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Arlen D Hanssen

Publications and source records attributed to Arlen D Hanssen.

70 records · Page 4Linked to original sources
PubMed2003

Orthopaedic crossfire--All patellae should be resurfaced during primary total knee arthroplasty: in the affirmative.

Patients with inflammatory arthritis, crystalline deposition disease, or severe patellofemoral arthritis have superior functional results with patellar resurfacing as compared with patellar retention. The only remaining issue is whether there is any advantage to resurfacing or retention in patients with osteoarthritic knees in the absence of severe patellofemoral arthritis. Although the answer is still unclear from available prospective randomized clinical trials, the evidence leans toward routine resurfacing of the patella during primary total knee arthroplasty in osteoarthritic knees too. Evidence exists that the results of patellar retention in osteoarthritic knees deteriorate with longer follow-up study. Long-term follow-up evaluations of available prospective clinical trials will be needed to assess this controversy more definitively.

Arthroplasty, Replacement, Knee↗
PubMed2003

Infection after shoulder instability surgery.

Currently, there are no reported series on the outcome of patients treated for infection after shoulder instability surgery. Therefore, the purpose of this study was to review patients who were treated for infection after shoulder instability surgery at our institution between 1980 and 2001 to determine the functional outcome and organisms responsible for infection. During this period, six patients were treated for infection after shoulder instability surgery. Three patients had an early postoperative infection, presenting 6 weeks or less from the time of instability surgery. Three patients had a late infection, presenting 8 months or greater from the time of surgery. Each of the three patients with a late infection had a sinus leading to a retained nonabsorbable suture. None of the six patients have had recurrent shoulder instability. Three patients had a polymicrobial infection and three patients had single organisms. Infection may be acute or significantly delayed from the time of the instability procedure. Additionally, among patients with late infection, there should be a high degree of suspicion for a nidus of infection surrounding nonabsorbable sutures.

Adult↗
PubMed2003

Use of erythropoietin in two-stage reimplantation total hip arthroplasty.

This study was done to quantify the effect of epoetin alfa on the transfusion requirements of patients having two-stage reimplantation for infected total hip arthroplasties. This prospective study included 30 consecutive patients treated with a two-stage reimplantation procedure during a 2-year period at one institution. Each patient received a standard dose of epoetin alpha (40,000 units) subcutaneous in the interval between resection and reimplantation. Transfusions were administered only when warranted by clinical symptoms and were not governed by predetermined hemoglobin levels. When compared with a control group of similar patients, the hemoglobin levels before reimplantation were significantly higher (14.0 g/dL versus 11.8 g/dL) and the median allogeneic blood requirements were significantly lower (0 units/patient [range, 0-6] versus 4.3 units per patient [range, 0-9]). Epoetin alfa used in the interval between the resection and reimplantation stage significantly increased the hemoglobin levels and decreased the rate of transfusion for patients having two-stage reimplantation total hip arthroplasty.

Aged↗
PubMed2003

Levofloxacin and trovafloxacin inhibition of experimental fracture-healing.

We previously have shown that experimental fractures exposed to ciprofloxacin have diminished fracture healing. The purpose of this study was to assess the effect of levofloxacin and trovafloxacin on experimental fracture healing to test the hypothesis that diminished fracture healing is a quinolone class effect. Sixty-one male Wistar rats were divided into three groups, which received 25 mg/kg of levofloxacin twice daily for 3 weeks, 35 mg/kg of trovafloxacin twice daily for 3 weeks, or no treatment, beginning 7 days after production of closed, nondisplaced, bilateral femoral fractures. The mean peak serum concentrations of levofloxacin and trovafloxacin drawn 30 minutes after administration were 6.9 and 7.0 microg/mL, respectively. Radiographic, histologic, and biomechanical studies were used to evaluate fracture healing. Torsional strength testing of fracture callus exposed to levofloxacin and trovafloxacin revealed a decrease in strength (299 and 257 N-mm, respectively) as compared with controls (364 N-mm). Radiographs revealed significantly more advanced healing in control animals (Goldberg score of 2.1) compared with the fractures in the rats treated with levofloxacin and trovafloxacin (Goldberg score of 1.5 in both groups). Fracture calluses in the animals treated with levofloxacin and trovafloxacin showed a lower histologic grade (5.3 and 3.5, respectively) as compared with control animals (7.5) representing a less mature callus with the presence of more cartilage and less woven bone. These data suggest that experimental fractures systemically exposed to levofloxacin or trovafloxacin have diminished healing during the early stages of fracture repair. The administration of quinolones during early fracture repair may compromise fracture healing in humans.

Animals↗
PubMed2003

Molecular and antibiofilm approaches to prosthetic joint infection.

