Safety, tolerability and efficacy of intra-articular Progenza in knee osteoarthritis: a randomized double-blind placebo-controlled single ascending dose study

Background

Cell therapies are being investigated as potential disease modifying treatment options for osteoarthritis (OA). Progenza (PRG) comprises in vitro expanded mesenchymal stem cells derived from human donor adipose tissue combined with cell culture supernatant. The primary objective of this first-in-human study was to evaluate the safety and tolerability of PRG.

Methods

We conducted a single centre, randomized, double-blind, placebo-controlled, single ascending dose study. Twenty patients aged 40–65 years with symptomatic Kellgren–Lawrence grade 1–3 knee OA were treated in two cohorts and randomized 4:1 to PRG or placebo. Cohort 1: 3.9 million cells (PRG 3.9M, n = 8) or placebo (n = 2) and cohort 2: 6.7 million cells (PRG 6.7M, n = 8) or placebo (n = 2). Each patient received a single intra-articular injection and was followed-up for 12 months.

Results

The study population comprised 20 patients (placebo, n = 4; PRG 3.9M, n = 8; PRG 6.7M, n = 8). All patients reported at least one treatment-emergent adverse event (TEAE). The majority of events [143/169 (84.6%)] were mild with 34 (20.1%) being considered by the investigator to be treatment related. There were no serious AEs or withdrawals due to AEs during the study. There was a statistically significant within group improvement in VAS pain scores from baseline at all timepoints for the PRG combined group, with highly significant improvements seen at months 3, 6, 9 and 12 (p ≤ 0.005) while VAS pain scores in the placebo group showed marginal improvement. A statistically significant improvement was also seen in WOMAC pain subscale scores from baseline at all timepoints for the PRG combined group while a marginal improvement in the placebo group was not statistically significant. Between screening and month 12, there was no decrease in average lateral tibial cartilage volume in the PRG 3.9M group while the placebo group showed a statistically significant cartilage loss. This difference between the placebo and PRG 3.9M group was statistically significant (LSM difference 106.47 mm³, 95% CI 13.56 mm³, 199.37 mm³, p = 0.028).

Conclusion

When administered as a single intra-articular injection to patients with symptomatic knee OA, PRG was safe and well tolerated. Furthermore, measurable improvements in symptoms and knee structure outcomes warrant further studies on PRG’s potential for disease modification in OA.

Trial registration ANZCTR, ACTRN12615000439549. Date registered: 7th May 2015, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=368355

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1420-z) contains supplementary material, which is available to authorized users.

Osteoarthritis year in review 2017: updates on imaging advancements

OBJECTIVE

This narrative review covers original research publications related to imaging advancements in osteoarthritis (OA) published in the English language between 1^st April 2016 and 30^th April 2017.

METHODS

Relevant human studies (excluding pre-clinical and in vitro studies), were searched and selected from PubMed database using the search terms of "osteoarthritis (OA)" in combination with "radiography", "magnetic resonance imaging (MRI)", "computed tomography (CT)", "ultrasound", "positron emission tomography (PET)," "single-photon emission computed tomography (SPECT)," and "scintigraphy". The included studies were sorted according to their relevance, novelty, and impact. Original research articles with both imaging advancements and novel clinical information were discussed in this review.

RESULTS

A large portion of the published studies were focused on MRI-based semi-quantitative and quantitative (morphological and structural) metrics of the knee joint to assess OA-related structural damages. New imaging technologies, such as PET, have been investigated for OA diagnosis and characterization, the delineation of predictive factors for OA progression, and to monitor the treatment responses.

CONCLUSION

Advanced imaging modalities play a pivotal role in OA research, and make a significant contribution to our understanding of OA diagnosis, pathogenesis, risk stratification, and prognosis.

Structural effects of intra-articular TGF-β1 in moderate to advanced knee osteoarthritis: MRI-based assessment in a randomized controlled trial

BACKGROUND

To determine effects of allogeneic human chondrocytes expressing TGF-β1 (TG-C) on structural progression of MRI features of knee osteoarthritis over a 1 year period.

METHODS

This phase II randomized controlled trial of TG-C included patients with moderate to advanced osteoarthritis. Patients were randomized to receive an intraarticular 3:1 mixture of non-transduced allogeneic human chondrocytes and TG-C or placebo. 3 T MRI was acquired for all patients at baseline and follow-up (3, 6 and 12 months). MRIs were assessed using the WORMS system including cartilage damage, bone marrow lesions (BMLs), meniscal damage/extrusion, Hoffa-, effusion-synovitis, and osteophytes. Analyses were performed on a whole knee level, compartmental level, and subregional level. Binary logistic regression with Generalized Estimating Equation was used to compare risks of progression, adjusting for baseline age and gender. Mann - Whitney - Wilcoxon tests were used to assess differences for continuous variables.

