Alpha-Tricalcium Phosphate Bone Cement in the Surgical Treatment of Open Mastoid Cavity

Hypothesis: This study aimed to evaluate the biocompatibility of alpha-tricalcium phosphate bone cement in the obliteration of the mastoid cavity in guinea pigs. Background: Treatment with open cavity mastoidectomy can present poor functional results in chronic otitis media with cholesteatoma, especially if the cavity is large. Partial or total obliteration of the cavity can overcome these problems. Alpha-tricalcium phosphate bone cement has physicochemical characteristics that suggest its potential in mastoid cavity obliteration. Materials and Methods: Twenty guinea pigs were studied. All animals underwent surgery involving the dorsal tympanic bulla. In the study group animals (n = 10), mastoid cavity obliteration was performed with alpha-tricalcium phosphate bone cement. In the control group animals (n = 10), the cavity was left unfilled. On postoperative day 60, the animals were sacrificed and studied for signs of rejection of the material and other complications. Temporal bones were removed for histopathological study, in which the type and degree of inflammatory response, as well as the degree of ossification, were analyzed. Results: The mortality rate was the same in both groups. Deaths were attributed to anesthetic complications in the initial postoperative period. In the animals that survived, there were no complications, and there was good healing of the incision in both groups. There were no clinical signs of rejection of the material, and the histopathological analysis of the cement group revealed no signs of foreign body reaction (inflammatory response). Conclusion: Alpha-tricalcium phosphate bone cement is biocompatible in the mastoid cavity of guinea pigs.

USE OF ANTIBIOTIC SPACERS FOR KNEE ENDOPROSTHESIS INFECTIONS TREATMENT

Objective: The aim of this study is to evaluate the use of cement spacers impregnated with antibiotics for the treatment of infections in the nonconventional endoprostheses of the knee. Methodology: We have treated seven patients since 2004 (of which six were submitted to surgery in our service and one patient had been submitted to a primary tumor surgery in another removal service) with deep infection in knee tumor prosthesis. All patients were submitted to endoprosthesis removal and reconstructed with antibiotic cement spacer All patients were monitored both clinically and by lab tests as for monitoring the evolution, being considered able for reviews after 6 (six) months without infections signs. Results: We have noted a small predominance of infectious processes on the prosthesis inserted on proximal tibia as compared with distal femur (57.1% x 42.9%). The mean follow-up time of patients was 68.2 months. During the follow up, one patient died as a result of the root disease. Six patients out of seven were regarded as cured and one persisted with infection signs and symptoms. Conclusion: The results obtained up to date have motivated us to continue using this method of treatment.

Influence of interimplant distances and placement depth on peri-implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs

Objectives The aim of this study was to histomorphometrically evaluate the influence of interimplant distances (ID) and implant placement depth on bone remodeling around contiguous Morse cone connection implants with `platform-shifting` in a dog model. Material and methods Bilateral mandibular premolars of six dogs were extracted, and after 12 weeks, each dog received 8 implants, four placed 1.5 mm subcrestally (SCL) on one side of the mandible and four placed equicrestally (ECL) on the other side, alternating the ID of 2 and 3 mm. The experimental groups were SCL with IDs of 2 mm (2 SCL) and 3 mm (3 SCL) and ECL with IDs of 2 mm (2 ECL) and 3 mm (3 ECL). Metallic crowns were immediately installed. After 8 weeks, the animals were euthanized and histomorphometric analyses were performed to compare bone remodeling in the groups. Results The SCL groups` indices of crestal bone resorption were significantly lower than those of ECL groups. In addition, the vertical bone resorption around the implants was also numerically inferior in the SCL groups, but without statistical significance. No differences were obtained between the different IDs. All the groups presented similar good levels of bone-to-implant contact and histological bone density. Conclusion The subcrestal placement of contiguous Morse cone connection implants with `platform shifting` was more efficient in preserving the interimplant crestal bone. The IDs of 2 and 3 mm did not affect the bone remodeling significantly under the present conditions. To cite this article:Barros RRM, Novaes AB Jr., Muglia VA, Iezzi G, Piattelli A. Influence of interimplant distances and placement depth on peri-implant bone remodeling of adjacent and immediately loaded Morse cone connection implants: a histomorphometric study in dogs.Clin. Oral Impl. Res. 21, 2010; 371-378.doi: 10.1111/j.1600-0501.2009.01860.x.

