Clinical and economic consequences of the treatment gap in knee osteoarthritis management

Microfragmented Adipose Tissue Injection Reduced Pain Compared With a Saline Control Among Patients With Symptomatic Osteoarthritis of the Knee During 1-Year Follow-Up: A Randomized Controlled Trial

PURPOSE

To evaluate the effectiveness of microfragmented adipose tissue (MFAT) for pain relief and improved joint functionality in osteoarthritis (OA) of the knee in a randomized controlled clinical trial with 1-year follow-up.

METHODS

Seventy-five patients were stratified by baseline pain level and randomized to 1 of 3 treatment groups: MFAT, corticosteroid (CS), or saline control (C) injection. Patients 18 years of age or older, diagnosed with symptomatic OA of the knee, with radiographic evidence of OA of the knee and a visual analog pain scale score of 3 of 10 or greater were included. Patients were excluded if they had any previous intra-articular knee injection, current knee ligamentous instability, or an allergy to lidocaine/corticosteroid. The visual analog pain scale, Western Ontario and McMaster Universities Osteoarthritis Index, and the Knee Injury and Osteoarthritis Outcome score (KOOS) were recorded preprocedure and at 2 weeks, 6 weeks, 3 and 6 months, and 1-year follow-up.

RESULTS

MFAT demonstrated consistent and statistically significant improvements across all primary outcome measures for joint pain and functionality compared with C. For MFAT, there was a significant improvement over baseline at each follow-up, with median (95% confidence interval) KOOS Pain score changes of 18.1 (11.1-26.4) at week 2 to 27.8 (19.4-37.5) at 1 year. For CS, the median KOOS pain score reached a maximum of 22.2 (15.3-30.6) at week 2, only to level off to 13.9 (-2.8 to 29.2), a level not statistically different from baseline, at 1 year. The median changes for C hovered around 6 to 11 points, with statistically significant improvements over baseline indicating a placebo effect. Similar trends were seen for the Western Ontario and McMaster Universities Osteoarthritis Index Pain score and VAS Pain score.

CONCLUSIONS

In this study, MFAT demonstrated a clinically significant improvement in primary outcome scores compared with the C group, whereas the CS group only showed statistically significant improvement compared with the C group at 2 and 6 weeks. This finding indicates that MFAT may be a viable alternative treatment for patients with OA of the knee who fall into the orthopaedic treatment gap.

LEVEL OF EVIDENCE

Level II, partially blinded, randomized controlled clinical trial.

Micro-Fragmented Adipose Tissue Demonstrates Comparable Clinical Efficacy to Other Orthobiologic Injections in Treating Symptomatic Knee Osteoarthritis: A Systematic Review of Level I to IV Clinical Studies

PURPOSE

To perform a systematic review of clinical outcomes in patients who underwent treatment with micro-fragmented aspirated tissue for symptoms of knee osteoarthritis.

METHODS

Medline, Embase, Scopus, and Google Scholar were screened for studies from 2000 to 2023. Risk of bias (ROB) was assessed using the Cochrane Collaboration's tools and the Risk Of Bias In Non-randomised Studies-of Interventions tool. Study quality was assessed with the modified Coleman Methodology Score and Methodological Index for Non-Randomized Studies score. Heterogeneity was assessed using χ2 and I2 statistics.

RESULTS

Twenty-one studies were included. One study had a high ROB, 1 had a critical ROB, 3 had serious ROB, and 16 had a moderate ROB. The mean Coleman score was 58, demonstrating fair study quality; the Methodological Index for Non-Randomized Studies score had a mean value of 13, indicating overall fair quality. Best evidence synthesis revealed moderate evidence. The visual analog scale score improved from 5.2 to 3.2 at 6 and 12 months. Knee injury and Osteoarthritis Outcome Score (KOOS) activities of daily living subscore improved from 58.8 to 70.2 at 6 months and 67.5 at 12 months. KOOS pain subscore improved from 54.3 to 70.2 at 6 months and 72.4 at 12 months. KOOS quality of life subscore improved from 33.1 to 43.6 at 6 months and 42.9 at 12 months. KOOS sports subscore improved from 23.7 to 43.6 at 6 months and 57.4 at 12 months. KOOS symptoms subscore improved from 55.3 to 70.1 at 6 months and 67.9 at 12 months. The Western Ontario and McMaster Universities Osteoarthritis Index score steadily increased from 61.8 at baseline to 78.4 at 12 months.

CONCLUSIONS

micro-fragmented aspirated tissue injection therapy for the treatment of symptomatic knee osteoarthritis is effective and improves pain and functional outcomes. Moderate study quality combined with a moderate risk of bias, moderate certainty of evidence, and moderate best synthesis evidence reduces external validity. Therefore, the results should be interpreted with a degree of caution.

LEVEL OF EVIDENCE

Level IV, systematic review of Level I-IV studies.

Genicular Artery Embolization, Radiofrequency Ablation, and Corticosteroid Therapy for Knee Osteoarthritis: A Cost-Effectiveness Analysis Using Randomized Clinical Trial Data

BACKGROUND. Many patients with knee osteoarthritis (KOA) have symptoms that are refractory to traditional nonsurgical treatments, such as intraarticular corticosteroid (CS) injection, but are not yet eligible are not yet eligible for or decline surgery. Genicular artery embolization (GAE) and radiofrequency ablation (RFA) are emerging adjunctive or alternative minimally invasive treatments. OBJECTIVE. The purpose of this study was to perform a cost-effectiveness analysis (CEA) comparing CS therapy, GAE, and RFA for the treatment of symptomatic KOA using a Markov model based on a de novo network meta-analysis (NMA) of randomized control trials. METHODS. A CEA was conducted to compare GAE and RFA to CS using a Markov cohort state-transition model from a U.S. Medicare payer's perspective over a 4-year time horizon. The model incorporated each treatment's success and attrition rates, costs, and utility benefit. Utility benefit values were derived at short-term (0.5-3 months) and long-term (6-12 months) posttreatment follow-up from an NMA of published randomized controlled trials using an outcome of improved knee pain and/or function. Analyses were conducted at a willingness-to-pay threshold of US$100,000 per quality-adjusted life year (QALY) gained. Sensitivity analyses were performed, including when simulating various cost setting scenarios (i.e., office vs hospital outpatient treatment). RESULTS. RFA showed larger treatment effect than GAE, which was more pronounced at short-term follow-up (standardized mean difference [SMD] for RFA, -1.6688 [95% CI, -2.7806 to -0.5571], p = .003; SMD for GAE, -0.3822 [95% CI, -1.9743 to 1.2100], p = .64) than at long-term follow-up. Across cost setting scenarios, incremental cost-effectiveness ratios relative to CS therapy were US$561-1563 per QALY gained for GAE versus US$76-429 per QALY gained for RFA (not counting scenarios in which RFA was dominated by CS). GAE showed higher cost-effectiveness probability compared with RFA (41.6-54.8% vs 18.4-29.2%, respectively). GAE was more cost-effective than RFA when the GAE clinical success rate and post-GAE utility value exceeded 32.1-51.0% and 0.562-0.617, respectively, and when the GAE quarterly attrition rate was less than 8.8-17.4%. RFA was more cost-effective when baseline pretreatment utility values exceeded 0.695-0.713. Neither GAE costs nor RFA costs were sensitive parameters. CONCLUSION. Across scenarios, GAE was consistently the most likely cost-effective treatment option compared with RFA and CS, although clinical success rates, attrition rates, and utility values impact its cost-effectiveness. CLINICAL IMPACT. GAE is likely to be more cost-effective than RFA or CS for treatment of symptomatic KOA.

The Outcomes at 3 Years in 82 Knees with Kellgren and Lawrence 2-3 Osteoarthritis Treated with an Autologous Protein Fluid Concentrate Produced with a Fluid Volume Reducer

INTRODUCTION

Knee osteoarthritis (OA) is a highly prevalent and debilitating condition with significant emotional and economic impacts. Current treatment options may only provide temporary pain relief and are not regenerative, thus the progression of knee OA is not deterred and total knee arthroplasty is inevitable. Injection therapies with orthobiologics possess regenerative potential and are an emerging treatment option. We present a prospective study aimed at examining patients with knee OA who had received an autologous platelet concentrate fluid (APCF) injection produced through a fluid volume reducer.

METHODS

This was an observational review of the results following an APCF injection in a cohort of patients at a single site. Patients were included in the study if they were diagnosed with K/L grade 2-3 knee OA and treated with an APCF knee injection. Patients were excluded if they had obtained an orthobiologic injection in the three months prior to study enrollment or if baseline data were unavailable. Knee score and function score were used to assess patients at the baseline and post-injection follow-ups.

RESULTS

Improvements for knee score were statistically significant for the follow-ups at three months, six months, one year, and three years. Function score improved, with statistically significant changes for the three month and three year follow-ups.

CONCLUSIONS

Our study demonstrates that there is some utility in using APCF injection for knee OA, with improvements that may be sustained up to three years in some patients.

