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Arlen D Hanssen

Publications and source records attributed to Arlen D Hanssen.

At least 19 recordsLinked to original sources
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

A quantitative composite scoring tool for orthopaedic residency screening and selection.

The ability to accurately screen and select orthopaedic resident applicants with eventual successful outcomes has been historically difficult. Many preresidency selection variables are subjective in nature and a more standardized objective scoring method seems desirable. A quantitative composite scoring tool (QCST) to be used in a standardized manner to help predict orthopaedic residency performance from application materials was developed. In 64 orthopaedic residents, four predictors (United States Medical Licensing Examination [USMLE] Part I scores, Alpha Omega Alpha status, junior year clinical clerkship honors grades, and the QCST score) were analyzed with respect to four residency outcomes assessments. The outcomes included three standardized assessments, the orthopaedic in-training examination scores (OITE), the American Board of Orthopaedic Surgery (ABOS) written and oral examinations, and an internal outcomes assessment, attainment of satisfactory chief resident associate (CRA) status. Collectively, the QCST score had the strongest association as a predictor for all three standardized outcomes assessments (p < 0.001). Honors grades during junior years clinical clerkships was most strongly associated with satisfactory CRA status (p < 0.001). A composite scoring tool that is an effective predictor of orthopaedic resident outcomes can be developed. Additional work is still required to refine this scoring tool for orthopaedic residency screening and selection.

Clinical Competence↗
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

Local antibiotic delivery with OsteoSet, DBX, and Collagraft.

Biodegradable local antibiotic delivery systems have gained interest for prophylaxis and treatment of musculoskeletal infections. We studied the biodegradable materials Osteo- Set, DBX and Collagraft for local delivery of vancomycin and gentamicin in vitro. We determined the antimicrobial activity of vancomycin and gentamicin after mixing with each biodegradable material and determined the release of each antimicrobial from each material in an intermittent flow chamber. Antimicrobial activity was expressed as percent of antimicrobial loaded into each sample that was detected; antimicrobial release was expressed as concentration (microg/mL) after timed intervals of chamber flow, peak concentration, area under the curve and percent antimicrobial recovered. Activity of vancomycin after mixing with Osteo- Set, DBX and Collagraft was > 73%. Activity of gentamicin after mixing with DBX was 100%; after mixing with OsteoSet and Collagraft it was reduced to < 61%. AUC0-48hrs of vancomycin was 469, 426 and 432 microg x hr/mL, and the AUC0-48hrs of gentamicin was 368, 306 and 301 microg x hr/mL after release from OsteoSet, DBX, and Collagraft, respectively. Recovered percentages of vancomycin were 39%, 11% and 25%, and recovered percentages of gentamicin were 39%, 9% and 23% after release from OsteoSet, DBX, and Collagraft, respectively. OsteoSet, DBX and Collagraft may be suitable for local delivery of vancomycin and gentamicin.

Absorbable Implants↗
PubMed2006

Patients preferred a mini-posterior THA to a contralateral two-incision THA.

The two-incision total hip arthroplasty (THA) technique has been touted as offering substantially faster recovery than other methods of THA, but direct comparison studies in similar groups of patients have not been done. We sought to determine if there was a difference in the early functional outcome after a two-incision THA compared to a mini-posterior THA as measured by the time to reach defined milestones of daily activity. We also evaluated which procedure the patients preferred. Twenty-six patients underwent staged bilateral total hip arthroplasties with a two-incision minimally invasive THA on one hip and a mini-posterior THA on the contralateral hip. The same comprehensive anesthesia and rapid rehabilitation protocol was used after each operation. Patients were reviewed retrospectively a minimum of 6 months after the second total hip arthroplasty. There were no differences in the time to discontinue ambulatory aids, return to driving, climb stairs, return to work, or walk 1/2 mile. Sixteen of 26 patients preferred the mini-posterior total hip arthroplasty and two patients had no preference. The added surgical technical difficulty of the two-incision minimally invasive total hip arthroplasty was not rewarded with an earlier return to functional activities and more patients preferred their mini-posterior total hip arthroplasty.

Arthroplasty, Replacement, Hip↗
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↗
PubMed2006

Intraoperative fractures of the acetabulum during primary total hip arthroplasty.

BACKGROUND: The intraoperative occurrence of an acetabular fracture is a rare complication of primary total hip arthroplasty. Previous reports have lacked a sufficiently large number of subjects to allow for an analysis of the causes and appropriate treatment of this problem. METHODS: Between 1990 and 2000, 7121 primary total hip arthroplasties were performed at our institution. We retrospectively reviewed the records in our Total Joint Registry and found that twenty-one patients (twenty-one hips) had sustained an intraoperative acetabular fracture. Nineteen of these patients (nineteen hips) had been followed until revision or for a minimum of two years (mean duration of follow-up, forty-four months). We evaluated the anatomic location, cause, treatment, and outcome of the fractures. Acetabular component designs were categorized as modular, nonmodular (monoblock), true hemispherical, or elliptical, and then each design was analyzed for fracture risk. RESULTS: No fractures occurred in association with cemented acetabular components. The fracture rate associated with uncemented components was 0.4%. In seventeen hips, the acetabular component was judged to be stable despite the detection of a fracture and the cup was retained. In four hips, the original cup was not stable and therefore was replaced with a design that allowed for supplemental screw fixation. All fractures united, and all cups demonstrated osseous ingrowth at the time of the most recent follow-up. Elliptical monoblock cups were associated with a significantly higher fracture rate than were elliptical modular cups (p < 0.0001) and hemispherical modular cups (p < 0.0001). There was no significant difference between elliptical modular and hemispherical modular components with regard to the fracture rate. CONCLUSIONS: Acetabular fracture during primary total hip arthroplasty is a rare complication of acetabular fixation without cement. In the present series, retention of a stable cup was associated with uneventful osseous ingrowth and excellent early-term outcomes. We found a high rate of fracture in association with the use of monoblock elliptical components. LEVEL OF EVIDENCE: Therapeutic Level III.

