Fate of the unrevised cemented stem following cup only revision: 227 hips at an average of 6 years follow-up.

BACKGROUND: After primary total hip replacement, aseptic loosening of the acetabular cup is more common than loosening of the femoral stem. Removal of a well-fixed stem adds to operative time, blood loss, risk of bone loss and fracture. There is limited evidence that isolated cup revision can be a safe option in revision hip arthroplasty. We question the following regarding the unrevised cemented stem after isolated cup revision: 1) Does the unrevised stem require revision after isolated cup revision? 2) When is the stem subsequently revised? 3) Why is the stem subsequently revised? 4) Do unrevised stems exhibit radiographic loosening? HYPOTHESIS: We hypothesise that after isolated cup revision most unrevised stems do not need subsequent revision, and that most do not exhibit evidence of radiographic loosening. PATIENTS AND METHODS: A retrospective analysis of all patients who underwent revision of the acetabular component only during revision hip arthroplasty between March 1970 and July 2013 was carried out. We assessed survival of the unrevised stem, reasons for subsequent revision, plus radiographic analysis for stem loosening. RESULTS: Two hundred and twenty-seven hips were included [215 patients with an average age at the time of primary surgery was 47 (13-70) years]. The Charnley stem was used in 161 cases; C-stem 65, Howse 1. Average time between primary surgery and cup revision was 15.9 (1.6-33.4) years. Average follow-up for all stems post-isolated cup revision was 6.1 (0.1-30.7) years. Twenty-eight stems (12.3%) were subsequently revised 5.1 (0.1-12.6) years after the isolated cup revision. Reasons for subsequent revision were: aseptic loosening (10); infection (8); dislocation (6); unreconstructable joint post-loose cup removal (2); fracture (2). Radiographic review was possible on 140 cases. Five femoral stems were revised and 2 others showed evidence of possible radiological loosening but were not revised. CONCLUSION: To our knowledge this is the largest series showing that isolated cup revision in the place of a well-fixed cemented stem is safe and is associated with ongoing good long-term survival of the stem. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Computer programs that teach the interpretation of image-based laboratory tests.

OBJECTIVE: To review the effort of the University of Washington (UW) Department of Laboratory Medicine to develop and use personal computer programs to teach the interpretation of image-based clinical laboratory tests to medical technologists and other health care workers. DATA SOURCES: Professional journals and books; Software owned by and licensed by the University of Washington. STUDY SELECTION: Not applicable. DATA EXTRACTION: Not applicable. DATA SYNTHESIS: We have been developing interactive personal computer (PC) programs for teaching image-based laboratory tests to medical technologists and other health care workers. The programs, called "Laboratory Tutors," are useful for teaching microscope-based tests and tests based on electrophoresis. Our programs include ANA-Tutor, which teaches the immunofluorescence assay for anti-nuclear antibodies; Gram Stain-Tutor, which teaches the direct Gram stain; Electrophoresis-Tutor, which teaches the interpretation of agarose gel protein electrophoretic patterns; Urinalysis-Tutor, which teaches the microscopic examination of urine sediment; in addition to other programs. The tutorials are all based on high-quality digital images that were acquired and processed using digital imaging systems. They require minimal computer literacy and have a number of advantages over standard approaches to teaching image-based laboratory tests. The computer tutorials are used in UW's medical technology and medical school curriculum, where they are used as supplements to traditional instruction. CONCLUSION: Laboratory tutors are computer programs that use high resolution digital images to teach the interpretation of image-based laboratory tests. We plan to continue to develop these programs, study their educational effectiveness, and update them periodically.

Buried or unburied K-wires for lateral condyle elbow fractures.

INTRODUCTION: Lateral humeral condyle fractures typically require a longer period of internal fixation than other distal humeral fractures due to the increased risk of non-union. K-wires can be buried and left in situ until union or they can be left unburied and require removal after four weeks, with plaster immobilisation until union. There is no consensus as to whether wire burial is preferable or not. The aim of this study was to determine whether K-wire burial is associated with more complications than non-buried wires in treating lateral condyle fractures of the elbow. METHODS: All patients with lateral humeral condyle fractures treated with K-wire fixation at our institution from May 2008 to August 2011 were included in the study. Fracture configuration, mode of reduction, wire burial and complications were assessed. RESULTS: Sixty-seven patients (19 girls and 48 boys, mean age: 6.5 years, range: 1-17 years) were included in the study. All had closed injuries and were treated with open reduction and K-wire fixation. K-wires were buried in 55 patients. Thirteen cases of buried wires eroded through skin and were removed on average 45 days (range: 30-58 days) post-operatively. Of the wire erosion cases, three developed microbiologically proven infections, one of which was a deep infection. There were a further three superficial wound infections in the absence of wire erosion through the skin. There were complications in 2 of the 12 cases in the unburied wires group: 1 microbiologically proven superficial wire site infection and 1 wire backed out after 11 days, requiring refixation. CONCLUSIONS: Wire erosion through the skin is the most common complication of K-wire burial. This may be due to the decrease in swelling after fracture fixation, making the wires more prominent under the skin. Skin integrity should be monitored closely if wires are buried.

