A creaky hinge needs lube. Why not your knee?
It’s common for overzealous orthopaedic surgeons and sports medicine specialists to recommend the injection of artificial “lubricant” into knees and other arthritic joints, or for a “pseudo-arthritis” like patellofemoral syndrome (PFPS).1 The actual substances are “hyaluronan” and “hylan” (Durolane®) which are basically synthetic replacements for the slippery component of the fluid in your joints.
“Knee lube,” in other words.
It’s clear that the procedure is common simply because the idea of lubricating arthritic knees really sounds like a good idea — so good that it’s done in spite of the fact that it barely works!
Twenty years of bad science news about viscosupplementation
I’m no surgeon or scientist, and I don’t even play one on TV … but I can quote them like a boss. And the authors of a 2003 summary of this subject for the Journal of the American Medical Association2 said that injecting synovial fluid into your knee …
… has a small effect when compared with … placebo. The presence of publication bias suggests even this effect may be overestimated.
That 2003 assessment was backed by a bigger 2012 one.3 Nearly 90 trials were reviewed and determined that this treatment is associated “with a small and clinically irrelevant benefit and an increased risk for serious adverse events.”
A 2015 review piled on: “did not show clinically important differences.”4 These are not bogus citations, by the way, and they are not cherry-picked. They are the major scientific reviews available on this topic.
And a 2022 review was utterly negative:5
Strong conclusive evidence indicates that viscosupplementation leads to a small reduction in knee osteoarthritis pain compared with placebo, but the difference is less than the minimal clinically important between group difference.
Geez, science, tell us what you really think.
Science is too polite to say it directly in these papers, but viscosupplementation is pure modern snake oil. No intellectually honest person could possibly look at the available scientific evidence and defend this treatment. I’m inclined to say that these are simply all washed up scientifically. Case closed. Nail in coffin. This article was first published in 2008, and I have updated it several times since (that’s the job). The case against “lube jobs” has gone from strong to checkmate in that time.
Risks of hyaluronan injection
It gets worse. These injections aren’t just ineffective… they’re potentially harmful. That 2022 review again:
Strong conclusive evidence indicates that viscosupplementation is also associated with an increased risk of serious adverse events compared with placebo.
Many patients are justifiably cautious about accepting the prescription of invasive procedures, even “just” an injection. Even when the risks are relatively low — which they are here — things can still go wrong any time you stick a needle into a knee. There is still a considerable personal and social “overhead” to such procedures. We should generally avoid any kind of invasive medical procedure unless the benefits are really quite clear. Really, like a charge of murder, it should probably be proven “beyond a reasonable doubt.” Such proof is simply not present in this case. And I have heard reports of nasty reactions.
They are clearly uncommon, but they do occur. No injection is ever completely risk-free.
Important perspective: you can treat osteoarthritis with a placebo surgery
Bear in mind when you consider this treatment method that in 2002 a (now famous) study showed a truly spectacular placebo effect:6 people with osteoarthritis improved equally well regardless of whether they received a real surgical procedure or a sham, which is a particularly striking example of the placebo effect and implies that belief can have an effect even on a “mechanical” knee problem. From the abstract:
In this controlled trial involving patients with osteoarthritis of the knee, the outcomes after arthroscopic lavage or arthroscopic debridement were no better than those after a placebo procedure.
The point is that the conditions inside your knee are probably not nearly as important as you might think. Also, surgeries and injections can be a lot less evidence-based than you might think!7
What about other joints?
Maybe this stuff works for shoulder pain? A 2008 study in Journal of Bone & Joint Surgery (American) found that injections of sodium hyaluronate into stubbornly painful shoulders were pretty helpful. It is, of course, completely possible that shoulders respond differently to this treatment than knees. It’s also possible there was something wrong with the study. But it’s worth noting.
