The burden of osteoarthritis (OA) is reaching epidemic proportions, affecting more than 30 million individuals in the United States.1 The number of knee replacements performed annually in the United States is expected to significantly increase during the next decade.2 Given the close link between obesity and OA, and the high prevalence of obesity, which now affects more than one-third (36.5%) of US adults,3 this trend will likely continue. Clinicians treating patients with knee OA face major challenges as they try to recommend the most effective conservative therapies to postpone total knee arthroplasty as long as possible. Unfortunately, despite good functional outcomes, up to 20% of patients are dissatisfied after a well-performed total knee arthroplasty; unfulfilled expectations are a principal source of dissatisfaction.4 Due to the earlier onset of disease, an increased duration of treatment is necessary. Compared with 1990, when the average duration of treatment was 3 years, by 2010 the estimated average duration of treatment for OA of the knee had increased to 23 years. Multiple factors have led to this, including younger individuals sustaining injuries and having surgical intervention.5–7
In a study conducted in the United Kingdom, 25% of individuals older than 55 years reported persistent knee pain during a 1-year period.8 Because many patients with OA of the knee have an elevated body mass index, weight loss has been shown to relieve symptoms and improve function as well as quality of life for patients with OA.9 Additional risk factors for OA include age, female sex, diet, and anatomic variations including malalignment of the knee.10 Furthermore, symptomatic knee OA has been reported in 10% of men and 13% of women 60 years and older.11 The senior author (J.M.B.) typically recommends dietary changes and exercise. However, patients have reported feeling like they are in a catch-22 situation when asked to lose weight to reduce their symptoms because their pathology makes it difficult for them to exercise. Some patients may consider consulting with a bariatric surgeon, although it is difficult to obtain insurance approval for bariatric procedures to relieve the pain from knee OA. The senior author also recommends that patients address other comorbidities, such as diabetes and heart disease, to optimize OA treatment outcomes, which is critical prior to the consideration of surgical intervention.12
Clearly, optimizing nutrition and maintaining a near normal body mass index are critical for preventing OA. Weight loss has been shown to reduce the incidence of OA by up to 90% in several studies.13,14 However, the long-term failure rate for dieting and weight loss is greater than 92%.13 Multiple oral nutraceuticals have been recommended to improve the symptoms of OA. Glucosamine and chondroitin sulfate and nonsteroidal anti-inflammatory drugs, including cyclooxygenase-2 inhibitors, are the drugs most commonly prescribed for initial treatment. Unfortunately, there are minimal data that glucosamine and chondroitin sulfate have any long-term benefit, and nonsteroidal anti-inflammatory drugs have a high incidence of gastrointestinal complications.13,14 Intra-articular injections are controversial, with the literature offering variable conclusions.
Steroid injections work by inhibiting the release of prostaglandins, which are the precursors to histamine—the primary inflammatory enzyme released by mast cells and basophils. The indications for intra-articular corticosteroids are varied; however, it is commonly believed that steroid longevity ranges from 2 to 4 weeks, depending on the degree of OA and synovitis in the joint.15 A systematic review study concluded that high–molecular-weight viscosupplementation was equivalent to intra-articular corticosteroids at 2 weeks but became more effective subsequent to the 2-week period.16 On November 13, 2017, Zilretta (Flexion Therapeutics, Burlington, Massachusetts) was released. Zilretta is triamcinolone acetonide corticosteroid embedded in a microsphere, which results in an extended-release formulation with lower plasma concentrations. Early data indicate that patients exhibit an improvement in pain and function for up to 12 to 16 weeks after injection.17 A recently published double-blinded, randomized, placebo-controlled multinational study of 484 patients concluded that Zilretta provided significant, clinically meaningful pain reduction compared with saline-solution placebo at the primary endpoint, week 12. A theoretical advantage of a sustained-release steroid is that due to the low plasma concentration, serum blood glucose is minimally affected.18
