Page 109 - Manual of Equine Field Surgery
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                                                                                                                                                      Semitendinosus Tenotomy and Myotomy                                                            105



















                                             -+------                            Bistoury


                                                                                 knife

                                           ••













                                                                                                                                                                                                                             Fibrotic
                                                                                                                                                                                                                                    .
                                                                                                                                                                                                                             region






                                                                                                                                                                                                                             Fibrous

                                                                                                                                                                                                                             bands












































                                                                                                                                                                              I                                 .


                                                                                                                                                                             ii  ~,r,.,-:,~..:e~







                   Figure  17-2  The  use  of a bistoury  knife  to  transect  restrictive  scar  tissue  on  the  distal  aspect  of  the  affected
                          .
                   region.












                   EXPECTED OUTCOME                                                                                                            COMPLICATIONS







                   Reported  cases  treated  with  tenotomy  have  had                                                                         Dehiscence,  seroma  formation,  and  infection  are



                   good  results,  but  only  a  small  number  of  cases                                                                      possible  but not common  if the  tenotomy  only is


                   have  been  reported.                         2•3   Horses  with  mild  scarring                                            performed.  If myotomy  is performed,  the  likeli-


                   often  improve  considerably  with  tenotomy,  and                                                                          hood  of these  complications  increases.  Extensive


                   the  procedure  has  minimal  complications.  In  the                                                                       postoperative  fibrosis may result  in recurrence  of


                    author's  opinion,  horses  with  more  severe fibrosis                                                                    the  gait abnormality.


                   generally  require  myotomy  for improvement  and


                   have  a  higher  likelihood  of  recurrence.  In  011e



                   report,  75o/o of horses  treated  with  myotomy  had                                                                       ALTERNATIVE PROCEDURES


                    75°/o or  greater  improvement  in  gait. At approxi-


                   mately  2-year  follow-up,  one third of these horses                                                                       Transection  of  the  semitendinosus  muscle's  in-


                    had  some  recurrence  of  gait  restriction.  Some                                                                        sertion  on  the  calcaneal  tuber  has  also  been


                   horses  with  some  recurrence  of  restriction  were                                                                       described  for  cases where  a taut band is palpable.



                    able  to  perform  at  their  intended  level.4  Horses                                                                    The  limb  is  protracted  during  surgery  after


                   with  fibrosis  confined  to  the  semitendinosus                                                                           tenotomy  of the  tibial  insertion.  If  a  taut  band


                   muscle  have  a  better  outcome  than  those  with                                                                         is palpable  over the  calcaneal  tuber  insertion,  it is


                    additional  fibrosis  in the  biceps  femoris  or semi-                                                                    transected  through  an  incision  caudal  and  distal


                    membranosus  muscles.5  In  cases where  muscles                                                                           to the first incision.2•7


                    other  than the  sernitendinosus  are involved, tran-                                                                             Complete  removal  of the  area of fibrosis and a


                    section  of fibrosis  in the  involved  muscle  may be                                                                     4-cm  portion of tendon has also been described."



                    beneficial.            1'6                                                                                                 The  procedure  can  be  effective,  but  a  high  inci-
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