A Cost-Effectiveness Analysis of Wittmann Patch-Assisted Abdominal Closure Compared to Planned Ventral Hernia in Management of the Open Abdomen

BACKGROUND

Inability to achieve primary fascial closure after damage control laparotomy is a frequently encountered problem by acute care and trauma surgeons. This study aims to compare the cost-effectiveness of Wittmann patch-assisted closure to the planned ventral hernia closure.

METHODS

A literature review was performed to determine the probabilities and outcomes for Wittmann patch-assisted primary closure and planned ventral hernia closure techniques. Average utility scores were obtained by a patient-administered survey for the following: rate of successful surgeries (uncomplicated abdominal wall closure), surgical site infection, wound dehiscence, abdominal hernia and enterocutaneous fistula. A visual analogue scale (VAS) was utilized to assess the survey responses and then converted to quality-adjusted life years (QALYs). Total cost for each strategy was calculated using Medicare billing codes. A decision tree was generated with rollback and incremental cost-utility ratio (ICUR) analyses. Sensitivity analyses were performed to account for uncertainty.

RESULTS

Wittmann patch-assisted closure was associated with higher clinical effectiveness of 19.43 QALYs compared to planned ventral hernia repair (19.38), with a relative cost reduction of US$7777. Rollback analysis supported Wittmann patch-assisted closure as the more cost-effective strategy. The resulting negative ICUR of -156,679.77 favored Wittmann patch-assisted closure. Monte Carlo analysis demonstrated a confidence of 96.8% that Wittmann patch-assisted closure was cost-effective.

CONCLUSIONS

This study demonstrates using the Wittmann patch-assisted closure strategy as a more cost-efficient management of the open abdomen compared to the planned ventral hernia approach.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Rotational resonance of nonaxisymmetric magnetic braking in the KSTAR tokamak

One of the important rotational resonances in nonaxisymmetric neoclassical transport has been experimentally validated in the KSTAR tokamak by applying highly nonresonant n=1 magnetic perturbations to rapidly rotating plasmas. These so-called bounce-harmonic resonances are expected to occur in the presence of magnetic braking perturbations when the toroidal rotation is fast enough to resonate with periodic parallel motions of trapped particles. The predicted and observed resonant peak along with the toroidal rotation implies that the toroidal rotation in tokamaks can be controlled naturally in favorable conditions to stability, using nonaxisymmetric magnetic perturbations.

Effects of electron-cyclotron-resonance-heating-induced internal kink mode on the toroidal rotation in the KSTAR Tokamak

It is observed that the magnitude of the toroidal rotation speed is reduced by the central electron cyclotron resonance heating (ECRH) regardless of the direction of the toroidal rotation. The magnetohydrodynamics activities generally appear with the rotation change due to ECRH. It is shown that the internal kink mode is induced by the central ECRH and breaks the toroidal symmetry. When the magnetohydrodynamics activities are present, the toroidal plasma viscosity is not negligible. The observed effects of ECRH on the toroidal plasma rotation are explained by the neoclassical toroidal viscosity in this Letter. It is found that the neoclassical toroidal viscosity torque caused by the internal kink mode damps the toroidal rotation.

Initial measurements of fast ion loss in KSTAR

A fast ion loss detector (FILD) has been installed and tested in Korea Superconducting Tokamak Advanced Research (KSTAR). KSTAR FILD measures the energy and the pitch-angle of the escaping ions with the striking positions on the scintillator plane. Measurements of the fast ion loss have been performed for the neutral beam heated plasmas. Initial experimental results indicate the prompt losses from neutral beam are dominant and the effects of the resonant magnetic perturbation on the fast ion loss are investigated. In addition, further design change of the detector-head in order to avoid excessive heat load and to detect the fusion products or the fast ions having order of MeV of energy is also discussed.

Suppression of edge localized modes in high-confinement KSTAR plasmas by nonaxisymmetric magnetic perturbations

Edge localized modes (ELMs) in high-confinement mode plasmas were completely suppressed in KSTAR by applying n=1 nonaxisymmetric magnetic perturbations. Initially, the ELMs were intensified with a reduction of frequency, but completely suppressed later. The electron density had an initial 10% decrease followed by a gradual increase as ELMs were suppressed. Interesting phenomena such as a saturated evolution of edge T(e) and broadband changes of magnetic fluctuations were observed, suggesting the change of edge transport by the applied magnetic perturbations.

Cancer survival in Incheon, Republic of Korea, 1997-2001

The Incheon cancer registry was established in 1997. Cancer is not a notifiable disease, hence registration of cases is done by active methods. The registry contributed survival data for 42 cancer sites or types registered during 1997-2001. The follow-up information has been obtained predominantly by passive methods, with median follow-up ranging between 1-44 months for various cancers. The proportion with histologically verified diagnosis for different cancers ranged between 16-100%; death certificates only (DCOs) comprised 0-51%; 49-100% of total registered cases were included for the survival analysis. The top-ranking cancers on 5-year age-standardized relative survival rates were testis (98%), thyroid (90%), ureter (87%), adrenal gland (86%), nonmelanoma skin (83%), corpus uteri (82%), Hodgkin lymphoma (81%), breast and cervix (74%). Five-year relative survival by age group showed a decreasing trend with increasing age groups for cancers of the stomach, small intestine, colon, gall bladder, larynx, lung, breast, cervix and ovary, and was fluctuating for other cancers.

