When Medicare’s Comprehensive Care for Joint Replacement (CJR) program was implemented in 2016, the health care community—especially orthopaedic surgeons— had 2 major concerns. First, would the program actually demonstrate the ability to decrease the costs of total joint replacements while maintaining the same, or improved, outcomes? Second, would CJR promote the unintended consequence of participating hospitals and surgeons ”cherry picking” lower-risk patients and steering clear of higher-risk (and presumably higher cost) patients? Both of these questions were at the heart of the study by Barnett et al. in a recent issue of the New England Journal of Medicine.
The authors evaluated hip and knee replacements at 75 metropolitan centers that were mandated to participate in the CJR program and compared the costs, complication rates, and patient demographics to similar procedures at 121 control centers that did not participate in CJR. The authors found significantly greater decreases in institutional spending per joint-replacement episode in institutions participating in the CJR compared to those that did not. Most of these savings appeared to come from CJR-participating institutions sending fewer patients to post-acute care facilities after surgery. Furthermore, the authors did not find differences between centers participating in the CJR and control centers in terms of composite complication rate or the percentage of procedures that were performed on high-risk patients.
While this 2-year evaluation does not provide the level of detail necessary to make far-reaching conclusions, it does address two of the biggest concerns related to CJR implementation from a health-systems perspective. There may be individual CJR-participating centers that are not saving Medicare money or that are cherry picking lower-risk patients, but overall the program appears to be doing what it set out to do—successfully motivating participating hospitals and healthcare facilities to look critically at what they can do to decrease the costs of a joint-replacement episode while simultaneously maintaining a high level of patient care. The Trump administration shifted CJR to a partly voluntary model in March 2018, and I hope policymakers consider these findings if further changes to the CJR model are planned.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Periprosthetic joint infections (PJIs) create a significant burden for patients, surgeons, and healthcare systems. That is why so much research has gone into how best to optimize certain patients preoperatively—such as those with obesity, diabetes, or kidney disease—to decrease the risk of these potentially catastrophic complications. Still, it is not always possible or feasible to optimize every “high-risk” patient who would benefit from a total hip or knee replacement, and therefore many such patients undergo surgery with an increased risk of infection. In such cases, surgeons need additional strategies to decrease PJI risk.
In the December 19, 2018 issue of JBJS, Inabathula et al. investigate whether providing high-risk total joint arthroplasty (TJA) patients with extended postoperative oral antibiotics decreased the risk of PJI within the first 90 days after surgery. In their retrospective cohort study, the authors examined >2,100 total hip and knee replacements performed at a single suburban academic hospital. The patients in 68% of these cases had at least one risk factor for infection. Among those high-risk patients, about half received 7 days of an oral postoperative antibiotic, while the others received only the standard 24 hours of postoperative intravenous (IV) antibiotics.
Relative to those who received IV antibiotics only, those who received extended oral antibiotics experienced an 81% reduction in infection for total knee arthroplasties and a 74% reduction in infection for total hip arthroplasties. I was stunned by such large reductions in infection rates obtained simply by adding an oral antibiotic twice a day for 7 days. Most arthroplasty surgeons go to great lengths to decrease the risk of joint infection by percentages much less than that.
While further investigations are needed and legitimate concerns exist regarding the propagation of antimicrobial-resistant organisms from medical antibiotic misuse, these data are very exciting. I agree with Monti Khatod, MD, who, in his commentary on this study, says that “care pathways that aim to improve modifiable risk factors should not be seen as obsolete based on the findings of this paper.” Furthermore, the study itself is at risk for treatment and selection biases that could greatly influence its outcomes. Nevertheless, getting a successful result in these patients is challenging and, if validated with further data, this research may help surgeons obtain better outcomes when treating high-risk patients in need of hip or knee replacements.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
The adult joint-reconstruction community has made great strides in the last 2 decades in understanding what causes aseptic loosening of arthroplasty components. For example, revelations about polyethylene particulate debris has led to the production of highly cross-linked polyethylene, which in turn has lowered wear rates, decreased revision rates, and increased the survivorship of total hip implants (see related OrthoBuzz post). Still, polyethylene debris is only one factor that can lead to aseptic loosening. Another important, yet often overlooked, factor is friction between the impacted acetabular shell and the host bone.
In the October 3, 2018 issue of The Journal, Bergmann et al. report data that help us better understand the “friction factor” in aseptic loosening. The authors implanted specially designed, instrumented acetabular components that measured in vivo friction moments among nine patients while they engaged in >1,400 different activities. The authors found that 124 of those activities led to friction moments >4 Nm—which appears to be the upper limit for facilitating a firm union between the acetabular component and the native socket.
