Correlations between radiographic assessments and MRI features of knee osteoarthritis--a cross-sectional study

The Value of Ultrasound Diagnostic Imaging of Meniscal Knee Injuries Verified by Experimental and Arthroscopic Investigations

(1) Introduction: Meniscal knee injuries may develop as the result of trauma or overloading. Ultrasound imaging is an observer-dependent modality, meaning that the assessment of structural damage depends on the investigator's experience.. None of the published papers provides a standardized method for ultrasound examination of knee menisci. The main goal of this study is to realize and standardize ultrasound imaging diagnostics of meniscal knee injuries based on individual features of ultrasound presentation and to evaluate the applicability of this modality in clinical practice. (2) Material and methods: This study consisted of two anatomical parts, including a clinical part that started with clinical examination of 50 patients with suspected meniscal knee injuries. After this we performed ultrasound examinations in patients with positive clinical test results, using sonographic confirmation for inclusion in the next stage. Finally, knee arthroscopy by two physicians in an operating room was performed, with procedures documented through photographs and video recordings, and analytic material obtained from patients in the control group documented similarly. (3) Results: In the clinical part of the study, arthroscopic examination revealed 13 longitudinal injuries (corresponding to 36% of all injuries in the group), 14 multidirectional injuries (corresponding to 28% of all injuries), 3 radial injuries (corresponding to 6% of all injuries), and 20 oblique injuries (corresponding to 40% of all injuries). The analysis of the sensitivity and specificity of the diagnostic test in terms of recognizing actual meniscal injuries on the basis of full-thickness or partial-thickness delamination, meniscal cyst oedema, and articular space stenosis revealed that the presence of at least two of these three characteristics was associated with the sensitivity of 88% and the specificity of 86% relative to the number of actual meniscal injuries as seen in arthroscopic examination. (4) Conclusions: Research results confirm that clinical examination combined with ultrasound imaging is a very efficient tool for evaluation of meniscal injuries.

Exploring the differences between radiographic joint space width and MRI cartilage thickness changes using data from the IMI-APPROACH cohort

OBJECTIVE

Longitudinal weight-bearing radiographic joint space width (JSW) and non-weight-bearing MRI-based cartilage thickness changes often show weak correlations. The current objective was to investigate these correlations, and to explore the influence of different factors that could contribute to longitudinal differences between the two methods.

METHODS

The current study included 178 participants with medial osteoarthritis (OA) out of the 297 knee OA participants enrolled in the IMI-APPROACH cohort. Changes over 2 years in medial JSW (ΔJSWmed), minimum JSW (ΔJSWmin), and medial femorotibial cartilage thickness (ΔMFTC) were assessed using linear regression, using measurements from radiographs and MRI acquired at baseline, 6 months, and 1 and 2 years. Pearson R correlations were calculated. The influence of cartilage quality (T2 mapping), meniscal extrusion (MOAKS scoring), potential pain-induced unloading (difference in knee-specific pain scores), and increased loading (BMI) on the correlations was analyzed by dividing participants in groups based on each factor separately, and comparing correlations (slope and strength) between groups using linear regression models.

RESULT

Correlations between ΔMFTC and ΔJSWmed and ΔJSWmin were statistically significant (p < 0.004) but weak (R < 0.35). Correlations were significantly different between groups based on cartilage quality and on meniscal extrusion: only patients with the lowest T2 values and with meniscal extrusion showed significant moderate correlations. Pain-induced unloading or BMI-induced loading did not influence correlations.

CONCLUSIONS

While the amount of loading does not seem to make a difference, weight-bearing radiographic JSW changes are a better reflection of non-weight-bearing MRI cartilage thickness changes in knees with higher quality cartilage and with meniscal extrusion.

Do Ahlbäck scores identify subgroups with different magnitudes of cartilage thickness loss in patients with moderate to severe radiographic osteoarthritis? One-year follow-up data from the Osteoarthritis Initiative

OBJECTIVE

Kellgren-Lawrence grades (KLG) are frequently used for patient selection in clinical trials. The Ahlbäck radiographic grading system has been developed for moderate and severe knee OA. KLG 3 is comparable to Ahlbäck 1 and KLG 4 is subdivided into Ahlbäck 2-5. The objective of this study was to investigate if the Ahlbäck scoring system is able to subdivide patients with moderate to severe knee OA (KLG 3/4) into groups with different sensitivity to change in cartilage thickness.

MATERIALS AND METHODS

This study was based on 108 Osteoarthritis Initiative (OAI) participants with KLG 3/4. Baseline KLG scores were available from the OAI database; Ahlbäck scores were performed using the same x-rays. Cartilage thickness change in the weight-bearing femorotibial cartilage was analysed from baseline and year 1 3D FLASH MRI for the entire femorotibial joint (FTJ), the medial (MFTC) and the lateral compartment (LFTC) and for the location-independent ordered values 1 and 16 (OV 1/OV 16) representing the subregions with largest loss (OV 1) and gain (OV 16) within each knee.

