Can Cadaver Testing Replicate In Vivo Kinematics of Total Knee Arthroplasty?

Introduction: Whether the kinematics of cadaveric knees recreate those of the patient's knees after total knee arthroplasty (TKA) remains unknown. This study compared in vivo and in vitro fluoroscopic kinematics of knees after TKA during knee bending using the same implant design.

Methods: Patients who had undergone cruciate-retaining and cruciate-substituting total knee arthroplasty (CR-TKA and CS-TKA) did squatting motions.

Serial changes in patient-reported outcome measures and satisfaction rate during long-term follow-up after total knee arthroplasty: a systematic review and meta-analysis.

Purpose: This study aimed to investigate the sequential changes in patient-reported outcome measures (PROMs) and the satisfaction rate during long-term follow-up after total knee arthroplasty (TKA).

Methods: Studies published until December 2023 were searched in MEDLINE, EMBASE, SCOPUS and Cochrane Library. The inclusion criteria were TKA as the primary procedure, a final post-operative follow-up period of at least seven years and reporting of PROMs data.

Biocompatibility Study of Purified and Low-Temperature-Sterilized Injectable Collagen for Soft Tissue Repair: Intramuscular Implantation in Rats.

The clinical application of collagen-based biomaterials is expanding rapidly, especially in tissue engineering and cosmetics. While oral supplements and injectable skin boosters are popular for enhancing skin health, clinical evidence supporting their effectiveness remains limited. Injectable products show potential in revitalizing skin, but safety concerns persist due to challenges in sterilization and the risk of biological contamination.

Electrostatic attachment of exosome onto a 3D-fabricated calcium silicate/polycaprolactone for enhanced bone regeneration.

Exosomes have garnered attention for use in bone regeneration, but their low activity, rapid degradation, and inaccurate delivery have been obstacles to their use in clinical applications. As such, there exists a need for an exosome-integrated delivery platform. Calcium silicate (Ca-Si) is considered one of the most promising bioceramics for bone regeneration because of its remarkable ability to promote hydroxyapatite formation, osteoblast proliferation, and differentiation.

Does the femoral component design modified in consideration of Asian anatomical characteristics fit better than the conventional design for Korean femora in reality?

Introduction: We aimed to investigate the anatomical and clinical advantages of an Asian-specific femoral component design with a high femoral aspect ratio, compared with the conventional femoral component design.

Materials And Methods: A retrospective analysis of the operation and outpatient clinic records of 239 knees operated on using an anatomically modified femoral component design (MFCD, Group A) and 153 knees operated on using a conventional femoral component design (CFCD, Group B) in Korean patients was performed. Three subgroups were created based on the mediolateral size of the two different femoral component designs.

Difference in Correction Power between Hybrid Lateral Closed-Wedge High Tibial Osteotomy and Medial Open-Wedge High Tibial Osteotomy was Associated with Severity of Varus Deformity and Different Hinge Distance from Center of Deformity.

Hybrid lateral closed-wedge high tibial osteotomy (HBHTO) carries certain advantages over medial open-wedge high tibial osteotomy (OWHTO). We investigated the potential difference in the required correction angle between HBHTO and OWHTO to achieve an equal amount of whole lower-extremity alignment correction, retrospectively analyzing the preoperative plain radiographic images of 100 patients. The medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), mechanical lateral distal femoral angle (mLDFA), hip-knee-ankle axis (HKA), length of the tibia, width of the tibial plateau, length of the lower limb (leg length), and location of the center of deformity (CD) were measured.

Elevated Lipid Metabolites in Stored Clinical OCA Media Correlate With Chondrocyte Death.

Background: A major limitation of osteochondral allografts (OCA) is the deterioration of cartilage health associated with cell death during prolonged storage. However, little is known about the mechanisms that contribute to chondrocyte death during storage.

Purpose/hypothesis: This study aimed to determine whether bioactive lipid metabolites accumulate in the storage media of OCA and whether they are associated with a loss of chondrocyte viability during prolonged storage.

Clinical Outcomes and Repair Integrity After Double-Row Modified Mason-Allen Repair Technique With a Single Knot in Small to Medium Supraspinatus Tears.

Background: Various arthroscopic rotator cuff repair techniques are being used for the treatment of rotator cuff tears with the development of surgical instruments. However, retears after repair are not completely avoidable, and efforts to reduce retears remain a challenge.

Purpose/hypothesis: To introduce a new repair technique, the double-row modified Mason-Allen technique with a single knot, and to compare clinical outcomes and retear rates with the single-row modified Mason-Allen technique.

