Abstract
In the bibliographical review, a survey of the anatomy of the splint bone region and the
different diseases which affect the splint bone as well as the suspensory apparatus of the
fetlock is given. The lacking details in the anatomical literature are pointed out. An analysis
of the different theories about the etiology and pathogenesis of the distal splint bone fracture
is performed.
Isolated limbs were used to investigate the soft tissue structures in the distal splint bone
region during anatomical preparations and to carry out loading experiments in order to verify
the different theories about the pathomechanism of distal splint bone fractures. Direct
magnification radiography (Feinfocus) and mobile computed tomography (Philips Tomoscan
M) were applied for documentation. Furthermore a retrospective evaluation of radiographs
and medical records from the patients with splint bone fractures at the Veterinary Faculty of
the University of Berlin was carried out.
The gap in the knowledge of the anatomical literature was closed and the discussion
between the different orthopaedical theories on the genesis of distal splint bone fractures
was clarified as a result of the presented study. According to this study, the distal splint bone
fracture can be considered as a fatigue fracture following the repetitive overloading of the
suspensory apparatus of the fetlock. During hyperextension of the fetlock joint, the distal
splint bone is exposed to the pulling force of the digital fascia leading to an avulsion fracture.
This supports the theory of distraction.
As a general guideline for the prophylaxis of injuries to the distal splint bones, horses should
not be exercised beyond their individual capabilities. Especially the suspensory apparatus of
the fetlock must not be chronically overloaded during exercise and certain orthopaedical
measures can be recommended. According to BOWMAN et al. (1982) the limiting factor for
the horse´s athletic performance after the operation of a distal splint bone fracture is the
complete healing of the concurrent suspensory desmitis. Therefore, the preservation of the
soundness of the suspensory apparatus as well as the distal splint bone should be
attempted by the use of egg bar shoes. |
