Biochemical bone markers are useful to monitor fracture repair

In vivo assessment of bone repair by an injectable nanocomposite scaffold for local co-delivery of autologous platelet-rich plasma and calcitonin in rat model

Background: Gellan gum is obtained from the bacterium Sphingomonas elodea and is a polysaccharide with carboxylic acid functional groups. The goal of this project was to investigate the osteoinductive effect of local administration of calcitonin through an injectable scaffold of gellan gum containing salmon calcitonin loaded in silsesquioxane nanoparticles, hydroxyapatite, and platelets rich plasma.Methods: The femur of rats was defected by creating a 2 × 5 mm² hole using an electric drill. The defect was filled with an injectable hydrogel scaffold composed of gellan gum enriched with salmon calcitonin loaded in silsesquioxane nanoparticles, hydroxyapatite, platelets rich plasma and then the radiologic images were taken. Bone densitometry and the histologic studies were carried out by Hematoxylin & Eosin test. Biochemical analysis was done to measure the serum alkaline phosphatase (ALP), calcium, calcitonin concentration.Results: Healing of the bone defects and bone densitometry in the treated group by calcitonin-loaded scaffold was significantly higher (p < 0.05) and bone formation occupied 75% of the defect that was greater than other groups. Serum ALP and calcium levels in the scaffold-loaded calcitonin group were more than the other groups (p < 0.05). The osteogenic marker genes also increased significantly (p < 0.05) with free calcitonin and the scaffold.Conclusions: Gellan gum-based scaffold loaded with calcitonin may be considered a promising local treatment to progress bone formation in repairing of skeletal injuries.

Future modalities to assess fracture healing

Objectives:

Methods:

Results:

Conclusions:

Monitoring of fracture healing. Update on current and future imaging modalities to predict union

Fracture nonunion causes considerable patient morbidity and an associated burden to society. Traditional reliance on radiographs to monitor union has limitations as bridging callus of long bone fractures can take three or more months to occur. Computed Tomographic (CT) scanning is becoming increasingly popular and can evaluate bridging callus in the late stages of healing to confirm union. The use of dynamic contrast enhanced Magnetic Resonance Imaging (MRI) and advances in nuclear imaging may yield benefits in the assessment of the infected nonunion. Emerging evidence supports the use of ultrasound to detect bridging callus prior to radiographic confirmation and it may be of use to predict patients at high risk of nonunion. This paper is part of a Supplement supported by The Osteosynthesis and Trauma Care Foundation (OTCF).

Changes of bone turnover markers after elderly hip fracture surgery

INTRODUCTION

Bone turnover markers (BTMs) can be used to monitor bone metabolism, while the actual clinical changing in hip fracture had not been certified to evaluate the changes of BTMs during the healing process after surgery of elderly hip fractures; and to get the effects of operation type, gender, serum 25(OH)D level, and age on bone turnover markers.

MATERIALS AND METHODS

A total of 100 elderly cases with hip fracture were selected, including 74 females and 26 males, and the patients were followed to 180-230 days after surgery. Serum levels of N-propeptide of type 1 collagen (P1NP), C-terminal crosslinking telopeptides of type 1 collagen (CTX), Osteocalcin (OC), and 25 hydroxy vitamin D (25OHD) were investigated. Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry (DXA).

RESULTS

(1) P1NP and CTX showed peak time at 30-60 days after operation, while OC keep going even at 180-230 days; P1NP showed less than 4 times elevation during healing, CTX and OC only had less than 2 times rise. (2) Female had higher serum CTX and OC than male, intramedullary nailing for intertrochanteric fracture patients had higher P1NP than hip replacement for femoral neck fracture patients, and both the degrees of increase were less than 50%. (3) Serum average 25(OH)D level had no effect on BTMs during the fracture healing; different from the young old (65-84 years), serum OC level of eldest older patients(≥ 85 years) decreased early in the process of fracture healing.