Korea Superconducting Tokamak Advanced Research vacuum and gas puffing system

A piezoelectric valve, which has a flow rate of about 463 mbar l/s, has been installed to fuel the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. The valve flow rate is in situ calibrated by analyzing the pressure rise curve while fueling the vessel at a constant rate. The calibration method and results are presented. In addition to the flow rate, other vacuum system parameters, such as the pumping speed and the vessel volume, were experimentally obtained. Based on these measurements, a KSTAR vacuum system simulator was developed to calculate the valve drive signal to obtain a programmed pressure trace. An arbitrarily shaped pressure trace was successfully controlled in KSTAR with this hardware and software system.

Zero valent iron and clay mixtures for removal of trichloroethylene, chromium(VI), and nitrate

A series of batch experiments on free swell, hydraulic conductivity, and contaminant removal efficiency was performed for the combination of bentonite and zero valent iron (ZVI), in order to identify the optimal mixing ratio between bentonite and ZVI. The swell volume of the bentonite-ZVI mixtures did not change with increasing ZVI, and the hydraulic conductivity decreased as the ZVI increased. The reduction rates and removal efficiencies of trichloroethylene (TCE), Chromium(VI), and nitrate increased as ZVI content increased, while there was no practical difference in removal efficiencies between 30% and 100% of ZVI weight contents. Therefore, 30% of the ZVI content was used as the optimal amount in this research since the physical properties, such as swell volume and hydraulic conductivity, as well as the contaminant sorption and reduction were the most efficient. From Raman spectrophotometer analysis, peaks of magnetite, maghemite, and hematite were observed on the surfaces of the bentonites that had been used for the mixtures. Since iron oxides are strong adsorbers of contaminants and magnetites can facilitate the electron transfer of irons, these formations are beneficial for the long-term performance of the iron metals.

Elective stenting for symptomatic middle cerebral artery stenosis presenting as transient ischaemic deficits or stroke attacks: short term arteriographical and clinical outcome

BACKGROUND

Although stent assisted angioplasty is an effective treatment for coronary and peripheral arterial disease, its efficacy in intracranial arteriosclerotic disease has not been verified.

OBJECTIVES

To assess the radiographic and clinical outcome of stent assisted angioplasty for symptomatic middle cerebral artery (MCA) stenosis.

METHODS

We attempted stent assisted angioplasty in 14 patients with symptomatic high grade stenosis (>60%) on the proximal portion of the MCA, who had experienced either recurrent transient ischaemic attacks (TIAs) resistant to medical therapy or one or more stroke attacks. Patient records were analysed for angiographic characteristics, degree of stenosis, pre-procedural regimen of anti-platelet and/or anti-coagulation agents, use of devices, procedure related complications, pre-operative and post-operative single photon emission computed tomography (SPECT) findings, and clinical and radiographic outcomes.

RESULTS

Stent assisted angioplasty was successfully performed in 8 of 14 patients without any serious complications and unsuccessful in 2 of 14 patients due to the tortuous curve of the internal carotid artery siphon. Four patients had complications. Two patients had an arterial rupture; one patient was rescued by an additional stent and balloon tamponade, the other patient died. Complications in the other two patients included thrombotic occlusion and distal thrombosis. Residual stenosis was less than 50% in diameter in all the patients. All eight patients who underwent follow up cerebral angiography had no restenosis. Follow up SPECT showed improved perfusion in the affected MCA territory in all the tested patients with TIA and in one of three stroke patients. Using the modified Rankin Scale at follow up, four of five TIA patients and five of six stroke patients were assessed as functionally improved or having a stable clinical status.

CONCLUSION

Although the re-stenosis rate in stent assisted angioplasty seems to be better than in primary balloon angioplasty as reported previously, the complication rate is still high. Elective stenting is an alternative therapeutic method for the prevention of secondary ischaemic stroke in stroke patients with MCA stenosis, and seems to be a potentially effective but also hazardous therapeutic technique in patients with recurrent TIAs. This study indicates the need for randomised control trial data of this intervention. Additionally, long term follow up data and additional clinical experience are required to assess the durability of this procedure.

High versus low dose rate intracavitary irradiation for adenocarcinoma of the uterine cervix

BACKGROUND

Traditionally, low dose rate (LDR) brachytherapy has been used as a standard modality in the treatment of patients with carcinoma of the uterine cervix. The purpose of this work was to evaluate the effects of high dose rate (HDR) brachytherapy on patients with adenocarcinoma of the uterine cervix and to compare them with the effects of LDR brachytherapy.

