Nutritional status as independent prognostic factor of outcome and mortality until five years after hip fracture: a comprehensive prospective study.

We determined the prognostic value of nutritional status for outcome after hip fracture. Nutritional status was a strong independent prognostic factor for clinical outcome and 5-year mortality. Physical function showed incomplete recovery. Elderly care should focus on prevention already before hip fracture. PURPOSE: To determine the prognostic value of nutritional status in hip fracture patients for multiple clinical and functional outcomes over 6 months, and for new fractures and survival over 5 years post-fracture. METHODS: We included 152 well-characterized subjects (age 55+ years) with a hip fracture from a previously published randomized controlled trial. Nutritional status was appraised using the Mini Nutritional Assessment (MNA). Multivariable linear, logistic and Cox regression models were fitted, adjusted for age, sex, ASA score, group and additional prognostic covariates identified in backward regression models. RESULTS: At baseline, impaired nutritional status was significantly associated with physical disability, depression, impaired cognition and lower quality of life. Prospective analyses showed that impaired baseline nutritional status was an independent prognostic factor for postoperative complications (OR 2.00, 95%CI 1.01-3.98, p = 0.047), discharge location from hospital (home vs. rehabilitation clinic, OR 0.41, 95%CI 0.18-0.98, p = 0.044), hospital readmission (OR 4.59, 95%CI 1.70-12.4, p = 0.003) and total length of hospital stay (HR of being discharged: 0.63, 96%CI 0.44-0.89, p = 0.008), as well as for 5-year mortality (HR 3.94, 95%CI 1.53-10.2, p = 0.005), but not for risk of new fractures (5y-HR 0.87, 95%CI 0.34-2.24, p = 0.769). Curves of physical disability over time showed that the three nutritional status categories followed almost parallel trajectories from baseline until 6 months after hip fracture, without complete recovery and even with further deterioration in malnourished subjects from 3 to 6 months post-fracture. CONCLUSION: As baselline nutritional status is a strong independent prognostic factor for clinical outcome after hip fracture, affecting even five-year survival, elderly health care should focus on prevention and identification of at-risk individuals already before hip fracture.

Kinematics and mechanical changes with step frequency at different running speeds.

PURPOSE: Running at a given speed can be achieved by taking large steps at a low frequency or on the contrary by taking small steps at a high frequency. The consequences of a change in step frequency, at a fixed speed, affects the stiffness of the lower limb differently. In this study, we compared the running mechanics and kinematics at different imposed step frequencies (from 2 step s-1 to 3.6 step s-1) to understand the relationship between kinematic and kinetic parameters. METHODS: Eight recreational male runners ran on a treadmill at 5 different speeds and 5 different step frequencies. The lower-limb segment motion and the ground reaction forces were recorded. Mechanical powers, general gait parameters, lower-limb movements and coordination were investigated. RESULTS: At low step frequencies, in order to limit the magnitude of the ground reaction force, the vertical stiffness is reduced and thus runners deviate from an elastic rebound. At high step frequencies, the stiffness is increased and the elastic rebound is optimised in its ability to absorb and restore energy during the contact phase. CONCLUSION: We studied the consequences of a change in step frequency on the bouncing mechanics of running. We showed that the lower limb stiffness and the intersegmental coordination of the lower-limb segments are affected by running step frequency rather than speed. The runner rather adapts their lower limb stiffness to match a step frequency for a given speed than the opposite.

A timeline of cognitive functioning in glioma patients who undergo awake brain tumor surgery.

