Compromised autophagy precedes meniscus degeneration and cartilage damage in mice.

Objective: Autophagy is a cellular homeostasis mechanism that facilitates normal cell function and survival. Objectives of this study were to determine associations between autophagic responses with meniscus injury, joint aging, and osteoarthritis (OA), and to establish the temporal relationship with structural changes in menisci and cartilage.

Methods: Constitutive activation of autophagy during aging was measured in GFP-LC3 transgenic reporter mice between 6 and 30 months.

Fresh Osteochondral Allograft Transplantation: Is Graft Storage Time Associated With Clinical Outcomes and Graft Survivorship?

Background: Regulatory concerns and the popularity of fresh osteochondral allograft (OCA) transplantation have led to a need for prolonged viable storage of osteochondral grafts. Tissue culture media allow a longer storage time but lead to chondrocyte death within the tissue. The long-term clinical consequence of prolonged storage is unknown.

Osteochondral Allograft Transplantation and Opening Wedge Tibial Osteotomy: Clinical Results of a Combined Single Procedure.

Objective To evaluate the outcome of patients who have undergone simultaneous osteotomy and osteochondral allograft (OCA) transplantation. Our hypothesis is that use of high tibial osteotomy and fresh OCA in a combined procedure is safe and effective without increasing morbidity in comparison to OCA alone. Design A case series of 17 patients underwent tibial osteotomy and simultaneous OCA during a single surgery.

Meniscal Tissue Engineering Using Aligned Collagen Fibrous Scaffolds: Comparison of Different Human Cell Sources.

Hydrogel and electrospun scaffold materials support cell attachment and neotissue development and can be tuned to structurally and mechanically resemble native extracellular matrix by altering either electrospun fiber or hydrogel properties. In this study, we examined meniscus tissue generation from different human cell sources including meniscus cells derived from vascular and avascular regions, human bone marrow-derived mesenchymal stem cells, synovial cells, and cells from the infrapatellar fat pad (IPFP). All cells were seeded onto aligned electrospun collagen type I scaffolds and were optionally encapsulated in a tricomponent hydrogel.

Autologous Bone Marrow Cell Stimulation and Allogenic Chondrocyte Implantation for the Repair of Full-Thickness Articular Cartilage Defects in a Rabbit Model.

Objective: The aim of this study was to evaluate the results of autologous bone marrow cell stimulation and allogenic chondrocyte implantation using 3-dimensional gel-type fibrin matrix in an animal model.

Design: Eighteen rabbits were divided into 2 treatment groups. One group was treated with a microfracture and covering of it with gel-type fibrin (AutoBMS; n = 9), and the other group was treated with allogenic chondrocytes mixed gel-type fibrin at the cartilage defect (AlloCI; n = 9).

Return to Sport and Recreational Activity After Osteochondral Allograft Transplantation in the Knee.

Background: Osteochondral allograft (OCA) transplantation is an integral part of the cartilage repair paradigm, but insufficient data are available regarding return to sport or recreational activity after the procedure.

Purpose: The purpose of this study was to determine if athletic patients undergoing OCA transplantation returned to sport, assess reasons for not returning to sport, and ascertain patient and graft-related characteristics that differed between those who returned or did not return to sport. The secondary aims were to assess graft survivorship and patient-reported subjective outcome measures (pain, function, satisfaction) among athletic patients undergoing OCA transplantation.

Fresh Osteochondral Allograft Transplantation for Fractures of the Knee.

Objective The purpose of this study was to evaluate functional outcomes and allograft survivorship among patients with knee fracture who underwent fresh osteochondral allograft (OCA) transplantation as a salvage treatment option. Design Retrospective analysis of prospectively collected data. Setting Department of Orthopaedic Surgery at one hospital.

Dynamical analysis of dislocation-associated factors in total hip replacements by hardware-in-the-loop simulation.

Since dislocation of total hip replacements (THR) remains a clinical problem, its mechanisms are still in the focus of research. Previous studies ignored the impact of soft tissue structures and dynamic processes or relied on simplified joint contact mechanics, thus, hindered a thorough understanding. Therefore, the purpose of the present study was to use hardware-in-the-loop (HiL) simulation to analyze systematically the impact of varying implant positions and designs as well as gluteal and posterior muscle function on THR instability under physiological-like loading conditions during dynamic movements.

Relevance of meniscal cell regional phenotype to tissue engineering.

Purpose: Meniscus contains heterogeneous populations of cells that have not been fully characterized. Cell phenotype is often lost during culture; however, culture expansion is typically required for tissue engineering. We examined and compared cell-surface molecule expression levels on human meniscus cells from the vascular and avascular regions and articular chondrocytes while documenting changes during culture-induced dedifferentiation.

Surgical interventions (microfracture, drilling, mosaicplasty, and allograft transplantation) for treating isolated cartilage defects of the knee in adults.

Background: Cartilage defects of the knee are often debilitating and predispose to osteoarthritis. Microfracture, drilling, mosaicplasty, and allograft transplantation are four surgical treatment options that are increasingly performed worldwide. We set out to examine the relative effects of these different methods.

Osteochondral Allograft Transplantation in Patients With Osteochondritis Dissecans of the Knee.

Background: Osteochondritis dissecans (OCD) of the knee can be difficult to treat. Cartilage restoration techniques are often indicated when the lesion or fragment cannot be salvaged and the patient remains symptomatic. Fresh osteochondral allograft (OCA) transplantation can restore both bone and cartilage defects characteristic of OCD.

