bluuebunny/crossref_metadata_2025_split huggingface dataset:
ACL rupture and posterior tibial slope - how do we handle this?
Authors: Dickschas Jörg 
Published: May 2020

Aims and Objectives: In recent publications on acl-ruptures and especially on failure of acl reconstruction there comes a strong focus on posterior tibial slope (PTS). ACL reconstructions with a PTS of >12° have an 8 times higher risk of recurrent instability and reconstruction failure. But many questions stay unclear so far-When do we have to correct the tibial slope? How do we correct it? What about simultaneous frontal axis deviations? In this publication a new algorhythm is presented. Materials and Methods: The following aspects have to be evaluated Is the PTS the only dimension of the deformity or do we have to correct the frontal axis simultaneuosly? Performing a anterior closed wedge extension osteotomy: when do we go distal the tuberosity and when do we perform a tuberosity osteotomy and use it as “bio plating”? Osteosynthesis only screws or always plate? Are there indications for a contineous correction, f.e. with a hexapod? Whats the role of preoperative range of motion of the knee (especially extension)? Always tunnel filling in the same surgery? What about PCL insufficiency and low PTS? Results: An algorhythm is presented giving a treatment path for the different questions mentioned. The procedures are shown step by step in clinical examples and surgery documentation for every pathway. Conclusion: Posterior tibial slope plays an critical role in ACl recontruction. In primary ACl tear a slope correction is probably not indicated. In ACL reconstruction failure a analysis of the PTS needs to be done and correction needs to be discussed. Simultaneuous varus deormities need to be corrected by openwedge valgisation - extension high tibial osteotomy (HTO), while as isolated PTS elevation is subject to an anterior closed wedge extension HTO. Preoperative range of motion needs to be respected not to create hyperextension. Osteosynthesis can be perormed with only screws using the tibial tubercle as “bio-plating”. In cases of former bone-tendeon-bone (BTB) ACL reconstruction a tibial tubercle osteotomy should be avoided and a infratuberositeal osteotomy should be performed and stabilized with plate osteosynthesis. In severe postraumatic cases contineous correction of the slope with fixateur externe, f.e. hexapodes, needs to be performed.
Why do MPFL reconstructions fail today?
Authors: Zimmermann Felix , Balcarek Peter 
Published: May 2020

Aims and Objectives: The medial patellofemoral ligament (MPFL) is the most important passive stabilizer of the patella. In recurrent lateral patellar dislocations reconstruction of the MPFL with an autologous tendon transplant is a frequently performed surgical procedure that shows a low redislocation rate between 1%-7%. However, a complication rate of up to 26% and a reoperation rate of 4% has also been observed. The question, therefore, arises which parameter determines MPFL reconstruction failure. Thus, the purpose of this study was to identify reasons for MPFL reconstruction failure with regard to patients’ complaints leading to reoperation. Materials and Methods: Between July 2015 and May 2019 28 patients (M/F 9/19; mean age 27 ± 8 years) with postoperative complaints after MPFL reconstructive surgery had to undergo revision surgery. Preoperative failure analysis included clinical examination (ROM, ReDPAT, J-sign, and Patella-Glide Test) and radiological imaging with regard to anatomical risk factors of patellar instability and MPFL tunnel positioning. Anatomical predisposition was assessed according to Dejour’s classification of trochlear dysplasia, tibial tuberosity-trochlear groove distance, tibial tuberosity-posterior cruciate ligament distance, patellar height, varus/valgus malalignment and torsional profile. Results: Three major reasons for revision surgery were identified: (1) patellar redislocation, (2) limited range of motion (ROM), and (3) anterior knee pain (AKP). Sixteen of the 28 patients (57%) suffered from recurrent patellar dislocation. Severe trochlear dysplasia (type B/D according to Dejour) (44%), valgus deformity (19%), increased patellar height (19%), and misplaced femoral drill channels (31%) could be identified as risk factors for redislocation. An increased TT-TG (>20mm) or TT-PCL (>24mm) distance could not be observed in any patient in this group. Limited ROM with an average maximum flexion ability of about 92 ± 26° was observed in 10 of the 28 patients (36%), of which 9 patients additionally complained of AKP. Misplaced femoral drill channels (80%), severe trochlear dysplasia (type B/D according to Dejour) (20%) and postoperative decreased patellar height (20%) could be identified as risk factors for postoperative limited ROM. Other reasons for postoperative AKP were increased femoral antetorsion (n=1) and retropatellar cartilage damage (n=2) without any loss of ROM. Conclusion: Recurrent dislocation of the patella, limited ROM and AKP were identified as most common complications after MPFL reconstruction leading to revision surgery. Failures are mainly due to neglected bony risk factors of patellar instability (trochlear dysplasia, patella alta and valgus deformity) and to misplaced femoral drill channels. Appropriate patient selection and an accurate surgical technique appear mandatory for a good clinical outcome when patellar instability is treated solely with an MPFL reconstruction.
Variability of functional knee phenotypes in osteoarthritic knees shows that a more personalized approach in TKA is needed
Authors: Moser Lukas , Hess Silvan , Behrend Henrik , Hirschmann Michael 
Published: May 2020

