Archive | February 2019

Rabbit Study Suggests Antibiotic-Releasing Implant Coating Could Cut Infection Risk

A study by Miller et al. in the February 20, 2019 issue of JBJS provides preclinical proof of concept that antibiotic-loaded coatings on orthopaedic implants could eventually reduce the incidence of implant-associated infection.

The researchers used in vivo bioluminescence imaging (BLI) and ex vivo analysis of colony-forming units (CFUs) to show the efficacy of an implant coating that released linezolid-rifampin over a 7-day period. Through a parapatellar arthrotomy, researchers reamed the femoral canal of 12 rabbits and inoculated the canals with a bioluminescent strain of MRSA. They then inserted a surgical grade titanium peg into each canal. All of the pegs were coated with a nanofiber coating; 6 of the pegs were loaded with the antibiotic coating and 6 were not.

Implants coated without antibiotics were associated with significantly increased in vivo BLI signals and significantly increased knee width, relative to implants with the antibiotic-releasing coatings. The animals were killed on day 7, and ex vivo analysis of CFUs isolated from soft tissue, bone, and implant specimens showed significantly increased CFUs in the specimens without the antibiotic-releasing coating, while CFUs were undetectable in the implants with antibiotics.

This larger-animal model to assess bacterial burden employed a clinically used orthopaedic implant and replicated a medial parapatellar arthrotomy in humans. According to the authors, the coating used is “highly versatile, and the polymers or drug concentrations could be modified for more rapid or longer release.” This rabbit model should be amenable to studying additional antibiotic-releasing strategies for possible translation to clinical research in humans.

Residual Pain after Joint Replacement

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.

References

  1. 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
  2. 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
  3. 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

Empathic Orthopaedists: Worth Waiting For

When I was a waiter during high school and college, I quickly learned the value of connecting with my customers. If I could fulfill whatever role they were looking me to fill (i.e., being fun and interactive, serious, acting invisible, or anything in between), I would usually be rewarded with a sizable tip or a compliment. I realized that I was not there primarily to help customers make food choices, but rather to make each customer feel as though I existed only to care for them. There is a big difference between those two roles, and I found myself thinking about those experiences while reading the article by Kortlever et al. in the February 20, 2019 issue of JBJS.

The authors aimed to determine whether an association existed between a patient’s wait time and the amount of time he or she spent with a surgeon and the patient’s perception of the surgeon’s empathy. Considering the well-established connection between the perceived empathy coming from a physician and patient satisfaction, this is an important question to examine. Interestingly, Kortlever et al. found that neither time-related variable was associated with perceived physician empathy, suggesting that decreasing wait times or spending more time with individual patients may not increase their satisfaction with the visit. However, the authors did find a direct, inverse association between surgeon stress levels and patient-perceived empathy. Specifically, for every 1-point increase in a surgeon’s self-reported stress (as measured with the Perceived Stress Scale short form), there was a 0.87 decrease in perceived empathy (as measured with the Jefferson Scale of Patient’s Perceptions of Physician Empathy).

Like most humans, patients value the quality of an interaction more than its duration. Similarly, patients are more concerned with what happens during their medical appointment than with the wait time that transpires before it. It probably does not take very long for a patient to feel that you are fully engaged with his or her concerns—or not—and increasing the length of a “bad” interaction usually will not increase its quality. Patients may not always know whether your medical advice is on target, but almost all of them can tell how much you care and whether you are “present” during their appointment.

I agree with the authors’ conclusion that the present findings indicate “that the patient-physician relationship is more built on actions and communications than on time spent.” I suspect that future studies will continue to show how powerful the perceptions of caring and empathy are when it comes to patient care.

Chad A. Krueger, MD
JBJS Deputy Editor for Social Media

Editor’s Note: Kortlever et al. cite a 2005 Instructional Course Lecture by Tongue et al. that describes easy-to-learn skills for effective and empathic patient-centered interviews. Click here for full text of that article.

What’s New in Pediatric Orthopaedics 2019

Every month, JBJS publishes a review of the most pertinent and impactful studies published in the orthopaedic literature during the previous year in one of 13 subspecialties. Click here for a collection of all OrthoBuzz subspecialty summaries.

