Standardised comparison of limonene-derived monoterpenes identifies structural determinants of anti-inflammatory activity.

Mint species are widely used in traditional and conventional medicine as topical analgesics for osteoarthritic pain and for disorders of the gastrointestinal and respiratory tracts which are all associated with chronic inflammation. To identify the structural determinants of anti-inflammatory activity and potency which are required for chemical optimization towards development of new anti-inflammatory drugs, a selected group of monoterpenes especially abundant in mint species was screened by measuring bacterial lipopolysacharide (LPS)-induced nitric oxide (NO) production in murine macrophages. Nine compounds significantly decreased LPS-induced NO production by more than 30%. IC50 values were calculated showing that the order of potency is: (S)-(+)-carvone > (R)-(-)-carvone > (+)-dihydrocarveol > (S)-8-hydroxycarvotanacetone > (R)-8-hydroxycarvotanacetone > (+)-dihydrocarvone > (-)-carveol > (-)-dihydrocarveol > (S)-(-)-pulegone. Considering the carbon numbering relative to the common precursor, limonene, the presence of an oxygenated group at C6 conjugated to a double bond at C1 and an isopropenyl group and S configuration at C4 are the major chemical features relevant for activity and potency. The most potent compound, (S)-(+)-carvone, significantly decreased the expression of NOS2 and IL-1ß in macrophages and in a cell model of osteoarthritis using primary human chondrocytes. (S)-(+)-carvone may be efficient in halting inflammation-related diseases, like osteoarthritis.

Expression and function of the nonclassical estrogen receptor, GPR30, in human cartilage and chondrocytes.

Estrogen hormones are important for cartilage homeostasis, but nothing is known regarding the expression and role of the membrane G protein-coupled estrogen receptor (GPER), G protein-coupled receptor 30 (GPR30), in adult articular chondrocytes. Using immunohistochemistry of cartilage sections, quantitative real-time polymerase chain reaction and Western blot of chondrocyte extracts, we found that these cells express GPR30. Nonetheless, the pattern of bands detected by two distinct antibodies does not overlap, suggesting that the proteins detected represent partially degraded forms of the receptor. Treatment with GPR30 agonists did not induce Akt or ERK1/2 phosphorylation, two known GPR30-activated signaling pathways, suggesting that GPR30 is not functional in human chondrocytes. Therefore, the protective anti-osteoarthritic role of estrogen hormones in cartilage homeostasis is likely independent of GPR30. This study was performed using human cartilage collected from the distal femoral condyles of multiorgan donors at the Bone and Tissue Bank of the University and Hospital Center of Coimbra.

Osteosynthesis of bilateral Vancouver B2 periprosthetic femoral fracture after a bilateral RM® total hip arthroplasty at 24 and 21-years follow-up: A case report.

INTRODUCTION: The management of periprosthetic femoral fractures following hip arthroplasty is challenging, and the choice between osteosynthesis of the fracture and the revision of the prosthesis is still matter of discussion. CASE REPORT: In a 81-year-old male patient, a bilateral Vancouver type-B2 periprosthetic femoral fracture with stem loosening occurred after an accidental fall. The patient had severe medical comorbidities. The radiographic study showed a bilateral Robert Mathys cementless total hip arthroplasty at 24 and 21-years follow-up. The fractures were treated with open reduction and fixation with locking compression plates. Bicortical fixation of the loose stem was obtained by the screws of the locking plate, due to the polymeric composition of the isoelastic femoral stem. Both fractures sites were augmented with bone allografts. At follow-up period of 12 months, the X-rays showed bone union of both fractures and bilateral stable stem fixation. The patient expressed high degree of satisfaction with surgery result. DISCUSSION: The standard treatment for Vancouver type-B2 periprosthetic femoral fractures is the removal of the loose implant, fixation of the fracture, and implantation of a new revision femoral stem. However, the implantation of two long revision hip prostheses is a major operation for an older patient with precarious health condition, which can contribute to higher risk of medical and prosthetic complications. CONCLUSION: In older patients with multiple comorbidities, the use of locking plates can be a valid treatment of bilateral Vancouver B2-periprosthetic femoral fractures following RM® cementless isoelastic stem, as an alternative surgical option to femoral stem revision.

Stable fixation of a madreporic Lord femoral prosthesis at 31-year follow-up in a total hip arthroplasty: A case report.