Aims and Objectives: Recently, the functional knee phenotype concept was introduced as a new system to classify the coronal alignment of the lower limb. Until now, this concept has only been applied to non-osteoarthritic knees. The purpose of this study was therefore to phenotype osteoarthritic knees according to this concept and investigate the distribution of these phenotypes. Materials and Methods: Preoperative CT scans of osteoarthritic knees scheduled for TKA collected between January 2017 and December 2019 in the KneePLAN 3D database (Symbios Orthopédie S.A.) were reviewed for patients meeting the following inclusion criteria: age>50 and <90, no signs of previous fractures, osteotomies and rheumatoid arthritis. A total of 2764 patients (1438 right and 1326 left lower limbs, Male:female ratio 1096 :1668) with a mean age ± standard deviation of 70±8.5years (range 50-90 years) were included. The following coronal alignment parameters were measured using a validated software (KneePLAN 3D, Symbios Orthopédie S.A): hip-knee-ankle angle (HKA), femoral mechanical angle (FMA), and tibial mechanical angle (TMA). Based on these measurements each leg was phenotyped according to the functional knee phenotype concept and the distribution of these phenotypes assessed. A phenotype thereby consists of a phenotype specific mean value (HKA, FMA or TMA value) and covers a range of ± 1.5° from this mean (e.g. 180°± 1.5). The phenotype specific mean values represent 3° increments of the angle starting from the rounded overall mean value of the angle. Results: There were 162 different functional knee phenotypes (122 male, 138 female and 97 mutual). The most common functional knee phenotype in males was VARHKA6°VARFMA3°NEUTMA0° accounting for 8% of all males. The most common functional knee phenotype in females was VARHKA3°NEUFMA0°NEUTMA0° accounting for 9% of the population. The ten most common functional phenotypes account for 50% and 42.8% of all females and males, respectively. Overall, 134 phenotypes accounted each for less than 1% of the total population (all 134 together for 26.4%). Conclusion: The broad variability of functional knee phenotypes in osteoarthritic knees shows that a more personalized TKA realignment strategy is needed. The challenge will be to identify the optimal alignment strategy for each functional knee phenotype.
Combined posteromedial or posterolateral PCL injuries: Anatomic repair and ligament bracing as a new treatment option - first results of a multicentre study
Authors: Gensior Tobias J. , Glaab Richard , Hepp Pierre , Zellner Johannes , Mester Bastian , Schoepp Christian 
Published: May 2020

