Steven M. Kurtz

The Use of Hyaluronic Acid and Corticosteroid Injections Among Medicare Patients With Knee Osteoarthritis

INTRODUCTION Hyaluronic acid (HA) and corticosteroid (CS) injections are frequently used in the management of osteoarthritis (OA) of the knee, despite a lack of strong evidence supporting their efficacy in the literature. The purpose of this study is to evaluate trends in HA and CS usage in Medicare patients over the past 15 years. METHODS The Medicare 5% national sample database was used to identify 581,022 patients (representing an estimated 11.6 million) with a diagnosis of knee OA between 1999 and 2013. RESULTS The percentage of newly diagnosed knee OA patients who received any injection trended from 39% in 1999 to 47% in 2006 and then declined to 37.5% in 2013. However, the mean number of injections per newly diagnosed OA patient nearly doubled from 0.27 to 0.45 for CS and from 0.18 to 0.36 for HA. Among those having both HA and CS injections, 69% had CS as first-line treatment, whereas 31% had HA first. CONCLUSION The percentage of newly diagnosed knee OA patients receiving injections peaked in 2007 and then decreased steadily through 2013, as did the proportion of patients receiving HA injections as first-line therapy. However, the number of injections per patient has increased significantly over the past 15 years in both groups.

Isoelastic Polyaryletheretherketone Implants for Total Joint Replacement

Publisher Summary PEEK biomaterials in orthopedics are currently in a period of consideration and conservative adoption. The traditional metal, ceramic, and polymer implants currently used for total hip and knee replacement are perceived by many surgeons and patients as reasonably successful, with survival rates in the elderly population exceeding 90% at 10 years. The clinical needs for the orthopedic community, therefore, have been focused on extending the longevity of existing implants for the elderly patient population, as well as on expanding the clinical success of total joint replacements to younger and more active patients. In orthopedics, novel implant technologies need to demonstrate sustained, long-term improved performance relative to historical alternatives. Animal studies and clinical data have been accumulated to demonstrate the viability of composite stems incorporating PEEK biomaterials as an alternative to monolithic metal alloys in hip stems. Other novel designs of PEEK implants are still in the early stages of clinical evaluation. PEEK and CFR-PEEK composites are now established as sufficiently versatile and durable for isoelastic orthopedic implants. The design ideal of isoelastic femoral stems shows clinical evidence of reasonably sustained fixation and reduced stress shielding when compared with traditional metallic stems. Of the variety of polymers that have been evaluated for composite hip stems over the past 40 years, only PEEK has demonstrated the requisite combination of mechanical properties, biocompatibility, manufacturability, and consistent availability throughout this time period.

Contemporary Total Hip Arthroplasty: Hard-on-Hard Bearings and Highly Crosslinked UHMWPE

Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.

Short-term Risk of Revision THA in the Medicare Population Has Not Improved With Time

IntroductionAdvances in surgical technique, implant design, and clinical care pathways have resulted in higher expectations for improved clinical outcomes after primary THA; however, despite these advances, it is unclear whether the risk of revision THA actually has decreased with time. Understanding trends in short- and mid-term risks of revision will be helpful in directing clinical, research, and policy efforts to improve THA outcomes.Question/purposesWe therefore asked (1) whether there have been changes in overall short- and mid-term risks of revision THA among patients in the Medicare population who underwent primary THA between 1998 and 2010; and (2) whether there are different demographic factors associated with short- and mid- term risks of revision THA.MethodsUsing the Medicare 5% national sample database, patients who underwent primary THA between 1998 and 2010 followed by subsequent revision through 2011 were identified by ICD-9-CM procedure codes 81.51 and 81.53/80.05/00.70–00.73, respectively. This dataset included a random sample of Medicare beneficiaries based on their social security number. Only patients with minimum 1-year followup after primary THA were included in our analysis. A total of 64,260 patients who underwent primary THA were identified from the 1998 to 2010 Medicare 5% dataset. Eighty-eight percent of the patients had 1-year followup providing a final study cohort of 56,700 patients. The risk of revision was evaluated at 1, 3, 5, and 7 years. Multivariate Cox regression was used to evaluate temporal trends in revision risk using two methods to account for time effects with periods 1998 to 2002, 2003 to 2007, and 2008 to 2010 for the index year of primary THA, and individual year of index of primary THA as independent variables. The analysis adjusted for patient age, sex, race, census region, Charlson score, and socioeconomic status.ResultsThe 7-year crude risk of revision THA declined from 7.10% in 1998 to 2002 to 6.09% in 2008 to 2010, representing a 14.4% overall reduction in adjusted risk of revision (p = 0.0058; 95% CI, 4.4%–23%). Similarly, the 5-year crude risk of revision THA declined from 5.96% in 1998 to 2002 to 5.11% in 2008 to 2010, representing a 14.2% overall reduction in adjusted risk of revision (p = 0.0069; 95% CI, 4.1%–23%). However, the adjusted risk of revision THA at 3 years was not different from 1998 to 2002 (4.70%) and 2008 to 2010 (4.03%; p = 0.1176). Similarly, the adjusted risk of revision at 1 year did not differ from 1998 to 2002 (2.83%) and 2008 to 2010 (2.42%; p = 0.3386). Patients with more comorbidities had a greater adjusted risk of revision (p < 0.001) at all times: 94% (95% CI, 58%–138%) and 56% (95% CI, 33%–84%) at 1 year and 7 years, respectively, for Charlson score of 5+ vs 0).ConclusionsAlthough the mid-term (5 and 7 years) risk of revision THA has decreased during the past 14 years among Medicare beneficiaries who underwent primary THA, the short-term risk has not. These findings suggest that greater clinical, research, and policy emphasis is needed to identify potentially avoidable causes of early failure after primary THA in patients in the Medicare population, and multistakeholder solutions are needed to optimize short-term outcomes.Level of EvidenceLevel III, therapeutic study.

Chapter 6 – Contemporary Total Hip Arthroplasty: Hard-on-Hard Bearings and Highly Crosslinked UHMWPE

Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.

Contemporary Total Hip Arthroplasty

Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.Publisher Summary This chapter summarizes metal-on-metal (MOM), ceramic-on-ceramic (COC) and ceramic-on-metal bearing (COM) alternative bearing designs and some of the unique trade-offs associated with their use in comparison with highly crosslinked ultra-high molecular weight polyethylene (UHMWPE). The history of MOM bearings is particularly noteworthy because it predates the use of UHMWPE in artificial hip joints. This study reviews the use of ceramics as a counterface in articulations with UHMWPE. Highly crosslinked UHMWPE remains the most widely used alternative to conventional UHMWPE in orthopedics. This chapter also provides an introduction to highly crosslinked and thermally stabilized UHMWPE and describes the characteristics of the most prevalent alternative to conventional UHMWPE in joint arthroplasty. Over the past 10 years, an extensive body of knowledge has emerged on different types of highly crosslinked UHMWPE materials that explores first- and second-generation materials in greater detail. Consequently, the chapter introduces highly crosslinked materials to provide a context with which to compare modern hard-on-hard bearing choices confronting contemporary orthopedic practitioners. Orthopedic surgeons and patients have even more alternative bearings for hip replacement to choose from than were available 5 years ago. Among hard-on-soft bearings, highly crosslinked UHMWPE has now superseded conventional UHMWPE for hip arthroplasty. There are alternative bearings as well that are reviewed in this chapter.