Can lumbopelvic fixation salvage unstable complex sacral fractures?

Percutaneous lumbopelvic fixation is effective in the management of unstable transverse sacral fractures

OBJECTIVES

Historically, fractures causing lumbopelvic dissociation have been managed with open lumbosacral fusion and instrumentation. Our aim was to evaluate outcomes and complications following surgical management of unstable transverse sacral fractures with percutaneous lumbopelvic fixation.

METHODS

Design: Retrospective case series.

SETTING

Academic Single Center, Level I Trauma Center. Patient Selection Criteria: Patients with lumbopelvic dissociation undergoing surgery. Outcome Measures and Comparisons: Patient demographics, mechanism of injury, ISS, associated injuries, radiographic classification (Roy-Camille), patient-reported outcomes (PROMIS PI, PF, D, and ODI), and complications were collected.

RESULTS

27 patients were enrolled with an average follow-up of 18.7 ± 17.6 months and age of 54.4 ± 25.1 years. All patients underwent lumbar pedicle screw and iliac screw placement. Sacral laminectomy was performed if the patient had a preoperative neurological deficit. Patients were counseled on instrumentation removal at 6-12 months. 67 % of patients sustained a fall, and 33 % were involved in an MVA. 52 % were Roy-Camille Type 2, and 32 % and 20 % were Types 1 and 3, respectively. The mean EBL was 261 ± 400 ml. 37 % required concurrent sacral laminectomy. There were no intraoperative complications and four postoperative complications, including surgical site infection, rod dislodgment, and deep venous thrombosis. 63 % underwent removal of instrumentation after fracture healing. ODI scores significantly improved from 6 weeks post-op (35.5 ± 4.5) to one-year follow-up (18.3 ± 9.6, p = 0.005), two-year follow-up (20.3 ± 10.0, p = 0.03), and final follow-up (16.4 ± 8.8, p = 0.002). Statistically significant improvements were observed in the PROMIS PI, PF, and D domains (p < 0.05).

CONCLUSION

Our study demonstrates that lumbopelvic instrumentation leads to successful management of unstable transverse sacral fractures, with improvement in PRO. The combination of percutaneous instrumentation without arthrodesis did not result in any fracture non-union.

LEVEL OF EVIDENCE

Level IV.

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.

Biomechanical comparison of four triangular osteosynthesis fixations for unilateral vertical sacral fractures

To compare the stability and biomechanical characteristics of four commonly used triangular osteosynthesis techniques to treat unilateral vertical sacral fractures and provide a clinical application reference. Finite element models of Tile C-type pelvic ring injury (unilateral Denis II sacral fracture) were produced. In four models, sacral fractures were fixed with a combination of unilateral L5, unilateral L4, and L5 iliac lumbar fixation with lengthened or normal sacroiliac screws. The biomechanical properties of the four fixation models were measured and compared under bipedal stance and lumbar rotation. The fixation stability of the model with the lengthened sacroiliac screw was excellent, and the fracture end was stable. The stability of fixation using unilateral L4 and L5 segments was close to that of unilateral L5 segment fixation. Triangular osteosynthesis transverse stabilization devices using lengthened sacroiliac screws can increase the vertical stability of the sacrum after internal fixation and increase the stability of the fracture. When triangular osteosynthesis lumbar fixation segments were selected, simultaneous fixation of L4 and L5 segments versus only L5 segments did not significantly enhance the vertical stability of the sacrum or the stability of the fracture end.

Biomechanical investigation of S2 alar-iliac screw and S1 pedicle screw fixation in the treatment of Denis type II sacral fractures

Although S2 alar-iliac screw technique has been widely used in spinal surgery, its applicability to pelvic fractures is largely unknown. This study aimed to evaluate the biomechanical stability of S2 alar-iliac screw and S1 pedicle screw fixation in the treatment of Denis II sacral fractures. Twenty-eight artificial pelvic fracture models were treated with unilateral lumbopelvic fixation, sacroiliac screw fixation, S2 alar-iliac screw and S1 pedicle screw fixation, and S2 alar-iliac screw and contralateral S1 pedicle screw fixation (Groups 1-4, respectively; N = 7 per group). Each model was cyclically tested under increasing axial compression. Optical motion-tracking was used to assess relative displacement and gap angle, and the number of failure cycles. Relative displacement was significantly smaller in Group 3 than in Groups 1 (p = 0.004) and 4 (p < 0.001) but not significantly different between Groups 3 and 2 (p = 0.290). The gap angle in Group 3 was significantly smaller than that in Group 1 (p = 0.009) on the sagittal plane but significantly larger than that in Group 4 (p = 0.006) on the horizontal plane. A number of failure cycles was significantly higher in Group 3 than in Groups 1 (p = 0.002) and 4 (p = 0.004) but not significantly different between Groups 3 and 2 (p = 0.910). From a biomechanical perspective, S2 alar-iliac screw and S1 pedicle screw fixation can provide good stability in the treatment of Denis II sacral fractures.

Breakage risk of different sacroiliac screws in unilateral sacral fractures a finite element analysis

Objective

To compare the breakage risk of lengthened sacroiliac screws and ordinary sacroiliac screws to treat unilateral vertical sacral fractures and provide a reference for clinical application.

Methods

A finite element model of Tile C pelvic ring injury (unilateral type Denis II fracture of the sacrum) was produced. The sacral fractures were fixed with a lengthened sacroiliac screw and ordinary sacroiliac screw in 6 types of models. The maximal von Mises stresses and stress distributions of the two kinds of screws when standing on both feet were measured and compared.

Results

The maximal von Mises stress of the lengthened screw was less than that of the ordinary screw. Compared with ordinary screw, the stress distribution in the lengthened screw was more homogeneous.

Conclusions

The breakage risk of screws fixed in double segments is lower than that of screws fixed in single segments, the breakage risk of lengthened screws is lower than that of ordinary screws, and the breakage risk of screws fixed in S2 segments is lower than that of screws fixed in S1 segments.

Technical Note on Placement of Low-Profile Triangular Osteosynthesis for Unstable Posterior Pelvic Ring Injuries

SUMMARY

Triangular osteosynthesis is a technique used to stabilize posterior pelvic ring injuries. Conventional triangular fixation can be problematic for several reasons, including the need for advanced skill sets to place instrumentation, difficulty with pelvic reduction and placing the connecting construct, and prominent instrumentation. The purpose of this study is 2-fold: (1) to describe in detail a technique for lumbopelvic fixation using implants that are easy to connect, allow distraction for complex lumbosacral displacements, and are placed in a location minimizing soft tissue prominence and (2) to present our initial case series using this technique. We present a retrospective review of 18 consecutively treated patients with this technique. Inclusion criteria were patients with complete disruption through the sacrum or sacroiliac joint from blunt trauma (OTA/AO type C injuries). Outcomes included pelvic reduction/malreduction, wound healing, and complications. Fourteen patients underwent unilateral fixation (81%), and 4 patients underwent bilateral fixation (19%). All patients (18 of the 18) had a well-reduced pelvis after fixation. No patient (0%) required a return trip to the operating room for loss of reduction/malreduction, wound breakdown, or implant failure. This study presents an updated technique for a low-profile triangular osteosynthesis construct with straightforward application for unstable posterior pelvic ring injuries. This technique does not require rod bending, results in a consistently more recessed iliac screw and connecting rod, and can be used in a wide variety of unstable posterior pelvic ring injuries, including comminuted sacral fractures, L5/S1 facet fractures, and vertical shear injuries.

