Validation of a second-generation appropriateness classification system for total knee arthroplasty: a prospective cohort study

BACKGROUND

To test the validity of a second-generation appropriateness system in a cohort of patients undergoing total knee arthroplasty (TKA).

METHODS

We applied the RAND/UCLA Appropriateness Method to derive our second-generation system and conducted a prospective study of patients diagnosed with knee osteoarthritis in eight public hospitals in Spain. Main outcome questionnaires were the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), Short-Form-12 (SF-12), and the Knee Society Score satisfaction scale (KSS), completed before and 6 months after TKA. Baseline, changes from baseline to 6 months (journey outcome), and 6-month scores (destination outcome) were compared according to appropriateness category. Percentage of patients attaining the minimal clinically important difference (MCID) and responders according to Outcome Measures in Rheumatology-Osteoarthritis Research Society (OMERACT-OARSI) criteria were also reported.

RESULTS

A total of 282 patients completed baseline and 6-month questionnaires. Of these, 142 (50.4%) were classified as Appropriate, 90 (31.9%) as Uncertain, and 50 (17.7%) as Inappropriate. Patients classified as Appropriate had worse preoperative pain, function, and satisfaction (p < 0.001) and had greater improvements (i.e., journey scores) than those classified as Inappropriate (p < 0.001). At 6 months, destination scores for pain, function, or satisfaction were not significantly different across appropriateness categories. The percentage of patients meeting responder criteria (p < 0.001) and attaining MCID was statistically higher in Appropriate versus Inappropriate groups in pain (p = 0.04) and function (p = 0.004).

CONCLUSIONS

The validity of our second-generation appropriateness system was generally supported. The findings highlight a critical issue in TKA healthcare: whether TKA appropriateness should be driven by the extent of improvement, by patient final state, or by both.

Association of knee OA structural phenotypes to risk for progression: a secondary analysis from the Foundation for National Institutes of Health Osteoarthritis Biomarkers study (FNIH)

PURPOSE

Aim was to stratify the knee MRIs of the Foundation for National Institutes of Health Osteoarthritis Biomarkers Consortium (FNIH) cohort into distinct structural phenotypes based on semiquantitative assessment and to determine risk for pain and structural progression over 48 months.

METHODS

The study sample from the FNIH project was selected as a nested case-control study with knees showing either 1) radiographic and pain progression (i.e., "composite" cases), 2) radiographic progression only ("JSL"), 3) pain progression only, and 4) neither radiographic nor pain progression. MRI was performed on 3T systems. MRIs were read according to the MOAKS scoring system. Knees were stratified into subchondral bone, cartilage/meniscus and inflammatory phenotypes using the baseline visits. The relation of each phenotype to risk of being in the combined JSL plus composite outcome or composite case only group compared to those not having that phenotype was determined using logistic regression. Only KL2 and 3 and those without root tears were included.

RESULTS

485 knees were included. 362 (75%) did not have any phenotype, while 95 (20%) had the bone phenotype, 22 (5%) the cartilage/meniscus phenotype and 19 (4%) the inflammatory phenotype. The bone phenotype was associated with a higher odds of the combined JSL plus composite outcome and composite outcome only (OR 1.81; [95%CI 1.14,2.85] and 1.65; 95%CI [1.04,2.61]) while the inflammatory (OR 0.96 [95%CI 0.38,2.42] and 1.25; 95%CI [0.48,3.25]) and the cartilage/meniscus phenotypes were not significantly associated with outcome (OR 1.30 95%CI [0.55,3.07] and 0.99; 95%CI [0.40,2,49]).

CONCLUSIONS

The bone phenotype was associated with increased risk of having both radiographic and pain progression. Phenotypic stratification may be useful to consider when selecting patients for inclusion in clinical trials.

Correlation between radiographic knee osteoarthritis and lifetime cigarette smoking amount in a Korean population: A cross-sectional study

Although the inverse correlation between smoking and degenerative arthritis is controversial, quantitative analysis of the correlation between lifetime cigarette smoking amount and degenerative arthritis has not been performed. We investigated the correlation between knee radiographic osteoarthritis (ROA) and lifetime cigarette smoking amount in the general population.This cross-sectional study used the Fifth and Sixth Korean National Health and Nutrition Examination Survey (2010-2013) data. Subjects included 11,638 community-dwelling adults aged ≥50 years. Knee ROA was defined as a Kellgren/Lawrence grade ≥2 on plain radiography. Lifetime cigarette smoking amount was calculated in terms of pack-year and further divided into quartile groups. Independent correlation between smoking and knee ROA was determined using odds ratios (OR) adjusted for age, sex, obesity, physical activity, and household income on multivariate logistic regression analysis.Knee ROA prevalence was 37.3%; prevalence of lifetime cigarette smokers was 26.0%. Subjects with knee ROA had higher mean age, female sex ratio, and body mass index but lower physical activity level. The adjusted logistic regression model revealed that female sex (OR, 2.110; 95% confidence interval [CI], 1.895-2.349) was significantly associated with knee ROA. Older age, obesity, and lower household income were positively correlated with knee ROA. Second-and fourth-quartile groups of smokers had the lower ROA prevalence than never-smokers (OR, 0.800; 95% CI, 0.643-0.99; OR, 0.812; 95% CI, 0.684-0.965, respectively).An inverse correlation with knee ROA was confirmed in mid-light to heavy smokers. Prospective studies are needed to reveal whether knee ROA involves smoking.

Knee Osteoarthritis Grade does not Correlate with Quadriceps Muscle Strength or Bone Properties of the Calcaneus in Men Aged 80 Years or More who Can Walk independently

Purpose: Muscle weakness and bone deterioration in the elderly are related to falls and fractures, resulting in decreased mobility. Knee osteoarthritis also may contribute to falls and fractures and thereby affect mortality rates. The Kellgren–Lawrence (KL) classification is widely used in the radiographic evaluation of knee osteoarthritis. Aims: This study aimed to evaluate the quadriceps strength and bone properties of the calcaneus for each KL grade, and to clarify the impact of knee osteoarthritis grade on quadriceps strength and bone properties. Methods: This prospective cross-sectional study included data on 108 male patients (213 knees), aged ≥80 years, who could walk independently. A handheld dynamometer was used to measure quadriceps strength. Bone properties were evaluated using broadband ultrasound attenuation with a portable bone densitometer. Weight-bearing standing knee radiographs were evaluated using KL classification. Quadriceps strength and bone properties were evaluated for each KL grade and the correlations between the grade and quadriceps strength and bone properties were assessed simultaneously. Results: The numbers of participants in KL grades I–IV were 46, 102, 45, and 20, respectively. There were no differences among grades for either quadriceps strength or bone properties. Conclusions: Participants exhibited good quadriceps strength and bone properties regardless of their KL grade. Relatively high mechanical loading of muscle and bone incurred while walking independently, likely explaining this result. Clinically, this study demonstrated the absence of correlations between KL grade and quadriceps strength and bone properties, as was previously reported in studies showing the absence of a correlation between KL grade and pain.

[Osteoarthritis classifications : Modification proposal for the criteria of Kellgren and Vallotton]

BACKGROUND

In imaging diagnostics, classification schemes are very common. As far as osteoarthritis is concerned, the Kellgren classification is the most popular. However, the Kellgren classification, which has been used for more than 50 years, is based on nonspecific criteria; thus, high interobserver variability has been reported. In addition, the Kellgren classifications have not been coordinated with magnetic resonance imaging (MRI)-based classification schemes, e.g., Vallotton.

AIM

In this paper, we present some modifications concerning the criteria for both the Kellgren classification and its comparison with the MRI-based Vallotton classification.

METHODS

The current surgical and imaging classifications and the precision of the nomenclature are analyzed. X‑ray and MRI findings are compared.

RESULTS

Suggestions for both a modification of the Kellgren classification as far as the criteria are concerned and a hierarchy (ranking) of X‑ray and MRI findings to make clinical decisions more valuable are proposed.

CONCLUSION

These proposed modifications (Kellgren and ranking) would be helpful for routine reporting and allow for better interobserver reliability, in particular for special reports (e.g. consultations, expert opinions, advanced diagnostics).

Characterization of synovial fluid metabolomic phenotypes of cartilage morphological changes associated with osteoarthritis

OBJECTIVE

Osteoarthritis (OA) is a multifactorial disease with etiological heterogeneity. The objective of this study was to classify OA subgroups by generating metabolomic phenotypes from human synovial fluid.

DESIGN

Post mortem synovial fluids (n = 75) were analyzed by high performance-liquid chromatography mass spectrometry (LC-MS) to measure changes in the global metabolome. Comparisons of healthy (grade 0), early OA (grades I-II), and late OA (grades III-IV) donor populations were considered to reveal phenotypes throughout disease progression.

RESULTS

Global metabolomic profiles in synovial fluid were distinct between healthy, early OA, and late OA donors. Pathways differentially activated among these groups included structural deterioration, glycerophospholipid metabolism, inflammation, central energy metabolism, oxidative stress, and vitamin metabolism. Within disease states (early and late OA), subgroups of donors revealed distinct phenotypes. Synovial fluid metabolomic phenotypes exhibited increased inflammation (early and late OA), oxidative stress (late OA), or structural deterioration (early and late OA) in the synovial fluid.

CONCLUSION

These results revealed distinct metabolic phenotypes in human synovial fluid, provide insight into pathogenesis, represent novel biomarkers, and can move toward developing personalized interventions for subgroups of OA patients.

