Page 98 - Manual of Equine Field Surgery
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94                         LIMB  SURGERIES







                                                                                                                                                                                  Common  digital
                                                                                                                                                                                  extensor  tendon








                                                                                                                                       Lateral digital

                                                                                                                                    extensortendon

                                                                                                                                                                                                                                      lnterosseous  medius  m.

                                                                                                                                                                                                                                            (suspensory  lig.)



                                                                                                                                            Palmar

                                                                                                                                         metacarpal
                                                                                                                                              n.  IV





                                                                                                                                             Dorsal  br.
                                                                                                                                             of ulnar  n.  -S~


                                                                                                                                                Lig.  of

                                                                                                                                              the  ergot



                                                                                                  Proximal                                                                                                                        Medial  palmar  a.v.
                                                                                                  lig. of the                                                                                                                      (palmar  common

                                                                                                  ergot                            Lateral  pal mar a. v.                                                                             digital  a.v.  II)
                                                                                                                                    (palmar  common

                                                                                                  lnterosseous                         digital  a. v.  111)                                                                Medial  palmar  n.
                                                                                                  medius

                                                                                                  (suspensory  lig.)                      Lateral  palmar  n.
                                                                                                                                                                                             ~~v/.'ff  DDFT>Within                              the digital

                                                                                                                                                                                         ~~~~"-SOFT                                    tendon  sheath












                                                                          /,,.L-,L---              Distal  Ilg. of

                                                                                                  the  ergot
























                                                                                                 Figure  15-2  Anatomy  of the  distal splint  bone.












                                                                                                                                                          fracture  site  and  ending  2 cm  distal  to  the  distal



                                                                                                                                                           aspect  of  the  splint  bone.  The  distal  end  of the


                                                                                                                                                           splint bone  is slightly  rounded  and  can usually be


                                                                                                                                                           palpated  directly.  If  the  region  is  significantly


                                                                                                                                                           swollen, the opposite  splint bone  can often be pal-


                                                                                                                                                           pated  and  used  as a rough  estimate  of the  distal



                                                                                                                                                           landmark.  The  incision  is  then  deepened  to  the


                                                                                                                                                           level of, but not through,  the periosteum.  In severe


                                                                                                                                                           cases, extensive scar tissue is present  surrounding


                                                                                                                                                           the splint  bone.  The  distal  end  of the  splint  bone


                                                                                                                                                           is  identified  and  sharp  dissection  used  to  free  it


                                                                                                                                                           from  its distal attachment  to the palmar fascia and


                                                                                                                                                           proximal  ligament  of the ergot  (Figure  15-3). The



                                                                                                                                                           end is then  grasped with  a towel clamp  or forceps,


                                                                                             .                                                             and  a  curved  osteotome  or  chisel  is  used  to

                                                                   ~""'u~·!                                                                                 sever the  attachments  to  the  third metacarpal  or



                                Figure  15-3  Freeing  the  splint  bone  from  its  distal                                                                 metatarsal  bone  (Figure  15-4).  Care  should  be


                                attachments.                                                                                                                taken  to  avoid  damaging  the  dorsal  metatarsal



                                                                                                                                                            artery  in the pelvic limb, which  may be difficult to


                                                                                                                                                            identify  in  cases with  extensive fibrous  tissue.


                                                                                                                                                                   In  some  cases, the  distal splint  bone  and  frac-


                                                                                                                                                            tured  portion  can  be  freed  past  the  fracture  site
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