Osteocyte Density in the Peri-Implant Bone of Immediately Loaded and Submerged Dental Implants

Background: The role of osteocytes in bone structure and function remains partially unresolved. Their participation in mechanotransduction, i.e., the conversion of a physical stimulus into a cellular response, has been hypothesized. The present study was an evaluation of the osteocyte density in the peri-implant bone of immediately loaded and submerged dental implants. Methods: Fourteen male patients were included in the study; all of them were partially edentulous and needed a posterior mandibular restoration. Implants were inserted in these areas; half of the sample was loaded immediately (included in a fixed provisional prosthesis on the same day as implant surgery), whereas the other half was left to heal submerged. Fourteen implants (seven immediately loaded and seven unloaded) were retrieved with a trephine after a healing period of 8 weeks. The specimens were treated to obtain thin ground sections, and histomorphometry was used to evaluate the osteocyte index in the peri-implant bone. Results: A higher and statistically significant number of osteocytes was found in the peri-implant bone around immediately loaded implants (P=0.0081). A correlation between the percentage of bone-implant contact and osteocyte density was found for immediately loaded implants (P=0.0480) but not for submerged implants (P=0.2667). Conclusion: The higher number of osteocytes in the peri-implant bone around immediately loaded implants could be related to the functional adaptation required by the loading stimulus, which also explains the hypothesized involvement of the osteocytes in the maintenance of the bone matrix. J Periodontol 2009;80:499-504.

Effects of a novel calcium aluminate cement on the early events of the progression of osteogenic cell cultures

The present study evaluated the progression of osteogenic cell cultures exposed to a novel calcium aluminate cement (CAC+) in comparison with the gold standard mineral trioxide aggregate (MTA). Cells were enzimatically isolated from newborn rat calvarial bone, plated on glass coverslips containing either CAC+ or a control MTA samples in the center, and grown under standard osteogenic conditions. Over the 10-day culture period, roundening of sample edges was clearly noticed only for MTA group. Although both cements supported osteogenic cell adhesion, spreading, and proliferation, CAC+-exposed cultures showed significantly higher values in terms of total cell number at days 3 and 7, and total protein content and alkaline phosphatase activity at day 10. The present in vitro results indicate that the exposure to CAC+ supports a higher differentiation of osteogenic cells compared with the ones exposed to MTA. Further experimental studies should consider CAC+ as a potential alternative to MTA when the repair of mineralized tissues is one of the desired outcomes in endodontic therapy.

Economic impact of treatment for surgical site infections in cases of total knee arthroplasty in a tertiary public hospital in Brazil

The aim of this study was to estimate the additional cost of treatment of a group of nosocomial infections in a tertiary public hospital. A retrospective observational cohort study was conducted by means of analyzing the medical records of 34 patients with infection after total knee arthroplasty, diagnosed in 2006 and 2007, who met the criteria for nosocomial infection according to the Centers for Disease Control and Prevention. To estimate the direct costs of treatment for these patients, the following data were gathered: length of hospital stay, laboratory tests, imaging examinations, and surgical procedures performed. Their costs were estimated from the minimum values according to the Brazilian Medical Association. The estimated cost of the antibiotics used was also obtained. The total length of stay in the ward was 976 days, at a cost of US$ 18,994.63, and, in the intensive care unit, it was 34 days at a cost of US$ 5,031.37. Forty-two debridement procedures were performed, at a cost of US$ 5,798.06, and 1965 tests (laboratory and imaging) were also performed, at a cost of US$ 15,359.25. US$ 20,845.01 was spent on antibiotics and US$ 1,735.16 on vacuum assisted closure therapy, microsurgical flaps, implant removal, spacer use, and surgical revision. The total additional cost of these cases of hospital infection in 2006 and 2007 was of US$ 91,843.75. Based on that, we demonstrate that the high cost of treatment for hospital infections emphasizes the importance of taking measures to prevent and control hospital infection.