The effectiveness of vitamin D supplementation in patients with end-stage knee osteoarthritis: Study protocol for a double-blinded, randomized controlled trial

Osteoarthritis (OA) knee is one of the most common chronic degenerative conditions that imposes clinical and economic burdens on individuals and societies worldwide. Previous studies showed vitamin D levels correlated positively with lean muscle mass and grip strength, implying that vitamin D supplementation may improve muscle health in knee OA subjects. This randomized controlled trial (RCT) aims to compare the effects of vitamin D supplementation on knee muscle strength, physical function, pain, and sarcopenia status in patients with end-stage knee OA. Patients and outcome assessors will be blinded to group allocation. Fifty-six end-stage knee OA patients with vitamin D insufficiency fulfilling our inclusion criteria will be invited to participate in this study. Patients will be randomly assigned to take vitamin D supplementation (4,000 IU capsule daily) or placebo for six months. Measurements will be taken at baseline, three and six-month after the commencement of the vitamin D supplement, and 6-month after the interventional period. The primary outcome includes the isometric quadriceps and hamstring muscle strength measured by a hand-held dynamometer. Secondary outcomes include pain, performance-based and self-reported physical function and sarcopenia status. The success of this study will provide scientific evidence of whether the relatively cheap and well-tolerated vitamin D supplement can improve quadriceps muscle strength, physical function, pain symptoms, and sarcopenia status of this increasingly large population for end-stage knee OA patients. The study has great clinical significance given Hong Kong's lengthy and growing waiting list for complete knee replacement procedures. Trial registration: The trial was registered on clinicaltrials.gov (NCT05981534) on 31st July 2023.

Genicular artery embolisation versus sham embolisation for symptomatic osteoarthritis of the knee: a randomised controlled trial

OBJECTIVE

To determine the efficacy of genicular artery embolisation (GAE) compared with sham GAE for pain reduction in patients with symptomatic mild-to-moderate knee osteoarthritis (KOA).

DESIGN

Double-blind randomised sham-controlled clinical trial conducted from June 2019 to December 2021. The follow-up period was 4 months.

SETTING

Single-centre study conducted at a university medical centre in Rotterdam, Netherlands.

PARTICIPANTS

58 adults with symptomatic mild-to-moderate KOA not improving with conservative treatment.

INTERVENTIONS

Participants were randomised to receive either GAE treatment or a sham GAE treatment.

MAIN OUTCOME MEASURES

The primary outcome was reduction of pain measured with the Knee Injury and Osteoarthritis Outcome Score pain subscale (0-100, with 0 representing the worst pain outcome and 100 the best) after 4 months. Outcomes were assessed at baseline and 1 and 4 months.

RESULTS

From June 2019 to December 2021, 58 patients were included. 29 patients were randomised to the GAE group and 29 to the sham group. All participants completed the study. The mean pain reduction after 4 months was 21.4 (95% CI 13.9 to 28.8) for the GAE group and 18.4 points (95% CI 11.6 to 25.1) for the sham group. The between-group difference for the mean pain reduction was 3.0 (95% CI -7.1 to 13.0) with an estimated Cohen's d effect size of d = 0.15 (95% CI -0.37 to 0.66). Group allocation was not a significant contributor to pain reduction (p = 0.31). No serious adverse events (AEs) occurred. 23 mild AEs occurred in the GAE group and 5 in the sham group.

CONCLUSION

We did not establish a clinical effect of GAE in patients with mild-to-moderate KOA as GAE produced a similar effect on pain reduction as a sham GAE procedure.

TRIAL REGISTRATION NUMBER

NCT03884049.

Trends and outcomes in the surgical management of young adults with knee osteoarthritis using high tibial osteotomy and unicompartmental knee arthroplasty

INTRODUCTION

A significant portion of knee osteoarthritis is diagnosed in patients under the age of 55, where greater activity demands make total knee arthroplasty less desirable. High tibial osteotomy (HTO) and unicompartmental knee arthroplasty (UKA) are useful alternatives, but there is little understanding of which procedure is advantageous. Hence, this study examines the utilization, complication, and reoperation rates among the HTO vs. UKA in young patients with primary osteoarthritis.

METHODS

A retrospective review of the National Surgical Quality Improvement Program was performed to identify 2318 patients < 55 years of age who received either a HTO or UKA for primary osteoarthritis between 2011 and 2021. Bivariate analyses compared preoperative and intraoperative characteristics among each procedure. Then, multivariate analyses examined if either procedure was associated with worse 30-day postoperative complications or need for reoperation, independent of the statistically significant pre- and intraoperative disparities.

RESULTS

UKAs were performed 14.2 times more commonly than HTOs, and the patients selected for HTO were more likely to be younger, have a lower BMI, have the healthiest ASA Class score, and less likely to have hypertension requiring medication (p < 0.001). HTOs took 17.5% longer to perform and had a longer average length of stay (p < 0.001), while UKAs were more likely to be performed out-patient (p < 0.001). HTOs also had higher rates of serious complications (p = 0.02), overall complications (p = 0.004), and need for reoperation (p = 0.004). Multivariate modelling demonstrated that procedure type was not a predictor of serious complications, but the use of HTO was significantly associated with any complications (odds ratio = 3.63, p = 0.001) and need for reoperation (3.21, p = 0.029).

CONCLUSION

Although healthier patients were selected for HTOs, UKAs were found to have a lower risk of complications and immediate reoperation. Additionally, UKAs had the advantage of lower operative burden, shorter length of stay, and a higher efficacy in outpatient settings.

Focal resurfacing of the knee - A systematic review and meta-analysis

PURPOSE

In order to assess the published validity of focal resurfacing of the knee, a systematic review and meta-analysis were conducted to (i) evaluate revision rates and implant survival of focal resurfacing of the knee; (ii) explore surgical complications; and (iii) evaluate patient reported clinical outcome measures.

METHODS

PubMED, Cochrane Library and Medline databases were searched by 2 independent reviewers in February 2022 for prospective and retrospective cohort studies evaluating any of the following implant types: HemiCAP®, UniCAP®, Episealer® or BioBoly®. Data on incidence of revision, complications and various patient reported outcome measures, such as Knee Society Score (KSS) or Knee Injury and Osteoarthritis Outcome Score (KOOS) was sourced.

RESULTS

A total of 24 published studies were identified with a total of 1465 enrolled patients. A revision rate of 12.97% over a 5.9 year weighted mean follow-up period was observed across all implant types. However, in one series a Kaplan-Meir survival as high as 92.6% at a 10-year follow-up period was noted. A statistically significant improvement was documented across multiple subjective clinical outcomes scores, for example a mean 4.56 point improvement of the VAS (0-10) pain score. The Kellgren-Lawrence score was used to evaluate the radiological progression of osteoarthritis and showed a small significant reduction in all anatomical locations, hence not supporting the hypothesis that focal femoral implants can lead to the progression of osteoarthritis in the affected compartment. There was a low reported incidence of post-operative complications such as aseptic loosening or deep wound infection.

CONCLUSIONS

Focal femoral resurfacing appears to be a viable treatment option for focal symptomatic chondral lesions in patients beyond biological reconstruction, with low revision rates and high patient satisfaction especially at short and medium length follow-up.

Musculoskeletal Embolotherapy

Painful articular musculoskeletal (MSK) conditions are common, debilitating and sometimes difficult to treat. Transcatheter embolisation may offer an alternative way to manage the pain associated with these conditions, but the field is still in its infancy. To date, the most commonly studied indication is knee osteoarthritis, but the technique has been trailed in multiple other tissue beds, including for adhesive capsulitis and tendinopathies. Whilst early results appear promising, the existing studies are mostly open-labelled and non-randomised; there is a need for high-quality evidence to robustly assess the procedures efficacy. In this review, we set out to evaluate the current evidence underlying the pathophysiology and mechanism of action of embolisation; discuss the technical aspects of the procedure including embolic selection, and appraise the published clinical outcomes and adverse effects. Finally, we discuss the future directions and research priorities in this rapidly developing field.

Clinical Outcomes of Unicompartmental Knee Arthroplasty in Patients with Full-versus Partial-Thickness Cartilage Loss: A Systematic Review and Meta-Analysis

OBJECTIVE

The objective of the study was to compare postoperative patient-reported outcomes and reoperation rates following unicompartmental knee arthroplasty (UKA) between patients with full-thickness cartilage loss (FTCL) and partial-thickness cartilage loss (PTCL).

DESIGN

Multiple databases, including PubMed, Embase, Cochrane Library, and CNKI, were searched until October 2019 for studies comparing the Oxford Knee Score (OKS), American Knee Society (AKS) score, and reoperation rates between patients with FTCL and PTCL following UKA. Data analysis was performed using Review Manager software.

RESULTS

A total of 613 UKA cases from 5 retrospective cohort studies were included. The mean difference in postoperative OKSs was significantly higher by 2.92 in FTCL group than in PTCL group (95% confidence interval [CI] = -5.29 to -0.55; P = 0.02). Improvement in OKS was significantly higher by 2.69 in FTCL group than in PTCL group (95% CI = -4.79 to -0.60; P = 0.01). However, the differences in OKSs were not clinically significant. The mean difference in AKS knee scores was similar between the 2 groups (95% CI = -9.14 to -3.34; P = 0.36), whereas the pooled mean difference in AKS function scores was higher by 5.63 in FTCL group than in PTCL group (95% CI = -9.27 to -1.98; P = 0.002), which was clinically relevant. The reoperation rates were statistically higher in PTCL group than in FTCL group (odds ratio = 2.24; 95% CI = 1.15 to 4.38; P = 0.02).