Movements such as muscle stretching in the lunge position, the breaststroke in swimming, 2-legged standing with muscles contracted, and a single-legged stance while moving the contralateral leg were among those that created the highest friction between the implant and the host bone—and that could impede bone ingrowth into the acetabular component and thus contribute to aseptic loosening. The study also highlights the importance of periodic unloading of the prosthetic joint to allow proper synovial lubrication, which helps minimize the effects of high-friction moments. The good news is that the vast majority of activities studied do not appear to result in friction forces above the 4 Nm threshold.
Although these data should be confirmed with other in-vivo instrumented prostheses (assuming there are more patients willing to receive acetabular components capable of delivering telemetric data), they provide practical insight into the real-world forces placed on total hip prostheses after implantation. Such information can be used to counsel patients regarding high-friction and sustained-loading activities to be avoided, and it can help physical therapists and surgeons tailor postoperative regimens that optimize patient recovery while minimizing the risk to implanted prostheses.
Marc Swiontkowski, MD
Every month, JBJS publishes a Specialty Update—a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in 13 subspecialties. Click here for a collection of all OrthoBuzz Specialty Update summaries.
This month, Mengnai Li, MD, co-author of the September 19, 2018 Specialty Update on Hip Replacement, selected the five most clinically compelling findings from among the more than 100 studies covered in the Specialty Update.
The Benefits of HXLPE
–A double-blinded study that randomized patients to receive either a conventional polyethylene liner or one made from highly cross-linked polyethylene (HXLPE) found that, after a minimum of 10 years, the HXLPE group had significantly lower wear rates, lower prevalence of osteolysis, and lower revision rates than the conventional-liner group.
Outcomes for Hip Fracture vs OA
–A propensity score-matched cohort analysis of NSQIP data found that total hip arthroplasty (THA) undertaken to treat hip fractures among Medicare beneficiaries was significantly associated with an increased risk of CMS-reportable complications, non-homebound discharge, and readmission, relative to THA undertaken to treat osteoarthritis.1
Infection Risk Factors
–A multicenter retrospective study found that a threshold of 7.7% for hemoglobin A1c was more predictive of periprosthetic joint infection than the commonly used 7%, and the authors suggest that 7.7% should be considered the goal in preoperative patient optimization.2
THA in Patients with RA
–Recently published guidelines from the American College of Rheumatology and AAHKS regarding antirheumatic medication use in patients with rheumatic diseases who are undergoing THA suggest the following:
- Continuing nonbiologic disease-modifying antirheumatic drugs (DMARDs)
- Continuing the same daily dose of corticosteroids
- Withholding biologic agents prior to surgery
- Planning surgery for the end of the biologic dosing cycle.
All recommendations are conditional due to the low or moderate-quality evidence on which they were based.3
–A double-blinded, randomized trial found that oral tranexamic acid (TXA) provided equivalent reductions in blood loss in the setting of primary THA, at greatly reduced cost, compared with intravenous TXA.
- Qin CD, Helfrich MM, Fitz DW, Hardt KD, Beal MD, Manning DW. The Lawrence D. Dorr Surgical Techniques & Technologies Award: differences in postoperative outcomes between total hip arthroplasty for fracture vs osteoarthritis. J Arthroplasty. 2017 Sep;32(9S):S3-7. Epub 2017 Feb 6.
- Tarabichi M, Shohat N, Kheir MM, Adelani M, Brigati D, Kearns SM, Patel P, Clohisy JC, Higuera CA, Levine BR, Schwarzkopf R, Parvizi J, Jiranek WA. Determining the threshold for HbA1c as a predictor for adverse outcomes after total joint arthroplasty: a multicenter, retrospective study. J Arthroplasty. 2017 Sep;32(9S): S263-7: 267.e1. Epub 2017 May 11.
- Goodman SM, Springer B, Guyatt G, Abdel MP, Dasa V, George M, Gewurz- Singer O, Giles JT, Johnson B, Lee S, Mandl LA, Mont MA, Sculco P, Sporer S, Stryker L, Turgunbaev M, Brause B, Chen AF, Gililland J, Goodman M, Hurley-Rosenblatt A, Kirou K, Losina E, MacKenzie R, Michaud K, Mikuls T, Russell L, Sah A, Miller AS, Singh JA, Yates A. 2017 American College of Rheumatology/American Association of Hip and Knee Surgeons guideline for the perioperative management of antirheumatic medication in patients with rheumatic diseases undergoing elective total hip or total knee arthroplasty. J Arthroplasty. 2017 Sep;32(9):2628-38. Epub 2017 Jun 16.
