Microsporidia and Acanthamoeba: the role of emerging corneal pathogens.

Parasitic organisms are increasingly recognized as human corneal pathogens. A notable increase in both well-defined Acanthamoeba keratitis and a more dramatic increase in reported cases of Microsporidia keratitis have suggested significant outbreaks of parasitic keratitis around the world. Historical and contemporary baselines as well as a familiar associated clinical presentation reinforce the significant outbreak of Acanthamoeba keratitis in the United States. The remarkable rise in cases of Microsporidia keratitis, however, lacks these established baselines and, further, describes a disease that is inconsistent with previous definitions of disease. While a well-defined, abrupt increase strongly suggests temporally related risk factors, most likely environmental, involved in the Acanthamoeba outbreak, the rise in Microsporidia keratitis suggests that increased awareness and improved diagnostic acumen are a significant factor in case ascertainment. Regardless, recent evidence indicates that both parasitic diseases are likely underreported in various forms of infectious keratitis, which may have unrecognized but significant implications in the pathogenesis of both primary protozoal and polymicrobial keratitis. Further understanding of the incidence and interaction of these organisms with current therapeutic regimens and more commonly recognized pathogens should significantly improve diagnosis and alter clinical outcomes.

Quantification of fracture healing from radiographs using the maximum callus index.

UNLABELLED: Callus formation and growth are an essential part of secondary fracture healing. Callus growth can be observed radiographically and measured using the "Callus Index," which is defined as the maximum diameter of the callus divided by the diameter of the bone. We compared three groups of patients with tibial fractures treated by external fixation, intramedullary nailing, and casting to assess the validity of using serial measurements of callus index as a measure of fracture healing. When callus index was plotted against time for each patient, the point at which the fracture began to remodel, indicated by the highest point of the curve, was observed as a consistent feature regardless of fixation method. This occurred on average at 2(1/2) weeks after plaster cast removal (14 weeks post injury), 5 weeks after external fixator removal (22 weeks post injury), and 27 weeks post injury for the intramedullary nailed fractures. Because remodeling only occurs once the fracture is stable, a peak in callus index is a reliable sign that the fracture has united. Serial measurements of callus index would therefore appear to offer a simple method of quantifying secondary fracture healing regardless of the treatment method used. LEVEL OF EVIDENCE: Level III, diagnostic study. See Guidelines for Authors for a complete description of levels of evidence.

Weight bearing after tibial fracture as a guide to healing.

BACKGROUND: Judging when it is safe to remove an external fixator or plaster cast requires clinical and radiological assessment, both of which are subjective. Weight bearing has been shown to increase with time post-fracture and we hypothesised that it could be used as an objective measure of fracture healing. METHODS: Ground reaction force (and hence weight bearing) and fracture stiffness were measured serially in a group of 12 patients with tibial fractures treated by external fixation. Ground reaction force was measured for both fractured and non-fractured limbs using a force plate and the fracture stiffness was measured using the Orthometer, a commercially produced device for measuring the stiffness of fractures treated by external fixation. FINDINGS: In 10 patients who made good recoveries, prior to fixator removal, weight bearing though the injured leg was seen to approach 90% of that through the uninjured leg and the fracture stiffness exceeded 15 Nm/deg. Two patients with delayed union achieved weight bearing of 40% of normal and a fracture stiffness of less than 5 Nm/deg at 20 weeks. INTERPRETATION: Weight bearing correlates reasonably well with fracture stiffness. It is quicker and easier to measure than fracture stiffness and potentially has relevance to other fracture fixation methods.

The Avon patellofemoral arthroplasty: five-year survivorship and functional results.

We report the mid-term results of a new patellofemoral arthroplasty for established isolated patellofemoral arthritis. We have reviewed the experience of 109 consecutive patellofemoral resurfacing arthroplasties in 85 patients who were followed up for at least five years. The five-year survival rate, with revision as the endpoint, was 95.8% (95% confidence interval 91.8% to 99.8%). There were no cases of loosening of the prosthesis. At five years the median Bristol pain score improved from 15 of 40 points (interquartile range 5 to 20) pre-operatively, to 35 (interquartile range 20 to 40), the median Melbourne score from 10 of 30 points (interquartile range 6 to 15) to 25 (interquartile range 20 to 29), and the median Oxford score from 18 of 48 points (interquartile range 13 to 24) to 39 (interquartile range 24 to 45). Successful results, judged on a Bristol pain score of at least 20 at five years, occurred in 80% (66) of knees. The main complication was radiological progression of arthritis, which occurred in 25 patients (28%) and emphasises the importance of the careful selection of patients. These results give increased confidence in the use of patellofemoral arthroplasty.