CONCLUSIONS

Patients with FTCL achieved superior postoperative patient-reported outcomes and lower reoperation rates following UKA compared with those with PTCL. Thus, we believe this procedure should only be applied to end-stage medial osteoarthritis of the knee joint.

Individualized metal implants for focal cartilage lesions in the knee can be cost-effective: A simulation on 47-year-old in a Swedish setting

OBJECTIVES

In the aging population, the knee is the joint most commonly causing impaired function and incapacity. While definite treatment by prosthetic replacement is often performed late, symptomatic knee cartilage lesions cause much suffering also in younger ages. Early intervention could, therefore, be instituted at an early stage to the benefit of both patients and society. Small, metal surface, resurfacing implants have been tested with promising results. A system that features patient-specific implants and surgical instruments shows good clinical results and favorable survival rates. This study aims to assess the cost utility of this metal device compared with microfracture (MFX), being the standard procedure in Sweden.

METHODS

We constructed a simulation model in Excel. In the model, a cohort of 47-year-old patients (which is the mean age of patients treated with the metal implant) with symptomatic knee cartilage lesions received either MFX or metal implantation. Outcomes for the cohort were simulated over 40 years, such as in a previously published model based on MFX, and sensitivity analyses (deterministic and probabilistic) of the results were undertaken. Data on transition probabilities, costs, and quality of life were taken from clinical data, published literature, and official price lists. Only direct medical costs were included.

RESULTS

Results from the analysis showed that the metal device is a cost-effective treatment strategy compared with MFX. The incremental cost-effectiveness ratio (ICER) reached acceptable levels at ∼5 years postoperatively. Over the full-time horizon of 40 years, the metal device was cost saving with concomitant gains in quality-adjusted life years (QALYs), translating to a dominant treatment strategy. Results were robust according to sensitivity analysis with the initial success rate of up to three years for both metal and MFX having the largest impact.

CONCLUSIONS

A metal implant may be a cost-effective treatment alternative for patients in their 40's when compared to MFX in a Swedish setting.

LEVEL OF EVIDENCE

5 [1].

Implantable Shock Absorber Provides Superior Pain Relief and Functional Improvement Compared With High Tibial Osteotomy in Patients with Mild-to-Moderate Medial Knee Osteoarthritis: A 2-Year Report

OBJECTIVE

Up to 10 million Americans below the age of 65 years have symptomatic knee osteoarthritis (OA) and may not yet be candidates for arthroplasty. In response, a subcutaneous implantable shock absorber (ISA) that unloads the knee has been developed. The safety and effectiveness of ISA treatment were compared against a surgical unloading control, high tibial osteotomy (HTO).

DESIGN

This was a prospective open-label cohort study with a historical control arm. Subjects underwent ISA placement or HTO. The primary endpoint was a composite variable combining pain, function, specific adverse events, integrity of implant or hardware, and conversion to subsequent surgery. Pain and function outcomes (Western Ontario and McMaster Universities Arthritis Index scores) were assessed through 24 months. Adverse events were tracked.

RESULTS

The primary endpoint demonstrated superiority of the ISA arm versus the HTO arm, with 85.6% of ISA subjects meeting all criteria compared with 65.5% of HTO subjects. In addition, all 5 secondary endpoints showed superiority of ISA over HTO. At 24 months, the proportions of subjects considered responders were 95.8% (ISA) versus 87.9% (HTO) for pain and 91.7% (ISA) versus 81.3% (HTO) for function. The ISA procedure was well tolerated, with 13.4 days to full weightbearing status versus 58.0 days for the HTO arm.

CONCLUSIONS

Treatment with an ISA demonstrated noninferiority and superiority versus treatment with HTO in subjects aged 25-65 years who had OA of the medial knee. Treatment with ISA has high clinical benefit and is durable through at least 24 months.

Tricompartment offloader knee brace reduces sagittal plane knee moments, quadriceps muscle activity, and pain during chair rise and lower in individuals with knee osteoarthritis

The Levitation tricompartment offloader (TCO) knee brace provides an assistive knee extension moment with the goal of unloading all three compartments of the knee and reducing pain for individuals with multicompartment knee osteoarthritis (OA). This study aimed to determine the effect of the TCO brace on sagittal plane knee moments, quadriceps muscle activity, and pain in individuals with multicompartment knee OA. Lower limb kinematics, kinetics, and electromyography data were collected during a chair rise and lower to determine differences between bracing conditions. TCO brace use significantly decreased the peak net knee external flexion moment in high power mode, providing extension assistance during chair rise [p<0.001; mean difference (MD) (98.75% CI) -0.8 (-1.0, -0.6)%BWxH] and bodyweight support during chair lower [p<0.001; -1.1 (-1.6, -0.7)%BWxH]. Quadriceps activation intensity was significantly reduced with brace use by up to 67% for the vastus medialis [Z = -2.55, p = 0.008] and up to 39% for the vastus lateralis [Z = -2.67, p = 0.004]. Participants reported significantly reduced knee pain with the TCO brace worn in high power mode compared to the no brace condition [p = 0.014; MD (97.5% CI) -18.8 (-32.22, -2.34) mm]. These results support the intended mechanism of joint unloading via extension assistance with the TCO brace. The observed biomechanical changes were accompanied by immediate reductions in user reported pain levels, and support the use of the TCO for conservative management to reduce knee pain in patients with multicompartment knee OA.

An implantable shock absorber yields an 85% survival-from-arthroplasty rate through 5 years in working-age patients with medial compartment knee osteoarthritis

PURPOSE

To evaluate the 5-year rate of survival without undergoing arthroplasty or high tibial osteotomy (HTO) in subjects with mild-to-moderate medial compartment knee osteoarthritis (OA) who were treated with an implantable shock absorber (ISA) system.

METHODS

Three prospective, sequential, multicenter, international, single-arm clinical trials were conducted comprising subjects who received an ISA for symptomatic medial knee OA after failing ≥ 6 months of conservative therapy. Study outcomes were analyzed cumulatively and by enrollment group when all subjects' follow-up data exceeded the 2-year threshold after ISA implantation. Primary outcome was survival rate without conversion to arthroplasty/HTO. Secondary outcomes were changes in Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) pain and function scores after ISA implantation.

RESULTS

All 171 enrolled subjects (age 51 ± 9 years, body-mass index 28.5 ± 3.5 kg/m², 38% female; study knee Kellgren-Lawrence score 2.7 ± 0.9 points) were followed for a minimum of 2, and up to 5, years after device implantation. Overall, 90.6% (155/171) of subjects survived without requiring arthroplasty/HTO at last follow-up (mean 3.2 ± 1.6 years). The Kaplan-Meyer median 3- and 5-year survival-without-arthroplasty point estimates were 89.8% (95% CI 86.5‒95.7%) and 84.9% (95% CI 75.1‒91.1%), respectively. The median 3-year estimated survival rate for the most recent study (n = 81) was 97.3%. The mean WOMAC Pain score decreased 71% from baseline to last follow-up after ISA implantation, from 58 ± 13 to 16 ± 17 points (p < 0.0001). The Function score improved 69%, decreasing from 56 ± 18 to 17 ± 17 points (p < 0.0001).

CONCLUSIONS

In younger patients with mild-to-moderate symptomatic medial compartment knee OA, implantation of the ISA device resulted in a 5-year survival rate of 85% from undergoing arthroplasty or HTO. The ISA system may be an effective treatment option for working-age patients with medial knee OA who are not candidates for or do not desire more invasive surgical approaches.

LEVEL OF EVIDENCE

II.

Warm needle acupuncture for osteoarthritis: An overview of systematic reviews and meta-analysis

Background

Osteoarthritis (OA) is a chronic disease that is a major cause of pain and functional disability. Warm needle acupuncture (WA) therapy has been widely used to treat OA. This overview summarizes the evidence from systematic reviews (SRs) and assesses the methodological quality of previous SRs that evaluated the use of WA therapy for OA.

Methods

We searched electronic databases to identify SRs that evaluated the efficacy of WA therapy for OA. Two reviewers independently extracted data and assessed the methodological quality of the reviews according to the A Measurement Tool to Assess Systematic Reviews (AMSTAR 2) tool. The reporting quality was assessed using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 (PRISMA 2020) guidelines. The quality of evidence was assessed according to the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach.

Results

Fifteen SRs were included in this study. WA therapy was more effective than control conditions for the treatment of OA. The results of the AMSTAR 2 tool showed that the methodological quality of all included studies was critically low. The items with the lowest scores were item 2 (reporting the protocol), item 7 (listing excluded studies and justifying the exclusions), and item 16 (including conflicts of interest). Regarding the PRISMA guidelines, 2 SRs exhibited greater than 85% compliance. The overall quality of evidence in the included SRs ranged from "very low" to "moderate."

Conclusion

This overview shows that WA therapy was more effective than the control treatment for OA. However, the methodological quality of the reviews was low, indicating the need for improvements in the collection of evidence. Future studies are needed to collect high-quality evidence regarding the use of WA for OA.

Systematic review registration

https://www.researchregistry.com/, Research Registry (reviewregistry1317).

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.

