Abstract
Vertical shear pelvic ring injuries require robust stabilization to prevent loss of reduction. We report a 36-year-old male motorcyclist with a Tile C1 unilateral vertical shear pelvic injury, presenting 42 mm pubic symphysis diastasis and ligamentous disruption. After temporary external fixation, definitive treatment used an anterior intrapelvic approach with anatomically contoured W-shaped double plating, allowing placement of long bicortical screws into the superior pubic ramus/anterior column, combined with percutaneous S1 iliosacral screws. Toe-touch weight bearing was recommended at 2 weeks postoperatively; however, the patient progressed to full weight bearing at this stage, without significant discomfort, and achieved full squat without pain by 4 weeks. At 12 months, pelvic alignment remained stable with no implant failure or symphyseal widening. Complete radiographic osseous bridging was not observed, yet the patient achieved excellent functional recovery. Reinforced double plating enabling long anterior column–directed screws may enhance anterior ring stiffness in unstable injuries where single plating may be insufficient.
Introduction
Pelvic ring fractures remain challenging due to complex anatomy and biomechanics, with significant morbidity [1]. Vertical shear injuries are highly unstable patterns characterized by posterior sacroiliac disruption and vertical displacement, often associated with severe anterior injury [2]. Posterior fixation provides primary stability, while anterior fixation contributes to rotational control and load sharing [2].
Symphyseal plating is commonly used for anterior fixation. However, in severe diastasis with extensive ligamentous rupture, single-plate constructs may be insufficient, resulting in loss of reduction, implant loosening, or breakage [3]. Although acute symphyseal arthrodesis is rarely indicated, it may be considered in selected cases of extreme instability or recurrent diastasis [3].
Mauffrey et al. described a reinforced anterior fixation strategy using anatomically contoured W-shaped double plating, allowing placement of long screws into the anterior column to improve stiffness [4]. We report a case treated with this technique combined with posterior percutaneous iliosacral screw fixation.
Case report
A 36-year-old male motorcyclist was admitted after collision with a motor vehicle. The patient was a chronic smoker. Examination revealed pelvic instability without neurological deficit. The patient remained hemodynamically stable. Injury Severity Score was 17.
Radiographs demonstrated a 42 mm pubic symphysis diastasis with posterior pelvic ring instability consistent with Tile C1/vertical shear injury (Fig. 1). Computed tomography (CT) confirmed right sacroiliac disruption and extensive posterior ligamentous injury (Fig. 1).
Preoperative imaging. (A) Anteroposterior pelvic radiograph. (B) Three-dimensional CT reconstruction, anterior view. (C) Three-dimensional CT reconstruction, anterosuperior view.
Given pelvic instability, temporary supra-acetabular external fixation was performed, followed by definitive fixation four days later. Through a Pfannenstiel approach, the pubic symphysis was exposed, reduced, and decorticated to enhance healing.
Symphyseal fixation with dual plating was performed using an anterior contoured W-shaped reconstruction plate secured with four 3.5-mm screws, rather than the 4.5-mm screws preferred in the original technique. At our institution, contoured 3.5-mm plates do not accept 4.5-mm screws after bending due to implant system constraints. A superior orthogonal reconstruction plate was then applied using six screws, including two central trans-symphyseal screws. This configuration enabled the placement of long bicortical screws traversing both plates, increasing construct rigidity. Posterior fixation was performed using two percutaneous S1 iliosacral screws. Postoperative radiographs and CT confirmed restoration of pelvic alignment with mild residual right sacroiliac joint widening (Fig. 2). Operative time was 155 minutes. Intraoperative blood loss was not systematically recorded.
Immediate postoperative imaging. (A) Anteroposterior pelvic radiograph. (B) Inlet pelvic radiograph. (C) Three-dimensional CT reconstruction, anterior view. (D) Three-dimensional CT reconstruction, superior view. (E) Sagittal CT reconstruction of the pubic symphysis demonstrating the spatial configuration of the anterior (inferior arrow) and superior (superior arrow) plates. (F) Axial cut of immediate postoperative pelvic CT demonstrating mild residual right sacroiliac joint widening.
Outcome and follow-up
Postoperative recovery was uneventful. Toe-touch weight bearing was recommended during the early postoperative period; however, the patient independently progressed to full weight bearing at 2 weeks postoperatively and to full squat without pain by 4 weeks (Fig. 3).
Early functional recovery after W-shaped double plating. (A) Full weight bearing at 2 weeks postoperatively without significant discomfort. (B) Full squat at 4 weeks, reflecting early functional stability of the pelvic ring.
Radiographic reduction and pelvic symmetry were assessed using a standardized diagonal cross-measurement technique on anteroposterior pelvic radiographs [5]. Absolute asymmetry improved from 8.6 mm preoperatively to 1.0 mm postoperatively and remained minimal at 12 months (0.5 mm). The deformity index remained low after fixation (0.004) and at final follow-up (0.002). The deformity ratio improved from 0.95 preoperatively to 0.99 postoperatively and remained close to 1.0 at 12 months (1.00) (Table 1). Patient-reported outcomes improved progressively, including SF-12 scores, Majeed pelvic score, and pain VAS (Table 2, Fig. 4).
