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Biomedical subjects

W Quinlan

Publications and source records attributed to W Quinlan.

At least 19 recordsLinked to original sources

Outcome following deep wound contamination in cemented arthroplasty.

Infection remains a devastating complication of joint replacement surgery causing a significant burden to both patient and surgeon. However, despite exhaustive prophylactic measures, intraoperative contamination still occurs during cemented arthroplasty with current infection rates of 1-2%. A study was undertaken to determine the incidence of perioperative contamination in cemented arthroplasty patients, to identify contaminating organisms, to identify contaminated regions within the operative wound, to identify factors associated with increased contamination, and finally to assess the medium-term clinical outcome in patients with confirmed intraoperative wound contamination. Eighty consecutive patients undergoing hip and knee cemented arthroplasty were prospectively enrolled over a 6-month period. All scrubbed personnel wore total body exhaust isolation suits and procedures were carried out in ultra-clean air theatres. Of 441 samples, contamination was identified at 21 sites (4.8%) representing a cohort of 18 patients (22.5%). Longer duration of surgery predisposed to higher contamination rates while lower contamination rates were significantly related to fewer gowned personnel within the ultra-clean system, and fewer total personnel in theatre during the procedure. None of the patients developed clinical evidence of deep prosthetic infection at follow-up. We noted a high incidence of intraoperative contamination despite standard prophylaxis. However, this was not reflected by a similar rate of postoperative infection. This may be due to a small bacterial inoculum in each case or may be due to the therapeutic effect of perioperative intravenous antibiotic prophylaxis.

Anti-Bacterial Agents↗

Revision of the Sheehan total knee arthroplasty.

The use of the Sheehan knee prosthesis extended from 1971 to 2002. It incorporated a semi-constrained hinge with intra-medullary stems cemented into the femur and tibia. While some authors have reported excellent short-term results, others have reported revision rates of up to 31% at 5--10 years. The aim of this study was to review the senior author's experience in revising these arthroplasties. We review 54 Sheehan total knee replacements and discuss the difficulties encountered during first and subsequent revisions and the often-complex reconstruction techniques used to overcome these.

Adult↗

Femoral cementing techniques in total hip replacement.

Clinical studies have shown that second-generation femoral cementing techniques at total hip replacement result in a superior fixation of the femoral stem. In an effort to determine what benefits further developments in cementing techniques would provide, we compared the morphology of the cement mantles produced by traditional finger-packing and gun-insertion techniques. The porosity of the cement mantles was quantified using computerised image analysis. The finger-packing technique caused large air inclusions that resulted in large pores in the substance of the cement mantle, whereas the cement-gun technique did not result in any individual pore with an equivalent diameter greater than 3 mm. The mean porosity of cement mantles prepared using the finger-insertion technique was 8.3%, whereas the mean porosity in gun-prepared mantles was 1.7%. The use of a cement gun significantly reduced the porosity of femoral cement mantles (P = 0.02). Reduction of defects in the substance of the cement mantle may account for the increased survival of femoral prostheses inserted when second-generation techniques were used. Further reduction of the porosity of the cement mantle could not be expected to produce as dramatic a clinical improvement in prosthesis fixation.

Arthroplasty, Replacement, Hip↗

Interprosthetic fracture of the femoral shaft.

Experience in the management of a complication of ipsilateral hip and knee arthroplasty is described. The cases of four female patients who sustained a femoral shaft fracture after ipsilateral hip and knee arthroplasty are reported. All fractures were treated operatively, and in all cases internal fixation devices failed. This complication of multiple joint arthroplasty presents a difficult management problem. Rigid fixation has a high failure rate for this type of fracture. Surface knee arthroplasty provides a better opportunity for internal fixation than a knee arthroplasty with a stemmed femoral component.

Aged↗

Risk of pelvic injury from femoral neck guidewires.

Many of the devices used in the internal fixation of femoral neck fractures are cannulated and require the initial placement of one or more guidewires for accurate positioning. These wires are occasionally advanced inadvertently through the hip joint and the acetabulum. Pelvic visceral damage may follow. To assess this risk, we inserted three guidewires to a depth of 16 cm into each femoral neck of ten cadavers and explored the pelvis during autopsy. Thirty-two of the 60 guidewires had penetrated a pelvic organ. The literature on intrapelvic injuries associated with hip surgery is reviewed, and suggestions are offered on the avoidance of pelvic penetration during hip fracture fixation.

