Patterns of weight change preceding hospitalization for heart failure.

Background: Weight gain is used by disease-management programs as a marker of heart failure decompensation, but little information is available to quantify the relationship between weight change in patients with heart failure and the risk for imminent hospitalization.

Methods And Results: We conducted a nested case-control study among patients with heart failure referred to a home monitoring system by managed care organizations. We matched 134 case patients with heart failure hospitalization to 134 control patients without heart failure hospitalization on the basis of age, sex, duration of home monitoring, heart failure severity, and baseline body weight.

Demystifying the NIH grant application process.

The process of applying to the National Institutes of Health (NIH) for grant funding can be daunting. The objective of this article is to help investigators successfully navigate the NIH grant application process. We focus on the practical aspects of this process, which are commonly learned through trial and error.

Magnetic resonance imaging to assess knee cartilage repair tissue after microfracture of chondral defects.

A noninvasive method to assess the repair tissue produced by chondral defect treatment techniques has not been established. The purpose of this study was to evaluate the ability of magnetic resonance imaging (MRI) specialized sequences to predict the presence and quality of repair tissue of knee articular cartilage defects treated by microfracture. Nineteen recreational or high-level athletes underwent standard microfracture technique for 22 traumatic full-thickness chondral defects.

The effects of ACL deficiency on mediolateral translation and varus-valgus rotation.

Background: The anterior cruciate ligament (ACL) constrains the anterior translation and axial rotation of the tibia. However, the effect of ACL injury on the mediolateral translation and varus-valgus rotation of the tibia is unknown. Because of the oblique orientation of the ACL, we hypothesized that ACL deficiency alters mediolateral translation and varus-valgus rotation.

Risk to the lateral geniculate artery during arthroscopic lateral meniscal suture passage.

Purpose: The purpose of this study was to evaluate the risk of lateral geniculate artery injury during suture passage through the lateral meniscus.

Methods: Sutures were passed via inside-out and outside-in techniques in 11 embalmed cadaveric knees. The number of punctures of the lateral geniculate artery and quantitative distances of needle penetrations were measured.

Photochemically cross-linked collagen gels as three-dimensional scaffolds for tissue engineering.

Collagen gels have many favorable attributes for tissue engineering, but the gels undergo dramatic contraction when cells are added because of the weak noncovalent bonds that form during spontaneous gelation. We hypothesized that photochemically cross-linking collagen gels would make suitable scaffolds for tissue engineering with favorable cell viability and minimal gel contraction. Rose Bengal and riboflavin were chosen as candidate photo-initiators for gel cross-linking using 532- and 458-nm-light wavelengths, respectively.

Access to primary care for Medicare beneficiaries.

Objectives: To determine the acceptance rate of new Medicare patients by all primary care physicians. Among primary care physicians accepting new patients, to determine whether demographic and geographic factors are associated with the likelihood of accepting new Medicare patients.

Design: Cross-sectional.

Lifestyle Interventions and Independence for Elders pilot study: recruitment and baseline characteristics.

Objectives: To describe several recruitment parameters derived from the Lifestyle Interventions and Independence for Elders pilot (LIFE-P) study for use in a full-scale trial of mobility disability prevention.

Design: A description of the recruiting methods and baseline characteristics of a four-site randomized, controlled trial testing the effectiveness of a physical activity intervention at preventing mobility disability.

Setting: The Cooper Institute, Dallas, Texas; Stanford University, Stanford, California; University of Pittsburgh, Pittsburgh, Pennsylvania; and Wake Forest University, Winston-Salem, North Carolina.

Predisposing factors and precipitants for bathing disability in older persons.

Objectives: To identify potential predisposing factors and precipitants for bathing disability.

Design: Prospective cohort study.

Setting: Greater New Haven, Connecticut.

Function of posterior cruciate ligament bundles during in vivo knee flexion.

Background: The biomechanical functions of the anterolateral and posteromedial bundles of the posterior cruciate ligament over the range of flexion of the knee joint remain unclear.

Hypothesis: The posterior cruciate ligament bundles have minimal length at low flexion angles and maximal length at high flexion angles.

Study Design: Descriptive laboratory study.

The in vivo kinematics of the anteromedial and posterolateral bundles of the anterior cruciate ligament during weightbearing knee flexion.

Background: Recently, double-bundle anterior cruciate ligament reconstruction has been advocated. However, there are little data on the in vivo biomechanics of the anteromedial and posterolateral bundles of the anterior cruciate ligament. Our objective was to measure the kinematics of the 2 bundles during weightbearing flexion.

Longitudinal change in positive affect in community-dwelling older persons.

Objectives: To determine whether positive affect, defined as emotional contentment and happiness, remains stable in late life and to identify predictors of longitudinal change in positive affect.

Design: Longitudinal observational study.

Setting: Community.

Effects of a physical activity intervention on measures of physical performance: Results of the lifestyle interventions and independence for Elders Pilot (LIFE-P) study.

Background: The Short Physical Performance Battery (SPPB), which includes walking, balance, and chair stands tests, independently predicts mobility disability and activities of daily living disability. To date, however, there is no definitive evidence from randomized controlled trials that SPPB scores can be improved. Our objective was to assess the effect of a comprehensive physical activity (PA) intervention on the SPPB and other physical performance measures.

Improved self-confidence was a mechanism of action in two geriatric trials evaluating physical interventions.

Objective: To evaluate the mechanisms of action in two successful geriatric clinical trials that tested multicomponent physical conditioning programs and to determine whether the pathways for overall benefit were through improvement in physical ability and/or self-confidence.

