Calcium gluconate supplementation is effective to balance calcium homeostasis in patients with gastrectomy

Calcium gluconate-based flame retardant towards simultaneously high-efficiency fire safety and mechanical enhancement for epoxy resin

Flame retardants containing biomass receive growing interest in environmental friendliness and sustainability but usually face the low flame-retardant efficiency and deterioration on mechanical property of matrix. Herein, a calcium gluconate-based flame retardant (CG@APP) was chemically prepared using calcium gluconate (CG) and ammonium polyphosphate (APP) via ion exchange reaction, and enabled the excellent fire safety and mechanical enhancement for epoxy resin (EP). The resulted EP composites containing 6 wt% CG@APP (EP/CG@APP6) exhibited V-0 ratings in UL-94 test. Furthermore, with respect to EP/APP6, the peak of heat release rate (pHRR) and peak of smoke production rate (pSPR) of EP/CG@APP6 decreased by 70.5 % and 50.0 %, respectively. The well synergistic flame-retardant mechanism of CG@APP between gaseous and solid phases was revealed to generate denser and more continuous charring residuals, which could do well work on insulation for heat transfer and fuel diffusion. In addition, the shell rich in hydroxyl group and Ca2+ on the surface of CG@APP well enhanced the interface compatibility through the hydrogen bond and coordinated bond, thus the tensile strength, flexural strength and impact strength of EP/CG@APP6 increased by 18.2 %, 4.5 % and 9.1 % compared with pure EP, respectively. This work provided a simple and sustainable way to construct excellent fire-safety composites.

International Delphi consensus guidelines for follow-up after prophylactic total gastrectomy: the Life after Prophylactic Total Gastrectomy (LAP-TG) study

BACKGROUND

Prophylactic total gastrectomy (PTG) remains the only means of preventing gastric cancer for people with genetic mutations predisposing to Hereditary Diffuse Gastric Cancer (HDGC), mainly in the CDH1 gene. The small but growing cohort of people undergoing PTG at a young age are expected to have a life-expectancy close to the general population, however, knowledge of the long-term effects of, and monitoring requirements after, PTG is limited. This study aims to define the standard of care for follow-up after PTG.

METHODS

Through a combination of literature review and two-round Delphi consensus of major HDGC/PTG units and physicians, and patient advocates, we produced a set of recommendations for follow-up after PTG.

RESULTS

There were 42 first round, and 62 second round, responses from clinicians, allied health professionals and patient advocates. The guidelines include recommendations for timing of assessments and specialties involved in providing follow-up, micronutrient supplementation and monitoring, bone health and the provision of written information.

CONCLUSION

While the evidence supporting the guidelines is limited, expert consensus provides a framework to best manage people following PTG, and could support the collection of information on the long-term effects of PTG.

Hypercalciuria switches Ca2+ signaling in proximal tubular cells, induces oxidative damage to promote calcium nephrolithiasis

Proximal tubule (PT) transports most of the renal Ca2+, which was usually described as paracellular (passive). We found a regulated Ca2+ entry pathway in PT cells via the apical transient receptor potential canonical 3 (TRPC3) channel, which initiates transcellular Ca2+ transport. Although TRPC3 knockout (-/-) mice were mildly hypercalciuric and displayed luminal calcium phosphate (CaP) crystals at Loop of Henle (LOH), no CaP + calcium oxalate (CaOx) mixed urine crystals were spotted, which are mostly found in calcium nephrolithiasis (CaNL). Thus, we used oral calcium gluconate (CaG; 2%) to raise the PT luminal [Ca2+]o further in TRPC3 -/- mice for developing such mixed stones to understand the mechanistic role of PT-Ca2+ signaling in CaNL. Expectedly, CaG-treated mice urine samples presented with numerous mixed crystals with remains of PT cells, which were pronounced in TRPC3 -/- mice, indicating PT cell damage. Notably, PT cells from CaG-treated groups switched their mode of Ca2+ entry from receptor-operated to store-operated pathway with a sustained rise in intracellular [Ca2+] ([Ca2+]i), indicating the stagnation in PT Ca2+ transport. Moreover, those PT cells from CaG-treated groups demonstrated an upregulation of calcification, inflammation, fibrotic, oxidative stress, and apoptotic genes; effects of which were more robust in TRPC3 ablated condition. Furthermore, kidneys from CaG-treated groups exhibited fibrosis, tubular injury and calcifications with significant reactive oxygen species generation in the urine, thus, indicating in vivo CaNL. Taken together, excess PT luminal Ca2+ due to escalation of hypercalciuria in TRPC3 ablated mice induced surplus CaP crystal formation and caused stagnation of PT [Ca2+]i, invoking PT cell injury, hence mixed stone formation.