In Vivo Kinematics and Cruciate Ligament Tension Are Not Restored to Normal After Bicruciate-Preserving Arthroplasty.

Background: Whether cruciate ligament forces in cruciate-preserving designs, such as unicompartmental knee arthroplasty (UKA) or bi-cruciate-retaining total knee arthroplasty (BCR-TKA), differ from those in normal knees remains unknown. The purpose of this study was to compare the in vivo kinematics and cruciate ligament force in knees before and after UKA or BCR-TKA to those in normal knees during high-flexion activity.

Methods: Overall, twenty normal knees, 17 knees with medial UKA, and 15 knees with BCR-TKA were fluoroscopically examined while performing a squatting activity.

Evolution of the throwing shoulder: why apes don't throw well and how that applies to throwing athletes.

Background: Humans have unique characteristics making us the only primate that can throw well while most other primates throw predominately underhand with poor speed and accuracy. The purpose of this study is to illuminate the uniquely human characteristics that allow us to throw so well. When treating an injury such as a labral tear or capsule tear, this study hopes the reader can gain a better understanding of the issues that lead to the tear and those that may determine the success of treatment besides the actual repair.

Is Prophylactic Antibiotic Use Necessary Before Dental Procedures in Primary and Revision TKA? A Propensity Score-matched, Large-database Study.

Background: The question of whether dental procedures increase the risk of periprosthetic joint infection (PJI) in patients who have undergone total joint arthroplasty (TJA) remains controversial.

Questions/purposes: (1) Are dental procedures associated with an increased incidence of PJI in the setting of either primary or revision TKA after controlling for relevant potentially confounding variables? (2) Is the administration of prophylactic antibiotics before dental procedures associated with any differences in this risk? (3) Which factors are associated with increased incidence of PJI after dental procedures?

Methods: This nationwide, retrospective, comparative, large-database study evaluated 591,602 patients who underwent unilateral primary or revision TKA between 2009 and 2019 using the Health Insurance Review and Assessment Service data in South Korea, in which all people in South Korea were registered and to which all medical institutions must charge any procedures they performed. The study population was divided into 530,156 patients with dental procedures and 61,446 patients without dental procedures based on whether the patients underwent a dental procedure at least 1 year after the index surgery.

A Network Meta-Analysis of Randomized Controlled Trials Assessing Intraoperative Anesthetic Therapies for Analgesic Efficacy and Morphine Consumption Following Total Knee Arthroplasty.

Background: The purpose of this study was to compare intraoperative anesthetic therapies for total knee arthroplasty (TKA) regarding postoperative analgesic efficacy and morphine consumption by conducting a systematic literature search.

Methods: Randomized controlled trials of TKA using various anesthetic therapies were identified from various databases from conception through December 31, 2021. A network meta-analysis of relevant literature was performed to investigate which treatment showed better outcomes.

Repair of medial meniscus posterior root tear is effective for root healing and cartilage regeneration in opening wedge high tibial osteotomy.

Purpose: This study aimed to determine whether the repair of a medial meniscus posterior root tear (MMPRT) is effective for MMPRT healing, cartilage regeneration, and clinical outcomes in opening wedge high tibial osteotomy (OWHTO).

Methods: This retrospective study included 80 patients who underwent OWHTO and subsequent second-look arthroscopy. The patients were divided into OWHTO-with-MMPRT-repair (n = 40) and OWHTO alone (n = 40) groups, and the healing rates (complete/partial/failure) were compared.

Medial patellofemoral ligament reconstruction appears to be a better treatment than repair, proximal realignment, or conservative management for primary patellar dislocation: A network meta-analysis.

Background: The purpose of this study was to compare the functional outcomes and re-dislocation rates of medial patellofemoral ligament (MPFL) reconstruction, MPFL repair, combined proximal realignment (CPR), and conservative management for primary patellar dislocation by conducting a systematic literature search of the available studies. The hypothesis was that MPFL repair and MPFL reconstruction would be better options for treating primary patellar dislocation.

Methods: Randomized controlled trials or prospective studies of primary patellar dislocation treated with MPFL reconstruction, MPFL repair, CPR, or conservative management were identified from the MEDLINE, EMBASE, and the Cochrane Library databases through December 31, 2021.

Determining the Relationship between Mechanical Properties and Quantitative Magnetic Resonance Imaging of Joint Soft Tissues Using Patient-Specific Templates.