The majority of patients with prosthetic joint replacement (arthroplasty) experience dramatic relief of pain and restoration of satisfactory joint function. In the United States, more than.5 million people have a primary arthroplasty each year. Less than 10% of prosthesis recipients have complications develop during their lifetime, commonly as a result of aseptic biomechanical failure, followed by prosthetic joint infection. The pathogenesis of prosthetic joint infection is related to bacteria in biofilms, in which they are protected from antimicrobial killing and host responses rendering these infections difficult to eradicate. Current microbiology laboratory methods for diagnosis of prosthetic joint infection depend on isolation of a pathogen by culture. However, these methods have neither ideal sensitivity nor ideal specificity. Therefore, culture-independent molecular methods have been used to improve the diagnosis of prosthetic joint infection. In the research setting, detection of 16S ribosomal deoxyribonucleic acid by polymerase chain reaction has been used in the molecular diagnosis of prosthetic joint infection. Various antibiofilm strategies directed at disruption of adherent bacteria are the focus of intense research to improve the detection of biofilm organisms and their eradication. In this article, molecular and antibiofilm approaches to prosthetic joint infection are reviewed.

Attachment Sites, Microbiological↗
PubMed2003

Results of treatment of infection in both knees after bilateral total knee arthroplasty.

BACKGROUND: The purpose of this study was to review the results and complications of treatment of simultaneous infection of both knees after bilateral total knee arthroplasty. METHODS: Between 1976 and 1999, twenty-one patients with a mean age of seventy-one years were treated for simultaneous infection of both knees after bilateral total knee arthroplasty. Two patients died within two years, and one patient was lost to follow-up after one year. The remaining eighteen patients were followed for a mean of five years. At the time of presentation, all twenty-one patients had had symptoms for less than three weeks. Eleven patients (twenty-two knees) were treated with attempts at prosthetic salvage with surgical débridement and administration of suppressive antibiotics. Resection arthroplasty was performed as the initial treatment in ten patients (twenty knees). RESULTS: Of the ten patients treated with initial resection, seven patients (fourteen knees) underwent subsequent reimplantation. All fourteen knees were functioning well at the time of the latest follow-up, and none had been revised at a mean of two years after reimplantation. Of the eleven patients (twenty-two knees) who had been initially treated with prosthetic salvage, nine patients (eighteen knees) had a recurrence of the infection that required a reoperation (bilateral resection arthroplasty in seven patients, bilateral above-the-knee amputation in one patient, and repeat débridement of both knees in one patient). Two of the seven patients who had resection underwent reimplantation six weeks postoperatively, and the other five patients (ten knees) did not have reimplantation because of low functional demands and prohibitive medical comorbidity. CONCLUSION: We believe that treatment of simultaneous infection of both knees after bilateral total knee arthroplasty should consist of bilateral resection arthroplasty and delayed reimplantation after a period of intravenous administration of organism-specific antibiotics.

Aged↗
PubMed2002

Delayed reimplantation arthroplasty for candidal prosthetic joint infection: a report of 4 cases and review of the literature.

Fungal prosthetic joint infection (PJI) is rare, with Candida species being the most frequently reported pathogen in the medical literature. The risk of relapse following delayed reimplantation arthroplasty for candidal PJI is unknown. We describe 4 new cases and summarize 6 previously reported cases of candidal PJI treated with delayed reimplantation arthroplasty. Ninety percent of the patients received antifungal therapy. Eight patients received amphotericin B either alone or in combination with other antifungals. One patient received fluconazole alone. The median duration of time from resection arthroplasty to reimplantation for total hip and total knee arthroplasties was 8.6 and 2.3 months, respectively. Eight patients did not have relapse of candidal PJI following delayed reimplantation arthroplasty after a median duration of follow-up of 50.7 months (range, 2--73 months). Candidal PJI can be successfully treated with delayed reimplantation arthroplasty after receipt appropriate antifungal therapy.

Adult↗
PubMed2002

Managing the infected knee: as good as it gets.

The clinical presentation is a useful guide for selecting the treatment of an infected total knee arthroplasty. Prosthesis retention is indicated in patients with infections that occur within 30 days after arthroplasty and in patients with well-functioning prostheses who develop an acute late hematogenous infection. Débridement attempts should be open and not arthroscopic. When prosthesis removal is required, the preferred approach is a delayed reconstructive technique, the 2-staged reimplantation, rather than a direct-exchange procedure. The use of block spacers or mobile articulating devices to deliver high-dose local antibiotics is recommended between implant removal and delayed revision surgery. The use of antibiotic-loaded acrylic cement for cemented prostheses or antibiotic-soaked bone-graft with cementless prostheses is helpful in the overall cure rate of infection.

Anti-Bacterial Agents↗
PubMed2002

Case challenges in knee surgery: what would you do?