RESULTS

Fifty-seven Patients were included in the TG-C group and 29 in the placebo group. At 12 months, knees in the TG-C group showed less progression of cartilage damage compared to placebo on a whole knee level (34.6% vs. 47.9%; adjusted RR 0.7, 95%CI [0.5-1.1], p = 0.077). Less progression of Hoffa-synovitis and effusion-synovitis was observed in the TG-C group compared to placebo (9.6% vs. 21.1%, adjusted RR 0.5, 95%CI [0.2,1.2], p = 0.115). No statistically significant differences were seen for BMLs, meniscal damage and osteophytes.

CONCLUSIONS

Intraarticular treatment with TG-C showed fewer patients in the treated group with progression in structural OA features and other MRI-defined inflammatory markers such as Hoffa-synovitis and effusion-synovitis. However, no differences were observed in regard to progression of BMLs and meniscal damage, or hypertrophic osteophyte formation.

TRIAL REGISTRATION

NCT01221441 .Registered 13th October, 2010.

Magnetic resonance imaging (MRI)-defined cartilage degeneration and joint pain are associated with poor physical function in knee osteoarthritis - the Oulu Knee Osteoarthritis study

OBJECTIVE

The main aim was to investigate the associations between Magnetic Resonance Imaging (MRI)-defined structural pathologies of the knee and physical function.

DESIGN

A cohort study with frequency matching on age and sex with eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee osteoarthritis (OA) and 57 asymptomatic subjects was conducted. The subjects underwent knee MRI, and the severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. WOMAC function subscores were recorded and physical function tests (20-m and 5-min walk, stair ascending and descending, timed up & go and repeated sit-to-stand tests) performed. The association between MRI-defined structural pathologies and physical function tests and WOMAC function subscores were evaluated by linear regression analysis with adjustment for demographic factors, other MRI-features and pain with using effect size (ES) as a measure of the magnitude of an association.

RESULTS

Cartilage degeneration showed significant association with poor physical performance in TUG-, stair ascending and descending-, 20-m- and 5-min walk-tests (ESs in the subjects with cartilage degeneration anywhere between 0.134 [95%CI 0.037-0.238] and 0.224 [0.013-0.335]) and with increased WOMAC function subscore (ES in the subjects with cartilage degeneration anywhere 0.088 [0.012-0.103]). Also, lateral meniscus maceration and extrusion were associated with poor performance in stair ascending test (ESs 0.067 [0.008-0.163] and 0.077 [0.012-0.177]).

CONCLUSIONS

After adjustments cartilage degeneration was associated with both decreased self-reported physical function and poor performance in the physical function tests. Furthermore, subjects with lateral meniscus maceration and extrusions showed significantly worse performance in stair ascending tests.

Is the atrophic phenotype of tibiofemoral osteoarthritis associated with faster progression of disease? The MOST study

OBJECTIVE

To assess the associations of atrophic tibiofemoral osteoarthritis (OA) with progression of radiographic joint space narrowing (JSN) and magnetic resonance imaging (MRI)-defined progression of cartilage damage.

DESIGN

Participants of the Multicenter Osteoarthritis (MOST) Study with available radiographic and MRI assessments at baseline and 30 months were included. The atrophic OA phenotype was defined as Osteoarthritis Research Society International (OARSI) grades 1 or 2 for JSN and grade 0 for osteophytes. Based on MRI, atrophic OA was defined as tibiofemoral (TF) cartilage damage grades ≥3 in at least 2 of 10 subregions with absent or tiny osteophytes in all TF subregions. Progression of JSN and cartilage loss on MRI, was defined as (1) no, (2) slow, and (3) fast progression. Co-variance and logistic regression with generalized estimated equations were performed to assess the association of atrophic knee OA with any progression, compared to non-atrophic OA knees.

RESULTS

A total of 476 knees from 432 participants were included. There were 50 (10.5%) knees with atrophic OA using the radiographic definition, and 16 (3.4%) knees with atrophic OA using MRI definition. Non-atrophic OA knees more commonly exhibited fast progression of JSN and cartilage damage. Logistic regression showed that the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss.

CONCLUSION

In this sample, the atrophic phenotype of knee OA was associated with a decreased likelihood of progression of JSN and cartilage loss compared to the non-atrophic knee OA phenotype.

Patellofemoral morphology and alignment: reference values and dose-response patterns for the relation to MRI features of patellofemoral osteoarthritis

OBJECTIVE

We aimed to (1) determine reference values for trochlear morphology and patellofemoral (PF) alignment in adults without magnetic resonance imaging (MRI)-defined PF full thickness cartilage damage or knee pain; and (2) evaluate dose-response patterns for these measures with prevalent MRI-defined PF structural damage and/or knee pain.

DESIGN

The Framingham Community Cohort is a population-based sample of ambulatory adults aged ≥50 years. We evaluated six morphology and alignment measures using MRI (n = 985), and reported reference values (mean ± 2SD) in a subsample without MRI-defined PF full thickness cartilage damage or knee pain (n = 563). With restricted cubic spline Poisson regression, we evaluated dose-response patterns of each of the six measures with prevalent MRI-defined PF structural damage or joint pain. Our primary outcome was full thickness cartilage damage.

