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Douglas R Osmon

Publications and source records attributed to Douglas R Osmon.

At least 19 recordsLinked to original sources
PubMed2006

Do follow-up imaging examinations provide useful prognostic information in patients with spine infection?

BACKGROUND: The ability of follow-up imaging examinations to predict treatment failure in patients with spine infections has not been well studied. METHODS: We conducted a retrospective cohort analysis of patients with spine infection who had both baseline and 4-8-week follow-up imaging results available at the Mayo Clinic (Rochester, MN) during the period of 1994-2002. Follow-up imaging findings were categorized as improved, equivocal, or worse, compared with the baseline findings, on the basis of a simple grading system that focused on associated soft-tissue findings. RESULTS: Baseline and 4-8-week follow-up imaging findings were available for 79 patients with spine infection who presented to the Mayo Clinic during 1994-2002. Thirty-five infections (44%) were due to Staphylococcus aureus, 9 (11%) were due to coagulase-negative staphylococci, and 16 (20%) were culture negative. Twenty-seven (34%), 38 (48%), and 14 (18%) follow-up images were graded improved, equivocal, or worse, respectively. The cumulative rates of 1-year survival free of microbiologically confirmed treatment failure were 100%, 89% (95% CI, 74%-96%), and 56% (95% CI, 24%-83%) for patients with improved, equivocal, and worse follow-up imaging findings, respectively (P=.004). Only 3 (6%) of 52 patients deemed to have had clinical improvement at the time of the follow-up imaging study experienced treatment failure. Elevated levels of inflammatory biomarkers identified 2 of these patients as high risk for treatment failure, and the levels were not performed for the third patient. CONCLUSIONS: Applying a simple grading scale to assess follow-up imaging examinations for patients with spinal infection stratifies their risk of treatment failure. Patients' clinical statuses and inflammatory biomarker responses may be helpful for selecting patients at high risk for treatment failure who should undergo follow-up magnetic resonance imaging.

Aged↗
PubMed2006

Lack of detection of human retrovirus-5 proviral DNA in synovial tissue and blood specimens from individuals with rheumatoid arthritis or osteoarthritis.

OBJECTIVE: Prior studies have suggested an association of human retrovirus 5 with rheumatoid arthritis. The purpose of this study was to determine if human retrovirus-5 proviral DNA is present in synovial tissue and blood specimens from patients with rheumatoid arthritis or osteoarthritis, or those without joint disease. METHODS: Synovial tissue and whole blood from 75 patients with rheumatoid arthritis, 75 patients with osteoarthritis, and 50 patients without a primary arthritis diagnosis were assayed by real-time quantitative polymerase chain reaction (PCR) using primers that amplify a 186-bp fragment of human retrovirus-5 proviral DNA. RESULTS: A total of 200 tissue specimens, 200 mononuclear cells, and 196 of 200 granulocyte specimens tested negative for human retrovirus-5 proviral DNA. No association between human retrovirus 5 and rheumatoid arthritis or osteoarthritis (P = 0.516) was identified. Granulocyte specimens from 4 patients, 2 with rheumatoid arthritis and 2 with osteoarthritis, yielded a low positive human retrovirus-5 proviral DNA signal (83-1,365 copies of human retrovirus-5 proviral DNA/ml blood). CONCLUSION: Contrary to prior reports, we did not find an association between human retrovirus 5 and rheumatoid arthritis or osteoarthritis using a real-time PCR assay. Our findings are consistent with the recent finding that human retrovirus 5 is actually rabbit endogenous retrovirus H.

Adolescent↗
PubMed2006

Comparative study of antimicrobial release kinetics from polymethylmethacrylate.

Polymethylmethacrylate loaded with antimicrobial agents (most commonly vancomycin and/or aminoglycosides) is used for treatment and prevention of orthopaedic infections. Emergence of organisms resistant to vancomycin or aminoglycosides or both has been reported. Therefore, we studied in vitro release from polymethylmethacrylate beads of antimicrobials with suitable spectra for orthopaedic infections, including cefazolin, ciprofloxacin, gatifloxacin, levofloxacin, linezolid, and rifampin (2.5%, 7.5%, and 15%). Beads were placed in a continuous flow chamber, and antimicrobial concentrations in chamber outflow were determined by bioassay at timed intervals thereafter. Release profiles were bimodal with initial rapid release of high concentrations followed by sustained, slow release. Antimicrobial agents studied showed varied release profiles, indicating that elution from polymethylmethacrylate is unique to individual antimicrobial agents. Increasing antimicrobial concentration in polymethylmethacrylate increased peak concentrations and area under the curve. Cefazolin, ciprofloxacin, gatifloxacin, levofloxacin, linezolid, and rifampin may be suitable for incorporation into polymethylmethacrylate for management of orthopaedic infections.