Explainable machine learning for knee osteoarthritis diagnosis based on a novel fuzzy feature selection methodology

Knee Osteoarthritis (ΚΟΑ) is a degenerative joint disease of the knee that results from the progressive loss of cartilage. Due to KOA's multifactorial nature and the poor understanding of its pathophysiology, there is a need for reliable tools that will reduce diagnostic errors made by clinicians. The existence of public databases has facilitated the advent of advanced analytics in KOA research however the heterogeneity of the available data along with the observed high feature dimensionality make this diagnosis task difficult. The objective of the present study is to provide a robust Feature Selection (FS) methodology that could: (i) handle the multidimensional nature of the available datasets and (ii) alleviate the defectiveness of existing feature selection techniques towards the identification of important risk factors which contribute to KOA diagnosis. For this aim, we used multidimensional data obtained from the Osteoarthritis Initiative database for individuals without or with KOA. The proposed fuzzy ensemble feature selection methodology aggregates the results of several FS algorithms (filter, wrapper and embedded ones) based on fuzzy logic. The effectiveness of the proposed methodology was evaluated using an extensive experimental setup that involved multiple competing FS algorithms and several well-known ML models. A 73.55% classification accuracy was achieved by the best performing model (Random Forest classifier) on a group of twenty-one selected risk factors. Explainability analysis was finally performed to quantify the impact of the selected features on the model's output thus enhancing our understanding of the rationale behind the decision-making mechanism of the best model.

Genicular artery embolization as a novel treatment for mild to moderate knee osteoarthritis: protocol design of a randomized sham-controlled clinical trial

Introduction

Knee osteoarthritis is a common disease with pain as the most prevalent symptom. Previous cohort studies have shown genicular artery embolization to reduce pain symptoms in patients with mild to moderate knee osteoarthritis. Patients resistant to conservative therapy but not eligible yet for surgical treatment due to young age or comorbidities may profit from an effective and sustained pain reduction treatment. This study is a randomized sham-controlled trial to evaluate the efficacy of genicular artery embolization in patients with knee osteoarthritis.

Methods and analysis

Fifty-eight patients with mild-to-moderate knee osteoarthritis will be recruited and randomly allocated to the treatment or control group in a 1:1 ratio. Participants in the treatment group will undergo genicular artery embolization. Patients in the control group will undergo sham treatment. Outcome measurements will be assessed at baseline and after 1, 4, 8, and 12 months with questionnaires, pressure pain threshold testing, and MR imaging. The MR imaging protocol is designed to (semi)quantitatively assess osteoarthritis in the knee joint. The primary outcome is the change from baseline of the Knee injury and Osteoarthritis Outcome Score (KOOS) pain subscale after 4 months. Secondary outcomes include change in osteoarthritis-related questionnaires, pressure pain threshold, and OA-related MRI features, particularly synovitis and bone marrow lesions.

Ethics and dissemination

This trial will determine the efficacy of genicular artery embolization compared to a sham treatment. This is of importance to assess before proceeding to larger-scale efficiency studies and, ultimately, implementing this treatment into day to day clinical practice.

Trial registration

ClinicalTrials.gov NCT03884049. Registered on 21 March 2019

Ultrasound-Based Quantification of Cartilage Damage After In Vivo Articulation With Metal Implants

OBJECTIVE

This study aims to evaluate the applicability of the ultrasound roughness index (URI) for quantitative assessment of cartilage quality ex vivo (post-mortem), after 6 months of in vivo articulation with a Focal Knee Resurfacing Implant (FKRI).

DESIGN

Goats received a metal FKRI (n = 8) or sham surgery (n = 8) in the medial femoral condyles. After 6 months animals were sacrificed, tibial plateaus were stained with Indian ink, and macroscopic scoring of the plateaus was performed based on the ink staining. The URI was calculated from high-frequency ultrasound images at several sections, covering both areas that articulated with the implant and non-articulating areas. Cartilage quality at the most damaged medial location was evaluated with a Modified Mankin Score (MMS).

RESULTS

The URI was significantly higher in the FKRI-articulating than in the sham plateaus at medial articulating sections, but not at sections that were not in direct contact with the implant, for example, under the meniscus. The mean macroscopic score and MMS were significantly higher in the FKRI-articulating group than in the sham group (P=0.035, P<0.001, respectively). Correlation coefficients between URI and macroscopic score were significant in medial areas that articulated with the implant. A significant correlation between URI and MMS was found at the most damaged medial location (ρ=0.72,P=0.0024).

CONCLUSIONS

This study demonstrates the potential of URI to evaluate cartilage roughness and altered surface morphology after in vivo articulation with a metal FKRI, rendering it a promising future tool for quantitative follow-up assessment of cartilage quality.

Eighty Percent Survival of Resurfacing Implants in the Knee After 10 Years: A Nationwide Cohort Study on 379 Procedures from the Danish Knee Arthroplasty Registry

OBJECTIVE

Focal cartilage injuries are debilitating and difficult to treat. Biological cartilage repair procedures are used for patients younger than 40 years, and knee arthroplasties are generally reserved for patients older than 60 years. Resurfacing implants are well suited for patients in this treatment gap. The objective was to investigate the 10-year survival of resurfacing implants in the Danish Knee Arthroplasty Registry.

DESIGN

In this retrospective cohort study, patients treated with resurfacing implants were followed longitudinally in the Danish Knee Arthroplasty Registry from 1997 to 2020. The primary endpoint was revision surgery. The survival of the resurfacing implants was analyzed by Kaplan-Meier method.

RESULTS

A total of 379 resurfacing implant procedures were retrieved from the Danish Knee Arthroplasty Registry. The mean age and weight of patients were 50 years (SD = 11) and 84 kg (SD = 17), respectively. The indications for surgery were as follows: secondary osteoarthritis (42%), primary osteoarthritis (32%), and osteochondral lesions (20%). Within the follow-up period, 70 (19%) of the implants were revised to arthroplasties. The 1-, 5-, and 10-year revision-free survival estimation was 0.95 (95% CI 0.93-0.97), 0.84 (95% CI 0.80-0.88), and 0.80 (95% CI 0.75-0.84), respectively. The median time to revision was 2 years.

CONCLUSION

The 10-year revision-free survival rate for resurfacing implants was 80%. Based on the revision rates, this treatment offers a viable alternative to biological cartilage repair methods in patients aged 40 to 60 years with focal cartilage pathology. Improved patient selection could further improve the implant survival rate. Further studies are needed to investigate this treatment method.

HemiCAP Knee Implants: Mid- to Long-Term Results

PURPOSE

The aim of the study was to investigate the long-term outcomes of the Focal Femoral Condyle Resurfacing Prosthesis (HemiCAP) using clinical and radiographic assessments, and to evaluate the revision and survival rates.

METHODS

Clinical evaluation was performed in those not revised and was able to participate. This was a prospective single-center cohort study of HemiCAP patients with 7 to 10 years of clinical and radiographic follow-up. The clinical examination included the Knee Society Score (KSS) and visual analogue scale (VAS) score. The radiographic examination included the Kellgren-Lawrence (KL) grade. Survival was estimated by Kaplan-Meier survival analysis, and potential risk factors for revision was evaluated by a regression analysis.

RESULTS

Of the 62 patients with 64 HemiCAP prostheses, 37 were HemiCAP condyle, 11 HemiCAP PF, and 16 HemiCAP Wave; 27 (42%) were revised-HemiCAP condyle 17 (42%), HemiCAP PF 4 (36%), HemiCAP Wave 6 (37%), and 1 died. Examinations were performed on 31 patients (86%). When compared with the preoperative data, there were significant increases in the KSS objective (mean = 51.5, standard deviation [SD] = 5.9 vs. mean =94.2, SD = 5.0) and function (mean = 51.0, SD = 6.2 vs. mean = 93.7, SD = 4.8) scores, a decrease in the VAS score (mean = 7.1, SD = 0.7 vs. mean = 2.7, SD = 1.7) and a decrease in the KL lateral score (mean = 1.1, SD = 0.3 vs. mean = 0.6, SD = 0.6). The mean follow-up was 7.3 years (SD 1.4) with minimum 4.2 years and maximum 10.2 years. No failures occurred in the series beyond 5 years.

CONCLUSIONS

As hypothesized, we found good clinical and radiographic outcomes, and for those patients who did not require revisions, there were long-term improvements in disability and function. This suggests that patient selection is a key element to successfully applying these devices in clinical practice.

Real-World Health Care Resource Utilization and Costs Among US Patients with Knee Osteoarthritis Compared with Controls

PURPOSE

To determine the prevalence, healthcare resource utilization and costs (HCRU&C) of knee osteoarthritis (OA) patients versus controls.

PATIENTS AND METHODS

Retrospective, matched-cohort administrative claims analysis using IBM MarketScan databases (2011-2017). Newly diagnosed, adult (18+ yrs) knee OA patients identified by ICD9/10 code were matched 1:1 to controls by age, sex, payer, and geography; alpha level set to 0.05. Prevalence was estimated for 2017. All-cause and knee OA-related HCRU&C reported per-patient-per-year (PPPY) over follow-up period up to 4 years.