Utility of monthly minodronate for osteoporosis after gastrectomy: Prospective multicenter randomized controlled trials

AIM

Osteoporosis in patients after gastrectomy is increasing with the aging of gastric cancer patients. Bisphosphonates are effective treatments for osteoporosis; however, their safety or efficacy in postgastrectomy patients has not been established. The purpose of this multicenter prospective intervention study was to investigate the impact of monthly minodronate on osteoporosis after gastrectomy.

METHODS

Of the 261 enrolled gastric cancer patients, 164 patients were diagnosed with osteoporosis based on criteria of the Japan Society of Osteoporosis. They were randomly assigned 1:1 to groups treated with active vitamin D (VD group) or monthly minodronate (MIN group). The primary endpoint was changes in lumbar bone mineral density (L-BMD) 12 mo after the start of administration. The secondary endpoints were changes in bone metabolism markers, adverse events (AEs), or treatment completion rates.

RESULTS

There was no significant difference in patient background between the VD (n = 82) and MIN (n = 82) groups. In the MIN group, the increase in L-BMD was significantly higher than that in the VD group (4.52% vs 1.72%, P = .001), with a significant reduction in bone metabolism markers; blood NTX (-25.6% vs -1.6%, P < .01) and serum bone-specific alkaline phosphatase (-34.3% vs -20.1%, P < .01). AEs were observed in 26.8% and 9.3% of the patients and treatment completion rates were 77.5% and 89.3% in the MIN and VD groups, respectively. Serious AEs were not observed in either group.

CONCLUSION

This study demonstrated the safety and efficacy of monthly minodronate, suggesting that this treatment may be useful for osteoporosis after gastrectomy (UMIN000015517).

Proton Pump Inhibitors and Fractures in Adults: A Critical Appraisal and Review of the Literature

Despite the large number of patients worldwide being on proton pump inhibitors (PPIs) for acid-related gastrointestinal disorders, uncertainty remains over their long-term safety. Particularly, the potential side effects of these drugs on bone health have been evaluated in the last years. The purpose of our narrative review is to gather and discuss results of clinical studies focusing on the interactions between PPIs and fracture risk. Data generated mainly from nested case-control studies and meta-analysis suggest that long-term/high-dose PPIs users are characterized by an increased risk of fragility fractures, mainly hip fractures. However, in these studies, the PPIs-induced bone impairment is often not adjusted for different confounding variables that could potentially affect bone health, and exposure to PPIs was reported using medical prescriptions without adherence evaluation. The mechanisms of the PPI-related bone damage are still unclear, but impaired micronutrients absorption, hypergastrinemia, and increased secretion of histamine may play a role. Clinicians should pay attention when prescribing PPIs to subjects with a preexistent high risk of fractures and consider antiosteoporotic drugs to manage this additive effect on the bone. However, further studies are needed to clarify PPIs action on the bone.

Bone metabolism is a key factor for clinical outcome of tibial plateau fractures

Purpose

Given that tibial plateau fractures (TPF) are rare, they may pose a challenge to the treating surgeon due to their variety of complex fracture patterns. Numerous studies have identified potential fracture-specific, surgery-related, and patient-related risk factors for impaired patient outcomes. However, reports on the influence of bone metabolism on functional outcomes are missing.