Acetamides↗
PubMed2006

Unusual aerobic and anaerobic bacteria associated with prosthetic joint infections.

The association of certain microorganisms, such as Staphylococcus epidermidis, Staphylococcus aureus, and beta-hemolytic streptococci, with prosthetic joint infection (PJI) has been recognized for many years. To our knowledge, a systematic review of the presentation and management of less commonly encountered species of coagulase-negative staphylococci, nutritional-variant streptococci, aerobic non-spore and spore forming Gram-positive or anaerobic bacteria is not available. We therefore sought to provide a comprehensive literature review of PJI due to these microorganisms that will provide a valuable and quick reference for clinicians caring for these patients. We conducted a Medline search of all case reports and case series of PJI due to unusual aerobic and anaerobic bacteria. The presentation, surgical, and medical management strategies were reviewed. Appropriate medical and surgical management of such infections is complex and evolving as newer diagnostic tests, surgical techniques and antimicrobials become available. Management of patients with these infections requires close collaboration between the orthopaedic surgeon, infectious disease specialist and microbiology laboratory.

Bacteria, Aerobic↗
PubMed2006

Recent intraarticular steroid injection may increase infection rates in primary THA.

We retrospectively determined the rate of therapeutic intraarticular steroid injection within 1 year before total hip arthroplasty (THA) for osteoarthritis and whether the injection of the steroid increased the risk of infection. In a retrospective matched cohort study, 224 primary THAs (217 patients) implanted within 1 year of intraarticular steroid injection (Group 1) were compared with 224 primary THAs (220 patients) in patients who had not received an injection (Group 2). The mean time between injection and THA was 112 days (SD, 81 days). In Group 1, there were three deep and 11 superficial infections compared with one deep and eight superficial infections in Group 2. The hazard ratios of deep and superficial infections were 3 (95% CI, 0.3, 29.8) and 1.5 (95% CI, 0.6, 3.6), respectively. Intraarticular steroid injection within 1 year of THA did not affect postoperative rates of infection. However, the mean time from steroid injection to THA was 44 days (SD, 23 days) in the few patients who had deep infection develop. While not statistically significant, this raises a concern of increased risk of deep infection when receiving a steroid injection within 6 weeks of THA. Caution should be used before giving an intraarticular steroid injection within 2 months before THA.

Adult↗
PubMed2006

Fungi, mycobacteria, zoonotic and other organisms in prosthetic joint infection.

A systematic review of the presentation and management of prosthetic joint infection (PJI) due to zoonotic microorganisms, fungi, mycobacteria and other unusual microorganisms is not available. We therefore sought to provide a resource for the practicing orthopaedic surgeon which will serve as a guide for making appropriate decisions in managing such rare, but potentially problematic conditions. We conducted a Medline search of all case reports of PJI due to these unusual microorganisms. Our review of the current literature showed the diagnosis of PJI due to zoonotic microorganisms, fungi, mycobacteria and other unusual microorganisms typically necessitates specialized diagnostic tests. Maintaining a high index of suspicion in diagnosis of such unusual microorganisms and requesting the appropriate laboratory tests at the time of surgical débridement is crucial for determining the microbiologic etiology of these infections. The appropriate medical and surgical management of such infections is complex and often requires the use of special antimicrobials with which the orthopaedist may not be familiar. Collaboration with an infectious disease specialist is advisable when treating these infections.

Humans↗
PubMed2006

Sonication of explanted prosthetic components in bags for diagnosis of prosthetic joint infection is associated with risk of contamination.