Activ C cervical disc replacement for myelopathy.

BACKGROUND: Cervical disc replacement is becoming an increasingly popular treatment option for cervical myelopathy. It retains motion at the affected segment, unlike anterior cervical discectomy and fusion. The aim of this study is to assess the outcomes of a series of patients who underwent Activ C disc replacement for cervical myelopathy. MATERIALS AND METHODS: A series of patients at the above Trust with clinical and radiological evidence of cervical myelopathy who were suitable for cervical disc replacement from 2007 to 2009 were included. Implants were inserted by one of two consultant surgeons {IMS, MO'M}. Patients were assessed preoperatively and at six, 12 and 24 months, postoperatively, with a visual analogue score (VAS) for neck and arm pain severity and frequency, the Neck Disability Index questionnaire (NDI) and the Centre for Epidemiologic Studies Depression questionnaire (CES-D). RESULTS: Ten patients underwent surgery between May 2007 and July 2009, 6 women, and 4 men. Average age was 54 years (40-64). Disc levels replaced were: four at C4-5; eight at C5-6; seven at C6-7. Three patients had one disc replaced, five patients had two discs replaced, and two patients had three discs replaced. The VAS for neck pain improved from 5.9 pre-operatively to 1.4-24 months postoperatively and the VAS arm pain improved from 5.4 to 2.6. The NDI improved from 51% preoperatively to 26.8% at 24 months postoperatively. The CES-D showed a slight increase from 19.5 preoperatively to 21.7 at 24 months, postoperatively. CONCLUSION: Cervical decompression and disc replacement improves pain and function in patients with cervical myelopathy. This benefit is maintained at 24 months post op, with no cases requiring revision.

Diagnostic considerations and interpretation of microbiological findings for evaluation of chronic prostatitis.

Seventy-five patients attending a clinic for chronic prostatitis were evaluated by use of lower urinary tract localization cultures. Coagulase-negative staphylococci, alpha-hemolytic streptococci, and diphtheroids were the most common isolates, but none of these organisms were pathogens, based on the absence of bacteriuria or evidence of an inflammatory response in prostatic secretions. Recognized uropathogens were isolated in 12 (16%) of the 75 cases and included Escherichia coli in 6 cases, Enterococcus spp. in 2 cases, and Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterobacter cloacae, and Staphylococcus saprophyticus in 1 case each. Laboratory evaluation of men with chronic prostatitis should concentrate on the isolation and antimicrobial susceptibility testing of bacteria that have an established pathogenic potential in the genitourinary tract.

A space-saving media table.

A space-saving media table designed to facilitate pouring large quantities of plated media in a small area is described.

Rapid antimicrobial susceptibility testing of isolates from blood cultures by direct inoculation and early reading of disk diffusion tests.

Disk diffusion tests, inoculated directly from positive blood cultures, were evaluated for accuracy of reading zone diameters after 4- and 6-h and overnight incubation. In comparisons with results from standard disk diffusion tests, the 4-h results were in agreement for 83% of tests with gram-positive organisms and 64% of tests with gram-negative organisms. When minor discrepancies were ignored, the 4-h readings were in agreement for 98% of the tests with gram-positive organisms and 95% of the tests with gram-negative organisms. After 6 h of incubation, 91% of the tests with gram-positive organisms and 86% of the tests with gram-negative organisms agreed with standard results. The agreement was 99% for tests with both gram-positive and gram-negative organisms when minor discrepancies were excluded. Very major discrepancies occurred in two tests (0.1%) with gram-positive organisms and were not observed in tests with gram-negative organisms. The frequencies of major discrepancies were 3.5% after 4 h, 0.6% after 6 h, and 0.7% after overnight incubation. Ampicillin and cephalothin tests with Escherichia coli and Klebsiella spp. accounted for 81% of the major discrepancies in tests with gram-negative organisms. Oxacillin tests accounted for more than half of the major discrepancies in tests with staphylococci. The results of this study, which did not include the newer antibiotics, indicate that direct susceptibility tests from blood cultures read after 6 h of incubation are more reliable than 4-h results and produce less than 1% major errors in comparisons with standard susceptibility tests.