Hyaluronic Acid Injections for Treatment of Advanced Osteoarthritis of the Knee: Utilization and Cost in a National Population Sample

Predictors of Patient-Reported Outcomes After Hyaluronic Acid Injections: Effect of Expectations and Psychological Stress

INTRODUCTION

Hyaluronic acid (HA) injections are a common nonsurgical treatment of knee osteoarthritis (OA). Patient expectations and psychological stress are believed to affect outcomes after orthopaedic procedures.

METHODS

This was a prospective cohort study seeking to identify factors predictive of greater patient-reported outcomes after HA injections, particularly expectations and psychological stress. 250 patients receiving a series of HA injections for knee OA were enrolled, with 196 being included for analysis. Demographics, surgical history, and preoperative Kellgren-Lawrence severity scores were collected, and patients completed the Knee Osteoarthritis Outcome Score (KOOS) questionnaire, a modified KOOS questionnaire assessing their 6-month postinjection expectations, and the Perceived Stress Scale before the first injection. Outcomes were assessed at 3 weeks and 3 and 6 months after the final injection.

RESULTS

KOOS scores improved from preinjection to 6-month follow-up but did not meet patients' expectations or minimal clinically important difference. Expectations correlated with 6-month KOOS pain, activities of daily living, sport, and quality of life subscales (ρ = 0.19 to 0.34), but not the symptom subscale (P = 0.10). Expectations (ρ = 0.31 to 0.37), younger age (ρ = -0.17 to -0.18), and greater perceived stress (ρ = 0.23) correlated with greater improvement from baseline KOOSs. Lower body mass index (ρ = -0.19 to -0.22), male sex (ρ = -0.17), and greater preinjection function (ρ = 0.37 to 0.46) correlated with greater 6-month outcomes. Stress measured on the Perceived Stress Scale did not correlate with 6-month KOOSs (P ≥ 0.27). Lower Kellgren-Lawrence severity score was weakly associated with greater 6-month KOOS activities of daily living and sport scores (ρ = -0.15 to -0.16) and greater improvement in the KOOS symptom score (ρ = -0.15).

DISCUSSION

This study identified that higher expectations, lower body mass index, younger age, male sex, lower radiographic severity, greater preinjection function, and greater perceived stress are associated with greater patient outcomes after HA injection. Physicians should consider these factors when counseling patients with knee OA about viscosupplementation.

STUDY TYPE

Prospective Cohort Study (Level of Evidence II).

Health Economic Assessments of Hyaluronic Acid Treatments for Knee Osteoarthritis: A Systematic Review

INTRODUCTION

Hyaluronic acid (HA) use to treat knee osteoarthritis (OA) has been extensively investigated in the literature. There are also multiple economic assessments comparing intra-articular HAs with oral anti-inflammatory medicines and other conservative measures (NSAIDs), as well as different types and formulations of HA. Owing to the broad landscape of evidence across this area, it is important to further understand the empirical data comparing HA products, as well as the health economic implications that exist between commercially available HAs. This systematic review aims to identify and summarize the available evidence comparing commercially available HA products in the USA, as well as the health economic evidence and socioeconomic outcomes associated with HA use for knee OA.

METHODS

A systematic literature review within the OVID Medline, Embase, HealthStar, and Cochrane EBM HTA databases was conducted. Articles were screened for eligibility, and a qualitative summary of the findings was provided based on specific themes: (1) trials comparing the safety and/or efficacy of two or more HA products in knee OA, (2) economic/cost analyses of HA use in knee OA, and (3) studies investigating healthcare resource utilization in patients treated with HA for knee OA.

RESULTS

The search strategy identified 398 studies, 27 of which were deemed eligible: 21 health economic analyses with US relevance and six head-to-head trials of HA products available in the USA, cumulatively assessing 5,782,156 patients with knee OA. The evidence demonstrates a clear distinction between high and low molecular weight HAs, as both efficacy and cost analyses provided favorable results for the high molecular weight options. In all but one cost analysis, HA use was a cost-effective option when compared to routine nonoperative care, captured in administrative databases, which typically included NSAID use and/or corticosteroids. HA saw benefits in delaying the need for total knee arthroplasty (TKA), decreasing the use of rescue medication, and limiting the need for additional corticosteroid injection. The included evidence highlights that the treatment's cost-effectiveness is improved when HA is utilized in earlier stages of the disease, as opposed to when HA is reserved for late stages of knee OA. Additionally, among HAs, Bio-HA and Hylan G-F 20 evidence made up the majority of available literature with beneficial efficacy and cost outcomes. Head-to-head evidence between them indicated similar pain outcomes; however, Bio-HA required less rescue with acetaminophen and had fewer joint effusions in this comparison.

