Ceramic-on-ceramic bearing fractures in total hip arthroplasty: an analysis of data from the National Joint Registry.

AIMS: Ceramic-on-ceramic (CoC) bearings in total hip arthroplasty (THA) are commonly used, but concerns exist regarding ceramic fracture. This study aims to report the risk of revision for fracture of modern CoC bearings and identify factors that might influence this risk, using data from the National Joint Registry (NJR) for England, Wales, Northern Ireland and the Isle of Man. PATIENTS AND METHODS: We analysed data on 223 362 bearings from 111 681 primary CoC THAs and 182 linked revisions for bearing fracture recorded in the NJR. We used implant codes to identify ceramic bearing composition and generated Kaplan-Meier estimates for implant survivorship. Logistic regression analyses were performed for implant size and patient specific variables to determine any associated risks for revision. RESULTS: A total of 222 852 bearings (99.8%) were CeramTec Biolox products. Revisions for fracture were linked to seven of 79 442 (0.009%) Biolox Delta heads, 38 of 31 982 (0.119%) Biolox Forte heads, 101 of 80 170 (0.126%) Biolox Delta liners and 35 of 31 258 (0.112%) Biolox Forte liners. Regression analysis of implant size revealed smaller heads had significantly higher odds of fracture (chi-squared 68.0, p < 0.001). The highest fracture risk was observed in the 28 mm Biolox Forte subgroup (0.382%). There were no fractures in the 40 mm head group for either ceramic type. Liner thickness was not predictive of fracture (p = 0.67). Body mass index (BMI) was independently associated with revision for both head fractures (odds ratio (OR) 1.09 per unit increase, p = 0.031) and liner fractures (OR 1.06 per unit increase, p = 0.006). CONCLUSIONS: We report the largest independent study of CoC bearing fractures to date. The risk of revision for CoC bearing fracture is very low but previous studies have underestimated this risk. There is good evidence that the latest generation of ceramic has greatly reduced the odds of head fracture but not of liner fracture. Small head size and high patient BMI are associated with an increased risk of ceramic bearing fracture. Cite this article: Bone Joint J 2017;99-B:1012-19.

Age-specific incidence, risk factors and outcome of acute abdominal aortic aneurysms in a defined population.

BACKGROUND: Contemporary population-based data on age-specific incidence and outcome from acute abdominal aortic aneurysm (AAA) events are needed to understand the impact of risk factor modification and demographic change, and to inform AAA screening policy. METHODS: In a prospective population-based study (Oxfordshire, UK, 2002-2014), event rates, incidence, early case fatality and long-term outcome from all acute AAA events were determined, both overall and in relation to the four main risk factors: smoking, hypertension, male sex and age. RESULTS: Over the 12-year interval, 103 incident acute AAA events occurred in the study population of 92,728 (men 72·8 per cent; 59·2 per cent 30-day case fatality rate). The incidence per 100,000 population per year was 55 in men aged 65-74 years, but increased to 112 at age 75-84 years and to 298 at age 85 years or above. Some 66·0 per cent of all events occurred in those aged 75 years or more. The incidence at 65-74 years was highest in male smokers (274 per 100,000 population per year); 27 (96 per cent) of 28 events in men aged less than 75 years occurred in ever-smokers. Mean(s.d.) age at event was lowest in current smokers (72·2(7·2) years), compared with that in ex-smokers (81·2(7·0) years) and never-smokers (83·3(7·9) years) (P < 0·001). Hypertension was the predominant risk factor in women (diagnosed in 93 per cent), with 20 (71 per cent) of all 28 events in women occurring in those aged 75 years or above with hypertension. The 30-day case fatality rate increased from 40 per cent at age below 75 years to 69 per cent at age 75 years or more (P = 0·008). CONCLUSION: Two-thirds of acute AAA events occurred at age 75 years or above, and more than 25 per cent of events were in women. Taken with the strong associations with smoking and hypertension, these findings could have implications for AAA screening.

Surgical site infection rate is lower in laparoscopic than open colorectal surgery.

