Aberrant infrapatellar fat metabolism is a notable feature provoking inflammation and fibrosis in the progression of osteoarthritis (OA). Irisin, a secretory subunit of fibronectin type III domain containing 5 (FNDC5) regulate adipose morphogenesis, energy expenditure, skeletal muscle, and bone metabolism. This study aims to characterize the biological roles of Irisin signaling in an infrapatellar fat formation and OA development. Injured articular specimens were harvested from 19 patients with end-stage knee OA and 11 patients with the femoral neck fracture. Knee joints in mice that overexpressed Irisin were subjected to intra-articular injection of collagenase to provoke OA. Expressions of Irisin, adipokines, and MMPs probed with RT-quantitative PCR. Infrapatellar adiposity, articular cartilage damage, and synovial integrity verified with histomorphometry and immunohistochemistry. Infrapatellar adipose and synovial tissues instead of articular cartilage exhibited Irisin immunostaining. Human OA specimens showed 40% decline in Irisin expression than the non-OA group. In vitro, the gain of Irisin function enabled synovial fibroblasts but not chondrocytes to display minor responses to the IL-1β provocation of MMP3 and MMP9 expression. Of note, Irisin signaling reduced adipogenic gene expression and adipocyte formation of mesenchymal progenitor cells. In collagenase-mediated OA knee pathogenesis, forced FNDC5 expression in articular compromised the collagenase-induced infrapatellar adipose hypertrophy, synovial hypercellularity, and membrane hyperplasia. These adipose-regulatory actions warded off the affected knees from cartilage destruction and gait aberrance. Likewise, intra-articular injection of Irisin recombinant protein mitigated the development of infrapatellar adiposity and synovitis slowing down the progression of cartilage erosion and walking profile irregularity. Affected joints and adipocytes responded to the Irisin recombinant protein treatment by reducing the expressions of cartilage-deleterious adipokines IL-6, leptin, and adiponectin through regulating PPAR&gamma, function. Irisin dysfunction is relevant to the existence of end-stage knee OA. Irisin signaling protects from excessive adipogenesis of mesenchymal precursor cells and diminished inflammation and cartilage catabolism actions aggravated by adipocytes and synovial cells. This study sheds emerging new light on the Irisin signaling stabilization of infrapatellar adipose homeostasis and the perspective of the therapeutic potential of Irisin recombinant protein for deescalating knee OA development

Aims. The aetiologies of common degenerative spine, hip, and knee pathologies are still not completely understood. Mechanical theories have suggested that those diseases are related to sagittal pelvic morphology and spinopelvic-femoral dynamics. The link between the most widely used parameter for sagittal pelvic morphology, pelvic incidence (PI), and the onset of degenerative lumbar, hip, and knee pathologies has not been studied in a large-scale setting. Methods. A total of 421 patients from the Cohort Hip and Cohort Knee (CHECK) database, a population-based observational cohort, with hip and knee complaints < 6 months, aged between 45 and 65 years old, and with lateral lumbar, hip, and knee radiographs available, were included. Sagittal spinopelvic parameters and pathologies (spondylolisthesis and degenerative disc disease (DDD)) were measured at eight-year follow-up and characteristics of hip and knee osteoarthritis (OA) at baseline and eight-year follow-up. Epidemiology of the degenerative disorders and clinical outcome scores (hip and knee pain and Western Ontario and McMaster Universities Osteoarthritis Index) were compared between low PI (< 50°), normal PI (50° to 60°), and high PI (> 60°) using generalized estimating equations. Results. Demographic details were not different between the different PI groups. L4 to L5 and L5 to S1 spondylolisthesis were more frequently present in subjects with high PI compared to low PI (L4 to L5, OR 3.717; p = 0.024 vs L5 to S1 OR 7.751; p = 0.001). L5 to S1 DDD occurred more in patients with low PI compared to high PI (OR 1.889; p = 0.010), whereas there were no differences in L4 to L5 DDD among individuals with a different PI. The incidence of hip OA was higher in participants with low PI compared to normal (OR 1.262; p = 0.414) or high PI (OR 1.337; p = 0.274), but not statistically different. The incidence of knee OA was higher in individuals with a high PI compared to low PI (OR 1.620; p = 0.034). Conclusion. High PI is a risk factor for development of spondylolisthesis and knee OA. Low pelvic incidence is related to DDD, and may be linked to OA of the hip. Level of Evidence: 1b. Cite this article: Bone Joint J 2020;102-B(9):1261–1267