Long-term disability after neck injury. a comparative study.

Claims for personal injury after whiplash injury cost the economy of the United Kingdom more than pound 3 billion per year, yet only very few patients have radiologically demonstrable pathology. Those sustaining fractures of the cervical spine have been subjected to greater force and may reasonably be expected to have worse symptoms than those with whiplash injuries. Using the neck disability index as the outcome measure, we compared pain and functional disability in four groups of patients who had suffered injury to the cervical spine. After a mean follow-up of 3.5 years, patients who had sustained fractures of the cervical spine had significantly lower levels of pain and disability than those who had received whiplash injuries and were pursuing compensation (p < 0.01), but had similar levels to those whiplash sufferers who had settled litigation or had never sought compensation. Functional recovery after neck injury was unrelated to the physical insult. The increased morbidity in whiplash patients is likely to be psychological and is associated with litigation.

A comparative study of the medial St Georg sled and kinematic total knee arthroplasties. Ten-year survivorship.

We have studied the long-term outcome of 408 primary medial St Georg Sled unicompartmental arthroplasties of the knee and 531 primary Kinematic total knee arthroplasties using survivorship analysis. The operations were performed by a number of surgeons under the supervision of two consultants at one orthopaedic centre. Prospective clinical assessment was carried out before and at 2, 5, 8, 10, 12 and 15 years after operation. Failure was defined as follows: revision or removal of the implant; the presence of moderate or severe pain; or 'worst-case' with all patients lost to follow-up. Cumulative survival rates at ten years were calculated using life tables. The follow-up rate was 97%. At ten years, 25 medial sled arthroplasties and 20 Kinematic knee arthroplasties had been revised. With revision or removal as the survivorship endpoint at ten years there was a success rate of 87.5% for the medial sled and 89.6% for the Kinematic knee arthroplasty. When moderate or severe pain was included these rates became 79.4% for both arthroplasties. There was no statistically significant (p > 0.05) difference between the rates of survival for the two arthroplasties using either of the endpoint criteria. Good or excellent results were recorded for 77.9% of the medial sled knees and 75.1% for the Kinematic knees. The former had 93.8% of cases with a final range of movement in excess of 90 degrees compared with 83.7% for the Kinematic knees (p < 0.01). We conclude that at a single orthopaedic centre in the UK, the St Georg Sled medial compartment arthroplasty for appropriate specific indications offers predictable survivorship at ten years which is comparable with that of the Kinematic total knee arthroplasty.

Precision of three topography instruments in keratoconus subjects.

PURPOSE: To determine the test-retest reliability of three popular and commercially available Placido-ring videokeratography instruments in subjects with keratoconus. METHODS: Nine subjects (16 eyes) with keratoconus of varying degrees of severity had up to four images per eye generated, in random order, from the EyeSys Model II, Dicon CT 200 and the Keratron Corneal Analyzer. Test-retest analyses for the images were sampled at four locations: 1.5 mm nasal, inferior, temporal, and superior from center. The average standard deviation of all points was used to determine the short-term variability of the measurements. RESULTS: The short-term variability (in diopters) of the Dicon, EyeSys, and Keratron was 0.61 to 3.31 D, 0.94 to 1.51 D, and 0.58 to 2.85 D, respectively, for axial distance maps and 1.07 to 6.82 D, 0.79 to 1.77 D, and 1.23 to 3.03 D for tangential curvature maps. CONCLUSION: Results support the notion of a loss in repeatability for all three instruments when corneal irregularity is present, which reduces test-retest reliability.

Coronary artery ectasia.

Coronary artery ectasia is an uncommon expression of coronary artery atherosclerosis and other diseases. It occurs in about 1.4 percent of the adult population. It is not distinguishable from obstructive coronary artery disease in severity of angina, clinical presentation, electrocardiograms, mortality, or outcome of coronary artery surgery. Although there is debate, treatment is indicated in the form of chronic warfarin anticoagulation to prevent coronary thrombus formation and its sequelae. Aspirin therapy may suffice in asymptomatic individuals.

The breast radiation injury litigation and the clinical oncologist.