RESULTS

Of the 108 patients, n = 30/78 had KLG 3/4. The corresponding Ahlbäck scores (1-5) were n = 30/33/36/9/10. Cartilage thickness changes between Ahlbäck groups showed no statistically significant difference for FTJ, MFTC, LFTC and OV 1, but change in OV 16 was significantly higher in Ahlbäck 4 knees (p = 0.03) compared to Ahlbäck 1-3 knees.

CONCLUSION

Radiographic knee OA grading with Ahlbäck scores was not superior to KLG for prediction of cartilage thickness loss over 1 year, in patients with moderate and severe knee OA supporting the continuous use of the easier and more widely used KLG.

Comparison between 2D radiographic weight-bearing joint space width and 3D MRI non-weight-bearing cartilage thickness measures in the knee using non-weight-bearing 2D and 3D CT as an intermediary

Background:

In knee osteoarthritis, radiographic joint space width (JSW) is frequently used as a surrogate marker for cartilage thickness; however, longitudinal changes in radiographic JSW have shown poor correlations with those of magnetic resonance imaging (MRI) cartilage thickness. There are fundamental differences between the techniques: radiographic JSW represents two-dimensional (2D), weight-bearing, bone-to-bone distance, while on MRI three-dimensional (3D) non-weight-bearing cartilage thickness is measured. In this exploratory study, computed tomography (CT) was included as a third technique, as it can measure bone-to-bone under non-weight-bearing conditions. The objective was to use CT to compare the impact of weight-bearing versus non-weight-bearing, as well as bone-to-bone JSW versus actual cartilage thickness, in the knee.

Methods:

Osteoarthritis patients (n = 20) who were treated with knee joint distraction were included. Weight-bearing radiographs, non-weight-bearing MRIs and CTs were acquired before and 2 years after treatment. The mean radiographic JSW and cartilage thickness of the most affected compartment were measured. From CT, the 3D median JSW was calculated and a 2D projectional image was rendered, positioned similarly and measured identically to the radiograph. Pearson correlations between the techniques were derived, both cross-sectionally and longitudinally.

Results:

Fourteen patients could be analyzed. Cross-sectionally, all comparisons showed moderate to strong significant correlations (R = 0.43–0.81; all p < 0.05). Longitudinal changes over time were small; only the correlations between 2D CT and 3D CT (R = 0.65; p = 0.01) and 3D CT and MRI (R = 0.62; p = 0.02) were statistically significant.

Conclusion:

The poor correlation between changes in radiographic JSW and MRI cartilage thickness appears primarily to result from the difference in weight-bearing, and less so from measuring bone-to-bone distance versus cartilage thickness.

Kellgren & Lawrence grading in cohort studies: methodological update and implications illustrated using data from the CHECK cohort

Objective

The Cohort Hip and Cohort Knee (CHECK) is a cohort of middle‐aged individuals with hip or knee pain. Radiographs were assigned Kellgren/Lawrence (K/L) scores under different conditions at each follow‐up visit for 10 years. We aimed to describe and consolidate each scoring approach, then illustrate implications of their use by comparing baseline K/L scores assigned using 2 of these approaches, and evaluating their respective associations with joint replacement and incident radiographic osteoarthritis (ROA).

Methods

We compared baseline K/L scores assigned to hips and knees using 2 scoring approaches: 1) assigned by senior researchers to baseline images alone and 2) assigned by trained readers, with images read paired and in known sequence with up to 10 years of follow‐up radiographs (Poisson regression). We evaluated the associations of baseline ROA (any: K/L grade ≥1; established: K/L ≥2) with joint replacement, and of K/L 1 joints with incident established ROA (survival analysis).

Results

Of 1,002 participants (79% women, mean ± SD age 55.9 ± 5.2 years, body mass index 26.2 ± 4.0 kg/m²), the second scoring approach had 2.4 times (95% confidence interval [95% CI] 1.8–3.1 for knees) and 2.9 times (95% CI 2.3–3.7 for hips) higher prevalence of established ROA than the first approach. Established hip ROA had a higher risk of joint replacement using the first approach (hazard ratio [HR] 24.2 [95% CI 15.0–39.8] versus second approach HR 7.7 [95% CI 4.9–12.1]), as did knees (HR 19.3 [95% CI 10.3–36.1] versus second approach HR 4.8 [95% CI 2.4–9.6]). The risk of incident ROA did not differ by approach.

Conclusion

This study demonstrates that evaluating ROA prevalence and predicting outcomes depends on the scoring approach.

Effect of vitamin D supplementation on pain and physical function in patients with knee osteoarthritis (OA): an OA Trial Bank protocol for a systematic review and individual patient data (IPD) meta-analysis

INTRODUCTION

Observational data suggest that vitamin D deficiency is associated with the onset and progression of knee osteoarthritis (OA). However, randomised controlled trials (RCTs) to date investigating the efficacy of vitamin D supplementation in knee OA have reported conflicting results. Further research is needed to clarify the effects of vitamin D on patient-reported outcomes and determine whether there are patient subgroups who may benefit from the supplementation. The aim of this individual patient data (IPD) meta-analysis is to identify patient-level predictors of treatment response to vitamin D supplementation on pain and physical function.

