High-Energy Pelvic Ring Disruptions with Complete Posterior Instability: Contemporary Reduction and Fixation Strategies

Fluoroscopic images of the sacroiliac joint alone are unable to identify simulated flexion or extension malreduction of the anterior pelvic ring in AO/OTA 61-B2.3 pelvic injuries

PURPOSE

Reduction of AO/OTA 61-B2.3 (APC2) pelvic fractures is challenging in the setting of anterior ring comminution. The anterior ring is visually much simpler to evaluate for flexion or extension hemipelvis deformity than the posterior ring, except in the setting of comminution, necessitating some other visual reference to judge hemipelvis reduction. We sought to test whether pelvic inlet and outlet fluoroscopy of the contours of the sacroiliac joint could be used in isolation to judge hemipelvis flexion or extension.

METHODS

Symphyseal and anterior SIJ ligaments were cut (6 cadaveric pelvis). The symphysis was held malreduced to produce one centimeter flexion and extension deformity: 1 cm was selected to mimic a maximum clinical scenario. The SIJ was assessed using inlet and outlet fluoroscopy. The scaled width of the SIJ was assessed at the joint apertures and midjoint on both inlet and outlet views. Joint widths in flexion and extension were compared against joint widths measured on the reduced SIJ using paired t-tests.

RESULTS

There was no statistical difference in the superior (p = 0.227, 0.675), middle (p = 0.203, 0.693), and inferior (p = 0.232, 0.961) SIJ widths between hemipelvis flexion or extension models against reduced SIJ on outlet views. There was no statistical difference in the anterior (p = 0.731, 0.662), middle (p = 0.257, 0.655), and posterior (p = 0.657, 0.363) SIJ widths between flexion or extension models against reduced SIJ on inlet views.

CONCLUSION

Inspection of SIJ width on inlet and outlet fluoroscopy cannot detect up to one centimeter of hemipelvis flexion or extension malreduction in the setting of AO/OTA 61-B2.3 (APC2) pelvic fractures with complex anterior injuries.

Identification of subtle residual sacroiliac joint flexion and extension malreductions in AO/OTA 61-C1.2 (APC3) pelvic injuries after provisional anterior ring reduction

PURPOSE

Hemipelvis reduction in the setting of AO/OTA 61-C1.2 (APC3) pelvic injuries can be challenging. A common strategy is to provisionally reduce or fix the anterior ring prior to definitive fixation of the posterior ring. In this scenario, it is difficult to assess whether residual sacroiliac joint (SIJ) widening is due to hemipelvis flexion/extension or lateral displacement. This simulation sought to identify a radiographic marker for posterior ilium flexion or extension malreduction in the setting of a reduced anterior ring.

METHODS

Symphyseal and both anterior and posterior SIJ ligaments were cut in 8 cadaveric pelvis. The symphysis was reduced and wired. One centimeter of posterior flexion or extension at the SIJ was created to mimic the clinical scenario of hemipelvis flexion or extension malreduction, and a lateral compressive force was applied. SIJ widening and the direction of anterior or posterior ileal displacement relative to the contralateral joint were assessed via inlet views. SIJ widening and the direction of cranial or caudal ileal displacement were assessed using outlet views. Comparisons between flexion and extension models used Fisher's exact test.

RESULTS

On outlet views, all flexed hemipelvis demonstrated caudal ileal translation at the superior SIJ, in contrast to all extended hemipelvis demonstrated cranial translation (p < 0.0005); the scenarios were easily distinguishable. Conversely, inlet imaging was unable to identify the direction of malreduction. Flexion/extension scenarios resulted in similar amounts of SIJ widening.

CONCLUSION

Residual flexion and extension hemipelvis malreductions in APC3 injuries after provisional anterior fixation can be differentiated by the direction of ileal displacement at the superior SIJ on the outlet view.

Upper sacral segment fixation with converging iliosacral screws: A technical trick for preoperative planning and case series

INTRODUCTION

There are some situations where pelvic surgeons may want to place iliosacral screws with differing trajectories (Sacroiliac and Sacral styles) but may not be able to because of overlapping trajectories.

