Treatment of unstable pelvic ring injuries with an internal anterior fixator and posterior fixation: initial clinical series

Modified pedicle screw-rod fixation versus open reduction plate fixation for the management of pubic symphysis diastasis: A retrospective study

Objective

Surgical intervention and fixation is the recognized measurement to treat pubic symphysis diastasis caused by high-energy trauma. The purpose of this retrospective study was to assess the clinical application of modified pedicle screw-rod fixation (modified PSRF) and open reduction plate fixation (ORPF) for treating pubic symphysis diastasis.

Methods

The data of this retrospective analysis were collected from 32 patients with pubic symphysis diastasis managed with modified PSRF or ORPF from January 2012 to December 2017, with or without posterior fixation. Indicators of clinical assessments including operating time, intraoperative blood loss, relevant surgical complications as well as follow-up were recorded. Majeed scores were performed for functional evaluation, as well as Matta criteria were applied to evaluate the quality of reduction.

Results

The average time from injury to operation was 2.9 days in modified PSRF group and 3.2 days in ORPF group. Significant differences regarding average operation time (41.8 min versus 64.3 min) and average intraoperative blood loss (46.6 ml versus 304.6 ml) were presented between modified PSRF groups and ORPF group. Neither Majeed scores nor Matta evaluation showed a significant difference between two groups. In ORPF group, the incision infection occurred in one patient and two patients developed loosening of screws. In modified PSRF group, loosening of screws was found in one patient during the operative procedure and one patient experienced femoral nerve palsy. Irritation to the lateral femoral cutaneous nerve (LFCN) was detected in two patients in modified PSRF group.

Conclusions

Satisfactory clinical outcomes were provided with applications of both fixation methods for treating pubic symphysis diastasis. Modified PSRF, as a minimal invasive technique, could serve as an effective and reasonable option for treating pubic symphysis diastasis.Level of evidence: III: retrospective cohort study.Trial registration: researchregistry3906.

Advancements in pelvic ring fracture surgery: Assessing INFIX screw placement accuracy with CT navigation

The management of unstable pelvic ring fractures, typically resulting from high-energy trauma, presents a significant clinical challenge due to the complexity of injuries. While effective in many cases, the traditional stabilization methods are fraught with various complications that can significantly impact patient recovery and quality of life (QOL). This study aims to evaluate the efficacy and precision of the anterior subcutaneous internal fixator (INFIX) technique when used with intraoperative computed tomography (CT) navigation, a novel approach intended to mitigate the limitations of conventional treatment modalities. Our retrospective case series encompasses 43 patients who sustained traumatic pelvic injuries and were subsequently treated with the INFIX technique from December 2020 to January 2024. The focus of this analysis was to assess the accuracy of INFIX screw placement facilitated by intraoperative CT navigation. A total of 81 INFIX screws were inserted, and our study findings reveal a high level of precision in screw placement, with only one screw deviating, resulting in an inaccuracy rate of merely 1.2 %. This highlights the significant advantage provided by intraoperative CT navigation. The high level of accuracy not only enhances the stability of the pelvic fixation but also substantially reduces the risk of complications commonly associated with screw misplacement, such as abdominal damage, vascular injury, and issues related to incorrect hardware positioning. In conclusion, the integration of the INFIX technique with intraoperative CT navigation in the treatment of unstable pelvic ring fractures represents a significant advancement in orthopedic trauma surgery. This study provides compelling evidence supporting the efficacy and precision of this approach, suggesting its potential as a superior alternative to traditional fixation methods. Further research, ideally through prospective studies involving larger patient cohorts, is needed to validate these findings and explore the long-term implications of this technique on patient recovery and QOL.

