The effect of high and low pressure pulsatile lavage on soft tissue and cortical blood flow: a canine segmental humerus fracture model.
OBJECTIVE
To determine the effect of high pressure pulsatile lavage (HPPL) and low pressure pulsatile lavage (LPPL) on cortical and soft tissue blood flow in a canine humerus segmental fracture model.


METHODS
Midshaft humeral osteotomies to create a 2-cm segment of diaphyseal bone were performed on bilateral canine humeri. Each osteotomy site was irrigated using either high pressure (n = 6) or low pressure (n = 5) pulsatile lavage prior to stabilization with a 5-mm steinman pin. Perfusion of cortical bone, periosteum, and biceps muscle was measured using Laser Doppler Flowmetry during four intraoperative intervals: pre-osteotomy, post-osteotomy, post-lavage, and post-nailing.


RESULTS
Following osteotomy, a significant drop occurred in cortical perfusion (HPPL P = 0.049, LPPL P = 0.021) and in periosteal flow (HPPL P = 0.019, LPPL P = 0.012). Following irrigation there was no significant decrease in blood flow in either group for muscle (HPPL P = 0.249, LPPL P = 0.41), periosteum (HPPL P = 0.381, LPPL P = 0.402), or cortex (HPPL P = 0.398, LPPL P = 0.352) measurements. There was no significant difference between irrigation groups in post-lavage perfusion values for muscle (P = 0.326), periosteum (P = 0.452), and cortex (P = 0.464). Cortical perfusion decreased significantly post-nailing (HPPL P = 0.027, LPPL P = 0.047). Measurements did not differ significantly between groups at any other time interval.


CONCLUSIONS
Although previous work has demonstrated an association between HPPL and detrimental structural changes in bone, this study demonstrates that HPPL does not adversely affect cortical or soft tissue blood flow acutely. Further, LPPL offers no acute benefit to cortical or soft tissue perfusion.
Di Pasquale
Dennis J
DJ
The Musculoskeletal Research Laboratory and the Division of Orthopaedic Surgery, Department of Surgery, St Michael's Hospital, University of Toronto, Toronto, ON, Canada.
Bhandari
Mohit
M
Tov
Alexei
A
Schemitsch
Emil H
EH
D000818:Animals; D004285:Dogs; D005594:Fracture Fixation, Intramedullary; D006810:Humeral Fractures / Q000601:surgery*; D006811:Humerus / Q000098:blood supply* / Q000601:surgery; D017078:Laser-Doppler Flowmetry; D023421:Models, Animal; D018482:Muscle, Skeletal / Q000098:blood supply*; D010027:Osteotomy; D010521:Periosteum / Q000098:blood supply*; D011312:Pressure; D012039:Regional Blood Flow; D007507:Therapeutic Irrigation / Q000379:methods*