The role of vitamin D in human fracture healing: a systematic review of the literature

Increase in calcidiol level is associated with improved sternal bone healing after cardiac surgery with sternotomy-REINFORCE-D trial results

INTRODUCTION

Heart surgery is associated with a sternotomy in most patients. Low serum calcidiol level below 80 nmol/l carries the risk of bone loss as a risk factor in sternotomy healing.

OBJECTIVES

The primary objective was to compare postoperative complications of sternotomy healing in two groups of patients treated with cholecalciferol or placebo. Secondary objectives were focused on the degree of sternal healing, length of hospitalization, number of days spent in ICU and mechanical ventilation, and number of repeated hospitalizations for sternotomy complications.

METHODOLOGY

Monocentric, randomized, double-blind, placebo-controlled, prospective study was conducted from September 2016 to December 2020 at Na Homolce Hospital. Of the 216 originally recruited and randomized subjects, 141 completed the study. Seventy-two subjects were enrolled in the cholecalciferol arm, and sixty-nine subjects in the placebo arm. The detailed methodology has been published previously. The results are presented as a comparison between two groups: calcidiol above 80 nmol/l (saturated subjects) and the calcidiol lower or equal to 80 nmol/l (unsaturated subjects).

RESULTS

Statistics include 141 subjects. After a 6-month follow-up, CT imaging and calcidiol levels were performed.

PRIMARY OBJECTIVE

postoperative complications in sternotomy were not among the population under or above 80 nmol/l statistical difference (p = 0.907).

SECONDARY OBJECTIVES

monitored parameters did not differ between individual arms. But the key was the state of saturation with calcidiol (> 80 nmol/l), which was associated with a significantly lower risk of complete non-healed sternotomy (p = 0.008).

CONCLUSION

Optimal calcidiol level (> 80 nmol/l) indicates a positive trend towards greater sternal healing. Cholecalciferol oral administration can be considered as a safe method how to achieve the required calcidiol concentration.

TRIAL REGISTRATION

EU Clinical Trials Register, EUDRA CT No: 2016-002606-39.

Vitamin D Supplementation May Prevent or Treat Deficiency After Total Knee Arthroplasty: A Retrospective Cohort Analysis

BACKGROUND

Vitamin D deficiency is associated with poorer functional outcomes and increased complication rates after total knee arthroplasty (TKA). Yet, there is no longer term study evaluating vitamin D levels and supplementation after TKA. Our study aimed to compare quantitative vitamin D levels and supplementation regimens after TKA stratified by patient sex and race.

METHODS

A retrospective cohort study of primary TKA patients at a single hospital from 2015 to 2022 was conducted. We analyzed vitamin D preoperatively and postoperatively up to 2 years. Vitamin D deficiency was defined as <30 ng/mL. A subgroup analysis was conducted in patients with vitamin D <21 ng/mL. Supplementation categories included none, low (<1,001 IU), medium (1,001 to 5,000 IU), and high (>5,000 IU).

RESULTS

A total of 400 (66.0% female) patients who underwent 430 primary TKA procedures were included, and 65.3% received supplementation. Patients who were vitamin D sufficient preoperatively demonstrated higher vitamin D levels and ability to maintain sufficiency postoperatively using low-dose supplementation compared with no supplementation ( P = 0.004). Those who were vitamin D deficient preoperatively demonstrated higher vitamin D levels postoperatively using medium to high doses ( P = 0.02). For patients who became deficient postoperatively, supplementation was associated with achieving repletion at an average of 10.2 months ( P < 0.001). Black patients demonstrated 2.8 times higher odds of having a vitamin D level less than 30 ng/mL ( P = 0.03).

CONCLUSION

Our study demonstrated that low-dose vitamin D supplementation (<1,001 IU) was beneficial for vitamin D-sufficient TKA patients to achieve higher levels and maintain vitamin D sufficiency. Vitamin D-deficient TKA patients benefitted from medium-to-high dose supplementation (1,001 to 5,000+), but only 33.7% achieved vitamin D repletion. This work highlights the need to continue vitamin D surveillance postoperatively and the need to continue vitamin D repletion.

The effect of vitamin D on the speed and quality of pediatric fracture healing

Purpose

To evaluate the effect of vitamin D on the speed and quality of pediatric fracture healing.

Methods

A 4-year prospective study of healthy children with shaft fractures of the forearm bones (treated with minimally invasive osteosynthesis) or femur (treated by traction or by minimally invasive osteosynthesis). All children had their vitamin D levels examined four times-at the time of the injury, 1, 3, and 5 months after the injury. Also, all children underwent radiograph follow-ups (same time as blood tests) to evaluate fracture healing. Children were, in the beginning, blindly divided into two similarly sized groups-one group was orally administered cholecalciferol throughout the follow-up, the second group was not, and we compared those groups.

Results

Altogether, 63 children were included in the study-36 supplemented and 27 non-supplemented. In supplemented children, the vitamin D levels increased statistically significantly during the follow-up period, in contrast to the non-supplemented group. The fracture healing on radiographs was also statistically significantly faster and better in the supplemented group. When we divided children according to fracture type, we observed statistically significantly better fracture healing in children with forearm fractures in the supplemented group for the whole study period. In children with femoral fractures, the healing in the supplemented group was statistically significantly better after 3 months; however, after 1 and 5 months, the difference was not statistically significant.

Conclusions

Based on our results, we recommend vitamin D testing and administration for children treated for forearm and femoral fractures.

Level of evidence

Level I.

Vitamin D status in healing of distal humeral fractures: Clinical observations

BACKGROUND

Fracture healing is a complex biological process that begins soon after a fracture has occurred. Whereas the role of vitamin D status on the maintenance of bone health is well established, the clinical effects of vitamin D deficiency in the healing of distal humeral fractures are less well explored. This study examines the role of vitamin D serum levels in distal humeral fractures (C2, C3) managed with open reduction and double plate fixation, by comparing its concentration in patients with or without radiographic signs of fracture healing and in control subjects. Our hypothesis is that 6 months from treatment vitamin D levels will be different between the groups of patients.

MATERIAL AND METHODS

We measured the vitamin D serum level in a cohort of consecutive adult patients aged 30 to 60 years. They included a group of subjects without fractures who were admitted to our clinic in the 6 months preceding the study (controls) and two groups of patients with humeral fractures who at 6-month follow-up showed or failed to show radiological signs of fracture healing.

RESULTS

The mean vitamin D concentration was 23.03 μg/L (±5.8) in the group with radiographic signs of fracture healing, 9.30 μg/L (±2.60) in the group with radiographic signs of delayed union and 26.15 μg/L (±11.76 μg/L) in the control group. Significantly different (p < 0.05) concentrations were measured between the fracture groups, between the group with radiographic signs of fracture healing and the control group and between the group with radiographic signs of delayed union and the control group.

DISCUSSION

Vitamin D is primarily involved in the stages of hard callus formation and remodelling. It also has several functions that affect the early stages of fracture healing. Vitamin D influences the cellular process of bone healing, although the underlying mechanism is still partly unclear. It would be useful to determine the vitamin D status of fracture patients at admission and to start supplementation, with periodic checks, to foster the consolidation phase. Although vitamin D is clearly not the only factor influencing the consolidation of a surgically treated distal humerus fracture, its concentration can easily be determined and managed. Our data suggest that vitamin D levels should be determined at admission and that fracture patients with low concentrations should be started on vitamin D supplementation.

Fat-soluble vitamins as biomarkers of nutritional status and their relation with complications in polytrauma patients

BACKGROUND AND AIMS

This exploratory observational prospective study aimed to evaluate fat-soluble vitamin plasma levels during hospital admission and its relation with the development of malnutrition and complications in polytrauma patients, considering the protocolized multivitamin supplementation during intensive care unit (ICU) admission.

METHODS

In 49 well-nourished polytrauma (injury severity score ≥ 16) patients admitted to the ICU of two level-1 trauma centers, vitamin A, D, and E levels were assessed weekly during hospital stay. All patients received multivitamin supplementation during ICU stay. Linear mixed-effect models were used to assess a trend in vitamin levels over time during hospital stay. Mixed-effects logistic regression analysis was performed to relate vitamin concentrations with malnutrition, defined as a subjective global assessment score ≤5, and complications.

