Gait Analysis to Monitor Fracture Healing of the Lower Leg

Fracture healing is typically monitored by infrequent radiographs. Radiographs come at the cost of radiation exposure and reflect fracture healing with a time lag due to delayed fracture mineralization following increases in stiffness. Since union problems frequently occur after fractures, better and timelier methods to monitor the healing process are required. In this review, we provide an overview of the changes in gait parameters following lower leg fractures to investigate whether gait analysis can be used to monitor fracture healing. Studies assessing gait after lower leg fractures that were treated either surgically or conservatively were included. Spatiotemporal gait parameters, kinematics, kinetics, and pedography showed improvements in the gait pattern throughout the healing process of lower leg fractures. Especially gait speed and asymmetry measures have a high potential to monitor fracture healing. Pedographic measurements showed differences in gait between patients with and without union. No literature was available for other gait measures, but it is expected that further parameters reflect progress in bone healing. In conclusion, gait analysis seems to be a valuable tool for monitoring the healing process and predicting the occurrence of non-union of lower leg fractures

Sacroiliac Screw Placement with Ease: CT-Guided Pelvic Fracture Osteosynthesis in the Elderly

Background and Objectives: The number of geriatric patients presenting with fragility fractures of the pelvis is increasing due to ageing Western societies. There are nonoperative and several operative treatment approaches. Many of which cause prolonged hospitalisation, so patients become bedridden and lose mobility and independence. This retrospective study evaluates the postoperative outcome of a computed tomography-guided (CT-guided) minimally invasive approach of sacroiliac screw osteosynthesis. The particular focus is to demonstrate its ease of use, feasibility with the equipment of virtually every hospital and beneficial outcomes to the patients. Materials and Methods: 28 patients (3 men, 25 women, age 80.5 ± 6.54 years) with fragility fractures of the pelvis types II-IV presenting between August 2015 and September 2021 were retrospectively reviewed. The operation was performed using the CT of the radiology department for intraoperative visualization of screw placement. Patients only received screw osteosynthesis of the posterior pelvic ring and cannulated screws underwent cement augmentation. Outcomes measured included demographic data, fracture type, postoperative parameters and complications encountered. The quality of life (QoL) was assessed using the German version of the EQ-5D-3L. Results: The average operation time was 32.4 ± 9.6 min for the unilateral and 50.7 ± 17.4 for the bilateral procedure. There was no significant difference between surgeons operating (p = 0.12). The postoperative CT scans were used to evaluate the outcome and showed only one case of penetration (by 1 mm) of the ventral cortex, which did not require operative revision. No case of major complication was reported. Following surgery, patients were discharged after a median of 4 days (Interquartile range 3–7.5). 53.4% of the patients were discharged home or to rehabilitation. The average score on the visual analogue scale of the EQ-5D-3L evaluating the overall wellbeing was 55.6 (Interquartile range (IQR) 0–60). Conclusions: This study shows that the operative method is safe to use in daily practice, is readily available and causes few complications. It permits immediate postoperative mobilization and adequate pain control. Independence and good quality of life are preserved

Flow cytometric quantification of apoptotic and proliferating cells applying an improved method for dissociation of spheroids

Spheroids are a promising tool for many cell culture applications, but their microscopic analysis is limited. Flow cytometry on a single cell basis, which requires a gentle but also efficient dissociation of spheroids, could be an alternative analysis. Mono-culture and coculture spheroids consisting of human fibroblasts and human endothelial cells were generated by the liquid overlay technique and were dissociated using AccuMax as a dissociation agent combined with gentle mechanical forces. This study aimed to quantify the number of apoptotic and proliferative cells. We were able to dissociate spheroids of differing size, age, and cellular composition in a single-step dissociation protocol within 10 min. The number of single cells was higher than 95% and in most cases, the viability of the cells after dissociation was higher than 85%. Coculture spheroids exhibited a higher sensitivity as shown by lower viability, higher amount of cellular debris, and a higher amount of apoptotic cells. Considerable expression of the proliferation marker Ki67 could only be seen in 1-day-old spheroids but was already downregulated on Day 3. In summary, our dissociation protocol enabled a fast and gentle dissociation of spheroids for the subsequent flow cytometric analysis. The chosen cell type had a strong influence on cell viability and apoptosis. Initially high rates of proliferative cells decreased rapidly and reached values of healthy tissue 3 days after generation of the spheroids. In conclusion, the flow cytometry of dissociated spheroids could be a promising analytical tool, which could be ideally combined with microscopic techniques

