Date of Award

2003

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology

Abstract

Tendinitis is a disorder caused by inflammation of the tendon fibers, characterized by collagen fiber disruption and cellular infiltration. Current treatments are lacking, in that they often are associated with unwanted side effects or can even cause an increased amount of damage via scar tissue formation. Pulsed electromagnetic fields (PEMFs) have been shown to be useful in treating wounds and healing non-union fractures. The purpose of the current study was to develop a quantitative rat model of mild tendinitis and subsequently to examine the efficacy of therapeutic electromagnetic fields (EMFs) on this injury. The EMFs used in the current study were: a pulsed field generator obtained from Electro Biology, Inc. (EBI coil) and a field generator obtained from EMF Therapeutics that is capable of delivering two signals (TEMF coil). Tendinitis was induced in Harlan Sprague Dawley rats by collagenase injections into the Achilles tendon, and animals were then exposed to one of the above EMFs. Tendons were collected at 24, 48, and 72 hours post-injury, as well as at 1 and 2 weeks post-injury for the acute phase analysis. Chronic phase analysis included tendon collection at 4 weeks post-injury. Methods used to assess edema revealed swelling to be maximal at 24 and 72 hours post-injury and to return to pre-injury levels by 1–2 weeks post-injury. The Achilles Functional Index was used to determine function. This method revealed a drop in function at 72 hours post-injury, as well as a return to normal by 1–2 weeks post-injury. A materials testing system (MTS) was used to determine the force required to rupture each tendon at the various time points. This data revealed a drop in strength of the tendon at 72 hours post-injury, with a return to higher levels by 2 weeks. No significant effects were seen with EMF exposure using the EBI coil. In contrast, differences in healing were observed using one of two signals from the TEMF coil. The work presented here was part of a comprehensive study which examined protein expression, blood parameters, and immune modulators to thoroughly characterize tendon injury and the possible role of EMF therapy in decreasing healing time.

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