A head-to-head comparison of EQ-5D-5L and SF-6D in Dutch patients with fractures visiting a Fracture Liaison Service

AIMS

This study compared the psychometric properties of EQ-5D-5L and SF-6D to assess the interchangeability of both instruments in patients with a recent fracture presenting at a Fracture Liaison Service (FLS).

MATERIALS AND METHODS

Data from a prospective observational study in a Dutch FLS clinic were used. Over 3 years, subjects were interviewed at several time points using EQ-5D-5L and SF-36. Floor and ceiling effects were evaluated. Agreement was evaluated by intra-class correlation coefficients and visualized in Bland-Altman plots. Spearman's rank correlation coefficients were applied to assess convergent validity. Mann-Whitney U test or Kruskal-Wallis H test as well as effect size (ES) were used to explore known-groups validity. Responsiveness was explored using standardized response mean (SRM) and ES. For each measurement property, hypotheses on direction and magnitude of effects were formulated.

RESULTS

A total of 499 patients were included. EQ-5D-5L had a considerable ceiling effect in comparison to SF-6D (21 vs. 1.2%). Moderate agreement between the (UK and Dutch) EQ-5D-5L and SF-6D was identified with intra-class correlation coefficients of 0.625 and 0.654, respectively. Bland-Altman plots revealed proportional bias as the differences in utilities between two instruments were highly dependent on the health states. High correlation between instruments was found (UK: rho = 0.758; Dutch: rho = 0.763). EQ-5D-5L and SF-6D utilities showed high correlation with physical component score but low correlation with mental component score of SF-36. Both instruments showed moderate discrimination (ES > 0.5) for subgroup by baseline fracture type, and moderate responsiveness (SRM > 0.5) in patients that sustained a subsequent fracture.

CONCLUSION

Both EQ-5D-5L and SF-6D appeared to be valid utility instruments in patients with fractures attending the FLS. However, they cannot be used interchangeably given only moderate agreement was identified, and differences in utilities and ceiling effect were revealed. Comparable construct validity and responsiveness were indicated, and neither instrument was found to be clearly superior.

Military Service Members with Major Lower Extremity Fractures Return to Running with a Passive-dynamic Ankle-foot Orthosis: Comparison with a Normative Population

BACKGROUND

Lower extremity fractures represent a high percentage of reported injuries in the United States military and can devastate a service member's career. A passive dynamic ankle-foot orthosis (PD-AFO) with a specialized rehabilitation program was initially designed to treat military service members after complex battlefield lower extremity injuries, returning a select group of motivated individuals back to running. For high-demand users of the PD-AFO, the spatiotemporal gait parameters, agility, and quality of life is not fully understood with respect to uninjured runners.

QUESTIONS/PURPOSES

Do patients who sustained a lower extremity fracture using a PD-AFO with a specialized rehabilitation program differ from uninjured service members acting as controls, as measured by (1) time-distance and biomechanical parameters associated with running, (2) agility testing (using the Comprehensive High-level Activity Mobility Predictor performance test and Four Square Step Test), and (3) the Short Musculoskeletal Function Assessment score.

METHODS

We conducted a retrospective data analysis of a longitudinally collected data registry of patients using a PD-AFO from 2015 to 2017 at a single institution. The specific study cohort were patients with a unilateral lower extremity fracture who used the PD-AFO for running. Patients had to be fit with a PD-AFO, have completed rehabilitation, and have undergone a three-dimensional (3-D) running analysis at a self-selected speed at the completion of the program. Of the 90 patients who used the PD-AFO for various reasons, 10 male service members with lower extremity fractures who used a PD-AFO for running (median [range] age 29 years [22 to 41], height 1.8 meters [1.7 to 1.9], weight 91.6 kg [70 to 112]) were compared with 15 uninjured male runners in the military (median age 33 years [21 to 42], height 1.8 meters [1.7 to 1.9], weight 81.6 kg [71.2 to 98.9]). The uninjured runners were active-duty service members who voluntarily participated in a gait analysis at their own self-selected running speeds; to meet eligibility for inclusion as an uninjured control, the members had to be fit for full duty without any medical restrictions, and they had to be able to run 5 miles. The controls were then matched to the study group by age, weight, and height. The primary study outcome variables were the running time-distance parameters and frontal and sagittal plane kinematics of the trunk and pelvis during running. The Four Square Step Test, Comprehensive High-level Activity Mobility Predictor scores, and Short Musculoskeletal Function Assessment scores were analyzed for all groups as secondary outcomes. Nonparametric analyses were performed to determine differences between the two groups at p < 0.05.

RESULTS

For the primary outcome, patients with a PD-AFO exhibited no differences compared with uninjured runners in median (range) running velocity (3.9 meters/second [3.4 to 4.2] versus 4.1 meters/second [3.1 to 4.8], median difference 0.2; p = 0.69), cadence (179 steps/minute [169 to 186] versus 173 steps/minute [159 to 191], median difference 5.8; p = 0.43), stride length (2.6 meters [2.4 to 2.9] versus 2.8 meters [2.3 to 3.3], median difference 0.2; p = 0.23), or sagittal plane parameters such as peak pelvic tilt (24° [15° to 33°] versus 22° [14° to 28°], median difference 1.6°; p = 0.43) and trunk forward flexion (16.2° [7.3° to 23°) versus 15.4° [4.2° to 21°), median difference 0.8°; p > 0.99) with the numbers available. For the secondary outcomes, runners with a PD-AFO performed worse in Comprehensive High-level Activity Mobility Predictor performance testing than uninjured runners did, with their four scores demonstrating a median (range) single-limb stance of 35 seconds (32 to 58) versus 60 seconds (60 to 60) (median difference 25 seconds; p < 0.001), t-test result of 15 seconds (13 to 20) versus 13 seconds (10 to 14) (median difference 2 seconds; p < 0.001), and Illinois Agility Test result of 22 seconds (20 to 25) versus 18 seconds (16 to 20) (median difference 4; p < 0.001). Edgren side step test result of 20 meters (16 to 26) versus 24 meters (16 to 29) (median difference 4 meters; p = 0.11) and the Four Square Step Test of 5.5 seconds (4.1 to 7.2) versus 4.2 seconds (3.1 to 7.3) (median difference 1.3 seconds; p = 0.39) were not different between the groups with an effect size of 0.83 and 0.75, respectively.

CONCLUSION

The results of our study demonstrate that service members run with discernible differences in high-level mobility and demonstrate inferior self-reported patient functioning while having no differences in speed and biomechanics compared with their noninjured counterparts with the sample size available. This study is an early report on functional gains of highly motivated service members with major lower extremity injuries who use a PD-AFO and formalized therapy program to run.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Congenital Metabolic Bone Disorders as a Cause of Bone Fragility

Bone fragility is a pathological condition caused by altered homeostasis of the mineralized bone mass with deterioration of the microarchitecture of the bone tissue, which results in a reduction of bone strength and an increased risk of fracture, even in the absence of high-impact trauma. The most common cause of bone fragility is primary osteoporosis in the elderly. However, bone fragility can manifest at any age, within the context of a wide spectrum of congenital rare bone metabolic diseases in which the inherited genetic defect alters correct bone modeling and remodeling at different points and aspects of bone synthesis and/or bone resorption, leading to defective bone tissue highly prone to long bone bowing, stress fractures and pseudofractures, and/or fragility fractures. To date, over 100 different Mendelian-inherited metabolic bone disorders have been identified and included in the OMIM database, associated with germinal heterozygote, compound heterozygote, or homozygote mutations, affecting over 80 different genes involved in the regulation of bone and mineral metabolism. This manuscript reviews clinical bone phenotypes, and the associated bone fragility in rare congenital metabolic bone disorders, following a disease taxonomic classification based on deranged bone metabolic activity.

Automated bone mineral density prediction and fracture risk assessment using plain radiographs via deep learning

Dual-energy X-ray absorptiometry (DXA) is underutilized to measure bone mineral density (BMD) and evaluate fracture risk. We present an automated tool to identify fractures, predict BMD, and evaluate fracture risk using plain radiographs. The tool performance is evaluated on 5164 and 18175 patients with pelvis/lumbar spine radiographs and Hologic DXA. The model is well calibrated with minimal bias in the hip (slope = 0.982, calibration-in-the-large = -0.003) and the lumbar spine BMD (slope = 0.978, calibration-in-the-large = 0.003). The area under the precision-recall curve and accuracy are 0.89 and 91.7% for hip osteoporosis, 0.89 and 86.2% for spine osteoporosis, 0.83 and 95.0% for high 10-year major fracture risk, and 0.96 and 90.0% for high hip fracture risk. The tool classifies 5206 (84.8%) patients with 95% positive or negative predictive value for osteoporosis, compared to 3008 DXA conducted at the same study period. This automated tool may help identify high-risk patients for osteoporosis.

Advanced glycation endproducts and bone quality: practical implications for people with type 2 diabetes

PURPOSE OF REVIEW

Individuals with type 2 diabetes (T2D) are at increased risk of fracture, often despite normal bone density. This observation suggests deficits in bone quality in the setting of abnormal glucose homeostasis. The goal of this article is to review recent developments in our understanding of how advanced glycation end products (AGEs) are incorporated into the skeleton with resultant deleterious effects on bone health and structural integrity in patients with T2D.

RECENT FINDINGS

The adverse effects of skeletal AGE accumulation on bone remodeling and the ability of the bone to deform and absorb energy prior to fracture have been demonstrated both at the bench as well as in small human studies; however, questions remain as to how these findings might be better explored in large, population-based investigations.

SUMMARY

Hyperglycemia drives systemic, circulating AGE formation with subsequent accumulation in the bone tissue. In those with T2D, studies suggest that AGEs diminish fracture resistance, though larger clinical studies are needed to better define the direct role of longstanding AGE accumulation on bone strength in humans as well as to motivate potential interventions to reverse or disrupt skeletal AGE deposition with the goal of fracture prevention.

