The most common complication arthroplasty surgeons worry about after total knee arthroplasty (TKA) is stiffness, which occurs in a reported 15.98% of cases.1 The notion of TKA patients doing their postoperative physical therapy (PT) on their own at home with a “virtual avatar” gives me pause because it might increase the risk of stiffness. However, if patients could save money, make satisfactory progress in the comfort of their own home, and not experience undue knee stiffness, virtual PT technology would be worth it.
In the January 15, 2020 issue of The Journal, Bettger et al. report on a randomized controlled trial that compared virtual to traditional PT after TKA. The authors hypothesized that virtual PT would cost less and would be clinically noninferior to traditional PT. The FDA-approved Virtual Exercise Rehabilitation Assistant (VERA) studied in this trial uses 3-D technology to track patient movement and an avatar (digitally simulated coach) to assist patients through PT exercises. Virtual PT technology like this not only has the potential to reduce costs (particularly travel costs incurred by patients who live in rural areas), but also to help address current and expected therapist shortages.
There were 143 patients in the virtual PT group and 144 in the traditional PT group. Patients randomized to virtual PT had the technology set up in their home prior to surgery. In addition to avatar-assisted home exercises, virtual PT patients had weekly “video visits” with a human therapist.
Bettger et al. found the median 12-week costs for virtual and traditional PT to be $1,050 and $2,805, respectively. Additionally, at 6 weeks, virtual PT was found to be noninferior to traditional PT in terms of patient outcome measures, knee range of motion, and gait speed. At 12 weeks, virtual PT was found to be noninferior to usual care in terms of pain and hospital readmissions.
I am relieved that virtual PT has the potential to provide cost savings, without apparently increasing the risk of knee stiffness. The cost savings and at-home convenience may be especially important for elderly TKA patients who are living on a fixed income and for whom transportation issues are often vexing. I hope technology like VERA continues to contribute to improved patient satisfaction and easier access to PT.
Jaime L. Bellamy, DO (@jaimelbellamyDO) is an orthopaedic surgeon specializing in hip and knee reconstruction in Fort Bragg, NC and a member of the JBJS Social Media Advisory Board.
- Can administrative data be used to analyze complications following total joint arthroplasty? Clair AJ, et al. J Arthroplasty, 2015;30(9 Suppl):17-20. http://dx.doi.org/10.1016/j.arth.2015.01.060
Every month, JBJS publishes 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 OrthoBuzz summaries of these “What’s New” articles. This month, author Michael J. Taunton, MD selected the 5 most clinically compelling findings from the more than 130 studies summarized in the January 15, 2020 “What’s New in Adult Reconstructive Knee Surgery.”
Unicompartmental Knee Arthroplasty (UKA)
—A prospective cohort study of 1,000 Oxford cementless UKAs indicated by standard Kozinn and Scott criteria found that revision-free survivorship at 10 years was 97%. Progression of lateral osteoarthritis and dislocation of the bearing were the most common reasons for revision.1
—Authors of a double-blinded, prospective, randomized study assigned 60 primary total knee arthroplasty (TKA) patients to receive either a continuous adductor canal block or a single-injection adductor canal block with adjuvant agents. They found no between-group differences in pain scores up to 42 hours postoperatively.2
Post-TKA Physical Therapy (PT)
—A prospective, randomized, noninferiority trial demonstrated that 290 post-TKA patients who were randomized to either outpatient PT, unsupervised web-based PT at home, or unsupervised printed-instruction-based PT at home had no difference in knee range of motion or in patient-reported outcomes at 4 to 6 weeks or 6 months postoperatively.3
—In a retrospective review of 29,695 total joint arthroplasties, preoperative penicillin allergy testing led to a 1.19% higher rate of infection-free survival at 10 years, principally by allowing more routine use of the prophylactic antibiotic cefazolin.4
—A retrospective case series found that patients undergoing revision TKA at an age of < 50 years had a survivorship free of re-revision of 66% at 10 years. Regardless of the reason for revision, this population also had a higher risk of mortality than the general population at 10 years.5
- Campi S, Pandit H, Hooper G, Snell D, Jenkins C, Dodd CAF, et al. Ten-year survival and seven-year functional results of cementless Oxford unicompartmental knee replacement: A prospective consecutive series of our first 1000 cases. Knee. 2018 Dec;25(6):1231-7. Epub 2018/08/29.
- Turner JD, Dobson SW, Henshaw DS, Edwards CJ, Weller RS, Reynolds JW, et al. Single-Injection Adductor Canal Block With Multiple Adjuvants Provides Equivalent Analgesia When Compared With Continuous Adductor Canal Blockade for Primary Total Knee Arthroplasty: A Double-Blinded, Randomized, Controlled, Equivalency Trial. J Arthroplasty. 2018 Oct;33(10):3160-6 e1. Epub 2018/06/16.
