The Effect of Price on Surgeons' Choice of Implants: A Randomized Controlled Survey

PURPOSE

Surgical costs are under scrutiny and surgeons are being held increasingly responsible for cost containment. In some instances, implants are the largest component of total procedure cost, yet previous studies reveal that surgeons' knowledge of implant prices is poor. Our study aims to (1) understand drivers behind implant selection and (2) assess whether educating surgeons about implant costs affects implant selection.

METHODS

We surveyed 226 orthopedic surgeons across 6 continents. The survey presented 8 clinical cases of upper extremity fractures with history, radiographs, and implant options. Surgeons were randomized to receive either a version with each implant's average selling price ("price-aware" group), or a version without prices ("price-naïve" group). Surgeons selected a surgical implant and ranked factors affecting implant choice. Descriptive statistics and univariate, multivariable, and subgroup analyses were performed.

RESULTS

For cases offering implants within the same class (eg, volar locking plates), price-awareness reduced implant cost by 9% to 11%. When offered different models of distal radius volar locking plates, 25% of price-naïve surgeons selected the most expensive plate compared with only 7% of price-aware surgeons. For cases offering different classes of implants (eg, plate vs external fixator), there was no difference in implant choice between price-aware and price-naïve surgeons. Familiarity with the implant was the most common reason for choosing an implant in both groups (35% vs 46%). Price-aware surgeons were more likely to rank cost as a factor (29% vs 21%).

CONCLUSIONS

Price awareness significantly influences surgeons' choice of a specific model within the same implant class. Merely including prices with a list of implants leads surgeons to select less expensive implants. This implies that an untapped opportunity exists to reduce surgical expenditures simply by enhancing surgeons' cost awareness.

TYPE OF STUDY/LEVEL OF EVIDENCE

Economic/Decision Analyses I.

Trigger finger: assessment of surgeon and patient preferences and priorities for decision making

PURPOSE

To test the null hypothesis that there are no differences in the priorities and preferences of patients with idiopathic trigger finger (TF) and hand surgeons.

METHODS

One hundred five hand surgeons of the Science of Variation Group and 84 patients with TF completed a survey about their priorities and preferences in decision making regarding the management of TF. The questionnaire was structured according the Ottawa Decision Support Framework for the development of a decision aid.

RESULTS

Patients desired orthotics more and surgery less than physicians. Patients and physicians disagreed on the main advantage of several treatment options for TFs and on disadvantages of the treatment options. Patients preferred to decide for themselves after receiving advice, whereas physicians preferred a shared decision. Patients preferred booklets, and physicians opted for Internet and video decision aids.

CONCLUSIONS

Comparing patients and hand surgeons, there were some differences in treatment preferences and perceived advantages and disadvantages regarding idiopathic TF-differences that might be addressed by a decision aid.

CLINICAL RELEVANCE

Information that helps inform patients of their options based on current best evidence might help them understand their own preferences and values, reduce decisional conflict, limit surgeon-to-surgeon variations, and improve health.

Effect of lipids on insect cell growth and expression of recombinant proteins in serum-free medium

The lipid emulsion components of a serum-free insect cell medium were varied and evaluated for effects on cell growth and recombinant protein expression. The growth of High-Five(TM) cells was significantly affected by polyol Pluronic F-68 and Tween-80, but not by lipids. Pluronic was essential for cell growth, while Tween-80 was required to achieve maximum cell densities. A dose response effect was observed for Tween-80 with optimal cell growth at a concentration of 25 mg/l. Cholesterol had a minor effect on cell growth, but was essential for the expression of recombinant proteins. The expression of β-galactosidase (β-gal) was directly affected by cholesterol with optimal expression at a concentration of 5.4 mg/l. Vitamin E, important as an antioxidant to stabilize lipids, did not directly affect recombinant protein expression. Although lipids were not required for cell growth, the presence of lipids were required during the cell growth phase in order to achieve efficient infection with baculovirus. These studies help to define the important components, and range of concentrations, for lipid emulsions which can effectively replace serum in insect cell culture.

Intraosseous pseudotumor of the distal radius in a patient with hemophilia: case report

Hemophilic pseudotumors are rare, particularly when they occur in the distal extremity of an adult patient. We present the case of a 68-year-old man with well-controlled factor VIII deficiency who presented with a lytic lesion of the distal radius that was identified as an intraosseous pseudotumor.

Induction of IL-10-producing CD4+ T-cells in chronic periodontitis

Precise immunological aspects of inflamed gingival mucosa remain to be elucidated in the murine experimental periodontitis model; therefore, we have characterized the mucosal immune cells in the inflamed gingiva of mice with alveolar bone reduction. Mice were orally infected with Porphyromonas gingivalis 15 times over 2 weeks. Gingival mononuclear cells (GMCs) were isolated from P. gingivalis- and sham-infected mice 1, 7, 15, and 30 days after the last infection. Although the greatest degree of periodontitis was seen in P. gingivalis-infected mice at 30 days after infection, the highest levels of IL-6 and TNF-α production were noted in the GMCs isolated 7 days after infection. Further, the frequency of RANKL(+)CD4(+) T-cells in GMCs of inflamed gingiva peaked 15 days after infection. Importantly, the number of Foxp3(+)CD4(+) CD25(+) regulatory T (Treg)-cells was increased only in the experimental group 30 days after infection. Thus, intracellular cytokine analysis revealed an increased number of IL-10-producing CD4(+) T-cells in inflamed gingiva when compared with the control group. These results suggest that there are potential roles for Treg cells during the chronic stage of periodontitis in the regulation of gingival inflammation and alveolar bone loss.