Spinopelvic fixation for vertically unstable AO type C pelvic fractures and sacral fractures with spinopelvic dissociation- A systematic review and pooled analysis involving 479 patients

BACKGROUND

Posterior pelvic ring injuries can be fixed using iliosacral screws, plates or bars. Another promising modality is spinopelvic fixation or triangular osteosynthesis, indicated in vertical instability and sacral fractures associated with spinopelvic dissociation.

QUESTION/PURPOSE

This systematic review and pooled analysis was conducted to analyze the outcomes (functional and radiological) of the use of spinopelvic fixation, as well as assess the associated complications and neurological recovery.

METHODS

A systematic review of literature was performed from the PubMed/Medline, EMBASE and the SCOPUS databases. All studies reporting on spinopelvic fixations, with a minimum follow up of 1 year were included in the review. Pooled analysis was done for the outcome and complication rates. The MINORS Tool was used for assessing the risk of bias.

RESULTS

A total of 22 studies were included with average follow-up between 12 and 86.4 months. There were 7 prospective and 15 retrospective case series. The functional outcomes were excellent/good in 90% cases, across 8 studies (95% CI 84-95%); radiological outcomes were excellent/good in 97% cases (95% CI 94-100%) across 5 studies. The most commonly reported complications were hardware prominence in 21.3% (95% CI 11.6,30.9%) and infections in 7.2% cases (95% CI 4.8,9.5%). 73% of the patients reported partial or complete improvement in their neurological condition.

CONCLUSION

Spinopelvic fixation is an effective method in vertical instability of the pelvis and sacral fractures with spinopelvic dissociations, with good to excellent radiological and functional outcomes. However, adequate precautions are needed to avoid infections and wound complications.

S2-Alar-Iliac Screw Fixation versus Iliac Screw Fixation in the Treatment of Sacral Fractures

PURPOSE

To compare the short-term therapeutic effects of S2-alar-iliac (S2AI) screw fixation and iliac screw fixation techniques in managing sacral fractures.

METHODS

From September 2015 to May 2020, 42 patients with sacral fractures who underwent lumbopelvic fixation by a single surgeon were analyzed. The patients were divided into the S2AI screw group (19 patients) and the iliac screw group (23 patients). Operative data, reduction quality, postoperative complications, and functional outcomes were evaluated.

RESULTS

The incidence of unplanned reoperation was significantly different between patients treated with S2AI screws than in those treated with iliac screws (0 versus 6, p = 0.02). The mean intraoperative estimated blood loss was 405.26 ± 229.67 mL in the S2AI screw group and 539.13 ± 246.32 mL in the iliac screw group (P = 0.08). No significant difference was observed in either group regarding the quality of reduction, functional outcome, or low back pain. The reduction quality based on the Matta criteria and excellent/good outcomes were 21/2 in the iliac screw group and 17/2 in the S2AI screw group. The functional outcomes based on the Majeed score and excellent/good/fair outcomes were 17/3/3 in the iliac screw group and 17/1/1 in the S2AI screw group. No complications, including implant breakage, loosening of the implant, or loss of reduction were found in either group during follow-up.

CONCLUSION

Both S2AI screws and iliac screws were effective in the treatment of sacral fractures. The use of S2AI screws, however, was independently associated with fewer unplanned reoperations for surgical site infection, wound dehiscence, and symptoms of screw protrusion than the use of iliac screws.

Minimally Invasive "Crab-Shaped Fixation" for Treating Patients with Fragility Fractures of the Pelvis

Introduction

In the aging society, fragility fracture of the pelvis (FFP) has become a problem. Although strong and minimally invasive fixation is required in FFP surgery, reports on relevant surgical results are scarce. Crab-shaped fixation (CSF) is a spinopelvic fixation that involves reconstruction of the posterior pelvic ring using spinal instrumentation. This study aimed to evaluate the walking ability and perioperative complications of patients who underwent CSF for FFP.

Methods

We included patients diagnosed with unstable FFPs, including sacral fracture, who required hospitalization. Demographic data, such as age, sex, bone mineral density, and Rommens classification, were evaluated. Surgical findings included estimated blood loss, operation time, and perioperative complications. The improvement in postoperative walking ability was evaluated based on the length of the postoperative period before the initiation of walker training and whether walking aids were required at 6 months post-surgery, compared with those who received conservative treatment for FFP.

Results

Our study included 6 cases that received CSF and 16 cases that received conservative treatment, in which all were females and presented with sacral fractures. The average age of the surgical patients, the operation time, and the estimated blood loss were 79.5±14.7 years, 180.7±28.7 min, and 124.2±29.4 mL, respectively. The average length of the postoperative period prior to the initiation of walker training was 10.8±12.3 days, which was significantly shorter than that of conservative treatment. With regard to perioperative complications, poor reduction of fracture dislocation was observed in one case as well as surgical site infection in another case, but the walking ability improved in all cases.

Conclusions

We evaluated the results of the posterior pelvic ring reconstruction with CSF for patients with vertically unstable FFPs, including sacral fractures. CSF is minimally invasive and would be useful as it allowed walker training during the early postoperative period, which improved patients' walking ability even during the in situ pelvic ring reconstruction.

Treatment of Unstable Posterior Pelvic Ring Injury with S2-Alar-Iliac Screw and S1 Pedicle Screw Fixation

OBJECTIVE

The S2-alar-iliac (S2AI) screws have been described as an alternative method for lumbosacropelvic fixation in place of iliac screws. However, the clinical effect of the short-segment S2AI screw fixation technique in the treatment of unstable posterior pelvic ring injuries remains unclear. In this study, we report the preliminary clinical results of the internal fixation connecting a S2-alar-iliac screw and a S1 pedicle screw (i.e., S2AI-S1 fixation) in the treatment of unstable pelvic posterior ring injuries.

METHODS

Twenty-five patients with unstable posterior pelvic ring injury were treated with S2AI-S1 fixation from February 2019 to June 2020. The incision length, surgical time, blood loss, frequency of intraoperative fluoroscopy, quality of reduction, complications, and functional outcome were analyzed.

RESULTS

A total of 29 groups of S2AI-S1 fixation were used in 25 patients. The mean incision length was 8.3 (6.2 - 10.3) cm, mean operative time was 86.4 (60 - 142) minutes, mean frequency of intraoperative fluoroscopy was 7.9 (4 - 12) times, and mean blood loss was 148 (50 - 500) mL. The mean postoperative follow-up time was 17.8 (10 - 26) months. The satisfaction rate of pelvic reduction quality was 25/29, and the satisfactory rate of functional outcome was 23/25. There were no obvious signs of screw prominence, screw loosening, or implant failure.

CONCLUSIONS

The case series presented in this study show the successful use of S2AI-S1 fixation to treat unstable posterior pelvic ring injuries. The S2AI-S1 fixation, not including the lumbar spine in the fixation range, is a simple, safe, and effective fixation method.

