Isolated anterior unilateral sacroiliac dislocation without pubic arch disjunction

Treatment of Anterior Dislocation of the Sacroiliac Joint via the Lateral-rectus Approach: Surgical Techniques and Preliminary Outcomes

OBJECTIVE

Anterior dislocation of the sacroiliac joint (ADSIJ) is caused by strong violence, and because of its low morbidity, there are no standardized diagnostic and therapeutical guidelines at this moment. This study aims to explore the surgical techniques and preliminary outcomes of the lateral-rectus approach (LRA) for treating ADSIJ.

METHODS

A retrospective study was conducted of 15 patients with ADSIJ from January 2016 to January 2021. The patients' age ranged from 1.8 years old to 57 years old (37 ± 18 years old). All patients underwent open reduction and internal fixation (ORIF) through the LRA. Eight patients were combined with lumbosacral plexus injury and underwent neurolysis during operation. Patients' fracture type, mechanism of injury, associated injuries, operation time and intraoperative bleeding volume were accessed by reviewing medical history. Quality of fracture reduction was evaluated with the Matta score. At 1-year follow-up, the functional rehabilitation was evaluated by the Majeed rehabilitation criteria. For those with lumbosacral plexus injury, the neuromotor function was evaluated using muscle strength grading proposed by the British Medical Research Council (BMRC) and recovery was recorded.

RESULTS

All 15 patients underwent the operation successfully. The surgical time ranged from 70 to 220 min (126 ± 42 min), and the intraoperative blood loss ranged from 180 to 2000 mL (816 ± 560 mL). Eighty percent of the cohort (12/15) were rated as excellent and good in the Matta score for fracture reduction quality after operation without surgical incision-related complications. At 1-year follow-up, the overall excellent and good rate was 73.3% (11/15) according to the Majeed criteria, the neuromotor function recovered completely in six cases and partially in two cases according to the BMRC muscle strength grading, and the recovery of sensory function was evaluated as excellent in six cases, good in one case and poor in one case, with an overall excellent and good rate of 87.5%.

CONCLUSION

The LRA can well expose the surrounding structures of the sacroiliac joint from the front, which helps surgeons reduce and fix the anterior dislocation of the sacroiliac joint under direct vision and effectively decompress the entrapment of the lumbosacral plexus to achieve better clinical efficacy.

A Locked Sacroiliac Joint Dislocation Requiring Open Reduction: A Case Report

CASE

Vertically unstable pelvic ring injuries are often associated with sacroiliac (SI) joint subluxations or dislocations. The following report describes an irreducible SI joint dislocation where the ilium was locked in a position superior to the sacrum. This injury was refractory to initial closed reduction techniques and ultimately required an open reduction.

CONCLUSIONS

This report demonstrates the limitations of closed manipulation for some vertically unstable pelvic ring injuries. It is critical to have a strong understanding of the anatomy and typical manipulations to succeed in both closed and open SI joint reduction attempts.

Anterior fracture dislocation of the sacroiliac joint: A case report and literature review

Publications describing the diagnosis and treatment of anterior dislocation of the sacroiliac joint are scarce. We report the case a 19-year-old female at 8 weeks' gestation who presented with anterior fracture dislocation of the right sacroiliac joint, posterior fracture dislocation of the left sacroiliac joint (crescent fracture), and incomplete abortion resulting from high energy trauma. Orthopedic surgery involved standard anterior sacroiliac joint plating using an ilioinguinal approach combined with a modified Stoppa approach. Three attempts at complete abortion failed. Complete abortion was eventually achieved by dilatation and curettage two weeks after orthopedic surgery. Our findings reveal a need to improve techniques for diagnosis and treatment of anterior fracture dislocation of the sacroiliac joint, so greater attention can be paid to the rapid and effective management of associated comorbidities, and those resulting from the initial trauma.

Investigation of Pelvic Injuries on Eighteen Post Mortem Human Subjects Submitted to Oblique Lateral Impacts

