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Better 24-Hour Pain Control with Periarticular vs. IV Steroids in TKA

Corticosteroids are commonly used in total knee arthroplasty (TKA) to reduce pain and prevent nausea. But are the effects of steroids different when administered locally rather than systemically? Hatayama et al. investigate this question in JBJS, where they report on a randomized controlled trial comparing periarticular injection with intravenous (IV) administration of corticosteroids. The authors assessed the drugs’ effects on pain control, the prevention of postoperative nausea, and inflammation and thromboembolism markers following TKA.

The 100 included patients were 50 to 85 years of age and underwent primary, unilateral TKA for osteoarthritis. Fifty patients were randomized to the intravenous group (10 mg dexamethasone IV 1 hour pre- and 24 hours postoperatively, along with periarticular placebo injection during the procedure), and 50 were randomized to the periarticular injection group (a 40-mg injection of triamcinolone acetonide during surgery, along with IV placebo 1 hour pre- and 24 hours postoperatively).

Patients in the periarticular injection group experienced better pain control at 24 hours postoperatively, both at rest and during walking. The antiemetic effect was similar and notable in both groups. The IV group showed a better anti-thromboembolic effect, as measured by prothrombin fragment 1.2 levels, but the incidence of deep venous thrombosis was low overall, each group having only 2 cases.

The authors also reported that, at 24 and 48 hours, interleukin-6 levels did not differ between the groups, while C-reactive protein (CRP) levels were significantly lower in the IV group. In contrast, 1 week after surgery, patients in the periarticular group had a significantly lower CRP. These inflammatory-marker findings lead Hatayama et al. to postulate that “the better [24-hour] pain control in the periarticular injection group was not because of reduced inflammation,” and they note that locally administered corticosteroids directly inhibit signal transmission in nociceptive fibers.

Accuracy of Rapid Alpha Defensin Test Confirmed

In June 2019, OrthoBuzz reported on the FDA approval of a rapid, lateral-flow alpha defensin test that helps detect periprosthetic joint infections (PJIs) from synovial fluid. In the January 20, 2021 issue of The Journal of Bone & Joint Surgery, Deirmengian et al. report findings from the Level II diagnostic-accuracy study that led to this FDA approval.

The authors compared diagnostic sensitivity and specificity of the lateral-flow alpha defensin test with the “gold-standard” PJI diagnostic criteria endorsed by the Musculoskeletal Infection Society (MSIS) in 2013. They made the comparison with 2 groups: a prospective patient cohort of 305 patients with a failed hip or knee arthroplasty (57 of whom were determined by MSIS criteria to have a PJI) and among a “control” cohort of 462 synovial fluid samples (65 of which met MSIS criteria for PJI).

After excluding 17 patients from the prospective cohort who had grossly bloody aspirates, the authors found a sensitivity of 94.3% and a specificity of 94.5% for the lateral-flow test in that group. Among the control cohort, the lateral-flow test’s sensitivity was 98.5% and its specificity was 98.2%. Furthermore, after combining data from the 2 cohorts, Deirmengian et al. found no performance difference between the lateral-flow test (which yields results in 10 to 15 minutes) and the lab-based alpha defensin ELISA test (which typically yields results in 24 hours). Finally, in a nonstatistical descriptive comparison between the 2 alpha defensin tests and 4 other individual lab tests used in the MISI criteria to diagnose PJI (such as synovial fluid white blood cell count and erythrocyte sedimentation rate), the authors concluded that “alpha defensin tests led to the highest raw number of correct diagnoses (accuracy).”

The 2018 International Consensus Meeting on Orthopaedic Infections included alpha defensin as a minor criterion. That decision, along with these findings and the FDA approval of the lateral-flow test, should lead to increased adoption of the rapid test—and to more data being published on its clinical utility.

What’s New in Adult Reconstructive Knee Surgery 2021

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 specialty-update summaries.

This month, author Michael J. Taunton, MD summarizes the 5 most compelling findings from the 130 studies highlighted in the January 20, 2021 “What’s New in Adult Reconstructive Knee Surgery.”