OBJECTIVE: Few studies have investigated whether surgical site infection (SSI) incidence differs between laparoscopic colorectal surgery (LCS) and open colorectal surgery (OCS). This study investigated the SSI incidence using the validated UK SSI Surveillance Service (SSISS) criteria for diagnosing wound infections. METHOD: Prospective data collection recorded patients' demographics, operative details, antibiotic use, wound evaluation and microbiological wound culture results, for consecutive patients undergoing elective resectional LCS and OCS. Postdischarge surveillance consisted of patient questionnaires sent out at 30 days and the primary care communication. RESULTS: A total of 122 patients underwent colorectal resections over 1 year (LCS 43; OCS 79). Patients' demographics and operative case-mix were similar for both groups, including body mass index (BMI), diabetic and smoking status. Operative duration was longer in the LCS group compared with OCS group (P = 0.012, Mann-Whitney U-test), but hospital stay was shorter for LCS (P = 0.0001, Mann-Whitney U-test). The SSI rate was significantly lower in the LCS than OCS group (7%vs 25% respectively; P = 0.015, two-tailed Fisher's exact test). BMI > 30 and operation length > 4 h influenced the risk of SSI formation (P < 0.05, chi-squared test). One LCS patient required conversion to a limited laparotomy. CONCLUSIONS: Surgical site infection incidence is significantly lower following LCS when compared with OCS. Confounding factors in this study include patient selection for LCS and nonrandomization.

A simple effective clean practice protocol significantly improves hand decontamination and infection control measures in the acute surgical setting.

BACKGROUND: The Hand Hygiene Liaison Group and Epic Projects (Pratt et al., J Hosp Infect 47[Suppl A], 2001) have asked specifically for further trials of educational interventions to improve hand decontamination compliance and infection control in the hospital setting. This study investigates the efficacy of a 'clean practice protocol' (CPP), derived from international guidelines, to improve compliance of infection-control practices by surgical teams in a large UK teaching hospital. METHODS: The key infection-control activities were summated to form the CPP presented here. An undisclosed infection-control audit of consultant-led ward-rounds from breast, gastrointestinal, vascular, urological, and intensive care departments was performed. The audit results were presented to the surgical teams, after which an education/awareness program was implemented. A repeat undisclosed audit was performed 3 months later. In both audits, infection-control activities were recorded together with consultation time and any patient infective complications. RESULTS: The surgical teams performed as follows in the initial audit: hand decontamination (28% of consultations), correct use of gloves (2%), instrument cleaning (0%), garment contamination (49%), and notes contamination (34%). Introduction of the CPP education program significantly improved hand decontamination to 87% (p < 0.0001), the correct use of gloves/aprons to 50% (p < 0.0001), and overall infection-control practice from 63% to 89% (p < 0.05). CONCLUSIONS: The introduction of the CPP significantly improved compliance of hand decontamination, correct usage of gloves and aprons, and overall infection-control in a large teaching hospital. The CPP is a highly effective auditing and educational tool that can be readily adapted for use in hospitals globally to monitor and improve infection-control practices.

The role of superficial venous surgery in the management of venous ulcers: a systematic review.

BACKGROUND: The complicated natural history of venous ulcers requires the continued development and improvement of treatments to ensure the most effective management. Compression therapy or surgical correction of superficial venous incompetence (SVI) are currently the main methods employed for the treatment for venous ulceration (VU). This review compares and summates the healing and recurrence rates for each treatment modality used over the last thirty years. METHODS: Sixty-one articles investigating compression and superficial venous surgical treatments were obtained from a systematic search of electronic databases (Medline, Embase, The Cochrane Library, and Google Scholar) and then an expanded reference list review. Patient demographics, CEAP classification, patterns of venous insufficiency, type of intervention, length of follow up, healing and recurrence rates for venous ulceration was assessed. Inadequate data in seven reports led to their exclusion. Recent randomised controlled trials (RCTs) specifically comparing superficial surgery to compression therapy were reviewed and data from non-randomised and/or 'small' clinical studies prior to 2000 underwent summation analysis. RESULTS: Five RCTs since 2000 demonstrate a similar healing rate of VU with surgery and conservative compression treatments, but a reduction in ulcer recurrence rate with surgery. The effect of deep venous incompetence (DVI) on the ulcer healing is unclear, but sub-group analysis of long-term data from the ESCHAR trial suggests that although surgery results in a less impressive reduction in ulcer recurrence in patients with DVI, these patients appear to still benefit from surgery due to the haemodynamic and clinical benefits that result. The RCTs also highlight that a significant proportion of VU patients are unsuitable for surgical treatment. Summation of data from earlier studies (before 2000), included twenty-one studies employing conservative compression alone resulted in an overall healing rate of 65% (range 34-95%) and ulcer recurrence of 33% (range 0-100%). In thirty-one studies investigating superficial venous surgery, the overall rate of ulcer healing was 81% (range 40-100%) with a post-operative recurrence rate of 15% (range 0-55%). The duration of follow up care in the surgical studies was approximately twice as long as in the conservative studies, which would lend to more reliable recurrence data. CONCLUSIONS: Evidence from the current literature, would suggest that superficial venous surgery is associated with similar rates of ulcer healing to compression alone, but with less recurrence. The effects of post-operative compression and DVI on the efficacy of surgery are still unclear.

