bluuebunny/crossref_metadata_2025 huggingface dataset:
Pain perception during and after VNUS ClosureFAST™ procedure
Authors: Roos M T , Borger van der Burg B L S , Wever J J
Published: March 2011

The objective of the study was first to quantify the level of pain that patients experience during VNUS ClosureFASTTM and in the first week following treatment. Secondly, to investigate the use of pain medication. Thirdly, to identify after how many days patients return to daily activities and whether pain is a factor of influence. A prospective descriptive cohort study was carried out. In all, 104 consecutive VNUS ClosureFAST procedures for greater saphenous vein (GSV) incompetence between 18 May and 28 August 2009 in the HagaZiekenhuis were included. A visual analogue score (VAS) was recorded immediately after the procedure. These patients were asked to register pain scores during the week following the procedure, the amount of pain medication if used and the time elapsed between the procedures and resuming daily activities. The average VAS score during the VNUS Closure procedure was four. The first three days after the procedure the VAS score was 2. After four days, the average score was 1. The average return to daily activities was on day two after the procedure. In total, 24% of all patients used paracetamol after the procedure. In summary, VNUS ClosureFAST procedure for GSV incompetence is not a painless treatment. After an average of two days, patients return to their daily activities. Pain does not seem to be a major factor in the resumption. Seventy-six percent of patients do not use any pain medication.
Proximal humeral replacement using a fixed-fulcrum endoprosthesis
Authors: Griffiths D. , Gikas P. D. , Jowett C. , Bayliss L. , Aston W. , Skinner J. , Cannon S. , Blunn G. , Briggs T. W. R. , Pollock R.
Published: March 2011

Between 1997 and 2007, 68 consecutive patients underwent replacement of the proximal humerus for tumour using a fixed-fulcrum massive endoprosthesis. Their mean age was 46 years (7 to 87). Ten patients were lost to follow-up and 16 patients died. The 42 surviving patients were assessed using the Musculoskeletal Tumor Society (MSTS) Score and the Toronto Extremity Salvage Score (TESS) at a mean follow-up of five years and 11 months (one year to ten years and nine months). The mean MSTS score was 72.3% (53.3% to 100%) and the mean TESS was 77.2% (58.6% to 100%).

Four of 42 patients received a new constrained humeral liner to reduce the risk of dislocation. This subgroup had a mean MSTS score of 77.7% and a mean TESS of 80.0%. The dislocation rate for the original prosthesis was 25.9; none of the patients with the new liner had a dislocation at a mean of 14.5 months (12 to 18).

Endoprosthetic replacement for tumours of the proximal humerus using this prosthesis is a reliable operation yielding good results without the documented problems of unconstrained prostheses. The performance of this prosthesis is expected to improve further with a new constrained humeral liner, which reduces the risk of dislocation.
An accelerated Ponseti versus the standard Ponseti method
Authors: Harnett P. , Freeman R. , Harrison W. J. , Brown L. C. , Beckles V.
Published: March 2011

We conducted a prospective randomised controlled trial to compare the standard Ponseti plaster method with an accelerated method for the treatment of idiopathic congenital talipes equinovarus. The standard weekly plaster-change method was accelerated to three times per week. We hypothesised that both methods would be equally effective in achieving correction. A total of 40 consecutive patients (61 feet) were entered into the trial. The initial median Pirani score was 5.5 (95% confidence interval 4.5 to 6.0) in the accelerated group and 5.0 (95% confidence interval 4.0 to 5.0) in the standard control group. The scores decreased by an average 4.5 in the accelerated group and 4.0 in the control group. There was no significant difference in the final Pirani score between the two groups (chi-squared test, p = 0.308). The median number of treatment days in plaster was 16 in the accelerated group and 42 in the control group (p < 0.001). Of the 19 patients in the accelerated group, three required plaster treatment for more than 21 days and were then assigned to the standard control method. Of the 40 patients, 36 were followed for a minimum of six months.

These results suggest that comparable outcomes can be achieved with an accelerated Ponseti method. The ability to complete all necessary manipulations within a three-week period facilitates treatment where patients have to travel long distances.
Use of quantitative intra-operative electrodiagnosis during partial ulnar nerve transfer to restore elbow flexion
Authors: Suzuki O. , Sunagawa T. , Yokota K. , Nakashima Y. , Shinomiya R. , Nakanishi K. , Ochi M.
Published: March 2011

The transfer of part of the ulnar nerve to the musculocutaneous nerve, first described by Oberlin, can restore flexion of the elbow following brachial plexus injury. In this study we evaluated the additional benefits and effectiveness of quantitative electrodiagnosis to select a donor fascicle. Eight patients who had undergone transfer of a simple fascicle of the ulnar nerve to the motor branch of the musculocutaneous nerve were evaluated. In two early patients electrodiagnosis had not been used. In the remaining six patients, however, all fascicles of the ulnar nerve were separated and electrodiagnosis was performed after stimulation with a commercially available electromyographic system. In these procedures, recording electrodes were placed in flexor carpi ulnaris and the first dorsal interosseous. A single fascicle in the flexor carpi ulnaris in which a high amplitude had been recorded was selected as a donor and transferred to the musculocutaneous nerve. In the two patients who had not undergone electrodiagnosis, the recovery of biceps proved insufficient for normal use. Conversely, in the six patients in whom quantitative electrodiagnosis was used, elbow flexion recovered to an M4 level.

