Effects of Extracorporeal Shock Wave Therapy on Desmitis of the Accessory Ligament of the Deep Digital Flexor Tendon in the Horse

Authors

  • R. Wayne Waguespack DVM, MS, Diplomate ACVS,

    1. Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA
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  • Daniel J. Burba DVM, Diplomate ACVS,

    1. Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA
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  • Jeremy D. Hubert BVSc, MS, Diplomate ACVS,

    1. Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA
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  • Martin A. Vidal BVSc, MS, PhD, Diplomate ACVS,

    1. Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA
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  • Larry G. Lomax DVM, PhD, Diplomate ACVP,

    1. Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA [Correction added after online publication 11 March 2011: Lead author name and all author affiliations corrected.]
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  • Sharon R. Chirgwin PhD,

    1. Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA [Correction added after online publication 11 March 2011: Lead author name and all author affiliations corrected.]
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  • Mandi J. Lopez DVM, MS, PhD, Diplomate ACVS

    1. Department of Veterinary Clinical Sciences, Louisiana State University, Baton Rouge, LA
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  • Presented in part at the Veterinary Orthopedic Society Meeting, Sun Valley, ID, March 2007.

Corresponding Author
R. Wayne Waguespack, DVM, MS, Diplomate ACVS, Department of Veterinary Clinical Sciences, JT Vaughan Large Animal Teaching Hospital, 1500 Wire Road, Auburn University, Auburn, AL 36849
E-mail: rww0001@auburn.edu

Abstract

Objective: To evaluate the effects of extracorporeal shock wave therapy (ESWT) on collagenase-induced lesions in the accessory ligament of the deep digital flexor tendon (ALDDFT) of horses.

Study Design: Paired, blinded controlled study.

Animals: Eight Thoroughbred horses (3 mares, 5 geldings; mean±SD weight, 464±26 kg, mean age, 8±1.7 years).

Methods: Lesions were created in both ALDDFTs of all horses by injection of 2 × 103 IU of collagenase type I. Percent lesion and structure (fiber alignment and echogenicity) were quantified with ultrasonographic imaging 3, 6, and 9 weeks after collagenase injection. After ultrasound examinations, ESWT (1000 shocks at 0.15 mJ/mm2) was applied to 1 ALDDFT in each horse. ALDDFT were harvested 15 weeks after collagenase injection and the microstructure, mRNA levels of collagen types I and III, and collagen and glycosaminoglycan content were evaluated.

Results: There were no differences in percent lesion, echogenicity, or fiber alignment between control- and ESWT-treated ligaments at each evaluation time; however, compared with 3-week values, there was a significant increase in percent lesion and echogenicity for EWST treated ligaments at 6 weeks and significant decrease in both variables for treated and control ligaments at 12 weeks. Fiber alignment improved significantly at 9 weeks in controls and at 12 weeks in treated and control ligaments. Collagen type I mRNA levels were significantly higher in the ESWT treatment group compared with the control group 15 weeks after collagenase injection though differences in other mRNA levels, microstructure, and composition were not significant.

Conclusions: Our results do not support an effect of ESWT on collagenase-induced lesions in the equine ALDDFT.

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