The low contact stress patellofemoral replacement

The low contact stress patellofemoral replacement consists of a trochlear component and a modular patellar component which has a metal-backed mobile polyethylene bearing. We present the early results of the use of this prosthesis for established isolated patellofemoral arthritis in 51 consecutive patellofemoral replacements in 35 patients. The mean follow-up was 25 months (5 to 60). The estimated survival rate at three years was 63% (95% confidence interval 47 to 80) with revision as the endpoint and 46% (95% confidence interval 30 to 63) with revision and ongoing moderate or severe pain as the endpoint.

The early results of the use of the low contact stress patellofemoral replacement are disappointing with a high rate of revision. We cannot therefore recommend its use.

Lung-cancer reduction from smoking cessation and radon remediation: a preliminary cost-analysis in Northamptonshire, UK

Domestic radon levels in parts of the United Kingdom are sufficiently high as to increase the risk of lung-cancer among residents. Public health campaigns in the county of Northamptonshire, a designated radon Affected Area with 6.3% of homes having average radon levels in excess of the UK Action Level of 200 Bq m(-3), have encouraged householders to test for radon and then, if indicated to be necessary, to carry out remediation in their homes. These campaigns have been only partially successful, since to date only 40% of Northamptonshire houses have been tested, and only 15% of those householders finding raised levels have proceeded to remediate. Those who remediate have been shown to have smaller families, to be older, and to include fewer smokers than the average population, suggesting that current strategies to reduce domestic radon exposure are not reaching those most at risk. During 2004-2005, the NHS Stop-Smoking Services in Northamptonshire assisted 2847 smokers to quit to the 4-week stage, the 15% (435) of these 4-week quitters remaining quitters at 1year forming the subjects of a retrospective study considering whether smoking cessation campaigns contribute significantly to radon risk reduction. Quantitative assessment of the risk of lung-cancer among the study population, from knowledge of the individuals' age, gender, and smoking habits, together with the radon levels in their homes, demonstrates that smoking cessation programmes have significant added value in reducing the incidence of lung-cancer in radon Affected Areas, and contribute a substantially greater health benefit at a lower cost than the alternative strategy of reducing radon levels in the smokers' homes, while they remain smokers. Both radon remediation and smoking cessation programmes are very cost effective in Northamptonshire, with smoking cessation being significantly more cost effective, and these are potentially valuable programmes to drive health improvements through promotion of the uptake or environmental management for radon in the home.

Effects of winter manure application in Ohio on the quality of surface runoff

Winter application of manure poses environmental risks. Seven continuous corn, instrumented watersheds (approximately 1 ha each) at the USDA-ARS North Appalachian Experimental Watershed research station near Coshocton, Ohio were used to evaluate the environmental impacts of winter manure application when using some of the Ohio Natural Resources Conservation Service recommendations. For 3 yr on frozen, sometimes snow-covered, ground in January or February, two watersheds received turkey litter, two received liquid swine manure, and three were control plots that received N fertilizer at planting (not manure). Manure was applied at an N rate for corn; the target level was 180 kg N ha(-1) with a 30-m setback from the application area to the bottom of each watershed. Four grassed plots (61 x 12 m) were used for beef slurry application (9.1 Mg ha(-1) wet weight); two plots had 61 x 12 m grassed filter areas below them, and two plots had 30 x 12 m filter areas. There were two control plots. Nutrient concentrations were sometimes high, especially in runoff soon after application. However, most events with high concentrations occurred with low flow volumes; therefore, transport was minimal. Applying manure at the N rate for crop needs resulted in excess application of P. Elevated P losses contributed to a greater potential of detrimental environmental impacts with P than with N. Filter strips reduced nutrient concentrations and transport, but the data were too limited to compare the effectiveness of the 30- and 61-m filter strips. Winter application of manure is not ideal, but by following prescribed guidelines, detrimental environmental impacts can be reduced.

Risks of complications by attending physicians after performing nighttime procedures

CONTEXT

Few data exist on the relationships between experienced physicians' work hours and sleep, and patient safety.

OBJECTIVE

To determine if sleep opportunities for attending surgeons and obstetricians/gynecologists are associated with the risk of complications.

DESIGN, SETTING, AND PATIENTS

Matched retrospective cohort study of procedures performed from January 1999 through June 2008 by attending physicians (86 surgeons and 134 obstetricians/gynecologists) who had been in the hospital performing another procedure involving adult patients for at least part of the preceding night (12 am-6 am, postnighttime procedures). Sleep opportunity was calculated as the time between end of the overnight procedure and start of the first procedure the following day. Matched control procedures included as many as 5 procedures of the same type performed by the same physician on days without preceding overnight procedures. Complications were identified and classified by a blinded 3-step process that included administrative screening, medical record reviews, and clinician ratings.