A Comparative Study of Functional Outcomes in Unstable Pelvic Ring Fractures Treated With Internal Fixator (INFIX) With and Without Sacroiliac Joint Screw Fixation

Introduction Despite constituting only 3-8% of orthopedic trauma cases, pelvic injuries are associated with high mortality rates, emphasizing the critical need for stable fixation rather than merely anatomical alignment. The use of an anterior, subcutaneous, internal pelvic fixator (INFIX), a novel technique, has shown promise in treating these injuries. Posterior pelvic ring injuries are challenging because they require a significant level of surgical training and technical expertise, and each treatment method has disadvantages. The aim of this study is to compare the clinical and biomechanical outcomes of INFIX with and without sacroiliac screw fixation for unstable pelvic fractures. Methods and methodology Retrospectively, we selected 20 patients with unstable pelvic ring injuries who had come to a high-volume tertiary care hospital and medical college in the state of Maharashtra, India. All the patients were operated on with INFIX; 10 with a sacroiliac joint screw and 10 without a sacroiliac joint screw. We followed up with the patients for six months and evaluated them according to the Majeed score. Results Functional outcomes differed little between INFIX patients operated on with and without a sacroiliac joint screw. However, morbidity, hospital stay, the need for ICU, radiation exposure, and technical ease of surgery were improved in INFIX patients without the sacroiliac screw procedure. We noted an average Majeed score of 78 in the INFIX-alone group and 77.2 in the group that received INFIX with a sacroiliac joint screw. Six months after the surgery, the patients showed signs of a stable bony union, had achieved a full range of motion, and reported no problems in their day-to-day work. Conclusion Although this was a short-term study, we conclude that INFIX without a sacroiliac joint screw showed a comparable functional outcome compared to INFIX with a sacroiliac joint screw. Patients with INFIX alone showed better results; they had reduced surgical time, reduced radiation exposure, and less evidence of neurological harm to the L5-S1 nerve root. The procedure was less complicated and easier for surgeons to learn. Its simplicity and speed were especially beneficial for obese patients.

Evaluating the stability of external fixators following pelvic injury: A systematic review of biomechanical testing methods

INTRODUCTION

This systematic review aims to identify previously used techniques in biomechanics to assess pelvic instability following pelvic injury, focusing on external fixation constructs.

METHODS

A systematic literature search was conducted to include biomechanical studies and to exclude clinical trials.

RESULTS

Of an initial 4666 studies found, 38 met the inclusion criteria. 84% of the included studies were retrieved from PubMed, Scopus, and Web of Science. The studies analysed 106 postmortem specimens, 154 synthetic bones, and 103 computational models. Most specimens were male (97% synthetic, 70% postmortem specimens). Both the type of injury and the classification system employed varied across studies. About 82% of the injuries assessed were of type C. Two different fixators were tested for FFPII and type A injury, five for type B injury, and fifteen for type C injury. Large variability was observed for external fixation constructs concerning device type and configuration, pin size, and geometry. Biomechanical studies deployed various methods to assess injury displacement, deformation, stiffness, and motion. Thereby, loading protocols differed and inconsistent definitions of failure were determined. Measurement techniques applied in biomechanical test setups included strain gauges, force transducers, and motion tracking techniques.

DISCUSSION AND CONCLUSION

An ideal fixation method should be safe, stable, non-obstructive, and have low complication rates. Although biomechanical testing should ensure that the load applied during testing is representative of a physiological load, a high degree of variability was found in the current literature in both the loading and measurement equipment. The lack of a standardised test design for fixation constructs in pelvic injuries across the studies challenges comparisons between them. When interpreting the results of biomechanical studies, it seems crucial to consider the limitations in cross-study comparability, with implications on their applicability to the clinical setting.

Surgical versus non-surgical management of lateral compression type-1 pelvic fracture in adults 60 years and older: the L1FE RCT

Background

Lateral compression type-1 pelvic fractures are a common fragility fracture in older adults. Patients who do not mobilise due to ongoing pain are at greater risk of immobility-related complications. Standard treatment in the United Kingdom is provision of pain relief and early mobilisation, unlike fragility hip fractures, which are usually treated surgically based on evidence that early surgery is associated with better outcomes. Currently there is no evidence on whether patients with lateral compression type-1 fragility fractures would have a better recovery with surgery than non-surgical management.