CONCLUSIONS

The available efficacy and safety data as well as health economic analyses on the use of HA for knee OA management suggest that there are economic benefits of this treatment option. From a healthcare system perspective, the body of HA literature summarizes favorable costs profile, decreased opioid and corticosteroid use as rescue medication, and a delay to the need for TKA in patients who have HA included in their treatment regimen.

The efficacy of platelet-rich plasma in treating osteoarthritis with an inflammatory phenotype: A 5-year follow up retrospective study

BACKGROUND

We aimed to explore whether platelet-rich plasma (PRP) can delay and reduce the incidence of total knee arthroplasty (TKA) and improve clinical symptoms in patients with inflammatory phenotype knee osteoarthritis (I-KOA).

METHODS

This was a retrospective cohort study with a 5-year follow up. We selected patients with I-KOA based on typical magnetic resonance imaging findings. Patients were divided into two groups: I-KOA and KOA. Subsequently, the patients underwent treatment for five consecutive years, receiving three fortnightly injections per year, totalling 15 injections per patient. The Kellgren-Lawrence (KL) grade and minimum joint space width (MJSW) were used to evaluate KOA progression. The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score, Knee Society score (KSS), and the minimal clinically important difference were used to evaluate the improvement of KOA symptoms. The incidence and timing of TKA were statistically analysed.

RESULTS

In total, 420 patients were included (I-KOA, n = 211; KOA, n = 209). No significant difference existed between both groups in the changes in the MJSW and KL grade at each time point. The I-KOA group exhibited significantly lower TKA incidence and delayed time to TKA. The WOMAC, KSS, and KSS function scores were significantly better in the I-KOA group than in the KOA group at each time point after treatment (P < 0.05).

CONCLUSION

The results of this retrospective study suggest that, compared with conventional KOA, intra-articular injection of PRP has better efficacy in patients with I-KOA but does not delay disease progression.

Patient Reported Outcomes Following Intraarticular Hyaluronic Acid for Knee Osteoarthritis

BACKGROUND

Intraarticular hyaluronic acid (IAHA) has been commonly used in the management of knee osteoarthritis (OA). This study sought to assess patient reported outcomes (PRO) following different formulations of HA injections for patients who have knee OA.

METHODS

A retrospective analysis was performed on patients who have knee OA and received IAHA knee injections from October 2018 to May 2022 in sports medicine (SM) and adult reconstructive (AR) clinics. Patients completed PRO measures including the Patient-Reported Outcome Measurement Information System (PROMIS ®) Mobility, Pain Interference, and Pain Intensity at baseline, 6-week, 6-month, and 12-month follow-up. Univariate and multivariate analyses were used to evaluate changes in PRO measures between baseline and follow-up periods and to evaluate differences between the SM and AR divisions. A total of 995 patients received IAHA for knee OA and completed PRO assessments.

RESULTS

There was no difference in the PROMIS® measures based on molecular weight at 6-weeks, 6-months, and 12-months. Except for 6-month Mobility scores between the SM and AR patients (-0.52 ± 5.46 vs 2.03 ± 6.95; P = 0.02), all other PROMIS® scores were similar. Mobility scores at 6-months were significantly different based on KL (Kellgren and Lawrence) grade (P = 0.005) but all other PROMIS® scores were similar.

CONCLUSION

Average change in PROMIS® scores were significantly different only for 6-month Mobility scores based on divisions and KL grade, but did not achieve minimally clinical important difference in most timepoints. Further studies are needed to investigate whether improvement is observed in specific patient populations.

The Effect of Intra-articular Hyaluronic Acid Injections and Payer Coverage on Total Knee Arthroplasty Procedures: Evidence From Large US Claims Database

Background

There is debate regarding the efficacy of intra-articular (IA) hyaluronic acid (HA) injections for the management of knee osteoarthritis (OA). This study aimed to determine if IA HA utilization and payer coverage of viscosupplementation affected the prevalence of total knee arthroplasty (TKA) procedures and the age of TKA patients.

Methods

We performed a retrospective analysis from 2014 to 2020 using a large national commercial claims data set. We analyzed the number of TKA procedures and the age of the patients in states that covered IA HA vs those with limited coverage. Mixed random effects and slopes models were used to identify the impact of the IA HA injections.

Results

Of 7,335,301 patients with knee OA, 440,606 (6.0%) received a TKA procedure at an average age of 59 years. The rate of TKA procedures increased by 0.56% per year (95% confidence interval [CI] 0.46-0.66; P < .001). Payer coverage of IA HA injections had no effect on TKA prevalence (P = .926). The age of surgical patients increased yearly by 0.15 years (95% CI 0.12-0.18; P < .001), regardless of IA HA injections (P = .990). After controlling for demographics and comorbidities, patients that received an IA HA injection had a higher probability of receiving a subsequent TKA (odds ratio = 2.83; 95% CI 2.80-2.87; P < .001); this finding was conditional of patients' age at the first diagnosis of knee OA.

Conclusions

Additional clinical trials should be employed to identify the role of HA injections in the treatment armamentarium for knee OA.