Bone mineral apparent density in juvenile dermatomyositis: the role of lean body mass and glucocorticoid use

Objective: To analyse bone mineral density (BMD) in juvenile dermatomyositis (JDM) and its possible association with body composition, disease activity, duration of disease, glucocorticoid (GC) use, and biochemical bone parameters, including osteoprotegerin (OPG) and receptor activator of nuclear factor B (RANKL). Methods: Twenty girls with JDM and 20 controls matched for gender and age were selected. Body composition and BMD were analysed by dual-energy X-ray absorptiometry (DXA) and bone mineral apparent density (BMAD) was calculated. Duration of disease, cumulative GC, and GC pulse therapy use were determined from medical records. Disease activity and muscle strength were measured by the Disease Activity Score (DAS), the Childhood Myositis Assessment Scale (CMAS), and the Manual Muscle Test (MMT). Inflammatory and bone metabolism parameters were also analysed. OPG and RANKL were measured in patients and controls using an enzyme-linked immunosorbent assay (ELISA). Results: A lower BMAD in the femoral neck (p< 0.001), total femur (p< 0.001), and whole body (p=0.005) was observed in JDM patients compared to controls. Body composition analysis showed a lower lean mass in JDM compared to controls (p=0.015), but no difference was observed with regard to fat mass. A trend of lower serum calcium was observed in JDM (p=0.05), whereas all other parameters analysed, including OPG and RANKL, were similar. Multiple linear regression analysis revealed that, in JDM, lean mass (p< 0.01) and GC pulse therapy use (p< 0.05) were independent factors for BMAD in the hip region. Conclusions: This study has identified low lean mass and GC pulse therapy use as the major factors for low hip BMAD in JDM patients.

Low bone mass in juvenile onset sclerosis systemic: the possible role for 25-hydroxyvitamin D insufficiency

Juvenile onset systemic sclerosis (JoSSc) is a rare disease, and there are no studies focusing in bone mineral density and biochemical bone parameters. Ten consecutive patients with JoSSc and 10 controls gender, age, menarche age, and physical activity matched were selected. Clinical data were obtained at the medical visit and chart review. Laboratorial analysis included autoantibodies, 25-hydroxyvitamin D (25OHD), intact parathyroid hormone, calcium, phosphorus, alkaline phosphatase and albumin sera levels. Bone mineral density was analyzed by dual-energy X-ray absorptiometry, and bone mineral apparent density (BMAD) was calculated. A lower BMAD in femoral neck (0.294 +/- A 0.060 vs. 0.395 +/- A 0.048 g/cm(3), P = 0.001) and total femur (0.134 +/- A 0.021 vs. 0.171 +/- A 0.022 g/cm(3), P = 0.002) was observed in JoSSc compared to controls. Likewise, a trend to lower BMAD in lumbar spine (0.117 +/- A 0.013 vs. 0.119 +/- A 0.012 g/cm(3), P = 0.06) was also found in these patients. Serum levels of 25OHD were significantly lower in JoSSc compared to controls (18.1 +/- A 6.4 vs. 25.1 +/- A 6.6 ng/mL, P = 0.04), and all patients had vitamin D insufficiency (< 20 ng/mL) compared to 40% of controls (P = 0.01). All other biochemical parameters were within normal range and alike in both groups. BMAD in femoral neck and total femur was correlated with 25OHD levels in JoSSc (r = 0.82, P = 0.004; r = 0.707, P = 0.02; respectively). We have identified a remarkable high prevalence of 25OHD insufficiency in JoSSc. Its correlation with hip BMAD suggests a causal effect and reinforces the need to incorporate this hormone evaluation in this disease management.

FUNCTIONAL COMPARISON BETWEEN SEPTIC AND ASEPTIC KNEE ARTHROPLASTY REVIEW

Introduction: Total knee arthroplasty (TKA) imposes many risks. TKA infection is not the most frequent complication, but is probably the most serious one. Two-step review is the procedure of choice in deep knee prosthesis infection. On the other hand, aseptic prosthesis detachment represents almost half of the primary arthroplasty review indications, Patient`s satisfaction level might diminish after reviews. Objective: The objective of this study was to compare the quality of life and final result of TKA review for septic and aseptic failures. Methods: The patients were assessed using the HSS and SF-36 scores. The patients were divided in two groups: one group submitted to two-step review (septic) and the other to one-step review (aseptic). The analysis of the data obtained shows better scores for the second group in HSS and in 06 of 08 domains of SF-36 classification. Conclusions: The on-step review of total knee arthroplasty leads to better functional outcomes.