Clinical and Patient-Related Outcome After Stabilization of Dorsal Pelvic Ring Fractures: A Retrospective Study Comparing Transiliac Fixator (TIFI) and Spinopelvic Fixation (SPF)

Purpose: Aim of this retrospective cohort study was the comparison of the transiliac fixator (TIFI) and spinopelvic fixation (SPF) for fixation of dorsal pelvic ring fractures in terms of clinical outcome, complications, and quality of life. Methods: Thirty-eight patients (23 men, 15 women; mean age 47 ± 19 years) with dorsal pelvic ring fractures (type-C-injuries after AO/OTA) that have been stabilized by either TIFI (group TIFI, n = 22) or SPF (group SPF, n = 16) between May 2015 and December 2018 were retrospectively reviewed. Outcome measurements included demographic data, perioperative parameters, and complications and were obtained from the medical information system. Quality of life was assessed using the German version of the short form 36 (SF-36) and short muskuloskeletal function assessment (SMFA-D). Clinical results were assessed using Merle d'Aubigné-Score, Iowa Pelvic Score, and Majeed Pelvic Score. Results: Both groups show relatively good post-operative results, which has previously been reported. Quality of life was comparable in both groups. Group TIFI was slightly superior regarding complication rates, cutting/suture time, and fluoroscopy time. Group SPF seemed to be superior regarding pain and pelvic scores. Conclusion: None of the methods could demonstrate significant superiority over the other. Management of pelvic injuries remains a highly individual challenge adapted to the individual patients' condition. Nevertheless, if fractures allow for stabilization with TIFI, the use of this method should be taken into consideration as a less invasive and more tissue-conserving approach.

Applicable safety analysis and biomechanical study of iliosacral triangular osteosynthesis

BACKGROUND

The aim of this study was to investigate the applicable safety and biomechanical stability of iliosacral triangular osteosynthesis (ITO) through 3D modeling and finite element (FE) analysis.

METHODS

Pelvic CT imaging data from 100 cases were imported into Mimics software for the construction of 3D pelvic models. The S2-alar-iliac (S2AI) screws and S2 sacroiliac screws were placed in the S2 segment with optimal distribution and their compatibility rate on the S2 safe channel was observed and analyzed. In the FE model, the posterior pelvic ring was fixed with two transsacral screws (TTS), triangular osteosynthesis (TO) and ITO, respectively. Four different loading methods were implemented in sequence to simulate the force in standing, flexion, right bending, and left twisting, respectively. The relative displacement and change in relative displacement of the three fixing methods were recorded and analyzed.

RESULTS

The theoretical compatibility rate of S2AI screw and S2 sacroiliac screw in S2 segment was 94%, of which 100% were in males and 88% in females. In the FE model, in terms of overall relative displacement, TTS group showed the smallest relative displacement, the ITO group showed the second smallest, and the TO group the largest relative displacement. The change in relative displacement of the TTS group displayed the smaller fluctuations in motion. The change in relative displacement of the TO group under right bending and left twisting displayed larger fluctuations, while the ITO group under flexion displayed larger fluctuations.

CONCLUSIONS

The simultaneous placement of S2AI screw and S2 sacroiliac screw in the S2 segment is theoretically safe. Although the biomechanical stability of ITO is slightly lower than TTS, it is better than TO, and can be used as a new method for the treatment of posterior pelvic ring injuries.

S2-alar-iliac screw and S1 pedicle screw fixation for the treatment of non-osteoporotic sacral fractures: a finite element study

Background

Five different sacral fracture fixation methods were compared using finite element (FE) analysis to study their biomechanical characteristics.

Methods

Denis type I sacral fractures were created by FE modeling. Five different fixation methods for the posterior pelvic ring were simulated: sacroiliac screw (SIS), lumbopelvic fixation (LPF), transiliac internal fixator (TIFI), S2-alar-iliac (S2AI) screw and S1 pedicle screw fixation (S2AI-S1) and S2AI screw and contralateral S1 pedicle screw fixation (S2AI-CS1). Four different loading methods were implemented in sequence to simulate the force in standing, flexion, right bending and left twisting, respectively. Vertical stiffness, relative displacement and change in relative displacement were recorded and analyzed.

Results

As predicted by the FE model, the vertical stiffness of the five groups in descending order was S2AI-S1, SIS, S2AI-CS1, LPF and TIFI. In terms of relative displacement, groups S2AI-S1 and S2AI-CS1 displayed a lower mean relative displacement, although group S2AI-CS1 exhibited greater displacement in the upper sacrum than group S2AI-S1. Group SIS displayed a moderate mean relative displacement, although the displacement of the upper sacrum was smaller than the corresponding displacement in group S2AI-CS1, while groups LPF and TIFI displayed larger mean relative displacements. Finally, in terms of change in relative displacement, groups TIFI and LPF displayed the greatest fluctuations in their motion, while groups SIS, S2AI-S1 and S2AI-CS1 displayed smaller fluctuations.

Conclusion

Compared with SIS, unilateral LPF and TIFI, group S2AI-S1 displayed the greatest biomechanical stability of the Denis type I sacral fracture FE models. When the S1 pedicle screw insertion point on the affected side is damaged, S2AI-CS1 can be used as an appropriate alternative to S2AI-S1.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02805-8.

Comparison of lumbopelvic fixation and iliosacral screw fixation for the treatment of bilateral sacral fractures

Background

Bilateral sacral fractures result in traumatic disruption of the posterior pelvic ring. Treatment for unstable posterior pelvic ring fractures should aim for fracture reduction and rigid fixation to facilitate early mobilization. Iliosacral screw fixation (ISF) and lumbopelvic fixation (LPF) were recommended for the treatment of these injuries. No algorithm or gold standard exists for surgery of these fractures.

Purpose

The purpose of this study was to evaluate the differences between ISF and LPF in bilateral sacral fractures regarding intraoperative procedures, complications and postoperative mobilization. The secondary aim was to determine whether demographics influence surgical treatment.

Methods

Over a 4-year period (2016–2019), 188 consecutive patients with pelvic ring injuries were treated at one academic level 1 trauma center and retrospectively identified. Fractures were classified according to the AO/OTA classification system. Seventy-seven patients were treated with LPF or ISF in combination with internal fixation of pubic rami fractures and could be included in this study. Comparisons were made between demographic and perioperative data. Infection, hematoma and hardware malpositioning were used as complication variables. Mobilization with unrestricted weight bearing was used as outcome variable. Follow-up was at least 6 months postoperatively.

Results

Operative stabilization of bilateral posterior pelvic ring injuries was performed in 77 patients. Therefore, 29 patients (females 59%) underwent LPF whereas 48 patients (females 83%) had bilateral ISF. The ISF group was older (76 yrs.) compared to the LPF group (62 yrs.) (p = 0.001), but no differences regarding BMI or comorbidities were detected. Time for surgery was reduced for patients who were treated with ISF compared to lumbopelvic fixation (73 min vs. 165 min; respectively, p < 0.001). But this did not result in reduced fluoroscopic time or radiation exposure. Overall complication rate was not different between the groups. Patients with LPF had a greater length of stay (p = 0.008) but were all weight bearing as tolerated when discharged (p < 0.001).

Conclusion

Bilateral posterior pelvic ring injuries of the sacrum can be sufficiently treated by LPF or ISF. LPF allows immediate weight bearing which may benefit younger patients and patients with an elevated risk for pneumonia or other pulmonary complications. Treatment with ISF reduces operative time, length of stay and postoperative wound infection. Elderly patients may be better suited for treatment with ISF if there is concern that the patient may not tolerate the increased operative time.

Unilateral lumbopelvic fixation for AO/OTA Type C1 and C2 pelvic fractures: Clinical efficacy and preliminary experiences in 23 patients

PURPOSE

To report the clinical outcomes and preliminary experiences of unilateral lumbopelvic fixation for patients with AO/OTA Type C1 and C2 pelvic fractures.