Methods

In a retrospective multicenter cohort study, 122 TPF of 121 patients were analyzed with respect to radiological and clinical outcomes (Rasmussen) with a mean follow-up of 35.7 ± 24.9 months. The risk factor assessment included bone metabolism-affecting comorbidities and medication.

Results

The findings showed that 95.9% of the patients reported a good-to-excellent clinical outcome, and 97.4% reported a good-to-excellent radiological outcome. Logistic regression revealed that potentially impaired bone metabolism (IBM) was an independent risk factor for the clinical (p = 0.016) but not the radiological outcome (Table 4). Patients with 41-type B fractures and a potential IBM had a seven times higher risk to present a fair-to-poor clinical outcome [OR 7.45, 95 CI (4.30, 12.92)]. The most common objective impairment was a limited range of motion in 16.4% of the patients, especially in 41-type C fractures (p = 0.06). The individual failure analysis additionally identified surgery-related options for improvement.

Conclusion

This study demonstrated that potential IBM was an independent risk factor for a poor-to-fair clinical outcome.

Supplement With Calcium or Alendronate Suppresses Osteopenia Due to Long Term Rabeprazole Treatment in Female Mice: Influence on Bone TRAP and Osteopontin Levels

Background and Purpose

Rabeprazole, a proton pump inhibitor (PPIs) is much endorsed to patients with increased gastric acidity. PPIs were accused to have osteoporotic effects on patients who chronically use them. The point of the current investigation was to decide the impact of rabeprazole on osteoporosis and to explore the modulatory effects of dietary calcium or alendronate on this side effect.

Methods

80 female mice were alienated into four groups maintained for 18 weeks: [1] Vehicle group: given distilled water in 12 ml/kg, P.O. [2] Rabeprazole control group: given rabeprazole in a dose equals 10 mg/kg every 48 h, P.O. [3] Rabeprazole + calcium: given rabeprazole (10 mg/kg every 48 h) along with calcium supplement. [4] Rabeprazole + alendronate: given rabeprazole (10 mg/kg every 48 h) and alendronate (1 mg/kg per week, i.p.). Serum calcium, phosphorus and parathyroid hormone were measured. Both femurs were kept in paraformaldehyde, and then the right one was used for X-ray examination with analysis by Digora software and the left one for histopathological examination (H&E) and immunohistochemical stains for osteopontin and tartrate resistant acid phosphatase (TRAP).

Results

Calcium supplementation or administration of alendronate along with rabeprazole significantly restored the mean bone density as shown by X-ray analysis. Femurs from mice received rabeprazole showed widely separated, thin-walled bone trabeculae and increased number of osteoclasts. Calcium or alendronate with rabeprazole showed thick bone trabeculae without full recovery from rabeprazole induced damage. Adding calcium supplementation to rabeprazole did not affect the histological abnormalities related to osteoclasts meanwhile alendronate produced inactivation of osteoclasts. Both calcium and alendronate decreased the rabeprazole-induced increment in the femur osteopontin level.

Conclusion

Calcium or alendronate can be recommended for female patients on PPI therapy who are at risk of osteopenia.

Effect of bisphosphonate on the prevention of bone loss in patients with gastric cancer after gastrectomy: A randomized controlled trial

BACKGROUND

Bone loss is highly prevalent after gastrectomy in gastric cancer patients. Therefore, the efficacy of medical treatment should be evaluated in patients undergoing gastrectomy.

METHODS

We conducted an unblinded, randomized controlled trial of patients who underwent gastrectomy to treat gastric cancer. The intention-to-treat participants (n = 107) were randomly assigned to receive either alendronate at a weekly dose of 70 mg and daily elemental calcium (500 mg) with cholecalciferol (1000 IU) or daily elemental calcium (500 mg) with cholecalciferol (1000 IU) only. The primary endpoint was defined by the changes in bone mineral density of four measurement sites: the lumbar spine, femur neck, total hip, and trochanter. Changes in bone turnover markers, osteocalcin and collagen I carboxyterminal telopeptide were also observed.

