Longitudinal assessment of MRI in hip osteoarthritis using SHOMRI and correlation with clinical progression

Clinical Assessment of Osteoarthritis Pain: Contemporary Scenario, Challenges, and Future Perspectives

The multifaceted nature of osteoarthritis (OA) pain presents a challenge in understanding and managing the condition. The diverse pain experiences, progression rates, individual responses to treatments, and complex disease mechanisms contribute to heterogeneity in the clinical studies outcomes. The lack of a standardized methodology for assessing and classifying OA pain challenges healthcare practitioners. This complicates the establishment of universally applicable protocols or standardized guidelines for treatment. This article explores the heterogeneity observed in clinical studies evaluating OA pain treatments, highlighting the necessity for refined methodologies, personalized patient categorization, and consistent outcome measures. It discusses the role of the multidimensional nature of OA pain, underlying pain mechanisms, and other contributing factors to the heterogeneity in outcome measures. Addressing these variations is crucial to establishing a more consistent framework for evidence-based treatments and advancing care of the patient with OA pain.

Defining hip osteoarthritis feature prevalence, severity, and change using the Scoring of Hip Osteoarthritis with MRI (SHOMRI)

OBJECTIVE

To define the reporting of Scoring Hip Osteoarthritis with MRI (SHOMRI) feature prevalence and severity, and to develop criteria to monitor feature change in longitudinal investigations.

METHODS

Twenty-five participants (50 hips) of the femoroacetabular impingement and hip osteoarthritis cohort study underwent baseline and 2-year follow-up 3 T hip MRIs. Eight hip OA features were assessed using the SHOMRI. All MRIs were read paired with knowledge of timepoint by two blinded musculoskeletal radiologists. We provide definitions to report SHOMRI feature prevalence, severity, and longitudinal change.

RESULTS

We report clear definitions for SHOMRI feature prevalence, severity, and change. When we applied the definitions to the studied cohort, we could detect the prevalence, severity, and change of hip OA features. For example, 88% of hips had labral tears (34% graded as severe tears) and 76% had cartilage defects (42% graded as full thickness). Over 70% of hips had feature change over 2 years, highlighting the sensitivity of SHOMRI definitions to assess longitudinal change of hip OA features. Intra-reader reliability was almost perfect (weighted (w)-kappa 0.86 to 1.00), with inter-reader reliability substantial to almost perfect (w-kappa 0.80 to 1.00).

CONCLUSION

This study is the first to provide definitions to report SHOMRI feature prevalence, severity, and change. The proposed definitions will enable comparison between hip MRI studies and improve our understanding of hip OA pathogenesis.

Defining hip cartilage repair: a modified delphi study to establish the Magnetic Resonance Evaluation of the Repair of Cartilage in the Hip (MERCH) score

PURPOSE

To develop a standardized scoring system to evaluate pre- to post-operative repair or reconstruction of hip cartilage using magnetic resonance imaging (MRI).

METHODS

A two-phase modified Delphi study was conducted. Phase 1 involved a survey with suggested criteria and diagrams to define various stages of articular cartilage repair and phase 2 involved an expert consensus meeting that discussed the survey responses and voted on final scoring criteria. The survey was emailed to members of the Canadian Hip Preservation Research Collaborative (CHIPR) and respondents included both board certified orthopedic surgeons as well as musculoskeletal radiologists.

RESULTS

Overall, there were 17 survey respondents from Canada and most (47%, 8/17) participants agreed that the minimum MRI protocol needed to evaluate cartilage repair was a 3.0 T MRI and 94% (17/18) agreed that the minimum time post-operatively that they felt they would be able to accurately evaluate cartilage repair on an MRI was 12 months. Following phases 1 and 2, the final Magnetic Resonance Evaluation of the Repair of Cartilage in the Hip (MERCH) score was developed with 7 domains, 3 criteria per domain: 1) volume fill of cartilage defect, 2) integration into adjacent cartilage, 3) surface of the repair tissue, 4) structure of the repair tissue, 5) bony overgrowth, 6) subchondral changes, and 7) delamination. The score ranges from 60 (optimal) to -20 points (worst/none).

CONCLUSIONS

This consensus project established a new MRI scoring system to evaluate post-operative cartilage restoration of the hip. The implementation of the MERCH score is essential in our ability to guide patient management and expectations in a rapidly evolving field and will help with standardizing our evaluation of cartilage repair in future research trials.

LEVEL OF EVIDENCE

Level II Diagnostic.

Osteoarthritis of the hip: is radiography still needed?

Diagnosis of hip osteoarthritis (OA) is based on clinical arguments, and medical imaging is obtained to confirm the diagnosis and rule out other possible sources of pain. Conventional radiographs are recommended as the first line imaging modality to investigate chronic hip pain. They should be obtained in a rigorous technique that includes an antero-posterior (AP) radiograph of the pelvis. The choice of the appropriate lateral view depends on the clinical indication, Lequesne's false profile being valuable in the assessment of OA. Magnetic resonance imaging (MRI) is more sensitive to detect joint effusion/synovitis, cartilage, labral, and bone marrow lesions. However, structural joint changes are frequent in asymptomatic population and neither radiographs nor MRI have shown a good correlation with pain and functional impairment. MRI seems to be more suitable than radiographs as a biomarker for clinical trials addressing early OA. The absence of a validated MR biomarker of early OA, together with issues related to machine availability and MRI protocol repeatability, prevent the widespread use of MRI in clinical trials.

