Biomechanical evaluation of locked plating fixation for unstable femoral neck fractures.

AIMS: Evaluate if treating an unstable femoral neck fracture with a locking plate and spring-loaded telescoping screw system would improve construct stability compared to gold standard treatment methods. METHODS: A 31B2 Pauwels' type III osteotomy with additional posterior wedge was cut into 30 fresh-frozen femur cadavers implanted with either: three cannulated screws in an inverted triangle configuration (CS), a sliding hip screw and anti-rotation screw (SHS), or a locking plate system with spring-loaded telescoping screws (LP). Dynamic cyclic compressive testing representative of walking with increasing weight-bearing was applied until failure was observed. Loss of fracture reduction was recorded using a high-resolution optical motion tracking system. RESULTS: LP constructs demonstrated the highest mean values for initial stiffness and failure load. LP and SHS constructs survived on mean over 50% more cycles and to loads 450 N higher than CS. During the early stages of cyclic loading, mean varus collapse of the femoral head was 0.5° (SD 0.8°) for LP, 0.7° (SD 0.7°) for SHS, and 1.9° (SD 2.3°) for CS (p = 0.071). At 30,000 cycles (1,050 N) mean femoral neck shortening was 1.8 mm (SD 1.9) for LP, 2.0 mm (SD 0.9) for SHS, and 3.2 mm (SD 2.5) for CS (p = 0.262). Mean leg shortening at construct failure was 4.9 mm (SD 2.7) for LP, 8.9 mm (SD 3.2) for SHS, and 7.0 mm (SD 4.3) for CS (p = 0.046). CONCLUSION: Use of the LP system provided similar (hip screw) or better (cannulated screws) biomechanical performance as the current gold standard methods suggesting that the LP system could be a promising alternative for the treatment of unstable fractures of the femoral neck.Cite this article: Bone Joint Res 2020;9(6):314-321.

Correction to: Comparison of two reinforcement rings for primary total hip arthroplasty addressing displaced acetabular fractures: a biomechanical analysis.

The original version of this article unfortunately contained a mistake.

Comparison of two reinforcement rings for primary total hip arthroplasty addressing displaced acetabular fractures: a biomechanical analysis.

INTRODUCTION: Aim of this study was to biomechanically compare two different acetabular cup fixation constructs in terms of fracture fixation for displaced acetabular fractures involving the anterior column with hemitransverse fracture under partial and full weight-bearing conditions. METHODS: Two different reinforcement rings designed as cages for primary THA were biomechanically tested in terms of managing a complex acetabular fracture. Single-leg stance cyclic loading was performed to assess fracture gap movement and fragment rotation. Twelve hemi pelvis Sawbones were divided into two groups: primary THA with acetabulum roof reinforcement plate (ARRP) (n = 6) and primary THA with Burch-Schneider reinforcement cage (BSRC) (n = 6). RESULTS: During loading under partial weight-bearing (250 N) fracture gap movement tended to be larger in the BSRC group as compared to the ARRP group. Under full weight-bearing conditions, the ARRP showed 60% significantly less motion (p = 0.035) of the os ilium to os ischii gap compared to BSRC. Fracture gap movements between the os ilium and spina iliaca fragments were significantly reduced by 76% (p = 0.048) for ARRP in contrast to BSRC. The ARRP group also demonstrated significantly less movement in the fracture gaps os ischii to quadrilateral plate (62% reduction, p = 0.009) and quadrilateral plate to spina iliaca (87% reduction, p < 0.001). Significantly less rotational movement of the quadrilateral plate to the os ilium was exhibited by the ARRP group (p = 0.015). CONCLUSIONS: The presented acetabulum roof-reinforcement plate (ARRP) provides stable conditions at the acetabular component with adequate stabilization of a displaced acetabular fracture.

[Kirschner wire osteosynthesis for fractures in childhood: bury wires or not? : Results of a survey on care reality in Germany]. / Kirschner-Draht-Osteosynthese bei Frakturen im Kindesalter: Drähte versenken oder nicht? : Ergebnisse einer Umfrage zur Versorgungsrealität in Deutschland.