CONCLUSIONS

BTMs reached the peak level in 30-60 days after surgery, P1NP showed less than 4 times elevation, and CTX and OC had less than 2 times rise. It was not necessary to take gender into account when observing P1NP, and it was not necessary to take fracture and operation type into account when observing CTX and OC.

Clinical Utility of Biochemical Marker of Bone Turnover: Fracture Risk Prediction and Bone Healing

Bone turnover markers (BTMs) are released during bone remodeling and are thought to reflect the metabolic activity of bone at the cellular level. This review examines BTM as a biological response marker for monitoring future fracture prediction and fracture healing processes. Substantial evidence has been of high value to investigate the use of BTM in fracture risk prediction; nevertheless, the conclusions of some studies are inconsistent due to their large variability. BTM is promising for fracture risk prediction for adopting international reference standards or providing absolute risks, such as 10-year fracture probabilities. There are uncertainties over their clinical use for monitoring osteoporotic fracture healing. More rigorous evidence is needed that can provide more detailed insights for fracture healing and for ascertaining the progression of fracture healing.

Bone Turnover in Vertebral Fractures: Does it Effect the Decision of Surgery?

Background and Aim:

Instrumentation is commonly used in spinal surgery to stabilize the fracture. In the present study, we aimed to compare the early and late changes seen in bone production and degradation products in patients with traumatic spinal fracture who had been treated surgically or conservatively.

Materials and Methods:

Forty-three patients were admitted to the Neurosurgery Department with thoracolumbar or lumbar fracture in this prospective study. Patients were divided into two groups of surgically treated (n = 23) and nonsurgically/conservatively treated (n = 20) patients. The early and late changes seen in bone production and degradation products were compared in patients with traumatic spinal fracture who had been treated surgically or conservatively.

Results:

In conservatively treated patients, although osteocalcin level was slightly increased and deoxypiridinoline (DPD)/creatinine was slightly decreased after the treatment, the difference was not statistically significant (P = 0.08 and P = 0.539, respectively). There is no significant difference between admission time, posttreatment late period osteocalcin level, and DPD/creatinine ratio between the two group of patients (P = 0.215 and P = 0.236, respectively).

Conclusion:

We suggest that the healing and fusion processes in fractured vertebrae not only followed by the radiological examination but also by noninvasive biochemical changes seen in the serum levels of bone formation and resorption markers.

Effectiveness of elcatonin for alleviating pain and inhibiting bone resorption in patients with osteoporotic vertebral fractures

Elderly patients with osteoporotic vertebral fractures often experience severe pain that reduces their quality of life (QOL). Calcitonin, a bone resorption inhibitor, has been reported to alleviate pain in such patients; however, few clinical studies have demonstrated this effect. The objective of this study was to compare changes in pain scores, activities of daily living (ADL), QOL, bone resorption, bone mineral density (BMD), and fracture healing among patients with new vertebral fractures who received different treatment modalities. We conducted an open-label, multicenter, randomized, parallel control group study comprising 107 female patients ≥55 years old with acute back pain from vertebral fracture. All subjects received either intramuscular injections of elcatonin, a derivative of calcitonin, or an oral nonsteroidal antiinflammatory drug (NSAID) combined with an active vitamin D₃ (VD3) analogue for 6 months. The pain was assessed using a visual analogue scale, and ADL and QOL were assessed using questionnaires. BMD was measured using dual-energy X-ray absorptiometry. A two-tailed significance level of 5% was used. The elcatonin IM group had significantly higher QOL score at 2 weeks and later, and significantly lower VAS and ADL scores than those in the NSAID + VD3 group at 1 month and later. The elcatonin IM group had significantly reduced TRACP-5b levels compared with those in the NSAID + VD3 group at 3 months and later and significantly higher percent changes in BMD than the NSAID + VD3 group. These results suggest that elcatonin significantly alleviated pain, inhibited bone resorption, and improved ADL, QOL, and BMD compared with NSAID + VD3.