With the rising rates, and associated costs, of total knee arthroplasty (TKA), enhanced clarity regarding patient appropriateness for TKA is warranted. Towards addressing this gap, we elucidated in qualitative research that surgeons and osteoarthritis (OA) patients considered TKA need, readiness/willingness, health status, and expectations of TKA most important in determining patient appropriateness for TKA. The current study evaluated the predictive validity of pre-TKA measures of these appropriateness domains for attainment of a good TKA outcome. This prospective cohort study recruited knee OA patients aged 30+ years referred for TKA at two hip/knee surgery centers in Alberta, Canada. Those receiving primary, unilateral TKA completed questionnaires pre-TKA assessing TKA need (WOMAC-pain, ICOAP-pain, NRS-pain, KOOS-physical function, Perceived Arthritis Coping Efficacy, prior OA treatment), TKA readiness/willingness (Patient Acceptable Symptom State (PASS), willingness to undergo TKA), health status (PHQ-8, BMI, MSK and non-MSK comorbidities), TKA expectations (HSS KR Expectations survey items) and contextual factors (e.g., age, gender, employment status). One-year post-TKA, we assessed for a ‘good outcome’ (yes/no), defined as improved knee symptoms (OARSI-OMERACT responder criteria) AND overall satisfaction with TKA results. Multiple logistic regression, stepwise variable selection, and best possible subsets regression was used to identify the model with the smallest number of independent variables and greatest discriminant validity for our outcome. Receiver Operating Characteristic (ROC) curves were generated to compare the discriminative ability of each appropriateness domain based on the ‘area under the ROC curve’ (AUC). Multivariable robust Poisson regression was used to assess the relationship of the variables to achievement of a good outcome. f 1,275 TKA recipients, 1,053 (82.6%) had complete data for analyses (mean age 66.9 years [SD 8.8]; 58.6% female). Mean WOMAC pain and KOOS-PS scores were 11.5/20 (SD 3.5) and 52.8/100 (SD 17.1), respectively. 78.1% (95% CI 75.4–80.5%) achieved a good outcome. Stepwise variable selection identified optimal discrimination was achieved with 13 variables. The three best 13-variable models included measures of TKA need (WOMAC pain, KOOS-PS), readiness/willingness (PASS, TKA willingness), health status (PHQ-8, troublesome hips, contralateral knee, low back), TKA expectations (the importance of improved psychological well-being, ability to go up stairs, kneel, and participate in recreational activities as TKA outcomes), and patient age. Model discrimination was fair for TKA need (AUC 0.68, 95% CI 0.63-0.72), TKA readiness/willingness (AUC 0.61, 95% CI 0.57-0.65), health status (AUC 0.59, 95% CI 0.54-0.63) and TKA expectations (AUC 0.58, 95% CI 0.54-0.62), but the model with all appropriateness variables had good discrimination (AUC 0.72, 95% CI 0.685-0.76). The likelihood of achieving a good outcome was significantly higher for those with greater knee pain, disability, unacceptable knee symptoms, definite willingness to undergo TKA, less depression who considered improved ability to perform recreational activities or climb stairs ‘very important’ TKA outcomes, and lower in those who considered it important that TKA improve psychological wellbeing or ability to kneel. Beyond surgical need (OA symptoms) and health status, assessment of patients’ readiness and willingness to undergo, and their expectations for, TKA, should be incorporated into assessment of patient appropriateness for surgery

Introduction. Pain related to knee osteoarthritis (OA) is a complex phenomenon that cannot be fully explained by radiographic disease severity. We hypothesized that pain phenotypes are likely to be derived from a confluence of factors across multiple domains: knee OA pathology, psychology, and neurophysiological pain processing. The purpose of this study was to identify distinct phenotypes of knee OA, using measures from the proposed domains. Methods. Data from 3494 subjects participating in the Osteoarthritis Initiative (OAI) study was analyzed. Variables analyzed included: radiographic OA severity (Kellgren-Lawrence grade), isometric quadriceps strength, Body Mass Index (BMI), comorbidities, CES-D Depression subscale score, Coping Strategies Questionnaire Catastrophizing subscale score, number of pain sites, and knee tenderness on physical examination. Variables used for comparison across classes included pain severity, WOMAC disability score, sex and age. Latent Class Analysis was performed. Model solutions were evaluated using the Bayesian Information Criterion. One-way ANOVAs and post hoc least significance difference tests were used for comparison of classes. Results. A four-class model was identified. Class 1 (57% of study population) had lesser radiographic OA, little psychological involvement, greater strength, and less pain sensitivity. Class 2 (28%) had higher rates of knee joint tenderness. Class 3 (10%) had greater psychological distress and more bodily pain sites. Class 4 (4%) had more comorbidities. Additionally, Class 1 was the youngest, had the lowest disability, and least pain. Class 4 was the oldest. Class 2 had a higher proportion of females. Class 3 had the worst disability and most pain. Conclusions. Four distinct pain phenotypes for knee OA were identified. Psychological factors, knee tenderness, and comorbidities appear to be important in defining phenotypes of OA-related pain. Therapies in knee OA should take a multicomponent approach, recognizing the factors most relevant to an individual's experience of pain

