Incidence of and Risk Factors for Screw Loosening after Iliosacral Screw Fixation for Posterior Pelvic Ring Injury

Purposes

Screw loosening is a common complication of iliosacral screw fixation, with subsequent loss of stability and fracture re-displacement. This study aimed to investigate the incidence of and risk factors for screw loosening after iliosacral screw fixation for posterior pelvic ring injury.

Methods

A total of 135 patients with posterior pelvic ring injuries who were treated with iliosacral screw fixation in our department between July 2015 and April 2021 were selected for this retrospective analysis. The possible risk factors for screw loosening were investigated using univariate and multivariate logistic regression analyses of patient demographics and trauma-related and iatrogenic variables, including age, sex, body mass index, Osteoporosis Self-Assessment Tool for Asians (OSTA) index, mechanism of injury, Young–Burgess classification, site of injury, type of injury, type of screw, mode of fixation, numbers of guidewire adjustments, accuracy of screw position, and quality of fracture reduction.

Results

The incidence of screw loosening was 15.6% (n = 21). The mean duration for screw loosening was 3.2 ± 1.5 months after operation. Univariate analysis results showed that the Young–Burgess classification, type of injury, site of injury, type of screw, mode of fixation, and OSTA index might be related to screw loosening (p < 0.05). According to the multivariate logistic regression, vertical shear injuries (Odds ratios [OR] 9.80, 95% Confidence intervals [CI] [1.96–73.28], p = 0.008), type of injury (OR 0.25, 95% CI [0.13–0.79], p = 0.027), common screws (OR 6.94, 95% CI [1.53–31.40], p = 0.012), screws insertion only at the level of the first sacral segment (S1) (OR 8.79, 95% CI [1.18–65.46], p = 0.034), injury site located in the medial sacral foramina (OR 6.28, 95% CI [1.16–34.06], p = 0.033), and lower OSTA index [OR 0.41, 95% CI [0.24–0.71], p = 0.001] were significantly related to screw loosening.

Conclusions

Vertical shear injuries, sacral fractures, injury site located in the medial sacral foramina, and lower OSTA index are significantly associated with the postoperative occurrence of screw loosening. Transiliac–transsacral screw fixation and screws insertion both at the level of the S1 and second sacral segment can prevent screw loosening.     

Foot Protective System : A Boon to Demining Soldiers

Background

A significant number of soldiers suffer serious injuries or die in the process of demining and a protective device is necessary in such operations.

Methods

All the patients involved in demining operations using the foot protection devices in last one year were analysed.

Results

We received 35 patients, of which only five had limb injuries and 30 had eye injuries. Of the five, three had closed calcaneal fractures and two contusion of foot. No fatality, amputation or compound fracture occured.

Conclusion

Early results after the use of this device during demining operations are encouraging.Key Words: Mine blast injury, Demining, Spider boot     

Radiation dose reduction during hysterosalpingography: an application of scanning-beam digital radiography

Hysterosalpingography was performed in 31 patients by means of a low-dose scanning-beam digital radiographic system. The technique permits adequate evaluation of gynecologic abnormalities while allowing significant reduction in radiation: 2.4-mR (6.1 X 10(-7) C/kg) exposure to the skin and 0.7-mrad (7 X 10(-6) Gy) mean dose to the ovaries per image obtained. Sixteen patients demonstrated readily recognizable and documented abnormalities, corroborated by laparoscopy, laparotomy, or other supportive evidence.