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

JBJS Reviews Editor’s Choice–Failed Total Knee Arthroplasty

Perhaps more than any other advance in orthopaedic surgery, total joint arthroplasty has improved the lives of millions of patients. Originally introduced in the form of hip replacement, nearly all of the major joints of the musculoskeletal system can now undergo arthroplasty, and total knee arthroplasty has established itself as one of the most successful interventions for reducing pain and improving function and quality of life. All total joint arthroplasties are associated with a risk of failure, and it is believed that, with the exception of the oldest patients, most individuals who undergo an arthroplasty will require a revision at some point during their lifetime. With total knee arthroplasty, advances in implant materials and design as well as operative technique have increased implant longevity and decreased the rate of revision to <5% within ten years.

As is typical of a successful intervention, surgeons who perform total knee arthroplasty recognize the need or opportunity to “push the envelope.” There is great demand for offering knee arthroplasty to younger, more active patients, and, in doing so, it is projected that the number of revision procedures will grow from the current annual incidence of 38,000 up to 270,000 by the year 2030. Thus, understanding the causes of failure will be essential for guiding future strategies.

In this month’s article by Bou Monsef et al., a systematic approach to identifying mechanisms of failure and appropriate treatment protocols for failed total knee arthroplasty are introduced. The authors make the important point that avoiding operative intervention before a diagnosis is made, even in cases of pain with no clear etiology, is essential. Individual discussions on the roles of infection, loosening and component failure, instability, stiffness, patellofemoral complications, and even neuromas are presented and placed in their proper perspective.

Indeed, one of the greatest frustrations in orthopaedic practice is the inability to identify the causative factors for a condition. The failure of a total knee arthroplasty may be associated with one or more contributing factors, including rare and unusual conditions such as the formation of heterotopic bone, the development of complex regional pain syndrome, the occurrence of hemarthrosis, and even hypersensitivity to certain metals. Interestingly, up to 17% of the general population expresses some sensitivity to the metals used in total knee implants such as nickel, chromium, and cobalt.

Failure of total knee arthroplasty can be devastating to the patient, but early diagnosis and careful systematic analysis of the potential etiologies can lead to a favorable outcome. This article provides a clear and concise approach to this problem and is a “must read” for surgeons who perform this operation now and the residents and fellows who will be caring for these patients in the decades to come.

Thomas A. Einhorn, MD, Editor

EHR is Top-of-Mind Tech for Orthopaedic Practice Management

In a recent survey by MedData Group, 65% of 254 physicians spanning all subspecialties and practice sizes said they expect electronic health records (EHRs) to have the greatest practice impact among all medical technologies in 2015. Among orthopaedists, 78% ranked EHRs as being the most influential practice technology. Diagnostic technologies ranked a distant second among physicians, but twice as many as last year considered this area of technology to be significant. The survey found that overall practice-management priorities in 2015 will focus on two areas: successful implementation of ICD-10 and better quality care for patients.

EHR chart

Income-Affecting Changes Coming in 2015 for Physicians

According to Medscape (login required), a dozen changes coming in 2015 could affect physician income and practice workflows. Here’s the list:

