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Persons with type 2 diabetes (T2D) who are treated with metformin may be at significantly reduced risk for total joint replacement (hip, knee) according to research from China published online January 19, 2023, in the Canadian Medical Association Journal.

The population-based matched cohort study of more than 40 000 participants found the risk of total knee replacement (TKR) or total hip replacement (THR) was reduced by 30% in participants who received metformin compared to those who did not.

Total joint replacement is often required in older adults with osteoarthritis (OA) primarily because there are no treatments available to prevent or reverse the chronic progressive joint disease, the authors write. They point to trends in the US where the demand for both TKR and THR is expected to reach 3.5 million by 2030 when a projected 572 000 surgeries will be required annually.

The investigators, led by Changhai Ding, MD, PhD, professor and director, Clinical Research and Orthopedic Centres, Zhujiang Hospital at Southern Medical University, Guangzhou, China, also point out that OA is common in those with T2D. In fact, T2D is a known OA risk factor, independent of body mass index and there is evidence that insulin resistance may hasten the development of OA. Interestingly, metformin, in addition to being the first line antihyperglycemic agent for T2D around the world, also has been associated with reducing risk of cardiovascular and inflammatory disease and shown to have chondroprotective effects. The authors cite evidence that intra-articular metformin administered shortly after joint injury has delayed OA development in animal models, as well.

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In the US…the demand for both TKR and THR is expected to reach 3.5 million by 2030 when a projected 572 000 surgeries will be required annually.

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Despite some evidence of a T2D-OA association, however, Ding et al say that, overall, studies looking at the potential correlation are “uncommon and inconclusive.”

To add to and help clarify existing findings, Ding et al tapped the Taiwan National Health Insurance Research Database, selecting adults aged ≥45 years who were diagnosed with T2D between 2000 and 2012. The investigators then identified those treated with metformin, defining a metformin user as anyone who had initiated the drug within 180 days before or after a diagnosis of T2D. Researchers matched metformin users by age, sex, and time of diagnosis with nonusers in the database. They conducted separate analyses using prescription time-distribution matching (PTDM) and propensity-score matching (PSM) to balance potential confounding variables.

The primary outcomes were TKR or THR after the index date (3 months after the first metformin prescription). The authors point out that because all cases were peer-reviewed before reimbursement was approved, the accuracy of the data on TKR and THR was high.

FINDINGS

The final study cohort numbered 40 694 participants with 20 347 each in the metformin user and nonuser groups. Mean age was 63 years 49.8% were women. A total of 837 patients underwent TKR and 148 underwent THR in the PTDM cohorts and an average of 90% of replacements were related to OA (97.5% for TKR, 50.7% for THR).

When Ding and colleagues compared participants who did not use metformin with those who did, use of metformin was associated with a lower cumulative incidence probability of TKR, THR or either joint replacement. The TKR incidence in the PTDM cohort was 2.96 vs 4.15 per 10 000 person-months for metformin users and nonusers respectively (adjusted hazard ratio [aHR] 0.71, 95% CI 0.61-0.84). For THR in this cohort incidence was 0.44 vs 0.83 per 10 000 person-months for users and nonusers respectively, with an adjusted HR of 0.61 (95% CI 0.41-0.92).

In the PSM cohort, when researchers compared metformin users with those who did not use the drug, the crude HR of total joint replacement was 0.73 (95% CI 0.61–0.87), and the adjusted HR was 0.75 (95% CI 0.62–0.89). They report a significant reduction in risk for TKR in metformin users compared to nonusers (aHR 0.76, 95% CI 0.62-0.92) and a similar but not significant reduction for THR (aHR 0.71, 95% CI 0.44-1.13) in the PMS cohort. Propensity-score matching analyses (10 163 participants not treated with metformin v. 10 163 treated with metformin) and sensitivity analyses using inverse probability of treatment weighting and competing risk regression showed similar results.

Diabetes and metabolic syndrome have both been linked to OA in the past, the investigators write. They point out also that although the biological mechanisms linking metformin with protection against OA remain unclear, the reduction in need for total joint replacement in T2D patients may be explained by metformin’s anti-inflammatory properties, its ability to sustain adenosine 5′-monophosphate–activated protein kinase activity in chondrocytes and to regulate metabolism.