HYPOTHESIS

Sacroiliac and Sacral style screws can be placed in S1 in select patients by using a preoperative planning technique off the 3D reconstructed surface rendered preoperative CT scan.

MATERIALS/METHODS

Retrospective review of all patients receiving iliosacral screws using the described technique.

RESULTS

Six patients received iliosacral screws using the described technique. When the preoperative planning technique demonstrated feasibility, all screws were able to be safely placed.

DISCUSSION

Placing Sacroiliac and Sacral style screws within S1 may be ideal in some injury patterns. The described technique allows pelvic surgeons facile in iliosacral screw techniques to preoperatively plan for this construct.

LEVEL OF EVIDENCE

VI; Retrospective case series.

Displaced posterior pelvic ring fractures treated with an unlocking closed reduction technique: Prognostic factors associated with closed reduction failure, reduction quality, and fixation failure

PURPOSES

This study aimed to evaluate the clinical effect of the unlocking closed reduction technique (UCRT) for the displaced posterior pelvic ring fractures and to analyze the factors associated with failure of closed reduction and fixation.

PATIENTS AND METHODS

Data from patients admitted with displaced posterior pelvic ring fractures initially treated with the URCT from July 2017 to January 2020 were extracted. Clinical and radiological factors including fracture classification, interval days from injury to surgery, number of screws, and type of fixation for the posterior pelvic ring were analyzed to evaluate their correlation with closed reduction failure, reduction quality, and fixation failure. Then a logistic regression model was used for statistical analysis to eliminate confusion factors.

RESULTS

Ninety-seven patients with displaced posterior pelvic ring fractures were followed for a mean of 1.7 years after surgery. Successful closed reduction and percutaneous fixation were achieved for 89 patients (91.8%), of which 82 patients (92.1%) achieved an excellent or good reduction. Closed reduction failure which converted to open reduction was recorded for eight patients (8.2%). AO/OTA type C3 fracture (p = 0.036) and osteoporosis (p = 0.012) were significant factors for closed reduction failure. Excellent was recorded for 76 patients (78.4%) and acute (1-21 days) interval days from injury to surgery was an associated factor for reduction quality. For AO/OTA type C1 fractures, no more than two short screws (unilateral iliosacral screws) or a single long screw (transiliac-transsacral screws) were independent prognostic factors of fixation failure (p = 0.026).

CONCLUSIONS

Displaced posterior pelvic ring fractures treated with the UCRT are associated with excellent/ good radiological results. However, in patients with AO/OTA type C3 pelvic fracture and osteoporosis, the backup plan of open reduction should be routinely prepared. The patient should be brought to the operating room within three weeks to get a good reduction result. Two long screws or one long screw combined with two short screws are required to create a strong construct for AO/OTA type C1 pelvic fractures.

Modified Lumbopelvic Technique Using S1 Pedicle Screws for Spinopelvic Dissociation U-Type and H-Type Sacral Fractures With Kyphotic Deformity

Spinopelvic dissociation injuries are complex injuries defined as discontinuity between the appendicular and axial skeleton. Fracture patterns are variable, but U-type and H-type fractures are common and often present with kyphotic deformity along with translational displacement and impaction. The ideal method of fixation has not been established for these injuries. The goals of treatment include restoration of alignment, stability, and neural decompression as needed. Traditional methods of lumbopelvic fixation have spanned the upper sacral fracture site. Our novel modified method of lumbopelvic fixation directly instruments the S1 body. This allows for direct manipulation of the fracture which we theorize improves reduction and increases stability across the fracture. This article characterizes the injury patterns, outlines the modified technique, and reports the clinical and radiographic outcomes of our modified lumbopelvic fixation technique and construct.

Minimally Invasive Percutaneous TightRope® System Fixation for an Unstable Posterior Pelvic Ring: Clinical Follow-up and Biomechanical Studies

Objective

To evaluate the mechanical stability and clinical efficacy of minimally invasive percutaneous TightRope® systems applied via gun‐shaped reduction forceps for unstable posterior pelvic ring fractures.