Effects of receptor activator nuclear factor κB gene polymorphisms on the susceptibility to knee osteoarthritis: A case-control study

The present study aimed to explore genetic association of receptor activator nuclear factor κB (RANK) polymorphisms with individual susceptibility to knee osteoarthritis (OA) in different Kellgren-Lawrence (KL) grades.This case-control study included 138 knee OA patients and 145 healthy individuals. RANK rs1805034 and rs8086340 polymorphisms were genotyped through polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The effects of RANK polymorphisms on knee OA risk were analyzed via χ test or Fisher exact test, and the results were expressed using odds ratios (ORs) with corresponding 95% confidence intervals (CIs).The C allele of rs1805034 polymorphism had significantly higher frequency in knee OA patients than in controls (P = .044), indicating that this allele could increase the risk of knee OA (OR = 1.424, 95% CI = 1.010-2.008). Besides, the CC genotype and C allele of the rs1805034 polymorphism were significantly associated with elevated risk of knee OA in moderate grade (CC vs TT: P = .018, OR = 3.071, 95% CI = 1.187-7.941; C vs T: P = .012, OR = 1.787, 95% CI = 1.131-2.823). However, rs8086340 polymorphism had no significant association with knee OA riskThe C allele of RANK rs1805034 polymorphism is closely correlated with increased risk of knee OA, especially for moderate grade.

Effect of Early Surgery vs Physical Therapy on Knee Function Among Patients With Nonobstructive Meniscal Tears: The ESCAPE Randomized Clinical Trial

IMPORTANCE

Despite recent studies suggesting arthroscopic partial meniscectomy (APM) is not more effective than physical therapy (PT), the procedure is still frequently performed in patients with meniscal tears.

OBJECTIVE

To assess whether PT is noninferior to APM for improving patient-reported knee function in patients with meniscal tears.

DESIGN, SETTING, AND PARTICIPANTS

Noninferiority, multicenter, randomized clinical trial conducted in 9 hospitals in the Netherlands. Participants were aged 45 to 70 years with nonobstructive meniscal tears (ie, no locking of the knee joint). Patients with knee instability, severe osteoarthritis, and body mass index greater than 35 were excluded. Recruitment took place between July 17, 2013, and November 4, 2015. Participants were followed up for 24 months (final participant follow-up, October 11, 2017).

INTERVENTIONS

Three hundred twenty-one participants were randomly assigned to APM (n = 159) or a predefined PT protocol (n = 162). The PT protocol consisted of 16 sessions of exercise therapy over 8 weeks focused on coordination and closed kinetic chain strength exercises.

MAIN OUTCOMES AND MEASURES

The primary outcome was change in patient-reported knee function on the International Knee Documentation Committee Subjective Knee Form (range, 0 to 100; from worse to best) from baseline over a 24-month follow-up period. The noninferiority margin was defined as a difference between treatment groups of 8 points and was assessed with a 1-sided α of .025. The primary analysis followed the intention-to-treat principle.

RESULTS

Among 321 patients who were randomized (mean [SD] age, 58 [6.6] years; 161 women [50%]), 289 (90%) completed the trial (161 women and 158 men). In the PT group, 47 participants (29%) had APM during the 24-month follow-up period, and 8 participants randomized to APM (5%) did not have APM. Over a 24-month follow-up period, knee function improved in the APM group by 26.2 points (from 44.8 to 71.5) and in the PT group by 20.4 points (from 46.5 to 67.7). The overall between-group difference was 3.6 points (97.5% CI, -∞ to 6.5; P value for noninferiority = .001). Adverse events occurred in 18 participants in the APM group and 12 in the PT group. Repeat surgery (3 in the APM group and 1 in the PT group) and additional outpatient visits for knee pain (6 in the APM group and 2 in the PT group) were the most frequent adverse events.

CONCLUSIONS AND RELEVANCE

Among patients with nonobstructive meniscal tears, PT was noninferior to APM for improving patient-reported knee function over a 24-month follow-up period. Based on these results, PT may be considered an alternative to surgery for patients with nonobstructive meniscal tears.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01850719.

A classification modeling approach for determining metabolite signatures in osteoarthritis

Multiple factors can help predict knee osteoarthritis (OA) patients from healthy individuals, including age, sex, and BMI, and possibly metabolite levels. Using plasma from individuals with primary OA undergoing total knee replacement and healthy volunteers, we measured lysophosphatidylcholine (lysoPC) and phosphatidylcholine (PC) analogues by metabolomics. Populations were stratified on demographic factors and lysoPC and PC analogue signatures were determined by univariate receiver-operator curve (AUC) analysis. Using signatures, multivariate classification modeling was performed using various algorithms to select the most consistent method as measured by AUC differences between resampled training and test sets. Lists of metabolites indicative of OA [AUC > 0.5] were identified for each stratum. The signature from males age > 50 years old encompassed the majority of identified metabolites, suggesting lysoPCs and PCs are dominant indicators of OA in older males. Principal component regression with logistic regression was the most consistent multivariate classification algorithm tested. Using this algorithm, classification of older males had fair power to classify OA patients from healthy individuals. Thus, individual levels of lysoPC and PC analogues may be indicative of individuals with OA in older populations, particularly males. Our metabolite signature modeling method is likely to increase classification power in validation cohorts.

Toward classification criteria for early osteoarthritis of the knee

OBJECTIVE

To propose draft classification criteria for early stage osteoarthritis (OA) of the knee for use in a primary care setting.

METHODS

A group of basic scientists, physician-scientists, rheumatologists, orthopedic surgeons, and physiotherapists in a workshop setting discussed potential classification criteria for early osteoarthritis of the knee. The workshop was divided into sessions around relevant topics with short state of the art presentations followed by breakout sessions, consensus discussions, and consolidation into a consensus document.

RESULTS

Three classes of criteria were agreed: (1) Pain, symptoms/signs, self-reported function, and quality of life using tools such as KOOS: scoring ≤85% in at least 2 out of these 4 categories; (2) Clinical examination: at least 1 present out of joint line tenderness or crepitus; (3) Knee radiographs: Kellgren & Lawrence (KL) grade of 0 or 1. MRI is at present not recommended as an aid to identify or define early OA in routine clinical practice or primary care, in light of the absence of validated consensus criteria and the high population prevalence of structural joint changes detected by this method. Biomarkers may have future utility in early OA classification, but no individual or set of biomarkers is yet robust enough.

CONCLUSION

Based on our consensus proposal, draft classification criteria for early OA of the knee for use in clinical studies should include patient reported outcomes such as pain and function, together with clinical signs and KL grade 0-1 on radiographs.

Analysis and multiclass classification of pathological knee joints using vibroarthrographic signals

BACKGROUND AND OBJECTIVE

Vibroarthrography (VAG) is a method developed for sensitive and objective assessment of articular function. Although the VAG method is still in development, it shows high accuracy, sensitivity and specificity when comparing results obtained from controls and the non-specific, knee-related disorder group. However, the multiclass classification remains practically unknown. Therefore the aim of this study was to extend the VAG method classification to 5 classes, according to different disorders of the patellofemoral joint.

METHODS

We assessed 121 knees of patients (95 knees with grade I-III chondromalacia patellae, 26 with osteoarthritis) and 66 knees from 33 healthy controls. The vibroarthrographic signals were collected during knee flexion/extension motion using an acceleration sensor. The genetic search algorithm was chosen to select the most relevant features of the VAG signal for classification. Four different algorithms were used for classification of selected features: logistic regression with automatic attribute selection (SimpleLogistic in Weka), multilayer perceptron with sigmoid activation function (MultilayerPerceptron), John Platt's sequential minimal optimization algorithm implementation of support vector classifier (SMO) and random forest tree (RandomForest). The generalization error of classification algorithms was evaluated by stratified 10-fold cross-validation.

RESULTS

We obtained levels of accuracy and AUC metrics over 90%, more than 93% sensitivity and more than 84% specificity for the logistic regression-based method (SimpleLogistic) for a 2-class classification. For the 5-class method, we obtained 69% and 90% accuracy and AUC respectively, and sensitivity and specificity over 91% and 69%.

CONCLUSIONS

The results of this study confirm the high usefulness of quantitative analysis of VAG signals based on classification techniques into normal and pathological knees and as a promising tool in classifying signals of various knee joint disorders and their stages.

Classification of patients with knee osteoarthritis in clinical phenotypes: Data from the osteoarthritis initiative

OBJECTIVES

The existence of phenotypes has been hypothesized to explain the large heterogeneity characterizing the knee osteoarthritis. In a previous systematic review of the literature, six main phenotypes were identified: Minimal Joint Disease (MJD), Malaligned Biomechanical (MB), Chronic Pain (CP), Inflammatory (I), Metabolic Syndrome (MS) and Bone and Cartilage Metabolism (BCM). The purpose of this study was to classify a sample of individuals with knee osteoarthritis (KOA) into pre-defined groups characterized by specific variables that can be linked to different disease mechanisms, and compare these phenotypes for demographic and health outcomes.

METHODS

599 patients were selected from the OAI database FNIH at 24 months' time to conduct the study. For each phenotype, cut offs of key variables were identified matching the results from previous studies in the field and the data available for the sample. The selection process consisted of 3 steps. At the end of each step, the subjects classified were excluded from the further classification stages. Patients meeting the criteria for more than one phenotype were classified separately into a 'complex KOA' group.

RESULTS

Phenotype allocation (including complex KOA) was successful for 84% of cases with an overlap of 20%. Disease duration was shorter in the MJD while the CP phenotype included a larger number of Women (81%). A significant effect of phenotypes on WOMAC pain (F = 16.736 p <0.001) and WOMAC physical function (F = 14.676, p < 0.001) was identified after controlling for disease duration.