Impact of serum magnesium and bone mineral density on systemic fractures in chronic hemodialysis patients

Introduction

Bone mineral density (BMD) measured with dual-energy X-ray absorptiometry (DXA) can be used to predict fractures, but its clinical utility has not been fully established in chronic kidney disease (CKD) patients. Magnesium is an essential trace element. Although magnesium is associated with the risk of fractures in non-CKD populations, the relationship is unknown in CKD patients.

Methods

BMD and serum magnesium levels were measured in 358 stable outpatients undergoing maintenance hemodialysis therapy. The primary outcome was fragility fracture. Patients were divided into groups according to the median level of magnesium and the normal threshold value of lumbar spine BMD.

Results

During the median follow-up period of 36 months, 36 (10.0%) fractures occurred. The cumulative incidence rates of fractures were 17.6% and 5.2% [adjusted hazard ratio (aHR) 2.31, 95% confidence interval (CI) 1.03–5.17, P = 0.030] in the lower (<2.6 mg/dL) and higher (≥2.6 mg/dL) magnesium (Mg) groups, respectively, and 21.2% and 7.3% (aHR 2.59, 95% CI 1.09–6.16, P = 0.027) in the low- and high-BMD groups, respectively. The lower-Mg and low-BMD group had a 9.21-fold higher risk of fractures (95% CI; 2.35–47.00; P = 0.0010) than the higher-Mg and high-BMD group. Furthermore, adding both magnesium levels and lumbar spine BMD levels to the established risk factors significantly improved the prediction of fractures (C-index: 0.784 to 0.830, p = 0.041).

Discussion/Conclusions

The combination of serum magnesium and lumbar spine BMD can be used for fracture risk stratification and synergistically improves the prediction of fractures in CKD patients.

Direct contribution of skeletal muscle mesenchymal progenitors to bone repair

Bone regenerates by activation of tissue resident stem/progenitor cells, formation of a fibrous callus followed by deposition of cartilage and bone matrices. Here, we show that mesenchymal progenitors residing in skeletal muscle adjacent to bone mediate the initial fibrotic response to bone injury and also participate in cartilage and bone formation. Combined lineage and single-cell RNA sequencing analyses reveal that skeletal muscle mesenchymal progenitors adopt a fibrogenic fate before they engage in chondrogenesis after fracture. In polytrauma, where bone and skeletal muscle are injured, skeletal muscle mesenchymal progenitors exhibit altered fibrogenesis and chondrogenesis. This leads to impaired bone healing, which is due to accumulation of fibrotic tissue originating from skeletal muscle and can be corrected by the anti-fibrotic agent Imatinib. These results elucidate the central role of skeletal muscle in bone regeneration and provide evidence that skeletal muscle can be targeted to prevent persistent callus fibrosis and improve bone healing after musculoskeletal trauma.

Relaxation capacity of cartilage is a critical factor in rate- and integrity-dependent fracture

Articular cartilage heals poorly but experiences mechanically induced damage across a broad range of loading rates and matrix integrity. Because loading rates and matrix integrity affect cartilage mechanical responses due to poroviscoelastic relaxation mechanisms, their effects on cartilage failure are important for assessing and preventing failure. This paper investigated rate- and integrity-dependent crack nucleation in cartilage from pre- to post-relaxation timescales. Rate-dependent crack nucleation and relaxation responses were obtained as a function of matrix integrity through microindentation. Total work for crack nucleation increased with decreased matrix integrity, and with decreased loading rates. Critical energy release rate of intact cartilage was estimated as 2.39 ± 1.39 to 2.48 ± 1.26 kJ m-2 in a pre-relaxation timescale. These findings showed that crack nucleation is delayed when cartilage can accommodate localized loading through poroviscoelastic relaxation mechanisms before fracture at a given loading rate and integrity state.

Long-term Functional Outcomes and Complications in Operative Versus Nonoperative Treatment for Displaced Midshaft Clavicle Fractures in Adolescents: A Retrospective Comparative Study

INTRODUCTION

Traditionally, midshaft clavicular fractures in adolescents are treated nonoperatively. In later years, a trend toward operative treatment can be observed. Documentation of the benefit of surgery in this group is scarce. The purpose of this study is to evaluate the long-term patient reported functional outcomes and complications for patients treated operatively and nonoperatively for displaced midshaft clavicular fractures. Using the same outcomes we also compared the operative methods.

METHODS

One hundred nine adolescents aged 12 to 18 years sustaining displaced midshaft clavicular fractures in the period 2010 to 2016 were identified in our computerized files. Sixty-one were treated nonoperatively, 48 operatively (22 plate and 26 intramedullary nail). Their radiographs and patient journals were examined for fracture classification, wound infection, sensory affection, surgery duration, hardware removal, and nonunion (n=109). Long-term function, pain, and satisfaction were measured with Quick Disability of Arm, Shoulder, and Hand (QuickDASH), Oxford Shoulder Score and Visual Analogue Scale (n=87).

RESULTS

Operative treatment: We could find no difference in functional score outcomes. The main outcome QuickDASH was excellent in both groups (median 0 nail vs. 2.26 plate). Surgery duration was shorter with intramedullary nail. We found 2 infections and 2 sensory affections in the plate group, and 1 infection and 1 sensory affection in the intramedullary nail group. There were 2 refractures in the nail group. Operative versus nonoperative treatment: there were no differences in functional outcomes between the operative and nonoperative groups. For the main outcome QuickDASH both groups scored excellently (median 1.12 operative vs. 0 nonoperative). The nonoperative group was more satisfied with the cosmetic result. There was 1 nonunion in the nonoperative group that later was operated.

CONCLUSIONS

Adolescents aged 12 to 18 years with displaced midshaft clavicular fractures show good long-term functional results after plate fixation, intramedullary nail, and nonoperative treatment. No additional benefit is demonstrated for surgery in our material. Nonoperatively treated patients are more satisfied with the cosmetic results. Little difference is seen between the operative methods in our study. We conclude that surgery should rarely be the choice of treatment for displaced midshaft clavicular fractures in adolescents.

LEVEL OF EVIDENCE

Level III study-retrospective comparative study.

Efficacy of once-weekly teriparatide in patients with glucocorticoid-induced osteoporosis: the TOWER-GO study

INTRODUCTION

Bisphosphonates are the standard treatment for glucocorticoid-induced osteoporosis (GIOP) with teriparatide being another option. While daily teriparatide has been shown to be effective in increasing bone mineral density (BMD), the efficacy of once-weekly teriparatide (56.5 µg) has not yet been evaluated. The TOWER-GO study, a 72-week, multicenter, open-label, randomized controlled trial, was conducted in patients with GIOP to compare the effects of once-weekly teriparatide and once-weekly alendronate 35 mg on BMD.

MATERIALS AND METHODS

Patients (N = 180) with GIOP for whom drug treatment was indicated according to the 2004 guidelines in Japan were randomized to receive once-weekly teriparatide (n = 89) or once-weekly alendronate (n = 91). The primary endpoint was the non-inferiority of percentage change in lumbar spine BMD at final follow-up. The secondary endpoints were the percentage change in BMD from baseline, incidence of bone fractures, and changes in bone turnover markers.

RESULTS

While the non-inferiority of teriparatide to alendronate was not confirmed, BMD increased significantly from baseline with teriparatide and alendronate by 5.09% and 4.04%, respectively (both p < 0.05), at 72 weeks. The incidence of vertebral and non-vertebral fractures was similar in both groups. Bone formation markers increased in the teriparatide group and decreased in the alendronate group.

CONCLUSIONS

The non-inferiority of once-weekly teriparatide versus once-weekly alendronate in BMD change at 72 weeks was not shown, but the increase in bone formation markers over time and the increase of BMD in GIOP patients treated with once-weekly teriparatide were confirmed.

Is Social Deprivation Associated with PROMIS Outcomes After Upper Extremity Fractures in Children?

BACKGROUND

We previously found that social deprivation was associated with worse perceived function and pain among children presenting with upper extremity fractures. We performed the current study to determine whether this differential in outcome scores would resolve after children received orthopaedic treatment for their fractures. This was needed to understand whether acute pain and impaired function were magnified by worse social deprivation or whether social deprivation was associated with differences in health perception even after injury resolution.

QUESTIONS/PURPOSES

Comparing patients from the least socially deprived national quartile and those from the most deprived quartile, we asked: (1) Are there differences in age, gender, race, or fracture location among children with upper extremity fractures? (2) After controlling for relevant confounding variables, is worse social deprivation associated with worse self-reported Patient-Reported Outcomes Measurement Information System (PROMIS) scores before and after the treatment of pediatric upper extremity fractures? (3) Is social deprivation associated with PROMIS score improvements as a result of fracture treatment?

METHODS

In this this retrospective, comparative study, we considered data from 1131 pediatric patients (aged 8 to 17 years) treated nonoperatively at a single tertiary academic medical center for isolated upper extremity fractures between June 2016 and June 2017. We used the Area Deprivation Index to define the patient's social deprivation by national quartiles to analyze those in the most- and least-deprived quartiles. After excluding patients with missing zip codes (n = 181), 18% (172 of 950) lived in the most socially deprived national quartile, while 31% (295 of 950) lived in the least socially deprived quartile. Among these 467 patients in the most- and least-deprived quartiles, 28% (129 of 467) were excluded for lack of follow-up and 9% (41 of 467) were excluded for incomplete PROMIS scores. The remaining 297 patients were analyzed (107 most-deprived quartile, 190 least-deprived quartile) longitudinally in the current study; they included 237 from our initial cross-sectional investigation that only considered reported health at presentation (60 patients added and 292 removed from the 529 patients in the original study, based on updated Area Deprivation Index quartiles). The primary outcomes were the self-completed pediatric PROMIS Upper Extremity Function, Pain Interference, and secondarily PROMIS Peer Relationships computer-adaptive tests. In each PROMIS assessment, higher scores indicated more of that domain (such as, higher function scores indicate better function but a higher pain score indicates more pain), and clinically relevant differences were approximately 3 points. Bivariate analysis compared patient age, gender, race, fracture type, and PROMIS scores between the most- and least-deprived groups. A multivariable linear regression analysis was used to determine factors associated with the final PROMIS scores.