A number of women with breast cancer believed they were suffering injury because radiotherapy had been given negligently. In March 1995, their solicitors were permitted by the High Court, to select 10 cases in order to further a group action. In the legal exchanges which followed, the principal issues put forward by the plaintiffs went through a number of modifications until finally, in December 1997, they were abandoned. Two cases came to trial and after a hearing of 21 days, the Judge found no negligence. Clinical oncologists should be aware of the course of the litigation and consider the lessons to be learned.

Dosimetric considerations in the treatment of inoperable endometrial carcinoma by a high dose rate afterloading packing technique.

A series of 23 patients with early adenocarcinoma of the endometrium who underwent a total of 37 modified Heyman packings treated on a high dose rate Microselectron has been reviewed. Using computed tomography (CT), the uterine wall thickness was measured retrospectively and doses calculated at a number of points on the uterine serosa and related normal tissues. The mean and maximum fundal serosal doses were found to be highest posteriorly and the sigmoid colon was adjacent to the posterior surface of the uterus in all instances. By superimposing the isodose distribution on CT sections of the uterus, it is now possible to prescribe to a serosal dose, or, in patients too heavy for the CT scanner, a dose can be prescribed to a point S, which is a reasonable approximation to the serosal position. Since the initial study, a further ten patients have been treated by the same method and, where relevant, data from all 33 patients have been used.

Quality assurance in brachytherapy: the role of the ICRU in achieving uniformity in dose and volume specification for reporting.

A quality assurance programme in brachytherapy implies a general consensus on the method of dose and volume specification for reporting. This in turn implies a consensus on certain definitions of terms and concepts. For several decades, the ICRU (International Commission on Radiation Units and Measurements) has been actively involved in an effort to reach a consensus between different brachytherapy centres worldwide, and to improve uniformity in reporting. The ICRU has prepared two reports containing recommendations for reporting brachytherapy treatments. The first, report #38 published in 1985, deals with intracavitary therapy in gynecology. The second deals with interstitial therapy, and is now in press. A summary of these two ICRU reports is presented here. Some definitions of terms and concepts are first recalled and discussed: Total Reference Air Kerma (TRAK), gross tumor volume (GTV), clinical target volume (CTV), treated volume, mean central dose, dose uniformity parameters, etc. Specific recommendations for reporting interstitial and intracavitary brachytherapy are then presented.

Physiological effect of endobronchial radiotherapy in patients with major airway occlusion by carcinoma.

BACKGROUND: Endobronchial radiotherapy by a high dose rate remote after-loading technique (high dose rate brachytherapy) has become an established treatment for major airway occlusion by inoperable carcinoma of the bronchus. Only limited objective data on its effect on pulmonary physiology and on radiographic and bronchoscopic appearances are available. The aim of this study was to make a detailed assessment of patients before and after high dose rate brachytherapy to determine which investigations were useful and to generate data for comparing this with other methods of treatment. METHODS: Twenty patients with major airway obstruction by inoperable lung cancer underwent a detailed assessment before receiving endobronchial radiotherapy (15 Gy at 1 cm in a single fraction) and six weeks after treatment. This included chest radiography, computed tomography of the thorax, bronchoscopy including an obstruction index, five minute walking tests, isotope ventilation and perfusion lung scanning, and full lung function tests with maximum inspiratory and expiratory flow-volume loops. RESULTS: Nineteen patients (mean age 69 years) completed the study. Symptomatic improvement occurred in 17 patients. A collapsed lobe or lung, seen on the chest radiograph in 13, reexpanded in nine. Bronchoscopic appearances improved in 18, the mean obstruction index decreasing from 6.2 to 2.8. The isotope scans showed significant increases in the percentage of total lung ventilation (V) and perfusion (Q) measured over the abnormal lung (V 17.7% to 27.7%, Q 15.1 to 21.9%). Five minute walking distance (305 to 329 m), forced expiratory volume in one second (FEV1 1.45 to 1.61 l), forced vital capacity (FVC 2.17 to 2.48 l) and ratio of forced expiratory to forced inspiratory flow rate at 50% vital capacity (FEF50/FIF50 0.58 to 0.88) all increased significantly. CONCLUSIONS: Endobronchial radiotherapy led to subjective benefit in most cases in terms of symptoms and bronchoscopic and radiological appearances. There was objective improvement in spirometric indices and in exercise tolerance with increased pulmonary ventilation and perfusion and evidence of decreased intrathoracic airway obstruction.

