Internal Fixation of Garden Type III Femoral Neck Fractures with Sliding Hip Screw and Anti-Rotation Screw: Does Increased Valgus Improve Healing?

Background and Objectives: The aim of this study was to compare the effect of valgus versus anatomic reduction on internal fixation of Garden type III femoral neck fractures using the sliding hip screw (SHS) and anti-rotation screw (ARS) regarding the radiographic and therapeutic outcome. Patients and Methods: A retrospective case-controlled study was performed in a level I trauma center. All patients between 2006 and 2020 aged younger than 70 years with a Garden type III femoral neck fracture and a Kellgren-Lawrence score under grade III stabilized using SHS and ARS were identified. One-hundred and nine patients were included, with a group distribution of sixty-eight patients in group A (anatomic reduction) and forty-one patients in group B (valgus reduction). Results: Mean age was 55 years, and the mean Kellgren-Lawrence score was 1 in both groups. Mean femoral neck angle was 130.5 ± 3.8° in group A and 142.8 ± 4.3° in group B (p = 0.001), with an over-correction of 12° in group B. Tip-apex distance was 10.0 ± 2.8 mm in group A versus 9.3 ± 2.8 mm in group B (p = 0.89). Healing time was 9 weeks in group A compared to 12 weeks in group B (p = 0.001). Failure rate was 4.4% in group A and 17.1% in group B (p = 0.027). Conclusions: Anatomic reduction of Garden type III femoral neck fractures in patients younger than 70 years treated using SHS and ARS resulted in significantly lower failure rates and shorter healing times than after valgus reduction. Therefore, it can be recommended to achieve anatomic reduction.

Recovery of the medial gastrocnemius muscle after calcaneus fracture differs between contractile and elastic components.

BACKGROUND: Calcaneal fractures result in severe functional impairments and walking restrictions. Postoperative evaluation mainly focusses on the restoration of calcaneal anatomy while ankle plantar flexor insufficiency remains largely neglected. This study aims to investigate biomechanical and morphologic adaptions of elastic and contractile components of the gastrocnemius medialis after unilateral calcaneal fracture. METHODS: 20 Patients (BMI: 27.6 ± 3.1 kgm-2, Age: 50 ± 12 years) were measured using gait analysis and portable ultrasound over a follow-up of three, six and twelve months after surgery. Data comparison was performed using 20 matched healthy controls (BMI: 26.2 ± 2.9 kgm-2, Age: 48 ± 11 years). Static and dynamic behavior of the gastrocnemius muscle tendon unit, muscle fascicle and the serial-elastic element as well ankle joint kinematics and kinetics were analyzed. FINDINGS: Within patients, a significant (p < 0.05) increase in fascicle length (by 67%) during single support and a decrease of serial elastic element shortening (by 20%) during push off was found between three and twelve months follow-up comparisons. Patients showed differences for fascicle lengthening and pennation angle increase during single support after three and six months compared to healthy controls. A smaller shortening of the serial-elastic element (by 29%) and muscle-tendon unit (by 16%) persisted even for the twelve month comparisons. INTERPRETATION: Patients with calcaneal fracture showed an incomplete restoration of the medial gastrocnemius dynamic morphological behavior. While muscle fascicle contraction almost recovered, the serial elastic component still showed restrictions regarding its shortening behavior. Limited foot mobility and plantarflexor strength as well as lowered responsiveness of elastic tissues to mechanical loading are regarded as key mechanisms.

Development of the center of pressure velocity in the healing process after intra-articular calcaneus fractures.