Osteoarthritis (OA) is the most common form of arthritis worldwide. It is a major cause of disability in the adult population with its prevalence expected to increase dramatically over the next 20 years. Although current therapies can alleviate symptoms and improve function in early course of the disease, OA inevitably progresses to end-stage disease requiring total joint arthroplasty. Mesenchymal stromal cells (MSCs) have emerged as a candidate cell type with great potential for intra-articular (IA) repair therapy. However, there is still a considerable lack of knowledge concerning their behaviour, biology and therapeutic effects. To start addressing this, we explored the secretory profile of bone marrow derived MSCs in early and end-stage knee OA synovial fluid (SF). Subjects were recruited and categorised into early [Kellgren-Lawrence (KL) grade I and II, n=12] and end-stage (KL grade III and IV, n=11) knee OA groups. The SF proteome of early and end-stage OA was tested before and three days after the addition of bone marrow MSCs (16.5×10^3, single donor) using multiplex ELISA (64 cytokines) and mass spectrometry (302 proteins detected). Non parametric Wilcoxon-signed rank test for paired samples was used to compare the levels of proteins before and after addition of MSCs in early and end-stage knee OA SF. Significant differences were determined after multiple comparisons correction (FDR) with a p<0.05. Gender distribution and BMI were not statistically different between the two cohorts (p>0.05). However, patients in early knee OA cohort were significantly younger (44.7 years, SD=7.1) than patients in the end-stage cohort (58.6 years, SD=4.4; p<0.05). In both early and end-stage knee OA, MSCs increased the levels of VEGF-A (by 320.24 pg/mL), IL-6 (by 826.78 pg/mL) and IL-8 (by 128.85 pg/mL), factors involved in angiogenesis; CXCL1/2/3 (by 103.35 pg/mL), CCL2 (by 1187.27 pg/mL), CCL3 (by 15.82 pg/mL) and CCL7 (by 10.43 pg/mL), growth factors and chemokines. However, CXCL5 (by 48.61 pg/mL) levels increased only in early knee OA, whereas PDGF-AA (by 15.36 pg/mL) and CXCL12 (by 497.19 pg/mL) levels increased only in end-stage knee OA. This study demonstrates that bone marrow derived MSCs secrete angiogenic and chemotactic factors both in early and end-stage knee OA. More importantly, MSCs show a differential reaction between early and end-stage OA. Functional assays are required to further understand on how the therapeutic effect of MSCs is modulated when exposed to OA SF

In addition to mechanical stresses, an inflammatory mediated association between obesity and knee osteoarthritis (OA) is increasingly being recognised. Adipokines, such as adiponectin and leptin, have been postulated as likely mediators. Clinical and epidemiological differences in OA by race have been reported. What contributes to these differences is not well understood. In this study, we examined the profile of adipokines in knee synovial fluid (SF) and the gene expression profile of the infra-patellar fat pad (IFP) by race among patients with end-stage knee OA scheduled for knee arthroplasty. Age, sex, weight and height (used to derive body mass index (BMI)) and race (White, Asian and Black) were elicited through self-report questionnaire prior to surgery. SF and IFP samples were collected at the time of surgery. Adipokines (adiponectin and leptin) were examined in the SF using MAGPIX Multiplex platform. IFP was profiled using Human Adipogenesis PCRArray and genes of interest were further validated via quantitative relative RT-PCR using Student's t-test. Overall differences in adiponectin and leptin concentrations were tested across race. Linear regression modeling was used to investigate the association between adiponectin and leptin concentrations (outcomes) and race (predictor; referent group: White), adjusting for age, sex and BMI. 67 patients (18 White, 33 Asian, 16 Black) were included. Mean SF adiponectin concentration was greatest in Whites (1175.05 ng/mL), followed by Blacks (868.53 ng/mL) and Asians (702.23 ng/mL) (p=0.034). The mean SF leptin concentration was highest in Blacks (44.88 ng/mL), followed by Whites (29.86 ng/mL) and Asians (20.18 ng/mL) (p=0.021). Regression analysis showed Asians had significantly lower adiponectin concentrations compared to Whites (p<0.05). However, leptin concentrations did not differ significantly by race after adjusting for covariates. Testing of the IFP, using the Adipogenesis PCRArray, showed significant higher expression of LEP gene (leptin, p=0.03) in Asians (n=4) compared to Whites (n=4). There appears to be important racial differences in the SF adiponectin profile among individuals with end-stage knee OA. Differential gene expression in the IFP across racial groups could be a potential contributory source for the noted SF variations. Further work to determine the source and function of adipokines in knee OA pathophysiology across racial groups is warranted

To identify the differences in inflammatory profiles between hip OA, knee OA and non-OA control cohorts and investigate the association between cytokine expression and clinical outcome measurements, specifically pain. A total of 250 individuals were recruited in three cohorts (100 knee OA, 50 hip OA, 100 control). Serum was collected and inflammatory profiles analysed using the Multiplex Human Cytokine Panel (Millipore) on the Luminex 100 platform (Luminex Corp., Austin, TX). The pain, physical function and activity limitations of hip OA cohort were scored using the WOMAC, SF-36, HHS and UCLA scores. All cytokine levels were compared between cohorts individually using Mann–Whitney–Wilcoxon (MWW) test with Bonferroni multiple comparison correction. Within hip OA cohorts, the effect of hip alignment (impingement and dysplasia) and radiographic grade (Kellgren and Lawrence grade, K/L grade) on cytokine levels were accessed by MWW test. Spearman's rank correlation test used to assess the association between cytokines and pain levels. The three cohorts showed distinct inflammatory profiles. Specifically, EGF, FGF-2, MCP-3, MIP-1a, IL-8 were significant different between knee and hip OA; FGF-2, GRO, IL-8, MCP-1, VEGF were significant different between hip OA and control; Eotaxin, GRO, MCP-1, MIP-1b, VEGF were significant different between knee OA and control (p-value < 0.0012). For hip OA cohorts, cytokines do not differ between K/L grade three and K/L grade four or between patients that displayed either impingement or dysplasia. Three cytokines were significant associated with pain: IL-6 (p-value = 0.045), MDC (p-value = 0.032) and IP-10 (p-value = 0.038). We have demonstrated that differences in serum inflammatory profiles exist between hip and knee OA patients. These differences suggest that OA may include different inflammatory subtypes according to affected joints. We also identified that the cytokine IL-6, MDC and IP-10 are associated with pain level in hip OA patients. These cytokines might help explain the inconsistent of presentation of pain with radiographical severity of OA joints. Future studies are needed to validate our findings and then to understand the following questions: (1) how differently affected joints are reflected in systematic biomarkers; (2) how these cytokines are biologically involved in the OA pain pathway

