This post comes from Fred Nelson, MD, an orthopaedic surgeon in the Department of Orthopedics at Henry Ford Hospital and a clinical associate professor at Wayne State Medical School. Some of Dr. Nelson’s tips go out weekly to more than 3,000 members of the Orthopaedic Research Society (ORS), and all are distributed to more than 30 orthopaedic residency programs. Those not sent to the ORS are periodically reposted in OrthoBuzz with the permission of Dr. Nelson.
In the absence of infection and aseptic loosening, significant postoperative pain persists in up to 20% of joint-replacement patients. In one study related to this predicament, investigators studied 3 groups of individuals: 1) those without a total joint replacement (TJR) and no self-reported pain, 2) patients with a well-functioning TJR and no self-reported pain (mean implant time of 1.5 years), and 3) patients with a painful TJR (self-reported pain of >8 on a 0 to10 VAS scale; mean implant time of 1.76 years)1.
Peripheral blood mononuclear cells were collected for use in a lymphocyte reactivity assay to detect anti-inflammatory (IL-1ra, IL-10, IL-13 and IL-11) and inflammatory cytokines or receptors (IL-1rII and TNFR1). In general, anti-inflammatory cytokine markers in patients with post-TJR pain were decreased compared to controls and to individuals with no pain following TJR, with IL-10 and IL-13 significantly decreased among painful TJR patients. TNFR1 was significantly elevated in those with painful TJRs, and IL-1rII was modestly elevated. The authors note that treating this “1-2 punch” of elevated proinflammatory cytokines and decreased anti-inflammatory cytokines may require “a complex pattern” of both inhibition of proinflammatory mechanisms as well as anti-inflammatory medications.
In a separate study, investigators used scanning electron microscopy (SEM) to try to determine whether implant corrosion was secondary to inflammatory cellular reactions or to the effects of electrocautery used in near proximity to metallic surfaces2. Twelve knee prostheses taken at necropsy were compared to an off-the-shelf cobalt-chromium knee implant intentionally exposed to Bovie and Aquamantys electrocautery sources. SEM data was collected using an identical method to that of the retrieved implants. Five of the 12 necropsy retrievals showed signs of inflammatory cell-induced corrosion. Compared to the necropsy-retrieved implants, the iron/carbon ratio of the Bovie electrocautery-damaged implant was significantly higher, suggesting that the mechanism by which immune cells corrode implants is different than the mechanism of electrocautery damage.
In a third study, which compared results of lymphocyte transformation testing (LTT) for metal sensitivity with histological and clinical findings in 27 cases of primary total knee arthroplasty (TKA), researchers found that LTT results alone were insufﬁcient for the diagnosis of TKA pain-relief failure due to an immune reaction3. A positive LTT might not indicate that an immune reaction is the cause of pain and stiffness post-TKA.
It will take more research to determine whether there is a connection between surface pitting and chronic knee pain in metal-sensitive persons, whether the elevated macrophage response is an associated risk factor, and whether that is associated with metallic material response.
- Lauryn S, Caicedo M, Jacobs J, Hallab NJ. Do TJR Patients with High Self-Reported Pain Levels Exhibit Decreased Serum Anti-inflammatory Cytokine Markers? Abstract 0135 Orthopaedic Research Society 2019
- Sorrels JA, Heise G, Morrow B, Arnholt C, Kurtz S, Mihalko WM. Inflammatory Cell- Induced Corrosion and Electrocautery Damaged TKA Implants. Abstract 0131 Orthopaedic Research Society 2019
- Yang S, Dipane M, Lu CH, Schmalzried TP, McPherson EJ. Lymphocyte Transformation Testing (LTT) in Cases of Pain Following Total Knee Arthroplasty: Little Relationship to Histopathologic Findings and Revision Outcomes. J Bone Joint Surg Am. 2019 Feb 6;101(3):257-264. doi: 10.2106/JBJS.18.00134. PMID: 30730485
Over the last 2 decades, research into how various “preexisting conditions” affect the outcomes of orthopaedic interventions has increasingly focused on the impact of mental health (a patient’s “state of mind” and coping abilities) and psychological diagnoses such as depression. The impact of mental health, depression, and personality characteristics on patient-reported outcomes following significant skeletal trauma has been well documented in the trauma literature. In addition, previous studies in knee arthroplasty have identified depression as a major factor in suboptimal patient outcomes.
In the October 17, 2018 issue of The Journal, Halawi et al. teased out the impact of depression and mental health—independently and in combination—on patient-reported outcomes following primary total joint arthroplasty (TJA) in 469 patients at a minimum follow-up of one year.