Annual volume projections for total joint arthroplasty (TJA) have been cited frequently and applied broadly, often to estimate future costs. But with a slowdown in the growth of the annual incidence of total knee arthroplasty (TKA), updated projections are needed, and that’s what Sloan et al. provide in the September 5, 2018 issue of JBJS.
Using the National Inpatient Sample to obtain TJA incidence data, the authors first analyzed the volume of primary TJA procedures performed from 2000 to 2014. They then performed regression analyses to project future volumes of TJA procedures. Here are the numbers based on the 2000-to-2014 data:
- Primary total hip arthroplasty (THA) is projected to grow 71%, to 635,000 annual procedures by 2030.
- Primary TKA is projected to grow 85%, to 1.26 million annual procedures by 2030.
However, the TKA procedure growth rate has slowed in recent years, and models based on 2008-to-2014 data project growth to only 935,000 annual TKAs by 2030—325,000 fewer procedures relative to the 2000-to-2014 models.
Earlier studies, notably one by Kurtz et al. in 2007, obviously could not account for the reduced growth rate in TKA after 2008. A 2008 analysis by Wilson et al., based on the Kurtz et al. data, estimated that annual Medicare expenditures on TJA procedures would climb from $5 billion in 2006 to $50 billion in 2030. “Using our projections,” say Sloan et al., “we predict that Medicare expenditures on these procedures in 2030 will be less than half of that predicted by Wilson et al.”
These findings lend credence to the authors’ observation that “it is imperative that projections of orthopaedic procedures be regularly evaluated and updated to reflect current rates.”
Allograft bone is used often in orthopaedic surgery. However, the use of structural allografts to address large acetabular defects in total hip arthroplasty (THA) is not common. But it may become more so in light of the study by Butscheidt et al. in the August 15, 2018 issue of JBJS. The authors add to our knowledge about these relatively rare procedures by evaluating the incorporation of structural acetabular allografts into host bone among 13 complete pelvic explants containing allograft that had been in place for a mean of 13 years.
Using sophisticated imaging and histological techniques, the authors found that in 10 out of the 13 specimens retrieved, 100% of the interface was characterized by direct contact and additional overlap of the allograft bone and the host bone. The remaining 3 allografts showed direct contact along 25% to 80% of the interface. The authors found no correlation between ingrowth of the host bone into the allograft and the amount of time the allograft had spent in situ, leading them to surmise that “a large proportion of the incorporation process may be completed within the first weeks.”
Large, structural allografts are not commonly used for acetabular reconstructions, as most surgeons seem to favor other options. (See the JBJS Clinical Summary on “Managing Acetabular Defects in Hip Arthroplasty.”) While a postmortem study of 13 cases may not be “practice-changing,“ the Butscheidt et al. analysis does provide some detailed clarity as to what surgeons can expect from these large allograft reconstructions in terms of incorporation with host bone. Obviously, one limitation of this study is that structural allografts that never incorporated with the host bone probably failed early and would not be available for analysis in a long-follow-up retrieval study.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
Under one name or another, The Journal of Bone & Joint Surgery has published quality orthopaedic content spanning three centuries. In 1919, our publication was called the Journal of Orthopaedic Surgery, and the first volume of that journal was Volume 1 of what we know today as JBJS.
Thus, the 24 issues we turn out in 2018 will constitute our 100th volume. To help celebrate this milestone, throughout the year we will be spotlighting 100 of the most influential JBJS articles on OrthoBuzz, making the original full-text content openly accessible for a limited time.
Unlike the scientific rigor of Journal content, the selection of this list was not entirely scientific. About half we picked from “JBJS Classics,” which were chosen previously by current and past JBJS Editors-in-Chief and Deputy Editors. We also selected JBJS articles that have been cited more than 1,000 times in other publications, according to Google Scholar search results. Finally, we considered “activity” on the Web of Science and The Journal’s websites.
We hope you enjoy and benefit from reading these groundbreaking articles from JBJS, as we mark our 100th volume. Here are two more:
Traumatic Arthritis of the Hip after Dislocation and Acetabular Fractures—Treatment by Mold Arthroplasty: An End-Result Study Using a New Method of Result Evaluation
W H Harris: JBJS, 1969 June; 51 (4): 737
The most lasting legacy from this classic 1969 article from William Harris is the author’s proposed hip score. A “single, reliable figure” designed to be equally applicable to different hip problems and different treatments, the Harris Hip Score is still used worldwide today in routine evaluations before and after hip arthroplasty. Not surprisingly, this article remains the most frequently cited paper in the hip arthroplasty literature.