RESULTS

Vitamin A levels increased 0.17 µmol/L per week (95% confidence interval 0.12-0.22, p < 0.001), vitamin D levels increased 1.49 nmol/L per week (95% confidence interval 0.64-2.33, p < 0.01), vitamin E levels increased 1.17 µmol/L per week (95% confidence interval 0.61-1.73, p < 0.001) during hospital stay (29 ± 17 days). Vitamin levels were not related to malnutrition or complications during hospital stay.

CONCLUSION

Vitamin A, D, and E levels increased due to supplementation during hospital admission. Plasma levels of vitamins A, D, and E do not seem to be useful as biomarkers for the nutritional status of polytrauma patients during hospital stay. No correlation with complications could be demonstrated.

Preoperative hypovitaminosis D and complications in plastic surgery: a pilot study

INTRODUCTION

Vitamin D plays a crucial role in various biological processes, including the well-known regulation of the immune system and calcium metabolism. While its involvement in the surgical outcomes of various medical specialties is recognized, there is a lack of consistent data regarding plastic surgery. This study aimed to assess preoperative serum levels of 25-hydroxyvitamin D and its relationship with complications in patients undergoing reconstructive and aesthetic plastic surgeries.

METHODS

prospective and observational cohort study, conducted from October 2021 to August 2023 at the Hospital das Clínicas, Universidade Federal de Pernambuco, involving 83 patients.

RESULTS

vitamin D levels were deemed deficient in 7 (8,4%) patients, insufficient in 36 (43,4%), and sufficient in 40 (48,2%). No direct association was demonstrated between deficient or insufficient serum levels of 25-hydroxyvitamin D and the incidence of complications in plastic surgery, even when considering comorbidities.

CONCLUSION

preoperative hypovitaminosis D was not associated with complications in plastic surgery.

Postoperative Vitamin D Surveillance and Supplementation in Revision Total Knee Arthroplasty Patients: A Retrospective Cohort Analysis

This study was a retrospective cohort analysis of 20 patients who underwent 23 revision total knee arthroplasty procedures in a single geographic region of the United States from January 2015 to February 2023. We analyzed their 25-OH vitamin D levels preoperatively and postoperatively at 1 month, 3 months, 6 months, 1 year, and 2 years. We categorized their supplementation regimens by dose: none, low dose (1000 IU and below), medium dose (1001-5000 IU), and high dose (>5000 IU). We found that there was a high incidence of vitamin D deficiency in this patient population.

Considerations Regarding Vitamin D in Foot and Ankle Treatment and Surgery

Although the impact that vitamin D has on bone healing is uncertain in foot and ankle (F&A) surgery, there is support for vitamin D supplementation (2000 IU/day) with calcium (1 g/day) to promote bone healing. Although orthopedic F&A surgeons are frequently the first provider to detect the harbingers of osteoporosis by the occurrence of fragility fractures, this should trigger referral to the appropriate specialist for assessment and treatment. There is circumstantial evidence suggesting a role of hypovitaminosis D in bone marrow edema syndrome and possibly osteochondritis dissecans. There should be a low threshold for assessing vitamin D levels in such patients.

Increased Early Postoperative Complication Rate after Osteoporotic Hip Fracture in Patients with Low 25 (OH) Vitamin D Levels

This study investigated the association of preoperative 25-hydroxy (25 (OH)) vitamin D levels with postoperative complications in osteoporotic hip fracture patients following surgery. We hypothesized that patients with low concentrations of 25 (OH) vitamin D might have an increased risk of developing adverse outcomes. Between January 2019 and December 2020, a retrospective observational study was conducted, including low-energy fragility fractures at the proximal femur. Regarding preoperative 25 (OH) vitamin D levels, patients were divided into two groups (<30 ng/mL and ≥30 ng/mL). Early and late postoperative complications were assessed and graded according to the Clavien-Dindo classification system. Logistic regression analysis was performed to demonstrate the association between preoperative 25 (OH) vitamin D levels (<30 ng/mL, ≥30 ng/mL) and postoperative complications after adjusting for age and sex. Of 314 patients, 222 patients (70.7%) had a 25 (OH) vitamin D level of <30 ng/mL. The mean serum 25 (OH) vitamin D level was 22.6 ng/mL (SD 13.2). In 116 patients (36.9%), postoperative complications were observed, with the most occurring in the short term (95 patients, 30.2%). Late postoperative complications were present in 21 patients (6.7%), most graded as Clavien I (57.1%). Logistic regression analysis identified a low vitamin D level (<30 ng/mL) as an independent risk factor for early postoperative complications (OR 2.06, 95% CI 1.14-3.73, p = 0.016), while no significant correlation was found in late complications (OR 1.08, 95% CI 0.40-2.95, p = 0.879). In conclusion, preoperative 25 (OH) vitamin D serum level might be an independent predictor for early postoperative complications. However, future studies are warranted to determine risk factors for long-term complications and establish appropriate intervention strategies.

Vitamin D: A Bridge between Kidney and Heart

Chronic kidney disease (CKD) and cardiovascular disease (CVD) are highly prevalent conditions, each significantly contributing to the global burden of morbidity and mortality. CVD and CKD share a great number of common risk factors, such as hypertension, diabetes, obesity, and smoking, among others. Their relationship extends beyond these factors, encompassing intricate interplay between the two systems. Within this complex network of pathophysiological processes, vitamin D has emerged as a potential linchpin, exerting influence over diverse physiological pathways implicated in both CKD and CVD. In recent years, scientific exploration has unveiled a close connection between these two prevalent conditions and vitamin D, a crucial hormone traditionally recognized for its role in bone health. This article aims to provide an extensive review of vitamin D's multifaceted and expanding actions concerning its involvement in CKD and CVD.

Vitamin D3 Release from MgO Doped 3D Printed TCP Scaffolds for Bone Regeneration

Regenerating bone tissue in critical-sized craniofacial bone defects remains challenging and requires the implementation of innovative bone implants with early stage osteogenesis and blood vessel formation. Vitamin D3 is incorporated into MgO-doped 3D-printed scaffolds for defect-specific and patient-specific implants in low load-bearing areas. This novel bone implant also promotes early stage osteogenesis and blood vessel development. Our results show that vitamin D3-loaded MgO-doped 3D-printed scaffolds enhance osteoblast cell proliferation 1.3-fold after being cultured for 7 days. Coculture studies on osteoblasts derived from human mesenchymal stem cells (hMSCs) and osteoclasts derived from monocytes show the upregulation of genes related to osteoblastogenesis and the downregulation of RANK-L, which is essential for osteoclastogenesis. Release of vitamin D3 also inhibits osteoclast differentiation by 1.9-fold after a 21-day culture. After 6 weeks, vitamin D3 release from MgO-doped 3D-printed scaffolds enhances the new bone formation, mineralization, and angiogenic potential. The multifunctional 3D-printed scaffolds can improve early stage osteogenesis and blood vessel formation in craniofacial bone defects.

Does Serum Vitamin D Influence the Prognosis of Critically Ill Patients with Trauma? A Prospective, Observational Study in a Trauma Center

Background

Vitamin D concentrations are associated with sepsis, pneumonia, and mortality in critically ill patients. However, the role of vitamin D in critically injured patients with trauma remains unknown. This study investigated the effects of vitamin D concentrations on outcomes in critically injured patients with trauma.

Methods

A prospective observational study was conducted by randomly selecting 100 patients among those who visited our trauma center. The serum vitamin D concentration was measured upon arrival at the hospital, and the length of stay in a trauma intensive care unit after admission, duration of mechanical ventilation, number of days spent in the hospital, development of complications, and death were investigated. The association between the surveyed variables and vitamin D concentrations was investigated using regression analysis.

Results

Of the 100 patients, 69 were men and 31 were women with an average age of 51.7 years. The average intensive care unit stay length was 18.4 days, and 6 patients (5.9%) died. Univariate regression analysis showed that the factors affecting patient mortality were age (p = 0.02), volume of blood transfused within 24 hours of arrival (p = 0.009), systolic blood pressure measured upon hospital arrival (p = 0.01), and serum lactate concentration measured upon hospital arrival (p = 0.03). Multivariate regression analysis showed that the factors affecting patient mortality were age (p = 0.01), volume of blood transfusion (p = 0.04), and systolic blood pressure measured upon hospital arrival (p = 0.01).