Radial Planes in Hip Magnetic Resonance Imaging: Techniques, Applications, and Perspectives

The hip cartilage and labrum, as the main targets of femoroacetabular impingement, sports-related or traumatic damage, as well as congenital and developmental abnormalities, have attracted increasing attention with the development of magnetic resonance imaging (MRI) and hip arthroscopy. MRI is a commonly used imaging modality to noninvasively visualize the hip cartilage and labral lesions. However, conventional orthogonal MRI planes encounter unique challenges given the ball-and-socket configuration of the hip joint, its anatomically abducted and anteverted orientation, and the thin, closely apposed cartilage enveloping the femoral head and acetabulum. Advancements in hip MRI's radial plane, which is acquired through the center of the hip joint, offer a solution. This technology provides true cross-sectional images of the cartilage and labrum perpendicular to the curvature of the joint, thereby mitigating the partial-volume-averaging effects. The integration of 3.0-Tesla high field strength and three-dimensional (3D) acquisition techniques further enhances the capabilities of the radial plane. This combination yields a high signal-to-noise ratio, high spatial resolution, high contrast between intraarticular structures, while minimizing partial-volume-averaging effects. Such improvements potentially facilitate the comprehensive detection of even minor chondral and labral lesions. The capability for multiplanar reconstruction from a single 3D volumetric acquisition further strengthens the usefulness of the radial plane by aiding in precise localization of hip cartilage and labral lesions, in line with hip arthroscopy findings. These advancements have the potential to standardize MRI evaluations and radiographic reporting systems for hip cartilage and labrum, offering precise guidance for hip arthroscopy. This article presents a comprehensive review of radial plane technology applied to the hip MRI, and discusses the morphological assessment and localization of hip cartilage and labral lesions utilizing this advanced imaging technique. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: Stage 2.

Pain in osteoarthritis from a symptom to a disease

Pain is the most frequent symptom of osteoarthritis (OA), occurring much more commonly than stiffness or disability. Classically, OA-related pain has been considered to be a nociceptive pain condition and an alarm signal correlated to the intensity of joint degradation. However, OA-related pain is a specific disease, with a complex pathophysiology, including neuropathic peripheral and central abnormalities, together with local inflammation involving all joint structures. Clinical findings emphasize that it is not a stable and linear condition, that pain experience is poorly correlated to structural modifications, and that the quality of pain in OA is important to consider, aside from its intensity. OA-related pain is modulated by many factors, including the individual patient's psychological and genetic factors, as well as the theoretical role of meteorological influences. Recent findings have improved our knowledge about the central mechanisms of OA pain, especially in persistent cases. A specific questionnaire on OA pain is currently being developed to assess more precisely the patient's experience and target specific pain mechanisms. In conclusion, OA-related pain should be analyzed specifically aside from OA, taking into account the complexity of OA pain as a disease, distinguishing different OA pain phenotypes, to guide more precisely analgesic treatment and OA global management.

Local Patterns in 2-Year T1ρ and T2 Changes of Hip Cartilage Are Related to Sex and Functional Data: A Prospective Evaluation on Hip Osteoarthritis Participants

BACKGROUND

Although T1ρ and T2 have emerged as early indicators for hip osteoarthritis (OA), there is little information regarding longitudinal changes across the cartilage in the early stages of this disease.

PURPOSE

To characterize the variability in 2-year hip cartilage T1ρ and T2 changes and investigate associations between these patterns of change and common indicators of hip OA.

STUDY TYPE

Prospective.

POPULATION

A total of 25 women (age: 51.9 ± 16.3 years old; BMI: 22.6 ± 2.0 kg/m2 ) and 17 men (age: 55.8 ± 14.9 years old; body mass index (BMI): 24.4 ± 3.8 kg/m2 ) who were healthy or with early-to-moderate hip OA.

FIELD STRENGTH/SEQUENCE

A 3 T MRI (GE), 3D combined T1ρ /T2 magnetization-prepared angle-modulated partitioned k-space spoiled gradient echo snapshots.

ASSESSMENT

Principal component (PC) analysis of Z-score difference maps of 2-year changes in hip cartilage T1ρ and T2 relaxation times, participant hip disability and osteoarthritis outcome scores (HOOS) and functional tests at 2-year follow-up.

STATISTICAL TESTS

Shapiro-Wilk test, unpaired t-tests, Kruskal Wallis tests, Pearson or Spearman (ρ) correlations. Significance was set at P < 0.05.

RESULTS

Women (-6.40 ± 14.48) had significantly lower T1ρ PC1 scores than men (10.05 ± 26.15). T1ρ PC4 was significantly correlated with HOOSsport , HOOSsymptoms , HOOSpain , HOOSadl , and HOOSqol at 2-year follow-up (ρ: [0.36, 0.50]). T1ρ PC2 and PC4 were significantly correlated with 30-second chair test (ρ = -0.39 and ρ = 0.24, respectively) and side plank (ρ = -0.32 and ρ = 0.21). T1ρ and T2 PC2 were significantly correlated with 40 m walk test (ρ = 0.34 and ρ = 0.31) and 30-second chair rise test (ρ = -0.39 and ρ = -0.32).