Explanted orthopedic implants from 54 patients with aseptic failure and 24 patients with prosthetic knee or hip infection were sonicated in polyethylene bags. The sensitivities of periprosthetic tissue and sonicate fluid cultures for the diagnosis of prosthetic joint infection were 54% and 75%, whereas the specificities were 98% and 87%, respectively. Sonication in bags improved bacterial recovery from the surface of orthopedic implants; however, it lacked specificity, due to bag leakage.

Adult↗
PubMed2005

Outcome of prosthetic joint infection in patients with rheumatoid arthritis: the impact of medical and surgical therapy in 200 episodes.

BACKGROUND: Prosthetic joint infection in patients with rheumatoid arthritis is a serious complication of total joint arthroplasty. Little information is available on the outcome of medical and surgical treatments of prosthetic joint infection in patients with rheumatoid arthritis. METHODS: We conducted a retrospective analysis of all patients with rheumatoid arthritis and a total hip or total knee arthroplasty infection evaluated at Mayo Clinic (Rochester, MN) between 1 January 1969 and 31 December 1995. RESULTS: A total of 200 first episodes of prosthetic joint infection in 160 patients with rheumatoid arthritis were diagnosed during the study period. Thirty-seven percent of prosthetic joint infection episodes were due to Staphylococcus aureus. Of these episodes, 23% and 19% were treated with debridement and retention of components and 2-stage exchange, respectively. The type of surgical procedure was the only analyzed clinical variable that was associated with treatment failure (P < .001). Rates of 5-year survival free of treatment failure for patients with prosthetic joint infection episodes treated with debridement and retention of components, 2-stage exchange, and resection arthroplasty were 32% (95% confidence interval [CI], 21%-49%), 79% (95% CI, 66%-93%), and 61% (95% CI, 49%-74%), respectively. CONCLUSIONS: S. aureus is the most common pathogen among patients with rheumatoid arthritis with prosthetic joint infection. Two-stage exchange was used in only 19% of the prosthetic joint infection episodes among patients with rheumatoid arthritis during the study period, but it was associated with the best outcome. The variable most strongly associated with the outcome was the type of surgical procedure.

Adult↗
PubMed2005

Antibiotic prophylaxis in orthopedic prosthetic surgery.

The problem of prophylaxis in orthopedic implant surgery will become increasingly important and complex as the population ages and requires more arthroplasty procedures, and the prevalence of antimicrobial-resistant bacteria meanwhile also continues to rise. Energy spent preventing prosthetic joint infection is more effective than that expended in treating the infection of a prosthetic joint, once established. Preventive measures encompass a wide array of variables related to host response, wound environment, and microorganisms. Prophylaxis should address these areas in the preoperative, intraoperative, and postoperative periods. Antimicrobial prophylaxis remains the single most effective method of reducing the prevalence of infection after total joint arthroplasty. In the postoperative period, prophylaxis aims to protect the prosthetic joint against hematogenous seeding from oral, urologic, skin, or gastrointestinal sources. Currently, dental and urologic advisory statements provide recommendations for antimicrobial prophylaxis for high-risk patients with total joint arthroplasty undergoing high-risk procedures. Close collaboration between the orthopedic surgeon, urologist, or dentist and the infectious disease specialist is crucial for providing recommendations regarding prophylaxis in special circumstances. In these particular circumstances, individual decisions should be made based on clinical judgment.

Anti-Bacterial Agents↗
PubMed2005

The diagnosis of prosthetic joint infection: current techniques and emerging technologies.

It is important to diagnose prosthetic joint infection accurately because the medical and surgical treatment of prosthetic joint infection differs from that of other causes of prosthetic joint failure. Recognition of the presence or absence of infection at or before the time of surgery is important in directing the appropriate surgical approach. Recovery and susceptibility testing of the infecting organism are essential to the selection of appropriate anti-infective therapy.

Bacteria↗
PubMed2005

Editorial comment.

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Congresses as Topic↗
PubMed2005

Prevention of wound contamination using DuraPrep solution plus Ioban 2 drapes.