Aims and Objectives: Acute, isolated PCL injuries can succesfully be managed non-operatively whereas combined PCL injuries usually require surgical management. Currently, there is a lack of evidence regarding the standard of treatment (repair vs. reconstruction, one-stage vs. two-stages procedures). Suture augmented repair leads to good and excellent results in cases of acute knee dislocations. This technique has not been investigated clinically in combined PCL injuries, yet. The aim of this multicentre study was to evaluate the clinical outcome after surgical repair with additional suture augmentation (ligament bracing) of all torn ligaments in acute combined pcl injuries (posteromedial or posterolateral). Materials and Methods: From 2016 to 2018, 25 patients with an acute combined PCL injury were treated with one stage anatomical repair and ligament bracing of the torn ligaments within 14 days at 6 trauma centres (5xGER, 1x SUI). Inclusion criteria: Follow-up min. 6 months, age > 18y. Exclusion criteria: ACL Injury, posteromedial AND posterolateral injury. During the follow-up evaluation, various scores were collected (International Knee Documentation Committee IKDC Score, Tegner Score , KOOS and Lysholm Score). Additional stress radiography was performed (TelosTM) postoperatively. Results: For now 14 combined PCL injuries (posteromedial or -lateral) with a follow-up of 20 months (range 8-33) were evaluated. 10 patients had a posteromedial (PCL + MCL/POL), 4 patients had a posterolateral (PCL + LCL) injury. 10 additional articular lesions were detected (6 meniscus tears, 4 grade IV chondral lesions) and 1 transitional peroneal nerve injury. The average IKDC score was 62.2±18.5, the average Lysholm score was 78±19.2, average KOOS 88.7±7.6. Median loss of activity in the Tegner score was 1 (range 0-5) point. Side-to-side pcl-stress-radiographs showed a difference at a mean of 4.8±3.0mm (range 1-10). 2 cases with symptomatic knee instability, both posterolateral, and 3 patients with knee stiffness needed reoperation. Interestingly, patients with posteromedial injuries showed predominantly good or excellent results according to Lysholm score and were graded as A (4/10) or B (2/10) whereas ligament bracing in posterolateral combined injuries had a high failure rate (Grade D 2/4). Conclusion: Primary anatomic repair and additional suture augmentation predominantly leads to good and excellent clinical results in cases of combined posteromedial PCL injuries. Patients with posterolateral injuries showed inferior clinical outcome and relatively high instability rates following ligament bracing. In conclusion, primary augmented suture repair seems to be a promising treatment option. The overall results of this study have to be evaluated for more exact recommendations.
Revision ACL Reconstruction - A retrospective failure analysis with a mean follow up of 35 months
Authors: Alm Lena , Krause Matthias , Frosch Karl-Heinz , Akoto Ralph 
Published: May 2020

Aims and Objectives: While patients following primary anterior cruciate ligament (ACL) surgery show satisfying results, the outcome after revision ACL reconstruction (ACLR) seems to be less favourable. The purpose of this study was to evaluate the outcome of patients after revision ACLR. We hypothesize that peripheral knee instabilities and further concomitant lesions are risk factors for failure of revision ACLR. Furthermore, we hypothesize that peripheral stabilisation will reduce the risk of failure. Materials and Methods: Between 2013 and 2016, 111 patients with revision ACLR (revision surgery after primary ACL reconstruction) were included in the retrospective study. All patients were clinically examined with a minimum of 2 years after revision surgery (mean 35 months) and identified as “failed revision ACLR” (side-to-side difference greater than 5mm and/or pivot-shift grade 2/3) and “stable revision ACLR”. Multiple logistic regression modeling was used to evaluate whether certain predisposing factors were associated with increased odds of failure of the revision ACLR. Results: Failure after revision ACLR occurred in 14.5% (n=16) of the cases. Preoperative medial knee instability (n=36) was associated with failure of revision ACLR, thus patients had a 17 times greater risk of failure when medial knee instability was diagnosed preoperatively. Also, the risk of failure was reduced when patients had peripheral medial (n=24) and/ or antero-lateral stabilisation (n=51). Increased posterior tibial slope (PTS, n=11 greater than 12°) and high-grade anterior knee laxity (side-to-side-difference greater than 5 mm and/or pivot-shift grade 3, n=41) were associated with failed revision ACLR. Furthermore, patients had a 9 times greater risk of failure when they were obese (BMI greater than 30 kg/m2, n=30). Also, postoperative functional scores in comparison to preoperative scores were shown to be significantly higher (Lysholm 85±27 vs. 51±31.9, p=0.024; Tegner 6.5± 1.3 vs. 4± 2.6, p=0.015). Conclusion: Results following revision anterior cruciate ligament reconstruction (ACLR) are less favourable than primary ACLR. Peripheral medial knee instability, high-grade anterior knee laxity, increased PTS and high BMI are risk factors for failure in revision ACLR while additional medial and/or antero-lateral stabilisation reduces the risk of failure.
The influence of High tibial osteotomies on the posterior tibial slope - Study of 190 medial open wedge and 89 lateral closed wedge cases
Authors: Schubert Ilona , Ferner Felix , Strohm Peter , Dickschas Jörg 
Published: May 2020

