Tag Archive | Joint replacement

JBJS Reviews Editor’s Choice–Outpatient Joint Replacement?

knee-spotlight-image.png“Necessity is the mother of invention.” In recent years, the demand for total hip, total knee, and unicompartmental knee arthroplasty has grown substantially. However, with limited resources and health-care budgets, there is a need to reduce hospital costs. To that end, a number of surgeons have begun to perform these procedures on an outpatient basis.

Indeed, as the demand for joint replacements grows, it will be imperative to improve patient safety and satisfaction while minimizing costs and optimizing the use of health-care resources. In order to accomplish this goal, surgical teams, nursing staff, and physiotherapists will need to work together to discharge patients from the hospital as soon as safely possible, including on the same day as the operation. The development of accelerated clinical pathways featuring a multidisciplinary approach and involving a range of health-care professionals will result in extensive preoperative patient education, early mobilization, and intensive physical therapy.

In the December 2016 issue of JBJS Reviews, Pollock et al. report on a systematic review that was performed to determine the safety and feasibility of outpatient total hip, total knee, and unicompartmental knee arthroplasty. The authors hypothesized that outpatient arthroplasty would be safe and feasible and that there would be similar complication rates, similar readmission and revision rates, similar clinical outcomes, and decreased costs in comparison with the findings associated with the inpatient procedure. The investigators demonstrated that, in selective patients, outpatient total hip, total knee, and unicompartmental knee arthroplasty can be performed safely and effectively.

A major caveat of this well-conducted study, however, is that, like any systematic review, its overall quality is based on the quality of the individual studies that make up the analysis. In this case, the studies included those that lacked sufficient internal validity, sample size, methodological consistency, and standardization of protocols and outcomes. Thus, going forward, there is a need for more rigorous and adequately powered randomized trials to definitively establish the safety, efficacy, and feasibility of outpatient hip and knee arthroplasty.

Thomas A. Einhorn, MD
Editor, JBJS Reviews

Accurate, Easy Risk Adjustment for Ortho Outcomes Is Possible

All you stats geeks out there will love the January 6, 2016 study in The Journal of Bone & Joint Surgery by Schilling and Bozic. We at OrthoBuzz are going to skip the gory statistical details for the most part and focus on the essential findings.

First the premise and purpose of the study: Because measuring and improving health care outcomes are nowadays top priorities, risk adjustment—methods to account for differences in patient characteristics across providers—has become a contentious issue. General risk-assessment models tend not to be well-tailored to orthopaedic procedures. So Schilling and Bozic developed a series of risk-adjustment models specific to 30-day morbidity and mortality following hip fracture repair (HFR), total hip arthroplasty (THA), and total knee arthroplasty (TKA). To develop their models, they used prospectively collected clinical data from the National Surgical Quality Improvement Program.

Here are the major findings: For THA and TKA, risk-adjustment models using age, sex, and American Society of Anesthesiologists (ASA) physical status classification were nearly as predictive as models using many additional covariates. HFR model discrimination improved with the addition of comorbidities and laboratory values. Vital signs did not improve model discrimination for any of the procedures.

The study confirms that it is possible to provide adequate risk adjustment for analyzing outcomes of these procedures using only a handful of the most predictive variables commonly available within the operative record. “More parsimonious models are a viable alternative when the adequacy of risk adjustment must be weighed against the cost and burden of large-scale data extraction from the clinical record,” the authors conclude.

Three Steps Cut Surgical Site Staph Infections after Joint Replacement

Surgical site infections (SSIs) can cancel out the benefits of surgery, and they’re the number-one cause of hospital readmissions following surgery. The most prevalent pathogenic culprit is Staphylococcus aureus.

A study of patients undergoing cardiac or hip or knee arthroplasty surgery at 20 hospitals in nine states found that the following protocol reduced the rate of complex (deep incisional or organ-space) S. aureus SSIs by about 40% overall—and by about 50% among patients undergoing hip or knee arthroplasty (an absolute difference of 17 infections per 10,000 joint replacements):

  • Preoperative screening of nasal samples
  • Intranasal mupirocin and chlorhexidine baths for up to five days prior to surgery for patients testing positive for methicillin-resistant S. aureus (MRSA) or methicillin-susceptible S. aureus (MSSA)
  • Perioperative prophylaxis with vancomycin plus cefazolin or cefuroxime for MRSA carriers and perioperative cefazolin or cefuroxime for all others

Rates of complex SSIs decreased most substantially among patients who were fully adherent to the protocol, although only 39% of the subjects experienced implementation of all the steps. Adherence rates were especially low among those who presented in urgent and emergency settings.