MATERIALS AND METHODS

Between May 2014 and Dec 2017, 23 consecutive patients with AO/OTA Type C1 and C2 pelvic factures were treated by unilateral lumbopelvic fixation. Estimated blood loss, operation duration, reduction quality, functional outcomes using Majeed scores and complications were evaluated. Subgroup analysis was used to assess the influence of unilateral lumbopelvic fixation on different type of pelvic fractures.

RESULTS

Fifteen patients with Type C1 pelvic fractures and eight patients with Type C2 fractures underwent unilateral lumbopelvic fixation respectively. The mean follow-up time till May 2019 was 34.3 ± 9.9 months (range 17-60 months). Mean estimated blood loss was 473 ml and mean operation duration was 156 min during unilateral lumbopelvic fixation. The mean vertical displacement of pelvis decreased from 10.1 ± 4.9 mm to 3.1 ± 1.9 mm after unilateral lumbopelvic fixation. Majeed score assessments were available for 22 patients. Of these, 13 patients were graded as excellent, 8 were good and one was fair. The results of subgroup analysis showed that there was no difference of estimated blood loss, operation duration, postoperative displacements of pelvis and Majeed scores between the patients with Type C1 and C2 fractures.

CONCLUSION

Unilateral lumbopelvic fixation could provide a well reduction quality and was an effective treatment for AO/OTA Type C1 and C2 pelvic fractures.

STUDY DESIGN

Retrospective evaluation of 23 consecutive patients with AO/OTA Type C1 and C2 pelvic fractures treated by unilateral lumbopelvic fixation.

An early experience of lumbopelvic fixation techniques at Alexandria University

Background

The aim of lumbopelvic fixation is to obtain a solid fusion across the lumbosacral junction. There are many indications for lumbopelvic fixation, namely, spinal deformity in cases requiring long segment fusion, pelvic obliquity, pseudarthrosis at the lumbosacral junction, infection or osteolytic tumors, and pathologic fractures. The classical iliac screws should be contained within the iliac bone but have some disadvantages: excessive soft tissue dissection needed for accurate insertion, screw prominence with patient discomfort, and usually, a side connector is needed to connect the iliac screws to the rest of the construct. Lumbopelvic fixation by insertion of S2 alar-iliac (S2AI) screws was recently described to overcome these disadvantages. In this study, the authors present the initial results for the evaluation of lumbopelvic fixation through the insertion of S2AI screws in 19 consecutive patients operated in the neurosurgery department at Alexandria University.

Objective

The aim of the study was to evaluate the efficacy and complications of lumbopelvic fixation through the use of S2 alar-iliac screws.

Methods

The authors conducted a retrospective cohort study of data collected from the database of patients who underwent lumbopelvic fixation through the insertion of S2AI screws from 2016 to 2019 at a single institution.

Results

There were 19 patients indicated for lumbopelvic fixation, operated by modern instrumentation systems using lumbar pedicle screws and S2 alar-iliac screws. There were 14 females and 5 males. The mean age at the time of the operation was 38.6 ± 19.4 years with a range from 11 to 65 years. There was a total of 37 S2AI screws, screw diameter was 7mm in all cases regardless of age, and the length of the screws ranged from 50 mm in a young female patient (11 years) to 90 mm in an old male patient (60 years). Two screws were inserted per patient except in one case with congenital scoliosis due to the bad bone quality and the multiple iatrogenic wrong paths. Postoperative VAS score for back pain was greatly improved in all patients after the first 6 months of follow-up from 8 ± 1.5 to 3.5 ± 1.2 (paired t-test = 11.182, P<0.001). All patients had a good spinal range of motion to maintain normal daily activities without any significant restrictions after the first 3 months of follow-up. Immediate postoperative radiological follow-up had revealed 2 cases of posterior pelvic breaches and one case with anterior pelvic breach but without clinical manifestations with no need for revision. Two cases of unilateral screw breakout were observed after the first 6 months of follow-up. Removal of screws after the first 6 months was done in one patient with spondylodiscitis due to the unresolved infection and screw pullout.

Conclusion

The insertion of S2AI screws is an effective technique for lumbopelvic fixation with a relatively low rate of complications. Pelvic breaches are the commonest complications encountered during the insertion of S2AI screws, although no significant clinical morbidities were reported.

Role of triangular osteosynthesis in vertically unstable transforaminal sacrum fractures: clinical and radiological outcomes

PURPOSE

We aim to report clinical and radiological results of triangular osteosynthesis for a homogenous group of vertically unstable transforaminal sacral fractures.

METHODS

Between 2013 and 2018, 22 consecutive patients with unstable sacral fractures were treated with triangular osteosynthesis consisting of iliosacral screw augmented by spinopelvic fixation. Patients were followed up prospectively as a single cohort. Bone union, complications, clinical and radiological outcomes were investigated.

RESULTS

Mean follow-up was 3.1 years (12-76 months). There was one bilateral fracture. Two patients underwent anterior plating for pubic symphyseal disruption. Based on Majeed and Iowa pelvic scores, 13 patients had excellent, seven had good and two had fair clinical outcome. All the patients could perform squatting, sitting cross-legged and kneeling without any restrictions. There were no additional neurological injuries. One patient had non-union of sacral fracture, one patient had deep infection, one patient had marginal wound necrosis and two patients complained of pain related to implant prominence. Two patients had connecting rod backout. All but one patient attained pre-operative work status.

CONCLUSION

Triangular osteosynthesis is a reliable procedure in treating unstable transforaminal sacral fractures. It permits early weight-bearing and facilitates faster functional recovery. Careful attention to details such as sacral dysmorphism, soft tissue injury, implant placement and anterior pelvic injury helps in keeping complications to an acceptable rate.

A Modified Triangular Osteosynthesis Protocol for the Rod and Pedicle Screw Fixation of Vertical Unstable Sacral Fractures

BACKGROUND

The stabilization of vertical unstable sacral fractures has been a complex problem that is a challenge to current standard approaches. Here, we attempted to evaluate a modified technique for sacral fractures.

METHODS

In the modified triangular osteosynthesis technique, we adopted a vertical and transverse fixation with a rod and pedicle screw system to reduce and fix sacral fractures in 28 subjects. The postsurgery effect of this technique was evaluated by physical examination and radiography.

RESULTS

In the postoperative day 1, the patients were able to move body position passively from the lateral side to supine and exercise their legs by themselves. After a follow up of 20 months, radiological evaluation showed that fracture fragment reduction was excellent in 18 (64%), good (displacement 5-10 mm) in 8 (29%), and fair (displacement 10-15 mm) in 2 (7%) patients. Three patients with a preoperative perineal neurological impairment had a complete recovery after surgical decompression. All patients had achieved bone union of fractures, and no loss of fracture reduction was detected.

CONCLUSIONS

The modified procedures offered an easier approach to fix vertical unstable sacral fractures, thereby achieving quicker and stable functionality. This suggests an alternative approach to manage unstable sacral fractures.

LEVEL OF EVIDENCE

4.

CLINICAL RELEVANCE

The stabilization of vertical unstable sacral fractures has been a complex problem that is a challenge to current standard approaches. We attempted to introduce a modified technique for sacral fractures.

Navigated iliac screw placement may reduce radiation and OR time in lumbopelvic fixation of unstable complex sacral fractures

Purpose

Instability of the posterior pelvic ring may be stabilized by lumbopelvic fixation. The optimal osseous corridor for iliac screw placement from the posterior superior iliac spine to the anterior inferior iliac spine requires multiple ap- and lateral-views with additional obturator-outlet and -inlet views.

The purpose of this study was to determine if navigated iliac screw placement for lumbopelvic fixation influences surgical time, fluoroscopy time, radiation exposure, and complication rates.