BACKGROUND: Calcaneal fractures are among the most common foot injuries and sometimes develop manifold post-surgical complications. Restricted foot movement is one of the main functional limitations which often persists during long-term rehabilitation. Therefore, it is important to quantitatively monitor the biomechanical foot mobility after calcaneal fracture from an early stage in order to achieve an optimal therapeutic treatment. RESEARCH QUESTION: Evaluation of the Center of Pressure velocity (vCOP) in patients after intrarticular calcaneal fractures during the healing progress from three to 24 months after surgery. METHODS: A total of 20 patients with unilateral calcaneal fracture were investigated by means of pedobarography and marker-based gait analysis at three, six, 12 and 24 months after surgery. Data for vCOP [m/s], maximum external dorsal extension moments during stance (DEmomentstance) and tibiotalar range of motion during mid stance (MS) and terminal stance (TS) were obtained. Functional evaluation was performed using clinical examination (e.g. calf circumference measurements) and patient-reported outcome measures (SF-36). RESULTS: When compared to the healthy side, vCOP of the injured side showed a significant reduction during MS (3 months: 48%, p < 0.001; 6 months: 13%; p = 0.040) and an significant increase during TS (3 months: 110%, p < 0.001; 6 months: 43%, p < 0.001; 12 months: 17%, p = 0.012). DEmomentstance of the fractured foot, showed a significant increase of 80% (p < 0.001) from three to 24 months after surgery, which correlated with vCOP at three and six months after surgery (p < 0.05; vCOP MS: 3 months: r = 0.876, 6 months: r = 0.685; vCOP TS: 3 months: r = -0.554, 6 months r = -0.626). SIGNIFICANCE: vCOP might serve as an indicator for foot mobility and function during the early healing phase after calcaneal fractures. As vCOP can be obtained by pedobarography it is more readily accessible an less costly compared to foot function obtained by marker based gait analysis.

Effects of assistive insole feedback training on immediate and multi-day partial weight bearing retention during walking: A pilot study.

BACKGROUND: Adherence to partial weight bearing (PWB) plays a crucial role in early rehabilitation and motor control. Dynamic biofeedback insole systems provide a supportive function on immediate PWB adherence, while important long-term retention effects and potential advantages to a conventional static training remain unknown. RESEARCH QUESTION: Is acoustic insole feedback training effective for the retention of prescribed PWB adherence and is there any advantage relative to static training using a conventional bathroom scale? Methods Twenty-four volunteers were randomized into two groups receiving biofeedback training (N = 12) via a mobile insole system (Loadsol®) or conventional training using a bathroom scale (N = 12). After initial PWB training (20 kg) of one randomized leg, the immediate and one-week retention effects were analysed using mean and maximum load (N) and overload rate (%). Statistical analysis was performed using a two-way repeated measures ANOVA with post-hoc pairwise comparisons (p < 0.05). RESULTS: A significantly (p < 0.001) improved immediate and long-term PWB adherence was found for the insole feedback group during walking. A significant (p < 0.001) reduction of the overload rate by 86% was found for the insole feedback group when compared to the conventional training group after one week. Significant (p < 0.01) reductions by 51% and 46% was also found for the mean and maximum load in the insole feedback group when compared to the conventional training group. SIGNIFICANCE: The use of insole feedback systems can serve as a viable tool to become familiar with PWB and to provide optimal retention of specified loads. Therefore, such systems serve as an advantageous training intervention to maintain a prescribed PWB during locomotion.

Recovery of gait and function during the first six months after tibial shaft fractures.

BACKGROUND: Tibial shaft fractures require surgical stabilization preferably by intramedullary nailing. Recovery is often unsatisfactory due to limited knee function and pain, resulting in reduced quality of life. The extent of these functional limitations with respect to gait deficits has not been sufficiently recognized. RESEARCH QUESTION: Are there functional limitations during gait and squat performance during the first six months after surgically treated tibial shaft fractures? METHODS: Twenty-three patients (BMI: 24 ± 3, Age:39 ± 15) with tibial shaft fractures and 23 healthy, matched controls (BMI: 24 ± 3, Age: 40 ± 14) were assessed using instrumented motion analysis two, three and six months after surgery. Kinematic and kinetic data of the lower extremities were collected during level walking and squat performance. Data were compared among follow-up time intervals and between groups. RESULTS: Significant improvements were found for all spatiotemporal parameters and most kinetic parameters. Even six months after surgery functional deficits persisted when compared to healthy controls. There were only slight improvements in sagittal knee and ankle kinematics as well as knee moments and power within the follow-up period. A significant difference compared to the healthy controls can still be observed in these parameters. SIGNIFICANCE: Although patients with tibia fractures demonstrated functional improvements over the early course of healing, some residual deficits in lower extremity movement biomechanics were identified at six months post surgery. In particular knee kinematics in squatting as well as knee kinematics and kinetics during walking only recovered incompletely. This result can help explain the often-reported functional limitations. CLINICAL TRIAL REGISTRATION NUMBER: German register for clinical trials (DRKS00023790).

Clinical and radiological evaluation of thoracic spine fractures with or without sternal fracture: is there a need for ventral stabilization?