RESULTS

Overall 2017 knee OA prevalence was 4% (615,514 knee OA/15.4M adults). A total of 510,605 patients meeting inclusion criteria were matched 1:1 with controls. The knee OA cohort had mean age 60 years and was 58% female. Versus controls, knee OA patients had significantly more PPPY outpatient (84.5 versus 45.0) and pharmacy (29.8 versus 19.8) claims, and significantly higher PPPY outpatient costs ($12,571 versus $6,465), and pharmacy costs ($3,655 versus $2,038). Knee OA patients incurred $7,707 more PPPY total healthcare costs than controls, of which $4,674 (60.6%) were knee OA-related medical claims and $1,926 (25%) were knee OA-related medications of interest. PPPY costs for nonselective NSAIDs, cyclooxygenase-2 (COX-2) inhibitors, intraarticular hyaluronic acid, non-acute opioids, and knee replacement were higher for knee OA patients than controls. Using median and mean all-cause total cost ($9,330 and $24,550, respectively), the estimated sum cost of knee OA patients in MarketScan ranged from $5.7B to $15B annually.

CONCLUSION

This retrospective analysis demonstrated an annual 2017 prevalence of 4.0% (≥18 years) and 13.2% (≥65 years) for newly diagnosed knee OA patients. Compared with controls, all-cause costs were significantly higher for knee OA patients, nearly double that of matched controls, attributable to increased medical and treatment costs and comorbidity treatment burden. Additionally, the estimated annual cost of knee OA treatment was substantial, ranging between $5.7 billion and $15 billion.

Intra-Articular Administration of Autologous Purified Adipose Tissue Associated with Arthroscopy Ameliorates Knee Osteoarthritis Symptoms

The aim of this study was to evaluate the safety and efficacy of the intra-articular administration of autologous purified adipose tissue to treat knee osteoarthritis (OA) following arthroscopy. Thirty patients with radiological evidence of knee OA were recruited. A small liposuction and arthroscopic lavage and debridement were performed in the same surgical time. The harvested fat was processed intraoperatively with Lipocell (Tiss'You, RSM) to purify the adipose tissue injected into the knee. Clinical evaluations were performed with VAS, Womac, and Lequesne questionnaires before treatment and after 1, 3, 6, and 12 months of follow-up. Pain, measured with VAS, significantly decreased, showing a reduction of 53% after 1 month and 83% after a year. Functional recovery, measured with Womac, showed an improvement of 47% after 1 month post-treatment and 84% after 1 year. No adverse effects have been observed. The intra-articular administration of purified adipose tissue associated with arthroscopic lavage and debridement is a safe and significantly effective strategy in improving the symptoms of knee osteoarthritis in up to 1 year of follow-up.

Total knee replacement after high tibial osteotomy: time-to-event analysis and predictors

BACKGROUND

An important aim of high tibial osteotomy (HTO) is to prevent or delay the need for total knee replacement (TKR). We sought to estimate the frequency and timing of conversion from HTO to TKR and the factors associated with it.

METHODS

We prospectively evaluated patients with osteoarthritis (OA) of the knee who underwent medial opening wedge HTO from 2002 to 2014 and analyzed the cumulative incidence of TKR in July 2019. The presence or absence of TKR on the HTO limb was identified from the orthopedic surgery reports and knee radiographs contained in the electronic medical records for each patient at London Health Sciences Centre. We used cumulative incidence curves to evaluate the primary outcome of time to TKR. We used multivariable Cox proportional hazards analysis to assess potential preoperative predictors including radiographic disease severity, malalignment, correction size, pain, sex, age, body mass index (BMI) and year of surgery.

RESULTS

Among 556 patients who underwent 643 HTO procedures, the cumulative incidence of TKR was 5% (95% confidence interval [CI] 3%-7%) at 5 years and 21% (95% CI 17%-26%) at 10 years. With the Cox proportional hazards multivariable model, the following preoperative factors were significantly associated with an increased rate of conversion: radiographic OA severity (adjusted hazard ratio [HR] 1.96, 95% CI 1.12-3.45), pain (adjusted HR 0.85, 95% CI 0.75-0.96)], female sex (adjusted HR 1.67, 95% CI 1.08-2.58), age (adjusted HR 1.50 per 10 yr, 95% CI 1.17-1.93) and BMI (adjusted HR 1.31 per 5 kng/m2, 95% CI 1.12-1.53).

INTERPRETATION

We found that 79% of knees did not undergo TKR within 10 years after undergoing medial opening wedge HTO. The strongest predictor of conversion to TKR is greater radiographic disease at the time of HTO.

Association between Baseline Osteoarthritic Features on MR Imaging and Clinical Outcome after Genicular Artery Embolization for Knee Osteoarthritis

PURPOSE

To explore the association between baseline osteoarthritis (OA)-related magnetic resonance (MR) imaging features and pain reduction after genicular artery embolization (GAE) in patients with mild-to-moderate symptomatic knee OA resistant to conservative therapy.

MATERIALS AND METHODS

This was a retrospective analysis of patients with mild-to-moderate symptomatic knee OA treated with GAE using imipenem-cilastatin sodium. The clinical outcome was scored at baseline and 6 months after treatment using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC). MR images were scored using the MR imaging osteoarthritis knee score. Linear regression was used to evaluate associations of before-treatment MR imaging scores with WOMAC_pain and WOMAC_total reduction after 6 months.

RESULTS

Fifty-four patients (22.2% male; median age, 69.4 years; median WOMAC_pain at baseline, 12) were evaluated. Of all OA features scored, a higher cartilage full-thickness defect score showed the strongest association with less reduction of both WOMAC_pain (B,-0.63 [95% confidence interval (CI), -0.91 to -0.34]; P < .001) and WOMAC_total scores (B, -1.77 [95% CI, -2.87 to -0.67]; P < .001) following treatment. The presence of grade 2-3 effusion synovitis (B, -2.99 [95% CI, -5.39 to -0.60]) bone marrow lesions (B, -0.52 [95% CI, -0.86 to -0.19]), osteophytes (B, -0.21 [95% CI, -0.36 to -0.06]), and cartilage defect surface area score (B, -0.25 [95% CI -0.42 to -0.08]) all showed a significant association with less WOMAC_pain reduction (all P < .05).

CONCLUSIONS

In patients with mild-to-moderate symptomatic knee OA treated with GAE, the presence and severity of full-thickness cartilage defects, effusion synovitis, bone marrow lesions, osteophytes, and cartilage surface area scores at baseline are associated with less favorable clinical outcomes at 6 months.

Cost-effectiveness of duloxetine for knee OA subjects: the role of pain severity

OBJECTIVE

Establish the impact of pain severity on the cost-effectiveness of generic duloxetine for knee osteoarthritis (OA) in the United States.

DESIGN

We used a validated computer simulation of knee OA to compare usual care (UC) - intra-articular injections, opioids, and total knee replacement (TKR) - to UC preceded by duloxetine in those no longer achieving pain relief from non-steroidal anti-inflammatory drugs (NSAIDs). Outcomes included quality-adjusted life years (QALYs), lifetime medical costs, and incremental cost-effectiveness ratios (ICERs). We considered cohorts with mean ages 57-75 years and Western Ontario and McMaster Osteoarthritis Index (WOMAC) pain 25-55 (0-100, 100-worst). We derived inputs from published data. We discounted costs and benefits 3% annually. We conducted sensitivity analyses of duloxetine efficacy, duration of pain relief, toxicity, and costs.

RESULTS

Among younger subjects with severe pain (WOMAC pain = 55), duloxetine led to an additional 9.6 QALYs per 1,000 subjects (ICER = $88,500/QALY). The likelihood of duloxetine being cost-effective at willingness-to-pay (WTP) thresholds of $50,000/QALY and $100,000/QALY was 40% and 54%. Offering duloxetine to older patients with severe pain led to ICERs >$150,000/QALY. Offering duloxetine to subjects with moderate pain (pain = 25) led to ICERs <$50,000/QALY, regardless of age. Among knee OA subjects with severe pain (pain = 55) who are unwilling or unable to undergo TKR, ICERs were <$50,600/QALY, regardless of age.

CONCLUSIONS

Duloxetine is a cost-effective addition to knee OA UC for subjects with moderate pain or those with severe pain unable or unwilling to undergo TKR. Among younger subjects with severe pain, duloxetine is cost-effective at WTP thresholds >$88,500/QALY.

Efficacy and safety of warm needle acupuncture in knee osteoarthritis: A protocol for systematic review and meta-analysis

BACKGROUND

Knee osteoarthritis (KOA) is a chronic disease, which is also recognized as a common disease affecting the elderly. However, the application of Western medicine is limited in clinical because of its obvious adverse reactions. Warm needle acupuncture (WNA) has a long history in the treatment of KOA and is widely used in Chinese. Here we will submit a protocol to evaluate the efficacy and safety of WNA in the treatment of KOA.

METHODS

We will search 5 English databases (PubMed, MEDLINE, Embase, Cochrane Library, Web of Science), 4 Chinese databases [China National Knowledge Infrastructure (CNKI), China Biology Medicine, Chinese Science and Technology Journal Database (VIP), and Wanfang database] and grey literature for randomized controlled trials of WNA in the treatment of KOA. The primary outcome measure is Western Ontario and McMaster Universities Arthritis Index (WOMAC), and the secondary outcome will include degree of knee flexion and adverse events caused by WNA, such as dizziness, nausea, abdominal pain, arrhythmia, etc. The selection of the literatures will be conducted by endnote X7 software, and we will use Review Manger V.5.3 software to conduct the meta-analysis.

RESULTS

This study will provide reliable evidence for WNA in the treatment of KAO.

