This basic science tip 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.
Over the decades, the meaning of the term “phenotype” has changed. In the past it was solely applied to inherited disorders and was based on physical appearance or clinical presentation. Similarly, the term “penetrance” was applied to the variations in phenotype severity relative to normal. Over time, it has been found that penetrance is usually a reflection of different mutations for the same gene at different parts of the allele, or a mutation in one of several specific genes that could contribute to a similar phenotype.
Now, both terms have been applied to a variety of genetic and environmental circumstances that may affect physical appearance and function. In osteoarthritis research, the term “phenotype” has increasingly been used to define physical, genetic, environmental, and other variables, both past and present.
The authors of a recent abstract use a modern application for the term phenotype to systematically review the literature for studies using knee characteristics relevant for phenotyping osteoarthritis (OA).1 A comprehensive search was performed limited to observational studies of individuals with symptomatic knee OA that identified phenotypes based on OA characteristics, and then the authors assessed phenotypic association with clinically important outcomes.
Based on their abstract, 34 of 2777 citations were included in a descriptive synthesis of the data. Clinical phenotypes were investigated most frequently, followed by laboratory, imaging, and etiologic phenotypes. Eight studies defined subgroups based on outcome trajectories (pain, function, and radiographic progression). Most studies used a single patient or disease characteristic to identify subgroups, while five included characteristics from multiple domains.
Evidence from multiple studies suggested that pain sensitization, psychological distress, radiographic severity, BMI, muscle strength, inflammation, and comorbidities are associated with clinically distinct phenotypes. Gender, obesity and other metabolic abnormalities, the pattern of cartilage damage, and inflammation may delineate distinct structural phenotypes. However, only a few of the 34 studies reviewed investigated the external validity of the chosen phenotypes or their prospective validity using longitudinal outcomes.
While the authors remarked on the heterogeneity of the data included in studies investigating knee OA phenotypes, they say that the phenotypic characteristics identified in their review could form a classification framework for future studies investigating OA phenotypes.
It should be noted that the FRAX score used to calculate fragility fracture risk could be considered a phenotypically based system, the validation of which is continuing.
- Deveza LA, Melo L, Yamato TP, Mills K, Ravi V, Hunter DJ. Knee osteoarthritis phenotypes and their relevance for outcomes: a systematic review. Osteoarthritis 2017 Aug 25. pii: S1063-4584(17)31156-1. doi: 10.1016/j.joca.2017.08.009. [Epub ahead of print].
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 June 2017, JBJS and OrthoBuzz readers will have open access to the JOSPT article titled “The Association of Recreational and Competitive Running With Hip and Knee Osteoarthritis: A Systematic Review and Meta-analysis.”
Based on 17 studies included in the meta-analysis, the authors found that recreational runners had a lower occurrence of osteoarthritis compared with competitive runners and sedentary controls.
When surgeons and patients discuss what treatment will work best for a particular musculoskeletal ailment, they often rely on both “subjective” and “objective” outcome data from previously published assessments. Reviewing both types of data is a good idea, because a study among more than 100 patients with shoulder osteoarthritis by Matsen et al. in the March 1, 2017 issue of The Journal of Bone & Joint Surgery found poor correlation between objective measures of active abduction and subjective patient self-assessments using the Simple Shoulder Test (SST).
The authors used a statistical method called “coefficient of determination”
to confirm “a highly variable relationship” between the patient-reported SST (subjective) and motor-sensor range-of-motion (objective) measurements. In less statistical language, many of the shoulders had good motion and poor self-assessed function, while others had poor motion and good self-assessed function.
The findings led the authors to conclude that “studies of treatment outcomes should include separate assessments of these 2 complementary aspects of shoulder function.” That conclusion was seconded and expanded upon in a commentary by Jeffrey S. Abrams, MD, who wrote that “either [subjective or objective] assessment used independently may lead to the wrong impression.”
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Chad Krueger, MD, in response to a recent study in the Annals of Internal Medicine.
Few disease processes are as prevalent within the United States as hip and knee osteoarthritis (OA). While OA is commonly thought to be a disease of older age, the reality is that over half of all individuals with knee arthritis are younger than 65. While some of those individuals will eventually go on to have a knee arthroplasty, before that, most OA patients try various other treatments in an effort to decrease pain and increase function. Medications such as NSAIDs and others are certainly a part of these treatment efforts, but nonpharmacologic treatments are also widely recommended.