Quantitative intra-operative electrodiagnosis is an effective method of selecting a favourable donor fascicle during the Oberlin procedure. Moreover, fascicles showing a high-amplitude in reading flexor carpi ulnaris are donor nerves that can restore normal elbow flexion without intrinsic loss.
Gender differences in the anatomy of the distal femur
Authors: Gillespie R. J. , Levine A. , Fitzgerald S. J. , Kolaczko J. , DeMaio M. , Marcus R. E. , Cooperman D. R.
Published: March 2011

Recently, gender-specific designs of total knee replacement have been developed to accommodate anatomical differences between males and females. We examined a group of male and female distal femora matched for age and height, to determine if there was a difference in the aspect ratio (mediolateral distance versus anteroposterior distance) and the height of the anterior flange between the genders. The Hamann-Todd Collection provided 1207 skeletally mature cadaver femora. The femoral length, the anteroposterior height, height of the lateral and medial flanges and the mediolateral width were measured in all the specimens. The mechanical axis of the femur, the cut articular width and the aspect ratio were assessed. Statistical analysis of the effect of gender upon the aspect ratio and the lateral and medial flanges was undertaken, controlling for age, height and race.

The mean aspect ratio of male femora was 1.21 (sd 0.07) and of female femora it was 1.16 (sd 0.06) (p < 0.001). There was no significant difference between male and female specimens in the mean size of the lateral flange (6.57 mm (sd 2.57) and 7.02 mm (sd 2.36), respectively; p = 0.099) or of the medial flange (3.03 mm (sd 2.47) and 3.56 mm (sd 2.32), respectively; p = 0.67). Future work in the design of knee prostheses should take into account the overall variability of the anatomy of the distal femur.
The pattern of the fracture and displacement of the fragments predict the outcome in proximal humeral fractures
Authors: Foruria A. M. , de Gracia M. M. , Larson D. R. , Munuera L. , Sanchez-Sotelo J.
Published: March 2011

Our aim was to determine the effect of the initial pattern of fracture and the displacement of fragments on the outcome of proximal humeral fractures treated conservatively. We followed 93 consecutive patients prospectively for one year. Final movement and strength were compared with those of the contralateral side. The final American Shoulder and Elbow Society score and the Disabilities of Arm, Shoulder and Hand and Short-Form 36 questionnaires were compared with those provided by the patient on the day of the injury. Radiographs and CT scans with three-dimensional reconstruction were obtained in all patients. The pattern of the fracture and the displacement of individual fragments were analysed and correlated with the final outcome. There were two cases of nonunion and six of avascular necrosis. The majority of the fractures (84 patients; 90%) followed one of the following four patterns: posteromedial (varus) impaction in 50 patients (54%), lateral (valgus) impaction in 13 (14%), isolated greater tuberosity in 15 (16%), and anteromedial impaction fracture in six (6%). Head orientation, impaction of the surgical neck and displacement of the tuberosity correlated strongly with the outcome.

In fractures with posteromedial impaction, a poor outcome was noted as the articular surface displaced inferiorly increasing its distance from the acromion. A poorer outcome was noted as a fractured greater tuberosity displaced medially overlapping with the posterior articular surface. Lateral impaction fractures had a worse outcome than other patterns of fracture.
Validation of the classification system for acetabular chondral lesions identified at arthroscopy in patients with femoroacetabular impingement
Authors: Konan S. , Rayan F. , Meermans G. , Witt J. , Haddad F. S.
Published: March 2011

There have been considerable recent advances in the understanding and management of femoroacetabular impingement and associated labral and chondral pathology. We have developed a classification system for acetabular chondral lesions. In our system, we use the six acetabular zones previously described by Ilizaliturri et al. The cartilage is then graded on a scale of 0 to 4 as follows: grade 0, normal articular cartilage lesions; grade 1, softening or wave sign; grade 2, cleavage lesion; grade 3, delamination; and grade 4, exposed bone. The site of the lesion is further classed as A, B or C based on whether the lesion is less than one-third of the distance from the acetabular rim to the cotyloid fossa, one-third to two-thirds of the same distance and greater than two-thirds of the distance, respectively. In order to validate the classification system, six surgeons graded ten video recordings of hip arthroscopy.

Our findings showed a high intra-observer reliability of the classification system with an intraclass correlation coefficient of 0.81 and a high interobserver reliability with an intraclass correlation coefficient of 0.88.

We have developed a simple reproducible classification system for lesions of the acetabular cartilage, which it is hoped will allow standardised documentation to be made of damage to the articular cartilage, particularly that associated with femoroacetabular impingement.
Damage of an Oxinium femoral head and polyethylene liner following ‘routine’ total hip replacement
Authors: McCalden R. W. , Charron K. D. , Davidson R. D. , Teeter M. G. , Holdsworth D. W.
Published: March 2011

We present a case of early retrieval of an Oxinium femoral head and corresponding polyethylene liner where there was significant surface damage to the head and polyethylene. The implants were retrieved at the time of revision surgery to correct leg-length discrepancy just 48 hours after the primary hip replacement. Appropriate analysis of the retrieved femoral head demonstrated loss of the Oxinium layer with exposure of the underlying substrate and transfer of titanium from the acetabular shell at the time of a reduction of the index total hip replacement. In addition, the level of damage to the polyethylene was extensive despite only 48 hours in situ.