OBJECTIVE: The treatment of thoracic spine (TS) fractures with additional sternal fractures compared to TS fractures without sternal fractures is discussed controversionally, because in some studies it was stated that sternal fractures decrease the thoracic stability. We hypothesized that both types of fractures can be treated the same way by posterior stabilization alone. METHODS: A total number of 69 patients with thoracic fractures, with or without additional sternal fractures, were examined, regarding the angle of kyphosis after fracture, postoperatively and after 6 and 12 months. We also recorded the outcome using the Odom's score and the time until patients returned to work and the activity level. RESULTS: It was found that the angle of kyphosis was nearly physiological after stabilization in both groups and a loss of reduction after 1 year was also comparable, either in the patients suffering from the additional sternal fracture or not. In addition, the Odom's score and the time until return to work and the activity level were comparable in both groups. CONCLUSION: We did not find any arguments to preserve additional anterior stabilization or reasons for different treatment strategies either additional sternal fractures occur in thoracic spine fractures or not.

Gait analysis - Available platforms for outcome assessment.

Movement or gait analysis has become a viable assessment tool not only used in sports science or basic biomechanical research, but has also expanded to be a very valuable instrument in clinical diagnostics, monitoring functional recovery and musculoskeletal rehabilitation. In this context, this method has long been an integral part solely in neurological disorders such as cerebral palsy. However, in the meantime the benefits have also become apparent in other medical areas, such as foot surgery, orthopaedic technology, or in patients after lower limb amputation. These procedures proved to better understand, objectify and quantify the individual causes of gait and movement disorders in order to optimize patient-specific therapy. Currently we are able to rely on a multitude of available measurement systems. These can either be used in everyday life for simple monitoring of one's own activity or to complement therapeutic approaches in the clinical and scientific environment. The following review highlights the various fields of movement analysis, including markerless motion capture, marker-based analysis, pedobarography and wearable sensors. Each of these areas presents its own field of application and potential usage as well as the advantages and disadvantages arising in this context. The following article will give an overview of the type of measurement technology used, the respective fields of application, and the selected parameters and their interpretation possibilities for each of the areas mentioned.

Upper Body Posture and Muscle Activation in Recreational Cyclists: Immediate Effects of Variable Cycling Setups.

Purpose: Discomfort during cycling can be counteracted by adjusting the seat position. However, the influence of changes in cycling position regarding quantitative biomechanical adaptions of the upper body in recreational cyclists is unclear. This study aims to investigate the effects of saddle position and reach distance on upper body kinematics and muscle activation. Methods: Twelve recreational cyclists were investigated in four different sitting positions on an adjustable cycle trainer. Trunk, pelvis, shoulder, elbow and spinal kinematics as well as lower back and elbow extensor activity were analyzed for combinations of normal and shortened reach distance including horizontal and 10° downward inclined saddle positions. Results: An inclined saddle increased activation of elbow extensors by almost 23 ± 8% (p < .01) while a shortened reach distance resulted in a more posterior pelvic tilt of up to 18 ± 2% (p < .01) and less trunk forward lean of 10 ± 9% (p < .01). Shoulder flexion reduced by up to 23 ± 16% (p < .05) while elbow flexion increased by 15 ± 22% (p < .05) with a shortened reach distance. No differences between configurations were found for spinal kinematics and lower back muscle activity. Conclusions: Changing the reach distance showed considerable biomechanical effects on upper body kinematics of the pelvis and trunk rather than on the spine or on lower back muscle activity. For reach distance, most compensation of postural changes of the upper body occurred by changes of shoulder and elbow angles while elbow extensor activation was only altered by saddle downward inclination.

Variability in trunk and pelvic movement of transfemoral amputees using a C-leg system compared to healthy controls.

OBJECTIVE: Gait variability is a measure of gait disturbance, and therefore constitutes a useful parameter for gait assessment as well as planning of therapeutic and medical interventions. To date, variability during walking has not been adequately analyzed in amputees. The aim of this examination was to evaluate trunk and pelvic movement variability in transfemoral amputees. The effect of different types of walking surfaces on variability in trunk and pelvic movement was also studied. METHOD: This prospective clinical examination compares 20 transfemoral amputees (17 ♂, 42 ±â€¯16 years; 3 ♀, 48 ±â€¯3 years) with a group of 20 age and mass matched healthy controls regarding the extent of variability in trunk and pelvic movement. Kinematic data of trunk and pelvic movement during walking on level, uneven ground and slope was captured by eight infrared cameras (Vicon Nexus ™, Oxford, UK). Variability in trunk and pelvic movement was analyzed. Univariate ANCOVA and ANOVA with repeated measures and post hoc tests were used for statistical comparison. Fall history was retrospectively collected from medical history to assess the association between falls and variability in trunk and pelvic movement. RESULTS: Trunk and pelvic movement variability in amputees was significantly higher during walking on uneven ground and slope compared to healthy controls (p ≤ 0.05). Variability in trunk and pelvic movement was increased during walking on uneven ground and slope compared to even ground for both groups (p ≤ 0.05). CONCLUSION: Amputees showed increased trunk and pelvic movement variability during walking on uneven ground and slope, indicating an affected gait pattern in comparison to healthy controls. Therefore, trunk and pelvic movement variability could be a potential marker for gait quality with diagnostic implications.