Methods

Bilateral lumbopelvic fixation was performed in 63 patients. Implants were inserted as previously described by Schildhauer. A passive optoelectronic navigation system with surface matching on L4 was utilized for navigated iliac screw placement. To compare groups, demographics were assessed. Operative time, fluoroscopic time, and radiation were delineated.

Results

Conventional fluoroscopic imaging for lumbopelvic fixation was performed in 32 patients and 31 patients underwent the procedure with navigated iliac screw placement. No differences were found between the groups regarding demographics, comorbidities, or additional surgical procedures.

Utilization of navigation led to fluoroscopy time reduction of more than 50% (3.2 vs. 8.6 min.; p < 0.001) resulting in reduced radiation (2004.5 vs. 5130.8 Gy*cm²; p < 0.001). Operative time was reduced in the navigation group (176.7 vs. 227.4 min; p = 0.002) despite the necessity of additional surface referencing.

Conclusion

For iliac screws, identifying the correct entry point and angle of implantation requires detailed anatomic knowledge and multiple radiographic views. In our study, additional navigation reduced operative time and fluoroscopy time resulting in a significant reduction of radiation exposure for patients and OR personnel.

Functional outcome of traumatic spinopelvic instabilities treated with lumbopelvic fixation

The aim of this study was to assess the functional outcome after lumbopelvic fixation (LPF) using the SMFA (short musculoskeletal functional assessment) score and discuss the results in the context of the existing literature. The last consecutive 50 patients who underwent a LPF from January 1st 2011 to December 31st 2014 were identified and administered the SMFA-questionnaire. Inclusion criteria were: (1) patient underwent LPF at our institution, (2) complete medical records, (3) minimum follow-up of 12 months. Out of the 50 recipients, 22 questionnaires were returned. Five questionnaires were incomplete and therefore seventeen were included for analysis. The mean age was 60.3 years (32–86 years; 9m/8f) and the follow-up averaged 26.9 months (14–48 months). Six patients (35.3%) suffered from a low-energy trauma and 11 patients (64.7%) suffered a high-energy trauma. Patients in the low-energy group were significantly older compared to patients in the high-energy group (72.2 vs. 53.8 years; p = 0.030). Five patients (29.4%) suffered from multiple injuries. Compared to patients with low-energy trauma, patients suffering from high-energy trauma showed significantly lower scores in “daily activities” (89.6 vs. 57.1; p = 0.031), “mobility” (84.7 vs. 45.5; p = 0.015) and “function” (74.9 vs. 43.4; p = 0.020). Our results suggest that patients with older age and those with concomitant injuries show a greater impairment according to the SMFA score. Even though mostly favorable functional outcomes were reported throughout the literature, patients still show some level of impairment and do not reach normative data at final follow-up.

Bone Mineral Density Mapping of Iliosacral Region: The Use of Hounsfield Units to Optimize Transsacral Screw Trajectory

Introduction

Trauma, degenerative, pediatric, and neuromuscular deformities often require placement of implants into sacrum for construct stability. In these scenarios, fixation to the ilium is often added. To date, multiple studies have validated the correlation between Hounsfield units (HU) as measured on computed tomography and bone mineral density (BMD) on dual-energy X-ray absorptiometry to assess bone quality and fracture risk. We sought to map the BMD of the iliosacral region at the S1 and S2 levels using HU.

Materials and Methods

Pelvic CT scans of 100 patients were evaluated. HU measurements were taken from the anterior and posterior ilium, sacral ala, and sacral body using a best-fit circle encompassing a maximal amount of cancellous bone. Following the collection of all data points, an analysis of variance model was created to test the means and standard deviations of each anatomic region.

Results

The highest mean BMD was found in the following locations (in descending order): S1 sacral body (279.72 HU, 95% confidence interval [CI], 261.75–297.69), S1 anterior ilium (254.45 HU, 95% CI, 236.64–272.27), S2 anterior ilium (229.88 HU, 95% CI, 211.39–248.36), and the S2 sacral body (191.58 HU, 95% CI, 173.31–209.85). Comparing the anterior ilium to the sacral ala, there was a higher BMD measurement at both the S1 level by 151.7 HU (p &lt; 0.001) and the S2 level by 170.3 HU (p &lt; 0.001). The anterior ilium also showed a significantly higher BMD when compared to measurements taken at the posterior ilium at the same level: at the S1 level by 100.5 HU (p &lt; 0.001) and at the S2 level by 52.2 HU (p = 0.0006). The vertebral body had significantly higher mean BMD measurements when compared to the sacral ala at the S1 level by 176.9 HU (p &lt; 0.001) and at the S2 level by 131.95 HU (p &lt; 0.001).

Conclusions

The findings indicate that there is significantly higher BMD density of the anterior ilium and sacral body when compared to the sacral ala at both the S1 and S2 levels. In addition, the anterior ilium appears to provide more dense bone than the posterior ilium, as measured by mean HU.

Direct anterior decompression of L4 and L5 nerve root in sacral fractures using the pararectus approach: a technical note

PURPOSE

To describe a new surgical technique for neurolysis and decompression of L4 and L5 nerve root entrapment after vertical sacral fractures via the pararectus approach for acetabular fractures, and to present four case examples.

PATIENTS AND METHODS

We retrospectively evaluated four patients suffering radiculopathy from entrapment of the L4 or L5 nerve root in vertical sacral fractures between January and December 2016. The mean follow-up period after surgery was 18 (range 7-27) months. All patients underwent direct decompression and neurolysis of the L4 and L5 nerve roots via the single-incision, intrapelvic, extraperitoneal pararectus approach.

RESULTS

In all patients, the L4 and L5 nerve root was successfully visualized and decompressed, proving feasibility of the pararectus approach for this indication. No patient presented with a neural tear. Complete neurologic recovery was present in one patient at last follow-up; two patients had incomplete recovery of their radiculopathy; and one patient had no improvement after nerve root decompression.

CONCLUSIONS

The pararectus approach allows for sufficient visualisation and direct decompression and neurolysis of the L4 and L5 nerve root entrapped in vertical sacral fractures. Although neurologic recovery was not achieved in all patients in this small case series, the approach may be a suitable alternative to posterior approaches and other anterior approaches such as the lateral window of the ilioinguinal approach.

WITHDRAWN: Vertical shear pelvic ring injuries: Management algorithm

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Neurological Outcome After Traumatic Transverse Sacral Fractures: A Systematic Review of 521 Patients Reported in the Literature

BACKGROUND

The purpose of this study was to determine the neurological outcome after transverse sacral fractures in patients with neurological impairment.

METHODS

A systematic review of the English, French, German, and Dutch literature was conducted. All study designs, including retrospective cohort studies and case reports, describing transverse sacral fractures were included. Two authors independently extracted the predefined data and scored the neurological impairment according to the Gibbons classification after the trauma and at the time of follow-up. The neurological outcomes were pooled according to the Gibbons classification.

RESULTS

No randomized controlled trials or prospective case series were found. A total of 139 articles were included, consisting of 81 case reports and 58 retrospective case series involving 521 patients. Regardless of the type of management, neurological recovery of at least 1 Gibbons category was reported in 62% of these patients. A comparison of the neurological outcome of nonoperatively treated patients and surgically treated patients showed similar neurological recovery rates. For the surgically treated patients, fixation of the fracture resulted in a better neurological improvement compared with an isolated decompression.