Objectives

To assess the clinical and cost effectiveness of surgical fixation with internal fixation device compared to non-surgical management of lateral compression type-1 fragility fractures in older adults.

Design

Pragmatic, randomised controlled superiority trial, with 12-month internal pilot; target sample size was 600 participants. Participants were randomised between surgical and non-surgical management (1 : 1 allocation ratio). An economic evaluation was planned.

Setting

UK Major Trauma Centres.

Participants

Patients aged 60 years or older with a lateral compression type-1 pelvic fracture, arising from a low-energy fall and unable to mobilise independently to a distance of 3 m and back due to pelvic pain 72 hours after injury.

Interventions

Internal fixation device surgical fixation and non-surgical management. Participants, surgeons and outcome assessors were not blinded to treatment allocation.

Main outcome measures

Primary outcome - average patient health-related quality of life, over 6 months, assessed by the EuroQol-5 Dimensions, five-level version utility score. Secondary outcomes (over the 6 months following injury) - self-rated health, physical function, mental health, pain, delirium, displacement of pelvis, mortality, complications and adverse events, and resource use data for the economic evaluation.

Results

The trial closed early, at the end of the internal pilot, due to low recruitment. The internal pilot was undertaken in two separate phases because of a pause in recruitment due to the coronavirus disease 2019 pandemic. The planned statistical and health economic analyses were not conducted. Outcome data were summarised descriptively. Eleven sites opened for recruitment for a combined total of 92 months. Three-hundred and sixteen patients were assessed for eligibility, of whom 43 were eligible (13.6%). The main reason for ineligibility was that the patient was able to mobilise independently to 3 m and back (n = 161). Of the 43 eligible participants, 36 (83.7%) were approached for consent, of whom 11 (30.6%) provided consent. The most common reason for eligible patients not consenting to take part was that they were unwilling to be randomised to a treatment (n = 10). There were 11 participants, 5 randomised to surgical management with internal fixation device and 6 to non-surgical management. The average age of participants was 83.0 years (interquartile range 76.0, 89.0) and the EuroQol-5 Dimensions, five-level version utility score at 6 months post randomisation (n = 8) was 0.32 (standard deviation 0.37). A limitation of the trial was that study objectives were not addressed due to poor recruitment.

Conclusions

It was not feasible to recruit to this trial in the current context. Further research to understand the treatment and recovery pathways of this group of patients, along with their outcomes, would be needed prior to undertaking a future trial.

Future work

Exploration of equipoise across different healthcare professional groups. Investigate longer-term patient outcomes.

Trial registration

This trial is registered as ISRCTN16478561.

Funding

This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/167/57) and is published in full in Health Technology Assessment; Vol. 28, No. 15. See the NIHR Funding and Awards website for further award information.

Clinical study of modified INFIX combined with sacroiliac joint screws for pelvic instable injuries

OBJECTIVE

The INFIX technique is becoming one of the most commonly performed surgical procedures for anterior pelvic ring instability injuries. The purpose of this article is to compare the clinical outcomes of modified anterior subcutaneous internal fixation (M-INFIX) with conventional anterior subcutaneous internal fixation (C-INFIX) for anterior pelvic ring instability injuries.

PATIENTS AND METHODS

A retrospective analysis of 36 cases of unstable pelvic injuries treated operatively at our institution, 20 of which were treated with C-INFIX and 16 with M-INFIX. Data collected included age, gender, ISS score, fracture typing, operative time, operative bleeding, postoperative complications, fracture healing time, Matta score, Majeed score, and follow-up time. Statistical sub-folding of each variable between the two groups was performed.