RESULTS

Between the two quartiles, the only demographic and injury characteristic difference was race, with Black children being overrepresented in the most-deprived group (most deprived: white 53% [57 of 107], Black 45% [48 of 107], other 2% [2 of 107]; least deprived: white 92% [174 of 190], Black 4% [7 of 190), other 5% [9 of 190]; p < 0.001). At presentation, accounting for patient gender, race, and fracture location, the most socially deprived quartile remained independently associated with the initial PROMIS Upper Extremity (β 5.8 [95% CI 3.2 to 8.4]; p < 0.001) scores. After accounting for patient gender, race, and number of days in care, we found that the social deprivation quartile remained independently associated with the final PROMIS Upper Extremity (β 4.9 [95% CI 2.3 to 7.6]; p < 0.001) and Pain Interference scores (β -4.4 [95% CI -2.3 to -6.6]; p < 0.001). Social deprivation quartile was not associated with any differential in treatment impact on change in PROMIS Upper Extremity function (8 ± 13 versus 8 ± 12; mean difference 0.4 [95% CI -3.4 to 2.6]; p = 0.79) or Pain Interference scores (8 ± 9 versus 6 ± 12; mean difference 1.1 [95% CI -1.4 to 3.5]; p = 0.39) from presentation to the conclusion of treatment.

CONCLUSION

Delivering upper extremity fracture care produces substantial improvement in pain and function that is consistent regardless of a child's degree of social deprivation. However, as social deprivation is associated with worse perceived health at treatment initiation and conclusion, prospective interventional trials are needed to determine how orthopaedic surgeons can act to reduce the health disparities in children associated with social deprivation. As fractures prompt interaction with our health care system, the orthopaedic community may be well placed to identify children who could benefit from enrollment in proven community health initiatives or to advocate for multidisciplinary care coordinators such as social workers in fracture clinics.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Apigenin promotes osteogenic differentiation of mesenchymal stem cells and accelerates bone fracture healing via activating Wnt/β-catenin signaling

Apigenin (API), a natural plant flavone, is abundantly found in common fruits and vegetables. As a bioactive flavonoid, API exhibits several activities including antiproliferation and anti-inflammation. A recent study showed that API could retard osteoporosis progress, indicating its role in the skeletal system. However, the detailed function and mechanism remain obscure. In the present study, API was found to promote osteogenic differentiation of mesenchymal stem cells (MSCs). And further investigation showed that API could enhance the expression of the critical transcription factor β-catenin and several downstream target genes of Wnt signaling, thus activated Wnt/β-catenin signaling. Using a rat femoral fracture model, API was found to improve new bone formation and accelerate fracture healing in vivo. In conclusion, our data demonstrated that API could promote osteogenesis in vitro and facilitate the fracture healing in vivo via activating Wnt/β-catenin signaling, indicating that API may be a promising therapeutic candidate for bone fracture repair.NEW & NOTEWORTHY1) API promoted osteogenic differentiation of human MSCs in vitro; 2) API facilitated bone formation and accelerated fracture healing in vivo; 3) API stimulated Wnt/β-catenin signaling during osteogenesis of human MSCs.

Longitudinal Evolution of Bone Microarchitecture and Bone Strength in Type 2 Diabetic Postmenopausal Women With and Without History of Fragility Fractures-A 5-Year Follow-Up Study Using High Resolution Peripheral Quantitative Computed Tomography

Introduction

Diabetic bone disease is characterized by an increased fracture risk which may be partly attributed to deficits in cortical bone quality such as higher cortical porosity. However, the temporal evolution of bone microarchitecture, strength, and particularly of cortical porosity in diabetic bone disease is still unknown. Here, we aimed to prospectively characterize the 5-year changes in bone microarchitecture, strength, and cortical porosity in type 2 diabetic (T2D) postmenopausal women with (DMFx) and without history of fragility fractures (DM) and to compare those to nondiabetic fracture free controls (Co) using high resolution peripheral quantitative computed tomography (HR-pQCT).

Methods

Thirty-two women underwent baseline HR-pQCT scanning of the ultradistal tibia and radius and a FU-scan 5 years later. Bone microarchitectural parameters, including cortical porosity, and bone strength estimates via µFEA were calculated for each timepoint and annualized. Linear regression models (adjusted for race and change in BMI) were used to compare the annualized percent changes in microarchitectural parameters between groups.

Results

At baseline at the tibia, DMFx subjects exhibited the highest porosity of the three groups (66.3% greater Ct.Po, 71.9% higher Ct.Po.Volume than DM subjects, p < 0.022). Longitudinally, porosity increased significantly over time in all three groups and at similar annual rates, while DMFx exhibited the greatest annual decreases in bone strength indices (compared to DM 4.7× and 6.7× greater decreases in failure load [F] and stiffness [K], p < 0.025; compared to Co 14.1× and 22.2× greater decreases in F and K, p < 0.020).

Conclusion

Our data suggest that despite different baseline levels in cortical porosity, T2D women with and without fractures experienced long-term porosity increases at a rate similar to non-diabetics. However, the annual loss in bone strength was greatest in T2D women with a history of a fragility fractures. This suggests a potentially non-linear course of cortical porosity development in T2D bone disease: major porosity may develop early in the course of disease, followed by a smaller steady annual increase in porosity which in turn can still have a detrimental effect on bone strength-depending on the amount of early cortical pre-damage.

Romosozumab followed by denosumab in Japanese women with high fracture risk in the FRAME trial

INTRODUCTION

This post-hoc analysis of the FRAME study investigated the long-term efficacy and safety of romosozumab followed by denosumab in postmenopausal Japanese women with osteoporosis at high fracture risk.

MATERIALS AND METHODS

Data from Japanese women with a high fracture risk participating in the international, randomised, double-blind, placebo-controlled, phase 3 FRAME study were analysed. High risk of fracture was defined as ≥ 1 fragility fracture with bone mineral density (BMD) ≤ - 2.5 standard deviations [SD], > 2 prevalent vertebral fractures, prevalent semiquantitative grade 3 vertebral fracture, or lumbar spine BMD < - 3.3 SD. Endpoints included incidence of new vertebral fracture at 12, 24 and 36 months and percentage change from baseline in BMD at the lumbar spine, total hip and femoral neck.

RESULTS

187 Japanese subjects at high risk of fracture were enrolled in FRAME. Incidence of new vertebral fractures was lower with romosozumab/denosumab vs. placebo/denosumab at 12, 24 and 36 months (relative risk reduction at all timepoints: 84%; p = 0.056). BMD increases at 12, 24 and 36 months were greater in subjects receiving romosozumab/denosumab than placebo/denosumab (lumbar spine: 16.3%, 21.5% and 23.2% vs 0.4%, 8.1% and 10.4%; total hip: 4.9%, 7.9% and 8.9% vs 0.4%, 2.8% and 4.1%; femoral neck: 4.8%, 7.6% and 8.1% vs 0.3%, 3.3% and 3.7%, respectively; all p < 0.001 vs placebo/denosumab). Adverse events were generally balanced between groups.

CONCLUSION

Romosozumab/denosumab in Japanese subjects at high risk of fracture resulted in significant BMD gains and numerically lower vertebral fracture rate vs. placebo/denosumab at all timepoints measured.

The effect of preperitoneal pelvic packing for hemodynamically unstable patients with pelvic fractures

PURPOSE

Hemodynamically unstable patients with pelvic fractures still represent a challenge to trauma surgeons and have a very high mortality. This study was designed to explore the effect of the interventions of direct preperitoneal pelvic packing for the hemodynamically unstable pelvic fractures.

METHODS

This retrospective study enrolled 67 cases of severe pelvic fractures with unstable hemodynamics from October 2011 to December 2019. All patients presented in our emergency center and received preperitoneal pelvic packing were included in this study. The indication was persistent systolic blood pressure ≤90 mmHg during initial resuscitation and after transfusion of two units of red blood cells. Patients with hemodynamic stability who need no preperitoneal pelvic packing to control bleeding were excluded. Their demographic characteristics, clinical features, laboratory results, therapeutic interventions, adverse events, and prognostic outcomes were collected from digital information system of electronic medical records. Statistics were described as mean ± standard deviation or medium and analyzed using pair sample t-test or Mann-Whitney U-test.

RESULTS

The patients' average age was 41.6 years, ranging from 10 to 88 years. Among them, 45 cases were male (67.2%) and 22 cases were female (32.8%). Significant difference was found regarding the systolic blood pressure (mmHg) in the emergency department (78.4 ± 13.9) and after preperitoneal pelvic packing in the surgery intensive care unit (100.1 ± 17.6) (p < 0.05). Simultaneously, the arterial base deficit (mmol/L) were significantly lower in the surgery intensive care unit (median -6, interquartile range -8 to -2) than in the emergency department (median -10, interquartile range -14 to -8) (p < 0.05). After preperitoneal pelvic packing, 15 patients (22.4%) underwent pelvic angiography for persistent hypotension or suspected ongoing haemorrhage. The overall mortality rate was 29.5% (20 of 67).

CONCLUSIONS

Preperitoneal pelvic packing, as a useful surgical technique, is less invasive and can be very efficient in early intra-pelvic bleed control.