The purpose of this report is to highlight the care that is required at the time of reduction, especially with these hard femoral counter-faces such as Oxinium. To our knowledge, the damage occurring at the time of reduction has not been previously reported following the retrieval of an otherwise well-functioning hip replacement.
Revision rates after total joint replacement
Authors: Labek G. , Thaler M. , Janda W. , Agreiter M. , Stöckl B.
Published: March 2011

In a systematic review, reports from national registers and clinical studies were identified and analysed with respect to revision rates after joint replacement, which were calculated as revisions per 100 observed component years.

After primary hip replacement, a mean of 1.29 revisions per 100 observed component years was seen. The results after primary total knee replacement are 1.26 revisions per 100 observed component years, and 1.53 after medial unicompartmental replacement. After total ankle replacement a mean of 3.29 revisions per 100 observed component years was seen.

The outcomes of total hip and knee replacement are almost identical. Revision rates of about 6% after five years and 12% after ten years are to be expected.
Ward-based rather than team-based junior surgical doctors reduce mortality for patients with a fracture of the proximal femur
Authors: Findlay J. M. , Keogh M. J. , Boulton C. , Forward D. P. , Moran C. G.
Published: March 2011

We performed a retrospective study of a departmental database to assess the efficacy of a new model of orthopaedic care on the outcome of patients with a fracture of the proximal femur. All 1578 patients admitted to a university teaching hospital with a fracture of the proximal femur between December 2007 and December 2009 were included. The allocation of Foundation doctors years 1 and 2 was restructured from individual teams covering several wards to pairs covering individual wards. No alterations were made in the numbers of doctors, their hours, out-of-hours cover, or any other aspect of standard patient care. Outcome measures comprised 30-day mortality and cause, complications and length of stay. Mortality was reduced from 11.7% to 7.6% (p = 0.007, Cox’s regression analysis); adjusted odds ratio was 1.559 (95% confidence interval 1.128 to 2.156). Reductions were seen in Clostridium difficile colitis (p = 0.017), deep wound infection (p = 0.043) and gastrointestinal haemorrhage (p = 0.033). There were no differences in any patient risk factors (except the prevalence of chronic obstructive pulmonary disease), cause of death and length of stay before and after intervention. The underlying mechanisms are unclear, but may include improved efficiency and medical contact time.

These findings may have implications for all specialties caring for patients on several wards, and we believe they justify a prospective trial to further assess this effect.
The role of tenodesis in surgery of the upper limb
Authors: Cash D. J. W. , Jones J. W. M.
Published: March 2011

This paper describes the presence of tenodesis effects in normal physiology and explores the uses of operative tenodesis in surgery of the upper limb.
The extended deltoid-splitting approach to the proximal humerus
Authors: Robinson C. M. , Murray I. R.
Published: March 2011

Fractures and nonunions of the proximal humerus are increasingly treated by open reduction and internal fixation. The extended deltopectoral approach remains the most widely used for this purpose. However, it provides only limited exposure of the lateral and posterior aspects of the proximal humerus. We have previously described the alternative extended deltoid-splitting approach. In this paper we outline variations and extensions of this technique that we have developed in the management of further patients with these fractures.
Does morbid obesity affect the outcome of total hip replacement?
Authors: McCalden R. W. , Charron K. D. , MacDonald S. J. , Bourne R. B. , Naudie D. D.
Published: March 2011

We evaluated the outcome of primary total hip replacement (THR) in 3290 patients with the primary diagnosis of osteoarthritis at a minimum follow-up of two years. They were stratified into categories of body mass index (BMI) based on the World Health Organisation classification of obesity. Statistical analysis was carried out to determine if there was a difference in the post-operative Western Ontario and McMaster Universities osteoarthritis index, the Harris hip score and the Short-Form-12 outcome based on the BMI.

While the pre- and post-operative scores were lower for the group classified as morbidly obese, the overall change in outcome scores suggested an equal if not greater improvement compared with the non-morbidly obese patients. The overall survivorship and rate of complications were similar in the BMI groups although there was a slightly higher rate of revision for sepsis in the morbidly obese group.