CONCLUSION

This study signifies the feasibility of a classification of KOA subjects in distinct phenotypes based on subgroup-specific characteristics.

Clinical comparison of oral administration and viscosupplementation of hyaluronic acid (HA) in early knee osteoarthritis

PURPOSE

Osteoarthritis (OA) is a progressive, chronic and degenerative joint disease characterized by a loss of articular cartilage. Treatment of OA is largely palliative based on nonsteroidal anti-inflammatory drugs, opioids and injections of steroids. Regarding conservative treatment, intra-articular injections of hyaluronic acid (HA) can play a role in early symptomatic knee OA.

MATERIALS AND METHODS

Between August 2015 and September 2015, sixty patients (32 males and 28 females) between 40 and 70 years old were randomly allocated into two groups: Half were treated with three weekly intra-articular injections of hyaluronic acid 1.6 % (group A), while the others were treated with Syalox 300 Plus^® (hyaluronic acid 300 mg + Boswellia serrata extract 100 mg) 1 tab/die for 20 days and afterward Syalox 150^® (hyaluronic acid 150 mg) 1 tab/die for other 20 days (group B). All patients were evaluated clinically with American Knee Society Score (AKSS) and visual analogue scale (VAS) for the pain before the treatment and after 3 months.

RESULTS

AKSS of the patients in both groups was significantly increased by the treatment, and VAS score was significantly reduced. In both groups, two subgroups were created with patients older than 60 years and patients younger than 60 years. Better results are reported in younger patients of group A and older subjects in group B.

CONCLUSIONS

Despite several limitations, the results of the study have shown that HA injection and oral administration may have beneficial therapeutic effects on patients with early osteoarthritis. Different outcomes in younger and older subject suggested a combined therapy first with local infiltrations and then with oral composition.

Comparison of Glucosamine-Chondroitin Sulfate with and without Methylsulfonylmethane in Grade I-II Knee Osteoarthritis: A Double Blind Randomized Controlled Trial

BACKGROUND

Glucosamine, chondroitinsulfate are frequently used to prevent further joint degeneration in osteoarthritis (OA). Methylsulfonylmethane (MSM) is a supplement containing organic sulphur and also reported to slow anatomical joint progressivity in the knee OA. The MSM is often combined with glucosamine and chondroitin sulfate. However, there are controversies whether glucosamine-chondroitin sulfate or their combination with methylsulfonylmethane could effectively reduce pain in OA. This study is aimed to compare clinical outcome of glucosamine-chondroitin sulfate (GC), glucosamine-chondroitin sulfate-methylsulfonylmethane (GCM), and placeboin patients with knee osteoarthritis (OA) Kellgren-Lawrence grade I-II.

METHODS

a double blind, randomized controlled clinical trial was conducted on 147 patients with knee OA Kellgren-Lawrence grade I-II. Patients were allocated by permuted block randomization into three groups: GC (n=49), GCM (n=50), or placebo (n=48) groups. GC group received 1500 mg of glucosamine + 1200 mg of chondroitin sulfate + 500 mg of saccharumlactis; GCM group received 1500 mg of glucosamine + 1200 mg of chondroitin sulfate + 500 mg of MSM; while placebo group received three matching capsules of saccharumlactis. The drugs were administered once daily for 3 consecutive months VAS and WOMAC scores were measured before treatment, then at 4th, 8th and 12th week after treatment.

RESULTS

on statistical analysis it was found that at the 12th week, there are significant difference between three treatment groups on the WOMAC score (p=0.03) and on the VAS score (p=0.004). When analyzed between weeks, GCM treatment group was found statistically significant on WOMAC score (p=0.01) and VAS score (p<0.001). Comparing the score difference between weeks, WOMAC score analysis showed significant difference between GC, GCM, and placebo in week 4 (p=0.049) and week 12 (p=0.01). In addition, VAS score also showed significant difference between groups in week 8 (p=0.006) and week 12 (p<0.001).

CONCLUSION

combination of glucosamine-chondroitinsulfate-methylsulfonylmethane showed clinical benefit for patients with knee OAK ellgren-Lawrence grade I-II compared with GC and placebo. GC did not make clinical improvement in overall groups of patients with knee OA Kellgren Lawrence grade I-II.

Determination of Pain Phenotypes in Knee Osteoarthritis: A Latent Class Analysis Using Data From the Osteoarthritis Initiative

OBJECTIVE

Knee osteoarthritis (OA) is a broadly applied diagnosis that may describe multiple subtypes of pain. The purpose of this study was to identify phenotypes of knee OA, using measures from the following pain-related domains: 1) knee OA pathology, 2) psychological distress, and 3) altered pain neurophysiology.

METHODS

Data were selected from a total of 3,494 participants at visit 6 of the Osteoarthritis Initiative study. Latent class analysis was applied to the following variables: radiographic OA severity, quadriceps strength, body mass index, the Charlson Comorbidity Index (CCI), the Center for Epidemiologic Studies Depression Scale, the Coping Strategies Questionnaire-Catastrophizing subscale, number of bodily pain sites, and knee joint tenderness at 4 sites. The resulting classes were compared on the following demographic and clinical factors: age, sex, pain severity, disability, walking speed, and use of arthritis-related health care.

RESULTS

A 4-class model was identified. Class 1 (4% of the study population) had higher CCI scores. Class 2 (24%) had higher knee joint sensitivity. Class 3 (10%) had greater psychological distress. Class 4 (62%) had lesser radiographic OA, little psychological involvement, greater strength, and less pain sensitivity. Additionally, class 1 was the oldest, on average. Class 4 was the youngest, had the lowest disability, and least pain. Class 3 had the worst disability and most pain.

CONCLUSION

Four distinct pain phenotypes of knee OA were identified. Psychological factors, comorbidity status, and joint sensitivity appear to be important in defining phenotypes of knee OA-related pain.

Classification of knee arthropathy with accelerometer-based vibroarthrography

One of the most common knee joint disorders is known as osteoarthritis which results from the progressive degeneration of cartilage and subchondral bone over time, affecting essentially elderly adults. Current evaluation techniques are either complex, expensive, invasive or simply fails into detection of small and progressive changes that occur within the knee. Vibroarthrography appeared as a new solution where the mechanical vibratory signals arising from the knee are recorded recurring only to an accelerometer and posteriorly analyzed enabling the differentiation between a healthy and an arthritic joint. In this study, a vibration-based classification system was created using a dataset with 92 healthy and 120 arthritic segments of knee joint signals collected from 19 healthy and 20 arthritic volunteers, evaluated with k-nearest neighbors and support vector machine classifiers. The best classification was obtained using the k-nearest neighbors classifier with only 6 time-frequency features with an overall accuracy of 89.8% and with a precision, recall and f-measure of 88.3%, 92.4% and 90.1%, respectively. Preliminary results showed that vibroarthrography can be a promising, non-invasive and low cost tool that could be used for screening purposes. Despite this encouraging results, several upgrades in the data collection process and analysis can be further implemented.

Development of a bedside pain assessment kit for the classification of patients with osteoarthritis

There are no standardized bedside assessments for subtyping patients with osteoarthritis (OA) based on pain mechanisms. Thus, we developed a bedside sensory testing kit (BSTK) to classify OA patients based on sensory profiles potentially indicative of pain mechanism. After usability and informal reliability testing (n = 22), the kit was tested in a formal reliability study (n = 20). Patients completed questionnaires and sensory testing: pressure algometry to detect hyperalgesia; repeat algometry after heterotopic noxious conditioning stimulation to measure diffuse noxious inhibitory control (DNIC); light touch using Von Frey filaments; and cold allodynia using a brass rod. The procedure was brief and well tolerated. Algometry and filament testing were highly reliable [intra-class correlation coefficients (ICCs) 0.71-0.91]; DNIC was acceptably reliable (ICCs 0.53-0.91); brass rod reliability was inconclusive. Patients were classified empirically into four groups: "All abnormal findings" (primary and secondary hyperalgesia and dysfunctional DNIC); "all normal findings"; and two intermediate groups. The "all abnormal findings" group had more neuropathic pain symptoms, and lower WOMAC total, stiffness, and activity scores than the "all normal findings" group. Simple BSTK procedures, consolidated in a kit, reliably classified OA patients into subgroups based on sensory profile, suggesting that OA patients differ in underlying pain mechanisms. Further research is needed to confirm these subgroups and determine their validity in predicting response to treatment.

Osteoarthritis Classification Scales: Interobserver Reliability and Arthroscopic Correlation

BACKGROUND

Osteoarthritis of the knee is commonly diagnosed and monitored with radiography. However, the reliability of radiographic classification systems for osteoarthritis and the correlation of these classifications with the actual degree of confirmed degeneration of the articular cartilage of the tibiofemoral joint have not been adequately studied.

METHODS

As the Multicenter ACL (anterior cruciate ligament) Revision Study (MARS) Group, we conducted a multicenter, prospective longitudinal cohort study of patients undergoing revision surgery after anterior cruciate ligament reconstruction. We followed 632 patients who underwent radiographic evaluation of the knee (an anteroposterior weight-bearing radiograph, a posteroanterior weight-bearing radiograph made with the knee in 45° of flexion [Rosenberg radiograph], or both) and arthroscopic evaluation of the articular surfaces. Three blinded examiners independently graded radiographic findings according to six commonly used systems-the Kellgren-Lawrence, International Knee Documentation Committee, Fairbank, Brandt et al., Ahlbäck, and Jäger-Wirth classifications. Interobserver reliability was assessed with use of the intraclass correlation coefficient. The association between radiographic classification and arthroscopic findings of tibiofemoral chondral disease was assessed with use of the Spearman correlation coefficient.