METHODS AND ANALYSIS

A systematic literature search will be conducted for RCTs of vitamin D supplementation on knee OA. Authors of original RCTs will be contacted to obtain the IPD. The primary outcomes will include long-term (≥12 months) pain and physical function. Secondary outcomes will include medium-term (≥6 months and <12 months) and short-term (<6 months) pain and physical function, as well as patient global assessment, quality of life and adverse events. Potential treatment effect modifiers to be examined in the subgroup analyses include age, gender, body mass index, baseline knee pain severity and physical function, baseline vitamin D level, radiographic stage, presence of bone marrow lesions on MRI, presence of clinical signs of local inflammation and concomitant depressive symptoms. Both one-step and two-step modelling methods will be used to determine the possible modifiable effect of each subgroup of interest.

ETHICS AND DISSEMINATION

Research ethical or governance approval is exempt for this study as no new data are being collected. This study will be the first IPD meta-analysis to clarify the effect of vitamin D supplementation on clinical symptoms in different subgroups of patients with knee OA. The findings will be disseminated through peer-review publications and conference presentations.

PROSPERO REGISTRATION NUMBER

CRD42018107740.

The association of leg length and offset reconstruction after total hip arthroplasty with clinical outcomes

BACKGROUND

Restoring native hip anatomy and biomechanics is important to create a well-functioning hip arthroplasty. This study investigated the association of hip offset and leg length after hip arthroplasty with clinical outcomes, including patient reported outcome measures, the Trendelenburg Test and gait analysis.

METHODS

In 77 patients undergoing primary hip arthroplasty for osteoarthritis (age mean = 65 SD = 11 years; BMI mean = 27 SD = 5 kg/m²), hip offset and leg length discrepancy were measured on anteroposterior radiographs. The Western Ontario & McMaster Universities Osteoarthritis Index, the Trendelenburg Test and gait were assessed preoperatively, and at 3 and 12 months postoperatively. An inertial measurement unit was used to derive biomechanical parameters, including spatiotemporal gait parameters and tilt angles of the pelvis. Relationships between radiographic and functional outcomes were investigated, and subgroups of patients with >15% decreased and increased femoral offset were analysed separately.

FINDINGS

Patient-reported function scores and clinical tests demonstrated a few significant, weak correlations with radiographic outcomes (Spearman's ρ range = 0.26-0.32; p < 0.05). Undercorrection of femoral offset was associated with lower patient-reported function scores and with more step irregularity as well as step asymmetry during gait. Postoperative leg length inequality was associated with increased frontal plane tilt angle of the pelvis during the Trendelenburg Test and increased sagittal plane motion of the pelvis during gait. Femoral offset subgroups demonstrated no significant differences for patient-reported function scores and outcomes of the Trendelenburg Test and gait analysis.

INTERPRETATION

Reduced hip offset and leg length discrepancy following hip arthroplasty seem to be marginally associated with worse clinical outcomes.

Relationship Between Varus Thrust During Gait and Low Back Pain in Individuals With Knee Osteoarthritis

OBJECTIVE

To test the hypothesis that varus thrust visualized during gait is associated with a higher prevalence of low back pain (LBP) in individuals with knee osteoarthritis (OA).

METHODS

Individuals with knee OA (Kellgren/Lawrence grade ≥1) underwent a gait observation to assess varus thrust. The participants identified LBP and its severity using questionnaires. Logistic regression analyses were performed to examine the association between varus thrust and LBP.

RESULTS

We included 205 participants (mean age 68.19 years; 72.20% women). A total of 45 participants (22.0%) showed varus thrust in their painful knee, in whom 31 (68.89%) and 18 (40.00%) were identified as having any LBP and moderate-to-severe LBP (numerical rating scale ≥4 points), respectively. Patients with varus thrust demonstrated a 3.6-fold higher risk of the presence of moderate-to-severe LBP (95% confidence interval [95% CI] 1.62-8.10). In patients with LBP, the presence of varus thrust was associated with more severe LBP intensity (proportional odds ratio 2.25 [95% CI 1.02-4.96]).

CONCLUSION

This study highlights the novel relationship between varus thrust and LBP, which supports the idea of a biomechanical link, the so-called knee-spine syndrome. These findings provide new insight for clarifying the pathogenesis of LBP related to knee OA.

The association of frontal plane alignment to MRI-defined worsening of patellofemoral osteoarthritis: the MOST study

OBJECTIVE

To determine the sex-specific relation of frontal plane alignment (FPA) to magnetic resonance imaging (MRI)-defined features of patellofemoral osteoarthritis, and also to tibiofemoral osteoarthritis and knee pain.

METHOD

The Multicenter Osteoarthritis Study is cohort study comprised of individuals with or at risk of knee osteoarthritis. We determined the sex-specific dose-response relation of baseline FPA to MRI-defined patellofemoral and tibiofemoral structural worsening, and incident knee pain, over 7 years.

