Scaffold-Free Osteochondral Engineering Using Embryonic-Derived Mesenchymal Stem Cell Spheroids.

In this study, we explored whether embryonic stem cell-derived mesenchymal stem cell (ES-MSC) cellular spheroids in combination with a closed chamber system could be used to create scaffold-free cartilage and endochondral graft tissues. ES-MSC cellular spheroids were cultured in chondrogenic medium for 3-4 days and seeded into a customizable Net Mold chamber system (NCS) and cultured in chondrogenic medium for an additional 18 days to fuse and form a single tissue construct. To assess potential for cartilage repair, cellular spheroids were matured in the NCS for only 7 days before implantation into human cartilage defects.

Is medial soft tissue laxity more important than lateral laxity after total knee arthroplasty?

Background: The optimal range of soft tissue balance that consistently leads to better patient outcomes has yet to be identified in total knee arthroplasty. This study aimed to analyze the effect of soft tissue tightness on Knee Society Score by grouping patients by extent of medial or lateral laxity and mediolateral balance.

Methods: Varus and valgus laxity were measured using stress radiographs for 95 varus-deformed osteoarthritis knees (82 patients).

Bioprinting Embryonic-Derived Stem Cells to Repair Human Chondral Defects.

Successful bioprinting requires an appropriate combination of bioinks, cells, and a delivery platform. To demonstrate the potential of bioprinting for regeneration of cartilage lesions we combined clinically relevant embryonic-derived mesenchymal stem cells (ES-MSCs) with a fibrin-based bioink that was delivered into chondral defects created in human osteoarthritic (OA) tissue using a bioprinting platform. We used an integrated multitool, 6-axis bioprinting system to laser scan and map the surface of chondral defects and bioprint within the cartilage defects and .

Isolated Medial Patellofemoral Ligament Reconstruction Under Increased Femoral Anteversion Is Associated With Increased Contact Pressure of Medial Patellofemoral Facet at Deep Flexion Angle: A Cadaveric Study.

Purpose: To analyze (1) whether isolated medial patellofemoral ligament (MPFL) reconstruction in increased femoral anteversion could replicate the patellofemoral (PF) pressure pattern of a hypothetical normal population and (2) the change of PF pressure according to MPFL state under the same anteversion setting.

Methods: Ten fresh-frozen cadaveric knees were used. Experiments were performed from knee flexion 0° to 90° with 3 MPFL state (intact, released, and reconstructed) and 3 anteversion (initial state, 10° and 20° more increased).

Corrigendum to 'Electrostatic attachment of exosome onto a 3D-fabricated calcium silicate-polycaprolactone for enhanced bone regeneration' [Mater. Today Bio (2024) 101283].

[This corrects the article DOI: 10.1016/j.mtbio.

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.

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.

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.