RESULTS

At baseline, there were no differences between the two groups in bone mineral density. In the lumbar spine and trochanter, there were no significant percentage changes compared with the baseline in the alendronate group, but a significant decrease was noted in the control group (p < 0.001 for both lumbar spine and trochanter). In the femur neck and total hip, a larger decrease was observed compared with the baseline in the control group (p < 0.001 for both femur neck and total hip). Significant percentage increases in serum osteocalcin compared with baseline were noted in the control group (p for trend <0.001), but there was no change in the alendronate group (p for trend = 0.713). Collagen I carboxyterminal telopeptide significantly declined in the alendronate group over 12 months (p for trend <0.001).

CONCLUSIONS

Prevention and treatment with bisphosphonate effectively reduces bone loss by suppressing bone resorption in gastric cancer patients undergoing gastrectomy.

Adverse Effects of Proton Pump Inhibitors-Evidence and Plausibility

Proton pump inhibitors (PPIs) have been increasingly used over the last decades and there are concerns about overuse and the numerous reported side-effects. It is uncertain whether associations between PPI use and potential side effects are causal. However, important evidence from experimental and mechanistic studies that could support a causal relationship may have been underestimated by epidemiologists and meta-analysists. In the current manuscript we review the combined epidemiological and mechanistic evidence of the adverse effects of PPI use.

Bone health in long-term gastric cancer survivors: A prospective study of high-dose vitamin D supplementation using an easy administration scheme

Bone disease in long-term survivors after gastric cancer resection has received little research attention. This study aimed to investigate bone health after curative resection of gastric cancer and the consequences of high-dose vitamin D supplementation in patients with low levels of 25-(OH)-vitamin D. Disease-free patients at least 24 months after gastric cancer resection represented the study cohort. Serum markers of bone metabolism were assessed at baseline and at 3 and 12 months. Bone mineral density and presence of fractures were assessed by X-ray at baseline. Patients with 25-(OH)-vitamin D ≤30 ng/mL at baseline received 16,000 IU of vitamin D3 every 10 days during the 1-year follow-up. Forty patients were included in the study. Mean time from surgery was 48.9 (24-109) months. Vitamin D insufficiency and secondary hyperparathyroidism were observed in 38 and 20 patients, respectively. Densitometry showed osteoporosis in 14 women and seven men and prevalent fractures in 12 women and six men at baseline. After 3 months of vitamin D supplementation, 35 patients reached values of 25-(OH)-vitamin D over 30 ng/mL. After 12 months, 38 patients were in the normal range of 25-(OH)-vitamin D. At the same time, iPTH levels and markers of bone turnover (C-terminal cross-linked telopeptide of type-I collagen, serum concentrations of bone-specific alkaline phosphatase and osteocalcin) significantly decreased after vitamin D intervention. Oral administration of high doses of vitamin D is easily implemented and restored 25-(OH)-vitamin D and iPTH values, which are frequently disturbed after gastric cancer resection.

Mutational analysis uncovers monogenic bone disorders in women with pregnancy-associated osteoporosis: three novel mutations in LRP5, COL1A1, and COL1A2

Pregnancy was found to be a skeletal risk factor promoting the initial onset of previously unrecognized monogenic bone disorders, thus explaining a proportion of cases with pregnancy-associated osteoporosis. Therapeutic measures should focus in particular on the normalization of the disturbed calcium homeostasis in order to enable the partial skeletal recovery.

INTRODUCTION

Pregnancy-associated osteoporosis (PAO) is a rare skeletal condition, which is characterized by a reduction in bone mineral density (BMD) in the course of pregnancy and lactation. Typical symptoms include vertebral compression fractures and transient osteoporosis of the hip. Since the etiology is not well understood, this prospective study was conducted in order to elucidate the relevance of pathogenic gene variants for the development of PAO.

METHODS

Seven consecutive cases with the diagnosis of PAO underwent a skeletal assessment (blood tests, DXA, HR-pQCT) and a comprehensive genetic analysis using a custom-designed gene panel.