Individuals with multi-compartment knee osteoarthritis (KOA) frequently experience challenges in activities of daily living (ADL) such as stair ambulation. The Levitation “Tri-Compartment Offloader” (TCO) knee brace was designed to reduce pain in individuals with multicompartment KOA. This brace uses novel spring technology to reduce tibiofemoral and patellofemoral forces via reduced quadriceps forces. Information on brace utility during stair ambulation is limited. This study evaluated the effect of the TCO during stair descent in patients with multicompartment KOA by assessing knee flexion moments (KFM), quadriceps activity and pain. Nine participants (6 male, age 61.4±8.1 yrs; BMI 30.4±4.0 kg/m2) were tested following informed consent. Participants had medial tibiofemoral and patellofemoral OA (Kellgren-Lawrence grades two to four) diagnosed by an orthopaedic surgeon. Joint kinetics and muscle activity were evaluated during stair descent to compare three bracing conditions: 1) without brace (OFF); 2) brace in low power (LOW); and 3) brace in high power (HIGH). The brace spring engages from 60° to 120° and 15° to 120° knee flexion in LOW and HIGH, respectively. Individual brace size and fit were adjusted by a trained researcher. Participants performed three trials of step-over-step stair descent for each bracing condition. Three-dimensional kinematics were acquired using an 8-camera motion capture system. Forty-one spherical reflective markers were attached to the skin (on each leg and pelvis segment) and 8 markers on the brace. Ground reaction forces and surface EMG from the vastus medialis (VM) and vastus lateralis (VL) were collected for the braced leg. Participants rated knee pain intensity performing the task following each bracing condition on a 10cm Visual Analog Scale ranging from “no pain” (0) to “worst imaginable pain” (100). Resultant brace and knee flexion angles and KFM were analysed during stair contact for the braced leg. The brace moment was determined using brace torque-angle curves and was subtracted from the calculated KFM. Resultant moments were normalized to bodyweight and height. Peak KFMs were calculated for the loading response (Peak1) and push-off (Peak2) phases of support. EMG signals were normalized and analysed during stair contact using wavelet analysis. Signal intensities were summed across wavelets and time to determine muscle power. Results were averaged across all 3 trials for each participant. Paired T-tests were used to determine differences between bracing conditions with a Bonferroni adjustment for multiple comparisons (α=0.025). Peak KFM was significantly lower compared to OFF with the brace worn in HIGH during the push-off phase (p Table 1: Average peak knee flexion moments, quadriceps muscle power and knee pain during stair descent in 3 brace conditions (n=9). Quadriceps activity, knee flexion moments and pain were significantly reduced with TCO brace wear during stair descent in KOA patients. These findings suggest that the TCO assists the quadriceps to reduce KFM and knee pain during stair descent. This is the first biomechanical evidence to support use of the TCO to reduce pain during an ADL that produces especially high knee forces and flexion moments. For any figures or tables, please contact the authors directly

Permanent patellar subluxation is treated with surgeries such as proximal realignment and distal realignment, however, it is difficult to cure this condition by using any methods. We performed mobile-bearing total knee arthroplasty (TKA) in a case of severe knee osteoarthritis complicated with permanent patellar subluxation since childhood, and obtained good results without performing any additional procedures. The patient was an 82-year-old woman with severe pain in the left knee. During the initial examination, the range of motion of the left knee joint was -10°of extension to 140°of flexion, and the Japanese Orthopaedic Association (JOA) score for knee osteoarthritis was 40 points (maximum score: 100). Preoperative radiographs showed a varus deformity in the left lower extremity with a femorotibial angle (FTA) of 188°, the axial view showed luxation of the patella. We performed TKA using a mobile-bearing implant. Intraoperative findings revealed that the central articular surface of the distal femur had disappeared, and that the patellar articular surface was concave and dome-shaped. The lateral patellofemoral ligament was released; this procedure was identical to that performed in conventional TKA. Postoperative radiographs showed good alignment, with an FTA of 173°. In the axial view, the patella was located in a reduced position at any angle of knee joint flexion. The postoperative range of motion of the left knee joint was 0°of extension to 130°of flexion. The patient was able to walk without the support of a T-shaped cane. There are many surgical treatments for permanent patellar subluxation. The appropriate treatment is selected according to the type and seriousness of the dislocation and the age of the patient. From the findings of the present case, we believe that in a case of knee osteoarthritis complicated with permanent patellar subluxation, surgery performed using a mobile-bearing implant would eliminate the necessity of performing additional proximal realignment and distal realignment