Radiographic pelvic symmetry assessment using the cross-measurement technique
| Parameter | Preoperative | Immediate postoperative | 12 months |
|---|---|---|---|
| X (cm) | 15.97 | 13.44 | 14.09 |
| Y (cm) | 15.11 | 13.34 | 14.04 |
| Absolute asymmetry (mm) | 8.6 | 1.0 | 0.5 |
| Deformity index | 0.028 | 0.004 | 0.002 |
| Deformity ratio | 0.95 | 0.99 | 1.00 |
X and Y represent diagonal pelvic measurements obtained on standardized anteroposterior pelvic radiographs.
Patient-reported outcome measures over follow-up
| Follow-up interval | SF-12 PCS | SF-12 MCS | Majeed score | VAS pain |
|---|---|---|---|---|
| 2 weeks | 26.25 | 52.66 | 30 | 7 |
| 4 weeks | 24.22 | 53.73 | 49 | 5 |
| 6 weeks | 30.63 | 54.02 | 57 | 3 |
| 3 months | 36.84 | 52.18 | 75 | 2 |
| 6 months | 46.62 | 48.77 | 86 | 2 |
| 12 months | 52.77 | 61.66 | 94 | 0 |
PCS: Physical Component Score; MCS: Mental Component Score; VAS: Visual Analog Scale.
Evolution of clinical outcome scores.
At 12 months, radiographs and CT demonstrated maintained pelvic alignment. Complete osseous bridging across the symphysis was not observed despite decortication (Fig. 5). The patient returned to full activities without pelvic pain or instability.
Twelve-month follow-up imaging. (A) Anteroposterior pelvic radiograph. (B) Inlet pelvic radiograph. (C) Three-dimensional CT reconstruction, anterior view. (D) Absence of osseous bridging across the symphysis.
Discussion
Vertical shear pelvic ring injuries require stabilization of both posterior and anterior components [2]. While posterior fixation provides primary stability, inadequate anterior fixation may compromise the construct, particularly in cases with marked symphyseal diastasis and extensive ligamentous disruption. Symphyseal plating remains standard, although implant failure has been reported in highly unstable injuries, and fusion may be considered in extreme cases [3].
Biomechanical investigations have demonstrated that construct stiffness varies according to fixation strategy. Screw fixation extending into the superior pubic ramus improves load distribution compared with short trans-symphyseal screws [6]. Double plating increases stiffness relative to single plating, although native pelvic stability is not completely restored [7]. The addition of a second plate increases operative time but requires minimal additional surgical exposure beyond the standard anterior intrapelvic approach. Therefore, increased construct complexity does not necessarily increase surgical morbidity.
Despite the use of 3.5-mm screws instead of 4.5-mm screws, postoperative sacroiliac joint widening, and early full weight bearing, no loss of reduction or implant failure was observed, indicating maintained construct stability [4]. The dual-plate configuration likely compensated for the reduced screw diameter by increasing overall fixation rigidity. Clinical symphyseal stability was maintained despite the absence of complete radiographic osseous bridging following decortication. These findings support that restoration of pelvic alignment is more relevant than radiographic fusion in acute trauma. Objective radiographic assessment using the cross-measurement technique [5] remains valuable, as reduction quality correlates with outcome [8]. Minor variations in absolute diagonal measurements likely reflect pelvic positioning or projection differences.
Smoking is a known risk factor for impaired bone healing [9], yet no implant failure occurred, likely related to rigid fixation and maintained reduction. Psychological factors may influence functional outcomes after pelvic trauma [10].
The present case demonstrates the feasibility of applying the W-shaped double plating construct outside the original reporting center, achieving sustained radiographic alignment and favorable functional recovery. The absence of implant failure and maintenance of reduction at 12 months support the applicability of this reinforced anterior fixation strategy in appropriately selected unstable injuries.
This report has limitations, including its single-case design, lack of biomechanical comparison, and follow-up limited to one year. Although the Majeed pelvic score is widely used for functional assessment after pelvic ring injuries, its cross-cultural validation in Portuguese has not been formally established.
Conclusion
In highly unstable vertical shear pelvic ring injuries with marked symphyseal diastasis, reinforced W-shaped double plating combined with posterior iliosacral fixation may provide durable stability. The ability to insert long anterior column–directed screws through both plates appears to be a key factor enhancing construct stiffness and maintaining reduction, even in the absence of radiographic symphyseal fusion. In selected cases of severe ligamentous disruption, reinforced anterior fixation strategies may offer additional stability.
Author contributions
Leonardo Vasconcelos Coelho (Conceptualization, Data curation, Formal analysis, Investigation, Writing—review & editing), Laís Kubo de Lima (Conceptualization, Data curation, Investigation, Resources, Writing—original draft), Julio Yukio Konasugawa (Data curation, Investigation, Methodology, Resources, Writing—original draft), Thiago Soares Coutinho (Investigation, Methodology, Writing—review & editing), Gustavo Henrique Carillo Ambrosio (Conceptualization, Formal analysis, Methodology, Project administration, Supervision, Validation), and Paulo Henrique Schmidt Lara (Formal analysis, Project administration, Supervision, Validation)
Conflicts of interest
None of the authors declare conflicts of interest.
Funding
None of the authors received (or will receive) payments or services, directly or indirectly from companies or scientific funding institutions to support any aspect of this work.
Consent
Written informed consent was obtained from the patient for publication of this case report and accompanying images.