BACKGROUND: The purpose of awake brain tumor surgery is to maximize the resection of the tumor and to minimize the risk of neurological and cognitive impairments. The aim of this study is to gain understanding of the development of possible postoperative cognitive deficits after awake brain tumor surgery in patients with suspected gliomas, by comparing preoperative, early postoperative, and late postoperative functioning. A more detailed timeline will be helpful in informing candidates for surgery about what to expect regarding their cognitive functioning. METHODS: Thirty-seven patients were included in this study. Cognitive functioning was measured by means of a broad cognitive screener preoperatively, days after surgery and months after surgery in patients who underwent awake brain tumor surgery with cognitive monitoring. The cognitive screener included tests for object naming, reading, attention span, working memory, inhibition, inhibition/switching, and visuoperception. We performed a Friedman ANOVA to analyze on group level. RESULTS: Overall, no significant differences were found between preoperative cognitive functioning, early postoperative cognitive functioning, and late postoperative cognitive functioning, except for performances on the inhibition task. Directly after surgery, patients were significantly slower on this task. However, in the following months after surgery, they returned to their preoperative level. CONCLUSION: The timeline of cognitive functioning after awake tumor surgery appeared overall stable in the early and late postoperative phase, except for inhibition, which is more difficult in the first days after awake brain tumor surgery. This more detailed timeline of cognitive functioning, in combination with future research, can possibly be contributing in informing patients and caregivers what to expect after awake brain tumor surgery.

Radiomics biopsy signature for predicting survival in patients with spinal bone metastases (SBMs).

STUDY DESIGN: Retrospective analysis of a registered cohort of patients treated and irradiated for metastases in the spinal column in a single institute. OBJECTIVE: This is the first study to develop and internally validate radiomics features for predicting six-month survival probability for patients with spinal bone metastases (SBM). BACKGROUND DATA: Extracted radiomics features from routine clinical CT images can be used to identify textural and intensity-based features unperceivable to human observers and associate them with a patient survival probability or disease progression. METHODS: A study was conducted on 250 patients treated for metastases in the spinal column irradiated for the first time between 2014 and 2016, at the MAASTRO clinic in Maastricht, the Netherlands. The first 150 available patients were used to develop the model and the subsequent 100 patient were considered as a test set for the model. A bootstrap (B = 400) stepwise model selection, which combines both the forward and backward variable elimination procedure, was used to select the most useful predictive features from the training data based on the Akaike information criterion (AIC). The stepwise selection procedure was applied to the 400 bootstrap samples, and the results were plotted as a histogram to visualize how often each variable was selected. Only variables selected more than 90 % of the time over the bootstrap runs were used to build the final model.A prognostic index (PI) called radiomics score (radscore) and clinical score (clinscore) was calculated for each patient. The prognostic index was not scaled, the original values were used which can be extracted from the model directly or calculated as a linear combination of the variables in the model multiplied by the respective beta value for each patient. RESULTS: The clinical model had a good discrimination power. The radiomics model, on the other hand, had an inferior performance with no added predictive power to the clinical model. The internal imaging characteristics do not seem to have a value in the prediction of survival. However, the Shape features were excluded from further analyses in our study since all biopsies had a standard shape hence no variability.

The influence of size and comminution of the posterior malleolus fragment on gait in trimalleolar ankle fractures.

BACKGROUND: Ankle fractures involving the posterior malleolus generally lead to worse outcome. However, no studies on gait in trimalleolar ankle fractures have evaluated the influence of size and comminution of the posterior malleolar fragment. METHODS: We expected patients with more severely comminuted posterior malleolus, more severe fracture type and larger posterior fragment to have reduced gait kinematics and poorer patient-reported outcomes. 26 trimalleolar ankle fracture patients were compared with 14 healthy controls and kinematically analyzed using the Oxford Foot Model. Functional outcome was based on 4 patient reported outcome questionnaires. Effects of posterior fragment size, comminution and Haraguchi fracture classification were determined on conventional and 3D CT-scans. FINDINGS: Trimalleolar patients had lower walking speed and reduced range of motion between the hindfoot and tibia in both loading and push-off phases in the sagittal and transverse planes. The range between the hindfoot and tibia in the sagittal plane in the push-off phase correlated significantly with patient reported outcomes. The absolute and relative surface area of the posterior fragment on conventional CT-scans and 3D CT-scans, correlated significantly with range of motion. Patients with a posterior malleolus size >10% of the posterior malleolus had lower flexion-extension between forefoot and hindfoot during loading phase than patients with a size ≤10%. INTERPRETATION: Trimalleolar fractures reduce walking speed and range of motion in the talocrural joint. Reduced range in the talocrural joint is associated with poorer outcomes. Posterior fragment size correlated significantly with range of motion in talocrural and midfoot joints and with patient reported outcomes. LEVEL OF EVIDENCE: Level 3, retrospective study.