RESULTS

For dose-response curves, prevalence ratios (PR) increased monotonically for all measures except patellar tilt, which rose with both lateral and medial tilt. Associations were generally strongest in the lateral PF compartment. PR for the strongest predictors of full thickness cartilage damage reached clinical relevance (PR > 1.5) at sulcus angle (SA) ≥135.0°; patellar tilt angle at ≤1.0° and ≥15.0°; and bisect offset ≥57.0%. Lateral trochlear inclination (LTI) achieved PR > 1.5 at ≤23.0° for full thickness cartilage damage with pain.

CONCLUSIONS

SA, patellar tilt, and bisect offset were most strongly associated with full thickness cartilage damage. LTI, patellar tilt and bisect offset had stronger associations with the addition of pain. These findings contribute to better identifying a subset of patients who may benefit from mechanically based interventions.

Is synovitis detected on non-contrast-enhanced magnetic resonance imaging associated with serum biomarkers and clinical signs of effusion? Data from the Osteoarthritis Initiative

OBJECTIVES

To determine the relationship between synovitis detected on non-contrast-enhanced (non-CE) magnetic resonance imaging (MRI), biochemical markers of inflammation, and clinical assessment of effusion in people with knee osteoarthritis (OA).

METHOD

We examined data from the OA Biomarkers Consortium within the Osteoarthritis Initiative (n = 600). Non-CE MRIs were semi-quantitatively scored (grades 0-3) for severity of Hoffa synovitis and effusion synovitis. Serum (s) matrix metalloproteinase-3 (sMMP-3), hyaluronic acid (sHA), and nitrated epitope of the α-helical region of type II collagen (sColl2-1NO2) were quantified. The bulge and patellar tap clinical tests were performed at baseline and performance characteristics were assessed for the detection of effusion synovitis on MRI. Multinomial logistic regression adjusted for covariates was used to assess the association between biochemical and imaging markers at baseline and over 12 and 24 months.

RESULTS

At baseline, sHA and sMMP-3 were associated with moderate to large (score ≥ 2, n = 117) effusion synovitis, with odds ratio = 1.35 and 1.30 per 1 standard deviation in biochemical markers (95% confidence intervals 1.07, 1.71 and 1.00, 1.69), c-statistics 0.640 and 0.626, respectively. The c-statistics for the presence of Hoffa synovitis (score ≥ 2) were 0.693, 0.694, and 0.694 for sHA, sMMP-3, and sColl2-1NO2, respectively. There was no significant association between biochemical markers (baseline and 12 and 24 month time-integrated concentrations) and changes in MRI markers. The bulge and patellar tap signs were 22.0% and 4.3% sensitive and 88.8% and 94.8% specific, respectively, for detecting effusion synovitis (score ≥ 1) on MRI.

CONCLUSIONS

sHA and sMMP-3 were modestly associated with effusion synovitis at baseline. Clinical signs of effusion are insensitive but highly specific for the presence of any effusion synovitis on non-CE MRI.

Is superolateral Hoffa's fat pad hyperintensity a marker of local patellofemoral joint disease? - The MOST study

PURPOSE

To determine the relation of superolateral Hoffa's fat pad (SHFP) hyperintensity to cartilage damage and bone marrow lesions (BMLs) in the patellofemoral joint (PFJ) and tibiofemoral joint (TFJ).

METHODS

We used data from the 60 and 84-month study visits from the Multicenter Osteoarthritis (MOST) study. SHFP hyperintensity and Hoffa-synovitis were graded from 0 to 3. Cartilage damage and BMLs were scored in the PFJ and TFJ. Structural damage was defined as: any cartilage damage, full-thickness cartilage damage and any BML. Worsening structural damage was defined as any increase in cartilage and BML scores. Logistic regression was used to determine the relation of SHFP hyperintensity and Hoffa-synovitis (>0) to structural damage, adjusting for age, sex and body mass index (BMI).

RESULTS

1,094 knees were included in the study. Compared to knees without SHFP hyperintensity, those with SHFP hyperintensity had 1.2 (95% Confidence Interval (CI), 1.1-1.4), 1.7 (1.3-2.3) and 1.6 (1.3-1.9) times the prevalence of any cartilage damage, full-thickness cartilage damage, and BMLs in the lateral PFJ respectively, and 1.1 (1.0-1.2), 1.3 (1.0-1.8), and 1.2 (1.0-1.4) times the prevalence of any cartilage damage, full-thickness cartilage damage, and BMLs in the medial PFJ. SHFP hyperintensity was associated with worsening BMLs in the medial PFJ (RR: 1.4 (1.0-1.9)). In general, there was no relation between SHFP hyperintensity and TFJ outcomes. Hoffa-synovitis was associated both cross-sectionally and longitudinally with structural damage, regardless of definition, in all compartments.

CONCLUSION

SHFP hyperintensity may be a local marker of PFJ structural damage.

