Comparison of Early Postoperative Stress Distribution around Short and Tapered Wedge Stems in Femurs with Different Femoral Marrow Cavity Geometries Using Finite Element Analysis.

Backgroud: In total hip arthroplasty (THA), the ideal stem length remains uncertain; different stem lengths are used in different cases or institutions. We aimed to compare the stress distributions of cementless tapered wedges and short stems in femurs with different femoral marrow geometries and determine the appropriate fit.

Methods: Finite element models were created and analyzed using HyperMesh and LS-DYNA R11.

COVID-19 with Suspected Secondary Pyogenic Arthritis of the Hip: A Case Report and Literature Review.

Introduction: COVID-19 may be associated with orthopedic symptoms, including myalgia and joint pain. There are reports of reactive arthritis and acute arthritis diagnosed after COVID-19; however, COVID-19-associated pyogenic arthritis has not been reported.

Case Report: We treated a young woman with secondary pyogenic hip arthritis that started after COVID-19.

Femoral Bowing Increases Early Postoperative Stress around the Femoral Stem in Humans: A Finite Element Analysis.

Background: This study aimed to clarify the characteristics of stress distribution caused by the placement of tapered wedge stems in bowed femurs compared with that in normal femurs and the effect of varus stem placement.

Methods: Models with normal and enhanced bowing were created from the right-side computed tomography data of a 17-year-old woman with the least bowing among 40 participants who underwent anterior cruciate ligament reconstruction or operative treatment for trauma in our hospital between January 2017 and May 2018. Finite element analysis was performed, assuming the tapered wedge stem was placed in the neutral and varus positions.

Relationship between perceived and structural leg length discrepancies of patients with hip osteoarthritis dysplasia.

Background: Only few studies have been conducted on leg length discrepancy (LLD) in patients with hip osteoarthritis (OA). This study aimed to examine the relationship between perceived LLD (pLLD) and structural LLD (sLLD) in patients with advanced OA and to determine the factors influencing both LLDs. This retrospective study aimed to answer the following questions: (1) are older adults less likely to perceive LLD than younger adults? (2) is there a relationship between pLLD and sLLD? and (3) is pLLD associated with patient satisfaction?

Hypothesis: We hypothesized that older adults are less likely to perceive LLD than younger adults.

Influence of femoral bowing on stress distribution of the proximal femur: a three-dimensional finite element analysis.

Background: Whether femoral bowing or its direction has a mechanical effect on the proximal femur is unclear. This study aimed to define the changes in stress distribution in the proximal femur associated with femoral bowing using finite element analysis.

Methods: We created four femoral models: original, entire lateral bowing, entire anterior bowing, and the middle of both (50% anterolateral bowing) from computed tomography data of women with standard bowing.

Stress distributions of the short stem and the tapered wedge stem at different alignments: a finite element analysis study.

Background: The mechanical effects of stem length reduction and stem alignment on the surrounding femur remain unknown. This study directly compared the stress distribution on the surrounding femur of existing tapered wedge stems and short stems and examined the properties of stress distribution at different stem alignments in three dimensions.

Methods: Finite element analysis was conducted for standing and walking.

Survival rates of different bearing surfaces with the same model of stem in total hip arthroplasty: predictive factors for revision surgery.

Introduction: Few studies have examined the survival rates of total hip arthroplasty (THA) with the same femoral stem, and the predictive factors leading to the revision of stemmed metal-on-metal (MoM) THA remain unknown. We determined the long-term survival rate of stemmed MoM THA compared with that of metal-on-polyethylene (MoP) bearing THA, the effect of head size and cup placement angle on revision rate, and predictors of revision.

Materials And Methods: A total of 130 hips in 110 patients who underwent primary THA by the same surgeon were included.

Contemporaneous Insufficiency Fractures of Bilateral Femoral Necks in an Older Patient Taking Bisphosphonate: A Case Report and Literature Review.

We report, to the best of our knowledge, the first case of simultaneous insufficiency fracture of the bilateral femoral neck in an older patient taking bisphosphonate. Femoral neck fractures frequently occur in older individuals because of traumatic incidents, such as a fall. A 74-year-old woman with osteoporosis was taking raloxifene hydrochloride and bisphosphonate for approximately 5 and 3 years, respectively.

Microvascular system of hip joint constituents with special reference to ultrastructural findings and early arteriosclerosis.

This study aimed to examine the ultrastructure of the arteries of the synovium, acetabular labrum, and ligamentum teres of the hip joint using light, scanning electron, and transmission electron microscopes to identify features of early arteriosclerosis. Tissues collected from three patients (under 40 years of age) with osteonecrosis of the femoral head were immersed in 8 N HCl at 60 °C for 20 min to digest collagen fibers for scanning electron microscopy. Tortuous arterioles and arteries were noted in the joint components, including the synovium, acetabular labrum, and ligamentum teres.