Conclusions

There were no statistically significant effects of serum vitamin D concentrations in critically ill patients with trauma on death during hospitalization.

Vitamin D status-associated postoperative complications in patients with hip dysplasia after periacetabular osteotomy: A case-control study

OBJECTIVES

This study aimed to clarify the relationship between vitamin D status and complications after periacetabular osteotomy.

METHODS

A total of 46 hips of 39 patients (3 men and 36 women; mean age at surgery, 41.0 years; mean postoperative follow-up duration, 63 months) were reviewed to obtain the following information: patients' serum 25-hydroxyvitamin D [25(OH)D] status, prevalence of postoperative delayed union of osteotomy sites in the greater trochanter (DUGT) and ischiopubic stress fractures (IPSFs), and risk factors.

RESULTS

The mean serum 25(OH)D level was 11.9 ng/ml. DUGT and IPSF were found in four (10.3%) and three (7.7%) patients, respectively. Serum 25(OH)D levels ≤ 11 ng/ml were significantly associated with DUGT in female patients (p = .02). Serum 25(OH)D levels ≤ 9 ng/ml and smoking were significantly associated with IPSF (p = 0.01 and 0.02, respectively). Overall, 21.7% of patients with serum 25(OH)D levels ≤ 11 ng/ml developed at least one complication; no complications occurred when serum 25(OH)D levels were >11 ng/ml.

CONCLUSION

Severe vitamin D deficiency was highly prevalent in relatively young patients. Vitamin D deficiency and smoking were independent risk factors for postoperative complications. Proactive supplementation is advisable to reduce postoperative complications, especially in patients with serum 25(OH)D levels ≤ 11 ng/ml.

Pharmacological agents for bone fracture healing: talking points from recent clinical trials

INTRODUCTION

Pharmacological strategies might influence bone healing in terms of time to union or quality of mature bone. This expert opinion discussed the current level I evidence on the experimental pharmacological agents used to favor bone fracture healing.

AREAS COVERED

This study was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses: the 2020 PRISMA statement. In April 2023, the following databases were accessed: PubMed, Web of Science, Google Scholar, Embase. All the randomized clinical trials investigating pharmacological agents for bone fracture healing were accessed. No time constraint was set for the search. The search was restricted to RCTs. No additional filters were used in the database search. Data from 19 RCTs (4067 patients) were collected. 78% (3160 of 4067) were women. The mean length of the follow-up was 9.3 months (range, 1-26 months). The mean age of the patients was 64.4 years (range, 8-84 years).

EXPERT OPINION

Calcitonin could favor bone fracture healing. Bisphosphonates (alendronate, zoledronate, clodronate), monoclonal antibodies (denosumab, romosozumab), statins, vitamin D and calcium supplementation, strontium ranelate, and ibuprofen did not influence bony healing. Concerning the effect of parathormone, current level I evidence is controversial, and additional studies are required.

LEVEL OF EVIDENCE

Level I, systematic review of RCTs.

Impact of Intravenous Iron Substitution on Serum Phosphate Levels and Bone Turnover Markers-An Open-Label Pilot Study

The association between intravenous iron substitution therapy and hypophosphatemia was previously reported in patients with iron deficiency anemia. However, the extent of hypophosphatemia is thought to depend on the type of iron supplementation. We hypothesized that the intravenous application of ferric carboxymaltose and iron sucrose leads to a different longitudinal adaptation in serum phosphate levels. In this open-label pilot study, a total of 20 patients with inflammatory bowel diseases or iron deficiency anemia were randomly assigned to one of two study groups (group 1: ferric carboxymaltose, n = 10; group 2: iron sucrose, n = 10). Serum values were controlled before iron substitution therapy, as well as 2, 4, and 12 weeks after the last drug administration. The primary objective of the study was the longitudinal evaluation of serum phosphate levels after iron substitution therapy with ferric carboxymaltose and iron sucrose. The secondary objective was the longitudinal investigation of calcium, 25-hydroxyvitamin D (25(OH)D), intact parathyroid hormone, procollagen type 1 amino-terminal propeptide (P1NP), beta-CrossLaps (CTX), hemoglobin (Hb), iron, ferritin, and transferrin saturation levels. Two weeks after drug administration, phosphate levels were significantly lower (p < 0.001) in group 1 and ferritin levels were significantly higher (p < 0.001) in group 1. Phosphate levels (0.8-1.45 mmol/L) were below the therapeutic threshold and ferritin levels (10-200 ng/mL for women and 30-300 ng/mL for men) were above the therapeutic threshold in group 1. P1NP (15-59 µg/L) and CTX (<0.57 ng/mL) levels were above the therapeutic threshold in group 2. Four weeks after drug administration, significant differences were still observed between both study groups for phosphate (p = 0.043) and ferritin (p = 0.0009). All serum values except for Hb were within the therapeutic thresholds. Twelve weeks after drug administration, no differences were observed in all serum values between both study groups. Hb values were within the therapeutic threshold in both study groups. Serum 25(OH)D levels did not differ between both study groups throughout the whole study period and remained within the therapeutic threshold.

Relationship Between Hypovitaminosis D and Fractures Among Adolescents With Overweight or Obesity

Adolescents with overweight/obesity are at risk for vitamin D insufficiency and deficiency. Both overweight/obesity and vitamin D insufficiency/deficiency may predispose to fractures. We enrolled 103 participants (53.3% females, 15.9 ± 2.2 years) in a retrospective case-control study to determine whether an association exists between fractures and a low 25-hydroxyvitamin D (25[OH]D) among adolescents whose body mass index (BMI) ≥ 85 percentile. Cases (n = 28) sustaining a low/medium impact fracture were matched to controls (n = 75) without a fracture history. A conditional-logistic regression analysis addressing the common vitamin D insufficiency/deficiency cutoffs was used. Overweight, obesity, and significant obesity rates were 10.7%, 53.4%, and 35.9%, respectively. Mean (±SD) 25(OH)D was 16.5 ± 6.4 ng/mL. In all, 25(OH)D insufficiency rates (level <20 ng/mL) were 70.5%. Matched cases and controls had similar 25(OH)D insufficiency/deficiency rates (P > .05). Controlling for race and seasonality showed no association between fractures and 25(OH)D insufficiency/deficiency (P > .05). These data suggest that fractures are not associated with low 25(OH)D levels among adolescents whose BMI ≥ 85th percentile.

Stem Cells and Their Derivatives: An Implication for the Regeneration of Nonunion Fractures

Despite advances in biomedical research, fracture nonunion rates have remained stable throughout the years. Long-bone fractures have a high likelihood of nonunion, but the specific biological pathways involved in this severe consequence are unknown. Fractures often heal in an organized sequence, including the production of a hematoma and an early stage of inflammation, the development of a soft callus and hard callus, and eventually the stage of bone remodeling. Deficient healing can result in a persistent bone defect with instability, discomfort, and loss of function. In the treatment of nonunions, mesenchymal stem cells (MSCs) prove to be a promising and safe alternative to the standard therapeutic strategies. Moreover, novel scaffolds are being created in order to use a synergistic biomimetic technique to rapidly generate bone tissue. MSCs respond to acellular biomimetic matrices by regenerating bone. Extracellular vesicles (EVs) derived from MSCs have recently gained interest in the field of musculoskeletal regeneration. Although many of these techniques and technologies are still in the preclinical stage and have not yet been approved for use in humans, novel approaches to accelerate bone healing via MSCs and/or MSC derivatives have the potential to reduce the physical, economic, and social burdens associated with nonhealing fractures and bone defects. In this review, we focus on providing an up-to-date summary of recent scientific studies dealing with the treatment of nonunion fractures in clinical and preclinical settings employing MSC-based therapeutic techniques.