Gait characteristics and functional outcomes during early follow-up are comparable in patients with calcaneal fractures treated by either the sinus tarsi or the extended lateral approach.

BACKGROUND: To overcome the substantial functional loss after calcaneal fractures (CF), surgical treatment currently consists of two strategies, namely the commonly used extended lateral approach (ELA) and the less invasive sinus tarsi approach (STA). Despite the comparable anatomical restoration, the biomechanical and functional outcome of these strategies during early rehabilitation has not yet been investigated. RESEARCH QUESTION: To evaluate changes in gait characteristics and functional development in patients with CF treated by either STA or ELA. METHODS: A total of 56 patients with unilateral CF were included in this retrospective study. 26 patients were treated by ELA while 30 patients underwent surgery through the STA. Functional and biomechanical measurements were performed at follow-up periods of three and six months. Foot and ankle kinetics and kinematics were extracted using instrumented gait analysis with a multi segment foot model. Physical and mental components of the Short Form 36 (SF-36) and total scoring of the AOFAS hindfoot scale were used for functional evaluation. Statistical analysis was performed using Mann Whitney and Student's t-test. Effect sizes of group differences were calculated using Cohen's d. RESULTS: Comparisons between ELA and STA showed no significant difference regarding the biomechanical and functional outcome. Within-group comparisons showed significant (p < 0.05) improvements from three to six month follow-up. Ankle joint and hindfoot kinematics showed increased mobility during walking of up to 34% and 26%, respectively. Maximum ankle joint moment also improved by up to 34% while vertical ground reaction force increased by 8%. Functional outcome only revealed significant changes in the physical component of SF-36. SIGNIFICANCE: ELA and STA treatments revealed comparable functional improvements in patients with unilateral intraarticular calcaneal fractures during early rehabilitation. The less invasive STA provides adequate restoration of dynamic foot function and could serve as a viable alternative to the commonly used ELA.

Relation between the amount of daily activity and gait quality in transfemoral amputees.

Gait variability is often associated with reduced coordination and increased instability during walking. Especially for patients with musculoskeletal conditions, variability in gait might be associated with the level of daily activity. Therefore, this study examines kinematic variability during walking and the association with daily activity in patients with transfemoral amputation. Therefore, 15 transfemoral amputees, using the C-leg prosthesis of Otto Bock, between 18 and 65 years were recruited during their hospital stay. All patients were able to walk without crutches in everyday life and were familiar with walking using the C-leg system. Gait parameters and data of variability were captured during walking in a gait laboratory by eight infrared cameras (Vicon). Daily activity was assessed using a three-dimensional acceleration sensor of VitaMove. Patients showed variability from 0.84° up to 1.96° in frontal pelvis motion and from 0.9° up to 4.02° in trunk obliquity. The results show a significant correlation between activity and variability in trunk (r = -0.58; P ≤ 0.05) and pelvis (r = -0.63; P ≤ 0.01) as well as gait velocity (r = 0.6; P ≤ 0.05). However, kinematic variability and gait velocity are not related to each other. In conclusion, the results show that kinematic gait variability is associated with the extent of activity and therefore presents an important parameter for assessing amputees' gait quality and daily activity.

CSF1R Stimulation Promotes Increased Neuroprotection by CD11c+ Microglia in EAE.

