The Cost of Joint Replacement: Comparing Two Approaches to Evaluating Costs of Total Hip and Knee Arthroplasty.

Background: In an era of mandatory bundled payments for total joint replacement, accurate analysis of the cost of procedures is essential for orthopaedic surgeons and their institutions to maintain viable practices. The purpose of this study was to compare traditional accounting and time-driven activity-based costing (TDABC) methods for estimating the total costs of total hip and knee arthroplasty care cycles.

Methods: We calculated the overall costs of elective primary total hip and total knee replacement care cycles at our academic medical center using traditional and TDABC accounting methods.

Quantifying Baseline Fixed Charge Density in Healthy Human Cartilage Endplate: A Two-point Electrical Conductivity Method.

Study Design: Regional measurements of fixed charge densities (FCDs) of healthy human cartilage endplate (CEP) using a two-point electrical conductivity approach.

Objective: The aim of this study was to determine the FCDs at four different regions (central, lateral, anterior, and posterior) of human CEP, and correlate the FCDs with tissue biochemical composition.

Summary Of Background Data: The CEP, a thin layer of hyaline cartilage on the cranial and caudal surfaces of the intervertebral disc, plays an irreplaceable role in maintaining the unique physiological mechano-electrochemical environment inside the disc.

The region-dependent biomechanical and biochemical properties of bovine cartilaginous endplate.

Regional biomechanical and biochemical properties of bovine cartilaginous endplate (CEP) and its role in disc mechanics and nutrition were determined. The equilibrium aggregate modulus and hydraulic permeability between the central and lateral regions were examined by confined compression testing. Biochemical assays were conducted to quantify the amount of water, collagen, and glycosaminoglycan (GAG).

Effect of cartilage endplate on cell based disc regeneration: a finite element analysis.

This study examines the effects of cartilage endplate (CEP) calcification and the injection of intervertebral disc (IVD) cells on the nutrition distributions inside the human IVD under physiological loading conditions using multiphasic finite element modeling. The human disc was modeled as an inhomogeneous mixture consisting of a charged elastic solid, water, ions (Na+ and Cl-), and nutrient solute (oxygen, glucose and lactate) phases. The effect of the endplate calcification was simulated by a reduction of the tissue porosity (i.

Lumbar spinal arthroplasty: analysis of one center's twenty best and twenty worst clinical outcomes.

Study Design: This is a retrospective analysis of data that were collected prospectively from 2 concurrent FDA IDE lumbar arthroplasty clinical trials performed at a single center.

Objectives: The purpose of this study was to determine if factors differentiating those patients with the best and worst clinical outcomes from total disc arthroplasty (TDR) could be identified.

Summary Of Background Data: Overall the results of TDR have been favorable, including recent results from 2 FDA IDE trials conducted in the United States.

Relationship between the length of time off work preoperatively and clinical outcome at 24-month follow-up in patients undergoing total disc replacement or fusion.

Background Context: A recent study involving interbody fusion patients found that preoperative work status was significantly related to clinical outcome. In another study comparing the best and worst outcomes of total disc replacement, among a battery of variables analyzed, the only one that differentiated the best and worst outcome groups was the length of time off work before total disc replacement.

Purpose: The purpose of this study was to determine if there was a relationship between the length of time off work and treatment outcome at 24-month follow-up.

Comparison of results of total disc replacement in postdiscectomy patients versus patients with no previous lumbar surgery.

Study Design: Data for this study were collected as part of a prospective Food and Drug Administration regulated IDE trial for the ProDisc total disc replacement.

Objective: The purpose of the study was to compare the results of total disc replacement (TDR) in patients with previous discectomy to patients who had no such previous surgery.

Summary Of Background Data: Discectomy is a well accepted surgical procedure for appropriately selected patients.

Two- to 3-Year Follow-Up of ProDisc-L: Results From a Prospective Randomized Trial of Arthroplasty Versus Fusion.

Background: Although total disc replacement has been performed for years outside the United States, relatively little available data address clinical outcomes, particularly data from prospective studies. We report the 24- to 36-month follow-up of one center's experience with the ProDisc-L artificial disc as part of a prospective, randomized trial comparing total disc arthroplasty to combined anterior-posterior lumbar fusion.

Methods: The study involved clinical results for 157 patients from a single center enrolled in the US Food and Drug Administration-regulated trial comparing ProDisc-L to fusion.

Lumbar spine arthroplasty: early results using the ProDisc II: a prospective randomized trial of arthroplasty versus fusion.

This study represents the first 39 patients with at least 6-month follow-up enrolled in a prospective randomized Food and Drug Administration study evaluating the safety and efficacy of the ProDisc II versus the control, a 360 degrees lumbar spinal fusion. Data were collected preoperatively and at 6 weeks, 3 months, and 6 months postoperatively. Visual Analog Scale (VAS), Oswestry Low Back Pain Disability Questionnaire (ODQ), and patient satisfaction rates were evaluated at these intervals, as well as range of motion, return to work, and recreational and ambulatory status.