Tag Archive | total knee arthroplasty

High Value Joint Replacements at Physician-Owned Hospitals

H image for OBuzzIn the November 15, 2017 issue of The Journal, Courtney et al. carefully evaluate CMS data to compare TKA and THA costs, complications, and patient satisfaction between physician-owned and non-physician-owned hospitals. The authors used risk-adjusted data when comparing complication scores between the two hospital types, in an attempt to address the oft-rendered claim that surgeons at physician-owned facilities “cherry pick” the healthiest patients and operate on the highest-risk patients in non-physician-owned facilities.

In general, the findings suggest that, for TKA and THA, physician-owned hospitals are associated with lower costs to Medicare, fewer complications and readmissions, and superior patient-satisfaction scores compared with non-physician-owned hospitals. These findings should come as no surprise to readers of The Journal. One fundamental principle of health care finance is that physicians control 70% to 80% of the total cost of care with their direct decisions. When physician incentives are aligned with those related to the facility, the result is better care at lower cost.

Nevertheless, many policymakers remain convinced that physician-owners are completely mercenary and base every decision on maximizing profit margins—even if that includes ordering unnecessary tests, performing unnecessary procedures, or using inferior implants. We need more transparency among physician-owners at local and national levels to address these usually-erroneous assumptions, which are frequently repeated by local non-physician-owned health systems. For example, we should be transparent with the percentage of the margin that ends up in the physician-owner’s pocket. Whatever the “right” percentage is, I believe it should not be the dominant factor in a physician’s total income..

The findings from Courtney et al. should spur further debate on this issue. I am confident that the best outcomes for individual patients and the public result when physicians (and their patients) stay in direct control of decision making regarding care, when surgeons are appropriately motivated to be cost- and outcome-effective, and when we all do our part to care for the under- and uninsured.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

New Level-I Data on TKA Blood Conservation

TXAMinimizing perioperative blood loss during total knee arthroplasty (TKA) helps curtail the risks and costs of allogeneic blood transfusions. Currently, the most popular pharmacological approach to blood conservation is the antifibrinolytic agent tranexamic acid (TXA). But in a randomized trial published in the October 4, 2017 edition of The Journal of Bone & Joint Surgery, Boese et al. found that a similar and much less expensive compound, epsilon-aminocaproic acid (EACA), performed almost as effectively and just as safely as TXA in patients undergoing unilateral knee replacement.

Although the 98 patients in the study who received TXA averaged less estimated blood loss than the 96 patients who received EACA, no transfusions were required in either group, and there were no statistically significant or clinically relevant between-group differences in the change in hemoglobin levels. On the safety/complication side, there were no statistically significant between-group differences in any measured parameter, including postoperative serum creatinine levels or renal, bleeding, or thrombotic complications. However, there were 3 pulmonary emboli in the EACA group compared with only 1 in the TXA group. While that was not a statistically significant difference, “an observed difference of this magnitude could limit the usefulness of EACA in TKA,” the authors caution.

This study did not compare the current cost of the two compounds, but back in 2012, when the authors’ institution added antifibrinolytics to their blood management program, TXA cost $43/g, compared with $0.20/g for EACA. The cost differential is striking, even when you consider that TXA is at least 7 times more potent than EACA on a molar basis, so less of the former drug is required.

Boese et al. conclude that “TXA does not have superior blood conservation effects or safety profile compared with EACA in TKA,” but they cite a need for future equivalence, superiority, and noninferiority trials with these drugs.

For TKA Pain Relief, Motor-Sparing Blocks Last Longer than Periarticular Infiltration

Adductor Canal Block for OBuzz
Analgesia after total knee arthroplasty (TKA) is a multimodal affair these days. Main goals include maintaining adequate patient comfort while limiting opiate use and permitting early mobilization.

In the August 2, 2017 issue of JBJS, Sogbein et al. report on a blinded randomized study comparing the performance of two types of analgesia often used in multimodal TKA pain-management protocols: preoperative motor-sparing knee blocks and intraoperative periarticular infiltrations.

Prior to surgery, the 35 patients in the motor-sparing block group received a midthigh adductor canal block under ultrasound guidance, combined with posterior pericapsular and lateral femoral cutaneous injections. The 35 patients in the periarticular infiltration group received study-labeled local anesthetics intraoperatively, just prior to component implantation.

Defining the “end of analgesia” as the point at which patient-reported pain at rest or activity rated ≥6 on the numerical rating scale and rescue analgesia was administered, the authors found that the duration of analgesia was significantly longer for the motor-sparing-block group compared with the periarticular-infiltration group. The infiltration group had significantly higher scores for pain at rest for the first 2 postoperative hours and for pain with knee movement at 2 and 4 hours. There were no between-group differences in time to mobilization, length of hospital stay, opiate consumption, or functional recovery.

