Implant surface alters compartmental-specific contributions to fixation strength in rats

Mechanical fixation of the implant to host bone is an important contributor to orthopedic implant survivorship. The relative importance of bone-implant contact, trabecular bone architecture, and cortical bone geometry to implant fixation strength has never been directly tested, especially in the settings of differential implant surface properties. Thus, using a rat model where titanium rods were placed into the intramedullary canal of the distal femur, we determined the relative contribution of bone-implant contact and peri-implant bone architecture to the fixation strength in implants with different surface roughness: highly polished and smooth (as-received) and dual acid-etched (DAE) implants. Using a training set that maximized variance in implant fixation strength, we initially examined correlation between implant fixation strength and outcome parameters from microcomputed tomography and found that osseointegration volume per total volume (OV/TV), trabecular bone volume per total volume (BV/TV), and cortical thickness (Ct.Th) were the single best compartment-specific predictors of fixation strength. We defined separate regression models to predict implant fixation strength for as-received and DAE implants. When the training set models were applied to independent validation sets, we found strong correlations between predicted and experimentally measured implant fixation strength, with r² = .843 in as received and r² = .825 in DAE implants. Interestingly, for as-received implants, OV/TV explained more of the total variance in implant fixation strength than the other variables, whereas in DAE implants, Ct.Th had the most explanatory power, suggesting that surface topography of implants affects which bone compartment is most important in providing implant fixation strength.     

A propensity score-matched comparison of recurrence outcomes after immediate implant vs autologous flap reconstruction in patients receiving neoadjuvant chemotherapy for breast cancer

Breast Cancer Research and Treatment - We compared oncologic outcomes between breast cancer patients who underwent immediate implant-based breast reconstruction (IBBR) and those who underwent...     

A patient with protrusion and multiple missing teeth treated with autotransplantation and space closure

Objective:To present a patient treated with submerging autotransplantation (SA) of an immature premolar and subsequent orthodontic space closure (OSC) and to report a 10-year follow-up result.Case and Method:A 10-year-old boy had multiple missing premolars with an asymmetric pattern (maxillary right first and second premolars, teeth 14 and 15; maxillary left second premolar, tooth 25; and mandibular right second premolar, tooth 45). After considering several treatment options, tooth 35 with immature root development underwent SA into the missing site of tooth 15 at a depth 5 mm below the occlusal plane and was stabilized with sutures to create a symmetric missing condition of the premolars in the four quadrants.Results:Three months after autotransplantation, spontaneous eruption of the transplanted tooth was observed. Nine months after autotransplantation, presence of the lamina dura of the transplanted tooth was confirmed with a periapical radiograph. Active orthodontic treatment was initiated to reduce lip protrusion by closing the missing spaces of teeth 14, 25, 35, and 45 and to correct dental midline deviation. After 33 months of active orthodontic treatment, Class I canine and molar relationships were obtained. During the 10-year follow-up, the pulp vitality of the transplanted tooth was maintained without any pathologic findings, including root resorption or pulp canal obliteration.Conclusions:In a patient with lip protrusion and multiple congenitally missing premolars with an asymmetric pattern, SA of one premolar from the normal quadrant into the quadrant missing two premolars with subsequent OSC of the missing sites of the other premolars can be an effective treatment modality.     

Typhoid fever complicated by multiple organ involvement: report of two cases

Typhoid fever complicated by multiple organ involvement has been rarely mentioned in the literature. We reported two cases of typhoid fever with several unusual manifestations, including acute renal failure, acute hepatitis, acute pancreatitis, disseminated intravascular coagulation, and lower gastrointestinal bleeding. A renal biopsy in the first case showed no pathological change. Bone marrow biopsy showed focal necrosis of matrix, which might have been due to severe illness. A liver biopsy in the second case showed a predominantly histiocytic proliferation with occasional neutrophilic infiltration in the portal areas and hepatic sinusoids. Focal necrosis, bile duct injury, and multiple eosinophilic bodies were also noted. After appropriate antimicrobial therapy, both patients recovered without any sequelae. The potential of multiple organ involvement is highlighted in typhoid fever, which, on rare occasions, may occur simultaneously in the same patient.     

Per-oral transgastric abdominal surgery

Laparoscopic surgery has several advantages over traditional surgery because it has been shown to be less invasive. The next logical step in the evolution of minimally invasive surgery may be to eliminate all abdominal incisions. The natural orifices provide a port of entry via the gastrointestinal tract to the peritoneal cavity. This approach would require the creation of a perforation, which is considered to be a major complication of endoscopy with significant morbidity and mortality. However, there are several recent studies that have described the technical feasibility and safety of a per-oral transgastric approach to the peritoneal cavity using conventional endoscopes. Theoretically, this approach could reduce postoperative abdominal wall pain, wound infection, hernia formation, and adhesions. This article aims to summarize the current status of transgastric surgery, currently referred to as natural orifice transluminal endoscopic surgery (NOTES), and to address some of its future challenges.     