RESULTS

There was no statistical difference between the C-INFIX and M-INFIX groups in terms of age, gender, ISS (Injury Severity Score), follow-up time, fracture typing, fracture healing time, and Majeed score (P > 0.05). the M-INFIX had a significantly lower incidence of postoperative complications than the C-INFIX group, especially in the incidence of Lateral femoral cutaneous nerve (LFCN) injury (P < 0.05). In contrast, the M-INFIX group had statistically higher operative time, intraoperative bleeding, and Matta score than the C-INFIX group (P < 0.05).

CONCLUSION

This study was based on a modified application of the surgical experience with C-INFIX and showed better clinical outcomes in terms of complication rates and quality of repositioning than the conventional surgical approach. These findings indicate that further analytical studies of this study would be valuable.

Experimental and numerical assessment of two reconstructive techniques for the fragility fractures of the pelvis type Ia

Anterior pelvic ring fractures are common in geriatric patients. The Supraacetabular External Fixator (SEF) is a relatively simple and effective surgical procedure. On the other hand, there is the option of a Subcutaneous Iliopubic Plate (SIP) osteosynthesis. Only limited comparative biomechanical data of these two devices are available. Therefore, this biomechanical study's objective was to compare the stabilizing effect of the SEF versus the SIP in a model of Fragility Fractures of the Pelvis (FFP) type Ia. A test stand for pelvic biomechanics testing that emulates the gait loading cycle with physiological relevance was used. The osteotomy on the right pelvic ring was stabilized either with the SEF or the SIP. Strain gauges were used to measure strain in the pelvic ring. The osteotomy's spatial interfragmentary displacement (SID) was monitored using a 3D digital image correlation system. The SEF stabilization reduced the SID by approximately 10%, whereas the locking SIP could reduce displacement by about 62%. Additionally, the SIP reduced the stress/strain levels by 67% in the posterior pelvic ring. We could demonstrate that the SIP is superior to SEF in treating FFP type Ia as it significantly reduced the osteotomy's SID and the strain in the posterior pelvic ring.

Internal fixator vs external fixator in the management of unstable pelvic ring injuries: A prospective comparative cohort study

BACKGROUND

Reconstruction of the pelvic ring anatomy in unstable anterior pelvic ring injuries is a significant step to reduce the mortality rate associated with these injuries efficiently. There is a debate on using either an anterior subcutaneous pelvis internal fixator (INFIX) or an anterior supra-acetabular external fixator (EXFIX) to manage an unstable anterior pelvic ring fracture.

AIM

To compare the functional and radiological outcomes and complications of INFIX vs EXFIX in managing unstable pelvic ring injuries.

METHODS

A prospective cohort study included 54 patients with unstable pelvic ring fractures. The patients were divided into two groups; the INFIX group, in which 30 cases were fixed by INFIX, and the EXFIX group, in which 24 patients were treated by EXFIX. The average age in the EXFIX group was 31.17 years (16-57 years), while in the INFIX group, it was 34.5 years (17-53 years). The study included 20 (66.7%) males and 10 (33.3%) females in the INFIX group and 10 (41.7%) males and 14 (58.3%) females in the EXFIX group. The radiological outcomes were evaluated using Matta and Tornetta's score, and the functional outcomes using the Majeed score.

RESULTS

The results revealed a statistically significant difference between both groups (P = 0.013) regarding radiological outcomes, according to Matta and Tornetta's score in favor of the INFIX group. Sitting, standing, and walking abilities were measured at a 3-mo follow-up visit using Majeed score modules. It was significantly better among the INFIX group than the EXFIX group in all three modules. At the final follow-up, both groups had no statistically significant difference according to the Majeed score; 92.35 in the INFIX group and 90.99 in the EXFIX group (P = 0.513). A lower surgical site infection rate was noticed in the INFIX group (P = 0.007).

CONCLUSION

Anterior subcutaneous pelvis INFIX is associated with better radiological outcomes and a lower infection rate than anterior supra-acetabular EXFIX in managing patients with unstable anterior pelvic ring fractures.