Perhaps for the jaw? It’s also worth noting that a review found “insufficient evidence to either support or refute the use of hyaluronate for treating patients with temporomandibular joint disorders.”8
Injections like this are catnip for cranks because they sound modern and plausible, and deliver terrific placebo, but their legitimacy is completely opaque to consumers. Even if viscosupplementation was legit, the consumer would still be faced with the impossibility of knowing. Consider this example from Consumer Health Digest #20-14, and note the scale of the operation (many clinics):
Knee-injecting chiropractor settles False Claim Act allegations
David Podell, a chiropractor who previously owned and managed a clinic in Edgewater, New Jersey, has agreed to pay the United States $2 million to resolve False Claims Act allegations that he knowingly billed Medicare for medically unnecessary viscosupplementation injections and knee braces and received illegal kickbacks.9 Podell and a business partner also promoted a business model to other chiropractors for running and marketing a clinic that specialized in the treatment of osteoarthritis through the administration of fluoroscopic-guided viscosupplementation injections and the provision of knee braces. This led to the formation of Osteo Relief Institutes (ORIs), from which—through his business partner—Podell received a percentage of their collections. The settlement follows the government’s earlier settlement with seven former ORIs and their owners, who agreed to pay the United States a total of more than $7.1 million to resolve their False Claims Act liability. … Podell allegedly caused his clinic and other ORIs to:
- bill Medicare for viscosupplementation injections for patients who did not need them
- use multiple brands of viscosupplements successively on patients without clinical support
- use discounted viscosupplements reimported from foreign countries
- provide unnecessary custom knee braces to patients
- solicit and receive kickbacks from a manufacturer of knee braces in exchange for ordering more of the manufacturer’s braces for his clinic
Related surgeries are also shockingly useless
The effectiveness of many orthopedic surgeries has been under seige since the early 2000s. It’s clear that many of them do not work,10 and popular knee surgeries in particular are scandalously ineffective. In addition to the failures of injecting lubricant, two other extremely common knee surgeries have also been condemned by one scientific test after another:
- partial meniscectomy — trimming and “cleaning up” torn and frayed menisci, the pads of cartilage in the knee join11
- knee debridement — “polishing” rough arthritic joint surfaces12
Medical guidelines now recommend against these procedures even when the need seems “obvious.”13
In addition to their futility, of course all surgeries involve risk: Thorlund et al reported 4 harmful outcomes per thousand surgeries, including symptomatic deep venous thrombosis, pulmonary embolism, infection, and death.
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About Paul Ingraham
I am a science writer in Vancouver, Canada. I was a Registered Massage Therapist for a decade and the assistant editor of ScienceBasedMedicine.org for several years. I’ve had many injuries as a runner and ultimate player, and I’ve been a chronic pain patient myself since 2015. Full bio. See you on Facebook or Twitter., or subscribe:
This article is a free chapter from PainScience.com’s huge patellofemoral pain syndrome (PFPS) tutorial, one of 110 chapters in all. The full book contains more thorough analysis of knee “lube jobs,” plus practical advice, tips, and tricks for managing patellofemoral pain. There are also several other excerpts and articles on the site about patellofemoral pain and related topics:
- Massage Therapy for Your Quads — Perfect Spot No. 8, another one for runners, the distal vastus lateralis of the quadriceps group
- The Causes of Runner's Knee Are Rarely Obvious — The science shows that you usually can’t blame IT band pain or patellofemoral pain on the structural quirks that seem like “obvious” problems
- Is Knee Pain More Common in Women? — The relationship between sex and knee pain, especially runner’s knee (IT band syndrome, patellofemoral pain)
- What Can a Runner With Knee Pain Do at the Gym? — Some training options and considerations for runners (and others) with overuse injuries of the knee
- Patellofemoral Pain Diagnosis with Bone Scan — If you have anterior knee pain, should you bother x-ray, MRI, CT scan, or bone scan?
- Does Cartilage Regeneration Work? — A review of knee cartilage “patching” with autologous chondrocyte implantation (ACI)
- Diagnosing Runner’s Knee — It usually starts with lateral knee pain during and after runs, but there are two major types
- Does Hip Strengthening Work for IT Band Syndrome? — The popular “weak hips” theory is itself weak
- Patellofemoral Pain & the Vastus Medialis Myth — Can just one quarter of the quadriceps be the key to anterior knee pain?
- Patellofemoral Tracking Syndrome — The beating heart of the conventional wisdom about patellofemoral pain is mostly nonsense
- Knee Debridement is a Completely Ineffective Procedure — Evidence that arthroscopic knee surgery for osteoarthritis is about as useful as a Nerf hammer
- Is Running on Pavement Risky? — Hard-surface running might be a risk factor for running injuries like patellofemoral pain, IT band syndrome, shin splints, and plantar fasciitis
What’s new in this article?
Five updates have been logged for this article since publication (2008). All PainScience.com updates are logged to show a long term commitment to quality, accuracy, and currency. more
Like good footnotes, update logging sets PainScience.com apart from most other health websites and blogs. It’s fine print, but important fine print, in the same spirit of transparency as the editing history available for Wikipedia pages.
I log any change to articles that might be of interest to a keen reader. Complete update logging started in 2016. Prior to that, I only logged major updates for the most popular and controversial articles.
See the What’s New? page for updates to all recent site updates.
2022 — Science update. A huge new review from the British Medical Journal is very “nail in the coffin” for viscosupplementation.
2020 — Added example of fraudulent promotion of unnecessary viscosupplementation.
2018 — Added citation to the most recent review available, Jevsevar 2015.
2016 — Added a section about other surgical procedures for context.
2017 — Science update, cited Siemieniuk.
2008 — Publication.
- Patellofemoral pain syndrome is not osteoarthritis, although they do get confused, because of the way typical patellar pain feels — a nagging ache — and a loose correlation with a slight degeneration of the kneecap cartilage (chondromalacia patellae). But, because it is perceived as being arthritis-y, it is a popular target for artificial synovial fluid injection.