CONCLUSIONS

This review could not provide evidence of improved neurological recovery after surgical treatment compared with nonoperative treatment. When surgical treatment was considered, there was a low level of evidence that fixation of the fracture results in better neurological improvement compared with isolated decompression.

LEVEL OF EVIDENCE

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

Spinopelvic Fixation Supplemented With Gullwing Plate for Multiplanar Sacral Fracture With Spinopelvic Dissociation: A Case Series With Short Term Follow Up

We describe a series of three patients who sustained multiplanar sacral fracture with spinopelvic dissociation treated with bilateral triangle osteosynthesis supplemented with a gullwing plate. Multiplanar sacral fracture causes the sacrum to divide into two parts which in severe cases, fracture displacement results in neurological injury. Spinopelvic fixation supplemented with a gullwing plate surgical treatment is still a viable option with an acceptable outcome. The average waiting time prior to surgery is 3 weeks.

Sacropelvic Fixation: A Comprehensive Review

Sacropelvic fixation is indicated in various clinical settings, most notably long spinal arthrodesis, reduction of high-grade spondylolisthesis, and complex sacral fractures. The sacropelvis is characterized by complex regional anatomy and poor bone quality. These factors make achieving solid fusion across the lumbosacral junction challenging. However, a better understanding of spinal biomechanics at that level has led to much higher fusion rates than those of the past. The newer fixation techniques are biomechanically superior to previous methods mainly because they achieve bony purchase anterior to the pivot point-first described by McCord et al. in 1994. Today, the two most widely used fixation techniques are iliac screws and S2-alar-iliac screws. Although these techniques are associated with very high rates of fusion, instrumentation-related pain and reoperation remain problematic. This review provides an overview of the regional anatomy and biomechanics at the lumbosacral junction, as well as a summary of fixation techniques with an emphasis on the most widely used techniques today. LEVEL OF EVIDENCE: IV.

Minimally invasive triangular osteosynthesis for highly unstable sacral fractures: Technical notes and preliminary clinical outcomes

Triangular osteosynthesis involves unilateral L5 iliac posterior instrumentation combined with an iliosacral screw fixation. The aim of this study was to describe this procedure and report the preliminary clinical results in patients with unstable sacral fractures treated with minimally invasive triangular osteosynthesis (MITO). Between 2012 and 2017, 10 patients (6 men and 3 women, mean age, 50 ± 23 years) with sacral fractures were treated with MITO and were followed up for a mean of 15.0 ± 8.5 months in our institution. Classification of sacral fracture, operative time, intraoperative bleeding, timing of full weight bearing, bone union, complications, and clinical outcomes were investigated. Two cases were classified as Denis zone 1, 2 cases as zone 2, and 6 as zone 3. Four patients had Roy-Camille type 1 fracture and 2 patients had type 2. All patients underwent MITO, which involved bilateral lumbopelvic fixation and a uni/bilateral iliosacral screw with stab incisions for percutaneous fixation or central longitudinal incision. The operative time was a mean of 182 ± 64 minutes, and the amount of intraoperative bleeding was a mean of 63 ± 74 g. Full-weight bearing was initiated at a mean of 8.2 ± 2.4 weeks. Eight fractures healed; 1 patient had pulmonary embolism and 1 had implant loosening. Based on Majeed score, 8 patients had "excellent" clinical outcomes, 1 patient had a "good" clinical outcome, and the other had a "fair" clinical outcome. MITO could be less invasive on the soft tissues and be a reliable procedure for bony union. It might provide sufficient stability to accelerate the commencement of post-operative rehabilitation, even in patients with highly unstable sacral fractures.

Sacroiliac screw versus a minimally invasive adjustable plate for Zone II sacral fractures: a retrospective study

OBJECTIVE

Fracture line of the sacrum always involves the Zone II region because sacral foramina are anatomically and physiologically weak regions of the sacrum. The purpose of this study is to compare the therapeutic effects of a sacroiliac screw and a minimally invasive adjustable plate (MIAP) for Zone II sacral fractures.

METHODS

Patients with unilateral Zone II sacral fractures fixed with a unilateral sacroiliac screw or MIAP from August 2009 to January 2016 were recruited into this study and were divided into two groups: group A (sacroiliac screw) and group B (MIAP). Surgical time, blood loss, frequency of intraoperative fluoroscopy, and relative complications were reviewed. Radiographs and CT scans were routinely acquired to evaluate the fracture displacement and reduction quality. Fracture healing was evaluated in the radiographs at each follow-up. Functional outcome was assessed based upon the Majeed scoring system at the final follow-up.

RESULTS

Thirty-one patients in group A and thirty-nine patients in group B were included in this study. No significant differences in average surgical time (P = 0.221) or blood loss (P = 0.234) were noted between group A and group B. The mean frequency of intraoperative fluoroscopy was 15.74±2.98 in group A and 6.08±1.94 in group B (P = 0.000). All fractures healed well within four months in all patients, and the healing time exhibited no significant difference between the two groups (P = 0.579). Satisfactory rates of reduction quality and functional outcome were not statistically different between the two groups (P > 0.05). The complication rate was 16.13% (5/31) in group A and 5.13% (2/39) in group B (P = 0.222).

CONCLUSION

MIAP has a fixation effect and exhibits reduction potential for Zone II sacral fractures. Favourable radiographic and functional results could be obtained through the MIAP technique, which is easy to conduct without pre-contouring. Compared with the unilateral S1 sacroiliac screw technique, repeated projections and iatrogenic sacral injury can be avoided.

Patient Weight-bearing after Pelvic Fracture Surgery-A Systematic Review of the Literature: What is the Modern Evidence Base?

Background

Little attention in the literature appears to have been paid to the issue of postoperative weight-bearing protocols for different injury patterns after pelvic fracture surgery. The primary aim of this study is to review the currently available literature to define the level of available evidence used to inform surgical decisions on weight-bearing after pelvic fracture surgery. Secondary aims are to assess the published methods of fracture classification, surgical management, and assessment or reporting of patient outcomes.

Methods

A systematic review of the English language literature from 1990 to 2016 was undertaken. Eligible papers were all papers reporting minimum 6-month outcomes following surgery for pelvic fractures in adults. Exclusion criteria included pathological fractures or those resulting from penetrating injury, solely osteoporotic fractures, or series with less than 6 months of follow-up data.

Results

There is very little published scientific data to inform the treating surgeon on postoperative weight-bearing protocols after pelvic fracture surgery, with no randomized trials and only 1 paper out of 122 stating this as a primary aim. More than half of the papers published did not state what postoperative protocol was employed. There is no standardization of outcome measures, with less than 20% of papers using the most common validated outcome scoring system; in contrast, there is good agreement on the use of either the Tile (75%) or Burgess and Young (20%) classification.

Limitations

Due to the lack of published studies looking at the topic of postoperative weight-bearing after pelvic fractures, no specific recommendations are possible. As large numbers of papers were included, they were not individually assessed for bias.

Conclusion

A review of postoperative weight-bearing regimes reveals a nonexistent scientific evidence base from which to make recommendations, although a consensus strategy has been identified. Future research needs to be directed at this topic, as has already been the case in numerous other fracture areas, since the advantages of early mobility are potentially significant. The reported methodology for assessing and reporting patient outcomes after pelvic fracture surgery reveals no consistent standards, and the majority of papers use no specific outcome scoring system.

How to cite this article

Rickman M, Link B-C, Solomon LB. Patient Weight-bearing after Pelvic Fracture Surgery-A Systematic Review of the Literature: What is the Modern Evidence Base? Strategies Trauma Limb Reconstr 2019;14(1):45-52.