Thus far this year, Google site “hits” for platelet-rich plasma (PRP) have already exceeded 20 million. A systematic review of PRP in knee OA noted that although the data were inconclusive, it may be effective.19 In a meta-analysis of PRP in knee OA, leukocyte-poor PRP had better results than leukocyte-rich PRP and hyaluronic acid, but local adverse reactions were higher with PRP.20 In a review of 6 level 1 studies, it was concluded that PRP may have beneficial effects for patients with mild to moderate OA on Western Ontario and McMaster Universities Osteoarthritis Index and International Knee Documentation Committee scores at 6 months.21 In some studies, PRP was not found to be more effective than high–molecular-weight viscosupplementation; however, leukocyte-rich PRP was used as the comparator in some of these studies.22,23 Other authors have concluded in level 1, prospective, randomized studies that PRP and high–molecular-weight hyaluronic acid yield similar results and result in moderate improvement in patients' symptoms from knee OA.24
Mesenchymal stem cells have been isolated from bone marrow, adipose tissue, synovium, blood, and amniotic fluid. Bone marrow mesenchymal stem cells are the most extensively studied. It has been reported that adipose tissue stem cells have the most stability, are significantly pluripotential, and have increased chondrogenicity. In a review of 7 randomized controlled trials using stem cell treatment for patients with knee OA, the overall results led to the conclusion that mesenchymal stem cell injections could potentially be efficacious for decreasing pain and may improve physical function.25 A systematic review from 1990 to 2013 of 9 animal and 7 human studies using bone marrow mesenchymal stem cells confirmed that “mesenchymal stem cells have shown potential for improving function and decreasing inflammation in animal studies with translation to patients still in question.”26 However, in a series of 37 patients with knee OA who were subjected to adipose stem cell injections, all had improved symptoms and appearance at second-look arthroscopy.27 Mesenchymal stem cells appear to be the most helpful in younger patients with mild to moderate knee OA and chronic patellar tendinosis.28
Hyaluronic acid has been in use since 1997, when it was first approved for humans.29 Endogenous hyaluronan is the major hydrodynamic component of joint synovial fluid. It is produced by type B synoviocytes and fibroblasts of the synovial membrane and has a molecular weight of 5×106 Da in a young individual.30 There are more than 10 different products available in the United States; however, only 2 are considered high molecular weight and/or are cross-linked (Table).31–33
Molecular Weight and Elasticity Comparison of Hyaluronan With Normal and Osteoarthritis Synovial Fluid
Cross-linking increases the residence time (amount of time the material remains in the joint) and the half-life of the compound by up to 8.8 days. With cross-linking, trace amounts of the injected hyaluronic acid can be found in the joint up to 26 weeks later. Without cross-linking, the half-life of hyaluronic acid can be as short as 3 to 20 hours and excretion of the hyaluronic acid additive will occur in the first 24 hours after.29,31,34,35 By prolonging the residence time, there is an increase in the production of endogenous hyaluronan and increased inhibition of matrix metal-loproteinases.36 In a review of 68 randomized studies with a minimum follow-up of 26 weeks, high–molecular-weight/cross-linked compounds (>3 million Da) had greater efficacy than low–molecular-weight compounds (<3 million Da) in all studies.37
The concentration and molecular weight of hyaluronan molecules are decreased by 33% to 50% in OA synovial fluid, and the loss of glycosaminoglycan in cartilage causes brittleness and decreases the resiliency of the matrix.38,39 Viscosupplementation enhances chondrocyte metabolism, decreases chondrocyte apoptosis, and stimulates synthesis of endogenous hyaluronic acid, which decreases shear secondary to increased viscosity and decreased elasticity of the synovial fluid.40 Other effects of high–molecular-weight viscosupplementation include chondrocyte death when added to bupivacaine.41 High–molecular-weight viscosupplementation appears to be helpful for patients with Kellgren II and III OA, but its effect in Kellgren IV disease is minimal. However, in a level 1, 2-year follow-up study, it did decrease the progression of cartilage degeneration in patients with mild to moderate OA.42 It appears to be helpful after arthroscopy of the knee for patients with grade II and grade III chondromalacia.43 When pharmacologic interventions were compared regarding their effectiveness for knee OA, the results of a network meta-analysis confirmed that high–molecular-weight/cross-linked viscosupplementation was the most efficacious treatment for pain but was not superior to the other interventions for function and stiffness.44