Waiting for a Knee Replacement
–Patient wait times for joint arthroplasty, exacerbated in many places by the COVID-19 pandemic, continue to increase. As measured by the EQ-5D, the health among 12% of 2,168 patients awaiting total knee arthroplasty (TKA) in a recent cross-sectional analysis was rated as “worse than death.”1 Joint-specific function and various comorbidities were associated with these findings.

UKA vs TKA
–The multicenter randomized TOPKAT trial2 compared unicompartmental knee arthroplasty (UKA) with TKA for treating medial compartment osteoarthritis. At the 5-year follow-up, there was no between-group difference in Oxford knee scores, but UKA was more cost-effective and provided an additional 0.24 quality-adjusted life year.

Perioperative Patient Optimization
–An observational study analyzing >1,000 total joint arthroplasties3 found that implementing a “perioperative orthopaedic surgical home”—a surgeon-led screening and optimization initiative targeting 8 common modifiable comorbidities—resulted in a 1.6% 30-day readmission rate (versus 5.3% among patients not involved in the initiative).

Pain Management and Opioids
–A randomized controlled trial of >300 patients undergoing primary total knee or hip arthroplasty4 demonstrated that reducing the number of 5-mg oxycodone pills prescribed at discharge from 90 to 30 resulted in the following findings 30 days postoperatively:

  • Similar between-group pain scores
  • No between-group differences in patient-reported outcomes
  • Significant reductions in unused opioid pills and in pain pills taken in the 30-pill group

Periprosthetic Joint Infection
–Patients undergoing primary TKA who had a history of periprosthetic joint infection (PJI) in another joint had a significantly higher risk of PJI after the primary TKA, compared with the risk among a matched cohort with no history of PJI.5

References

  1. Scott CEH, MacDonald DJ, Howie CR. ‘Worse than death’ and waiting for a joint arthroplasty. Bone Joint J.2019 Aug;101-B(8):941-50.
  2. Beard DJ, Davies LJ, Cook JA, MacLennan G, Price A, Kent S, Hudson J, Carr A, Leal J, Campbell H, Fitzpatrick R, Arden N, Murray D, Campbell MK; TOPKAT Study Group. The clinical and cost-effectiveness of total versus partial knee replacement in patients with medial compartment osteoarthritis (TOPKAT): 5-year outcomes of a randomised controlled trial. 2019 Aug 31;394(10200):746-56. Epub 2019 Jul 17.
  3. Kim KY, Anoushiravani AA, Chen KK, Li R, Bosco JA, Slover JD, Iorio R. Perioperative orthopedic surgical home: optimizing total joint arthroplasty candidates and preventing readmission. J Arthroplasty.2019 Jul;34(7S):S91-6. Epub 2019 Jan 18.
  4. Hannon CP, Calkins TE, Li J, Culvern C, Darrith B, Nam D, Gerlinger TL, Buvanendran A, Della Valle CJ. The James A. Rand Young Investigator’s Award: large opioid prescriptions are unnecessary after total joint arthroplasty: a randomized controlled trial. J Arthroplasty.2019 Jul;34(7S):S4-10. Epub 2019 Feb 4.
  5. Chalmers BP, Weston JT, Osmon DR, Hanssen AD, Berry DJ, Abdel MP. Prior hip or knee prosthetic joint infection in another joint increases risk three-fold of prosthetic joint infection after primary total knee arthroplasty: a matched control study. Bone Joint J.2019 Jul;101-B(7_Supple_C):91-7.

When Does I&D Beat 2-Stage Exchange in Second rTKA?

It’s hard to contemplate “conservative treatment” in the case of a revised total knee arthroplasty (rTKA) with extensive instrumentation that needs a reoperation due to periprosthetic joint infection (PJI), because all the treatment options in that scenario are pretty complex. In the January 6, 2021 issue of JBJS, Barry et al. report on a retrospective review of 87 revisions of extensively instrumented rTKAs that found that irrigation and debridement (I&D) with chronic antibiotic suppression was as effective as 2-stage exchange in preventing another reoperation for infection—and more effective in terms of maintaining knee function.