INTRODUCTION: Lord total hip prosthesis was discontinued due to high revision rates of the smooth threaded acetabular component and negative effects of stress shielding in the proximal femur. PRESENTATION OF CASE: We report the outcome of a Lord cementless femoral stem, in a 55-year-old woman. In 1984, the patient underwent a Lord total hip arthroplasty for the treatment of advanced dysplastic osteoarthritis of the left hip. After 12 years, the cementless acetabular component of the prosthesis had been revised due to aseptic loosening. An acetabular metallic support ring and a cemented polyethylene cup were implanted, the femoral stem was not changed. The acetabular bone loss was reconstructed with morsellised cancellous bone allografts by the impacting technique. No complications were reported during the period of 19 years of the postoperative course. At the last clinical and radiological evaluations, the patient presented an asymptomatic hip and expressed high degree of satisfaction with the surgery result. The femoral stem was stable, with no measurable subsidence or radiolucent lines around the stem. DISCUSSION: Several reports have presented a high clinical success rate with the fully-porous-coated Lord femoral stem in both primary and revision cases. However, the long-term results showed a substantial rate of proximal femoral bone loss and thigh pain. CONCLUSION: In our case, the Lord stem showed an excellent long-term result at the 31-year follow-up. To our knowledge, there is no published report with results of the Lord stem longer than 26-year's follow-up.

Fracture Characterization of Human Cortical Bone Under Mode I Loading.

A miniaturized version of the double cantilever beam (DCB) test is used to determine the fracture energy in human cortical bone under pure mode I loading. An equivalent crack length based data-reduction scheme is used with remarkable advantages relative to classical methods. Digital image correlation (DIC) technique is employed to determine crack opening displacement at the crack tip being correlated with the evolution of fracture energy. A method is presented to obtain the cohesive law (trapezoidal bilinear softening) mimicking the mechanical behavior observed in bone. Cohesive zone modeling (CZM) (finite-element method) was performed to validate the procedure showing excellent agreement.

Favorable outcome of a total hip arthroplasty with insufficient bone coverage of the roof reinforcement ring.

INTRODUCTION: Total hip arthroplasty in patients with developmental dysplasia of the hip can be a complex procedure due to acetabular and proximal femoral deformities. PRESENTATION OF CASE: A 59-year-old male patient underwent a total hip arthroplasty for the treatment of end-stage dysplastic osteoarthritis. A roof reinforcement ring, a cemented polyethylene cup, and a cementless stem were used. A portion of the superior rim of the ring was uncovered by the host bone. Morsellized autogenous femoral-head graft was impacted to fill the space between the superior rim of the ring and the superior part of the dysplastic acetabulum. At the follow-up after 5-years, the patient had no complaints and was very satisfied with the operation result. The hip radiograph revealed no signs of instability of the acetabular component, and no bone graft resorption. DISCUSSION: Favorable results were described using metal rings and conical femoral stems for the treatment of the developmental dysplasia of the hip. The superior rim of the metal ring should be against host bone for 60% of its support. Despite the suboptimal implantation of the ring compromising, apparently, mechanical stability of the arthroplasty, the outcome was favorable. CONCLUSION: This result can be supported by the good fixation of the metal ring to the pelvis with screws, the adequate orientation of both components of the total hip arthroplasty, and the bone graft incorporation.

Bone turnover markers for early detection of fracture healing disturbances: A review of the scientific literature.

Imaging techniques are the standard method for assessment of fracture healing processes. However, these methods are perhaps not entirely reliable for early detection of complications, the most frequent of these being delayed union and non-union. A prompt diagnosis of such disorders could prevent prolonged patient distress and disability. Efforts should be directed towards the development of new technologies for improving accuracy in diagnosing complications following bone fractures. The variation in the levels of bone turnover markers (BTMs) have been assessed with regard to there ability to predict impaired fracture healing at an early stage, nevertheless the conclusions of some studies are not consensual. In this article the authors have revised the potential of BTMs as early predictors of prognosis in adult patients presenting traumatic bone fractures but who did not suffer from osteopenia or postmenopausal osteoporosis. The available information from the different studies performed in this field was systematized in order to highlight the most promising BTMs for the assessment of fracture healing outcome.

A technique to remove a stable all-polyethylene cemented acetabular liner in revision hip arthroplasty: A case report.