In 2013, the American Academy of Orthopaedic Surgeons recommended against the use of viscosupplementation based on a small series of studies using the minimum clinically important improvement criterion and minimal clinically important difference as the metric for determining efficacy. In 2014, Bannuru et al45 outlined how this metric was used inappropriately in the clinical practice guideline review. Since the 2013 publication of the nonarthroplasty treatment of OA guidelines by the American Academy of Orthopaedic Surgeons, there have been more than 33 noncoverage decisions affecting more than 50 million patients in the United States. This has occurred despite multiple articles confirming the efficacy of high–molecular-weight/cross-linked viscosupplementation.44,46–50 In a 2016 article on viscosupplementation for knee OA, Johal et al.51 concluded that “a careful examination of the most recently published articles suggests that viscosupplementation is a safe option with a clinically important reduction in pain for younger patients with knee OA in those formulations with higher molecular weight or hyaluronic acid cross-linking.” Furthermore, in 2 separate studies, the greater the number of high–molecular-weight hyaluronic acid injections, the greater the delay in total knee arthroplasty.52,53 Finally, when the cost-effectiveness of viscosupplementation was compared with that of nonsteroidal anti-inflammatory drugs and analgesics, quality of life years were significantly increased with high–molecular-weight hyaluronic acid, thus representing a greater effect and a decrease in cost.54
The conservative treatment of OA of the knee is important and should be exhausted prior to total knee replacement. Total knee replacement does not fulfill patient expectations, as more than one-third continue to report residual symptoms and only 66% feel that their knee is “normal.”33 Improvement in the microbiology of the cartilage cell has not been proven for PRP and stem cells, and they are not reimbursed by payers. However, many patients have noted improvement in symptoms subsequent to injections. Research beyond animal studies will hopefully provide answers regarding the effectiveness of these bioinjectables. Although in most series high–molecular-weight/cross-linked hyaluronic acid has been shown to be helpful, the lack of insurance coverage has resulted in a decrease in its use nationwide. Steroid injections reduce inflammation and offer temporary relief and, with the introduction of a corticosteroid that improves the residence time within the knee joint, may offer a sustained improvement in symptoms. The use of injectable treatments is important prior to surgical intervention in patients with knee OA. A conservatively directed, logical approach should be used for each patient with knee OA prior to consideration of surgery.
- Cisternas MG, Murphy L, Sacks JJ, Solomon DH, Pasta DJ, Helmick CG. Alternative methods for defining osteoarthritis and the impact on estimating prevalence in a US population-based survey. Arthritis Care Res (Hoboken). 2016; 68(5):574–580. doi:10.1002/acr.22721 [CrossRef]
- Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg Am. 2007; 89(4):780–785.
- Centers for Disease Control and Prevention. Adult obesity facts. https://www.cdc.gov/obesity/data/adult.html. Accessed August 29, 2017.
- Husain A, Lee GC. Establishing realistic patient expectations following total knee arthroplasty. J Am Acad Orthop Surg. 2015; 23(12):707–713. doi:10.5435/JAAOS-D-14-00049 [CrossRef]
- National Center for Health Statistics. U.S. Decennial Life Tables for 1989–91. Hyattsville, MD: National Center for Health Statistics; 1997.
- Lubar D, White PH, Callahan LF, et al. A national public health agenda for osteoarthritis 2010. Semin Arthritis Rheum. 2010; 39(5):323–326. doi:10.1016/j.semarthrit.2010.02.002 [CrossRef]
- Miniño AM, Murphy SL. Death in the United States, 2010. Hyattsville, MD: National Center for Health Statistics; 2012.
- Peat G, McCarney R, Croft P. Knee pain and osteoarthritis in older adults: a review of community burden and current use of primary health care. Ann Rheum Dis. 2001; 60(2):91–97. doi:10.1136/ard.60.2.91 [CrossRef]
- Bliddal H, Leeds AR, Christensen R. Osteoarthritis, obesity and weight loss: evidence, hypotheses and horizons. A scoping review. Obes Rev. 2014; 15(7):578–586. doi:10.1111/obr.12173 [CrossRef]
- Palazzo C, Nguyen C, Lefevre-Colau MM, Rannou F, Poiraudeau S. Risk factors and burden of osteoarthritis. Ann Phys Rehabil Med. 2016; 59(3):134–138. doi:10.1016/j.rehab.2016.01.006 [CrossRef]
- Zhang Y, Jordan JM. Epidemiology of osteoarthritis. Clin Geriatr Med. 2010; 26(3):355–369. doi:10.1016/j.cger.2010.03.001 [CrossRef]
- Bert JM, Hooper J, Moen S. Outpatient total joint arthroplasty. Curr Rev Musculoskelet Med. 2017; 10(4):567–574. doi:10.1007/s12178-017-9451-2 [CrossRef]
- de Vos BC, Landsmeer MLA, van Middelkoop M, et al. Long-term effects of a lifestyle intervention and oral glucosamine sulphate in primary care on incident knee OA in over-weight women. Rheumatology (Oxford). 2017; 56(8):1326–1334. doi:10.1093/rheumatology/kex145 [CrossRef]
- Runhaar J, Deroisy R, van Middelkoop M, et al. The role of diet and exercise and of glucosamine sulfate in the prevention of knee osteoarthritis: further results from the PRevention of Knee Osteoarthritis in Over-weight Females (PROOF) study. Semin Arthritis Rheum. 2016; 45(4)(suppl):S42–S48. doi:10.1016/j.semarthrit.2015.11.001 [CrossRef]
- Wernecke C, Braun HJ, Dragoo JL. The effect of intra-articular corticosteroids on articular cartilage: a systematic review. Orthop J Sports Med. 2015; 3(5):2325967115581163. doi:10.1177/2325967115581163 [CrossRef]
- Jüni P, Hari R, Rutjes AW, et al. Intra-articular corticosteroid for knee osteoarthritis. Cochrane Database Syst Rev. 2015; 10:CD005328.