This month, Kelly L. VanderHave, MD, co-author of the February 20, 2019 “What’s New in Pediatric Orthopaedics,” selected the five most compelling findings from among the more than 50 noteworthy studies summarized in the article.

Pediatric Trauma
—A before-and-after comparison found that, after implementation of a dedicated, weekday operating room reserved for pediatric trauma, length of stay for 5 common pediatric orthopaedic fractures was reduced by >5 hours. In addition, cost was reduced by about $1,200 per patient; complication rates improved slightly; frequency of after-hours surgery decreased by 48%; and wait times for surgery were significantly reduced.

—Forty-two patients with a distal radial buckle fracture received a removable wrist brace during an initial clinic visit, along with instructions to wear it for 3 to 4 weeks. No follow-up was scheduled, but the family was contacted at 1 week and at 5 to 10 months following treatment. No complications or refractures occurred; 100% of respondents said they would select the same treatment.1

Pediatric Sports Medicine
—Among a continuous cohort of 85 patients (mean age 13.9 years) who underwent primary ACL reconstruction (77% with open physes at time of surgery) and who were followed for a  minimum of 2 years, overall prevalence of a second ACL surgery was 32%, including 16 ACL graft ruptures and 11 contralateral ACL tears. A slower return to sport was found to be protective against a second ACL injury.

Infection and Scoliosis Surgery
—A preliminary study of 36 pediatric patients who underwent a total of 191 procedures for early-onset scoliosis found that the use of vancomycin powder during closure significantly decreased the rate of surgical site infection (13.8% per procedure in the control group versus 4.8% per procedure in the vancomycin group).

Clubfoot
—A retrospective review of >1,100 clubfeet that were presumed to be idiopathic upon presentation found that the condition in 112 feet (8.9%) was later determined to be associated with neurological, syndromic, chromosomal, or spinal abnormalities—and therefore nonidiopathic.2 The nonidiopathic group was less likely to have a good result at the 2- and 5-year follow-up, and more likely to require surgery. The authors conclude, however, that surgery is avoidable for most patients with nonidiopathic clubfoot.

References

  1. Kuba MHM, Izuka BH. One brace: one visit: treatment of pediatric distal radius fractures with a removable wrist brace and no follow-up visit. J Pediatr Orthop.2018 Jul;38(6):e338-42.
  2. Richards BS, Faulks S. Clubfoot infants initially thought to be idiopathic, but later found not to be. How do they do with nonoperative treatment?J Pediatr Orthop. 2017 Apr 10. [Epub ahead of print].

Benchmark Data on Aseptic Revision after Knee Replacement

The main advantage of joint registries is their large number of recorded procedures, ideally with very few patient “types” not represented in the database. This is the case with the Australian Orthopaedic Association National Joint Replacement Registry, which includes data on almost 100% of all joint replacements performed in Australia since 2002. In the February 20, 2019 issue of The Journal, Jorgenson et al. analyze almost 6,000 major aseptic total knee arthroplasty (TKA) revisions from a cohort of 478,000 primary TKAs registered between 1999 and 2015. This analysis provides robust benchmark data for patients and surgeons, although it comes too late for the 3% of patients who required such a revision surgery within the 15-year study period.

The authors found that fixed bearings were revised for aseptic reasons at a significantly lower rate than mobile bearings (2.7% vs 4.1%, respectively) and that patients <55 years old had an almost 8-fold higher revision rate compared to patients ≥75 years old ( 7.8% versus 1.0%, respectively). The study also found lower aseptic revision rates with minimally stabilized total knee prostheses compared to posterior-stabilized prostheses, and higher aseptic revision rates with completely cementless fixation relative to either hybrid or fully cemented fixation. These are valuable data for arthroplasty surgeons in terms of selecting implants and surgical techniques and for preoperative counseling of patients—especially younger ones. While many of these findings have been previously reported, these registry-based results add significant strength to published data.