Morbid obesity does not affect the post-operative outcome after THR, with the possible exception of a marginally increased rate of infection. Therefore withholding surgery based on the BMI is not justified.
Design of cyclometalated iridium(III) polypyridine complexes as luminescent biological labels and probes
Authors: Lo Kenneth Kam-Wing , Zhang Kenneth Yin , Li Steve Po-Yam
Published: March 2011

The interesting emission properties of cyclometalated iridium(III) polypyridine complexes, originated from a range of excited states, have been well documented. The intense and long-lived emission of these complexes has been exploited in various areas of research including photovoltaic cells, chemosensors, and light-emitting devices. Additionally, there is an emerging interest in the applications of these luminescent complexes in various biological studies. In this paper, we summarize our recent work on the utilization of luminescent cyclometalated iridium(III) polypyridine complexes as biomolecular and cellular probes.
A Case of Severe Eosinophilia in a Preterm Infant
Authors: Shahein Abdul R. , Gonzalez Silvio , Carcao Manuel , Abdelhaleem Mohamed , Hellmann Jonathan , McNamara Patrick J.
Published: March 2011

Eosinophilia of prematurity is commonly seen in premature infants as a result of many causes, although a sustained or progressive form is uncommon. Different pathophysiological hypotheses include decreased circulating adrenal steroids and foreign antigen exposure. We present here a case of prolonged extreme eosinophilia in a preterm infant complicated by thrombocytopenia. The patient's eosinophil count reached 91.48 × 109/L and remitted with nonspecific treatment. A comprehensive clinical, laboratory, and radiologic assessment is usually required in the context of a hypereosinophilic preterm infant to recognize the triggering etiology. Nonspecific treatment was the modality of choice because of unclear etiology in our case. Preterm infants with blood eosinophilia might not need immunomodulatory treatment despite extremely high absolute eosinophil counts.
Race/Ethnicity Is Not Associated With Mortality in the PICU
Authors: Epstein David , Wong Carolyn F. , Khemani Robinder G. , Moromisato David Y. , Waters Karen , Kipke Michele D. , Markovitz Barry P.
Published: March 2011

OBJECTIVE:

To determine if a difference in survival exists between children of different racial/ethnic groups who were admitted to the PICU, after controlling for severity of illness (pediatric index of mortality 2).

METHODS:

We used the largest national clinical PICU database (Virtual PICU Performance System) with data from 31 hospitals, from 2005 to 2008. Children 18 years and younger were included. We collected demographic, pediatric index of mortality 2, diagnosis, and PICU mortality data. Logistic regression models were constructed to identify PICU mortality risk factors.

RESULTS:

The analysis of 80 739 patients revealed that, after controlling for severity of illness, being female (odds ratio [OR]: 1.12 [95% confidence interval (CI): 1.02–1.24] P = .019), 1 month or younger (OR: 1.39 [95% CI: 1.17–1.65] P < .001) or 12 years or older (OR: 1.34 [95% CI: 1.17–1.52] P < .001), or having an infectious diagnosis (OR: 2.22 [95% CI: 1.83–2.71] P < .001) or oncologic diagnosis (OR: 1.50 [95% CI: 1.14–1.99] P = .004) increased PICU mortality. Having “other” insurance type (OR: 1.58 [95% CI: 1.11–2.24] P = .010) or being Asian/Indian/Pacific Islander (OR: 1.35 [95% CI: 1.01–1.81] P = .042) seemed also to be mortality risk factors; however, because of heterogeneity and small group sizes (1.7% and 2.5% of the study population, respectively), these results are inconclusive.

CONCLUSIONS:

Although gender, age, and diagnosis showed an effect on severity of illness-adjusted PICU mortality, race/ethnicity did not. Additional investigation is warranted because the present results (ie, insurance type) may be proxy measurements for other influences not collected in this database, such as sociocultural and socioeconomic factors.
Effectiveness of Preventive Dental Treatments by Physicians for Young Medicaid Enrollees
Authors: Pahel Bhavna T. , Rozier R. Gary , Stearns Sally C. , Quiñonez Rocio B.
Published: March 2011

OBJECTIVE:

To estimate the effectiveness of a medical office–based preventive dental program (Into the Mouths of Babes [IMB]), which included fluoride varnish application, in reducing treatments related to dental caries.

METHODS:

We used longitudinal claims and enrollment data for all children aged 72 months or younger enrolled in North Carolina Medicaid from 2000 through 2006. Regression analyses compared subgroups of children who received up to 6 IMB visits at ages 6 to 35 months with children who received no IMB visits. Analyses were adjusted for child and area characteristics.

RESULTS:

Children enrolled in North Carolina Medicaid with ≥4 IMB visits experienced, on average, a 17% reduction in dental-caries–related treatments up to 6 years of age compared with children with no IMB visits. When we simulated data for initial IMB visits at 12 and 15 months of age, there was a cumulative 49% reduction in caries-related treatments at 17 months of age. The cumulative effectiveness declined because of an increase in treatments from 24 to 36 months, an increase in referrals for dental caries occurred with increasing time since fluoride application, and emergence of teeth not initially treated with fluoride.

