The Role and Timing of Treatment Strategies During Two-Stage Revision for Periprosthetic Joint Infections.

INTRODUCTION: Prosthetic joint infection continues to be a source of significant morbidity to patients and an economic burden to society as a whole. Two-stage revision is the current gold standard for treatment of periprosthetic joint infection in North America. Despite this, much discussion persists about treatment strategies surrounding the interim of the two-stage revision and treatment beyond reimplantation. The aim of this review is to answer some of these questions, specifically: are C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) helpful prior to reimplantation, is aspiration helpful, what is the role and timing for systemic antibiotics, and is there a role for oral suppression following second-stage reimplantation? METHODS: A literature review was completed in an attempt to address unanswered questions associated with two-stage reimplantation. Investigators' recommendations and current practices are described. RESULTS: ESR and CRP are less reliable in the interim of a two-stage revision than for diagnosis of infection in a primary total joint arthroplasty. There is inconclusive evidence regarding the utility of joint aspiration in two-stage revisions. Additionally, no evidence has been developed for length of IV antibiotic treatment after second-stage reimplantation, and in a few studies, oral antibiotic suppression has shown some benefit in reducing reinfection rates. CONCLUSION: The question of optimum treatment strategies has yet to be answered: attempts are underway to obtain suitable data with multi-center studies and large patient populations. Periprosthetic joint infection is a serious and life altering complication and with continued research we can further clarify treatment strategies.

Primary Care Management of Plantar Fasciitis.

Plantar fasciitis (PF) is present in 10% of the population and is the most common cause of plantar heel pain. PF is painful, can alter daily activities and presents as a sharp pain localized to the plantar foot and medial heel. The underlying etiology involves microtrauma to the plantar fascia, specifically at its insertion point on the calcaneus. Successful management of plantar fasciitis is typically achieved with the conservative therapy approaches discussed.

Effects of exogenous crosslinking on in vitro tensile and compressive moduli of lumbar intervertebral discs.

BACKGROUND: Collagen crosslinks may play a vital role in preventing ongoing disc degeneration. Age-accumulating crosslinks have been thought to increase brittleness and reduce fatigue resistance. However recent studies have demonstrated increases in fatigue resistance, joint stability and nutritional flow properties resulting from crosslink augmentation. In this study, multi-directional moduli of bovine lumbar intervertebral discs were measured in vitro, including circumferential tension, radial compression, axial tension, and axial compression in control and crosslinked specimens. METHODS: Four types of annulus fibrosus specimens were dissected from control and crosslinked discs. Cross-sectional areas were measured using a non-contact laser measurement system and then four separate mechanical tests were conducted using a materials testing machine with custom-made loading fixtures. FINDINGS: The circumferential specimens demonstrated the highest moduli in both low stiffness and linear elastic regions. After a crosslink treatment, the modulus increased more in circumferential tension compared to axial tension and more in axial compression compared to radial compression. Other tensile properties had higher increases in circumferential tension compared to axial tension after crosslinking. INTERPRETATION: Assuming form follows function, circumferential tension is the predominant type of stress experienced by non-degenerated annulus fibrosus. The anisotropic mechanical properties of the annulus fibrosus is non-uniformly affected by crosslink augmentation. Dominant effects were in the directions with greater inherent stiffnesses. These results suggest some beneficial effects of crosslink augmentation on the mechanical properties of the annulus fibrosus: increase in ultimate strength, yield strength, toughness, and modulus in the principal stress directions.