Repair of Avascular Meniscus Tears with Electrospun Collagen Scaffolds Seeded with Human Cells.

The self-healing capacity of an injured meniscus is limited to the vascularized regions and is especially challenging in the inner avascular regions. As such, we investigated the use of human meniscus cell-seeded electrospun (ES) collagen type I scaffolds to produce meniscal tissue and explored whether these cell-seeded scaffolds can be implanted to repair defects created in meniscal avascular tissue explants. Human meniscal cells (derived from vascular and avascular meniscal tissue) were seeded on ES scaffolds and cultured.

Hyaluronan concentration and size distribution in human knee synovial fluid: variations with age and cartilage degeneration.

Background: One potential mechanism for early superficial cartilage wear in normal joints is alteration of the lubricant content and quality of synovial fluid. The purpose of this study was to determine if the concentration and quality of the lubricant, hyaluronan, in synovial fluid: (1) was similar in left and right knees; (2) exhibited similar age-associated trends, whether collected postmortem or antemortem; and (3) varied with age and grade of joint degeneration.

Methods: Human synovial fluid of donors (23-91 years) without osteoarthritis was analyzed for the concentrations of protein, hyaluronan, and hyaluronan in the molecular weight ranges of 2.

Control of Retinal Ganglion Cell Positioning and Neurite Growth: Combining 3D Printing with Radial Electrospun Scaffolds.

Retinal ganglion cells (RGCs) are responsible for the transfer of signals from the retina to the brain. As part of the central nervous system, RGCs are unable to regenerate following injury, and implanted cells have limited capacity to orient and integrate in vivo. During development, secreted guidance molecules along with signals from extracellular matrix and the vasculature guide cell positioning, for example, around the fovea, and axon outgrowth; however, these changes are temporally regulated and are not the same in the adult.

Osteochondral Allograft Transplantation of the Femoral Trochlea.

Background: Osteochondral allograft (OCA) transplantation is a recognized treatment modality for cartilage damage in the knee. Few reports are available on outcomes of OCA in the patellofemoral joint, and there are no reports on lesions isolated to the femoral trochlea.

Purpose: To evaluate graft survivorship and clinical outcomes in patients who had an OCA to the femoral trochlea.

Histopathological analyses of murine menisci: implications for joint aging and osteoarthritis.

Objective: To establish a standardized protocol for histopathological assessment of murine menisci that can be applied to evaluate transgenic, knock-out/in, and surgically induced OA models.

Methods: Knee joints from C57BL/6J mice (6-36 months) as well as from mice with surgically-induced OA were processed and cut into sagittal sections. All sections included the anterior and posterior horns of the menisci and were graded for (1) surface integrity, (2) cellularity, (3) Safranin-O staining distribution and intensity.

Evaluation of bound and pore water in cortical bone using ultrashort-TE MRI.

Bone water exists in different states with the majority bound to the organic matrix and to mineral, and a smaller fraction in 'free' form in the pores of cortical bone. In this study, we aimed to develop and evaluate ultrashort-TE (UTE) MRI techniques for the assessment of T2*, T1 and concentration of collagen-bound and pore water in cortical bone using a 3-T clinical whole-body scanner. UTE MRI, together with an isotope study using tritiated and distilled water (THO-H2O) exchange, as well as gravimetric analysis, were performed on ten sectioned bovine bone samples.

The Use of Osteochondral Allograft Transplantation for Primary Treatment of Cartilage Lesions in the Knee.

Objective: To assess the outcome of osteochondral allograft (OCA) transplantation as the primary treatment for cartilage injury in patients with no previous surgical treatment.

Study Design: Case series. Patients were identified in our outcomes database.

Outcomes of anatomic shoulder arthroplasty in primary osteoarthritis in type B glenoids.

Background: Primary glenohumeral osteoarthritis with posterior wear of the glenoid and posterior subluxation of the humerus (Walch type B) presents a challenge to the treating surgeon. Our hypothesis was that glenoids with biconcavity (B2) would be associated with worse outcomes (functional scores and complications) than B1 glenoids.

Materials And Methods: We retrospectively analyzed prospectively collected data on 112 anatomic total shoulder arthroplasties (104 patients) with B glenoids.

Osteochondral Allograft MRI Scoring System (OCAMRISS) in the Knee: Interobserver Agreement and Clinical Application.

Introduction: Osteochondral allograft (OCA) transplantation is a suitable treatment option for large osteochondral defects. Magnetic resonance imaging (MRI) is an objective, reproducible, noninvasive monitoring tool for postoperative assessment after cartilage surgery.

Objective: To correlate Osteochondral Allograft MRI Scoring System (OCAMRISS) in patients undergoing OCA transplantation in the knee with clinical outcomes and determine interobserver agreement of this scoring system.

Osteochondral Allograft Transplantation for Knee Lesions after Failure of Cartilage Repair Surgery.

Objective: The objective of this study was to assess the outcome of osteochondral allograft (OCA) transplantation as a salvage procedure after various cartilage repair surgeries.

Design: One hundred sixty-four knees in 163 patients (mean age = 32.6 years; range = 11-59 years; 55% males) were treated with OCA transplantation after subchondral marrow stimulation (SMS), osteochondral autograft transplantation (OAT), and autologous chondrocyte implantation (ACI).