory findings of the subjective, clinical outcome and corresponding radiological findings between different surgical subgroups. Randomized-controlled long-term investigations seem mandatory and the next step in future clinical research of Spine Study Group of the German Trauma Society.

Accuracy of minimally invasive navigated acetabular and iliosacral fracture stabilization using a targeting and noninvasive registration device

BACKGROUND

To assess the feasibility and accuracy of guide pin (GP) placement using a combined noninvasive patient immobilization and stereotactic targeting system in computer-assisted percutaneous pelvic fracture stabilization.

METHODS

A total of 12 patients with negligible dislocated unstable pelvic fractures were enrolled in this study, performed between February 2002 and October 2005. Our original plans included 13 GP placements in the iliosacral area (SF) and 8 in the acetabular (AF) area. Patients were bedded on a noninvasive dual-vacuum immobilization device. Interventions were planned on a navigation system using intraoperatively acquired CT data. Radiodense markers glued to the skin and the immobilization device provided synchronization between virtual data set and real anatomical situation. A stereotactic targeting device was used for stabilization of GP tracking. GP positions were verified intraoperatively by CT, followed by fracture stabilization with cannulated screws.

RESULTS

Mean GP placement accuracy according to plan: (1) SF-cohort: 2.8 mm (SD 2.0 mm, range 0.5-9.0 mm) at the bony entry point and 3.8 mm (SD 2.3 mm, range 0.6-9.5 mm) at the target point. (2) AF-cohort: 3.0 mm (SD 0.9 mm, range 1.6-4.9 mm) at the bony entry point and 3.9 mm (SD 1.9 mm, range 1.6-7.5 mm) at the target point. GP placement succeeded optimally in 11 out of 13 cases in the SF-cohort, and 6 out of 8 cases in the AF-cohort. The individual average dose-length product (DLP) per successful finished procedure was 1,576 mGy x cm (SD 812 mGy x cm, range 561-2,739 mGy x cm).

CONCLUSION

Our findings substantiate application of the noninvasive patient immobilization and stereotactic targeting system as effective in computer-assited percutaneous stabilization of sacral bone fractures/SI joint disruptions and coronally oriented acetabular dome fractures. We recommend according to the ALARA (as low as reasonable achievable) principle: first, the kV and mAs values have to be reduced. Second, the scanned volume has to be strictly limited to the area of interest. Third, the number of control CTs have to be minimized. Also, the IsoC might be a better choice for implant tracking below 12 cm to reduce the radiation dose to the minimum. We believe that for all high-precise GP placements in the acetabular column area, further improvements in GP guidance (inhibiting pin tip slipping and detecting intraosseous GP deflection) are necessary.

Extent of corpectomy determines primary stability following isolated anterior reconstruction in a thoracolumbar fracture model

BACKGROUND

Based on the development of minimal-invasive techniques and introduction of new implants enabling secure reconstruction an increasing number of patients are treated by isolated anterior column surgery. Most biomechanical studies dealing with thoracolumbar fracture models use worst-case scenarios of complete corpectomies to simulate vertebral body defects neglecting the influence of remaining cortical bone in partial corpus instability. Using a standardized partial and total corpectomy model we investigated the effect of the extent of corpectomy on stiffness in an anterior reconstruction model.

METHODS

Twelve human thoracolumbar specimens (Th11-L3) were loaded in a spine simulator with pure moments in the three motion planes. Following intact testing partial corp- and discectomy and later complete corpectomy of L1 were performed. Defects were instrumented by vertebral body replacements and additional anterior plating systems bridging the defect from Th12 to L2. Intersegmental rotations were measured between Th12 and L2.

FINDINGS

Significantly (P<0.05) increased range of motion was found in reconstructions of total compared to partial corpectomy. Total corpectomy reconstructions showed solely in lateral bending a significant reduction of range of motion compared to the intact state, while in axial rotation and flexion/extension it was significantly increased. Partial corpectomy reconstructions resulted in significantly reduced range of motion for lateral bending and flexion/extension compared to the intact specimen.

INTERPRETATION

Isolated anterior reconstructions of the thoracolumbar spine revealed sufficient stiffness in the partial vertebral corpus defect. In contrast, total corpectomy did not show an adequate stiffness. Especially in regard to rotational stiffness additional posterior fixation has to be recommended.