Introduction. Knee osteoarthritis (OA) is a major contributor to disability in seniors and affecting millions of people around the world. Its main problem and the biggest factor in the disability of patients is pain. Pain renders patient inactive and develops lower extremity muscle wasting and worsens patient status adversely. However no radical solution existed until now. Recently I discovered a very valid manipulative technique (Squeeze-hold) for OA knee. This study presents the one-year follow-up data (three cases) by this treatment. Methods. Subjects. The subjects were three severe knee OA patients who had their data collected for 12 months after having a treatment. Treatment (squeeze-hold): The lower limb muscles (all muscles attached to the knee joint) were squeezed and held by hand. Each squeeze was performed in linear sequence all the way through the lower limbs. The squeezes were held for 20 seconds. This treatment was performed on a weekly basis. Evaluation: The conditions of the OA were evaluated using a Kellgren-Lawrence Grading Scale. Visual analogue scale as indicator of pain and Japanese Knee Osteoarthritis Measure as indicator of the activity restriction were recorded every month for a year. Results. In all three cases, OA knee pain and ADL were gradually improved by sustained once-a-week treatment. The daily activities were gradually increased. After a year, the pain passed approximately away. In case 1 and 2, a limitation in ROM did not show a marked improvement and joint contracture remained. Discussion. Squeeze-hold therapy that is approach to lower-limb muscles relieved OA knee pain. It is suggested by the fact that lower-limb muscles is responsible for the pain. And the physical activity of knee OA patient increases with decreasing pain effected by Squeeze-hold therapy. This increase in physical activity provides increase in joint movement and it lead to improve articular metabolism. Cyclical loading increases chondrocyte activity. Additionally, It inhibits the release of matrix metalloproteinase, pro-inflammatory mediators and shear stress-induced nitric oxide that induces chondrocyte apoptosis. And further, this increased physical activity improves muscle-strengthening of the lower extremity. It is plausible that these effects may continuously lead to decreased pain and improved ADL. A primary pain in knee OA can be attributed to inflammation of knee joint capsule or within knee joint capsule. And the pain leads to muscular hypertonicity thereby a bigger secondary pain develops in the muscles. Decreased physical activity due to the pain worsens pathological condition to induce greater pain. By this means, there might be formed pain-deterioration chain. Squeeze-hold therapy reduces the myogenic pain and cut the pain-deterioration chain. However, ROM could not improve though the pain and ADL activity imploved. This treatment ought to be performed before the formation of articular contracture. The results indicate Squeeze-hold treatment for lower-limb muscles might improves OA knee pain and limited ADL. However, this study had only three cases. Further research efforts are needed to identify the adaptation to diverse clinical symptoms knee OA

Are there any patho-anatomical features that might predispose to primary knee OA? We investigated the 3D geometry of the load bearing zones of both distal femur and proximal tibias, in varus, straight and valgus knees. We then correlated these findings with the location of wear patches measured intra-operatively. Patients presenting with knee pain were recruited following ethics approval and consent. Hips, knees and ankles were CT-ed. Straight and Rosenburg weight bearing X-Rays were obtained. Excluded were: Ahlbäck grade “>1”, previous fractures, bone surgery, deformities, and any known secondary causes of OA. 72 knees were eligible. 3D models were constructed using Mimics (Materialise Inc, Belgium) and femurs oriented to a standard reference frame. Femoral condyle Extension Facets (EF) were outlined with the aid of gaussian curvature analysis, then best-fit spheres attached to the Extension, as well as Flexion Facets(FF). Resected tibial plateaus from surgery were collected and photographed, and Matlab combined the average tibia plateau wear pattern. Of the 72 knees (N=72), the mean age was 58, SD=11. 38 were male and 34 female. The average hip-knee-ankle (HKA) angle was 1° varus (SD=4°). Knees were assigned into three groups: valgus, straight or varus based on HKA angle. Root Mean Square (RMS) errors of the medial and lateral extension spheres were 0.4mm and 0.2mm respectively. EF sphere radii measurements were validated with Bland-Altman Plots showing good intra- and interobserver reliability (+/− 1.96 SD). The radii (mm) of the extension spheres were standardised to the medial FF sphere. Radii for the standardised medial EF sphere were as follows; Valgus (M=44.74mm, SD=7.89, n=11), Straight (M=44.63mm, SD=7.23, n=38), Varus (M=50.46mm, SD=8.14, n=23). Ratios of the Medial: Lateral EF Spheres were calculated for the three groups: Valgus (M=1.35, SD=.25, n=11), Straight (M=1.38, SD=.23, n=38), Varus (M=1.6, SD=.38, n=23). Data was analysed with a MANOVA, ANOVA and Fisher's pairwise LSD in SPSS ver 22, reducing the chance of type 1 error. The varus knees extension facets were significantly flatter with a larger radius than the straight or valgus group (p=0.004 and p=0.033) respectively. In the axial view, the medial extension facet centers appear to overlie the tibial wear patch exactly, commonly in the antero-medial aspect of the medial tibial plateau. For the first time, we have characterised the extension facets of the femoral condyles reliably. Varus knees have a flatter medial EF even before the onset of bony attrition. A flatter EF might lead to menisci extrusion in full extension, and early menisci failure. In addition, the spherical centre of the EF exactly overlies the wear patch on the antero-medial portion of the tibia plateau, suggesting that a flatter medial extension facet may be causally related to the generation of early primary OA in varus knees