Relationships Between Level and Change in Sarcopenia and Other Body Composition Components and Adverse Health Outcomes: Findings from the Health, Aging, and Body Composition Study

We investigated how baseline values and rates of decline in components of sarcopenia and other body composition parameters relate to adverse clinical outcomes using the Health, Aging, and Body Composition Study. 2689 participants aged 70-79 years were studied. Appendicular lean mass, whole body fat mass, and total hip BMD were ascertained using DXA; muscle strength by grip dynamometry; and muscle function by gait speed. Baseline values and 2-3 year conditional changes (independent of baseline) in each characteristic were examined as predictors of mortality, hospital admission, low trauma fracture, and recurrent falls in the subsequent 10-14 years using Cox regression (generalized estimating equations used for recurrent falls) with adjustment for sex, ethnicity, age, and potential confounders. Lower levels and greater declines in all parameters (excluding hip BMD level) were associated (p < 0.05) with increased rates of mortality; fully-adjusted hazard ratios per SD lower gait speed and grip strength were 1.27 (95% CI 1.19, 1.36) and 1.14 (1.07, 1.21), respectively. Risk factors of hospital admission included lower levels and greater declines in gait speed and grip strength, and greater declines in hip BMD. Lower levels and greater declines in fat mass and hip BMD were associated with low trauma fracture. Lower gait speed, higher fat mass, and both lower levels and greater declines in grip strength were related to recurrent falls. Lower baseline levels and greater declines in musculoskeletal parameters were related to adverse outcomes. Interventions to maximize peak levels in earlier life and reduce rates of age-related decline may reduce the burden of disease in this age group.

Improved prediction of fracture risk leveraging a genome-wide polygenic risk score

BACKGROUND

Accurately quantifying the risk of osteoporotic fracture is important for directing appropriate clinical interventions. While skeletal measures such as heel quantitative speed of sound (SOS) and dual-energy X-ray absorptiometry bone mineral density are able to predict the risk of osteoporotic fracture, the utility of such measurements is subject to the availability of equipment and human resources. Using data from 341,449 individuals of white British ancestry, we previously developed a genome-wide polygenic risk score (PRS), called gSOS, that captured 25.0% of the total variance in SOS. Here, we test whether gSOS can improve fracture risk prediction.

METHODS

We examined the predictive power of gSOS in five genome-wide genotyped cohorts, including 90,172 individuals of European ancestry and 25,034 individuals of Asian ancestry. We calculated gSOS for each individual and tested for the association between gSOS and incident major osteoporotic fracture and hip fracture. We tested whether adding gSOS to the risk prediction models had added value over models using other commonly used clinical risk factors.

RESULTS

A standard deviation decrease in gSOS was associated with an increased odds of incident major osteoporotic fracture in populations of European ancestry, with odds ratios ranging from 1.35 to 1.46 in four cohorts. It was also associated with a 1.26-fold (95% confidence interval (CI) 1.13-1.41) increased odds of incident major osteoporotic fracture in the Asian population. We demonstrated that gSOS was more predictive of incident major osteoporotic fracture (area under the receiver operating characteristic curve (AUROC) = 0.734; 95% CI 0.727-0.740) and incident hip fracture (AUROC = 0.798; 95% CI 0.791-0.805) than most traditional clinical risk factors, including prior fracture, use of corticosteroids, rheumatoid arthritis, and smoking. We also showed that adding gSOS to the Fracture Risk Assessment Tool (FRAX) could refine the risk prediction with a positive net reclassification index ranging from 0.024 to 0.072.

CONCLUSIONS

We generated and validated a PRS for SOS which was associated with the risk of fracture. This score was more strongly associated with the risk of fracture than many clinical risk factors and provided an improvement in risk prediction. gSOS should be explored as a tool to improve risk stratification to identify individuals at high risk of fracture.

The Progress of Stem Cell Technology for Skeletal Regeneration

Skeletal disorders, such as osteoarthritis and bone fractures, are among the major conditions that can compromise the quality of daily life of elderly individuals. To treat them, regenerative therapies using skeletal cells have been an attractive choice for patients with unmet clinical needs. Currently, there are two major strategies to prepare the cell sources. The first is to use induced pluripotent stem cells (iPSCs) or embryonic stem cells (ESCs), which can recapitulate the skeletal developmental process and differentiate into various skeletal cells. Skeletal tissues are derived from three distinct origins: the neural crest, paraxial mesoderm, and lateral plate mesoderm. Thus, various protocols have been proposed to recapitulate the sequential process of skeletal development. The second strategy is to extract stem cells from skeletal tissues. In addition to mesenchymal stem/stromal cells (MSCs), multiple cell types have been identified as alternative cell sources. These cells have distinct multipotent properties allowing them to differentiate into skeletal cells and various potential applications for skeletal regeneration. In this review, we summarize state-of-the-art research in stem cell differentiation based on the understanding of embryogenic skeletal development and stem cells existing in skeletal tissues. We then discuss the potential applications of these cell types for regenerative medicine.

Biological basis of child health 6: development of the skeletal system and orthopaedic conditions

This article is the sixth in a series on the biological basis of child health. It provides an overview of the development of the skeletal system before and after birth, and outlines the potential congenital anomalies that may occur. The article explains the structure and function of the bones before describing the role of the joints, tendons and ligaments. It also outlines the presentation and management of some of the common orthopaedic conditions seen in infants and children, including fractures, osteogenesis imperfecta, scoliosis, juvenile idiopathic arthritis, developmental dysplasia of the hip and achondroplasia.

Advances in Bone tissue engineering: A fundamental review

Bone is a dynamic tissue that can always rebuild itself by modeling and remodeling to maintain functionality. This tissue is responsible for several vital functions in the body, such as providing structural support for soft tissues and the body, being the central region of hematopoiesis in human adults, and contributing to mineral homeostasis. Besides, it has an innate ability of auto-regeneration when damaged. All of these processes involve several molecular cues related to biochemical and mechanical stimulus. However, when the lesion is complicated or too big, it is necessary to intervene surgically, which may not effectively solve the problem. Bone tissue engineering seeks to provide resources to resolve these clinical issues and has been advancing in recent years, presenting promising devices for bone tissue repair. The understanding of some important biofactors and bone stem-cells influence might be crucial for an effective regenerative medicine, since bone is one of the most transplanted tissues. So, the purpose of this article is to provide an overview of the bone tissue, including the role of stem cells and some of the bioactive molecules associated with these processes. Finally, we will suggest future directions for bone tissue engineering area that might be helpful in order to produce biomimetic bone substitutes that become a real alternative to translational medicine.

Overview of Skeletal Repair (Fracture Healing and Its Assessment)

The study of postnatal skeletal repair is of immense clinical interest. Optimal repair of skeletal tissue is necessary in all varieties of elective and reparative orthopedic surgical treatments. However, the repair of fractures is unique in this context in that fractures are one of the most common traumas that humans experience and are the end-point manifestation of osteoporosis, the most common chronic disease of aging. In the first part of this introduction the basic biology of fracture healing is presented. The second part discusses the primary methodological approaches that are used to examine repair of skeletal hard tissue and specific considerations for choosing among and implementing these approaches.

Minimal Pain Decrease Between 2 and 4 Weeks After Nonoperative Management of a Displaced Midshaft Clavicle Fracture Is Associated with a High Risk of Symptomatic Nonunion

BACKGROUND

The main long-term benefit of operative treatment of displaced midshaft clavicular fractures is the reduction in nonunion risk, and as this risk is generally low, the ideal approach would be to operate only patients at high risk of nonunion. However, most current surgical decision models use baseline variables to estimate the nonunion risk, and the value of these models remains unclear. Pain in the early weeks after fracture could be potentially be an indirect measurement of fracture healing, and so it is a potential proxy variable that could lead to simpler prediction models.

QUESTIONS/PURPOSES

(1) Is pain a possible proxy variable for the development of symptomatic nonunion after nonoperative treatment of midshaft clavicular fractures? (2) How reliable is the model we created that uses pain as a proxy variable for symptomatic nonunion of nonoperatively treated clavicle fractures?

METHODS

In this secondary retrospective analysis of an earlier randomized trial, we studied prospectively collected data from 64 nonoperatively treated patients aged 18 years to 60 years. In the original randomized trial, we compared operative and nonoperative treatment of displaced midshaft clavicular fractures. In all, 150 patients were included in the study, of whom 71 received nonoperative treatment. Patients were predominantly males (75%, 48 of 64) with a mean age of 38 ± SD 12 years; most fractures were comminuted and shortened more than 1 cm. All 71 patients who were nonoperatively treated were potentially eligible for this secondary analysis; of those, 11% (8 of 71) were lost to follow-up, leaving 63 patients from the nonoperative treatment arm and one patient from the operative treatment arm (who declined surgical treatment after randomization but was followed in this group according to the intention-to-treat principle) for analysis here. Nonunion was defined as lack of callus formation, persistent fracture lines and/or sclerotic edges of the bones at the fracture site on plain radiographs at 6 months follow-up. Nonunions were regarded as symptomatic if pain, tenderness, and local crepitation were present at the fracture site. Seventeen percent (11 of 64) of patients had symptomatic nonunions. After investigating differences in early pain scores between the union and nonunion groups, we defined the VASratio as the VAS pain score at 4 weeks divided by the VAS pain score at 2 weeks. Week 2 VAS pain score was chosen as baseline after visual inspection of a linear mixed model that showed increased divergence in pain scores between union and nonunion group at 2 weeks after fracture. Week 4 was chosen as the cutoff because we wanted a reasonable time frame for the detection of pain reduction and did not want to delay surgical treatment more than necessary. Odds ratios for various risk factors were calculated using logistic regression analyses. We used a receiver operating characteristic curve analysis to identify cutoff values for the VASratio.

RESULTS

An increase in absolute pain score at 4 weeks after fracture (odds ratio 1.8 per 1 point increase [95% confidence interval 1.1 to 3.4]) was associated with an increased risk of nonunion 6 months after fracture. Likewise, we found that an increasing VASratio (OR 1.02 per 0.01 point increase [95% CI 1.002 to 1.06]) was also associated with nonunion. Receiver operating curve analysis found that the best cutoff value of VASratio was about 0.6. Patients with a VASratio above 0.6 had a relative risk of developing nonunion of 18 (95% CI 2 to 130) compared with patients with a VASratio below 0.6. Sparse-data bias could be present, as is evident from this wide confidence interval, though even at the low end of the confidence interval, the relative risk was 2, which may still improve surgical decision-making.