- Fleischman AN, Crizer MP, Tarabichi M, Smith S, Rothman RH, Lonner JH, et al. 2018 John N. Insall Award: Recovery of Knee Flexion With Unsupervised Home Exercise Is Not Inferior to Outpatient Physical Therapy After TKA: A Randomized Trial. Clin Orthop Relat Res. 2019 Jan;477(1):60-9. Epub 2019/02/23.
- Wyles CC, Hevesi M, Osmon DR, Park MA, Habermann EB, Lewallen DG, et al. 2019 John Charnley Award: Increased risk of prosthetic joint infection following primary total knee and hip arthroplasty with the use of alternative antibiotics to cefazolin: the value of allergy testing for antibiotic prophylaxis. Bone Joint J. 2019 Jun;101-B(6_Supple_B):9-15. Epub 2019/05/31.
- Chalmers BP, Pallante GD, Sierra RJ, Lewallen DG, Pagnano MW, Trousdale RT. Contemporary Revision Total Knee Arthroplasty in Patients Younger Than 50 Years: 1 in 3 Risk of Re-Revision by 10 Years. J Arthroplasty. 2019 Jul;34(7S):S266-S70. Epub 2019/03/03.
Mark Miller, MD is a professor of orthopaedic surgery at the University of Virginia, founder and co-director of the Miller Review Courses, and former deputy editor for sports medicine at JBJS. In a piece he authored recently for The Conversation, Dr. Miller labeled stem-cell treatments for knee osteoarthritis (OA) “unproven, expensive, and potentially dangerous.”
About 2 years ago, Dr. Miller himself underwent bilateral knee replacements for severe knee arthritis. He understands why patients may fall prey to misleading marketing hype that claims stem cell treatments can help people postpone or entirely avoid knee replacement. (See related OrthoBuzz post.) “My mission,” he writes, is to “try to keep the enthusiasm regarding new cutting-edge options in check,” adding that “the excitement about stem cells has outpaced the science,” especially when it comes to knee OA.
Although stem cell injections have been promoted as a way to regenerate cartilage in arthritic joints, Dr. Miller echoes the American Association of Hip and Knee Surgeons when he says that “there are no proven…therapies that can delay or reverse the progressive joint destruction that occurs with osteoarthritis.” Moreover, the do-no-harm part of the Hippocratic oath requires doctors to give their patients “a clear picture of the potential benefits and side effects of their treatment options,” writes Dr. Miller, who cited a December 20, 2018 New York Times article describing 12 patients who were hospitalized for serious infections after receiving stem cell injections into their knees, shoulders, or spines.
For their part, Dr. Miller says patients should employ the “buyer beware” concept because stem cell therapy for osteoarthritis is not only unproven but also expensive—and usually not covered by medical insurance. The best approach to knee OA, says Dr. Miller, is what is nowadays called shared decision making: “Physicians need to work closely with patients to help them understand their options and which choice may be best for them.”
The word “infection” contains 9 letters, but it’s a four-letter word for orthopaedic surgeons. Postoperative infections are complications that we all deal with, but we try hard to avoid them. Infections after elective sports surgeries can have especially devastating long-term consequences. Thankfully, scientific advances such as improved sterile techniques and more powerful prophylactic antibiotics have helped us decrease the rates of perioperative infections. But more can always be done in this arena.
Baron et al. discuss one additional infection-fighting approach in the December 18, 2019 issue of JBJS, where they report on findings from a retrospective cohort study that looked at 90-day infection rates after >1,600 anterior cruciate ligament (ACL) reconstructions. Specifically, they investigated whether the rates of infection differed when the ACL grafts were prepared with or without a vancomycin irrigant. The average patient age was 27 years old, and all the surgeries (84.1% of which were primary reconstructions) were performed by 1 of 6 fellowship-trained surgeons. The graft was soaked in vancomycin solution in 798 cases (48.7%), while the remaining 51.3% did not use vancomycin.
Baron et al. found that 11 of the reconstructions were complicated by infection within 90 days, but only 1 of those 11 infections occurred in the vancomycin group (p=0.032). After controlling for various confounding factors, the authors found that increased body mass index and increased operative time were also significantly associated with postoperative infection, while age, sex, smoking, surgeon, and insurance type were not.
These results reveal an 89.4% relative risk reduction in postoperative infections after ACL reconstructions when grafts are bathed in vancomycin solution, although the absolute rate of infection among non-soaked grafts (1.2%) was still quite low. Time and more rigorous study designs will tell us whether this is a big step forward in the evolution of infection prevention, but these results should at least prompt further investigation.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
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.
