The intersection of aging and estrogen in osteoarthritis.

Osteoarthritis (OA) is a chronic joint disease characterized by cartilage degradation, inflammation, and pain. While multiple factors contribute to OA development, age and sex are primary risk factors, particularly affecting postmenopausal women. The dramatic increase in OA risk after menopause suggests estrogen deficiency accelerates disease progression.

From IMPACT to RECLAIM: A Single-Stage Cell Therapy for Articular Cartilage Repair and a Platform for Musculoskeletal Tissue Regeneration.

Purpose Of Review: Cartilage injury does not heal spontaneously. The current cell-based cartilage treatments have either demonstrated poor clinical outcomes, require two surgeries, or are costly and logistically challenging. To overcome these challenges, our team has developed a one-stage, two cell-type surgical cell therapy for acute chondral defects.

Outcomes of Direct Anterior Total Hip Arthroplasty in Patients Who Have Preoperative Gluteal Tendinopathy and Muscle Tears: A Propensity-Matched Analysis.

Background: The gluteus medius and minimus muscles play a critical role in hip biomechanics; however, there is a paucity of literature examining the impact of preoperative gluteal pathology on outcomes following total hip arthroplasty (THA). This study compared pain, satisfaction, and functional outcomes among patients who had and did not have preoperative gluteal pathology after direct anterior (DA) THA.

Methods: Using an institutional total joint registry, patients undergoing DA THA for osteoarthritis between 2010 and 2022 were retrospectively reviewed.

Is Periacetabular Osteotomy With Hip Arthroscopy Superior to Periacetabular Osteotomy Alone? A Systematic Review and Meta-Analysis.

Introduction: There remains ongoing controversy regarding the optimal treatment strategy of hip dysplasia, with some advocating for the addition of hip arthroscopy to periacetabular osteotomy (PAO) to address concomitant labral tears. The purpose of this systematic review was to compare the clinical outcomes, complications, and joint preservation of PAO and PAO with hip arthroscopy.

Methods: A literature search was done, and studies were included if they reported outcomes of PAO with concomitant hip arthroscopy, PAO with staged hip arthroscopy, or compared outcomes of PAO alone versus PAO with hip arthroscopy.

Transcriptomic Changes During the Replicative Senescence of Human Articular Chondrocytes.

Aging is a major risk factor for osteoarthritis (OA), but the specific mechanisms connecting aging and OA remain unclear. Although chondrocytes rarely divide in adult articular cartilage, they undergo replicative senescence in vitro, offering a model to study aging-related changes under controlled conditions. OA cartilage was obtained from an 80-year-old male and a 72-year-old female, while normal cartilage was sourced from a 26-year-old male.

Primary Hip Arthroscopy in Patients With Acetabular Dysplasia: A Systematic Review of Published Clinical Outcomes at Minimum 5-Year Follow-up.

Background: Hip arthroscopy in patients with borderline hip dysplasia has satisfactory outcomes at short-term follow-up; however, the data on midterm outcomes are inconsistent, and failure rates are high in some studies, limiting understanding of the role and utility of hip arthroscopy in this patient cohort.

Purpose: To provide an up-to-date, evidence-based review of the clinical outcomes of primary hip arthroscopy in patients with frank or borderline hip dysplasia at ≥5-year follow-up and report the failure rate and progression to total hip arthroplasty in this cohort.

Study Design: Systematic review; Level of evidence, 4.

Minimum 10-Year Outcomes of Matrix-Induced Autologous Chondrocyte Implantation in the Knee: A Systematic Review.

Background: Matrix-induced autologous chondrocyte implantation (MACI) is an established cell-based therapy for the treatment of chondral defects of the knee. As long-term outcomes are now being reported in the literature, it is important to systematically review available evidence to better inform clinical practice.

Purpose: To report (1) subjective patient-reported outcomes (PROs) and (2) the rate of graft failure, reoperation, and progression to total knee arthroplasty (TKA) after undergoing MACI of the knee at a minimum 10-year follow-up.

Transcriptomic changes during the replicative senescence of human articular chondrocytes.

Osteoarthritis (OA) is a degenerative joint disease and a leading cause of disability worldwide. Aging is a major risk factor for OA, but the specific mechanisms underlying this connection remain unclear. Although chondrocytes rarely divide in adult articular cartilage, they undergo replicative senescence which provides an opportunity to study changes related to aging under controlled laboratory conditions.

Gene Delivery to Chondrocytes.