The average follow-up of the cases studied was 3.2 years, and the authors carefully defined “extensive instrumentation.” Among the 56 patients who were managed with I&D and suppression and the 31 who were managed with the initiation of 2-stage exchange (average age in both groups approximately 67 years), no significant differences were found in the rates of reoperation for infection or mortality. However, 9 of the 31 patients (29%) in the 2-stage group never underwent the second-stage reimplantation. Among those 9, 3 died prior to reimplantation and 2 underwent amputation due to failure of infection control.

Moreover, at the time of the latest follow-up, a significantly higher percentage of patients in the I&D group were ambulatory (76.8% vs 54.8% in the 2-stage group) and were able to functionally bend their knee (85.7% vs 45.2% in the 2-stage group). The authors surmise that these 2 findings are related to the soft-tissue damage and bone loss that typically occur during stage-1 removal of rTKA components.

Barry et al. conclude that in similar situations “deviating from the so-called gold standard of 2-stage exchange and accepting the modest results of I&D may be in the best interest of the patient,” as long as there are no loose implants in the existing construct. But the “sobering” mortality rates in the study (39.3% in the I&D group and 38.7% in the 2-stage group) remind us that this clinical scenario is extremely challenging for patients and surgeons, no matter which option is selected.

Click here to view an “Author Insights” video about this study with co-author Jeffrey Barry, MD.

Same-Patient Trial Design Measures Incremental Improvements in TKA Outcomes

The clinical and functional outcomes after total knee arthroplasty (TKA) are generally very favorable. The 15% to 20% of subpar patient-reported outcomes are usually related to persistent pain. Orthopaedic researchers have exhaustively investigated patient factors and technical considerations to address dissatisfaction in this minority population of TKA patients.

Meanwhile, the orthopaedic community has focused on prosthetic design in its attempts to incrementally improve outcomes for the 80% to 85% of generally satisfied TKA patients. Clearly documenting those incremental improvements often requires elegant study design. That’s what we see in the January 6, 2021 issue of The Journal, where Kim et al. report findings from a randomized trial in which 2 different knee-implant designs were compared in the same patients after primary simultaneous bilateral TKA.

Each of the 50 patients (49 of them women) received a posterior-stabilized design in 1 knee and an ultracongruent prosthesis in the other. Kim et al. selected the Forgotten Joint Score (FJS) as the primary outcome. The FJS is a 12-item questionnaire that assesses patient awareness of the artificial joint during daily activities. At 2 years, the researchers found no between-knee differences in FJS. The ultracongruent knees showed more anteroposterior laxity and less femoral rollback than the posterior-stabilized knees, but there were, again, no between-group differences in following measures:

  • Range of motion
  • Knee Society and WOMAC scores
  • Side Preference and patient satisfaction

The ultracongruent advancement in prosthetic design does not appear to offer clinically important advantages over the posterior-stabilized design. But if additional TKA patients can be recruited into studies using clever and effective experimental designs like this one, the future is bright for more robust assessments of the incremental impact of prosthetic design on functional and clinical outcomes.

Click here to view an Infographic summarizing this study.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

FDA OKs Synthetic Implant for Repairing ACL Tears

OrthoBuzz has been following the development of the Bridge-Enhanced ACL Repair (BEAR) implant—a synthetic alternative to graft-based anterior cruciate ligament reconstruction—since 2015 (see previous OrthoBuzz posts). On December 16, 2020 the FDA granted authorization to Miach Orthopaedics, Inc. to market the implant.

The BEAR implant is made from bovine collagen. After securing it with sutures to the torn ends of a completely ruptured ACL, the surgeon injects the patient’s own blood into the implant, which forms a clot that enhances ligament healing. Within 8 weeks, the implant is resorbed and replaced by the body’s own tissue.