RESULTS

Overall, 45° posteroanterior flexion weight-bearing radiographs had higher interobserver reliability (intraclass correlation coefficient = 0.63; 95% confidence interval, 0.61 to 0.65) compared with anteroposterior radiographs (intraclass correlation coefficient = 0.55; 95% confidence interval, 0.53 to 0.56). Similarly, the 45° posteroanterior flexion weight-bearing radiographs had higher correlation with arthroscopic findings of chondral disease (Spearman rho = 0.36; 95% confidence interval, 0.32 to 0.39) compared with anteroposterior radiographs (Spearman rho = 0.29; 95% confidence interval, 0.26 to 0.32). With respect to standards for the magnitude of the reliability coefficient and correlation coefficient (Spearman rho), the International Knee Documentation Committee classification demonstrated the best combination of good interobserver reliability and medium correlation with arthroscopic findings.

CONCLUSIONS

The overall estimates with the six radiographic classification systems demonstrated moderate (anteroposterior radiographs) to good (45° posteroanterior flexion weight-bearing radiographs) interobserver reliability and medium correlation with arthroscopic findings. The International Knee Documentation Committee classification assessed with use of 45° posteroanterior flexion weight-bearing radiographs had the most favorable combination of reliability and correlation.

LEVEL OF EVIDENCE

Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

[Total knee replacement due to grade IV gonarthrosis]

OBJECTIVE

To describe the clinical evolution of patients with total knee replacement surgery due to grade IV gonarthrosis secondary to varus angular deformity.

MATERIAL AND METHODS

A descriptive trial where we included patients who underwent total knee arthroplasty due to gonarthrosis secondary to varus angular deformity. We used the following variables, sex, age, affected side, type of approach, type of prosthesis, type of gait post-surgically, infection, vascular status, post-surgical pain, rejection of prosthetic material, varusflection angular deformity pre and post-surgically.

RESULTS

We reviewed 13 files, 69.2% men and 30.8% women, the mean age was 72.38, minimum 56, maximum 82, DE 7.11 years. Six (46.2%) left knees and 7 (53.8%) right knees. All patients had a medial parapatellar approach and bone balancing, 23.1% had ligament balancing; 7.6% had a total knee replacement stabilized posteriorly and 93.3% not stabilized posteriorly; 1 (7.6%) patient had infection, none had vascular involvement, 76.9% had to walk with a cane, 15.4% walked on their own and 7.6% had no gait. The average grade of the angular deformity pre-surgery was 15.77 and the average post-surgery was less than or equal to 5 degrees, the difference of average grades pre and post-surgery was 36.719 and in flection 0.439, p = 0.00 and p = 0.669 respectively (paired t).

CONCLUSION

We can conclude that the clinical evolution of patients with gonarthrosis secondary to varus angular deformity who underwent TKA is good, complications are similar to those in the literature.

Ultrasound monitoring of the treatment of clinically significant knee osteoarthritis

OBJECTIVES

The study presented an ultrasound (US) monitoring of treatment as a new imaging US method with the results of therapy of clinically significant knee osteoarthritis.

BACKGROUND

X-ray is widely used for knee osteoarthritis classification, which does not involve the evaluation of the soft tissue. High frequency and high resolution US of joints (arthrosonography, echoarthrography) assess not only morphologic but also functional changes in the knee joint.

METHODS

In the prospective study, 110 patients with clinically significant knee osteoarthritis were treated non-operative. US examination and US monitoring of therapy was performed during 24 weeks therapy period. A remission of pathomorphologic (marginal osteofytes) and pathophysiologic (effusion in anterior knee and Baker´s cyst) attributes were evaluated according the US classification.

RESULTS

Pathomorphologic attributes changes showed a static state, without remission or progression. Pathophysiologic attributes changes showed a remission during the study period. The highest remission was in the first three weeks, 60 % anterior knee effusion and 62 % Baker´s cyst. At the end of study, no changes from the initial US grade was observed in 16 % of effusion in anterior knee and 22 % of Baker´s cyst. Therapeutic resistant Baker´s cyst was present at the end of study in 36 %.

CONCLUSION

We demonstrated a new method - US monitoring of therapy, which can objectivize the efficiency of treatment of clinically significant knee osteoarthritis. We would recommend US monitoring of therapy for the routine use in orthopedic clinical praxis (Tab. 6, Graph 3, Fig. 3, Ref. 15).

The histological features of anteromedial gonarthrosis--the comparison of two grading systems in a human phenotype of osteoarthritis

Anteromedial gonarthrosis (AMG) displays a well recognised pattern of cartilage damage on the medial tibial plateau. Anteriorly there is a full thickness cartilage defect, with transition to a partial thickness defect, becoming full thickness cartilage in the posterior third of the tibial plateau. The retained posterior cartilage is macroscopically normal. This study characterises the histological changes of AMG and examines the usefulness of two histological assessment tools. Sixteen unicompartmental resection specimens of patients with primary AMG were assessed. Samples were stained with Haematoxylin and Eosin and Safranin-O stains and scored using the modified Mankin grade, and the OOCHAS assessment tool. Each specimen was assessed at five regions along the antero-posterior axis starting from the exposed bone to the region of macroscopically normal cartilage. From anterior to posterior the staining showed a consistent increase in structural integrity and cellularity of the cartilage, matched by a qualitative increase in GAG content. Mean modified Mankin and OOCHAS scores showed a progressive decrease in grade (p < 0.001). The OOCHAS grade had a good correlation with the modified Mankin grade (ρ = 0.886) and there was good intra- and inter-observer variability with both assessment tools. We conclude that there is progressive decrease in histological score from anterior to posterior in AMG and that the macroscopically normal cartilage seen posteriorly is histologically normal. Both the modified Mankin and OOOCHAS assessment tools are useful in histological grading but we found the OOCHAS easier and quicker to use. We propose that AMG represents a spatial model of progressive cartilage damage.

The association of anthropometric measures and osteoarthritis knee in non-obese subjects: a cross sectional study

OBJECTIVE

Body mass index (BMI) and knee osteoarthritis have a strong association, but other anthropometric measures lack such associations. To date, no study has evaluated non-obese knee osteoarthritis to negate the systemic and metabolic effects of obesity. This study examines the validity of the contention that BMI and other anthropometric measures have a significant relationship with knee osteoarthritis.

METHODS

In total, 180 subjects with a diagnosis of knee osteoarthritis were recruited and classified according to Kellgren-Lawrence (KL) grades. Body mass index, mid-upper arm circumference, waist-hip ratio and triceps-skinfold thickness were recorded by standard procedures. Osteoarthritis outcome scores (WOMAC) were evaluated.

RESULTS

(1) In both genders, the BMI was significantly higher for KL grade 4 than for grade 2; triceps-skinfold thickness was positively correlated with the joint space width of the tibial medial compartment. (2) In males, triceps-skinfold thickness significantly increased as the KL grades moved from 2 to 4; the significantly higher BMI found in varus aligned knees was positively correlated with WOMAC scores. (3) In females, the waist-hip ratio was significantly higher for KL grade 4 than for grade 2; a significant correlation was found between BMI and WOMAC scores. The waist-hip ratio was significantly associated with varus aligned knees and it positively correlated with WOMAC scores and with the joint space width of the tibial medial compartment. The mid-upper arm circumference demonstrated no correlation with knee osteoarthritis. CONCLUS'ON: This study validates the contention that BMI and other anthropometric measures have a significant association with knee osteoarthritis. Contrary to common belief, the triceps-skinfold thickness (peripheral fat) in males and the waist-hip ratio (central fat) in females were more strongly associated with knee osteoarthritis than BMI.

[Study on correlation between the pathological changes under arthroscopy and the cytokine levels in the knee osteoarthritis of the Blood Stasis type]

OBJECTIVE

To explore the correlation between cytokine levels and the pathological changes under arthroscopy in knee osteoarthritis of Blood Stasis type.

METHODS

From 2009.2 to 2010.3, 90 patients with knee osteoarthritis were reviewed. Among the patients, 17 patients were male and 73 patients were female, ranging in age from 40 to 70 years, averaged 57.2 years, the duration of the disease ranged from 1 month to 10 years, with a mean of 3.4 years. Thirty-one patients had osteoarthritis in left knee, and 59 patients in right knee. The patients had the syndrome of blood stasis. All the patients had pain and morning stiffness; most patients had joint interlocking; and all the patients didn't have joint swelling. The synovial fluid was collected before surgery, and ELISA was used to detect the contents of interleukin-1beta and transforming growth factor-beta1. At the same time, the pathological changes of the joint were observed under the arthroscopy. Based on the above datum analysis, the severity of knee osteoarthritis of blood stasis type was studied, and the correlation between different types of pathological changes under arthroscopy and cytokine levels was analyzed.

