Session X - Pelvis/Geriatrics

*Functional Outcomes of Unstable Posterior Pelvic Ring Disruptions Treated with Iliosacral Screw Fixation

Nimrod Rozen, MD; Hans J. Kreder, MD; Cornelia M. Borkhoff, MD; David Cogley, MD; Dan Dabby, MD; Michael McKee, MD; Emil H. Schemitsch, MD; David J.G. Stephen, MD, University of Toronto, Toronto, ON, Canada (all authors ­ a-AO-ASIF Foundation)

Purpose: There are few reports in the literature regarding patients' functional outcome after iliosacral screw fixation. The purpose of this study was to assess the functional outcome of patients with unstable posterior pelvic ring disruptions treated with iliosacral screw fixation.

Methods: Eighty patients (37 men) with an unstable posterior pelvic ring disruption treated with iliosacral screw fixation from 1989 to 2000 with a minimum of 1-year follow-up were identified from a prospectively collected trauma database. The mean age of the cohort at injury was 36 ± 15 years, and the mean length of follow-up was 2.9 years (range, 1.0 to 5.8). Patients treated with iliosacral screw fixation placed either percutaneously or open with no plate fixation to the sacroiliac joint were included. Fifteen patients with an associated acetabular fracture were excluded. Functional outcome was measured with use of validated functional outcome questionnaires (MFA and SF-36). Details regarding injury, treatment, and complications were gathered from the hospital chart. An observer who was blinded as to the patients' functional outcome reviewed the relevant radiographs. Multiple regression analysis was used to identify factors that had an adverse effect on outcome. Adjustments for age, gender, length of follow-up, and co-morbidities were made for the multiple regression analyses.

Results: The mean ISS and GCS of the patients were 32 (range, 14 to 66) and 14 (range, 4 to 15), respectively. Forty-five percent of the patients presented with an associated head injury and 16% with an associated nerve injury. Seven patients presented with a vascular injury, five of which underwent urgent arterial embolization. Eight patients had an open pelvic fracture;14 were Tile B and 51 were Tile C. Sixty-three percent of the patients had sacroiliac joint dislocations with an involved sacral fracture: 32% Denis 1, 56% Denis 2, and 12% Denis 3. The screw was placed percutaneously in 57 cases, and open in 8. One screw was used in 41 cases; two screws or more were used in the remaining 24 cases. The maximum residual displacement was >10 mm in 14% of patients; the surgeon achieved an anatomical reduction in 27% of patients. The rate of infection was 4.6%; the infections resolved after soft tissue debridement. The risk of iatrogenic nerve injury was 1.6%. Three patients had failure of fixation with two patients requiring removal of hardware. One patient suffered a superior gluteal artery pseudoaneurysm, successfully embolized. Forty-four of 65 patients completed the functional outcome evaluation. Patient function was significantly adversely affected, with a mean overall MFA score of 39.2 ± 23.8, with detrimental effects on lower extremity function, sleep, and on home and leisure activities. Patient function was significantly worse compared to the health status of the Canadian normal population for all SF-36 scores. The physical component summary for the SF-36 was 28.3 ± 12.1; this score was worse than the scores for 97.5% of the Canadian normal population (P <0.05). Functional outcome was worse for those patients with a greater residual posterior and cephalad displacement of the hemipelvis at follow-up (P <0.05).

Conclusion: Physical function remains significantly compromised for patients with posterior pelvic injuries treated with iliosacral screws. Every effort should be made to obtain an anatomic reduction because residual displacement is associated with compromised function.