The Effect of Vitamin D Supplementation for Bone Healing in Fracture Patients: A Systematic Review

While most literature on vitamin D supplementation in fracture patients focuses on fracture prevention, the effect of vitamin D on bone healing is a much less studied concept. The primary aim of this systematic review was to assess whether vitamin D supplementation in fracture patients improves clinical or radiological union complications. The secondary aims were to assess supplementation effect on patient functional outcome scores and bone mineral density (BMD). A systematic search of all relevant articles was performed using the following databases: MEDLINE, Embase, Google Scholar, and Web of Science. The population selection included human patients with a fresh fracture treated conservatively or operatively. The intervention included any form of vitamin D supplementation, compared to no supplementation or a placebo. The primary outcomes assessed were clinical or radiological union rates or complications arising from the nonunion. The secondary outcomes assessed were functional outcome scores, BMD scores after treatment, and pain scores. A total of fourteen studies, assessing a total of 2734 patients, were included. Eight studies assessed the effect of vitamin D on clinical or radiological union. Five studies reported no significant difference in complication rates when supplementing fracture patients. Alternatively, three studies reported a positive effect with supplementation between the groups. One of these studies found a difference only for early orthopaedic complications (<30 days), but no differences in late complications. The other two studies found significant differences in clinical union; however, no changes were observed in radiological union. Six studies investigated functional outcome scores after supplementation. Four of these studies found no significant differences between most functional outcome scores. Only three studies reported BMD outcomes, one of which found limited effect on total hip BMD. The overall findings are that vitamin D alone does little to influence fracture healing and subsequent union rates or functional outcome. The studies suggestive of a positive effect were generally of a lower quality. Further high quality RCTs are needed to justify routine supplementation at the time of fracture.

Optimal concentration of mesenchymal stem cells for fracture healing in a rat model with long bone fracture

BACKGROUND

There is still no consensus on which concentration of mesenchymal stem cells (MSCs) to use for promoting fracture healing in a rat model of long bone fracture.

AIM

To assess the optimal concentration of MSCs for promoting fracture healing in a rat model.

METHODS

Wistar rats were divided into four groups according to MSC concentrations: Normal saline (C), 2.5 × 10⁶ (L), 5.0 × 10⁶ (M), and 10.0 × 10⁶ (H) groups. The MSCs were injected directly into the fracture site. The rats were sacrificed at 2 and 6 wk post-fracture. New bone formation [bone volume (BV) and percentage BV (PBV)] was evaluated using micro-computed tomography (CT). Histological analysis was performed to evaluate fracture healing score. The protein expression of factors related to MSC migration [stromal cell-derived factor 1 (SDF-1), transforming growth factor-beta 1 (TGF-β1)] and angiogenesis [vascular endothelial growth factor (VEGF)] was evaluated using western blot analysis. The expression of cytokines associated with osteogenesis [bone morphogenetic protein-2 (BMP-2), TGF-β1 and VEGF] was evaluated using real-time polymerase chain reaction.

RESULTS

Micro-CT showed that BV and PBV was significantly increased in groups M and H compared to that in group C at 6 wk post-fracture (P = 0.040, P = 0.009; P = 0.004, P = 0.001, respectively). Significantly more cartilaginous tissue and immature bone were formed in groups M and H than in group C at 2 and 6 wk post-fracture (P = 0.018, P = 0.010; P = 0.032, P = 0.050, respectively). At 2 wk post-fracture, SDF-1, TGF-β1 and VEGF expression were significantly higher in groups M and H than in group L (P = 0.031, P = 0.014; P < 0.001, P < 0.001; P = 0.025, P < 0.001, respectively). BMP-2 and VEGF expression were significantly higher in groups M and H than in group C at 6 wk post-fracture (P = 0.037, P = 0.038; P = 0.021, P = 0.010). Compared to group L, TGF-β1 expression was significantly higher in groups H (P = 0.016). There were no significant differences in expression levels of chemokines related to MSC migration, angiogenesis and cytokines associated with osteogenesis between M and H groups at 2 and 6 wk post-fracture.

CONCLUSION

The administration of at least 5.0 × 10⁶ MSCs was optimal to promote fracture healing in a rat model of long bone fractures.

The Relationship Between Time Until Full Weight Bearing After Hip Fractures and Vitamin D Levels in Patients Aged 50 Years and Above

Introduction Hip fractures are common in the elderly, especially with vitamin D deficiency. Currently, there is a paucity of case-control studies regarding the relationship between the time until full weight bearing of hip fractures and vitamin D levels in Saudi Arabia. Our aim is to determine time until full weight bearing of hip fractures in patients with vitamin D deficiency compared with normal vitamin D in the age of 50 and above. Materials and methods This was a hospital-based non-interventional retrospective case-control study conducted among patients with hip fractures aged 50 years and above between January 2017 and April 2021. It was done at King Abdulaziz university hospital, Jeddah, Saudi Arabia. A review of the medical records and operation records for the relative operation was done to check patients' lab values around the time of the operation and following the documented healing process. Data were analyzed using SPSS version 26 (IBM Inc., Armonk, New York). Correlation analysis was performed using Spearman's test, and a p-value of 0.05 was considered statistically significant.  Results In our research, 36 patients were participants in the study, with about two-thirds (22) of the participants being female (61.1%). 52.8% of the participants had an age ranging from 71-80 years, with a mean age of 75.66 ± 9.53 years. A non-significant relationship between the time until full weight bearing of hip fractures and the vitamin d levels is demonstrated. By that, the research question was disproved by the given data.  Conclusion The time until full weight bearing of hip fracture is not significantly related to vitamin D level. In this study, the majority of patients (77.1%) were vitamin D deficient, which raises our concern for vitamin D deficiency to be a major health problem in our society. However, this evidence should be further assessed in larger trials. Additional studies on this topic are recommended to be done.

Fracture Healing in the Setting of Endocrine Diseases, Aging, and Cellular Senescence

More than 2.1 million age-related fractures occur in the United States annually, resulting in an immense socioeconomic burden. Importantly, the age-related deterioration of bone structure is associated with impaired bone healing. Fracture healing is a dynamic process which can be divided into four stages. While the initial hematoma generates an inflammatory environment in which mesenchymal stem cells and macrophages orchestrate the framework for repair, angiogenesis and cartilage formation mark the second healing period. In the central region, endochondral ossification favors soft callus development while next to the fractured bony ends, intramembranous ossification directly forms woven bone. The third stage is characterized by removal and calcification of the endochondral cartilage. Finally, the chronic remodeling phase concludes the healing process. Impaired fracture healing due to aging is related to detrimental changes at the cellular level. Macrophages, osteocytes, and chondrocytes express markers of senescence, leading to reduced self-renewal and proliferative capacity. A prolonged phase of "inflammaging" results in an extended remodeling phase, characterized by a senescent microenvironment and deteriorating healing capacity. Although there is evidence that in the setting of injury, at least in some tissues, senescent cells may play a beneficial role in facilitating tissue repair, recent data demonstrate that clearing senescent cells enhances fracture repair. In this review, we summarize the physiological as well as pathological processes during fracture healing in endocrine disease and aging in order to establish a broad understanding of the biomechanical as well as molecular mechanisms involved in bone repair.

Serum sclerostin levels in osteoporotic fracture patients

PURPOSE

Sclerostin inhibits bone formation and stimulates bone resorption. Previous studies found a positive association between bone density and serum sclerostin, but literature on sclerostin levels in osteoporotic fracture patients is scarce. The aim of the present study was to compare the serum sclerostin levels in osteoporotic and non-osteoporotic fracture patients and to assess the correlation of the sclerostin levels with bone mineral density and vitamin D status.

METHODS

In this cross-sectional study, we included patients over 50 years, with an extremity fracture after low-energy trauma treated between 2012 and 2018, with biobank samples and available bone density measurements by Dual X-ray Absorption. Osteoporosis was diagnosed according the World Health Organisation criteria. Vitamin D deficiency was defined as a 25(OH)D concentration < 30 nmol/L. After defrosting biobank samples, serum sclerostin was measured using the human SOST (sclerostin) enzyme-linked immunosorbent assay kit. We prespecified a subgroup analysis including only female patients.

RESULTS

179 patients were included of whom 139(78%) were female. In 46 patients (25.7%), osteoporosis was diagnosed. Bone mineral density was positively associated with sclerostin levels (r = 0.17, p = 0.026) and patients with osteoporosis had a significantly lower serum sclerostin compared to non-osteoporotic fracture patients (mean 41.9 pmol/L vs 48.1 pmol/L; p = 0.03). This difference remained significant after correction for potential confounders. Similar results were found in the subgroup of female patients. No association between serum sclerostin and vitamin D deficiency was found.

CONCLUSION

Osteoporotic fracture patients had lower levels of sclerostin than non-osteoporotic fracture patients. Future research should focus on the use of sclerostin as biomarker for osteoporosis in fracture patients.