RESULTS

The contents of IL-1beta and TGF-beta1 in synovial fluid were (28.18 +/- 5.57) pg/ml and (51.69 +/- 6.56) pg/ml respectively. The level of IL-1beta of grade III-IV cartilage degeneration was (30.65 +/- 3.48) pg/ml, which was significantly higher than (20.55 +/- 3.50) pg/ml of grade I-II cartilage degeneration group; the level of TGF-beta1 of grade I-II cartilage degeneration was (58.18 +/- 3.98) pg/ml,which was significantly higher than (49.59 +/- 5.83) pg/ml of grade II-IV cartilage degeneration group. IL-1beta and cartilage degeneration was positively correlated, the correlation coefficient was 0.744; TGF-beta1 and cartilage degeneration was negatively correlated, the correlation coefficient was -0.563. The level of IL-1beta of grade II-III synovial hyperplasia was (33.48 +/- 2.95) pg/ml, which was significantly higher than (25.40 +/- 4.50) pg/ml of grade I synovial hyperplasia group; IL-beta was positively correlated with synovial hyperplasia, the cor- relation coefficient was 0.801. The levels of IL-1beta of grade I osteophyte formation was (34.18 +/- 2.69) pg/ml, which was significantly higher than (25.74 +/- 4.48) pg/ml of grade 0 osteophyte formation group; the level of TGF-beta 1 of grade 0 osteophyte formation was (53.11 +/- 6.78) pg/ml, which was higher than (48.21 +/- 4.47) pg/ml of grade I osteophyte formation group. IL-1beta was positively correlated with osteophyte formation, the correlation coefficient was 0.762; TGF-beta1 was negatively correlated with osteophyte formation, the correlation coefficient was - 0.340.

CONCLUSION

All the patients with knee osteoarthritis identified as blood stasis syndrome have pathological changes such as articular cartilage degeneration and synovial hyperplasia. The level of IL-1beta has important reference value to estimate the severity of cartilage degeneration, synovial hyperplasia and osteophyte proliferation.

[Study on the correlation between syndrome differ classification of knee osteoarthritis and X-ray image]

OBJECTIVE

To study the correlation between syndrome differ classification of knee osteoarthritis and X-ray image, so as to provide evidence for clinical diagnosis and treatment.

METHODS

From Jun. 2007 to Dec. 2007, 78 patients (108 knees) with knee osteoarthritis were reviewed, including 65 females (89 knees) and 13 males (19 knees), ranging in age from 41 to 77 years. According to the standards for the differentiation of syndrome in the treatment of knee osteoarthritis defined in Principle of Clinical Research for New Traditional Herbs, the patients were divided into three types: Type I, insufficiency of the liver and kidney, with stagnation of tendons and muscles, 43 knees; Type II, insufficiency of the spleen and kidney, with dampness infusion into bone and joints, 26 knees; Type I, deficiency of the liver and kidney, with inter-obstruction of phlegm and stasis 39 knees. Normotopia and lateral plain film of knee joint of weigh loading and in erect position, and patellofemoral Skyline plain flim was taken. Joint space narrow, osteophyte generation, subchondral osteosclerosis and subchondral cystic degeneration were evaluated. All data were analyzed by K independent samples nonparametric test in order to find out the correlation between syndrome differ classification of knee osteoarthritis and X-ray image.

RESULTS

It was shown that after K independent samples nonparametric test about syndrome differ classification of knee osteoarthritis and X-ray image: there were significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte and Type II was the most serious, Type I was secondary, Type II was the lightest. Other index had no obvious difference among the three groups.

CONCLUSION

There is certain correlation between syndrome differ classification of knee osteoarthritis and X-ray image. There are significant differences among three types about lateral patella osteophyte, condyles of tibia osteophyte, the Type II is the most serious,Type I is secondary, Type II is the lightest. Consequently, it can be deduced that worse osteophyte is one of accordances of Type II-insufficiency of the spleen and kidney, with dampness infusion into bone and joints. And, the Type II is more serious stage in radiologic manifestation.

[Comparative study between different radiographic plans in knee osteoarthritis]

Perform a comparative analysis (with the criteria of Ahlbäck original classification) of the anteroposterior (AP) weight-bearing radiograph of knee in extension and of Rosenberg(2) view, in symptomatic arthritic knees. The analysis aims at revealing agreement or disagreement between (AP) view and Rosenberg view and the degree of articular degeneration and the advantages of these views.

PATIENTS AND METHODS

From January 2005 to March 2007, a prospective study was conducted with 76 selected patients (111 arthritic knees) attending the outpatient clinic, at the knee unit, and subjected to the radiographs proposed in the present study. Of the total number of patients (76), 52 were females and 24 males, having an average age of 62 (range, 50- 82 years). 41 patients had unilateral degeneration and 35 patients had bilateral degeneration. Of the total number of assessed knees (111), 66 were right knees and 45 were left knees. The study used the Kappa statistical analysis, which assesses interobserver agreement of qualitative data.

RESULTS

According to the Ahlbäck score, there was agreement between the orthopedist and the radiologist in 98.2% of cases in the AP weight-bearing view, and in 88.3% in the Rosenberg view. A highly significant agreement on both views between the orthopedist and the radiologist was noticed. However, the degree of agreement was higher for the AP weigh-bearing view than for the Rosenberg view. According to the Ahlbäck score, the AP weight-bearing view agreed with the Rosenberg view in only 27% of the cases for the orthopaedist, and in 31.5% for the radiologist. No significant agreement was found between the AP weight-bearing view and the Rosenberg view for the orthopedist and the radiologist.

CONCLUSIONS

There is no significant disagreement between experts concerning the classification of knee osteoarthritis, according to the Ahlbäck score, both for the AP weight-bearing view and the Rosenberg view. There is no agreement between the views, concerning the classification of knee osteoarthritis, both for the orthopedist and the radiologist, the Rosenberg view having shown more clearly the degree of articular degeneration. The posteroanterior view of Rosenberg provided a better assessment of degeneration of the articular surface, which in some cases led to a change in the classification of knee osteoarthritis and was routinely used.

Longitudinal long-term results of surgical treatment in patients with osteochondritis dissecans of the femoral condyles

In a longitudinal study, we performed a second follow-up examination on patients suffering from osteochondritis dissecans at the femoral condyles 10 years after a first follow-up, which had been performed 10 years after surgical treatment. Results (clinical score; radiological signs of OA) were analysed depending on the stage of the epiphyseal plate at the time of surgery, the used surgical procedure was divided into retrograde and anterograde procedures, and removal of loose bodies depending on the stage of the lesion. The analysis clearly exhibited that JOCD patients demonstrated better results than AOCD patients. The clinical score obtained after 10 years improved significantly with time, particularly for JOCD patients. Overall, when a retrograde procedure had been used in cases with an intact cartilage layer clinical results were better than those obtained in patients in whom an anterograde procedure with restoration of the joint surface or simple removal of the loose fragments had been performed. After a mean follow-up of 20 years the mean OA-stage was 0.27 in JOCD patients, whereas in AOCD patients a mean OA-stage of 1.55 was detected. Worst OA-changes were detected in patients in whom acrylic glue had been used for refixation of the loose bodies.

Radiological evaluation of the proximal tibiofibular joint in knees with severe primary osteoarthritis

The proximal tibiofibular joint (PTFJ) can be considered to be the fourth compartment of knee joint. Although degenerative diseases of the knee joint may also have detrimental effects on the PTFJ until now, details of arthritic affection of PTFJ in the elderly who have severe femorotibial arthritis have not been described. Convenience samples of knees of elderly patients with Kellgren-Lawrence grade III-IV primary osteoarthritis were investigated further in order to determine the X-ray findings of PTFJ. Sixty knees in 34 patients with an average age of 71 years (61-86 years) were examined. Both knees were examined in 26 patients. On the radiographs, 23 joints were grade IV, 14 were grade III, and 23 were grade II. At most, only minor differences were seen between knees on the same patient in terms of lower extremity alignment, grade of TFJ degeneration, grade of PTFJ degeneration, and type of PTFJ. Interobserver correlation was good for radiographic evaluation of PTFJ (kappa = 0.557). By intraobserver analysis with McNemar test, there was no statistically significant difference between the radiographic evaluations of PTFJ (p = 0.167). Arthritic grades of PTFJ and tibiofemoral joints were strongly correlated (Pearson coefficient r = 0.58, p < 0.001). No significant relation was found between type of PTFJ and grade of arthritis (chi(2) test, p = 0.42). In the light of these findings, the proximal tibiofibular joint should be evaluated for arthritic findings that may be responsible for lateral knee pain before a total knee arthroplasty operation is considered. The type of PTFJ is not related to the degree of this joint arthritis.

Efficacy of periosteal stimulation therapy for the treatment of osteoarthritis-associated chronic knee pain: an initial controlled clinical trial

OBJECTIVES

To examine the efficacy of periosteal stimulation therapy (PST, osteopuncture) for the treatment of chronic pain associated with advanced knee osteoarthritis.

DESIGN

Randomized, controlled clinical trial.

SETTING

Outpatient pain clinic.

PARTICIPANTS

Eighty-eight community-dwelling older adults with moderate knee pain or greater for 3 months or longer and Kellgren-Lawrence (K-L) grade 2 through 4 radiographic severity (80% had K-L 4).

INTERVENTION

Participants were randomized to receive PST or control PST once a week for 6 weeks.

MEASUREMENTS

Pain severity and self-reported function (Western Ontario and McMasters University Osteoarthritis Index (WOMAC)) and physical performance (Short Physical Performance Battery (SPPB)) were assessed at baseline, after the last PST session (post), and 3 months later (follow-up). Pain severity was also assessed monthly using the multidimensional pain inventory short form.

RESULTS

Pain was reduced significantly more in the PST group than in the control PST group at post (P=.003; mean WOMAC pain subscale baseline 9.4 vs 6.4) and 1 month later (P<.001), but by 2 months, pain levels had regressed to pre-intervention levels. The group-by-time interaction for the WOMAC function scale was significant at post (P=.04) but not at follow-up (P=.63). No significant group differences were found for the SPPB. Neither analgesic use nor global improvement differed between groups. There were four treatment dropouts.

CONCLUSION

PST affords short-term modest pain reduction for older adults with advanced knee OA. Future research should test the effectiveness of booster treatments in sustaining analgesic benefits and of combining PST with therapeutic exercise in ameliorating disability risk.

