The use of biological agents in the treatment of rheumatoid arthritis (RA) has grown constantly since the approval of the first therapeutic monoclonal antibody against tumor necrosis factor-alpha (TNF) in 1996. While these agents transformed RA treatment, not all patients respond to these agents. Moreover, the cost of these agents is high, and some patients may suffer from adverse events. Thus, the prediction of individual response to biological treatment has become a major clinical challenge in RA. Recent studies have provided evidence that biomarkers may be identified predictive of the response to therapy with these agents. This article will review some of the recent advances in the biomarkers and therapeutic drug monitoring as predictors of response to TNF inhibitor therapies in patients with RA.
{"title":"Predictors of response to TNF inhibitors in rheumatoid arthritis - do we have new tools for personalized medicine?","authors":"Ismail Simsek","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The use of biological agents in the treatment of rheumatoid arthritis (RA) has grown constantly since the approval of the first therapeutic monoclonal antibody against tumor necrosis factor-alpha (TNF) in 1996. While these agents transformed RA treatment, not all patients respond to these agents. Moreover, the cost of these agents is high, and some patients may suffer from adverse events. Thus, the prediction of individual response to biological treatment has become a major clinical challenge in RA. Recent studies have provided evidence that biomarkers may be identified predictive of the response to therapy with these agents. This article will review some of the recent advances in the biomarkers and therapeutic drug monitoring as predictors of response to TNF inhibitor therapies in patients with RA.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":" ","pages":"187-90"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31135904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
New data published or presented in the past year has expanded our understanding of the clinical use of interleukin 6 (IL-6) inhibitors and their role in the management of rheumatoid arthritis (RA) and other rheumatic diseases. Data has become available on the use of tocilizumab (TCZ) in comparison to adalimumab, as therapy in RA patients with an inadequate response to TNF inhibitors and on its role as monotherapy. Early data on the efficacy and safety of subcutaneously administered TCZ suggests a potential role for this formulation of the drug. Extension studies of the use of TCZ in systemic juvenile inflammatory arthritis have confirmed the long-term efficacy of the drug in this illness, while studies on the use of TCZ and other IL-6 inhibitors in spondyloarthropathies has been less encouraging. Finally, new agents targeting the IL-6 pathway have entered late stage clinical trials, and the early results are promising.
{"title":"IL-6 inhibition for the treatment of rheumatoid arthritis and other conditions.","authors":"Robert S Woodrick, Eric M Ruderman","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>New data published or presented in the past year has expanded our understanding of the clinical use of interleukin 6 (IL-6) inhibitors and their role in the management of rheumatoid arthritis (RA) and other rheumatic diseases. Data has become available on the use of tocilizumab (TCZ) in comparison to adalimumab, as therapy in RA patients with an inadequate response to TNF inhibitors and on its role as monotherapy. Early data on the efficacy and safety of subcutaneously administered TCZ suggests a potential role for this formulation of the drug. Extension studies of the use of TCZ in systemic juvenile inflammatory arthritis have confirmed the long-term efficacy of the drug in this illness, while studies on the use of TCZ and other IL-6 inhibitors in spondyloarthropathies has been less encouraging. Finally, new agents targeting the IL-6 pathway have entered late stage clinical trials, and the early results are promising.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":" ","pages":"195-9"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31135906","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L T Suezie Kim, Catherine N Laible, Leon D Rybak, Timothy B Rapp
Incidental bone tumors are, by definition, asymptomatic lesions that are discovered through routine radiographs obtained for other reasons. Generally, these lesions are benign and latent, requiring no further intervention except observation. However, occasionally these radiographs will detect benign aggressive processes or even malignant lesions that do require further treatment and referral to a tumor specialist. Oftentimes, there are characteristic findings on radiographs that are pathognomonic. Knowledge of these findings can simplify the treatment algorithm for a practicing general orthopaedist. This article will describe radiographic characteristics of benign and malignant bone lesions and their typical presentations. It will then focus on the types of bone lesions that are often found incidentally by routine radiography. Specific recommendations, including recommendation for referrals to orthopaedic tumor specialists, will be noted for lesions described. Most malignant lesions will present with pain and a constellation of history and physical exam findings that will signal the patient to seek medical care; although they will be mentioned for the sake of comparison and completeness, they will not be the focus of this review.