INTRODUCTION: Kirschner wire osteosynthesis is considered to be the standard technique for surgical fixation of displaced supracondylar humeral and distal radial fractures in children. The Kirschner wires can be left exposed or buried under the skin. Advantages of the epicutaneous technique are, e. g. the efficiency (cost, effort) and the possibility for wire removal without the necessity of a second anesthesia. On the other hand, there is a concern about higher infection rates as well as traumatization of the children due to externally visible wires. METHODS: A web-based survey of members of the DGU, DGOU, DGOOC, and the pediatric traumatology section of the DGU (SKT) was performed to evaluate current treatment concepts in Germany. The pros and cons for each technique were recorded and the need for a clinical study was examined. In addition, a cost analysis was performed for both methods. The results from the literature are summarized and discussed. RESULTS: A total of 710 questionnaires were evaluated. The majority of the respondents were trauma surgeons working in a hospital (80%). The buried technique was superior in both fracture groups (supracondylar humeral fractures 73% and distal radius fractures 69%), whereas a relevant difference could be found depending on the profession. The main reason for the subcutaneous technique was anxiety or observed higher infections using the epicutaneous technique. CONCLUSION: In Germany, the majority of wires are buried under the skin due to a fear of higher infection rates. In addition, other influencing factors such as pain and traditional approaches play a significant role. With respect to the results in the literature as well as a possible improvement of efficiency and avoidance of a second anesthesia, a multicentric clinical study seems necessary in the future to compare both techniques.

[Evolution and principles of intramedullary locked nailing]. / Entwicklung und Prinzipien der Verriegelungsmarknagelung.

Key factors for successful osteosynthetic fracture stabilization are anatomical fracture reduction, restoration of axis and torsion alignment as well as tissue-preserving operative techniques. In long bone fractures, the use of intramedullary long bridging nailing offers ideal conditions for bone healing, as axial and rotational stability is provided by canal-filling nails and locking screws. In addition, the tissue in the fracture region is protected as the intramedullary nail insertion is distant from the fracture. The indication spectrum for modern intramedullary locked nailing includes diaphyseal fractures of long bones, metaphyseal fractures and reconstructions, as well as treatment of nonunion, osteotomy and arthrodesis of the lower extremities. Continuous improvements in nail design and instrumentation as well as the introduction of anatomical reconstruction nails will optimize the spectrum and effectiveness of intramedullary osteosynthesis even further.

[Transitional fractures : Epiphyseal injuries in adolescence]. / Übergangsfraktur : Epiphysenverletzungen im Adoleszentenalter.

The so-called transitional fractures describe articular fractures in adolescents with partial closure of the epiphyseal growth plate. This shows a specific stereotype fracture pattern, which can be differentiated into biplane, triplane I and triplane II fractures depending on the involvement of the metaphysis and the number of fragments. The diagnostics and therapy can differ from fractures where the epiphyseal growth plate is still open. The main focus for surgical treatment is the reconstruction of the articular surface whereas relevant growth disturbances no longer need to be feared when the epiphysis has already begun to close.

[The Postero-Lateral Approach--An Alternative to Closed Anterior-Posterior Screw Fixation of a Dislocated Postero-Lateral Fragment of the Distal Tibia in Complex Ankle Fractures]. / Der posterolaterale Zugang--eine Alternative zur geschlossenen anterior-posterioren Schraubenosteosynthese bei komplexen Sprunggelenkfrakturen.

