J Am Acad Orthop Surg Glob Res Rev
January 2022
Introduction: Grand rounds have been weekly gatherings at academic orthopaedic surgery programs across the country for decades. During the 50th year of grand rounds at our institution, the COVID-19 pandemic prompted the transformation of this in-person forum into a virtual setting. The purpose of this study was to detail this initiative and to report survey data providing participant-reported perceptions and satisfaction of virtual versus in-person grand rounds.
View Article and Find Full Text PDFIntervertebral disc (IVD) degeneration is significantly correlated with the changes in structure and material properties of adjacent vertebral bone, possibly through mechanical and electrical interactions. However, the mechanisms underlying the alteration of the mechanical and electrical environment at the disc-vertebra interface related with disc degeneration have not been well studied. The objective of this study was to numerically investigate the long-term distributions of mechanical and electrical signals on the disc-vertebra interface with disc degeneration.
View Article and Find Full Text PDFThe objective of this study was to quantitatively analyze the effect of diurnal loading on the transport of various charged antibiotics into negatively charged human intervertebral disc (IVD). Transport of charged antibiotics into a human lumbar disc was analyzed using a 3D finite element model. The valence (z) of the electrical charge of antibiotics varied from z = +2 (positively charged) to z = -2 (negatively charged).
View Article and Find Full Text PDFSpine (Phila Pa 1976)
September 2019
Study Design: Simulation of antibiotics transport into human intervertebral disc with intravenous infusion.
Objective: The objective of this study was to quantitatively investigate antibiotic concentrations in the disc.
Summary Of Background Data: Intravenous infusion of antibiotics is typically used to treat intervertebral disc infection in clinics.
Delivering charged antibiotics to the intervertebral disc is challenging because of the avascular, negatively charged extracellular matrix (ECM) of the tissue. The purpose of this study was to measure the apparent diffusion coefficient of two clinically relevant, charged antibiotics, vancomycin (positively charged) and oxacillin (negatively charged) in IVD. A one-dimensional steady state diffusion experiment was employed to measure the apparent diffusion coefficient of the two antibiotics in bovine coccygeal annulus fibrosus (AF) tissue.
View Article and Find Full Text PDFLittle quantitative information exists on the kinetics of charged antibiotic penetration into human intervertebral discs (IVD). This information is crucial for determining the dosage to use, timing of administration, and duration of treatment for infected IVDs. The objective of this study was to quantitatively analyze the transport of various charged antibiotics into human lumbar IVDs.
View Article and Find Full Text PDFThe objective of this study was to investigate the spatial and temporal variations of water content in intervertebral discs during degeneration and repair processes. We hypothesized that the patterns of water content distribution in the discs are related to the intensity patterns observed in T2-weighted MRI images. Water content distributions in the mildly (e.
View Article and Find Full Text PDFThe efficacy of biological therapies on intervertebral disc repair was quantitatively studied using a three-dimensional finite element model based on a cell-activity coupled multiphasic mixture theory. In this model, cell metabolism and matrix synthesis and degradation were considered. Three types of biological therapies-increasing the cell density (Case I), increasing the glycosaminoglycan (GAG) synthesis rate (Case II), and decreasing the GAG degradation rate (Case III)-to the nucleus pulposus (NP) of each of two degenerated discs [one mildly degenerated (e.
View Article and Find Full Text PDFSpine (Phila Pa 1976)
November 2014
Study Design: Simulate the progression of human disc degeneration.
Objective: The objective of this study was to quantitatively analyze and simulate the changes in cell density, nutritional level, proteoglycan (PG) content, water content, and volume during human disc degeneration using a numerical method.
Summary Of Background Data: Understanding the cause and progression of intervertebral disc degeneration is crucial for developing effective treatment strategies for intervertebral disc degeneration-related diseases.
The avascular intervertebral disc (IVD) receives nutrition via transport from surrounding vasculature; poor nutrition is believed to be a main cause of disc degeneration. In this study, we investigated the effects of mechanical deformation and anisotropy on the transport of two important nutrients--oxygen and glucose--in human annulus fibrosus (AF). The diffusivities of oxygen and glucose were measured under three levels of uniaxial confined compression--0, 10, and 20%--and in three directions--axial, circumferential, and radial.