In an editorial accompanying the study, Preeti Malani, MD wrote that “although the absolute difference [in infections] seems modest, each complex SSI prevented is clinically meaningful.”

Joint Replacement Associated with Postop Weight Loss in Obese Patients

The relationships between body weight and joint replacement are debated often in the orthopaedic community. Some surgeons are so concerned about perioperative complications related to obesity that they recommend delaying arthroplasty in obese patients until weight loss is achieved.

But what are the likelihood and implications of weight changes after joint replacement? For those answers, in the June 3, 2015 edition of JBJS, Ast et al. tracked differences in body mass index (BMI) among nearly 7,000 patients for two years after total hip arthroplasty (THA) or total knee arthroplasty (TKA). Establishing a 5% BMI change as “clinically meaningful,” the researchers found that:

  • Most patients (73% of those undergoing THA and 69% of those undergoing TKA) experienced no weight change.
  • Female patients, patients with a higher preoperative BMI, and those undergoing TKA were most likely to lose weight after surgery.
  • Weight loss was associated with improved clinical outcomes after THA, but not after TKA. However, weight gain in general was associated with inferior clinical outcomes.
  • Those with better preoperative functional status were less likely to gain weight after THA or TKA.

Countering conventional wisdom that weight loss after total joint arthroplasty is unlikely, Ast. Et al. emphasize that “obese patients who undergo total joint arthroplasty are more likely than non-obese patients to lose weight after surgery.”

Medicare to “Unbundle” Postoperative Care by 2018

During a well-attended symposium on bundled payment initiatives for joint replacement at the 2015 AAOS Annual Meeting, speakers shared enlightening pearls and pitfalls related to Medicare’s Bundled Payments for Care Improvement initiative. But no one mentioned the fact that by 2018, Medicare will shift the 90-day global period for joint replacement—and all other covered surgeries—to a 0-day global period.

This fact is discussed in an eye-opening Perspective by Mulcahey et al. in the April 9 New England Journal of Medicine. Noting that bundled payments in general are designed to improve care and reduce cost, the authors call this decision, which would essentially unbundle postoperative visits, “striking.” The shift to a 0-day global period for surgery is based on an HHS Inspector General audit that found that the number of postoperative encounters between surgeons and patients are actually well below the number paid for in the 90-day bundle. Total knee arthroplasty, for example, includes three inpatient, one hospital-discharge, and three outpatient surgeon visits in its 90-day package.

Mulcahey et al. contend that “removing some or all postoperative visits from global packages will reduce procedure payment rates” for surgeons, but it remains to be seen how surgeons, orthopaedic and otherwise, will respond to the policy change. OrthoBuzz will keep you posted.

JBJS Classics: Periprosthetic Bone Loss in Total Hip Arthroplasty

JBJS-Classics-logoEach month during the coming year, OrthoBuzz will bring you a current commentary on a “classic” article from The Journal of Bone & Joint Surgery. These articles have been selected by the Editor-in-Chief and Deputy Editors of The Journal because of their long-standing significance to the orthopaedic community and the many citations they receive in the literature. Our OrthoBuzz commentators will highlight the impact that these JBJS articles have had on the practice of orthopaedics. Please feel free to join the conversation about these classics by clicking on the “Leave a Comment” button in the box to the left.

This classic investigation on periprosthetic bone loss (J Bone Joint Surg Am 1992; 74:849–863) was conducted by Tom Schmalzried in the early 1990s working in William Harris’ laboratory.  Specimens from osteolytic lesions both near and far from the articular surface in 34 total hip arthroplasties were studied by plain and polarized light microscopy, as well as transmission electron microscopy.

The authors emphasized the role of activated macrophages containing micron and submicron polyethylene particles in the bone resorption evident in the areas of osteolysis.  They speculated that the polyethylene-laden joint fluid migrated and penetrated far from the bearing surface to the points of least resistance.  Thus, the concept of an effective joint space (i.e., all periprosthetic regions that are accessible to joint fluid and its particulate debris by the pumping action of the joint) was introduced into the orthopaedic lexicon.