Reliability, reproducibility and variability of the traditional Histologic/Histochemical Grading System vs the new OARSI Osteoarthritis Cartilage Histopathology Assessment System

OBJECTIVE

For many years, the Histologic/Histochemical Grading System (HHGS) for osteoarthritis monitoring has been used as a histological scoring system for the quality of cartilage. There are, however, some limitations using this grading system. The goal of the investigation presented in this paper was to examine the hypothesized advantage of the recently introduced Osteoarthritis Research Society International (OARSI) Cartilage Histopathology Assessment System (OOCHAS) as compared to the most frequently used HHGS by means of reliability, reproducibility, and variability evaluation as well as the correlation analysis between the two systems in goat knee articular cartilage.

METHODS

Nine hundred and thirty-six sections of Dutch Milk goat articular knee cartilage were scored using light microscopy. Three observers applied the HHGS for all sections and subsequently, the OOCHAS. The same scoring procedure was repeated after a minimum interval of 1 week. For each system the reliability, reproducibility and variability as well as the correlation between both systems were determined.

RESULTS

The reliability of the OOCHAS was higher as compared to the HHGS. Both the HHGS as well the OOCHAS have an excellent intra- and inter-observer reproducibility and variability and a good positive correlation between the scores.

CONCLUSIONS

Although the HHGS has proven to be an excellent tool for histological scoring of cartilage quality, we recommend the OOCHAS as the premium choice while stressing the importance of further research investigating the correlation of the histological results to macroscopic and biochemical parameters.

Comparative assessment of outcome in osteoarthritis of the knee: the utility of knee scores

PURPOSE OF THE STUDY

The utility of scoring systems, which are used to determine health status or treatment benefit in patients with knee osteoarthritis is under discussion. Therefore it was the purpose of our investigation to evaluate the reliability and the concordance of two established knee scoring systems.

METHODS

Thirty-eight patients with unilateral knee osteoarthritis were scored by the Hospital for Special Surgery score and the Knee Society score. Two blinded observers rated the patients independently in order to determine the concordance of the scores, the correlation between the overall scores and their subscales such as "pain", "function" and "range of motion" and the inter-observer and intra-observer reliability.

RESULTS

There was a high correlation between the overall scores (r= 0.80) and between the scores and their subscales "range of motion" (r=0.89) and "function" (r=0.74). The correlation of scores for "pain" was slightly less (r=0.61). Mean inter-observer reliability ranged between r=0.58 and r=0.61. Mean intra-observer reliability was high for the overall scores as well as for the subscales of both scoring systems (r=0.64 to r=0.93 and r=0.73 to r=0.92).

CONCLUSION

We have found that the assessment of overall scores as well as of their main subscales is concordant and reliable in our patient sample. The application of these scoring systems in measuring health status in patients with knee osteoarthritis appears to be an acceptable method of audit. However, we feel that presentation of the results of knee scoring systems should include detailed information on the main subscales, since this allows for a better understanding of results.

Knee joint loading differs in individuals with mild compared with moderate medial knee osteoarthritis

OBJECTIVE

To compare the knee joint loading patterns in individuals with differing radiographic grades of knee osteoarthritis (OA) for characterization of the mechanical implications of different structural states, and to compare the knee adduction angular impulse, a measure of gait complementary to the commonly used peak knee adduction moment.

METHODS

Asymptomatic subjects (those without knee OA) having a Kellgren/Lawrence (K/L) radiographic severity grade of 0 or 1 (n = 28) and subjects with symptomatic knee OA having K/L grades of 2 (n = 66) or 3 (n = 23) were recruited. Gait analysis was used to calculate the peak external knee adduction moment and the external knee adduction angular impulse for the whole stance and for the 4 subdivisions of stance.

RESULTS

Both the peak knee adduction moment and the knee adduction angular impulse increased with K/L radiographic grade (P < 0.05). However, only the knee adduction angular impulse differed between subjects with moderate (grade 3) and those with mild (grade 2) radiographic knee OA (P < 0.05).

CONCLUSION

The differences between mild and moderate symptomatic radiographic knee OA are not only structural but also functional, based on the magnitude of load in the medial knee joint. Moreover, knee adduction angular impulse provides additional information beyond that available from the peak knee adduction moment, and may therefore be an important gait parameter to include in OA research. These findings are important for our understanding of the pathophysiologic mechanisms of OA.

Clinical evaluation of T2 values of patellar cartilage in patients with osteoarthritis

OBJECTIVE

The transverse relaxation time constant, T2, of articular cartilage has been proposed as a biomarker for osteoarthritis (OA). Previous studies have not clearly defined the relationship between cartilage T2 values and clinical methods of grading OA or known factors associated with OA. This study compared T2 values of patellar cartilage grouped by radiographic stage of patello-femoral OA and by body mass index (BMI).

METHODS

T2 values of patellar cartilage were calculated for 113 subjects using images acquired on a 1.5 T clinical scanner. Radiographs of the patello-femoral joint were graded for OA grading using the Kellgren-Lawrence scale.

RESULTS

No differences of T2 values were found across the stages of OA (P = 0.25), but the factor of BMI did have a significant effect (P < 0.0001) on T2 value.

CONCLUSIONS

The results indicate the T2 values are not sensitive to changes in radiographic stages of OA. In addition, differences of T2 values with BMI signify structural changes occurring within the patello-femoral joint and that BMI may be considered a factor for a potential increase of T2 values. Future studies comparing different OA grading methods with T2 mapping may highlight the sensitivity of T2 mapping in a clinical setting.

Relationship between the shape of tibial spurs on X-ray and meniscal changes on MRI in early osteoarthritis of the knee

OBJECTIVE

The purpose of this study was to evaluate the relationship between the shape of tibial spurs on plain X-rays and the meniscal changes on magnetic resonance imaging (MRI) in early osteoarthritis of the knee.

MATERIALS AND METHODS

Sixty-three patients (age range, 40 to 59 years; average, 51.8) underwent X-ray and MRI examinations of their knees. Ligament injuries caused by trauma and Kellgren Radiographic Grades III and IV on X-ray were excluded. The shapes of the medial and lateral tibial spurs on X-ray were classified into four types: (a) normal type; (b) horizontal type, in which the spur protruded horizontally; (c) upward type, in which the spur protruded upward; and (d) downward type, in which the spur protruded downward. The femorotibial angle (FTA) on the X-rays was also measured. The medial and lateral meniscal displacement rates on MRI were measured by the proportion by which the meniscal lesion protruded from the edge of the tibial joint surface to the overall meniscal width. The medial and lateral meniscal signal changes on MRI were classified into three types: (a) normal type; (b) intrameniscal type, which showed a high signal within the meniscus; and (c) tear type, which showed a high signal extending to the tibial joint surface. The relationships between the shape of the medial and lateral tibial spur classification on X-ray, the medial and lateral meniscal displacement rates on MRI, the medial and lateral meniscal signal changes on MRI and the FTA were evaluated statistically.

RESULTS

Statistically significant correlations were observed between the medial tibial spur classification on X-ray, the medial meniscal displacement rate on MRI and the medial meniscal signal change classification on MRI. In the downward type of medial tibial spur, the medial meniscal displacement rate (50.46+/-17.95%) and the percentage (8 out of 8 cases; 100%) involving the tear type of medial meniscus were greater than the other types. Statistical significance was not observed among the lateral tibial spur classification on X-ray, the lateral meniscal displacement rate on MRI and the lateral meniscal signal change classification on MRI. However, in the horizontal type of lateral tibial spur, the percentage (7 out of 10 cases; 70%) involving the tear type of lateral meniscus was greater than the other types. Correlations tended to be observed between the medial meniscal displacement rate on MRI and the FTA.

CONCLUSIONS

In this study, there was a relationship between the shape of the tibial spur on X-ray and the meniscal changes on MRI in early osteoarthritis of the knee. The shape of the medial tibial spur on X-ray can be a useful indicator for predicting the progression of osteoarthritis of the knee. A downward type of medial tibial spur classification on X-ray may be a risk factor for developing severe osteoarthritis of the knee.

[Rating scale for osteoarthritis knee assessment]

BACKGROUND

We undertook this study to develop a grading scale to assess knee osteoarthritis using the Bristol Score.

METHODS

Between August and November 2004, a clinimetrical, prospective, group-controlled, observational, cross-sectional and analytical study was done. The study sample was comprised of 55 patients, 35 years old and over, with clinical-radiographic diagnosis of knee osteoarthritis following the American Academy of Rheumatology criteria. The Bristol Score was used in 25 patients by two standardized orthopedic surgeons. Sensitivity, consistency and validity of the Bristol Score were determined. The new grading scale to assess osteoarthritis Magdalena de las Salinas H-1(MSH1) was used in 30 patients. Sensitivity, consistency and validity of the MSH1 were also determined. Both indexes were compared in these terms. An osteoarthritis radiographic score was developed to assess the validity of the MSH1.

RESULTS

Inter-observer intraclass correlation coefficient (ICC) for the Bristol Score in its categories was total 0.62, function 0.84, pain 0.40 and movement 0.89. Inter-observer ICC for MSH1 in its categories was total 0.91, function 0.92, pain 0.79 and movement 0.86 (p <0.0001). Inter-observer weighed kappa of the Bristol Score was 0.51 (p = 0.002), with 80% agreement. The weighed kappa for the MSH1 was 0.81 (p <0.0001) with 90% agreement. Correlation between the Bristol Score and the osteoarthritis radiographic score was -0.29 (p = 0.049). Correlation between the MSH1 and the radiographic score of osteoarthritis was -0.62 (p <0.01).