METHODS

From January 1971 to December 1992, 104 patients suffering from adenocarcinoma of the uterine cervix were treated with radiation therapy in the Department of Radiation Oncology, Yonsei University. LDR brachytherapy was carried out on 34 patients and HDR brachytherapy on 70 patients. In the LDR group, eight patients were in stage IB, six in IIA, 12 in IIB, three in IIIA and five in IIIB. External radiation therapy was delivered with 10 MV X-rays, 2 Gy fraction per day, total dose of whole pelvis 36-52 Gy (median 46 Gy). LDR radium intracavitary irradiation was performed with a Henschke applicator, 37-59 Gy targeted at point A (median 43 Gy). In the HDR group, there were 16 patients in stage IB, six in IIA, 32 in IIB and 16 in IIIB. The total whole pelvis dose of external radiation was 40-50 Gy (median 44 Gy), daily 1.8-2.0 Gy. HDR Co-60 intracavitary irradiation was performed with a remotely controlled after-loading system (RALS), 30-48 Gy (median 39 Gy) targeted at point A, three times per week, 3 Gy per fraction.

RESULTS

The 5-year overall survival rate in the LDR group was 72.9, 61.9 and 35.7% in stage I, II and III, respectively and the corresponding figures for HDR were 87.1, 58.3 and 43.8% (p > 0.05). There was no statistical difference between the HDR group and the LDR group in terms of the 5-year overall survival rate from adenocarcinoma of the uterine cervix. There was a late complication rate of 12% in the LDR group and 27% in the HDR group. The incidence of late complications in stages II and III was higher in the HDR group than in the LDR group (31.6 vs 16.7% in stage II, 37.3% vs 12.5% in stage III, p > 0.05). No prognostic factors were evident in the comparison between the two groups.

CONCLUSION

There was no difference in terms of 5-year survival rate in the patients with adenocarcinoma of the uterine cervix between those treated with HDR and those treated with LDR brachytherapy. Even though late complication rates were higher in the HDR group, most of them were classified as grade I. This retrospective study suggests that HDR brachytherapy may be able to replace LDR brachytherapy in the treatment of adenocarcinoma of the uterine cervix.

Could ionizing radiation forestall cauliflower ear?

Repeated trauma to the ear very often results in "cauliflower ear." Many methods have been suggested to prevent an injured ear from demonstrating a cauliflowerlike deformity. The principles of treatment are evacuation of the hematoma, control of the reaccumulation of fluid, and maintenance of the cartilage contour. The authors studied the effect of ionizing radiation on deformed rabbit ears induced by repeated trauma. Twenty ears (10 rabbits) were used in the experiment. The animals were divided into four groups (control, preradiation, low dose, and high dose). Hematoma was produced by pounding the lateral side of the auricle 10 times with a 50-g weight at a height of 15 cm. The thickness of the injured and uninjured sites was measured, and histological analysis was performed for each group. The thickness of the ears of the irradiated groups was significantly less than the control group. The authors think that radiation treatment of repeatedly injured ears could prevent ear deformity, and could possibly be an adjunctive form of management of cauliflower ear in addition to hematoma evacuation and compression therapy.

Bilateral transient radial nerve palsies in an infant after cardiac surgery

PURPOSE

To describe the case of an infant who suffered bilateral transient radial nerve palsies after cardiac surgery.

CLINICAL FEATURES

A one-month-old baby was found to have bilateral wrist and finger drop after the removal of splints that has been applied to the right hand for 14 days and to the right hand for six days during perioperative management of Blalock-Taussig shunt surgery. The hand splints had been applied to the forearms with adhesive silky tape to keep peripheral vascular lines in place. The patient also suffered from several episodes of cardiogenic shock, hypoxemia and generalized edema relating to cardiac dysfunction during this fine period. Given the findings of no impairment of median or ulnar nerves and brachioradial muscle, it was suspected that bandaging with adhesive tapes caused peripheral radial nerve damage at the level of posterior interosseus nerve on forearm. Diminished oxygen delivery and edema may additionally have contributed to peripheral nerve ischemia. The aforementioned neurologic symptoms resolved spontaneously after several days.

CONCLUSION

Prolonged compression by bandaging of splints on forearm may have resulted in ischemic damage to the posterior interosseus nerve branch combined with extensor carpi radialis longus nerve branch of the radial nerve. We should attempt to reduce the frequency and duration of splinting of the extremities, especially in sedated, paralyzed babies, given the potential risk of compression neuropathy.

Isolation of peptide ligands that inhibit glutamate racemase activity from a random phage display library

Several new antibacterial agents are currently being developed in response to the emergence of bacterial resistance to existing antibiotic substances. The new agents include compounds that interfere with bacterial membrane function. The peptidoglycan component of the bacterial cell wall is synthesized by glutamate racemase, and this enzyme is responsible for the biosynthesis of d-glutamate, which is an essential component of cell wall peptidoglycan. In this study, we screened a phage display library expressing random dodecapeptides on the surface of bacteriophage against an Escherichia coli glutamate racemase, and isolated specific peptide sequences that bind to the enzyme. Twenty-seven positive phage clones were analyzed, and seven different peptide sequences were obtained. Among them, the peptide sequence His-Pro-Trp-His-Lys-Lys-His-Pro-Asp-Arg-Lys-Thr was found most frequently, suggesting that this peptide might have the highest affinity to glutamate racemase. The positive phage clones and HPWHKKHPDRKT synthetic peptide were able to inhibit glutamate racemase activity in vitro, implying that our peptide inhibitors may be utilized for the molecular design of new potential antibacterial agents targeting cell wall synthesis.