A need for a simplified approach to venous thromboembolism prophylaxis in acute medical inpatients.

Venous thromboembolism (VTE) is a major cause of morbidity and mortality in the UK. Studies have shown that pulmonary embolism causes or contributes to approximately 1 in 10 hospital deaths of medical patients admitted to general hospitals in the UK (Lindblad B, Sternby NH, Bergqvist D. BMJ 1991; 302: 709-11), with pulmonary embolus being the most common preventable cause of hospital death. Thromboprophylaxis is safe, highly effective and cost effective, but despite various current clinical guidelines, physicians fail to prescribe prophylaxis for the majority of medical inpatients at risk of VTE. This article outlines the current evidence for VTE prophylaxis in medical patients and discusses the reasons behind the insufficient use of prophylaxis in the acute medical setting.

L-arginine effects on Na+ transport in M-1 mouse cortical collecting duct cells--a cationic amino acid absorbing epithelium.

The effect of L-arginine on transepithelial ion transport was examined in cultured M-1 mouse renal cortical collecting duct (CCD) cells using continuous short circuit current (Isc) measurements in HCO3-/CO2 buffered solution. Steady state Isc averaged 73.8 +/- 3.2 microA/cm2 (n = 126) and was reduced by 94 +/- 0.6% (n = 16) by the apical addition of 100 microM amiloride. This confirms that the predominant electrogenic ion transport in M-1 cells is Na+ absorption via the epithelial sodium channel (ENaC). Experiments using the cationic amino acid L-lysine (radiolabeled) as a stable arginine analogue show that the combined activity of an apical system y+ and a basal amino acid transport system y+L are responsible for most cationic amino acid transport across M-1 cells. Together they generate net absorptive cationic amino acid flux. Application of L-arginine (10 mM) either apically or basolaterally induced a transient peak increase in Isc averaging 36.6 +/- 5.4 microA/cm2 (n = 19) and 32.0 +/- 7.2 microA/cm2 (n = 8), respectively. The response was preserved in the absence of bath Cl- (n = 4), but was abolished either in the absence of apical Na+ (n = 4) or by apical addition of 100 microM amiloride (n = 6). L-lysine, which cannot serve as a precursor of NO, caused a response similar to that of L-arginine (n = 4); neither L-NMMA (100 microM; n = 3) nor L-NAME (1 mM; n = 4) (both NO-synthase inhibitors) affected the Isc response to L-arginine. The effects of arginine or lysine were replicated by alkalinization that mimicked the transient alkalinization of the bath solution upon addition of these amino acids. We conclude that in M-1 cells L-arginine stimulates Na+ absorption via a pH-dependent, but NO-independent mechanism. The observed net cationic amino acid absorption will counteract passive cationic amino acid leak into the CCD in the presence of electrogenic Na+ transport, consistent with reports of stimulated expression of Na+ and cationic amino acid transporters by aldosterone.

The corporate social responsiveness orientation of hospital directors: does occupational background make a difference?

The results of a survey of 184 directors from 15 hospitals are analyzed to determine their corporate social responsiveness orientation. They indicate that board members whose occupational background is not in health care exhibit greater concern for economic performance and the legal component of corporate responsibility than their counterparts whose occupational background is in health care. No significant differences between the two groups were observed with respect to the ethical and discretionary dimensions of corporate social responsibility. Some explanations as well as limited generalizations and implications are developed.

Laser radar reflective tomography utilizing a streak camera for precise range resolution.

Tomography is used to reconstruct 2-D images from 1-D range-resolved laser radar data. A doubled mode-locked Nd:YAG pulsed laser illuminates a conical object, and a receiver utilizing a streak camera resolves the reflected light in time.

Selective targeting of magnetic albumin microspheres containing low-dose doxorubicin: total remission in Yoshida sarcoma-bearing rats.