“Given our findings and those of a previous observational study, a randomized trial of the efficacy of metformin in patients with OA is indicated. Metformin has been studied in patients without diabetes mellitus and was found to be safe,” they conclude.

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Reference: Zhu Z, Huang J-Y, Ruan G, et al. Metformin use and associated risk of total joint replacement in patients with type 2 diabetes: a population-based matched cohort study. CMAJ. 2022;194:E1672-84. doi:10.1503/cmaj.220952

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“We’re more concerned about a patient’s health over their chronological age,” says Mark Shekhman, MD, an orthopedic surgeon at the Bone & Joint Institute at Hartford Hospital. “There is no real limit to the age.”

Considering a joint replacement in your 70s or 80s? Join the club.

Dr. Shekhman has reassured plenty of 70- and 80-year-old patients: Not only are they not too old for a joint replacement — they’re in the most common age group.

“Patients in their 70s and 80s are old enough to have worn out their joints, but usually healthy enough to go through surgery,” says Dr. Shekhman.

Even patients in their 90s can be candidates.

Many joint replacement patients in their 90s had passed on the procedure earlier in life, believing they were too old. But after years of severe pain and even disability, they find themselves rethinking their decision.

“Finally they say, ‘I can’t live like this anymore,’” says Dr. Shekhman. “In this case, I recommend that they have a family meeting to discuss the somewhat increased risks given their age. If all family members agree that the benefits outweigh the risks, then we go ahead with the medical screening process.”

Thanks to medical advances, joint replacements are safer at every age.

Does this all sound too good to be true?

Twenty years ago, maybe. But today, we have the benefit of less invasive techniques and gentler anesthesia methods — which make joint replacements safer than ever.

“With the advancement of medical technology, the surgery is a less physiologically stressful experience for the body than it once was. We’re not replacing major organ systems like the heart or liver,” says Dr. Shekhman. “The risks today are quite low for all age groups.”

The real question: Are you healthy enough to get your hip or knee replaced?

At every age, deciding whether to have an elective procedure comes down to whether you’re healthy enough — even for a relatively low-risk procedure like a joint replacement.

This is where a thorough medical screening process comes in.

“We wouldn’t jump out of a plane without a parachute,” says Dr. Shekhman. “And we wouldn’t proceed with surgery without a thorough screening process to make sure a patient is ready and safe.”

Age is certainly a factor, but it’s far from the only one.

For example, a 60-year-old with a history of smoking, diabetes, obesity and heart disease might have too many health risks to qualify for an elective joint replacement. Meanwhile, a comparatively active and healthy 90-year-old could get the green light.

The takeaway: You’re never too old to ask about a knee or hip replacement.

These surgeries often transform quality of life: They can relieve severe pain from arthritis and other conditions, and return you to activities that mean the most to you. Plus, the benefits are practically immediate.

“The patient can walk on the replaced joint the same day, fully weight-bearing, within a few hours after the operation,” says Dr. Shekhman.

So if you’ve been considering a knee or hip replacement, it’s worth a conversation with your doctor — even if you’re getting up there in years.

Haven’t you heard? Eighty is the new sixty.

Originally Appeared Here

Metformin may help reduce risk for total joint replacement in patients with type 2 diabetes (T2D), data suggest.

Over a 24-month follow-up period, metformin use was associated with a 30% decrease in the risk of total knee and hip replacements, according to Changhai Ding, MBBS, MMed, MD, associate director of the Menzies Institute for Medical Research at the University of Tasmania in Hobart, Australia, and colleagues.

“Randomized controlled clinical trials in patients with osteoarthritis are warranted to determine whether metformin is effective in decreasing the need for joint replacement,” wrote the investigators.

Their findings were published online December 19 in the Canadian Medical Association Journal.

Low Doses Beneficial

The investigators identified patients diagnosed with T2D from 2000 to 2012 in the Taiwan National Health Insurance Research Database and compared those who used metformin with those who did not. They used prescription time-distribution matching and propensity-score matching to balance potential confounders between users and nonusers.

