Consideration for the validation of clinical laboratory methods in nonclinical fields.

In new drug development, cells or animals are treated with the selected candidate compound to confirm its efficacy and safety in nonclinical studies. Clinical laboratory tests are carried out using samples from experimental animals in these studies. The clinical laboratory test method validation in nonclinical fields should be conducted keeping in mind that the circumstances differ from those in clinical settings.

Second-look arthroscopy after meniscus repair and synovial mesenchymal stem cell transplantation to treat degenerative flaps and radial tears of the medial meniscus: A case report.

Background: The purpose of this study was to compare arthroscopic findings of a degenerative flap and radial tear of the medial meniscus (MM) before and one year after treatment by meniscus repair and synovial mesenchymal stem cell (MSC) transplantation.

Methods: Patients with a degenerative flap and radial MM tear that would generally be treated by meniscectomy were included. The patients ranged in age from 45 to 62 years and all underwent meniscus repair and synovium harvest at time 0.

Effects of different surgical procedures for meniscus injury on two-year clinical and radiological outcomes after anterior cruciate ligament reconstructions. -TMDU MAKS study.

Background: The treatment of meniscus injuries combined with anterior cruciate ligament (ACL) reconstruction would be important to improve outcomes after ACL reconstruction. However, the effects of treatment methods for meniscus after ACL reconstruction have not been thoroughly investigated. The objective of this study was to investigate the effects of treatment methods for meniscus on clinical and radiological outcomes at 2 years after ACL reconstruction.

Two- and three-dimensional optical coherence tomography to differentiate degenerative changes in a rat meniscectomy model.

Optical coherence tomography (OCT) is an attractive tool for evaluating cartilage. We developed an OCT system that reconstructs and analyzes a three-dimensional (3D) OCT image by determining the cartilage surface and cartilage-bone boundary from the image taken with currently available OCT devices. We examined the usefulness of 3D renderings of OCT images.

Knee laxity, lateral meniscus tear and distal femur morphology influence pivot shift test grade in ACL injury patients.

Purpose: Although several factors have been considered to be associated with pivot shift test grade in ACL injured patients, a conclusion regarding which factors contribute to the pivot shift test grade has not been reached. The purpose of this study was to identify factors associated with preoperative pivot shift test grade.

Methods: Three hundred and sixty-six consecutive patients who underwent ACL reconstruction in our hospital were enrolled in the study.

Morphological changes in synovial mesenchymal stem cells during their adhesion to the meniscus.

Synovial mesenchymal stem cells (MSCs) are an attractive cell source for transplantation because of their high chondrogenic potential, especially in areas like the meniscus of the knee. A synovial MSC suspension placed onto the meniscus for 10 min promoted healing of repaired meniscal tears that generally do not heal. Here, we quantified the proportion of human synovial MSCs that adhered to a porcine abraded meniscus, clarified their morphological changes, and revealed the mechanism by which the synovial MSCs adhered to the meniscus.

Investigation of association between the preoperative intra-articular anesthetic test and persistent pain after total knee arthroplasty.

Background: A better understanding of the etiology of persistent pain after total knee arthroplasty (TKA) is required to prevent unfavorable outcomes. The purpose of this study was to investigate the association of persistent pain after TKA, patient characteristics, and the remaining pain ratio per the preoperative intra-articular anesthetic test.

Methods: This study included 89 patients who underwent TKA and underwent an intra-articular anesthetic test preoperatively.

Projected Cartilage Area Ratio Determined by 3-Dimensional MRI Analysis: Validation of a Novel Technique to Evaluate Articular Cartilage.

Unlabelled: We have developed 3-dimensional (3D) magnetic resonance imaging (MRI) analysis software that allows measurement of the with a particular thickness intended to allow quantitation of the cartilage in the knee. Our aims in this study were to validate the projected cartilage area ratio in both pig and human knees and to examine the ratio in patients reporting knee pain.

Methods: After 3D MRI reconstruction, the femoral cartilage was projected onto a flat surface.

Risk factors for residual anterolateral rotational instability after double bundle anterior cruciate ligament reconstruction: Evaluation by quantitative assessment of the pivot shift phenomenon using triaxial accelerometer.

Background: Exact knowledge of risk factors for residual anterolateral rotatinoal instability (ALRI) after anterior cruciate ligament (ACL) reconstruction is limited. The purpose of this study was to analyse possible risk factors for ALRI after ACL reconstruction.