Postural control in the elephant.

As the largest extant legged animals, elephants arguably face the most extreme challenge for stable standing. In this study, we investigated the displacement of the centre of pressure of 12 elephants during quiet standing. We found that the average amplitude of the oscillations in the lateral and fore-aft directions was less than 1.5 cm. Such amplitudes for postural oscillation are comparable with those of dogs and other species, suggesting that some aspects of sensorimotor postural control do not scale with size.

The bouncing mechanism of running against hindering, or with aiding traction forces: a comparison with running on a slope.

PURPOSE: Much like running on a slope, running against/with a horizontal traction force which either hinders/aids the forward motion of the runner creates a shift in the positive and negative muscular work, which in turn modifies the bouncing mechanism of running. The purpose of the study is to (1) investigate the energy changes of the centre of mass and the storage/release of energy throughout the step during running associated with speed and increasing hindering and aiding traction forces; and (2) compare these changes to those observed when running on a slope. METHODS: Ground reaction forces were measured on eight subjects running on an instrumented treadmill against different traction forces at different speeds. RESULTS: As compared to unperturbed running, running against/with a traction force increases/decreases positive external work by ~ 20-70% and decreases/increases negative work by ~ 40-60%, depending on speed and traction force. The external power to maintain forward motion against a traction is contained by increasing the pushing time and step frequency. When running with an aiding force, the external power during the brake is limited by increasing braking time. Furthermore, the aerial time is increased to reduce the power required to reset the limbs each step. CONCLUSION: Our results show that the bouncing mechanism of running against/with a hindering/aiding traction force is equivalent to that of running on a positive/negative slope.

The Use of Metal Sublaminar Wires in Modern Growth-Guidance Scoliosis Surgery: A Report of 4 Cases and Literature Review.

BACKGROUND: To avoid early fusion and allow residual growth of the spine in early onset scoliosis (EOS) treatment, growth-guided scoliosis surgery can be performed. Four patients with EOS are presented in which a growth-guidance instrumentation is used with sliding titanium (Ti) sublaminar cables. Residual growth of the spine can be preserved using metal sublaminar wiring; however, several drawbacks of this technique and type of material are illustrated. METHODS: Four patients with progressive neuromuscular scoliosis were treated with a posterior stabilization. A fusionless growth-guidance instrumentation was used consisting of a combination of lumbar pedicle screws and sliding Ti sublaminar cables along cobalt chrome rods. RESULTS: In 2 cases, the described growth-guidance technique provided sufficient stability and correction of the curvature with preservation of growth. In 2 patients, the instrumentation failed due to upper thoracic sublaminar wire breakage. The ongoing abrasion of the rod-wire interface caused severe metallosis. In these cases, a debridement and revision surgery was performed with partial fusion of the spine. CONCLUSIONS: Growth-guidance techniques with sliding metal sublaminar wires seem to be a valuable solution for the preservation of spinal growth in EOS surgery. High curvatures, however, have a higher chance of failure and demand for more corrective strength and support of the instrumentation. The use of metal sublaminar wires in a "sliding" instrumentation can lead to early breakage and metallosis. LEVEL OF EVIDENCE: 4, case series. CLINICAL RELEVANCE: Surgeons should be aware of possible complications associated with the use of metal laminar wires in spinal fusion and growth-guidance scoliosis surgery. The implementation of materials containing higher fatigue strength and lower friction properties (eg, UHMWPE wires) may avoid these potential complication risks.

Subsidence after total lumbar disc replacement is predictable and related to clinical outcome.