Characteristics of acute groin injuries in the adductor muscles: A detailed MRI study in athletes

Acute adductor injuries account for the majority of acute groin injuries; however, little is known about specific injury characteristics, which could be important for the understanding of etiology and management of these injuries. The study aim was to describe acute adductor injuries in athletes using magnetic resonance imaging (MRI). Male athletes with acute groin pain and an MRI confirmed acute adductor muscle injury were prospectively included. MRI was performed within 7 days of injury using a standardized protocol and a reliable assessment approach. 156 athletes presented with acute groin pain of which 71 athletes were included, median age 27 years (range 18-37). There were 46 isolated muscle injuries and 25 athletes with multiple adductor injuries. In total, 111 acute adductor muscle injuries were recorded; 62 adductor longus, 18 adductor brevis, 17 pectineus, 9 obturator externus, 4 gracilis, and 1 adductor magnus injury. Adductor longus injuries occurred at three main injury locations; proximal insertion (26%), intramuscular musculo-tendinous junction (MTJ) of the proximal tendon (26%) and the MTJ of the distal tendon (37%). Intramuscular tendon injury was seen in one case. At the proximal insertion, 12 of 16 injuries were complete avulsions. This study shows that acute adductor injuries generally occur in isolation from other muscle groups. Adductor longus is the most frequently injured muscle in isolation and in combination with other adductor muscle injuries. Three characteristic adductor longus injury locations were observed on MRI, with avulsion injuries accounting for three-quarters of injuries at the proximal insertion, and intramuscular tendon injury was uncommon.

Correlations of Medial Joint Space Width on Fixed-Flexed Standing Computed Tomography and Radiographs With Cartilage and Meniscal Morphology on Magnetic Resonance Imaging

OBJECTIVE

To assess whether medial tibiofemoral joint space width (JSW) on 3-dimensional (3-D) standing computed tomography (SCT) correlates more closely with magnetic resonance imaging cartilage morphology (CM) and meniscal scores than does radiographic 2-D JSW.

METHODS

Participants in the Multicenter Osteoarthritis Study, who had standing fixed-flexion posteroanterior knee radiographs, were recruited. Medial tibiofemoral 3-D JSW on SCT and 2-D JSW on fixed-flexion radiographs were compared with medial tibiofemoral cartilage and meniscal morphology using the Whole-Organ Magnetic Resonance Imaging Score (WORMS). Associations between the area of the articular surface with 3-D JSW <2.5 mm on SCT, radiographic minimal 2-D JSW, and the WORMS-CM and meniscal scores were assessed using Spearman's rho.

RESULTS

For the 19 participants included (33 knees), mean ± SD age was 66.9 ± 5.4 years, body mass index was 29.5 ± 4.4 kg/m(2) , 42.1% of participants were female, and the Kellgren/Lawrence grades were 0 (21.2%), 1 (36.4%), 2 (18.2%), and 3 (24.2%). The articular surface area with 3-D JSW <2.5 mm on SCT correlated with WORMS-CM scores for the central medial tibia (rs  = 0.84, P < 0.001), central medial femur (rs  = 0.60, P < 0.007), and posterior medial meniscal tear (rs  = 0.39, P < 0.026), as did other cut points for 3-D JSW. Correlations with radiographic minimal 2-D JSW were -0.66, -0.52, and -0.40, respectively, differing from SCT only for tibial cartilage (P = 0.001).

CONCLUSION

Greater surface area with a low JSW, measured by SCT, correlates more strongly with the severity of tibial cartilage lesions, while correlating with medial femoral cartilage and meniscal damage to a similar extent as radiographic minimal JSW. SCT may enable valid stratification of participants in clinical trials, through quickly and inexpensively characterizing osteoarthritis features.

Varus thrust during walking and the risk of incident and worsening medial tibiofemoral MRI lesions: the Multicenter Osteoarthritis Study

OBJECTIVE

To determine the association of varus thrust during walking to incident and worsening medial tibiofemoral cartilage damage and bone marrow lesions (BMLs) over 2 years in older adults with or at risk for osteoarthritis (OA).

METHOD

Subjects from the Multicenter Osteoarthritis Study (MOST) were studied. Varus thrust was visually assessed from high-speed videos of forward walking trials. Baseline and two-year MRIs were acquired from one knee per subject and read for cartilage loss and BMLs. Logistic regression with generalized estimating equations was used to estimate the odds of incident and worsening cartilage loss and BMLs, adjusting for age, sex, race, body mass index (BMI), and clinic site. The analysis was repeated stratified by varus, neutral, and valgus alignment.

RESULTS

1007 participants contributed one knee each. Varus thrust was observed in 29.9% of knees. Knees with thrust had 2.17 [95% CI: 1.51, 3.11] times the odds of incident medial BML, 2.51 [1.85, 3.40] times the odds of worsening medial BML, and 1.85 [1.35, 2.55] times the odds of worsening medial cartilage loss. When stratified by alignment, varus knees also had significantly increased odds of these outcomes.

CONCLUSION

Varus thrust observed during walking is associated with increased odds of incident and worsening medial BMLs and worsening medial cartilage loss. Increased odds of these outcomes persist in varus-aligned knees.

