Polyacrylamide hydrogel (iPAAG1), is CE marked for treating symptomatic knee osteoarthritis (OA), meeting the need for an effective, long-lasting, and safe non-surgical option. This study evaluates the efficacy and safety of a single 6 ml intra-articular injection of iPAAG in participants with moderate to severe knee OA over a 5-year post-treatment period, presenting data from the 4-year follow up. This prospective multicentre study (3 sites in Denmark) involved 49 participants (31 females) with an average age of 70 (range 44 – 86 years). They received a single 6 mL iPAAG injection. All participants provided informed consent and re-consented to continue after 1 year. The study followed GCP principles and was approved by Danish health authorities and local Health Research Ethics committees. Twenty-seven participants completed the 4-year follow-up. The study evaluated WOMAC pain, stiffness, function, and Patient Global Assessment (PGA) of disease impact. Changes from baseline were analysed using a mixed model for repeated measurement (MMRM). Sensitivity analyses were applied on the extension data, where the MMRM analysis was repeated only including patients in the extension phase and an ANCOVA model was used, replacing missing values at 4-years with baseline values (BOCF).Introduction
Method
Knee braces are limited to providing passive support. There is currently no brace available providing both continuous monitoring and active robot-assisted movements of the knee joint. This project aimed to develop a wearable intelligent motorised robotic knee brace to support and monitor rehabilitation for a range of knee conditions including post-surgical rehabilitation. This brace can be used at home providing ambulatory continuous passive movement obviating the need for hospital admissions. A wearable sensing system monitoring knee range of motion was developed to provide remote feedback to clinicians and real-time guidance for patients. A prototype of an exoskeleton providing dynamic motion assistance was developed to help patients complete their exercise goals and strengthen their muscles. The accuracy and reliability of those functions were validated in human participants during exercises including knee flexion/extension (FE) in bed and in chair, sit-to-stand and stand-to-sit.Abstract
Introduction
Methodology
The effectiveness of single intra-articular injections of polyacrylamide hydrogel (iPAAG) and hyaluronic acid (HA) was compared in subgroups of participants from an RCT based on baseline age, BMI or Kellgren-Lawrence (KL) grade. 239 participants were randomised to 6 mL iPAAG (Arthrosamid; n=119) or 6 mL HA (Synvisc-One; n=120). Participants continued analgesics (except 48 hours prior to visits) and non-pharmacological therapy. Topical therapies and intra-articular corticosteroids were not allowed. Pre-specified subgroup analyses (age: <70 years, ≥70 years; BMI: normal, overweight, obese; KL grade: 2, 3, 4, 2–3) of change from baseline in WOMAC pain subscale at 52 weeks were based on the least squares means for the treatment-by-week interaction effect using a mixed model for repeated measurement with a restricted maximum likelihood-based approach.Abstract
Introduction
Methodology
Osteoarthritis (OA) affects more than four million people in the UK alone. Bone marrow lesions (BMLs) are a common feature of subchondral bone pathology in OA. Both bone volume fraction and mineral density within the BML are abnormal. The aim of this study was to investigate the effect of a potential treatment (bone augmentation) for BMLs on the knee joint mechanics in cases with healthy and fully degenerated cartilage, using finite element (FE) models of the joint to study the effect of BML size. FE models of a human tibiofemoral joint were created based on models from the Open Knee project (simtk.org). Following initial mesh convergence studies, each model was manipulated in ScanIP (Synopsys-Simpleware, UK) to incorporate a BML 2mm below the surface of the tibial contact region. Models representing extreme cases (healthy cartilage, no cartilage; BML region as an empty cavity or filled with bone substitution material (200GPa)) were generated, each with different sizes of BML. Models were tested under a representative physiological load of 2kN.Abstract
Introduction
Methods
Follow-up of arthroplasty varies widely across the UK. The aim of this NIHR-funded study was to employ a mixed-methods approach to examine the requirements for arthroplasty follow-up and produce evidence-based and consensus-based recommendations. It has been supported by BHS, BASK, BOA, ODEP and NJR. Four interconnected work packages have recently been completed: (1) a systematic literature review; (2a) analysis of routinely collected National Health Service data from four national data sets to understand when and which patients present for revision surgery; (2b) prospective data regarding how patients currently present for revision surgery; (3) economic modelling to simulate long-term costs and quality-adjusted life years associated with different follow-up care models and (4) a Delphi-consensus process, involving all stakeholders, to develop a policy document to guide appropriate follow-up care after primary hip and knee arthroplasty.
For ODEP10A∗ minimum implants, it is safe to disinvest in routine follow-up from 1 to 10 years post non-complex hip and knee replacement provided there is rapid access to orthopaedic review For ODEP10A∗ minimum implants in complex cases, or non-ODEP10A∗ minimum implants, periodic follow-up post hip and knee replacement may be required from 1 to 10 years At 10 years post hip and knee replacement, we recommend clinical, which may be virtual, and radiographic evaluation After 10 years post hip and knee replacement, frequency of further follow-up should be based on the 10-year assessment; ongoing rapid access to orthopaedic review is still required These recommendations apply to post primary hip and knee replacement follow-up The 10-year time point in these recommendations is based on a lack of robust evidence beyond ten years The term complex cases refer to individual patient and surgical factors that may increase the risk for replacement failure
Overarching statements
Bone marrow lesions (BMLs) have been extensively linked to the osteoarthritis (OA) disease pathway in the knee. Semi-quantitative evaluation has been unable to effectively study the spatial and temporal distribution of BMLs and consequently little is understood about their natural history. This study used a novel statistical model to precisely locate the BMLs within the subchondral bone and compare BML distribution with the distribution of denuded cartilage. MR images from individuals (n=88) with radiographic evidence of OA were selected from the Osteoarthritis Initiative. Slice-by-slice, subvoxel delineation of the lesions was performed across the paired images using the criteria laid out by Roemer (2009). A statistical bone model was fitted to each image across the cohort, creating a dense set of anatomically corresponded points which allowed BML depth, position and volume to be calculated. The association between BML and denudation was also measured semi-quantitatively by visually scoring the lesions as either overlapping or adjacent to denuded AC, or not. At baseline 75 subjects had BMLs present in at least one compartment. Of the 188 compartments with BMLs 46% demonstrated change greater than 727mm cubed, the calculated smallest detectable difference. The majority of lesions were found in medial compartments compared to lateral compartments and the patella (Figure 1A). Furthermore, in the baseline images 76.9% of all BMLs either overlapped or were adjacent to denuded bone. The closeness of this relationship in four individuals is shown in Figure 1B. The distribution of lesions follows a clear trend with the majority found in the patellofemoral joint, medial femoro-tibial joint and medial tibial compartment. Moreover the novel method of measurement and display of BMLs demonstrates that there is a striking similarity between the spatial distribution of BMLs and denuded cartilage in subjects with OA. This co-location infers the lesions have a mechanical origin much like the lesions that occur in healthy patients as a direct result of trauma. It is therefore suggested that OA associated BMLs are in fact no different from the BMLs caused by mechanical damage, but occur as a result of localised disruption to the joint mechanics, a common feature of OA.
