The combination of intraoperative CT navigation and C-arm fluoroscopy for INFIX and percutaneous TITS screw placement in the treatment of pelvic ring injury: technical note

Background The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture. Methods A typical case is presented in this study. An 86-year-old woman suffered from an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation were selected to optimize surgical invasiveness and proper implant placement. Results The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer. Conclusions The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.

Percutaneous iliosacral screw and trans-iliac trans-sacral screw with single C-arm fluoroscope intensifier is a safe treatment for pelvic ring injuries

To elucidate the accuracy, efficacy, and safety of percutaneous iliosacral screw (ISS) and trans-iliac trans-sacral screw (TITS) insertion using a single C-arm fluoroscopy intensifier. Additionally, the potential risk factors that might cause mal-positioned screws were identified. Patients with pelvic ring injuries who underwent percutaneous screw fixation in a single medical institute were divided into an ISS group (n = 59) and a TITS group (n = 62) and assessed. The angles deviated from ideal orientation (ADIO) of the implanted screw were measured, and potential risk factors for mal-positioned screws were analyzed. Overall, the reduction quality of the pelvic ring was good or excellent in 70 patients (82.4%) by Matta’s criteria and in 48 patients (56.5%) by Lefaivre’s criteria. ADIO measurements of the ISS and TITS groups via multi-planar computed tomography were 9.16° ± 6.97° and 3.09° ± 2.8° in the axial view, respectively, and 5.92° ± 3.65° and 2.10° ± 2.01° in the coronal view, respectively. Univariate statistical analysis revealed body mass index as the single potential risk factor of mal-positioned screws. With careful preoperative planning and intraoperative preparations, placing ISS and TITS under the guidance of single C-arm fluoroscopy intensifier is a reliable and safe technique. Caution should be exercised when performing this procedure in patients with a high body mass index.

Lateral Compression Sacral Fractures Have Less Favourable Outcome Compared to Crescent Fractures in Patients Less Than 50 Years Old

Background. Lateral compression (LC) accounts for a wide spectrum of pelvic ring injuries (PRIs). The primary aim of this study was to assess the health-related quality of life outcomes of surgically fixed LC crescent versus sacral fractures in patients less than 50 years old after high energy trauma. Material and methods. We retrospectively reviewed the database for PRIs treated surgically from Decem­ber 2011 to January 2019 at our tertiary level trauma centre. The EuroQoL-5D (EQ5D5L) questionnaire was elec­tronically sent to all patients. Multiple linear regression was conducted to determine the predictors of quality-adjusted life-years (QALYs). Results. The study included 37 patients. The mean age was 26 SD 9.46 years. The mean duration of follow-up was 3.78 (r:1-9) years. Twenty-one (56.8%) and 16 (43.2%) patients sustained sacral fractures and crescent fractures, respectively. Multi-regression analysis showed that any patient with LC injury without a sacral fracture is expected to have a utility value of QALY= 0.876. A reduction of 0.072 units in QALYs is expected in the presence of sacral fracture. About 71% of patients with sacral fractures were able to return to work and this probability increased by 40% among patients with crescent fractures (RR=1.4, p=.015). Conclusions. 1. Younger patients with crescent fractures tend to have better quality of life (higher EQ5D and QALYs) compared to those with LC sacral fractures. 2. Moreover, patients with LC sacral fractures have less chan­ce to return to their pre-injury level of work compared to those with crescent fractures.

Does Cement Augmentation of the Sacroiliac Screw Lead to Superior Biomechanical Results for Fixation of the Posterior Pelvic Ring? A Biomechanical Study

Background and Objectives: The stability of the pelvic ring mainly depends on the integrity of its posterior part. Percutaneous sacroiliac (SI) screws are widely implanted as standard of care treatment. The main risk factors for their fixation failure are related to vertical shear or transforaminal sacral fractures. The aim of this study was to compare the biomechanical performance of fixations using one (Group 1) or two (Group 2) standard SI screws versus one SI screw with bone cement augmentation (Group 3). Materials and Methods: Unstable fractures of the pelvic ring (AO/OTA 61-C1.3, FFP IIc) were simulated in 21 artificial pelvises by means of vertical osteotomies in the ipsilateral anterior and posterior pelvic ring. A supra-acetabular external fixator was applied to address the anterior fracture. All specimens were tested under progressively increasing cyclic loading until failure, with monitoring by means of motion tracking. Fracture site displacement and cycles to failure were evaluated. Results: Fracture displacement after 500 cycles was lowest in Group 3 (0.76 cm [0.30] (median [interquartile range, IQR])) followed by Group 1 (1.42 cm, [0.21]) and Group 2 (1.42 cm [1.66]), with significant differences between Groups 1 and 3, p = 0.04. Fracture displacement after 1000 cycles was significantly lower in Group 3 (1.15 cm [0.37]) compared to both Group 1 (2.19 cm [2.39]) and Group 2 (2.23 cm [3.65]), p ≤ 0.04. Cycles to failure (Group 1: 3930 ± 890 (mean ± standard deviation), Group 2: 3676 ± 348, Group 3: 3764 ± 645) did not differ significantly between the groups, p = 0.79. Conclusions: In our biomechanical setup cement augmentation of one SI screw resulted in significantly less displacement compared to the use of one or two SI screws. However, the number of cycles to failure was not significantly different between the groups. Cement augmentation of one SI screw seems to be a useful treatment option for posterior pelvic ring fixation, especially in osteoporotic bone.