Comparison between semiquantitative and quantitative methods for the assessment of knee synovitis in osteoarthritis using non-enhanced and gadolinium-enhanced MRI

OBJECTIVE

To compare different semiquantitative and quantitative methods using both non-enhanced and gadolinium-enhanced MRI techniques for the assessment of synovitis in knee osteoarthritis (OA).

METHODS

Knees with end-stage clinical OA in patients undergoing total knee replacement surgery were included in this cross-sectional study. MRI was performed on all knees. Standard non-enhanced and gadolinium-enhanced sequences were acquired. Using non-enhanced MRI, we semiquantitatively assessed two features widely used as surrogates for synovitis: effusion-synovitis and Hoffa-synovitis. Using gadolinium-enhanced sequences, we semiquantitatively assessed synovial thickness. We quantitatively evaluated the total synovial volume on the gadolinium-enhanced sequences as well. We assessed the correlations of effusion-synovitis and Hoffa-synovitis with synovial thickness and volume, applying Spearman correlation analysis. The diagnostic performance of both synovitis features on non-enhanced MRI was assessed using synovial thickness on gadolinium-enhanced MRI as the reference.

RESULTS

A total of 104 subjects (one knee per subject) were included. Correlations of effusion-synovitis with synovial thickness and volume were r = 0.41 and r = 0.43 (P < .001) r = 0.32 and r = 0.39 (P < .0001).

CONCLUSION

Using synovial thickness assessed on gadolinium-enhanced sequences as the reference, effusion-synovitis showed superior correlations and sensitivity. Effusion-synovitis should be preferred over Hoffa-synovitis as a surrogate marker for synovial thickening, in studies of knee OA for which gadolinium-enhanced sequences are not available.

Association of baseline knee sagittal dynamic joint stiffness during gait and 2-year patellofemoral cartilage damage worsening in knee osteoarthritis

OBJECTIVE

Knee sagittal dynamic joint stiffness (DJS) describes the biomechanical interaction between change in external knee flexion moment and flexion angular excursion during gait. In theory, greater DJS may particularly stress the patellofemoral (PF) compartment and thereby contribute to PF osteoarthritis (OA) worsening. We hypothesized that greater baseline knee sagittal DJS is associated with PF cartilage damage worsening 2 years later.

METHODS

Participants all had OA in at least one knee. Knee kinematics and kinetics during gait were recorded using motion capture systems and force plates. Knee sagittal DJS was computed as the slope of the linear regression line for knee flexion moments vs angles during the loading response phase. Knee magnetic resonance imaging (MRI) scans were obtained at baseline and 2 years later. We assessed the association between baseline DJS and baseline-to-2-year PF cartilage damage worsening using logistic regression with generalized estimating equations (GEE).

RESULTS

Our sample had 391 knees (204 persons): mean age 64.2 years (SD 10.0); body mass index (BMI) 28.4 kg/m² (5.7); 76.5% women. Baseline knee sagittal DJS was associated with baseline-to-2-year cartilage damage worsening in the lateral (OR = 5.35, 95% CI: 2.37-12.05) and any PF (OR = 2.99, 95% CI: 1.27-7.04) compartment. Individual components of baseline DJS (i.e., change in knee moment or angle) were not associated with subsequent PF disease worsening.

CONCLUSION

Capturing the concomitant effect of knee kinetics and kinematics during gait, knee sagittal DJS is a potentially modifiable risk factor for PF disease worsening.

Role of physical activity in cartilage damage progression of subjects with baseline full-thickness cartilage defects in medial tibiofemoral compartment: data from the Osteoarthritis Initiative

OBJECTIVE

To assess the association between physical activity and cartilage damage progression in medial tibiofemoral compartment (MTFC) using 2-year follow-up magnetic resonance imaging (MRI) in subjects with denuded areas of subchondral bone (dABs) at the central weight-bearing medial femur (cMF) at baseline MRI examination.

METHODS

One hundred subjects from the Osteoarthritis Initiative (OAI) progression cohort with dABs at the cMF at 3T MRI at baseline (51% men; mean age 62.2 years, range 45-79) were included. Sagittal 3D dual-echo steady-state with water excitation images were used to assess 2-year MTFC cartilage change. Associations between 2-year average Physical Activity Scale for the Elderly (PASE) and 2-year MTFC cartilage change were assessed by linear regression analysis. Subgroup analyses were performed.

RESULTS

No associations between PASE and 2-year MTFC cartilage change were observed in the entire cohort. Similarly, in the subgroup with cartilage loss during the 2 years, the non-refuted confidence intervals for the regression coefficients were tightly clustered around the null value (regression coefficients for: mean cMF.ThCtAB = -0.00059; 98.75% CI: -0.00130 to 0.00012), cMF.dAB% = 0.02176; 98.75% CI: -0.02514 to 0.06865, Mean MT.ThCtAB = -0.00013; 98.75% CI: -0.00064 to 0.00038, MT.dAB% = 0.02543; 98.75% CI: -0.01485 to 0.06571.