The Effect of Core Stabilization Training on Improving Gait and Self-Perceived Function in Patients with Knee Osteoarthritis: A Single-Arm Clinical Trial

The treatment of patients with knee osteoarthritis is typically focused on the involved lower extremity. There is a gap in the literature concerning the effectiveness of core stabilization training on the treatment of patients with knee osteoarthritis. This investigation aimed to determine whether core stabilization improved the gait and functional ability of patients with knee osteoarthritis. Eighteen participants with knee osteoarthritis completed the six-week core stabilization intervention. Participants completed the gait motion analysis and the Knee Injury and Osteoarthritis Outcome Score to assess self-perceived function, pre- and post-intervention. Gait speed improved (p = 0.006, d = 0.59), while the external knee adduction moment decreased (p = 0.034, d = −0.90). Moreover, self-reported function improved (p < 0.001, d = 1.26). The gait speed and external knee adduction moment changes met minimal detectable change thresholds, while gait speed also met the minimal clinically important difference. A six-week core stabilization program can thus improve gait speed and reduce the external knee adduction moment, which is tied to disease progression. Increased functional scores post-intervention indicate an important clinical improvement. Core stabilization training is a safe and potentially effective treatment option for this population.

Hyaluronic Acid Injections for Knee Osteoarthritis: Has Utilization Among Medicare Beneficiaries Changed Between 2012 and 2018?

BACKGROUND

The utilization of hyaluronic acid (HA) for the management of knee osteoarthritis (OA) remains controversial, and more information is needed regarding how its utilization and financial burden have changed over recent years. The purpose of our analysis was to evaluate changes in overall utilization and health-care costs associated with HA injections among Medicare beneficiaries over a contemporary time frame.

METHODS

The 2012 to 2018 Medicare Fee-for-Service Provider Utilization and Payment Public Use Files (PUFs) were utilized for our analysis. Organized by Healthcare Common Procedure Coding System (HCPCS) codes, these files capture 100% of Medicare Part B claims. Payment and utilization data were collected for all HCPCS codes corresponding to injection of an HA formulation. The number of services involving HA as well as the total cost of HA administration in 2020 U.S. dollars were tabulated. Mann-Kendall trend tests were used to evaluate trends in utilization for providers nationally and when segregated by specialty.

RESULTS

Total HA utilization increased significantly from 2012 (n = 1,090,503) through 2018 (n = 1,209,489; p = 0.04). Although orthopaedic surgeons did not demonstrate significant changes in total utilization rates (p = 0.23), the average number of services per orthopaedic surgeon increased significantly (p = 0.02). Reflecting a substantial growth in the number of advanced practice providers (APPs) providing injections, there was a significant increase in utilization and associated costs among physician assistants (p < 0.01) and nurse practitioners (p < 0.01). Total costs associated with HA services increased significantly from $290.10 million to $325.02 million (p < 0.01).

CONCLUSIONS

Despite the 2013 American Academy of Orthopaedic Surgeons clinical practice guideline recommending against the clinical utility of these injections, HA services continued to be widely implemented among Medicare beneficiaries. Although there were variations across specialties when evaluating overall utilization rates as well as rates per provider, APPs largely contributed to the increase seen in the U.S. over this study period. More data are needed to support continued implementation and spending on this low-value care.

Analysis of the Cost and Efficacy of Intra-Articular Knee Injections

INTRODUCTION

Intra-articular joint injections have been used with the goal of providing patients with symptomatic relief. Recently, however, the efficacy of corticosteroid (CS) and hyaluronic acid (HA) injections in the management of knee osteoarthritis (OA) is questionable. In this analysis, we investigated the costs associated with injections by assessing overall use, conversion and average time to total knee arthroplasty (TKA), and reimbursement.

METHODS

Patients aged 50 to 70 years with a knee-related diagnosis of pain, effusion, or OA were identified in the Humana insurance national data set. Patients who received intra-articular injections were stratified by the type and number of injection(s) received. The subsequent rates of TKA were compared with Kaplan-Meier curves for patients who underwent CS injections, HA injections, and a benchmarking cohort of patients with OA and no history of knee injections in the medical record. Average time to TKA was determined from index diagnosis, and total cost was compared using Wilcoxon rank sum analyses.

RESULTS

A total of 778,686 patients were identified. Of these, 637,112 had no knee injection history, while 124,129 received CS and 17,445 received HA injections. The 10-year conversion to TKA was highest in HA cohort (31.6%), followed by the CS cohort (24.0%) and the noninjection cohort (7.3%) (P < 0.001). Time to TKA increased with number of injections for both injection types. For patients who underwent TKA, median cost was greater in HA ($16,687) and CS ($15,563) cohorts relative to noninjection cohort ($14,733) (P < 0.001).

