title: Anterior revision of a dislocated ProDisc prosthesis at the L4-5 level.
abstract: METHODS
  A case report describing our experience with anterior revision surgery for a dislocated ProDisc artificial disc at the L4-5 level, 2.5 years after the initial surgery.
  
  
  OBJECTIVE
  To highlight the difficulties and risks associated with the use of a repeat anterior approach for the revision of a ProDisc that has failed at the L4-5 level.
  
  
  BACKGROUND
  As the ProDisc has a central vertical keel, more intensive vascular mobilization is required to remove the dislocated implant during surgery than that required in patients who must undergo a revision of the SB-Charité disc. To our knowledge, no prior report addresses whether the anterior removal of a ProDisc at the L4-5 level is possible in patients with severe retroperitoneal fibrosis.
  
  
  METHODS
  We describe our surgical experience with the anterior revision of a lumbar ProDisc that failed at the L4-5 level. Revision surgery (anterior lumbar interbody fusion with percutaneous pedicle screw fixation) was performed 2.5 years after the initial surgery because of the anterior dislocation of the artificial disc after the patient had engaged in heavy lifting. The operation was performed with a repeat retroperitoneal approach. The multiple venous injuries that occurred intraoperatively were well controlled with a 5/0 polypropylene (Prolene) suture, but the patient lost a significant amount of blood (3800 mL) during surgery.
  
  
  RESULTS
  The patient recovered from surgery without sequelae, and her preoperative symptoms resolved.
  
  
  CONCLUSIONS
  A ProDisc revision case at L4-5 level must be attempted with preparation of available venous balloon catheter for emergent bleeding control, cell saver, pulse oxymeter on great toe, and ureteral catheter. In our opinion, usage of adhesion barrier material should be considered in anterior lumbar surgery to make revision exposure easier and safer.
authors.affiliation: Department of Thoracic and Cardiovascular Surgery, Wooridul Spine Hospital, Seoul, Korea.
authors.forename: Sang Hyeop
authors.initials: SH
authors.lastname: Jeon
authors.forename: Won Gyu
authors.initials: WG
authors.lastname: Choi
authors.forename: Sang-Ho
authors.initials: SH
authors.lastname: Lee
mesh_terms: D016063:Blood Loss, Surgical; D001810:Blood Volume; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000009:adverse effects; D016896:Treatment Outcome