CONCLUSION

In the entire group of subjects with dABs at the cMF at baseline, no association between physical activity and 2-year MTFC cartilage change was detected. Due to the limited sample size of our study, small-sized effects may not have been detected in our study.

Associations between MRI-defined structural pathology and generalized and localized knee pain - the Oulu Knee Osteoarthritis study

OBJECTIVE

To determine the associations between multi-feature structural pathology assessed using magnetic resonance imaging (MRI) and the presence of knee pain, and to determine the associations between the locations of structural changes and different knee pain patterns.

METHOD

Eighty symptomatic subjects with knee pain and suspicion or diagnosis of knee OA and 63 asymptomatic subjects underwent knee MRI. Severity of structural changes was graded by MRI Osteoarthritis Knee Score (MOAKS) in separate knee locations. The associations between cartilage damage, bone marrow lesions (BMLs), osteophytes, Hoffa's synovitis, effusion-synovitis, meniscal damage and structural pathologies in ligaments, tendons and bursas and both the presence of pain and the knee pain patterns were assessed.

RESULTS

The presence of Hoffa's synovitis (adjusted RR 1.6, 95% CI 1.2-1.3) and osteophytes in any region (2.07, 1.19-3.60) was significantly associated with the presence of pain. Any Hoffa's synovitis was associated with patellar pain (adjusted RR 4.70, 95% CI 1.19-3.60) and moderate-to-severe Hoffa's synovitis with diffuse pain (2.25, 1.13-4.50). Medial knee pain was associated with cartilage loss in the medial tibia (adjusted RR 2.66, 95% CI 1.22-5.80), osteophytes in the medial tibia (2.66, 1.17-6.07) and medial femur (2.55, 1.07-6.09), medial meniscal maceration (2.20, 1.01-4.79) and anterior meniscal extrusions (2.78, 1.14-6.75).

CONCLUSIONS

Hoffa's synovitis and osteophytes were strongly associated with the presence of knee pain. Medial pain was associated most often with medially located structural pathologies.

Knee kinematics and kinetics are associated with early patellofemoral osteoarthritis following anterior cruciate ligament reconstruction

OBJECTIVE

Patellofemoral osteoarthritis (PFOA) commonly occurs following anterior cruciate ligament reconstruction (ACLR). Our study aimed to compare knee kinematics and kinetics during a hop-landing task between individuals with and without early PFOA post-ACLR.

DESIGN

Forty-five individuals (mean ± SD 26 ± 5 years) 1-2 years post-ACLR underwent 3T isotropic MRI scans and 3D biomechanical assessment of a standardised forward hop task. Knee kinematics (initial contact, peak, excursion) in all three planes and sagittal plane kinetics (peak) were compared between 15 participants with early PFOA (MRI-defined patellofemoral cartilage lesion) and 30 participants with no PFOA (absence of patellofemoral cartilage lesion on MRI) using analysis of covariance (ANCOVA), adjusted for age, BMI, sex and the presence of early tibiofemoral OA.

RESULTS

Compared to participants without PFOA, those with early PFOA exhibited smaller peak knee flexion angles (mean difference, 95% confidence interval [CI]: -5.2°, -9.9 to -0.4; P = 0.035) and moments (-4.2 Nm/kg.m, -7.8 to -0.6; P = 0.024), and greater knee internal rotation excursion (5.3°, 2.0 to 8.6; P = 0.002).

CONCLUSIONS

Individuals with early PFOA within the first 2-years following ACLR exhibit distinct kinematic and kinetic features during a high-load landing task. These findings provide new information regarding common post-ACLR biomechanical patterns and PFOA. Since management strategies, such as altering knee load, are more effective during the early stages of disease, this knowledge will help to inform clinical management of early PFOA post-ACLR.

Long term use of analgesics and risk of osteoarthritis progressions and knee replacement: propensity score matched cohort analysis of data from the Osteoarthritis Initiative

OBJECTIVES

To determine the association between the long-term use of analgesics and progression of osteoarthritis (OA) as evidenced by up to 3-years follow-up worsening of radiographic Kellgren-Lawrence (KL) grade and incidence of knee replacement (KR).

DESIGN

Using nearest neighbor matching of the propensity scores with caliper in the Osteoarthritis Initiative (OAI) cohort, 173 index (Analgesic +) and 173 referent (Analgesic -) subjects were included. Analgesic + and - subjects had analgesics in all and none of their visits, respectively. Analgesic + and - subjects were balanced in their demographics, baseline, first, second and third year body mass index (BMI), Western Ontario and McMaster (WOMAC) total score, Physical and Mental health summary scales (SF-12), Physical Activity Scale for the Elderly (PASE) and Charleston Comorbidity Scale. Analgesic + and - subjects were also matched for baseline radiographic KL grade. Interval increase in the KL grade and incidence of KR were defined as the outcome.

