Discrepancies in long-leg alignment and knee joint line obliquity between two- and three-dimensional measurements under weight-bearing conditions: Effects on coronal plane alignment of the knee classification.

Background: Long-leg alignment and joint line obliquity have traditionally been assessed using two-dimensional (2D) radiography, but the accuracy of this measurement has remained unclear. This study aimed to evaluate the accuracy of 2D measurements of lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA) using upright three-dimensional (3D) computed tomography (CT).

Methods: This study involved 66 knees from 38 patients (34 women, four men) with knee osteoarthritis (OA), categorized by Kellgren-Lawrence (KL) grade.

The tibial tubercle-to-trochlear groove distance changes in standing weight-bearing condition: An upright weight-bearing computed tomography analysis.

Background: The tibial tubercle-to-trochlear groove (TT-TG) distance and Insall-Salvati (I/S) ratio are widely used to determine the need for distal realignment in conjunction with medial patellofemoral ligament (MPFL) reconstruction in patients with recurrent patellar dislocation. A TT-TG distance >20 mm and an I/S ratio >1.3 are significant anatomical risk factors for patellar instability.

Alteration of knee joint moment after anterior cruciate ligament reconstruction conditions in subjects with and without meniscal pathology.

Background: The effects of anterior cruciate ligament (ACL) reconstruction on postoperative gait biomechanics remain controversial, and the influence of meniscus pathology on pre- and post-ACL reconstruction biomechanical changes has not yet been studied. Here, we aimed to clarify the difference in knee joint moment between pre- and post-ACL reconstruction conditions in subjects with and without meniscal pathology.

Methods: Twenty-four subjects with unilateral ACL reconstruction injuries participated in this study.

Simple parameters to identify patients treatable with early definitive fixation: A nationwide study.

Introduction: Early appropriate care (EAC) is widely accepted as a safe strategy to perform early definitive fracture fixation, and good clinical outcomes have been reported in selected, multiply injured patients, although the optimal candidate for early definitive fixation (EDF) has not been validated. The aim of this study was to identify simple clinical parameters to help select patients who could undergo EDF.

Methods: Patients with extremity injuries who underwent open reduction and internal fixation were retrospectively identified, using data from the Japan Trauma Data Bank (JTDB).

Extra-articular location of the three-dimensional mechanical axis in advanced knee osteoarthritis: an upright computed tomography study.

Purpose: One of the most widely used benchmarks of lower-limb alignment is the mechanical axis (MA), which passes through the centers of the femoral head and the ankle in the weight-bearing position. However, where the MA passes through three-dimensionally (3D) is unclear. We investigated the MA in 3D (3D-MA) in knee osteoarthritis (OA) using upright computed tomography (CT).

Occult proximal femoral fracture with radiating leg pain masquerading as sciatica: a case report.

Background: Occult proximal femoral fractures do not appear as fracture lines in radiographs, causing misdiagnosis and delayed diagnosis unless additional imaging studies, such as computed tomography or magnetic resonance imaging, are performed. Here, we present a 51-year-old male with an occult proximal femoral fracture who experienced radiating unilateral leg pain that took 3 months to be diagnosed because his symptoms mimicked lumbar spine disease.

Case Presentation: A 51-year-old Japanese male experienced persistent lower back and left thigh pain after falling off a bicycle, and was referred to our hospital 3 months thereafter.

Three-dimensional joint surface orientation does not correlate with two-dimensional coronal joint line orientation in knee osteoarthritis: Three-dimensional analysis of upright computed tomography.

Background: Two-dimensional (2D) coronal joint line orientation on radiography under weight-bearing conditions has been widely used in evaluating knee osteoarthritis (OA). However, the effects of tibial rotation remain unknown. The present study aimed to newly define three-dimensional (3D) joint surface orientation relative to the floor as an unchangeable 3D angle unaffected by tibial rotation using upright computed tomography (CT), and to investigate correlations between 3D and 2D parameters in knee OA.

Levels of preoperative cerebrospinal fluid pro-inflammatory mediators and chronic pain after total knee arthroplasty surgery.

Background: Patients undergoing total knee arthroplasty (TKA) surgery are at high risk of chronic postsurgical pain (CPSP). Accumulating evidence suggests an active role of neuroinflammation in chronic pain. However, its role in the progression to CPSP following TKA surgery remains unanswered.

The Stat3 inhibitor F0648-0027 is a potential therapeutic against rheumatoid arthritis.

Rheumatoid arthritis (RA) is a disease characterized by chronic joint inflammation, pain and joint destruction, leading to alteration in activities of daily living, yet pathological mechanisms underlying the condition are not fully clarified. To date, various therapeutic agents have been developed as RA therapy including DMARDs and/or biological agents that target inflammatory cytokines or inhibit JAK. Here we asked whether inhibiting signal transducer and activator of transcription 3 (Stat3) activity would antagonize RA.

Pain detect questionnaire and pain catastrophizing scale affect gait pattern in patients with knee osteoarthritis.

Purpose: Although pain phenotype affects clinical score in patients with knee osteoarthritis (OA), little information has been available on the relationship between pain phenotype and gait analysis. The purpose was to investigate the relationship between pain phenotype and gait parameters.  METHODS: A total of 34 patients (24 females and 10 males) with end-stage medial compartmental knee OA participated.

A novel anteroposterior axis of the tibia for total knee arthroplasty: An upright weight-bearing computed tomography analysis.

