Epiphyseal Etiology for Juvenile Osteochondritis Dissecans?

Most patients with clinically apparent juvenile osteochondritis dissecans (JOCD) are between 12 and 19 years of age. Often the disease can be treated successfully with nonoperative modalities, but even in cases where the initial lesion resolves, patients may be predisposed to osteoarthritis later in life. While repetitive microtrauma is suspected to be involved in the development of JOCD, the exact etiology remains poorly understood, even 130 years after the condition was first described.

In the December 19, 2018 issue of The Journal, Toth et al. histologically examined 59 biopsy samples from the central condyles of 26 pediatric cadavers to look for areas of epiphyseal cartilage necrosis. Hypothesizing that such evaluation would reveal some lesions similar to those found in animals, the authors did indeed identify 6 samples with 1 or more areas of necrotic cartilage, which were either incorporated into subchondral bone or associated with focal failure of endochondral ossification. Those characteristics are consistent with a similar disease process called osteochondrosis manifesta seen in pigs and horses.  While the clinical significance of these findings remains to be determined, the authors suggest that they may help explain an epiphyseal etiology of JOCD, and the data suggest that these microscopic changes (some of which are rendered in this article as whole-slide images) are probably present in young people 5 to 10 years prior to the clinical manifestations of JOCD.

These findings lend credence to the theory that the underlying etiology of JOCD primarily involves the epiphyseal growth plate rather than subchondral bone. Furthermore, the similarities between these cadaveric specimens and osteochondrosis manifesta lesions in porcine and equine femoral condyles may help us develop improved models to better diagnose, prevent, and treat this pathology.

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

Extended Oral Antibiotics May Cut PJI Risk When Risk Factors Aren’t Modifiable

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

What We Owe our Patients—Continuous Improvement

It has been said that a surgeon’s skill and judgment account for between 80% and 90% of a patient’s outcome. (I believe this is true for both surgical and nonsurgical treatments.) Throw in a physician’s ability to listen and clearly communicate with patients, and I am sure we are approaching that 90% mark. That means that when we conduct randomized trials comparing two types of knee prostheses or fracture-fixation constructs, we are, in essence, scrutinizing only about 10% of the patient-outcome equation. 

So how do we best evaluate the 90% of the outcome equation that is physician-dependent? With the advent of “bundled” episodes of care, the orthopaedic community has emphasized the need for risk-adjustment in evaluating surgeon performance. Clearly, there are certain patients who are at higher risk for worse outcomes than others, such as those with diabetes, nicotine abuse, advanced age, and less social support.

In the December 19. 2018 issue of The Journal, Thigpen et al. report on patient outcomes 6 months after arthroscopic rotator cuff repair in 995 patients treated by 34 surgeons. The authors evaluated patient-reported outcomes from all surgeons using both unadjusted and adjusted ASES change scores. The adjusted scores took into account about a dozen baseline patient characteristics, including symptom severity, functional and mental scores, medical comorbidities, and Workers’ Compensation status. Relative to performance rankings based on unadjusted data, risk adjustment significantly altered the rankings for 91% of the surgeons.  According to the authors, these findings “underpin the importance of risk-adjustment approaches to accurately report surgeon performance.”

But what is of even greater interest to me is that risk adjustment led to positive increases in patient outcomes for some surgeons, while decreasing outcomes for other surgeons. Some of these outcome differences likely reflect each surgeon’s patient-selection biases, but in the words of the authors, the numbers strongly suggest “that there is a meaningful, distinguishable difference in patient outcomes between surgeons.”

What should we do with this data? In my opinion, surgeons in the lower 80%  of the list, at least, ought to be engaging with the surgeons who demonstrated the highest adjusted performance scores to understand what is helping them obtain outcomes that are superior to everyone else’s. We owe it to our patients to understand what our personal outcomes are for at least the most common conditions we treat. I believe it borders on unethical behavior to quote patients outcome data of a procedure from the peer-reviewed literature when we have no idea how our personal results compare. Orthopaedic surgeons need to be more active in lobbying our groups and health systems to support best practices for clinical outcome data collection and reporting so we can, in turn, improve our care by adopting the best practices of the surgeons with the best outcomes.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Outcomes of the Ponseti Method for Untreated Clubfeet in Nepalese Patients

Full Article

Background:
To our knowledge, there are no reports of the Ponseti method initiated after walking age and with >10 years of follow-up. Our goal was to report the clinical findings and patient-reported outcomes for children with a previously untreated idiopathic clubfoot who were seen when they were between 1 and 5 years old, were treated with the Ponseti method, and had a minimum follow-up of 10 years.