Background. The knee is the commonest joint to be affected by osteoarthritis, with the medial compartment commonly affected. Knee osteoarthritis is commonly bilateral, yet symptoms may initially present unilaterally. Higher knee adduction moment has been associated with the development and progression of medial compartment knee osteoarthritis. Objectives. To assess the effect of lateral wedge insoles on the asymptomatic knee of patients with unilateral symptoms of medial compartment knee osteoarthritis. Methods. Twenty patients were assessed using a 3D optoelectronic tracking system, with 16 infrared camera, passive markers and four force platforms. Three different insoles were tested; a standard control shoe, the Boston lateral wedge insole (inclined at 5° throughout the full length of the insole) and the Salford insole (inclined at 5° throughout the full length of the insole, with medial arch support). A minimum of 5 trials per each insole were used. Kinetic and kinematic data were collected and processed using Qualysis Track Manager ® and Visual 3D™. Results. There was a significant reduction in knee adduction moment for both the Salford and Boston insoles as compared to the control shoe. This was 9.5–14.2% for the asymptomatic side, and 5.8–10.7% for the symptomatic side for the Salford and Boston insoles respectively. Although the reduction was larger on the asymptomatic side, this was not statistically significant. Patients reported significant reduction in pain with both Salford and Boston insoles as compared to the control shoe, and found the Salford insole to be the most comfortable. Stride length and walking speed was significantly higher with the Salford insole. Conclusions. This study confirms the effect of lateral wedge insoles on reducing knee adduction moment in patients with medial compartment osteoarthritis, in both the symptomatic and asymptomatic knees. Long-term follow-up studies are required to confirm the effect of treating the asymptomatic side on disease progression

How do we treat severe knee OA with bowing deformity of tibia after malunion. Correction osteotomy with TKA was usually performed. However, there were risks of severe several complications. This is a case report of the patient received TKA didn't accept the risks of correction osteotomy. 74 year-old- lady consulted our clinic with chief complains of left knee pain and disability of walking. Her left knee pain began 20 years ago without any episodes. Her walking ability getting worse gradually in these 5 months. However, she have been received conservative treatment. She suffered left tibia fracture and received ORIF at age 21. Her course of after the surgery was not satisfied with infection. Finally her tibia achieved union. However, her tibia demonstrated bowing and shortening with varus deformity. Her knee joint also demonstrated varus deformity with ROM 95(ext. −20, flex. 115). There were pressure pain at the medial joint space, demonstrated varus-valgus instability. Roentgenograms showed severe OA with defect of medial tibial condyle (Fig.1) and malunion of the tibia with bowing deformity. Mechanical FTA angle was 151 degrees (Fig.2). Deformity angle of the malunion tibia was 25 degrees. Severe knee OA with tibia deformity was indication of TKA with correction tibial osteotomy. We proposed TKA with correction tibial osteotomy for her. We also explain risks and benefits of the surgery for her. She didn't want osteotomy for risks of infection and non-union, she decided that she receive only TKA. We planned TKA with tibial extension stem and fix with tilting position in the tibia shaft using bone cement. TKA was performed the same as planning (Fig.3). Her leg alignment corrected good position with ROM 125 (ext. 0, flex. 125) at follow-up. It was recommended that TKA for severe deformity without correction osteotomy is generally performed under 20 degrees of the correction angle. Our case was out of indication for this point of view. However, precise check of the pre-surgical roentgenograms could get solution of the difficult surgery. We are thinking of longevity of the implants because of unexpected stress, so we should need long follow–up of this case

Introduction. Osteoarthritis (OA) represents a leading cause of disability and a growing burden on healthcare budgets. OA is particularly vexing for young, active patients who have failed less invasive therapies but are not ideal candidates for HTO or arthroplasty. Often, patients suffering in this wide therapeutic gap face a debilitating spiral of disease progression, increasing pain, and decreasing activity until they become suitable arthroplasty patients. An implantable unloading device was evaluated for the treatment of medial knee OA in this patient population. Joint overload has been cited as a contributor to OA onset or progression. In response, the KineSpring® System (Moximed, Inc, USA) has been designed to reduce the load acting on the knee. The unloader is implanted in the subcutaneous tissue without violating the joint capsule, thus preserving the option of future primary arthroplasty. The implant may be particularly useful for young, active patients, given the reversibility of the procedure and the preservation of normal flexibility and range of motion. Methods and Results. The KineSpring System was implanted in 79 patients with isolated medial knee OA, and the longest duration exceeds two and a half years. Treated patients were young and obese (mean age: 52 years, range 32–75; mean BMI: > 30 kg/m. 2. , range 21–45). Acute implant success, adverse events, and clinical outcomes using validated patient reported outcomes tools were recorded at baseline, post-op, 2 and 6 weeks, and 3, 6, 12 and 24 months post-op. All centers received ethics committee approvals prior to enrolling patients in the study. Mean surgical time was 72 min (range 45–153 minutes), and all patients were discharged after a few days. Patients recovered rapidly, achieving full weight bearing within 1–2 wks and normal range of motion by 6 weeks. Most patients experienced significant pain relief and functional improvement by six weeks, with results sustained beyond the two-year follow-up visit. WOMAC Pain improved from 43 at baseline to 13 at 2 years (p<0.001), WOMAC Function improved from 43 at baseline to 11 at 2 years (p<0.001), and WOMAC Stiffness improved from 52 at baseline to 18 at 2 years (p<0.001). Patients reported satisfaction with implant and its appearance. Conclusions. The KineSpring System provided pain relief and functional improvement in a young and obese patient population that may not be ideal for HTO or arthroplasty. This unloading device, with these successful results, fills a major gap in treatment options for young and active OA patients

