Showing papers by "Arlen D. Hanssen published in 2003"

Molecular and antibiofilm approaches to prosthetic joint infection.

Abstract: 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.

Molecular and antibiofilm approaches to prosthetic joint infection : Proceedings of the musculoskeletal Infection Society 2002

Abstract: 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.

Outcome of Penicillin-Susceptible Streptococcal Prosthetic Joint Infection Treated with Debridement and Retention of the Prosthesis

Abstract: Debridement with retention of the prosthesis was the initial treatment modality for 19 cases of penicillin-susceptible streptococcal prosthetic joint infection that occurred in 18 patients who presented to the Mayo Clinic (Rochester, Minnesota) during 1969-1998. All of the cases of prosthetic joint infection occurred >30 days after implantation of the prosthesis, which was well fixed at the time of debridement. The median duration of symptoms before debridement was 4 days (range, 1-10 days). Treatment failure (defined as relapse of infection with the original microorganism) occurred in 2 cases (10.5%) during a median follow-up period of 3.9 years (range, 0.3-21.7 years). The 1-year cumulative risk of relapse was 11% (95% confidence interval, 0%-26%). Relapse of prosthetic joint infection due to penicillin-susceptible streptococci after debridement and retention of the prosthesis is uncommon. For patients who present with a well-fixed prosthesis and a short duration of symptoms, debridement with retention appears to be an effective treatment modality.

Cemented long-stem revision total knee arthroplasty.

Abstract: From 1981 to 1989, 38 cemented, posterior, stabilized, revision, total knee arthroplasties (TKAs) were performed at the authors' institution using the stemmed kinematic stabilizer prosthesis of a single design. The mean clinical follow-up after the index procedure was 10.1 years. The Knee Society pain score averaged 17 points before revision and improved to 51 points at last follow-up, and the function score averaged 48 points before revision and improved to 57 at last follow-up. Ten-year component survival free of revision or removal for any reason was 96.7%; 11-year component survival free of revision for aseptic loosening was 95.7%. Cemented stem fixation in revision TKA provides good clinical results with durable fixation at an average of 10 years' follow-up.

Levofloxacin and trovafloxacin inhibition of experimental fracture-healing.

Abstract: 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

Total knee arthroplasty in post-traumatic arthrosis of the knee

Abstract: Total knee arthroplasty is an effective method of treatment for the majority of patients with a prior distal femoral or tibial plateau fracture and end-stage arthritis. There is a higher complication rate and overall poorer outcome when compared with routine primary total knee arthroplasty. In patients for whom the goals of optimal limb and implant alignment are achieved, the results are comparable with routine primary knee arthroplasty. Patients with suboptimal component positioning or residual deformity have a poorer outcome. The technical challenges encountered can require skills, implant systems, and methods usually reserved for complex revision arthroplasty.

Advances in the laboratory diagnosis of prosthetic joint infection

Abstract: Prosthetic joint implant surgery (arthroplasty) provides restoration of movement to almost half a million people each year in the USA, with major health and economic benefits. While the majority of recipients experience dramatic relief of preoperative pain at the arthroplasty site, some prostheses fail to achieve this result. This is most commonly the result of aseptic biomechanical failure or prosthetic joint infection (PJI), both of which are associated with significant morbidity. Because the management of PJI differs from that of aseptic failure, it is important to accurately differentiate these two entities. Current laboratory methods for diagnosis of PJI depend on isolation of a pathogen by culture from a clinical specimen (e.g., synovial fluid, periprosthetic tissue). However, as PJI is typically a low organism burden and focal infection caused by commensal micro-organisms, these methods have neither ideal sensitivity nor ideal specificity. Therefore, culture-independent molecular methods have been used to improve the diagnosis of PJI. In the research setting, detection of 16S ribosomal DNA (rDNA) by polymerase chain reaction has been the prime focus of the molecular diagnosis of PJI. In this article, advantages and limitations of conventional and molecular methods for the laboratory diagnosis of PJI are reviewed, as is the use of methods that may improve detection of organisms in the biofilm environment. The diagnosis of PJI remains challenging and a rapid, sensitive and specific method is needed for appropriate surgical and medical treatment decisions in the growing arthroplasty population.

Infection after shoulder instability surgery

Abstract: 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.

Cementation of an acetabular liner into a well-fixed acetabular shell during revision total hip arthroplasty.

