Date Published: April 8, 2019
Publisher: Public Library of Science
Author(s): Yao-Tung Tsai, Chun-Liang Hsu, Chun-Chi Hung, Yu-Ching Chou, Chia-Chun Wu, Tsu-Te Yeh, Gabriel Costa Serrão de Araújo.
There are various methods of fixation for anterior pelvic ring fractures. We report our experience with modified pedicle screw-rod fixation (MPSRF) via a minimally invasive method. Fourteen patients with anterior pelvic ring fracture were treated by internal fixation (conventional plate fixation, n = 7; MPSRF, n = 7). Intraoperative blood loss, operative time, post-operative fracture reduction grading by radiography, and complication rates were compared and statistically analyzed. Patients treated with MPSRF had a shorter operative time (-36 min, P = 0.378) and significantly less blood loss (-264 ml, P = 0.026) than patients in the conventional plate fixation group. Postoperative radiological evaluations were similar between the groups (P > 0.05). The complication rate was lower in the MPSRF group (1/7 patients) than in the plate fixation group (2/7 patients). Modified pedicle screw-rod fixation is a viable treatment for anterior pelvic ring fixation and can reduce blood loss.
The pelvic ring structure is composed of two innominate bones and the sacrum. The anterior pelvic ring consists of the bilateral pubic rami connected by the pubic symphysis. The posterior ring includes the sacrum and two innominate bones joined at the sacroiliac joints by ligaments. The posterior ring provides 70% of pelvic stability and the anterior ring provides the remaining 30% . Bruce et al. showed that posterior ring fracture involving portions of the anterior pelvic ring is more likely to develop displacement . In order to achieve better reduction and stable fixation, combined posterior and anterior fixation is important. Anterior ring fixation is performed for insecure posterior ring fixation, augmentation of the pelvic ring, or isolated straddle fracture. Anterior pelvic ring stabilization can be achieved by external fixation or internal fixation. The internal fixation methods include a plate , an antegrade or retrograde screw , a subcutaneous pelvic bridge by the occipitocervical spinal implant , an anterior pelvic internal fixator with supra-acetabular spinal pedicle screws and a subcutaneous connecting rod (INFIX), or modifications of the INFIX [6–8].
This was a retrospective case-series study approved by the Institutional Review Board of the Tri-Service General Hospital (Approval no.: 2-106-05-092). Evaluation of medical documents and radiographic images of patients with anterior pelvic ring fracture treated with plate fixation or MPSRF at the Tri-Service General Hospital between June 2011 and May 2018 was conducted. Informed consent was obtained from all patients included in the study.
Successful pelvic fracture surgery remains a challenge for orthopedic surgeons due to the complex anatomy and fracture pattern. These patients also have a high percentage of associated injuries (primary hit). Thus, short surgical time and reduced blood loss in pelvic surgery are important factors to prevent secondary hit in these patients. Extensive surgical dissection to expose the pelvic brim is required in conventional surgery using plate fixation for anterior pelvic fracture repair. This may aggravate surrounding tissue damage and increase intraoperative blood loss. After the fracture site had been reduced, contouring the plate is time-consuming during the operation . In our study, compared to conventional plate fixation, MPSRF had some advantages, especially in terms of reduced blood loss (with significant difference) and shorter operative time. Limited dissection of the iliacus muscle from the ilium could reduce blood loss with the MPSRF method. Compared to contouring the plate intraoperatively, bending the rod was easier and less time-consuming. A polyaxial pedicle screw was used in our study and can reduce the difficulty of rod application and manipulation, also reducing operative time. Meena et al. reported that the modified Stoppa approach provided a shorter operative time when compared to the ilioinguinal approach in anterior acetabular fracture . In our study, different surgical approaches might have led to further reduction in operative time in group 2.