The aim of this study was to investigate the sacroiliac joint injury mechanism. Two test configurations were selected from full scale car crashes conducted with the WorldSID 50^th dummy resulting in high sacroiliac joint loads and low pubic symphysis force, i.e. severe conditions for the sacroiliac joint. The two test conditions were reproduced in laboratory using a 150-155 kg guided probe propelled respectively at 8 m/s and 7.5 m/s and with different shapes and orientations for the plate impacting the pelvis. Nine Post Mortem Human Subject (PMHS) were tested in each of the two configurations (eighteen PMHS in total). In order to get information on the time of fracture, eleven strain gauges were glued on the pelvic bone of each PMHS. Results - In the first configuration, five PMHS out of nine sustained AIS2+ pelvic injuries. All five presented sacroiliac joint injuries associated with pubic area injuries. In the second configuration, four specimens out of nine sustained AIS2+ pelvic injuries. Two of them presented sacroiliac joint fractures associated with pubic area injuries. The other two presented injuries at the pubic area and acetabulum only. The strain gauges signals suggested that the pubic fractures occurred before the sacroiliac joint fractures in the great majority of the cases (five cases out of seven). Conclusions - Even in the oblique impact conditions of the present study, the pubic symphysis area was observed to be the weakest zone of the pelvis and its failure the predominant cause of sacroiliac joint injuries. It was hypothesized that the failure of the pubic rami allowed the hemi-pelvis to rotate inward, and that this closing-book motion induced the failure of the sacroiliac joint.

A Comparison of Sacroiliac and Pubic Rami Fracture Occurrences in Oblique Side Impact Tests on Nine Post Mortem Human Subjects

The WorldSID dummy can be equipped with both a pubic and a sacroiliac joint (S-I joint) loadcell. Although a pubic force criterion and the associated injury risk curve are currently available and used in regulation (ECE95, FMVSS214), as of today injury mechanisms, injury criteria, and injury assessment reference values are not available for the sacroiliac joint itself. The aim of this study was to investigate the sacroiliac joint injury mechanism. Three configurations were identified from full-scale car crashes conducted with the WorldSID 50th percentile male where the force passing through the pubis in all three tests was approximately 1500 N while the sacroiliac Fy/Mx peak values were 4500 N/50 Nm, 2400 N/130 Nm, and 5300 N/150 Nm, respectively. These tests were reproduced using a 150 kg guided probe impacting Post Mortem Human Subjects (PMHS) at 8 m/s, 5.4 m/s and 7.5 m/s. The shape and the orientation of the impacting face of the probe were selected to match the WorldSID pubic Fy and sacroiliac Fy/Mx loads of the three vehicle test configurations. Three PMHS were tested in each of the three configurations (nine PMHS in total).

RESULTS

In the first PMHS configuration, one specimen sustained an AIS 3 injury and one sustained an AIS 4 injury (an unstable pelvis with complete disruption of the posterior arch, a sacroiliac joint disruption associated with an iliac fracture, and a pubic symphysis separation). In the second configuration, all specimens sustained a fracture of the superior lateral iliac wing (AIS 2). In the third configuration, one specimen sustained a partial disruption of the anterior arch (AIS 2). Based on the data from strain gauges located on the pubic rami and near the sacroiliac joint, the pubic rami fractures were identified as occurring prior to the sacroiliac fractures.

CONCLUSIONS

Out of nine impactor tests performed, the PMHS S-I joint injuries were observed to consistently be associated with pelvic anterior arch fractures. In addition, from the injury sequences derived from strain gauges located on the specimen pelvises and on the injury assessments obtained by necropsy, the S-I joint fractures were observed to occur after the anterior arch fractures.

Anterior fracture dislocation of sacroiliac joint: A rare type of crescent fracture

Crescent fractures of the pelvis are usually described as posterior sacro iliac fracture dislocations. Rarely anterior displacement of the fractured iliac fragment along with dislocation has been reported in crescent fractures. Four cases of anterior fracture dislocation of the sacro iliac joint managed in the last two years by a single surgeon are presented. The injury mechanism, radiological diagnosis, management protocol along with functional outcomes of all the four patients have been discussed. CT scan is essential in the diagnosis and preoperative planning of this injury pattern. Early fixation along with proper reduction leads to excellent functional outcome in this subset of lateral compression injuries of the pelvis.

Lumbar plexus injury in an anterior fracture dislocation of sacroiliac joint: a case report and review of literature

Displaced unstable pelvic fractures are commonly associated with disruption of the osteoarticular junction of the sacroiliac joint. Posterior sacroiliac dislocation are commonly reported but there are only few reports the anterior type of sacroiliac dislocation where the iliac bone fractures and displaces anterior to sacrum, often in combination with fractures of pubic rami and symphyseal injuries. We present a case of an anterior type of sacroiliac fracture dislocation which was associated with a lumbar plexus injury involving both motor and sensory components. Preoperative neurological assessment was done by MRI scan. The tented nerve roots were explored and decompressed surgically, and sacroiliac fixation was done after reduction in the fracture and joint.