Cadaver↗

16- to 25-year follow-up study of cemented arthroplasty of the hip in patients aged 50 years or younger.

The clinical outcome of the cemented Charnley hip arthroplasty at follow-up periods of 16-25 years was evaluated retrospectively in patients aged 50 years or younger. One hundred thirty-two of a total of 167 hip arthroplasties were studied. The overall probability of survival of the implant at 20 years was 75% Survival of those with rheumatoid disease was 80% compared with 64% for those with osteoarthritis. Female sex was associated with a better prognosis. Accelerated wear was associated with decreased survival of the prosthesis. Varus orientation of the femoral component significantly influenced failure (P < .01). Radiographic loosening of the acetabular component was well tolerated, but loosening of the femoral component was significantly associated with pain (P = .01).

Adolescent↗

Risks of radiation exposure to orthopaedic surgeons.

The risks of occupational radiation exposure for orthopaedic surgeons has not been well documented. The use of fluoroscopy in orthopaedics has reduced morbidity and by reducing operative time and by reducing the invasiveness of procedures. Increasingly procedures requiring the use of fluoroscopy are being developed. In a prospective study we have monitored cumulative radiation exposure over a 6-month period. The exposure levels are well below the maximum dose limits for ionizing radiation as recommended by European Economic Communities EURATOM directives. Experimentally using a phantom patient it was shown that the exposure to ionizing radiation during the insertion of a dynamic hip screw was minimal. Despite the low level of exposure care should be exercised when using fluoroscopy.

Film Dosimetry↗

Bacterial arthritis in the neurosurgical patient: report on four cases.

Bacterial arthritis that occurred in four patients during neurosurgical convalescence is reported. Three patients had a cerebral aneurysm clipped after a subarachnoid hemorrhage, and one had herpes simplex encephalitis with a possible temporal lobe hemorrhage. All four patients had been treated with steroids. A total of six joints were infected, two patients with an infection in one joint each, and two with a metachronous infection in two joints. The interval between the onset of local symptoms and the definitive diagnosis ranged from 0 to 44 days. A delay in diagnosis severely compromises joint function, and all four of these patients were left with an associated significant musculoskeletal disability. Bacterial arthritis is well recognized in the immunocompromised patient, but, to our knowledge, has not been described in this particular clinical setting. A patient with a sustained pyrexia of unknown origin in the neurosurgical convalescent period should be suspected of having an occult musculoskeletal infection. An isotope bone scan to facilitate early diagnosis is recommended, and this, combined with specific aggressive therapy, should preserve joint function.

Adult↗

The Guildford elbow.

The Guildford elbow is a new unconstrained elbow arthroplasty. From 1985 to 1991, this arthroplasty was used in 24 patients with rheumatoid arthritis. The patients were reviewed after an average of 28 months (4-59 months). Good to excellent results were obtained in 95% regarding pain relief and functional improvement. Complications were few, with only one case of clinical loosening and three of radiological loosening. Ulnar nerve hypo-aesthesia was common but did not jeopardize the final result in any patient.

Adult↗

Contrasting levels of in vitro cytokine production by rheumatoid synovial tissues demonstrating different patterns of mononuclear cell infiltration.

Synovial membrane samples obtained at knee arthroplasty from 22 patients with rheumatoid arthritis (RA) were characterized histologically. Two groups were identified. Tissue samples from 15 patients demonstrated multiple focal lymphoid aggregates of mononuclear cells (group A). Samples from the remaining seven patients demonstrated diffuse mononuclear cell infiltration (group B). Samples of each synovial membrane (0.25 g) were cultured for cytokine production. The highest levels of IL-1 beta and IL-6 were produced by group A tissues: 19.1 +/- 19.6 ng/ml IL-1 beta (mean +/- s.d.) and 264.4 +/- 301.9 ng/ml IL-6, versus 3.8 +/- 6.6 ng/ml and 54.7 +/- 42.6 ng/ml respectively. Small quantities of IL-2 and IL-4 were measured in both groups: the levels of IL-2 in group A cultures were highest (P = 0.04). Moreover, using MoAbs, the most intense cytokine staining in the tissues was detected in group A. Similar total numbers of each cell subpopulation and similar quantities of immunoglobulin and rheumatoid factor synthesis were measured in both groups. It is suggested that the presence of multiple focal lymphoid aggregates associated with higher levels of cytokine production observed in group A represent a greater degree of immunological activation, and may represent a subgroup of patients with a greater potential for articular destruction.