Aims and Objectives: High tibial osteotomies (HTO) are nowadays an established method to treat unicompartmental, medial gonarthrosis. Common surgical HTO techniques include medial open wedge (MOW) and lateral closed wedge osteotomies (LCW). In addition to the intended change in the frontal plane these surgical techniques take influence on various other biomechanical issues of the knee joint e.g. the posterior tibial slope (PTS). Aim of this study was to rate and evaluate changes of the tibial slope by HTOs dependent on the used surgical technique (MOW versus LCW). Materials and Methods: 414 HTOs, that had been performed in our institution between 2004 and November 2018, were reviewed retrospectively. 135 cases were excluded. The included 279 cases from 247 patients were divided into two groups dependent on the used surgical technique (MOW/LCW). In both groups the values of PTS were defined by measuring the proximal posterior tibia angle (PPTA) on lateral x-rays of the knee from before and 4 to 6 weeks after surgery. The change of PTS was evaluated as delta-PPTA. Microsoft Excel was used for statistical analysis. Results: 279 cases were included: 190 were assigned to the group of MOW and 89 to the group of LCW osteotomies. Considering demographic data the MOW-group showed a gender distribution of 124 men/ 46 women in 93 left and 97 right knees, and the LCW-group of 46 men/43 women in 40 left and 49 right knees. The mean value of age in the MOW group was 47,6 +/- 10 years (15-70 years) and in the LCW-group 40,6+/-13,7 years (15-67 years). Before surgery there was no statistical significant difference in the PPTA-values between both groups (p=0,720): The mean PPTA in the MOW-group measured 79,9°+/-3,2° (68-88°), in the LCW-group 80,6°+/-2,6° (74-88°). The change caused by surgery showed no statistical significance in the MOW-group (delta-PPTA 0,07°+/- 2,9° [-12° bis 11°]). However, in the LCW-Gruppe we observed a significant (p<0,001) decrease of the PTS (delta-PPTA -3,09°+/- 4,5° [-12°bis 5°]). Nevertheless, the analysis of delta-PPTA in the LCW-group over the timeline of the study period showed tendencies of a decline of slope-reduction. Conclusion: As the PTS plays a relevant role in biomechanics of the knee joint a consideration of the impact of changes in PTS by HTOs is indispensable. Our results support the common thesis of a slope-reduction by LCW osteotomies but nevertheless the analysis throughout the study period showed a reduction of the slope-decrease over timeline. The common thesis of a slope-increase by MOW osteotomies was not supported by our results which showed no significant change.
Teaching natural selection in early elementary classrooms: can a storybook intervention reduce teleological misunderstandings?
Authors: Brown Sarah A. , Ronfard Samuel , Kelemen Deborah 
Published: May 2020