Demographic Discrepancies of Vitamin D Deficiency in Craniofacial Fracture Patients

Background

The relationship between craniofacial fracture and vitamin D status has not been studied. Given the important role vitamin D status plays in postfracture prognosis, a deep investigation into this relationship is due. The primary objective of this study was to assess the demographic discrepancies in the vitamin D status of patients with craniofacial fracture.

Methods

The Cerner Health Facts database was used to collect data on serum 25-hydroxyvitamin D, demographics, hospital admission and discharge, and fracture type of 76 craniofacial fracture patients with available vitamin D levels from October 2015 until May 2018. Pairwise Spearman Correlation was used for multivariate data analysis.

Results

Of the 76 craniofacial fracture patients identified, 55.3% were insufficient in vitamin D and 32.9% were deficient in vitamin D. Vitamin D deficiency and insufficiency were more common in women, African American individuals, and patients over 50 years of age.

Conclusions

The investigation revealed a high prevalence of vitamin D deficiency and insufficiency in craniofacial fracture patients. Despite the higher incidence of fractures in men and Caucasian individuals, women and African American individuals with craniofacial fractures had poorer vitamin D status. Clinicians should consider empiric vitamin D supplementation following craniofacial fracture in high-risk groups.

Bone turnover markers as surrogates of fracture healing after intramedullary fixation of tibia and femur fractures

Aims

Bone turnover markers (BTMs) follow distinct trends after fractures and limited evidence suggests differential levels in BTMs in patients with delayed healing. The effect of vitamin D, and other factors that influence BTMs and fracture healing, is important to elucidate the use of BTMs as surrogates of fracture healing. We sought to determine whether BTMs can be used as early markers of delayed fracture healing, and the effect of vitamin D on BTM response after fracture.

Methods

A total of 102 participants aged 18 to 50 years (median 28 years (interquartile range 23 to 35)), receiving an intramedullary nail for a tibial or femoral shaft fracture, were enrolled in a randomized controlled trial comparing vitamin D₃ supplementation to placebo. Serum C-terminal telopeptide of type I collagen (CTX; bone resorption marker) and N-terminal propeptide of type I procollagen (P1NP; bone formation marker) were measured at baseline, six weeks, and 12 weeks post-injury. Clinical and radiological fracture healing was assessed at three months.

Results

CTX and P1NP concentrations peaked at six weeks in all groups. Elevated six-week CTX and P1NP were associated with radiological healing at 12 weeks post-injury (odds ratio (OR) 10.5; 95% confidence interval 2.71 to 53.5, p = 0.002). We found no association between CTX or P1NP and functional healing. Baseline serum 25(OH)D showed a weak inverse relationship with P1NP (p = 0.036) and CTX (p = 0.221) at 12 weeks, but we observed no association between vitamin D supplementation and either BTM.

Conclusion

Given the association between six-week BTM concentrations and three-month radiological fracture healing, CTX and P1NP appear to be potential surrogate markers of fracture healing.

Cite this article: Bone Joint Res 2022;11(4):239–250.

Calcifediol (25OH Vitamin D3) Deficiency: A Risk Factor from Early to Old Age

Vitamin D deficiency is the main cause of nutritional rickets in children and osteomalacia in adults. There is consensus that nutritional access to vitamin D can be estimated by measuring serum concentrations of 25OHD and vitamin D deficiency can thus be considered as calcifediol deficiency. However, the threshold for vitamin D/calcifediol sufficiency remains a matter of debate. Vitamin D/calcifediol deficiency has been associated with musculoskeletal effects but also multiple adverse extra-skeletal consequences. If these consequences improve or if they can be treated with vitamin D supplementation is still unclear. Observational studies suggest a higher infection risk in people with low calcifediol levels. There is also a consistent association between serum calcifediol and cardiovascular events and deaths, but large-scale, long-term intervention studies did not show any benefit on cardiovascular outcomes from supplementation, at least not in subjects without clear vitamin D deficiency. Cancer risk also did not change with vitamin D treatment, although there are some data that higher serum calcifediol is associated with longer survival in cancer patients. In pregnant women, vitamin D supplementation decreases the risk of pre-eclampsia, gestational diabetes mellitus, and low birth weight. Although preclinical studies showed that the vitamin D endocrine system plays a role in certain neural cells as well as brain structure and function, there is no evidence to support a beneficial effect of vitamin D in neurodegenerative diseases. Vitamin D supplementation may marginally affect overall mortality risk especially in elderly subjects with low serum calcifediol concentrations.

Characterization of vitamin D deficiency and use of a standardized supplementation protocol in orthopaedic trauma patients

PURPOSE

The objectives of this study were to assess the incidence of vitamin D deficiency in orthopaedic trauma patients, evaluate the safety and efficacy of a vitamin D supplementation protocol, and investigate the utility of vitamin D supplementation in reducing nonunions.

METHODS

Three hundred seventy patients with operative tibia and/or fibula fractures were retrospectively reviewed. Both overall and matched cohorts were analysed.

RESULTS

Ninety-eight per cent (n = 210) were found to have vitamin D insufficiency (serum 25(OH)D level < 30 ng/ml). There were no cases of vitamin D toxicity following vitamin D replacement. Median follow-up vitamin D level was 22.7 ng/mL. No statistical difference between union rates was found between either the two consecutive cohorts or matched cohorts.

CONCLUSION

This vitamin D replacement protocol was a safe treatment for hypovitaminosis D, but post hoc analysis shows there would need to be over 1200 matched patients to achieve adequate power.

Association of Pre-Operative Vitamin D Levels and Severity of Fracture among Orthopedic Trauma Patients in A Single, Tertiary-Level Hospital

Background/Purpose

The high prevalence of hypovitaminosis D among trauma patients have been related to risk of fractures, falls, non-union and poor operative outcomes. There is limited evidence that ties up Vitamin D levels with fracture severity. The objective of this study is to determine the association of pre-operative Vitamin D levels and fracture severity.

Methods

This was a retrospective, cross-sectional study of patients with extremity fractures classified according to the AO Trauma classification system with baseline pre-operative vitamin D levels. The association between vitamin D levels and fracture severity of surgically treated trauma patients were analyzed. Sub-group analysis was performed on patients without osteoporosis and those patients who suffered from low-energy trauma.

Results

Ninety-six (96) patients were included. Those with severe fractures (AO -C fractures, 31B1.3/B2.3 and 31A3) were associated with lower Vitamin D levels (µ  =  17.87 µg/mL) (p < 0.001). There was a strong, positive significant correlation ( rs (4)  =  .426, p  =  < 0.001) between hypovitaminosis D and increasing fracture severity. This significant association of hypovitaminosis D with worse fracture patterns remains in the patient sub-group without osteoporosis ( p  =  0.030), and in those who sustained low-mechanism injuries (­ p­ < 0.001).

Conclusion

We present initial evidence that low pre-operative Vitamin D level is associated with increasing fracture severity at the time of injury. Early detection, surveillance and management of low vitamin D levels can lead to drastic changes in the holistic approach to fracture prevention and treatment.

How can the orthopedic surgeon ensure optimal vitamin D status in patients operated for an osteoporotic fracture?

In this narrative review, the role of vitamin D deficiency in the pathophysiology, healing of fragility fractures, and rehabilitation is discussed. Vitamin D status can be assessed by measuring serum 25(OH)-vitamin D level with standardized assays. There is a high prevalence of vitamin D insufficiency (25(OH)D < 50 nmol/l (i.e., 20 ng/mL)) or deficiency (25(OH)D < 25 nmol/l (i.e., 10 ng/mL)) in patients with fragility fractures and especially in those with a hip fracture. The evidence on the effects of vitamin D deficiency and/or vitamin D supplementation on fracture healing and material osseointegration is still limited. However, it appears that vitamin D have a rather positive influence on these processes. The fracture liaison service (FLS) model can help to inform orthopedic surgeons, all caregivers, and fractured patients about the importance of optimal vitamin D status in the management of patients with fragility fractures. Therefore, vitamin D status should be included in Capture the Fracture® program as an outcome of FLS in addition to dual-energy X-ray absorptiometry (DXA) and specific antiosteoporosis medication. Vitamin D plays a significant role in the pathophysiology and healing of fragility fractures and in rehabilitation after fracture. Correction of vitamin D deficiency should be one of the main outcomes in fracture liaison services.