In vivo glucocorticoids regulate cyclooxygenase-2 but not cyclooxygenase-1 in peritoneal macrophages

Acute inflammatory stimuli elevate both the production of prostaglandins and the synthesis and activity of prostaglandin synthase/cyclooxygenase enzyme (COX) in murine peritoneal macrophages. Adrenalectomy also elevates prostaglandin production, COX synthesis and COX activity in these cells. We have utilized cDNA probes and antisera specific for the products of the prostaglandin synthase/cyclooxygenase-1 (COX-1) and TIS10/prostaglandin synthase-2/cyclooxygenase-2 (COX-2) genes to demonstrate that adrenalectomy causes elevation of mRNA and protein from the COX-2 gene, but not from the COX-1 gene, in peritoneal macrophages. Dexamethasone replacement suppressed the elevation of COX-2 mRNA message, COX-2 protein and the increased COX enzyme activity observed in adrenalectomized animals. In contrast, both COX-1 message and COX-1 protein levels were unaffected either by adrenalectomy or by dexamethasone administration. Thus, under normal physiological conditions, tonic glucocorticoid inhibition appears to play a major role in the in vivo regulation of the COX-2 gene. These data are consistent with COX-1 being the constitutive, housekeeping enzyme in macrophages in normal physiological conditions and with the enhanced prostaglandin synthesis seen after an inflammatory stimulus resulting from the rapid induction and activity of COX-2.

Transforming growth factor beta 1 augments mitogen-induced prostaglandin synthesis and expression of the TIS10/prostaglandin synthase 2 gene both in Swiss 3T3 cells and in murine embryo fibroblasts

Transforming growth factor-beta (TGF-beta), a potent cytokine, modulates a wide variety of biological responses. Among its actions, TGF-beta can augment prostaglandin synthesis in several cell types. Although TGF-beta alone has no effect on prostaglandin production in Swiss 3T3 cells, we find that TGF-beta augments the ability of tetradecanoyl phorbol acetate (TPA) or serum to stimulate PGE2 production. The TIS10 gene is a primary response gene encoding a second form of prostaglandin synthase (PGS), the rate-limiting enzyme in the biosynthesis of prostaglandins, thromboxanes, and prostacyclins from arachidonic acid. TIS10/PGS-2 expression is induced by mitogens in Swiss 3T3 cells. TGF-beta also augments mitogen-induced synthesis and accumulation of TIS10/PGS-2 protein and induction of TIS10/PGS-2 message in Swiss 3T3 cells. In contrast, TGF-beta has little or no effect on the level of PGS-1 (EC1.14.99.1) message, either alone or in concert with TPA or serum. TGF-beta concentrations in the range of 0.01-0.10 ng/ml (0.4-4.0 pM) maximally enhance mitogen induction of TIS10/PGS-2 message. TPA-induced accumulation of unspliced TIS10/PGS-2 transcript is augmented by TGF-beta, suggesting that this cytokine exerts its effect on expression of the TIS10/PGS-2 gene by transcriptional regulation. TGF-beta also augments TPA-induced prostaglandin production, TIS10/PGS-2 antigen accumulation, and TIS10/PGS-2 message induction in primary cultures of mouse embryo fibroblasts. Dexamethasone attenuates TGF-beta enhancement of all these mitogen-induced responses: PGE2 accumulation, appearance of TIS10/PGS-2 protein and message, and accumulation of TIS10/PGS-2 unprocessed transcript.

TGF-beta 1 inhibits both endotoxin-induced prostaglandin synthesis and expression of the TIS10/prostaglandin synthase 2 gene in murine macrophages

Activated macrophages produce substantial quantities of paracrine mediators, including cytokines, nitric oxide, and prostaglandins. Transforming growth factor beta 1 (TGF-beta) is a potent modulator of immune function. TGF-beta inhibits the cytotoxic activity of endotoxin/lipopolysaccharide (LPS)-activated macrophage cell lines and primary macrophage cultures, reducing their expression of cytokines and nitric oxide. In this report we demonstrate that TGF-beta also attenuates the LPS-induced synthesis and secretion of prostaglandin E2 in murine RAW 264.7 macrophage cells. Macrophage activation also induces accumulation of the recently described ligand-responsive prostaglandin synthase (PGS) TIS10/PGS-2. While TGF-beta alone has no effect on expression from the TIS10/PGS-2 gene, this cytokine inhibits LPS-induced TIS10/PGS-2 protein accumulation and synthesis, as well as LPS-induced TIS10/PGS-2 message accumulation in RAW 264.7 cells. TGF-beta concentrations in the range of 0.1-1.0 ng/ml (4-40 pM) maximally inhibit LPS-induced TIS10/PGS-2 message accumulation. In contrast, neither LPS nor TGF-beta has any effect on the level of PGS-1 (EC 1.14.99.1) message. TGF-beta also attenuates LPS-induced accumulation of unspliced TIS10/PGS-2 transcripts in RAW 264.7 cells, suggesting that this cytokine exerts its effects on TIS10/PGS-2 expression at the transcriptional level. TGF-beta inhibits the LPS-induced accumulation of TIS10/PGS-2 protein and message in cultured murine peritoneal macrophages, as well as in macrophage cell lines.