INTRODUCTION: The removal of a well-fixed acetabular component in a total hip arthroplasty can cause bone fractures, excessive bleeding, as well as extended bone loss. The reimplantation of a new acetabular component may be compromised. PRESENTATION OF CASE: We report a technique using 2 cork-screws for removal a stable cemented acetabular component for the treatment of a recurrent dislocation of a cemented total hip arthroplasty, due to acetabular malposition. DISCUSSION: A diversity of approaches and tools has been used for extraction of the acetabular prosthesis. Using 2 cork-screws it is possible to create fissures and fractures into the cement mantle, and greater manual control is obtained facilitating the manipulation of the acetabular component in different directions. The cup-cemented bond can be disrupted, the host bone is preserved and the risks of complications are minimized. CONCLUSION: This technique is simple, available in any environment, reproducible, non-costly, non-timing consuming and safe.

Evaluation of the anti-inflammatory, anti-catabolic and pro-anabolic effects of E-caryophyllene, myrcene and limonene in a cell model of osteoarthritis.

Osteoarthritis is a progressive joint disease and a major cause of disability for which no curative therapies are yet available. To identify compounds with potential anti-osteoarthritic properties, in this study, we screened one sesquiterpene, E-caryophyllene, and two monoterpenes, myrcene and limonene, hydrocarbon compounds for anti-inflammatory, anti-catabolic and pro-anabolic activities in human chondrocytes. At non-cytotoxic concentrations, myrcene and limonene inhibited IL-1ß-induced nitric oxide production (IC50=37.3µg/ml and 85.3µg/ml, respectively), but E-caryophyllene was inactive. Myrcene, and limonene to a lesser extent, also decreased IL-1ß-induced NF-κB, JNK and p38 activation and the expression of inflammatory (iNOS) and catabolic (MMP-1 and MMP-13) genes, while increasing the expression of anti-catabolic genes (TIMP-1 and -3 by myrcene and TIMP-1 by limonene). Limonene increased ERK1/2 activation by 30%, while myrcene decreased it by 26%, relative to IL-1ß-treated cells. None of the compounds tested was able to increase the expression of cartilage matrix-specific genes (collagen II and aggrecan), but both compounds prevented the increased expression of the non-cartilage specific, collagen I, induced by IL-1ß. These data show that myrcene has significant anti-inflammatory and anti-catabolic effects in human chondrocytes and, thus, its ability to halt or, at least, slow down cartilage destruction and osteoarthritis progression warrants further investigation.

Differential effects of the essential oils of Lavandula luisieri and Eryngium duriaei subsp. juresianum in cell models of two chronic inflammatory diseases.

CONTEXT: Effective drugs to treat osteoarthritis (OA) and inflammatory bowel disease (IBD) are needed. OBJECTIVE: To identify essential oils (EOs) with anti-inflammatory activity in cell models of OA and IBD. MATERIALS AND METHODS: EOs from Eryngium duriaei subsp. juresianum (M. Laínz) M. Laínz (Apiaceae), Laserpitium eliasii subsp. thalictrifolium Sennen & Pau (Apiaceae), Lavandula luisieri (Rozeira) Rivas-Martínez (Lamiaceae), Othantus maritimus (L.) Hoff. & Link (Asteraceae), and Thapsia villosa L. (Apiaceae) were analyzed by GC and GC/MS. The anti-inflammatory activity of EOs (5-200 µg/mL) was evaluated by measuring inducible nitric oxide synthase (iNOS) and nuclear factor-κB (NF-κB) activation (total and phosphorylated IκB-α), in primary human chondrocytes and the intestinal cell line, C2BBe1, stimulated with interleukin-1ß (IL-1ß) or interferon-γ (IFN-γ), IL-1ß and tumor necrosis factor-α (TNF-α), respectively. RESULTS: The EO of L. luisieri significantly reduced iNOS (by 54.9 and 81.0%, respectively) and phosphorylated IκB-α (by 87.4% and 62.3%, respectively) in both cell models. The EO of E. duriaei subsp. juresianum caused similar effects in human chondrocytes, but was inactive in intestinal cells, even at higher concentrations. The EOs of L. eliasii subsp. thalictrifolium and O. maritimus decreased iNOS expression by 45.2 ± 8.7% and 45.2 ± 6.2%, respectively, in C2BBe1 cells and were inactive in chondrocytes. The EO of T. villosa was inactive in both cell types. DISCUSSION AND CONCLUSION: This is the first study showing anti-inflammatory effects of the EOs of L. luisieri and E. duriaei subsp. juresianum. These effects are specific of the cell type and may be valuable to develop new therapies or as sources of active compounds with improved efficacy and selectivity towards OA and IBD.