RESULTS

In women only, greater varus alignment was associated with medial patellofemoral osteophytes (risk ratio [RR] 1.7 [95% CI 1.2, 2.6]) and valgus with lateral patellofemoral osteophytes (RR 1.9 [1.0, 3.6]). In men, greater varus increased risk for medial tibiofemoral cartilage worsening (RR 1.7 [1.1, 2.6]), and valgus for lateral tibiofemoral cartilage worsening (RR 1.8 [1.6, 2.2]). In women, findings were similar for tibiofemoral cartilage, but varus also increased risk for medial bone marrow lesions [BMLs] (RR 2.2 [1.6, 3.1]) and medial osteophytes (RR 1.8 [1.3, 2.5]), and valgus for lateral BMLs (RR 3.3 [2.2, 4.5]) and osteophytes (RR 2.0 [1.2, 3.2]). Varus increased risk of incident pain in men (RR 1.7 [1.4, 2.2]) and women (RR 1.3 [1.0, 1.6]), valgus did so in men only (RR 1.5 [1.1, 1.9]).

CONCLUSION

FPA was associated with patellofemoral osteophyte worsening in women, though overall was more strongly associated with tibiofemoral than patellofemoral osteoarthritis feature worsening. FPA in women was more consistently associated with structural worsening, yet men had higher associations with incident pain.

Quadriceps Weakness in Individuals with Coexisting Medial and Lateral Osteoarthritis

Background

This study examined whether individuals who have mild medial osteoarthritis (OA) of the knee with coexisting lateral OA have less muscle strength than individuals who do not have lateral OA.

Methods

A series of 153 individuals (84% of whom were women) between 48 and 88 years old who had Kellgren and Lawrence (KL) grade-2 OA in the medial compartment of the knee underwent radiographic evaluation to assess the presence of lateral OA, which was graded with the system of the Osteoarthritis Research Society International (OARSI) atlas as well as the KL system. The isometric maximum strengths of the quadriceps, the hip abductors, and the hip extensors were evaluated with use of a handheld dynamometer.

Results

Individuals who had coexisting medial and lateral OA had more severe knee pain and weaker quadriceps than those who did not have lateral OA. The study adjusted for age and sex both for the OARSI atlas system (adjusted difference in mean strength: 0.272 Nm/kg, 95% confidence interval [CI]: 0.143 to 0.401 Nm/kg) and for KL grading (adjusted difference in mean strength: 0.185 Nm/kg, 95% CI: 0.061 to 0.309 Nm/kg). Logistic regression analysis showed that weakness of the quadriceps increased the odds of the presence of lateral OA sevenfold after adjustments using the OARSI atlas were made for age, sex, anatomical axis, range of motion of the knee, and intensity of pain in the knee.

Conclusions

Individuals who had coexisting medial and lateral OA had weaker quadriceps than individuals who had mild medial OA alone. Paying close attention to quadriceps weakness might provide a key to clarifying the pathogenesis of bicompartmental disease in the tibiofemoral joint.

Level of Evidence

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Ageing and Osteoarthritis

The increase in global lifespan has in turn increased the prevalence of osteoarthritis which is now the most common type of arthritis. Cartilage tissue located on articular joints erodes during osteoarthritis which causes pain and may lead to a crippling loss of function in patients. The pathophysiology of osteoarthritis has been understudied and currently no disease modifying treatments exist. The only current end-point treatment remains joint replacement surgery. The primary risk factor for osteoarthritis is age. Clinical and basic research is now focused on understanding the ageing process of cartilage and its role in osteoarthritis. This chapter will outline the physiology of cartilage tissue, the clinical presentation and treatment options for the disease and the cellular ageing processes which are involved in the pathophysiology of the disease.

Coexisting lateral tibiofemoral osteoarthritis is associated with worse knee pain in patients with mild medial osteoarthritis

OBJECTIVE

To examine the clinical impact of coexisting lateral osteoarthritis (OA) in knees with mild medial OA.

DESIGN

In patients with Kellgren/Lawrence (K/L) grade 2 OA in the medial compartment (n = 100; age: 56-89 years; 80.0% female), anteroposterior knee radiography was used to assess the presence of lateral OA, using grading systems from the Osteoarthritis Research Society International (OARSI) atlas and the K/L classification. The Japanese Knee Osteoarthritis Measure (JKOM), knee range of motion (ROM), and performance-based functional measures (10 m walk, timed up and go and five repetition chair stand maneuvers) were evaluated. The outcomes were compared between patients with and without lateral OA using an analysis of covariance (ANCOVA) or nonparametric rank ANCOVA. Furthermore, ordinal logistic regression analysis was performed, with responses on individual JKOM pain questionnaires as the outcomes and lateral OA as the predictor.