PURPOSE: As yet, there are no studies describing a relationship between radiographic subsidence after lumbar total disc replacement (TDR) and patient symptoms. To investigate if subsidence, in terms of penetrated bone volume or angular rotation over time (ΔPBV and ΔAR), is related to clinical outcome. To assess if subsidence can be predicted by position implant asymmetry (IA) or relative size of the TDR, areal undersizing index (AUI) on direct post-operative radiographs. METHODS: Retrospective cohort study consists of 209 consecutive patients with lumbar TDR for degenerative disc disease. A three-dimensional graphical representation of the implant in relation to the bony endplates was created on conventional radiographs. Consequently, the PBV, AR, IA and AUI were calculated, direct post-operative (DPO) and at last follow-up (LFU). For clinical evaluation, patients with substantial pain (VAS ≥ 50) and malfunction (ODI ≥ 40) were considered failures. RESULTS: At a mean follow-up of 16.7 years, 152 patients (73%) were available for analysis. In 32 patients, revision by spinal fusion had been performed. Both ΔAR (4.33° vs. 1.83°, p = 0.019) and ΔPBV (1448.4 mm3 vs. 747.3 mm3, p = 0.003) were significantly higher in the failure-compared to the success-group. Using ROC curves, thresholds for symptomatic subsidence were defined as ΔPBV ≥ 829 mm3 or PBV-LFU ≥ 1223 mm3 [area under the curve (AUC) 0.723, p = 0.003 and 0.724, p = 0.005, respectively]. Associations between symptomatic subsidence and AUI-DPO ≥ 0.50 (AUC 0.750, p = 0.002) and AR-DPO ≥ 3.95° (AUC 0.690, p = 0.022) were found. CONCLUSION: Subsidence of a TDR is associated with a worse clinical outcome. The occurrence of subsidence is higher in case of incorrect placement or shape mismatch.

Percutaneous cement augmentation in the treatment of osteoporotic vertebral fractures (OVFs) in the elderly: a systematic review.

PURPOSE: A systematic review, to study treatment effects for osteoporotic vertebral fractures (OVFs) in the elderly including all available evidence from controlled trials on percutaneous cement augmentation. METHODS: Primary studies, published up to December, 2019, were searched in PubMed and the Cochrane Library. Selected were all prospective controlled studies including patients > 65 years of age and reporting on at least one main outcome. Main outcomes were pain, disability and quality of life (QOL) 1 day post-intervention and at 6 months postoperatively. Excluded were meta-analyses or reviews, retrospective or non-controlled studies, case studies, patients' groups with neoplastic and/or traumatic fractures and/or neurologically compromised patients. RESULTS: Eighteen studies comprising 2165 patients (n = 1117 percutaneous cement augmentation, n = 800 conservative treatment (CT), n = 248 placebo) with a mean follow-up of up to 12 months were included. Pooled results showed significant pain relief in favor of percutaneous cement augmentation compared to CT, direct postoperative and at 6 months follow-up. At 6 months, a significant difference was observed for functional disability scores in favor of percutaneous cement augmentation. When comparing percutaneous cement augmentation to placebo, no significant differences were observed. CONCLUSION: This review incorporates all current available evidence (RCTs and non-RCTs) on the efficacy of percutaneous cement augmentation in the treatment of OVFs in the elderly. Despite methodological heterogeneity of the included studies, this review shows overall significant sustained pain relief and superior functional effect in the short- and long term for percutaneous cement augmentation compared to conservative treatment. These slides can be retrieved under Electronic Supplementary Material.

Long-term clinical outcome of the Charité III total lumbar disc replacement.