Percutaneous Treatment of Locked Pubic Symphysis with the Anterior Subcutaneous Pelvic Fixator (INFIX): A Case Report

CASE

A 54-year-old woman was involved in a motor vehicle collision and sustained a lateral compression type 1 pelvic ring fracture with pubic symphyseal dislocation or a "locked pubic symphysis." Her injury failed to reduce with closed reduction maneuvers under anesthesia and necessitated a percutaneous reduction using a distraction force applied through supra-acetabular placed pedicle screws. This anterior subcutaneous internal pelvic fixator (INFIX) was also used to stabilize the injury.

CONCLUSION

This is the first reported case where a locked pubic symphysis, which failed standard closed reduction measures, was reduced and stabilized through a percutaneous technique, using the INFIX.

Evaluation of cannulated compression headless screws as an alternative implant for superior pubic ramus fracture fixation: a biomechanical study

BACKGROUND/PURPOSE

Pubic ramus fractures account for the most common types of pelvic fractures. The standard surgical approach for superior pubic ramus fractures (SPRF) is a minimally invasive percutaneous screw fixation. However, percutaneous closed reduction and internal fixation of anterior pelvic ring injuries have high failure rates of up to 15%. The aim of this biomechanical study was to evaluate the stability of SPRF following stabilization with retrograde placed cannulated compression headless screw (CCHS) versus conventional fully and partially threaded screws in an artificial pelvic bone model.

METHODS

SPRF type II as described by Nakatani et al. was created by means of osteotomies in eighteen anatomical composite hemi-pelvises. Specimens were stratified into three groups of six specimens each (n = 6) for fixation with either a 7.3 mm partially threaded cannulated screw (group RST), a 7.3 mm fully threaded cannulated screw (group RSV), or a 7.5 mm partially threaded cannulated CCHS (group CCS). Each hemi-pelvic specimen was tested in an inverted upright standing position under progressively increasing cyclic axial loading. The peak load, starting at 200 N, was monotonically increased at a rate of 0.1 N/cycle until 10 mm actuator displacement.

RESULTS

Total and torsional displacement were associated with higher values for RST versus CCS and RSV, with significant differences between RST and CCS for both these parameters (p ≤ 0.033). The differences between RST and RSV were significant for total displacement (p = 0.020), and a trend toward significance for torsional displacement (p = 0.061) was observed. For both failure criteria 2 mm total displacement and 5° torsional displacement, CCS was associated with significantly higher number of cycles compared to RST (p ≤ 0.040).

CONCLUSION

CCHS fixation presented predominantly superior stability to the standard surgical treatment and could therefore be a possible alternative implant for retrograde SPRF screw fixation, whereas partially threaded screws in group RST were associated with inferior biomechanical stability.

Iliac dysmorphism: defining radiographic characteristics and association with pelvic osseous corridor size

INTRODUCTION

Insertion of iliac wing implants requires understanding of the curvilinear shape of the ilium. This study serves to quantitatively identify the area of iliac inner-outer table convergence (IOTC), characterize the iliac wing osseous corridor, and define the gluteal pillar osseous corridor.

METHODS

Computed tomography scans of 100 male and 100 female hemipelves were evaluated. The iliac wing was studied using manual best-fit analysis of the bounds of the inner and outer cortices. The IOTC was defined as the location of the iliac wing with an intercortical width less than 5 mm. The shortest distance from the apex of the iliac crest to the superior border of the IOTC was defined as the iliac wing osseous corridor. Finally, the width of the gluteal pillar corridor from the gluteus medius tubercle to the ischial tuberosity was measured.

RESULTS

The IOTC is an elliptical area measuring 22.3 cm². All ilia had an area where the inner and outer cortices converged to an intercortical width of less than 5 mm; 48% converged to a single cortex. The shortest mean distance from the superior edge of the iliac crest to the beginning of the IOTC was 20.3 mm in men and 13.8 mm in women (p < 0.001). The gluteal pillar diameter averaged 5.3 mm in men and 4.3 mm in women (p < 0.001).