RESULTS

Knees with coexisting lateral OA had a significantly worse score of JKOM pain question compared with those without, after adjusting for covariates. The presence of lateral OA was significantly associated with knee pain while ascending/descending stairs and standing. These results were consistent between different definitions of the K/L and OARSI grading systems. The knee ROM and performance-based functional measures were not significantly different between patients with and without lateral OA.

CONCLUSION

Knees with concomitant lateral and mild medial OA may be more symptomatic compared to those without lateral OA. These findings might help to define a clinically distinct subgroup based on a simple radiographic finding in mild knee OA.

Severity and distribution of cartilage damage and bone marrow edema in the patellofemoral and tibiofemoral joints in knee osteoarthritis determined by MRI

The aim of the present study was to analyze the distribution and severity of cartilage damage (CD) and bone marrow edema (BME) of the patellofemoral and tibiofemoral joints (PFJ and TFJ, respectively) in patients with knee osteoarthritis (OA), and to determine whether a correlation exists between BME and CD in knee OA, using magnetic resonance imaging (MRI). Forty-five patients diagnosed with knee OA (KOA group) and 20 healthy individuals (control group) underwent sagittal multi-echo recalled gradient echo sequence scans, in addition to four conventional MR sequence scans. Knee joints were divided into 15 subregions by the whole-organ MRI scoring method. MRIs of each subregion were analyzed for the presence of CD, CD score and BME score. The knee joint activity functional score was determined using the Western Ontario and McMaster Universities Arthritis Index (WOMAC) in the KOA group. Statistical analyses were used to compare the CD incidence; CD score and BME score between the PFJ and TFJ. Whether a correlation existed among body mass index, BME score, WOMAC pain score and CD score was also examined. Among the 675 subregions analyzed in the KOA group, 131 exhibited CD (CD score, 1-6). These 131 subregions were primarily in the PFJ (80/131, 61.07%), with the remainder in the TFJ (51/131, 38.93%). Thirty-three subregions had a CD score of 1, including 24 PFJ subregions (72.73%) and 9 TFJ subregions (27.27%). Among the 103 subregions with BME, the PFJ accounted for 60 (58.25%) and the TFJ for 43 (41.75%). A significant positive correlation was found between the BME and CD scores. In conclusion, CD and BME occurred earlier and more often in the PFJ compared to the TFJ in knee OA, and BME is an indirect sign of CD.

Osteoarthritis year in review 2016: imaging

PURPOSE

The current narrative review covers original research related to imaging in osteoarthritis (OA) in humans published in English between April 1st 2015 and March 31st 2016, in peer reviewed journals available in Medline via PubMed (http://www.ncbi.nlm.nih.gov/pubmed/).

METHODS

Relevant studies in humans, subjectively decided by the authors, contributing significantly to the OA imaging field, were selected from an extensive Medline search using the terms "Osteoarthritis" in combination with "MRI", "Imaging", "Radiography", "X-rays", "Ultrasound", "Computed tomography", "Nuclear medicine", "PET-CT", "PET-MRI", "Scintigraphy", "SPECT". Publications were sorted according to relevance for the OA imaging research community with an emphasis on high impact special interest journals using the software for systematic reviews www.covidence.org.

RESULTS

An overview of newly published studies compared to studies reported previous years is presented, followed by a review of selected imaging studies of primarily knee, hip and hand OA focussing on (1) results for detection of OA and OA-related pathology (2) studies dealing with treatments and (3) studies focussing on prognosis of disease progression or joint replacement. A record high number of 1420 articles were published, among others, of new technologies and tools for improved morphological and pathophysiological understanding of OA-related changes in joints. Also, imaging data were presented of monitoring treatment effect and prognosis of OA progression, primarily using established radiographic, magnetic resonance imaging (MRI), and ultrasound (US) methods.

CONCLUSION

Imaging continues to play an important role in OA research, where several exciting new technologies and computer aided analysis methods are emerging to complement the conventional imaging approaches.

Assessment of physical function following total hip arthroplasty: Inertial sensor based gait analysis is supplementary to patient-reported outcome measures

BACKGROUND

Functional outcome assessment after total hip arthroplasty often involves subjective patient-reported outcome measures whereas analysis of gait is more objective. The study's aims were to compare subjective and objective functional outcomes after total hip arthroplasty between patients with low and high self-reported levels of pre-operative physical function.

METHODS

Patients undergoing total hip arthroplasty (n=36; m/f=18/18; mean age=63.9; SD=9.8 years; BMI=26.3; SD=3.5) were divided into a low and high function subgroup, and prospective measures of WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) function score and gait were compared at baseline and 3 and 12 months post-operatively.

FINDINGS

WOMAC function scores significantly improved in both low and high function subgroups at 3 months post-operatively whereas gait parameters only improved in patients with a low pre-operative function. Between 3 and 12 months post-operatively, WOMAC function scores had not significantly further improved whereas several gait parameters significantly improved in the low function group. WOMAC function scores and gait parameters were only moderately correlated (Spearman's r=0.33-0.51).