CONCLUSION

A pain score that exhibits no or minimal change from 2 to 4 weeks after nonoperative treatment of a displaced midshaft fracture of the clavicle is associated with a high risk that symptomatic nonunion will develop. Patients with no or minimal change in pain in the early weeks may be candidates for surgery to reduce the risk of symptomatic nonunion. As this was a retrospective study, with a risk of sparse-data bias, the predictive value of the VASratio needs to be further investigated in large prospective studies before clinical use.

LEVEL OF EVIDENCE

Level III, diagnostic study.

Understanding Bone Disease in Patients with Diabetic Kidney Disease: a Narrative Review

PURPOSE OF REVIEW

Both diabetes and kidney disease associate with the development of bone disease and an increased risk of fragility fractures. The etiologies of bone disease in patients with diabetic kidney disease (DKD) are multiple and complex. This review explores the association between DKD and bone disease and discusses how the presence of both diabetes and kidney disease may impair bone quality and increase fracture risk. Diagnostic tools as well as future research areas are also discussed.

RECENT FINDINGS

Patients with DKD have an increased risk of fragility fracture, most pronounced in patients with type 1 diabetes, and in DKD a high prevalence of adynamic bone disease is found. Recent studies have demonstrated disturbances in the interplay between bone regulating factors in DKD, such as relative hypoparathyroidism and alterations of bone-derived hormones including fibroblast growth factor-23 (FGF-23), sclerostin and klotho, which lead to bone disease. This review examines the current knowledge on bone disease in patients with DKD, clinical considerations for patient care, as well as subjects for future research.

Zoledronic acid sequential therapy could avoid disadvantages due to the discontinuation of less than 3-year denosumab treatment

INTRODUCTION

Rapid descent in bone mineral density (BMD) and ascent in bone turnover marker (BTM) occur within the short period following denosumab (Dmab) discontinuation. In addition, the incidence of vertebral fracture also rises within the short period. The purpose of this study is to investigate the effects of sequential therapy using zoledronic acid (ZOL) on any adverse events after Dmab discontinuation.

MATERIALS AND METHODS

This study was a multicenter retrospective observational study, and the subjects were osteoporosis patients who visited our institutions between 2013 and 2018. We performed sequential therapy using ZOL for 30 patients who had difficulty continuing Dmab, due to physical or social reasons, and investigated the fracture incidence and BMD/BTM changes at 4 time points (at the start of Dmab, the start of ZOL, 6 months after ZOL and 12 months after ZOL).

RESULTS

No new vertebral/nonvertebral fractures were observed at each time point after switching from Dmab to ZOL in any of the 30 patients. The BMD/BTM changes were evaluated in 18 of the 30 cases, since all data of lumbar/femoral neck BMDs and TRACP-5b at 4 time points was only available in 18 cases. BMDs significantly increased at each time point compared with that at the start of Dmab. Serum TRACP-5b significantly decreased at each time point compared with that at the start of Dmab.

CONCLUSION

It was suggested that sequential therapy using ZOL could suppress the decrease of BMD, and increase of BTM, if the period of Dmab administration was less than 3 years.

Assessment, Quantification, and Management of Fracture Pain: from Animals to the Clinic

PURPOSE OF REVIEW

Fractures are painful and disabling injuries that can occur due to trauma, especially when compounded with pathologic conditions, such as osteoporosis in older adults. It is well documented that acute pain management plays an integral role in the treatment of orthopedic patients. There is no current therapy available to completely control post-fracture pain that does not interfere with bone healing or have major adverse effects. In this review, we focus on recent advances in the understanding of pain behaviors post-fracture.

RECENT FINDINGS

We review animal models of bone fracture and the assays that have been developed to assess and quantify spontaneous and evoked pain behaviors, including the two most commonly used assays: dynamic weight bearing and von Frey testing to assess withdrawal from a cutaneous (hindpaw) stimulus. Additionally, we discuss the assessment and quantification of fracture pain in the clinical setting, including the use of numeric pain rating scales, satisfaction with pain relief, and other biopsychosocial factor measurements. We review how pain behaviors in animal models and clinical cases can change with the use of current pain management therapies. We conclude by discussing the use of pain behavioral analyses in assessing potential therapeutic treatment options for addressing acute and chronic fracture pain without compromising fracture healing. There currently is a lack of effective treatment options for fracture pain that reliably relieve pain without potentially interfering with bone healing. Continued development and verification of reliable measurements of fracture pain in both pre-clinical and clinical settings is an essential aspect of continued research into novel analgesic treatments for fracture pain.

Advanced Modeling Methods-Applications to Bone Fracture Mechanics

PURPOSE OF REVIEW

The goal of this review is to summarize recent advances in modeling of bone fracture using fracture mechanics-based approaches at multiple length scales spanning nano- to macroscale.

RECENT FINDINGS

Despite the additional information that fracture mechanics-based models provide over strength-based ones, the application of this approach to assessing bone fracture is still somewhat limited. Macroscale fracture models of bone have demonstrated the potential of this approach in uncovering the contributions of geometry, material property variation, as well as loading mode and rate on whole bone fracture response. Cortical and cancellous microscale models of bone have advanced the understanding of individual contributions of microstructure, microarchitecture, local material properties, and material distribution on microscale fracture resistance of bone. Nano/submicroscale models have provided additional insight into the effect of specific changes in mineral, collagen, and non-collagenous proteins as well as their interaction on energy dissipation and fracture resistance at small length scales. Advanced modeling approaches based on fracture mechanics provide unique information about the underlying multiscale fracture mechanisms in bone and how these mechanisms are influenced by the structural and material constituents of bone at different length scales. Fracture mechanics-based modeling provides a powerful approach that complements experimental evaluations and advances the understanding of critical determinants of fracture risk.

Sedentary behavior: barriers and facilitators among older adults after hip fracture surgery. A qualitative study

OBJECTIVES

Understand the experience of older adults after hip fracture surgery considering barriers and facilitators related to sedentary behavior.

METHODS

A qualitative study using a semi-structured interview with three men and eight women aged 60 years or older after hip fracture surgery.

RESULTS

Five barriers emerged: physical complaints, lack of accessibility, fear of falling, demotivation and negative social representation of old age, and two facilitators: overcoming dependency and having a caregiver.

CONCLUSION

Our results highlight that physical complaints commonly addressed by physical therapists on their interventions are not the only impediments to reduce sedentary behavior. Important individual and social barriers should not be neglected when physical therapists conduct interventions to reduce sedentary behavior to maximize functional recovery in older adults after hip fracture surgery. Future clinical trials are required to investigate the effectiveness of more comprehensive interventions to reduce sedentary behavior in this population.

Circumstances of human conflicts with bears and patterns of bear maul injuries in Bhutan: Review of records 2015-2019

Bhutan is one of the biological hotspots in the world where humans and natural flora and fauna co-exist in close proximity. Bhutan is home to two species of bears: Sloth Bear and Himalayan Black Bear. Human conflicts with bears are reported from all over the country. This study describes the profile of the victims and the pattern of injury resulting from bear attacks and circumstances around human conflicts with bears in Bhutan between 2015 and 2019. This was a cross-sectional study with a review of hospital records of patients treated at the National Referral Hospital from 01 January 2015 till 31 December 2019. Data were extracted into a structured pro forma and entered into EpiData Entry 3.1 and analysed in STATA 13.1. There were thirty-four patients who were provided care for bear maul injuries, with an average annual caseload of 6.8 cases per year. The injury prevalence was 100% and the kill prevalence was 0%. Bear attacks were reported from fourteen of twenty districts of the country. The mean age of the victims was 49 (±13) years. Males (26, 76%) and farmers (26, 76%) were the common victims; the risk of bear attacks was 0.16 per 100,000 farmers per year. The commonest region of the body attacked was the face (29, 85%) and victims were provided emergency and rehabilitative care within and outside the country. Thirty-three victims (97%) were provided post-exposure prophylaxis for rabies. All victims received antibiotics despite the lack of national guidelines on the choice of antibiotics post-bear maul. Human-bear conflict is multi-faceted, puts a considerable strain on bear-conservation efforts and requires multi-disciplinary efforts in the prevention of human injury and socioeconomic losses.

Biomarkers of Bone Turnover Identify Subsets of Chronic Kidney Disease Patients at Higher Risk for Fracture

BACKGROUND

We sought to identify biomarkers that indicate low turnover on bone histomorphometry in chronic kidney disease (CKD) patients, and subsequently determined whether this panel identified differential risk for fractures in community-dwelling older adults.

METHODS

Among CKD patients who underwent iliac crest bone biopsies and histomorphometry, we evaluated candidate biomarkers to differentiate low turnover from other bone disease. We applied this biomarker panel to 641 participants in the Health Aging and Body Composition Study (Health ABC) study with estimated glomerular filtration rate (eGFR) less than 60 mL/min/1.73 m2 who were followed for fracture. Cox proportional hazards models evaluated the association of bone mineral density (BMD) with fracture risk and determined whether biomarker-defined low bone turnover modified fracture risk at any level of BMD.

RESULTS

In 39 CKD patients age 64 ± 13 years, 85% female, with mean eGFR 37 ± 14 mL/min/1.73 m2 who underwent bone biopsy, lower fibroblast growth factor (FGF)-23, higher ɑ-Klotho, and lower parathyroid hormone (PTH) indicated low bone turnover in accordance with bone histomorphometry parameters (individual area under the curve = 0.62, 0.73, and 0.55 respectively; sensitivity = 22%, specificity = 100%). In Health ABC, 641 participants with CKD were age 75 ± 3 years , 49% female, with mean eGFR 48 ± 10 mL/min/1.73 m2. For every SD lower hip BMD at baseline, there was an 8-fold higher fracture risk in individuals with biomarker-defined low turnover (hazard ratio 8.10 [95% CI, 3.40-19.30]) vs a 2-fold higher risk in the remaining individuals (hazard ratio 2.28 [95% CI, 1.69-3.08]) (Pinteraction = .082).