The FDA’s authorization was based on results from a 100-patient randomized clinical trial, in which 65 patients received the BEAR implant and 35 underwent conventional autograft reconstruction. After 2 years, patient-reported outcomes in both groups were similar for pain, knee function, and sports activity, and arthrometry showed nearly identical joint-laxity outcomes. It remains to be seen how durable the BEAR implant will be over time and how much arthritis will develop in BEAR-treated knees 15 or 20 years from now.

The FDA’s marketing authorization for the BEAR implant was granted under the agency’s de novo device review pathway. That means that subsequent similar devices can be reviewed through the FDA’s 510(k) process, which requires a demonstration of “substantial equivalence” to the predicate device.

Knee OA: Does It Start with Stiff Menisci or Soft Cartilage?

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.

As an orthopaedic surgeon, I often noticed the rigidity of the meniscus as I excised it during a total knee replacement. Focused on the job at hand, however, I never closely considered the involvement of menisci in degenerative joint disease. But German researchers recently hypothesized that early biomechanical changes in meniscal tissue occur before articular cartilage changes in knee osteoarthritis.1

To test their hypothesis, they dissected 12 cadaver knees with Kellgren-Lawrence (KL) scores between 1 and 2 and 12 knees with KL scores between 3 and 4. The menisci were carefully embedded in a cast of polymethylmethacrylate using bony attachments to hold the specimens for Einst testing at the anterior horn, pars intermedia, and posterior horn. (Instantaneous modulus of elasticity [Einst] is the measure of the initial response of a viscoelastic material to an initial load before long-term deformity occurs.)  The exposed tibial surface was then cut 10 mm below the joint for Einst testing at the same zones, and the researchers also measured the articular cartilage-to-cartilage contact area.

Mann-Whitney U-testing revealed higher meniscal Einst values with increasing degeneration for both lateral and medial menisci, while the underlying tibial articular cartilage showed a decrease in Einst in the medial compartment. These findings suggest that knee joint degeneration might very well begin with a stiffening of the menisci, followed by articular cartilage softening.

The wide variation in Einst values uncovered in this study leaves open the possibility there is more than one pathway by which the biochemical response to meniscal cytokine expression would lead to subsequent articular cartilage breakdown. Nevertheless, the authors suggest that their findings might prompt the treatment and diagnostic paradigms of knee osteoarthritis to change, “focusing on the degeneration detection of the menisci instead of the articular cartilage.”

Reference 

  1. Seitz AM, Osthaus F, Ignatius A, Dürselen L. Degeneration alters first the biomechanical properties of human menisci before affecting the tibial cartilage. ORS 2020 Annual Meeting Paper No.0687

A Deeper Dive into Diabetes and Total Joint Replacement

There are many more “types” of diabetes than the pathophysiologic designations of Type 1 and Type 2. In the December 16, 2020 issue of The Journal of Bone & Joint Surgery, Na et al. delineate 4 different diabetes categories and determine their impact on 90-day complications and readmission rates after elective total joint arthroplasty (TJA) among Medicare patients. One premise for this investigation was that, although diabetes is a known risk factor for arthroplasty complications, alternative payment models such as the federally run Comprehensive Care for Joint Replacement (CJR) program adjust their payments only in diabetes cases where the comorbidity is coded as severe.

The authors stratified diabetes into 4 groups as follows:

  1. No diabetes
  2. Controlled-uncomplicated diabetes
  3. Controlled-complicated diabetes
  4. Uncontrolled diabetes

Among the >500,000 total knee arthroplasties (TKAs) and total hip arthroplasties (THAs) analyzed, the authors found the following when comparing data from the 3 diabetes groups with the no-diabetes group:

  • The odds of TKA complications were significantly higher for those with uncontrolled diabetes (odds ratio [OR] = 1.29).
  • The odds of THA complications were significantly higher for those with controlled-complicated diabetes (OR = 1.45).
  • The odds of readmission were significantly higher in all diabetes groups for both TKA (ORs = 1.21 to 1.48) and THA (ORs = 1.20 to 1.70).