CONCLUSIONS:

North Carolina's IMB program was effective in reducing caries-related treatments for children with ≥4 IMB visits. Multiple applications of fluoride at the time of primary tooth emergence seem to be most beneficial. Referrals to dentists for treatment of existing disease detected by physicians during IMB implementation limited the cumulative reductions in caries-related treatments, but also contributed to improved oral health.
Low-Dose Propranolol for Multiple Hepatic and Cutaneous Hemangiomas With Deranged Liver Function
Authors: Tan Swee Thong , Itinteang Tinte , Leadbitter Philip
Published: March 2011

We report here the case of an infant with multiple hepatic and cutaneous infantile hemangiomas (IHs) associated with deranged liver function who was treated successfully with low-dose propranolol. We also discuss our recent data that show that IH is a developmental anomaly of hemogenic endothelium derived from primitive mesoderm with a neural crest-cell phenotype. We previously presented evidence that this hemogenic endothelium is governed by the renin-angiotensin system, which we propose can account for both the action of propranolol and the process of spontaneous involution of IH. We further speculate on the possibility of using inhibitors of angiotensin-converting enzyme and that of angiotensin II receptor 2 as potential alternative therapies.
Neurodevelopmental Outcomes of Triplets or Higher-Order Extremely Low Birth Weight Infants
Authors: Wadhawan Rajan , Oh William , Vohr Betty R. , Wrage Lisa , Das Abhik , Bell Edward F. , Laptook Abbot R. , Shankaran Seetha , Stoll Barbara J. , Walsh Michele C. , Higgins Rosemary D. ,   for the Eunice Kennedy Shriver National Institute of Child Health & Human Development Neonatal Research Network
Published: March 2011

BACKGROUND:

Extremely low birth weight twins have a higher rate of death or neurodevelopmental impairment than singletons. Higher-order extremely low birth weight multiple births may have an even higher rate of death or neurodevelopmental impairment.

METHODS:

Extremely low birth weight (birth weight 401–1000 g) multiple births born in participating centers of the Neonatal Research Network between 1996 and 2005 were assessed for death or neurodevelopmental impairment at 18 to 22 months' corrected age. Neurodevelopmental impairment was defined by the presence of 1 or more of the following: moderate to severe cerebral palsy; mental developmental index score or psychomotor developmental index score less than 70; severe bilateral deafness; or blindness. Infants who died within 12 hours of birth were excluded. Maternal and infant demographic and clinical variables were compared among singleton, twin, and triplet or higher-order infants. Logistic regression analysis was performed to establish the association between singletons, twins, and triplet or higher-order multiples and death or neurodevelopmental impairment, controlling for confounding variables that may affect death or neurodevelopmental impairment.

RESULTS:

Our cohort consisted of 8296 singleton, 2164 twin, and 521 triplet or higher-order infants. The risk of death or neurodevelopmental impairment was increased in triplets or higher-order multiples when compared with singletons (adjusted odds ratio: 1.7 [95% confidence interval: 1.29–2.24]), and there was a trend toward an increased risk when compared with twins (adjusted odds ratio: 1.27 [95% confidence: 0.95–1.71]).

CONCLUSIONS:

Triplet or higher-order births are associated with an increased risk of death or neurodevelopmental impairment at 18 to 22 months' corrected age when compared with extremely low birth weight singleton infants, and there was a trend toward an increased risk when compared with twins.
Cerebral Oxygenation Is Depressed During Sleep in Healthy Term Infants When They Sleep Prone
Authors: Wong Flora Y. , Witcombe Nicole B. , Yiallourou Stephanie R. , Yorkston Sophie , Dymowski Alicia R. , Krishnan Lalitha , Walker Adrian M. , Horne Rosemary S. C.
Published: March 2011

OBJECTIVE:

Prone sleeping is a major risk factor for the sudden infant death syndrome and is associated with lower blood pressure and impaired arousability from sleep, both of which may be signs of cerebral hypoxia. However, the impact of sleep position on cerebral oxygenation during infancy remains unknown. We assessed the effects of sleeping position, sleep state, and postnatal age on cerebral oxygenation by measuring tissue oxygenation index (TOI) during the first 6 months of infancy.

SUBJECTS AND METHODS:

Seventeen healthy term infants (8 girls and 9 boys) were recruited as study participants. Infants were studied at ages 2 to 4 weeks, 2 to 3 months, and 5 to 6 months by use of daytime polysomnography, with additional measurements of blood pressure (Finometer, FMS Finometer Medical Systems, Amsterdam, Netherlands) and tissue oxygenation index (TOI) (NIRO 200 spectrophotometer, Hamamatsu Photonics KK, Tokyo, Japan).

RESULTS:

In infants who slept in the prone position, TOI was lower in both quiet sleep (QS) and active sleep (AS) at age 2 to 4 weeks and in QS at age 2 to 3 months (P < .05). TOI was lower in AS compared with QS in infants aged 2 to 4 weeks (P < .05). When the infants reached 5 to 6 months of age, TOI was greater in AS (P < .05), as there was a profound decrease in TOI during QS (P < .05) over this period. No relationship was identified between blood pressure and TOI at any age.

