Ostene, a New Water-Soluble Bone Hemostasis Agent

Development of novel waxy bone haemostatic agents composed of biodegradable polymers with osteogenic-enhancing peptides in rabbit models

OBJECTIVES

The use of bone wax (BW) is controversial for sternal haemostasis because it increases the risk of wound infection and inhibits bone healing. We developed new waxy bone haemostatic agents made from biodegradable polymers containing peptides and evaluated them using rabbit models.

METHODS

We designed 2 types of waxy bone haemostatic agents: peptide wax (PW) and non-peptide wax (NPW), which used poly(ε-caprolactone)-based biodegradable polymers with or without an osteogenesis-enhancing peptide, respectively. Rabbits were randomly divided into 4 groups based on treatment with BW, NPW, PW or no treatment. In a tibial defect model, the bleeding amount was measured and bone healing was evaluated by micro-computed tomography over 16 weeks. Bone healing in a median sternotomy model was assessed for 2 weeks using X-ray, micro-computed tomography, histological examination and flexural strength testing.

RESULTS

The textures of PW and NPW (n = 12 each) were similar to that of BW and achieved a comparable degree of haemostasis. The crevice area of the sternal fracture line in the BW group was significantly larger than that in other groups (n = 10 each). The PW group demonstrated the strongest sternal flexural strength (n = 10), with complete tibial healing at 16 weeks. No groups exhibited wound infection, including osteomyelitis.

CONCLUSIONS

Waxy biodegradable haemostatic agents showed satisfactory results in haemostasis and bone healing in rabbit models and may be an effective alternative to BW.

Evaluating the Efficacy of Water-Soluble Bone Wax (Tableau Wax) in Reducing Blood Loss in Spinal Fusion Surgery: A Randomized, Controlled, Pilot Study

Background and Objectives: Lumbar decompression with fusion surgery is an effective treatment for spinal stenosis, but critical postoperative hematoma is a concern. Bone wax has been widely used to control bone bleeding but it has some drawbacks. This study aimed to evaluate the efficacy of Tableau wax, a bioabsorbable hemostatic material, in patients undergoing spinal fusion surgery through a pilot study design. Materials and Methods: A total of 31 patients were enrolled in this single-surgeon, single-institution study. The participants underwent transforaminal lumbar interbody fusion surgery and were randomly assigned to the control group (Bone wax) or test group (Tableau wax). Demographic data, pre- and post-operative hemoglobin levels, blood loss volume, surgical time, Oswestry Disability Index, and EQ-5D scores were recorded. Results: The study showed no significant difference in preoperative and postoperative hemoglobin levels, Oswestry Disability Index, and EQ-5D scores between the groups. However, the Tableau wax group had a significantly lower reduction in hemoglobin levels (1.3 ± 1.0 g/dL) and blood loss (438.2 mL) compared to the Bone wax group (2.2 ± 0.9 g/dL and 663.1 mL, respectively; p = 0.018 and p = 0.022).

Hemostatic Agents in Orthopedic Surgery

Controlling blood loss is a crucial aspect of orthopedic surgery. Hemostatic agents can be used intraoperatively in combination with antifibrinolytics as part of an overall strategy to limit blood loss. Several new hemostatic agents have recently come to the market designed specifically for vascular surgery but have found uses in other surgical fields, including orthopedics. This article reviews the mechanisms of action and best uses of various mechanical hemostats, active hemostats, flowable hemostats, and fibrin sealants for achieving hemostasis in orthopedic surgery. Mechanical and active hemostats have been reported to successfully decrease blood loss from cancellous bone, capillaries, and venules. Flowable hemostats are generally favorable for use in small spaces where the swelling capabilities of mechanical and active hemostats can be detrimental to surrounding structures. Sealants are best used for closing defects in tissues.

Topical Coagulant Agents

Topical hemostatic agents have continued to develop as knowledge of coagulation physiology and pathophysiology has evolved. The addition of knowledge of hemostatic agents to a surgeon's armamentarium helps to push the boundaries of life-saving care. As the understanding of the complex physiology of coagulation and hemorrhage improves, so will the potential for developing hemostatic agents that are safe, affordable, and readily available. This article discusses topical coagulant agents and hemostatic materials currently available in the surgery. The relevant agents/materials, their characteristics, different utility in surgical hemostasis, and their relevant benefits and drawbacks are reviewed.

