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Background: Autologous chondrocyte implantation (ACI) involves the use of a periosteal patch (ACI-P) as a cover for transplanted chondrocytes. Theoretically, this periosteal patch provides mesenchymal stem cells and growth factors that encourage chondrocyte development/differentiation. However, there is a significant rate of graft hypertrophy with the use of periosteum compared with using a type I/III collagen patch (ACI-C). This type I/III collagen patch, although not approved by the United States Food and Drug Administration for ACI, has been used extensively in Europe and in an “off-label” nature in the United States as a cover during ACI. Purpose: To examine the cost effectiveness of ACI and determine whether ACI-C is more cost effective than ACI-P. Study Design: Economic and decision analysis; Level of evidence, 2. Methods: Outcome data and complication rates from patients undergoing ACI (ACI-P and ACI-C) were derived from the best evidence in the literature. Costs were determined by examining the typical patient charges undergoing ACI at a local orthopaedic hospital. The costs, results, and complication rates were used to develop a decision analysis model comparing ACI-P to ACI-C. Results: The cost of ACI-P was $66,752 and for ACI-C was $66,939.50 ($187.50 difference). The cost per quality-adjusted life year (QALY) for ACI-P was $9466 compared with $9243 for ACI-C. Sensitivity analysis was performed regarding the additional cost of the type I/III collagen patch ($780) in ACI-C as well as the rate of graft hypertrophy after ACI-P (25%). This analysis revealed that the cost of the type I/III collagen patch would have to reach $1721, or the rate of graft hypertrophy after ACI-P reduced to almost 11%, before ACI-P became more cost effective than ACI-C. Conclusion: This cost-effectiveness analysis reveals that, while both ACI-P and ACI-C are cost effective, ACI-C is slightly more cost effective than ACI-P. This is likely secondary to the significant rate of patch-related complications associated with ACI-P, which is significantly reduced with ACI-C. Although the model is very sensitive to differences in outcomes between ACI-P and ACI-C, there is no high-quality evidence to suggest that there is a significant difference between the two. Thus, ACI-P becomes more cost effective if the cost of the type I/III collagen membrane is significantly increased or if the rate of graft hypertrophy after ACI-P were to be markedly reduced.

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To understand the generality and mechanisms of previously reported rod hue biases, we examined whether they are present for small foveal stimuli by comparing the wavelengths of the three spectral unique hues under dark-adapted and flash-bleached conditions. Rod green bias~shift of unique yellow! and rod blue bias~shift of unique green! were found for some observers with 18-diameter foveal stimuli, the size most likely to stimulate rods. Smaller stimuli~0.28 and 0.68 diameter!, which were least likely to stimulate rods, produced no large or consistent differences between dark-adapted and bleached conditions. This suggests that rod hue biases result from the local stimulation of rods by light, not from remote suppression by dark-adapted, unstimulated rods, and not from bleaching light artifacts.

Background:Anterior cruciate ligament (ACL) injuries are common in American football players. The risk of subsequent ACL reinjury to either the ipsilateral or the contralateral knee in National Football League (NFL) draftees with a history of successful ACL reconstruction before entering the NFL remains unknown.Hypothesis:NFL athletes with a history of successful ACL reconstruction before being drafted will likely demonstrate increased risk of subsequent ACL injury when compared with a control cohort consisting of players of similar positions and draft class.Study Design:Cohort study; Level of evidence, 3.Methods:Detailed orthopaedic evaluations of NFL Combine participants from 2006 to 2012 were obtained to identify players entering the NFL draft with a history of successful ACL reconstruction. A control cohort was created in a 2:1 ratio, consisting of players matched by position and draft class.Results:Of the 2016 players invited to the NFL Combine during the study period, 100 met the inclusion criteria. A total of 26 subsequent ACL reinjuries (12 ipsilateral, 14 contralateral) occurred in 25 players (25%) while playing in the NFL, with injuries occurring at a mean of 22.1 months after the NFL draft. In comparison, 18 of the 200 (9%) carefully matched cohort players without history of prior ACL injury sustained a new ACL injury during this time period (P < .001).Conclusion:NFL athletes with a history of successful ACL reconstruction before being drafted into the NFL have a significantly higher rate of subsequent ACL reinjury while playing in the NFL when compared with a carefully matched cohort of players without a history of prior ACL injury.