Delivering genes to chondrocytes offers new possibilities both clinically, for treating conditions that affect cartilage, and in the laboratory, for studying the biology of chondrocytes. Advances in gene therapy have created a number of different viral and non-viral vectors for this purpose. These vectors may be deployed in an ex vivo fashion, where chondrocytes are genetically modified outside the body, or by in vivo delivery where the vector is introduced directly into the body; in the case of articular and meniscal cartilage in vivo delivery is typically by intra-articular injection.

Segmental defect healing in the presence or absence of recombinant human BMP2: Novel insights from a rat model.

This study defined and compared the course of native, impaired and growth factor-stimulated bone regeneration in a rat femoral defect model. A mid-diaphyseal defect with rigid internal fixation was surgically created in the right femur of male Fischer rats and serially analyzed over 36 weeks. Native bone regeneration was modeled using a sub-critical, 1 mm size defect, which healed uneventfully.

Viral Gene Delivery in Chondrocytes.

Viral gene transfer, known as transduction, is a powerful research tool for studying the biology of chondrocytes in novel ways and also a technology enabling the use of gene therapy for regenerating cartilage and treating diseases that affect cartilage, such as osteoarthritis. Adenovirus, retrovirus, lentivirus, and adeno-associated virus (AAV) are most commonly used to transduce chondrocytes. Although AAV is able to transduce chondrocytes in situ by intra-articular injection, chondrocytes are most commonly transduced in monolayer culture using the four vectors mentioned above.

Expedited gene delivery for osteochondral defect repair in a rabbit knee model: A one-year investigation.

Objective: To evaluate a single-step, gene-based procedure for repairing osteochondral lesions.

Design: Osteochondral lesions were created in the patellar groove of skeletally mature rabbits. Autologous bone marrow aspirates were mixed with adenovirus vectors carrying cDNA encoding green fluorescent protein (Ad.

IL-1Ra gene transfer potentiates BMP2-mediated bone healing by redirecting osteogenesis toward endochondral ossification.

An estimated 100,000 patients each year in the United States suffer severe disability from bone defects that fail to heal, a condition where bone-regenerative therapies could provide substantial clinical benefits. Although recombinant human bone morphogenetic protein-2 (rhBMP2) is an osteogenic growth factor that is clinically approved for this purpose, it is only effective when used at exceedingly high doses that incur substantial costs, induce severe inflammation, produce adverse side effects, and form morphologically abnormal bone. Using a validated rat femoral segmental defect model, we show that bone formed in response to clinically relevant doses of rhBMP2 is accompanied by elevated expression of interleukin-1 (IL-1).

Efficient healing of large osseous segmental defects using optimized chemically modified messenger RNA encoding BMP-2.

Large segmental osseous defects heal poorly. Recombinant, human bone morphogenetic protein-2 (rhBMP-2) is used clinically to promote bone healing, but it is applied at very high doses that cause adverse side effects and raise costs while providing only incremental benefit. We describe a previously unexplored, alternative approach to bone regeneration using chemically modified messenger RNA (cmRNA).

Neuromuscular Training Improves Self-Reported Function and Single-Leg Landing Hip Biomechanics in Athletes After Anterior Cruciate Ligament Reconstruction.

Background: Neuromuscular training (NMT) has been shown to attenuate high-risk biomechanics in uninjured athletes. At the time that athletes return to sport after anterior cruciate ligament (ACL) reconstruction (ACLR), they demonstrate hip biomechanical deficits associated with injury to the reconstructed knee versus the uninjured contralateral knee.

Purpose: The primary purpose of the study was to examine whether an NMT program can improve single-leg drop (SLD) landing hip biomechanics for athletes after ACLR.

Knee Biomechanical Deficits During a Single-Leg Landing Task Are Addressed With Neuromuscular Training in Anterior Cruciate Ligament-Reconstructed Athletes.

Objective: Faulty neuromuscular and biomechanical deficits of the knee are nearly ubiquitous in athletes after anterior cruciate ligament (ACL) reconstruction (ACLR). Knee biomechanical deficits are directly associated with an increased risk of second ACL injury, which typically occurs during a sports-related movement on a single limb. To date, the biomechanical effects of a neuromuscular training (NMT) program on knee biomechanics during a single-leg landing task have not been investigated.

The association of psychological readiness to return to sport after anterior cruciate ligament reconstruction and hip and knee landing kinematics.