PURPOSE: To compare the long-term clinical results and complications of two revision strategies for patients with failed total disc replacements (TDRs). METHODS: In 19 patients, the TDR was removed and the intervertebral defect was filled with a femoral head bone strut graft. In addition, instrumented posterolateral fusion was performed (removal group). In 36 patients, only a posterolateral instrumented fusion was performed (fusion group). Visual analogue scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed. RESULTS: The median follow-up was 12.3 years (range 5.3-24.3). In both the removal and fusion group, a similar (p = 0.515 and p = 0419, respectively) but significant decrease in VAS- (p = 0.001 and p = 0.001, respectively) and ODI-score (p = 0.033 and p = 0.013, respectively) at post-revision surgery compared to pre-revision surgery was seen. A clinically relevant improvement in VAS- and ODI-score was found in 62.5% and 43.8% in the removal group and in 43.5% and 39.1% in the fusion group (p = 0.242 and p = 0.773, respectively). Removal of the TDR was associated with substantial intra-operative complications such as major vessel bleeding and ureter lesion. The percentage of late reoperations for complications such as pseudarthrosis was comparable for both revision strategies. CONCLUSIONS: Revision of a failed TDR is clinically beneficial in about half of the patients. No clear benefits for additional TDR removal as compared to posterolateral instrumented fusion alone could be identified. Particularly, when considering the substantial risks and complications, great caution is warranted with removal of the TDR. These slides can be retrieved under Electronic Supplementary Material.

Reliability and Clinical Usefulness of Current Classifications in Traumatic Thoracolumbar Fractures: A Systematic Review of the Literature.

BACKGROUND: A validated classification remains the key to an appropriate treatment algorithm of traumatic thoracolumbar fractures. Considering the development of many classifications, it is remarkable that consensus about treatment is still lacking. We conducted a systematic review to investigate which classification can be used best for treatment decision making in thoracolumbar fractures. METHODS: A comprehensive search was conducted using PubMed, Embase, CINAHL, and Cochrane using the following search terms: classification (mesh), spinal fractures (mesh), and corresponding synonyms. All hits were viewed by 2 independent researchers. Papers were included if analyzing the reliability (kappa values) and clinical usefulness (specificity or sensitivity of an algorithm) of currently most used classifications (Magerl/AO, thoracolumbar injury classification and severity score [TLICS] or thoracolumbar injury severity score, and the new AO spine). RESULTS: Twenty articles are included. The presented kappa values indicate moderate to substantial agreement for all 3 classifications. Regarding the clinical usefulness, > 90% agreement between actual treatment and classification recommendation is reported for most fractures. However, it appears that over 50% of the patients with a stable burst fracture (TLICS 2, AO-A3/A4) in daily practice are operated, so in these cases treatment decision is not primarily based on classification. CONCLUSION: AO, TLICS, and new AO spine classifications have acceptable accuracy (kappa > 0.4), but are limited in clinical usefulness since the treatment recommendation is not always implemented in clinical practice. Differences in treatment decision making arise from several causes, such as surgeon and patient preferences and prognostic factors that are not included in classifications yet. The recently validated thoracolumbar AO spine injury score seems promising for use in clinical practice, because of inclusion of patient-specific modifiers. Future research should prove its definite value in treatment decision making. LEVEL OF EVIDENCE: 2. CLINICAL RELEVANCE: Without the appropriate treatment, the impact of traumatic thoracolumbar fractures can be devastating. Therefore it is important to achieve consensus in the treatment of thoracolumbar fractures.

Neuromechanical adjustments when walking with an aiding or hindering horizontal force.

PURPOSE: Walking against a constant horizontal traction force which either hinders or aids the motion of the centre of mass of the body (COM) will create a discrepancy between the positive and negative work being done by the muscles and may thus affect the mechanics and energetics of walking. We aimed at investigating how this imbalance affects the exchange between potential and kinetic energy of the COM and how its dynamics is related to specific spatiotemporal organisation of motor pool activity in the spinal cord. To understand if and how the spinal cord activation may be associated with COM dynamics, we also compared the neuromechanical adjustments brought on by a horizontal force with published data about those brought on by a slope. METHODS: Ten subjects walked on a treadmill at different speeds with different traction forces. We recorded kinetics, kinematics, and electromyographic activity of 16 lower-limb muscles and assessed the spinal locomotor output by mapping them onto the rostrocaudal location of the motoneuron pools. RESULTS: When walking with a hindering force, the major part of the exchange between potential and kinetic energy of the COM occurs during the first part of stance, whereas with an aiding force exchanges increase during the second part of stance. Those changes occur since limb and trunk orientations remain aligned with the average orientation of the ground reaction force vector. Our results also show the sacral motor pools decreased their activity with an aiding force and increased with a hindering one, whereas the lumbar motor pools increased their engagement both with an aiding and a hindering force. CONCLUSION: Our findings suggest that applying a constant horizontal force results in similar modifications of COM dynamics and spinal motor output to those observed when walking on slopes, consistent with common principles of motor pool functioning and biomechanics of locomotion.