CONCLUSIONS:

In healthy infants cerebral oxygenation is reduced during sleep in the prone position. This reduction may underpin the reduced arousability from sleep exhibited by healthy infants who sleep prone, a finding that provides new insight into potential risks of prone sleeping and mechanisms of sudden infant death syndrome.
Ultraviolet Radiation: A Hazard to Children and Adolescents
Authors: Balk Sophie J. ,   the Council on Environmental Health and Section on Dermatology
Published: March 2011

Sunlight sustains life on earth. Sunlight is essential for vitamin D synthesis in the skin. The sun's ultraviolet rays can be hazardous, however, because excessive exposure causes skin cancer and other adverse health effects. Skin cancer is a major public health problem; more than 2 million new cases are diagnosed in the United States each year. Ultraviolet radiation (UVR) causes the 3 major forms of skin cancer: basal cell carcinoma; squamous cell carcinoma; and cutaneous malignant melanoma. Exposure to UVR from sunlight and artificial sources early in life elevates the risk of developing skin cancer. Approximately 25% of sun exposure occurs before 18 years of age. The risk of skin cancer is increased when people overexpose themselves to sun and intentionally expose themselves to artificial sources of UVR. Public awareness of the risk is not optimal, compliance with sun protection is inconsistent, and skin-cancer rates continue to rise in all age groups including the younger population. People continue to sunburn, and teenagers and adults are frequent visitors to tanning parlors. Sun exposure and vitamin D status are intertwined. Adequate vitamin D is needed for bone health in children and adults. In addition, there is accumulating information suggesting a beneficial influence of vitamin D on various health conditions. Cutaneous vitamin D production requires sunlight, and many factors complicate the efficiency of vitamin D production that results from sunlight exposure. Ensuring vitamin D adequacy while promoting sun-protection strategies, therefore, requires renewed attention to evaluating the adequacy of dietary and supplemental vitamin D. Daily intake of 400 IU of vitamin D will prevent vitamin D deficiency rickets in infants. The vitamin D supplementation amounts necessary to support optimal health in older children and adolescents are less clear. This report updates information on the relationship of sun exposure to skin cancer and other adverse health effects, the relationship of exposure to artificial sources of UVR and skin cancer, sun-protection methods, vitamin D, community skin-cancer–prevention efforts, and the pediatrician's role in preventing skin cancer. In addition to pediatricians' efforts, a sustained public health effort is needed to change attitudes and behaviors regarding UVR exposure.
Novel Solution to Cement Strength Retrogression
Authors: Gibson Sarah
Published: March 2011

When Portland cement is exposed to high temperature environments it experiences "strength retrogression", which is characterized by the breakdown of the set cement matrix. This results in loss of zonal isolation and/or pipe support, impacting the operational life span of the wellbore and its eventual abandonment. To prevent this, it is standard industry practice to incorporate extra silica into the cement slurry. Silica flour or sand is usually dry-blended with the bulk cement at concentrations of 35-40% bwoc. However, this methodology carries health risks, complicates operations (especially off-shore) and introduces costs that could be avoided.

With the North Sea being a mature drilling arena, it requires ever more complicated well bores to access remaining deposits and therefore operators are continually looking for more cost-effective methods of achieving this. Coupled with the desire to reduce the impact on the environment of our work, a new method for introducing silica to cement slurries was introduced. Since its arrival to the market in 2003, the use of a liquid strength retrogression prevention additive has steadily been gaining acceptance throughout the industry. This paper reviews the benefits of such a system, especially during exploration work and short rig hire contracts, and some of the issues encountered in bringing these gains to customers. Overcoming handling and shelf-life problems will lead to reduced costs and allow more operators to take advantage of this solution.
Continuous Motion Rig. A Detailed Study of a 750 Ton Capacity, 3600 m/hr Trip Speed Rig
Authors: Grinrød Mads , Krohn Helge
Published: March 2011

The basic principles for a Continuous Motion Rig (CMR) has been presented earlier (IADC/SPE128253).The CMR concept allows jointed pipe to be run or pulled in a continuous manner.

Several benefits besides significant improvement in tripping speed results from continuous movement of pipe. This new rig concept can be used on all rigs –on or offshore where well costs, well safety and efficiency are important issues.

The CMR concept based on a 750 ton system has been studied in a Joint Industry Project (JIP).

This paper discusses aspects of the Continuous Motion Rig such as system benefits, equipment, control system and layout based on findings in the Joint Industry Project. Design basis in JIP was set at 3600 m/hr trip speed corresponding to 1 m/sec continuous running or pulling of drill pipe. High efficiency demands a fully automated rig as concerns surface processes involved in normal drilling operations. This automation requires rethinking control systems. Continuous motion technology opens up possibilities to explore and exploit deeper deposits economically.
Approaching the Technical Limit: Mature Basin Benefits from Influx of Advanced Drilling Rigs/Tool Technology
Authors: Márquez Hugo , Crovetto Marcelo
Published: March 2011

An operator working a mature field in southern Argentina's San Jorge Basin wanted to use the latest drilling technologies to establish a new field benchmark. The basin has been producing hydrocarbons for approximately 100 years, and most operators active in the area were reluctant to apply high-end technology to develop what the industry considered to be marginal reserves.

In spite of the economic risk, a plan was initiated in Q1 2009 to deploy new automated flexible-drilling rigs in conjunction with high-performance downhole tools designed to efficiently use the rig's increased hydraulic horsepower capabilities. Due to hole deviation problems, a reliable yet cost effective vertical drilling system was employed, because it could withstand the application's extreme flow rates, high weight on bit (WOB), and still deliver the required wellbore trajectory and superior borehole quality. The deviation control system uses a high-power positive displacement motor (PDM) and proven packed hole bottomhole assembly (BHA) design techniques.