Ideally, data such as these would be controlled for confounding variables such as surgeon experience and additional patient-specific variables such as activity demands and medical comorbidities. Still, these data provide useful prosthesis-specific factors for shared decision making with patients. We look forward to more helpful information from this and other national joint registries and encourage the continued growth of similar registries in other subspecialties.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Arthroscopy Beats PT for FAI at 8 Months

OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent BMJ studythe following commentary comes from Matthew R. Schmitz, MD, FAOA.

Femoroacetabular impingement (FAI) syndrome continues to be a hot topic in the orthopaedic community. The first two decades of this century have seen huge increases in the number of hip arthroscopies performed in the US and UK,1,2 most of those to treat FAI.  In the February 7, 2019 issue of BMJ, Palmer et al., reporting on behalf of the Femoroacetabular Impingement Trial (FAIT), published preliminary findings from a multicenter randomized controlled trial comparing arthroscopic hip surgery to activity modification and physiotherapy for symptomatic FAI.3

The trial randomized 222 patients with a clinical diagnosis of FAI into each cohort (110 in the physiotherapy group and 112 in the arthroscopy group). Follow-up assessments were performed by clinicians blinded to the treatment arm, and attempts were made to standardize both interventions. The participants will eventually be followed for 3 years, but this early report evaluated outcomes 8 months after randomization, with follow-up data available for  >80% of patients in both groups.

Baseline characteristics with regard to demographics, radiographic findings, and clinical measurements were similar between the two groups. After adjusting for multiple potential confounders, the authors found that the mean Hip Outcomes Score Activities of Daily Living (HOS ADL) was 10 points higher in the arthroscopy group than in the physiotherapy group, exceeding the prespecified minimum clinically important difference (MCID) of 9 points. The MCID was reached in 51% of surgical patients compared to 32% in the therapy cohort. In addition, the patient acceptable symptomatic state (PASS)—defined as a HOS ADL ≥87 points—was achieved in 48% of surgical patients and only 19% of therapy patients. Relative to the physiotherapy group, the arthroscopic group also had better hip flexion and superior results in a variety of commonly used hip patient-reported outcomes scores.

The 8-month data from this study show that there is a real improvement in patient function and reported outcomes from arthroscopic management for FAI. It will be important, however, to follow these patients for the entire 3 years of the FAIT study to show whether these improvements persist. It should also be emphasized that only half of the patients treated with surgical management achieved MCID at the 8-month point. That finding supports what I tell patients in my young-adult hip-preservation clinics, which seems relevant as baseball season starts: There are rarely any home runs in arthroscopic hip surgery. There are mainly singles and doubles that we hope to stretch into doubles and triples. Still, it appears that even those base hits with arthroscopic surgery are better than the physiotherapy alternative—at least in the early innings of the game.

Matthew R. Schmitz, MD, FAOA is an orthopaedic surgeon specializing in adolescent sports and young adult hip preservation at the San Antonio Military Medical Center in San Antonio, TX. He is also a member of the JBJS Social Media Advisory Board.

References

  1. Maradit Kremers H, Schilz SR, Van Houten HK et al. Trends in Utilization and Outcomes of Hip Arthrocopy in the United States Between 2005 and 2013. J Arthroplasty 2017; 32:750-5.
  2. Palmer AJ, Malak TT, Broomfield J, et al. Past and projected temporal trends in arthroscopic hip surgery in England between 2002 and 2018. BMJ Open Sport Exerc Med 2016;2:e000082
  3. Palmer AJ, Gupta VA, Fernquest S, et al. Arthroscopic hip surgery compared with physiotherapy and activity modification for the treatment of symptomatic femoroacetabular impingement: multicenter randomized controlled trial. BMJ 2019; 364:l185

Letting Go of the Script

OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent New England Journal of Medicine Perspectivethe following commentary comes from Adam Bitterman, DO.

The physician-patient relationship is highly regarded and has withstood the test of time. Unfortunately, today it appears to be under significant stress. While it is still possible to maintain a meaningful and professional doctor-patient connection, the balance between arriving at a correct diagnosis, moving down your patient list, and truly caring for each individual patient is difficult to find. The advent of electronic medical records (and their attendant task lists and button clicking) and satisfaction scores have not made maintaining meaningful patient relationships any easier.