To determine whether the mechanical properties of joint soft tissues such as cartilage can be calculated from quantitative magnetic resonance imaging (MRI) data, we investigated whether the mechanical properties of articular cartilage and meniscus scheduled to be resected during arthroplasty are correlated with the T2 relaxation time on quantitative MRI at the same location. Six patients who had undergone knee arthroplasty and seven who had undergone hip arthroplasty were examined. For the knee joint, the articular cartilage and lateral meniscus of the distal lateral condyle of the femur and proximal lateral tibia were examined, while for the hip joint, the articular cartilage above the femoral head was studied.

Bicruciate-retaining total knee arthroplasty procedure reduced tensile force in the middle and posterior components of lateral collateral ligament during deep knee flexion activities with no effect on tensile force of the medial collateral ligament.

Purpose: To analyse the effects of bicruciate-retaining total knee arthroplasty (BCR-TKA) on the tensile force of the collateral ligaments during two deep knee flexion activities, cross-leg sitting and squatting.

Methods: Thirteen patients (15 knees) treated using bicruciate-retaining total knee arthroplasty (BCR-TKA) for knee joint osteoarthritis were analysed. Knee joint kinematics during cross-leg sitting (open-chain flexion) and squatting (closed-chain flexion) were evaluated through fluoroscopy.

Senescent cell population with ZEB1 transcription factor as its main regulator promotes osteoarthritis in cartilage and meniscus.

Objectives: Single-cell level analysis of articular cartilage and meniscus tissues from human healthy and osteoarthritis (OA) knees.

Methods: Single-cell RNA sequencing (scRNA-seq) analyses were performed on articular cartilage and meniscus tissues from healthy (n=6, n=7) and OA (n=6, n=6) knees. Expression of genes of interest was validated using immunohistochemistry and RNA-seq and function was analysed by gene overexpression and depletion.

Challenges Facing the Translation of Embryonic Stem Cell Therapy for the Treatment of Cartilage Lesions.

Osteoarthritis is a common disease resulting in significant disability without approved disease-modifying treatment (other than total joint replacement). Stem cell-based therapy is being actively explored for the repair of cartilage lesions in the treatment and prevention of osteoarthritis. Embryonic stem cells are a very attractive source as they address many of the limitations inherent in autologous stem cells, such as variability in function and limited expansion.

ALK-5 Inhibitors for Efficient Derivation of Mesenchymal Stem Cells from Human Embryonic Stem Cells.

Successful tissue regeneration requires a clinically viable source of mesenchymal stem cells (MSCs). We explored activin receptor-like kinase (ALK)-5 inhibitors to rapidly derive an MSC-like phenotype with high cartilage forming capacity from a xeno-free human embryonic cell line. Embryonic stem cell (ESC) lines (H9 and HADC100) were treated with the ALK-5 inhibitor SB431542; HADC100 cells were additionally treated with ALK-5 inhibitors SB525334 or GW788388.

Subject-specific computational modeling of acromioclavicular and coracoclavicular ligaments.

Background: Disruption of the acromioclavicular joint is a common injury. Despite the different surgical procedures described for treating this injury, complications such as loss of reduction and failure of fixation remain unacceptably high. We developed a computer model of the acromioclavicular joint to better understand the biomechanical contributions of the ligaments that are typically injured.

Tibial sagittal and rotational alignment reduce patellofemoral stresses in posterior stabilized total knee arthroplasty.

Patellofemoral joint complications remain an important issue in total knee arthroplasty. We compared the patellofemoral contact status between cruciate-retaining and posterior-stabilized designs with varying degrees of tibial sagittal and rotational alignment using a computer simulation to ensure proper alignments in total knee arthroplasty. Knee kinematics, patellofemoral contact force and quadriceps force were computed using a musculoskeletal modeling program (LifeMOD/KneeSIM 2010; LifeModeler, Inc.

The mechanosensitive ion channel PIEZO1 is expressed in tendons and regulates physical performance.

How mechanical stress affects physical performance via tendons is not fully understood. Piezo1 is a mechanosensitive ion channel, and E756del was recently found as a gain-of-function variant that is common in individuals of African descent. We generated tendon-specific knock-in mice using R2482H , a mouse gain-of-function variant, and found that they had higher jumping abilities and faster running speeds than wild-type or muscle-specific knock-in mice.

Postoperative Valgus Laxity and Medial Pivot Kinematics Are Significantly Associated With Better Clinical Outcomes.

Background: The relative impact of soft tissue balance and knee laxity on clinical outcomes after total knee arthroplasty (TKA) is not fully understood. We analyzed associations among knee laxity, kinematics, and patient-reported outcomes.

Methods: Knee Society Scores were recorded in 67 patients before and after primary TKA for osteoarthritis with varus deformity (N = 78).