The new tools were run on several wells in the field with outstanding results. This paper will outline the learning curve and engineering process that led to advanced performance and improvements: new-technology adaptation to the actual and aggressive drilling plans that helped the operator reduce drilling costs, delivery of a high-quality in-gauge wellbore and efficiently achieving the mandated drilling schedule.
Emergency Severance of Casing for Deepwater Operations: A Design Build and Test Programme of Novel Technologies
Authors: Richmond N. , Bamford N. J. , Bamford A. S.
Published: March 2011

In deep-water, emergency disconnection while running casing, is the action of last resort. It requires the casing to be sheared and the well bore sealed. In an 18-3/4" BOP cutting casing sizes of 9-5/8" and above can be difficult and may impinge on the bore of the BOP.

An Annular Cutting Tool (ACT) has been developed that can be implemented inside an API housing, spool piece or an extension to a BOP ram body. The ACT has been designed to work with conventional drill pipe blind rams. The cutting mechanism is swarf free and produces a good quality cut for later re-entry to the well.

After engineering design, a prototype tool to cut 7-5/8" casing was developed and tested. The system in its current state of design, uses a rotating plenum driven by a sealed bevel gear cartridge, with six elliptical pistons each incorporating a cutting wheel. The paper will describe the selection and testing of bearing and seals and how the drive and control system was optimised to cut the casing in less than 45 seconds required by API RP 53. The effects will be illustrated of varying system rotational speed and applied pressure to the cutting wheels.

Plans for future testing are described including; the effects of varying pipe grade, wall thickness, and casing load conditions consisting of different combinations of tension and bending.

The ACT design has to ensure that there are two physical blocks between the wellbore pressure and the external seawater environment; each of these blocks is independently tested.
Challenging Multilateral and Completion Design for a Deepwater Well in Italy: Decision Support through Risk Analysis
Authors: Repetto C. , Sanasi C. , Di Vincenzo S. , Cordeddu C. , Maccarini G. Ricci , Tufo M. , Michelez J. , Rossi N.
Published: March 2011

Oil and gas industry is increasingly approaching more challenging situations where it is of primarily importance to carefully assess the technical solutions to maximize productivity, to evaluate the economic worth of investment and identify all the risks and opportunities involved in the project.

A challenging subsea well is planned to be drilled and completed in a deep offshore field in the Adriatic Sea (Italy).

This project includes all the challenges and criticalities related to: deepwater wells, sour environment, gas lift wells, multilateral and intelligent wells.

The objective of the study was to provide decision support for the selection of the most suitable multilateral and completion design addressing, through a probabilistic approach, all the uncertainties regarding reservoir characteristics, well design and productivity in terms of duration and cost.

A multidisciplinary working team, including drilling and completion engineers, geologists and reservoir engineers, has been created in order to assess all the aspects of the project with its opportunities and criticalities.

Different scenarios have been compared with regards to the available technologies for multilateral and intelligent completions.

The first step of the analysis was the identification of the uncertainties (opportunities and risks) related to technical, organizational or environmental issues, successively reported in a probabilistic time and cost model.

A dedicated fault tree approach was deemed useful to focus on the combination of events leading to a potential branch loss and to calculate the associated probability.

All uncertainties were then combined with production profiles into a technical unit cost ($/bbl).

This paper describes workflow and results. The results provide the managers with a comprehensive picture of a complex issue to make the investment right decision at a given confidence level.

This should provide a guideline to engineers, geologists and managers on the risked approach for the development of complex projects.
Intergranular Cracking of Oil Field Tubular Components Resulting from the Tempering Process
Authors: Koneti Srinivasa , Gokhale Samit , Wadsworth Thomas
Published: March 2011

Oil country tubular components manufactured from low carbon and alloy steels often fail through brittle intergranular cracking when exposed to an environment containing aqueous H2S. Such failures promulgate the notion that detection of intergranular cracking morphology on fracture surfaces is confirmation of failure through sulfide stress cracking (SSC) or hydrogen embrittlement, even when no evidence exists for exposure to H2S or a source of nascent hydrogen. Study of intergranular cracking related failures has shown that such failures can occur not only when the component is exposed to H2S, but can also be caused by temper embrittlement due to improper heat treatment.

This paper presents case studies and lessons learned from the analysis of such failures. The paper is based on the results of metallurgical analyses performed during the investigations as well as the results of the follow up re-heat treatments performed with different heat treatment parameters and procedures. If a component fracture presents signs of intergranular cracking with no supporting evidence of environmental attack, failure resulting from temper embrittlement is a strong possibility that must be considered and investigated.

For the failures analyzed, the manufacturing and heat treatment operations performed on the component at the mill were studied. Re-heat treatment and material testing of a failed component was performed to study the temper embrittlement phenomenon. By re-heat treating the failed component, temper embrittlement of the material was removed with substantial improvement in the material properties. If the component had undergone proper heat treatment and had the properties of the re-heat treated steel initially, the failure likely would have been avoided.