However, as Bennell et al. clearly state in their Annals article, patients face multiple barriers to the implementation of these nonoperative, nonpharmacologic modalities, including cost and transportation to relevant clinical specialists. The authors used these barriers as the rationale for a randomized trial in which an intervention group of knee OA patients received Internet-based educational material, online pain-coping skills training, and videoconferencing with a physiotherapist who provided individualized exercises for each patient. A control group received only the educational material.
At 3 and 9 months, both groups showed improvements in pain and function, but the intervention group had significantly greater improvements than the control group. More importantly, the people in the intervention group largely adhered to all online programs on their own and were very satisfied with the prescribed treatments, especially the video-based physiotherapy component.
Internet-based health interventions are certainly not new. However, my suspicion is that 20 years from now we will look back and wonder why we did not use them more often. They are self-directed, cost-effective, reproducible, and available to any of the 87% of Americans over the age of 50 who, according to the Pew Research Center, use the Internet. These online interventions require no driving to an office, and patients can easily track their own progress by seeing how many modules they have completed.
While there are certainly limitations to the findings from Benell et al., as an accompanying editorial by Lisa Mandl, MD points out, the study serves as a very strong proof of concept that should be expanded upon. Dr. Mandl herself proclaims that “these results are encouraging and show that ‘telemedicine’ is clearly ready for prime time.”
With the number of ways we “stay connected” always increasing, it seems important for orthopaedists to learn how to use these technologies to benefit our patients. Doing so may require some adjustments, but the ultimate goal of improving the quality of life for our patients warrants whatever creativity and open-mindedness might be necessary.
Chad Krueger, MD is a military orthopaedic surgeon at Womack Army Medical Center in Fort Bragg, North Carolina.
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, Gwo-Chin Lee, MD, author of the January 18, 2017 Specialty Update on Adult Reconstructive Knee Surgery, selected the five most clinically compelling findings from among the more than 100 studies summarized in the Specialty Update.
Nonoperative Knee OA Treatment
—Weight loss is one popular nonoperative recommendation for treating symptoms of knee osteoarthritis (OA). An analysis of data from the Osteoarthritis Initiative found that delayed progression of cartilage degeneration, as revealed on MRI and clinical symptoms, positively correlated with BMI reductions >10% over 48 months.1
Total Knee Arthroplasty
—In total knee arthroplasty (TKA), the drive toward producing normal anatomy has led to explorations of alternative alignment paradigms. A prospective randomized study found that small deviations from the traditional mechanical axis (known as kinematic alignment) can be well tolerated and do not lead to decreased survivorship or poorer functional outcomes at short-term follow up.2
—Controversy exists about the optimal method to achieve stemmed implant fixation in revision TKA. A randomized controlled trial of TKA patients with mild to moderate tibial bone loss found no difference in tibial implant micromotion between cemented and hybrid press-fit stem designs, based on radiostereometric analysis.
Blood Management in TKA
—Minimizing blood loss and transfusions is crucial to minimizing complications after TKA. A randomized, double-blind, placebo-controlled trial found that intra-articular and intravenous administration of tranexamic acid (TXA) was more effective than intravenous TXA alone, without an increased risk of venous thromboembolism (VTE). However, the optimal regimen for TXA remains undefined.
—VTE prophylaxis is essential for all patients undergoing TKA. A risk-stratification study of pulmonary embolism (PE) after elective total joint arthroplasty reported that the incidence of PE within 30 days after either hip or knee replacement was 0.5%. Risk factors associated with PE were age of > 70 years, female sex, and higher BMI. The presence of anemia was protective against PE. The authors developed an easy-to-use scoring system to determine risk for VTE to help guide chemical prophylaxis.3
- Gersing AS, Solka M, Joseph GB, Schwaiger BJ, Heilmeier U, Feuerriegel G, Nevitt MC, McCulloch CE,Link TM. Progression of cartilage degeneration and clinical symptoms in obese and overweight individuals is dependent on the amount of weight loss: 48-month data from the Osteoarthritis Initiative. Osteoarthritis Cartilage. 2016 Jul;24(7):1126-34. Epub 2016 Jan 30.
- Calliess T, Bauer K, Stukenborg-Colsman C, Windhagen H, Budde S, Ettinger M. PSI kinematic versus non-PSI mechanical alignment in total knee arthroplasty: a prospective, randomized study. Knee Surg Sports Traumatol Arthrosc. 2016 Apr 27. [Epub ahead of print]
- Bohl DD, Maltenfort MG, Huang R, Parvizi J, Lieberman JR, Della Valle CJ. Development and validation of a risk stratification system for pulmonary embolism after elective primary total joint arthroplasty. J Arthroplasty. 2016 Sep;31(9)(Suppl):187-91. Epub 2016 Mar 17.
