Publications by authors named "Gregory Adamson"

Background: There is a relative paucity of studies examining how the superior capsule reconstruction (SCR) may alter the kinematics of the glenohumeral joint capsule itself, specifically with respect to rotation and translation in the anterior-posterior and superior-inferior planes. This then raises the possibility that the SCR may be having unintended consequences on glenohumeral kinematics. The purpose of this study was to quantify the glenohumeral joint kinematics following Fascia Lata SCR (FL-SCR).

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Background: Pulmonary hypertension in children often progresses despite optimal therapy. This document provides an evidence-based clinical practice guideline for the management of children with progressive pulmonary hypertension despite optimal therapy.

Methods: A multidisciplinary panel identified pertinent questions regarding the management of children with pulmonary hypertension that has progressed despite optimal therapy, conducted systematic reviews of the relevant literature, and applied the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach to develop clinical recommendations.

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Children with severe Group 1 pulmonary arterial hypertension (PAH) have an unpredictable response to subcutaneous treprostinil (TRE) therapy, which may be influenced by age, disease severity, or other unknown variables at time of initiation. In this retrospective single-center cohort study, we hypothesized that younger age at TRE initiation, early hemodynamic response (a decrease in pulmonary vascular resistance by ≥30% at follow-up catheterization), and less severe baseline hemodynamics (Rp:Rs < 1.1) would each be associated with better clinical outcomes.

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Purpose: To evaluate the biomechanical effects of acellular human dermal allograft tuberoplasty (AHDAT) in a cadaveric model of an irreparable supraspinatus + anterior one-half infraspinatus (stage III) rotator cuff tear.

Methods: Eight cadaveric shoulders were tested at 20°, 40°, and 60° of glenohumeral abduction (AB) and 0°, 30°, 60°, and 90° of external rotation (ER). Superior humeral translation, acromiohumeral distance, and subacromial contact were quantified for 4 conditions: (1) intact, (2) stage III tear (entire supraspinatus and anterior one-half infraspinatus), (3) single-layer AHDAT, and (4) double-layer AHDAT.

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Introduction: Chylothorax following paediatric cardiac surgery is associated with significant morbidity, particularly those that are refractory to conservative therapy. It is our impression that there is important variability in the medical, surgical, and interventional therapies used to manage refractory chylothorax between congenital heart programmes. We therefore conducted a survey study of current practices for managing refractory chylothorax.

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Article Synopsis
  • - The study investigates the effectiveness of two surgical methods—conjoint tendon transfer and open Bankart repair—for treating shoulder instability in cadaver models with 10% glenoid bone loss, which is known to increase the risk of surgery failure.
  • - Eight cadaver shoulders were tested to assess factors like range of motion and joint stiffness under various conditions: intact shoulder, Bankart lesion with bone loss, shoulder with tendon transfer, and shoulder after open repair.
  • - Results showed that having a Bankart lesion increased shoulder range of motion, while the conjoint tendon transfer provided some stiffness benefits, but the Bankart repair did not maintain the range of motion compared to normal shoulders.
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Purpose: To evaluate the effect of hip flexion and rotation on excursion of the gluteus medius (Gmed) and minimus (Gmin) myotendinous unit.

Methods: Seven hips from 4 cadaveric specimens (males, 68.5 ± 18.

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Objective: To describe the acute hemodynamic effect of vasopressin on the Fontan circulation, including systemic and pulmonary pressures and resistances, left atrial pressure, and cardiac index.

Design: Prospective, open-label, nonrandomized study (NCT04463394).

Setting: Cardiac catheterization laboratory at Lucile Packard Children's Hospital, Stanford.

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Article Synopsis
  • The study aimed to evaluate a new looping stitch for distal biceps tendon fixation against the traditional Krackow stitch in terms of biomechanical properties and needle penetration.
  • Using matched pairs of human tendons, researchers compared the stitching methods by measuring constructs under various loads, assessing stiffness, deformation, and ultimate load.
  • Results showed that while both stitches had similar stiffness and deformation, the looping stitch was significantly stronger, with an average ultimate load of 312.7 N compared to the Krackow stitch's 223.7 N.
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Background: The optimal tibial fixation of anterior cruciate ligament (ACL) reconstruction (ACLR) grafts remains controversial.

Purpose/hypothesis: The purpose of this study was to compare the biomechanical characteristics of the TensionLoc (TL) cortical fixation device with the Double Spike Plate (DSP) fixation device for ACL tibial fixation using both bone-patellar tendon-bone (BTB) and quadriceps grafts. It was hypothesized that there would be no differences in biomechanical characteristics between the fixation devices regardless of graft type.

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Background: The objective of this study was to quantify the valgus laxity and strain of the elbow ulnar collateral ligament (UCL) complex after repeated valgus stretching and subsequent recovery. Understanding these changes may have important implications in improving strategies for injury prevention and treatment. The hypothesis was that the UCL complex will demonstrate a permanent increase in valgus laxity and region-specific increase in strain as well as region-specific recovery characteristics.

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Article Synopsis
  • Earlier diagnosis of chylothorax in children after cardiac surgery can reduce the duration of the condition, but traditional fluid testing can delay detection, especially in non-enterally fed patients.
  • Researchers aimed to create and validate a prediction model to detect chylothorax earlier using patient data from two hospitals.
  • The key factors in the model were chest tube output on the first day after surgery and the practice of delayed sternal closure, with higher outputs indicating a greater likelihood of chylothorax, improving the model's accuracy for detection.
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Introduction: Latissimus dorsi and teres major (LDTM) tendon transfer has demonstrated better clinical outcomes compared to Latissimus dorsi (LD) transfer for irreparable anterosuperior cuff (subscapularis/supraspinatus) tears; however, the biomechanical effects of these procedures are unknown. Therefore, the objective of this study was to compare kinematics and internal rotation of LDTM transfer to LD transfer for anterosuperior cuff tear.