The authors come to 3 basic conclusions based on these findings:

  1. The odds of hospital readmission and complications following an elective TKA or THA are increased for Medicare beneficiaries who have diabetes.
  2. It would be reasonable to defer arthroplasty surgery for those with uncontrolled diabetes to allow them to achieve glycemic control.
  3. The Centers for Medicare & Medicaid Services should include less-severe diabetes and associated systemic complications in alternative-payment model adjustments.

Click here for an “Author Insight” video about this study from co-author Annalisa Na, PhD, DPT.

Tibial BME Not Associated with Adverse Post-HTO Outcomes

Medial opening-wedge high tibial osteotomy (MOHTO) is a tried-and-true joint preservation technique for medial compartment knee osteoarthritis with varus alignment. Multiple studies have shown good short- and medium-term Kaplan-Meier survival with MOHTO, but questions remain regarding potential factors that lead to deteriorating outcomes over time. One such question is whether the presence of medial tibial bone marrow edema (BME) in a varus-aligned knee prior to MOHTO might lead to worse outcomes or survival afterward.

In the December 2, 2020 issue of The Journal, Yang et al. investigated this question with a retrospective case series of 105 patients with preoperative BME on MRI who underwent MOHTO. The BME was reviewed and graded by 2 independent observers based on both the diameter of the lesion and the volume of the medial tibia affected. The researchers radiographically evaluated postoperative alignment correction and compared preoperative and postoperative patient-reported outcomes using the Hospital for Special Surgery (HSS) score, Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Knee Society Score (KSS), and Short Form-12 (SF-12).

At an average follow-up of 6.2 years, Yang et al. found significant improvements in all patient-reported outcomes—with no correlation between outcomes and the presence or extent of BME. Overall survival was 95.2% at 6.2 years, showing that the improvements were durable throughout the study period, despite the preoperative presence of BME.

Although it would have been helpful to have a comparison group to see whether there were any functional-outcome differences between patients with and without BME, this study shows that MOHTO is a reliable and effective treatment for patients with BME, at least up until 6 years. And certainly, as the authors assert in the final sentence, “Preoperative BME should not be considered a contraindication for MOHTO.”

Matthew R. Schmitz, MD
JBJS Deputy Editor for Social Media

RCT: “Mini-Navigation” Improves TKA Component Alignment

Alignment is one of the most important factors affecting the longevity of total knee arthroplasty (TKA) prostheses. Among the many available tools for attaining good alignment are new palm-sized, accelerometer-based navigation systems. In the November 18, 2020 issue of The Journal of Bone & Joint Surgery, Minoda et al. deliver robust evidence from a multicenter randomized controlled trial comparing post-TKA coronal alignment with such a “mini-navigation” system versus results using conventional navigation.

The 90 TKAs analyzed (45 in each group) were performed by 8 different surgeons across 5 hospitals in Japan. The primary outcome was the number of tibial-prosthesis alignment outliers, defined as alignment error of >2° relative to neutral, based on weight-bearing radiographs 6 months after surgery. Researchers also compared absolute differences from neutral alignment for both tibial and femoral components, operative time, and complications.

Relative to conventional navigation, the mini-navigation system reduced the number of outliers in tibial alignment and hip-knee-ankle (HKA) angle. In addition, the absolute differences in the coronal alignment of the femoral and tibial prostheses were less in the mini-navigation group. Researchers found no increase in operative time with the portable navigation system, nor was there any observed increase in perioperative complications compared with conventional navigation.

Conversely, there were no significant between-group differences in postoperative Knee Society scores, but the authors note that “another study design with a longer follow-up period” is needed to evaluate the patient-centered clinical effects of prosthetic alignment using portable navigation. Both the authors and Andrew P. Kurmis, FRACS(Ortho), who commented on the study, assert that the true value of navigation systems (mini and full-sized alike) probably lies in higher reproducibility of tibial-component alignment relative to conventional navigation, regardless of the skill and experience of the surgeon.