Methods: Quantitative assessment of the pivot shift phenomenon by measuring tibial acceleration was performed in 46 patients during primary double-bundle ACL reconstructions.

Benefit of subcutaneous patient controlled analgesia after total knee arthroplasty.

Purpose: Subcutaneous patient-controlled analgesia (PCA) has been widely used for orthopedic surgeries including total knee arthroplasty (TKA). This study aims to clarify the usefulness of subcutaneous PCA in the early phase after TKA.

Methods: Our subjects consisted of 88 osteoarthritis knee patients who underwent primary TKA, and were classified into two groups: 42 patients received a subcutaneous PCA (containing fentanyl and droleptan) after operation (PCA group), and 46 patients were managed without a subcutaneous PCA (control group).

Anatomic femoral tunnel placement is difficult by the transtibial technique: comparison of three different femoral tunnel drilling techniques in double-bundle anterior cruciate ligament reconstructions.

Purpose: To compare the position and direction of femoral and tibial tunnels for both the anteromedial bundle (AMB) and posterolateral bundle (PLB) among three different femoral tunnel drilling techniques, transtibial (TT), transportal (TP), and outside-in (OI) techniques, in anatomic double-bundle ACL reconstruction to clarify advantages and disadvantages of each technique.

Methods: One-hundred and thirty-nine patients underwent primary ACL reconstruction with an autologous semitendinosus tendon in our institution between 2014 and 2016. Thirteen patients were excluded according to the exclusion criteria.

The effect of a longitudinal tear of the medial meniscus on medial meniscal extrusion in anterior cruciate ligament injury patients.

Purpose: The purpose of this study was to investigate the effect of a longitudinal tear of the medial meniscus (MM) and its meniscal repair on MM extrusion in anterior cruciate ligament (ACL)-injured patients. The hypothesis underlying this study was that a longitudinal tear of the MM is correlated with MM extrusion, and that the extrusion would persist after ACL reconstruction with concomitant MM repair.

Methods: Forty-three ACL-injured patients with a concomitant MM longitudinal tear were included in the MM tear group.

Additional Use of Synovial Mesenchymal Stem Cell Transplantation Following Surgical Repair of a Complex Degenerative Tear of the Medial Meniscus of the Knee: A Case Report.

Complex degenerative tears of the medial meniscus in the knee are usually treated using meniscectomy. However, this procedure increases the risk of osteoarthritis, while other treatments aimed at meniscal repair remain challenging due to the high possibility of failure. The use of synovial mesenchymal stem cells (MSCs) is an attractive additional approach for meniscal repair, as these cells have high proliferative and chondrogenic potential.

Cryopreservation in 95% serum with 5% DMSO maintains colony formation and chondrogenic abilities in human synovial mesenchymal stem cells.

Background: Synovial mesenchymal stem cells (MSCs) are an attractive cell source for cartilage and meniscus regeneration. The optimum cryopreservation medium has not been determined, but dimethylsulfoxide (DMSO) should be excluded, if possible, because of its toxicity. The purposes of our study were to examine the possible benefits of higher concentrations of serum and the effectiveness of 100% serum (without DMSO) for the cryopreservation of synovial MSCs.

Contribution of Additional Anterolateral Structure Augmentation to Controlling Pivot Shift in Anterior Cruciate Ligament Reconstruction.

Background: Several types of anterolateral structure (ALS) augmentation procedures in anterior cruciate ligament (ACL) reconstruction have been reported. However, information is limited regarding the effect of additional ALS augmentation on rotatory stability in a clinical setting.

Purpose/hypothesis: This study aimed to investigate the contribution of additional ALS augmentation in ACL reconstruction in cases with a high risk of residual pivot shift.

Correction to: Coronal and sagittal laxity affects clinical outcomes in posterior-stabilized total knee arthroplasty: assessment of well-functioning knees.

Unfortunately, the co-author "Hiroki Katagiri' was omitted in the original publication from the author group. The author name is added here. The original article has been corrected.

Comparison of High-Hydrostatic-Pressure Decellularized Versus Freeze-Thawed Porcine Menisci.

The meniscus functions as a load distributor and secondary stabilizer in the knee, and the loss of the meniscus increases the risk of osteoarthritis. Freeze-thawed menisci are used in clinical practice to replace defective menisci; however, the disadvantages of freeze-thawed tissues include disease transmission and immune rejection. In this study, we decellularized menisci using high hydrostatic pressure (HHP) and compared the decellularized menisci with freeze-thawed menisci.