RESULTS

Included subjects had average 6.5 years of follow-up. By the third year, 44 subjects had an interval increase in the KL grade; 29 in Analgesic + and 15 among Analgesic - subjects (P = 0.024). By the eighth-year, 41 subjects had their first KR; 29 in Analgesic + and 12 among Analgesic - subjects (P = 0.005). Hazard Ratio (HR) of OA progression and KR for Analgesic + subjects was 1.91 (1.02-3.57) and 2.57 (1.31-5.04), respectively.

CONCLUSIONS

Long-term use of analgesics may be associated with radiographic progression of knee OA and increased risk of future KR.

Brief Report: Cartilage Thickness Change as an Imaging Biomarker of Knee Osteoarthritis Progression: Data From the Foundation for the National Institutes of Health Osteoarthritis Biomarkers Consortium

OBJECTIVE

To investigate the association of cartilage thickness change over 24 months, as determined by magnetic resonance imaging (MRI), with knee osteoarthritis (OA) progression at 24-48 months.

METHODS

This nested case-control study included 600 knees with a baseline Kellgren/Lawrence (K/L) grade of 1-3 from 600 Osteoarthritis Initiative (OAI) participants. Case knees (n = 194) had both medial tibiofemoral radiographic joint space loss (≥0.7 mm) and a persistent increase in the Western Ontario and McMaster Universities Osteoarthritis Index pain score (≥9 on a 0-100 scale) 24-48 months from baseline. Control knees (n = 406) included 200 with neither radiographic nor pain progression, 103 with radiographic progression only, and 103 with pain progression only. Medial and lateral femorotibial cartilage was segmented from sagittal 3T MRIs at baseline, 12 months, and 24 months. Logistic regression was used to assess the association of change in cartilage thickness, with a focus on the central medial femorotibial compartment, and OA progression.

RESULTS

Central medial femorotibial compartment thickness loss was significantly associated with case status, with an odds ratio (OR) of 1.9 (95% confidence interval [95% CI] 1.6-2.3) (P < 0.0001). Association with case status reached P < 0.05 for both the central femur (OR 1.8 [95% CI 1.5-2.2]) and the central tibia (OR 1.6 [95% CI 1.3-1.9]). Lateral femorotibial compartment cartilage thickness loss, in contrast, was not significantly associated with case status. A reduction in central medial femorotibial compartment cartilage thickness was strongly associated with radiographic progression (OR 4.0 [95% CI 2.9-5.3]; P < 0.0001) and only weakly associated with pain progression (OR 1.3 [95% CI 1.1-1.6]; P < 0.01).

CONCLUSION

Our findings indicate that loss of medial femorotibial cartilage thickness over 24 months is associated with the combination of radiographic and pain progression in the knee, with a stronger association for radiographic progression.

Relationship Between Medial Meniscal Extrusion and Cartilage Loss in Specific Femorotibial Subregions: Data From the Osteoarthritis Initiative

OBJECTIVE

Medial meniscal extrusion is known to be related to structural progression of knee osteoarthritis. However, it is unclear whether medial meniscal extrusion is more strongly associated with cartilage loss in certain medial femorotibial subregions than in others.

METHODS

Segmentation of the medial tibial and femoral cartilage (baseline; 1-year followup) and the medial meniscus (baseline) was performed in 60 participants with frequent knee pain (mean ± SD ages 61.3 ± 9.2 years, body mass index 31.3 ± 3.9 kg/m(2) ) and with unilateral medial radiographic joint space narrowing (JSN) grades 1-3, using double-echo steady-state magnetic resonance images. Medial meniscal extrusion distance and extrusion area (percentage) between the external meniscal and tibial margin at baseline, and longitudinal medial cartilage loss in 8 anatomic subregions were determined.

RESULTS

A significant association (Pearson's correlation coefficient) was seen between medial meniscal extrusion area in JSN knees and cartilage loss over 1 year throughout the entire medial femorotibial compartment. The strongest correlation was with cartilage loss in the external medial tibia (r =-0.34, P < 0.01 in JSN; r =-0.30, P = 0.02 in knees without JSN).

CONCLUSION

Medial meniscal extrusion was associated with subsequent medial cartilage loss. The external medial tibial cartilage may be particularly vulnerable to thinning once the meniscus extrudes and its surface is exposed to direct, nonphysiological, cartilage-to-cartilage contact.

Validity and responsiveness of a new measure of knee osteophytes for osteoarthritis studies: data from the osteoarthritis initiative

PURPOSE

To validate a novel quantitative MRI method to measure osteophyte volume.

METHODS

90 subjects were selected from the Progression Cohort of the Osteoarthritis Initiative (OAI) at baseline and 48 months, and analyzed using a semi-automated software tool. Marginal osteophyte volume was calculated for four compartments of the central weight-bearing region of the tibiofemoral joint. Standardized response mean (SRM) for change in volume was used to quantify responsiveness. Concurrent validity was assessed via a comparison with MRI Osteoarthritis Knee Score (MOAKS) using Kruskal-Wallis analysis and Spearman's correlation coefficient. Intra- and inter-reader reliability was assessed on a subset of 20 knees using intra-class correlation coefficients (ICCs) and the root mean square standard deviation (RMSSD).