Long-term clinical outcome of two revision strategies for failed total disc replacements.

PURPOSE: To compare the long-term clinical results and complications of two revision strategies for patients with failed total disc replacements (TDRs). METHODS: In 19 patients, the TDR was removed and the intervertebral defect was filled with a femoral head bone strut graft. In addition, instrumented posterolateral fusion was performed (removal group). In 36 patients, only a posterolateral instrumented fusion was performed (fusion group). Visual Analogue Scale (VAS) for pain and Oswestry Disability Index (ODI) were completed pre- and post-revision surgery. Intra- and post-operative complications of both revision strategies were assessed. RESULTS: The median follow-up was 12.3 years (range 5.3-24.3). In both the removal and fusion groups, a similar (p = 0.515 and p = 0419, respectively) but significant decrease in VAS (p = 0.001 and p = 0.001, respectively) and ODI score (p = 0.033 and p = 0.013, respectively) at post-revision surgery compared to pre-revision surgery was seen. A clinically relevant improvement in VAS and ODI score was found in 62.5% and 43.8% in the removal group and in 43.5% and 39.1% in the fusion group (p = 0.242 and p = 0.773, respectively). Removal of the TDR was associated with substantial intra-operative complications such as major vessel bleeding and ureter lesion. The percentage of late re-operations for complications such as pseudarthrosis were comparable for both revision strategies. CONCLUSIONS: Revision of a failed TDR is clinically beneficial in about half of the patients. No clear benefits for additional TDR removal as compared to posterolateral instrumented fusion alone could be identified. In particular, when considering the substantial risks and complications, great caution is warranted with removal of the TDR. These slides can be retrieved under Electronic Supplementary Material.

Color-Mapping of 4D-CTA for the Detection of Cranial Arteriovenous Shunts.

BACKGROUND AND PURPOSE: 4D CT angiography is increasingly used in clinical practice for the assessment of different neurovascular disorders. Optimized processing of 4D-CTA is crucial for diagnostic interpretation because of the large amount of data that is generated. A color-mapping method for 4D-CTA is presented for improved and enhanced visualization of the cerebral vasculature hemodynamics. This method was applied to detect cranial AVFs. MATERIALS AND METHODS: All patients who underwent both 4D-CTA and DSA in our hospital from 2011 to 2018 for the clinical suspicion of a cranial AVF or carotid cavernous fistula were retrospectively collected. Temporal information in the cerebral vasculature was visualized using a patient-specific color scale. All color-maps were evaluated by 3 observers for the presence or absence of an AVF or carotid cavernous fistula. The presence or absence of cortical venous reflux was evaluated as a secondary outcome measure. RESULTS: In total, 31 patients were included, 21 patients with and 10 without an AVF. Arterialization of venous structures in AVFs was accurately visualized using color-mapping. There was high sensitivity (86%-100%) and moderate-to-high specificity (70%-100%) for the detection of AVFs on color-mapping 4D-CTA, even without the availability of dynamic subtraction rendering. The diagnostic performance of the 3 observers in the detection of cortical venous reflux was variable (sensitivity, 43%-88%; specificity, 60%-80%). CONCLUSIONS: Arterialization of venous structures can be visualized using color-mapping of 4D-CTA and proves to be accurate for the detection of cranial AVFs. This finding makes color-mapping a promising visualization technique for assessing temporal hemodynamics in 4D-CTA.

Differential activation of lumbar and sacral motor pools during walking at different speeds and slopes.