SPONTANEOUS FRACTURE OF THE FEMORAL NECK FOLLOWING PFN REMOVAL

Femoral neck fracture without associated trauma following consolidation of a transtrochanteric fracture is a rare event. The authors report a case of transtrochanteric fracture that was treated with PFN and which presented fracturing of the femoral neck two weeks after removal of the device. This occurrence was treated with partial arthroplasty.

Vascularized Bone Grafts for Upper Limb Reconstruction: Defects at the Distal Radius, Wrist, and Hand

Vascularized bone grafts have been successfully applied for the reconstruction of bone defects at the forearm, distal radius, carpus, and hand. Vascularized bone grafts are most commonly used in revision cases in which other approaches have failed. Vascularized bone grafts can be obtained from a variety of donor sites, including the fibula, the iliac crest, the distal radius (corticocancellous segments and vascularized periosteum), the metacarpals and metatarsals, and the medial femoral condyle (corticoperiosteal flaps). Their vascularity is preserved as either pedicled autografts or free flaps to carry the optimum biological potential to enhance union. The grafts can also be transferred as composite tissue flaps to reconstruct compound tissue defects. Selection of the most appropriate donor flap site is multifactorial. Considerations include size matching between donor and defect, the structural characteristics of the graft, the mechanical demands of the defect, proximity to the donor area, the need for an anastomosis, the duration of the procedure, and the donor site morbidity. This article focuses on defects of the distal radius, the wrist, and the hand. (J Hand Surg 2010;35A:1710-1718. (C) 2010 Published by Elsevier Inc. on behalf of the American Society for Surgery of the Hand.)

Chondrosarcoma of Bone Lessons From 46 Operated Cases in a Single Institution

Background Bone chondrosarcomas are rare malignant tumors that have variable biologic behavior, and their treatment is controversial. For low-grade tumors, there is no consensus on whether intralesional en bloc resections are the best treatment. Questions/purposes We therefore compared patients with Grade 1 and Grade 2 primary central chondrosarcomas to (1) determine difference in survival and (2) local recurrence rates; and (3) determine any association of histological grade with some clinical and demographic characteristics. Methods We retrospectively reviewed 46 patients with grade 1 and 2 chondrosarcomas. There were 25 men and 21 women with a mean age of 43 years (range, 17-79 years). Minimum followup was 32 months (mean, 99 months; range, 32-312 months) for the patients who remained alive in the end of the study. Twenty-three of the tumors were intracompartmental (Enneking A); of these, 19 were Grade 1 and 4 were Grade 2. Twenty-three tumors were extracompartmental (Enneking B); of these, 4 were Grade 1 and 19 were Grade 2. Twenty-five patients underwent intralesional resection, 18 had wide resection, and three had amputations. Results The overall survival rate was 94% and the disease-free survival rate was 90%. Among the 23 Grade 1 tumors, we observed six local recurrences and none of these patients died; among the 23 Grade 2 tumors, 10 recurred and two patients died. Local recurrence negatively influenced survival. Conclusions For lesions with radiographic characteristics of intracompartmental Grade 1 chondrosarcoma, we believe intralesional resection followed by electrocauterization and cement is the best treatment. When the imaging suggests aggressive (Grade 2 or 3) chondrosarcoma, then wide resection is promptly indicated.

