Internal fixation of S1-S3 iliosacral screws and pubic screw as the best configuration for unstable pelvic fracture with unilateral vertical sacral fracture (AO type C1.3)

L4 fixation is not necessary in L5-Iliac spinopelvic fixation after trauma, but coadjutant transilio-transsacral fixation is

INTRODUCTION

Spinopelvic dissociation (SPD) is a severe injury characterized by a discontinuity between the spine and the bony pelvis consisting of a bilateral longitudinal sacral fracture, most of the times through sacral neuroforamen, and a horizontal fracture, usually through the S1 or S2 body. The introduction of the concept of triangular osteosynthesis has shown to be an advance in the stability of spinopelvic fixation (SPF). However, a controversy exists as to whether the spinal fixation should reach up to L4 and, if so, it should be combined with transiliac-transsacral screws (TTS).

OBJECTIVE

The purpose of this study is to compare the biomechanical behavior in the laboratory of four different osteosynthesis constructs for SPD, including spinopelvic fixation of L5 versus L4 and L5; along with or without TTS in both cases.

MATERIAL AND METHODS

By means of a formerly described method by the authors, an unstable standardized H-type sacral fracture in twenty synthetic replicas of a male pelvis articulated to the lumbar spine, L1 to sacrum, (Model: 1300, SawbonesTM; Pacific Research Laboratories, Vashon, WA, USA), instrumented with four different techniques, were mechanically tested. We made 4 different constructs in 5 specimen samples for each construct. Groups: Group 1. Instrumentation of the L5-Iliac bones with TTS. Group 2. Instrumentation of the L4-L5-Iliac bones with TTS. Group 3. Instrumentation of L5-Iliac bones without TTS. Group 4: Instrumentation of L4-L5-Iliac bones without TTS.

RESULTS AND CONCLUSIONS

According to our results, it can be concluded that in SPD, better stability is obtained when proximal fixation is only up to L5, without including L4 (alternative hypothesis), the addition of transiliac-transsacral fixations is essential.

Treatment of Unstable Sacral Fractures with Robotically-aided Minimally Invasive Triangular Fixation

OBJECTIVE

The treatment of unstable sacral fractures is huge challenge to surgeons. Robotically-aided minimally invasive triangular fixation (RoboTFX) is the most advanced technique up to now. This study is to evaluate the clinical outcomes of unstable sacral fractures treated with RoboTFX.

METHODS

From March 2017 to October 2021, 48 consecutive patients with unstable sacral fractures were included in the study. All patients received surgical treatment with triangular fixation (TFX). Patients were divided into four groups according to the number of fractures (uni- or bilateral) and surgical method employed (RoboTFX or traditional open TFX). Between these four groups, clinical data on operation time, intraoperative bleeding, intraoperative fluoroscopy time, infection rate, fracture healing rates, insertion accuracy, Majeed pelvic outcome score, Mears' criterion, and Gibbons score were compared. Quantitative data were expressed as mean ± standard deviation and compared using Student's t-test. Categorical variable were compared using the Pearson's χ2 test.

RESULTS

Comparing unilateral RoboTFX versus open TFX, neither fracture healing rate, infection rate, Majeed pelvic outcome score, Mears' radiological evaluation criterion, nor Gibbons score of the two groups were statistically significantly different (p > 0.05). However, operation time, intraoperative bleeding, intraoperative fluoroscopy time, and insertion accuracy in the RoboTFX group were all significantly better than those of the traditional open group (p < 0.05). Likewise, operation time, intraoperative bleeding, intraoperative fluoroscopy time, and accuracy of fixation insertion of the bilateral RoboTFX group were significantly better than those of the bilateral open group (p < 0.05). Meanwhile infection rate, fracture healing rate, Majeed score, Mears' criterion, and Gibbons score of two groups were not significantly different (p > 0.05).

CONCLUSION

RoboTFX has the advantages of less operation time, less intraoperative bleeding and fluoroscopy, more accurate fixation insertion, and a higher healing rate compared to traditional open methods in the treatment of unstable sacral fractures. However, RoboTFX requires a few critical considerations, and the indications of its operation should be strictly evaluated.