Knowing a winning business idea when you see one

Identifying which business ideas have real commercial potential is fraught with uncertainty, and even the most admired companies have stumbled. It's not as if they don't know what the challenges of innovation are. A new product has to offer customers exceptional utility at an attractive price, and the company must be able to deliver it at a tidy profit. But the uncertainties surrounding innovation are so great that even the most insightful managers have a hard time evaluating the commercial readiness of new business ideas. In this article, W. Chan Kim and Renée Mauborgne introduce three tools that managers can use to help strip away some of that uncertainty. The first tool, "the buyer utility map," indicates how likely it is that customers will be attracted to a new business idea. The second, "the price corridor of the mass," identifies what price will unlock the greatest number of customers. And the third tool, "the business model guide," offers a framework for figuring out whether and how a company can profitably deliver the new idea at the targeted price. Applying the tools, though, is not the end of the story. Many innovations have to overcome adoption hurdles--strong resistance from stakeholders inside and outside the company. Often overlooked in the planning process, adoption hurdles can make or break the commercial viability of even the most powerful new ideas. The authors conclude by discussing how managers can head off negative reactions from stakeholders.

Role of reactive oxygen species in acetylcholine-induced preconditioning in cardiomyocytes

We examined the ability of ACh to mimic ischemic preconditioning in cardiomyocytes and the role of ATP-sensitive potassium (KATP) channels and mitochondrial reactive oxygen species (ROS) in mediating this effect. Chick embryonic ventricular myocytes were studied in a flow-through chamber while flow rate, pH, PO2, and PCO2 were controlled. Cell viability was quantified with propidium iodide (5 microM), and production of ROS was measured using 2', 7'-dichlorofluorescin diacetate. Data were expressed as means +/- SE. Preconditioning with 10 min of ischemia followed by 10 min of reoxygenation or 10 min of ACh (1 mM) followed by a drug-free period before 1 h of ischemia and 3 h of reoxygenation reduced cell death to the same extent [preconditioning 19 +/- 2% (n = 6, P < 0.05) ACh 21 +/- 5% (n = 6, P < 0.05) vs controls 42 +/- 5% (n = 9)]. Like preconditioning, ACh increased ROS production threefold before ischemia [0.60 +/- 0.16 (n = 7, P < 0.05) vs. controls, 0.16 +/- 0. 03 (n = 6); arbitrary units]. Protection and increased ROS production during ACh preconditioning were abolished with 5-hydroxydecanoate (5-HD, 100 microM), a selective mitochondrial K(ATP) channel antagonist, and the thiol reductant 2-mercaptopropionyl glycine (2-MPG, 1 mM), an antioxidant [cell death: 5-HD+ACh 37 +/- 7% (n = 5), 2-MPG+ACh 47 +/- 6% (n = 6); ROS signals: 5-HD+ACh 0.09 +/- 0.03 (n = 5), 2-MPG+ACh 0.01 +/- 0.04 (n = 4)]. In addition, ACh-induced ROS signaling was blocked by the mitochondrial site III electron transport inhibitor myxothiazol (0.02 +/- 0.07, n = 5). These results demonstrate that activation of mitochondrial K(ATP) channels and increased ROS production from mitochondria are important intracellular signals that participate in ACh-induced preconditioning in cardiomyocytes.

Reciprocal inhibition between the forearm muscles in patients with paroxysmal kinesigenic dyskinesia

We measured the changes of forearm flexor H reflexes produced by conditioning radial nerve stimulation at delays of -2, 0, 2, 4, 7.5, 10, 25 and 75 ms in 10 patients with PKD and six with generalized seizure disorder. We compared the results with 12 normal volunteers. In the patients with PKD, we compared the amounts of reciprocal inhibition between the severely and the asymptomatic or mildly affected sides of arms. Follow-up studies were done in eight PKD patients after they responded to the anticonvulsant treatment. At each delay, patients with seizure disorders showed comparable amounts of changes with controls. Patients with PKD showed paradoxical facilitation at a delay of 0 ms, enhanced facilitation between 2 to 7.5 ms delays and attenuated inhibition at a delay of 75 ms. There were no significant differences in the amount of reciprocal inhibition according to the severity of clinical symptoms. Follow-up studies showed no significant changes of reciprocal inhibition compared to the baseline data. In PKD, paradoxical facilitation and enhanced first relative facilitation period may be caused by defective spinal interneurons. In addition to the defective reciprocal inhibition, abnormalities of supraspinal inputs seem to be involved in the genesis of PKD.