CONCLUSION

The conclusion of this study will testify the efficacy and safety of WNA in the treatment of KAO.

REGISTRATION

OSF Preregistration. 2020, October 11; osf.io/bu5qw.

Varus alignment of the proximal tibia is associated with structural progression in early to moderate varus osteoarthritis of the knee

PURPOSE

Lower limb malalignment is a strong predictor of progression in knee osteoarthritis. The purpose of this study is to identify the individual alignment variables that predict progression in early to moderate osteoarthritis of the knee.

METHOD

A longitudinal cohort study using data from the Osteoarthritis Initiative. In total, 955 individuals (1329 knees) with early to moderate osteoarthritis (Kellgren-Lawrence grade 1, 2 or 3) were identified. All subjects had full-limb radiographs analysed using the Osteotomy module within Medicad^® Classic (Hectec GMBH) to give a series of individual alignment variables relevant to the coronal alignment of the lower limb. Logistic regression models, with generalised estimating equations were used to identify which of these individual alignment variables predict symptom worsening (WOMAC score > 9 points) and or structural progression (joint space narrowing progression in the medial compartment > 0.7mm) over 24 months.

RESULTS

Individual alignment variable were associated with both valgus and varus alignment (mechanical Lateral Distal Femoral Angle, Medial Proximal Tibial Angle and mechanical Lateral Distal Tibial Angle). Only the Medial Proximal Tibial Angle was significantly associated with structural progression and none of the variables was associated with symptom progression. The odds of joint space narrowing progression in the medial compartment occurring at 24 months increased by 21% for every one degree decrease (more varus) in Medial Proximal Tibial Angle (p < 0.001) CONCLUSIONS: Our results suggest that the risk of structural progression in the medial compartment is associated with greater varus alignment of the proximal tibia.

LEVEL OF EVIDENCE

Level III, retrospective cohort study.

What Is the Appropriate Price for Platelet-Rich Plasma Injections for Knee Osteoarthritis? A Cost-Effectiveness Analysis Based on Evidence From Level I Randomized Controlled Trials

PURPOSE

To identify the price of treatment at which platelet-rich plasma (PRP) is cost-effective relative to hyaluronic acid (HA) and saline solution intra-articular injections.

METHODS

A systemized review process of the PubMed, Embase, and MEDLINE databases was undertaken to identify randomized controlled trials comparing PRP with HA and saline solution with up to 1 year of follow-up. Level I trials that reported Western Ontario and McMaster Universities Arthritis Index Likert scores were included. These scores were converted into utility scores. Cost data were obtained from Centers for Medicare & Medicaid Services fee schedules. Total costs included the costs of the injectable, clinic appointments, and procedures. The change in utility scores from baseline to 6 months and 1 year for the PRP, HA, and saline solution groups was divided by total cost to determine utility gained per dollar and to identify the price needed for PRP to be cost-effective relative to these other injection options.

RESULTS

Nine randomized controlled trials met the inclusion criteria. A total of 882 patients were included: 483 in the PRP group, 338 in the HA group, and 61 in the saline solution group. Baseline mean utility scores ranged from 0.55 to 0.57 for the PRP, HA, and saline solution groups. The 6-month gains in utility were 0.12, 0.02, and -0.06, respectively. The 12-month gains in utility from before injection were 0.14, 0.03, and 0.06, respectively. The lowest total costs for HA and saline solution were $681.93 and $516.29, respectively. For PRP to be cost-effective, the total treatment cost would have to be less than $3,703.03 and $1,192.08 for 6- and 12-month outcomes, respectively.

CONCLUSIONS

For patients with symptomatic knee osteoarthritis, PRP is cost-effective, from the payer perspective, at a total price (inclusive of clinic visits, the procedure, and the injectable) of less than $1,192.08 over a 12-month period, relative to HA and saline solution.

LEVEL OF EVIDENCE

Level I, systematic review.

A Practical Guide to Class IIa Medical Device Development

There are many beneficial medical device ideas based on clinical needs and laboratory research, but medical device development is an expensive, time-consuming and complex challenge. Research and quality management, which are both needed to develop a medical device, are two distinct fields, initiated by a researcher or a clinician having a concept for a medical device, and it is often challenging to find and achieve the proper steps to create a licensed product. Thus, in this paper, we demonstrate the required mindset and main steps of the medical device development procedure through an existing example, a Class IIa medical device, called hypACT Inject Auto. HypACT is a specific syringe, which is capable of blood drawing and serum from platelet-rich fibrin (SPRF) isolation in one step in a closed system. SPRF is intended to be used to improve joint functions in the case of musculoskeletal diseases, specifically osteoarthritis.

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.

Efficacy and safety of intra-articular injection of tropomyosin receptor kinase A inhibitor in painful knee osteoarthritis: a randomized, double-blind and placebo-controlled study

OBJECTIVE

This trial evaluated the efficacy and safety of GZ389988A, a tropomyosin receptor kinase A (TrkA) inhibitor, in subjects with painful knee osteoarthritis (OA).

METHOD

In this single center, double-blind, placebo-controlled and randomized trial, 104 subjects with moderate-to-severe knee OA pain were enrolled to receive a single intra-articular (IA) injection of either GZ389988A or placebo. Efficacy measures were assessed over 12 weeks and included walking pain (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC] A1), overall knee pain, WOMAC A, B, C and total score, Patient Global Impression of Change (PGIC), OMERACT-OARSI responder rate and rescue medication use. Adverse events (AEs) were monitored up to 24 weeks.

RESULTS

The primary efficacy endpoint was met with a between-group difference of -7.49 (VAS 0-100) on WOMAC A1 changes over 4 weeks (P < 0.05 favoring GZ389988A). The secondary outcome on WOMAC A1 changes over 12 weeks had a between-group difference of -6.78 (P = 0.064). Among weekly assessments, statistically significant greater improvement in the GZ389988A group was observed in WOMAC A1, overall knee pain and/or WOMAC A at weeks 2-5. Although not statistically significant, improvements over placebo on pain and WOMAC C persisted over 12 weeks. Greater AE incidence was observed in the GZ389988A group including transient and self-limited injection joint inflammatory reactions with a spike of acetaminophen intake within the first week post-injection.

CONCLUSION

IA injection of TrkA inhibitor GZ389988A in knee OA subjects reduced pain with a numerically functional gain and an acceptable safety profile. (ClinicalTrials.gov, NCT02845271).

Comparison of gait, functional activities, and patient-reported outcome measures in patients with knee osteoarthritis and healthy adults using 3D motion analysis and activity monitoring: an exploratory case-control analysis

Objective

To examine functional performance differences using kinematic and kinetic analysis between participants with and without knee osteoarthritis (OA) to determine which outcomes best characterize persons with and without knee OA.

Methods

Participants with unilateral moderate knee OA (Kellgren–Lawrence grades 2 or 3) and controls without knee pain were matched for age, gender, and body mass index. Primary outcomes included temporal parameters, joint rotations and moments, and ground reaction forces assessed via 3D motion capture during walking and ascending/descending stairs. Secondary outcomes included timed functional activities (sit to stand; tying shoelaces), 48 hrs lower limb activity monitoring, and patient-reported outcome measures (Knee Injury and Osteoarthritis Outcome Score, Western Ontario and McMaster Universities Osteoarthritis Index, European Quality of Life–5 Dimensions).

Results

Eight matched pairs were analyzed. Compared with controls, OA participants exhibited significant reductions in peak frontal hip and sagittal knee moments, and decreased peak anterior ground reaction force with the affected limb while walking. Ascending stairs, OA participants had slower speed, fewer strides per minute, longer cycle and stance times, and increased trunk range of motion (ROM) in assessments of both limbs; longer swing time and reduced ankle ROM in the affected limb; and increased knee frontal ROM in the unaffected limb. Descending stairs, OA participants had fewer strides per minute and decreased trunk transverse ROM in assessments of both limbs; increased knee frontal ROM in the affected limb; and longer strides, shorter stance and cycle times, increased trunk sagittal and decreased knee transverse ROMs in the unaffected limbs vs controls. Compared with controls, OA participants had slower walking cadence (120–130 vs 100–110 steps/min, respectively), took significantly longer on timed functional measures, and had significantly worse scores in patient-reported outcomes.

Conclusion

Several objectives and patient-reported measures examined in this study could potentially be considered as outcomes in pharmacologic or physical therapy OA trials.

Functional Outcomes Following Microfragmented Adipose Tissue Versus Bone Marrow Aspirate Concentrate Injections for Symptomatic Knee Osteoarthritis

This study aimed to determine whether autologous orthobiologic tissue source affects pain and functional outcomes in patients with symptomatic knee osteoarthritis (OA) who received microfragmented adipose tissue (MFAT) or bone marrow aspirate concentrate (BMAC) injection. We retrospectively reviewed prospectively collected data from patients who received BMAC or MFAT injection for symptomatic knee OA. Patients completed baseline and follow-up surveys. Each survey included the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, Emory Quality of Life (EQOL) questionnaire, and Visual Analog Scale (VAS) for pain. The follow-up responses were compared with baseline for all patients and between BMAC and MFAT groups. A total of 110 patients met inclusion criteria, with 76 patients (BMAC 41, MFAT 35) and 106 knees (BMAC 58, MFAT 48) having appropriate follow-up data. The BMAC group included 17 females and 24 males, with a mean age of 59 ± 11 years. The MFAT group included 23 females and 12 males, with a mean age of 63 ± 11 years. Minimum follow-up time was 0.5 years. Mean follow-up time was 1.80 ± 0.88 years for BMAC and 1.09 ± 0.49 years for MFAT. Both groups had significant improvement in EQOL, VAS, and all KOOS parameters preprocedure versus postprocedure (p < .001). There was not a significant difference when comparing postprocedure scores between groups (p = .09, .38, .63, .94, .17, .15, .70, respectively). These data demonstrate significant improvement in pain and function with both MFAT and BMAC injections in patients with symptomatic knee OA without a significant difference in improvement when comparing the two autologous tissue sources. Stem Cells Translational Medicine 2019;8:1149-1156.