DATA CONCLUSION

Men exhibited accelerated T1ρ increases across the femoral cartilage compared to women, suggesting sex should be considered when evaluating early hip OA. Participants with poorer HOOS and function exhibited greater T1ρ and T2 increases in superior and anterior femoral cartilage and greater T1ρ increases in the anterior femoral cartilage. These patterns of short-term relaxometry increases could indicate hip OA progression.

EVIDENCE LEVEL

2 TECHNICAL EFFICACY: Stage 3.

Structural features of subchondral bone cysts and adjacent tissues in hip osteoarthritis

OBJECTIVE

Focal lesions within the subchondral bone, termed subchondral bone cysts (SBCs), are clinically accepted radiographic markers of advanced osteoarthritis (OA), but their etiology in the hip is not well understood.

DESIGN

This study used micro-computed tomography (μCT), and histological and immunocytological analysis to examine the prevalence, size, location, and morphological and cellular features of SBCs found within 34 femoral heads (14 male, 20 female; age range = 43-80 years) obtained from total hip arthroplasty procedures.

RESULTS

SBCs were common-present in 91% of the femoral heads examined-and frequently commuted with the surface of the femoral head, but otherwise showed no preferred anatomical location. Few associations were found between SBC features and patient characteristics such as BMI, age and sex. SBCs were also heterogenous in composition, ranging from fibrous (most common) to predominantly fatty (least common) and often containing vasculature, nerve fibers, cartilage islands, and bony spicules. Despite this heterogeneity, focal abnormalities in bone density and cartilage thickness were consistently observed. Bone adjacent to SBCs was denser than that in the primary compressive group, and cartilage thickness in regions overlying SBCs was lower than in non-overlying regions. In contrast to these local bony changes, μCT-based finite element analyses indicated that the stiffness of the primary compressive group was only mildly affected by SBCs.

CONCLUSIONS

These findings indicate that SBCs in the femoral head involve extensive perturbations in cellular activity, culminating in myriad skeletal tissue types and spatially heterogenous changes in bone and cartilage morphology that are likely to affect OA progression.

The Use of Scoring Hip Osteoarthritis with MRI as an Assessment Tool for Physiotherapeutic Treatment in Patients with Osteoarthritis of the Hip

Rehabilitation programs are considered effective at reducing the impact of osteoarthritis (OA) of the hip; however, studies using reliable measures related to OA biomarkers to assess the effects of rehabilitation are lacking. The objective of this study was to investigate whether an MRI-based (Magnetic Resonance Imaging-based), semi-quantitative system for an OA severity assessment is feasible for the evaluation of the structural changes in the joint observed during a long-term physiotherapy program in patients with hip OA. The study group consisted of 37 adult OA patients who participated in a 12-month physiotherapy program. The Scoring hip osteoarthritis with MRI (SHOMRI) system was used to evaluate the severity of structural changes related to hip OA. Hip disability and the osteoarthritis outcome score (HOOS) and the core set of performance-based tests recommended by Osteoarthritis Research Society International were used for functional assessment. SHOMRI showed excellent inter- and intra-rater agreement, proving to be a reliable method for the evaluation of hip abnormalities. At the 12-month follow-up no statistically significant changes were observed within the hip joint; however, a trend of structural progression was detected. There was a negative correlation between most of the SHOMRI and HOOS subscales at baseline and the 12-month follow-up. Although SHOMRI provides a reliable assessment of the hip joint in patients with OA it showed a limited value in detecting significant changes over time in the patients receiving physiotherapy over a 12-month period.

One-year outcomes following physical therapist-led intervention for chronic hip-related groin pain: Ancillary analysis of a pilot multicenter randomized clinical trial

Evidence related to physical therapist-led intervention for patients with chronic hip-related groin pain (HRGP) is limited. The purpose was to assess sustainability of treatment effects for people with HRGP undergoing two physical therapist-led interventions. We completed an ancillary analysis of a pilot multicenter, randomized clinical trial. Forty-six patients with chronic HRGP, 15-40 years, were enrolled. Patients were randomized to participate in 10 sessions over 12 weeks of either movement pattern training (MoveTrain) or traditional strength/flexibility (Standard). Participants completed self-report questionnaires before treatment and 6 and 12 months after treatment completion. Outcome measures included Hip disability and Osteoarthritis and Outcome Score (HOOS), Patient Specific Functional Scale and Numeric Pain Rating Scale for average and worst pain. Continuous data were analyzed with mixed model repeated measures analysis of variance (RM-ANOVA) within each group. Numeric pain rating scale (NPRS) was analyzed using multinomial generalized estimating equations (GEE) with a cumulative logit. Reported p values are from statistical contrasts within the RM-ANOVAs and GEEs testing a priori hypotheses regarding change from pretest to month 6, and pretest to month 12. A total of 43/46 (93.5%) participants completed treatment, 40 (87.0%) completed 6 and 38 (82.6%) completed 12 month questionnaires. At 6 and 12 months, both groups demonstrated clinically significant improvements, compared to pretest, in all subscales of HOOS (p < 0.01), Patient Specific Functional Scale (p < 0.001), and NPRS (p < 0.0001). Among patients with chronic HRGP, both MoveTrain and Standard resulted in improved outcomes that were sustained 12 months after treatment. Further investigation in a larger sample is needed to confirm our findings.