Preliminary report on usefulness of magnetic resonance imaging for outcome prediction in early-stage Legg-Calvé-Perthes disease

The usefulness of magnetic resonance imaging (MRI) for predicting prognosis was evaluated in 11 patients with unilateral early-stage Legg-Calvé-Perthes disease who were treated with a non-weight-bearing abduction brace. Six to 10 months after disease onset, severity of cartilage hypertrophy and physeal curvature of the femoral head were scored on MRI. Femoral head deformity was radiographically evaluated. Among five patients whose MRI score was 8 or greater, radiographic evaluation after the treatment was "poor" or "fair," whereas evaluation for the other six patients whose MRI score was 7 or less was "good." The MRI scores indicated possible occurrence of femoral head deformation. Treatment method should be considered carefully when the MRI score is high.

Effects of screw types in cementless fixation of tibial tray implants: stability and strength assessment

OBJECTIVE

To test the stability and strength of tibial trays fixed with cortical screws and tibial trays fixed with cancellous screws under axial and anterior-posterior shear loading conditions.

DESIGN

Five matched human fresh frozen cadaver knees without prior pathology were used as paired specimens for comparison of cortical to cancellous screw fixation of tibial trays.

BACKGROUND

Current cementless fixation of tibial trays in total knee arthroplasty is obtained by using a combination of stems, keels, posts, pegs, and screws. To date there has been no study comparing isolated cortical and cancellous screw fixation in cementless arthroplasty.

METHODS

An Instron machine and a video digitizing system were used to examine tibial tray lift-off, subsidence, and anterior-posterior load to failure at the bone-implant interface in five matched pairs of knees and compare the difference between cancellous and cortical screw fixation.

RESULTS

Non-destructive cyclic testing showed a significant difference between the two types of screws for tibial tray subsidence with cancellous fixation greater than cortical (P < 0.05), but not for lift-off (P > 0.05). Load to failure testing in anterior-posterior direction did not result in a significant difference between the two types of screws for initial stiffness and ultimate load (P > 0.05), but did result in a significant difference of energy absorbed to failure (P < 0.01).

CONCLUSIONS

The difference in amount of subsidence between cortical and cancellous fixation could possibly be due to microfractures of the underlying trabecular bone with cancellous fixation. Neither screw type was able to completely fix the tibial tray to bone and prevent micromotion. Although the load at failure for anterior-posterior shear was similar for the two screw types, the energy absorbed was greater for the cortical screws which may be a result of additional strength provided by the cortical bone surrounding the screw.

Creating new market space

Most companies focus on matching and beating their rivals. As a result, their strategies tend to take on similar dimensions. What ensues is head-to-head competition based largely on incremental improvements in cost, quality, or both. The authors have studied how innovative companies break free from the competitive pack by staking out fundamentally new market space--that is, by creating products or services for which there are no direct competitors. This path to value innovation requires a different competitive mind-set and a systematic way of looking for opportunities. Instead of looking within the conventional boundaries that define how an industry competes, managers can look methodically across them. By so doing, they can find unoccupied territory that represents real value innovation. Rather than looking at competitors within their own industry, for example, managers can ask why customers make the trade-off between substitute products or services. Home Depot, for example, looked across the substitutes serving home improvement needs. Intuit looked across the substitutes available to individuals managing their personal finances. In both cases, powerful insights were derived from looking at familiar data from a new perspective. Similar insights can be gleaned by looking across strategic groups within an industry; across buyer groups; across complementary product and service offerings; across the functional-emotional orientation of an industry; and even across time. To help readers explore new market space systematically, the authors developed a tool, the value curve, that can be used to represent visually a range of value propositions.

Initial stability comparison of modular hip implants in synthetic femurs

Synthetic femurs were used to assess the initial bone-implant interface stability of three total hip systems: Wright Medical Technology's Infinity smooth trochanteric module (S-TM), Infinity porous-coated trochanteric module (PC-TM), and Johnson and Johnson S-ROM with a porous surface. The hips were implanted into synthetic femurs, rigidly fixed, and subjected to internal rotation and cyclic, axial compressive loads. The results showed that all three implants achieved good initial implant stability and would be expected to permit bone ingrowth. The porous-coated implants showed greater initial implant stability with less axial micromotion compared with the smooth implants. This finding suggests that surface texture plays a role in initial stability of uncemented prostheses if the bone behaves similar to the material used in this study.

Intracranial hemorrhage associated with idiopathic thrombocytopenic purpura: report of seven patients and a meta-analysis

We present the results of a meta-analysis using clinical data obtained from seven of our patients and 24 previously reported patients with idiopathic thrombocytopenic purpura complicated by intracranial hemorrhage. Twenty-four had an intracerebral hemorrhage (ICH) and seven had a subdural hematoma (SDH). Mean age of the patients with ICH was significantly younger than those with SDH. The mortality rate of ICH associated with ITP was similar to that of spontaneous ICH. All seven patients with SDH improved without sequelae.

Structural integrity of implanted WMT infinity hip and Osteonics Omnifit hip in fresh cadaveric femurs

Five matched pairs of fresh human femurs were used to quantitatively assess the structural integrity of the implanted Wright Medical Technology modular Infinity hip and the Osteonics single-piece Omnifit hip. The results showed that neither bone implant system was able to recreate the femoral anteversion of the intact femur (p < 0.05). Although the micromotion at the bone-implant interface was well within the limits of achieving bone ingrowth, the axial micromotion was greater for the Infinity hip than for the Omnifit hip (p < 0.05), but the rotational micromotion did not show a significant difference between the two bone implant systems (p > 0.5). The anterior proximal femur deformation patterns were similar for both the two bone implant systems and intact femurs. However, the medial proximal femur deformation patterns showed that the Infinity hip-implanted femur was more similar to the intact femur than the Osteonics Omnifit hip-implanted femur.