Is a Washer a Mandatory Component in Young Trauma Patients with S1-S2 Iliosacral Screw Fixation of Posterior Pelvis Ring Injuries? A Biomechanical Study

Background and purpose: Cannulated screws are standard implants for percutaneous fixa-tion of posterior pelvis ring injuries. The choice of whether to use these screws in combination with a washer is still undecided. The aim of this study was to evaluate the biomechanical competence of S1-S2 sacroiliac (SI) screw fixation with and without using a washer across three different screw designs. Material and Methods: Twenty-four composite pelvises were used and an SI joint injury type APC III according to the Young and Burgess classification was simulated. Fixation of the posterior pelvis ring was performed using either partially threaded short screws, fully threaded short screws, or fully threaded long transsacral screws. Biomechanical testing was performed under progressively increasing cyclic loading until failure, with monitoring of the intersegmental and bone-implant movements via motion tracking. Results: The number of cycles to failure and the corresponding load at failure (N) were significantly higher for the fully threaded short screws with a washer (3972 ± 600/398.6 ± 30.0) versus its counterpart without a washer (2993 ± 527/349.7 ± 26.4), p = 0.026. In contrast, these two parameters did not reveal any significant differences when comparing fixations with and without a washer using either partially threaded short of fully threaded long transsacral screws, p ≥ 0.359. Conclusions: From a biomechanical perspective, a washer could be optional when using partially threaded short or fully threaded long transsacral S1-S2 screws for treatment of posterior pelvis ring injuries in young trauma patients. Yet, the omission of the washer in fully threaded short screws could lead to a significant diminished biomechanical stability.

Evaluation of Cannulated Compression Headless Screw (CCHS) as an alternative implant in comparison to standard S1-S2 screw fixation of the posterior pelvis ring: a biomechanical study

BACKGROUND/PURPOSE

Posterior pelvis ring injuries represent typical high-energy trauma injuries in young adults. Joint stabilization with two cannulated sacroiliac (SI) screws at the level of sacral vertebrae S1 and S2 is a well-established procedure. However, high failure- and implant removal (IR) rates have been reported. Especially, the washer recovery can pose the most difficult part of the IR surgery, which is often associated with complications. The aim of this biomechanical study was to evaluate the stability of S1-S2 fixation of the SI joint using three different screw designs.

METHODS

Eighteen artificial hemi-pelvises were assigned to three groups (n = 6) for SI joint stabilization through S1 and S2 corridors using either two 7.5 mm cannulated compression headless screws (group CCH), two 7.3 mm partially threaded SI screws (group PT), or two 7.3 mm fully threaded SI screws (group FT). An SI joint dislocation injury type III APC according to the Young and Burgess classification was simulated before implantation. All specimens were biomechanically tested to failure in upright standing position under progressively increasing cyclic loading. Interfragmentary and bone-implant movements were captured via motion tracking and evaluated at four time points between 4000 and 7000 cycles.

RESULTS

Combined interfragmentary angular displacement movements in coronal and transverse plane between ilium and sacrum, evaluated over the measured four time points, were significantly bigger in group FT versus both groups CCH and PT, p ≤ 0.047. In addition, angular displacement of the screw axis within the ilium under consideration of both these planes was significantly bigger in group FT versus group PT, p = 0.038. However, no significant differences were observed among the groups for screw tip cutout movements in the sacrum, p = 0.321. Cycles to failure were highest in group PT (9885 ± 1712), followed by group CCH (9820 ± 597), and group FT (7202 ± 1087), being significantly lower in group FT compared to both groups CCH and PT, p ≤ 0.027.

CONCLUSION

From a biomechanical perspective, S1-S2 SI joint fixation using two cannulated compression headless screws or two partially threaded SI screws exhibited better interfragmentary stability compared to two fully threaded SI screws. The former can therefore be considered as a valid alternative to standard SI screw fixation in posterior pelvis ring injuries. In addition, partially threaded screw fixation was associated with less bone-implant movements versus fully threaded screw fixation. Further human cadaveric biomechanical studies with larger sample size should be initiated to understand better the potential of cannulated compression headless screw fixation for the therapy of the injured posterior pelvis ring in young trauma patients.

Pelvic antropometric measurement in 3D CT for placement of two unilateral iliosacral S1 - 7.3 mm screws

PURPOSE

Stability of the dorsal pelvic ring is important for patient mobilisation and can be restored using several surgical procedures after fracture. Placement of percutaneous iliosacral screws is a reliable and minimal-invasive technique to achieve stabilisation of the dorsal pelvic ring by placement of two screws in the first sacral vertebra. Aim of this study was to evaluate 3D CT scans regarding the anatomical possibility to place two 7.3 mm iliosacral screws for fixation of the dorsal pelvic ring.

METHODS

3D CT datasets of 500 consecutive trauma patients with 1000 hemipelves of a mid-european level I trauma centre with or without pelvic injury were evaluated and measured bilaterally in this retrospective study.

RESULTS

One thousand hemipelvic datasets of 500 patients (157 females, 343 males) with a mean age of 49.7 years (18 to 95) were included in this study. Only 16 hemipelves (1.6%, 11 in females, 5 in males) in 14 patients (2.8%, 9 females = 5.73%, 5 males = 1.5%) showed too narrow corridors so that 7.3 mm screw placement would not be possible (p = 0.001). In women, too narrow corridors occurred 3.9 times as often as in men. Only two females showed this bilaterally.