DISCUSSION

Compared with the noninjection cohort, both HA and CS cohorts experienced increased costs and increased time to TKA. However, while the cost incurred in HA cohort was greater than that in CS cohort, no appreciable benefit was demonstrated for conversion or time to TKA. Therefore, if intra-articular knee injections are indicated for the nonsurgical management of knee OA, the results of this study support CS over HA.

Intra-articular Hyaluronic Acid for Osteoarthritis of the Knee in the United States: A Systematic Review of Economic Evaluations

Background:

The economic impact of intra-articular hyaluronic acid (IAHA) for the treatment of knee pain associated with osteoarthritis (OA) has been evaluated in the United States, but not systematically summarized.

Objective:

We reviewed the literature to determine the economic impact of IAHA for pain associated with knee OA in the United States.

Methods:

A literature review was performed in PubMed (including MEDLINE and MEDLINE In-Process), Embase, the Cochrane Database of Systematic Reviews, and National Health Service Economic Evaluation Database and was limited to English language human studies published from January 2000 to October 2020.

Results:

The literature search identified 215 unique abstracts; of these, 47 were selected for full-text review and 21 studies met the inclusion criteria. Intra-articular hyaluronic acid injections delayed progression to total knee arthroplasty (TKA), and repeated courses of treatment successfully delayed TKA by more than 5 years. Intra-articular hyaluronic acid was found to reduce the use of pain medications overall and reduce the number of patients receiving opioid prescriptions by 6% (P < .001). Several studies showed that IAHA is more cost-effective in treating pain associated with knee OA compared with conventional care with nonsteroidal anti-inflammatory drugs (NSAIDs), analgesics, and corticosteroids, and several authors concluded that IAHA should be the dominant treatment strategy.

Conclusions:

Current studies suggest that IAHA may reduce the use of pain medications, such as NSAIDs and opioids, and impact time to TKA procedures, thus potentially decreasing overall treatment costs of knee OA over time. Furthermore, IAHA was determined to be cost-effective against NSAIDs, corticosteroids, analgesics, and conservative treatment. As the safety and efficacy of IAHA for knee OA have been well established, the findings from our literature review may be used to inform future economic evaluations.

Factors Associated with Knee Arthroplasty in a Knee Osteoarthritis Patient Cohort Treated with Intra-articular Injections of Hylan G-F 20

Hylan G-F 20 viscosupplementation can be used to treat knee osteoarthritis pain. This study evaluated time to knee arthroplasty (KA), KA risk factors, and health care resource utilization in patients aged ≥18 years with claims in the Optum Clinformatics Data Mart database (2006-2016) for knee osteoarthritis treated with at least one course of hylan G-F 20. Kaplan-Meier analysis estimated KA risk from osteoarthritis diagnosis and first hylan G-F 20 treatment. KA risk factors were determined using multivariate Cox regression. Among 62,033 patients treated with hylan G-F 20 and/or hylan G-F 20 single intra-articular injection, 60 to 64% did not undergo KA 8 years following first injection. KA risk factors from time of osteoarthritis diagnosis and first hylan G-F 20 treatment were similar: increased age, fewer comorbidities, fewer hylan G-F 20 treatments, female sex, and no ultrasound/fluoroscopy for injection guidance. Patients who underwent KA versus those who did not had more office visits and claims for opioids, nonsteroidal anti-inflammatory drugs, and physical therapy. Patients less likely to undergo KA were younger (<40 years), had more comorbidities, received more courses of hylan G-F 20, were males, or received ultrasound/fluoroscopic injection guidance. Patients who did not receive KA versus those who did used fewer health care resources.

Treatment Efficacy with a Novel Hyaluronic Acid-Based Hydrogel for Osteoarthritis of the Knee

Background: Prior trials investigating the treatment of symptomatic osteoarthritis (OA) with hyaluronic-acid-derived products injections have provided optimistic results. The study was directed to assess the effectiveness of an innovative hyaluronic-acid-based hydrogel (Hymovis^®) in the treatment of symptomatic knee OA. Methods: A prospective, single-center, clinical trial was performed. Thirty-five patients with degenerative knee OA were included. Inclusion criteria were: age between 45–80, radiographic Kellgren grade II or III osteoarthritis, minimum 35 mm score on the Visual Analogue Scale (VAS), pain for at least 6 months and agreement to participate in the study. Patients received two injections at a one-week interval. The evaluator assessed the patients using the Western Ontario and McMaster University Osteoarthritis Index (WOMAC) and VAS. Evaluation was performed before, at 2 and 6 months after the injections. Results: A significant improvement on the WOMAC Index pain subscale was observed at 6 months after the injection. At two months, pain subscale score decreased from 10.34 to 9.34. At six months, a significant decrement in pain parameters compared to baseline was observed (from 10.34 to 7.72; p = 0.0004). Median points on VAS significantly ameliorated after 6 months (from 74.2 to 57.3 cm; p < 0.0001). Regarding physical function, a statistically significant difference compared to baseline was observed at the end of the study (from 29.74 to 25.18; p = 0.0025). WOMAC Index stiffness component did not differ from baseline at any time during follow-up. Conclusions: Pain relief installed with a delayed on-set but had a prolonged duration. The novel hyaluronic acid-based hydrogel (Hymovis^®) had effective results, particularly after six months post-injections and offers a therapeutic advancement in the treatment of moderate to severe osteoarthritis.