The study included 20,347 metformin-treated participants and 20,347 nonusers. The mean age at baseline was 63 years, and 49.8% of participants were women. Metformin users tended to have more severe diabetes. Common comorbidities in the cohort included hypertension and hyperlipidemia, but only about 16% in both groups had osteoarthritis. At baseline, participants also used various analgesics, as well as other diabetes drugs ranging from sulfonylureas to insulin.

Compared with nonusers, metformin users had had a 30% lower risk of total knee or hip replacement (adjusted hazard ratio [HR], 0.70). The incidence of total knee replacement among metformin nonusers and users was 4.15 per 10,000 person-months and 2.96 per 10,000 person-months, respectively. The incidence of total hip replacement was 0.83 per 10,000 person-months in nonusers and 0.44 per 10,000 person-months in users.

By joint type, the adjusted HR was 0.71 for total knee replacement and 0.61 for total hip replacement among metformin users.

The effect was observed at daily doses of less than 1 g, as well as daily doses of 1 g or more. “This suggests that metformin at a lower dosage could have effects on osteoarthritis,” Ding told Medscape Medical News. “Metformin is a safe, well-tolerated oral medication, even at higher but routinely used dosages. Therefore, for initial clinical trials, we still recommend the efficacy of metformin at routine dosages on knee osteoarthritis. If the effects are confirmed, we may explore whether a lower dosage of metformin is effective.”

Similar results emerged from propensity-score matching analyses and sensitivity analyses of 10,163 participants in each treatment group using inverse probability-of-treatment weighting and competing risk regression.

The biological mechanisms linking metformin and osteoarthritis have yet to be clarified, Ding explained. “Multiple mechanisms may be involved, including anti-inflammation, sustaining adenosine 5′-monophosphate-activated protein kinase activity in chondrocytes and dorsal root ganglia, and regulating metabolism.”

A previous study suggested an association between metformin and reduced annual loss of medial cartilage volume, and another found an association between metformin and reduced joint replacement surgery, said Ding. But another study reported no significant association between metformin use and osteoarthritis risk in patients with T2D. Recently, a retrospective cohort study by Li et al found that metformin users with diabetes had a 19% lower risk for total knee replacement than nonusers.

Ding’s group has begun a randomized clinical trial to see whether metformin can alleviate tibiofemoral cartilage volume loss in overweight patients with osteoarthritis.

No Uniform Indications

Commenting on the current findings for Medscape, Grace Hsiao-Wei Lo, MD, an assistant professor of immunology, allergy, and rheumatology at Baylor College of Medicine in Houston, Texas, called the observational study “thought-provoking.” She had concerns about the way it was conducted, however, including the potentially problematic features of the small percentage of the T2D cohort who had osteoarthritis. Another concern was the fact that the investigators only examined metformin, although patients used various other diabetic and analgesic drugs that might have had an effect. Metformin’s effect on osteoarthritis may result partly from its modest weight-loss effects, said Lo, who was not involved in the study.

“Another issue with the study is that there is no set indication of the need for total knee or hip replacement. Each surgeon has a different standard,” she added. “And there’s lots of evidence that replacements are largely dependent not on need but on the interest of participants. “So, it’s not necessarily that a patient needs total joint replacement, it’s that they want it.”

Observational studies like this one are a long way from getting us to the prescribing of metformin specifically to prevent or mitigate osteoarthritis, David T. Felson, MD, MPH, a rheumatology researcher and a professor of medicine at Boston University, Boston, Massachusetts, told Medscape. Felson was not involved in the study.

“The drug’s mechanisms in osteoarthritis are still unclear. Its effect may be related to adenosine 5′-monophosphate-activated protein kinase activity,” he said. “The drug has pleiotropic effects and is safely used to treat other diseases such as polycystic ovarian syndrome. It may have antisenescence properties, since it’s been shown to extend life a bit in animals.” That said, Felson added, “Like statins, it’s not going be added to the drinking water anytime soon!”

This study was supported by the National Natural Science Foundation of China, Guangzhou Science and Technology Program, Guangdong Basic and Applied Basic Research Foundation, and Wu Jieping Medical Foundation Program. Ding, Lo, and Felson reported no competing interests.

CMAJ. Published online December 19, 2022. Full text.

Diana Swift is a freelance medical journalist based in Toronto, Ontario, Canada.

For more news, follow Medscape on  Facebook,   Twitter,   Instagram, and  YouTube.