Early-Onset, Progressive, Frequent, Extensive, and Severe Bone Mineral and Renal Complications in Multiple Endocrine Neoplasia Type 1-Associated Primary Hyperparathyroidism

Differences in bone mineral density (BMD) patterns have been recently reported between multiple endocrine neoplasia type 1-related primary hyperparathyroidism (HPT/MEN1) and sporadic primary HPT However studies on the early and later outcomes of bone/renal complications in HPT/MEN1 are lacking In this cross sectional study performed in a tertiary academic hospital 36 patients cases with uncontrolled HPT from 8 unrelated MEN1 families underwent dual energy X ray absorptiometry (DXA) scanning of the proximal one third of the distal radius (1/3DR) femoral neck, total hip, and lumbar spine (LS) The mean age of the patients was 389 +/- 145 years Parathyroid hormone (PTH)/calcium values were mildly elevated despite an overall high percentage of bone demineralization (77 8%) In the younger group (<50 years of age) demineralization in the 1/3DR was more frequent more severe and occurred earlier (40% Z-score 1 81 +/- 0 26) The older group (>50 years of age) had a higher frequency of bone demineralization at all sites (p < 005) and a larger number of affected bone sites (p < 0001), and BMD was more severely compromised in the 1/3DR (p = 007) and LS (p= 002) BMD values were lower in symptomatic (88 9%) than in asymptomatic HPT patients (p < 006) Patients with long standing HPT (>10 years) and gastnnoma/HPT presented significantly lower 1/3DR BMD values Urolithiasis occurred earlier (<30 years) and more frequently (75%) and was associated with related renal comorbidities (50%) and renal insufficiency in the older group (33%) Bone mineral- and urolithiasis-related renal complications in HPT/MEN1 are early onset frequent extensive severe and progressive These data should be considered in the individualized clinical/surgical management of patients with MEN1 associated HPT (C) 2010 American Society for Bone and Mineral Research

Characterization and in vitro activities of cell-free antigens from Histoplasma capsulatum-loaded biodegradable microspheres

In the last decades, the incidence of histoplasmosis, a pulmonary fungal disease caused by Histoplasma capsulatum, has increased worldwide. In this context, vaccines for the prevention of this infection or therapies are necessary. Cell-free antigens (CFAgs) from H. capsulatum when administered for murine immunization purposes are able to confer protection and control of the infection, since they activate cellular immunity. However the most of vaccination procedures need several anti, gens administrations and immunoadjuvants, which are not approved for use in humans. The aim of this study was to develop and characterize a vaccination approach using biodegradable PLGA microspheres (MS) that could allow the controlled and/or sustained release of the encapsulated antigens from H. capsulatum. CFAgs-loaded MS presented a size less than 10 mu m, were marked engulfed by bone marrow-derived macrophages (BMDM phi) and induced the nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production by these cells. Our data show that CFAgs-loaded MS induce cell activation, suggesting an immunostimulant effect to be further investigated during immunization procedures. CFAgs-loaded MS present potential to be used as vaccine in order to confer protection against H. capsulatum infection. (C) 2009 Elsevier B.V. All rights reserved.

Consequences of lifetime isolated growth hormone (GH) deficiency and effects of short-term GH treatment on bone in adults with a mutation in the GHRH-receptor gene

Growth hormone (GH) influences bone mass maintenance. However, the consequences of lifetime isolated GH deficiency (IGHD) on bone are not well established. We assessed the bone status and the effect of 6 months of GH replacement in GH-naive adults with IGHD due to a homozygous mutation of the GH-releasing hormone (GHRH)-receptor gene (GHRHR). We studied 20 individuals (10 men) with IGHD at baseline, after 6 months of depot GH treatment, and 6 and 12 months after discontinuation of GH. Quantitative ultrasound (QUS) of the heel was performed and serum osteocalcin (OC) and C-terminal cross-linking telopeptide of type I collagen (ICTP) were measured. QUS was also performed at baseline and 12 months later in a group of 20 normal control individuals (CO), who did not receive GH treatment. At baseline, the IGHD group had a lower T-score on QUS than CO (-1.15 +/- 0.9 vs. -0.07 +/- 0.9, P < 0.001). GH treatment improved this parameter, with improvement persisting for 12 months post-treatment (T-score for IGHD = -0.59 +/- 0.9, P < 0.05). GH also caused an increase in serum OC (baseline vs. pGH, P < 0.001) and ICTP (baseline vs. pGH, P < 0.01). The increase in OC was more marked during treatment and its reduction was slower after GH discontinuation than in ICTP. These data suggest that lifetime severe IGHD is associated with significant reduction in QUS parameters, which are partially reversed by short-term depot GH treatment. The treatment induces a biochemical pattern of bone anabolism that persists for at least 6 months after treatment discontinuation.