Glycopolymers Prepared by Alternating Ring-Opening Metathesis Polymerization Provide Access to Distinct, Multivalent Structures for the Probing of Biological Activity.

A myriad of biological processes are facilitated by ligand-receptor interactions. The low affinities of these interactions are typically enhanced by multivalent engagements to promote binding. However, each biological interaction requires a unique display and orientation of ligands.

Inflammatory biomarkers and state of the tibiofemoral joint in the osteoarthritic knee: a narrative review.

Background: The healing process is initiated by injurious stimuli in response to cellular damage. Upon recruiting proinflammatory biomarkers to the tissue site of injury, the release of additional biomarkers occurs, including the likes of cytokines, matrix molecules, macrophages, neutrophils, and others. This influx of immune system mediators can occur for chronic periods, and though its intention is for healing the original injurious stimuli, it is also suspected of causing long term cartilage impairment following internal structure damage.

Triblock Glycopolymers with Two 10-mer Blocks of Activating Sugars Enhance the Activation of Acrosomal Exocytosis in Mouse Sperm.

Carbohydrate recognition is imperative for the induction of sperm acrosomal exocytosis (AE), an essential phenomenon in mammalian fertilization. In mouse sperm, polynorbornene 100-mers displaying fucose or mannose moieties were effective at inducing AE. In contrast, glycopolymers exhibiting glucose sugars resulted in no AE activation.

Anatomic Anterolateral Ligament Reconstruction with Iliotibial Band Graft and Concomitant Anterior Cruciate Ligament Reconstruction.

Anterior cruciate ligament (ACL) reconstruction (ACLR) attempts to restore native ACL function. Persistent anterolateral instability is a common symptom after ACLR that can lead to worse patient outcomes. Additional surgeries, like anterolateral ligament reconstruction (ALLR), can augment the ACL graft and help increase anterolateral rotational stability.

Effect of anti-inflammatory treatments on patient outcomes and concentrations of inflammatory modulators in the post-surgical and post-traumatic tibiofemoral joint setting: a narrative review.

Background And Objective: There are several anti-inflammatory therapeutic options that can be used in the context of post-surgical and post-traumatic knee settings. Each of these options carries with it certain benefits, as well as potential issues depending on the duration and administration of each therapy. An understanding of how these anti-inflammatory drugs modulate various biomarkers of inflammation is also necessary in understanding how they can affect patient and objective outcomes following acute knee injury or surgery.

Inflammatory synovial biomarkers and state of the tibiofemoral joint in the post-surgical settings: a narrative review.

Background And Objective: Knee surgery attempts to restore the native biomechanics of the knee, improve stability, and decrease the progression of osteoarthritis (OA). However, despite improvements in surgical techniques, tissue degradation and OA are common after knee surgery, occurring in higher rates in surgical knees compared to non-surgical knees. The aim of this study is to analyze previous literature to determine which synovial fluid biomarkers contribute to knee tissue degradation and decrease patient outcomes in the post-surgical setting of the knee.

Structural properties of optically clear bacterial cellulose produced by Komagataeibacter hansenii using arabitol.

Bacterial cellulose (BC) exhibits beneficial properties for use in biomedical applications but is limited by its lack of tunable transparency capabilities. To overcome this deficiency, a novel method to synthesize transparent BC materials using an alternative carbon source, namely arabitol, was developed. Characterization of the BC pellicles was performed for yield, transparency, surface morphology, and molecular assembly.

saxs characterization of thermoresponsive behavior of a poly(ethylene glycol)-graft-(poly(vinyl caprolactam)-co-poly(vinyl acetate)) amphiphilic graft copolymer.

We report the thermoresponsive assembly and rheology of an amphiphilic thermosensitive graft copolymer, poly(ethylene glycol)-graft-(poly(vinyl caprolactam)--poly(vinyl acetate)) (commercial name Soluplus), which has been investigated for potential biomedical applications. It has received attention due to is ability to solubilize hydrophobic drugs and for its thickening behavior close to body temperature. Through use of the synchrotron at Brookhaven National Lab, and collaboration with the department of energy, the nanoscale structure and properties can be probed in greater detail.

Comparative Outcomes Occur After Superficial Medial Collateral Ligament Augmented Repair vs Reconstruction: A Prospective Multicenter Randomized Controlled Equivalence Trial.