CONCLUSIONS

MSH1 achieved better validity than the Bristol Score and can be considered a reliable instrument to assess knee osteoarthritis.

Utility of delayed gadolinium-enhanced MRI (dGEMRIC) for qualitative evaluation of articular cartilage of patellofemoral joint

Delayed gadolinium-enhanced MRI of cartilage (dGEMRIC) was used for the measurement of relative proteoglycan depletion of articular cartilage in the patellofemoral (PF) joint following a proprietary protocol, which was compared with the X-ray images, proton density weighted MR images (PDWI) and arthroscopic findings. The study examined 30 knees. The ages ranged from 16 to 74 (average 40.3) years. The Gd-DTPA(2-)containing contrast medium was used in a single dose. The subjects were made to exercise the knee joint for 10 min; and MR images were taken 2 h after intravenous injection of contrast medium. T1-calculated images were produced and the region of interest (ROI) was set as follows. (1) ROI1: entire articular cartilage in a slice through the center of the patella. (2) ROI2: low signal region in T1-calculated images, which were set in a blind fashion by two observers. (3) ROI3: articular cartilage on one side that includes ROI2 where low signal region were detected (medial or lateral). ROI3 was set to examine the contrast of ROI2 with surrounding articular cartilage. The average T1 values of ROI1 was 393.5+/-33.6 ms for radiographic grade 0 and 361.3+/-11.1 ms for grade I, which showed a significant difference (P=0.036). The T1 value of ROI2 was 351.6+/-28.2 ms for grade I, 361.9+/-38.3 ms for grade II, 362.1+/-67.7 ms for grade III, and 297.8+/-54.1 ms for grade IV according to arthroscopic Outerbridge classification. All cases, that demonstrated decrease of T1 values on dGEMRIC (ROI2), showed abnormal arthroscopic or direct viewing findings. The ratio (ROI3/ROI2) in cases of only slight damage classified as Outerbridge grade I (6 cases) was an average of 1.04+/-0.02 and was 1.0 or greater in all cases, thereby indicating well-defined contrast with the surrounding cartilage. The diagnosis of damage in articular cartilage was possible in all 16 cases with radiographic K-L grade I on dGEMRIC, while the intensity changes were not found in 10 of 16 cases on PDWI. The dGEMRIC with a single-dose would be useful on a diagnosis of the area demonstrating early relative proteoglycan depletion in the articular cartilage of the PF joint prior to any discernible changes in the subchondral bone on X-ray images and exceeds to plain MR images for examining deterioration of articular cartilage.

Are they relevant? A critical evaluation of the international classification of functioning, disability, and health core sets for osteoarthritis from the perspective of patients with knee osteoarthritis in Singapore

OBJECTIVES

To determine the extent to which health items identified from the perspective of patients with knee osteoarthritis can be linked with the International Classification of Functioning, Disability and Health (ICF); and to evaluate critically the content validity of ICF comprehensive and brief core sets for osteoarthritis.

METHODS

Items identified from a focus group study were linked independently by two researchers based on the 10 a priori linking rules. Both percentage agreement and kappa statistics were calculated to measure interobserver agreement. Any disagreements were resolved by reaching a consensus among the researchers. The categories linked with all items were compared with the comprehensive core set, while the categories linked with those items reported as important by over 30% of subjects within each of three local ethnic groups (Chinese, Malay, and Indian) were compared with the brief core set. Both comparisons were made only at the second level of the ICF.

RESULTS

In all, 74 items were linked with 44 different ICF categories through 105 linkages with generally good interobserver agreement. The 69 items were linked with the ICF at the third or fourth levels. Both commonalities and disparities were found through comparison between the categories linked with these items and both core sets.

CONCLUSIONS

All items could be successfully linked with the ICF. The comprehensive core set showed good content validity, while the brief core set needs to be supported by more empirical evidence in various sociocultural contexts. This study specifically complemented the development and refinement of both core sets from the perspective of patients with knee osteoarthritis.

Gap balancing in total knee arthroplasty

It is well known that the success of total knee arthroplasty is collectively dependent on the proper recreation of the joint line, appropriate soft tissue balancing, and respectful management of the extensor mechanism. One of the most decisive factors within the surgeon's control is the reestablishment of proper knee kinematics through both medial-lateral and flexion-extension ligamentous balancing. This can be accomplished only by a comprehensive intraoperative evaluation in full flexion, mid flexion, and full extension to minimize potential gap mismatches. Most of the discussion will focus on this aspect of soft tissue balancing, but this does not undermine the importance of the other aforementioned principles of successful knee arthroplasty.

Ahlbäck grading of osteoarthritis of the knee: poor reproducibility and validity based on visual inspection of the joint

BACKGROUND

Staging of osteoarthritis (OA) of the knee is commonly based on the Ahlbäck classification. Its value has been questioned, however. We therefore evaluated the reproducibility and validity of this classification of knee osteoarthritis.

PATIENTS AND METHODS

48 patients (48 knees) (medial OA: n = 30; lateral OA: n = 8) operated with total knee prostheses were studied. Weight-bearing radiographs were evaluated twice by 4 observers. Presence of bone attrition on radiographs was compared with observations of the resected parts of the distal femur and proximal tibia.

RESULTS

When the same observer classified the radio-graphs twice according to Ahlbäck, the repeatability was fair in both medial OA (kappa values = 0.15-0.65) and lateral OA (0.59-0.76), and between different observers it was poor (kappa: 0.1). Comparison between radiographic classification and classification based on visual inspection of the bone pieces removed during arthroplasty revealed an acceptable sensitivity in both medial (67-95%) and lateral OA (43-86%), but the specificity was low (medial: 11-67%; lateral: 25-75%).

INTERPRETATION

The main problem with the Ahlbäck classification was that a joint space could often be seen radiographically despite the presence of bone attrition on the preparations. According to our study, conventional radiographs do not give sufficient information for correct grading.

Validation of American College of Rheumatology classification criteria for knee osteoarthritis using arthroscopically defined cartilage damage scores

OBJECTIVE

To validate the ability of the American College of Rheumatology (ACR) clinical classification criteria and the ACR clinical plus radiographic classification criteria for osteoarthritis of the knee to predict articular cartilage damage.

METHODS

Ninety subjects with knee osteoarthritis (OA) who were enrolled in a prospective study determining the therapeutic efficacy of arthroscopic irrigation were characterized as to whether they fulfilled the ACR clinical classification criteria or the ACR clinical plus radiographic classification criteria. Ten rheumatoid arthritis (RA) patients were included as controls. Cartilage damage was defined using the ACR/Knee Arthroscopy Osteoarthritis Scale (ACR/KAOS) system, which is a validated outcome instrument for knee OA based on arthroscopic visualization. Mean values of the damage scores in each group were calculated and compared by t-test to determine statistical significance between the 3 groups.

RESULTS

The mean ACR/KAOS score for the 10 RA patients was 1.8 [SD 1.22; range 0 to 4]. Of the 90 OA patients who underwent arthroscopy, only 73 patients had sufficient videotape to make an accurate assessment by the blinded assessor. The mean ACR/KAOS score for the 6 OA patients who fulfilled only the ACR clinical classification was 17.4 [SD 11.3; range 5 to 34.3] and the mean ACR/KAOS score for the 67 patients who fulfilled the ACR clinical plus radiographic classification criteria was 42.0 [SD 29.1; range 5.1 to 118.4]. These differences were statistically significant (RA versus OA clinical P=0.02; RA versus OA clinical+radiographic P<or=0.01). Nonparametric multivariate analysis did not reveal significant correlations between ACR/KAOS scores and WOMAC global scores (r=0.11, P=0.39), patient VAS (r=0.29, P=0.022), and age (r=0.29, P=0.08).

CONCLUSIONS

The ACR clinical and clinical plus radiographic criteria for OA of the knee accurately predict cartilage damage as assessed by arthroscopy. Furthermore, the ACR clinical classification criteria identify OA patients with cartilage damage before any radiographic change, while the ACR clinical plus radiographic classification criteria identify OA patients with more severe cartilage damage.

RELEVANCE

The ACR classification criteria correlates well with articular cartilage damage in patients with OA.

Factors associated with functional limitation in stair climbing in female Japanese patients with knee osteoarthritis

BACKGROUND

Osteoarthritis (OA) of the knee is a common form of arthritis, and affects quality of life. We investigated factors associated with functional limitation in stair climbing among female Japanese patients with knee OA. As weight is a known risk factor for knee OA, we focused on body weight at 40 years of age, and examined the association with present weight, past weight, and weight change.

METHODS

Subjects were 360 Japanese women aged 40-92 years who were newly diagnosed with knee OA at 3 university hospitals over a 1-year period. Factors associated with the severity of functional limitation in stair climbing were assessed by calculating odds ratios (OR) using the proportional odds model in logistic regression.

RESULTS

Weight at diagnosis showed a positive association with severe functional limitation in stair climbing; however, a negative association was observed for weight change since age 40. Further analysis indicated that the association with weight at age 40 (highest vs. lowest quartile, OR=2.84, 95% confidence interval: 1.03-7.83, trend p=0.071) is stronger than weight at diagnosis. Other significant characteristics were age (70+ vs. 40-59 years, OR=7.37), previous knee pain and/or swelling 12 years or more before diagnosis (OR=2.67), and physical work (OR=1.94). In addition, higher parity was found to be a negatively associated factor (for tripara or more, OR=0.41).

CONCLUSIONS

This study identified factors, such as heavy weight at age 40 and physical labor, which are potentially useful for preventing severe functional limitation for female knee OA patients. In addition, higher parity was associated with milder stair climbing limitation.

Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis

BACKGROUND

Glucosamine and chondroitin sulfate are used to treat osteoarthritis. The multicenter, double-blind, placebo- and celecoxib-controlled Glucosamine/chondroitin Arthritis Intervention Trial (GAIT) evaluated their efficacy and safety as a treatment for knee pain from osteoarthritis.

METHODS

We randomly assigned 1583 patients with symptomatic knee osteoarthritis to receive 1500 mg of glucosamine daily, 1200 mg of chondroitin sulfate daily, both glucosamine and chondroitin sulfate, 200 mg of celecoxib daily, or placebo for 24 weeks. Up to 4000 mg of acetaminophen daily was allowed as rescue analgesia. Assignment was stratified according to the severity of knee pain (mild [N=1229] vs. moderate to severe [N=354]). The primary outcome measure was a 20 percent decrease in knee pain from baseline to week 24.

RESULTS

The mean age of the patients was 59 years, and 64 percent were women. Overall, glucosamine and chondroitin sulfate were not significantly better than placebo in reducing knee pain by 20 percent. As compared with the rate of response to placebo (60.1 percent), the rate of response to glucosamine was 3.9 percentage points higher (P=0.30), the rate of response to chondroitin sulfate was 5.3 percentage points higher (P=0.17), and the rate of response to combined treatment was 6.5 percentage points higher (P=0.09). The rate of response in the celecoxib control group was 10.0 percentage points higher than that in the placebo control group (P=0.008). For patients with moderate-to-severe pain at baseline, the rate of response was significantly higher with combined therapy than with placebo (79.2 percent vs. 54.3 percent, P=0.002). Adverse events were mild, infrequent, and evenly distributed among the groups.

CONCLUSIONS

Glucosamine and chondroitin sulfate alone or in combination did not reduce pain effectively in the overall group of patients with osteoarthritis of the knee. Exploratory analyses suggest that the combination of glucosamine and chondroitin sulfate may be effective in the subgroup of patients with moderate-to-severe knee pain. (ClinicalTrials.gov number, NCT00032890.).

Effects of repetitive shortwave diathermy for reducing synovitis in patients with knee osteoarthritis: an ultrasonographic study

BACKGROUND AND PURPOSE

Shortwave (SW) diathermy can be used to improve vascular circulation and reduce inflammation and pain for patients with osteoarthritis. However, reduction in synovial inflammation has never been explored. The purpose of this study was to investigate whether repetitive SW diathermy, using ultrasonographic examination, could reduce synovitis in patients with knee osteoarthritis.

SUBJECTS AND METHODS

Thirty subjects with 44 osteoarthritic knees participated in this study. Eleven subjects received SW, and 10 subjects received SW and nonsteroidal anti-inflammatory drugs. Nine subjects received no treatment and served as a control group. Synovial sac thickness superior, medial, and lateral to the patella was measured using ultrasonography. The sum of these 3 measurements was taken as the total synovial sac thickness. Subjects in the treatment groups underwent ultrasonographic examination before and after 10, 20, and 30 treatments, whereas control subjects underwent ultrasonographic examination before the experiment and then once every 2 or 3 weeks for a total of 3 follow-up measurements.

RESULTS

After 10 SW diathermy treatments, the total synovial sac thickness in both treatment groups was significantly less than the initial thickness, and the synovial sac continued to become significantly thinner with 20 sessions of treatment. These observations were not made in the control subjects.

DISCUSSION AND CONCLUSION

The results indicate that SW diathermy in patients with knee osteoarthritis can significantly reduce both synovial thickness and knee pain. Such reductions of synovial sac thickness and pain index continue over treatment sessions.

[Clinical and radiographic characteristics of patients with osteoarthritis of knees]

The study of 60 outpatients with clinical diagnosis of the osteoarthritis (OA) of the knees is performed. Measured parameters were: general demographic data, clinical data and standard radiographic x-ray of knees in standing position, graduated by Kellgren and Lawrence clasificiation from 0-4. The aim of this study was to establish clinical and radiographic features of OA of knees and to compare those characteristiscs in the two subgroups of patients according to radiographic stages: a group of an early disease (stages 0 or 1) and a group of late disease (stages from 2 to 4). The mean age was 60 years with range from 39 to 85 years. 85% of patients were female. Distribution of patients according to Kellgren and Lawrence radiographic stages was as follows: 13 patients (21,7%) in grade 0, 17 (28,3%) in grade 1, 10 (16,7%) in grade 2, 11 (18,3%) in grade 3, and nine patients (15%) in grade 4. Crepitus on movement was registered in aproximatelly 80% of all patients, with no difference between early and late disease. Instability of the knee was present in eleven patients (18%), with more than a half of them (56%) in a radiographic grade 4 of OA of knees. There were no difference between functional parameters comparing original group of patients and two sub-groupes. Crepitus on movement was not related to any specific radiographic stage of disease, but instability of knee was frequently registered in late disease.

Serum cartilage oligomeric matrix protein and other biomarker profiles in tibiofemoral and patellofemoral osteoarthritis of the knee

OBJECTIVES

There is some evidence that tibiofemoral osteoarthritis (TFJ OA) and patellofemoral osteoarthritis (PFJ OA) may have different risk factors. To investigate the possibility that these conditions are separate disease entities, we compared biomarker profiles of patients with each disease.

METHODS

Serum samples were taken from 222 patients who had knee pain and X-ray signs of knee OA. Eighty-two had only medial TFJ OA and 38 only PFJ OA in one or both knees. The remaining patients had either mixed disease or equivocal radiographic evidence of OA. The following biomarkers were measured in serum samples from baseline and follow-up visits: cartilage oligomeric matrix protein (COMP), glycosaminoglycan, keratan sulphate epitope 5D4, YKL-40, osteocalcin, C-telopeptide of type I collagen, hyaluronan and C-reactive protein.

RESULTS

The two subsets of OA (TFJ and PFJ) had similar radiographic disease severity and there were no significant differences in the presence and patterns of pain scores (visual analogue scale and Western Ontario and McMaster Universities Osteoarthritis Index). No difference was found for the biomarkers between the two groups, with one exception. Both baseline and area under the curve per month COMP concentrations were significantly higher in the TFJ than the PFJ group (P<0.01).

CONCLUSIONS

The reduced serum COMP in PFJ disease compared with TFJ OA could be due to small articular cartilage volume in the latter or to a qualitative difference in cartilage metabolism.

Use of hip and knee clinical scoring systems in prosthesis surgery in Norwegian hospitals

In a postal survey of all orthopaedic surgery departments performing total hip or knee replacements in Norway, we inquired about the use of hip or knee scoring systems and their impact. All 63 eligible hospitals responded to the questionnaire. Thirteen (21%) reported routine use of hip clinical scoring systems, and five (9%) used knee clinical scoring systems. The Harris hip score and The Knee Society clinical rating system were the most prevalent. We received five different versions of the Harris hip score. The regional/university hospitals most commonly used clinical scoring systems. The adoption of clinical scoring systems did not differ with the annual procedure volumes of the hospitals.

Improvement of Muscle Strength in Osteoarthritic Knee Patients After Intraarticular Knee Injection of Hyaluronan

OBJECTIVE

The objective of this study was to investigate whether the knee concentric and eccentric muscle strengths can be improved in patients with bilateral knee osteoarthritis after intraarticular hyaluronan injections.

DESIGN

A total of 25 patients with bilateral knee osteoarthritis and with a radiographic Ahlbäck grading scale of I or II participated in this study. One session of intraarticular knee injection of hyaluronan was given to both knees (weekly intraarticular knee hyaluronan injections for a total of 5 wks). Knee concentric and eccentric muscle strengths were recorded between 10 and 90 degrees of knee flexion. The recordings were done on two angular velocities, 80 and 240 degrees/sec. This study took place in a tertiary medical center with a gait laboratory and a KIN-COM isokinetic dynamometer.

RESULTS

An increase in concentric and eccentric muscle strength adjusted for body weight (P < 0.01) was observed in both knees, ranging between 5.1% and 27.7%.

CONCLUSION

The decreased knee muscle contraction strength (concentric and eccentric) can be improved in knee osteoarthritis patients with an Ahlbäck grading scale of I or II after five weekly intraarticular knee injections of hyaluronan.

Association between radiographic joint space narrowing, function, pain and muscle power in severe osteoarthritis of the knee

OBJECTIVE

To examine the association between radiographic classification of severe knee osteoarthritis and measurements of function, pain and power.

DESIGN

Cross-sectional study.

SETTING

Specialist orthopaedic hospital.

SUBJECTS

One hundred and twenty-three patients on the waiting list for elective knee arthroplasty.

OUTCOME MEASURES

Weight-bearing antero-posterior radiographs scored for severity of osteoarthritis using the Kellgren and Lawrence scale. Function measured using the function subscale of the WOMAC (Western Ontario and McMaster Universities) index, timed tests of walking speed and sit-to-stand. Pain measured using the pain subscale of the WOMAC index and a visual analogue scale. Extensor strength of the lower limb measured with the leg extensor power rig.

RESULTS

Within any radiographic grade there was considerable variation in function: WOMAC function for patients with grade 2 mean 64 (47-86), grade 3 mean 47 (12-89) grade 4 mean 45 (2-92). There was poor correlation between radiographic score function, pain or muscle power, with no statistically significant associations. A wide range of scores was also seen within patients with the same radiographic grade.

CONCLUSIONS

Radiographic score was not found to be closely associated with function. Amongst patients with the same radiographic score there was considerable variation in function, pain and power.