The role of vitamin D and vitamin D deficiency in orthopaedics and traumatology-a narrative overview of the literature

Vitamin D is considered to play an important role in musculoskeletal health. It’s classical function is the regulation of calcium and phosphate homeostasis, thus ensuring a balanced bone metabolism that is characterised by an equal amount of bone resorption and bone formation. In the past decades, a plethora of pre-clinical and clinical studies reporting on potential health-beneficial properties of vitamin D have emerged. Moreover, there is an abundance of reports highlighting vitamin D deficiency and insufficiency in patients with almost innumerable diseases. Further, it is estimated that more than one billion people globally are affected by insufficient vitamin D levels. As such, research on vitamin D has been particularly popular over the past years. In orthopaedics and traumatology, most studies describe favourable effects of vitamin D in general. However, the relative importance of vitamin D is oftentimes debated. In this narrative review of the literature, we consider first, the properties of vitamin D and how vitamin D, vitamin D deficiency and the vitamin D receptor (VDR) impact on musculoskeletal health. Secondly, we provide an overview of studies reporting the prevalence of vitamin D deficiency in traumatology and diverse orthopaedic diseases including bone oncology. Lastly, we emphasise recent findings and touch on future perspectives in vitamin D research.

Vitamin D status and complications, readmissions, and mortality after hip fracture

Low vitamin D in patients with hip fracture is common. In the present study, 407 of 872 (47%) patients had serum calcidiol less than 50 nmol/L. Patients with low vitamin D had more delirium, more new hip fractures, and more medical readmissions, but not more orthopedic complications after 1 year.

INTRODUCTION

We wanted to study the relation between vitamin D level and postoperative orthopedic and medical complications in patients with hip fracture. In addition, we investigated the effect of giving a single-dose cholecalciferol 100.000 IU.

METHODS

Data were taken from the local hip fracture register. Logistic regression analyses including vitamin D level and potentially confounding variables were performed for complications and readmissions.

RESULTS

A total of 407 (47%) of 872 included hip fractures had low vitamin D at baseline. A total of 155 (18%) developed delirium, and the risk was higher in vitamin D-deficient patients (odds ratio (OR) 1.48, 95% confidence interval (CI) 1.04 to 2.12; p = 0.03). A total of 261 (30%) were readmitted for non-hip-related conditions. Low vitamin D was associated with a higher risk of medical readmissions within 30 days (OR 1.64 (1.03 to 2.61); p = 0.036) and 12 weeks (OR 1.47 (95% CI 1.02 to 2.12); p = 0.039). There was a higher risk of a new hip fracture (OR 2.84 (95% CI 1.15 to 7.03) p = 0.024) in vitamin D-deficient patients. A total of 105 (12%) developed at least one orthopedic complication, with no correlation to baseline vitamin D. Among vitamin D-deficient patients, those receiving a single-dose of 100.000 IU cholecalciferol had fewer orthopedic complications (OR 0.32 (95% CI 0.11 to 0.97) p = 0.044) the first 30 days after surgery.

CONCLUSION

Low vitamin D at admission for hip fracture increased the risk of delirium, a new hip fracture, and medical readmissions, but not orthopedic complications. The role of vitamin D supplementation to prevent orthopedic complications requires further study.

Diode laser assisted horizontal bone defect regeneration in the treatment of peri-implantitis

Our findings show the use of a diode laser to remove inflamed tissue and regenerate the horizontal bone defects around the implant. These findings could be applied in the clinic.

The importance of vitamin D in treatment of fracture non-union: A case report

The prevalence of hypovitaminosis D is currently increasing. A wide variety of diseases and complications are associated with low vitamin D serum concentrations, including poor fracture healing and fracture non-union. A healthy 44-y-old man presented himself with pain due to a non-union of a femoral shaft fracture at 4 y after the initial injury. The fracture had been operated upon three times and was adequately fixated in anatomic position. Hypovitaminosis D was diagnosed, and subsequent supplementation resulted in complete union of the fracture with full pain relief. This case illustrates the importance of adequate serum vitamin D levels in fracture healing, in addition to other fracture healing facilitating factors. With the increasing prevalence of hypovitaminosis D and possibly associated fracture-related complications, routine vitamin D determination should become part of clinical workup in cases of fracture non-union.

Hematopoietic Wnts Modulate Endochondral Ossification During Fracture Healing

Wnt signaling plays a critical role in bone formation, homeostasis, and injury repair. Multiple cell types in bone have been proposed to produce the Wnts required for these processes. The specific role of Wnts produced from cells of hematopoietic origin has not been previously characterized. Here, we examined if hematopoietic Wnts play a role in physiological musculoskeletal development and in fracture healing. Wnt secretion from hematopoietic cells was blocked by genetic knockout of the essential Wnt modifying enzyme PORCN, achieved by crossing Vav-Cre transgenic mice with Porcn^flox mice. Knockout mice were compared with their wild-type littermates for musculoskeletal development including bone quantity and quality at maturation. Fracture healing including callus quality and quantity was assessed in a diaphyseal fracture model using quantitative micro computer-assisted tomographic scans, histological analysis, as well as biomechanical torsional and 4-point bending stress tests. The hematopoietic Porcn knockout mice had normal musculoskeletal development, with normal bone quantity and quality on micro-CT scans of the vertebrae. They also had normal gross skeletal dimensions and normal bone strength. Hematopoietic Wnt depletion in the healing fracture resulted in fewer osteoclasts in the fracture callus, with a resultant delay in callus remodeling. All calluses eventually progressed to full maturation. Hematopoietic Wnts, while not essential, modulate osteoclast numbers during fracture healing. These osteoclasts participate in callus maturation and remodeling. This demonstrates the importance of diverse Wnt sources in bone repair.

Vitamin D and the athlete-patient: state of the art

Vitamin D deficiency is common in athletes. The conventional measurement of vitamin D levels provides a general indicator of body stores. However, there are nuances in its interpretation as values of 25(OH)D do not correlate absolutely with the amount of 'bioavailable' vitamin to the cells. Vitamin D should be regarded as a hormone and influences between 5% and 10% of our total genome. Determining the precise effect of the vitamin, isolated from the actions of other cofactors, is not straightforward and restricts our complete understanding of all of its actions. Deficiency has harmful effects on not only bone and muscle but also wider areas, including immunity and respiratory and neurological activities. More caution should be applied regarding the ability of supranormal vitamin D levels to elevate athletic performance. Hopefully, future research will shed more light on optimal levels of vitamin D and supplementation regimes, and improved understanding of its intracellular control of our genetic mechanisms and how extrinsic influences modify its activity.

Investigating changes in calcium, phosphorus, alkaline phosphatase, and 25-hydroxy Vitamin D after surgical repair of fractures of femur or tibia

Background:

The recovery of long bones after fracture requires a specific process to restore the natural bone anatomy as well as its proper function. Changes in calcium, phosphorus, alkaline phosphatase and 25-hydroxy vitamin D can be justified either in the fracture process or in the repair procedure. The aim of this sectional study is to investigate changes in all these compounds after the surgical repair of fractures of femur and tibia bones.

Materials and Methods:

A random sample of 68 patients was selected from whom referring to a hospital with fractures of femur or tibia and candidate for repair surgery. The mentioned bone markers were measured at the time after surgery, six and twelve weeks after the surgery with laboratory-specific kits. A p-value, lower than 0.05, was considered to be statistically significant.

Result:

Of the patients, 34 were with fractures of femur and 34 were with fractures of tibia, equally. The patients were aged 2 to 69 with a mean age of 27.93 ± 14.8 years old. The means of calcium (p = 0.001) and phosphorus (p = 0.014) at three intervals were statistically significant difference. In contrast, the means serum alkaline phosphatase and vitamin D levels did not show any significant changes over time (p = 0.042).