BACKGROUND: The dislocated posterolateral fragment of the distal tibia is considered as a key fragment for the successful reduction of comminuted ankle fractures. The reduction of this fragment can either be achieved indirectly by joint reduction using the technique of closed anterior-posterior screw fixation, or directly using the open posterolateral approach followed by plate fixation. The aim of this study was to compare the outcome after stabilization of the dislocated posterolateral tibia fragment using either closed reduction and screw fixation, or open reduction and plate fixation via the posterolateral approach in complex ankle fractures. PATIENTS/MATERIAL AND METHODS: In a prospective study between 01/2010 and 12/2012, all mono-injured patients with closed ankle fractures and dislocated posterolateral tibia fragments were assessed 12 months after osteosynthesis. Parameters included: size of the posterolateral tibia fragment relative to the tibial joint surface (CT scan, in %) as an indicator of injury severity, unreduced area of tibial joint surface postoperatively, treatment outcome assessed by using the "Ankle Fracture Scoring System" (AFSS), as well as epidemiological data and duration of the initial hospital treatment. RESULTS: In 11 patients (10 female, 1 male; age 51.6 ± 2.6 years [mean ± SEM], size of tibia fragment 42.1 ± 2.5 %) the fragment fixation was performed using a posterolateral approach. Impaired postoperative wound healing occurred in 2 patients of this group. In the comparison group, 12 patients were treated using the technique of closed anterior-posterior screw fixation (10 female, 2 male; age 59.5 ± 6.7 years, size of tibia fragment 45.9 ± 1.5 %). One patient of this group suffered an incomplete lesion of the superficial peroneal nerve. Radiological evaluation of the joint surface using CT scan imaging demonstrated significantly less dislocation of the tibial joint surface following the open posterolateral approach (0.60 ± 0.20 mm) compared to the closed anterior-posterior screw fixation (1.03 ± 0.08 mm; p < 0.05). Assessment of the treatment outcome using the AFSS demonstrated a significantly higher score of 97.4 ± 6.4 in the group with a posterolateral approach compared to a score of 74.4 ± 12.1 (p < 0.05) in the group with an anterior-posterior screw fixation. CONCLUSION: In comparison to the anterior-posterior screw fixation, open reduction and fixation of the dislocated, posterolateral key fragment of the distal tibia using a posterolateral approach resulted in a more accurate fracture reduction and significantly better functional outcome 12 months after surgery. In addition, no increased rate of postoperative complications, or extended hospital stay was observed but there was less severe post-traumatic joint arthritis. The results of this study suggest that in complex ankle factures the open fixation of the dislocated posterolateral fragment is recommended as an alternative surgical procedure and may be beneficial for both clinical and radiological long-term outcomes.

[Antegrade femoral intramedullary nailing in a lateral position]. / Technik der antegraden Femurmarknagelung in Seitenlage.

BACKGROUND: Intramedullary nailing is the gold standard for the treatment of femoral shaft fractures; however, rotational malalignment remains a common complication. The patient can be positioned on the fracture table in a supine position or alternatively in the lateral decubitus position without any traction. OBJECTIVE: The aim of this article is to describe an effective method to control intraoperative torsion of the femur. METHOD: The surgical technique described in this article is the standard procedure for femoral shaft fractures and subtrochanteric fractures in this level 1 trauma center. The patient is positioned in a lateral position on a radiolucent table with free draping of the injured leg. Using the C-arm, reduction can be performed with this technique with precise placing of the nails and torsion can be exactly adjusted and controlled with the aid of the femoral neck axis, the distal locking holes and both parallel femoral condyles. RESULTS: The described technique represents an effective method for the intraoperative control of femoral torsion. With an acceptable and most probably clinically irrelevant bias, this technique is able to avoid significant rotational malalignment. It does not prolong the operative procedure and does not require additional navigation settings. It has also been shown to be helpful in the treatment of subtrochanteric fractures. CONCLUSION: The surgical technique of anterograde intramedullary nailing using the lateral decubitus position without any traction device and free draping of the injured leg represents a safe and reliable treatment concept and offers logistical advantages compared to the supine position of the patient on a fracture table. Together with other described methods of intraoperative torsional control of femoral fractures, the radiological technique described in this study is an easily applicable and safe method, which needs to be confirmed in clinical studies.

[Intramedullary nailing vs. locking plate osteosynthesis in proximal humeral fractures: Long-term outcome]. / Marknagel- vs. winkelstabile Plattenosteosynthese bei proximalen Humerusfrakturen: Langzeitergebnisse.