CONCLUSIONS

In CKD patients who underwent bone biopsy, lower FGF-23, higher ɑ-Klotho, and lower PTH together had high specificity for identifying low bone turnover. When applied to older individuals with CKD, BMD was more strongly associated with fracture risk in those with biomarker-defined low turnover.

Rotary-jet spun polycaprolactone/nano-hydroxyapatite scaffolds modified by simulated body fluid influenced the flexural mode of the neoformed bone

Polycaprolactone (PCL) is a biocompatible, biodegradable synthetic polymer which in combination with nanohydroxyapatite (nHAp) can give rise to a low cost, nontoxic bioactive product with excellent mechanical properties and slow degradation. Here we produced, characterized and evaluated in vivo the bone formation of PCL/nHAp scaffolds produced by the rotary jet spinning technique. The scaffolds produced were firstly soaked into simulated body fluid for 21 days to also obtain nHAp onto PCL/nHAp scaffolds. Afterwards, the scaffolds were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy and Raman spectroscopy. For in vivo experiments, 20 male Wistar rats were used and randomly divided in 4 experimental groups (n = 5). A critical defect of 3 mm in diameter was made in the tibia of the animals, which were filled with G1 control (clot); G2-PCL scaffold; G3-PCL/nHAp (5%) scaffold; G4-PCL/nHAp (20%) scaffold. All animals were euthanized 60 days after surgery, and the bone repair in the right tibiae were evaluated by radiographic analysis, histological analysis and histomorphometric analysis. While in the left tibias, the areas of bone repair were submitted to the flexural strength test. Radiographic and histomorphometric analyses no showed statistical difference in new bone formation between the groups, but in the three-point flexural tests, the PCL/nHAp (20%) scaffold positively influenced the flexural mode of the neoformed bone. These findings indicate that PCL/nHAp (20%) scaffold improve biomechanical properties of neoformed bone and could be used for bone medicine regenerative.

Risk of Nonunion with Nonselective NSAIDs, COX-2 Inhibitors, and Opioids

BACKGROUND

Cyclooxygenase-2 (COX-2) has been found to be important for fracture-healing in animal models, raising concerns about use of nonsteroidal anti-inflammatory drugs (NSAIDs) and selective COX-2 inhibitors after fractures. We evaluated associations of NSAIDs, COX-2 inhibitors, and opioids with nonunion after long-bone fracture.

METHODS

Using private health insurance claims data from Optum's de-identified Clinformatics Data Mart database from January 1, 2000, to September 30, 2015, we identified adults with a single long-bone fracture or commonly paired long-bone fractures who had 1 year of available follow-up data. Using multivariable logistic regression models, we examined associations between NSAID, COX-2-inhibitor, or opioid prescription fills after the fracture and the risk of nonunion within 1 year, defined as a nonunion diagnosis with a procedure to treat the nonunion.

RESULTS

A nonunion diagnosis with a procedure to treat the nonunion was identified after 2,996 (0.9%) of the 339,864 fracture episodes, with rates varying by fracture site. The risk of that outcome was greater in patients who had filled COX-2-inhibitor prescriptions (adjusted odds ratio = 1.84 [95% confidence interval = 1.38 to 2.46]) or opioid prescriptions (1.69 [1.53 to 1.86]), but not in patients who had filled nonselective-NSAID prescriptions (1.07 [0.93 to 1.23]) after the fracture. Results were similar when the outcome definition was changed to just a nonunion diagnosis.

CONCLUSIONS

COX-2 inhibitors, but not nonselective NSAIDs, were associated with a greater risk of nonunion after fracture. Opioids were also associated with nonunion risk, although patients filling prescriptions for opioids may have had more severe fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Patient Satisfaction Is Improved With Exposure to Trauma Recovery Services

INTRODUCTION

The purpose of this study is to assess the impact of Trauma Recovery Services (TRS), a program facilitating engagement and recovery on satisfaction after orthopaedic trauma.

METHODS

Two hundred ninety-four patients with surgically managed extremity fractures were prospectively surveyed. Satisfaction was assessed after 12 months using a 13-question telephone survey, rated on a Likert scale from 1 to 5 (with five being excellent). TRS resource utilization during and after hospitalization was recorded. Eighty-eight patients (30%) used TRS.

RESULTS

Overall satisfaction was high with a mean score of 4.32. Although no differences were observed between the control group and patients with TRS utilization in age, sex, race, insurance, smoking history, or employment status, TRS patients sustained more high-energy mechanisms (81% versus 56%) and had more associated psychiatric illness (33% versus 17%), both P < 0.01. Multivariable regression indicated general exposure to TRS to be an independent predictor of higher overall care ratings (B = 1.31; P = 0.03).

DISCUSSION

Utilization of TRS was the greatest predictor of better overall care ratings. This study builds on existing evidence demonstrating the positive impact of Trauma Survivor Network programming. We conclude that a hospital-wide program supporting patient education and engagement can effectively increase patient satisfaction after traumatic injury.

LEVEL OF EVIDENCE

Prognostic Level II.

Hypophosphatasia in Adults: Clinical Spectrum and Its Association With Genetics and Metabolic Substrates

BACKGROUND

Hypophosphatasia (HPP) is a rare metabolic bone disorder caused by mutations in the alkaline phosphatase (ALPL) gene, and characterized by low circulating alkaline phosphatase (ALP) levels and bone, muscle, dental and systemic manifestations. In this case series we investigate the clinical spectrum, genetic and biochemical profile of adult HPP patients from the University Hospitals Leuven, Belgium.

METHODOLOGY

Adults with HPP were identified through medical record review. Inclusion criteria were: (1) age ≥ 16 yr; (2) consecutively low ALP levels not explained by secondary causes; (3) one or more of the following supporting criteria: biochemical evidence of elevated enzyme substrates; subtrochanteric fractures, metatarsal fractures or other typical clinical features; family history of HPP; a known or likely pathogenic ALPL mutation.

RESULTS

Nineteen patients met our inclusion criteria (n = 2 infantile, n = 6 childhood, n = 10 adult-onset HPP and one asymptomatic carrier). Fractures and dental abnormalities were the most reported symptoms. Fatigue was reported in n = 7/19 patients (37%), three of which had previously been misdiagnosed as having chronic fatigue syndrome and/or fibromyalgia. Empirical pyridoxine therapy in four patients (without seizures) did not provide symptomatic relief. N = 7/19 patients (37%) were inappropriately treated or planned to be treated with antiresorptive treatment. Two patients developed atypical femoral fractures following exposure to bisphosphonates and/or denosumab. Patients detected by screening were less severely affected, while patients with homozygous or compound heterozygous mutations had the most severe symptoms, significantly lower circulating ALP levels (p = 0.013) and significantly higher pyridoxal-5'-phosphate (p = 0.0018) and urinary phosphoethanolamine (p = 0.0001) concentrations.

CONCLUSIONS

Screening may detect mainly less severely affected individuals, which may nevertheless avoid misdiagnosis and inappropriate antiresorptive drug exposure. Patients with biallelic mutations had more severe symptoms, significantly lower ALP and higher substrate levels. Whether the latter finding has implications for the classification and treatment of HPP should be investigated further in larger cohorts.

Bazedoxifene effects on osteoprotegerin, insulin-like growth factor, tumor necrosis factor and bone mineral density

To observe the clinical effect of estrogenic drugs (Bazedoxifene) on bone targeting in the treatment of osteoporosis and explore its mechanism.

METHODS

112 patients with postmenopausal osteoporosis who received Bazedoxifene drugs in our hospital from January to December 2018 were collected as a study group, and 56 patients treated with calcium alone were collected as a control group. the risk of adverse events such as bone mineral density, osteoprotegerin (OPG), insulin-like growth factor (IGF), tumor necrosis factor (TNF-α), and fracture after treatment were analyzed before and after treatment.

RESULTS

There was no significant difference in the mean lumbar positive position (L2-4) and right femoral neck bone density and OPG, IGF, TNF-α level between the two groups before treatment (P&gt;0.05). The total effective rate of clinical treatment in the study group was 88.39%, the control group was 23.21%, the difference between the two groups was statistically significant (P˂0.05). After treatment, the mean lumbar positive position (L2-4) and the right femoral neck bone density and OPG, IGF in the study group were higher than those in the control group, lower than those in the control group (P&lt;0.05). the occurrence of adverse events such as fracture, spinal deformation and fatigue in the study group after 12 months of treatment was significantly lower than that in the control group (P&lt;0.05), but there was no significant difference in the occurrence of hot flashes and venous thromboembolism between the two groups (P&gt;0.05).

CONCLUSION

Bazedoxifene is an effective drug for the treatment of postmenopausal osteoporosis. It can not only prevent the rapid loss of bone mass, effectively relieve the symptoms of menopause, but also improve bone density and reduce the risk of fracture.

Controversies in Fracture Healing: Early Versus Late Dynamization

Dynamization of fracture fixation constructs provides early rigidity for primary bone healing and late motion for secondary healing. A review of laboratory, animal, and clinical studies investigating the impact, and optimal timing, of dynamization is limited by lack of standardization across studies. However, in animal models, dynamization improves histologic and biomechanical properties compared with statically rigid or flexible controls. In animals, dynamization at 3 to 4 weeks showed improved histologic results. In clinical studies, it showed faster, stronger, and stiffer bone healing. Clinical success dynamizing external fixators and intramedullary nails suggests a role for late dynamization in other fixation types, such as bridge plating. [Orthopedics. 2020;43(3):e125-e133.].