Hip Joint Cartilage Defects in Professional Ballet Dancers: A 5-year Longitudinal Study

OBJECTIVE

A causal link between ballet, hip pain, and pathology has not been established. Change in ballet dancers' hip pain and cartilage defect scores were investigated over 5 years.

DESIGN

Longitudinal.

SETTING

Professional ballet company.

PARTICIPANTS

Twenty-one professional ballet dancers (52% men).

INDEPENDENT VARIABLES

Baseline and follow-up Copenhagen Hip and Groin Outcome Score (HAGOS-pain subscale); incidence of hip-related pain and levels of dance participation collected daily over 5 years; bony morphology measured on baseline 3T magnetic resonance imaging (MRI).

MAIN OUTCOME MEASURE

Change in cartilage defect score on MRI between baseline and 5-year follow-up.

RESULTS

Cartilage scores did not increase in 19 (90%) dancers. There was one new cartilage defect and one progressed in severity. At follow-up, all 6 dancers with cartilage defects were men. Group HAGOS pain scores were high 97.5 (7.5) and not related to cartilage defects (P = 0.12). Five (83%) dancers with baseline cartilage defects reported HAGOS pain scores <100 at follow-up. There were no time-loss hip injuries over 5 years. Two (33%) dancers with cartilage defects recorded hip-related pain (one reported minor training modification). Femoral neck-shaft angles (NSAs) were lower in men with cartilage defects [129.3 degrees (3.4 degrees)] compared with those without cartilage defects [138.4 degrees (4.5 degrees); P = 0.004].

CONCLUSIONS

Elite level ballet did not negatively affect cartilage health over 5 years. Cartilage defects were related to low femoral NSAs. Most cartilage defects did not progress and there was minimal impact on dance participation and pain levels. Longer follow-up is required to determine the long-term sequelae for those with cartilage defects.

LEVEL OF EVIDENCE

1b.

Prevalence of early hip OA features on MRI in high-impact athletes. The femoroacetabular impingement and hip osteoarthritis cohort (FORCe) study

OBJECTIVE

To compare early hip osteoarthritis (OA) features on magnetic resonance imaging (MRI) in high-impact athletes with and without hip and/or groin pain, and to evaluate associations between early hip OA features, the International Hip Outcome Tool (iHOT33) and Copenhagen Hip and Groin Outcome Score (HAGOS).

DESIGN

This case-control study evaluated data of the femoroacetabular impingement and hip osteoarthritis cohort (FORCe). One hundred and eighty-two symptomatic (hip and/or groin pain >6 months and positive flexion-adduction-internal-rotation (FADIR) test) and 55 pain-free high-impact athletes (soccer or Australian football (AF)) without definite radiographic hip OA underwent hip MRI. The Scoring Hip Osteoarthritis with MRI (SHOMRI) method quantified and graded the severity of OA features. Each participant completed the iHOT33 and HAGOS.

RESULTS

Hip and/or groin pain was associated with higher total SHOMRI (0-96) (mean difference 1.4, 95% CI: 0.7-2.2), labral score (adjusted incidence rate ratio (aIRR) 1.33, 95% CI: 1.1-1.6). Differences in prevalence of cartilage defects, labral tears and paralabral cysts between symptomatic and pain-free participants were inconclusive. There was a lower prevalence of effusion-synovitis in symptomatic participants when compared to pain-free participants (adjusted odds ratio (aOR) 0.46 (95% CI: 0.3-0.8). Early hip OA features were not associated with iHOT33 or HAGOS.

CONCLUSIONS

A complex and poorly understood relationship exists between hip and/or groin pain and early hip OA features present on MRI in high-impact athletes without radiographic OA. Hip and/or groin pain was associated with higher SHOMRI and labral scores.

Histological evaluation of acetabular bone quality during revision hip arthroplasty

PURPOSE

Aim of this study was to evaluate acetabular bone vitality during revision hip arthroplasty and to compare the bone quality between revision and primary acetabular arthroplasty.

METHODS

During primary and revision total hip arthroplasty surgeries, biopsies were taken from the acetabulum after reaming. The samples (osteochondral cylinders of approximately ⩽1 cm long and 3 mm thickness), after removing the mineral component, were cut longitudinally with a thickness section of 5 µm and colored with hematoxylin-eosin dichromic dye and then evaluated histologically by optical microscopy with 40× magnification. Preoperative radiographs were evaluated.

RESULTS

According to inclusion and exclusion criteria, 14 patients formed the revision group patients (mean age: 67.9 years, average time before revision 8.8 years, SD ± 7.06) and 5 patients formed the control primary group (mean age: 61.4 years). The bone quality of the revision group was generally poorer than the primary group, while similar vitality and bone quality has been found between septic and aseptic group. Variables such as age, gender and BMI did not significantly contribute to define bone quality classes.