Anatomically based patellar resection criteria for total knee arthroplasty

Thirty-six patellae were used to geometrically assess anatomically based patellar resection criteria for total knee arthroplasty. The plane of resection was defined in the coronal plane by three distinct anatomic landmarks on the undersurface of the patella: the medial and lateral edges of the quadriceps tendon insertion and the lateral edge of the patellar ligament insertion. The depth of the resection plane is defined by the anatomic landmark points approximately 1 mm posterior to the posterior aspect of the superior and inferior ligament insertions. Following resection, the resected patellae were geometrically characterized using two dimensional rectangular Cartesian coordinate system. The anatomically based patellar resection yielded a simple, consistent, and reliable method for patellar resection for total knee arthroplasty. The proportionate geometric characteristics of both the remaining anterior piece and the resected posterior piece were remarkably uniform. Following resection, the remaining patellar thickness was 65.6+/-5.3% (mean+/-SD) of the original thickness. The maximum width to height ratio of the resected surface was approximately 1:1. The thickness to diameter ratio of the resected portion of the patella was approximately 1:5. The apex of the patella was slightly off to the medial-distal quadrant from the geometric center of the resected surface. The results of this study indicate that anatomically based patellar resection criteria may help reduce the surgical variations associated with patellar resurfacing in total knee arthroplasties with dome-shaped prostheses.

Recurrent herpes zoster myelitis

Recurrent zoster myelitis is quite rare. We present a previously healthy 27-year-old woman who developed recurrent attacks of myelopathy shortly after the characteristic skin rashes of herpes zoster. Magnetic resonance imaging studies demonstrated each lesion in the spinal cord at the same segments as the skin lesions. She had two attacks at opposite sites at the same spinal cord level and complete recovery after being treated with intravenous acyclovir. We suspect that direct invasion of varicella zoster virus was the cause of recurrent myelopathy in our patient.

Patellofemoral joint kinematics and contact pressures in total knee arthroplasty

Patellofemoral joint kinematics, contact areas, and contact pressures were measured concomitantly before and after total knee arthroplasty in 10 fresh frozen human cadaver knees using an Instron machine, a custom patellofemoral joint testing jig, axial bone markers, a continuous video digitizing system, and Fuji pressure sensitive film. The implant used in this study was the Kirschner Performance Knee System with an all polyethylene, domed patellar component. For all tests, the patella was aligned in its anatomically neutral position. Patellofemoral joint contact areas decreased as much as 19-fold after total knee arthroplasty. Mean patellofemoral joint contact pressures increased as much as 32-fold, and peak patellofemoral joint contact pressures increased as much as 22-fold after total knee arthroplasty. No statistically significant differences between preoperative and postoperative specimens were observed with respect to the patellofemoral, patellotibial, or patellar tilt angles from 30 degrees to 120 degrees knee flexion. Thus, the elevated patellofemoral joint contact pressures observed after total knee arthroplasty in vitro are not a primary consequence of iatrogenically altered patellofemoral kinematics.

Fair process: managing in the knowledge economy

Unlike the traditional factors of production--land, labor, and capital--knowledge is a resource that can't be forced out of people. But creating and sharing knowledge is essential to fostering innovation, the key challenge of the knowledge-based economy. To create a climate in which employees volunteer their creativity and expertise, managers need to look beyond the traditional tools at their disposal. They need to build trust. The authors have studied the links between trust, idea sharing, and corporate performance for more than a decade. They have explored the question of why managers of local subsidiaries so often fail to share information with executives at headquarters. They have studied the dynamics of idea sharing in product development teams, joint ventures, supplier partnerships, and corporate transformations. They offer an explanation for why people resist change even when it would benefit them directly. In every case, the decisive factor was what the authors call fair process--fairness in the way a company makes and executes decisions. The elements of fair process are simple: Engage people's input in decisions that directly affect them. Explain why decisions are made the way they are. Make clear what will be expected of employees after the changes are made. Fair process may sound like a soft issue, but it is crucial to building trust and unlocking ideas. Without it, people are apt to withhold their full cooperation and their creativity. The results are costly: ideas that never see daylight and initiatives that are never seized.

Radiation treatment in patients with recurrent Kimura's disease

PURPOSE

To assess the benefits of radiotherapy for patients with recurrent Kimura's disease and to document the role of radiation treatment as a successful mode of therapy.

METHODS AND MATERIALS

From 1985 to 1991, a total of 26 patients with Kimura's disease were treated by local excision and/or systemic steroids at Yonsei University, Yonsei Cancer Center Hospital. Seventeen patients among them eventually had local recurrence after surgical excision. The 17 patients with recurrent Kimura's disease were divided into two groups on the basis of those who received radiation treatment and those who did not. Eight patients in the nonradiation group were treated by systemic steroids alone with individualized doses and schedules. The remaining nine patients in the radiation group were treated by external beam irradiation. The prescribed radiation doses varied from 21.6 to 45 Gy. A comparative analysis on treatment results between both groups was undertaken retrospectively.