{"title":"\"Incidental\" bone lesions--when to refer to the tumor specialist.","authors":"L T Suezie Kim, Catherine N Laible, Leon D Rybak, Timothy B Rapp","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Incidental bone tumors are, by definition, asymptomatic lesions that are discovered through routine radiographs obtained for other reasons. Generally, these lesions are benign and latent, requiring no further intervention except observation. However, occasionally these radiographs will detect benign aggressive processes or even malignant lesions that do require further treatment and referral to a tumor specialist. Oftentimes, there are characteristic findings on radiographs that are pathognomonic. Knowledge of these findings can simplify the treatment algorithm for a practicing general orthopaedist. This article will describe radiographic characteristics of benign and malignant bone lesions and their typical presentations. It will then focus on the types of bone lesions that are often found incidentally by routine radiography. Specific recommendations, including recommendation for referrals to orthopaedic tumor specialists, will be noted for lesions described. Most malignant lesions will present with pain and a constellation of history and physical exam findings that will signal the patient to seek medical care; although they will be mentioned for the sake of comparison and completeness, they will not be the focus of this review.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"235-40"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31147664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The footprint is thought to be an important fact in rotator cuff repairs and has been used to compare various cuff fixation techniques. The following experiment used two different measurement sensors to evaluate the footprint as it is affected by suture tensions in a transosseous equivalent suture bridge repair. It was found that suture tension has a direct effect on footprint contact area and pressure and thus could affect healing and fixation stability and should be characterized in any study of comparative fixation techniques.
{"title":"Effects of suture tension on the footprint of rotator cuff repairs--technical note.","authors":"Frederick J Kummer","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>The footprint is thought to be an important fact in rotator cuff repairs and has been used to compare various cuff fixation techniques. The following experiment used two different measurement sensors to evaluate the footprint as it is affected by suture tensions in a transosseous equivalent suture bridge repair. It was found that suture tension has a direct effect on footprint contact area and pressure and thus could affect healing and fixation stability and should be characterized in any study of comparative fixation techniques.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"259-61"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31147669","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vikas Bachhal, Vijay Goni, Ashish Taneja, B K Shashidhar, Kamal Bali
Although bilateral anterior dislocation of shoulder is not that uncommon, there have been only 12 published reports on bilateral anterior fracture dislocation of shoulder. The associated fractures have mostly been greater tuberosity fractures with bilateral three part fractures being reported in only two cases. To our knowledge, a bilateral four part anterior fracture dislocation of the shoulder has not yet been reported in the English literature. We here report a case of bilateral anterior fracture dislocation with four part fracture of both proximal humeri in a 60-year-old male due to electrocution. Considering the comparatively old age of the patient and excessive comminution of both the fractures, a bilateral hemiarthroplasty was done. At the last follow-up after more than 2 years, the patient was pain free with ability to comfortably carry out most of the activities of daily life. Through our case report, we highlight the rarity of the condition and review the available literature on the subject. We also emphasize the importance of meticulous perioperative planning when dealing with such cases to ensure a satisfactory long-term outcome.
{"title":"Bilateral four-part anterior fracture dislocation of the shoulder--a case report and review of literature.","authors":"Vikas Bachhal, Vijay Goni, Ashish Taneja, B K Shashidhar, Kamal Bali","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Although bilateral anterior dislocation of shoulder is not that uncommon, there have been only 12 published reports on bilateral anterior fracture dislocation of shoulder. The associated fractures have mostly been greater tuberosity fractures with bilateral three part fractures being reported in only two cases. To our knowledge, a bilateral four part anterior fracture dislocation of the shoulder has not yet been reported in the English literature. We here report a case of bilateral anterior fracture dislocation with four part fracture of both proximal humeri in a 60-year-old male due to electrocution. Considering the comparatively old age of the patient and excessive comminution of both the fractures, a bilateral hemiarthroplasty was done. At the last follow-up after more than 2 years, the patient was pain free with ability to comfortably carry out most of the activities of daily life. Through our case report, we highlight the rarity of the condition and review the available literature on the subject. We also emphasize the importance of meticulous perioperative planning when dealing with such cases to ensure a satisfactory long-term outcome.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"268-72"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31146381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wire breakage and migration is a known complication of using a wire tension band construct to treat displaced patella fractures. We report a case of a broken K-wire that migrated from the patella completely into the proximal tibia without complication 9 years after the index surgery. This report highlights the fact that wire migration can occur long after fracture healing and be relatively asymptomatic. But because the complications of wire migration can be deadly, it requires diligence on the part of the physician to educate the patient that new knee pain after operative fixation requires formal evaluation by the treating surgeon.
{"title":"Progressive migration of broken Kirschner wire into the proximal tibia following tension-band wiring technique of a patellar fracture--case report.","authors":"Sanjit R Konda, Alan Dayan, Kenneth A Egol","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Wire breakage and migration is a known complication of using a wire tension band construct to treat displaced patella fractures. We report a case of a broken K-wire that migrated from the patella completely into the proximal tibia without complication 9 years after the index surgery. This report highlights the fact that wire migration can occur long after fracture healing and be relatively asymptomatic. But because the complications of wire migration can be deadly, it requires diligence on the part of the physician to educate the patient that new knee pain after operative fixation requires formal evaluation by the treating surgeon.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"279-82"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31146384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Osteochondral defects of the femoral head are rare and principles of treatment include anatomic reduction, rigid fixation, enhancement of blood supply, and restoration of articular congruity. In this report, we present a case where the defect of the femoral head was treated with surgical dislocation of hip anteriorly and mosaicplasty. At 3-year follow-up, the patient was symptom free with near complete incorporation of the graft radiographically. Our observations in this case suggest that mosaicplasty with an open approach is an alternative treatment in the osteochondral defects of the femoral head.