RESULTS

All cases showed a reduced BMD (DXA T-score, lumbar spine - 3.2 ± 1.0; left femur - 2.2 ± 0.5; right femur - 1.9 ± 0.5), while the spine was affected more severely (p < 0.05). The trabecular and cortical thickness was overall reduced in HR-pQCT, while the trabecular number showed no alterations in most cases. The genetic analysis revealed three novel mutations in LRP5, COL1A1, and COL1A2.

CONCLUSION

Our data show that previously unrecognized monogenic bone disorders play an important role in PAO. Pregnancy should be considered a skeletal risk factor, which can promote the initial clinical onset of such skeletal disorders. The underlying increased calcium demand is essential in terms of prophylactic and therapeutic measures, which are especially required in individuals with a genetically determined low bone mass. The implementation of this knowledge in clinical practice can enable the partial recovery of the skeleton. Consistent genetic studies are needed to analyze the frequency of pathogenic variants in women with PAO.

A retrospective analysis of bone mineral status in patients requiring spinal surgery

Background

Impaired bone quality is associated with poor outcome of spinal surgery. The aim of the study was to assess the bone mineral status of patients scheduled to undergo spinal surgery and to report frequencies of bone mineral disorders.

Methods

We retrospectively analyzed the bone mineral status of 144 patients requiring spinal surgery including bone mineral density by dual-energy X-ray absorptiometry (DXA) as well as laboratory data with serum levels of 25-hydroxyvitamin D (25-OH-D), parathyroid hormone, calcium, bone specific alkaline phosphate, osteocalcin, and gastrin. High-resolution peripheral quantitative computed tomography (HR-pQCT) was additionally performed in a subgroup of 67 patients with T-Score below − 1.5 or history of vertebral fracture.

Results

Among 144 patients, 126 patients (87.5%) were older than 60 years. Mean age was 70.1 years. 42 patients (29.1%) had suffered from a vertebral compression fracture. 12 previously undiagnosed vertebral deformities were detected in 12 patients by vertebral fracture assessment (VFA). Osteoporosis was present in 39 patients (27.1%) and osteopenia in 63 patients (43.8%). Only 16 patients (11.1%) had received anti-osteoporotic therapy, while 54 patients (37.5%) had an indication for specific anti-osteoporotic therapy but had not received it yet. The majority of patients had inadequate vitamin D status (73.6%) and 34.7% of patients showed secondary hyperparathyroidism as a sign for a significant disturbed calcium homeostasis. In a subgroup of 67 patients, severe vertebral deformities were associated with stronger deficits in bone microarchitecture at the distal radius compared to the distal tibia.

Conclusions

This study shows that bone metabolism disorders are highly prevalent in elderly patients scheduled for spinal surgery. Vertebral deformities are associated with a predominant deterioration of bone microstructure at the distal radius. As impaired bone quality can compromise surgical outcome, we strongly recommend an evaluation of bone mineral status prior to operation and anti-osteoporotic therapy if necessary.

[Morphological characteristics of osteopetrosis]

Osteopetrosis is a rare inherited bone disorder characterized by increased bone density owing to failure in bone resorption by the osteoclasts. The disease is genetically and histologically heterogeneous with a wide spectrum of microscopic findings. The histology varies from cases with a total absence of osteoclasts to bone biopsies characterized by high numbers of enlarged multinucleated osteoclasts on a background of sclerotic cancellous bone with or without additional defect of mineralization of the bone matrix. Here we present typical cases of human osteopetrosis on the basis of bone biopsies with four distinct genotypes (mutations of TNFRSF11A, TCIRG1, CNCL7, KINDLIN-3 genes) and discuss genotype-phenotype relationships. Analyzing human bone biopsies of rare skeletal disorders might improve our understanding of bone metabolism with possible implications for the clinical management of other bone diseases.