The authors used the validated SF-12 MCS instrument to assess patient baseline mental health at the time of surgery. They also used the widely accepted WOMAC score to assess joint-specific pain, stiffness, and physical function before and after surgery. Using these tools, the authors showed that, while depression alone may diminish some patient-reported gains obtained from arthroplasty, it does not seem to affect a patient’s overall outcome as much as poor mental health prior to surgery. In this study, patients with depression but good mental health achieved patient-reported outcomes comparable to those among normal controls. Still, patients without depression and in good mental health were found to have the most robust improvements after undergoing TJA.
Orthopaedic surgeons need to better understand the interplay between these complex psychological states and patient outcomes. These authors conclude that the effect of depression on patient-reported outcomes is “less pessimistic than previously thought,” but we welcome further studies examining the link between “the mind” and orthopaedic outcomes. Finally, we should be ready to refer patients to our mental health colleagues when we detect a potential underlying nonphysical condition that might adversely affect the magnitude of benefit from the treatments we offer.
Marc Swiontkowski, MD
Patients with diabetes have an increased risk of postoperative complications following total joint arthroplasty (TJA). Additionally, perioperative hyperglycemia has been identified as a common and independent risk factor for periprosthetic joint infection, even among patients without diabetes. Therefore, knowing a patient’s glycemic status prior to surgery is very helpful.
In the November 15, 2017 edition of The Journal of Bone & Joint Surgery, Shohat et al. demonstrate that serum fructosamine, a measure of glycemic control obtainable via a simple and inexpensive blood test, is a good predictor of adverse outcomes among TJA patients—whether or not they have diabetes.
Researchers screened 829 patients undergoing TJA for serum fructosamine and HbA1c—a common measure, levels of which <7% are typically considered good glycemic control. Patients with fructosamine levels ≥292 µmol/L had a significantly higher risk of postoperative deep infection, readmission, and reoperation, while HbA1c levels ≥7% showed no significant correlations with any of those three adverse outcomes. Among the 51 patients who had fructosamine levels ≥292 µmol/L, 39% did not have HbA1c levels ≥7%, and 35% did not have diabetes.
In addition to being more predictive of postsurgical complications than HbA1c, fructosamine is also a more practical measurement. A high HbA1c level during preop screening could mean postponing surgery for 2 to 3 months, while the patient waits to see whether HbA1c levels come down. Fructosamine levels, on the other hand, change within 14 to 21 days, so patients could be reassessed for glycemic control after only 2 or 3 weeks.
While conceding that the ≥292 µmol/L threshold for fructosamine suggested in this study should not be etched in stone, the authors conclude that “fructosamine could serve as the screening marker of choice” for presurgical glycemic assessment. However, because the study did not examine whether correcting fructosamine levels leads to reduced postoperative complications, a prospective clinical trial to answer that question is needed.
Are you confused and frustrated by Medicare’s Quality-Incentive Programs, such as the Merit Based Incentive Payment System (MIPS), Comprehensive Care for Joint Replacement (CJR) program, and the Surgical Hip and Femur Fracture Treatment (SHFFT) model? If so, this webinar is for you.
On Tuesday, August 15, 2017 at 8:00 PM EDT, The Journal of Bone & Joint Surgery (JBJS) and the American Orthopaedic Association (AOA) will host a complimentary LIVE webinar featuring the following speakers and topics:
- Brian McCardel, MD will discuss choosing MIPS-related quality measures, improving performance on those measures, and qualifying for bonuses.
- Thomas Barber, MD, FAOA will focus on managing clinical care including how to deliver low-cost high-quality care for high-risk orthopaedic patients.
- Alexandra Page, MD will discuss partnering with hospitals and post-acute organizations to improve patient care and reap financial rewards.
Moderated by Douglas Lundy, MD, FAOA, the webinar will include a live Q&A session between the audience and panelists.
An estimated 7 million people living in the US have undergone a total joint arthroplasty (TJA), and the demand for total hip arthroplasty (THA) and total knee arthroplasty (TKA) will almost certainly increase during the next 15 years. But how many people can expect to have an additional TJA after having a first one?
That’s the question Sanders et al. address in their historical cohort study, published in the March 1, 2017 edition of The Journal of Bone & Joint Surgery. They followed more than 4,000 patients who underwent either THA or TKA between 1969 and 2008 to assess the likelihood of those patients undergoing a subsequent, non-revision TJA.
Here’s what they found:
- Twenty years after an initial THA, the likelihood of a contralateral hip replacement was 29%.
- Ten years after an initial THA, the likelihood of a contralateral knee replacement was 6%, and the likelihood of an ipsilateral knee replacement was 2% at 20 years.
- Twenty years after an initial TKA, the likelihood of a contralateral knee replacement was 45%.