MAIN OUTCOME MEASURES

Rates of complications in postnighttime procedures as compared with controls; rates of complications in postnighttime procedures among physicians with more than 6-hour sleep opportunities vs those with sleep opportunities of 6 hours or less.

RESULTS

A total of 919 surgical and 957 obstetrical postnighttime procedures were matched with 3552 and 3945 control procedures, respectively. Complications occurred in 101 postnighttime procedures (5.4%) and 365 control procedures (4.9%) (odds ratio, 1.09; 95% confidence interval [CI], 0.84-1.41). Complications occurred in 82 of 1317 postnighttime procedures with sleep opportunities of 6 hours or less (6.2%) vs 19 of 559 postnighttime procedures with sleep opportunities of more than 6 hours (3.4%) (odds ratio, 1.72; 95% CI, 1.02-2.89). Postnighttime procedures completed after working more than 12 hours (n = 958) compared with 12 hours or less (n = 918) had nonsignificantly higher complication rates (6.5% vs 4.3%; odds ratio, 1.47; 95% CI, 0.96-2.27).

CONCLUSION

Overall, procedures performed the day after attending physicians worked overnight were not associated with significantly increased complication rates, although there was an increased rate of complications among postnighttime surgical procedures performed by physicians with sleep opportunities of less than 6 hours.

Identification of prognostic signatures in breast cancer microarray data using Bayesian techniques

We apply a new Bayesian data analysis technique (latent process decomposition) to four recent microarray datasets for breast cancer. Compared to hierarchical cluster analysis, for example, this technique has advantages such as objective assessment of the optimal number of sample or gene clusters in the data, penalization of overcomplex models fitting to noise in the data and a common latent space of explanatory variables for samples and genes. Our analysis provides a clearer insight into these datasets, enabling assignment of patients to one of four principal processes, each with a distinct clinical outcome. One process is indolent and associated with under-expression across a number of genes associated with tumour growth. One process is associated with over expression of GRB7 and ERBB2. The most aggressive process is associated with abnormal expression of transcription factor genes, including members of the FOX family of transcription factor genes.

BC2001: A multicenter phase III randomized trial of standard versus reduced volume radiotherapy for muscle invasive bladder cancer (ISCRTN:68324339)

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Background: Radiotherapy (RT) is an alternative to radical cystectomy in the management of muscle invasive bladder cancer. Limitations are probability of attaining and maintaining local tumour control and risk of late bladder toxicity. BC2001 tests whether concomitant chemotherapy (CT) improves loco-regional control and whether RT volume modification reduces late toxicity without detriment to tumour control. Methods: Pts were randomized in a 2x2 factorial design to (i) RT vs RT + concomitant CT (5FU 500mg/m2 d1–5 wks 1 & 4 + mitomycin C 12mg/m2 d1) and/or (ii) standard RT to tumour and whole bladder with 1.5cm margin (sRT) vs reduced volume RT (rvRT) where tumour + 1.5cm margin was treated to 100(±5)% target dose and remaining bladder received 80% target dose. RT dose was 55Gy/20F or 64Gy/32F according to local practice. RT volume comparison results (primary endpoint RTOG toxicity at 1 yr) are reported. Target sample size was 480 pts but the RT randomisation closed early due to slow recruitment. Estimated power is 73% (two-sided α = 0.05) to detect a 20% difference in G3/4 toxicity. Results: 219 pts were recruited (108 sRT; 111 rvRT); 49 received neoadjuvant CT; 31 sRT and 33 rvRT were randomised to concomitant CT. Median age was 74 yrs. Median follow up is 36 mths. There was no difference in loco-regional disease-free survival (LRDFS: HR = 1.06, 95% CI: 0.62–1.84) nor overall survival (HR = 0.99, (0.61 - 1.35)) between randomised RT groups. 2yr LRDFS is 71% in both RT groups. 27 (16) sRT vs 32 (15) rvRT pts have had local (invasive) recurrences (p = 0.09); 32 pts have undergone salvage cystectomy. No difference was seen in CTC G3/4 acute toxicity (26% sRT vs 21% rvRT, p = 0.35), RTOG G3/4 toxicity at 12 mths (8% sRT vs 4% rvRT, p = 0.27) nor Lent Som G3/4 toxicity at 12 mths (45% sRT vs 34% rvRT, p = 0.21). Bladder capacity fell significantly in sRT group (mean reduction at 12 mths: 59mls, 95%CI: 47–118mls, p = 0.02) but not in rvRT group. Conclusions: RT in the modern era can attain local control in most patients with T2-T3 bladder cancer. Acute and late toxicity was less than anticipated in both treatment groups. Modifying standard RT volumes had minimal effect on local control and toxicity in this trial. 2 yr toxicity and quality of life data will be presented.

No significant financial relationships to disclose.