Effect of elcatonin versus nonsteroidal anti-inflammatory medications for acute back pain in patients with osteoporotic vertebral fracture: a multiclinic randomized controlled trial

The aim of this study was to compare the efficacy of elcatonin injections and oral nonsteroidal anti-inflammatory drugs (NSAIDs) for patients with osteoporosis who have acute lumbar pain after experiencing new vertebral compression fractures. Two hundred twenty-eight Japanese female patients (mean age 77.3 years) with acute lumbar pain from osteoporotic vertebral fractures were randomly divided into two groups. Patients in one group were given an NSAID (NSAIDs group) and patients in the other group were given weekly intramuscular injections of 20 units of elcatonin (elcatonin group). All patients underwent follow-up examinations up to 6 weeks from the start of the trial. Outcome measures were the level of functional impairment according to the Japan Questionnaire for Osteoporotic Pain (JQ22), the Roland-Morris Disability Questionnaire (RDQ), and a visual analog scale (VAS) of pain intensity. Statistical analyses focused on (1) the time course of pain and functional level using linear mixed effects models to analyze the longitudinal data and (2) the effectiveness of elcatonin injection with mean difference values and 95 % confidence intervals. Significant differences were seen over time between the initial values and the postintervention values (4 and 6 weeks) in JQ22, RDQ, and VAS scores (effect size d > 0.4) in each group. The mean differences between the elcatonin group and the NSAIDs group in each measure at 4 and 6 weeks were -4.8 and -8.3 for the JQ22, -1.3 and -2.6 for the RDQ, and -11.3 and -11.5 for the VAS, shifted to elcatonin. Once weekly elcatonin injection was more effective than NSAIDs for treating acute lumbar pain and improving mobility in Japanese women with osteoporotic vertebral fractures.

Fracture healing: A review of clinical, imaging and laboratory diagnostic options

A fundamental issue in clinical orthopaedics is the determination of when a fracture is united. However, there are no established "gold standards," nor standardized methods for assessing union, which has resulted in significant disagreement among orthopaedic surgeons in both clinical practice and research. A great deal of investigative work has been directed to addressing this problem, with a number of exciting new techniques described. This review provides a brief summary of the burden of nonunion fractures and addresses some of the challenges related to the assessment of fracture healing. The tools currently available to determine union are discussed, including various imaging modalities, biomechanical testing methods, and laboratory and clinical assessments. The evaluation of fracture healing in the setting of both patient care and clinical research is integral to the orthopaedic practice. Weighted integration of several available metrics must be considered to create a composite outcome measure of patient prognosis.

Current Options for Determining Fracture Union

Determining whether a bone fracture is healed is one of the most important and fundamental clinical determinations made in orthopaedics. However, there are currently no standardized methods of assessing fracture union, which in turn has created significant disagreement among orthopaedic surgeons in both clinical and research settings. An extensive amount of research has been dedicated to finding novel and reliable ways of determining healing with some promising results. Recent advancements in imaging techniques and introduction of new radiographic scores have helped decrease the amount of disagreement on this topic among physicians. The knowledge gained from biomechanical studies of bone healing has helped us refine our tools and create more efficient and practical research instruments. Additionally, a deeper understanding of the molecular pathways involved in the bone healing process has led to emergence of serologic markers as possible candidates in assessment of fracture union. In addition to our current physician centered methods, patient-centered approaches assessing quality of life and function are gaining popularity in assessment of fracture union. Despite these advances, assessment of union remains an imperfect practice in the clinical setting. Therefore, clinicians need to draw on multiple modalities that directly and indirectly measure or correlate with bone healing when counseling patients.