DISCUSSION

All ilia converge to a thin and frequently unicortical central region. A 4.5 mm iliac wing lag screw will not breach the cortex if it remains within 20 mm or 14 mm distal to the cranial aspect of the iliac crest in males and females, respectively. Not only is the gluteal pillar smaller than previously thought, in 41% of males and 73% of females, it is not be large enough for 5 mm implants.

CONCLUSION

This study quantitatively assesses the dimensions of the IOTC, the iliac crest osseous corridor, and the gluteal pillar. Overall, our findings provide improved understanding of the limits for implant use in the iliac wing as well as better appreciation of the complex osteology of the ilium. This will help surgeons to identify safe areas for implant placement and avoid inadvertent cortical penetration.

Spinopelvic In Situ Fixation and Early Mobilization: A Case Report and Literature Review

Pelvic fractures with sacroiliac extension are significant and complicated orthopedic injuries that pose a challenge in management and favorable outcomes. A 50-year-old obese female presented after a motor vehicle accident with pelvic fracture lateral compression. The patient underwent anterior external fixation with a left sacroiliac screw (SIS) on the next day of admission and was kept in a non-weight-bearing state. During her hospital stay, she developed deep vein thrombosis (DVT) and was treated. During the follow-up on the sixth week, the patient was not complying with her immobilization instructions and was exposing the left lower limb to weight bearing. The radiologic evaluation demonstrated a pulled-out SIS with a stable fracture. Considering that the patient was obese, had a history of DVT and COVID-19 infection, and the fracture was minimally displaced, it was decided to perform a spinopelvic in-situ fixation from L4 to S2 and augment it with a left SIS. The patient tolerated the surgery well and was referred to physiotherapy for early mobilization with full weight bearing. During her six-month and two-year follow-ups, she was well mobilized with no active complaints, and radiographic studies showed good healing, no displacement, no signs of instability, and a stable construct. Our case report presents a very rare and difficult but successful management of a fracture displacement in a non-compliant patient with one pulled-out screw through fast-tracked in situ spinopelvic fixation with early mobilization and full weight bearing. To our knowledge, this is one of the rare reports detailing a patient undergoing in situ spinopelvic fixation due to minimally displaced fracture with comorbidities such as obesity and DVT. Our report demonstrates the viability of accepting pulled-out screws, with respect to the patient's health, the fracture's geometry, a quick follow-up in situ spinopelvic fixation, early mobilization, full weight-bearing outcomes, and a lower risk for complications.

A retrospective analysis of minimally invasive internal fixation versus nonoperative conservative management of pelvic ring fragility fractures and the elderly

OBJECTIVE

We aimed to investigate the adoption of treatment patterns for hip fractures combined with minimally invasive surgical treatment of fragility fractures of the pelvis in older individuals and reviewed and analysed the treatment efficacy and feasibility.

METHODS AND DATA

From September 2017 to February 2021, 135 older individuals with fragility fractures of the pelvis were admitted to our hospital. We retrospectively analysed patients who received surgical or conservative treatments. The general preoperative data, including sex, age, disease duration, cause of injury, AO/OTA type, BMI, bone mineral density, time from injury to admission, time from injury to surgery, ASA classification, number of underlying diseases, mean bed rest, clinical fracture healing, VAS score and Majeed functional score, were recorded.

RESULTS

The mean follow-up time for all 135 patients was 10.5 ± 3.6 months. Among 135 patients, 95 survived, and 11 and 29 patients passed after the surgical (mortality rate = 17.74%) and conservative (mortality rate = 39.73%) treatments, respectively. The average follow-up time for the 95 surviving patients was 14.5 ± 1.8 months. The Majeed and VAS scores for the operation group were significantly better than those of the conservative group. The bed rest and fracture healing times were also shorter in the surgical treatment group than in the conservative group.