Dr. Richard Berger – a renowned hip and knee replacement surgeon at Midwest Orthopaedics at Rush and assistant professor at Rush University Medical Center, Chicago, is known for pioneering a minimally invasive joint replacement procedure that cuts less tissue and allows patients a quicker recovery, and his B.E.S.T Experience Telehealth program: a concierge-style service for out-of-state patients.

Dr. Berger is now offering the “BEST” pre-surgical and post-surgical consults via telehealth. These virtual consults are very thorough and include the pre-surgery prep classes and some instructions post-surgery about activities around the home and even assistance with physical therapy. They are a cost-saver for out-of-town patients, who now don’t have to pay for travel expenses, such as transportation and lodging.

For more information on the BEST, or to book an appointment, log on to outpatienthipandknee.com

For appointments with Dr. Richard Berger, call 312-432-2557 or visit www.outpatienthipandknee.com

Introduction

Although a substantial portion of the United States population has been infected with and recovered from Coronavirus Disease-19 (COVID-19), many patients may have persistent symptoms and complications from disease-driven respiratory disease, arrhythmias, and venous thromboembolism (VTE). With institutions resuming elective total joint arthroplasties (TJA), it is unclear whether a prior resolved diagnosis of COVID has any implications on postoperative outcomes.

Methods

All elective TJA performed in 2021 at our institution were retrospectively reviewed and a history of prior COVID+ result recorded. Baseline demographics, days from prior COVID+ result to surgery date, preoperative methicillin-resistant Staphylococcus aureus (MRSA) nares colonization, and laboratory markers were obtained to determine baseline characteristics. Postoperative estimated blood loss (EBL), length of stay (LOS), rate of revision surgery, and discharge destination were compared between groups. Perioperative and postoperative rates of VTE, urinary tract infection (UTI), pneumonia, postoperative oxygen supplementation, cardiac arrhythmia, renal disease, sepsis, and periprosthetic joint infections within six months of surgery were recorded.

Results

Of the 155 elective TJA performed in 2021, 24 patients had a prior COVID+ diagnosis with a mean of 253 days from positive result to surgery date. There were no significant differences in baseline demographics, comorbidities, and preoperative lab markers between groups. Surgeries on patients with a prior COVID+ had a significantly higher EBL (260 vs 175cc), but postoperative outcomes of VTE, UTI, pneumonia, oxygen supplementation requirement, nares MRSA+, cardiac disease, and infection rates between groups were similar. Bivariate logistic regression revealed increased days from COVID+ diagnosis (>6 months) to surgery date were associated with a shorter LOS.

Conclusion

Although a prior COVID+ diagnosis had increased intraoperative blood loss, there were no significant differences in respiratory, infectious, cardiac, and thromboembolic complications up to six months after elective TJA. This study suggests that asymptomatic C+ patients receiving elective TJA do not require more aggressive prophylactic anticoagulation or antibiotic regimens to prevent VTE or perioperative infections. As institutions around the nation resume pre-COVID rates of arthroplasty surgeries, a prior diagnosis of COVID appears to have no effects on postoperative complications.

Introduction

Materials & Methods

Results

Discussion

Conclusions

Enoxaparin bested aspirin for preventing symptomatic venous thromboembolism (VTE) after total hip or total knee arthroplasty when used without initial anticoagulation in the CRISTAL randomized trial.

These events occurred within 90 days of surgery in 3.45% of aspirin-treated patients compared with 1.82% of enoxaparin-treated patients, which didn’t hit noninferiority criteria but did show significant superiority for enoxaparin (P=0.007).

That primary endpoint advantage was driven by a 1.61-percentage point lower rate of deep vein thrombosis (DVT), specifically below-the-knee cases.

No significant differences emerged between groups for above-knee DVT or pulmonary embolism, Verinder S. Sidhu, MS, of the Ingham Institute for Applied Medical Research in Liverpool, Australia, and colleagues reported in JAMA.

In interpreting the study findings, the group cautioned that “below-knee DVT represents a less clinically important form of VTE compared with above-knee DVT or pulmonary embolism, and the clinical importance of these findings remains uncertain.”