- After an initial TKA, the likelihood of a contralateral hip replacement was 3% at 20 years, and the likelihood of an ipsilateral hip replacement was 2% at 20 years.
In those undergoing an initial THA, younger age was a significant predictor of contralateral hip replacement, and in those undergoing an initial TKA, older age was a predictor of ipsilateral or contralateral hip replacement.
The authors conclude that “patients undergoing [THA] or [TKA] can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure in noncognate joints within 20 years of initial arthroplasty.” They caution, however, that these findings may not be generalizable to populations with more racial or socioeconomic diversity than the predominantly Caucasian population they studied.
In the September 7, 2016 issue of The Journal, Sutton III et al. report results from a sophisticated analysis of the National Surgical Quality Improvement Program (NSQIP) database confirming that hospital discharge 0 to 2 days after total joint arthroplasty (TJA) is safe in select patients in terms of 30-day major-complication and readmission rates. Large dataset analyses like this represent the next step in confirming what has been going on at the grass-roots level across the world—a movement toward outpatient TJAs and/or very early discharges following those procedures. (See related “Global Forum” article in the July 6, 2016 JBJS.)
This trend has been associated with very high patient satisfaction and low morbidity. The movement away from multiple-day hospital admission and toward rapid discharge to home or alternative postoperative care environments such as hotels or rehabilitation centers has far surpassed the novelty stage and is under way in every major metropolitan area around the world. The trend is a welcome motivation for us to address patient expectations for the postoperative period, which are specifically linked to more judicious use of narcotic medication accompanied by regional and local anesthetic efforts and liberal use of nonsteroidal anti-inflammatory medication. Total joint replacement is the ideal surgical intervention to lead this no- or short-hospitalization movement because of the standardized surgical approaches and requirements for implants, blood-loss management, and thromboprophylaxis.
I envision a time in the not-too-distant future where 80% to 90% of musculoskeletal post-intervention care takes place outside of the hospital environment, a shift that will require efficient use of remote-monitoring technology and continued improvement in post-intervention pain management. Hospitals will then become the setting for very complex events like organ transplantation, appropriate intensive care, and high-level trauma care. This will result in lowering the overall cost of care, improving patient satisfaction (who among us would not rather sleep in our own bed?), and minimizing nosocomial complications.
Marc Swiontkowski, MD
Despite advances in sterile techniques and evidence-based use of perioperative antibiotics, periprosthetic joint infections still occur in 1% of primary and 3% to 7% of revision total joint arthroplasties. But a “smart” antimicrobial polymer coating, described in the July 20, 2016 Journal of Bone & Joint Surgery, has great potential to cut those percentages.
Stavrakis et al. devised a nontoxic, biodegradable polymer coating (called PEG-PPS for short) that locally delivers antibiotics (vancomycin and tigecycline in this study) both passively and actively, with the active release initiated by the presence of bacteria.
The authors tested the efficacy of the coating both in vitro and in vivo. In vitro, the release of antibiotics from the coating was enhanced in the presence of an oxidative environment, as would occur during a periprosthetic joint infection, demonstrating the coating’s “smartness.”
In vivo, using a mouse model of post-arthroplasty infection caused by Staphylococcus aureus, the authors showed radiographically that implants coated with PEG-PPS alone had a dramatic degree of periprosthetic osteolysis by postoperative day 7, compared with antibiotic-encapsulated PEG-PPS implants, which showed no detectable osteolysis. Similarly, the number of colony forming units of S. aureus cultured from implants on postoperative day 21 was significantly lower in the antibiotic-encapsulated implants than in the PEG-PPS-alone implants. (Interestingly, the tigecycline coating was more effective than the vancomycin coating in preventing bacterial colonization.)
While acknowledging that this proof-of-concept study needs to be replicated with other infectious organisms and in larger animals and humans, the authors conclude that PEG-PPS delivery of antibiotics has “great potential to minimize the incidence of postoperative infection following arthroplasty.”
OrthoBuzz occasionally receives posts from guest bloggers. This “guest post” comes from Richard S. Yoon, MD and Alexander McLawhorn, MD, MBA.
Starting on April 1, 2016, Medicare will implement its Comprehensive Care for Joint Replacement (CJR) model in about 800 hospitals in 67 metropolitan areas around the United States. Finalized in November 2015, the CJR initiative is intended to enhance value for patients undergoing lower extremity joint replacement (LEJR) by motivating institutions to achieve quality improvement via cost control. (For a complete discussion of “value” in orthopaedics, see “Measuring Value in Orthopaedic Surgery” in JBJS Reviews.)