CONCLUSIONS

The study confirms the differences in quality and bone vitality between cases and controls and the necessity to find strategies to improve the osteointegrative processes in revision arthroplasties.

Patient-reported outcome measures in osteoarthritis: a systematic search and review of their use and psychometric properties

Introduction

Patient-reported outcome measures (PROM) or self-completed questionnaires have been used to report outcomes in osteoarthritis (OA) for over 35 years. Choices will always need to be made about what should be measured and, if relevant, what would be the most appropriate PROM to use. The current study aims to describe the available PROMs used in OA and their performance quality, so that informed choices can be made about the most appropriate PROM for a particular task.

Methods

The study included a systematic search for PROMs that have been in use over 17 years (period 2000–2016), and to catalogue their psychometric properties, and to present the evidence in a user-friendly fashion.

Results

78 PROMs were identified with psychometric evidence available. The domains of pain, self-care, mobility and work dominated, whereas domains such as cleaning and laundry and leisure, together with psychological and contextual factors, were poorly served. The most frequently used PROMs included the Western Ontario McMaster Osteoarthritis Index, the Short Form 36 and the Knee Disability and Osteoarthritis Outcome Score which, between them, appeared in more than 4000 papers. Most domains had at least one PROM with the highest level of psychometric evidence.

Conclusion

A broad range of PROMs are available for measuring OA outcomes. Some have good psychometric evidence, others not so. Some important psychological areas such as self-efficacy were poorly served. The study provides a current baseline for what is available, and identifies the shortfall in key domains if the full biopsychosocial model is to be explored.

Using the Scoring Hip Osteoarthritis with Magnetic Resonance Imaging (SHOMRI) system to assess intra-articular pathology in femoroacetabular impingement

There is currently no widely accepted classification system of intra-articular damage in the setting of femoroacetabular impingement (FAI). The goal of this study is to correlate the Scoring Hip Osteoarthritis with Magnetic Resonance Imaging (SHOMRI) system with arthroscopic findings in symptomatic FAI patients to justify its use in this setting. Symptomatic FAI patients scheduled for hip arthroscopy were prospectively enrolled. Prior to surgery, radiographs, and an MRI were obtained of the affected hip and all patients completed the Hip disability and Osteoarthritis Outcome Score (HOOS) questionnaire. Each MRI was graded using the SHOMRI system. Intraoperatively, cartilage and labral injury grades were recorded. SHOMRI scores were then correlated with the intraoperative cartilage and labral grades as well as preoperative radiographic findings and HOOS scores. Forty-three patients were analyzed (mean age 35.7 years, 58.1% male). SHOMRI total scores correlated with intraoperative femoral cartilage grade (ρ = 0.42; p = 0.002), acetabular cartilage grade (ρ = 0.30; p = 0.046), and labral tear grade (ρ = 0.42; p = 0.003) as well as with preoperative Tönnis grade (ρ = 0.37, p = 0.013), HOOS pain score (ρ = -0.33; p = 0.039), HOOS ADL score (ρ = -0.39; p = 0.007), and HOOS sports score (ρ = -0.30; p = 0.037). In conclusion, total scores from the SHOMRI system showed significant correlation with arthroscopic findings as well as radiographic gradings and clinical symptoms in patients with FAI. Use of this quantitative system to assess the burden of chondrolabral damage in FAI appears valid. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:3064-3070, 2018.

Magnetic Resonance Imaging Parameters at 1 Year Correlate With Clinical Outcomes Up to 17 Years After Autologous Chondrocyte Implantation

Background:

The ability to predict the long-term success of surgical treatment in orthopaedics is invaluable, particularly in clinical trials. The quality of repair tissue formed 1 year after autologous chondrocyte implantation (ACI) in the knee was analyzed and compared with clinical outcomes over time.

Hypothesis:

Better quality repair tissue and a better appearance on magnetic resonance imaging (MRI) 1 year after ACI lead to improved longer-term clinical outcomes.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

Repair tissue quality was assessed using either MRI (11.5 ± 1.4 [n = 91] or 39.2 ± 18.5 [n = 76] months after ACI) or histology (16.3 ± 11.0 months [n = 102] after ACI). MRI scans were scored using the whole-organ magnetic resonance imaging score (WORMS) and the magnetic resonance observation of cartilage repair tissue (MOCART) score, with additional assessments of subchondral bone marrow and cysts. Histology of repair tissue was performed using the Oswestry cartilage score (OsScore) and the International Cartilage Repair Society (ICRS) II score. Clinical outcomes were assessed using the modified Lysholm score preoperatively, at the time of MRI or biopsy, and at a mean 8.4 ± 3.7 years (maximum, 17.8 years) after ACI.

Results:

At 12 months, the total MOCART score and some of its individual parameters correlated significantly with clinical outcomes. The degree of defect fill, overall signal intensity, and surface of repair tissue at 12 months also significantly correlated with longer-term outcomes. The presence of cysts or effusion (WORMS) significantly correlated with clinical outcomes at 12 months, while the presence of synovial cysts/bursae preoperatively or the absence of loose bodies at 12 months correlated significantly with long-term clinical outcomes. Thirty percent of repair tissue biopsies contained hyaline cartilage, 65% contained fibrocartilage, and 5% contained fibrous tissue. Despite no correlation between the histological scores and clinical outcomes at the time of biopsy, a lack of hyaline cartilage or poor basal integration was associated with increased pain; adhesions visible on MRI also correlated with significantly better histological scores.