- Lo GH, LaValley M, McAlindon T, Felson DT. Intra-articular hyaluronic acid in treatment of knee osteoarthritis: a meta-analysis. JAMA. 2003;290(23):3115–3121.
- Rutjes AWS, Jüni P, da Costa BR, et al. Viscosupplementation for Osteoarthritis of the Knee: A Systematic Review and Meta-analysis. Ann Intern Med. 2012 Aug;157(3):180–91. PubMed 22868835 ❐
- Jevsevar D, Donnelly P, Brown GA, Cummins DS. Viscosupplementation for Osteoarthritis of the Knee: A Systematic Review of the Evidence. J Bone Joint Surg Am. 2015 Dec;97(24):2047–60. PubMed 26677239 ❐
- Pereira TV, Jüni P, Saadat P, et al. Viscosupplementation for knee osteoarthritis: systematic review and meta-analysis. BMJ. 2022;378. PubMed 36333100 ❐ PainSci Bibliography 51382 ❐
- Moseley JB, O’Malley K, Petersen NJ, et al. A controlled trial of arthroscopic surgery for osteoarthritis of the knee. N Engl J Med. 2002 Jul 11;347(2):81–8. PubMed 12110735 ❐ PainSci Bibliography 56845 ❐
Surgeries have always been surprisingly based on tradition, authority, and educated guessing rather than good scientific trials; as they are tested properly, compared to a placebo (a sham surgery), many are failing. Moseley 2002 was the first of many to compare orthopedic (“carpentry”) surgeries to shams. By 2016, at least four more such procedures had been shown to have no benefit (Louw 2016), and that trend has continued since.
The need for placebo-controlled trials of surgeries (and the damning results) is explored in much greater detail — and very readably — in the excellent 2016 book, Surgery: The ultimate placebo, by Ian Harris.
- Shi Z, Guo C, Awad M. Hyaluronate for temporomandibular joint disorders. Coch. 2002. PainSci Bibliography 56202 ❐
- New Jersey chiropractor agrees to pay $2 million to resolve allegations of unnecessary knee injections and knee braces and related kickbacks. US Department of Justice news release. April 6, 2020.
- Louw A, Diener I, Fernández-de-Las-Peñas C, Puentedura EJ. Sham Surgery in Orthopedics: A Systematic Review of the Literature. Pain Med. 2016 Jul. PubMed 27402957 ❐ PainSci Bibliography 53458 ❐
This review of a half dozen good quality tests of four popular orthopedic (“carpentry”) surgeries found that none of them were more effective than a placebo. It’s an eyebrow-raiser that Louw et al could find only six good (controlled) trials of orthopedic surgeries at all — there should have been more — and all of them were bad news.
The surgeries that failed their tests were:
- vertebroplasty for osteoporotic compression fractures (stabilizing crushed verebtrae)
- intradiscal electrothermal therapy (burninating nerve fibres)
- arthroscopic debridement for osteoarthritis (“polishing” rough arthritic joint surfaces)
- open debridement of common extensor tendons for tennis elbow (scraping the tendon)
Surgeries have always been surprisingly based on tradition, authority, and educated guessing rather than good scientific trials; as they are tested properly, compared to a placebo (a sham surgery), many are failing. This review of the trend does a great job of explaining the problem. This is one of the best academic citations to support the claim that “sham surgery has shown to be just as effective as actual surgery in reducing pain and disability.” The need for placebo-controlled trials of surgeries (and the damning results) is explored in much greater detail — and very readably — in the excellent book, Surgery: The ultimate placebo, by Ian Harris.
- www.nytimes.com [Internet]. Kolata G. The Right to Know That an Operation Is ‘Next to Useless’; 2016 August 3 [cited 18 Aug 28]. PainSci Bibliography 53296 ❐
An excellent plain language overview of the scandalous futility of meniscectomy, from the relentless Gina Kolata at the NY Times. For a formal scientific review, see Thorlund.
- Ingraham. Knee Debridement is a Completely Ineffective Procedure: Evidence that arthroscopic knee surgery for osteoarthritis is about as useful as a Nerf hammer. PainScience.com. 1621 words. For a scientific review, see
- Siemieniuk RAC, Harris IA, Agoritsas T, et al. Arthroscopic surgery for degenerative knee arthritis and meniscal tears: a clinical practice guideline. BMJ. 2017 May;357:j1982. PubMed 28490431 ❐ PainSci Bibliography 52778 ❐
These guidelines “make a strong recommendation against the use of arthroscopy in nearly all patients with degenerative knee disease … ” regardless of “imaging evidence of osteoarthritis, mechanical symptoms, or sudden symptom onset.” The authors believe this is the last word on the subject: “further research is unlikely to alter this recommendation.”