Micronutrient deficiencies in patients with chronic atrophic autoimmune gastritis: A review

Chronic atrophic autoimmune gastritis (CAAG) is an organ-specific autoimmune disease characterized by an immune response, which is directed towards the parietal cells and intrinsic factor of the gastric body and fundus and leads to hypochlorhydria, hypergastrinemia and inadequate production of the intrinsic factor. As a result, the stomach’s secretion of essential substances, such as hydrochloric acid and intrinsic factor, is reduced, leading to digestive impairments. The most common is vitamin B12 deficiency, which results in a megaloblastic anemia and iron malabsorption, leading to iron deficiency anemia. However, in the last years the deficiency of several other vitamins and micronutrients, such as vitamin C, vitamin D, folic acid and calcium, has been increasingly described in patients with CAAG. In addition the occurrence of multiple vitamin deficiencies may lead to severe hematological, neurological and skeletal manifestations in CAAG patients and highlights the importance of an integrated evaluation of these patients. Nevertheless, the nutritional deficiencies in CAAG are largely understudied. We have investigated the frequency and associated features of nutritional deficiencies in CAAG in order to focus on any deficit that may be clinically significant, but relatively easy to correct. This descriptive review updates and summarizes the literature on different nutrient deficiencies in CAAG in order to optimize the treatment and the follow-up of patients affected with CAAG.

[Calcium and vitamin D in bone metabolism: Clinical importance for fracture treatment]

A balanced calcium homeostasis is of critical importance not only for bone remodeling, the physiological process of bone resorption and bone formation that constantly renews bone throughout life but also for normal fracture healing. Given that disturbances of calcium homeostasis are present in 50 % of the German population and that this might result in delayed fracture healing after correct surgical treatment, this paper focusses on calcium and vitamin D in the daily practice in orthopedics and trauma surgery. To ensure the required enteral calcium uptake the following three conditions are required: (1) sufficient calcium intake via the nutrition, (2) a 25-hydroxyvitamin D serum level > 30 µg/l and (3) the presence of sufficient gastric acidification. Given the endemic vitamin D deficiency in Germany as well as the constantly increasing number of people using proton pump inhibitors on a regular basis, it is necessary to closely connect trauma orthopedic surgery and osteological treatment. The first issue to be dealt with is to control and if needed normalize calcium homeostasis in order to allow a normal undisturbed fracture healing process after both conservative as well as operative treatment of fractures.

Bone biology in the elderly: clinical importance for fracture treatment

Age-related bone impairment often leads to fragility fractures in the elderly. Although excellent surgical care is widely provided, diagnosis and treatment of the underlying bone disorder are often not kept in mind. The interplay of the three major bone cells – osteoblasts, osteoclasts, and osteocytes – is normally well regulated via the secretion of messengers to control bone remodeling. Possible imbalances that might occur in the elderly are partly due to age, genetic risk factors, and adverse lifestyle factors but importantly also due to imbalances in calcium homeostasis (mostly due to vitamin D deficiency or hypochlorhydria), which have to be eliminated. Therefore, the cooperation between the trauma surgeon and the osteologist is of major importance to diagnose and treat the respective patients at risk. We propose that any patient suffering from fragility fractures is rigorously screened for osteoporosis and metabolic bone diseases. This includes bone density measurement by dual-energy X-ray absorptiometry, laboratory tests for calcium, phosphate, vitamin D, and bone turnover markers, as well as additional diagnostic modalities if needed. Thereby, most risk factors, including vitamin D deficiency, can be identified and treated while patients who meet the criteria for a specific therapy (i.e. antiresorptive and osteoanabolic) receive such. If local health systems succeed to manage this process of secondary fracture prevention, morbidity and mortality of fragility fractures will decline to a minimum level.