Low-level laser therapy (LLLT) has been used in multiple countries to treat the pain and function deficits associated with knee osteoarthritis (OA). The wavelength typically used is in the near-infrared region. However, this therapy is not recommended by most clinical guidelines, including those of the Osteoarthritis Research Society International. The hesitancy to recommend LLLT is due largely to conflicting published findings and unresolved dose-related issues such as wavelength, intensity, and frequency of treatment. For treating knee OA, the World Association for Laser Therapy (WALT) recommends applying four times the laser dose with continuous rather than pulsed irradiation.
To try to resolve conflicting evidence, Stausholm et al. conducted a systematic review and meta-analysis of randomized, placebo-controlled trials of LLLT, distilling 22 trials from 2,735 initially identified articles.1 Pain, as measured by a 0 to 100 mm visual analog scale (VAS), was significantly reduced by LLLT compared with placebo at the end of therapy (14.23 mm VAS; 95% CI 7.31 to 21.14) and during follow-ups 1 to 12 weeks later (15.92 mm VAS; 95% CI 6.47 to 25.37). Subgroup analysis revealed that pain was significantly reduced by the recommended LLLT doses compared with placebo at the end of therapy (18.71 mm VAS; 95% CI 9.42 to 27.99) and during follow-ups 2 to 12 weeks after the end of therapy (23.23 mm VAS; 95% CI 10.60 to 35.86).
Pain reduction from the recommended doses peaked during follow-ups 2 to 4 weeks after the end of therapy. Disability was also significantly reduced by LLLT, and no adverse events were reported in any of the studies. Notably, in light of JBJS Editor-in-Chief Marc Swiontkowski’s recent comments about the quality of meta-analyses, this meta-analysis was reported in accordance with PRISMA guidelines and all included trials were evaluated for risk of bias.
What remains unclear is how far past the skin the varied wavelengths and intensities (usually 1 to 8 Joules) of laser energy penetrate. Likewise, tissue heating has not been measured or analyzed. Still, at present, it appears that LLLT used with WALT guidelines is a safe and potentially effective treatment for the pain and dysfunction of knee OA.
- Stausholm MB, Naterstad IF Msc, Joensen J, Lopes-Martins RÁB, Sæbø H Msc, Lund H, Fersum KV, Bjordal JM. Efficacy of low-level laser therapy on pain and disability in knee osteoarthritis: systematic review and meta-analysis of randomised placebo-controlled trials. BMJ Open. 2019 Oct 28;9(10):e031142. doi: 10.1136/bmjopen-2019-031142. PMID: 31662383
Rotational malalignment of the femoral component during total knee arthroplasty (TKA) is associated with poor outcomes, but how best to assess femoral component rotation intraoperatively remains an unanswered question for arthroplasty surgeons. Now, in the largest study of its kind, Jang et al. conclude in the December 4, 2019 issue of JBJS that combining 3 reference axes is the optimal strategy for ensuring accurate femoral component positioning, sex/ethnic generalizability, and intraoperative efficiency.
The authors compared 5 reference axes commonly used for intraoperative assessment of femoral component rotation by mapping them to >2,100 entire-femur CT scans from patients with nonarthritic knees. Using the surgical transepicondylar axis (sTEA) as the gold-standard reference, Jang et al. found that no single other axis was both highly accurate and relatively immune to ethnic and sex variability. Based on their findings, they instead recommend using a combination of 3 axes—posterior condylar axis externally rotated 3° (PCA + 3° ER), the Whiteside or sulcus line, and the anatomical transepicondylar axis (aTEA)—to ensure rotational alignment.
The authors also suggest a straightforward intraoperative process for using these 3 axes:
- Start with the PCA + 3° ER, which most accurately approximates the gold-standard sTEA.
- Then use the Whiteside or sulcus line, neither of which is significantly affected by sex or ethnicity.
- Finally, palpate for the aTEA to narrow the margin of error.
Citing a limitation to this CT-based study of nonarthritic knees, the authors note that “we could not account for the effects of cartilage wear or other changes caused by degenerative arthritis.”
Along the spectrum of early and late adopters in medicine, most orthopaedic surgeons fall in the middle. They wait for science to prove the efficacy and safety of an innovation, carefully review the published studies regarding that innovation, and adopt it if it will improve their patients’ outcomes.
In the December 4, 2019 issue of JBJS, Jules-Elysee et al. compare tranexamic acid (TXA) administered intravenously (IV) versus topically in a double-blinded, randomized controlled trial (RCT) of patients undergoing primary total knee arthroplasty (TKA). Level-I evidence is rare in the orthopaedic literature, so when a well-performed RCT comes out, we should closely evaluate its findings.
A potent antifibrinolytic, TXA has been shown in multiple studies to decrease blood loss associated with major orthopaedic procedures. However, there are persistent (but not necessarily evidence-based) concerns about its potential to cause thrombogenic complications, and the safest and most effective route of TXA administration remains an open question.