A new distractable implant for vertebral body replacement: biomechanical testing of four implants for the thoracolumbar spine

INTRODUCTION

Expandable titanium implants for vertebral body replacement in the thoracolumbar spine have been well established in the reconstruction of the anterior spinal column. Load transfer at the bone-implant interface remains a point of concern. The purpose of the study was to compare the performance in axial load transfer from the implant to the vertebral body in four different implants, all of them in clinical use to date.

MATERIALS AND METHODS

We tested a second generation implant (Synex II) in comparison to three different expandable titanium cages: Synex I, Obelisc and X-Tenz. Twenty-four intact fresh frozen human lumbar vertebrae (L1-L4) were distributed into four identical groups according to bone mineral density (BMD). The BMD was determined by quantitative computed tomography (qCT). Specimens were loaded in craniocaudal direction with a material testing machine (Mini Bionix II) at a constant speed of 5 mm/min. Load displacement curves were continuously recorded for each specimen until failure (diminishment of compressive force (F) and/or obvious implant migration through the vertebral body end plate). One-way analysis of variance (ANOVA) and post-hoc tests (Bonferroni) were applied to detect differences at 1, 2, 3, and 4 mm displacement (F (1-4 mm)) between implant groups.

RESULT

No significant differences were observed with regard to maximum compression force (F (max)) and displacement (d (max)) until failure: Synex II (1,782.3 N/4.67 mm); Synex I (1,645.3 N/4.72 mm); Obelisc (1,314.0 N/4.24 mm); X-Tenz (1470.3 N/6.92 mm). However, the mean compression force at 1-4 mm displacement (F (1-4 mm): 300-1,600 N) was highest for Synex II. The difference at 2 mm displacement was significant (p = 0.028) between Synex II (F (2 mm) = 879 N) and X-Tenz (F (2 mm) = 339 N).

CONCLUSION

The modified end plate design of Synex II was found to perform comparably at least with regard to the compressive performance at the implant-bone interface. The risk of the new implant for collapse into the vertebral body might be reduced when compared to the competitors.

[Operative treatment of traumatic fractures of the thorax and lumbar spine. Part II: surgical treatment and radiological findings]

The Spine Study Group (AG WS) of the German Trauma Association (DGU) presents its second prospective Internet-based multicenter study (MCS II) for the treatment of thoracic and lumbar spinal injuries. This second part of the study report focuses on the surgical treatment, course of treatment, and radiological findings in a study population of 865 patients. A total of 158 (18,3%) thoracic, 595 (68,8%) thoracolumbar, and 112 (12,9%) lumbar spine injuries were treated. Of these, 733 patients received operative treatment (OP group). Fifty-two patients were treated non-operatively and 69 patients were treated with kyphoplasty/vertebroplasty without additional instrumentation (Plasty group). In the OP group, 380 (51.8%) patients were instrumented from a posterior (dorsal) position, 34 (4.6%) from an anterior (ventral) position, and 319 (43.5%) cases with a combined posteroanterior procedure. Angular stable internal spine fixator systems were used in 86-97% of the cases for posterior and/or combined posteroanterior procedures. For anterior procedures, angular stable plate systems were used in a majority of cases (51.1%) for the instrumentation of mainly one or two segment lesions (72.7%). In 188 cases (53,3%), vertebral body replacement implants (cages) were used and were mainly implanted via endoscopic approaches (67,4%) to the thoracic spine and/or the thoracolumbar junction. The average operating time was 152 min in posterior-, 208 min in anterior-, and 298 min in combined postero-anterior procedures (p<0,001). The average blood loss was highest in combined operations, measuring 959 ml vs. 650 ml in posterior vs. 534 ml in anterior operations (p<0,001).Computer-assisted intraoperative navigation systems were used in 95 cases. At the time of hospital admission, 58,7% of the patients had spinal canal narrowing of an average of 36% (5-95%) at the level of their injury. The average spinal canal narrowing in patients with a complete spinal cord injury (Frankel/ASIA A) was calculated to be 70%, vs. 50% in patients with incomplete neurologic deficits (Frankel/ASIA B-D), and 20% in patients without neurologic deficits (Frankel/ASIS E; p<0,001). The average procedure in the plasty treatment subgroup was 50 min (18-145 min) to address one (n=59) or two (n=10) injured vertebral bodies. In patients with nonoperative treatment mainly three-point-corsets (n=36) were administered for a duration of 6-12 weeks. During their hospital stay 93 of 195 (44,7%) patients with initial neurologic deficits improved at least one Frankel/ASIA grade until the day of discharge. Two patients (0,2%) showed a neurologic deterioration. The highest rate of complete spinal cord injury (n=36, 23%) was associated with thoracic spine injuries. Nine (1%) patients died during the initial course of treatment. A total of 105 (14,3%) cases with intraoperative (n=56) and/or postoperative complications (n=69) were registered. The most common intraoperative complication was bleeding (n=35, 4,8%). A higher relative frequency of intraoperative complications was noticed in combined (n=34, 10,7%) vs. isolated posterior (n=22, 5,9%; p=0,021) procedures. The most common postoperative complication was associated with wound healing problems in 14 (1,9%) patients. Except in the non-operative treatment subgroup, a correction of the posttraumatic measured radiological deformity was achieved to a different extent within every treatment subgroup. There were no statistically significant differences between the postoperative radiological results of the treatment subgroups (dorsal vs. combination), taking into consideration the influence of relevant parameters such as different fracture types, patient age, and the amount of posttraumatic deformity (p=0,34, ANOVA).