Abstract: Cementing a polyethylene liner into a well-fixed acetabular shell during revision hip arthroplasty may be appropriate in select patients. The purpose of this study was to review our early results with this technique. Sixteen patients with >2-year follow-up or who had any complications at <2 years from surgery were identified. Indications for this technique included: failure of the previous locking mechanism, significant polyethylene wear, malposition of the well-fixed metal shell, and previous removal of the liner with a retained acetabular shell. One acetabular shell has been revised at 13 months for multiple dislocations. Hip scores improved an average of 24.2 points. Radiographs revealed no polyethylene dissociation or acetabular loosening. Complications occurred in 7 patients. Initial results appear successful at providing secure fixation, while preventing the bone loss that might occur with removal of a well-fixed component.

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

Abstract: 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 debridement 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 debridement 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. Level of Evidence: Therapeutic study, Level III-2 (retrospective cohort study). See Instructions to Authors for a complete description of levels of evidence.

Orthopaedic crossfire®—allpatellae should be resurfaced during primary total kneearthroplasty: In the affirmative

Abstract: Patients with inflammatory arthritis, crystallinedeposition disease, or severe patellofemoral arthritis havesuperior functional results with patellar resurfacing as comparedwith patellar retention. The only remaining issue is whetherthere is any advantage to resurfacing or retention in patientswith osteoarthritic knees in the absence of severe patellofemoralarthritis. Although the answer is still unclear from availableprospective randomized clinical trials, the evidence leans towardroutine resurfacing of the patella during primary total kneearthroplasty in osteoarthritic knees too. Evidence exists thatthe results of patellar retention in osteoarthritic kneesdeteriorate with longer follow-up study. Long-term follow-upevaluations of available prospective clinical trials will beneeded to assess this controversy more definitively. © 2003Elsevier Inc. All rights reserved.

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

Abstract: 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.

Patellar revision: bringing back the bone.

Abstract: Severe patellar loss, which precludes adequate fixation of another patellar implant, may be treated by patellectomy, retention of the remaining patellar bony shell (resection arthroplasty), gull wing osteotomy, or patellar bone grafting. In contrast to other treatment alternatives, patellar bone grafting uniquely imparts the potential for restoration of patellar bone. Technique: It is helpful to retain the pseudomeniscus of scar tissue and most of the peripatellar fibrosis tissue to facilitate suture fixation of the tissue flap to the patellar rim. The patellar shell is prepared by removing all fibrous membrane in the crevices of the remaining patellar bone. The tissue flap is created from one of several sources including large flaps of peripatellar fibrotic tissue or a free tissue flap obtained from either the suprapatellar pouch or the fascia lata obtained in the lateral gutter of the knee joint. The tissue flap is sewn to the peripheral patellar rim and peripatellar fibrosis tissue with multiple, nonabsorbable size zero sutures to provide a watertight closure. A small purse string opening is left in one portion of the tissue flap repair to facilitate delivery of bone graft into the patellar defect. Cancellous autograft is harvested from the metaphyseal portion of the central femur during preparation of the femur for the revision implant. In the absence of locally available cancellous autograft, cancellous allograft bone can be used. The bone graft is prepared by morsellising the bone into small fragments of approximately 5 to 8 mm in height and width to facilitate tight impaction of the bone graft into the patellar shell-tissue flap construct. The bone graft is tightly impacted through the opening of the fascial flap into the patellar bone defect with enough volume so that the height of the final patellar construct has a final height measuring more than 20 mm. The tissue flap is then completely closed to contain the bone graft within the patellar shell. The peripatellar arthrotomy is provisionally repaired with several sutures or towel clips to mould the patellar construct in the femoral trochlea as the knee is placed through the full range of motion. Postoperative rehabilitation is not altered from the usual revision knee arthroplasty protocol. In contrast with the treatment alternatives of patellectomy or retention of the bony shell, this new surgical procedure uniquely imparts the potential for restoration of patellar bone stock and may improve the functional outcome in these patients by facilitating patellar tracking and improving quadriceps leverage. The procedure is simple to perform and does not require sophisticated instrumentation or a long learning curve. Based on the current satisfactory short-term to mid-term clinical results, this surgical procedure provides an important addition to the armamentarium of the revision knee arthroplasty surgeon.