Efficacy and safety of a novel hemostatic material, BoneStat, compared with Ostene and Bone Wax in a rat calvarial defect model

Hemostasis has critical significance during surgical procedures. Bone Wax has traditionally been commonly used for bone hemostasis despite well-documented undesirable side effects: hindering osteogenesis and induction of inflammatory reactions with consequent increase in infection rates. A later developed formulation, Ostene, offers an alternative to Bone Wax with lesser undesired effects. In this study, BoneStat, a newly developed bone hemostatic formulation comprising water-soluble alkylene oxide co-polymers, was evaluated for water solubility, hemostatic efficacy, ease of handling, bone healing efficacy, and inflammatory reactions compared with Bone Wax and Ostene in a rat calvarial defect model. More than 95% of BoneStat was dissolved in water within 48 h, as was Ostene, but not Bone Wax. The time to hemostasis using BoneStat was significantly faster than with Ostene or Bone Wax. BoneStat also improved ease of handling compared to Ostene or BoneWax. BoneStat- and Ostene-treated groups constantly showed better bone healing than with Bone Wax. The BoneStat and Ostene groups presented no evidence of chronic inflammation reaction contrary to Bone Wax. These results suggest improved hemostasis, ease of handling, non-hindering bone healing, and unnoticeable chronic inflammatory reactions with BoneStat. Thus, Bonestat is a useful and reliable formulation for mechanical hemostasis.

Efficacy and Safety of Bioabsorbable Bone Hemostatic Agent in Total Knee Arthroplasty: A Prospective Randomized Controlled Trial

Although a bioabsorbable bone hemostatic agent (BBHA) was developed approximately 20 years ago to overcome the shortcomings of conventional bone wax, its bleeding control capacity has not yet been studied. This study was aimed at investigating the efficacy and safety of BBHA in total knee arthroplasty (TKA). Sixty-two patients who underwent unilateral primary TKA for knee osteoarthritis were included and randomized to the control or BBHA group. Before releasing the tourniquet, BBHA was applied on the bone-cut surface that was not covered by implants. The primary variable was the drainage volume during the postoperative period. The secondary outcomes were total estimated blood loss (EBL), hemoglobin level, hematocrit level, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) level, range of motion (ROM), pain visual analog scale (VAS) score, and rate of complications. There were no significant differences in drainage volume or EBL between the 2 groups. Hemoglobin and hematocrit levels were higher in the BBHA group during the 4-week postoperative period; however, the intergroup differences were not significant. The ESR, CRP, ROM, and pain VAS scores in the BBHA group were not significantly different from the corresponding values in the control group. No specific complications were observed. Although BBHA was found to be safe without complications, it did not decrease bleeding after TKA in general cases. Further studies are necessary to evaluate the efficacy of BBHA in patients with coagulation problems.

The role of hemostatic devices in neurosurgery. A systematic review

Hemostasis represents a fundamental step in every surgical procedure. During neurosurgical procedures, proper and robust hemostasis into confined spaces can significantly reduce the odds of perioperative complications. Over the decades, multiple methods have been applied, and several medical devices have been developed to promote and guarantee proper hemostasis. This study presents a systematic review of the most used intraoperative hemostatic methods and devices in neurosurgery. Insightful research was performed on the PubMed database according to the PRISMA guidelines. This comprehensive review of scientific literature represents a synoptic panel where the most used intraoperative hemostatic methods and devices available today in neurosurgery are classified and described.

Recent developments in controlling sternal wound infection after cardiac surgery and measures to enhance sternal healing

One of the major risks of cardiac surgery is the occurrence of infection at the sternal wound site. Sternal wound infections are primarily classified into superficial infection and deep sternal wound infection or mediastinitis. A patient is diagnosed with mediastinitis if microorganisms are present in their mediastinal tissue/fluid or with the observation of sternal wound infection during operation and with characteristic symptoms including chest pain, fever, and purulent drainage from the mediastinum. It is usually caused by Staphylococcal organisms in 75.8% of cases and the rest is caused by gram-negative bacteria. Currently, in cardiac surgery, hemostasis is achieved using electrocautery and bone wax, and the sternum is closed using wire cerclage. Several studies show that bone wax can act as a nidus for initiation of infection and the oozing blood and hematoma at the site can promote the growth of infectious organisms. Many research groups have developed different types of biomaterials and reported on the prevention of infection and healing of the sternum. These materials are reported to have both positive and negative effects. In this review, we highlight the current clinical practices undertaken to prevent infection and bleeding as well as research progress in this field and their outcomes in controlling bleeding, infection, and enhancing sternal healing.