INTERPRETATION

In a cohort of patients undergoing total hip arthroplasty, pre-operative differences in mean WOMAC function scores and gait parameters between low and high function subgroups disappeared by 3 months post-operatively. Gait parameters only improved significantly during the first 3 post-operative months in patients with a low pre-operative function, highlighting the importance of investigating relative changes rather than the absolute changes and the need to consider patients with high and low functions separately.

Effects of an unloader knee brace on knee-related symptoms and function in people with post-traumatic knee osteoarthritis after anterior cruciate ligament reconstruction

BACKGROUND AND PURPOSE

This pilot study evaluated the immediate and four-week effects of an unloader knee brace on knee-related symptoms and performance-based function in people with knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR).

METHODS

Individuals with knee OA, five to 20years post-ACLR, were recruited for two within-subject randomized studies: immediate effects (n=18) and four-week effects (n=11). Patient-reported knee-related symptoms (knee pain, perceived task difficulty, confidence, stability) were assessed during hop for distance and step-down tests, while performance-based function was assessed with hopping distance under three conditions: i) no brace; ii) unadjusted brace (sagittal plane support); and iii) adjusted brace (sagittal plane support with varus/valgus readjustment). Participants in the four-week brace effect study were randomized to wear the unadjusted or adjusted brace for four weeks after baseline (no brace) testing, and repeated tests in their allocated brace at four-week follow-up. Friedman tests evaluated differences between the three brace conditions for each variable for the immediate brace effect study (p<0.05), and Wilcoxon signed-rank tests evaluated differences between no brace and allocated brace for the four-week study (p<0.05).

RESULTS

The adjusted and unadjusted unloader braces produced immediate improvements in knee confidence during hop for distance, and knee pain during step-down. Following the four-week brace intervention, the allocated brace improved knee confidence, perceived task difficulty and stability during hop for distance; and knee pain, perceived task difficulty, confidence, and stability during step-down.

CONCLUSIONS

The unloader knee brace, adjusted or unadjusted, has the potential to improve knee-related symptoms associated with knee OA after ACLR.

A systematic review of the relationship between subchondral bone features, pain and structural pathology in peripheral joint osteoarthritis

INTRODUCTION

Bone is an integral part of the osteoarthritis (OA) process. We conducted a systematic literature review in order to understand the relationship between non-conventional radiographic imaging of subchondral bone, pain, structural pathology and joint replacement in peripheral joint OA.

METHODS

A search of the Medline, EMBASE and Cochrane library databases was performed for original articles reporting association between non-conventional radiographic imaging-assessed subchondral bone pathologies and joint replacement, pain or structural progression in knee, hip, hand, ankle and foot OA. Each association was qualitatively characterised by a synthesis of the data from each analysis based upon study design, adequacy of covariate adjustment and quality scoring.

RESULTS

In total 2456 abstracts were screened and 139 papers were included (70 cross-sectional, 71 longitudinal analyses; 116 knee, 15 hip, six hand, two ankle and involved 113 MRI, eight DXA, four CT, eight scintigraphic and eight 2D shape analyses). BMLs, osteophytes and bone shape were independently associated with structural progression or joint replacement. BMLs and bone shape were independently associated with longitudinal change in pain and incident frequent knee pain respectively.

CONCLUSION

Subchondral bone features have independent associations with structural progression, pain and joint replacement in peripheral OA in the hip and hand but especially in the knee. For peripheral OA sites other than the knee, there are fewer associations and independent associations of bone pathologies with these important OA outcomes which may reflect fewer studies; for example the foot and ankle were poorly studied. Subchondral OA bone appears to be a relevant therapeutic target.

SYSTEMATIC REVIEW

PROSPERO registration number: CRD 42013005009.

Classification of histologically scored human knee osteochondral plugs by quantitative analysis of magnetic resonance images at 3T

This work evaluates the ability of quantitative MRI to discriminate between normal and pathological human osteochondral plugs characterized by the Osteoarthritis Research Society International (OARSI) histological system. Normal and osteoarthritic human osteochondral plugs were scored using the OARSI histological system and imaged at 3 T using MRI sequences producing T1 and T2 contrast and measuring T1, T2, and T2* relaxation times, magnetization transfer, and diffusion. The classification accuracies of quantitative MRI parameters and corresponding weighted image intensities were evaluated. Classification models based on the Mahalanobis distance metric for each MRI measurement were trained and validated using leave-one-out cross-validation with plugs grouped according to OARSI histological grade and score. MRI measurements used for classification were performed using a region-of-interest analysis which included superficial, deep, and full-thickness cartilage. The best classifiers based on OARSI grade and score were T1- and T2-weighted image intensities, which yielded accuracies of 0.68 and 0.75, respectively. Classification accuracies using OARSI score-based group membership were generally higher when compared with grade-based group membership. MRI-based classification--either using quantitative MRI parameters or weighted image intensities--is able to detect early osteoarthritic tissue changes as classified by the OARSI histological system. These findings suggest the benefit of incorporating quantitative MRI acquisitions in a comprehensive clinical evaluation of OA.

