Do asymptomatic patients have normal function after percutaneous fixation of the posterior pelvic ring? A case-control pilot study

A biomechanics study on ligamentous injury in anterior-posterior compression type II pelvic injury

Background

Anterior-posterior compression (APC) type II pelvis fracture is caused by the destruction of pelvic ligaments. This study aims to explore ligaments injury in APC type II pelvic injury.

Method

Fourteen human cadaveric pelvis samples with sacrospinous ligament (SPL), sacrotuberous ligament (SBL), anterior sacroiliac ligament (ASL), and partial bone retaining unilaterally were acquired for this study. They were randomly divided into hemipelvis restricted and unrestricted groups. We recorded the separation distance of the pubic symphysis and anterior sacroiliac joint, external rotation angle, and force when ASL ruptured. We observed the external rotation damage to the pelvic bone and ligaments.

Result

When ASL failed, there was no significant difference in pubic symphysis separation (28.6 ± 8.4 mm to 23.6 ± 8.2 mm, P = 0.11) and anterior sacroiliac joint separation (11.4 ± 3.8 mm to 9.7 ± 3.9 mm, P = 0.30) between restricted and unrestricted groups. The external rotation angle (33.9 ± 5.5° to 48.9 ± 5.2°, P < 0.01) and force (553.9 ± 82.6 N to 756.6 ± 41.4 N, P < 0.01) were significantly different. Pubic symphysis separation between two groups ranged from 14 to 40 mm. In the restricted group, both SBL and SPL were injured. SPL ruptured first, and then SBL and the interosseous sacroiliac ligament were damaged while the posterior ligament remained unharmed. In the unrestricted group, interosseous sacroiliac ligament and posterior sacroiliac ligaments were damaged, while SBL and SPL were not. When the ASL, SBL, and SPL all failed, pubic symphysis and anterior sacroiliac joint separation between two groups increased significantly (from 28.6 ± 8.4 to 42.0 ± 7.6 mm, 11.4 ± 3.8 to 16.7 ± 4.2 mm respectively, all P < 0.05).

Conclusion

Pelvic external rotation injury is either hemipelvic restricted or unrestricted, which can result in different outcomes. When the ASL ruptures, the unrestricted group needs greater external rotation angle and force, without SBL or SPL injury, while both SBL and SPL were injured in another group. When ASL fails in two groups, pubic symphysis separation fluctuates considerably. Finally, when the ASL ruptures, SBL and SPL may be undamaged.

Inaccuracies in the Use of the Majeed Pelvic Outcome Score: A Systematic Literature Review

OBJECTIVES

To evaluate the accuracy with which the Majeed Pelvic Score has been reported in the English literature.

DATA SOURCES

Databases used to search for literature were PubMed, Embase, and Ovid, restricted to English language from inception to October 2, 2018.

STUDY SELECTION

Search words used were: Majeed, pelvis, and outcome.

DATA EXTRACTION

Articles were assessed for descriptions of scoring and proper reporting of Majeed Pelvic Outcome Score.

DATA SYNTHESIS

Descriptive statistics were used to report the outcome of our findings.

CONCLUSIONS

Ninty-two English articles were identified. Twenty-four (26%) articles were identified as including methodology related to the use and scoring of the Majeed Pelvic score. The remaining 68 presented mean Majeed scores with no methodological information. None (0/92) discussed how the range of possible scores for the most severe function was applied. Six (7%) reported adjusted scores for patients not working. Three (3%) included a discussion of the scores as adjusted for patients working before injury compared with those not working. Ten (11%) addressed the categorization of scores by excellent to poor describing what raw scores defined those categories. We observed poor accuracy and notable inconsistency in the use and reporting of the Majeed Pelvic Outcome Score in the literature. These data demonstrate that interpretation and comparison of research reporting this score should be done cautiously. Future studies should include specific information as to how the Majeed instrument calculated to allow for verification of the presented scores and subsequent conclusions.

Tape suture for stabilization of incomplete posterior pelvic ring fractures-biomechanical analysis of a new minimally invasive treatment for incomplete lateral compression pelvic ring fractures

Background

Incomplete lateral compression fractures (including AO Type B2.1) are among the most common pelvic ring injuries. Although the treatment of choice remains controversial, sacroiliac (SI) screws are commonly used for the operative treatment of incomplete lateral compression fractures of the pelvic ring. However, the disadvantages of SI screws include the risk of nerve root or blood vessel injury. Recently, tape sutures have been found useful as stabilizing material for the treatment of injuries of the syndesmosis, the rotator cuff and knee ligaments. In this current study, we aimed to test the biomechanical feasibility of tape sutures to stabilize the pelvis in the setting of AO Type B2.1 injury.

Methods

Six human cadaveric pelvises underwent cyclic loading to compare the biomechanical stability of different osteosynthesis methods in a B2.1 fracture model. The methods tested in this experiment were a FiberTape® suture and the currently established SI screw. A 3D ultrasound tracking system was used to measure fracture fragment motion. Linear regression was used to model displacement and stiffness at the posterior and anterior pelvic ring.

Results

At the posterior fracture site, the FiberTape® demonstrated similar displacement (2.2 ± 0.8 mm) and stiffness (52.2 ± 18.0 N/mm) compared to the sacroiliac screw (displacement 2.1 ± 0.6 mm, P >  0.999; stiffness 50.8 ± 13.0 N/mm, P > 0.999).

Considering the anterior fracture site, the FiberTape® again demonstrated similar displacement (3.8 ± 1.3 mm) and stiffness (29.5 ± 9.0 N/mm) compared to the sacroiliac screw (displacement 2.9 ± 0.8 mm, P = 0.2196; stiffness 37.5 ± 11.5 N/mm, P = 0.0711).

Conclusion

The newly presented osteosynthesis, the FiberTape®, shows promising results for the stabilization of the posterior pelvic ring in AO Type B2.1 lateral compression fractures compared to a sacroiliac screw osteosynthesis based on its minimal-invasiveness and the statistically similar biomechanical properties.