Page 114 - Manual of Equine Field Surgery
P. 114

110                       LIMB  SURGERIES







                          occurs. This may be related  to performing  surgery


                          too  soon  after  diagnostic  anesthesia,  traumatic


                          surgical technique,  excessive postoperative  move-


                          ment,  or incisional  site problems.  Ideally, surgery


                          should  not  be  performed  for  a  minimum  of



                          2 weeks after  diagnostic  anesthesia  of the  palmar


                          digital  nerve.  Surgical  technique  and  handling  of


                          the  nerve  should  be  as  atraumatic  as  possible,


                          and  excessive  dissection  minimized.  Adequate


                          postoperative  rest  and  proper  bandaging  tech-


                          niques  should  be  emphasized  to the  owner.  Loss


                          of the  hoof wall  as a result  of ischemia  is  a rare



                         but possible  complication.  Reasons  for  its occur-

                                                                                                                                                     Figure  18-5  Exposure of the palmar digital nerve in
                          rence  are not well understood.4
                                                                                                                                                     the  proximal  and  distal  incisions  t1sed  in  Black's


                                                                                                                                                     method  of neurectomy.





                         ALTERNATIVE  PROCEDURES







                         Black's Technique




                         This method  of neurectomy  allows for removal  of


                         a longer  section  of nerve,  decreasing  the  chances


                         of  accessory  nerve  branch  innervation  to  the



                         region.  The  proximal  nerve  ending  may  also  lie


                         deeper  ill  the incision,  potentially  decreasing  the


                         incidence  of neuroma  formation.                                          5


                                A 2-cm  skin  incision  is made  over the  abaxial


                         border  of  the  DDFT  just  above  the  medial  or



                         lateral  cartilage  of the  third  phalanx  in  the distal


                         pastern  region.  The  incision  is extended  carefully


                         through  the subcutaneous  tissue.  Blunt  dissection


                         is used  to isolate  the palmar  digital  nerve.  Identi-


                         fication  of the  nerve  is confirmed  by crimping  of                                                                      Figure  18-6  The  nerve  has  been  transected  proxi-


                         the  nerve  after  it has been  stretched  and  released                                                                   mally and pulled  through the  distal incision  in Black's


                         and  palpating  longitudinal  fibers when  the  nerve                                                                      method  of neurectomy.



                         is stretched  over the smooth  portion of an instru-


                         ment.  Closed  Kelly  forceps  are  placed  below  the


                         nerve,  and traction  is applied  to identify  the loca-


                         tion of the  nerve  in  the  proximal  pastern  region.


                         A 2-cm  incision  is made  in the  proximal  pastern



                         region  distal to the base of the proximal  sesamoid


                         bone  directly  over  the  nerve  being  held  ill  trac-


                         tion. The  nerve is isolated  in this region,  and  trac-


                         tion  is applied  to  the proximal  and  distal  ends  to


                         ensure  the  same  nerve  is  exposed  through  both


                        incisions  (Figure  18-5).  A  new  scalpel  blade  is


                        then  used to transect  the nerve as proximal  as pos-



                        sible  through  the  upper  incision.  Traction  is


                        applied  to the  distal end  of the nerve in the  distal


                        incision,  and  a  6-  to  8-cm  portion  of  nerve  is


                        stripped  through  the  incision  (Figure  18-6).  The


                        exposed  nerve  is then  severed  as distally  as possi-                                                                    Figure  18-7                   Two-day postoperative  view of the inci-



                        ble, and the skin is closed routinely (Figure  18-7).                                                                       sions used in Black's method  of neurectomy.
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