Surgical interventions for symptomatic mild to moderate knee osteoarthritis

BACKGROUND

Osteoarthritis affecting the knee is common and represents a continuum of disease from early cartilage thinning to full-thickness cartilage loss, bony erosion, and deformity. Many studies do not stratify their results based on the severity of the disease at baseline or recruitment.

OBJECTIVES

To assess the benefits and harms of surgical intervention for the management of symptomatic mild to moderate knee osteoarthritis defined as knee pain and radiographic evidence of non-end stage osteoarthritis (Kellgren-Lawrence grade 1, 2, 3 or equivalent on MRI/arthroscopy). Outcomes of interest included pain, function, radiographic progression, quality of life, short-term serious adverse events, re-operation rates and withdrawals due to adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase up to May 2018. We also conducted searches of ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform for ongoing trials. Authors of trials were contacted if some but not all their participants appeared to fit our inclusion criteria.

SELECTION CRITERIA

We included randomised controlled trials that compared surgery to non-surgical interventions (including sham and placebo control groups, exercise or physiotherapy, and analgesic or other medication), injectable therapies, and trials that compared one type of surgical intervention to another surgical intervention in people with symptomatic mild to moderate knee osteoarthritis.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials and extracted data using standardised forms. We analysed the quality of evidence using the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) approach.

MAIN RESULTS

A total of five studies involving 566 participants were identified as eligible for this review. Single studies compared arthroscopic partial meniscectomy to physical therapy (320 participants), arthroscopic surgery (debridement ± synovectomy ± chondroplasty) to closed needle joint lavage with saline (32 participants) and high tibial osteotomy surgery to knee joint distraction surgery (62 participants). Two studies (152 participants) compared arthroscopic surgery (washout ± debridement; debridement) to a hyaluronic acid injection. Only one study was at low risk of selection bias, and due to the difficulty of blinding participants to their treatment, all studies were at risk of performance and detection bias.Reporting of results in this summary has been restricted to the primary comparison: surgical intervention versus non-surgical intervention.A single study, included 320 participants with symptoms consistent with meniscal tear. All subjects had the meniscal tear confirmed on knee MRI and radiographic evidence of mild to moderate osteoarthritis (osteophytes, cartilage defect or joint space narrowing). Patients with severe osteoarthritis (KL grade 4) were excluded. The study compared arthroscopic partial meniscectomy and physical therapy to physical therapy alone (a six-week individualised progressive home exercise program). This study was at low risk of selection bias and outcome reporting biases, but was susceptible to performance and detection biases. A high rate of cross-over (30.2%) occurred from the physical therapy group to the arthroscopic group.Low-quality evidence suggests there may be little difference in pain and function at 12 months follow-up in people who have arthroscopic partial meniscectomy and those who have physical therapy. Evidence was downgraded to low quality due to risk of bias and imprecision.Mean pain was 19.3 points on a 0 to 100 point KOOS pain scale with physical therapy at 12 months follow-up and was 0.2 points better with surgery (95% confidence interval (CI) 4.05 better to 3.65 points worse with surgery, an absolute improvement of 0.2% (95% CI 4% better to 4% worse) and relative improvement 0.4% (95% CI 9% better to 8% worse) (low quality evidence). Mean function was 14.5 on a 0 to 100 point KOOS function scale with physical therapy at 12 months follow-up and 0.8 points better with surgery (95% CI 4.3 better to 2.7 worse); 0.8% absolute improvement (95% CI 4% better to 3% worse) and 2.1% relative improvement (95% CI 11% better to 7% worse) (low quality evidence).Radiographic structural osteoarthritis progression and quality of life outcomes were not reported.Due to very low quality evidence, we are uncertain if surgery is associated with an increased risk of serious adverse events, incidence of total knee replacement or withdrawal rates. Evidence was downgraded twice due to very low event rates, and once for risk of bias.At 12 months, the surgery group had a total of three serious adverse events including fatal pulmonary embolism, myocardial infarction and hypoxaemia. The physical therapy alone group had two serious adverse events including sudden death and stroke (Peto OR 1.58, 95% CI 0.27 to 9.21); 1% more events with surgery (95% CI 2% less to 3% more) and 58% relative change (95% CI 73% less to 821% more). One participant in each group withdrew due to adverse events.Two of 164 participants (1.2%) in the physical therapy group and three of 156 in the surgery group underwent conversion to total knee replacement within 12 months (Peto OR 1.76, 95% CI 0.43 to 7.13); 1% more events with surgery (95% CI 2% less to 5% more); 76% relative change (95% CI 57% less to 613% more).

AUTHORS' CONCLUSIONS

The review found no placebo-or sham-controlled trials of surgery in participants with symptomatic mild to moderate knee osteoarthritis. There was low quality evidence that there may be no evidence of a difference between arthroscopic partial meniscectomy surgery and a home exercise program for the treatment of this condition. Similarly, low-quality evidence from a few small trials indicates there may not be any benefit of arthroscopic surgery over other non-surgical treatments including saline irrigation and hyaluronic acid injection, or one type of surgery over another. We are uncertain of the risk of adverse events or of progressing to total knee replacement due to very small event rates. Thus, there is uncertainty around the current evidence to support or oppose the use of surgery in mild to moderate knee osteoarthritis. As no benefit has been demonstrated from the low quality trials included in this review, it is possible that future higher quality trials for these surgical interventions may not contradict these results.

Prognostic Factors for Return to Sport After High Tibial Osteotomy: A Directed Acyclic Graph Approach

BACKGROUND

High tibial osteotomy (HTO) is increasingly used in young and physically active patients with knee osteoarthritis. These patients have high expectations, including return to sport (RTS). By retaining native knee structures, a return to highly knee-demanding activities seems possible. However, evidence on patient-related outcomes, including RTS, is sparse. Also, time to RTS has never been described. Furthermore, prognostic factors for RTS after HTO have never been investigated. These data may further justify HTO as a surgical alternative to knee arthroplasty.

PURPOSE

To investigate the extent and timing of RTS after HTO in the largest cohort investigated for RTS to date and to identify prognostic factors for successful RTS.

STUDY DESIGN

Case-control study; Level of evidence, 3.

METHODS

Consecutive patients with HTO, operated on between 2012 and 2015, received a questionnaire. First, pre- and postoperative sports participation questions were asked. Also, time to RTS, sports level and frequency, impact level, the presymptomatic and postoperative Tegner activity score (1-10; higher is more active), and the postoperative Lysholm score (0-100; higher is better) were collected. Finally, prognostic factors for RTS were analyzed using a logistic regression model. Covariates were selected based on univariate analysis and a directed acyclic graph.

RESULTS

We included 340 eligible patients of whom 294 sufficiently completed the questionnaire. The mean follow-up was 3.7 years (± 1.0 years). Out of 256 patients participating in sports preoperatively, 210 patients (82%) returned to sport postoperatively, of whom 158 (75%) returned within 6 months. We observed a shift to participation in lower-impact activities, although 44% of reported sports activities at final follow-up were intermediate- or high-impact sports. The median Tegner score decreased from 5.0 (interquartile range [IQR], 4.0-6.0) presymptomatically to 4.0 (IQR, 3.0-4.0) at follow-up (P < .001). The mean Lysholm score at follow-up was 68 (SD, ± 22). No significant differences were found between patients with varus or valgus osteoarthritis. The strongest prognostic factor for RTS was continued sports participation in the year before surgery (odds ratio, 2.81; 95% CI, 1.37-5.76).

CONCLUSION

More than 8 of 10 patients returned to sport after HTO. Continued preoperative sports participation was associated with a successful RTS. Future studies need to identify additional prognostic factors.

Contributions of muscles and external forces to medial knee load reduction due to osteoarthritis braces

BACKGROUND

Braces for medial knee osteoarthritis can reduce medial joint loads through a combination of three mechanisms: application of an external brace abduction moment, alteration of gait dynamics, and reduced activation of antagonistic muscles. Although the effect of knee bracing has been reported independently for each of these parameters, no previous study has quantified their relative contributions to reducing medial knee loads.

METHODS

In this study, we used a detailed musculoskeletal model to investigate immediate changes in medial and lateral loads caused by two different knee braces: OA Assist and OA Adjuster 3 (DJO Global). Seventeen osteoarthritis subjects and eighteen healthy controls performed overground gait trials in unbraced and braced conditions.

