Comparative Study of Soft-Tissue of Metacarpus 3 and Metatarsus 3 before and after Exercise in Horses Using Ultrasonography

Abstract

In order to establish the reference data concerning the diagnosis of sport injuries, the soft-tissue structures of the metacarpus 3 and metatarsus 3 of the left limbs of 23 horses were assessed by the use of diagnostic ultrasound with the 7.5 MHz transducer. Each region was assessed, according to its length of palmar surface, by division into three parts named as LFU (left forelimb upper part), LFM (left forelimb middle part), LFL (left forelimb lower part ), LHU (left hindlimb upper part ), LHM (left hindlimb middle part), and LHL (left hindlimb lower part). The target tissues that the ultrasonography identified were superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), inferior check ligament (ICL), and suspensory ligament (SL). The results showed that, when the horses were measured at rest, the circumferences and areas were ranged from 32.7±0.9 mm to 50.8±1.8 mm and 0.64±0.08 scm to 1.39±0.13 scm (SDFT), 36.8±1.4 mm to 49.8±1.8 mm and 0.76±0.08 scm to 2.12±0.23 scm (DDFT), 41.0±1.5 mm to 46.3±1.9 mm and 1.09±0.14 scm to 1.36±0.13 scm (ICL) , and 42.0±2.1 mm to 50 .4±2.0 mm and 1.21±0.09 scm to 1.70±0.11 scm (SL), respectively . After ten-minutes non-bearing exercise, the circumferences and areas of the four structures changed to 36.6±0.8 mm to 49.5±1.8 mm and 0.85±0.09 scm to 1.80±0.13 scm (SDFT), 40.7±1.5 mm to 55.6±1.6 mm and 0.98±0.06 scm to 2.20±0.14 scm (DDFT), 39.1±1.1 mm to 45.0±1.4 mm and 1.14±0.10 scm to 1.32±0.11 scm (ICL), and 43.8±1.0 mm to 51.6±1.7 mm and 1.37±0.13 scm to 1.87±0.37 scm (SL), respectively. The percentage ratios of the cross-sectional areas measured before and after exercise were calculated according to the above respective data and the highly significant differences (P ＜ 0.01) connected with the structures of SDFT (for LFU,LFM,LHM, LHU and LHL), DDFT (for LFU, LFL and LHU) and SL (for LFU, LFL, LHU and LHL).