Acetabulum↗
PubMed2006

Management of infection at the site of a total knee arthroplasty.

Infection following total knee arthroplasty remains a major complication in joint reconstruction, resulting in significant morbidity to the patient and increased hospital costs. The diagnosis of infection is often made based on clinical criteria, although adjunctive measures including blood work, plain radiographs, and arthrocentesis are often helpful in confirming the diagnosis and planning subsequent treatment. For patients in whom the diagnosis of infection cannot be immediately confirmed, an acute intraoperative tissue analysis by a skilled pathologist and experienced surgeon is required. Treatment of this complication is directed by the chronicity of the infection, stability of the components, and medical status of the patient. Although débridement with component retention may be successful in the acute postoperative stage of joint replacement, a two-staged revision with removal of all components followed by an adequate course of parenteral antibiotics prior to reimplantation remains the gold standard for eradicating chronic infection. The addition of antibiotic-impregnated cement spacers (static or articulating) has also been implicated as a useful adjunct to treatment. Long-term suppressive antibiotic treatment, arthrodesis, resection arthroplasty, and amputation are reserved for specific clinical situations in which a staged revision or débridement are unlikely to yield favorable results.

Anti-Bacterial Agents↗
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

Radiographic evaluation of a monoblock acetabular component: a multicenter study with 2- to 5-year results.

Serial radiographs of a porous tantalum monoblock acetabular cup design were evaluated for cup stability and signs of successful osteointegration. Of 574 primary consecutive total hip replacements in 542 patients performed by 9 surgeons at 7 hospitals, 414 cases were available for minimum 2-year follow-up. Follow-up averaged 33 months and ranged from 24 to 58 months. Postoperative radiographs revealed acetabular gaps in 100 zones in 80 (19%) hips: 29 in zone I, 67 in zone II, and 4 in zone III. At last follow-up, 84 (84%) of the zones with gaps completely filled in, and all 4- and 5-mm gaps filled in. There was no progression of any postoperative gap, no evidence of continuous periacetabular interface radiolucencies, no evidence of lysis, and no revisions for loosening. Although these short-term results are encouraging, further follow-up will be required to assess whether the monoblock design and the low modulus of elasticity of porous tantalum will reduce the incidence of periacetabular stress shielding and occurrence of osteolysis.

Acetabulum↗
PubMed2005

What would you do? Case challenges in hip surgery.

Evaluation and management of 4 challenging hip case scenarios were discussed in an interactive session with a moderator and 5 experts in hip reconstruction. Case-based discussion included total hip arthroplasty for posttraumatic arthritis after acetabular fracture, total hip arthroplasty after failed intertrochanteric hip fracture, total hip arthroplasty for hip dysplasia, and total hip arthroplasty in the case of proximal femoral deformity.

Acetabulum↗
PubMed2005

Flexion instability without dislocation after posterior stabilized total knees.

UNLABELLED: Flexion instability after cruciate-retaining total knee arthroplasty has been well documented. We identified an analogous patient group with symptomatic flexion instability without dislocation after primary posterior stabilized total knee arthroplasty. We sought to determine the typical symptoms and exam findings that lead to the diagnosis, to assess the reliability of revision total knee arthroplasty as a treatment, and to assess the technical difficulties encountered during revision total knee arthroplasty. Between 1995 and 2001, 10 patients had revision of a well-fixed posterior stabilized total knee arthroplasty for isolated symptomatic flexion instability. The typical constellation of symptoms and physical findings included a sense of instability without giving way, recurrent knee effusions, multiple areas of soft tissue tenderness about the knee, and substantial anterior tibial translation at 90 degrees of flexion. The revision operation focused on balancing the flexion and extension gaps while taking care to fill the enlarged flexion gap. Revision total knee arthroplasty was reliable in alleviating pain (mean Knee Society Pain scores improved from 68 points preoperatively to 89 points postoperatively), improving stability (nine of 10 patients had < 5 mm anterior tibial translation postoperatively) and improving patient satisfaction (nine of 10 patients were satisfied). We had no particular technical difficulties with the revision total knee arthroplasty procedures and had reliably achieved well-balanced flexion and extension gaps. LEVEL OF EVIDENCE: Therapeutic study, Level IV-1 (case series). See the Guidelines for Authors for a complete description of levels of evidence.

Aged↗
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↗