Conclusion:

These results demonstrate that MRI at 12 months can predict longer-term clinical outcomes after ACI. Further investigation regarding the presence of cysts, effusion, and adhesions and their relationship with histological and clinical outcomes may yield new insights into the mechanisms of cartilage repair and potential sources of pain.

Using multidimensional topological data analysis to identify traits of hip osteoarthritis

BACKGROUND

Osteoarthritis (OA) is a multifaceted disease with many variables affecting diagnosis and progression. Topological data analysis (TDA) is a state-of-the-art big data analytics tool that can combine all variables into multidimensional space. TDA is used to simultaneously analyze imaging and gait analysis techniques.

PURPOSE

To identify biochemical and biomechanical biomarkers able to classify different disease progression phenotypes in subjects with and without radiographic signs of hip OA.

STUDY TYPE

Longitudinal study for comparison of progressive and nonprogressive subjects.

POPULATION

In all, 102 subjects with and without radiographic signs of hip osteoarthritis.

FIELD STRENGTH/SEQUENCE

3T, SPGR 3D MAPSS T_1ρ /T₂ , intermediate-weighted fat-suppressed fast spin-echo (FSE).

ASSESSMENT

Multidimensional data analysis including cartilage composition, bone shape, Kellgren-Lawrence (KL) classification of osteoarthritis, scoring hip osteoarthritis with MRI (SHOMRI), hip disability and osteoarthritis outcome score (HOOS).

STATISTICAL TESTS

Analysis done using TDA, Kolmogorov-Smirnov (KS) testing, and Benjamini-Hochberg to rank P-value results to correct for multiple comparisons.

RESULTS

Subjects in the later stages of the disease had an increased SHOMRI score (P < 0.0001), increased KL (P = 0.0012), and older age (P < 0.0001). Subjects in the healthier group showed intact cartilage and less pain. Subjects found between these two groups had a range of symptoms. Analysis of this subgroup identified knee biomechanics (P < 0.0001) as an initial marker of the disease that is noticeable before the morphological progression and degeneration. Further analysis of an OA subgroup with femoroacetabular impingement (FAI) showed anterior labral tears to be the most significant marker (P = 0.0017) between those FAI subjects with and without OA symptoms.

DATA CONCLUSION

The data-driven analysis obtained with TDA proposes new phenotypes of these subjects that partially overlap with the radiographic-based classical disease status classification and also shows the potential for further examination of an early onset biomechanical intervention.

LEVEL OF EVIDENCE

2 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;48:1046-1058.

RADIOGRAPHIC HIP OSTEOARTHRITIS IS PREVALENT, AND IS RELATED TO CAM DEFORMITY 12-24 MONTHS POST-HIP ARTHROSCOPY

BACKGROUND

The prevalence of radiographic hip osteoarthritis (OA), and its relationship with outcomes after hip arthroscopy is unclear.

OBJECTIVES

The aims of this study were to: (i) describe the prevalence of OA and cam deformity 12-24 months post hip arthroscopy; (ii) to determine the association between radiographic OA and cam deformity, surgical and clinical findings and symptoms; and (iii) describe the differences between legs for radiological and clinical findings.

STUDY DESIGN

Cross sectional study.

METHODS

Seventy patients, mean age 36.7(range 18-59) years, 12-24 months post-arthroscopy.

MAIN OUTCOME MEASURES

Outcomes were collected prospectively via clinical and radiographic examination. (i)Prevalence of OA and cam deformity measured on and anteroposterior pelvic radiographs; (ii)Hip disability and Osteoarthritis Outcome Score (HOOS) and International Hip Outcome Tool (iHOT-33) patient-reported outcomes (PROs); (iii)hip internal and external rotation range of motion (ROM). Associations between OA and surgical findings, PROs and clinical findings were determined using generalized estimated equations, between operated and non-operated sides.

RESULTS

The prevalence of OA was 37%. The likelihood of OA 12-24 months after surgery was positively associated with alpha angle size 12-24 months post-hip arthroscopy surgery (p=0.010). There were no differences between operated and non-operated legs in radiographic or clinical findings.

CONCLUSION

Radiographic OA is prevalent in a population which has undergone hip arthroscopy. Increased OA severity is associated with a higher alpha angle 12-24 months post-surgery.

LEVEL OF EVIDENCE

Cross-sectional study Level IV.

What is the prevalence of imaging-defined intra-articular hip pathologies in people with and without pain? A systematic review and meta-analysis

BACKGROUND

Intra-articular hip pathologies are thought to be associated with the development of hip and groin pain. A better understanding of the relationship between symptoms and imaging findings may improve the management of individuals with intra-articular hip pathologies.

OBJECTIVE

To undertake a systematic review and meta-analysis to determine the prevalence of intra-articular hip pathologies in individuals with and without pain.