Routine Diagnostic Tests for Periprosthetic Joint Infection Demonstrate a High False-Negative Rate

 
Background:
Current guidelines recommend serum erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) as the first-line testing for evaluation of suspected periprosthetic joint infection, in addition to synovial white blood-cell (WBC) count and polymorphonuclear percentage. However, the sensitivity and other diagnostic measures of these tests and the influence of organisms on these inflammatory markers remain inadequately investigated.

Surgeon-as-Patient: Tech Data May Cloud Clinical Judgment

The 24th installment of our “What’s Important” series in the JBJS Orthopaedic Forum comes from orthopaedic surgeon Jack W. Crosland. In detailing his recent experience as a patient at a prestigious university teaching hospital, Dr. Crosland declares that what’s important for physicians is “listening and reasoning.”

His thesis is that in the current health care system,  the “technology component” of clinical decision making—lab results and imaging data, for example—has become overemphasized, while reliance on information obtained from patients is underemphasized.

In his essay, Dr. Crosland says that his dual perspective as patient and surgeon further convinced him that “physicians can get more pertinent and valuable information from a thorough patient interview than from any other source.”

Dr. Crosland is not radically antitechnology, but he does conclude that “technology should be used to confirm a diagnosis or narrow the list in a differential diagnosis, but it should not be the primary resource to diagnose disease or to determine treatment modalities.”

If you would like JBJS to consider a “What’s Important” story for publication, please submit a manuscript via Editorial Manager. When asked to select an article type, please choose Orthopaedic Forum and include“What’s Important:” at the beginning of the title.

Confirmed: TXA Works Well in Adolescent Scoliosis Surgery

The evidence favoring tranexamic acid (TXA) for reducing surgical blood loss is ample and growing, but until now robust data were sparse regarding its efficacy in the setting of adolescent idiopathic scoliosis surgery. In the December 5, 2018 issue of The Journal of Bone & Joint Surgery, Goobie et al. report on a randomized, blinded, placebo-controlled trial showing that, in that population, TXA reduced perioperative blood loss by 27%, compared with blood loss in a placebo group.

Even with recent advances in scoliosis surgical technique, blood transfusions are common. And, because transfusions are associated with significant morbidity and mortality, limiting operative blood loss and reducing the need for transfusion have become focal points for orthopaedic surgeons.

In this Level-I trial, >100 patients between the ages of 10 and 18 years undergoing elective posterior instrumented spinal fusion were randomized to receive either TXA (infusion of a 50-mg/kg loading dose and a 10-mg/kg/h maintenance dose) or normal saline (delivered in the same way and dose) during surgery. The TXA group demonstrated an overall 27% reduction in cumulative blood loss and a 2-fold reduction in the percentage of patients with clinically relevant blood loss (defined as >20 mL/kg).

The cumulative effect of reduced blood loss was enhanced over time, with the positive effect of TXA being most evident in procedures lasting >4 hours. None of the patients in the TXA group required a transfusion or developed side effects such as thromboembolism or seizures.

In an interesting sidenote, the authors asked the participating orthopaedic surgeons, who were blinded to the randomization, to guess which group each patient had been assigned to by evaluating the relative ooziness of the surgical field. The surgeons guessed correctly 72% of the time.

Overall, these findings prompted the authors to conclude that “the use of TXA as part of a multimodal blood management strategy, as was employed in this study, should be considered the standard of care for patients undergoing surgery for adolescent idiopathic scoliosis.”

Using CT Data to Diagnose Osteoporosis

Osteoporosis is a “silent” disease, often becoming apparent only after a patient older than 50 sustains a low-energy fracture of the wrist, proximal humerus, or hip. Monitoring serum vitamin D levels and DEXA testing represent ideal screening methods to prevent these sentinel fragility fractures. In addition, through programs such as the AOA’s “Own the Bone” initiative, the orthopaedic community has taken a leadership role in diagnosing and treating osteoporosis after the disease presents as a fragility fracture. Own the Bone is active in all 50 states and, through local physician leadership, is identifying individuals who present with a fragility fracture so they can receive follow-up care that helps mitigate bone loss and prevent secondary fractures.

We still have a long way to go, however. Recent analyses show that only 30% of candidate patients (albeit up from 20%) are receiving this type of evidence-based care. The best-case scenario would be to identify at-risk men and women (osteoporosis does not affect women exclusively) before a potentially serious injury.

In the December 5, 2018 issue of The Journal, Anderson et al. present strong evidence that computed tomography (CT) can provide accurate data for diagnosing osteoporosis. CT is increasingly used (perhaps overused in some settings) across a spectrum of diagnostic investigations. The osseous-related data from these scans can be used to glean accurate information regarding a patient’s bone quality by analyzing the Hounsfield unit (HU) values of bone captured opportunistically by CT.  HU data are routinely ignored, but the values correlate strongly with bone mineral density, and they could help us recommend preventive care to our patients before a fragility fracture occurs. (For example, a threshold of <135 HU for the L1 vertebral body indicates a risk for osteoporosis.)