Hypochlorhydria-induced calcium malabsorption does not affect fracture healing but increases post-traumatic bone loss in the intact skeleton

Efficient calcium absorption is essential for skeletal health. Patients with impaired gastric acidification display low bone mass and increased fracture risk because calcium absorption is dependent on gastric pH. We investigated fracture healing and post-traumatic bone turnover in mice deficient in Cckbr, encoding a gastrin receptor that affects acid secretion by parietal cells. Cckbr-/- mice display hypochlorhydria, calcium malabsorption, and osteopenia. Cckbr-/- and wildtype (WT) mice received a femur osteotomy and were fed either a standard or calcium-enriched diet. Healed and intact bones were assessed by biomechanical testing, histomorphometry, micro-computed tomography, and quantitative backscattering. Parathyroid hormone (PTH) serum levels were determined by enzyme-linked immunosorbent assay. Fracture healing was unaffected in Cckbr-/- mice. However, Cckbr-/- mice displayed increased calcium mobilization from the intact skeleton during bone healing, confirmed by significantly elevated PTH levels and osteoclast numbers compared to WT mice. Calcium supplementation significantly reduced secondary hyperparathyroidism and bone resorption in the intact skeleton in both genotypes, but more efficiently in WT mice. Furthermore, calcium administration improved bone healing in WT mice, indicated by significantly increased mechanical properties and bone mineral density of the fracture callus, whereas it had no significant effect in Cckbr-/- mice. Therefore, under conditions of hypochlorhydria-induced calcium malabsorption, calcium, which is essential for callus mineralization, appears to be increasingly mobilized from the intact skeleton in favor of fracture healing. Calcium supplementation during fracture healing prevented systemic calcium mobilization, thereby maintaining bone mass and improving fracture healing in healthy individuals whereas the effect was limited by gastric hypochlorhydria. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 34:1914-1921, 2016.

"Fracturoscopy" is Superior to Fluoroscopy in the Articular Reconstruction of Complex Tibial Plateau Fractures-An Arthroscopy Assisted Fracture Reduction Technique

OBJECTIVE

To analyze the anatomic accuracy of fracture reduction controlled by fluoroscopy as compared with arthroscopically assisted reduction ("fracturoscopy") in patients with complex tibial plateau fractures (AO/OTA 41-C). Quality of fracturoscopy-guided reduction was checked with postoperative computed tomography.

DESIGN

Prospective observational study.

SETTING

Urban level 1 trauma center.

PATIENTS

Seventeen consecutive patients, with a complex, bicondylar tibial plateau fracture.

INTERVENTION

The intraoperative, open insertion of an arthroscope (2.4-mm or 2.8-mm optics), to visualize the articular surface and fracture reduction.

MAIN OUTCOME MEASUREMENTS

Ability to detect residual fracture depression or gap after previous open reduction under fluoroscopic guidance.

RESULTS

An open fracture reduction with fluoroscopic guidance was performed in all cases. In 7 cases, open reduction and fluoroscopy resulted in satisfactory fracture reduction (fluoroscopy group). In 10 of 17 cases, subsequent "fracturoscopy" showed persistent fracture depression (≥2 mm, fracturoscopy group) with the need for intraoperative correction. Patients in the fracturoscopy group demonstrated significantly greater preoperative fragment depression (12.55 ± 6.56 mm) and a larger preoperative fracture gap (7.83 ± 5.49 mm) compared with patients with a satisfactory reduction under fluoroscopy (depression 4.97 ± 4.02 mm, P = 0.016; gap 2.47 ± 1.07 mm, P = 0.023). Fluoroscopy was not successful in achieving satisfactory reduction in cases in which the postero-latero-central region was affected (P = 0.004, χ test). Postoperative computed tomography demonstrated satisfactory articular reconstruction in all cases.

CONCLUSIONS

Intraoperative fracturoscopy permitted a significantly improved visualization of fracture fragment displacement, specifically in the postero-latero-central region of the tibial plateau, as compared with fluoroscopy. Fracturoscopy is recommended for fractures involving the postero-latero-central region of the tibial plateau.

LEVEL OF EVIDENCE

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

[Vitamin D metabolism of the bone]

BACKGROUND

Bone health is a crucial requirement for individual mobility. Preventive, diagnostic, and therapeutic actions to preserve or restore bone health are major tasks for orthopedic surgeons and health practitioners in musculoskeletal medicine.