Remove or Retain the PCL in TKA?

Posterior Stabilized Knee for OBuzz.jpegIn the world of total knee arthroplasty (TKA), the arguments about retaining the posterior cruciate ligament (PCL) versus stabilizing the knee with posterior-stabilized components have raged for more than 30 years. The number of cohort studies and controlled trials attempting to clarify the issue have been too high to count. In the July 5, 2017 issue of The Journal, Vertullo et al. use the power of the Australian national joint registry to add additional important clinical information to the debate.

More than 62,000 TKA cases formed the substrate of this analysis. In a study-design twist, the revision-related outcomes were analyzed on the basis of the preference surgeons had for the two different design options, not on the basis of which prostheses were actually used. Consequently, there was a likelihood that the cohort of patients treated by surgeons who had a preference for posterior-stabilized designs would include some PCL-retained cases, and vice-versa. The authors claim that this “instrumental variable analysis” has “the capacity to remove the confounding by indication or disease severity against posterior-stabilized total knee replacements.” However, as with any registry study, there were still many confounding variables that could have influenced the revision rate, not the least of which is surgeon skill in component alignment and ligament tensioning.

Nevertheless, with selection bias minimized, Vertullo et al. found a real difference in revision rates favoring retention of the PCL. That finding does make biomechanical sense to this non-arthroplasty surgeon, who would expect less stress on the tibial component-bone interface at the extremes of knee motion with the PCL-retaining procedure.

Biomechanics notwithstanding, I think this very large registry-based arthroplasty study will influence the debate going forward, but I doubt it will end the debate or that it will change the TKA practices of many surgeons worldwide. For a more definitive and potentially practice-changing resolution to this clinical conundrum, we’ll need a very large (2,000 to 3,000 patients in each arm) international trial where surgeons and patients accept randomization between these two choices.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

The Opioid Epidemic: Consequences Beyond Addiction

knee-spotlight-image.pngThe orthopaedic community worldwide—and especially those of us in the US, the nation most notorious for over-prescribing—has become very cognizant of the epidemic of opioid abuse. Ironically, the current problem was fueled partly by the “fifth vital sign” movement of 10 to 20 years ago, when physicians were encouraged (brow-beaten, in my opinion) to increase the use of opioid medications to “prevent” high pain scores.

Researchers internationally are now pursuing clarification on the appropriate use of these medications. The societal consequences of opioid addiction, which all too often starts with a musculoskeletal injury and/or orthopaedic procedure, have been well documented in the social-science and lay literature. In the May 17, 2017 issue of The Journal, Smith et al. detail an additional consequence to the chronic use of opioid drugs—the negative impact of preoperative opioids on pain outcomes following knee replacement surgery.

Approximately one-quarter of the 156 total knee arthroplasty (TKA) patients analyzed had had at least one preoperative opioid prescription.  Patients who used opioids prior to TKA obtained less pain relief from the operation than those who had not used pre-TKA opioids. The authors also found that pain catastrophizing was the only factor measured that was independently associated with pre-TKA opioid use.

To be sure, we need to disseminate this information to the primary care community so they will be more judicious about prescribing these medications for knee arthritis. Additionally, knee surgeons should consider working with primary care providers to wean their TKA-eligible patients off these medications, with the understanding that chronic use preoperatively compromises postsurgical pain relief and functional outcomes.

We have previously published in The Journal the fact that the use of opioids is largely a cultural expectation that varies by country; physicians outside the US often achieve excellent postoperative pain management success without the use of these medications. My bottom line: We must continue to press forward to limit the use of opioid medications in both pre- and postoperative settings.

Marc Swiontkowski, MD
JBJS Editor-in-Chief

Total Joint Arthroplasty: Does One Lead to Another?

TJA and Second TJA.jpegAn estimated 7 million people living in the US have undergone a total joint arthroplasty (TJA), and the demand for total hip arthroplasty (THA) and total knee arthroplasty (TKA) will almost certainly increase during the next 15 years.  But how many people can expect to have an additional TJA after having a first one?

That’s the question Sanders et al. address in their historical cohort study, published in the March 1, 2017 edition of The Journal of Bone & Joint Surgery. They followed more than 4,000 patients who underwent either THA or TKA between 1969 and 2008 to assess the likelihood of those patients undergoing a subsequent, non-revision TJA.

Here’s what they found:

  • Twenty years after an initial THA, the likelihood of a contralateral hip replacement was 29%.
  • Ten years after an initial THA, the likelihood of a contralateral knee replacement was 6%, and the likelihood of an ipsilateral knee replacement was 2% at 20 years.
  • Twenty years after an initial TKA, the likelihood of a contralateral knee replacement was 45%.
  • After an initial TKA, the likelihood of a contralateral hip replacement was 3% at 20 years, and the likelihood of an ipsilateral hip replacement was 2% at 20 years.