Materials and methods

This study consists of two parts: a clinical retrospective study and a randomized controlled biomechanical test. For the clinical study, a retrospective analysis of posterior pelvic ring fractures was performed between June 2015 and May 2020. Eighteen patients underwent surgery using two TightRope® systems to fix a broken posterior pelvic ring because of unstable AO type C1 and C2 pelvic ring fractures. The patients were followed up for at least 2 years, and all patients were evaluated using the Majeed scoring system and vertical displacement. In the biomechanical tests, six embalmed adult pelvic specimens were used. The fractures were subjected to TightRope®, IS screw, and TBP fixation in a randomized block design. The specimens were placed in a biomechanical testing machine in a standing neutral posture. A cyclic vertical load of up to 500 N was applied, and the displacement of the specimens was recorded by the testing machine. The ultimate load in each group of specimens was recorded. The displacement and ultimate load were compared and analyzed by statistical methods.

Results

At a mean follow‐up of 38.89 ± 8.72 months, the functional Majeed score was excellent in 14 patients and good in four patients. The final radiological examinations showed that the outcome was excellent in 14 patients and good in four patients. In these patients, no serious clinical complications were found. Weight‐bearing was delayed in four patients. In biomechanical tests, the displacement of the specimens fixed with TightRope® was significantly lower than that of the specimens fixed with TBP (P < 0.05) when the load ranged from 300 to 500 N. The displacement in the IS screw group was significantly lower than that in either the TBP or TightRope® group (P < 0.05) when the load ranged from 0 to 500 N. The ultimate load in the IS screw group (1798 ± 83.53 N) was significantly greater than that in the TBP group (1352 ± 74.41 N) (t = 9.78, P < 0.0001) and the TightRope® group (1347 ± 54.28 N) (t = 11.11, P < 0.0001). However, no significant difference was observed between the TightRope® and TBP groups (t = 0.13, P = 0.90).

Conclusion

Percutaneous posterior TightRope® system shows strong stability in mechanical experiments and shows good results in clinical follow‐up while this system has certain advantages in lower surgical requirements and lower risk of related nerve and vascular structural damage.

Three-year functional outcome after open pelvic fracture treatment: a retrospective case series from a level I trauma center

PURPOSE

Open pelvic fractures have high mortality rates, and survivors may have ongoing functional deficits from severe trauma and invasive life-saving procedures. However, there are limited reports regarding the functional status evaluation following open pelvic fractures. We aimed to report the treatment experiences and short-term functional outcomes of patients with open pelvic fractures.

METHODS

We retrospectively reviewed the data of 19 consecutive patients with pelvic fractures who underwent treatment at a single institute between January 2014 and June 2018. The resuscitation protocol, osteosynthesis strategy, reduction quality of the pelvic ring, and functional outcomes were analyzed.

RESULTS

The incidence and mortality rates in patients with open pelvic fractures were 4.9 and 21.6%, respectively. Ten, one, and seven of the open wounds related to the pelvic fractures were located in Faringer zones I, II, and III, respectively. Fractures of four patients were categorized as classes 1 and 2, and those of 11 patients as class 3, according to the Jones-Powell classification. Eleven of 19 (57.9%) and 9 of 19 (47.5%) revealed excellent reduction quality by Matta/Torenetta and Lefaivre criteria, respectively. The Merle d'Aubigné score improved at each evaluation but stagnated after 24 months. The Majeed hip score also improved at the 12-month evaluation but the improvement stopped thereafter. At a 3-year follow-up, the patients with excellent reduction of the pelvic ring showed the highest functional performances.

CONCLUSION

Improvements in functional status of patients with open pelvic fractures can be anticipated based on the reduction quality of the pelvis ring.

