Lateral Compression Type 2 Pelvic Fractures-A Clinical Study of Fracture Displacement Measurement and Closed Reduction

Abstract

Objective: To evaluate the displacement in four lateral compression type 2 (LC2) fracture subtypes (iliac wing and three kinds of crescent fractures) and to investigate the appropriate closed reduction for treatment using a pelvic reduction frame.

Methods: A total of 71 patients with LC2 pelvic fractures from February 2014 to November 2019 were included in this retrospective cohort study. Preoperative X-ray and computed tomography data were used to assess the direction of the fracture displacement and the sacroiliac joint dislocation. The fractures in all patients were reduced with a pelvic reduction frame and fixed with percutaneous screws as well as an anterior subcutaneous pelvic ring internal fixator. Two different closed reduction strategies were adopted, one was first longitudinal traction and then transverse traction, the other was first transverse traction then longitudinal and LC2 traction. The Matta score system was used to evaluate the postoperative X-ray and the Majeed score system was used for follow-up evaluation.

Results: A total of 13 iliac wing fractures (86.7%) and 16 Day type 1 fractures (94.1%) were vertically stable with only internal displacement, the ring width displacements were 5 (3, 8.75) and 8 (4, 12) mm, the posterior superior iliac spine (PSIS) differences were 0 (0, 0) mm and 0 (0, 0) mm. A total of 21 Day type 2 fractures (95.5%) and 16 Day type 3 fractures (94.1%) were characterized by cephalic and dorsal fracture dislocation on the basis of internal displacement, the ring width displacements were 6 (4.25, 12) and 4 (0, 7.5) mm and the PSIS differences were 4 (2, 5) and 0 (0, 3.75) mm. Based on the Matta scores, excellent reduction was achieved in 51 patients, good reduction in 17 patients, and poor reduction in three patients. The average Majeed score was 91.6, with a minimum outpatient follow-up of 12 months (average 31.6 months).

Conclusion: LC2 fractures involve two different kinds of fracture displacement: internal displacement only and a combination of internal, cephalic, and dorsal dislocation through the sacroiliac joint. Good clinical outcomes can be achieved for LC2 fractures using two different closed reduction strategies.

Keywords: Closed reduction; Crescent fracture; Lateral compression injury; Pelvic fracture; Pelvic reduction frame.

FIGURE 1

Pelvic reduction frame cooperation with the C‐arm and the navigation robot

FIGURE 2

Abridged general view. Type 1: iliac wing fracture and Day type 1 crescent fracture with the fracture line in a transverse direction and transverse displacement required longitudinal traction first (red arrow) followed by transverse traction (blue arrow). Type 2: Day types 2 and 3 crescent fracture with fracture line in a longitudinal direction and dislocation as well as longitudinal displacement required transverse traction first (red arrow) followed by longitudinal and lateral compression type 2 (LC2) traction (blue arrow)

FIGURE 3

Typical cases from each group with preoperative and postoperative images

FIGURE 4

The fracture line and the direction of fracture dislocation in the iliac wing fracture (13/15 patients) and Day type 1 (16/17 patients) groups were transverse; the fracture line and the direction of fracture dislocation in Day type 2 (21/22 patients) and Day type 3 (16/17 patients) groups were longitudinal

FIGURE 5

The initial displacement in the four groups was compared and the results were expressed as the median (IQR, interquartile range) (mm). The displacements in the iliac wing fracture and Day 1 groups were practically the same. The displacements in the Day types 2 and 3 groups were also practically the same. All four groups had lateral compression of the pelvic ring and an increase in the ischial height. The differences in the iliac wing height and posterior superior iliac spine in the iliac wing fracture and Day type 1 groups were less than those in the Day type 2 and 3 groups