OrthoBuzz occasionally receives posts from guest bloggers. This guest post comes from Richard Yoon, MD and Grigory Gershkovich, MD.
The AAOS recently reviewed the evidence for surgical management of osteoarthritis of the knee (SMOAK) and issued a set of appropriate use criteria (AUC) that help determine the appropriateness of clinical practice guidelines (CPGs). These AUC can be accessed on the OrthoGuidelines website: www.orthoguidelines.org/auc.
The AUC were developed after a panel of specialists reviewed the 2015 CPGs on SMOAK and made appropriateness assessments for a multitude of clinical scenarios and treatments. The panel found 21% of the voted-on items “appropriate”; 25% were designated “maybe appropriate,” and 54% were ranked as “rarely appropriate.”
Importantly, these AUC do not provide a substitute for surgical decision making. The physician should always determine treatment on an individual basis, ideally with the patient fully engaged in the decision.
This OrthoBuzz post summarizes some of the updated conclusions according to three clinical time points—pre-operative, peri-operative, and postoperative—specifying the strength of supporting evidence. This post is not intended to review appropriateness for every clinical scenario. We encourage physicians to explore the OrthoGuidelines website for complete AUC information.
Strong evidence: Obese patients exhibit minimal improvement after total knee arthroplasty
(TKA), and such patients should be counseled accordingly.
Moderate evidence: Diabetic patients have a higher risk of complications after TKA.
Moderate evidence: An 8-month delay to TKA does not worsen outcomes.
Strong evidence: Both peri-articular local anesthetics and peripheral nerve blocks decrease postoperative pain and opioid requirements.
Moderate evidence: Neuraxial anesthesia may decrease complication rates and improve select peri-operative outcomes.
Moderate evidence: Judicious use of tourniquets decreases blood loss, but tourniquets may also increase short-term post-operative pain.
Strong evidence: The use of tranexamic acid (TXA) reduces post-operative blood loss and the need for transfusions.
Strong evidence: Drains do not help reduce complications or improve outcomes.
Strong evidence: There is no difference in outcomes between cruciate-retaining and posterior stabilized implants.
Strong evidence: All-polyethylene and modular components yield similar outcomes.
Strong, moderate, and limited evidence to support either cemented or cementless techniques, as similar outcomes and complication rates were found.
Strong evidence: There is no difference in pain/function with patellar resurfacing.
Moderate evidence: Patellar resurfacing decreases 5-year re-operation rates.
Moderate evidence shows no difference between unicompartmental knee arthroplasty (UKA) and high tibial osteotomy (HTO).
Moderate evidence favors TKA over UKA to avoid future revisions.
Strong evidence against the use of intraoperative navigation and patient-specific instrumentation, as no difference in outcomes has been observed.
Strong evidence: Rehab/PT started on day of surgery reduces length of stay.
Moderate evidence: Rehab/PT started on day of surgery reduces pain and improves function.
Strong evidence: The use of continuous passive motion machines does not improve outcomes after TKA.
Richard Yoon, MD is a fellow in orthopaedic traumatology and complex adult reconstruction at Orlando Regional Medical Center.
Grigory Gershkovich, MD is chief resident at Albert Einstein Medical Center in Philadelphia. He will be completing a hand fellowship at the University of Chicago in 2017-2018.
Early on, patients with knee osteoarthritis (OA) often get sufficient pain relief with nonsteroidal anti-inflammatory drugs. But as the condition progresses, many opt for knee replacement. Although knee replacement shows remarkable long-term results, immediate postsurgical pain management is a crucial consideration for orthopaedists and patients.
On Tuesday, December 13, 2016 at 12:30 PM EST, The Journal of Bone & Joint Surgery (JBJS) and PAIN, the official journal of the International Association for the Study of Pain, will host a complimentary webinar focused on relieving pain before and after surgery for knee arthritis.
- Sachiyuki Tsukada, MD, coauthor of a study in JBJS, will compare pain relief and side effects from intraoperative periarticular injections versus postoperative epidural analgesia after unilateral knee replacement.
- PAIN author Lars Arendt-Nielsen, Dr.Med.Sci, will delve into findings from a study examining biomarker and clinical outcomes associated with the COX-2 inhibitor etoricoxib in patients with knee OA.