Figure skating: Increasing numbers of revolutions in jumps at the European and World Championships

Figure skating is associated with a high prevalence of sport-specific injuries and overuse symptoms. Impacts are of greater magnitude in jumps with more revolutions that are thus connected to a greater risk of injury. While figure skating programs seem to have recently increased in difficulty, performance trends have not yet been reported in the literature. We hypothesized increasing performance and decreasing age trends of the best athletes who competed at international level in recent years. Furthermore, we aimed to identify and analyse objective performance parameters and to assess a potential link between age and the risk of injury. The development of the number of double, triple and quadruple jumps in the singles figure skating events at the World and European Championships since the introduction of the new ISU Judging System in the 2004/2005 season was analysed using regression statistics and Student's T-Tests. In all groups, the numbers of jumps with fewer rotations significantly decreased in the favour of jumps with more rotations. Women only started to perform jumps with four rotations in 2019. In the men, the number of quadruple jumps increased from an average of less than one to more than three in recent years (European and World Championships, both p < 0.001). In the European, but not in the World Championships, the average age increased in the men and decreased in the women (European Championships, men and women p = 0.006). Our study was the first to assess performance trends in elite figure skating. The incidence of injuries and overuse syndromes in figure skating needs to be monitored cautiously, as increases can be expected following recent gains in performance and jump complexity

Figure skating : Increasing numbers of revolutions in jumps at the European and World Championships

Figure skating is associated with a high prevalence of sport-specific injuries and overuse symptoms. Impacts are of greater magnitude in jumps with more revolutions that are thus connected to a greater risk of injury. While figure skating programs seem to have recently increased in difficulty, performance trends have not yet been reported in the literature. We hypothesized increasing performance and decreasing age trends of the best athletes who competed at international level in recent years. Furthermore, we aimed to identify and analyse objective performance parameters and to assess a potential link between age and the risk of injury. The development of the number of double, triple and quadruple jumps in the singles figure skating events at the World and European Championships since the introduction of the new ISU Judging System in the 2004/2005 season was analysed using regression statistics and Student’s T-Tests. In all groups, the numbers of jumps with fewer rotations significantly decreased in the favour of jumps with more rotations. Women only started to perform jumps with four rotations in 2019. In the men, the number of quadruple jumps increased from an average of less than one to more than three in recent years (European and World Championships, both p < 0.001). In the European, but not in the World Championships, the average age increased in the men and decreased in the women (European Championships, men and women p = 0.006). Our study was the first to assess performance trends in elite figure skating. The incidence of injuries and overuse syndromes in figure skating needs to be monitored cautiously, as increases can be expected following recent gains in performance and jump complexity

Reappraisal of clinical trauma trials: the critical impact of anthropometric parameters on fracture gap micro-mechanics-observations from a simulation-based study

The evidence base of surgical fracture care is extremely sparse with only few sound RCTs available. It is hypothesized that anthropometric factors relevantly infuence mechanical conditions in the fracture gap, thereby interfering with the mechanoinduction of fracture healing. Development of a fnite element model of a tibia fracture, which is the basis of an in silico population (n= 300) by systematic variation of anthropometric parameters. Simulations of the stance phase and correlation between anthropometric parameters and the mechanical stimulus in the fracture gap. Analysis of the infuence of anthropometric parameters on statistical dispersion between in silico trial cohorts with respect to the probability to generate two, with respect to anthropometric parameters statistically diferent trial cohorts, given the same power assumptions. The mechanical impact in the fracture gap correlates with anthropometric parameters; confrming the hypothesis that anthropometric factors are a relevant entity. On a cohort level simulation of a fracture trial showed that given an adequate power the principle of randomization successfully levels out the impact of anthropometric factors. From a clinical perspective these group sizes are difcult to achieve, especially when considering that the trials takes advantage of a „laboratory approach “, i.e. the fracture type has not been varied, such that in real world trials the cohort size have to be even larger to level out the diferent confgurations of fractures gaps. Anthropometric parameters have a signifcant impact on the fracture gap mechanics. The cohort sizes necessary to level out this efect are difcult or unrealistic to achieve in RCTs, which is the reason for sparse evidence in orthotrauma. New approaches to clinical trials taking advantage of modelling and simulation techniques need to be developed and explored

Dose-dependent dominance : How cell densities design stromal cell functions during soft tissue healing