Purpose. Whether the presence of knee effusion in individuals with knee osteoarthritis (OA) affects periarticular neuromuscular control during gait and thus the joint loading environment is unknown. The purpose was to test the hypothesis that knee effusion presence alters periarticular neuromuscular patterns during gait in individuals with moderate knee OA. Method. 40 patients with medial compartment knee OA participated after giving informed consent. Patients were assessed for the presence of effusion using a brush test and were assigned to the knee effusion (n=20) and no knee effusion (n=20) groups. Surface electrodes were placed in a bipolar configuration over the lateral and medial gastrocnemius, vastus lateralis and medialis, rectus femoris and the lateral and medial hamstrings of the affected limb. Five trials of self-selected walking were completed. Electromyograms (EMG) were collected using an AMT-8 EMG system (Bortec Inc.). An Optotrak motion capture system (Northern Digital Inc.) recorded leg motion. Euler rotations were used to derive knee angles. EMG waveforms were low-pass filtered and amplitude normalized to maximal effort voluntary isometric contractions. Quadriceps, gastrocnemius and hamstring strength was measured from torques produced against a Cybex dynamometer. Principal Component Analysis extracted the predominant waveform features and weighting scores were calculated for each measured waveform. Analysis of variance models test for main effects (group, muscle) and interactions (alpha = 0.05). Bonferonni post hoc testing was employed. Results. No differences in age, body mass index, knee pain, Western Ontario McMaster Osteoarthritis Index scores, gait velocity and muscle strength were found between groups (p>0.05). Gastrocnemius activation was not influenced by the presence of effusion (p>0.05). For individuals with effusion, a greater overall quadriceps activation was found and a prolonged hamstring activation into mid-stance only (p<0.05). Range of motion excursion from heel strike to peak extension during terminal stance was greater with effusion (p<0.05). Conclusion. The hypothesis that knee effusion in those with moderate knee OA is associated with alterations in quadricep and hamstring muscle activation patterns and sagittal plane knee motion during gait was supported. Quadriceps muscle inhibition during the normalization exercises may provide a partial explanation, consistent with results from acute effusion models. However, the hamstring alteration during mid-stance only, no strength differences between the two groups and altered kinematics support that mechanisms other than muscle inhibition are responsible for the altered patterns. These novel findings are a first step at understanding the effects of knee effusion on periarticular muscle function during gait that subsequently can affect the mechanical environment of the joint in those with a more chronic effusion

Quadriceps femoris muscle weakness has long been associated with disuse atrophy in symptomatic knee osteoarthritis but more recently implicated in the aetiology of this condition. The purpose of this study was to assess the benefits of two interventions aimed at increasing quadriceps strength in subjects with moderate to severe knee osteoarthritis. Twenty-eight patients, aged fifty-five to seventy-five, were recruited and randomised to either a six-week home resistance-training exercise program or a six-week neuromuscular electrical stimulation (NMES) program. Eleven patients matched for age, gender and osteoarthritis severity formed a control group, receiving standard care. The resistance-training group performed six exercises three times per week, while the NMES group used the garment stimulator for twenty minutes five times per week Outcome measures included isometric and isokinetic quadriceps strength, functional capacity, quadriceps cross-sectional area, and validated health survey scores. These measures were assessed at baseline, post-intervention and at 6-weeks post-intervention. Both intervention groups showed significant improvements in all functional tests, in the global health survey, and in quadriceps cross-sectional area immediately post-intervention. An increase in isokinetic strength was seen in the exercise group only. With the exception of isokinetic strength, all benefits were maintained six weeks post-intervention. Both a six-week home resistance-training program and a six-week NMES program produce significant improvements in functional performance as well as physical and mental health for patients with moderate to severe knee osteoarthritis. Home-based NMES is an acceptable alternative to physical therapy, and is especially appropriate for patients who have difficulty complying with an exercise program

Aims. A new therapy, based on the intra-articular injection of autologous conditioned serum (ACS), is used in several European countries for osteoarthritis (OA) treatment. ACS is generated by incubating venous blood with medical grade glass beads. Peripheral blood leukocytes produce elevated amounts of endogenous anti-inflammatory cytokines such as interleukin-1 receptor antagonist (IL-1Ra) and growth factors that are recovered in the serum(1). ACS has been shown to improve the clinical lameness in horses significantly to enhance the healing of muscle injuries in animal models, and in human athletes. In the present study, the efficacy and safety of ACS was compared to intra-articular hyaluronan (HA), and saline in patients with confirmed knee OA. Methods. In a prospective, randomised, patient- and observer-blind trial with three parallel groups, 376 patients with knee OA were included in an intention to treat (ITT-) analysis. Efficacy was assessed by patient-administered outcome instruments (WOMAC, VAS, SF-8, GPA) after 7, 13 and 26 weeks (blinded) and Two-years (non-blinded). The frequency and severity of adverse events were used as safety parameters. Results. In all treatment groups, intra-articular injections produced a significant reduction in WOMAC-scores and weight-bearing pain (VAS). However, responses to ACS were stronger. The superiority of ACS and either HA or saline was statistically significant for all outcome measures and time points. No significant differences between HA treatment and saline injections (p>0.05, at all time points and outcome measures) were recorded. Frequency of adverse advents (AE) was comparable in the ACS- and the saline-group (p>0.05). Conclusion. The results demonstrate that ACS is effective, long-lasting and well tolerated in the management of chronic, idiopathic OA of the knee. So far, the efficacy of ACS is defined through improvement in clinical signs and symptoms, particularly pain. It remains to be determined whether they are disease-modifying, chondroprotective, or even chondroregenerative, sequelae