RESULTS

The average change in osteophyte volume (ΔV) was 196 mm(3) (SD = 272 mm(3)), and the baseline to 48-month SRM was 0.72. An increase in osteophyte volume was observed for 84% (76/90) of the subjects. Kruskal-Wallis analysis across the four MOAKS osteophyte categories was significant for medial and lateral compartments of both the tibia and femur (P < 0.001 for all). The intra-reader ICC was 0.98, and RMSSD was 82 mm(3), while inter-reader ICC was 0.97 and RMSSD was 91 mm(3). A statistically significant positive correlation was observed between osteophyte volume and several MOAKS cartilage and BML scores. The reader time was approximately 10 min per knee.

CONCLUSIONS

The method is responsive, efficient, and precise, making it practical for use in large cohort studies and observational research.

Baseline radiographic osteoarthritis and semi-quantitatively assessed meniscal damage and extrusion and cartilage damage on MRI is related to quantitatively defined cartilage thickness loss in knee osteoarthritis: the Multicenter Osteoarthritis Study

OBJECTIVES

To provide a comprehensive simultaneous relation of various semiquantitative knee OA MRI features as well as the presence of baseline radiographic osteoarthritis (OA) to quantitative longitudinal cartilage loss.

METHODS

We studied Multicenter OA Study (MOST) participants from a longitudinal observational study that included quantitative MRI measurement of cartilage thickness. These subjects also had Whole Organ MRI Score (WORMS) scoring of cartilage damage, bone marrow lesions (BMLs), meniscal pathology, and synovitis, as well as baseline radiographic evaluation for Kellgren and Lawrence (KL) grading. Knee compartments were classified as progressors when exceeding thresholds of measurement variability in normal knees. All potential risk factors of cartilage loss were dichotomized into "present" (score ≥2 for cartilage, ≥1 for others) or "absent". Differences in baseline scores of ipsi-compartmental risk factors were compared between progressor and non-progressor knees by multivariable logistic regression, adjusting for age, sex, body mass index, alignment axis (degrees) and baseline KL grade. Odds ratios (OR) and 95% CIs were calculated for medial femorotibial compartment (MFTC) and lateral femorotibial compartment (LFTC) cartilage loss. Cartilage loss across both compartments was studied using Generalized Estimating Equations.

RESULTS

196 knees of 196 participants were included (age 59.8 ± 6.3 years [mean ± SD], BMI 29.5 ± 4.6, 62% women). For combined analyses of MFTC and LFTC, baseline factors related to cartilage loss were radiographic OA (KL grade ≥2: aOR 4.8 [2.4-9.5], cartilage damage (aOR 2.3 [1.2-4.4])), meniscal damage (aOR 3.9 [2.1-7.4]) and extrusion (aOR 2.9 [1.6-5.3]), all in the ipsilateral compartment, but not BMLs or synovitis.

CONCLUSION

Baseline radiographic OA and semiquantitatively (SQ) assessed MRI-detected cartilage damage, meniscal damage and extrusion, but not BMLs or synovitis is related to quantitatively measured ipsi-compartmental cartilage thinning over 30 months.

Knee joint subchondral bone structure alterations in active athletes: a cross-sectional case-control study

OBJECTIVE

It has been shown that trabecular bone structure parameters extracted from radiographs known as fractal signature analysis (FSA) are able to predict structural outcomes such as radiographic osteoarthritis (OA) progression. Little is known about their involvement in early disease or about differences between subjects exposed to increased joint loading such as young active athletes compared to non-athletes. Aim was to compare horizontal and vertical dimensions of bone texture considering athlete status, gender, previous anterior cruciate ligament (ACL) surgery and age.

DESIGN

Included were 685 patients of which 135 consecutive athletes (82% soccer players) 18-36 years old and 550 non-athletes controls in the same age range had knee radiography for assessment of subacute or chronic knee complaints. Regions of interest (ROI) were placed in the subchondral medial and lateral tibial plateaus. Fractal signatures were calculated in the horizontal and vertical dimensions. Curve fitting algorithms were applied taking into account all four risk factors in the same model adjusting for each other.

RESULTS

For the horizontal dimensions significant differences were observed for gender (estimate (E) 0.098 (95% confidence interval(CI)) (-0.009, 0.008), P < .0001), previous ACL surgery (E -0.031, 95% CI (-0.043, -0.019), P < .0001) and highest age group (E -0.039, 95% CI (-0.048, -0.029), P < .0001). For vertical dimensions, significant differences were shown for athletes (E -0.012, 95% CI (-0.020, -0.004), P < .0001), gender (E 0.056, 95% CI (0.049, 0.062), P < .0001), and age range from 28 to 32 years (E -0.028, 95% CI (-0.037, -0.019), P < .0001).

CONCLUSIONS

Trabecular bone structure differs between athletes and non-athletes, in regard to previous ACL surgery, gender and higher age.