  1. Rise of High-Deductible Health Plans – According to the Kaiser Family Foundation, 18% of insured patients have at least a $2,000 deductible.   Higher deductibles often mean more paperwork for practices, the need to provide cost estimates in advance, and increasing involvement with collection agencies.
  2. Declining Malpractice Premiums– For three benchmark specialties, ob/gyns, internists, and general surgeons, malpractice insurance premiums decreased by 13% since 2008. Some experts attribute the declines to tort reforms that were enacted many years ago, but most expect that premiums, which have proven to be cyclical, will start rising again.
  3. ICD-10 Really Coming– Many experts are saying the Oct. 1, 2015 deadline for the new ICD-10 coding system is for real this time, after repeated implementation delays. Although ICD-10 is supposed to cut down on errors and speed reimbursement, many physicians are skeptical that the technology will work.
  4. ACOs Enter a Crucial Year – 2015 marks the end of the 3- year shared-savings Medicare ACO contract, which shielded ACOs from losing money. Those that stay in the program will face financial penalties if they don’t hit certain targets. The Centers for Medicare & Medicaid Services (CMS) said that only one quarter existing Medicare ACOs received a shared-savings bonus.
  5. Concerns about Telemedicine– More patients may start using web- and phone-based physician services in 2015. The three largest telemedicine companies more than doubled their volume from 2011 to 2013 and continue to grow. Telemedicine does seem to be siphoning some patients from traditional practices, but the main concern is the quality of telemedicine-based diagnoses and treatments.
  6. Competition from Retail Clinics– Visits to walk-in, retail clinics skyrocketed by 400% from 2007 to 2009. Consultant Thomas Charland advises doctors to forge reciprocal referral relationships with retail clinics, rather than fighting them.
  7. PCPs to Lose Enhanced Medicaid Payments – At the beginning of 2015, Medicaid reimbursements for PCPs will fall back to their pre-“enhanced” levels, which average 40% below Medicare. Unless Congress extends the funding, some PCPs may be forced to reconsider how many Medicaid patients their practices can afford to take.
  8. Meaningful Use: Carrot Becomes Stick – In 2015, penalties for not entering the Medicare Meaningful Use program begin, starting at 1% of Medicare payments and moving to 3% in 2017. A survey by Medscape shows that 3 out of 4 doctors who have an EHR are attesting to Meaningful Use.
  9. Penalties Start under PQRS– In 2015. The Physician Quality Reporting System turns from voluntary to penalty-eligible. The penalty for not reporting quality data is 1.5% in 2015 and rises to 2% in 2016.
  10. New Physician-Payment Websites– Open Payment and Medicare payment websites report payments made to doctors either from Medicare or from drug and device manufacturers. Both websites have had technical glitches and have posted inaccurate information.
  11. Medicare Will Pay for Chronic Care Outreach –Medicare will pay physicians in 2015 for managing patients with two or more chronic conditions by phone or email. Doctors will receive $40.39 per patient per month for providing a minimum of 20 minutes of care. To qualify, doctors need to have an EHR system and be able to exchange patient information with other caregivers.
  12. New CPT Modifiers for Greater Specificity – Starting in January, instead of the catch-all, amorphous modifier 59, CMS will implement four new subset modifiers – XE, XS, XP and XU. The intention is to increase efficiency of payments to doctors.

Healthcare Spending Growth Hits 50-Year Low

Healthcare spending in 2013 grew at the slowest rate since 1960, according to a recent article in Modern Healthcare. According to federal data, the nation spent $2.9 trillion on healthcare last year, which was an increase of 3.6% from the prior year—and the weakest spending growth since 1960. Reasons cited for the slowdown include aftermath from the Great Recession, changes in health benefits, and federal healthcare spending rollbacks triggered by the Affordable Care Act. For example, Medicare spending increased in 2013 by 3.4%, down from 4% growth in 2012. Spending on technology and construction to upgrade or expand healthcare services dropped during the recession and still has not rebounded. Most analysts don’t expect this growth slowdown to carry into 2014, although quarterly national estimates for 2014 suggest spending growth below 4%. While some of the slowdown in healthcare spending growth may be attributed to doctors and other healthcare professionals running more efficient practices, health spending in 2013 still consumed 17.4% of the US gross domestic product.

Meniscal Surgery Linked to Increased Risk of “Radiographic” Osteoarthritis

Researchers at the recent annual meeting of the Radiological Society of North America presented data showing that knees undergoing surgery for meniscal tears are at higher risk of developing radiographically evident osteoarthritis one year postsurgery than knees with meniscal damage that do not undergo surgery. Presenter Frank Roemer, MD said the retrospective study found that, relative to non-arthritic knees, the risk of cartilage loss was significantly increased for knees exhibiting any prevalent meniscal damage without surgery (odds ratio = 1.5), and markedly further increased for meniscally damaged knees that had surgery (odds ratio = 13.1).

Nevertheless, many people undergoing meniscal surgery benefit clinically, especially if they experienced locking of the knee before surgery. Also, people found to have “radiographic” osteoarthritis may not experience the pain or mobility limitations seen with clinically evident arthritis. Still, Roemer concluded that patients and their doctors should include the possibility of accelerated onset of arthritis when discussing the pros and cons of meniscal surgery.

“Perioperative Surgical Home” Teams Improve Outcomes for TKA Patients

A team-based Perioperative Surgical Home (PSH) model helped reduce length of hospital stay and increase the chances of home rather than nursing-facility discharge for 405 total knee arthroplasty (TKA) patients, relative to 546 TKA patients who received usual care.