Age-related impairment of quality of joint motion in vibroarthrographic signal analysis

Aging is associated with degenerative changes in articular surfaces leading to quantitative and qualitative impairment of joint motion. Therefore, the aim of this study is to evaluate an age-related quality of the patellofemoral joint (PFJ) motion in the vibroarthrographic (VAG) signal analysis. Two hundred and twenty individuals were enrolled in this study and divided into five groups according to age. The VAG signals were collected during flexion/extension knee motion using an acceleration sensor and described using four parameters (VMS, P1, P2, and H). We observed that values of parameters VMS, P1, and P2 increase in accordance with the age, but H level decreases. The most significant differences were achieved between the youngest and the oldest participants' groups. Moreover, we show that parameters VMS, P1, and P2 positively correlate with age, contrary to negatively associated H parameter. Our results suggest that the impairment of joint motion is a result of age-related osteoarticular degenerative changes.

Joint motion quality in vibroacoustic signal analysis for patients with patellofemoral joint disorders

BACKGROUND

Chondromalacia, lateral patellar compression syndrome and osteoarthritis are common patellofemoral joint disorders leading to functional and/or structural disturbances in articular surfaces. The objective of the study was to evaluate their impact on joint motion quality via the vibroacoustic signal generated during joint movement analysis.

METHODS

Seventy-three patients (30 with chondromalacia, 21 with lateral patellar compression syndrome, and 22 with osteoarthritis) and 32 healthy controls were tested during flexion/extension knee motion for vibroacoustic signals using an acceleration sensor. Estimated parameters: variation of mean square (VMS), difference between mean of four maximum and mean of four minimum values (R4), power spectral density for frequency of 50-250 Hz (P1) and 250-450 Hz (P2) were analyzed.

RESULTS

Vibroacoustic signals recorded for particular disorders were characterized by significantly higher values of parameters in comparison to the control group. Moreover, differences were found among the various types of patellofemoral joint disturbances. Chondromalacia and osteoarthritis groups showed differences in all parameters examined. In addition, osteoarthritis patients exhibited differences in VMS, P1 and P2 values in comparison to lateral patellar compression syndrome patients. However, only the value of R4 was found to differ between knees with lateral patellar compression syndrome and those with chondromalacia.

CONCLUSION

Our results suggest that particular disorders are characterized by specific vibroacoustic patterns of waveforms as well as values of analyzed parameters.

An ultrasound score for knee osteoarthritis: a cross-sectional validation study

OBJECTIVE

To develop standardized musculoskeletal ultrasound (MUS) procedures and scoring for detecting knee osteoarthritis (OA) and test the MUS score's ability to discern various degrees of knee OA, in comparison with plain radiography and the 'Knee injury and Osteoarthritis Outcome Score' (KOOS) domains as comparators.

METHOD

A cross-sectional study of MUS examinations in 45 patients with knee OA. Validity, reliability, and reproducibility were evaluated.

RESULTS

MUS examination for knee OA consists of five separate domains assessing (1) predominantly morphological changes in the medial compartment, (2) predominantly inflammation in the medial compartment, (3) predominantly morphological changes in the lateral compartment, (4) predominantly inflammation in the lateral compartment, and (5) effusion. MUS scores displayed substantial reliability and reproducibility, with interclass correlations coefficients ranging from 0.75 to 0.97 for the five domains. Construct validity was confirmed with statistically significant correlation coefficients (0.47-0.81, P < 0.01).

CONCLUSION

The MUS score suggested in this study was reliable and valid in detecting knee OA. In comparison with standing radiographs of the knees, the score detected all aspects of knee OA with relevant precision.

Métodos de análise da composição corporal em adultos obesos

Os métodos de avaliação da composição corporal em obesos têm sido amplamente discutidos, uma vez que nesses indivíduos a avaliação é dificultada devido às limitações dos equipamentos e características dos métodos utilizados. Esta sessão temática tem o objetivo de esclarecer as características, vantagens e limitações dos métodos de avaliação da composição corporal em adultos obesos. A quantificação de gordura corporal e mas-sa livre de gordura, assim como a avaliação da perda de massa muscular e de massa óssea em obesos são temas de grande interesse científico, uma vez que são utilizados para diagnosticar a obesidade osteosarcopênica. A avaliação da composição corporal de obesos pelo modelo de múltiplos compartimentos é padrão-ouro na prática científica. Por outro lado, o método de absorciometria radiológica de feixe duplo é considerado o padrão de referência em pesquisas e na prática clínica. Estudos indicam que a ressonância magnética e a tomografia computadorizada, em alguns casos, são fortemente correlacionadas com a absorciometria radiológica de feixe duplo. Os demais métodos apresentam limitações em avaliar a composição corporal, bem como suas modificações durante a redução ponderal em indivíduos obesos.

Is increased joint loading detrimental to obese patients with knee osteoarthritis? A secondary data analysis from a randomized trial

OBJECTIVE

To investigate whether increased knee joint loading due to improved ambulatory function and walking speed following weight loss achieved over 16 weeks accelerates symptomatic and structural disease progression over a subsequent 1 year weight maintenance period in an obese population with knee osteoarthritis (OA).