What's old is best again Is anterior plating best for fixation of type-C pelvic fractures? A systematic review and meta-analysis

BACKGROUND

Type-C pelvic fractures are a rare but potentially fatal injury that often leads to poor outcomes, despite surgical fixation. Many fixation methods are used but the optimal method remains contentious, with failure and complications common. This study compared outcomes for each fixation method.

METHODS

A systematic review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). A search of studies which reported on outcomes after surgically treated type-C pelvic fractures was undertaken. Data retrieved included fixation method, length of follow up, surgical revision, and complications rates (hardware breakage, post-operative outcomes, screw mal-positioning, screw loosening, loss of reduction and infection). Study quality was assessed using the Methodological Index for Non-Randomised Studies (MINORS). Pooled revision, outcome and complication rates were calculated using a quality-adjusted model in MetaXL 5.3.

RESULTS

Fifty-two studies met the inclusion criteria representing 1567 patients and 7 fixation methods. The meta-analyses demonstrated high rates of 'less-than-good' outcomes for most fixation methods, with a higher rate for bilateral injuries (overall 23%; unilateral 21% v bilateral 41%). The mean pooled rate for surgical revision rate was 4%, hardware breakage 3%, screw mal-positioning 2%, screw loosening 3%, loss of reduction 5% and infection 4%. Each fixation method had different performance profiles; however, anterior plating outperformed all other fixation methods for patient outcomes, with a 'less-than-good' rate of just 7% vs the pooled mean of 23% and demonstrated at or below pooled mean rates for all complications except revision which was 5%.

CONCLUSIONS

Post-operative outcomes for surgically treated type-C pelvic fractures revealed a 'less-than-good' pooled outcome rate of 23% and a revision rate of 4%. Anterior plates outperformed most other systems particularly for patient reported outcomes. Pooled revision, patient-reported outcome and complication rates for type-C pelvic fractures have not previously been reported and these data provide a benchmark for practice and future research.

Early weight bearing in acetabular and pelvic fractures

Background and aim of the work:

The incidence of pelvic and acetabular fractures is increasing during the years, counting 37 pelvic fractures per 100000 people annually. No weight bearing or toe touch weight bearing are usually chosen in the initial management to allow fracture and ligamentous healing and avoid fracture displacement and fixation failure. On the other hand, early weight bearing may stimulate fracture healing and allow prompt functional recovery, faster return to work and recreational activities and reduce complications linked to late rehabilitation. Aim of the study is to review the literature about weight bearing indications for pelvic and acetabular fractures to highlight clinical and biomechanical evidence supporting early weight bearing.

Methods:

Two independent reviewers independently extracted studies on early weight bearing of pelvic and acetabular fractures. All selected studies were screened independently based on title and abstract. Then the full text of any article that either judged potentially eligible was acquired and reviewed again. Any disagreement was resolved by discussing the full text manuscripts.

Results:

44 studies including reviews, meta-analysis, clinical and biomechanical studies were selected.

Conclusions:

Despite biomechanical data, few clinical evidences can be found to support early weight bearing in pelvic and especially acetabular fractures treatment. The promising results of some clinical experiences, however, should direct further studies to clearly define the indications and limits of early weight bearing in these injuries. Recognizing intrinsic lesion stability and bone and fixation technique quality, together with patient age and compliance, should be the mainstay for post-operative management choice. (www.actabiomedica.it)

Posterior Stabilization of Unstable Sacral Fractures: A Single-Center Experience of Percutaneous Sacroiliac Screw and Lumbopelvic Fixation in 67 Cases

Study Design

This is a retrospective study.

Purpose

Recent advances in intraoperative imaging and closed reduction techniques have led to a shifting trend toward surgical management in every unstable sacral fracture. This study aimed to evaluate the clinicoradiological outcome of the sacroiliac (SI) screw and lumbopelvic fixation (LPF) techniques and thereby delineate the indications for each.

Overview of Literature

Optimal management guidelines for unstable sacral fractures are still lacking probably due to the rarity of these injuries and varying fixation trends.