Horizontal Resorption of Fresh-Frozen Corticocancellous Bone Blocks in the Reconstruction of the Atrophic Maxilla at 5 Months.

BACKGROUND: Reliable implant-supported rehabilitation of an alveolar ridge needs sufficient volume of bone. In order to achieve a prosthetic-driven positioning, bone graft techniques may be required. PURPOSE: This prospective cohort study aims to clinically evaluate the amount of resorption of corticocancellous fresh-frozen allografts bone blocks used in the reconstruction of the severe atrophic maxilla. MATERIALS AND METHODS: Twenty-two partial and totally edentulous patients underwent bone augmentation procedures with fresh-frozen allogenous blocks from the iliac crest under local anesthesia. Implants were inserted into the grafted sites after a healing period of 5 months. Final fixed prosthesis was delivered ± 4 months later. Ridge width analysis and measurements were performed with a caliper before and after grafting and at implant insertion. Bone biopsies were performed in 16 patients. RESULTS: A total of 98 onlay block allografts were used in 22 patients with an initial mean alveolar ridge width of 3.41 ± 1.36 mm. Early exposure of blocks was observed in four situations and one of these completely resorbed. Mean horizontal bone gain was 3.63 ± 1.28 mm (p < .01). Mean buccal bone resorption between allograph placement and the reopening stage was 0.49 ± 0.54 mm, meaning approximately 7.1% (95% confidence interval: [5.6%, 8.6%]) of total ridge width loss during the integration period. One hundred thirty dental implants were placed with good primary stability (≥ 30 Ncm). Four implants presented early failure before the prosthetic delivery (96.7% implant survival). All patients were successfully rehabilitated. Histomorphometric analysis revealed 20.9 ± 5.8% of vital bone in close contact to the remaining grafted bone. A positive strong correlation (adjusted R(2) = 0.44, p = .003) was found between healing time and vital bone percentage. CONCLUSIONS: Augmentation procedures performed using fresh-frozen allografts from the iliac crest are a suitable alternative in the reconstruction of the atrophic maxilla with low resorption rate at 5 months, allowing proper stability of dental implants followed by fixed prosthetic rehabilitation.

Cemented total hip arthroplasty with retention of some existing hardware.

We report a case of a 63-year-old man who presented an end stage hip osteoarthritis 42 years after a proximal femoral osteotomy performed for the treatment of an intracapsular femoral neck fracture. A cemented total hip arthroplasty was implanted using a standard posterior approach. The osteotomy hardware was totally covered with a new cortical bone formation. A layer of bone tissue was removed, the screw heads were broken and the nail plate was also removed. The screw threaded portions were retained because they did not interfere with cemented femoral stem implantation. Fourteen years after total hip arthroplasty, the patient reported no pain and expressed high satisfaction with the surgery. The hip radiograph showed wear of the polyethylene cup and no periprosthetic osteolysis. Retention of hardware can be considered, especially in patients who have had hardware for several years, without any negative symptoms.

Anti-inflammatory and chondroprotective activity of (+)-α-pinene: structural and enantiomeric selectivity.

Previous studies have suggested that α-pinene, a common volatile plant metabolite, may have anti-inflammatory effects in human chondrocytes, thus exhibiting potential antiosteoarthritic activity. The objective of this study was to further characterize the potential antiosteoarthritic activity of selected pinene derivatives by evaluating their ability to modulate inflammation and extracellular matrix remodeling in human chondrocytes and to correlate the biological and chemical properties by determining whether the effects are isomer- and/or enantiomer-selective. To further elucidate chemicopharmacological interactions, the activities of other naturally occurring monoterpenes with the pinane nucleus were also investigated. At noncytotoxic concentrations, (+)-α-pinene (1) elicited the most potent inhibition of the IL-1ß-induced inflammatory and catabolic pathways, namely, NF-κB and JNK activation and the expression of the inflammatory (iNOS) and catabolic (MMP-1 and -13) genes. (-)-α-Pinene (2) was less active than the (+)-enantiomer (1), and ß-pinene (3) was inactive. E-Pinane (4) and oxygenated pinane-derived compounds, pinocarveol (5), myrtenal (6), (E)-myrtanol (7), myrtenol (8), and (Z)-verbenol (9), were less effective or even completely inactive and more cytotoxic than the pinenes tested (1-3). The data obtained show isomer- and enantiomer-selective anti-inflammatory and anticatabolic effects of α-pinene in human chondrocytes, (+)-α-pinene (1) being the most promising for further studies to determine its potential value as an antiosteoarthritic drug.