METHODS

Seven electronic databases were searched in February 2017 for studies investigating the prevalence of intra-articular hip pathologies using MRI, MRA or CT. Two independent reviewers conducted the search, study selection, quality appraisal and data extraction. Meta-analysis was performed when studies were deemed homogenous, with a strength of evidence assigned to pooled results.

RESULTS

In general, studies were moderate to high risk of bias, with only five studies adjudged to be low risk of bias. The 29 studies reporting on the prevalence of intra-articular hip pathologies identified limited evidence of a labral tear prevalence of 62% (95% CI 47% to 75%) in symptomatic individuals, with moderate evidence identifying a labral tear prevalence of 54% (95% CI 41% to 66%) in asymptomatic individuals. Limited evidence demonstrated a cartilage defect prevalence of 64% (95% CI 25% to 91%) in symptomatic individuals, compared with moderate evidence of a cartilage defect prevalence of 12% (95% CI 7% to 21%) in asymptomatic individuals.

CONCLUSION

The prevalence of intra-articular hip pathologies is highly variable in both symptomatic and asymptomatic populations. The prevalence of intra-articular hip pathologies appears to be higher in symptomatic individuals. However, imaging-defined intra-articular hip pathologies are also frequently seen in asymptomatic individuals, highlighting a potential discordant relationship between imaging pathology and pain.

PROSPERO REGISTRATION NUMBER

CRD42016035444.

Study of the interactions between proximal femur 3d bone shape, cartilage health, and biomechanics in patients with hip Osteoarthritis

In this study quantitative MRI and gait analysis were used to investigate the relationships between proximal femur 3D bone shape, cartilage morphology, cartilage biochemical composition, and joint biomechanics in subject with hip Osteoarthritis (OA). Eighty subjects underwent unilateral hip MR-imaging: T1ρ and T2 relaxation times were extracted through voxel based relaxometry and bone shape was assessed with 3D MRI-based statistical shape modeling. In addition, 3D gait analysis was performed in seventy-six of the studied subjects. Associations between shape, cartilage lesion presence, severity, and cartilage T1ρ and T2 were analyzed with linear regression and statistical parametric mapping. An ad hoc analysis was performed to investigate biomechanics and shape associations. Our results showed that subjects with a higher neck shaft angle in the coronal plane (higher mode 1, coxa valga), thicker femoral neck and a less spherical femoral head (higher mode 5, pistol grip) exhibited more severe acetabular and femoral cartilage abnormalities, showing different interactions with demographics factors. Subjects with coxa valga also demonstrated a prolongation of T1ρ and T2. Subjects with pistol grip deformity exhibited reduced hip internal rotation angles and subjects with coxa valga exhibited higher peak hip adduction moment and moment impulse. The results of this study establish a clear relationship between 3D proximal femur shape variations and markers of hip joint degeneration-morphological, compositional, well as insight on the possible interactions with demographics and biomechanics, suggesting that 3D MRI-based bone shape maybe a promising biomarker of early hip joint degeneration. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:330-341, 2018.

iPhone Sensors in Tracking Outcome Variables of the 30-Second Chair Stand Test and Stair Climb Test to Evaluate Disability: Cross-Sectional Pilot Study

Background

Performance tests are important to characterize patient disabilities and functional changes. The Osteoarthritis Research Society International and others recommend the 30-second Chair Stand Test and Stair Climb Test, among others, as core tests that capture two distinct types of disability during activities of daily living. However, these two tests are limited by current protocols of testing in clinics. There is a need for an alternative that allows remote testing of functional capabilities during these tests in the osteoarthritis patient population.

Objective

Objectives are to (1) develop an app for testing the functionality of an iPhone’s accelerometer and gravity sensor and (2) conduct a pilot study objectively evaluating the criterion validity and test-retest reliability of outcome variables obtained from these sensors during the 30-second Chair Stand Test and Stair Climb Test.

Methods

An iOS app was developed with data collection capabilities from the built-in iPhone accelerometer and gravity sensor tools and linked to Google Firebase. A total of 24 subjects performed the 30-second Chair Stand Test with an iPhone accelerometer collecting data and an external rater manually counting sit-to-stand repetitions. A total of 21 subjects performed the Stair Climb Test with an iPhone gravity sensor turned on and an external rater timing the duration of the test on a stopwatch. App data from Firebase were converted into graphical data and exported into MATLAB for data filtering. Multiple iterations of a data processing algorithm were used to increase robustness and accuracy. MATLAB-generated outcome variables were compared to the manually determined outcome variables of each test. Pearson’s correlation coefficients (PCCs), Bland-Altman plots, intraclass correlation coefficients (ICCs), standard errors of measurement, and repeatability coefficients were generated to evaluate criterion validity, agreement, and test-retest reliability of iPhone sensor data against gold-standard manual measurements.

Results

App accelerometer data during the 30-second Chair Stand Test (PCC=.890) and gravity sensor data during the Stair Climb Test (PCC=.865) were highly correlated to gold-standard manual measurements. Greater than 95% of values on Bland-Altman plots comparing the manual data to the app data fell within the 95% limits of agreement. Strong intraclass correlation was found for trials of the 30-second Chair Stand Test (ICC=.968) and Stair Climb Test (ICC=.902). Standard errors of measurement for both tests were found to be within acceptable thresholds for MATLAB. Repeatability coefficients for the 30-second Chair Stand Test and Stair Climb Test were 0.629 and 1.20, respectively.

