Vacuum phenomenon in pelvic fractures

Prevalence of fracture progression in fragility fractures of the pelvis: Systematic review and meta-analysis

BACKGROUND

Fragility fractures of the pelvis (FFP) are a growing problem in aging populations. Fracture progression (FP) occasionally occurs during FFP treatment; however, its prevalence remains unclear. This systematic review and meta-analysis aimed to assess the prevalence of FP among patients with FFP.

METHODS

We performed a systematic review and meta-analysis in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. All cohort studies that reported the prevalence of FP in patients with FFP were included. FP was defined as the appearance of additional pelvic fractures after the initial FFP. We searched the CENTRAL, MEDLINE, and EMBASE databases until April 2024. The pooled prevalence was generated using a random-effects model and presented as a 95 % confidence interval (CI) and prediction interval (PI). We assessed the risk of bias in each study using the Joanna Briggs Institute's Prevalence Critical Appraisal Tool.

RESULTS

This review included eight studies (925 patients). The pooled prevalence of FP in patients with FFP was 11 % (95 % CI, 5-19 %; 95 % PI, 0-44 %). Subgroup analysis showed that the pooled prevalence of FP in patients with FFP (conservative treatment vs. surgery for initial FFP) was 16 % (95 % CI, 9-24 %) and 2 % (95 % CI, 0-11 %), respectively (test for subgroup difference, P = 0.03). Additional analysis showed that in patients with FP, the pooled prevalence of the fractured site (ipsilateral site, contralateral site, and both sites) was 66 %, 12 %, and 19 %, respectively. The pooled prevalence of fractured bone (pubis, ischium, ilium, and sacrum) was 25 %, 0 %, 15 %, and 68 %, respectively. The risk of bias in the patient sampling method and sufficient data analysis in all included studies was high.

CONCLUSION

This review suggests that the prevalence of FP in patients with FFP is relatively high. Clinicians should recognize FP as a possible diagnosis in patients experiencing additional pain after FFP. However, further prospective studies with adequate patient sampling are required to confirm the true prevalence.

Clinical study of vacuum phenomenon in closed pelvic fracture

BACKGROUND

This study aimed to examine the prevalence and clinical findings of the vacuum phenomenon (VP) in closed pelvic fractures.

METHODS

We retrospectively reviewed 352 patients with closed pelvic fractures who presented to our institution from January 2017 to December 2020. Pelvic fractures were diagnosed by plain radiography and computed tomography (CT). The default "bone window" was used for inspection in the cross section. Electronic medical records were consulted by two orthopedic physicians to obtain patient information. The VP of pelvic fracture, fracture classification, injury mechanism, and image data were evaluated, and the demographic parameter data were statistically analyzed. The follow-up time was 12-18 months.

RESULTS

Among them, 169 were males and 183 were females with ages ranging from 3 to 100 years, with an average of 49.6 ± 19.3 years. VP in pelvic fractures was detected by CT in 109 (31%) of the 352 patients with pelvic fractures. Patients were divided into the high-energy trauma group (278 cases) and fragility fractures of the pelvis (FFP) group (74 cases) according to the injury mechanism. In the high-energy trauma group, 227 cases were treated surgically and 201 cases had bony healing. The healing time was 9.8 ± 5.3 weeks. In the FFP group, 54 cases were treated surgically and 49 cases had bone healing. The healing time was 9.3 ± 3.8 weeks. Fractures progressed in nine patients. VP was mostly located in the sacroiliac joint in our study.

CONCLUSIONS

The incidence of VP in pelvic fractures is statistically high and is affected by many factors, such as examination technique, joint position, population composition, etc. Therefore, the VP is not a reliable sign of pelvic injury. Clinically, we need to determine the nature of VP in conjunction with gas patterns, laboratory tests, history, and physical examination.