Necrotizing Faciitis after shoulder mobilization and intra-articular infiltration with betametasone.

Necrotizing Fasciitis is a rapidly progressive, potentially fatal infection of superficial fasciae and subcutaneous tissue, usually resulting from an inciting trauma to the skin. Medical literature refers few cases of necrotizing fasciitis related to intra-articular infiltrations, that often lead to patients death. This report describes the clinical events on a 55 year-old diabetic patient who developed upper extremity Necrotizing Fasciitis, 18 days after shoulder mobilization and intra-articular infiltration, due to Staphylococcus epidermidis. An early surgical debridement was performed and antibiotherapy was established, resulting in a successful outcome, despite the functional disability. We point out, through this case, the possibility of intra-articular injections of drugs causing Necrotizing Fasciitis, especially in risk patients.

A Fasceíte Necrosante é uma infeção de rápida progressão, potencialmente fatal, das fáscias superficiais e tecido celular subcutâneo, que resulta geralmente de um traumatismo da pele. Há poucos relatos na literatura médica de casos de Fasceíte Necrosante relacionados com infiltrações intrarticulares, que culminaram com frequência na morte dos doentes. Este relato descreve os eventos clínicos de um doente diabetico de 55 anos que desenvolveu uma Fasceíte Necrosante por Staphylococcus epidermidis do membro superior, 18 dias após uma mobilização do ombro e infiltração intrarticular. O doente foi submetido a desbridamento cirúrgico e antibioterapia precoces, que foram bem sucedidos, apesar da limitação functional. Com este caso alertamos para a possibilidade de uma Fasceíte Necrosante, após infiltração intrarticular de fármacos, particularmente em doentes de risco.

Expression and function of K(ATP) channels in normal and osteoarthritic human chondrocytes: possible role in glucose sensing.

ATP-sensitive potassium [K(ATP)] channels sense intracellular ATP/ADP levels, being essential components of a glucose-sensing apparatus in various cells that couples glucose metabolism, intracellular ATP/ADP levels and membrane potential. These channels are present in human chondrocytes, but their subunit composition and functions are unknown. This study aimed at elucidating the subunit composition of K(ATP) channels expressed in human chondrocytes and determining whether they play a role in regulating the abundance of major glucose transporters, GLUT-1 and GLUT-3, and glucose transport capacity. The results obtained show that human chondrocytes express the pore forming subunits, Kir6.1 and Kir6.2, at the mRNA and protein levels and the regulatory sulfonylurea receptor (SUR) subunits, SUR2A and SUR2B, but not SUR1. The expression of these subunits was no affected by culture under hyperglycemia-like conditions. Functional impairment of the channel activity, using a SUR blocker (glibenclamide 10 or 20 nM), reduced the protein levels of GLUT-1 and GLUT-3 by approximately 30% in normal chondrocytes, while in cells from cartilage with increasing osteoarthritic (OA) grade no changes were observed. Glucose transport capacity, however, was not affected in normal or OA chondrocytes. These results show that K(ATP) channel activity regulates the abundance of GLUT-1 and GLUT-3, although other mechanisms are involved in regulating the overall glucose transport capacity of human chondrocytes. Therefore, K(ATP) channels are potential components of a broad glucose sensing apparatus that modulates glucose transporters and allows human chondrocytes to adjust to varying extracellular glucose concentrations. This function of K(ATP) channels seems to be impaired in OA chondrocytes.

Rapid progression of a severe femoral bone loss in a stable revision hip prosthesis: causes and management.

We report a case of a severe bone loss of the proximal femur with a rapid progression, in a 72-year-old male patient with a stable total revision hip prosthesis. The patient had a persistent mechanical thigh pain. The blood laboratory values were normal. Infection disease and osteolytic bone tumor were excluded. A surgical procedure was performed. The native bone of the proximal femur was resorbed and replaced by a dense fibrous tissue with some sclerotic bone fragments. A large amount of a brownish fluid and a red-brown and friable tissue were found in the pseudojoint cavity. The proximal femur was reconstructed using a large amount of cryopreserved cancellous bone allograft, with retention of the femoral prosthesis. The mechanism of the bone lesion can be related not only to the host response to the wear particles, but mainly to the fluid pressure in the effective joint space. Femoral progressive osteolysis in a stable hip prosthesis is an indication for surgery in useful time, before adverse bone remodeling can begin and lead to major bone loss.