Combined posterior-anterior stabilisation of thoracolumbar injuries utilising a vertebral body replacing implant

The authors report on a prospectively followed series of 35 patients with injuries of the thoracolumbar spine from T7 to L3. The radiological course after combined posterior-anterior surgery with anterior column reconstruction with a distractible vertebral body replacing implant demonstrated a stable reconstruction technique with almost no re-kyphosing. In 18/18 patients with CT follow-up intervertebral fusion was observed as bony bridging lateral to the VBR implant. The functional/clinical outcome of the patients was analysed with a set of eight validated outcome scales. After an average follow-up period of 2(1/2) years encouraging results were noticed. The neurological improvement rate (> or =1 Frankel/ASIA grade) was 8/12 patients (67%) with a complete recovery in 6 cases. 17/29 patients returned to former occupation; 20/29 patients returned to former leisure activities; 24/28 patients rated their general outcome as "unlimited and pain free" or "occasionally and/or mild complaints" with a VAS score of >80 (scale 0-100). The psychometric questionnaires revealed good results with strong correlation comparing the different scoring systems statistically: mean McGill Pain Questionnaire 12.5 (0-40); mean Oswestry Disability Index 20% (0-51). 13/29 patients scored <4 in the Roland and Morris Disability Questionnaire. The German back pain questionnaire (Funktionsfragebogen Hannover Rücken) showed a mean "functional capacity" of 75%, corresponding with moderate restriction. We concluded the presented method as highly effective to completely reduce and maintain an anatomic spinal alignment. The outcome tended to be better in comparison with non-operatively treated patients as well as with norm populations with low back pain.

Influence of osteoporosis on fracture fixation--a systematic literature review

The goal of our systematic literature search was to prove whether the experimentally shown influence of osteoporosis on fracture fixation could be confirmed in clinical studies. Despite significant effects in several studies, this is not supported by pooled data due to lack of accurate osteoporosis assessment and complication definitions.

INTRODUCTION

The fact that osteoporosis causes fractures is well-known; the assumption that it aggravates their orthopaedic treatment has not been proven. The goal of our systematic literature search was to find out whether the experimentally proven influence of osteoporosis on fracture fixation could be confirmed in clinical studies.

METHODS

A systematic electronic database search was performed identifying articles that evaluated complications after fracture fixation among patients suspected of having osteoporosis as measured by BMD or surrogates including Singh index or risk factors. To determine complications risks (relative risk within 95% confidence interval) data were pooled across studies, weighted by sample size and stratified by treatment type.

RESULTS

Ten studies out of 77 randomized controlled trials (51 hip, 23 distal radius and three proximal humerus studies) and three systematic reviews finally met eligibility criteria. Despite significant differences of the relative complication risk between osteoporotic and non-osteoporotic patients in several studies, this could not be proven in the pooled data.

CONCLUSIONS

In contrast to biomechanical evidence that local osteoporosis affects anchorage of implants, this could not be reproduced in clinical studies, due to the lack of accurate osteoporosis assessment, missing complication definitions and heterogeneous inclusion criteria in these studies. Prospective studies are required that address specifically the correlation between local bone status and the risk of fixation failure.