- Bodick N, Lufkin J, Willwerth C, et al. An intra-articular, extended-release formulation of triamcinolone acetonide prolongs and amplifies analgesic effect in patients with osteoarthritis of the knee: a randomized clinical trial. J Bone Joint Surg Am.2015; 97(11):877–888. doi:10.2106/JBJS.N.00918 [CrossRef]
- Conaghan P, Hunter D, Cohen S, et al. Effects of a single intra-articular injection of a microsphere formulation of triamcinolone acetonide on knee osteoarthritis pain. J Bone Joint Surg Am. 2018; 100(8):666–677. doi:10.2106/JBJS.17.00154 [CrossRef]
- Lai LP, Stitik TP, Foye PM, Georgy JS, Patibanda V, Chen B. Use of platelet-rich plasma in intra-articular knee injections for osteoarthritis: a systematic review. PM R. 2015; 7(6):637–648. doi:10.1016/j.pmrj.2015.02.003 [CrossRef]
- Riboh JC, Saltzman BM, Yanke AB, Fortier L, Cole BJ. Effect of leukocyte concentration on the efficacy of platelet-rich plasma in the treatment of knee osteoarthritis. Am J Sports Med. 2016; 44(3):792–800. doi:10.1177/0363546515580787 [CrossRef]
- Khoshbin A, Leroux T, Wasserstein D, et al. The efficacy of platelet-rich plasma in the treatment of symptomatic knee osteoarthritis: a systematic review with quantitative synthesis. Arthroscopy. 2013; 29(12):2037–2048. doi:10.1016/j.arthro.2013.09.006 [CrossRef]
- Filardo G, Kon E, Di Martino A, et al. Platelet-rich plasma vs hyaluronic acid to treat knee degenerative pathology: study design and preliminary results of a randomized controlled trial. BMC Musculoskelet Disord. 2012; 13:229. doi:10.1186/1471-2474-13-229 [CrossRef]
- Patel S, Dhillon MS, Aggarwal S, Marwaha N, Jain A. Treatment with platelet-rich plasma is more effective than placebo for knee osteoarthritis: a prospective, double-blind, randomized trial. Am J Sports Med. 2013; 41(2):356–364. doi:10.1177/0363546512471299 [CrossRef]
- Cole BJ, Karas V, Hussey K, Pilz K, Fortier LA.Hyaluronic acid versus platelet-rich plasma: a prospective, double-blind randomized controlled trial comparing clinical outcomes and effects on intra-articular biology for the treatment of knee osteoarthritis. Am J Sports Med. 2017; 45(2):339–346. doi:10.1177/0363546516665809 [CrossRef]
- Xia P, Wang X, Lin Q, Li X. Efficacy of mesenchymal stem cells injection for the management of knee osteoarthritis: a systematic review and meta-analysis. Int Orthop. 2015; 39(12):2363–2372. doi:10.1007/s00264-015-2785-8 [CrossRef]
- Wolfstadt JI, Cole BJ, Ogilvie-Harris DJ, Viswanathan S, Chahal J. Current concepts: the role of mesenchymal stem cells in the management of knee osteoarthritis. Sports Health. 2015; 7(1):38–44. doi:10.1177/1941738114529727 [CrossRef]
- Kim YS, Choi YJ, Suh DS, et al. Mesenchymal stem cell implantation in osteoarthritic knees: is fibrin glue effective as a scaffold?Am J Sports Med. 2015; 43(1):176–185. doi:10.1177/0363546514554190 [CrossRef]
- Bradley J. Biologics for the knee: what really works and what I do in my practice. Paper presented at: American Academy of Orthopaedic Surgeons. Specialty Day; March 10, 2018. ; New Orleans, Louisiana. .