Background: The traditional anteroposterior (AP) axis (i.e., Akagi's line) has been widely used as the tibial component AP axis during total knee arthroplasty (TKA).

Biomechanical features of drop vertical jump are different among various sporting activities.

Background: Risk for non-contact anterior cruciate ligament (ACL) injury can be assessed based on drop vertical jump (DVJ). However, biomechanics of DVJ may differ with various sporting activities. The purpose of the present study was to clarify whether biomechanical features of DVJ are different among various sporting activities in female athletes.

Knee varus alters three-dimensional ankle alignment in standing- a study with upright computed tomography.

Background: For knee osteoarthritis (OA) treatment, it is important to correct the lower limb alignment including the foot. However, in the upright position, lower limb alignment is generally assessed from the body surface or radiographs, and it is a challenge to capture the exact characteristics of three-dimensional lower limb alignment. The purpose of the study was to measure lower limb alignment in patients with knee OA using upright computed tomography (CT) and radiography, and to identify features of knee joint deformity.

Increased migratory activity and cartilage regeneration by superficial-zone chondrocytes in enzymatically treated cartilage explants.

Background: Limited chondrocyte migration and impaired cartilage-to-cartilage healing is a barrier in cartilage regenerative therapy. Collagenase treatment and delivery of a chemotactic agent may play a positive role in chondrocyte repopulation at the site of cartilage damage. This study evaluated chondrocyte migratory activity after enzymatic treatment in cultured cartilage explant.

Effects of Dual Task Interference on Biomechanics of The Entire Lower Extremity During the Drop Vertical Jump.

The dual task is an important factor affecting knee biomechanics during jump-landing tasks. Athletes often have trouble in performing two tasks concurrently and a dual task can deteriorate landing performance. However, it is still unknown whether a dual task will affect the entire lower extremity.

Application of an indentation sensor for the arthroscopic measurement of articular cartilage stiffness.

Direct measurement of cartilage stiffness provides useful clinical information and enables us to develop treatment strategies for patients. We applied an indentation sensor to evaluate cartilage stiffness under arthroscopic control. The purpose of this study was to validate the arthroscopic indentation sensor using cadaver knees and to measure cartilage stiffness in clinical cases.

A novel fabrication process of up-scalable microfiber-shaped tendon-like tissue with high cell density for uniformed macroscale assembly.

This paper describes up-scalable microfiber-shaped tissues for macroscale tendon tissue reconstruction in vitro. C3H10T1/2 cells were encapsulated in a calcium alginate hydrogel microfiber that was fabricated via a double coaxial microfluidic device. The C3H10T1/2 cells gradually merged to construct the microfiber-shaped tendon-like tissue.

Fatigue and recovery have different effects on knee biomechanics of drop vertical jump between female collegiate and recreational athletes.

Background: Although fatigue is known as one of the risk factors for noncontact anterior cruciate ligament injury, the effects of fatigue and recovery can be different based on the level of competition. However, it is unknown whether female recreational athletes are susceptible to fatigue or not, compared to female collegiate athletes with greater physical activity. The purpose of the present study was to examine and clarify the effects of fatigue and recovery on knee biomechanics of the drop vertical jump (DVJ) in female recreational athletes compared to female collegiate athletes.

Kinematically Aligned Total Knee Arthroplasty Using Medial Pivot Knee Prosthesis Enhances Medial Pivot Motion: A Comparative Kinematic Study With Mechanically Aligned Total Knee Arthroplasty.

Background: Clinical outcomes of kinematically aligned total knee arthroplasty (KA-TKA) have been reported as comparable or superior to those of mechanically aligned TKA (MA-TKA). However, cruciate-retaining prostheses have mostly been used for KA-TKA. This study used medial pivot knee prostheses for KA-TKA, and knee kinematics after KA-TKA were assessed and compared with those after MA-TKA.

Adipose-Derived Stem Cell Sheets Improve Early Biomechanical Graft Strength in Rabbits After Anterior Cruciate Ligament Reconstruction.

Background: Although various reconstruction techniques are available for anterior cruciate ligament (ACL) injuries, a long recovery time is required before patients return to sports activities, as the reconstructed ACL requires time to regain strength. To date, several studies have reported use of mesenchymal stem cells in orthopaedic surgery; however, no studies have used adipose-derived stem cell (ADSC) sheets in ACL reconstruction (ACLR).

Hypothesis: ADSC sheet transplantation can improve biomechanical strength of the autograft used in ACLR.

Synoviolin is not a pathogenic factor for auto-inflammatory diseases.

Auto-inflammatory syndromes are rare diseases characterized by arthritis and joint destruction, symptoms similar to but distinct from rheumatoid arthritis (RA). Therapeutic targets have not been well characterized for auto-inflammatory syndromes, although the E3 ligase Synoviolin was previously shown to be a novel therapeutic target for RA. Here, we show that Synoviolin loss has little impact on a model of auto-inflammatory diseases.

Influence of Patella thickness on Patellofemoral pressure in total knee Arthroplasty.

Background: Patellofemoral complications are one of the major issues after total knee arthroplasty (TKA). Excessive patellofemoral joint pressure is associated with complications after TKA surgery, and the amount of patellar osteotomy has a direct effect on patellofemoral joint pressure. The purpose of this study was to evaluate the influence of patella thickness on patellofemoral pressure in TKA.