BACKGROUND: For the treatment of proximal humeral fractures two major therapeutic principles can be employed: intramedullary nailing (PHN) or locking plate osteosynthesis. The aim of this study was to evaluate and compare clinical and radiological long-term outcome of proximal humeral fracture stabilization using PHN or angular stable plating. MATERIALS AND METHODS: In a retrospective study between March 2009 and March 2010, we analyzed 72 out of 118 patients with unified proximal humeral fracture who had been treated at least 3 years previously using PHN (44 patients) or angular stable plating (28 patients) in a level 1 trauma center. Functional and radiological outcomes were assessed at least 3 years after trauma using the Constant and Murley score and SF-36 score. RESULTS: According to the Neer classification, there were 31 3-part fractures (PHN: 23; plate: 8) and 41 4-part fractures (PHN: 21; plate: 20), respectively. No clinical symptoms after 3 years were observed in 42 patients, whereas in 30 patients clinical symptoms were evaluated related to pain and/or loss of function. Functional outcome using the Constant and Murley score demonstrated a total score of 73 points (ipsilateral side) vs. 88 points (contralateral side) in all evaluated patients, on average. CONCLUSION: Both PHN and angular stable plating are adequate treatment options for proximal humeral fractures. Both systems require precise preoperative planning and advanced surgical experience. No significant differences in long-term clinical and radiological outcome between implants regarding fracture classification, age of patient, and choice of implant were found.

[Auxiliary cerclage-wiring in internal fixation of displaced acetabular fractures]. / Auxiliäre Cerclage zur Reposition und Retention dislozierter Acetabulumfrakturen.

BACKGROUND: Displaced fractures of the acetabulum involving the quadrilateral plate continue to be a surgical challenge. In this study, we describe our operation technique of auxiliary acetabular cerclage-wiring combined with plate osteosynthesis and present our results as well as short-term outcome. PATIENTS AND METHODS: All patients aged 18 years and older treated with auxiliary cerclage-wiring between 2007 and 2012 were included in this study. Fractures were classified according to Letournel. Cerclage wiring was used when reposition and retention of the fracture was insufficient with plates and screws alone. Short-term outcome was evaluated by the German Short Musculoskeletal Functional Assessment (SMFA-D) questionnaire. RESULTS: Data from 23 patients were collected. The follow-up period was 7 months (range 2-23 months). Of the 23 patients, 22 showed excellent fracture reduction and retention. One patient had to undergo revision surgery due to loss of reposition. Patients showed good functional outcome. CONCLUSION: Auxiliary acetabular cerclage-wiring is a safe and effective method for fracture reduction and retention especially in displaced acetabular fractures involving the quadrilateral plate.

In the shadow of the Cosmetic Directive--inconsistencies in EU environmental hazard classification requirements for UV-filters.

UV-filters are chemicals with potentially environmental hazardous properties. In the European Union (EU), UV-filters contained in sunscreen products are currently regulated by the Cosmetic Directive (from July 2013 by the Cosmetic Products Regulation). Environmental hazard classifications according to the regulation on classification, labelling and packaging of substances and mixtures (CLP) must be determined for UV-filters contained in industrial chemical products, whereas UV-filters contained in sunscreens are exempted from CLP. In this study we determined the potential environmental hazard classifications of UV-filters and sunscreen products if the CLP regulation was to be required for cosmetic products. Two sunscreen products were evaluated in accordance with the aquatic environmental hazard criteria for mixtures. The results highlight that the inconsistencies in the current EU regulation of UV filters hamper the risk management of environmental hazards of UV filters used in cosmetic products. Almost 50% of the investigated UV-filters approved for use in cosmetic products on the European market according to the current Cosmetic Directive were identified to meet the CLP classification as being hazardous to the aquatic environment. Assuming a worst-case scenario, the two examined sunscreens could both be classified as hazardous to the aquatic environment with long-lasting effects according to CLP classification criteria. Hence, if the CLP regulation was applicable to sunscreen products, both brands could potentially be labelled with the environmental hazard pictogram and associated hazard and precautionary statements. Including cosmetic products, and thereby sunscreens, in the CLP regulation would contribute to a more harmonized and transparent regulation of potentially hazardous substances on the EU market.