Although the findings identified in this study were not necessarily new, the insights proffered by the authors radically altered our thoughts about osteolysis.  Using this concept of effective joint space, subsequent investigators and innovators identified methods and designs of hip replacements to retard osteolysis by limiting the generation and spread of particulate debris.

Thus, the 1990s were marked by the development of solid acetabular cups, nonmodular monoblock components, improved liner locking mechanisms to avoid backside wear, circumferentially coated femoral stems, highly crossed-linked polyethylene to lessen abrasive wear, and metal and ceramic bearing surfaces.  As appreciated by most orthopaedic residents, the article also led to a generation of questions on the Orthopaedics In-Training Exam (OITE) about the importance of macrophages in the pathogenesis of osteolysis.

Recently, some investigators speculate on a more significant mechanical effect of metal-on-metal joint fluid in causing the pseudotumors and muscle damage/necrosis that is frequently evident.  Regardless of whether the primary effect of small particle-laden joint fluid is biologic or mechanical, I believe that the theory of effective joint space remains a valid anatomic concept for all arthroplasty surgeons.

Robert Bucholz, MD

JBJS Deputy Editor for Adult Reconstruction and Trauma

Does “Prehab” Lower Episode-of-Care Costs in TJA?

Many orthopaedic surgeons still believe that physical therapy (PT) services simply add to the total cost of care without improving patient outcomes. During my orthopaedic education, several knowledgeable attending surgeons said patients can be shown exercises in the orthopaedic clinic and do them on their own to avoid the increased expense of PT services. This belief extended to preoperative PT (“prehab”) to prepare patients for joint-replacement procedures. Until now, the impact of prehab on the total cost of care had not been rigorously evaluated.

In a well-designed study in the October 1, 2014 edition of The Journal, Snow et al. investigated whether preoperative PT affected total episode-of-care cost for hip- and knee-replacement procedures. They used CMS (Centers for Medicare & Medicaid Services) data from 169 urban and rural hospitals in Ohio and gleaned 4733 complete records to answer the question. The outcome measures of interest were utilization of post-acute care in the first 90 days after the procedure and total episode-of-care costs. The study defined post-acute care as admission to a skilled nursing facility, use of inpatient rehabilitation services, or use of home health services.

Nearly 80% of patients who did not receive preoperative PT services utilized post-acute care services, compared with 54% of patients who did receive prehab services. This resulted in a mean cost reduction of $871 per episode (after adjusting for age and comorbidities), with much of the savings accruing from decreased use of skilled nursing facilities. In their discussion, the authors note that prehab in this study generally consisted of only one or two sessions, and they therefore suggest that “the value of preoperative physical therapy was primarily due to patient training on postoperative assistive walking devices, planning for recovery, and managing patient expectations, and not from multiple, intensive training sessions to develop strength and range of motion.”

So it seems that prehab can reduce the overall cost of care in the setting of joint replacement.  Further investigations using commercial insurance datasets to supplement this CMS data will be useful in developing treatment protocols and policies in this age of global payments for episodes of care.

Marc Swiontkowski. MD, Editor-in-Chief, JBJS

FDA OKs RF Pain-Management System for Use in People with Metal Implants

The FDA removed the metal-implant contraindication for the Provant Therapy System, making Provant available for use in patients with metallic joint-replacement components and internal-fixation devices. Provant  uses pulsed radio-frequency (RF) waves to treat postoperative pain and edema in superficial soft tissue. The prescription device, which is used by patients at home, includes an RF generator that induces the production of endogenous opioids in keratocytes. Scott Brooks, CEO of Provant’s manufacturer, Regenesis Biomedical, said the company is now reaching out to orthopaedic and rehabilitation clinicians to educate them on the benefits of the therapy.

Q & A with Dr. Ran Schwarzkopf and His Experience Using Google Glass

After reading our item about Google Glass in the January OrthoBuzz, Dr. Ran Schwarzkopf, assistant clinical professor of orthopaedics at the University of California, Irvine (UCI), wrote us to explain briefly how teams of surgeons, nurses, and anesthesiologists use the technology at UCI. Dr. Schwarzkopf kindly responded to our follow-up questions in the following interview.

JBJS: Thank you, Dr. Schwarzkopf, for sharing your experiences with OrthoBuzz.  First, can you tell us a bit about yourself?