METHODS

Data from a prospective study of weight loss in obese patients with knee OA (the CARtilage in obese knee OsteoarThritis (CAROT) study) were used to determine changes in knee joint compressive loadings (model estimated) during walking after a successful 16 week weight loss intervention. The participants were divided into 'Unloaders' (participants that reduced joint loads) and 'Loaders' (participants that increased joint loads). The primary symptomatic outcome was changes in knee symptoms, measured with the Knee injury and Osteoarthritis Outcome Score (KOOS) questionnaire, during a subsequent 52 weeks weight maintenance period. The primary structural outcome was changes in tibiofemoral cartilage loss assessed semi-quantitatively (Boston Leeds Knee Osteoarthritis Score (BLOKS) from MRI after the 52 weight maintenance period.

RESULTS

157 participants (82% of the CAROT cohort) with medial and/or lateral knee OA were classified as Unloaders (n = 100) or Loaders (n = 57). The groups showed similar significant changes in symptoms (group difference: -2.4 KOOS points [95% CI -6.8:1.9]) and cartilage loss (group difference: -0.06 BLOKS points [95% CI -0.22:0.11) after 1 year, with no statistically significant differences between Loaders and Unloaders.

CONCLUSION

For obese patients undergoing a significant weight loss, increased knee joint loading for 1 year was not associated with accelerated symptomatic and structural disease progression compared to a similar weight loss group that had reduced ambulatory compressive knee joint loads.

CLINICALTRIALSGOV

NCT00655941.

Osteoarthritis year 2013 in review: imaging

PURPOSE

To review recent original research publications related to imaging of osteoarthritis (OA) and identify emerging trends and significant advances.

METHODS

Relevant articles were identified through a search of the PubMed database using the query terms "OA" in combination with "imaging", "radiography", "MRI", "ultrasound", "computed tomography", and "nuclear medicine"; either published or in press between March 2012 and March 2013. Abstracts were reviewed to exclude review articles, case reports, and studies not focused on imaging using routine clinical imaging measures.

RESULTS

Initial query yielded 932 references, which were reduced to 328 citations following the initial review. MRI (118 references) and radiography (129 refs) remain the primary imaging modalities in OA studies, with fewer reports using computed tomography (CT) (35 refs) and ultrasound (23 refs). MRI parametric mapping techniques remain an active research area (33 refs) with growth in T2*- and T1-rho mapping publications compared to prior years. Although the knee is the major joint studied (210 refs) there is interest in the hip (106 refs) and hand (29 refs). Imaging continues to focus on evaluation of cartilage (173 refs) and bone (119 refs).

CONCLUSION

Imaging plays a major role in OA research with publications continuing along traditional lines of investigation. Translational and clinical research application of compositional MRI techniques is becoming more common driven in part by the availability of T2 mapping data from the Osteoarthritis Initiative (OAI). New imaging techniques continue to be developed with a goal of identifying methods with greater specificity and responsiveness to changes in the joint, and novel functional neuroimaging techniques to study central pain. Publications related to imaging of OA continue to be heavily focused on quantitative and semiquantitative MRI evaluation of the knee with increasing application of compositional MRI techniques in the hip.

Altered visual and feet proprioceptive feedbacks during quiet standing increase postural sway in patients with severe knee osteoarthritis

Objective

The objective was to investigate how postural control in knee osteoarthritis (KOA) patients, with different structural severities and pain levels, is reorganized under different sensory conditions.

Methods

Forty-two obese patients (BMI range from 30.1 to 48.7 kg*m⁻², age range from 50 to 74 years) with KOA were evaluated. One minute of quiet standing was assessed on a force platform during 4 different sensory conditions, applied 3 times at random: Eyes open (EO) and eyes closed (EC) standing on firm and soft (foam) surfaces (EO-soft and EC-soft). Centre of pressure (Cop) standard deviation, speed, range and Cop mean position in both directions (anterior-posterior and medial-lateral) were extracted from the force platform data. Structural disease severity was assessed from semiflexed standing radiographs and graded by the Kellgren and Lawrence (KL) score. Pain intensity immediately before the measurements was assessed by numeric rating scale (range: 0–10).

Results

The patients were divided into “less severe” (KL 1 and 2, n = 24) and “severe” (KL>2, n = 18) group. The CoP range in the medial-lateral direction was larger in the severe group when compared with the less severe group during EC-soft condition (P<0.01). Positive correlation between pain intensity and postural sway (range in medial-lateral direction) was found during EC condition, indicating that the higher the pain intensity, the less effective is the postural control applied to restore an equilibrium position while standing without visual information.

Conclusion

The results support that: (i) the postural reorganization under manipulation of the different sensory information is worse in obese KOA patients with severe degeneration and/or high pain intensity when compared with less impaired patients, and (ii) higher pain intensity is related to worse body balance in obese KOA patients.