Orthopaedists should discuss the possibility of asking their radiologist colleagues who read CT scans of older patients to routinely share that data. When indicated, we could promptly refer patients back to their primary care provider for discussion of pharmacological treatment and lifestyle changes proven to help prevent primary fragility fractures. There is little doubt that our patients are getting older. Reviewing CT data  could help us dramatically improve preventive care and decrease the risk of first-time fragility fractures.

Click here for additional OrthoBuzz posts about fragility fractures.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

What’s New in Musculoskeletal Basic Science 2018

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, Matthew J. Allen, VetMB, PhD, author of the December 5, 2018 Specialty Update on Musculoskeletal Basic Science, focuses on the five most compelling findings from among the more than 60 noteworthy studies summarized in the article.

Gene Editing in Orthopaedics

–Gene-editing tools such as CRISPR-Cas9 have great potential as a means of introducing therapeutic genes into mesenchymal stem cells that can then be targeted to tissues in vivo. These researchers1 reported on genetically modified stem cells that have the potential to differentiate into chondrocytes encoding a natural inhibitor of interleukin-1, providing an opportunity for localized release of immunomodulatory factors.

Managing Orthopaedic Infections

–A novel study2 in which transmission electron microscopy was used to identify viable bacteria deep within the canalicular structure of cortical bone, remote from the site of an infected implant, suggests that effective debridement requires the removal of not just necrotic tissue, but also of adjacent, apparently unaffected bone.

Computational Modeling of Human Movement

–This report3 presented a human musculoskeletal model that provided extremely accurate predictions of ground reaction forces during simulated walking and squatting. As similar models are developed and validated, surgeons will have improved tools for evaluating patients, planning surgery, and making decisions about which procedure/implant is most appropriate for an individual patient.

Sex-Related Differences

–This report4 demonstrated sexually dimorphic regulation of gene-expression profiles in bone marrow osteoprogenitor cells that could partly explain clinical observations in sex differences in peak bone mass, bone remodeling, and immunomodulation.

Biological Enhancement of Ligament Healing

–Among several basic science papers focused on the optimal healing and durable fixation of tendons and ligaments, this notable work5 reported on the translation of bridge-enhanced ligament repair for the anterior cruciate ligament.

References

  1. Brunger JM, Zutshi A, Willard VP, Gersbach CA, Guilak F. CRISPR/Cas9 editing of murine induced pluripotent stem cells for engineering inflammation-resistant tissues. Arthritis Rheumatol.2017 May;69(5):1111-21. Epub 2017 Mar 31.
  2. de Mesy Bentley KL, Trombetta R, Nishitani K, Bello-Irizarry SN, Ninomiya M, Zhang L, Chung HL, McGrath JL, Daiss JL, Awad HA, Kates SL, Schwarz EM. Evidence of Staphylococcus aureus deformation, proliferation, and migration in canaliculi of live cortical bone in murine models of osteomyelitis. J Bone Miner Res.2017 May;32(5):985-90. Epub 2017 Jan 26.
  3. Jung Y, Koo YJ, Koo S. Simultaneous estimation of ground reaction force and knee contact force during walking and squatting. Int J Precis Eng Manuf.2017;18(9):1263-8.
  4. Kot A, Zhong ZA, Zhang H, Lay YE, Lane NE, Yao W. Sex dimorphic regulation of osteoprogenitor progesterone in bone stromal cells. J Mol Endocrinol.2017 Nov;59(4):351-63. Epub 2017 Sep 4.
  5. Perrone GS, Proffen BL, Kiapour AM, Sieker JT, Fleming BC, Murray MM. Bench-to-bedside: bridge-enhanced anterior cruciate ligament repair. J Orthop Res.2017 Dec;35(12):2606-12. Epub 2017 Jul 9.

December 2018 Article Exchange with JOSPT

In 2015, JBJS launched an “article exchange” collaboration with the Journal of Orthopaedic & Sports Physical Therapy (JOSPT) to support multidisciplinary integration, continuity of care, and excellent patient outcomes in orthopaedics and sports medicine.

During the month of December 2018, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “Perceptions of Rehabilitation and Return to Sport Among High School Athletes With Anterior Cruciate Ligament Reconstruction: A Qualitative Research Study.

In this cross-sectional study, researchers looked at 10 high-school-aged individuals who had undergone ACL reconstruction surgery and had not returned to sport. They found that psychosocial barriers to return to sport (e.g., persistent uncertainty about full recovery) were reported with greater consistency than physical barriers. The authors suggest that peer mentoring groups to facilitate psychosocial support during rehabilitation might help.