Lunate fracture healing after partial capitate shortening in Kienböck disease

BACKGROUND

It is unclear whether lunate fracture types in Kienböck disease correlate with the degree of fracture healing. This study aimed to review the clinical results of stage 3 Kienböck disease treated using partial capitate shortening (PCS) and to evaluate the healing rates of lunate fractures based on the fracture types.

METHODS

Twenty-three patients were clinically and radiographically followed up for >2 years after PCS. The preoperative location and postoperative healing of the lunate fracture were evaluated using plain radiography, computed tomography, and/or magnetic resonance imaging. Results were evaluated using the Kienböck scoring system by Nakamura.

RESULTS

PCS was clinically effective, demonstrating excellent and good results in 11 and 11 patients, respectively. Pain evaluated using the visual analog scale, wrist extension, flexion motion, and grip strength significantly improved postoperatively (p < 0.01). Fractures were preoperatively detected in all 23 cases. Fracture locations were preoperatively classified into five subtypes based on radiographs: volar pole in five patients, dorsal pole in three, coronal in five, transverse in nine, and ulnar in one. The overall union rate of the lunate fracture was 48%, whereas none of the coronal fractures healed.

CONCLUSIONS

PCS was effective in treating stage 3 Kienböck disease. Coronal lunate fractures had a poor healing rate relative to those of the other fracture types.

STUDY DESIGN

Clinical, retrospective study.

[A boy with acute pain in his right buttock]

A 14-year-old boy presented to the emergency department with pain in his right buttock after a breakdance move. He got injured while simultaneously hyperflexing his hip and extending his knee. Upon physical examination he had tenderness over his right ischial tuberosity and an inability to perform combined hip extension and knee flexion. Radiography and CT-imaging showed an avulsion fracture of the ischial tuberosity.

Bone Health Following Bariatric Surgery: An Update

Obesity rates are increasing rapidly, and bariatric surgery is currently the most effective tool for weight loss. Recently, bariatric surgery induced bone loss has gained attention. Such detrimental effect on bone is multifactorial and causes may include nutrient deficiencies, gut and gonadal hormonal changes, mechanical unloading, loss of lean mass, increased bone marrow fat, and increased risk of fall. This review describes the available evidence on bone loss and fracture risk following bariatric surgery and summarizes the guidelines on the topic. Increased bone resorption starts early postsurgery, and bone markers peak at 1-2 yr. Across studies, the drop in areal bone mineral density is inconsistent at the lumbar spine, while a 2%-5% drop at 6 mo and a 6%-10.5% at 9-12 mo are observed at the total hip. Conversely, studies using quantitative CT showed a 6%-7% decrease in volumetric bone mineral density at the lumbar spine at 6-12 mo postsurgery. These studies also report significant bone loss at the radius and tibia, in addition to alteration in bone microarchitecture. Fracture risk increases 2 yr after surgery, more so following malabsorptive procedures. Fractures were reported at axial, weight bearing sites and at appendicular sites. The available evidence is very heterogeneous, and mostly derived from studies on Roux-en-y gastric bypass in premenopausal women. Data on restrictive procedures is scarce. Our findings suggest that the early postoperative phase represents the "golden window" to intervene and promote bone health. More research is needed to determine the effect of different bariatric procedures on bone, to identify optimal interventions to prevent bone loss and to characterize high risk individuals who should be targeted.

The Association between Fast Increase in Bone Turnover During the Menopause Transition and Subsequent Fracture

CONTEXT

Bone turnover increases rapidly during the menopause transition (MT) and plateaus above premenopausal levels in early postmenopause. It is uncertain whether higher bone turnover is associated with fracture in midlife women with near-normal bone mineral density (BMD).

OBJECTIVE

Examine whether faster increases in bone turnover during the MT (2 years before to 2 years after the final menstrual period [FMP]), and greater bone turnover during early postmenopause (≥2 years after the FMP) are risk factors for subsequent fracture, accounting for BMD.

DESIGN AND SETTING

The Study of Women's Health Across the Nation, a longitudinal cohort study of the MT.

PARTICIPANTS

A total of 484 women (initially pre- or early perimenopausal, who transitioned to postmenopause) with bone turnover (urine collagen type I N-telopeptide), BMD, and fracture data.

MAIN OUTCOME MEASURE

Incident fracture after the MT.

RESULTS

Adjusting for age, race/ethnicity, fracture before the MT, cigarette use, body mass index, and study site in Cox proportional hazards regression, each SD increment in the rate of increase in bone turnover during the MT was associated with 24% greater hazard of incident fracture in postmenopause (P = .008). Accounting for the same covariates, each SD increment in bone turnover during early postmenopause was associated with a 27% greater hazard of fracture (P = .01). Associations remained significant after controlling for MT rate of change and early postmenopausal level of BMD.

CONCLUSION

Faster increases in bone turnover during the MT and greater bone turnover in early postmenopause forecast future fractures.

Effect of acupuncture therapy on fracture healing in rats with femur fractures

OBJECTIVE

To investigate the effect of acupuncture therapy on fracture healing in rats with femur fractures.

METHODS

A total of 10 groups were formed; control group, groups sacrificed on 7th, 14th, and 21st days of fracture formation, groups to which acupuncture was applied for 7, 14, and 21 d, groups to which fracture and acupuncture were applied for 7, 14, and 21 d. A transverse fracture line was formed in femurs of rats by using a Gigli saw. The Kirschner wire was driven retrograde down from the fracture line to proximal part of the bone and then, the fracture was fixed towards distal part. Acupuncture was applied to the rats for 7, 14, and 21 d as 4 sessions per week after formation of the fracture.

RESULTS

Malondialdehyde (MDA), reduced glutathione (GSH) levels, catalase (CAT), glutathione-S-transferase (GST), superoxide dismutase (SOD), and glucose-6-phosphate dehydrogenase (G6PD) activities were measured. Despite the increased MDA levels, G6PD and SOD activities reduced during the fracture healing. There was a statistically significant increase in MDA, GSH levels, and G6PD activity in fracture groups compared to control group, but CAT, GST, and SOD activities decreased. The use of acupuncture enhanced callus development and bone mineralization during bone healing.

CONCLUSION

The acupuncture therapy can affect suppression of the effects of free oxygen radicals and regulation of the antioxidant enzyme activity in fracture healing. Thus, it is suggested that acupuncture treatment would be beneficial for fracture healing in order to eliminate the negative effects induced by oxygen free radicals.

Effects of photobiomodulation in the treatment of fractures: a systematic review and meta-analysis of randomized clinical trials

Several therapeutic strategies have been proposed to optimize the conventional treatment of fractures. Photobiomodulation (PBM) appears to help reduce pain and control inflammation, and it also accelerates bone repair. This systematic review aimed to evaluate the effectiveness and safety of PBM with low-level laser therapy (LLLT) in the bone fracture healing process. We included randomized controlled trials (RCTs) comparing the effects of PBM with those of any other intervention in adults with lower or upper limb bone fractures. The primary outcomes investigated were pain reduction, radiographic healing, and adverse events. The searches were conducted in October 2018. Two RCTs were included that compared PBM to the placebo. A meta-analysis showed significant difference in favor of PBM for pain reduction (MD 1.19, 95% CI [0.61 to 1.77], 106 participants, two RCTs), but this difference was not clinically significant. One RCT (50 participants) showed a clinical and statistical improvement in physical function (MD - 14.60, 95% CI [- 21.39 to - 7.81]) and no difference in radiographic healing, regarding absence of fracture line (RR 1.00, 95% CI [0.93 to 1.08]) and visible bone callus (RR 0.33, 95% CI [0.01 to 7.81]). The certainty of evidence was classified as low to very low. Based on the evidence of low to very low certainty, PBM seems to be associated with the improvement of pain and function. Therefore, new RCTs are required that meet the recommendations of CONSORT to prove the effectiveness and safety of this intervention and support its recommendation in clinical practice.

Vibration acceleration promotes endochondral formation during fracture healing through cellular chondrogenic differentiation

Vibration acceleration through whole body vibration has been reported to promote fracture healing. However, the mechanism responsible for this effect remains unclear. Purpose of this study was to determine whether vibration acceleration directly affects cells around the fracture site and promotes endochondral ossification. Four-week-old female Wistar Hannover rats were divided into two groups (vibration [V group] and control [C group]). The eighth ribs on both sides were cut vertically using scissors. From postoperative day 3 to 11, vibration acceleration using Power Plate^® (30 Hz, low amplitude [30-Low], 10 min/day) was applied in the V group. Mature calluses appeared earlier in the V group than in the C group by histological analysis. The GAG content in the fracture callus on day 6 was significantly higher in the V group than in the C group. The mRNA expressions of SOX-9, aggrecan, and Col-II in the fracture callus on day 6 and Col-X on day 9 were significantly higher in the V group than in the C group. For in vitro analysis, four different conditions of vibration acceleration (30 or 50 Hz with low or high amplitude [30-Low, 30-High, 50-Low, and 50-High], 10 min/day) were applied to a prechondrogenic cell (ATDC5) and an undifferentiated cell (C3H10T1/2). There was no significant difference in cell proliferation between the control and any of the four vibration conditions for both cell lines. For both cell lines, alcian blue staining was greater under 30-Low and 50-Low conditions than under control as well as 30-High and 50-High conditions on days 7 and 14. Vibration acceleration under 30-L condition upregulated chondrogenic gene expressions of SOX-9, aggrecan, Col-II, and Col-X. Low-amplitude vibration acceleration can promote endochondral ossification in the fracture healing in vivo and chondrogenic differentiation in vitro.

Novel algorithm generating strategy to identify high fracture risk population using a hybrid intervention threshold

INTRODUCTION

The aim of this study was to develop an algorithm to identify high-risk populations of fragility fractures in Taiwan.

