CLINICAL SIGNIFICANCE AND PROGNOSIS OF DEEP DIGITAL FLEXOR TENDINOPATHY ASSESSED OVER TIME USING MRI

Abstract

Deep digital flexor (DDF) tendinopathy is one of the most frequent causes of foot lameness and the prognosis is guarded. The progress of lesion healing may be followed by magnetic resonance (MR) imaging to formulate a prognosis and to adapt the rehabilitation program. We assessed the correlation of outcome with total tendon damage and temporal resolution of MR abnormalities. Images from 34 horses with DDF tendinopathy that had undergone at least two low-field standing MR examinations of the foot (mean 2.5 ± 1.3 times) were reviewed. No horse having a T1-GRE hyperintense lesion over 30 mm in length or over 10% tendon cross-sectional area returned to its previous activity level. Horses with concomitant lesions had worse outcome than horses with DDF tendinopathy only (P = 0.005). In all horses including those with excellent outcome, the lesion persisted, even mildly, in T1-GRE and PD images. Horses with tendon lesion resolution on STIR-FSE and T2-FSE images on recheck examination had a better outcome (P = 0.0004 and P = 0.002, respectively), and all horses that returned to their previous level of performance had complete resolution of signal hyperintensity on the STIR-FSE sequence. Although rehabilitation remains multifactorial, characteristics of DDF tendinopathy and concomitant lesions on first and recheck MR examinations allow refining the prognosis.

MRI and navicular disease – on the brink of success or another false dawn?

“…Horses with lesions longer than 35 mm or greater than 20 per cent of the tendon cross-sectional area invariably remained lame (Vanel and others 2012). Finally, the response to treatment has also begun to be documented.…”

Magnetic resonance protocols in equine lameness examination, used sequences, and interpretation

“…T2* GE should be used especially when looking for hyperacute blood, because it detects effects of methemoglobin and deoxyhemoglobin (Edelman 1986, Kidwell et al 2004. The value of T2* GE is limited in protocol for deep digital flexor tendon, while its signal is similar to T1 GE and does not significantly change during the process of healing (Vanel et al 2012). In standing low-field MRI basic protocol may consist of T1 GE, T2 FSE and STIR in sagittal, transverse and frontal planes (Mair and Kinns 2005).…”

“…Maher et al (2011) have suggested that tendon lesions with increased signal on PD images without signal increase on STIR and T2w images can be associated with degeneration. What is more, this pattern is visible during early stages of injury, and can retain even months or years after tendon fiber disruption (Maher et al 2011). Vanel et al (2012 have assumed that STIR FSE sequence is the most reliable in deep digital flexor tendinopathy outcome and decreased signal was associated with lameness improvement.…”

Magnetic resonance imaging and foot lameness. Problem solved? Or do we know we know less now that we know more?

“…The prognosis has also been effectively linked with the size of the tendon lesion. Horses with lesions longer than 35 mm or >20% of the tendon cross‐sectional area invariably remained lame , while those longer than 30 mm or >10% of tendon cross‐sectional area invariably did not return to previous levels of athletic activity.…”