Translation of bone wax and its substitutes: History, clinical status and future directions

Bone wax, primarily composed of beeswax and softening agent, is a century-old material used to control bleeding of disrupted bone surfaces by acting as a mechanical barrier to seal the wound. The current bone wax products are commonly packed in easy-to-open foil in the form of sterile sticks or plates, with excellent malleability and smooth consistency, enabling cost-effective and easy handling approach for bleeding control. It has also been reported that the inert nature of bone wax causes complications including foreign body reaction, infection promotion and bone healing inhibition. With the advances in biomaterials and the market boost of bone haemostatic materials, the arena of bone wax substitute research has expanded to a wide spectrum of material formulations and forms. However, the development of substitutes of bone wax for translation is a pivotal yet challenging topic because currently a potential candidate is recommended to be just as simple to use, effective and inexpensive to produce as traditional bone wax but also be absorbable and osteogenic. This review provides an overview of bone wax including its history, clinical applications and associated complication. In addition, emerging substitutes of bone wax and outlooks of future directions including the standardised evaluation methods are also discussed as an effort to catalyse the innovation and translation of bone haemostatic agents in the near future. The translational potential of this article: Occurrence of osseous haemorrhage is common in surgically incised or traumatically fractured bone. It is essential to stop bone bleeding to avoid further pathologic consequences such as tissue necrosis and eventually mortalities due to blood loss. Medical sterile bone wax is a classical material for haemostasis of bone during orthopaedic surgeries, thoracic surgeries, neurological surgeries and so on. Along with its widespread use, complications such as foreign body reaction, bone healing inhibition and infection promotion associated with bone wax are observed. With the growing knowledge in biomaterials and the boost of market of bone haemostatic materials, bone wax substitute research is thriving. An overview of bone and its substitutes together with evolution of their design criteria is carried out in this work, providing information for the innovation and translation of bone haemostatic agents in the near future.

Blood loss mitigation and replacement in facial surgery: a review

PURPOSE OF REVIEW

To provide a comprehensive overview of the predisposing factors that contribute to a risk of excess bleeding for surgical therapy in the head and neck regions, provide a thorough overview of techniques and tools for managing blood loss complications, and provide intervention algorithms to help guide clinical decision making.

RECENT FINDINGS

With the current landscape of medications and reversal agents, protocols for intervention in a variety of situations, and new tools for blood loss management all rapidly changing and being developed it is critical to stay up to date to provide patients the best care in the most critical of situations.

SUMMARY

With the risk of blood loss complications in head and neck surgery ranging from minimal to extreme surgeons require a comprehensive understanding risk factors, patient evaluation tools, and proper management algorithms. The first opportunity to prevent unnecessary blood loss and blood loss complications is the health history and physical appointment where a clinician can identify any medications, conditions, or other predisposing factors that would elevate a patient's risk of excess bleeding and the necessity for treatment augmentation. Although not all complications can be prevented because of the natural physiological variation that occurs from patient to patient, despite proper and proper diagnostics, a full working knowledge of most likely complications, hemostatic tools, and concise communication with team members can prevent a lot of blood loss and the complications associated.

The effect of the new hemostatic agent Ostene® on bone healing: An experimental study in rabbits

