@phdthesis{oai:rakuno.repo.nii.ac.jp:00005563,
 author = {佐藤, 綾乃},
 month = {Sep},
 note = {Thesis, Congenital flexural limb deformities restrict the range of motion because of structural abnormality of the affected limbs, leading to lameness. In cattle, metacarpophalangeal flexural deformities (MPFD) in the forelimbs as congenital limb deformities are the most common disorder. The relationship between MPFD and flexural muscles and tendons and/or suspensory ligament has not been clarified. There are no pre-surgical diagnosis methods or medical care guidelines for MPFD calves. The purpose of this study was to establish an objective diagnosis and surgical guidelines. The influences of the superficial digital flexor tendons (SDFT) and deep digital flexor tendons (DDFT) on the moment of the metacarpophalangeal joint (MPJ) in MPFD were evaluated using imaging analysis, and the relationships were confirmed by the transection of flexor tendons in MPFD calves. The purpose of chapter I was to estimate the influences of the flexor tendons on the angle formed by the dorsal aspect of the claw and ground (toe angle) of the forelimbs of beef calves. In chapter I, the calves underwent measurement of the body weight, body height, and toe angle in both forelimbs and the forelimb circumference in the metacarpal region, metacarpophalangeal region, and pastern. In addition, sonograms of the pastern on palmar surfaces of the inner and outer claws of both forelimbs were analyzed for the thickness of the DDFT and SDFT. As the results, the toe angle at one day old was 44.3 ± 10.4° for left forelimbs and 45.4 ± 10.7° for right forelimbs. The toe angles at one day old had no correlation with the flexor tendons. The toe angle at 28 days old was 50.5 ± 5.8° for left forelimbs and 50.9 ± 5.6° for right forelimbs. The toe angles at 28 days old showed no correlation with the flexor tendons. The DDFT and SDFT at one day old showed no scarcely correlation with other measurement values. The DDFT at 28 days old was thicker than at one days old and was correlated with the body weight and forelimb circumference. The thickness of the SDFT at 28 days old was almost the same as at one day old and was correlated with the forelimb circumference. As the result, although acral flexor tendons of the forelimbs at one day old showed immature supporting tissues, the thickness of the DDFT was increased to balance with body growth. The toe angle showed no correlation with flexor tendons in calves. The purpose of chapter II was to establish an evaluation method using radiography in MPFD calves, and radiographs of the lateral angle of the MPJ and distal interphalangeal joint (DIPJ) were measured in dairy breed calves. As the results, the lateral angle of the MPJ in all MPFD forelimbs classified by the inspection as mild, moderate, and severe were significantly narrower than normal forelimbs. The lateromedial projection radiographs of MPFD calves were useful for morphological evaluation. The purpose of chapter III was to study the involvement of the SDFT and DDFT in the MPJ and DIPJ in severe MPFD calves. Ten model forelimbs with different contraction ratios of the SDFT and DDFT were created and compared with severe MPFD forelimbs by radiography in chapter II. As the results, the morphological pathology of the MPJ in severe MPFD forelimbs was reproducible with all types of model forelimbs. The morphological pathology of the DIPJ in severe MPFD forelimbs was reproducible with the model forelimbs with high contraction ratios of the DDFT. It was considered that the morphological pathology in severe MPFD forelimbs involved not only the SDFT but also the DDFT. In chapter IV, the calves with severe MPFD forelimbs were treated surgically by transection of the SDFT and DDFT, with observation of the post-surgical process. After radiography, MPFD calves were treated with transection of the SDFT and DDFT, and calves underwent a gait test at 2 and 7 days post-surgery. In the gait test, when MPFD calves exhibited lameness, the calves were treated with external fixation. At 14 days post-surgery, the prognosis was evaluated. At 2 days post-surgery, 11 of 15 severe MPFD forelimbs (73%) were treated by external fixation and these forelimbs were considered to show marked abnormality of flexural morphology on radiographs. It was suggested that MPFD forelimbs were involved with the flexor tendons and other soft tissues including the suspensory ligament. However, almost all MPFD calves showed improved flexural limbs and lameness by attachment of the external fixation post-surgery. At 14 days post-surgery, 8 of 9 severe MFPD calves (89%) including 13 of 15 severe MPFD forelimbs (87%) showed a good prognosis. It was suggested that proactive surgical treatment involving transection of the SDFT and DDFT was useful for the treatment of severe MPFD calves. In this study, it was considered that the flexural morphology of severe MPFD forelimbs involved the SDFT, DDFT, and other soft tissues including the suspensory ligament. Surgical treatment of transection of the SDFT and DDFT with external fixation postsurgery promoted a high cure rate among severe MPFD calves. Radiographs of severe MPFD calves were useful for evaluation of the flexural morphology and provided more detailed information compared with severity classification.},
 school = {酪農学園大学},
 title = {子牛肢端の先天性屈曲変形に関する画像解析に基づく臨床的研究},
 year = {2018}
}