Dr. Ran Schwarzkopf: I am an assistant professor in the Department of Orthopaedic Surgery at UCI, where I head the Adult Reconstruction Joint Replacement Service. I trained at NYU Hospital for Joint Diseases and completed a fellowship in adult reconstruction at Brigham and Women’s Hospital in Boston. I am part of the UCI Joint Replacement Surgical Home, which is a perioperative clinical care model jointly run by orthopaedics and anesthesiology.

JBJS: We understand that you’ve been using Google Glass in some interesting ways.  How did the program get started?

Dr. Schwarzkopf: UCI has always been a pioneer in incorporating new technology into medical care. We have a long tradition of innovation and entrepreneurship. Due to the orthopaedic department’s close relationship with our anesthesia department and our successful Joint Replacement Surgical Home, we were approached by Pristine, a company that develops platforms for integrated medical systems. Together we decided to explore the use of different interactive glasses for operative applications. We started working with Google Glass as our first glass prototype, but we have also examined similar products from other companies. Together with the developers at Pristine, we designed different clinical pathways for optimizing the use of the Glass to enhance our clinical work from both the orthopaedic and anesthesiology perspectives.

JBJS: Was there a particular challenge you hoped Google Glass would help you address?

Dr. Schwarzkopf: In today’s orthopaedic operative environment, efficiency, cost reduction, and successful outcomes need to go hand in hand. We were looking to increase team interactivity and real-time communication while decreasing waste and unnecessary traffic in the operating room. We also wanted  to enhance our resident learning options. Our anesthesia colleagues were looking to improve communication between their team members with real-time visuals.

JBJS: Please describe some of the things you and your colleagues have done using Google Glass?

Dr. Schwarzkopf:  The orthopaedic team was able to broadcast surgery live to team members who were not inside the operating room, giving residents and visitors the ability to observe the procedure from the “surgeon’s point of view” without increasing traffic in the operating room. The surgeon was also able to view both check-lists and images on his glass view screen during the procedure. The nursing team inside the OR was able to communicate with our nurse manager without needing to exit the room or use the phone through a tablet screen outside the OR. Our anesthesia team includes an attending anesthesiologist and two residents or nurse anesthetists in two separate rooms. The anesthesiologist can observe both rooms from his tablet and can communicate with the physician/nurse inside. He can see both the monitors and the patient and help with decision making and problem solving without the need for constant paging and phone calls.

JBJS: What is the greatest benefit from this technology?

Dr. Schwarzkopf:  I think the greatest benefit is the increased integration of the operating team and the streamlined processes that the technology affords us. We are able to communicate and provide oversight in a whole new way. It decreases traffic in the operating room and increases the speed of communication and care given to the patient.

JBJS: What surprised you the most about your experience with Google Glass?

Dr. Schwarzkopf:  The ability to build a complex control tree, which enables one supervising physician to oversee others in a completely new way. We can now see through other peoples’ eyes and we can help and communicate in real time, without old-fashioned back-and-forth information transfer.

JBJS: By using several pairs of Google Glass simultaneously, you have been able to link surgeons, nurses, and anesthesiologists. What are the most important benefits of that type of teamwork?  What barriers remain to greater collaboration?

Dr. Schwarzkopf:  The ability to pair several glasses together is one of the main advantages of this new technology. We observed greater and more efficient teamwork on all sides—surgical, nursing, and anesthesia. The benefits include decreased OR traffic and cost reduction through reduced procedure times. The ability of a supervisor to see through his trainees’ eyes is priceless. We can now directly control actions beyond our immediate line of sight and we can do it without time-consuming back-and-forth communications. When you can see what your resident sees, the phrase “lost in translation” will no longer be relevant. The main barriers that remain are mostly technical, such as the hands-free or voice-activated ability to control the camera angle and “wink” control of the Glass activity. That’s being worked on as we speak.

JBJS: In honor of the 125th anniversary of JBJS this year, we are interested in what orthopaedists think might be important trends in the future. Looking ahead to the next 20 years or so, what do you think might be three significant advances or changes in orthopaedics?

Dr. Schwarzkopf:  We will see significant changes in the way health care is managed and provided, mostly due to changes in regulation and federal guidelines. Resident education will incorporate more advanced methods to allow residents to improve their proficiency while still abiding by increasingly restrictive work-hour regulations. On the technological side I think we will see much more influence from the “gaming” world, like enhanced/augmented reality technology.

JBJS: Thank you very much, Dr. Schwarzkopf. We wish you continued success with all the innovations taking place at UCI.