Methods

Out of the 67 patients, 40 and 27 were in the SI and LPF groups, respectively. The electronic medical record for each patient was reviewed, including patient demographic data, mode of trauma, coexisting injuries, neurological status (Gibbon's four-grade system), Injury Severity Score, time from admission to operative stabilization, type of surgical stabilization, complications, return to the operating room, and treatment outcome measures using Majeed's functional grading system and Matta's radiological criteria. The minimum follow-up period was 2 years.

Results

Noncomminuted longitudinal injuries with normal neurology and acceptable closed reduction have undergone SI screw fixation (n=40). Irreducible, comminuted, or high transverse fractures associated with dysmorphic anatomy or neurodeficit were managed by LPF (n=27). Excellent and good Majeed and Matta scores at 86.57% and 92.54% of the patients, respectively, were postoperatively achieved.

Conclusions

Unstable sacral fractures can be effectively managed with percutaneous SI screw including vertically unstable injuries by paying strict attention to preoperative patient selection whereas LPF can be reserved for comminuted fractures, unacceptable closed reduction, associated neurodeficit, lumbosacral dysmorphism, and high transverse fractures.

Triangular Osteosynthesis Using an S1 Pedicle Screw and S2 Alar Iliac Screw for a Unilateral Vertically Displaced Sacral Fracture

BACKGROUND

Managing unilateral vertically displaced sacral fractures remains a challenge. A triangular osteosynthesis (TOS), which involves fixing the fractured sacrum using unilateral spinopelvic fixation and a supplemental ilio-sacral screw, continues to gain popularity as it facilitates early mobilization and improves the long-term outcome. However, it has limitations, such as destruction of the L5-S1 joint, the need for additional removal surgery, and an increased risk of infection due to the large incision. An S1 pediculoiliac construct was proposed to overcome this limitations. Its use also has complications, however, including a painful hardware prominence due to the traditional iliac screw, excessive soft tissue retraction, and limited reduction capability.

CASE DESCRIPTION

A 20-year-old woman fell from a height of 6 meters and sustained a vertical shear type sacral fracture on the left side with substantial vertical displacement. We reduced and fixed the fracture using a TOS using an S1 pedicle screw and an S2 alar iliac screw (S2AIS). The patient was allowed immediate weight-bearing as tolerated. We achieved good reduction and union with a small vertical incision, without the destruction of L5-S1 joints, a symptomatic implant prominence, or wound complications.

CONCLUSIONS

For unilateral vertically unstable sacral fractures, TOS using S1 pedicle screws and S2AIS is safe and has the advantage such as maintaining mobility in the lumbar pelvic region, small size wounds, and reduced soft tissue damage, and it may have a potentially low infection rate. Further studies are needed to determine the specific indications and validate the effectiveness of this procedure.

The Anterior Subcutaneous Pelvic Ring Fixator: No Biomechanical Advantages Compared with External Fixation

BACKGROUND

Subcutaneous fixation of the anterior pelvic ring is an emerging surgical technique for trauma patients. The aim of this study was to biomechanically evaluate 2 internal fixation devices for stabilizing a disrupted pelvic ring and compare them with traditional external fixation.

METHODS

Thirty-six synthetic pelvises with a simulated unstable ring fracture (anteroposterior compression type III) were divided into 3 groups. Group A underwent fixation with a supra-acetabular external fixator; group B, with an internal fixator using the USS II polyaxial system; and group C, with an internal fixator using the Click'X polyaxial system. Biomechanical testing included measurement of peak-to-peak displacement at 300, 400, and 500 N; total displacement; plastic deformation; stiffness; and fracture-line displacement.

RESULTS

Statistical analysis of all measured parameters revealed no significant differences among the groups. However, vertical displacement of the preshaped connecting rod within the screw heads occurred as a result of inadequate stability of the internal fixation at the rod-screw interface.

CONCLUSIONS

Although internal fixator devices are placed close to the bone and should therefore maintain greater stiffness, our data did not support the hypothesis of superior stability. Special attention is required when using a curved connecting rod as the rod is easily displaced, placing relevant anatomical structures at risk. These devices require further refinement to avoid potential patient injury.