Adult↗

Mortality and morbidity associated with hip fractures.

In this study 147 patients with hip fractures were reviewed and reassessed to establish their mortality and morbidity. The early mortality was 10.8% and this rose to 27% at three months. The major factors which determined mortality and morbidity were the age of the patient, male sex, and the degree of social dependence of the patient both before and after the fracture. The site of the fracture or the type of anaesthetic used did not significantly affect the outcome. The shortage of Nursing Home and long-term care facilities resulted in prolonged hospital stay for many patients.

Aged↗

Radiological assessment of atlanto-axial injuries.

Injury to the cervical spine is a potentially lethal condition, and the accurate detection of such injury is essential. Plain cervical radiography remains the first line of investigation, despite well documented difficulty with interpretation. There have been many studies demonstrating unreliability of plain cervical radiography in detecting atlanto-axial injuries. We report a group of patients in which false-positive interpretation of such injuries occurred.

Accidents↗

Analysis of the histologic variation of synovitis in rheumatoid arthritis.

One hundred forty-five synovial biopsy specimens were obtained from 30 procedures performed on the knee joints of 29 patients with rheumatoid arthritis. All patients had clinically active rheumatoid arthritis and none had received slow-acting disease-modifying drugs or intraarticular corticosteroids. Scores were assigned to each biopsy specimen for each of 6 histologic features to quantify variation within each joint. In the majority of knee joint biopsies, there was considerable clustering of scores for all histologic features. Thus, on a scale of 0-10, 82% of the scores for synoviocyte hyperplasia were within 1 point of the median score for a given joint. Similarly, between 69% and 85% of the scores for the remaining features (fibrosis, vessel proliferation, perivascular infiltrates, focal aggregates, and diffuse infiltrates of lymphocytes) were within 1 point of the median values. Multiple biopsies were obtained at arthroscopy in 8 patients. Tissue was selected from areas of apparent maximal and minimal involvement, to enhance the likelihood of regional histologic variation. Of the scores for synoviocyte hyperplasia, 91% were within 1 point of the median values for a given joint, and of the scores for the remaining 5 features, 72-94% fell within 1 point of the median values. In addition, highly significant statistical correlations of the intensity of synovial lining layer hyperplasia, vessel proliferation, mononuclear cell infiltration, fibrosis, and clinical measurements of synovitis were observed.

Arthritis, Rheumatoid↗

Strut fracture and other events after valve replacement with the 60 degree convexoconcave Björk-Shiley prosthesis.

A total of 688 patients received 808 Björk-Shiley prostheses during a 5 year span. Cumulative duration of follow-up totaled 1175.4 patient-years (1368 valve-years). Linearized rates in percent per patient-year for valve-related events (95% confidence limits) were: strut fracture, 0.5 (0.00 to 1.03); infective endocarditis, 0.94 (0.39 to 1.49); thromboembolism, 2.2 (1.37 to 3.052); valve impingement, 0.3 (0.00 to 0.77); and anticoagulant-related hemorrhage, 3.1 (2.15 to 4.14). No valve thrombosis occurred. Actuarial patient survival, including in-hospital mortality, was: aortic valve replacement, 79.8 +/- 3.4%; mitral valve replacement, 71.7 +/- 4.9%; double valve replacement, 59.8 +/- 7.5%. Incremental risk factors for death were age over 65 (p = .001), preoperative infective endocarditis (p = .04), and associated procedures (p = .0002). Although this prosthesis carries a low risk of infective endocarditis and thromboembolism, concern has been raised regarding its structural integrity.

Actuarial Analysis↗

Supracondylar fractures of the humerus in adults.

Thirty consecutive supracondylar fractures of the humerus, treated by open reduction and internal fixation over a 4-year period from 1980 to 1984, are reviewed. We feel that anatomical reduction with rigid fixation allowing immediate postoperative movement gives the least morbidity and best results.

Adult↗