Nonoperative Treatment Compared with Plate Fixation of Displaced Midshaft Clavicular Fractures
Canadian Orthopaedic Trauma Society: JBJS, 2007 January; 89 (1): 1
Amid the ongoing debate about whether to operate on which type of clavicle fractures, this multicenter, randomized clinical trial stands out for its rigorous design and focus on patient-oriented outcomes. Local irritation and unsightly prominence from hardware notwithstanding, these findings support primary plate fixation of completely displaced midshaft clavicle fractures in active adult patients.
Some people are tired of reading and hearing about the opioid crisis in America. When this topic comes up at meetings, there are rumblings in the crowd. When it’s brought up during hospital safety briefings, there are not-so-subtle eye-rolls, and occasionally I hear frank assertions of “enough already” when new information on the topic appears in the literature. Yet, as two studies in the July 18, 2018 edition of JBJS highlight, this topic is not going away any time soon. And for good reason. We are only starting to scratch the surface of the serious unintended consequences—beyond the risk of addiction—from overly aggressive prescribing and consumption of narcotics.
The first article, by Zhu et al., directly addresses the topic of overprescribing by doctors in China. The authors evaluated how many opioid pills were given to patients who sustained fractures that were treated nonoperatively. The mean number of opioid pills patients reported consuming (7.2) was less than half the mean number prescribed (14.7). More than 70% of patients did not consume all the opioid pills they were prescribed, and 10% of patients consumed no opioids at all. Zhu et al. conclude that “if opioids are used [in this setting], surgeons should prescribe the smallest dose for the shortest time after considering the injury location and type of fracture or dislocation.”
The second article, by Weick et al., underscores the patient-outcome and societal impact of opioid use prior to total hip and knee arthroplasty. Patients from North America who consumed opioids for 60+ days prior to their joint replacement had a significantly increased risk of revision at both the 1-year and 3-year postoperative follow-ups, compared to similar patients who were opioid-naïve before surgery. Similarly, patients who used opioids for 60+ days prior to undergoing a total hip or knee arthroplasty had a significantly increased risk of 30-day readmission, compared to patients who were opioid-naïve. All these differences held when the authors made adjustments for patient age, sex, and comorbidities—meaning that tens of thousands of patients each year can expect to have worse outcomes (and add a large cost burden to the health care system) simply by being on opioid medications for two months preoperatively.
These articles address two very different research questions in two very different regions of the world, but they help expose the chasm in our knowledge surrounding opioid use and misuse. We have been prescribing patients more narcotics than they need while just starting to recognize the importance of minimizing opioid use preoperatively in an effort to maximize surgical outcomes. These two competing impulses emphasize why further opioid-related studies are important. While continuing to look at the negative effects these medications can have on patients, we have to take a hard look at our contribution to the problem.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media
At any given time, a patient’s blood-glucose level is easy to measure. Beyond the standard pre/postoperative lab values, there are finger sticks, transdermal meters, and other modalities that make taking a patient’s glucose “snapshot” pretty straightforward. So why don’t we surgeons keep track of it more frequently before and after joint replacement, when, according to the prognostic study by Shohat et al. in the July 5, 2018 issue of JBJS, fluctuating glucose levels can have a critical impact on outcomes?
By retrospectively studying more than 5,000 patients who had undergone either total hip or total knee arthroplasty, the authors found that increased variability of glucose levels (measured by a coefficient of variation) was associated with increased risks of 90-day mortality, surgical-site infection, and periprosthetic joint infection. Specifically, the authors demonstrated that for every 10-percentage-point increase in the glycemic coefficient of variation, the risk of 90-day mortality increased by 26%, and the risk of periprosthetic or surgical-site infection increased by 20%. These are remarkable increases in extremely important outcome measures, and the associations held regardless of the patient’s mean glucose values prior to or after the surgery. In fact, some of the highest levels of glucose variability were found in patients who had well-controlled glucose levels preoperatively. Furthermore, as Charles Cornell, MD points out in a commentary on this study, “Glucose variability appears to affect surgical prognosis more than chronic hyperglycemia.”
These findings were surprising and a bit concerning. I don’t tend to order routine blood-glucose measurements postoperatively on patients who appear to be euglycemic based on preoperative testing. Yet, according to these data, maybe I should. Findings of high glucose variability postoperatively might now prompt me to consult with endocrine or perioperative medicine specialists or at least consider informing patients with fluctuating glucose levels that they may be at increased risk of serious postoperative complications.
Measuring a patient’s blood sugar is neither challenging nor prohibitively expensive. So why don’t we monitor it more closely? Probably because, until now, we have not had a compelling reason to do so with “low-risk” patients. What this study suggests is that our definition of a “low-risk” patient from a glycemic-control standpoint may be misinformed. And while further research needs to be performed to corroborate these findings, that is a pretty scary thought to digest.
Chad A. Krueger, MD
JBJS Deputy Editor for Social Media