In an interactive case presentation session, the faculty discussed management of complex primary and revision knee arthroplasty issues. Principles discussed included: preoperative evaluation of the failed knee arthroplasty, intra-articular versus extra-articular deformity correction, ligamentous balancing, managing the unstable total knee arthroplasty, bone deficiency management, rotational positioning of prosthetic components, selection of articular constraint in the revision knee, and extensor mechanism balancing.

Arthroplasty, Replacement, Knee↗
PubMed2002

Patellar component resection arthroplasty for the severely compromised patella.

When severe bone loss precludes reimplantation of a new patellar component during revision knee arthroplasty, the treatment options include patellar bone grafting, patellar component resection arthroplasty, and patellectomy. The purpose of this study was to evaluate the clinical and functional results of patellar component resection arthroplasty for the severely compromised patella for which insertion of another patellar component was not possible. Thirty-five knees (31 patients) were treated with patellar component resection arthroplasty for aseptic patellar component failure associated with severely compromised patellar bone stock. Followup averaged 7.9 years (range, 2-18 years). There was a significant improvement in Knee Society pain and function scores. Pain relief was more dramatic than functional improvement. The range of motion also improved significantly and in particular preoperative extensor lag was resolved in the majority of patients. Patients treated with isolated patellar resection arthroplasty were more likely to have continuing pain and require reoperation compared with patients who had concomitant revision of the tibial and femoral components. Correct positioning and the stability of tibial and femoral components should be tested carefully at the time of patellar resection arthroplasty and considered for revision if malpositioned either axially or rotationally.

Adult↗
PubMed2002

Evaluation of a staging system for infected hip arthroplasty.

A previously reported staging system for prosthetic joint infection was evaluated in 26 consecutive patients with an infected hip arthroplasty. Six patients were treated by a definitive resection arthroplasty whereas the remaining 20 patients received delayed insertion of another hip arthroplasty. Four of the 20 patients (20%) receiving a new prosthesis had reinfection develop. The only variable in common among the patients who had reinfection was the use of a massive femoral structural allograft at reconstruction. Because of the small number of patients in this study, the power of statistical analysis did not allow definitive determination of the effect of the staging system score with respect to recurrent infection. Based on this study, recommendations can be suggested for addition and deletion of certain variables within the existing staging system. Although the concept of a staging system for treatment of an infected hip arthroplasty is promising, the number of patients required to evaluate the use of a staging system will require a multicenter collaborative study.

Adult↗
PubMed2002

Antimicrobial release kinetics from polymethylmethacrylate in a novel continuous flow chamber.

Polymethylmethacrylate is used for local delivery of antimicrobials in the treatment of musculoskeletal infections. A novel continuous flow chamber system was designed to measure in vitro antimicrobial release. Three-millimeter beads containing amikacin, gentamicin, tobramycin, or vancomycin [concentration of 7.5% (weight per weight)] were placed individually in a continuous flow chamber with a total volume of 1 mL Kreb's Ringer buffer flowing at 1 mL/hour. Effluent was sampled hourly for 24 hours and then every 2 hours up to 48 hours; antimicrobial concentrations were measured in triplicate by bioassay. The mean peak concentrations were 40.9, 30.1, 30.0, and 19.1 microg/mL; the mean areas under the concentration time curves (Time 0 to infinity) were 263, 327, 110, and 180 hours x microg/mL of antibiotic; and the mean percentages of initial amount of antimicrobial released were 11.7%, 14.5%, 6.6%, and 10.9% for tobramycin, gentamicin, amikacin, and vancomycin, respectively. The results for each polymethylmethacrylate-antimicrobial agent combination were reproducible. In contrast to other in vitro elution systems, this novel system operates under the premise that there is dynamic flow surrounding polymethylmethacrylate in vivo and permits rapid in vitro comparison of the relative release of antimicrobial agents from polymethylmethacrylate.

Amikacin↗
PubMed2002

Total knee arthroplasty after prior bone or joint sepsis about the knee.

The current study was done to determine the effect of current methods to diagnose and treat infection on the incidence of deep prosthetic infection after total knee arthroplasty for patients with previous sepsis or osteomyelitis about the knee. Between 1989 and 1999, one surgeon did 20 consecutive primary total knee arthroplasties in 19 patients with a previous history of either septic arthritis or osteomyelitis about the knee. Antibiotic-impregnated cement was used in all patients. One patient was lost to followup and two patients died before 2 years from the arthroplasty. The remaining 16 patients were followed up for an average of 5 years (range, 2-11 years). There was one (5%) recurrent deep periprosthetic infection for which the patient required resection arthroplasty at 3.5 years. No patients required chronic antibiotic suppression. With careful preoperative and intraoperative evaluation and the routine use of antibiotic bone cement for fixation, total knee arthroplasty, in patients with prior bone or joint sepsis about the knee can provide good pain relief, functional improvement, and an acceptably low rate of deep prosthetic infection.

Aged↗