Introduction: Ostene® is a water-soluble wax-like alkylene oxide copolymer preparation for use as a mechanical hemostatic agent. This study aims to evaluate the effects of Ostene® on bone healing. Materials and Methods: Twenty albino rabbits were divided into four groups according to post-treatment follow-up (24 hr, 3 days, 7 days, 14 days) with five rabbits in each group. Each rabbit in all groups was treated with two study materials (Ostene® and Gelfoam®). Three holes were made in the mandibular bone of each rabbit using 5mm surgical bur; two holes were made on right side: one for testing Ostene® and another for Gelfoam®. A third hole, on the left side of mandible, was not treated, and was used as a control. Finally, the incision was closed. The specimens were collected at different days post-treatment and examined by histopathology. Result and Discussion: This study showed that there is a significant difference (p-value≤ 0.05) between the Ostene® group and the other groups (Gelfoam® and control). At 24 hr post intervention, there is a significant difference in osteoblast cell formation (p-value=0.03), and osteoclast cell formation (p-value=0.05). New blood vessel formation, osteoblast and osteoclast cell formation for Ostene® group at 3 days post-intervention were also significantly different (p-values = 0.05, 0.03, 0.04, respectively). At 7 days post-intervention p-values were 0.05 for osteoblast formation and 0.04 for osteoclast formation, respectively. After 14 days of healing p-value for osteoblast cell formation in the Ostene® group was 0.05 and 0.04 for osteoclast cell formation. Conclusions: The bone hemostatic agent Ostene® is an effective at enhancing osteogenesis by initiating proliferation of osteoblast and osteoclast cells.

Clinical experience in managing temporomandibular joint ankylosis: five-year appraisal in a Nigerian subpopulation

Objectives

Temporomandibular joint ankylosis (TMJA) is a joint pathology caused by bony and/or fibrous adhesion of the joint apparatus, resulting in partial or total loss of function.

Materials and Methods

This is a retrospective study conducted between 2012 and 2016 in the northwest region of Nigeria. The data retrieved includes gender, age, etiology of ankylosis, duration of ankylosis, laterality of ankylosis, type of imaging technique, type of airway management, types of incision, surgical procedure, mouth opening, interpositional materials used, and complications. Results were presented as simple frequencies and descriptive statistics.

Results

Thirty-six patients with TMJA were evaluated during the study period. There were 21 males (58.3%) and 15 females (41.7%), yielding a male:female ratio of 1.4:1. The patients' age ranged from 5 to 33 years with mean±standard deviation (13.8±6.6 years). Thirty-five cases (97.2%) were determined to be true/bony ankylosis, while only 1 case (2.8%) was false/fibrous ankylosis. Most of the TMJA cases (16 cases, 44.4%) were secondary to a fall. In our series, the most commonly utilized incision was the Bramley-Al-Kayat (15 cases, 41.7%). The mostly commonly performed procedures were condylectomies and upper ramus ostectomies (12 cases each, 33.3%), while the most commonly used interpositional material was temporalis fascia (14 cases, 38.9%). The complications that developed included 4 cases (11.1%) of severe hemorrhage, 1 case (2.8%) of facial nerve palsy, and 1 case (2.8%) of re-ankylosis.

Conclusion

Plain radiographs, with their shortcomings, still have significant roles in investigating TMJA. Aggressive postoperative physiotherapy for a minimum of 6 months is paramount for successful treatment.

Biomaterials and Advanced Technologies for Hemostatic Management of Bleeding

Bleeding complications arising from trauma, surgery, and as congenital, disease-associated, or drug-induced blood disorders can cause significant morbidities and mortalities in civilian and military populations. Therefore, stoppage of bleeding (hemostasis) is of paramount clinical significance in prophylactic, surgical, and emergency scenarios. For externally accessible injuries, a variety of natural and synthetic biomaterials have undergone robust research, leading to hemostatic technologies including glues, bandages, tamponades, tourniquets, dressings, and procoagulant powders. In contrast, treatment of internal noncompressible hemorrhage still heavily depends on transfusion of whole blood or blood's hemostatic components (platelets, fibrinogen, and coagulation factors). Transfusion of platelets poses significant challenges of limited availability, high cost, contamination risks, short shelf-life, low portability, performance variability, and immunological side effects, while use of fibrinogen or coagulation factors provides only partial mechanisms for hemostasis. With such considerations, significant interdisciplinary research endeavors have been focused on developing materials and technologies that can be manufactured conveniently, sterilized to minimize contamination and enhance shelf-life, and administered intravenously to mimic, leverage, and amplify physiological hemostatic mechanisms. Here, a comprehensive review regarding the various topical, intracavitary, and intravenous hemostatic technologies in terms of materials, mechanisms, and state-of-art is provided, and challenges and opportunities to help advancement of the field are discussed.