Conclusion:

In conclusion, the means of calcium and phosphorus over the follow-up were statistically significant. The observed difference of vitamin D after the surgery, as well the level of alkaline phosphatase for femoral fracture between male and female are one of our important findings. (www.actabiomedica.it)

Vitamin D for Improved Bone Health and Prevention of Stress Fractures: A Review of the Literature

Vitamin D is a vital nutrient and hormone needed for many essential functions in overall health. There is growing literature examining the role of vitamin D not only in the general population but also in athletes. The most predominantly studied area of vitamin D pertains to bone health. Recently, there has been increased investigation into the relationship of vitamin D and stress fractures, including genetic polymorphisms, levels of 25-hydroxyvitamin D, and bioavailable vitamin D. This review will address the most recent developments of vitamin D research and its important role in bone health in athletes.

Bone regeneration in a mouse model of type 1 diabetes: Influence of sex, vitamin D3, and insulin

AIM

This study set forth a question: are there any differences in bone responses to insulin and/or vitamin D3 treatment in female and male type 1 diabetic (T1D) mice?

MAIN METHODS

To address this issue, a non-critical sized femur defect was created in streptozotocin (STZ)-T1D mice. Control non-diabetic and T1D female and male mice received: saline; vitamin D3; insulin; or vitamin D3 plus insulin, for 21 days.

KEY FINDINGS

Female and male T1D mice showed impaired bone healing, as indicated by histological and micro-computed tomography (micro-CT) analysis. Vitamin D3 or insulin improved the bone regeneration in T1D mice, irrespective of sex. Vitamin D3 plus insulin did not exhibit any additional effects. There were no differences regarding the numbers of TRAP-stained osteoclasts in either evaluated groups. The osteoblast-related gene osterix was upregulated in vitamin D3-treated male T1D mice, as revealed by RT-qPCR. Female T1D mice treated with vitamin D3, insulin, or vitamin D3 plus insulin presented an increased expression of insulin growth factor-1 (IGF-1) mRNA. Conversely, IGF-1 mRNA levels were reduced by the same treatments in male TD1 mice.

SIGNIFICANCE

Altogether, the results suggested that T1D similarly delayed the osseous healing in female and male mice, with beneficial effects for either vitamin D3 or insulin in T1D mice of both sexes. However, data indicated marked sex differences regarding the expression of genes implicated in bone formation, in T1D mice treated with vitamin D3 and/or insulin.

Pleiotropic actions of Vitamin D in composite musculoskeletal trauma

Composite tissue injuries are the result of high energy impacts caused by motor vehicle accidents, gunshot wounds or blasts. These are highly traumatic injuries characterized by wide-spread, penetrating wounds affecting the entire musculoskeletal system, and are generally defined by frank volumetric muscle loss with concomitant segmental bone defects. At the tissue level, the breadth of damage to multiple tissue systems, and potential for infection from penetration, have been shown to lead to an exaggerated, often chronic inflammatory response with subsequent dysregulation of normal musculoskeletal healing mechanisms. Aside from the direct effects of inflammation on myogenesis and osteogenesis, frank muscle loss has been shown to directly impair fracture union and ultimately contribute to failed wound regeneration. Care for these injuries requires extensive surgical intervention and acute care strategies. However, often these interventions do not adequately mitigate inflammation or promote proper musculoskeletal injury repair and force amputation of the limb. Therefore, identification of factors that can promote tissue regeneration and mitigate inflammation could be key to restoring wound healing after composite tissue injury. One such factor that may directly affect both inflammation and tissue regeneration in response to these multi-tissue injuries may be Vitamin D. Beyond traditional roles, the pleiotropic and localized actions of Vitamin D are increasingly being recognized in most aspects of wound healing in complex tissue injuries - e.g., regulation of inflammation, myogenesis, fracture callus mineralization and remodeling. Conversely, pre-existing Vitamin D deficiency leads to musculoskeletal dysfunction, increased fracture risk or fracture non-unions, decreased strength/function and reduced capacity to heal wounds through increased inflammation. This Vitamin D deficient state requires acute supplementation in order to quickly restore circulating levels to an optimal level, thereby facilitating a robust wound healing response. Herein, the purpose of this review is to address the roles and critical functions of Vitamin D throughout the wound healing process. Findings from this review suggest that careful monitoring and/or supplementation of Vitamin D may be critical for wound regeneration in composite tissue injuries.

Smoking Increases Postoperative Complications After Distal Radius Fracture Fixation: A Review of 417 Patients From a Level 1 Trauma Center

Background: Unstable distal radius fractures that undergo surgical stabilization have varying complication rates in the literature. Smoking is known to affect bone healing and implant fixation rates but has never been definitively shown to affect postoperative outcomes of surgically managed distal radius fractures. Methods: A retrospective review was performed of patients with surgically treated distal radius fractures at a Level 1 Trauma Center who had at least 6 weeks of follow-up over a 5-year period. Charts were reviewed for basic demographic information, comorbidities, details about the operative procedure, and early complications. Notable physical examination findings were noted, such as wrist stiffness and distal radius tenderness to palpation. Statistical analysis was performed to compare the smoking and nonsmoking groups. To control for confounding differences, a hierarchical multivariable regression analysis was performed. Results: Four hundred seventeen patients were included in the study, and 24.6% were current smokers at the time of surgery. The overall complication rate for smokers was 9.8% compared with 5.6% in nonsmokers. The smoking cohort showed significantly higher rates of hardware removal, nonunion, revision procedures, wrist stiffness, and distal radius tenderness. When controlling for the confounding variables of diabetes and obesity, smokers still had significantly higher rates of the same complications. Conclusion: Patients who smoke have a statistically significant higher rate of postoperative distal radius tenderness, wrist stiffness, nonunion, hardware removal, and revision procedures compared with those who do not smoke in a review of 417 total patients undergoing surgical fixation for distal radius fractures.

The Life of a Fracture: Biologic Progression, Healing Gone Awry, and Evaluation of Union

New knowledge about the molecular biology of fracture-healing provides opportunities for intervention and reduction of risk for specific phases that are affected by disease and medications. Modifiable and nonmodifiable risk factors can prolong healing, and the informed clinician should optimize each patient to provide the best chance for union. Techniques to monitor progression of fracture-healing have not changed substantially over time; new objective modalities are needed.

The biology and treatment of acute long-bones diaphyseal fractures: Overview of the current options for bone healing enhancement

Diaphyseal fractures represent a complex biological entity that could often end into impaired bone-healing, with delayed union and non-union occurring up to 10% of cases. The role of the modern orthopaedic surgeon is to optimize the fracture healing environment, recognize and eliminate possible interfering factors, and choose the best suited surgical fixation technique. The impaired reparative process after surgical intervention can be modulated with different surgical techniques, such as dynamization or exchange nailing after failed intramedullary nailing. Moreover, the mechanical stability of a nail can be improved through augmentation plating, bone grafting or external fixation techniques with satisfactory results. According to the "diamond concept", local therapies, such as osteoconductive scaffolds, bone growth factors, and osteogenic cells can be successfully applied in "polytherapy" for the enhancement of delayed union and non-union of long bones diaphyseal fractures. Moreover, systemic anti-osteoporosis anabolic drugs, such as teriparatide, have been proposed as off-label treatment for bone healing enhancement both in fresh complex shaft fractures and impaired unions, especially for fragility fractures. The article aims to review the biological and mechanical principles of failed reparative osteogenesis of diaphyseal fractures after surgical treatment. Moreover, the evidence about the modern non-surgical and pharmacological options for bone healing enhancement will discussed.

Effects of Vitamin D Receptor Knockout and Vitamin D Deficiency on Corneal Epithelial Wound Healing and Nerve Density in Diabetic Mice

Diabetic keratopathy occurs in ∼70% of all people with diabetes. This study was designed to examine the effects of vitamin D receptor knockout (VDR-/-) and vitamin D deficiency (VDD) on corneal epithelial wound healing and nerve density in diabetic mice. Diabetes was induced using the low-dose streptozotocin method. Corneal epithelial wounds were created using an Algerbrush, and wound healing was monitored over time. Corneal nerve density was measured in unwounded mice. VDR-/- and VDD diabetic mice (diabetic for 8 and 20 weeks, respectively) had slower healing ratios than wild-type diabetic mice. VDR-/- and VDD diabetic mice also showed significantly decreased nerve density. Reduced wound healing ratios and nerve densities were not fully rescued by a supplemental diet rich in calcium, lactose, and phosphate. We conclude that VDR-/- and VDD significantly reduce both corneal epithelial wound healing and nerve density in diabetic mice. Because the supplemental diet did not rescue wound healing or nerve density, these effects are likely not specifically related to hypocalcemia. This work supports the hypothesis that low vitamin D levels can exacerbate preexisting ophthalmic conditions, such as diabetes.