A technique to remove a well-fixed titanium-coated RM acetabular cup in revision hip arthroplasty.

A major concern during revision hip arthroplasty is acetabular bone loss and bleeding during the extraction of well-fixed cementless acetabular cup, because no interface exists between the host bone and the cup. Forceful removal of such component using curved gouges and osteotomes often leads to extended bone loss and compromises reimplantation of a new socket. In the following case report, we removed a well-fixed polyethylene titanium-coated RM acetabular cup with 20 years of follow-up, by significant wear of the polyethylene layer. The isoelastic femoral stem was also removed by mechanical failure. We report a technique for removal of the cementless acetabular cup using powered acetabular reamers. The RM cup was sequentially reamed and when the polyethylene layer was thin enough, the remaining cup was removed easily by hand tools. The acetabular bone stock is preserved and the risks of bone fractures and bleeding are minimized. To our knowledge, these principles were applied only in cemented cups. We have used this technique in 10 cases with excellent results and no complications were noted. This is a simple, reproducible, non-costly, non-timing consuming, safe and successful technique to remove well-fixed titanium-coated RM acetabular cups.

Role of glucose as a modulator of anabolic and catabolic gene expression in normal and osteoarthritic human chondrocytes.

Cartilage matrix homeostasis involves a dynamic balance between numerous signals that modulate chondrocyte functions. This study aimed at elucidating the role of the extracellular glucose concentration in modulating anabolic and catabolic gene expression in normal and osteoarthritic (OA) human chondrocytes and its ability to modify the gene expression responses induced by pro-anabolic stimuli, namely Transforming Growth Factor-ß (TGF). For this, we analyzed by real time RT-PCR the expression of articular cartilage matrix-specific and non-specific genes, namely collagen types II and I, respectively. The expression of the matrix metalloproteinases (MMPs)-1 and -13, which plays a major role in cartilage degradation in arthritic conditions, and of their tissue inhibitors (TIMP) was also measured. The results showed that exposure to high glucose (30 mM) increased the mRNA levels of both MMPs in OA chondrocytes, whereas in normal ones only MMP-1 increased. Collagen II mRNA was similarly increased in normal and OA chondrocytes, but the increase lasted longer in the later. Exposure to high glucose for 24 h prevented TGF-induced downregulation of MMP-13 gene expression in normal and OA chondrocytes, while the inhibitory effect of TGF on MMP-1 expression was only partially reduced. Other responses were not significantly modified. In conclusion, exposure of human chondrocytes to high glucose, as occurs in vivo in diabetes mellitus patients and in vitro for the production of engineered cartilage, favors the chondrocyte catabolic program. This may promote articular cartilage degradation, facilitating OA development and/or progression, as well as compromise the quality and consequent in vivo efficacy of tissue engineered cartilage.

Physicochemical characterization of biomaterials commonly used in dentistry as bone substitutes--comparison with human bone.

The present work focuses on the physicochemical characterization of selected mineral-based biomaterials that are frequently used in dental applications. The selected materials are commercially available as granules from different biological origins: bovine, porcine, and coralline. Natural and calcined human bone were used for comparison purposes. Besides a classical rationalization of chemical composition and crystallinity, a major emphasis was placed on the measurement of various morphostructural properties such as particle size, porosity, density, and specific surface area. Such properties are crucial to acquiring a full interpretation of the in vivo performance. The studied samples exhibited distinct particle sizes (between 200 and 1000 microm) and shapes. Mercury intrusion revealed not only that the total sample porosity varied considerably (33% for OsteoBiol, 50% for PepGen P-15, and 60% for BioOss) but also that a significant percentage of that porosity corresponded to submicron pores. Biocoral was not analyzed by this technique as it possesses larger pores than those of the porosimeter upper limit. The density values determined for the calcined samples were close to the theoretical values of hydroxyapatite. However, the values for the collagenated samples were lower, in accordance with their lower mineral content. The specific surface areas ranged from less than 1 m(2)/g (Biocoral) up to 60 m(2)/g (BioOss). The chemical and phase composition of most of the samples, the exception being Biocoral (aragonite), were hydroxyapatite based. Nonetheless, the samples exhibited different organic material content as a consequence of the distinct heat treatments that each had received.