High-concentration continuous local antibacterial perfusion therapy: safety and potential efficacy for acute and chronic periprosthetic knee joint infection.

Background: Periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA) are among the most challenging pathologies to manage. Recently, continuous local antibiotic perfusion (CLAP) therapy has been introduced for treating musculoskeletal infections in orthopedics. This study aimed to determine the outcomes and risks of CLAP therapy combined with conventional treatment for PJIs after TKA.

Three-stage total knee arthroplasty combined with deformity correction and leg lengthening using Taylor spatial frames and conversion to internal fixation for severe intra- and extra-articular deformities and hypoplasia in a patient with hemophilic knee arthropathy: A case report.

Background: Hemophilic arthropathy is a cause of severe knee deformity, because chronic synovitis due to repeated hemarthrosis affects the area of the epiphyseal plates in juvenile cases. Total knee arthroplasty (TKA) is the standard treatment for end-stage knee arthropathy. However, it is difficult to perform one-stage TKA in patients with severe intra- and extra-articular deformities.

Effect of the Inverted V-Shaped Osteotomy on Patellofemoral Joint and Tibial Morphometry as Compared With the Medial Opening Wedge High Tibial Osteotomy.

Background: Recent studies have reported that medial opening wedge (OW) high tibial osteotomy (HTO) induces patella baja, resulting in degenerative changes in the patellofemoral joint. We have developed an inverted V-shaped (iV) HTO, which is classified as a neutral wedge osteotomy.

Hypotheses: The study hypotheses were as follows: (1) patellar height, posterior tibial slope, and tibial length will not change between pre- and postoperative evaluations after iV-HTO; (2) the lateral shift ratio of the patella and the distance between the tibial tubercle and the trochlear groove may be significantly decreased after iV-HTO.

Impact of Surgical Timing on Clinical Outcomes in Anatomic Double-Bundle Anterior Cruciate Ligament Reconstruction Using Hamstring Tendon Autografts.

Background: To date, no studies have analyzed the influence on clinical outcomes of the interval between an anterior cruciate ligament (ACL) injury and double-bundle (DB) reconstruction with hamstring tendon autografts.

Hypotheses: (1) Performing ACL reconstruction sooner after an injury will reduce postoperative anterior and rotatory knee instability, (2) postoperative range of knee motion or functional results will not be affected by different intervals between injury and surgery, and (3) preoperative isokinetic peak torque of the quadriceps and hamstring muscles will be lower in patients undergoing surgery earlier, while postoperative muscle strength will not be affected by surgery timing.

Study Design: Cohort study; Level of evidence, 3.

CCL21/CCR7 axis regulating juvenile cartilage repair can enhance cartilage healing in adults.

Juvenile tissue healing is capable of extensive scarless healing that is distinct from the scar-forming process of the adult healing response. Although many growth factors can be found in the juvenile healing process, the molecular mechanisms of juvenile tissue healing are poorly understood. Here we show that juvenile mice deficient in the chemokine receptor CCR7 exhibit diminished large-scale healing potential, whereas CCR7-depleted adult mice undergo normal scar-forming healing similar to wild type mice.

Chondrogenic differentiation of mouse induced pluripotent stem cells using the three-dimensional culture with ultra-purified alginate gel.

As articular cartilages have rarely healed by themselves because of their characteristics of avascularity and low cell density, surgical intervention is ideal for patients with cartilaginous injuries. Because of structural characteristics of the cartilage tissue, a three-dimensional culture of stem cells in biomaterials is a favorable system on cartilage tissue engineering. Induced pluripotent stem cells (iPSCs) are a new cell source in cartilage tissue engineering for its characteristics of self-renewal capability and pluripotency.

Osteochondral Autograft Transplantation Technique Augmented by an Ultrapurified Alginate Gel Enhances Osteochondral Repair in a Rabbit Model.

Background: One of the most important limitations of osteochondral autograft transplantation (OAT) is the adverse effect on donor sites in the knee. To decrease the number and/or size of osteochondral defects, we devised a method with biomaterial implantation after OAT.

Hypothesis: OAT augmented by ultrapurified alginate (UPAL) gel enhances cartilage repair capacity.

Effects of Ultra-Purified Alginate Gel Implantation on Meniscal Defects in Rabbits.

Background: Many tissue-engineered methods for meniscal repair have been studied, but their utility remains unclear.

Hypothesis: Implantation of low-endotoxin, ultra-purified alginate (UPAL) gel without cells could induce fibrocartilage regeneration on meniscal defects in rabbits.

Study Design: Controlled laboratory study.

Bone Marrow Stimulation Technique Augmented by an Ultrapurified Alginate Gel Enhances Cartilage Repair in a Canine Model.

Background: The optimal treatment for a medium- or large-sized cartilage lesion is still controversial. Since an ultrapurified alginate (UPAL) gel enhances cartilage repair in animal models, this material is expected to improve the efficacy of the current treatment strategies for cartilage lesions.

Hypothesis: The bone marrow stimulation technique (BMST) augmented by UPAL gel can induce hyaline-like cartilage repair.

Depletion of Gangliosides Enhances Articular Cartilage Repair in Mice.

Elucidation of the healing mechanisms in damaged tissues is a critical step for establishing breakthroughs in tissue engineering. Articular cartilage is clinically one of the most successful tissues to be repaired with regenerative medicine because of its homogeneous extracellular matrix and few cell types. However, we only poorly understand cartilage repair mechanisms, and hence, regenerated cartilage remains inferior to the native tissues.