b'AAEP FORUM SARAH PLEVIN, BVMS, MRCVS, CVA, DIPL. ABVP,ACVSMRTheHorse.com/AAEP-ForumA Novel Tool for Tendon Injury RehabO verstrain injuries to the superficialand organized tendon bundles. Blue digital flexor tendon (SDFT), which(Type 2) indicates wavy or swollen tendon runs down the back of the can- bundles. This can represent remodeling non bone, are among the most commontendon or inferior repair. Red (Type 3) musculoskeletal injuries veterinariansrepresents fibrillar tissue (the building diagnose in equine athletes. The manyblock of tendon) from partial tendon rup-IMAGES COURTESY DR. HANS VAN SCHIEtreatment options have three things inture or initial healing. Black (Type 4) are common: time out of training, expense,cells or fluid and represent core lesions and no guarantee of success. where no normal tendon tissue exists.It makes sense, then, that injury pre- How does it work? A standard linear vention is always the goal; failing that,array ultrasound probe mounted on a we need a method to optimally guidemotorized tracking device noninvasively rehabilitation. and automatically moves down the SDFT Unfortunately, current imaging ap- With ultrasound tissue characterization, an ul- over a 12-centimeter scanning distance. proaches limit how accurately veterinari- trasound probe mounted onto a tracking deviceAs it does, the device captures transverse ans can monitor the tendon. So, althoughrecords up to 600 images. images (horizontal planes) at regular we can use conventional ultrasound todistances and stores them in real time for confirm the presence of a core lesion, weResearchers studying humans ( Dockingprocessing. The system records images are often unable to fully evaluate tendonet al., 2015) and horses (Docking et al.,every 0.2 millimeters to generate a tendon structure, follow healing, or provide effec- 2012; Plevin et al., 2019) have reportedvolume of 600 images. Image acquisition tive rehabilitation guidelines post-injury.ultrasound tissue characterization to betakes approximately 45 seconds.A new ultrasound technology, however,highly reproducible and user-independent.Vets can subsequently use this volume called ultrasound tissue characterizationTheir results suggest its sensitive enoughto visualize the tendon in 3D to determine could get us one step closer to achievingto detect the effect of changing loadsits structural composition and quantify the goals of preventing injury and opti- (exercise) on tendon within days. Thistendon matrix integrity.mizing rehabilitation. provides practitioners the opportunity toHow can it help rehabilitation? Scien-Ultrasound tissue characterization is anot only support rehab but also monitortists have shown that appropriate pro-relatively new technique aimed at alleviat- tendons throughout training. Research isgressive loading helps stimulate optimal ing some of the problems encounteredongoing to determine whether the tech- tendon remodeling andhealingthis is with conventional ultrasound. It providesnology could help vets predict injuries.where this technique has the potential to a 3D reconstruction of the tendon andCurrently, its used in elite humanbe most useful. classifies it by color-coded echo types(Achilles tendon) and equine (SDFT) ath- By offering real-time information on based on the integrity of the tendon ultra- letes to monitor tendon health and guidetendon matrix integrity, ultrasound tissue structure (that which is only visible withinjury rehabilitation. characterization allows vets to take ad-an electron microscope). According to vanWhat do the colors mean? Green (Typevantage of the limited window for appro-Schie et al., this method allows practi- 1 echoes) indicates normal, well-aligned,priate tendon remodeling after injury. By tioners to discriminate between healthymapping the healing tendons ultrastruc-normal, adaptive/remodeling, and injured/ ture and remodeling response to exercise healing tissue, often when conventionalat each step in the rehab regimen, ultra-ultrasound findings are unremarkable. sound tissue characterization allows us to The key is successive evaluations, al- optimize the most vital tool in our rehab lowing vets to look at tendon structurearsenal: exercise. Although research is differences over time. Consecutive examsongoing, ultrasound tissue characteriza-allow them to determine if a tendon istion seemingly affords vets opportunity to static, adaptive, healing, or degeneratingtailor exercise regimens for the individual and recommend appropriate changes intendon, potentially allowing for a more training intensity.successful return from injury.hAmerican Association of Equine Practitioners, 4033 Iron Works Parkway, Lexington, KY40511859/233-0147www.aaep.org8April 2020The Horse|TheHorse.com'