RESULTS

The majority of the recurrent cases in the nonradiation group treated by steroids alone experienced rapid rerecurrence of the disease. In contrast, all of the patients except one case in the radiation group achieved excellent local control with moderate doses of radiation. There was a significant difference in the rerecurrence rate between the patients of the radiation group (11%) and the nonradiation group (75%). No clear dose-response relationship could be derived from the patients of the radiation group. No secondary malignancies in the irradiated areas have been observed.

CONCLUSION

Our results suggest that radiation treatment is preferable as an alternative option for patients with recurrent Kimura's disease who have failed to achieve local control by other modalities.

Locked-in syndrome with bilateral peduncular infarct

Locked-in syndrome due to midbrain infarct is very rare. This report describes a patient with locked-in syndrome whose magnetic resonance images showed bilateral infarcts in the cerebral peduncle. Cerebral angiography disclosed bilateral irregular thrombotic narrowing of the vertebral and proximal basilar arteries with rostral basilar artery occlusion, a previously unreported findings.

Value innovation: the strategic logic of high growth

Why are some companies able to sustain high growth in revenues and profits--and others are not? To answer that question, the authors, both of INSEAD, spent five years studying more than 30 companies around the world. They found that the difference between the high-growth companies and their less successful competitors was in each group's assumptions about strategy. Managers of the less successful companies followed conventional strategic logic. Managers of the high-growth companies followed what the authors call the logic of value innovation. Conventional strategic logic and value innovation differ along the basic dimensions of strategy. Many companies take their industry's conditions as given; value innovators don't. Many companies let competitors set the parameters of their strategic thinking; value innovators do not use rivals as benchmarks. Rather than focus on the differences among customers, value innovators look for what customers value in common. Rather than view opportunities through the lens of existing assets and capabilities, value innovators ask, What if we start anew? The authors tell the story of the French hotelier Accor, which discarded the notion of what a hotel is supposed to look like in order to offer what most customers want: a good night's sleep at a low price. And Virgin Atlantic challenged industry conventions by eliminating first-class service and channeling savings into innovations for business-class passengers. Those companies didn't set out to build advantages over the competition, but they ended up achieving the greatest competitive advantages.

Spasmodic dysphonia associated with a left ventrolateral putaminal lesion

A 34-year-old man presented with a 30-year history of spasmodic dysphonia. He developed a speech disturbance 1 month after a closed head injury due to a fall. Sighing, coughing, and crying were normal. He had a tremor of the right hand when he drew a vertical line. His out-stretched right hand had a minimal dystonic posture with occasional jerks of the fingers. T1-weighted axial brain MRI study showed a low signal intensity lesion at the putamen; coronal and axial T2-weighted MRI brain scans showed a high and low signal intensity lesion confined to the middle part of the ventrolateral putamen. Damage to the ventrolateral putamen may have caused abnormal voluntary control of the laryngeal muscles.

The influence of fixed rotational deformities of the femur on the patellofemoral contact pressures in human cadaver knees

Patellofemoral contact pressures resulting from fixed rotational deformities of the femur were studied in human cadaver knees. The increase in the degree of fixed rotational deformities of the femur results in a nonlinear increase in patellofemoral contact pressures on the contralateral facets of the patella (i.e., external rotational deformity resulted in a contact pressure increase on the medial facet, and internal rotational deformity resulted in a contact pressure increase on the lateral facet of the patella). With the initial isometric tension of 200 N in the quadriceps tendon for 30 degrees, 60 degrees, 90 degrees, and 120 degrees knee flexion, the peak contact pressure showed no significant differences between the medial and lateral facets of the patella in its anatomic position. At 20 degrees of rotational deformity of the femur, only a slight increase was noted for the tension in the quadriceps tendon and the patellofemoral contact pressures on the contralateral facets of the patella. However, at 30 degrees rotational deformity of the femur, both the external and internal rotational deformity of the femur showed a significant increase in the tension of the quadriceps tendon and the patellofemoral contact pressures on contralateral facets of the patella. The greatest increase in patellofemoral contact pressures was observed at 30 degrees and 60 degrees knee flexion for both the external and internal rotational deformity of the femur. The external rotational deformity of the femur for all knee flexion angles showed significantly higher peak patellofemoral contact pressure increases on the medial facet of the patella as compared with the lateral patellofemoral contact pressure increase resulting from internal rotational deformity of the femur.

[A case of pelvic paragonimiasis combined with myoma uteri and pelvic inflammatory disease]

Paragonimus westermani is a lung fluke of humans that is usually found in the lungs but may be found elsewhere in many unusual locations. A case of pelvic paragonimiasis was found incidentally by surgical intervention of inflammatory disease and myoma uteri. She was a 51-year-old Korean woman complaining of lower abdominal pain and intermittent vaginal spotting. Numerous Paragonimus ova were observed in the resected omentum in the pelvis after total abdominal hysterectomy. It is suggested that pelvic paragonimiasis may be one of causative agents of pelvic inflammatory disease.