BIOLOGICAL ENHANCEMENTS FOR ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION

The anterior cruciate ligament (ACL) is mostly responsible for providing knee stability. ACL injury has a marked effect on daily activities, causing pain, dysfunction, and elevated healthcare costs. ACL reconstruction (ACLR) is the standard treatment for this injury. However, despite good results, ACLR is associated with a significant rate of failure. In this context, the mechanical and biological causes must be considered. From a biological perspective, the ACLR depends on the osseointegration of the graft in the adjacent bone and the process of intra-articular ligamentization for good results. Here, we discuss the mechanisms underlying the normal graft healing process after ACLR and its biological modulation, thus, presenting novel strategies for biological enhancements of the ACL graft. Level of evidence III, Systematic review of level III studies.

Tobacco and bone fractures: A review of the facts and issues that every orthopaedic surgeon should know

Objectives

The aim of this study was to review the impact of smoking tobacco on the musculoskeletal system, and on bone fractures in particular.

Methods

English-language publications of human and animal studies categorizing subjects into smokers and nonsmokers were sourced from MEDLINE, The Cochrane Library, and SCOPUS. This review specifically focused on the risk, surgical treatment, and prevention of fracture complications in smokers.

Results

Smokers have an increased risk of fracture and experience more complications with delayed bone healing, even if they have already stopped smoking, because some adverse effects persist for a prolonged period. Some risks can be reduced during and after surgery by local and general prevention, and smoking cessation is an important factor in lessening this risk. However, if a patient wants to stop smoking at the time of a fracture, the cessation strategies in reducing tobacco use are not easy to implement. The patient should also be warned that using e-cigarettes or other tobaccos does not appear to reduce adverse effects on health.

Conclusion

The evidence reviewed in this study shows that smoking has a negative effect in terms of the risk and treatment of fractures.

Cite this article: J. Hernigou, F. Schuind. Tobacco and bone fractures: A review of the facts and issues that every orthopaedic surgeon should know. Bone Joint Res 2019;8:255–265. DOI: 10.1302/2046-3758.86.BJR-2018-0344.R1.

Obtaining Vitamin D Levels in Children With Fractures Improves Supplementation Compliance

BACKGROUND

Obtaining ideal serum 25-vitamin D (25VitD) levels (>30 ng/mL) is imperative in childhood to achieve peak bone mass. Supplementation compliance in children recommended to take vitamin D postfracture was evaluated. The questions we sought to answer were: Is there (1) a compliance difference between patients with known versus unknown 25VitD levels; (2) an association between compliance and age; and (3) an association between fracture severity and initial 25VitD level.

METHODS

One physician analyzed compliance in 1818 fracture patients 2 to 18 years (42% female) with known (48%) and unknown 25VitD. Patient/caregiver's self-reported adherence to supplementation as "yes" (4 d/wk minimum) or "no" defined compliance. Compliance relating to fracture severity via Abbreviated Injury Scale (AIS), 25VitD level, and age, was analyzed.

RESULTS

Patients with 25VitD levels were more compliant than patients without (61%, n=532/872; 21%, n=206/946; P<0.001). In total, 83% (n=104/125) of AIS 3 patients were compliant, compared with 49% (n=628/1292) of AIS 1/2 patients (P<0.001). Compliance increased with age (odds ratio: 1.09, 95% confidence interval: 1.061-1.120, P<0.001).

CONCLUSIONS

Compliance increased when 25VitD levels were obtained, improving with fracture severity. Clinicians should order 25VitD levels on fracture patients to improve supplementation compliance.

LEVEL OF EVIDENCE

This is a level IV prognostic study which aims to investigate the effects of various patient characteristics on compliance.

Vitamin D and foot and ankle trauma: An individual or societal problem

BACKGROUND

Vitamin D deficiency is a worldwide health concern. Hypovitaminosis D may adversely affect recovery from bone injury. The authors aimed to perform an audit of the Vitamin D status of patients in three centres in the United Kingdom presenting with foot and ankle osseous damage.

METHODS

Serum 25-hydroxyvitamin-D (vitamin D) levels were obtained in patients presenting with imaging confirmed foot and ankle osseous trauma. Variables including age, gender, ethnicity, location, season, month, anatomical location and type of bone injury were recorded.

RESULTS

308 patients were included from three different centres. 66.6% were female. The average age was 47.7 (range; 10-85). The mean hydroxyvitamin-D levels were 52.0 nmol/L (SD 28.5). 18.8% were grossly deficient, 23.7% deficient, 34.7% insufficient and 22.7% within normal range. 351 separate bone injuries were identified of which 104 were categorised as stress reactions, 134 as stress fractures, 105 as fractures and 8 non-unions. Age, gender, anatomical location and fracture type did not statistically affect vitamin D levels. Ethnicity did affect Vitamin D levels: non-Caucasians mean levels were 32.4 nmols/L compared to Caucasian levels of 53.2 nmol/L (p=0.0026).

CONCLUSION

Only 18.8% of our trauma patients had a normal Vitamin D level and 22.7% were grossly deficient. Patient age, gender, anatomical location and injury type did not statistically affect vitamin D levels. No difference between trauma and elective patients were found. Hypovitaminosis D is a problem of society in general rather than specific to certain foot and ankle injury patterns or particular patient groups sustaining trauma.

LEVEL OF EVIDENCE

2b.

Optimizing the Host in Fracture Surgery

Multiple factors impact fracture healing; thus, endocrine optimization and nutritional optimization warrant investigation in the acute fracture and nonunion patient. This article presents current evidence regarding the role of the endocrinologists and the dietician in the fracture patient as well as the most recent data assessing the vitamin D axis in these populations. Similarly, the most recent information regarding the use and risks of NSAIDs in fracture healing are presented. The fracture surgeon must consider each individual patient and weigh the benefits versus the costs of host optimization.

Surgical Considerations in Managing Osteoporosis, Osteopenia, and Vitamin D Deficiency During Arthroscopic Rotator Cuff Repair

Osteopenia and osteoporosis are common in older adults and are associated with increased risk of fragility fractures. Vitamin D deficiency caused by chronic disease, poor nutrition, and inadequate sun exposure affects bone quality. Chronic rotator cuff tears can deteriorate the bone mineral density of the greater tuberosity and have been linked to reduced anchor pullout strength and high re-tear rate after repair especially in older patients with larger tear size. This article summarizes the current evidence on rotator cuff tear and bone quality and provides treatment strategies for rotator cuff repair in patients with poor bone quality.

Serum 25(OH)D is associated with an altered bone turnover marker response after a hip fracture

C-terminal telopeptide of type I collagen (CTX) and procollagen type 1 N-terminal propeptide (P1NP) are bone turnover markers (BTMs) that are promising surrogate measures of fracture healing; however, it is unknown if their response is affected by other bone healing metabolites. Since 70% of fracture patients are reported to have insufficient serum vitamin D, we sought to determine if serum 25(OH)D levels are associated with differential changes in CTX and P1NP concentrations after hip fracture. This prospective cohort included hip fracture patients 65 years of age or older admitted to one of eight Baltimore-area hospitals. Serum samples were collected at baseline, 2-, 6-, and 12-month post-fracture. A mixed-effects repeated-measures analysis was used to determine the longitudinal association between vitamin D deficiency (25(OH)D < 20 ng/ml) and CTX and P1NP. Baseline lab values were obtained for 296 participants (mean age, 80.8 years; 51% male; 55% 25(OH)D < 20 ng/ml). During the acute fracture healing period P1NP concentrations increased by 14% (95%CI: 7-21%, p < 0.01) while CTX levels did not change (p = 0.07). Both CTX and P1NP decreased below baseline at 6 and 12 months. CTX levels were higher in participants with baseline 25(OH)D < 20 ng/ml (p = 0.01). There was no association between 25(OH)D < 20 ng/ml and P1NP levels over the study duration (p = 0.33). Data from this large, longitudinal cohort support claims that CTX and P1NP concentrations change during fracture healing; however, the differential response of CTX among vitamin D deficient patients highlights important questions for its utility as a reliable surrogate marker of fracture healing. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.