Organization of spinal motor output has become of interest for investigating differential activation of lumbar and sacral motor pools during locomotor tasks. Motor pools are associated with functional grouping of motoneurons of the lower limb muscles. Here we examined how the spatiotemporal organization of lumbar and sacral motor pool activity during walking is orchestrated with slope of terrain and speed of progression. Ten subjects walked on an instrumented treadmill at different slopes and imposed speeds. Kinetics, kinematics, and electromyography of 16 lower limb muscles were recorded. The spinal locomotor output was assessed by decomposing the coordinated muscle activation profiles into a small set of common factors and by mapping them onto the rostrocaudal location of the motoneuron pools. Our results show that lumbar and sacral motor pool activity depend on slope and speed. Compared with level walking, sacral motor pools decrease their activity at negative slopes and increase at positive slopes, whereas lumbar motor pools increase their engagement when both positive and negative slope increase. These findings are consistent with a differential involvement of the lumbar and the sacral motor pools in relation to changes in positive and negative center of body mass mechanical power production due to slope and speed.NEW & NOTEWORTHY In this study, the spatiotemporal maps of motoneuron activity in the spinal cord were assessed during walking at different slopes and speeds. We found differential involvement of lumbar and sacral motor pools in relation to changes in positive and negative center of body mass power production due to slope and speed. The results are consistent with recent findings about the specialization of neuronal networks located at different segments of the spinal cord for performing specific locomotor tasks.

Long-term functional outcome of distal radius fractures is associated with early post-fracture bone stiffness of the fracture region: An HR-pQCT exploratory study.

Identifying determinants of long-term functional outcome after a distal radius fracture is challenging. Previously, we reported on the association between early HR-pQCT measurements and clinical outcome 12 weeks after a conservatively treated distal radius fracture. We extended the follow-up and assessed functional outcome after two years in relation to early HR-pQCT derived bone parameters. HR-pQCT scans of the fracture region were performed in 15 postmenopausal women with a distal radius fracture at 1-2 (baseline), 3-4 weeks and 26 months post-fracture. Additionally, the contralateral distal radius was scanned at baseline. Bone density, micro-architecture parameters and bone stiffness using micro-finite element analysis (µFEA) were evaluated. During all visits, wrist pain and function were assessed using the patient-rated wrist evaluation questionnaire (PRWE), quantifying functional outcome with a score between 0 and 100. Two-year PRWE was associated with torsional and bending stiffness 3-4 weeks post-fracture (R2: 0.49, p = 0.006 and R2: 0.54, p = 0.003, respectively). In contrast, early micro-architecture parameters of the fracture region or contralateral bone parameters did not show any association with long-term outcome. This exploratory study indicates that HR-pQCT with µFEA performed within four weeks after a distal radius fracture captures biomechanical fracture characteristics that are associated with long-term functional outcome and therefore could be a valuable early outcome measure in clinical trials and clinical practice.

Effect of walking speed on the intersegmental coordination of lower-limb segments in elderly adults.

BACKGROUND: Ageing brings profound changes in walking gait. For example, older adults reduce the modification of pelvic and trunk kinematics with walking speed. However, the modification of the coordination between lower-limb segments with age has never been investigated across various controlled speeds. RESEARCH QUESTION: Is the effect of speed on the intersegmental coordination different between elderly and young adults? METHODS: Nineteen senior and eight young adults walked on a treadmill at speeds ranging from 0.56 to 1.94 m s-1. The motion of the lower-limb segments in the sagittal plane was recorded by cinematography. When the angles of the thigh, shank and foot during a stride are plotted one versus the other, they describe loops constraint on a plane. The coordination between lower-limb segments was thus evaluated by performing a principal component analysis between the thigh, shank and foot elevation angles. The effect of speed and age on the intersegmental coordination was examined using a two-level linear mixed model ANOVA. RESULTS: In both age groups the orientation of the plane changes with speed, due to a more in-phase shank and foot motion. However, the effect of speed on the covariation plane is lessened with age. SIGNIFICANCE: Our results demonstrate that there is an age-related specific adjustment of the intersegmental coordination to speed. In particular, older adults restrict their repertoire of angular segment motion. These differences in coordination are mainly related to different foot-shank coordination.