"Macrophage" nitric oxide synthase is a glucocorticoid-inhibitable primary response gene in 3T3 cells

Both nitric oxide and prostaglandins are potent paracrine mediators of intercellular communication. An endotoxin-lipopolysaccharide (LPS) inducible form of nitric oxide synthase (mac-NOS) has recently been cloned from murine macrophages. An inducible prostaglandin synthase (TIS10/PGS-2), cloned from 3T3 cells, is also induced in LPS-activated macrophage. Because of the wide range of ligands that induce primary response genes in 3T3 cells, the ease of studying chimeric promoter constructs in 3T3 cells, and the importance of both nitric oxide and prostaglandins as paracrine mediators, we examined expression of mac-NOS in 3T3 cells. Tetradecanoyl phorbol-13-acetate (TPA), forskolin, platelet-derived growth factor, fibroblast growth factor, and serum all induce mac-NOS expression in Swiss 3T3 cells. Thus the mac-NOS gene can respond to a far wider range of inducers than previously suspected. mac-NOS is a primary response gene; cycloheximide does not block induction. TPA-induced mac-NOS and TIS10/PGS-2 mRNA accumulation patterns are similar. LPS is a potent inducer of mac-NOS in Swiss 3T3 cells but cannot induce TIS10/PGS-2. In contrast, v-src expression induces TIS10/PGS-2 message, but not iNOS message in a BALB/c 3T3 cell line containing a temperature-sensitive v-src gene. Dexamethasone (DEX) prevents induction of TIS10/PGS-2, but not most other primary response genes. DEX also blocks mac-NOS induction in Swiss 3T3 cells. The inducible TIS10/PGS-2 and mac-NOS genes, responsible for the production of two distinct paracrine agents, appear to share many regulatory features in 3T3 cells.

Transforming growth factor beta differentially modulates the inducible nitric oxide synthase gene in distinct cell types

Nitric oxide is a mediator of paracrine cell signalling. An inducible form of nitric oxide synthase (iNOS) is expressed in macrophages and in Swiss 3T3 cells. Transforming growth factor beta (TGF-beta) is a cytokine that modulates many cellular functions. We find that TGF-beta cannot induce iNOS mRNA expression, either in macrophage cell lines or in Swiss 3T3 cells. However, TGF-beta attenuates lipopolysaccharide induction of iNOS mRNA in macrophages. In contrast, TGF-beta enhances iNOS induction by phorbol ester, serum or lipopolysaccharide in 3T3 cells. Thus TGF-beta can inhibit or augment iNOS mRNA induction in response to primary inducers, depending on the cell type in question.

An ion-exchange chromatography procedure for the isolation and concentration of basic amino acids and polyamines from complex biological samples prior to high-performance liquid chromatography

The original objective of this study was to develop a selective and sensitive method for the analysis and quantification of basic amino acids from biological samples via reversed-phase high-performance liquid chromatography. Using various previously described techniques for the separation of amino acids, we were unsuccessful in measuring levels of histidine, arginine, ornithine, and lysine in biological samples due to the presence of interfering compounds. A "cleanup" procedure for the isolation of the basic amino acids using a weakly acidic cation exchange resin, Biorex-70 (Bio-Rad), is described in detail. Upon separation from the bulk of the neutral and acidic amino acids, the basic amino acids were subjected to precolumn fluorescence derivatization using 9-fluorenylmethyl chloroformate (FMOC) and the fluorescent derivatives were separated by RP-HPLC. The advantages of this method over previously described amino acid analysis techniques are (i) isolation and stable recovery (greater than 95%) of the desired basic amino acids, (ii) sensitivity of detection (low pmol range), (iii) complete resolution of derivatized amino acids via HPLC, (iv) limited amount of sample required for analysis, and (v) samples readily concentrated by lyophilization or rotoevaporating. This ion-exchange cleanup procedure was also adapted for the analysis of polyamines in concentrated culture media samples and proved additionally advantageous by eliminating the use of costly C-18 extraction columns required by previously described techniques.

CNMGRAF—graphic presentation services for network management

Two key problems in the design of systems and network management applications are: how to efficiently manage large quantities of related data, and how to allow the application user to view this data at a user-defined level of detail. This paper describes an architecture for network management facilities that may help solve these problems. It also describes CNMgraf (Communications Network Management Graphics Facility), which was developed to test the presentation service model defined by this architecture.