Background: Although previous studies have reported good short-term results for superficial medial collateral ligament (sMCL) reconstruction, whether an augmented MCL repair is clinically equivalent remains unclear.

Purpose/hypothesis: The purpose of this study was to compare clinical outcomes between randomized groups that underwent sMCL augmentation repair and sMCL autograft reconstruction. The hypothesis was that there would be no significant differences in objective or subjective outcomes between groups.

Full thickness quadriceps tendon grafts with bone had similar material properties to bone-patellar tendon-bone and a four-strand semitendinosus grafts: a biomechanical study.

Purpose: Despite increasing interest in utilizing quadriceps tendon (QT) grafts in anterior cruciate ligament reconstruction (ACLR), data on the optimal quadriceps graft thickness are limited. The purpose of this study was to characterize the mechanical properties for the quadriceps tendon, comparing full-thickness (FT) QT grafts with and without bone to a partial-thickness (PT) QT graft, and comparing the three QT grafts to four-stranded semitendinosus (4-SST) and bone-patellar tendon-bone (BTB) grafts and one experimental graft, the two-stranded rectus femoris (RF).

Methods: Forty-eight (n = 48) young cadaveric grafts (mean age 32 ± 6 years) were utilized for testing with N = 8 specimens in each of the following groups; (1) FT QT with bone, (2) FT QT without bone, (3) PT QT without bone, (4) BTB, (5) RF, and (6) 4-SST.

Qualitative and Quantitative Anatomy of the Human Quadriceps Tendon in Young Cadaveric Specimens.

Background: A detailed understanding of the anatomy of the quadriceps tendon (QT) is clinically relevant, owing to its increased use as a graft in anterior cruciate ligament reconstruction.

Purpose: To qualitatively and quantitatively describe the anatomy of the QT in younger adult specimens.

Study Design: Descriptive laboratory study.

An Acute Osteochondral Defect Secondary to Fabella Impaction: A Case Report.

Case: A healthy 37-year-old man sustained a knee injury after performing a deep flexion maneuver while skiing and noted immediate knee pain and swelling. Because of persistent inability to fully extend his knee and persistent posterolateral knee pain, he was evaluated and noted to have an acute osteochondral defect of the posterolateral femoral condyle directly adjacent to his fabella. After a trial of nonoperative interventions, he elected to undergo an arthroscopic-assisted open excision of the fabella and a chondroplasty of the posterolateral femoral condyle defect.

Increased posterior tibial slope results in increased incidence of posterior lateral meniscal root tears in ACL reconstruction patients.

Purpose: While the association with acute anterior cruciate ligament (ACL) tears has been established, other risk factors and associated pathologies which occur with a concomitant lateral meniscal posterior root tear (LMPRT) are not well defined. The purpose of this study was to compare the risk factors and concomitant pathologies between patients with LMPRT and patients without LMPRTs in the setting of a primary ACL tear.

Methods: Patients with a LMPRT identified at the time of primary ACL reconstruction by a single surgeon were identified.

Beighton Score, Tibial Slope, Tibial Subluxation, Quadriceps Circumference Difference, and Family History Are Risk Factors for Anterior Cruciate Ligament Graft Failure: A Retrospective Comparison of Primary and Revision Anterior Cruciate Ligament Reconstructions.

Purpose: To assess patient history, physical examination findings, magnetic resonance imaging (MRI) and 3-dimensional computed tomographic (3D CT) measurements of those with anterior cruciate ligament (ACL) graft failure compared with primary ACL tear patients to better discern risk factors for ACL graft failure.

Methods: We performed a retrospective review comparing patients who underwent revision ACL reconstruction (ACLR) with a primary ACLR group with minimum 1-year follow-up. Preoperative history, examination, and imaging data were collected and compared.

High-Grade Posterolateral Tibial Plateau Impaction Fractures in the Setting of a Primary Anterior Cruciate Ligament Tear Are Correlated With an Increased Preoperative Pivot Shift and Inferior Postoperative Outcomes After Anterior Cruciate Ligament Reconstruction.

Background: Impaction fractures of the posterolateral tibial plateau have been previously described to occur in association with anterior cruciate ligament (ACL) tears; however, the effect of these injuries on patient-reported outcomes (PROs) after ACL reconstruction (ACLR) is not well known.