Effect of ultrasound-detected synovitis on therapeutic efficacy of hyaluronic acid injection for symptomatic knee osteoarthritis

Objective

To determine whether ultrasound (US)-detected synovitis affects the therapeutic efficacy of hyaluronic acid (HA) injection for treating knee OA.

Methods

Patients with symptomatic knee OA were recruited. All the patients received HA injection two times at 2-week intervals. Clinical assessments were performed using a visual analogue scale (VAS) and the Western Ontario and McMaster Universities OA Index (WOMAC) at baseline and 1 and 6 months after treatment. Imaging evaluation was based on complete knee US examination and the Kellgren–Lawrence grading. Suprapatellar synovial fluid (SF) depth, synovial hypertrophy (SH) and vascularity were measured through US.

Results

In total, 137 patients who fulfilled the inclusion criteria were included in the analysis. All patients demonstrated improvement in VAS and WOMAC scores at 1 and 6 months after treatment (P < 0.001). Moreover, regression model-based analysis revealed significant associations of SF depth with the VAS and WOMAC scores in all patients. Each centimetre increase in the effusion diameter was associated with a decrease in the 1-month post-treatment VAS improvement percentage (15.26; 95% CI: 0.05, 29.5; P = 0.042) and 6-month post-treatment WOMAC improvement (37.43; 95% CI: 37.68, 50.69; P < 0.01). However, SH and vascularity were not significantly associated with VAS or WOMAC scores.

Conclusion

Ultrasound detected suprapatellar effusion predicts reduced efficacy of HA injection in knee OA

The Cost-Effectiveness of Platelet-Rich Plasma Compared With Hyaluronic Acid Injections for the Treatment of Knee Osteoarthritis

PURPOSE

To examine the cost-effectiveness of a series (total of 3 injections) of intra-articular platelet-rich plasma (PRP) injections in comparison to that of hyaluronic acid (HA) viscosupplementation for the treatment of symptomatic knee osteoarthritis.

METHODS

Outcome data regarding the use of PRP or HA injections for the treatment of symptomatic knee osteoarthritis were determined from the highest-quality data (Level I) available in the literature until 2015. Health utility values were then derived from these high-quality data. Costs were determined by examining typical charges for patients undergoing a series of either PRP or HA injections for the treatment of this condition at a large private orthopaedic practice. These health utility values and costs were used to create an expected-value decision analysis model.

RESULTS

The results of the model revealed that the cost per quality-adjusted life-year (QALY) of a series of PRP injections was $8,635.23/QALY and that of a series of HA injections was $5,331.75/QALY. A series of PRP injections was associated with a higher initial cost than a series of HA injections (difference, $1,433.67); however, PRP was also more effective (higher utility value) than HA by 0.11 QALYs (0.69 vs 0.58, P = .0062) at 1 year. The incremental cost-effectiveness ratio of the use of PRP injections as opposed to HA was $12,628.15/QALY.

CONCLUSIONS

Although a series of either PRP ($8,635.23/QALY) or HA ($5,331.75/QALY) injections for the treatment of symptomatic knee osteoarthritis would be considered cost-effective (cost per QALY < $50,000), PRP injections were not more cost-effective than HA injections. However, PRP was significantly more effective at 1 year, and being associated with an incremental cost-effectiveness ratio of $12,628.15/QALY when compared with HA, a series of PRP injections should be considered a reasonable and acceptable alternative to HA injections for the treatment of symptomatic knee osteoarthritis.

LEVEL OF EVIDENCE

Level II, economic and decision analysis of Level I studies.

Use of Herbal Medications for Treatment of Osteoarthritis and Rheumatoid Arthritis

Arthritis is a chronic condition that affects nearly a quarter of the United States population. Osteoarthritis (OA) and rheumatoid arthritis (RA) are two major forms of arthritis associated with severe joint pain and reduced quality of life. Various pharmacological interventions may be utilized for arthritis treatment when non-pharmacological therapy is insufficient. However, pharmacological therapy can be associated with serious side effects and high costs. Therefore, alternative therapies have been under investigation. Herbal medications have shown the potential for safe and effective management of arthritis. For this review, we attempt to summarize the mechanisms, safety, and efficacy of herbal treatments for OA and RA. After searching electronic databases, we identified nine herbs among 23 clinical trials used for the treatment of OA or RA patients. Improvement of OA and RA symptoms, pain, and inflammation was demonstrated. The herbs exhibited strong anti-inflammatory and anti-oxidant activities, contributing to a reduction in inflammation and tissue damage. Several herbs elucidated new mechanisms for OA and RA treatment as well. Though these herbs have shown promise for OA and RA treatment, more studies and clinical trials are required for determining safety and efficacy, bioactivity, and optimal bioavailability.

