Osteoarthritis year in review 2019: rehabilitation and outcomes.

OBJECTIVE: Inactivity and obesity are risk factors for osteoarthritis (OA) progression. The purpose of this review was to highlight intervention parameters of exercise and lifestyle diet interventions on clinical outcomes in OA that were published over 15 months, starting January 1, 2018. DESIGN: Systematic literature searches were performed in Medline (Pubmed, OVID), Scopus, CINAHL, CENTRAL and Embase from January 1, 2018 to April 1, 2019. Key words included osteoarthritis, exercise, physical activity, diet and nutrition. Randomized controlled designs and data synthesis papers (systematic reviews, meta-analyses, clinical guidelines) written in English, that included humans with OA of any joint were included. Trials were evaluated using the Physiotherapy Evidence Database (PEDro) critical appraisal tool and the Template for Intervention Description and Replication (TIDieR). Systematic reviews and meta-analyses were evaluated using A MeaSurement Tool to Assess systematic Reviews 2 (AMSTAR 2). Intervention details (RCTs) and key finding from papers were summarized. RESULTS: Of 540 titles and abstracts retrieved, 147 full articles were reviewed and 53 met the inclusion criteria, comprised of 39 RCTs and 14 synthesis papers. By addressing inactivity, exercise effectively improves clinical outcomes and, based on low-moderate quality evidence, without further damage to cartilage or synovial tissue. By comparison, much less work focused on minimizing obesity. Diet must be combined with exercise to improve pain, but alone, can improve physical function. CONCLUSIONS: Future work is necessary to identify the ideal exercise frequency and intensity and lifestyle diet intervention parameters. Improved adherence to reporting guidelines in future work will greatly enhance the OA rehabilitation field.

Biomechanical effects of valgus knee bracing: a systematic review and meta-analysis.

To review and synthesize the biomechanical effects of valgus knee bracing for patients with medial knee osteoarthritis (OA). Electronic databases were searched from their inception to May 2014. Two reviewers independently determined study eligibility, rated study quality and extracted data. Where possible, data were combined into meta-analyses and pooled estimates with 95% confidence intervals (CI) for standardized mean differences (SMD) were calculated. Thirty studies were included with 478 subjects tested while using a valgus knee brace. Various biomechanical methods suggested valgus braces can decrease direct measures of medial knee compressive force, indirect measures representing the mediolateral distribution of load across the knee, quadriceps/hamstring and quadriceps/gastrocnemius co-contraction ratios, and increase medial joint space during gait. Meta-analysis from 17 studies suggested a statistically significant decrease in the external knee adduction moment (KAM) during walking, with a moderate-to-high effect size (SMD = 0.61; 95% CI: 0.39, 0.83; P < 0.001). Meta-regression identified a near-significant association for the KAM effect size and duration of brace use only (ß, -0.01; 95% CI: -0.03, 0.0001; P = 0.06); with longer durations of brace use associated with smaller treatment effects. Minor complications were commonly reported during brace use and included slipping, discomfort and poor fit, blisters and skin irritation. Systematic review and meta-analysis suggests valgus knee braces can alter knee joint loads through a combination of mechanisms, with moderate-to-high effect sizes in biomechanical outcomes.

Reassortant analysis of guinea pig virulence of pichinde virus variants.

The new world arenavirus Pichinde (PIC) is the basis of an accepted small animal model for human Lassa fever. PIC (Munchique strain) variant P2 is attenuated in guinea pigs, whereas variant P18 is extremely virulent. Previous sequence analysis of the S segments of these two viruses indicated a small number of possible virulence markers in the glycoprotein precursor (GPC) and nucleoprotein (NP) genes. In order to determine the role of these S segment genes in guinea pig virulence in this system, we have generated reassortant viruses. When tested in outbred guinea pigs, the reassortant containing the S segment from the virulent parent P18 (S18L2) caused significantly higher morbidity than the reciprocal reassortant. This increased morbidity was associated with higher viral titers in serum and spleen. However, the S18L2 reassortant was not as fully virulent in this system as the P18 parent, indicating a role for L segment genes in virulence.