Conclusions

App-based performance testing of the 30-second Chair Stand Test and Stair Climb Test is valid and reliable, suggesting its applicability to future, larger-scale studies in the osteoarthritis patient population.

Pain in osteoarthritis. Implications for optimal management

Pain is an ubiquitous symptom in osteoarticular diseases, occurring much more commonly than stiffness or disability. OA of the knee, hand, or hip affects around 20% of adults in various populations and is dramatically increasing in many countries, mostly related to age and obesity, leading to an increased number of people having OA pain, and creating a huge burden related to disability and health care costs. OA-related pain, has been classically considered to be a nociceptive pain condition. Clinicians have considered pain to be an alarm signal, correlated to the intensity of joint degradation. In OA, most authors have focused their studies on joint architecture and local degradation, considering pain as only a symptom, a consequence of joint damage. However, OA-related pain is a specific disease, with a complex pathophysiology, including neuropathic peripheral and central abnormalities, together with local inflammation involving all joint structures. Clinical findings emphasize that it is not a stable and linear condition, that pain experience is independent of structural modifications, and that the quality of pain in OA is important to consider, aside from its intensity. OA-related pain is modulated by many factors, including the individual patient's psychological and genetic factors, as well as the theoretical role of meteorological influences. Recent neuroimaging findings have improved our knowledge about central mechanisms of OA pain, especially in persistent cases.

Joint Loading in the Sagittal Plane During Gait Is Associated With Hip Joint Abnormalities in Patients With Femoroacetabular Impingement

BACKGROUND

Femoroacetabular impingement (FAI) is a morphological abnormality of the hip joint that results in functional impairments during various activities of daily living (ADL) such as walking. Purpose/Hypothesis: The purpose of this study was to determine if lower extremity joint loading differed between patients with FAI and controls and to determine whether these altered biomechanical parameters were associated with intra-articular abnormalities. It was hypothesized that patients with FAI would exhibit altered lower extremity joint loading during walking when compared with healthy controls and that these altered joint loading patterns would be associated with intra-articular abnormalities.

STUDY DESIGN

Controlled laboratory study.

METHODS

Lower extremity kinetics was assessed during walking at a self-selected speed in 15 presurgical patients with FAI and 34 healthy controls matched for age and body mass index. All participants underwent unilateral hip magnetic resonance imaging (MRI) to assess hip joint abnormalities. Hip joint abnormalities were assessed using a semiquantitative MRI-based scoring system. Self-reported outcomes of pain and function were obtained using the Hip disability and Osteoarthritis Outcome Score (HOOS), and physical performance was measured using the 6-minute walk test (6MWT). Group differences were assessed using an independent t test and analysis of variance. In the patients with FAI, associations of joint kinetics with HOOS subscores and intra-articular abnormalities were assessed using the Pearson ( r) and Spearman (ρ) correlation coefficients, respectively.

RESULTS

Compared with the control group, the FAI group exhibited a significantly increased severity of acetabular (FAI: 1.87 ± 1.55; control: 0.47 ± 0.79; P < .001) and femoral (FAI: 3.27 ± 2.79; control: 1.21 ± 1.55; P = .002) cartilage abnormalities, increased levels of pain (FAI: 65.0 ± 18.8; control: 98.2 ± 3.4; P = .001), and reduced function (FAI: 67.2 ± 21.5; control: 98.9 ± 3.4; P < .001) but similar walking speeds (FAI: 1.55 ± 0.19 m/s; control: 1.63 ± 0.22 m/s; P = .20) and 6MWT performance (FAI: 628.0 ± 91.2 m; control: 667.2 ± 73.4 m; P = .13). The FAI group demonstrated increased hip flexion moment impulses (FAI: 0.14 ± 0.04 N·m·s/kg; control: 0.11 ± 0.03 N·m·s/kg; P = .03), peak ankle dorsiflexion moments (FAI: 1.64 ± 0.16 N·m/kg; control: 1.46 ± 0.31 N·m/kg; P = .04), and ankle dorsiflexion moment impulses (FAI: 0.39 ± 0.07 N·m·s/kg; control: 0.31 ± 0.07 N·m·s/kg; P = .01) compared with the control group. Within the FAI group, an increased hip flexion moment impulse during walking was significantly correlated with increased pain ( r = -0.60, P = .03), decreased ADL ( r = -0.57, P = .04), and increased severity of acetabular cartilage abnormalities (ρ = 0.82, P < .01).

CONCLUSION

Patients with FAI exhibited altered hip and ankle joint loading patterns during walking. These data suggest that patients with FAI demonstrate both local and distal joint alterations during walking and that hip joint loading is directly related to hip joint abnormalities.

CLINICAL RELEVANCE

The results of this study suggest that the hip flexion moment impulse may be an important biomechanical parameter to understand FAI, as the hip flexion moment impulse during walking was shown to be directly related to hip joint abnormalities on MRI.