Regular soft tissue healing relies on the well‐organized interaction of different stromal cell types with endothelial cells. However, spatiotemporal conditions might provoke high densities of one special stromal cell type, potentially leading to impaired healing. Detailed knowledge of the functions of rivaling stromal cell types aiming for tissue contraction and stabilization as well as vascular support is mandatory. By the application of an in vitro approach comprising the evaluation of cell proliferation, cell morphology, myofibroblastoid differentiation, and cytokine release, we verified a density‐dependent modulation of these functions among juvenile and adult fibroblasts, pericytes, and adipose‐derived stem cells during their interaction with microvascular endothelial cells in cocultures. Results indicate that juvenile fibroblasts rather support angiogenesis via paracrine regulation at the early stage of healing, a role potentially compromised in adult fibroblasts. In contrast, pericytes showed a more versatile character aiming at angiogenesis, vessel stabilization, and tissue contraction. Such a universal character was even more pronounced among adipose‐derived stem cells. The explicit knowledge of the characteristic functions of stromal cell types is a prerequisite for the development of new analytical and therapeutic approaches for impaired soft tissue healing. The present study delivers new considerations concerning the roles of rivaling stromal cell types within a granulation tissue, pointing to extraordinary properties of pericytes and adipose‐derived stem cells

regeneration and healing

There are two models for studying degradation and lamination of hyaline articular cartilage: the Silberberg mouse (Silberberg et al. 1965a, b) and the ACL-cut model on animals (Draenert and Draenert 1981). The Silberberg mouse develops during the first year of severe varus osteoarthritis in the knee joint. The varus deformation is induced by hormones. The osteoarthritis reveals all signs of a progredient degradation of the joint with the development of osteophytes (Fig. 4.1) and destruction of the hyaline cartilage, which is abraded in layers (Figs. 4.2 and 4.3). Simultaneous with the destruction, reparation processes with newly produced ground substance and proliferating cells can be observed (Fig. 4.4)

Effects of age, body height, body weight, body mass index and handgrip strength on the trajectory of the plantar pressure stance-phase curve of the gait cycle

The analysis of gait patterns and plantar pressure distributions via insoles is increasingly used to monitor patients and treatment progress, such as recovery after surgeries. Despite the popularity of pedography, also known as baropodography, characteristic effects of anthropometric and other individual parameters on the trajectory of the stance phase curve of the gait cycle have not been previously reported. We hypothesized characteristic changes of age, body height, body weight, body mass index and handgrip strength on the plantar pressure curve trajectory during gait in healthy participants. Thirty-seven healthy women and men with an average age of 43.65 ± 17.59 years were fitted with Moticon OpenGO insoles equipped with 16 pressure sensors each. Data were recorded at a frequency of 100 Hz during walking at 4 km/h on a level treadmill for 1 minute. Data were processed via a custom-made step detection algorithm. The loading and unloading slopes as well as force extrema-based parameters were computed and characteristic correlations with the targeted parameters were identified via multiple linear regression analysis. Age showed a negative correlation with the mean loading slope. Body height correlated with Fmeanload and the loading slope. Body weight and the body mass index correlated with all analyzed parameters, except the loading slope. In addition, handgrip strength correlated with changes in the second half of the stance phase and did not affect the first half, which is likely due to stronger kick-off. However, only up to 46% of the variability can be explained by age, body weight, height, body mass index and hand grip strength. Thus, further factors must affect the trajectory of the gait cycle curve that were not considered in the present analysis. In conclusion, all analyzed measures affect the trajectory of the stance phase curve. When analyzing insole data, it might be useful to correct for the factors that were identified by using the regression coefficients presented in this paper

Performance Increases in Pair Skating and Ice Dance at International Championships and Olympic Games

In pair skating and ice dance, performance seems to have increased at international competitions, which is potentially associated with changes in athlete age. We hypothesized increasing age, numbers of total points and more complex jumps of the best elite couples at international championships in recent years. Corresponding data were assessed via the results databases of the European and World Championships, as well as the Winter Olympics since 2005. Linear regression statistics were conducted, and significance was assessed via one-way ANOVAs. There were no significant changes in age. Increases in total points were found in both disciplines (World and European Championships both p < 0.001 for both disciplines, Olympics pair skating p = 0.003, ice dance n/a). Significant increases were found in the number of double and triple twist jumps at the European Championships (Double p = 0.046, triple p = 0.041), but not at the World Championships or the Olympics. At the World Championships, single solo jumps decreased (p = 0.031) in favor of triple jumps, which increased (p = 0.020), without a similar effect at the European Championships or Olympics. In conclusion, increases in total points and more complex jumps were observed at international championships without associated changes in age. Attention should be given to possible changes in the incidence of acute and overuse injuries following this development