RESULTS

Across all subjects, bracing reduced medial loads by 0.1 to 0.3 times bodyweight (BW), or roughly 10%, and increased lateral loads by 0.03 to 0.2 BW. Changes in gait kinematics due to bracing were subtle, and had little effect on medial and lateral joint loads. The knee adduction moment was unaltered unless the brace moment was included in its computation. Only one muscle, biceps femoris, showed a significant change in EMG with bracing, but this did not contribute to altered peak medial contact loads.

CONCLUSIONS

Knee braces reduced medial tibiofemoral loads primarily by applying a direct, and substantial, abduction moment to each subject's knee. To further enhance brace effectiveness, future brace designs should seek to enhance the magnitude of this unloader moment, and possibly exploit additional kinematic or neuromuscular gait modifications.

Towards reaching consensus on hyaluronic acid efficacy in knee osteoarthritis

Intra-articular injection of hyaluronic acid (HA) is a controversial treatment for knee osteoarthritis (OA). While clinical efficacy of HA relative to saline injections has been demonstrated in many studies, these results are of limited value in real-world clinical practice since saline injection is not a knee OA treatment. Instead, rigorous postmarket comparative studies of HA versus approved knee OA treatments are encouraged. The conduct of such studies is particularly important given the paucity and heterogeneous nature of current evidence regarding nonsurgical knee OA treatment. KEY POINTS: • Societal guidelines recommend nonsteroidal anti-inflammatory drugs and corticosteroid injections, but not hyaluronic acid injections, for knee osteoarthritis (OA) despite inconsistent supportive data. • This article encourages rigorous comparative post-approval studies to clarify the role of nonsurgical treatments used in clinical practice for knee OA.

UniCAP offers a long term treatment for middle-aged patients, who are not revised within the first 9 years

PURPOSE

The aim of this study was to investigate the long-term outcome of the unicompartmental knee resurfacing prosthesis (UniCAP) using clinical and radiographic assessments, and to evaluate the revision and survival rates.

METHODS

This was a prospective cohort study of patients with UniCAP prostheses with 6-9 years of follow-up. The clinical examination included the Knee Society Score (KSS) and Visual Analogue Scale (VAS) score. The radiographic examination included the Kellgren-Lawrence (KL) grading scale. A comparison analysis of the clinical preoperative and follow-up data and a Kaplan-Meier survival analysis were performed.

RESULTS

Of the 64 UniCAP patients, 36 (56%) were revised and one died. Examinations were performed on 23 (85%) of them. When compared with the preoperative data, the examinations showed a significant increase in the KSS objective [mean = 47.4, standard deviation (SD) = 5.8 vs. mean = 90.0, SD = 6.9] and function (mean = 46.7, SD = 6.8 vs. mean = 91.1, SD = 6.9) scores, a decrease in the VAS-score (mean = 7.3, SD = 0.5 vs. mean = 3.4, SD = 1.4) and a significant increase in the KL medial score (mean = 1.7, SD = 0.6 vs. mean = 2.1, SD = 0.5). The Kaplan-Meier survival rate after 5 years indicated good long-term outcomes.

CONCLUSIONS

There was a survival rate of approximately 40% after 9 years of follow-up, but in the group of patients (35-65 years old) not eligible for a final total arthroplasty. These patients were often left with pain and disability. This implant can be a temporary or even long-term treatment because it improved the disability and function over the long-term without a major progression in the osteoarthritis, function or pain. Long term results of this mini-prosthesis have not been previously reported.

LEVEL OF EVIDENCE

IV.

The Knee Osteoarthritis Grading System for Arthroplasty

BACKGROUND

The aim of this study is to validate the Knee Osteoarthritis Grading System (KOGS) of progressive osteoarthritic degeneration for the tri-compartmental knee. This system defines the site and severity of osteoarthritis to determine a specific knee arthroplasty.

METHODS

The radiographic sequence for KOGS includes standing coronal (anteroposterior), lateral, 30° skyline patella, 15° and 45° Rosenberg and stress views in 20° of flexion. Cohen's kappa and related agreement statistical methods were used to assess the level of concordance of the 7 evaluators between A and B cohorts for each evaluator and also against the actual arthroplasty used. Sensitivity and specificity was also assessed for the KOGS in identifying true partial knee arthroplasties (PKAs) and total knee arthroplasties (TKAs) as decided from the cohort A evaluations.

RESULTS

From a cohort of 330 patients who were included in the study, 71 (22.5%) underwent a TKA procedure, 258 (78.2%) a PKA, and 1 (0.3%) was neither a TKA nor PKA. KOGS was able to identify true PKAs (sensitivity) in the range of 92.2%-98.5% across all the different evaluators. The KOGS method was able to identify a PKA or a TKA with an accuracy ranging from 92% to 98.8% across all different evaluators. The surgical results after 20 months are at least comparable with the expected average in the academic literature.

CONCLUSION

The KOGS classification provides a reliable and accurate tool to assess suitability of an individual patient for undergoing PKA or TKA.

A Case Report of the Successful Conversion of One of the Longest Standing KineSpring Joint Unloading Systems

Introduction

We present the case of a successful conversion of a KineSpring joint unloading system to a total knee replacement. This is, to the best of our knowledge, the so far longest surviving implant in Germany that has been successfully converted.

Case Report

The patient is a 75-year-old woman who presented to clinic with problems of her left knee. She had a KineSpring joint unloading system implanted in March 2011 for severe medial osteoarthritis of her left knee that was unresponsive to maximal conservative treatment. After nearly 7 pain-free years, we successfully converted the KineSpring joint unloading system into a total knee replacement (Vega, Aesculap, Germany).

Conclusion

The KineSpring joint unloading system is possible treatment option for younger patients with mild-to-moderate osteoarthritis of the knee reluctant to total knee replacement, without compromising further surgical options.

Can UKA after KineSpring system failure be a viable option? A case report

Background and aim of the Work: The KineSpring System is an alternative treatment offered in selected symptomatic patients suffering from mild to moderate medial knee osteoarthritis (OA). This device reduces medial compartment loads in the OA knee without compromising the integrity of the lateral or patellofemoral knee compartments, maintaining the normal knee anatomy. Currently, papers about KineSpring System installation show promising results. The current authors describe a case of unicompartmental knee arthroplasty (UKA) employed to treat medial knee OA after Kinespring system failure. Methods: A 64-year old male patient presented to our hospital after failure of a Kinespring system implantation into his left knee at an external hospital, where the outcomes obtained were not satisfactory. The surgical options discussed with the patient were the TKA or medial UKA. A medial UKA was preferred by the patient. Results: One year from UKA, the patient complained of frequent joint effusions and weight bearing pain despite a good ROM without radiographic signs of implant loosening. Therefore, after two years we replaced UKA with total knee arthroplasty (TKA). Conclusions: Further experience is needed to provide reliable clinical data about the results of the UKA after KineSpring System discharge. (www.actabiomedica.it)

Sample size calculations for detecting disease-modifying osteoarthritis drug effects on the incidence of end-stage knee osteoarthritis in clinical trials: Data from the Osteoarthritis Initiative

OBJECTIVE

We previously published data representing calculations for sample sizes assuming that the reduction of the incidence of knee joint replacement (KJR) would be an endpoint to prove efficacy of a disease-modifying drug in osteoarthritis (DMOAD). The sample sizes required for such hypothetical studies appeared to be high, rendering those studies unrealistic in the clinical research setting for practical reasons. The purpose of this work is to calculate sample sizes for hypothetical trials for DMOAD efficacy using a proxy for reaching end-stage knee osteoarthritis (esKOA) as an endpoint.

METHODS

Based on a sub-population of the Osteoarthritis Initiative, the cumulative incidence for both esKOA and KJR were calculated for a period of four years. The sample sizes of hypothetical DMOAD trials were then calculated for particular sub-cohorts of the OAI subpopulation, subdividing the groups according to age, Kellgren-Lawrence (KL) grades and gender.

RESULTS

Both the incidence for esKOA and for KJR over the four year period increase along with rising age, severity of OA and being female. The sample sizes to detect DMOAD efficacy are considerably smaller if reduction of the incidence of esKOA is chosen as an endpoint instead of reduction of the incidence of KJR.

CONCLUSION

In the future, generating health-economic data may become increasingly important to gain reimbursement. By choosing esKOA as an endpoint in DMOAD trials, we are able to show in our work that clinical trials in the field of OA are feasible, merely including a few hundred study participants per study arm.

Natural Products for Promoting Joint Health and Managing Osteoarthritis

PURPOSE OF REVIEW

Osteoarthritis, the most common joint disease, is associated with substantial medical costs, lost productivity, and reduced quality of life. However, available pharmaceutical treatments have limitations in terms of efficacy and long-term safety.

RECENT FINDINGS

In vitro evidence suggests that some natural products may possess anti-inflammatory and anti-oxidative properties and may inhibit the release of key osteoarthritis-related cytokines. There is, therefore, ongoing interest in identifying natural products that safely promote joint health and treat osteoarthritis. Numerous plant extracts, including curcumin, Boswellia extract, and pycnogenol, have shown effect sizes (ES) for reducing pain and functional disability larger than those observed with analgesics and products such as glucosamine and chondroitin. The ES for methylsulfonylmethane and avocado/soybean unsaponifiables are also considered to be clinically relevant. Data from a small number of studies using natural products for treating osteoarthritis are promising but require confirmation in further well-designed clinical trials.