Increased lymphocyte beta-adrenergic receptor density in progressive multiple sclerosis is specific for the CD8+, CD28- suppressor cell

Beta-adrenergic receptor density on T cells from healthy humans is greatest on suppressor cells (CD8+, CD28-) and the effect of catecholamines, secreted by the sympathetic nervous system, predominates on this subset. The sympathetic skin response, a measure of sympathetic nervous system function, is absent in most patients with chronic progressive multiple sclerosis (MS). We measured beta-adrenergic receptor density on suppressor cells, cytotoxic cells, and monocytes from patients with chronic progressive MS and healthy control subjects. Control receptor density on suppressor cells was 2.8 +/- 0.3 fmol/10(6) cells versus a density of 5.1 +/- 0.7 fmol/10(6) cells for patients. Cytotoxic cell (CD8+, CD28+) receptor density was 1.4 +/- 0.4 fmol/10(6) cells in control subjects and 0.9 +/- 0.3 fmol/10(6) cells in the patients. Monocytes displayed beta-adrenergic receptor densities of 2.6 +/- 0.4 fmol/10(6) cells in normal individuals and 2.7 +/- 0.4 fmol/10(6) cells in the patient group. CD8 lymphocyte beta-adrenergic receptor densities in patients with relapsing-remitting and those with stable MS were not different from control values, yet were significantly less than the values for patients with chronic progressive MS. We find that mononuclear cells from healthy control subjects and patients with chronic progressive MS proliferate in response to 200 units/ml of recombinant human interleukin-2 (IL-2) similarly. However, IL-2 treatment increased beta-adrenergic receptor density on normal mononuclear cells, but failed to increase it on mononuclear cells from patients with chronic progressive MS.(ABSTRACT TRUNCATED AT 250 WORDS)

Survivorship comparison of THARIES and conventional hip arthroplasty in patients younger than 40 years old

Early and high failure rates for conventional hip replacements in young and active patients are well documented. The hypothesis tested in this study is total hip articular replacement by internal eccentric shells (THARIES) resurfacing hip arthroplasty is a sufficiently durable alternative to conventional total hips in patients younger than 40 years old. Survivorship analysis techniques were applied to 106 THARIES and 98 conventional hip replacements. The primary outcome variable investigated was time to failure, as measured by the need for revision of the prosthesis in the absence of sepsis. Other definitions of prosthesis failure were also investigated. Analysis revealed that even within this young, high-risk population there were subpopulations with different risks for failure. The lowest risk patients comprised all rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) patients, regardless of age. The intermediate risk patients comprised all non-RA, non-JRA patients older than 30 years of age and the highest-risk patients were all non-RA, non-JRA patients younger than 30 years of age. A comparison of THARIES and conventional prostheses within each of these three subpopulations revealed similar patterns of failure over time, with the conventional total hip replacement having significantly better hip function than the THARIES group only in the highest-risk population, when using a failure definition of revision surgery for aseptic loosening. A broader and more important conclusion was that all acrylic-fixed implants, THARIES or THRs are predicted to undergo early mechanical loosenings in younger-than-30, non-RA, non-JRA patients. In patients younger than 30 years age acrylic fixation of THA is inadvisable.

Canine porous resurfacing hip arthroplasty. Long-term results

Long-term experimental data support the hypothesis that biologic bone ingrowth into porous surfaces in a hip-resurfacing model is a viable alternative to stem-type porous implants. Ingrowth of bone was demonstrated in long-term canine arthroplasty. The components were well fixed and stable at the time of sacrifice, although ingrowth occurred to varying degrees. The ingrowth and quality of remodeling was influenced by stress. Dislocations were overcome by a change in surgical technique. Loosening and neck fractures were associated with insufficient stability at operation or to component impingement (prevented by modifications of design). The formation of metal debris-filled cysts is a concern and appeared to be associated with the poor quality of porous sintering and possibly abrasion. The effects of increased surface area of the porous components such as increased corrosion products on biologic compatibility are still not well defined and require further research and longer follow-up examination.

New advances in bone research

An edited summary of an Interdepartmental Conference arranged by the Department of Medicine, UCLA School of Medicine, Los Angeles. William M. Pardridge, MD, Associate Professor of Medicine, is Director of Conferences.

Failure of treatment of ununited fractures of the carpal scaphoid. The role of non-compliance

We studied the results in thirty patients who had grafting of an ununited fracture of the carpal scaphoid bone. Psychiatric evaluations revealed that the thirteen patients who had a non-union of the initial scaphoid bone graft had significant psychiatric problems, whereas the seventeen patients in whom the non-union had healed after initial bone-grafting of the scaphoid did not have psychiatric abnormalities. Technically successful surgical revisions in the first group of patients did not result in significant clinical improvement. We concluded that most failures of the bone grafts were related to non-compliance on the part of the patient and that some of the operations could have been avoided if the underlying psychiatric problems had been recognized preoperatively.