Characteristics of bone turnover in the long bone metaphysis fractured patients with normal or low Bone Mineral Density (BMD)

The incidence of osteoporotic fractures increases as our population ages. Until now, the exact biochemical processes that occur during the healing of metaphyseal fractures remain unclear. Diagnostic instruments that allow a dynamic insight into the fracture healing process are as yet unavailable. In the present matched pair analysis, we study the time course of the osteoanabolic markers bone specific alkaline phosphatase (BAP) and transforming growth factor β1 (TGFβ1), as well as the osteocatabolic markers crosslinked C-telopeptide of type-I-collagen (β-CTX) and serum band 5 tartrate-resistant acid phosphatase (TRAP5b), during the healing of fractures that have a low level of bone mineral density (BMD) compared with fractures that have a normal BMD. Between March 2007 and February 2009, 30 patients aged older than 50 years who suffered a metaphyseal fracture were included in our study. BMDs were verified by dual energy Xray absorptiometry (DXEA) scans. The levels of BTMs were examined over an 8-week period. Osteoanabolic BAP levels in those with low levels of BMD were significantly different from the BAP levels in those with normal BMD. BAP levels in the former group increased constantly, whereas the latter group showed an initial strong decrease in BAP followed by slowly rising values. Osteocatabolic β-CTX increased in the bone of the normal BMD group constantly, whereas these levels decreased significantly in the bone of the group with low BMD from the first week. TRAP5b was significantly reduced in the low level BMD group. With this work, we conduct first insights into the molecular biology of the fracture healing process in patients with low levels of BMD that explains the mechanism of its fracture healing. The results may be one reason for the reduced healing qualities in bones with low BMD.

Fracture non-union: Can biomarkers predict outcome?

Delayed bone healing and non-union occurs in approximately 10-15% of long bone fractures. Both pathologies may result in prolonged period of pain, disability and repetitive operative interventions. Despite intense investigations and progress done in understanding the pathophysiologic processes governing bone healing, the diagnostic tools have not been altered. The clinical findings and radiographic features remain the two important landmarks of diagnosing non-union and even when the diagnosis is established there is debate on the ideal timing and mode of intervention. Emerging evidence suggest that there are certain molecules and genes that can serve as predictors of potentially unsuccessful fracture union. This article summarises the current evidence on the available 'bio-markers'to predict fracture non-union.

Characteristics of bone metabolism markers during the healing of osteoporotic versus nonosteoporotic metaphyseal long bone fractures: a matched pair analysis

PURPOSE

The activity and metabolism of fracture healing can be monitored quantitatively by measuring bone turnover markers (BTMs) in serum or urine. However, in osteoporotic bone, the exact metabolism processes during the healing of metaphyseal fractures remain unknown. There is no diagnostic approach which currently allows dynamic insight into the fracture healing processes in order to monitor the progression of healing and to assist in therapeutic decision making.

METHODS

Between March 2007 and February 2009, 30 patients over 50 years of age who suffered a metaphyseal fracture were included in our study. The levels of the osteoanabolic marker BAP (bone-specific alkaline phosphatase) and osteocatabolic marker β-CTX [crosslinked C-(CTX)-telopeptide-of-type-I-collagen] were monitored during the fracture healing of osteoporotic and nonosteoporotic fractures for a duration of 8 weeks.

RESULTS

After an initial decrease of BAP in the first week, the BAP level steadily increased through the fourth week in both groups. The levels of BAP in the osteoporotic group surpassed the healthy group. β-CTX steadily increased in healthy bone up to the fourth week; in osteoporotic bone, β-CTX first increased and, thereafter, decreased from the first week onwards.

CONCLUSIONS

In this work, the first molecular biological aspects of osteoporotic fracture healing have been uncovered, helping to explain the mechanisms of delayed fracture healing in osteoporotic bone. The early decrease of reduced β-CTX as well as elevated BAP during the healing process may be the first aspects within the delayed healing of osteoporotic bone. Further studies are necessary in order to achieve more detailed insight to fracture healing and to ascertain the progression of fracture healing as being essential (criteria) for therapeutic decision making.