Given similarly low incidences of major thromboembolic events and mortality, the results are unlikely to convince clinicians who use aspirin prophylaxis to switch, noted Noel C. Chan, MD, and Mohit Bhandari, MD, PhD, both of McMaster University in Hamilton, Ontario, in an accompanying editorial.

“Reducing nonfatal VTE is important, but any benefits with thromboprophylaxis require a trade-off with bleeding risk, costs to the health care system, and convenience to patients, all of which make aspirin particularly attractive for thromboprophylaxis,” they wrote.

In the CRISTAL trial, none of the six secondary outcomes came out different for enoxaparin versus aspirin, including mortality, major bleeding, 90-day readmission or reoperation, reoperation within 6 months, and drug adherence.

A recent large randomized clinical trial from Canada reported noninferiority of aspirin to rivaroxaban (Xarelto) for VTE prophylaxis after total hip or knee arthroplasty. “However, both groups received rivaroxaban for 5 days prior to randomization to either aspirin or continued rivaroxaban,” noted Sidhu’s group.

CRISTAL took that one step further for 9,711 adults (median age 68, 56.8% women) undergoing total hip or knee arthroplasty for osteoarthritis who were not getting preoperative anticoagulation. The 31 participating hospitals in Australia were cluster-randomized within a national registry to give aspirin 100 mg daily or enoxaparin 40 mg daily (except for those with underweight and poor kidney function) as the sole antithrombotic prophylaxis following a standardized protocol for a specified period before crossing over to the other agent.

Both regimens started within 24 hours of surgery and were continued for 35 days after hip arthroplasty and for 14 days after knee arthroplasty. Intraoperative and postoperative intermittent pneumatic compression calf devices were also used universally, along with compression stockings and mobilization on day 0 or day 1 postoperatively.

However, an important limitation was that the study was terminated early at 62% of the planned enrollment of 15,562.

The editorialists pointed out that this “reduced the power to detect differences in clinically important VTE,” and the researchers acknowledged that the study might not have been powered to detect certain significant between-group differences, specifically the numerically higher rate of pulmonary embolism in the aspirin group (1.1% vs 0.6% with enoxaparin, P=0.17).

Another issue, the editorialists wrote, was “the potential for diagnostic suspicion bias in patients taking aspirin because physicians making the decision to perform leg ultrasound or lung imaging were not masked to the assigned prophylactic treatment.”

The researchers added that another potential influence on the findings was that the 15% of people taking aspirin before the trial stayed on it, such that the group randomized to enoxaparin continued aspirin in addition to enoxaparin, whereas the aspirin group didn’t take additional aspirin.

They suggested that a cost-effectiveness analysis might be warranted “to better understand the clinical relevance of the trial results.”

On June 14, 2022, a group of plaintiffs filed a motion with the U.S. Judicial Panel on Multidistrict Litigation (JPML) to consolidate all Exactech joint replacement lawsuits in the U.S. District Court for the Eastern District of New York.

The plaintiffs claim that each of the actions involves common questions of fact and that consolidation would “serve the convenience of the parties and witnesses,” and “promote the just and efficient conduct of the litigation.”

Exactech Recalls Knee and Ankle Replacements Because of Insert Problems

In February 2022, Exactech issued a recall that impacted more than 140,000 Opetetrak, Optetrak Logic, and Truliant knee replacement systems as well as an additional 1,500 Vantage ankle replacements.

All of these devices used polyethylene inserts that according to Exactech, were packaged in non-conforming vacuum bags that lacked an additional protective layer. These bags could allow air to come into contact with the plastic inserts, which could cause oxidation and increase the risk that the devices would fail once implanted into a patient’s body.

Exactech has had similar problems with some of its hip implants, including the Connexion, Novation, and Acumatch. These have also shown a higher risk of premature failure because of problems with the polyethylene liner.

Plaintiffs Claim Faulty Inserts Led to Premature Implant Failures

According to the motion to transfer, there are already 27 Exactech lawsuits pending in 11 district courts across the country, with seven of those pending in the Eastern District of New York.

All of the cases involve similar allegations, with plaintiffs claiming that they received an Exactech knee or hip implant including polyethylene components that failed prematurely. The motion seeks to consolidate all of these cases—and any involving Exactech ankle replacements—into one court for pre-trial proceedings.

