T1 Pelvic and Lumbar Pelvic Angles Normative Values: A Prospective Cohort Study of 472 Asymptomatic Volunteers.

Study Design: Cross-sectional analysis of a prospectively enrolled cohort.

Objective: Determine the normative values of the T1 Pelvic Angle (TPA) and Lumbar Pelvic Angle (LPA) in an asymptomatic cohort of volunteers.

Summary Of Background Data: The TPA and LPA have been introduced as sagittal spino-pelvic parameters to guide correction of adult spinal deformity.

COVID-19 orthopaedic trauma volumes: a Canadian experience during lockdown and staged reopening.

Objectives: The aim of this study is to report the impact of public health measures (PHM), including their relaxation, on surgical orthopaedic trauma volumes. We hypothesize an initial reduction in orthopaedic trauma volumes during lockdown followed by a surge as Stages 1 and 2 of reopening progressed in Summer 2020.

Methods: All unscheduled surgical orthopaedic trauma cases from March through August were retrospectively reviewed in Calgary, Alberta, Canada, from 2008 to 2020.

Does Age Influence Patient-Reported Outcomes in Unilateral Primary Total Hip and Knee Arthroplasty?

Background: Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are used to treat patients with end-stage arthritis. Previous studies have not demonstrated a consistent relationship between age and patient-reported outcomes. The purpose of this study is to assess the impact of age on patient-reported outcomes after unilateral primary THA or TKA.

Impact of 3D Printed Calcaneal Models on Fracture Understanding and Confidence in Orthopedic Surgery Residents.

Objective: To determine if three-dimensionally printed (3Dp) fracture models can improve orthopedic trainee education.

Design: A prospective comparison study of orthopedic trainees and attending surgeons was performed, where a range of calcaneal fractures were used for creating anonymized 3Dp models. Study participants rotated through workstations viewing computed tomography images and either a digital 3D volume rendering or 3Dp model of the fractured calcaneus.

Cartilage boundary lubrication synergism is mediated by hyaluronan concentration and PRG4 concentration and structure.

Background: Proteoglycan 4 (PRG4) and hyaluronan (HA) are key synovial fluid constituents that contribute synergistically to cartilage boundary lubrication; however, the effects of their concentrations as well as their structure, both of which can be altered in osteoarthritis, on this functional synergism are unknown. The objectives of this study were to evaluate cartilage boundary lubricating ability of 1) PRG4 + HA in solution at constant HA concentration in a range of PRG4 concentrations, 2) constant PRG4 concentration in a range of HA concentrations, 3) HA + reduced/alkylated (R/A) PRG4, and 4) hylan G-F 20 + PRG4.

Methods: Static and kinetic friction coefficients (μ(static,Neq), <μ(kinetic,Neq)>) were measured using a previously characterized cartilage-cartilage boundary mode friction test for the following concentrations of purified PRG4 and HA: Test 1: HA (1.

Metabolic analysis of knee synovial fluid as a potential diagnostic approach for osteoarthritis.

Osteoarthritis (OA) is a leading cause of chronic joint pain in the older human population. Diagnosis of OA at an earlier stage may enable the development of new treatments to one day effectively modify the progression and prognosis of the disease. In this work, we explore whether an integrated metabolomics approach could be utilized for the diagnosis of OA.

Articular Joint Lubricants during Osteoarthritis and Rheumatoid Arthritis Display Altered Levels and Molecular Species.

Background: Hyaluronic acid (HA), lubricin, and phospholipid species (PLs) contribute independently or together to the boundary lubrication of articular joints that is provided by synovial fluid (SF). Our study is the first reporting quantitative data about the molecular weight (MW) forms of HA, lubricin, and PLs in SF from cohorts of healthy donors, patients with early (eOA)- or late (lOA)-stage osteoarthritis (OA), and patients with active rheumatoid arthritis (RA).

Methods: We used human SF from unaffected controls, eOA, lOA, and RA.

Effects of concentration and structure on proteoglycan 4 rheology and interaction with hyaluronan.

Background: The contribution of proteoglycan 4 (PRG4) to synovial fluid and hyaluronan (HA) solution rheology are poorly understood. The effects of PRG4 disulfide-bonded structure on viscosity and viscosity of newly available full-length recombinant human PRG4 (rhPRG4) have not previously been reported.

Objective: This study determined the viscosity of PRG4 and rhPRG4, R/A (reduced and alkylated) PRG4 and rhPRG4, and PRG4 and rhPRG4+HA solutions.

Characterization of proteoglycan 4 and hyaluronan composition and lubrication function of ovine synovial fluid following knee surgery.

The objective of this study was to determine changes in (1) proteoglycan 4 (PRG4) and hyaluronan (HA) concentration, (2) HA molecular weight (MW) distribution, and (3) cartilage boundary lubricating ability of synovial fluid (SF) from surgical sham (SHAM), anterior cruciate ligament (ACL)/medial collateral ligament (MCL) transection, and lateral meniscectomy (MEN) in a post-knee surgery ovine model. Ovine SF (oSF) was collected at euthanization 20 weeks after surgery, with the contralateral joint serving as the non-operative control. PRG4 and HA concentration in oSF was measured by sandwich enzyme-linked immunosorbent assay, and HA MW distribution by agarose gel electrophoresis.

Diminished cartilage-lubricating ability of human osteoarthritic synovial fluid deficient in proteoglycan 4: Restoration through proteoglycan 4 supplementation.

Objective: The purposes of this study were 1) to quantify the proteoglycan 4 (PRG4) and hyaluronan (HA) content in synovial fluid (SF) from normal donors and from patients with chronic osteoarthritis (OA) and 2) to assess the cartilage boundary-lubricating ability of PRG4-deficient OA SF as compared to that of normal SF, with and without supplementation with PRG4 and/or HA.

Methods: OA SF was aspirated from the knee joints of patients with symptomatic chronic knee OA prior to therapeutic injection. PRG4 concentrations were measured using a custom sandwich enzyme-linked immunosorbent assay (ELISA), and HA concentrations were measured using a commercially available ELISA.