Are polymorphisms of molecules involved in bone healing correlated to aseptic femoral and tibial shaft non-unions?

Fracture healing is a well-organized process between several molecules and mediators. As known from other diseases, genetic polymorphisms may exhibit different expression patterns in these mediators. Concerning fracture healing, this may lead to an extended healing process or non-union. We investigated the incidence of polymorphisms in patients with aseptic non-unions after femoral and tibial shaft fractures as compared to patients with uneventful healing. Exclusion criteria were smoking, diabetes, bilateral fractures, systemic corticoid therapy, and septic non-unions. Analysis of allele frequencies and genotype distribution of various mediators were carried out following PCR. Clinical parameters such as injury severity and in-hospital were analyzed. Fifty patients following non-union (group NU) were enrolled, the control group consisted of 44 patients (group H). A significant association of a PDGF haplotype and non-unions following fracture could be observed. There was a significantly increased in-hospital time and amount of surgical procedures in group NU. Polymorphisms within the PDGF gene seem to be a genetic risk factor for the development of non-unions of the lower extremity following fracture. The early identification of high risk patients could result in an adapted therapeutical strategy and might contribute to a significant decrease of posttraumatic non-unions.

TRACP 5b and CTX as osteological markers of delayed fracture healing

Radiological studies are the standard method to monitor fracture healing but they do not allow a timely assessment of bone healing. Biochemical markers react rapidly to changes in bone metabolism during fracture healing and could be an additional tool to monitor this process. The goal of this study was to observe changes in serum biomarkers and evaluate the possible differences in the serum levels of tartrate-resistant acid phosphatase 5b (TRACP 5b), total N-terminal propeptide of type I collagen (PINP), bone-specific alkaline phosphatase (BAP), and C-terminal cross-linking telopeptide of type I collagen (CTX) in patients with normal and delayed fracture healing. Several serum samples were collected for one year after the surgical treatment of long bone fractures in 248 patients. From this large pool, 15 patients with atrophic nonunion were matched to 15 patients with normal bone healing. Post-operative changes in osteological markers were monitored during the 1st, 2nd, 4th, 8th, 12th and 52nd weeks. The patients were followed both clinically and radiologically for the entire one-year duration of the study. In the first week, the absolute values of CTX decreased significantly (p=0.0164) in cases of delayed fracture healing. The relative values of TRACP 5b were significantly decreased at weeks 4 (p=0.0066) and 8 (p=0.0043). BAP and PINP levels decreased in the first week followed by an increase, but there were no significant differences in the absolute or relative values during the healing process in both patient groups. For the first time, we have demonstrated changes in serum concentrations of TRACP 5b, PINP, BAP, and CTX during normal and delayed fracture healing. Characteristic changes in systemic TRACP 5b and CTX levels could reflect the initial process of successful fracture healing and may be used in clinical practice to monitor the healing process. Furthermore, it could be very important for determining the beneficial effects of additional treatments such as ultrasound or BMPs in clinical trials.

Role of common biochemical markers for the assessment of fracture union

The progress of fracture union requires close monitoring. Whereas, clinical examination and radiographic studies assess the outcome, biochemical markers like serum alkaline phosphatase and urinary hydroxyproline reflect the actual status of bone resorption and bone formation over a short time frame. 36 patients of long bone fracture were randomly allocated for the study. When the patient reported to the Department of Orthopedics after fracture, serum and urinary samples were collected and X-ray of the affected part were taken. Subsequent samples were collected and X-ray taken just after management (either operative or conservative), after 3rd, 5th, 8th and 12th week, respectively after onset of fracture. According to the course of callus formation the patients were divided into two groups that progressed to proper union or malunion. The levels of serum alkaline phosphatase, urinary total and free hydroxyproline levels were measured and statistically analysed and compared. A statistically significant positive correlation between total urinary hydroxyproline excretion and serum alkaline phosphatase indicate progress towards satisfactory union. Thus, serial monitoring of biochemical markers of bone turnover can be used as an adjunct to clinical and radiological evidence of fracture healing.