Medicare hopes CJR will promote standardized, coordinated care that takes each LEJR patient seamlessly through an “episode of care” that maximizes outcomes at a reduced cost. Episodes are triggered by hospital admission and are limited to admissions resulting in a discharge paid under MS-DRG 469 or 470. For CJR purposes, episodes last for 90 days following discharge.
Initially, episode target prices will be based on historical hospital-specific reimbursements, but over time, the target prices will increasingly reflect regional averages. If a hospital’s average LEJR episode cost is below the target price, it can receive a “bonus” from CMS. If its average cost is above the target price, it will owe CMS the difference. CMS has designed a gradual rollout plan to mitigate downside risk in the first year and provide current and future participants adequate time to implement evidence-based, cost-effective care and other quality programs in their institutions.
Richard Iorio, MD, chief of adult reconstruction at NYU-Langone Medical Center’s Department of Orthopaedic Surgery, says, “There will be definite winners and losers in CJR. Once geographic pricing becomes the dominant metric for target prices, there will be intense price competition in geographic areas and potential access problems for high risk patients.” At the moment, CJR stratifies risk based only on MS-DRG code and whether a patient has a hip fracture. Unless a more robust risk stratification method is implemented, “cherry-picking” patients may become a significant issue. (See related OrthoBuzz post “Tool for Pre-TJA Risk Stratification.”)
If you are an orthopaedic surgeon who performs LEJR, ask your department head or health system about CJR, because strategies that minimize cost and maximize quality may vary from hospital to hospital. Alignment of hospitals and surgeons is probably the most critical success factor with CJR. To that end, gainsharing— a key component of well-functioning hospital-surgeon partnerships within any bundled-payment environment —for individual orthopaedic surgeons is specifically allowed within the CJR final rule.
Click here for more information, including FAQs and a list of participating areas.
Richard S Yoon, MD is executive chief resident at the NYU Hospital for Joint Diseases.
Alexander McLawhorn, MD, MBA is an arthroplasty fellow at the Hospital for Special Surgery.
A case-control study by Boraiah et al. in the December 2, 2015 JBJS describes a risk-stratification tool that helps predict which patients undergoing total joint arthroplasty (TJA) are likely to be readmitted to the hospital after discharge. The authors used the tool—dubbed the Readmission Risk Assessment Tool, or RRAT—preoperatively among 207 patients who were subsequently readmitted after primary TJA and two cohorts of 234 patients each (one random and one age-matched) who were not.
The total RRAT score for each individual is the cumulative sum of all scores for modifiable risk factors such as infection, smoking, obesity, diabetes, and VTE. Non-modifiable risk factors such as age, sex, race, and socioeconomic status are not included in the scoring system.
The median RRAT score for those readmitted was 3; the median RRAT score for those not readmitted was 1. An RRAT score of ≥3 was significantly associated with higher odds of readmission. Surgical site infection was the most common cause of readmission (found in 45% of the 207 readmitted patients).
The authors note that in the current and future climate of value-based health care, “any unplanned readmission will have financial consequences on the provider and health-care institution”—not to mention the burden readmissions place on patients. While admitting that the RRAT needs to be further evaluated and validated in larger cohorts and that it may not be possible to modify individual risk factors into “an acceptable range” prior to TJA, the authors suggest that risk stratification with the RRAT “can present a ‘teachable moment’ and an opportunity for shared decision-making discussions.”
Forced air warming devices are in widespread use in our orthopaedic surgical suites—and for good reason: Hypothermia can be a major factor in poor patient outcomes due to its negative impact on myocardial function, pharmacokinetics, and other aspects of patient physiology. While maintaining normothermia in surgical patients lowers the risk of postoperative surgical site infections, recent literature has raised concerns about an increased risk of infection in arthroplasty cases in which forced air warming was used.
The December 17, 2014 JBJS literature review by Sikka et al. focuses on this conundrum. It is a well-written summary of current knowledge that clearly outlines the deficiencies in the available data. The authors emphasize that the studies yielding both positive and negative findings are in most cases tainted with detection and selection bias related to industry-funded research designs. This is an area that is begging for a large randomized controlled trial.
However, because of the <1% overall incidence of infection following lower-limb arthroplasty, such a trial will require large numbers of patients. Also essential for such an investigation will be an experienced clinical trialist, meticulous methods, and an apriori definition of “infection.” It is doubtful that registry data analysis can adequately determine the efficacy of forced air warming in preventing major intraoperative adverse events or its impact on postoperative infection, but an analysis of all available data would be a good start.
I look forward to future well-designed studies in this area that will further clarify patient benefit as well as risk. In the meantime, Sikka et al. stress the importance of following all manufacturer instructions for use and maintenance of any patient-warming device.
Marc Swiontkowski, MD