In this study, the IV group received TXA once before tourniquet inflation and again 3 hours later, along with a topical placebo given 5 minutes before tourniquet release. The topical group received an IV placebo at the same time intervals as the IV group, along with TXA delivered topically in the wound prior to tourniquet release. The authors found lower systemic levels of plasmin-anti-plasmin (PAP, a measure of fibrinolysis) in both groups 1 hour after tourniquet release, but PAP levels remained significantly lower in the IV group (indicating higher antifibrinolytic activity) 4 hours after tourniquet release, which was likely related to the second IV dose of TXA.
The authors also found no between-group difference in systemic or wound levels of prothrombin fragment 1.2 (PF1.2, a marker of thrombin generation), indicating there was no increase in thrombogenicity in the IV group. Interestingly, Jules-Elysee also found that the IV group had significantly higher hemoglobin and hematocrit levels 1 and 2 days after surgery, and those patients had a significantly shorter hospital stay.
Finding no major between-group differences in the mechanism of action, coagulation, or fibrinolytic profile, the authors concluded that a single IV dose of TXA may be the most simple protocol for hospitals to adopt if they are still concerned about TXA safety. Perhaps these Level-I findings will help some of the late adopters get over their fears about the safety of IV TXA.
Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media
Every month, JBJS publishes 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 such OrthoBuzz summaries.
This month, co-author Nitin B. Jain, MD, MSPH selected the most clinically compelling findings from the 40 studies summarized in the November 20, 2019 “What’s New in Orthopaedic Rehabilitation.”
–A randomized controlled trial compared pain-related function, pain intensity, and adverse effects among 240 patients with chronic back, hip, or knee pain who were randomized to receive opioids or non-opioid medication.1 After 12 months, there were no between-group differences in pain-related function. Statistically, the pain intensity score was significantly lower in the non-opioid group, although the difference is probably not clinically meaningful. Adverse events were significantly more frequent in the opioid group.
–A series of nested case-control studies found that the use of the NSAID diclofenac was associated with an increase in the risk of myocardial infarction in patients with spondyloarthritis and osteoarthritis, relative to those taking the NSAID naproxen.2
–Intra-articular injections of corticosteroids or hyaluronic acid are often used for pain relief prior to an eventual total knee arthroplasty (TKA). An analysis of insurance data found that patients who had either type of injection within three months of a TKA had a higher risk of periprosthetic joint infection (PJI) after the operation than those who had injections >3 months prior to TKA.
Partial-Thickness Rotator Cuff Tears
–A randomized controlled trial of 78 patients with a partial-thickness rotator cuff compared outcomes of those who underwent immediate arthroscopic repair with outcomes among those who delayed operative repair until completing 6 months of nonoperative treatment, which included activity modification, PT, corticosteroid injections, and NSAIDs.3 At 2 and 12 months post-repair, both groups demonstrated improved function relative to initial evaluations. At the final follow-up, there were no significant between-group differences in range of motion, VAS, Constant score, or ASES score. Ten (29.4%) of the patients in the delayed group dropped out of the study due to symptom improvement.
Stem Cell Therapy
–A systematic review that assessed 46 studies investigating stem cell therapy for articular cartilage repair4 found low mean methodology scores, indicating overall poor-quality research. Only 1 of the 46 studies was classified as excellent, prompting the authors to conclude that evidence to support the use of stem cell therapy for cartilage repair is limited by a lack of high-quality studies and heterogeneity in the cell lines studied.
- Krebs EE, Gravely A, Nugent S, Jensen AC, DeRonne B, Goldsmith ES, Kroenke K, Bair MJ, Noorbaloochi S. Effect of opioid vs nonopioid medications on pain-related function in patients with chronic back pain or hip or knee osteoarthritis pain: the SPACE randomized clinical trial. JAMA. 2018 Mar 6;319(9):872-82.
- Dubreuil M, Louie-Gao Q, Peloquin CE, Choi HK, Zhang Y, Neogi T. Risk ofcmyocardial infarction with use of selected non-steroidal anti-inflammatory drugs incpatients with spondyloarthritis and osteoarthritis. Ann Rheum Dis. 2018 Aug;77(8): 1137-42. Epub 2018 Apr 19.
- Kim YS, Lee HJ, Kim JH, Noh DY. When should we repair partial-thickness rotator cuff tears? Outcome comparison between immediate surgical repair versus delayed repair after 6-month period of nonsurgical treatment. Am J Sports Med. 2018 Apr;46(5):1091-6. Epub 2018 Mar 5.
- Park YB, Ha CW, Rhim JH, Lee HJ. Stem cell therapy for articular cartilage repair: review of the entity of cell populations used and the result of the clinical application of each entity. Am J Sports Med. 2018 Aug;46(10):2540-52. Epub 2017 Oct 12.