Functional outcomes in pelvic fractures and the factors affecting them- A short term, prospective observational study at a tertiary care hospital

BACKGROUND

Pelvic fractures are markers of high energy trauma and are associated with significant morbidity and mortality. With evolution of modern diagnostic tools and intervention their management has come a long way.

RESEARCH QUESTION

Whether or not modern healthcare could provide the victims of such high energy trauma with a good functional outcome and optimal quality of life, such that they are able to perform their activities of daily living independently?

OBJECTIVES

To evaluate the functional outcomes in pelvic fractures and to find out factors that could indicate the prognosis.

METHODOLOGY

Ours is a prospective observational study with 75 patients at a tertiary care hospital between September 2015 to December 2016. The minimum duration of follow up was six months. Patients' demographic profile, mode and pattern of injury, associated injuries, management and subsequent complications, if any were recorded prospectively. Functional outcomes were assessed using the Majeed score. All preoperative parameters were correlated statistically with the Majeed score to find out their association.

RESULTS

Majeed scores were excellent in 27 patients, good in 29 patients, fair in 12 patients and poor in 7 patients. Overall functional outcome were good due to availability of sophisticated diagnostic tools, dedicated trauma management team and experienced pelvi-acetabular surgeon. Poorer outcomes were seen in male gender, associated urogenital injuries, associated acetabulum and sacrum fractures, associated nerve injuries and bedsore. No association were seen with age, fracture pattern, treatment modality and timing of surgery.

CONCLUSION

With modern day diagnostic and therapeutic modalities the functional outcome a patient could achieve is promising. With associated risk factors guiding the outcome, the health care provider can individualise the management and decrease the overall morbidity and mortality of such high energy injuries.

Reduction and temporary stabilization of Tile C pelvic ring injuries using a posteriorly based external fixation system

Tile C pelvic ring injuries are challenging to manage even in the most experienced hands. The majority of such injuries can be managed using percutaneous reduction techniques, and the posterior ring can be stabilized using percutaneous transiliac-transsacral screw fixation. However, a subgroup of patients present with inadequate bony corridors, significant sacral zone 2 comminution or significant lateral/vertical displacement of the hemipelvis through a complete sacral fracture. Percutaneous strategies in such circumstances can be dangerous. Those patients may benefit from prone positioning and open reduction of the sacral fracture with fixation through tension band plating or lumbo-pelvic fixation. Soft tissue handling is critical, and direct reduction techniques around the sacrum can be difficult due to the complex anatomy and the fragile nature of the sacrum making clamp placement and tightening a challenge. In this paper, we propose a mini-invasive technique of indirect reduction and temporary stabilization, which is soft tissue friendly and permits maintenance of reduction during definitive fixation surgical.

Current concepts in spondylopelvic dissociation

INTRODUCTION

Spondylopelvic dissociation is an uncommon and complex injury that results from high-energy trauma with axial overloading through the sacrum. Due to the life-threatening nature of these injuries, standard Advanced Trauma Life Support^® (ATLS) protocol must be used in the trauma setting as part of the initial management of these patients. The key to diagnosis is a good physical exam coupled with high level of suspicion. Radicular neurological deficits commonly are present in spondylopelvic dissociation (L5's roots) and should be documented for future evaluations. Radiographic views and CT-scan is preferred for the diagnosis.

BIOMECHANICS AND CLASSIFICATION

The authors briefly describe the anatomy and biomechanics of the pelvis, and present the main classifications used to define this rare lesion.

TREATMENT

Discussion about setting the boundaries of surgical stabilization, if there is still a role for conservative treatment, the importance of the initial treatment and the timing of intervention. Decompression is mandatory in the presence of canal compromise and progressive neurological deficit, regardless of biomechanical criteria for surgery. Kyphotic deformity occurs at the site of sacral transverse fracture and also reduces anteroposterior pelvis diameter. The technique of reduction and posterior surgical stabilization is emphasized. If residual kyphosis remains after bilateral lumbopelvic fixation by shifting of the lower sacral segment, we use S2 and/or S3 screws connected to transitional rods to additional reduction. An illustrated case is shown.

COMPLICATIONS

The infection of the wound and the failure of the implants are the most frequent complications of this surgical treatment.

CONCLUSION

Posterior stabilization is widely recognized as crucial in the treatment of pelvic disruptions. The concept of circumferential restoration of pelvic ring by bilateral lumbopelvic fixation and anterior fixation seems to be a nice option to increase stabilization and avoid bone misalignment.

Does Lumbopelvic Fixation Add Stability? A Cadaveric Biomechanical Analysis of an Unstable Pelvic Fracture Model

OBJECTIVE

We sought to determine the role of lumbopelvic fixation (LPF) in the treatment of zone II sacral fractures with varying levels of sacral comminution combined with anterior pelvic ring (PR) instability. We also sought to determine the proximal extent of LPF necessary for adequate stabilization and the role of LPF in complex sacral fractures when only 1 transiliac-transsacral (TI-TS) screw is feasible.

MATERIALS AND METHODS

Fifteen L4 to pelvis fresh-frozen cadaveric specimens were tested intact in flexion-extension (FE) and axial rotation (AR) in a bilateral stance gliding hip model. Two comminution severities were simulated through the sacral foramen using an oscillating saw, with either a single vertical fracture (small gap, 1 mm) or 2 vertical fractures 10 mm apart with the intermediary bone removed (large gap). We assessed sacral fracture zone (SZ), PR, and total lumbopelvic (TL) stability during FE and AR. The following variables were tested: (1) presence of transverse cross-connector, (2) presence of anterior plate, (3) extent of LPF (L4 vs. L5), (4) fracture gap size (small vs. large), (5) number of TI-TS screws (1 vs. 2).

RESULTS

The transverse cross-connector and anterior plate significantly increased PR stability during AR (P = 0.02 and P = 0.01, respectively). Increased sacral comminution significantly affected SZ stability during FE (P = 0.01). Two versus 1 TI-TS screw in a large-gap model significantly affected TL stability (P = 0.04) and trended toward increased SZ stabilization during FE (P = 0.08). Addition of LPF (L4 and L5) significantly improved SZ and TL stability during AR and FE (P < 0.05). LPF in combination with TI-TS screws resulted in the least amount of motion across all 3 zones (SZ, PR, and TL) compared with all other constructs in both small-gap and large-gap models.

CONCLUSIONS

The role of LPF in the treatment of complex sacral fractures is supported, especially in the setting of sacral comminution. LPF with proximal fixation at L4 in a hybrid approach might be needed in highly comminuted cases and when only 1 TI-TS screw is feasible to obtain maximum biomechanical support across the fracture zone.