The use of the preoperative skin preparation DuraPrep is thought to enhance the adhesion qualities of an incise drape. If there is less drape lift it was hypothesized that there may be a reduction in wound contamination. We did a single-center, randomized trial to determine if a preoperative skin preparation containing DuraPrep solution plus Ioban 2 drapes reduced wound contamination in total joint replacement surgery compared with a povidone iodine scrub and paint plus Ioban 2 drapes. Secondary research questions focused on comparisons of differences in drape lift and cost between the two groups. Of the 176 evaluable patients, the proportion of patients with a contaminated wound was similar in the two groups (DuraPrep 28.0% versus povidone iodine 36.4%). The mean drape lift in the DuraPrep group was less than the povidone iodine group (1.5 cm versus 9.9 cm respectively). The mean cost of prepping was lower for the DuraPrep group compared with the povidone iodine group (dollars 93.36 and dollars 248.91, respectively). A preoperative skin preparation regimen containing DuraPrep solution plus Ioban 2 drapes is equivalent to a povidone iodine scrub and paint and Ioban 2 for the prevention of wound contamination during total joint replacement surgery. Improved drape lift and cost may influence the choice between the two methods.

Adult↗
PubMed2005

High rate of aminoglycoside resistance among staphylococci causing prosthetic joint infection.

Gentamicin and tobramycin are two aminoglycosides commonly impregnated into polymethylmethacrylate for treatment and prevention of prosthetic joint infection. Susceptibilities of staphylococci to aminoglycosides are not reported routinely in the United States. The gentamicin and tobramycin minimum inhibitory value of 93 staphylococci from patients with PJI were determined. Forty-one and 66% of the isolates were resistant to gentamicin and tobramycin, respectively. Methicillin-resistant Staphylococcus aureus isolates were more likely to be resistant to gentamicin or tobramycin than were their methicillin susceptible counterparts. The findings suggest that consideration should be given to the further study of agents other than aminoglycosides for incorporation into polymethylmethacrylate for the treatment and prevention of prosthetic joint infection.

Anti-Bacterial Agents↗
PubMed2005

Epidemiology, treatment, and prevention of community-acquired methicillin-resistant Staphylococcus aureus infections.

Since first described In 1961, methicillin-resistant Staphylococcus aureus (MRSA) has become a common nosocomial pathogen. Substantial increases in MRSA infections among nonhospitalized patients are being reported. Methicillin-resistant S. aureus is the most common isolate from skin and soft tissue infections in selected centers in the United States. Community-acquired MRSA strains differ from nosocomial strains in clinically relevant ways, such as in their propensity to cause skin and soft tissue infection and severe necrotizing pneumonia. Clinicians in numerous specialties, particularly primary care physicians, will likely evaluate patients presentIng with community-acquired MRSA and should become familiar with the epidemiology and clinical characteristics of and evolving therapeutic and preventive strategies for this infection.

Community-Acquired Infections↗
PubMed2004

Synovial fluid leukocyte count and differential for the diagnosis of prosthetic knee infection.

PURPOSE: Criteria for the interpretation of synovial fluid are well established for native joint disorders but lacking for the evaluation of prosthetic joint failure. Our aim was to define cutoff values for synovial fluid leukocyte count and neutrophil percentage for differentiating aseptic failure and prosthetic joint infection. METHODS: We performed a prospective study of 133 patients in whom synovial fluid specimens were collected before total knee arthroplasty revision between January 1998 and December 2003. Patients with underlying inflammatory joint disease were excluded. RESULTS: Aseptic failure was diagnosed in 99 patients and prosthetic joint infection was diagnosed in 34 patients. The synovial fluid leukocyte count was significantly higher in patients with prosthetic joint infection (median, 18.9 x 10(3)/microL; range, 0.3 to 178 x 10(3)/microL) than in those with aseptic failure (median, 0.3 x 10(3)/microL; range, 0.1 to 16 x 10(3)/microL; P <0.0001); the neutrophil percentage was also significantly higher in patients with prosthetic joint infection (median [range], 92% [55% to 100%] vs. 7% [0% to 79%], P <0.0001). A leukocyte count of >1.7 x 10(3)/microL had a sensitivity of 94% and a specificity of 88% for diagnosing prosthetic joint infection; a differential of >65% neutrophils had a sensitivity of 97% and a specificity of 98%. Staphylococcus aureus was the only pathogen associated with leukocyte counts >100 x 10(3)/microL. CONCLUSION: A synovial fluid leukocyte differential of >65% neutrophils (or a leukocyte count of >1.7 x 10(3)/microL) is a sensitive and specific test for the diagnosis of prosthetic knee infection in patients without underlying inflammatory joint disease.

Adult↗