Magnetically responsive albumin microspheres containing doxorubicin hydrochloride were selectively localized in Yoshida sarcoma tumors. Tumors were implanted subcutaneously in the tail of Holtzman rats and allowed to grow to at least 200 mm2 size before initiation of experimental treatment. Drug-bearing microspheres at a dose level of either 0.5 or 2.5 mg/kg were infused proximal to the tumor via the ventral caudal artery. A bipolar permanent magnet was placed adjacent to the tumor during the infusion to effect localization. Control animals were treated with free doxorubicin infused intra-arterially at 5.0 mg/kg or 0.5 mg/kg. In other test groups animals received placebo microspheres localized in the tumor via influence of the external magnetic field, or drug-containing microspheres were infused without utilization of the magnet to effect localization. Of the 22 animals receiving magnetically localized doxorubicin microspheres 17 had total histological remission of the tumor. The remaining animals demonstrated marked tumor regression representing as much as 500-600 mm2 decrease in tumor size. While no deaths or metastases occurred in the groups receiving localized drug, animals treated with free doxorubicin, placebo microspheres or non-localized doxorubicin microspheres exhibited a significant increase in tumor size with metastases and subsequent death in 90-100% of the animals. No significant differences were noted in tumor regression/remission data between the 0.5 and 2.5 mg/kg dose levels of magnetically localized doxorubicin spheres. These results represent a significant advance in targeted chemotherapy in that 77% of the animals in the magnetically localized doxorubicin microsphere treatment groups exhibited total remission after only one regimen of drug therapy.

Selective targeting of magnetic albumin microspheres to the Yoshida sarcoma: ultrastructural evaluation of microsphere disposition.

Magnetic albumin microspheres (1 micron average diameter) were selectively targeted to subcutaneous solid Yoshida sarcoma tumors (average size 450 mm2) in Holtzman rats. This was accomplished by placing an external magnet adjacent to the tumor while the microspheres were infused. Microspheres contained ultra-fine particles of Fe3O4 and no drug (placebo). Placebo microspheres were used due to the previously demonstrated rapid tumoricidal effect of targeted low-dose doxorubicin microspheres. Animals were killed 10 min, 60 min, 30 min, 24 hr and 72 hr after microsphere administration and tumors were examined by transmission electron microscopy to determine the in vivo disposition of the magnetically targeted microspheres. Using placebo microspheres, we have demonstrated microspheres endocytosed in endothelial cells as early as 10 min after infusion. By 30 min microspheres can be seen in the extravascular compartment, sitting adjacent to tumor cells and occasionally in tumor cells. By 24 hr the majority of microspheres have been endocytosed by tumor cells. Microspheres were still observed within tumor cells as late as 72 hr after administration. The rapid extravasation and cellular uptake of magnetically focused microspheres explains the extremely rapid tumoricidal effect previously observed when doxorubicin-containing microspheres were targeted to the tumor.

Tumor remission in Yoshida sarcoma-bearing rts by selective targeting of magnetic albumin microspheres containing doxorubicin.

Magnetically responsive albumin microspheres containing doxorubicin and magnetite (Fe3O4) were selectively targeted to Yoshida sarcoma tumors in rats by utilizing an extracorporeal magnet. Tumor cells were inoculated subcutaneously in the tail of rats, and the tumors were allowed to grow to an average size of 9 X 45 mm prior to initiating treatment. Drug-bearing microspheres (0.5 mg of doxorubicin per kg of body weight) were infused proximal to the tumor through the ventral caudal artery while the tumor was exposed to an external magnetic field of 5500 Oe for 30 min. Control animals received free doxorubicin administered either intravenously (5 mg/kg) or infused intraarterially (5 and 0.5 mg/kg), drug-bearing microspheres infused intraarterially (0.5mg/kg), without the external magnet, or placebo microspheres with magnetic localization. Of the 12 animals treated with a single dose in the experimental group, 9 exhibited total remission of the tumor, representing a disappearance of tumors as large as 60 mm in length. Marked tumor regression was observed in the remaining three rats, and no deaths or metastases occurred in the experimental group. In contrast, significant increases in tumor size with widespread metastases occurred in all control groups and most rats died. These experiments indicate that targeting of oncolytic agents to solid neoplasms by magnetic microspheres may be a means of increasing the efficacy and decreasing the toxicity of antitumor agents.

Orally active esters of cephalosporin antibiotics. 3. Synthesis and biological properties of aminoacyloxymethyl esters of 7-[D(-)-mandelamido]-3-[[(1-methyl-1H-tetrazol-5-yl)thio]methyl]-3-cephem-4-carboxylic acid.

The synthesis of six amino acid acyloxymethyl esters of cefamandole (1), a semisynthetic broad-spectrum cephalosporin antibiotic, is described. These esters were examined as potentially useful orally active antibiotic prodrugs. When tested for oral efficacy against Streptococcus pyogenes C203 in mouse protection tests, the esters were not notably more active than lithium cefamandole. Further studies demonstrated that significant blood and urine levels of 1 were not obtained after dosing 2a, 2b, and 2f orally at 17 mg/kg in mice. A study of the stability to chemical hydrolysis and the possible relationship of hydrolysis to the lack of oral absorption of these esters is also presented.