Microglia are resident immune cells of the central nervous system. Their development and maintenance depend on stimulation of Colony Stimulating Factor-1 receptor (CSF1R). Microglia play an important role in neurodevelopment and a population of microglia that expresses the complement receptor CD11c is critical for primary myelination. This population is virtually absent in the healthy adult brain but increases dramatically upon neuroinflammatory conditions, and these microglia are suggested to play a protective role in central nervous system (CNS) diseases. To date, the molecular trigger for their expansion is unknown. Here we showed that stimulation of CSF1R by either of its ligands, CSF1 and interleukin (IL)-34, can induce expansion of CD11c+ microglia. In addition, such stimulation resulted in amelioration of EAE symptoms and decreased demyelination. Treatment with CSF1R ligands also induced expression of the chemokine CCL2, and we showed that experimental overexpression of CCL2 in the brain led to a dramatic increase of CD11c+ microglia, independent of CCR2. Moreover, this led to elevated CSF1 expression, suggesting a positive feedback loop between CSF1R and CCL2. These data provide new insights to microglia biology and open new perspectives for modulating microglial activity in neuroinflammatory diseases such as multiple sclerosis.

Effects of knee orthosis adjustment on biomechanical performance and clinical outcome in patients with medial knee osteoarthritis.

BACKGROUND: Valgus bracing in medial knee osteoarthritis aims to improve gait function by reducing the loading of the medial compartment. Orthosis composition and optimal adjustment is essential to achieve biomechanical and clinical effectiveness. OBJECTIVES: To investigate biomechanical functionality during gait, pain relief and compliance in patients with knee osteoarthritis using a lightweight adjustable knee unloader orthosis. STUDY DESIGN: Prospective observational clinical trial. METHODS: Instrumented gait analysis in 22 patients with unilateral medial knee osteoarthritis was performed after a 2-week orthosis acclimatisation period. Kinematics and kinetics during gait as well as force transmission from the orthosis to the knee were analysed. Measurements were performed without, at individualised and at reduced orthosis setting. The assessment was supplemented by patient-related pain sensation and compliance questionnaires. RESULTS: Orthosis wear significantly reduced the knee adduction moment by up to 20% depending on orthosis adjustment, whereas pain sensation was significantly reduced by 16%. A significant positive correlation was found between force transmissions and knee adduction moment as well as for frontal knee angle. Compliance was good with a main daily use of 2-6 h. CONCLUSION: The orthosis provides significant biomechanical improvements, pain relief and good patient compliance. Patients had a biomechanical benefit for the individualised and reduced orthosis adjustments. Clinical relevance In patients with medial knee osteoarthritis, a lightweight medial unloader orthosis effectively reduced external knee adduction moment and pain sensation during daily activities. Thus, use of lightweight orthoses effectively supports conservative treatment in medial knee osteoarthritis.

A novel microglial subset plays a key role in myelinogenesis in developing brain.

Microglia are resident macrophages of the central nervous system that contribute to homeostasis and neuroinflammation. Although known to play an important role in brain development, their exact function has not been fully described. Here, we show that in contrast to healthy adult and inflammation-activated cells, neonatal microglia show a unique myelinogenic and neurogenic phenotype. A CD11c+ microglial subset that predominates in primary myelinating areas of the developing brain expresses genes for neuronal and glial survival, migration, and differentiation. These cells are the major source of insulin-like growth factor 1, and its selective depletion from CD11c+ microglia leads to impairment of primary myelination. CD11c-targeted toxin regimens induced a selective transcriptional response in neonates, distinct from adult microglia. CD11c+ microglia are also found in clusters of repopulating microglia after experimental ablation and in neuroinflammation in adult mice, but despite some similarities, they do not recapitulate neonatal microglial characteristics. We therefore identify a unique phenotype of neonatal microglia that deliver signals necessary for myelination and neurogenesis.

Effect of different handgrip angles on work distribution during hand cycling at submaximal power levels.

The effect of different handle angles on work distribution during hand cycling was determined. Able-bodied subjects performed hand cycling at 20% of maximum power level (mean (SD) power level: 90.0 (25.8) W) at a cadence of 70 rpm using handle angles of +/-30 degrees, +/-15 degrees and 0 degrees. The handle angle had a significant effect on work during the pull down (p < 0.001) and lift up (p = 0.005) sector, whereby the highest work was performed with handle angles of +30 degrees and -15 degrees respectively. The cycle sector had a significant effect on work (p < 0.001) and significantly (p = 0.002) higher work was performed in the pull down sector (25% higher than mean work over one cycle) as compared to the lift up sector (30% lower than mean work over one cycle). Therefore, a fixed handle angle of +30 degrees is suggested to be optimal for power generation. The results of this study help to optimise the handbike-user interface. A more pronated handle angle compared to the one conventionally used was found to improve the performance of hand cycling and thereby the mobility of disabled people.