Valgus knee unloader braces are often prescribed as treatment for knee osteoarthritis (OA). These braces are designed to redistribute the loading in the knee, thereby reducing medial contact forces. Patient response to bracing is variable; some patients experience improvements in joint loading, pain, and function, others see little to no effect. We hypothesised that patients who experienced beneficial response to the brace, measured by reductions in medial contact force, could be predicted based on static and dynamic measures. Participants completed a WOMAC questionnaire and walked overground with and without an OA Assist knee brace in a motion capture lab. Eighteen patients with medial compartment OA (8 female, 53.8±7.0 years, BMI 30.3±4.1, median Kellgren-Lawrence grade 4 (range 1–4)) were evaluated. The abduction moment applied by the brace was estimated by multiplying brace deflection by the pre-determined brace stiffness. A generic musculoskeletal model was scaled for each participant based on standing full length radiographs and anatomical markers. Inverse kinematics, inverse dynamics, residual reduction, and muscle analysis were completed in OpenSim 3.2. A static optimisation was then performed to estimate muscle forces and then tibiofemoral contact forces were calculated. Brace effectiveness was defined by the difference in the first peak of the medial contact force between braced and unbraced conditions. Principal component analysis was performed on the hip, knee, and ankle angles and moments from the unbraced walking condition to extract the principal component (PC) scores for these variables. A linear regression procedure was used to determine which variables related to brace effectiveness. Potential regressors included: hip-knee-ankle angle and medial joint space measured radiographically; KL grade; mass; WOMAC scores; unbraced walking speed; and the first two principal component scores for each of the unbraced hip, knee, and ankle joint angles and moments. KL grade, walking speed, and hip adduction moment PC1, which represented the magnitude of the first peak were all found to be correlated with change in medial contact force. The brace was more successful in reducing medial contact force in subjects with higher KL grades, faster self-selected walking speeds, and larger peak external hip adduction moments. The R2 value for the overall regression model was 0.78. The best predictor of brace effectiveness was the hip adduction moment, indicating the need to consider dynamic measures. Participants who had hip adduction moments and walking speeds similar to those of their healthy counterparts saw a greater reduction in medial contact force. Thus, those who responded to bracing had more severe OA as measured by the KL grade but had not experienced changes in their hip adduction moment due to OA. The results of this study suggest that there is potential for an objective criterion for valgus knee brace use to be established

In August 2007 NICE issued its guidance for the treatment of patients with knee osteoarthritis (OA) with arthroscopic lavage. The recommendations stated that referral for arthroscopic lavage and debridement should not be offered as part of treatment for osteoarthritis, unless the person has osteoarthritis with a clear history of ‘mechanical locking’ (not gelling, giving way, or x-ray evidence of loose bodies). The aim of this study was to assess both the application of these guidelines over a four month period and whether this procedure had improved symptoms at first follow-up. This was a retrospective review from August-December 2011. The total number of arthroscopies performed during this period was obtained from theatre records. Further data was obtained through the hospital's electronic database. The diagnosis of OA was made through the analysis of referral and clinic letters, plain radiographs, MRI reports and operation notes. Only those patients with persisting OA symptoms were included, those with OA and recent history of injury or trauma were excluded. During this time period, 222 knee arthroscopies were performed in total, 99 were identified with persistent OA symptoms. Having identified these patients, referral letters were further analysed to identify the initial presenting symptom. Of the 99, 50 presented with pain, 28 presented with pain plus another symptom other than locking e.g. stiffness/swelling/giving-way, 21 presented with pain plus mechanical locking. According to current guidelines only these 21 patients should have been offered arthroscopic lavage as a form of treatment. In addition to these findings we identified what procedures had been carried out during arthroscopy for each symptom. Of those presenting with pain, 82% had a washout and debridement, 8% had washout, 4% had partial medial meniscectomy, 4% had lateral patellar release and 2% had partial lateral meniscectomy. Those with pain plus other symptoms not including locking, 82% had washout and debridement, 11% had partial medial meniscectomy, and 7% had a washout. Of those presenting with pain plus mechanical locking, 81% had washout and debridement and 19% had partial medial meniscectomy. Following the procedure, we analysed the outcome of symptoms at first-follow up. The mean follow-up time was 8 weeks. Of those presenting with just pain, 44% showed improvement, 52% had no change/on-going symptoms, 2% were unknown. Of those with pain plus other symptoms other than locking, 57% showed improvement, 35% had no change/on-going symptoms, 8% unknown. Of those with pain plus mechanical locking, 80% showed improvement, 10% had no change/on-going symptoms, 10% unknown. The results of this study support the current evidence that unless there are clear mechanical symptoms of locking, the use of arthroscopy in arthritic knee joints should be judicious and the reasons should be clearly documented

Introduction. Intra-articular (IA) injections of corticosteroids and hyaluronic acid (HA) products are used to treat patients with knee osteoarthritis pain that has not responded to more conservative treatment. Corticosteroids are a standard of care despite only suggestive clinical evidence of 12 or more weeks of pain relief. However the duration of pain relief with this treatment appears to be short and not a long term solution. Methods. A double-blinded, randomised, active controlled, multicentre non-inferiority trial with 442 subjects provided a pragmatic comparison of HA to methylprednisolone. These patients were collected prospectively and with excellent long term follow-up. Results. The HA responder rates were good at 12 weeks and better at the later time points (6 to 9 months) while the methylprednisolone rate decreased significantly by 26 weeks. Conclusion. HA appears to be a reasonable mid to long term solution for patients with Kellgren grade 1 and 2 arthritis. It lasts longer than steroids and has what appears to be a cost-effective advantage