Prioritising pharmaceuticals for environmental risk assessment: Towards adequate and feasible first-tier selection.

The presence of pharmaceuticals in the aquatic environment, and the concerns for negative effects on aquatic organisms, has gained increasing attention over the last years. As ecotoxicity data are lacking for most active pharmaceutical ingredients (APIs), it is important to identify strategies to prioritise APIs for ecotoxicity testing and environmental monitoring. We have used nine previously proposed prioritisation schemes, both risk- and hazard-based, to rank 582 APIs. The similarities and differences in overall ranking results and input data were compared. Moreover, we analysed how well the methods ranked seven relatively well-studied APIs. It is concluded that the hazard-based methods were more successful in correctly ranking the well-studied APIs, but the fish plasma model, which includes human pharmacological data, also showed a high success rate. The results of the analyses show that the input data availability vary significantly; some data, such as logP, are available for most API while information about environmental concentrations and bioconcentration are still scarce. The results also suggest that the exposure estimates in risk-based methods need to be improved and that the inclusion of effect measures at first-tier prioritisation might underestimate risks. It is proposed that in order to develop an adequate prioritisation scheme, improved data on exposure such as degradation and sewage treatment removal and bioconcentration ability should be further considered. The use of ATC codes may also be useful for the development of a prioritisation scheme that includes the mode of action of pharmaceuticals and, to some extent, mixture effects.

[Severe polytrauma with an ISS ≥ 50]. / Das schwere Polytrauma mit einem ISS ≥ 50.

In Germany 427,500 persons per year are injured in traffic accidents. So we analysed in a retrospective study the post-traumatic quality of life of patients suffering from a severe trauma (ISS ≥ 50). Highlights of interest were: (i) pattern of injury, (ii) injured part of the body, (iii) days in ICU, (iv) outcome, (v) actual state of health, (vi) mental health. Between 1/2000 and 12/2005, 1,435 patients with multiple trauma were hospitalised in the Trauma Center Murnau. 88 suffered from a severe trauma with ISS ≥ 50. 23 % of these patients had a good outcome and 36 % died. Actually, more than half of the patients were physically handicapped or suffered from pain. 41 % showed characteristics typical for a post-traumatic stress disorder. In conclusion the patients with severe trauma had a good survival rate, but they showed a poor post-traumatic quality of life. Thus, in the time after trauma it is important to treat the "whole patient" and not only the physical lesions.

Reporting and evaluation criteria as means towards a transparent use of ecotoxicity data for environmental risk assessment of pharmaceuticals.

Ecotoxicity data with high reliability and relevance are needed to guarantee the scientific quality of environmental risk assessments of pharmaceuticals. The main advantages of a more structured approach to data evaluation include increased transparency and predictability of the risk assessment process, and the possibility to use non-standard data. In this collaboration, between the research project MistraPharma and the German Federal Environment Agency, a new set of reporting and evaluation criteria is presented and discussed. The new criteria are based on the approaches in the literature and the OECD reporting requirements, and have been further developed to include both reliability and relevance of test data. Intended users are risk assessors and researchers performing ecotoxicological experiments, but the criteria can also be used for education purposes and in the peer-review process for scientific papers. This approach intends to bridge the gap between the regulator and the scientist's needs and way of work.

Chemical risks and consumer products: the toxicity of shoe soles.

The European chemicals legislation, REACH, aims to ensure a high level of protection of human health and the environment. However, chemicals included in consumer products are covered only to a very limited extent even though they constitute the main source of chemical emissions. Shoes are large volume products and the overall aim of the present study was to study the ecotoxicological effects of three types of shoe soles and relate these effects to chemical emissions to the aquatic environment. The shoe soles were abraded and leached in water for 29 days and the alga Ceramium tenuicorne and the crustacean Nitocra spinipes were exposed to different concentrations of the leachate. Chemical analyses were performed to determine the chemical contents of the leachate. The main conclusions are that the shoe soles contain substances that are toxic to both test organisms, and that the toxicity is mainly explained by the presence of zinc. The estimated concentration of zinc from shoe soles in storm water runoff is low, but it still contributes to the overall load of chemicals and metals in the environment. The outlined test procedures may, in our view, provide a useful screening tool for assessing the risk that chemicals in consumer articles pose to the environment.