Study Design And Setting: PREHAB and DRIVER were conducted by the Yale Pepper Center. PREHAB participants received an individualized program that focused on the impairments present (standardly tailored design); DRIVER participants received the entire intervention (global design).

The effect of anterior cruciate ligament deficiency on the in vivo elongation of the medial and lateral collateral ligaments.

Background: Although anterior cruciate ligament deficiency has been shown to lead to joint degeneration, few quantitative data have been reported on its effect on soft tissue structures surrounding the knee joint.

Hypothesis: Anterior cruciate ligament deficiency will alter the deformation of both collateral ligaments during in vivo weight-bearing knee function from 0 degrees to 90 degrees.

Study Design: Controlled laboratory study.

The biomechanical function of the patellar tendon during in-vivo weight-bearing flexion.

Few studies have investigated the function of the patellar tendon in-vivo. This study quantified the three-dimensional (3D) kinematics of the patellar tendon during weight-bearing flexion. Eleven subjects were imaged using magnetic resonance (MR).

The treatment of articular cartilage defects using the microfracture technique.

Chondral defects of the articular surface pose a challenging problem to the orthopedic surgeon. The goal of surgery is to alleviate pain, maximize function, and prevent degenerative changes in the future. A number of techniques have been described to treat these lesions.

The epidemiology of bathing disability in older persons.

Objectives: To quantify the burden of bathing disability over time; to determine whether the burden of bathing disability differs according to age, sex, and physical frailty; and to evaluate the relationship between disability in bathing and disability in other essential activities of daily living (ADLs).

Design: Prospective cohort study.

Setting: General community in greater New Haven, Connecticut.

Effects of auricular chondrocyte expansion on neocartilage formation in photocrosslinked hyaluronic acid networks.

The overall objective of this study was to examine the effects of in vitro expansion on neocartilage formation by auricular chondrocytes photoencapsulated in a hyaluronic acid (HA) hydrogel as a next step toward the clinical application of tissue engineering therapies for treatment of damaged cartilage. Swine auricular chondrocytes were encapsulated either directly after isolation (p = 0), or after further in vitro expansion ( p = 1 and p = 2) in a 2 wt%, 50-kDa HA hydrogel and implanted subcutaneously in the dorsum of nude mice. After 12 weeks, constructs were explanted for mechanical testing and biochemical and immunohistochemical analysis and compared to controls of HA gels alone and native cartilage.

Bathing disability and the risk of long-term admission to a nursing home.

Background: The prevalence of disability in bathing and the likelihood of a long-term nursing home admission increase substantially with age. We performed a prospective study to determine whether the occurrence of persistent disability in bathing is associated with the risk of a long-term nursing home admission, independent of potential confounders, including persistent disability in other essential activities of daily living.

Methods: We studied 754 community-living persons, 70 years old or older, who were nondisabled in four essential activities of daily living.

In vivo kinematics of the knee after anterior cruciate ligament reconstruction: a clinical and functional evaluation.

Background: Recent follow-up studies have reported a high incidence of joint degeneration in patients with anterior cruciate ligament reconstruction. Abnormal kinematics after anterior cruciate ligament reconstruction have been thought to contribute to the degeneration.

Hypothesis: Anterior cruciate ligament reconstruction, which was designed to restore anterior knee laxity under anterior tibial loads, does not reproduce knee kinematics under in vivo physiological loading conditions.

Anterior cruciate ligament deficiency alters the in vivo motion of the tibiofemoral cartilage contact points in both the anteroposterior and mediolateral directions.

Background: Quantifying the effects of anterior cruciate ligament deficiency on joint biomechanics is critical in order to better understand the mechanisms of joint degeneration in anterior cruciate ligament-deficient knees and to improve the surgical treatment of anterior cruciate ligament injuries. We investigated the changes in position of the in vivo tibiofemoral articular cartilage contact points in anterior cruciate ligament-deficient and intact contralateral knees with use of a newly developed dual orthogonal fluoroscopic and magnetic resonance imaging technique.

Methods: Nine patients with an anterior cruciate ligament rupture in one knee and a normal contralateral knee were recruited.

An allogenic cell-based implant for meniscal lesions.

Background: Meniscal tears in the avascular zones do not heal. Although tissue-engineering approaches using cells seeded onto scaffolds could expand the indication for meniscal repair, harvesting autologous cells could cause additional trauma to the patient. Allogenic cells, however, could provide an unlimited amount of cells.

Comparison of the ACL and ACL graft forces before and after ACL reconstruction: an in-vitro robotic investigation.

Background: Long-term follow-up studies have indicated that there is an increased incidence of arthrosis following anterior cruciate ligament (ACL) reconstruction, suggesting that the reconstruction may not reproduce intact ACL biomechanics. We studied not only the magnitude but also the orientation of the ACL and ACL graft forces.

Methods: 10 knee specimens were tested on a robotic testing system with the ACL intact, deficient, and reconstructed (using a bone-patella tendon-bone graft).

The 6 degrees of freedom kinematics of the knee after anterior cruciate ligament deficiency: an in vivo imaging analysis.

Background: Previous studies of knee joint function after anterior cruciate ligament deficiency have focused on measuring anterior-posterior translation and internal-external rotation. Few studies have measured the effects of anterior cruciate ligament deficiency on 6 degrees of freedom knee kinematics in vivo.

Objective: To measure the 6 degrees of freedom knee kinematics of patients with anterior cruciate ligament deficiency.