Methods: Eight cadaveric shoulders were tested in four conditions; (1) intact, (2) anterosuperior rotator cuff tear, (3) LDTM transfer, and (4) LD transfer.

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Left atrial hypertension (LAH) may contribute to pulmonary hypertension (PH) in premature infants with bronchopulmonary dysplasia (BPD). Primary causes of LAH in infants with BPD include left ventricular diastolic dysfunction or hemodynamically significant left to right shunt. The incidence of LAH, which is definitively diagnosed by cardiac catheterization, and its contribution to PH is unknown in patients with BPD-PH.

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Purpose: The purpose of this study was to compare the biomechanical characteristics of a fascia lata superior capsule reconstruction (FL-SCR) to the native superior capsule.

Methods: The native superior capsule of 8 cadaveric shoulders was tested with cyclic loading from 10 to 50 N for 30 cycles in 20° of glenohumeral abduction followed by load to failure at 60 mm/min. Following native superior capsule testing, FL-SCR was performed, which was tested as described for the native capsule.

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Background Despite favorable outcomes of surgical pulmonary artery (PA) reconstruction, isolated proximal stenting of the central PAs is common clinical practice for patients with peripheral PA stenosis in association with Williams and Alagille syndromes. Given the technical challenges of PA reconstruction and the morbidities associated with transcatheter interventions, the hemodynamic consequences of all treatment strategies must be rigorously assessed. Our study aims to model, assess, and predict hemodynamic outcomes of transcatheter interventions in these patients.

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Achieving an optimal surgical result in patients with major aortopulmonary collateral arteries (MAPCAs) requires a thorough preoperative evaluation of the anatomy and physiology of the pulmonary circulation. This review provides a detailed description of diagnostic catheterization in patients with MAPCAs, including a summary of catheterization techniques, an overview of commonly used terms, and a review of MAPCA and pulmonary artery angiographic anatomy.

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Purpose: To compare the biomechanical effects of superior capsule reconstruction (SCR) graft fixation length determined at 20° and 40° of glenohumeral (GH) abduction.

Methods: Humeral translation, rotational range of motion (ROM), and subacromial contact pressure were quantified at 0°, 30°, and 60° of GH abduction in the scapular plane in 6 cadaveric shoulders for the following states: intact, massive rotator cuff tear, SCR with dermal allograft fixed at 20° of GH abduction (SCR 20), and SCR with dermal allograft fixed at 40° of GH abduction (SCR 40). Statistical analysis was conducted using a repeated-measures analysis of variance and a paired t test (P < .

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Purpose: The purpose of this study was to biomechanically assess superior stability, subacromial contact pressures, and glenohumeral kinematics of a V-shaped anterior cable reconstruction with semitendinosus allograft (VST) in a massive rotator cuff tear (MCT) model.

Methods: Eight cadaveric shoulders (mean age, 66 years; range, 48 to 72 years) were tested with a custom testing system used to evaluate superior translation, subacromial contact pressure, and glenohumeral kinematics at 0°, 20°, and 40° glenohumeral abduction and 0°, 30°, 60°, and 90° of external rotation (ER). Conditions tested included (1) native state, (2) MCT (complete supraspinatus and ½ infraspinatus), a (3) VST.

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Background: The potential use of a patellar tendon allograft for superior capsular reconstruction has been demonstrated biomechanically; however, there are concerns regarding compromised fixation strength owing to the longitudinal orientation of the fibers in the patellar tendon. Therefore, the purpose of this study was to compare the fixation strength of superior capsule reconstruction using a patellar tendon allograft to the intact superior capsule.

Methods: The structural properties of the intact native superior capsule (NSC) followed by superior capsular reconstruction using a patellar tendon allograft (PT-SCR) were tested in eight cadaveric specimens.

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Purpose: To quantitatively biomechanically assess superior stability, subacromial contact pressures, and glenohumeral kinematics of an in situ biceps tenodesis and a box-shaped long head of the biceps tendon (LHBT) superior capsule reconstruction (SCR) in a superior massive rotator cuff tear (MCT) model.

Methods: Eight cadaveric shoulders (mean age, 62 years; range, 46-70 years) were tested with a custom testing system used to evaluate range of motion, superior translation, and subacromial contact pressure at 0°, 20°, and 40° of abduction. Conditions tested included native state, MCT (complete supraspinatus and one-half of the infraspinatus), a box-shaped LHBT SCR, and an in situ biceps tenodesis.

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Cyclamen aldehyde (CA; 3-(4-isopropylphenyl)-2-methylpropanal) is a widely used fragrance material. Repeated dose studies in rats revealed adverse effects on sperm maturation. Here we review all the mechanistic and in vivo evidence, to determine relevancy to human health.

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Objectives: The objective of this study was to assess procedural outcomes of balloon pulmonary artery (PA) angioplasty procedures after complete repair of tetralogy of Fallot with major aortopulmonary collateral arteries (TOF/MAPCAs).

Background: Our approach to patients with TOF/MAPCAs emphasizes early complete unifocalization and repair. Major PA reinterventions are relatively uncommon.

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