CONCLUSION

The evaluation of 3D CT scans of the pelvis showed the importance of planning iliosacral screw placement, especially if two 7.3 mm screws are intended to be placed in the first sacral vertebra.

Low Superior Pubic Ramus Screw Failure Rate With Combined Anterior and Posterior Pelvic Ring Fixation

OBJECTIVES

To determine whether fracture pattern, implant size, fixation direction, or the amount of posterior pelvic ring fixation influences superior ramus medullary screw fixation failure.

DESIGN

Retrospective cohort review.

SETTING

Regional Level 1 trauma center.

PATIENTS/PARTICIPANTS

After exclusion criteria, 95 patients with 111 superior ramus fractures with 3 months minimum follow-up were included.

INTERVENTION

All patients underwent anterior and posterior pelvic ring fixation.

MAIN OUTCOME MEASUREMENTS

Comparison of immediate postoperative radiographs and/or computer tomography scan with the latest postoperative image to calculate interval fracture displacement and implant position. Postoperative fracture displacement or implant position change greater than 1 cm were considered fixation failures.

RESULTS

Five screws were defined as failures (4.5%), including 3 retrograde, 3 with bicortical fixation, 4 with a 4.5-mm screw, and 1 with a 7.0-mm screw. Fracture patterns included 2 oblique and 3 comminuted fractures. Based on the Nakatani classification, there were 3 zone II, 1 zone I, and 1 zone III. Failure modes included 3 with cut-out along the screw head and 1 cut-out and 1 cut-through at the screw tip.

CONCLUSIONS

Our incidence of superior pubic ramus intramedullary screw fixation failure was 4.5%. Even with anterior and posterior fixation along with precise technique, failures still occur without a common failure predictor. The percutaneous advantages and proven strength provided by an intramedullary implant make it desirable to help reestablish global pelvic ring stability. Biomechanical and clinical studies are needed to further understand intramedullary superior ramus screw fixation.

LEVEL OF EVIDENCE

Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Sacral fractures: An updated and comprehensive review

Sacral fractures are often underdiagnosed but are relatively frequent in the setting of pelvic ring injury. Causes include traumatic insults and osteoporosis. Sacral fractures have become more frequent owing to the growth of the elderly population worldwide as osteoporosis is an age-related disease. Misdiagnosed and neglected sacral fractures can result in chronic back pain, spine deformity, and instability. Unfortunately, the wide range of classification systems hinders adequate communication among clinicians. Therefore, a complete understanding of the pathology, and communication within the interdisciplinary team, are necessary to ensure adequate treatment and satisfactory clinical outcomes. The aim of this manuscript is to present the current knowledge available regarding classification systems, clinical assessment, decision-making factors, and current treatment options.

Surgical technique of percutaneous iliosacral screw fixation in S3 level in unstable pelvic fracture with closed degloving injury and morrell lavallee lesion: Two case reports

This paper is very special because:

•

This is the first paper describing the technique of percutaneous Iliosacral screw insertion at the level of S3.

•

This is very severe and life threatening cases with with polytrauma who rarely survived in good outcome.

•

This technique of surgery provide good to excellent functional outcome for both patient.

Introduction

Percutaneous screw fixation is considered the best option in unstable pelvic fracture with severe soft tissue injury. However, fixation technique at the level of S3 has not been well established. This paper showed the feasible surgical technique of S3 screw insertion in unstable pelvic fracture with severe soft tissue injury.

Methods

We reported 2 cases of unstable pelvic injury of an 11 years old boy with Marvin-Tile (MT) C1 pelvic fracture with sacroiliac (SI) joint disruption, skin avulsion and Morel-Lavallée lesion. Second case was 30 years old male with open pelvic fracture MTB2 and vertical sacral fracture Denis zone I with Morel-Lavallée lesion, intraperitoneal bladder rupture, infected laparotomy wound dehiscence. We performed percutaneous screws insertion on both pubic rami and IS screw on S1 and S3 to both cases. Functional outcome was evaluated using Majeed and Hannover pelvic score.

Results

All patients survived and had good reduction with no residual displacement on SI joint. The former case at 21-month follow up presented with excellent outcome (100/100) by Majeed score and very good outcome (4/4) by Hannover score; while the latter case, at 18-month, present with good outcome (85/100) Majeed score and fair outcome (2/4) Hannover score.

Conclusions

Percutaneous screw fixation at the level of S3 is feasible and can be inserted in S3 level by sacroiliac type and sacral type with minimal soft tissue intervention and good functional outcome.