Less invasive lumbopelvic fixation technique using a percutaneous pedicle screw system for unstable pelvic ring fracture in a patient with severe multiple traumas

Pelvic ring fractures are defined as life-threatening injuries that can be treated surgically with external or internal fixation. The authors report on an 81-year-old woman with an unstable pelvic fracture accompanying multiple traumas that was successfully treated with a less invasive procedure. The patient was injured in a traffic accident and sustained a total of 20 fractures, including pelvic ring, bilateral rib, and lumbar transverse processes fractures, and multiple fractures of both upper and lower extremities. The pelvic ring fracture was unstable with fractures of the bilateral sacrum with right sacroiliac disruption, right superior and inferior pubic rami, left superior pubic ramus, and ischium. During emergency surgery, bilateral external fixation was applied to the iliac crest to stabilize the pelvic ring. Second and third surgeries were performed 11 and 18 days after the first emergency surgery, respectively, to treat the multiple fractures. At the third surgery, the pelvic ring fracture was stabilized surgically using a less invasive posterior fixation technique. In this technique, 2 iliac screws were inserted on each side following an 8-cm midline posterior incision from the S-1 to S-3 spinous process, with the subcutaneous tissue detached from the fascia of the paraspinal muscles. The S-2 spinous process was removed and 2 rods were connected to bilateral iliac screws to stabilize the bilateral ilium in a switchback fashion. A crosslink device was applied to connect the 2 rods at the base of the S-2 spinous process. Following pelvic fixation, percutaneous pedicle screws were inserted into L-4 and L-5 vertebral bodies on both sides, and connected to the cranial rod connecting the bilateral iliac screws, thus completing the lumbopelvic fixation. The postoperative course was favorable with no postoperative complications. At the 10-month follow-up, bone union had been achieved at the superior ramus of the pubis, the patient did not complain of pain, and her activities of daily life returned to preinjury status. Unstable pelvic ring fractures need to be sufficiently stabilized for good surgical outcome. However, to avoid postoperative complications, a less invasive treatment is preferred, particularly in cases with poor general condition. This procedure is less invasive and provides sufficient stabilization to the unstable pelvic ring fracture, and thus is the ideal surgical procedure for such cases.

The biomechanical advantages of bilateral lumbo-iliac fixation in unilateral comminuted sacral fractures without sacroiliac screw safe channel: A finite element analysis

BACKGROUND

The aim of this study was to compare the biomechanical characteristics between bilateral and unilateral lumbo-iliac fixation in unilateral comminuted sacral fractures (USF) by finite element analysis.

METHODS

A 3-dimensional finite element model of unilateral sacral fractures was simulated. Three kinds of implants were instrumented into the model, including the unilateral lumbopelvic fixation (ULF), bilateral lumbopelvic fixation (BLF), and unilateral iliac fixation with bilateral lumbar pedicle screws (UBF). Loads of compression and rotation were distributed to the superior endplate of L3. To evaluate the biomechanical properties, the construct stiffness, the micromotion of the fractures, the stress distribution of implants, and the balance of hemilumbar vertebra are recorded and analyzed.

RESULTS

The highest construct stiffness was provided by BLF. In BLF model, the displacement between iliums was only 0.009 mm (compressional) and 0.001 mm (rotational), which was less than that under normal condition (0.02 mm). The maximum von Misses stress of implants appeared on the UBF. By using unilateral fixation, the L4 endured obvious imbalance on bilateral hemivertebra. A marked difference was exposed in BLF and UBF models, and the equilibrium of stress and activity was shown.

CONCLUSION

From the finite element view, the stability of ULF is insufficient to reconstruct the posterior pelvic ring. Furthermore, the unilateral fixation may lead to imbalance of lumbar vertebra and pelvis. On the contrary, the BLF can provide satisfied stability and lumbar balance.

Spinopelvic Fixation of Sacroiliac Joint Fractures and Fracture-Dislocations: A Clinical 8 Years Follow-Up Study

BACKGROUND

Pelvic ring injuries and sacroiliac dislocations have significant impacts on patient's quality of life. Several techniques have been described for posterior pelvic fixation. The current study has been designed to evaluate the spinopelvic method of fixation for sacroiliac fractures and fracture-dislocations.

METHODS

Between January 2006 and December 2014, 14 patients with sacroiliac joint fractures, dislocation and fracture-dislocation were treated by Spinopelvic fixation at Shahid Sadoughi Training Hospital, Yazd, Iran. Patients were seen in follow up, on average, out to 32 months after surgery. Computed tomographic (CT) scans of patients with sacral fractures were reviewed to determine the presence of injuries. A functional assessment of the patients was performed using Majeed's score. Patient demographics, reduction quality, loss of fixation, outcomes and complications, return to activity, and screw hardware characteristics are described.

RESULTS

The injury was unilateral in 11 (78.5%) patients and bilateral in 3 (21.5%). Associated injuries were present in all patients, including fractures, dislocation and abdominal injuries. Lower limb length discrepancy was less than 10 mm in all patients except two. Displacement, as a measure of quality of reduction was less than 5 mm in 13 patients. The mean Majeed score was 78/100. Wound infection and hardware failure were observed in 3 (21.4%) and 1 (7.1%) cases, respectively. In this study most patients (85%) return to work postoperatively.

CONCLUSION

According to the findings, spinopelvic fixation is a safe and effective technique for treatment of sacroiliac injuries. This method can obtain early partial to full weight bearing and possibly reduce the complications.

Standalone percutaneous transiliac plating of vertically unstable sacral fractures: outcomes, complications, and recommendations

PURPOSE

The aim of this study is to evaluate results of a standalone percutaneous posterior plating of the vertically unstable sacral fractures, to analyze the influencing factors, to discuss encountered complications, and to express the related recommendations.

METHODS

Forty two cases were included; all of them had type C vertical sacral fractures; and 16 cases had associated nerve roots injury. Subcutaneous 3.5-mm reconstruction plate was used in all cases, through vertical incisions in 28 cases and transverse incisions in 14 cases. Hannover pelvic outcome scoring system was implemented for results evaluation.

RESULTS

The mean follow-up period was 22.1 ± 7.5 months; the mean operative time was 43.3 ± 7 min; the mean surgical incision length was 4.6 ± 1.1 cm. 14 cases had excellent scores, 16 cases had good scores, 6 cases had fair scores, and 6 cases had poor scores. Younger age groups had significantly better outcome (P = 0.015), whereas the comminuted sacrum had significantly worse score (P = 0.041). Final residual posterior displacements significantly improved (P = 0.001) in comparison to the initial displacement. The nerve roots injury had final significant recovery (P = 0.012). Transverse skin incisions had subjectively significant satisfaction (P = 0.017).

CONCLUSIONS

Percutaneous 3.5-mm reconstruction plate is a good alternative to percutaneous iliosacral screws in vertically unstable sacral fractures; especially in the presence of contraindication to the latter. It is simple procedure with minimal incisions; short operative time; less radiological exposure; good mechanical stability; and less iatrogenic injuries.

[Unilateral triangular lumbopelvic stabilization: indications and techniques]

Operative fixation has become treatment of choice for unstable sacral fractures. Osteosynthesis for these fractures results in loss of reduction in up to 15%. Vertical sacral fractures involving the S1 facet joint (Isler 2 and 3) may lead to multidirectional instability. Multidirectional instability of the posterior pelvic ring and lumbopelvic junction may be stabilized and forces balanced by a so-called lumbopelvic triangular fixation. Lumbopelvic triangular fixation combines vertical fixation between the lumbar vertebral pedicle and the ilium, with horizontal fixation, as an iliosacral screw or a transiliacal plate osteosynthesis. The iliac screw is directed from the posterior superior iliac spine (PSIS) to the anterior inferior iliac spine (AIIS). Thereby, lumbopelvic fixation decreases the load to the sacrum and SI joint and transfers axial loads from the lumbar spine directly onto the ilium. Triangular lumbopelvic fixation allows early full weight bearing and therefore reduces prolonged immobilization. The placement of iliac screws may be a complex surgical procedure. Thus, the technique requires thorough surgical preparation and operative logistics. Wound-related complications may occur. Preexisting Morell-Lavalée lesions increase the risk for infection. Prominent implants cause local irritation and pain. Hardware prominence and pain are markedly reduced with screw head recession into the PSIS.