Novel bone wax based on poly(ethylene glycol)-calcium phosphate cement mixtures

Classic bone wax is associated with drawbacks such as the risk of infection, inflammation and hindered osteogenesis. Here, we developed a novel self-setting bone wax on the basis of hydrophilic poly(ethylene glycol) (PEG) and hydroxyapatite (HA) forming calcium phosphate cement (CPC), to overcome the problems that are linked to the use of conventional beeswax systems. Amounts of up to 10 wt.% of pregelatinized starch were additionally supplemented as hemostatic agent. After exposure to a humid environment, the PEG phase dissolved and was exchanged by penetrating water that interacted with the HA precursor (tetracalcium phosphate (TTCP)/monetite) to form highly porous, nanocrystalline HA via a dissolution/precipitation reaction. Simultaneously, pregelatinized starch could gel and supply the bone wax with liquid sealing features. The novel bone wax formulation was found to be cohesive, malleable and after hardening under aqueous conditions, it had a mechanical performance (∼2.5 MPa compressive strength) that is comparable to that of cancellous bone. It withstood systolic blood pressure conditions for several days and showed antibacterial properties for almost one week, even though 60% of the incorporated drug vancomycin hydrochloride was already released after 8h of deposition by diffusion controlled processes.

STATEMENT OF SIGNIFICANCE

The study investigated the development of alternative bone waxes on the basis of a hydroxyapatite (HA) forming calcium phosphate cement (CPC) system. Conventional bone waxes are composed of non-biodegradable beeswax/vaseline mixtures that are often linked to infection, inflammation and hindered osteogenesis. We combined the usage of bioresorbable polymers, the supplementation with hemostatic agents and the incorporation of a mineral component to overcome those drawbacks. Self-setting CPC precursors (tetracalcium phosphate (TTCP), monetite) were embedded in a resorbable matrix of poly(ethylene glycol) (PEG) and supplemented with pregelatinized starch. This formulation was found to be malleable and cohesive underwater. While immersion in an aqueous environment, CPC precursors formed highly porous, nanocrystalline HA via dissolution/precipitation reaction as water penetrated the novel wax formulation and PEG molecules simultaneously dissolved. The bone wax further withstood blood pressure conditions. After hardening, mechanical performance was comparable to that of cancellous bone and we also successfully provided the bone wax with antibacterial properties. In our opinion, the described bone wax formulation outmatches conventional bone waxes, as it circumvents the detriments being associated with the term "bone wax". Our wax has a novel composition and would broaden the application of CPC and besides, the general interest in bone waxes will increase, as they were long considered as a "first-line treatment" to avoid.

Self-Assembling Peptide Nanofibrous Hydrogel on Immediate Hemostasis and Accelerative Osteosis

The use of local agents to achieve hemostasis of bone that does not interfere with repair and recovery is a complex and emergency subject in surgery. In this study, the dual functional biodegradable self-assembling nanopeptide (SAP) RADA16-I was synthesized by solid phase synthesis and was shown to exhibit immediate hemostasis and accelerative osteosis. The RADA16-I showed good performance as a hemostatic agent, which was investigated by comparison with the effects of bone wax in the ilium bone defect model of New Zealand rabbits. The RADA16-I exhibited efficient function of bone regeneration in both radiographic analysis and histological examination, while the bone wax inhibited osteogenesis. Moreover, in in vivo experiment, the RADA16-I was shown to exhibit excellent biocompatibility, while the group with bone wax showed a severe inflammatory response at the interface with bone. Thus, the RADA16-I is proven to be an excellent biocompatible material with effective dual function of hemostasis and osteosis.

Bilayer electrospun poly(vinyl alcohol)–gelatin mat and biphasic calcium phosphate–pectin–gelatin hydrogel for application in bone hemorrhage

A bilayer composite scaffold consisting of a biphasic calcium phosphate–pectin–gelatin hydrogel and an electrospun poly(vinyl alcohol)–gelatin matrix was developed and investigated for application in bone hemorrhage. The aim of this research is to develop a new biomaterial system that provides a hemostatic effect on bone hemorrhage and does not interfere with native bone regeneration. The role of electrospun poly(vinyl alcohol)–gelatin in scaffolds is to provide the covering of the wound, while encapsulation and absorption of red blood cells are attributed to the biphasic calcium phosphate–pectin–gelatin hydrogel. Cell viability and cell proliferation were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Live/Dead assay, and immunofluorescence assay using pre-osteoblast MC3T3-E1 cells. The effects with and without hemostatic bilayer scaffolds on rat calvaria were compared at 1 and 3 weeks. The hemostatic bilayer agent showed good blood absorption behavior and efficient bone healing properties after 3 weeks, as observed by micro-computed tomography and hematoxylin and eosin staining.