Background: Anterior cruciate ligament tears have a negative psychological impact on athletes. Currently, it is not clear if psychological readiness to return to sport has an impact on an athlete's landing biomechanics. Thus the purpose of the study is to investigate whether there is an association of psychological readiness to return to sport and single-leg landing biomechanics.

Multiplanar Loading of the Knee and Its Influence on Anterior Cruciate Ligament and Medial Collateral Ligament Strain During Simulated Landings and Noncontact Tears.

Background: Anterior cruciate ligament (ACL) tears and concomitant medial collateral ligament (MCL) injuries are known to occur during dynamic athletic tasks that place combinatorial frontal and transverse plane loads on the knee. A mechanical impact simulator that produces clinical presentation of ACL injury allows for the quantification of individual loading contributors leading to ACL failure.

Purpose/hypothesis: The objective was to delineate the relationship between knee abduction moment, anterior tibial shear, and internal tibial rotation applied at the knee and ACL strain during physiologically defined simulations of impact at a knee flexion angle representative of initial contact landing from a jump.

Neuromuscular Training Improves Biomechanical Deficits at the Knee in Anterior Cruciate Ligament-Reconstructed Athletes.

Objective: Athletes who return to sport after anterior cruciate ligament reconstruction (ACLR) demonstrate persistent biomechanical and neuromuscular deficits of the knee. There is limited evidence on what effect a neuromuscular training (NMT) program has on knee biomechanics in a cohort of athletes with ACLR. Therefore, the primary aim of this study was to quantify the effect of an NMT program on knee biomechanics in a cohort of ACLR athletes.

External loads associated with anterior cruciate ligament injuries increase the correlation between tibial slope and ligament strain during in vitro simulations of in vivo landings.

Background: The aim of the present study was to evaluate the relationship between tibial slope angle and ligament strain during in vitro landing simulations that induce ACL failure through the application of variable external loading at the knee. The hypothesis tested was that steeper posterior tibial slope angle would be associated with higher ACL strain during a simulated landing task across all external loading conditions.

Methods: Kinetics previously derived from an in vivo cohort performing drop landings were reproduced on 45 cadaveric knees via the mechanical impact simulator.

Effect of Concussions on Lower Extremity Injury Rates at a Division I Collegiate Football Program.

Background: Football has one of the highest injury rates (IRs) in sports, ranging from 4.1 to 8.6 per 1000 athlete-exposures (AEs).

Biomechanical Deficits at the Hip in Athletes With ACL Reconstruction Are Ameliorated With Neuromuscular Training.

Background: The efficacy of a neuromuscular training (NMT) program to ameliorate known hip biomechanical risk factors for athletes with anterior cruciate ligament reconstruction (ACLR) is currently unknown. Purpose/Hypothesis: The purpose was to quantify the effects of an NMT program on hip biomechanics among athletes with ACLR and to compare posttraining hip biomechanics with a control group. The hypotheses were that known hip biomechanical risk factors of anterior cruciate ligament (ACL) injury would be significantly reduced among athletes with ACLR after the NMT program and that posttraining hip biomechanics between the ACLR and control cohorts would not differ.

Validation of Noncontact Anterior Cruciate Ligament Tears Produced by a Mechanical Impact Simulator Against the Clinical Presentation of Injury.

Background: Anterior cruciate ligament (ACL) injuries are catastrophic events that affect athletic careers and lead to long-term degenerative knee changes. As injuries are believed to occur within the first 50 milliseconds after initial contact during a rapid deceleration task, impact simulators that rapidly deliver impulse loads to cadaveric specimens have been developed. However, no impactor has reproducibly and reliably created ACL injures in a distribution that mimics clinical observation.

Factors Associated With Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction Surgery.

Background: Anterior cruciate ligament (ACL) injury has a significant psychological effect, and a negative psychological state is a commonly cited reason for a reduction or cessation of sports participation after ACL reconstruction (ACLR) surgery.

Purpose: To identify factors that contribute to an athlete's psychological readiness to return to sport (RTS) after ACLR.

Study Design: Cross-sectional study; Level of evidence, 3.

Sex-Based Differences of Medial Collateral Ligament and Anterior Cruciate Ligament Strains With Cadaveric Impact Simulations.

Background: Female patients sustain noncontact knee ligament injuries at a greater rate compared with their male counterparts. The cause of these differences in the injury rate and the movements that load the ligaments until failure are still under dispute in the literature.

Purpose/hypotheses: This study was designed to determine differences in anterior cruciate ligament (ACL) and medial collateral ligament (MCL) strains between male and female cadaveric specimens during a simulated athletic task.