AbstractBackgroundDespite the importance of understanding the mechanism of natural selection for both academic success and everyday decision-making, this concept is one of the most challenging to learn in contemporary science. In addition to cumulative socio-cultural influences, intuitive cognitive biases such as the teleological bias—the early developing tendency to explain phenomena in terms of function or purpose—contribute to the difficulty of accurate learning when the process is taught in high school or later. In this work, we therefore investigate—for the first time—the viability of a teacher-led classroom-based storybook intervention for teaching natural selection in early elementary school. The intervention was designed to counteract teleological explanations of adaptation. In consequence, we specifically examined the nature and extent of elementary school children’s teleological reasoning about biological trait change before and after this intervention.ResultsSecond and third grade students demonstrated a variety of misunderstandings at pretest, including teleological preconceptions. Most of these teleological ideas were explicitly accompanied by incorrect mechanistic ideas, confirming that the teleological reasoning observed in this young sample reflected fundamental misunderstandings of adaptation as a goal-directed event. Overall, learning from the classroom intervention was substantial, with students performing significantly better on all measures of natural selection understanding at posttest. Interestingly, explicit teleological reasoning displayed at the pretest did not have a differentially greater impact on learning than other kinds of marked pretest misunderstandings. One explanation for this might be that children displaying teleological misunderstandings at pretest also tended to demonstrate more biological factual knowledge than other students. Another explanation might be that pretest misunderstandings that were not overtly teleological were, nevertheless, implicitly teleological due to the nature of the mechanisms that they referenced. The differential impact of teleological preconceptions on learning might therefore have been underestimated.ConclusionsIn summary, early elementary school children show substantial abilities to accurately learn natural selection from a limited but scalable classroom-based storybook intervention. While children often display explicit teleological preconceptions, it is unclear whether these ideas represent greater impediments to learning about adaptation than other substantial misunderstandings. Reasons for this, and limitations of the present research, are discussed.
Comparison of clinical features of acute lower respiratory tract infections in infants with RSV/HRV infection, and incidences of subsequent wheezing or asthma in childhood
Authors: Ding Qin , Xu Lili , Zhu Yun , Xu Baoping , Chen Xiangpeng , Duan Yali , Xie Zhengde , Shen Kunling 
Published: May 2020

AbstractBackgroundTo compare the clinical characteristics of acute lower respiratory tract infections (ALRTIs) caused by respiratory syncytial virus (RSV) and human rhinovirus (HRV) and to explore the relationship between the development of recurrent wheezing/asthma and RSV/ HRV infections in infancy.MethodsRetrospective study was conducted to compare the clinical characteristics of acute lower respiratory tract infections (ALRTIs). Hospitalized patients with ALRTIs from March 2007 to December 2016 were screened. Single RSV cases (s-RSV), single HRV cases (s-HRV), and cases who had co-infection with the two viruses were enrolled. Follow-up was performed to determine whether either specific respiratory virus infection was related to subsequent development of recurrent wheezing/asthma.ResultsThe s-RSV children were the youngest (P = 0.021), they experienced the most serious condition (P < 0.001) and respiratory failure (P < 0.001), they also required highest demand of oxygen therapy (P < 0.001). And in s-RSV group, the incidence of development of recurrent wheezing was significantly higher in subgroup with the family history of wheezing than that without (P < 0.001).ConclusionThe s-RSV cases suffered from the worst severity of illness, respiratory failure and required highest demand of oxygen therapy. Recurrent wheezing was more common in s-RSV group with family history of wheezing than those without.
Thrombocytopenia and platelet course on hospital mortality in neurological intensive care unit: a retrospective observational study from large database
Authors: Zhou Dawei , Li Zhimin , Wu Lei , Shi Guangzhi , Zhou Jianxin 
Published: May 2020

Abstract
Background
Thrombocytopenia (TP) has been shown to be an independent predictor of mortality in the intensive care unit (ICU) patients. Studies are lacking in the neurological ICU (NICU) population. The aim was to evaluate the incidence of TP in NICU and the relationship between TP and outcomes.

Methods
We conducted a retrospective multicenter study of prospectively collected data of all patients admitted to the NICU between 2014 and 2015 from a large database (eICU Collaborative Research Database). The main exposure was TP at admission and TP developed during NICU stay. Multivariable logistic regression and Cox proportional hazard models were used to evaluate the relationship of TP at admission and platelet course with hospital mortality. The primary outcome was hospital mortality.

Results
7450 patients in NICU from 17 hospitals were included. Hospital mortality was 9%. TP at admission was present in 20% of patients, TP developed during NICU stay was present in 13.2% of patients. TP at admission was not associated with hospital mortality after adjusting for confounders (OR 1.14 [95% CI 0.92–1.41, p = 0.237]). Hospital mortality of continuous TP during NICU stay was 15% while hospital mortality of recovery from TP at admission was 6% (p < 0.001). Patients with TP developed during NICU stay had higher odds ratio for hospital mortality (OR 1.65 [95% CI 1.3–2.09, p < 0.001]).

Conclusions
Thrombocytopenia is common in NICU and patients who have thrombocytopenia not resolving have increased mortality. Patients’ recovery from thrombocytopenia may predict a good prognosis.