- Ottaviani RA, Wooley P, Song Z, Markel DC. Inflammatory and immunological responses to hyaluronan preparations: study of a murine biocompatibility model. J Bone Joint Surg Am. 2007; 89(1):148–157. doi:10.2106/JBJS.E.01135 [CrossRef]
- Watterson JR, Esdaile JM. Viscosupplementation: therapeutic mechanisms and clinical potential in osteoarthritis of the knee. J Am Acad Orthop Surg. 2000; 8(5):277–284. doi:10.5435/00124635-200009000-00001 [CrossRef]
- Mazzucco D, McKinley G, Scott RD, Spector M. Rheology of joint fluid in total knee arthroplasty patients. J Orthop Res. 2002; 20(6):1157–1163. doi:10.1016/S0736-0266(02)00050-5 [CrossRef]
- Balaza EA, Watson D, Duff IF, Roseman S. Hyaluronic acid in synovial fluid: I. Molecular parameters of hyaluronic acid in normal and arthritic human fluids. Arthritis Rheum. 1967; 10(4):357–376. doi:10.1002/art.1780100407 [CrossRef]
- Praest BM, Greiling H, Koch R. Assay of synovial fluid parameters: hyaluronan concentration as a potential marker for joint diseases. Clinica Chimica Acta. 1997; 266:117–128. doi:10.1016/S0009-8981(97)00122-8 [CrossRef]
- Adams ME, Lussier AJ, Peyron JG. A risk-benefit assessment of injections of hyaluronan and its derivatives in the treatment of osteoarthritis of the knee. Drug Saf. 2000; 23(2):115–130. doi:10.2165/00002018-200023020-00003 [CrossRef]
- Fraser JR, Kimpton WG, Pierscionek BK, Cahill RN. The kinetics of hyaluronan in normal and acutely inflamed synovial joints: observations with experimental arthritis in sheep. Semin Arthritis Rheum. 1993; 22(6) (suppl 1):9–17. doi:10.1016/S0049-0172(10)80015-0 [CrossRef]
- Jackson DW, Simon TM. Intra-articular distribution and residence time of Hylan A and B: a study in the goat knee. Osteoarthritis Cartilage. 2006; 14(12):1248–1257. doi:10.1016/j.joca.2006.05.015 [CrossRef]
- Altman RD, Bedi A, Karlsson J, Sancheti P, Schemitsch E. Product differences in intra-articular hyaluronic acids for osteoarthritis of the knee. Am J Sports Med. 2016; 44(8):2158–2165. doi:10.1177/0363546515609599 [CrossRef]
- Barbero A, Grogan S, Schäfer D, Heberer M, Mainil-Varlet P, Martin I. Age related changes in human articular chondrocyte yield, proliferation and post-expansion chondrogenic capacity. Osteoarthritis Cartilage. 2004; 12(6):476–484. doi:10.1016/j.joca.2004.02.010 [CrossRef]
- DeGroot J, Verzijl N, Jacobs KM, et al. Accumulation of advanced glycation endproducts reduces chondrocyte-mediated extracellular matrix turnover in human articular cartilage. Osteoarthritis Cartilage. 2001; 9(8):720–726. doi:10.1053/joca.2001.0469 [CrossRef]
- Bagga H, Burkhardt D, Sambrook P, March L. Long-term effects of intraarticular hyaluronan on synovial fluid in osteoarthritis of the knee. J Rheumatol. 2006; 33(5):946–950.