In her February 7, 2019 Perspective piece for The New England Journal of Medicine, cardiologist Dr. Lisa Rosenbaum describes her encounters with the medical system as a patient after sustaining a Jones fracture. As she highlights her experience from the initial presentation in the emergency department to the follow-up examination with an orthopedic surgeon, she describes the repeated sensation of being a diagnosis treated by an algorithm rather than an individual with an ailment receiving care.

She also highlights an anecdote about another patient’s family pleading with a staff physician to “get off your script” and focus on treating the unique patient. Invoking the legacy of Sir Robert Jones, the orthopaedist after whom the foot fracture is named, Dr. Rosenbaum observes that “medicine teeters atop an edifice of workarounds,” as physicians try to play by the rules while taking good care of patients.

Standardization and treatment protocols have a useful role in many instances, but we physicians must remember that behind every complaint is a patient, an individual with personal connections to friends and family. It is easy to get caught up in the standardized protocols that reside within electronic medical records, but it takes only a moment to disconnect yourself from the screen and keyboard and provide the creative connection that patients desire. (A study in the upcoming February 20, 2019 JBJS addresses this topic.)

Although you may be encountering your seventh patient of the day with a Jones fracture, for each of those people, their foot is all that matters. It is our job—a decidedly difficult one—to provide the unique and sometimes creative treatment plan to all our patients, while somehow maintaining a top-tier standard of care that is reproducible for all.

Adam Bitterman, DO is a fellowship-trained foot and ankle surgeon practicing at Northwell Health in Huntington, NY. He is also a member of the JBJS Social Media Advisory Board.

PE Prevention—There’s an App for That

OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Matthew Herring, MD in response to a recent study in the Journal of Orthopaedic Trauma.

Pulmonary embolism (PE) is a potentially life-threatening complication among many orthopaedic trauma patients. PE can be a silent killer, with only about 30% of fatal PEs being detected before death. Chemical prophylaxis with “blood thinners” such as injectable enoxaparin is effective in mitigating the risk of PE, but in the poly-traumatized patient, its application is often contraindicated. In an effort to develop a more effective approach to PE prevention in the trauma population, Starr et al. built a tool to estimate the risk of PE early and effectively, and then developed a multidisciplinary protocol for deep vein thrombosis (DVT) prophylaxis. They present their preliminary experience with the risk-assessment tool and the new protocol in the February 2019 issue of the Journal of Orthopaedic Trauma.

The smart-phone app (ParkLandOrtho) to risk-stratify trauma patients in the ED is based on 7 easily captured variables that the authors’ prior work identified as statistically significant predictors for developing a PE. Patients who are identified as “high risk” are aggressively started on enoxaparin, with the first dose ideally given prior to ED discharge. If contraindications for chemical prophylaxis are present, enoxaparin is withheld for up to 24 hours after admission. After 24 hours, if the patient is still unable to receive enoxaparin, a removable inferior vena cava (IVC) filter is placed.

The authors performed a retrospective review of PE incidence among 368 consecutive orthopaedic trauma patients admitted to their hospital after this new protocol was implemented and compared it to PE incidence among a historic cohort of 420 similar consecutive patients admitted during the year prior to the protocol. The two groups were similar in age and injury severity. In the control group, 51 patients were retrospectively classified as high risk, and 9 patients (2.1%) developed symptomatic PEs, one of which was fatal. In the group managed under the new protocol, 40 patients were identified as high risk, and only 1 patient (0.27%) developed a nonfatal PE. The difference in incidence of PE between the two groups was statistically significant (P = 0.02).

This paper highlights two significant achievements in my opinion. First, I was excited to see the success of a smart-phone app to facilitate rapid risk assessment. This was a significant key to the success of the multidisciplinary PE protocol, which depends on buy-in and compliance. Second, this thoughtful, decisive, and team-based protocol for DVT/PE prophylaxis in an orthopaedic trauma setting seems to be making a meaningful impact on patient outcomes.

The authors report that they are currently designing a multicenter trial to prospectively validate their protocol. I eagerly await this and hope that their next step includes a ParklandOrtho app release for Android devices, as it is only available now for iPhone and Samsung users.