Bone turnover marker profile in relation to the menstrual cycle of premenopausal healthy women

OBJECTIVE

To explore the bone turnover marker profile during the menstrual cycle of premenopausal women.

DESIGN

This was a noninterventional study. Levels of bone turnover markers, including serum C-terminal telopeptide of type I collagen (sCTX), bone-specific alkaline phosphatase, osteocalcin, procollagen type 1 N propeptide, and urinary N-terminal telopeptide of type I collagen, were measured in blood and urine samples during one menstrual cycle. Levels were expressed as raw test results and percent change from serum luteinizing hormone peak. Differences in mean levels of bone turnover markers between menstrual phases and subphases were examined.

RESULTS

Fifty-five women comprised the per-protocol population. Mean sCTX values were 0.48 ng/mL during the follicular phase (FP), 0.47 ng/mL at serum luteinizing hormone peak, and 0.43 ng/mL during the luteal phase (LP). Additionally, the mean percent change from luteinizing hormone peak varied from +4.35% during the FP to -5.11% during the LP (P = 0.0014). Mean sCTX levels during the early and through mid FP were significantly higher than levels during the mid and late LP. The pattern for urinary N-terminal telopeptide of type I collagen was similar to that of sCTX but not statistically significant. There was a statistically significant tendency for procollagen type I N propeptide levels to be lower during the FP relative to the LP. Levels of osteocalcin and bone-specific alkaline phosphatase did not vary significantly during the menstrual cycle.

CONCLUSIONS

Levels of some bone turnover markers varied during the menstrual cycle. A statistically significant change in sCTX (9.46%) occurred between the FP and LP of the menstrual cycle.

[Biochemical bone resorption markers during the healing of osteoporotic fractures]

BACKGROUND

This study investigated the progression and clinical relevance of biochemical resorption marker values during fracture healing in osteoporosis.

PATIENTS AND METHODS

In 44 patients with distal radius fractures and 29 patients without fractures, the blood and urine concentrations of pyridinoline (PYD), deoxypyridinoline (DPD), N-telopeptides (NTx), and bone sialoprotein (BSP) were recorded on the day of trauma as well as during further progression. All postmenopausal patients underwent bone density measurement. Accordingly, patients were divided into premenopausal, postmenopausal osteoporotic, and postmenopausal nonosteoporotic groups.

RESULTS

Between the groups, PYD, DPD, and NTx showed significant differences in their initial values. However, their further relative progression was primarily affected by the chosen therapy.

CONCLUSION

Bone resorption markers can diagnostically point to osteoporosis and are significant parameters in fracture healing.

Sequential changes of bone metabolism in normal and delayed union of the spine

Time-dependent changes in bone markers in delayed or nonunion of vertebral fracture were compared with those of normal union. Thirty-three patients with a fresh vertebral fracture were enrolled. Urinary Type I collagen C-terminal telopeptide, pyridinoline, deoxypyridinoline, serum C-terminal telopeptide, and N-midportion of osteocalcin (OC(N-mid)) were determined at the time of hospital admission (within 24 hours after the fracture event in all cases) and at 2, 4, 12, 24, and 48 weeks thereafter. Subjects were divided into two groups according to the results of MR images taken 48 weeks after fracture. Twenty-four were normally united (Group N) and nine had delayed or nonunion (Group D) of the spine. No differences between values of bone resorption markers in Group N and Group D were observed at any time. Serum OC(N-mid) in Group N started to increase at 2 weeks and reached the peak value at 24 weeks (180%); however, serum OC(N-mid) in Group D increased at most 120% from baseline to 4 weeks. Values of serum OC(N-mid) in Group N were higher at 24 and 48 weeks than those in Group D. Impairment of fracture healing was strongly associated with a deficit in the increase of osteocalcin in the later stage of fracture repair.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.