MATERIALS AND METHODS

A total of 16,539 postmenopausal women and men (age ≥ 50 years) were identified from the Taiwan Osteoporosis Survey database. Using the Taiwan FRAX^® tool, the 10-year probability of major osteoporotic fracture (MOF) and hip fracture (HF) and the individual intervention threshold (IIT) of each participant were calculated. Subjects with either a probability above the IIT or those with MOF ≥ 20% or HF ≥ 9% were included as group A. Subjects with a bone mineral density (BMD) T-score at femoral neck based on healthy subjects of ≤ - 2.5 were included in group B. We tested several cutoff points for MOF and HF so that the number of patients in group A and group B were similar. A novel country-specific hybrid intervention threshold along with an algorithm was generated to identify high fracture risk individuals.

RESULTS

3173 (19.2%) and 3129 (18.9%) participants were categorized to groups A and B, respectively. Participants in group B had a significantly lower BMD (p < 0.001), but clinical characteristics, especially the 10-year probability of MOF (p < 0.001) or HF (p < 0.001), were significantly worse in group A. We found the algorithm generated from the hybrid intervention threshold is practical.

CONCLUSION

The strategy of generating an algorithm for fracture prevention by novel hybrid intervention threshold is more efficient as it identifies patients with a higher risk of fragility fracture and could be a template for other country-specific policies.

Dnmt3b ablation impairs fracture repair through upregulation of Notch pathway

We previously established that DNA methyltransferase 3b (Dnmt3b) is the sole Dnmt responsive to fracture repair and that Dnmt3b expression is induced in progenitor cells during fracture repair. In the current study, we confirmed that Dnmt3b ablation in mesenchymal progenitor cells (MPCs) resulted in impaired endochondral ossification, delayed fracture repair, and reduced mechanical strength of the newly formed bone in Prx1-Cre;Dnmt3bf/f (Dnmt3bPrx1) mice. Mechanistically, deletion of Dnmt3b in MPCs led to reduced chondrogenic and osteogenic differentiation in vitro. We further identified Rbpjκ as a downstream target of Dnmt3b in MPCs. In fact, we located 2 Dnmt3b binding sites in the murine proximal Rbpjκ promoter and gene body and confirmed Dnmt3b interaction with the 2 binding sites by ChIP assays. Luciferase assays showed functional utilization of the Dnmt3b binding sites in murine C3H10T1/2 cells. Importantly, we showed that the MPC differentiation defect observed in Dnmt3b deficiency cells was due to the upregulation of Rbpjκ, evident by restored MPC differentiation upon Rbpjκ inhibition. Consistent with in vitro findings, Rbpjκ blockage via dual antiplatelet therapy reversed the differentiation defect and accelerated fracture repair in Dnmt3bPrx1 mice. Collectively, our data suggest that Dnmt3b suppresses Notch signaling during MPC differentiation and is necessary for normal fracture repair.

Physical activity and skeletal health in adults

The purpose of this Review is to examine the associations between physical activity and skeletal health, with an emphasis on observational studies with fracture outcomes and randomised controlled trials (RCTs) of physical activity interventions in adults older than 40 years. In general, increased physical activity-primarily leisure time activity or moderate or vigorous physical activity-is associated with a 1-40% lower risk of hip and all fractures. The primary limitation of these studies relates to health status; healthy people are more likely to exercise and less likely to fracture. Although there is no sufficiently powered RCT of exercise with a fracture outcome, there is evidence that some types of exercise prevent falls and bone loss, and meta-analyses support the anti-fracture effectiveness of exercise. RCTs and meta-analyses suggest that programmes combining impact exercise with moderate or high-intensity progressive resistance exercise might maintain or improve bone mass and prevent fractures, and that functional strength and balance training prevents falls.

Patient outcomes association with patient factors and care provided: trauma registry derived cohort study

OBJECTIVE

To determine the association of delay in treatment with injury-specific patient outcomes.

METHODS

This was a single-center, longitudinal cohort study on orthopaedic trauma registry. Data on patients enrolled between June 2015 and June 2018 were analyzed. Data was collected from admitted consenting patients' medical records. Definitive surgical care provided after 24 hours was considered as 'delayed surgical treatment'. Outcomes of patients were serially assessed on follow-up visits up to 12 months using injury-specific scoring system.

RESULTS

A total of 789 patients, were enrolled with 856 upper or lower extremity injuries altogether; in 67 cases both extremities were involved. Surgery was done in 90% while 10% were managed conservatively. A delay in the surgical procedure was experienced by 185(23%) patients. Mortality was 3.28% (6 of 185) in the delayed treatment group and 1% (6 of 603 patients) in the early treatment group (p=0.046). In proximal femur there was a nonsignificant trend towards better outcomes in the early treatment group at 3 and 12 months (p=0.06), while in Tibial shaft fractures, there was a non-significant trend towards better outcomes in the delayed treatment group at 3 and 6-months (p=0.09). There was no association between treatment delay for distal radius and proximal humerus fractures and their outcomes.

CONCLUSIONS

Our trauma registry model provides outcomes data enabling identification of patient subsets who did not achieve good outcome, and suggests possible role of delay in surgical treatment beyond 24 hours in the outcomes..

Lithium for Fracture Treatment (LiFT): a double-blind randomised control trial protocol

INTRODUCTION

Fracture healing can fail in up to 10% of cases despite appropriate treatment. While lithium has been the standard treatment for bipolar disorder, it may also have a significant impact to increase bone healing in patients with long bone fractures. To translate this knowledge into clinical practice, a randomised clinical trial (RCT) is proposed.

METHODS AND ANALYSIS

A multicentre double blind, placebo-controlled RCT is proposed to evaluate the efficacy of lithium to increase the rate and predictability of long bone fracture healing in healthy adults compared to lactose placebo treatment. 160 healthy individuals from 18 to 55 years of age presenting with shaft fractures of the femur, tibia/fibula, humerus or clavicle will be eligible. Fractures will be randomised to placebo (lactose) or treatment (300 mg lithium carbonate) group within 2 weeks of the injury. The primary outcome measure will be radiographic union defined as visible callus bridging on three of the four cortices at the fracture site using a validated radiographic union score. Secondary outcome measures will include functional assessment and pain scoring.

ETHICS AND DISSEMINATION

Participant confidentiality will be maintained with publication of results. Research Ethics Board Approval: Sunnybrook Research Institute (REB # 356-2016). Health Canada Approval (HC6-24-C201560). Results of the main trial and secondary endpoints will be submitted for publication in a peer-reviewed journal and presented at conferences.

TRIAL REGISTRATION NUMBER

NCT02999022.

PTH1-34 improves bone healing by promoting angiogenesis and facilitating MSCs migration and differentiation in a stabilized fracture mouse model

Objective

PTH_1-34 (parathyroid hormone 1–34) is the only clinical drug to promote osteogenesis. MSCs (mesenchymal stem cells) have multidirectional differentiation potential and are closely related to fracture healing. This study was to explore the effects of PTH_1-34 on proliferation and differentiation of endothelial cells and MSCs in vitro, and on angiogenesis, and MSCs migration during fracture healing in vivo.

Methods

Mice with stabilized fracture were assigned to 4 groups: CON, PTH (PTH_1-34 40 μg/kg/day), MSC (transplanted with 10⁵ MSCs), PTH+MSCs. Mice were sacrificed 14 days after fracture, and callus tissues were harvested for microCT scan and immunohistochemistry analysis. The effects of PTH_1-34 on angiogenesis, and MSCs differentiation and migration were assessed by wound healing, tube formation and immunofluorescence staining.

Results

Treatment with either PTH_1-34, or MSCs promoted bone healing and vascular formation in fracture callus. The callus bone mass, bone volume, and bone mineral density were all greater in PTH and/or MSC groups than they were in CON (p<0.05). PTH_1-34 increased small vessels formation (diameter ≤50μm), whereas MSCs increased the large ones (diameter >50μm). Expression of CD31 within calluses and trabecular bones were significantly higher in PTH_1-34 treated group than that of not (p<0.05). Expression of CD31, VEGFR, VEGFR2, and vWF was upregulated, and wound healing and tube formation were increased in MSCs treated with PTH_1-34 compared to that of control.

Conclusions

PTH_1-34 improved the proliferation and differentiation of endothelial cells and MSCs, enhancing migration of MSCs to bone callus to promote angiogenesis and osteogenesis, and facilitating fracture healing.

Fracture-induced changes in biomarkers CTX, PINP, OC, and BAP-a systematic review

To assess the time from fracture until bone turnover markers (BTM), which are biochemical markers reflecting in vivo bone formation and resorptive activity, have returned to a stable level since BTM have been shown to be at least as good as bone mineral density in monitoring the effect of anti-resorptive treatment in osteoporosis. This study searched for articles in PUBMED, CINAHL, Medline, EM-BASE, and Cochrane, and identified 3486 unique articles. These articles were screened based on predefined inclusion and exclusion criteria. Seven articles addressing time to normalization of either CTX, PINP, osteocalcin, or bone-specific alkaline phosphatase after a recent fracture were identified and these were analyzed qualitatively. CTX appeared to return to baseline within 6 months. PINP appeared to return to baseline within 6 months and interestingly dip below baseline after a year. Osteocalcin was elevated throughout the first year after a fracture, with most changes in the first 6 months. Bone-specific alkaline phosphatase (BAP) was increased for up to a year, however with a discrepancy between used assays. Seven studies were identified, showing CTX and PINP to return to baseline within 6 months. OC was elevated for 12 months. BAP was increased for up to a year. However, none of these studies had fasting patients and a long follow-up period with regular measurements. The studies could indicate that the BTM CTX and PINP have returned to baseline within 6 months; however, further studies are needed assessing pre-analytical factors while having a long follow-up. Bone turnover markers appear as good as or better than bone mineral density in monitoring the effect of anti-resorptive medication in osteoporosis. This study tries to identify the time from fracture until BTM are back at baseline. Most studies did not however take pre-analytical variation into consideration. Further research is therefore needed.