Coronal and sagittal laxity affects clinical outcomes in posterior-stabilized total knee arthroplasty: assessment of well-functioning knees.

Purpose: Both coronal and sagittal laxity of well-functioning knees after total knee arthroplasty (TKA) was examined, and the correlations between the joint laxity and the clinical outcomes were analyzed to clarify the adequate joint laxity for the prosthesis, and the relationship between the laxity and the outcomes.

Methods: Forty well-functioning TKA knees with a high-flexion posterior-stabilized (PS) prosthesis were studied. All patients were diagnosed as having osteoarthritis with varus deformity and were followed up for 2 years or more.

Effect of meniscus repair on pivot-shift during anterior cruciate ligament reconstruction: Objective evaluation using triaxial accelerometer.

Background: Some types of meniscus tear, especially lateral meniscus tear, have been reported to be associated with rotatory knee laxity. However, precise information regarding the effect of meniscus repair on rotatory laxity is limited. The purpose of this study was to investigate the effects of lateral and medial meniscus repair on rotatory laxity in anterior cruciate ligament (ACL) injured knees.

Anterior cruciate ligament-derived mesenchymal stromal cells have a propensity to differentiate into the ligament lineage.

Introduction: The anterior cruciate ligament (ACL) consists of various components, such as collagen, elastin fibres, and fibroblasts. Because ACL has a poor regenerative ability, ACL reconstruction need require the use of autologous tendons. In recent years, tissue-resident stem cells have been studied to promote ACL regeneration as an alternatively method.

Comparison of three approaches for femoral tunnel during double-bundle anterior cruciate ligament reconstruction: A case controlled study.

Background: It is still controversial whether which femoral tunnel creation technique is best during anterior cruciate ligament reconstruction (ACLR). We aimed to clarify the features of three different techniques based on the femoral tunnel position created with the same tunnel-creating concept and the measurement data.

Methods: The femoral tunnel of double-bundle (DB) ACLR was created using the behind-remnant approach in a remnant preserved manner following the policy of our institute.

Canine mesenchymal stem cells from synovium have a higher chondrogenic potential than those from infrapatellar fat pad, adipose tissue, and bone marrow.

Osteoarthritis (OA), a common chronic joint disorder in both humans and canines, is characterized by a progressive loss of articular cartilage. Canines can serve as an animal model of OA for human medicine, and this research can simultaneously establish effective veterinary treatments for canine OA. One attractive treatment that can lead to cartilage regeneration is the use of mesenchymal stem cells (MSCs).

Risk factors for residual pivot shift after anterior cruciate ligament reconstruction: data from the MAKS group.

Purpose: To investigate the risk factors for residual pivot shift test after anterior cruciate ligament (ACL) reconstruction based on a multicenter prospective cohort study.

Methods: This study included patients who were registered in the Multicenter Arthroscopic Knee Surgery Study, a prospective longitudinal multicenter cohort study, and who underwent primary ACL reconstruction using autologous hamstring tendon graft between 2013 and 2016. The exclusion criteria included prior injuries or surgeries in the contralateral knee, prior ligamentous injuries in the involved knee, grade 2 or 3 concomitant ligament injuries, and inflammatory or other forms of osteoarthritis.

Petaloid recombinant peptide enhances in vitro cartilage formation by synovial mesenchymal stem cells.

In vitro chondrogenesis of mesenchymal stem cells (MSCs) mimics in vivo chondrogenesis of MSCs. However, the size of the cartilage pellets that can be attained in vitro is limited by current methods; therefore, some modifications are required to obtain larger pellets. Petaloid pieces of recombinant peptide (petaloid RCP) have the advantage of creating spaces between cells in culture.

Trends in isolated meniscus repair and meniscectomy in Japan, 2011-2016.

Background: Meniscus surgery is the most commonly performed orthopedic surgery, and despite recent emphasis on saving the meniscus, the current status of meniscus surgeries is little known in many countries, including Japan. The National Database of Health Insurance Claims and Specific Health Checkups of Japan and the Statistics of Medical Care Activities in Public Health Insurance track meniscus surgeries through health insurance claims. The National Database provides the numbers for 2014 and 2015, and the Statistics of Medical Care Activities provides the numbers from June 2011 to June 2016.