The Swedish Environmental Classification and Information System for Pharmaceuticals--an empirical investigation of the motivations, intentions and expectations underlying its development and implementation.

In 2005 the Swedish Association of the Pharmaceutical Industry (LIF) initiated a national environmental classification and information system for pharmaceuticals. This investigation reports the results from a survey, conducted among the persons involved in the start-up process. The aim of this study is to generate knowledge contributing to the clarification of the motivations, expectations, and intentions underlying the development and implementation of the system. The decision to implement a classification and information system for pharmaceuticals was the result of a combination of several driving forces, mainly political pressure and a possibility to increase the industries' goodwill, while at the same time keeping the process under the industries' control. The expected possible effects of the system, other than increased goodwill, are according to this survey assumed to be low. The system offers little guidance for end-users in the substitution of one pharmaceutical for another. One possible reason for this could be that LIF needs to observe the interests of all its members' and should not affect competition. The affiliation of the involved actors correlates to how these actors view and value the system, but this has not hampered the collaborative process to develop and implement it.

Acrylamide and cancer risk--expert risk assessments and the public debate.

This study has two parts. In the first part, fourteen carcinogen risk assessments of acrylamide made by different expert groups during the years 1976-2002 are compared in terms of their overall conclusions and their use of primary data. In the second part, the public debate on acrylamide and cancer risks and the questioning of the expert risk assessment, that arose as a reaction to the identification of this substance in staple food is discussed. In the first part it is shown that the expert risk assessors concur to a large degree about the assessment of the acrylamide potential to cause cancer. Three risk assessors have concluded that acrylamide is neither carcinogenic to humans nor to animals, while eleven risk assessors have concluded that acrylamide is carcinogenic in animals and is likely to be carcinogenic in humans. The differences in the overall conclusions seem to a large extent be explained by an evolving database. The risk assessors agree considerably on how to interpret and evaluate the available primary data, but the coverage of the available references is low. These results are also compared to those previously published on risk assessments of trichloroethylene. In the second part the arguments used in the public debate to question the expert risk assessment are summarized and it is argued that they are not based on the principles generally accepted in toxicological risk assessment.

Interpretations of primary carcinogenicity data in 29 trichloroethylene risk assessments.

This paper explores to what extent interpretations of individual primary carcinogenicity data differ between different risk assessors, and discusses possible reasons for such differences as well as their impact on the overall risk assessment conclusions. For this purpose 29 different TCE carcinogenicity risk assessments are used as examples. It is concluded that the TCE risk assessors surprisingly often interpret and evaluate primary data differently. Two particular reasons for differences in data interpretation are discussed: different assessments of statistics, and different assessments of whether the results obtained in bioassays have toxicological relevance. Differences in the interpretation and evaluation of epidemiological data are also explored and discussed.

The use and evaluation of primary data in 29 trichloroethylene carcinogen risk assessments.

This paper reports the results from a detailed study on how risk assessments of chemicals are actually made. The study is performed by comparing 29 cancer risk assessments made of one and the same chemical substance, namely, trichloroethylene. In this paper, the conclusions that are drawn in these risk assessment documents are described, and differences between the conclusions are explored. This is made within the framework of a proposed cancer risk assessment index. The selection of scientific data for risk assessment purposes is analyzed and the different risk assessors' interpretations and evaluations of individual primary data are compared. It is concluded that the data sets utilized by the trichloroethylene risk assessors are surprisingly incomplete and that biased data selection may have influenced some of the risk assessors' conclusions. Different risk assessors often interpret and evaluate one and the same study in different ways. There are also indications of both interpretation bias and evaluation bias for some of the risk assessors.