{"title":"Mosaicplasty for the treatment of the osteochondral lesion in the femoral head.","authors":"Tuluhan Yunus Emre, Hakan Cift, Bahadir Seyhan, Erman Ceyhan, Macit Uzun","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Osteochondral defects of the femoral head are rare and principles of treatment include anatomic reduction, rigid fixation, enhancement of blood supply, and restoration of articular congruity. In this report, we present a case where the defect of the femoral head was treated with surgical dislocation of hip anteriorly and mosaicplasty. At 3-year follow-up, the patient was symptom free with near complete incorporation of the graft radiographically. Our observations in this case suggest that mosaicplasty with an open approach is an alternative treatment in the osteochondral defects of the femoral head.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"288-90"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31146386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Keith W Chan, Kevin Kaplan, Crispin C Ong, Michael G Walsh, Mark E Schweitzer, Orrin H Sherman
Purpose: Accurate prediction of autograft size for anterior cruciate ligament reconstruction can assist in preoperative planning and decision-making regarding graft choices. This study seeks to determine the accuracy of MRI measurements by comparing intraoperative measurements of the patella, semitendinosis, and gracilis tendons while correlating these measurements with patient anthropometric data such as gender, height, and weight.
Methods: A series of 20 consecutive patients were enrolled who underwent a magnetic resonance imaging study of the knee and proceeded with surgical reconstruction of the anterior cruciate ligament. Intraoperative measurements of the diameter of semitendinosis and gracilis tendons or width of patella tendon were compared to radiographic measurements obtained on the MRI. These measurements were analyzed using a paired t-test as well as regression analysis to evaluate strength of correlation between measurements and also to determine correlation with height, weight, and gender.
Results: There was no statistical difference between intraoperative and radiographic measurements (p > 0.05). There was strong correlation (Pearson r = 0.98, p = 0.00) found between intraoperative and radiographic measurements of the autograft tendons. Weaker correlation was seen with gender, height, and weight with intraoperative measurements.
Conclusions: Measuring the diameter of the semitendinosis and gracilis tendons and patellar width on MRI can give an accurate prediction of actual intraoperative sizes of these anatomic structures. Height, weight, and gender were also correlated with tendon sizes implying that a patient of female gender or of smaller stature in height or weight may have smaller tendon sizes. Routine use of preoperative MRI measurements can guide surgeons with specific graft preferences to other surgical options if the graft is measured to be insufficient in size.
目的:准确预测自体前交叉韧带重建术中移植物的大小,有助于术前规划和选择移植物。本研究旨在通过比较术中髌骨、半腱膜和股薄肌腱的测量来确定MRI测量的准确性,同时将这些测量结果与患者的人体测量数据(如性别、身高和体重)相关联。方法:连续20例患者接受了膝关节的磁共振成像研究,并进行了前交叉韧带的手术重建。术中测量半腱膜和股薄肌腱的直径或髌骨肌腱的宽度与MRI上获得的x线测量结果进行比较。使用配对t检验和回归分析对这些测量值进行分析,以评估测量值之间的相关性强度,并确定与身高、体重和性别的相关性。结果:术中与x线测量差异无统计学意义(p > 0.05)。术中自体肌腱的测量与影像学测量有很强的相关性(Pearson r = 0.98, p = 0.00)。术中测量与性别、身高、体重相关性较弱。结论:在MRI上测量半腱膜和股薄肌腱的直径和髌骨宽度可以准确预测这些解剖结构的实际术中大小。身高、体重和性别也与肌腱大小相关,这意味着女性或身高或体重较小的患者可能具有较小的肌腱大小。常规使用术前MRI测量可以指导外科医生对特定移植物的偏好,如果测量的移植物尺寸不足,可以选择其他手术方案。
{"title":"Using magnetic resonance imaging to determine preoperative autograft sizes in anterior cruciate ligament reconstruction.","authors":"Keith W Chan, Kevin Kaplan, Crispin C Ong, Michael G Walsh, Mark E Schweitzer, Orrin H Sherman","doi":"","DOIUrl":"","url":null,"abstract":"<p><strong>Purpose: </strong>Accurate prediction of autograft size for anterior cruciate ligament reconstruction can assist in preoperative planning and decision-making regarding graft choices. This study seeks to determine the accuracy of MRI measurements by comparing intraoperative measurements of the patella, semitendinosis, and gracilis tendons while correlating these measurements with patient anthropometric data such as gender, height, and weight.</p><p><strong>Methods: </strong>A series of 20 consecutive patients were enrolled who underwent a magnetic resonance imaging study of the knee and proceeded with surgical reconstruction of the anterior cruciate ligament. Intraoperative measurements of the diameter of semitendinosis and gracilis tendons or width of patella tendon were compared to radiographic measurements obtained on the MRI. These measurements were analyzed using a paired t-test as well as regression analysis to evaluate strength of correlation between measurements and also to determine correlation with height, weight, and gender.</p><p><strong>Results: </strong>There was no statistical difference between intraoperative and radiographic measurements (p > 0.05). There was strong correlation (Pearson r = 0.98, p = 0.00) found between intraoperative and radiographic measurements of the autograft tendons. Weaker correlation was seen with gender, height, and weight with intraoperative measurements.