View Article and Find Full Text PDFThe intervertebral disc (IVD) receives important nutrients, such as glucose, from surrounding blood vessels. Poor nutritional supply is believed to play a key role in disc degeneration. Several investigators have presented finite element models of the IVD to investigate disc nutrition; however, none has predicted nutrient levels and cell viability in the disc with a realistic 3D geometry and tissue properties coupled to mechanical deformation.
View Article and Find Full Text PDFObjective: To evaluate the utility of quantitative computerized pain drawings (CPDs) in a sample of spine patients before and after surgery.
Design: Analysis of changes in quantified CPDs, the Oswestry Disability Index (ODI), the Short Form-36 Health Survey Questionnaire (SF-36), and numerical ratings of pain intensity before and after surgery.
Setting: Private clinic in large metropolitan area.
Poor nutritional supply to the intervertebral disc is believed to be an important factor leading to disc degeneration. However, little is known regarding nutritional transport in human annulus fibrosus (AF) and its relation to tissue morphology. We hypothesized that solute diffusivity in human AF is anisotropic and inhomogeneous, and that transport behaviors are associated with tissue composition and structure.
View Article and Find Full Text PDFThis Practice Point commentary discusses a retrospective case series by Han et al. that investigated the management of spinal disease during pregnancy. On the basis of their experiences with 10 patients, Han et al.
View Article and Find Full Text PDFUnlabelled: The literature suggests preoperative autologous blood donation in total joint arthroplasty is associated with increased overall transfusion rates compared with nondonation and is not cost-effective for all patients. We asked whether the amount of intraoperative blood loss and blood replacement differs between autologous donors and nondonors in elective spine surgery and whether the rates of allogeneic blood transfusions differ between the two groups; we then determined the cost of wasted predonated units. We retrospectively reviewed 676 patients who underwent elective lumbar spine surgery and compared relevant data to that in a matched cohort of 51 patients who predonated blood and 51 patients who received only cell-saver blood and underwent instrumented spinal fusion.
View Article and Find Full Text PDFSpine (Phila Pa 1976)
October 2007
Study Design: The study used nonhuman primates to investigate changes in the vertebral bodies adjacent to acutely narrowed intervertebral discs.
Objective: To describe changes in the vertebral bodies adjacent to acutely narrowed intervertebral discs in the lumbar spine.
Summary Of Background Data: Alterations in the intervertebral disc are known to affect the adjacent vertebral bodies.
Spine (Phila Pa 1976)
November 2006
Study Design: Investigation of the transport behavior of ions in intervertebral disc using an electrical conductivity method.
Objectives: To determine the electrical conductivity and ion diffusivity of nucleus pulposus and anulus fibrosus in 3 major directions (axial, circumferential, and radial).
Summary Of Background Data: Knowledge of diffusivity of small molecules is important for understanding nutrition supply in intervertebral disc and disc degeneration.
Spine (Phila Pa 1976)
May 2004
Study Design: A prospective randomized study.
Objectives: To study the risk of infection, hematoma, and neurologic deficits following extensive lumbar spine surgery in patients with or without prophylactic closed wound suction drain placement.
Summary Of Background Data: One randomized study assessing prophylactic drain placement in one-level lumbar spine surgery suggested that the use of a wound drain is not effective at preventing infection and may actually increase the rate of this complication.
Many clinicians find it difficult to differentiate between symptoms caused by a spine disorder or a hip disorder. If surgery is indicated, the order in which these operations take place is an important factor in the patient's long-term outcome. A prospective evaluation and retrospective chart review of patients with lower extremity pain was performed at the principal investigator's clinic to determine which signs and symptoms best predict the primary source of pain in patients with hip and spine disorders.
View Article and Find Full Text PDFSpine (Phila Pa 1976)
May 2002
Study Design: Determination of clinical results at least 2 years after lumbar spine surgery during which spinal stiffness measurements were made.
Objectives: To determine whether spine stiffness is predictive of clinical results after lumbar spine surgery for spinal stenosis, disc herniation, or degenerative spondylolisthesis.
Summary Of Background Data: The implied clinical wisdom is that instability of the spine portends a poor prognosis for relief of back pain after surgery in the absence of a fusion.
Study Design: Prospective trial.
Objectives: To test an intraoperative diagnostic tool to determine if it provided the surgeon with a safe, reproducible, accurate, quantitative measure of lumbar spine motion segment stability.
Summary Of Background Data: Several devices have been developed to measure motion segment stiffness, however, few have been tested intraoperatively on humans, and none, to the best of the authors' knowledge have been tested as extensively as the device described in this study.