Pharmacokinetics of single-dose cefmetazole following intramuscular administration of cefmetazole sodium to healthy male volunteers.

The tolerance and pharmacokinetics of cefmetazole were studied in healthy male volunteers who received a placebo (sterile saline) or a single dose of cefmetazole sodium intramuscularly. Drug-treated volunteers received one of four doses, 0.375, 0.750, 1, or 2 g. The drug was well tolerated, with no adverse medical events or laboratory changes observed during the study that could affect the pharmacokinetic interpretation of the data. Cefmetazole concentrations were determined by using a specific high-performance liquid chromatographic method. Serum cefmetazole concentrations were well described by a one-compartment open model with first-order absorption and elimination. Cefmetazole was rapidly absorbed in most volunteers, with a mean time to maximum concentration in serum of 1.24 +/- 0.12 h (+/- standard error of the mean), and the mean maximum concentration in serum increased from 17.0 +/- 1.6 to 74.2 +/- 9.5 micrograms/ml over the 0.375- to 2-g dose range. Maximum concentrations in serum, areas under serum concentration-time curve, and urinary excretion of intact drug increased in proportion to cefmetazole sodium dose. Times at which maximum concentrations in serum occurred, apparent volumes of distribution, steady-state volumes of distribution, absorption and elimination half-lives, and systemic clearances did not change significantly (P greater than 0.05) with drug dose. Although absorption and elimination half-lives were not significantly different in 10 of 40 volunteers (P greater than 0.05), in a majority of subjects elimination half-lives were approximately 10 times longer than absorption half-lives. The mean recovery of intact drug in urine ranged from 68.8 to 86.0% over the dose range studied, with a mean recovery over all doses of 77.1 +/- 2.4%. Rental clearances were significantly lower (P < 0.05) for the two lowest doses (93.0 and 84.3 versus 115.0 and 118.0 ml/min); these differences are not considered clinically important. The results of this study indicate that cefmetazole pharmacokinetics are linear after administration of single intramuscular doses ranging from 0.375 to 2 g, that clinically relevant concentrations of cefmetazole in serum (1 to 2 micrograms/ml) persist in a majority of volunteers for more than 8 h after administration of 0.750-g or higher doses, and that clinically relevant concentrations of cefmetazole continue to be excreted in urine 8 to 12 h after administration of 0.375- to 2-g doses.     

Assessment of Synvisc treatment in osteoarthritis

Background. Viscosupplementation is a relatively new method for the treatment of osteoarthritis (OA). The main goal of this project was to assess the safety and clinical utility of Hylan G-F20 (Synvisc(R)) in the treatment of pain associated with osteoarthritis of the knee. The type and frequency of additional therapies used during Synvisc(R) treatment were also assessed. It was a prospective project designed for monitoring Synvisc(R)-prescribing habits in usual medical care.
Material and method. One hundred ninety knee joints in 187 patients were studied (OA symptoms were bilateral in 3 women). Synvisc(R) was indicated for the local treatment of pain in osteoarthritis of the knee. After the diagnosis, Synvisc(R) therapy was started at the recommended dose of 2 ml per intra-articular injection once
a week (at 1-week intervals), three injections in total. The data collected, including medical history, physical examination, radiographic examination and treatment efficacy (overall assessment performed at each visit), were recorded on case report forms designed to facilitate statistical analysis. The physicians completed visual Analogue Scale (VAS) for overall assessment of OA pain at each visit. The clinical outcome was recorded after the end of therapy. The patient data were collected by physicians taking part in this project only.
Results. In 156 cases (82.1%) either a substantial improvement or subsidence of symptoms was observed. In 34 cases (17.9%) the improvement was small or there was no change in the patient's condition. There were local adverse reactions in 2 patients (1.07%). There was no need to cease the treatment, to hospitalise a patient or to start any additional treatment. In 167 patients (89.3%) there was no need to start any non-pharmacological concomitant treatment.
Conclusions. In summary, Synvisc(R) viscosupplementation should be rated among the safest and most effective methods for the treatment of OA, for it alleviates OA-related pain, thus reducing the need for NSAIDs and steroid injections. The use of Synvisc(R) in OA patients alleviates pain regardless of sex and age, the effect being the most pronounced in patients with low- and medium-grade radiographic changes.