Hemostatic polymers: the concept, state of the art and perspectives

This article presents a critical overview of the most significant developments in the use of polymers as hemostatic agents.

Infection following operations on the central nervous system: deconstructing the myth of the sterile field

Neurosurgical patients are at a high risk for infectious sequelae following operations. For neurosurgery in particular, the risk of surgical site infection has a unique implication given the proximity of the CSF and the CNS. Patient factors contribute to some degree; for example, cancer and trauma are often associated with impaired nutritional status, known risk factors for infection. Additionally, care-based factors for infection must also be considered, such as the length of surgery, the administration of steroids, and tissue devascularization (such as a craniotomy bone flap). When postoperative infection does occur, attention is commonly focused on potential lapses in surgical “sterility.” Evidence suggests that the surgical field is not free of microorganisms. The authors propose a paradigm shift in the nomenclature of the surgical field from “sterile” to “clean.” Continued efforts aimed at optimizing immune capacity and host defenses to combat potential infection are warranted.

Does bone wax induce a chronic inflammatory articular reaction?

BACKGROUND

Bone wax is used to control femoral neck bleeding during open femoroacetabular impingement (FAI) surgery. Despite its widespread use, only a few case reports and small case series describe side effects after extraarticular use. It is unclear whether intraarticular use of bone wax leads to such complications. However, during revision FAI surgery, we have observed various degrees of articular inflammatory reactions.

QUESTIONS/PURPOSES

We therefore investigated whether the bone wax used intraarticularly to control femoral neck bleeding during FAI surgery could be associated with the inflammatory reactions observed at revision surgery.

METHODS

We visually inspected the area and analyzed biopsy specimens from all 14 patients undergoing revision surgery from March 2005 to March 2006, 11 of whom had bone wax used at the time of original surgery. The three patients who did not have bone wax were used as controls.

RESULTS

Bone wax was identified macroscopically on the femoral neck at the time of the revision surgery in all 11 patients. In all 11 patients, biopsy results indicated a foreign body-type chronic synovial inflammation. Five patients also had an associated synovial lymphoplasmacytic inflammatory reaction. No inflammatory reaction was observed in the biopsy specimens obtained from the three patients in whom bone wax was not originally used.

CONCLUSIONS

Our findings suggest a synovial foreign body reaction, with or without an associated lymphoplasmacytic chronic inflammatory reaction, may be associated with intraarticular use of bone wax.

The effect of three hemostatic agents on early bone healing in an animal model

Background

Resorbable bone hemostasis materials, oxidized regenerated cellulose (ORC) and microfibrillar collagen (MFC), remain at the site of application for up to 8 weeks and may impair osteogenesis. Our experimental study compared the effect of a water-soluble alkylene oxide copolymer (AOC) to ORC and MFC versus no hemostatic material on early bone healing.

Methods

Two circular 2.7 mm non-critical defects were made in each tibia of 12 rabbits. Sufficient AOC, ORC or MFC was applied to achieve hemostasis, and effectiveness recorded. An autologous blood clot was applied to control defects. Rabbits were sacrificed at 17 days, tibiae excised and fixed. Bone healing was quantitatively measured by micro-computed tomography (micro-CT) expressed as fractional bone volume, and qualitatively assessed by histological examination of decalcified sections.

Results

Hemostasis was immediate after application of MFC and AOC, after 1-2 minutes with ORC, and >5 minutes for control. At 17 days post-surgery, micro-CT analysis showed near-complete healing in control and AOC groups, partial healing in the ORC group and minimal healing in the MFC group. Fractional bone volume was 8 fold greater in the control and AOC groups than in the MFC group (0.42 ± 0.06, 0.40 ± 0.03 vs 0.05 ± 0.01, P < 0.001) and over 1.5-fold greater than in the ORC group (0.25 ± 0.03, P < 0.05). By histology, MFC remained at the application site with minimal healing at the defect margins and early fibrotic tissue within the defect. ORC-treated defects showed partial healing but with early fibrotic tissue in the marrow space. Conversely, control and AOC-treated defects demonstrated newly formed woven bone rich in cellular activity with no evidence of AOC remaining at the application site.

