High pressure pulsatile lavage of contaminated human tibiae: an in vitro study.

OBJECTIVE: This study was designed to examine the effect of high pressure pulsatile lavage (HPPL) on bone destruction and propagation of bacteria in experimentally contaminated human tibiae. METHODS: Using an in vitro model, nine human tibiae from above-knee amputations were tested. A mid-diaphyseal tibial shaft fracture was created, and each end of the fracture was contaminated with bacteria (six tibiae with Staphylococcus aureus, three tibiae with Escherichia coli). The proximal end was designated as the control and the distal end was the test site. The test site was debrided by HPPL (seventy pounds/square inch, 1,200 milliliters/minute, 1,050 cycles/minute) with three liters of normal saline, whereas the control site did not receive any form of irrigation. Serial sections at increasing distance from the fracture site were cultured and the numbers of bacterial colony-forming units (CFUs) were determined at each level. The degree of macroscopic architectural change in each serial section was graded on an ordinal scale. RESULTS: Analysis of culture data revealed a reproducible pattern of bacterial propagation into the intramedullary canal. Peak bacterial seeding occurred at two to three centimeters from the fracture site (p = 0.023, Wilcoxon signed rank test). The degree of bone destruction varied proportionally with the depth into the canal and was found to be predictive of the extent of bacterial propagation determined by culture data. CONCLUSION: In an in vitro model of a contaminated fracture, HPPL resulted in bacterial seeding into the intramedullary canal and significant damage to the architecture of the bone. These observations might have clinical significance.

High and low pressure pulsatile lavage of contaminated tibial fractures: an in vitro study of bacterial adherence and bone damage.

OBJECTIVE: This study was designed to examine the effect of pulsatile irrigation on microscopic bone architecture and its time-dependent efficacy in removing adherent slime-producing bacteria from cortical bone. DESIGN: Using an in vitro model, ten-millimeter transverse cut sections from five human tibiae were contaminated with Staphylococcus aureus and subjected to either high pressure pulsatile lavage (HPPL; seventy pounds per square inch, normal saline) or low pressure pulsatile lavage (LPPL; fourteen pounds per square inch, normal saline) or served as controls. Alteration of bony architecture was quantified by using a previously described ordinal scale and histomorphometric analysis of each transverse cut section of tibia. To assess the time-dependent effectiveness of pulsatile lavage in removing adherent bacteria from bone, ten-millimeter transverse cut sections from ten canine tibiae were contaminated with S. aureus and subjected to high or low pressure pulsatile lavage immediately or after one, three, or six hours. Scanning electron microscopy and bacterial cultures were used to assess the removal of adherent bacteria. RESULTS: HPPL resulted in significantly greater macroscopic damage than was seen with LPPL or in controls (ANOVA, p < 0.001). Histomorphometry revealed that HPPL was associated with significantly larger and more numerous fissures or defects in the cortical bone when compared with low pressure irrigation (p < 0.001). However, high and low pressure lavage were associated with similar degrees of periosteal separation from the cortical bone surface (p = 0.87). Both high and low pressure lavage were effective in removing adherent bacteria from bone at three hours irrigation delay, but only high pressure lavage removed adherent bacteria from bone at six hours delay. CONCLUSION: In this in vitro study, compared with HPPL, LPPL led to less structural damage and was equally effective in removing bacteria within three hours debridement delay; however, the efficacy of LPPL at six hours debridement delay is questionable. This finding may have clinical significance in the development of infection following open tibial fractures.

Early versus delayed operative management of closed tibial fractures.

Fractures of the tibial shaft are the most common long bone fractures. Operative treatment of isolated closed tibial shaft fractures frequently is delayed in favor of treatment of life threatening injuries. A retrospective chart review of 200 tibial fractures was performed. These injuries were managed by two surgeons at a Level 1 trauma center between 1989 and 1996. Strict inclusion criteria identified 54 patients with an isolated closed tibial fracture. Postoperative hospital stay and complication rates were recorded. At a mean followup of 3.6 years, a quality of life questionnaire was administered via telephone calls to these patients. Two patient groups were identified: Group 1, 21 patients (< 12-hour surgical delay); and Group 2, 33 patients (> 12-hour surgical delay). Both groups were similar for baseline characteristics. Group 2 patients remained an extra 4.6 days in the hospital. A Kaplan-Meier analysis revealed that by the eighth postoperative day, all Group 1 patients were discharged from the hospital, whereas 47.8% of Group 2 patients remained in the hospital. Plate fixation was associated with a greater incidence of complications when compared with intramedullary nail internal fixation. Complication rates were significantly greater in the delayed surgical group. A multiple regression analysis revealed that surgical delay and postoperative complications accounted for 35% of the total variance in postoperative hospital stay. Time to surgical treatment was not prognostic of long term quality of life. Surgical delay results in longer postoperative hospital stays, greater complication rates, and increased total cost to the health care system.

Organ injuries associated with femoral fractures: implications for severity of injury in motor vehicle collisions.

OBJECTIVE: To determine if motor vehicle collisions (MVCs) resulting in femoral fractures were associated with a different injury severity and pattern of injury compared with crashes in which victims did not sustain femoral fractures. METHODS: Retrospective review of seriously injured motor vehicle occupants admitted to a regional trauma unit (Hamilton General Hospital) during a 69-month period (April 1991 to December 1996) for whom detailed crash details were known. RESULTS: Data for 733 motor vehicle occupants with Injury Severity Scores greater than 12 were available; 112 occupants (15.3%) sustained femoral fractures, and 621 occupants (84.7%) did not sustain femoral fractures. Victims with femoral fractures had a significantly higher mean Injury Severity Score (29.4 compared with 25.3 for non-femoral fracture group; p<0.001). The femoral fracture group had a higher incidence of bowel (p<0.012) and hemopneumothorax (p<0.02) injuries as well as an increased incidence of upper and lower extremity (p<0.001) and pelvic (p<0.05) fractures. CONCLUSION: The presence of a femoral fracture is strongly associated with the pattern and severity of injuries sustained by occupants in MVCs. A high index of suspicion is warranted in identifying associated organ injuries in MVC victims with concomitant femoral fractures.