Knee OA cost comparison for hyaluronic acid and knee arthroplasty

BACKGROUND

Limiting treatment to those recommended by the American Academy of Orthopaedic Surgeon Clinical Practice Guidelines has been suggested to decrease costs by 45% in the year prior to total knee arthroplasty, but this only focuses on expenditures leading up to, but not including, the surgery and not the entire episode of care. We evaluated the treatment costs following knee osteoarthritis (OA) diagnosis and determined whether these are different for patients who use intra-articular hyaluronic acid (HA) and/or knee arthroplasty.

METHODS

Claims data from a large commercial database containing de-identified data of more than 100 million patients with continuous coverage from 2012 to 2016 was used to evaluate the cumulative cost of care for over 2 million de-identified members with knee OA over a 4.5-year period between 2011 and 2015. Median cumulative costs were then stratified for patients with or without HA and/or knee arthroplasty.

RESULTS

Knee OA treatment costs for 1,567,024 patients over the 4.5-year period was $6.60 billion (mean $4210/patient) as calculated by the authors. HA and knee arthroplasty accounted for 3.0 and 61.5% of the overall costs, respectively. For patients who underwent knee arthroplasty, a spike in median costs occurred sooner for patients without HA use (around the 5- to 6-month time point) compared to patients treated with HA (around the 16- to 17-month time point).

CONCLUSIONS

Non-arthroplasty therapies, as calculated by the authors, accounted for about one third of the costs in treating knee OA in our cohort. Although some have theorized that limiting the use of HA may reduce the costs of OA treatment, HA only comprised a small fraction (3%) of the overall costs. Among patients who underwent knee arthroplasty, those treated with HA experienced elevated costs from the surgery later than those without HA, which reflects their longer time to undergoing knee arthroplasty. The ability to delay or avoid knee arthroplasty altogether can have a substantial impact on the cost to the healthcare system.

Hyaluronic Acid Injections or Oral Nonsteroidal Anti-inflammatory Drugs for Knee Osteoarthritis: Systematic Review and Meta-analysis of Randomized Trials

BACKGROUND

Intra-articular hyaluronic acid (HA) injections and oral nonsteroidal anti-inflammatory drugs (NSAIDs) are common treatments for symptomatic knee osteoarthritis (OA). However, the comparative effects of these treatments are unclear.

PURPOSE

To compare the efficacy and safety of intra-articular HA injections compared with oral NSAIDs for the treatment of knee OA.

STUDY DESIGN

Systematic review; Level of evidence, 1.

METHODS

We systematically searched Medline, Embase, and the Cochrane Central Register of Controlled Trials for randomized trials of knee OA treatment with HA injections compared with oral NSAIDs. The main outcomes were knee pain, knee function, adverse events (AEs), serious AEs, study withdrawals, and study withdrawals because of AEs. Pooled effect sizes were reported at the final follow-up with standardized mean difference (SMD) for efficacy outcomes and risk ratio (RR) for safety outcomes.

RESULTS

In 6 randomized trials of 831 patients (414 HA, 417 NSAIDs), with follow-up ranging from 5 to 26 weeks, HA injections were associated with small, statistically significant improvements in knee pain (SMD, 0.15; P = .04) and knee function (SMD, 0.23; P = .01) compared with oral NSAIDs. The risk of AEs was lower with HA compared with NSAIDs (19.8% vs 29.0%; RR, 0.74; P = .01). The risk of a serious AE (RR, 1.37; P = .71), study withdrawal (RR, 1.05; P = .68), or study withdrawal because of an AE (RR, 0.65; P = .22) was comparable between groups. Gastrointestinal concerns were the most frequent AE reported, occurring more often with NSAIDs (23.4% vs 14.1%; P = .001). AEs reported more frequently with HA injections were injection site pain (11.7% vs 4.7%; P < .001), headache (8.4% vs 4.4%; P = .03), and arthralgia (8.1% vs 2.9%; P = .001). Significant heterogeneity or publication bias was not observed for any outcome.

CONCLUSION

Comparing short-term outcomes of HA injections with oral NSAIDs for treatment of knee OA, HA injections provided statistically significant but not clinically important improvements in knee pain and function, along with a lower overall risk of AEs.

Stem Cells and Platelet-rich Plasma for Knee Osteoarthritis: Prevalence and Cost in South Florida

INTRODUCTION

The use of stem cell therapy (SCT) and platelet-rich plasma (PRP) injection for knee osteoarthritis (OA) is extremely controversial and at best experimental stage. These treatments are being offered across the nation for "cash-only payments." Our objectives were to determine (1) what proportion of board-certified orthopedic surgeons in Miami-Dade County offer SCT or PRP and (2) how much do practices charge for these services.