Although there were no significant differences in 30-day readmission rates between the two groups, average length of hospital stay for the PSH group was 1.9 days versus 3.2 days for the usual-care group. Only 6% of PSH patients went to a skilled nursing facility after hospital discharge, compared with 20% in the usual-care group. Using current cost structures, the Kaiser Permanente researchers estimated a total savings of $942,000, two-thirds from shorter hospital stays and a third from bypassing skilled nursing facilities.

The PSH teams were led by anesthesiologists, and the results were reported at the 2014 annual meeting of the American Society of Anesthesiologists. Preoperative medical optimization, an important aspect of this care model, began with appointments with anesthesiologists 3 to 14 days prior to scheduled surgery. The authors do not specifically cite orthopaedic surgeon involvement on these teams, but there’s every reason to believe surgeons did participate—and that surgeons could lead such teams.

Another Nail in the Glucosamine/Chondroitin Coffin

Add findings from a recent study in Arthritis & Rheumatology to the growing body of evidence indicating that glucosamine and chondroitin supplements have no measurable impact on relieving knee osteoarthritis (OA). These findings add support to existing guidelines that recommend against the use of these supplements for OA treatment (see related OrthoBuzz article).

Utilizing a so-called “new user” design, researchers analyzed four-year follow-up data on more than 1,600 people who were not using glucosamine/chondroitin at baseline. In addition to measuring joint space width, researchers captured knee symptoms with WOMAC pain, stiffness, and function scales. They also employed marginal structural models to control for time-varying confounders. In the end, there were “no clinically significant differences” between supplement users and non-users, and the study authors claimed that, in addition to being consistent with meta-analyses of glucosamine/chondroitin, these findings extend the data set to include “a more general population with knee OA.

Operation Walk Gives People in Need Free Hip and Knee Replacements

This week (December 1-6, 2014), 120 people in 23 states are scheduled to receive a hip or knee replacement free of charge.  These gifts of pain-free mobility come from Operation Walk USA, a coalition of 85 orthopaedic surgeons that has provided more than $13 million in services to nearly 500 patients since 2010. Patients eligible for Operation Walk USA services are US citizens and permanent residents who do not qualify for government assistance programs but cannot afford the surgery on their own.

Case in point is 50-year-old Army veteran David Chalker, who is scheduled for a bilateral hip replacement this week. Unrelenting and severe hip pain forced Chalker to leave his machinist job, which in turn led to mounting debt and an inability to afford health insurance.

New Albany, Ohio orthopaedist Dr. Adolph Lombardi, Operation Walk USA’s founder, told Reuters that finding hospitals willing to donate space is the biggest barrier to the program’s growth. But thanks to additional non-physician volunteers such as nurses, technicians, and physical therapists, pre- and post-operation services are also free for patients. And device manufacturers donate the implants.

JBJS Webinar Now On-Demand – Return to Sports after ACL Reconstruction

“When will I be able to play again?” Following ACL reconstruction surgery, that’s a question physical therapists and orthopaedic surgeons invariably hear—often repeatedly—from their athletically inclined patients.

The multiple factors that go into answering this difficult question are the subject of this complimentary webinar.

Current evidence suggests that approximately 50 to 60 percent of patients post ACL-reconstruction eventually return to sports at preinjury levels. But the timing of that return—and the many variables leading to it—create a series of challenging clinical decision points. This webinars explores the most relevant surgical, rehabilitative, and patient-centered factors that contribute to sound decisions in which surgeons, physical therapists, and patients participate fully.

Moderated by Robert Marx, MD, JBJS Associate Editor for Evidence-based Orthopaedics, this webinar focuses on two articles, one from each journal.

After the articles’ primary authors present their data, two additional return-to-sports experts add their perspectives to this body of research.

Moderator:

Robert Marx, MD

Presenting authors:

Freddie Fu, MD and Terese Chmielewski, PT, PhD, SCS

Commentators:

Kevin Wilk, PT, DPT, FAPTA and Kurt Spindler, MD

Register now!

This webinar is brought to you by the Journal of Orthopaedic & Sports Physical Therapy and The Journal of Bone and Joint Surgery

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