The Exactech recall includes polyethylene inserts manufactured as early as 2004 and packaged in out-of-specification vacuum bags that didn’t contain a second barrier layer. When these inserts fail, plaintiffs have to undergo revision surgery to remove the failed insert as well as other components, depending on the extent of the damage caused by the premature wear.

Degradation of the polyethylene can result in component loosening, tissue damage, osteolysis, permanent bone loss, and other injuries leading to complex revision surgeries and extensive recovery times.

Knee, Hip, and Ankle Devices All Share Similar Problems

The devices at issue for this proposed consolidated litigation include:

• Opetrak Tibial Insert (knee implant)
• Truliant Tibial Insert (knee implant)
• Vantage Tibial Insert (ankle implant)
• Connexion GXL Acetabular Liner (hip implant)

All of the liners that are included with these implants have been recalled. The plaintiffs seeking consolidation note that the cases involving these different implants are all related because their failures can be traced to the faulty polyethylene liner.

Despite CMS implementing a price transparency mandate, most hospitals are failing to comply when it comes to Total Joint Arthroplasty (TJA) procedures.

Hospitals are falling short of compliance on the price transparency mandate when it comes to two of the most common inpatient procedures.

According to a study by Clinical Orthopaedics and Related Research, only 32% of hospitals were fully compliant with price transparency on knee and hip replacement, or TJA.

When breaking down the results by individual procedures, 21% and 18% of hospitals provided the required information to be compliant for CPT codes 27447 and 27130, respectively, while 18% and 19% of hospitals did so for DRG codes 469 and 470.

Since the price transparency rule went into effect on January 1, 2021, CMS requires hospitals to provide five types of online price information for selected services: the total charge, the charges the hospital privately negotiated with health insurers, the minimum and maximum negotiated charges, and the amount the facility is willing to accept in cash.

Researchers of the study stated they chose to investigate price transparency for TJA procedures because of how widely used they are, making it some of the most commonly sought-after pricing information for orthopedic surgery patients.

The low compliance rates found in the study suggest hospitals are either struggling to implement the necessary changes to be compliant or are willfully ignoring the mandate.

“It is possible that hospitals have delayed compliance with the hope that related requirements may change or that current delays in enforcement may continue,” the authors wrote. “Although it is unclear whether legislation will change, the low rates of compliance demonstrated in our analysis should encourage hospitals to provide related information to avoid penalties expected to be enforced starting July 1, 2022.”

The study looked at 400 hospitals in December 2021 and searched each hospital’s website for a machine-readable file providing the five requirements for compliance. The researchers also considered hospitals pseudocompliant if they provided some type of gross price information.

The pseudocompliance rates were moderately higher, with 36% and 31% of hospitals offering total charges for CPT codes 27447 and 27130, respectively, and 34% and 50% of hospitals doing so for DRG codes 469 and 470.

Additionally, 13% of hospitals failed to provide machine-readable files, while 21% required users to provide personal information.

A recent JAMA study highlighted hospitals’ avoidance of price transparency, with the findings showing roughly 51% of facilities did provide either a machine-readable file or a shoppable display.

Only two hospitals, Northside Hospital Atlanta and Northside Hospital Cherokee, have so far been fined by CMS for failing to comply with price transparency requirements.

More fines are expected, but the authors of the TJA study believe hospitals should not only act to comply for the sake of their wallets, but also for the sake of their patients.

“Given the potential influence compliance and price sharing may have on empowering patients’ healthcare decisions and reducing healthcare expenditures in the United States, hospitals should use our analysis to identify where their compliance is lacking and to understand how to make their pricing information more readily available and comprehendible for the patients that they serve,” the researchers concluded.

Taking aspirin after a joint replacement surgery could increase the risk of blood clots, according to a study published Aug. 23 in the Journal of the American Medical Association.

In the study, 9,711 patients who underwent hip and knee replacements were split into two groups. One group was treated strictly with aspirin after the surgery, while the other was only given the anticoagulant enoxaparin.

After 90 days, researchers evaluated both groups and found that venous thromboembolism occurred in 256 patients. The group treated strictly with aspirin were nearly twice as likely to develop VTE, according to the study.

The aspirin group saw a 3.45 percent VTE rate, while only 1.82 percent of the enoxaparin group experienced VTE.