- Liu S, Zhang QS, Hester W, O'Brien MJ, Savoie FH, You Z. Hyaluronan protects bovine articular chondrocytes against cell death induced by bupivacaine at supraphysiologic temperatures. Am J Sports Med. 2012; 40(6):1375–1383. doi:10.1177/0363546512439025 [CrossRef]
- Wang Y, Hall S, Hanna F, et al. Effects of Hylan G-F 20 supplementation on cartilage preservation detected by magnetic resonance imaging in osteoarthritis of the knee: a two-year single-blind clinical trial. BMC Musculoskelet Disord. 2011; 12:195. doi:10.1186/1471-2474-12-195 [CrossRef]
- Bert JM, Waddell DD. Viscosupplementation with hylan g-f 20 in patients with osteoarthrosis of the knee. Ther Adv Musculoskelet Dis. 2010; 2(3):127–132. doi:10.1177/1759720X10370930 [CrossRef]
- Bannuru RR, Schmid CH, Kent DM, Vaysbrot EE, Wong JB, McAlindon TE. Comparative effectiveness of pharmacologic interventions for knee osteoarthritis: a systematic review and network meta-analysis. Ann Intern Med. 2015; 162(1):46–54. doi:10.7326/M14-1231 [CrossRef]
- Bannuru RR, Vaysbrot EE, McIntyre LF. Did the American Academy of Orthopaedic Surgeons osteoarthritis guidelines miss the mark?Arthroscopy. 2014; 30(1):86–89. doi:10.1016/j.arthro.2013.10.007 [CrossRef]
- Evaniew N, Simunovic N, Karlsson K. Cochrane in CORR: viscosupplementation for the treatment of osteoarthritis of the knee. Clin Orthop Relat Res.2014; 472(7):2028–2034. doi:10.1007/s11999-013-3378-8 [CrossRef]
- Percope de Andrade MA, Campos TV, Abreu-E-Silva GM. Supplementary methods in the nonsurgical treatment of osteoarthritis. Arthroscopy. 2015; 31(4):785–792. doi:10.1016/j.arthro.2014.11.021 [CrossRef]
- Xing D, Wang B, Liu Q, et al. Intra-articular hyaluronic acid in treating knee osteoarthritis: a PRISMA-compliant systematic review of overlapping meta-analysis. Sci Rep. 2016; 6:32790. doi:10.1038/srep32790 [CrossRef]
- Campbell K, Saltzman BM, Mascarenhas R, et al. Does PRP provide clinically superior outcomes compared with other therapy in the treatment of knee OA? A systematic review of overlapping meta-analyses. Arthroscopy.2015; 31(11):2071–2282.
- Bannuru RR, Vaysbrot EE, Sullivan MC, McAlindon TE. Relative efficacy of hyaluronic acid in comparison with NSAIDs for knee osteoarthritis: a systematic review and meta-analysis. Semin Arthritis Rheum. 2014; 43(5):593–599. doi:10.1016/j.semarthrit.2013.10.002 [CrossRef]
- Johal H, Devji T, Schemitsch EH, Bhandari M. Viscosupplementation in knee osteoarthritis: evidence revisited. JBJS Rev. 2016; 4(4):e11–e111. doi:10.2106/JBJS.RVW.15.00098 [CrossRef]
- Miller LE, Block JE. An 8-week knee osteoarthritis treatment program of hyaluronic acid injection, deliberate physical rehabilitation, and patient education is cost effective at 2 years follow-up: the OsteoArthritis Centers of America(SM) experience. Clin Med Insights Arthritis Musculoskelet Disord. 2014; 7:49–55. doi:10.4137/CMAMD.S18356 [CrossRef]
- Waddell DD, Joseph B. Delayed total knee replacement with hylan G-F 20. J Knee Surg. 2016; 29(2):159–168.
- Hatoum HT, Fierlinger AL, Lin SJ, Altman RD. Cost-effectiveness analysis of intra-articular injections of a high molecular weight bioengineered hyaluronic acid for the treatment of osteoarthritis knee pain. J Med Econ. 2014; 17(5):326–337. doi:10.3111/13696998.2014.902843 [CrossRef]
Molecular Weight and Elasticity Comparison of Hyaluronan With Normal and Osteoarthritis Synovial Fluid
|Synovial Fluid and Various Hyaluronic Products||Molecular Weight (Million Daltons)||Elasticity (Pascals at 2.5 Hz)|
|Healthy, young synovial fluid32||6||117|
|Osteoarthritic synovial fluid31,33||1.9||1.9|
|Hyalganc (sodium hyaluronate)||0.5 to 0.7||0.6|
|Supartzd (sodium hyaluronate)||0.6 to 1.2||9|
|Orthovisce (high–molecular-weight hyaluronan)||1 to 2.9||60|
|Euflexxaf (1% sodium hyaluronate)||2.4 to 3.6||92|