METHODS

All board-certified orthopedic surgeons' offices in Miami-Dade County were identified by their American Academy of Orthopaedic Surgeons active membership. Offices were contacted and presented a hypothetical patient with end-stage OA searching for treatment (SCT or PRP injections) before having to undergo surgery.

RESULTS

Of the 96 registered American Academy of Orthopaedic Surgeons member's offices, 91 (94.7%) were contacted, 36% of offices offered PRP, and 24.5% offered SCT. However, 81% of the offices were transparent on the pricing of PRP, whereas 42% gave a price for SCT. Remaining practices stated that pricing would be "determined or discussed" during a scheduled visit. Mean cost for PRP injection was $897 (range, $350 to $1,700), and for SCT injection, it was $3,100 (range, $1,200 to $6,000).

DISCUSSION

Biological injectables as treatment of knee OA have potential use in the nonsurgical management of this disease. Data on the effectiveness are lacking and are conflicting. Data should continue to be investigational.

LEVEL OF EVIDENCE

Level IV.

The effect of hyaluronic acid on the corrosion of an orthopedic CoCrMo-alloy in simulated inflammatory conditions

During joint inflammation, various reactive oxygen species (ROS) are present in the surrounding tissue and joint fluid. In the laboratory, hydrogen peroxide (H₂O₂) is typically used to simulate inflammatory conditions, and media containing proteins and hyaluronic acid (HA) are employed to simulate joint synovial fluid. Electrochemical interactions between H₂O₂ and HA in the presence of a CoCrMo surface are expected, since HA molecules contain redox-active moieties. We hypothesized that any redox reactions of these moieties with ROS will mitigate the oxidizing effect of H₂O₂ on the CoCrMo surface, limiting the corrosion rate of the metal. Non-destructive electrochemical measurements (open circuit potential, linear polarization resistance and electrochemical impedance spectroscopy) were used to investigate the corrosion response of CoCrMo in synovial model fluid containing physiologically relevant concentrations of albumin proteins and hyaluronic acid, with and without H₂O₂. Two different molarities of H₂O₂, 3 mM and 30 mM, were tested. While both molarities are within physiological limits, 3mM is well within the range HA could mitigate, whereas 30 mM is not. Contrary to our hypothesis, HA did not alleviate corrosion in 3 mM H₂O₂ and even caused a corrosion increase in the case of 30 mM H₂O₂. The decrease in corrosion resistance of the alloy may be attributed to the complexation of degenerated HA molecular chains with chromium ions released from the metallic surface, which are necessary to build a protective oxide film. This finding has clinical implications, suggesting that HA accelerates corrosion of CoCrMo implants in the presence of strong inflammation.

Cost-of-illness of knee osteoarthritis: potential cost savings by not undergoing arthroplasty within the first 2 years

Purpose

Although knee arthroplasty (KA) is the largest source of hospitalization costs for knee osteoarthritis (OA), some studies have suggested reducing the use of “low-value” interventions, such as intra-articular hyaluronic acid (HA), to lower health care costs. However, those studies fail to consider that HA has demonstrated benefits in extending time to more costly KA or avoiding KA altogether. We evaluated 1) the overall knee OA costs (direct) within a 2-year period; 2) the relative contribution of HA and KA costs; 3) the direct cost savings from HA patients not undergoing KA.

Patients and methods

Knee OA patients were identified from the Optum Clinformatics data set, which includes physician, facility, and pharmacy claims data from privately insured patients of all ages. Patients were stratified in the no HA, non-hylan G-F 20, and hylan G-F 20 cohorts. The cumulative costs (payer perspective) were evaluated for all knee OA-related claims (adjusted to Consumer Price Index Jan 2017$) for patients who had at least 2 years follow-up. Costs were stratified into various clinical categories.

Results

The study cohort included 2,030,497 knee OA patients, of which 65,144 patients (3.2%) underwent KA. The cost of treating knee OA within the 2-year follow-up period was estimated to be $4.99 billion (B). The majority of the costs (69%) were attributed to KA patients (3.2% of patients). In all, 15.9% of the HA patients underwent KA within 2 years, but HA only contributed 1.7% to the total costs for these patients. The remaining 84.1% of HA patients did not undergo KA, which saved an estimated total of $1.54B (average $20,740 per patient) or 83.9%, after accounting for their non-KA therapies.

Conclusion

Our study estimated substantial cost savings through a large percentage of HA patients not undergoing KA. Although a fraction of patients moved on from their conservative therapy to undergo KA within the 2-year period, HA attributed to <2% of their total treatment costs.

