Fri., 10/5/12 Pelvis & Acetabulum, PAPER #59, 3:17 pm OTA-2012
•Transiliac-Transsacral Screw Fixation in C-Type Pelvic Ring Injuries Reduces Postoperative Failure
Gregory Y. Blaisdell, MD1; James C. Krieg, MD2; Milton L. Chip Routt Jr, MD2;
1University of Washington Department of Orthopaedics and Sports Medicine,
Seattle, Washington, USA;
2Harborview Medical Center, Seattle, Washington, USA
Purpose: Vertically unstable pelvic ring injuries (OTA 61-C) have been challenging to treat with standard iliosacral screw technique over time. These injuries are at risk for early postoperative displacement despite adequate reduction and fixation. Up until late 2005, cannulated screws of sufficient length to traverse the entire length of the posterior pelvic ring using S1 or S2 pathways were not available. Transiliac-transsacral screw use has been increasingly utilized with the goal of more durable fixation. We hypothesized that transiliac-transsacral screw fixation of OTA 61-C injuries would reduce the short-term complications compared with the use of iliosacral screws alone.
Methods: We studied two groups of 61-C injuries retrospectively. The iliosacral-only group (IS) included obviously vertically displaced pelvic ring injuries from January 1 to December 31, 2005. This time period was the last consecutive year in which transiliac-transsacral screws had not come into use. The transiliac-transsacral group (TI-TS) included vertically displaced pelvic ring injuries treated between October 1, 2009 and September 31, 2010 with at least one transiliac-transsacral screw. Careful scrutiny of injury films to avoid inclusion of lateral compression injuries produced 19 patients for the 2005 group and 15 patients for the 2010 group. All U-, Y-, and H-type sacral fractures were excluded. Failure in fixation was determined to be a combined displacement of 1 cm on the inlet and outlet films at final follow-up compared to immediate postoperative films.
Results: The IS group consisted of 19 patients with 23 C-type hemipelvis injuries, 11 of which were complete sacral fractures, 4 were sacroiliac dislocations, and 8 were sacroiliac fracture-dislocations. The TI-TS group consisted of 15 patients with 22 C-type hemipelves, of which 6 were complete sacral fractures, 8 sacroiliac fracture-dislocations, and 8 sacroiliac dislocations. Posterior fixation in the IS group consisted of 41 screws all in the upper sacral segment. The TI-TS group consisted of 40 screws, 27 TI-TS screws (14 in S1 osseus pathway, 13 in S2 pathway) and 13 iliosacral screws all in the upper sacral segment. There were no cases of screw intrusion into the S1 or S2 foramina or alar cortical breach in either group. Failures of fixation occurred in 53% of the IS patients (10 of 19 patients, average 20-mm displacement) and 20% of TI-TS patients (3 of 15 patients, average 14-mm displacement). There was one nonunion in the IS group that required bone grafting and repeat fixation. There was one infected fibrous union in the TI-TS group that was stable on radiographs and asymptomatic upon hardware removal. In the IS group, two bent and one broken iliosacral screws were noted at final follow-up, and one bent screw was noted in the TI-TS group. There were nine loose washers in each group at final follow-up, but only one screw that had measurably backed out (TI-TS patient). This screw was removed as an outpatient procedure.
Conclusion: OTA 61-C type pelvic ring injuries are challenging to treat, and are associated with a high rate of postoperative displacement. Compared with iliosacral screws, transiliac-transsacral screw fixation decreases the number of fixation failures, without changing the safety profile of the fixation type. Assuming adequate reduction to allow safe placement, this fixation type should be strongly considered for vertically unstable injuries.
Alphabetical Disclosure Listing (808K PDF)
• The FDA has not cleared this drug and/or medical device for the use described in this presentation (i.e., the drug or medical device is being discussed for an “off label” use). ◆FDA information not available at time of printing. Δ OTA Grant.