In those undergoing an initial THA, younger age was a significant predictor of contralateral hip replacement, and in those undergoing an initial TKA, older age was a predictor of ipsilateral or contralateral hip replacement.

The authors conclude that “patients undergoing [THA] or [TKA] can be informed of a 30% to 45% chance of a surgical procedure in a contralateral cognate joint and about a 5% chance of a surgical procedure in noncognate joints within 20 years of initial arthroplasty.” They caution, however, that these findings may not be generalizable to populations with more racial or socioeconomic diversity than the predominantly Caucasian population they studied.

New Knee Content from JBJS

knee-spotlight-image.pngThe recently launched JBJS Knee Spotlight offers highly relevant and potentially practice-changing knee content from the most trusted source of orthopaedic information.

Here are the five JBJS articles to which you will have full-text access through the Knee Spotlight during the month of March 2017:

  • Improved Accuracy of Component Positioning with Robotic-Assisted Unicompartmental Knee Arthroplasty: Data from a Prospective, Randomized Controlled Study
  • The Effect of Timing of Manipulation Under Anesthesia to Improve Range of Motion and Functional Outcomes Following Total Knee Arthroplasty
  • Anatomic Single-Bundle ACL Reconstruction Is Possible with Use of the Modified Transtibial Technique: A Comparison with the Anteromedial Transportal Technique
  • Autologous Chondrocyte Implantation in the Knee: Mid-Term to Long-Term Results
  • Outcomes of Unicompartmental Knee Arthroplasty After Aseptic Revision to Total Knee Arthroplasty: A Comparative Study of 768 TKAs and 578 UKAs Revised to TKAs from the Norwegian Arthroplasty Register (1994 to 2011)

Knee studies offered on the JBJS Knee Spotlight will be updated monthly, so check the site often.

Visit the JBJS Knee Spotlight website today.

What’s New in Adult Reconstructive Knee Surgery

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/PE Prophylaxis

—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

References

  1. 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.
  2. 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]
  3. 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.

 

New Knee Content from JBJS

knee-spotlight-image.pngThe recently launched JBJS Knee Spotlight offers highly relevant and potentially practice-changing knee content from the most trusted source of orthopaedic information.

Here are the five JBJS articles to which you will have full-text access through the Knee Spotlight during the month of February 2017:

  • Comparison of Highly Cross-Linked and Conventional Polyethylene in Posterior Cruciate-Substituting Total Knee Arthroplasty in the Same Patients

  • What’s New in Adult Reconstructive Knee Surgery

  • Hinged External Fixation in the Treatment of Knee Dislocations: A Prospective Randomized Study

  • A Randomized, Controlled, Prospective Study Evaluating the Effect of Patellar Eversion on Functional Outcomes in Primary Total Knee Arthroplasty

  • Comparison of Functional Outcome Measures After ACL Reconstruction in Competitive Soccer Players: A Randomized Trial

Knee studies offered on the JBJS Knee Spotlight will be updated monthly, so check the site often.

Visit the JBJS Knee Spotlight website today.

Long-Term Opioid Use Before TKA Raises Risk of Revision

Opioid and TKA Revision.gifGiven the prevalence of opioid prescriptions, many patients present for total knee arthroplasty (TKA) having been on long-term opioid therapy. In the January 4, 2017 edition of The Journal of Bone & Joint Surgery, Ben-Ari et al. determined that patients taking opiate medications for more than three months prior to their TKA were significantly more likely than non-users of opioids to undergo revision surgery within a year after the index procedure.

Among the more than 32,000 TKA patients from Veterans Affairs (VA) databases included in the study, nearly 40% were long-term opioid users prior to surgery. Despite that high percentage, the authors found that chronic kidney disease was the leading risk factor for knee revision among the relevant variables they examined. And even though the authors used a sophisticated natural language/machine-learning tool to analyze postoperative notes, they found no association between long-term opioid use and the etiology of the revisions.

In a commentary accompanying the study, Michael Reich, MD and Richard Walker, MD, note that the study’s very specific VA demographic (94% male) may hamper the generalizability of the findings, especially because most TKAs are currently performed in women. Nevertheless, the commentators conclude that:

  • “The study illuminates the value in limiting opioid use during the nonoperative treatment of patients with knee arthritis.”
  • “Patients who are taking opioids when they present for TKA could reasonably be encouraged to decrease opioid use during preoperative preparation.”
  • “Preoperative use of opioids should be considered among modifiable risk factors and comorbidities when deciding whether to perform TKA.”