Conclusions

Early healing appeared to be impaired by the presence of MFC and impeded by the presence of ORC. In contrast, AOC did not inhibit bone healing and suggest that AOC may be a better bone hemostatic material for procedures where bony fusion is critical and immediate hemostasis required.

Bone healing after median sternotomy: a comparison of two hemostatic devices

Background

Bone wax is traditionally used as part of surgical procedures to prevent bleeding from exposed spongy bone. It is an effective hemostatic device which creates a physical barrier. Unfortunately it interferes with subsequent bone healing and increases the risk of infection in experimental studies. Recently, a water-soluble, synthetic, hemostatic compound (Ostene^®) was introduced to serve the same purpose as bone wax without hampering bone healing. This study aims to compare sternal healing after application of either bone wax or Ostene^®.

Methods

Twenty-four pigs were randomized into one of three treatment groups: Ostene^®, bone wax or no hemostatic treatment (control). Each animal was subjected to midline sternotomy. Either Ostene^® or bone wax was applied to the spongy bone surfaces until local hemostasis was ensured. The control group received no hemostatic treatment. The wound was left open for 60 min before closing to simulate conditions alike those of cardiac surgery. All sterni were harvested 6 weeks after intervention.

Bone density and the area of the bone defect were determined with peripheral quantitative CT-scanning; bone healing was displayed with plain X-ray and chronic inflammation was histologically assessed.

Results

Both CT-scanning and plain X-ray disclosed that bone healing was significantly impaired in the bone wax group (p < 0.01) compared with the other two groups, and the former group had significantly more chronic inflammation (p < 0.01) than the two latter.

Conclusion

Bone wax inhibits bone healing and induces chronic inflammation in a porcine model. Ostene^® treated animals displayed bone healing characteristics and inflammatory reactions similar to those of the control group without application of a hemostatic agent.

Ostene, a new alkylene oxide copolymer bone hemostatic material, does not inhibit bone healing

OBJECTIVE

In this study, we investigate the effects of a soft bone hemostatic wax comprised of water-soluble alkylene oxide copolymers (Ostene; Ceremed, Inc., Los Angeles, CA) on bone healing in a rat calvaria defect model. We compared the effects with a control (no hemostatic agent) and bone wax, an insoluble and nonresorbable material commonly used for bone hemostasis.

METHODS

Two bilateral 3-mm circular noncritical-sized defects were made in the calvariae of 30 rats. Alkylene oxide copolymer or bone wax was applied or no hemostatic material was used (control). After 3, 6, and 12 weeks, rats were sacrificed and the calvariae excised. Bone healing, expressed as fractional bone volume (+/- standard error of the mean), was measured by microcomputed tomography.

RESULTS

Immediate hemostasis was achieved equally with bone wax and alkylene oxide copolymer. Bone wax-filled defects remained unchanged at all time points with negligible healing observed. At 3 weeks, no evidence of alkylene oxide copolymer was observed at the application site, with fractional bone volume significantly greater than bone wax-treated defects (0.20 +/- 0.03 versus 0.02 +/- 0.01; P = 0.0003). At 6 and 12-weeks, alkylene oxide copolymer-treated defects continued to show significantly greater healing versus bone wax (0.18 +/- 0.04 versus 0.05 +/- 0.01 and 0.31 +/- 0.04 versus 0.06 +/- 0.02, respectively). At all time points, alkylene oxide copolymer-treated and control defects showed good healing with no significant difference.

CONCLUSION

Alkylene oxide copolymer is an effective hemostatic agent that does not inhibit osteogenesis or bone healing.

Is bonewax safe and does it help?

BACKGROUND

Bonewax is routinely used to seal sternal edges after median sternotomy. Adverse effects on sternal healing, however, have been proclaimed although clear evidence does not exist. We performed a study on coronary bypass patients with or without bonewax application to verify negative effects and risk factors for early rethoracotomy, wound healing problems, and mediastinitis.

METHODS

In a prospectively randomized study on 400 patients undergoing isolated coronary bypass surgery, 200 patients with (bonewax) and 200 patients without bonewax (nonwax) application after median sternotomy were compared. Blood product consumption, early rethoracotomy, sternum stabilization, mediastinitis, and early mortality were compared. Risk factors such as age, sex, diabetes mellitus, and bonewax were analyzed by means of logistical regression analysis.