Long term results of Cathetron high dose rate intracavitary radiotherapy in the treatment of carcinoma of the cervix.

Between 1967 and 1974, 371 patients with carcinoma of the cervix have been treated by a combination of external beam radiotherapy and fractionated high dose rate brachytherapy using the Cathetron. A retrospective review was undertaken in 1986 and median follow-up time was 6 years. Life table analysis of survival and complications to 16 years was undertaken. International Federation of Gynaecology and Obstetrics (FIGO) stage distribution was 26%, 46% and 28% for Stages I, II and III, respectively, and 5 year survival was likewise 94% 63% and 37%. Age and histological type or grade were not found to influence survival. Recurrent disease was recorded in 142 patients; the first site was within the pelvis in 25% and as distant metastases in 17%. Following development of pelvic recurrence median survival was 28 weeks. Salvage surgery was performed in 32 patients, of whom five probably obtained survival benefit. Significant late morbidity was seen in a total of 71 patients (19%); in seven patients this was at more than one site. Late morbidity to the small bowel was recorded as Grade 2 in 10 patients and Grade 3 in 13; to the rectum, Grade 2 in 10 patients and Grade 3 in two patients; to the bladder, Grade 2 in 15 patients and to the vagina Grade 2 in 29 patients. Median time to onset for small bowel morbidity was 14 months, for rectum 18 months, for vagina 20 months and for bladder 52 months. 82% of all late morbidity had been seen by 5 years of follow-up, no case of late morbidity of recurrence was seen between 11 and 18 years of follow-up. These results are comparable to those reported for other methods in use at the time the patients were treated.

Cancer of the cervix in women under 40 years of age, a regional survey, 1975-1984.

OBJECTIVE: To review the method and results of treatment of carcinoma of the cervix in women less than 40 years old. DESIGN: Retrospective review of all available case records. SETTING: Yorkshire Regional Health Authority. SUBJECTS: 428 women less than 40 years old treated for stage IB-IV carcinoma of the cervix between 1975 and 1984 inclusive. MAIN OUTCOME MEASURES: Overall survival by stage, effect of age, identifiable factors of prognostic significance, survival, grade 3 morbidity and pattern of recurrence in relation to treatment. RESULTS: The 5-year actuarial percentage survival by stage was 78.4 (IB), 54.4 (II), 18.4 (III) and 0 (IV). Identifiable factors of prognostic importance were stage, nodal metastases (P less than 0.001) and tumour grade (P less than 0.01). CONCLUSION: Primary surgical treatment for young women with early disease allows ovarian conservation and the avoidance of radiotherapy in 80% of them. Such treatment results in less local recurrence, particularly evident in patients with moderate or poorly differentiated tumours and a lower incidence of serious morbidity.

Concomitant pelvic irradiation, 5-fluorouracil and mitomycin C in the treatment of advanced cervical carcinoma.

This was a Phase II study of 24 late (FIGO) Stage IIb and 39 Stage III patients. External beam radiotherapy was given daily, five days a week, using 15 x 15 cm parallel opposed pelvic fields. The first 20 patients had 45.00 Gy mid-plane dose in 20 fractions, Days 1-28, the last 43 patients had 50.40 Gy in 28 fractions, Days 1-43. This was followed by an intracavitary boost of 17.00 Gy to Point A in two fractions over seven days. The first seven patients had concomitant 5-fluorouracil (5FU) 1 g/m2/day (maximum 1.5 g/day) Days 2-5, 30-33 and 57-60, with mitomycin C 10 mg/m2 (maximum 15 mg) Days 2 and 57. Two patients had WHO Grade 4 cytopenia, and only two were able to have full dose intensity. The 5FU dose was reduced to 0.8 g/m2/day, for Days 2-5 and 30-33; mitomycin C was given on Day 2 only. Treatment morbidity with the reduced chemotherapy intensity was comparable with that of radiotherapy alone. Median follow-up was 16 months (range 6-44). Median survival was 35 months. The results were compared with historical controls treated using the same radiation method alone. Two-year survival for late Stage IIb patients was 67% with the combination and 72% with radiotherapy alone; for Stage III, 67% and 49% respectively. Two-year pelvic control for late Stage IIb was 87% (combination) and 84% (radiotherapy alone) and for Stage III, 61% and 55% respectively. In contrast to reports from other centres, these results do not show an overall significant improvement on radiotherapy alone. A Phase III study may not be practicable.