Impact of Clinical Practice Guidelines on Use of Intra-Articular Hyaluronic Acid and Corticosteroid Injections for Knee Osteoarthritis

BACKGROUND

The efficacy of corticosteroid and hyaluronic acid injections for knee osteoarthritis has been questioned. The purpose of this study was to determine the impact of the American Academy of Orthopaedic Surgeons (AAOS) clinical practice guidelines on the use of these injections in the United States and determine if utilization differed by provider specialty.

METHODS

Patients with knee osteoarthritis were identified within the Humana database from 2007 to 2015, and the percentage of patients receiving a knee injection relative to the number of patients having an encounter for knee osteoarthritis was calculated and was trended for the study period. The impact of each edition of the AAOS clinical practice guidelines on injection use was evaluated with segmented regression analysis. Injection trends were also analyzed relative to the specialty of the provider performing the injection.

RESULTS

Of 1,065,175 patients with knee osteoarthritis, 405,101 (38.0%) received a corticosteroid injection and 137,005 (12.9%) received a hyaluronic acid injection. The rate of increase in hyaluronic acid use, per 100 patients with knee osteoarthritis, decreased from 0.15 to 0.07 injection per quarter year (p = 0.02) after the first clinical practice guideline, and the increase changed to a decrease at a rate of -0.12 injection per quarter (p < 0.001) after the second clinical practice guideline. After the first clinical practice guideline, the rate of increase in utilization of corticosteroids, per 100 patients with knee osteoarthritis, significantly lessened to 0.12 injection per quarter (p < 0.001), and after the second clinical practice guideline, corticosteroid injection use plateaued (p = 0.72). The trend in use of hyaluronic acid injections by orthopaedic surgeons and pain specialists decreased with time following the second-edition clinical practice guideline but did not change for primary care physicians or nonoperative musculoskeletal providers.

CONCLUSIONS

Subtle but significant changes in hyaluronic acid and corticosteroid injections occurred following the publication of both clinical practice guidelines. Although the clinical practice guidelines did impact injection use, given the high costs of these injections and their questionable clinical efficacy, further interventions beyond publishing clinical practice guidelines are needed to encourage higher-value care for patients with knee osteoarthritis.

Osteoarthritis year in review 2017: clinical

This review is based on a systematic review of the literature relevant to clinical topics in osteoarthritis (OA) performed for the time period February 22, 2016 to April 1, 2017. A PubMed search using the terms "osteoarthritis" and "treatment or epidemiology" returned over 800 papers, of which 57 are reviewed here, with inclusion primarily based on relevance to clinical OA. Epidemiologic studies in this time frame focused on the incidence and prevalence of OA, comorbidities and mortality in relation to OA (particularly obesity and cardiovascular disease), and multiple joint involvement. Papers on therapeutic approaches to OA considered: non-pharmacologic options, a number of topical, oral, and intra-articular therapies, as well as the cost-effectiveness of some OA treatments. There an enormous need to identify novel strategies to reduce the impact of this highly prevalent and debilitating condition.

Hyaluronic acid injections for osteoarthritis of the knee: predictors of successful treatment

PURPOSE

This study aimed to identify patient and treatment factors that predict a favourable response to intra-articular hyaluronic acid (HA) treatment to better guide patient and treatment selection.

METHODS

This prospective, observational study evaluated patients with mild-to-moderate (Kellgren-Lawrence grades 1-3) primary knee osteoarthritis treated between March 2013 and May 2016. Patient function and pain scores were assessed by the Western Ontario and McMaster Universities Arthritis Index/Knee Injury and Osteoarthritis Outcome Score (WOMAC/KOOS) and visual analogue scale (VAS) surveys, with response to treatment defined according to the Osteoarthritis Research Society International (OARSI) 2004 criteria. Surveys were completed at each injection and three months post-treatment. Patients were followed an average of 27 months.

RESULTS

Of 102 patients, 57% had a positive response. Those at least twice as likely to respond were patients with grades 1-2 osteoarthritis or a positive response to the first injection and those who were ≥60 years. Gender, race, body mass index (BMI), smoking status, HA brand, and initial VAS and WOMAC/KOOS scores were not significant predictors of success. Mean time to arthroplasty following injection series was 11 months (30% of nonresponders, 12% of responders). The VAS strongly correlated with KOOS pain scores and successful outcomes.

CONCLUSION

Patients with mild-to-moderate osteoarthritis (grades 1-2) and those responding positively to the first injection were twice as likely to respond positively to the injection series, as were patients ≥60 years. Patients who did not respond positively were more likely to proceed to arthroplasty. The VAS appears to be a reliable method of defining and monitoring treatment success. Judicious patient selection and counseling may improve outcomes associated with intra-articular HA injections.

Knee Osteoarthritis: A Primer

The purpose of this article is to provide a synopsis of the current medical understanding of knee osteoarthritis. We describe the prevalence, causes and associated risk factors, symptoms, diagnosis and classification, and treatment options. A quiz serves to assist readers in their understanding of the presented material.