Use of a four pin and methylmethacrylate fixation in L7 and the iliac body to stabilize lumbosacral fracture-luxations: a clinical and anatomic study.
OBJECTIVE
To describe the clinical outcome of a 4 pin lumbosacral fixation technique for lumbosacral fracture-luxations, and to refine placement technique for iliac pins based on canine cadaver studies.


METHODS
Retrospective and anatomic study.


METHODS
Dogs (n=5) with lumbosacral fracture-luxations and 8 cadaveric canine pelvi.


METHODS
Lumbosacral fracture-luxations were stabilized with a 4 pin (positive-profile threaded) and bone cement fixation. Caudal pins were inserted in the iliac body and cranial pins were inserted into the L7 or L6 pedicle and body. Follow-up examinations and radiographs were performed to assess patient outcome. Intramedullary pins were inserted into the iliac bodies of 8 cadaver pelvi. Radiographs were taken to measure pin insertion angles and define ideal insertion angles that would maximize pin purchase in the ilium.


RESULTS
Follow-up neurologic examination was normal in 4 dogs. Radiographic healing of the fracture was evident in 5 dogs. One implant failure occurred but did not require re-operation. For cadaver iliac pins, mean craniocaudal insertion angle was 29 degrees and mean lateromedial insertion angle was 20 degrees.


CONCLUSIONS
Four pin and bone cement fixation effectively stabilizes lumbosacral fracture luxations. The iliac body provides ample bone stock, which can be maximized using an average craniocaudal pin trajectory of 29 degrees and an average lateromedial pin trajectory of 20 degrees.


CONCLUSIONS
Lumbosacral fracture-luxations can be stabilized with 4 pin and bone cement fixation in the lumbar vertebrae and iliac body, using 29 and 20 degrees as guidelines for the craniocaudal and lateromedial pin insertion angles in the ilium.
Weh
J Micheal
JM
Foster Hospital for Small Animals, Cummings School of Veterinary Medicine, Tufts University, North Grafton, MA 01536, USA. michael.weh@tufts.edu
Kraus
Karl H
KH
D000818:Animals; D001843:Bone Cements; D001858:Bone Nails / Q000662:veterinary; D001864:Bone Wires / Q000662:veterinary; D002102:Cadaver; D004285:Dogs / Q000293:injuries* / Q000601:surgery*; D005260:Female; D005593:Fracture Fixation, Internal / Q000295:instrumentation / Q000379:methods / Q000662:veterinary*; D017102:Fracture Healing; D004204:Joint Dislocations / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D008161:Lumbosacral Region / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery*; D008297:Male; D020366:Methylmethacrylate; D011859:Radiography; D012447:Sacrum / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D016103:Spinal Fractures / Q000000981:diagnostic imaging / Q000601:surgery / Q000662:veterinary*; D016896:Treatment Outcome
D001843:Bone Cements; D020366:Methylmethacrylate