The paper presents the metallurgical and analytical techniques that need to be utilized to identify the temper embrittlement mechanism. This paper also provides guidelines on traits related to alloying elements used, impurity elements, and tempering temperatures commonly associated with failures caused by temper embrittlement.
Coating Optimized for Abrasion and Fatigue Resistance for Use in Extreme Well Geometries
Authors: McCormick John E. , Le Joe , Evans Chad
Published: March 2011

Extreme well geometries, extended reach wells, and other applications that test the technological limitations of drill strings and tools are becoming more commonplace in the industry. A new high velocity oxy fuel (HVOF) applied tungsten carbide coating has been developed for use on performance drilling tools for these challenging applications. Tungsten carbide coatings are known for abrasion resistance and lab testing has proven this coating is also ductile.

Key benefits include reducing the risk of damage or failure of critical drilling tools and pushing the technology envelope. Extensive testing shows excellent resistance to repeated bending cycles, which leads to cracking and possibly catastrophic failures in drilling environments.

In order to develop a suitable coating for fatigue resistance, abrasion resistance and cost, several hard-facing coatings and application methods that have been continuously developed for downhole tool applications were selected for extensive lab testing. The coating hardness and the ductility of the matrix within which the tungsten carbide resides were optimized, inducing more abrasion resistance and raising the fatigue life. Rotating drilling tools now have a coating that has been identified and tested as acceptable for use in extreme well geometries.

Directional assemblies, jars, torque and drag reduction subs, and any other rotating tools susceptible to wear that are used in high dogleg environments are all potential beneficiaries of a highly reliable coating.

A test with a standard tungsten carbide HVOF hard-facing coating and application method generated cracks within the coating. These cracks did not propagate into the base metal, but it is conventionally impossible for inspectors to differentiate between cracks in the coating vs. the base metal. The decision was made to explore different methods with regard to the coating thickness, matrix ductility, application method.

Multiple coatings tested on varying sizes of tools has led to the development of a tungsten carbide coating that has withstood 10,000,000 cycles at 12 deg/100 ft, and an additional 2,000,000 cycles at 25 deg/100 ft, without the development of fatigue cracks. The test was concluded when the mounting apparatus gave out.

The coating will assist in pushing the technical envelope that restricts operators from economically reaching reservoirs in today's challenging energy environment. Main contributions are an expansion of the technology envelope and the reduction of risk related to damaged tools and failures while drilling challenging wells.
Fatigue-Based Tubular Connection Performance for a CSS Operation
Authors: Hsu S.-Y. , Searles K. H. , Aylor A. W.
Published: March 2011

The Cold Lake heavy oil development, located in northeast Alberta, Canada, began commercial operation in 1985 and uses a thermal recovery process called cyclic steam stimulation (CSS). During steaming and production cycles, the dilation and re-compaction that occur within the reservoir cause the overburden to deform much like the motion of flexing a thick telephone book. At weak overburden layers, shear slip plane(s) can form due to excessive shear stress. Over multiple steaming/production cycles, the cyclic flexing and associated shear slip may lead to overburden casing fatigue failures.

In this paper, a multi-scale geomechanics modeling methodology is presented to predict the onset of casing and connection failures due to CSS-induced ultra low cyclic fatigue (ULCF). The modeling methodology consists of building a global model of single or multiple pads, a next level submodel of near-well formation and cement, and a final submodel of casing and connection. To predict the ULCF life, an algorithm based on the concept of cyclic void growth is incorporated into the casing/connection submodel. It provides the capability to predict the number of steam cycles to failure using the concepts of demand (load) and capacity (resistance).

A sensitivity study of connection offset to shear slip plane suggested that fatigue life could be extended by placing the connection away from shear slip planes. A series of parametric studies were also conducted to characterize the impact of threaded connection design on fatigue life. Several design scenarios were studied including upset pin, oversized coupling, special clearance coupling, and truncated-length coupling. By selectively reducing the coupling length (truncated) or outer diameter (special clearance), the fatigue life could be prolonged. Based on these promising results, new connection design concepts are being considered for CSS operations in Cold Lake.
One Sack Rapid Mix and Pump Solution to Severe Lost Circulation
Authors: Clapper Dennis K. , Szabo Joseph J. , Spence Steven , Otto Mike , Creelman Brian , Lewis Tom G. , McGuffey Gary
Published: March 2011

Lost circulation events continue to plague drilling operations. Severe lost circulation can result in complete loss of the hole along with drilling equipment. When attempting to stop massive losses, rapid preparation and placement of a lost circulation treatment will improve the frequency of successful application. A fiber pill formulation has been developed to address common operational concerns that exist with current lost circulation pill procedures. The one-sack product is designed for rapid mixing and pumping with a minimum of equipment. This product does not require any activators, retarders, set time calculations, or temperature activation. Laboratory testing has demonstrated the ability of the fiber pill slurries to rapidly dewater/de-oil and form a sealing plug. Testing also indicates that the fiber product formulated as a weighted pill with barite will form a plug with measurable compressive strength. The fiber product can be used with a wide range of fluids including freshwater, brines, and base oils. The product, which meets environmental requirements for use in the Gulf of Mexico, can be rapidly mixed and pumped on location using standard rig equipment. The fiber formulation is compatible with all mud systems and is easily removed with standard solids control equipment. This new approach to control severe losses has been successfully applied in several field tests. A few of these field applications will be discussed in detail.