Moderated by JBJS Associate Editor Nitin Jain, MD, the webinar will include an additional perspective from musculoskeletal pain-management expert Michael Taunton, MD. The last 15 minutes will be devoted to a live Q&A session, during which the audience can ask questions of all three panelists.
Seats are limited, so register now!
Thumbs account for approximately 40% of human hand function, playing a critical role during work, play, and activities of daily living. Arthritis at the base of the thumb (basilar or trapeziometacarpal joint) is one of the most common forms of hand osteoarthritis, affecting as many as 40 percent of the female population older than 55.
This complimentary webinar, hosted jointly by The Journal of Bone & Joint Surgery (JBJS) and the Journal of Orthopaedic & Sports Physical Therapy (JOSPT), will look at the efficacy of both nonoperative and surgical approaches to basilar thumb arthritis.
- Co-authors Jorge Villafañe, PT, PhD, and Joshua Cleland, PT, PhD, will discuss results from a randomized trial in JOSPTthat compared a multimodal program of exercise and mobilization to a placebo in the management of basilar thumb arthritis.
- E.R. Hovius, MD, co-author of a randomized trial in JBJS comparing trapeziometacarpal fusion with trapeziectomy plus ligament reconstruction, will delineate the findings from this Level I study.
Moderated by Sanjeev Kakar, MD, a hand surgeon at the Mayo Clinic in Rochester, Minnesota, the webinar will include additional perspectives from two expert commentators—Krysia Dziedzic, PhD, and Peter Stern, MD.
Hyaluronic Acid Injections for Treatment of Advanced Osteoarthritis of the Knee: Utilization and Cost in a National Population Sample
There is a rise in knee osteoarthritis, particularly in the aging U.S. population. A practice known as hyaluronic acid (HA) injections is used for the treatment of knee osteoarthritis; however, its efficacy and cost-effectiveness are being debated. In this study, the utilization and costs of HA injections were evaluated during the 12 months preceding total knee arthroplasty (TKA) and the usage of HA injections in end-stage knee osteoarthitis management in relation to other treatments was also evaluated. Truven Health Analytics databases (MarketScan Commercial Claims and Encounters and Medicare Supplemental and Cooridination of Benefits) were reviewed in order to find patients who underwent TKA from 2005 to 2012. All patient-specific osteoarthritis-related health care, including medications, corticosteroid injections, HA injections, imaging, and office visits, as well as payment information were analyzed during the 12 months before TKA.
244,059 patients met the inclusion criteria, and 35,935 (14.7%) of them had > 1 HA injections in the 12-month period. HA accounted for 16.4% of all payments related to osteoarthritis, coming in second only to imaging studies (18.2%). In terms of treatment-specific payments, HA injections accounted for 25.2%, a rate higher than that of any other treatment. Compared with patients who did not receive HA injections, patients who had the injections were significantly more likely to receive additional knee osteoarthritis-related treatment.
HA injections are still frequently used to treat osteoarthritis of the knee even though there have been numerous studies that question their efficacy and cost-effectiveness for that purpose. Based on the results and a lack of data supporting the effectiveness of HA injections in the current cost-conscious health-care climate, the authors of this study concluded that decreasing the use of HA injections for patients with end-stage knee osteoarthritis may substantially reduce cost without adversely affecting the quality of care.
Maybe—but only if larger, longer-term studies replicate the findings from a randomized trial of 144 patients (mean age = 66 years) published recently in the Annals of the Rheumatic Diseases.
Subjects with knee osteoarthritis (OA) in the double-blind Annals study received either placebo or up to 25 mg per week of oral methotrexate over a 28-week period. At 28 weeks, researchers found greater reductions in knee pain and larger improvements in scores of physical function and activities of daily living in the methotrexate group than in the placebo group. The authors also noted a significantly greater reduction in synovitis, measured both clinically and with ultrasound, in the methotrexate group relative to the placebo group.
Methotrexate is a powerful drug prescribed to treat certain cancers and refractory rheumatoid arthritis, but it has many well-known and potentially serious side effects, such as hematopoietic suppression and liver toxicity. Nevertheless, these authors reported few adverse events; those that did occur included self-limiting mucositis, alopecia, GI disturbance, and transaminitis.
While some people are thought to have a more inflammatory phenotype of osteoarthritis than others, this study did not stratify patients along inflammatory lines, so further research will be needed to determine whether methotrexate’s clinical benefits accrue equally to OA patients generally, or mostly to those with the inflammatory subtype.