Purpose: (1) To assess the effect of posterolateral tibial plateau impaction fractures on preoperative clinical knee stability assessed by the Lachman and pivot-shift examinations and (2) to assess the effect of impaction fractures on PROs after ACLR.

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

Global Forum: Orthopaedic Physicians in the Winter and Summer Olympic Games.

In training for and performing in the sporting competitions of the Olympic Games, athletes endure a variety of injuries that can lead to the development of a chronic musculoskeletal condition. Injury surveillance studies are in place for each event to collect epidemiological data in an attempt to enhance injury prevention for future Winter and Summer Olympic Games. Periodic health evaluations also are used to screen for injuries and monitor athletes' health in order to take measures to reduce the risk of reinjury.

Clinical Presentation and Outcomes Associated With Fabellectomy in the Setting of Fabella Syndrome.

Background: Clinical outcomes pertaining to isolated lateral fabellectomy in the setting of fabella syndrome are limited to small case reports at this time.

Purpose: To assess the most common presenting symptoms, clinical outcomes, and satisfaction after fabella excision in the setting of fabella syndrome.

Study Design: Case series; Level of evidence, 4.

Clinical Characteristics and Outcomes After Anatomic Reconstruction of the Proximal Tibiofibular Joint.

Purpose: To assess the most common presenting symptoms, clinical outcomes, and satisfaction after anatomic reconstruction of the proximal tibiofibular joint (PTFJ) with a free semitendinosus autograft.

Methods: Consecutive patients with minimum 2-year follow-up after isolated anatomic PTFJ reconstruction were retrospectively reviewed. Patients were evaluated with the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score and Lysholm Knee Survey score along with a simple numeric patient satisfaction score (0-10, with 10 rated as perfect).

Acromioclavicular and Coracoclavicular Ligament Reconstruction for Acromioclavicular Joint Instability.

Numerous operative techniques have been described for acromioclavicular and coracoclavicular ligament reconstruction for the treatment of acromioclavicular joint instability. Injuries of this nature are commonly sustained by contact-sport athletes in high-impact collisions or falls. Traumatic injury to the acromioclavicular joint and ligamentous structures can range in severity, as can the degree of subsequent joint instability.

Morphologic Variants of Posterolateral Tibial Plateau Impaction Fractures in the Setting of Primary Anterior Cruciate Ligament Tear.

Background: Impaction fractures of the posterolateral tibial plateau commonly occur in the setting of anterior cruciate ligament (ACL) tears, with considerable variability found in fracture size and morphologic features.

Purpose: The primary objective was to characterize different morphologic variants of posterolateral tibial plateau impaction fractures. The secondary objective was to investigate the association between these impaction fracture variants and concomitant meniscal and ligamentous injuries.

Posterior Medial Meniscus Root Tears Potentiate the Effect of Increased Tibial Slope on Anterior Cruciate Ligament Graft Forces.

Background: Increased posterior tibial slope and posterior medial meniscus root tears increase the force experienced by the anterior cruciate ligament (ACL) and predispose patients to higher rates of primary ACL injury or ACL graft failure after an ACL reconstruction (ACLR). However, the interplay among sagittal plane tibial slope, medial meniscus root tears, and ACLR graft force remains inadequately defined.

Purpose/hypothesis: The purpose was to quantify the effect of sagittal plane tibial slope on ACLR graft force at varying knee flexion angles with an intact medial meniscus, a posterior medial meniscus root tear, and a medial meniscus root repair.

Injury of the Meniscus Root.

Meniscus root tears biomechanically disrupt normal joint loading and lead to joint overload with the possible development of spontaneous osteonecrosis of the knee and early-onset osteoarthritis. Proper identification and treatment of meniscal root tears has been proven to restore joint loading and improve patient outcomes.

Comprehensive review of the physical exam for glenohumeral instability.

Glenohumeral instability is a common pathology of the shoulder joint, especially among young athletes. Despite advancements in technology and the widespread use of diagnostic imaging, a careful history and physical examination still remain the cornerstone of diagnosing patients with shoulder instability. Due to the involvement of many static and dynamic stabilizers, proficient physical examination can be challenging.