Matthew Herring, MD is a fellow in orthopaedic trauma at the University of California, San Francisco and a member of the JBJS Social Media Advisory Board.

More Help Predicting Risk of Second SCFE

Up to 40% of kids who experience a slipped capital femoral epiphysis (SCFE) in one hip develop a slip in the contralateral hip. Recent research in pediatric orthopaedics has attempted to identify risk factors for a second SCFE in patients who have had a first. A retrospective study by Maranho et al. in the February 6, 2019 issue of JBJS provides additional evidence about one particular risk factor.

The authors radiographically measured the epiphyseal tilt, epiphyseal extension ratio, alpha angle, and epiphyseal angle of the uninvolved, contralateral hip among 318 patients (mean age of 12.4 years) who presented for treatment of a unilateral SCFE between 2000 and 2017. After adjusting for triradiate cartilage status, Maranho et al. found that, over a minimum follow-up of 18 months:

  • Increased posterior epiphyseal tilt was associated with an increased risk of contralateral SCFE, which corroborates recent findings. Specifically, an epiphyseal tilt of >10° corresponded to a 54% predicted probability of a contralateral slip in patients with open triradiate cartilage.
  • Increased epiphyseal extension around the metaphysis in the superior plane had a protective effect against a contralateral SCFE. For each 0.01 increase in superior epiphyseal extension ratio, the odds of a contralateral slip decreased by 6%.
  • The alpha angle and epiphyseal angle were not independently associated with a contralateral slip.

Clinically, the authors suggest that the tilt findings may be more useful than the extension-ratio findings, especially when it comes to the difficult decision around whether to perform prophylactic percutaneous pinning of the contralateral hip. They write that “prophylactic fixation may be discussed with the families of patients presenting with unilateral SCFE who have a tilt angle of >10°,” noting that this threshold “would result in a low proportion of patients undergoing unnecessary prophylactic pinning.” Maranho et al. are quick to add that even contralateral hips with epiphyseal tilt angles <10° are at risk of SCFE and should be closely monitored.

Read the JBJS Clinical Summary on SCFE.

Musculoskeletal Infections: Oral Antibiotics Not Inferior to IV

OrthoBuzz occasionally receives posts from guest bloggers. In response to a recent New England Journal of Medicine studythe following commentary comes from Daniel Leas, MD and Joseph R. Hsu, MD.

Deep infections continue to be one of the most resource-intensive problems that orthopaedic surgeons face. Long-standing dogma has favored 6 or more weeks of intravenous (IV) antibiotics, resulting in increased healthcare costs during both the inpatient and outpatient treatment periods.

To explore the possibility of utilizing targeted oral antibiotics as an alternative, effective treatment for musculoskeletal infections, the OVIVA (Oral versus Intravenous Antibiotics) multicenter research collaboration conducted a prospective, randomized controlled trial. A total of 1,054 patients with deep musculoskeletal infections were randomized to oral or IV arms for 6 weeks of antibiotic treatment and followed for 1 year to determine treatment efficacy. The primary end point was treatment failure within 1 year, defined as the presence of predefined clinical symptoms of deep infection, microbiologic evidence of continued infection, or histologic presence of microorganisms or inflammatory tissue. Secondary outcomes included catheter-associated complications, discontinuation of therapy, and Clostridium difficile diarrhea.

Of the 1,054 patients enrolled, 909 patients were included in the final analysis. Treatment failure occurred in 14.6% of patients treated with IV antibiotics and 13.2% of patients in the oral-therapy group. This -1.4% difference indicated noninferiority based on the predetermined 7.5% noninferiority margin. Secondary outcomes between the groups differed only in catheter-related complications being more common in the IV group (9.4% vs 1.0% in the oral group).

These findings and conclusions should challenge us to re-evaluate the basis for extended IV antibiotics to treat complex musculoskeletal infections, and to consider a greater role for oral antibiotics for such infections. Further study of this question focused on patients with retained hardware is warranted.

Daniel P. Leas, MD is a PGY-5 orthopaedic resident at Carolinas Medical Center.

Joseph R. Hsu, MD is a Professor of Orthopaedic Trauma and Vice Chair of Quality at the Atrium Health Musculoskeletal Institute.