RESULTS

In the context of the widespread vitamin D deficiency in Germany, it is relevant to keep in mind thatserum calcitriol levels above > 30 µg/l are necessary for optimal bone metabolism and bone health. In particular, because vitamin D deficiency not only increases the amount of non-mineralized bone matrix (osteoid), but it can also cause negative changes in the mineralized bone tissue. Widening of the osteons and osteocyte lacunae, together with increased bone aging under the osteoid layer, can lead to reduced fracture resistance.

CONCLUSION

Integration of bone metabolism into the orthopedic strategy is an important concept for optimizing treatment in modern musculoskeletal medicine.

Intact bone vitality and increased accumulation of nonmineralized bone matrix in biopsy specimens of juvenile osteochondritis dissecans: a histological analysis

BACKGROUND

Although commonly proposed to be the starting point of juvenile osteochondritis dissecans (JOCD), avascular osteonecrosis (AVN) has been an inconsistent finding in histological studies. Analysis of early-stage lesions is required to elucidate the origins of OCD and justify proper treatment.

PURPOSE

To analyze histological sections of JOCD lesions with special emphasis on bone vitality.

STUDY DESIGN

Cross-sectional study; Level of evidence, 3.

METHODS

Of 64 patients with 74 JOCD lesions (20 females, mean age, 11.4 years; 44 males, mean age, 12.7 years), 34 required surgery because of lesion instability or failed nonoperative treatment. From 9 patients, 11 histological specimens were obtained. Lesions were classified according to the International Cartilage Repair Society (ICRS). Two additional histological control sections were harvested from children without JOCD manifestation. Undecalcified histological sections were histomorphometrically analyzed. To analyze the skeletal health of the patients, biochemical analyses with special emphasis on bone metabolism were performed.

RESULTS

Histologically, no osteonecrosis was visible in any of the cases. Osteocyte distribution was similar among OCD lesions and controls. ICRS OCD I lesions (n = 6) showed no intralesional separation. In ICRS OCD II and III lesions (n = 5), there was a subchondral fracture concomitant with histological characteristics of active repair mechanism (increased bone formation: osteoid volume P = .008, osteoblast number P = .046; resorption: osteoclast number P = .005; and tissue fibrosis compared with controls). Instead, in ICRS OCD I lesions, subchondral osteoid volume (P = .010) and osteoblast number (P = .046) were significantly increased compared with controls; however, no active repair mechanisms (no increased bone resorption or fibrous tissue) were detected, suggesting a focal lack of mineralization. Fifty-seven of 64 patients (89.1%) showed a vitamin D deficiency. The median vitamin D serum level of the patients with ICRS OCD I lesions was 13.6 µg/L.

CONCLUSION

In the present study, osteonecrosis was not found in histological specimens of JOCD. As a secondary finding, focal accumulations of nonmineralized bone matrix indicating a lack of mineralization in ICRS OCD I lesions were revealed. This finding correlated with a low level of vitamin D in the affected children.

SECONDARY HYPERPARATHYROIDISM AFTER BARIATRIC SURGERY: TREATMENT IS WITH CALCIUM CARBONATE OR CALCIUM CITRATE?

BACKGROUND

Bariatric surgery, especially Roux-en-Y gastric bypass, can cause serious nutritional complications arising from poor absorption of essential nutrients. Secondary hyperparathyroidism is one such complications that leads to increased parathyroid hormone levels due to a decrease in calcium and vitamin D, which may compromise bone health.

AIM

To compare calcium carbonate and calcium citrate in the treatment of secondary hyperparathyroidism.

METHOD

Patients were selected on the basis of their abnormal biochemical test and treatment was randomly done with citrate or calcium carbonate.

RESULTS

After 60 days of supplementation, biochemical tests were repeated, showing improvement in both groups.

CONCLUSION

Supplementation with calcium (citrate or carbonate) and vitamin D is recommended after surgery for prevention of secondary hyperparathyroidism.