</p><p><strong>Conclusions: </strong>Measuring the diameter of the semitendinosis and gracilis tendons and patellar width on MRI can give an accurate prediction of actual intraoperative sizes of these anatomic structures. Height, weight, and gender were also correlated with tendon sizes implying that a patient of female gender or of smaller stature in height or weight may have smaller tendon sizes. Routine use of preoperative MRI measurements can guide surgeons with specific graft preferences to other surgical options if the graft is measured to be insufficient in size.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"241-5"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31147665","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ran Schwarzkopf, Scott Hadley, Justin M Weatherall, Steven C Gross, Scott E Marvin
Recent resurgence in the interest of barbed suture has extended its application to wound closures in total joint surgery. Improved suture biomaterials and barb geometry has lead to consideration for its use in various orthopedic procedures including arthroplasty. The reported superior wound tensile stress distribution, no need for knots, and ability to close multiple layers with one suture make it an attractive option for deep wound closure after total joint surgery. However, inherent to the design of this suture are barbs that pose a risk of glove perforation and the potential for the transmission of blood borne pathogens. This study reports no increase in the incidence of glove perforation with use of barbed suture for deep wound closure after total joint arthroplasty.
{"title":"Barbed sutures for arthroplasty closure--does it decrease the risk of glove perforation?","authors":"Ran Schwarzkopf, Scott Hadley, Justin M Weatherall, Steven C Gross, Scott E Marvin","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Recent resurgence in the interest of barbed suture has extended its application to wound closures in total joint surgery. Improved suture biomaterials and barb geometry has lead to consideration for its use in various orthopedic procedures including arthroplasty. The reported superior wound tensile stress distribution, no need for knots, and ability to close multiple layers with one suture make it an attractive option for deep wound closure after total joint surgery. However, inherent to the design of this suture are barbs that pose a risk of glove perforation and the potential for the transmission of blood borne pathogens. This study reports no increase in the incidence of glove perforation with use of barbed suture for deep wound closure after total joint arthroplasty.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 4","pages":"250-3"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"31147667","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patient registries are very popular. On the other hand, scientific data collections in registries are commonly observational and retrospective and, in many instances, are prone to biases. Same thing is true of administrative data bases. The selection of the control group(s) is probably the Achilles heel of scientific data collection in observational studies, and there are historical examples of how a properly chosen control group can help or its absence deceive us. Somewhat more recently recognized biases are the wandering comparisons of risk, confounding by disease severity, channeling bias, depletion of the susceptible, and the immortal time bias. The last bias can especially be deceiving and give us false hopes of new remedies. A particularly important selection bias we have come across is what we call the "mortality bias." This is where the mortality in a mother population lessens the mortality in the registry that stems from this mother population simply because deaths in the former cannot be represented in the latter.
{"title":"Beware of registries for their biases.","authors":"Hasan Yazici","doi":"","DOIUrl":"","url":null,"abstract":"<p><p>Patient registries are very popular. On the other hand, scientific data collections in registries are commonly observational and retrospective and, in many instances, are prone to biases. Same thing is true of administrative data bases. The selection of the control group(s) is probably the Achilles heel of scientific data collection in observational studies, and there are historical examples of how a properly chosen control group can help or its absence deceive us. Somewhat more recently recognized biases are the wandering comparisons of risk, confounding by disease severity, channeling bias, depletion of the susceptible, and the immortal time bias. The last bias can especially be deceiving and give us false hopes of new remedies. A particularly important selection bias we have come across is what we call the \"mortality bias.\" This is where the mortality in a mother population lessens the mortality in the registry that stems from this mother population simply because deaths in the former cannot be represented in the latter.</p>","PeriodicalId":72485,"journal":{"name":"Bulletin of the NYU hospital for joint diseases","volume":"70 2","pages":"95-8"},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"30833244","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}