RESULTS

Blood product consumption was almost identical in both groups (red blood cells, 3.9 +/- 4.7 units in the bonewax group; 3.8 +/- 3.4 units in the nonwax patients; fresh frozen plasma, 0.5 +/- 1.6 units versus 0.5 +/- 1.3 units; platelet concentrates, 0.07 +/- 0.3 units versus 0.04 +/- 0.2 units). Early rethoracotomy (bonewax 6.5%; nonwax 5%), sternal stabilization (bonewax 3%; nonwax 3%), and mediastinitis (bonewax 1%; nonwax 0.5%) did not differ significantly. Early mortality was 2.5% in the bonewax group and 0.5% in the nonwax cohort. Bonewax did not appear as an independent risk factor for adverse outcome.

CONCLUSIONS

Negative effects of bonewax on the percentage of postoperative complications and outcome were not shown. However, positive effects such as a reduction of blood product substitution were also not observed. Using bonewax on sternal edges is obviously safe but not particularly beneficial.

Infection rates and healing using bone wax and a soluble polymer material

The effects of using a newly available water-soluble polymer bone hemostatic material in a contaminated environment were assessed in a rabbit tibial defect model. Infection rates and healing of polymer-treated bone were compared with the infection and healing of bone wax-treated bone and untreated controls after a bacterial challenge. Defects created in 24 rabbit tibias were treated with the polymer or bone wax, or left without a hemostatic agent. The defects were inoculated with Staphylococcus aureus ATCC-29213 (2.5 x 10(4) colony-forming units). After 4 weeks, all defects treated with bone wax were infected and osteomyelitis had developed, and none had evidence of bone healing. In the polymer and control groups, two defects in each group (25%) had osteomyelitis develop. The remaining six defects in each group (75%) showed no osteomyelitis and exhibited normal bone healing. The polymer-treated defects had a considerably lower rate of osteomyelitis and positive bone cultures compared with the bone wax-treated group. There were no differences between the polymer-treated and control groups in the rates of osteomyelitis, positive cultures, or bone healing. The use of a soluble polymer as an alternative to bone wax may decrease the rates of postoperative bone infections.

Topical hemostatic agents: a review

Topical hemostatic agents play an important role in both common and specialized dermatologic procedures. These agents can be classified based on their mechanism of action and include physical or mechanical agents, caustic agents, biologic physical agents, and physiologic agents. Some agents induce protein coagulation and precipitation resulting in occlusion of small cutaneous vessels, while others take advantage of latter stages in the coagulation cascade, activating biologic responses to bleeding. Traditional and newer topical hemostatic agents are discussed in this review, and the benefits and costs of each agent will be provided.

Donor site evaluation after autologous osteochondral mosaicplasty for cartilaginous lesions of the elbow joint

BACKGROUND

One significant disadvantage of autologous osteochondral mosaicplasty (mosaicplasty) is the harvesting of osteochondral grafts from the normal articular area of the knee joint. However, the effect of harvesting grafts on knee function remains unclear.

PURPOSE

To clarify the functional effects on the donor knee of harvesting osteochondral grafts and to perform magnetic resonance imaging evaluation of donor site repair after mosaicplasty for capitellar osteochondritis dissecans in young athletes.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Eleven male competitive athletes with advanced lesions of capitellar osteochondritis dissecans underwent mosaicplasties. The surgical technique involves obtaining small-sized cylindrical osteochondral grafts from the lateral periphery of the femoral condyle at the level of the patellofemoral joint and transplanting them to osteochondral defects in the capitellum. Assessment at a mean follow-up of 26 months included local findings of the donor knees, a Lysholm knee scoring scale, International Knee Documentation Committee standard evaluation form, and magnetic resonance imaging evaluation.

RESULTS

All patients returned to a competitive level of their previous sports without any donor site disturbances. Based on the Lysholm knee score and International Knee Documentation Committee evaluation form, all knees were graded as excellent and normal, respectively. The magnetic resonance imaging showed 50% to 100% defect fill in 6 of 9 patients and normal or nearly normal signals in 4 patients at the donor sites.

CONCLUSION

No adverse effects of osteochondral graft harvest on donor knee function were found after mosaicplasty for capitellar osteochondritis dissecans in young athletes. However, magnetic resonance imaging indicates that the donor site is resurfaced with fibrous tissue.