CONCLUSION

The use of a minimally invasive surgical treatment combined with the geriatric hip fracture treatment model to treat fragility fractures of the pelvis improved the quality of life in older patients.

Lateral compression type 1 fracture fixation in the elderly (L1FE): study protocol for a randomised controlled trial (with internal pilot) comparing the effects of INFIX surgery and non-surgical management for treating patients with lateral compression type 1 (LC-1) fragility fractures

BACKGROUND

Lateral compression type1 (LC-1) fragility fractures are a common, painful injury in older adults resulting in reduced mobility. The incidence of these fractures is increasing with the growing older adult population. The current standard of care is non-surgical management; however, patients with this injury are at risk of long-term immobility and related complications. INFIX is a pelvic fixation device used in younger patients with high-energy fractures. The device is fitted via a percutaneous technique with no external pin sites and has good purchase even in osteoporotic bone. It therefore has the potential to be well tolerated in patients with LC-1 fragility fractures. INFIX could improve patients' ability to mobilise and reduce the risk of immobility-related complications. However, there is a risk of complications related to surgery, and robust evidence is required on patient outcomes. This study will investigate the clinical and cost-effectiveness of surgical fixation with INFIX compared to non-surgical management of LC-1 fragility fractures in older adults.

METHODS

A multi-centre randomised controlled trial of 600 patients allocated 1:1 to non-surgical management or INFIX surgery. The study will have a 12-month internal pilot to assess recruitment and trial feasibility. The primary outcome will be the patient quality of life over 6 months, measured by the patient-reported EQ-5D-5L. The secondary outcomes will include physical function, mental health, pain, delirium, imaging assessment, resource use, and complications.

DISCUSSION

The L1FE study aims to compare the clinical and cost-effectiveness of surgical and non-surgical management of people aged 60 years and older with LC-1 fragility fractures. The trial is sufficiently powered and rigorously designed to inform future clinical and patient decision-making and allocation of NHS resources.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number Registry ISRCTN16478561. Registered on 8 April 2019.

Modified percutaneous iliosacral screw and anterior internal fixator technique for treating unstable pelvic fractures: a retrospective study

BACKGROUND

The commonly used technique for treating unstable pelvic fractures with sacroiliac screws and anterior internal fixator (INFIX) is prone to complications, such as injury to the pelvic vasculature and nerves, life-threatening bleeding, lateral femoral cutaneous neuritis, and wound infection. This study investigated the clinical effects of using a modified percutaneous iliosacral screw and INFIX technique for treating unstable pelvic fractures.

METHODS

A retrospective analysis of minimally invasive internal fixation using modified incision of an anterior-ring INFIX application combined with modified percutaneous iliosacral screw placement was performed for 22 cases of unstable pelvic fractures from January 2017 to December 2018. Based on the Tile classification, there were 4 type B1, 7 type B2, 5 type B3 and 6 type C1 injuries. Preoperatively, the length and orientation of the internal fixation were computer-simulated and measured. On postoperative day 3, pelvic radiographs and three-dimensional computed tomograms were used to assess fracture reduction and fixation. All patients were regularly followed up at 4 weeks, 12 weeks, 6 months, 12 months, 24 months and annually thereafter. Fracture healing, complications, visual analogue scale (VAS) scores, the quality of fracture repositioning and Majeed score were assessed during follow-up.

RESULTS

All patients were followed up for a mean of 25.23 ± 1.48 months. All fractures healed without loss of reduction and no patient showed evidence of delayed union or nonunion. Two years postoperatively, the mean VAS score was 0.32 ± 0.09 and the mean Majeed score was 94.32 ± 1.86.

CONCLUSION

The modified percutaneous iliosacral screw technique increases the anterior tilt of the sacroiliac screw by shifting the entry point posteriorly to increase the safety of the screw placement. Downward modification of the INFIX incision reduces the risk of lateral femoral cutaneous nerve injury. This technique is safe, effective and well tolerated by patients.

Investigation of the risk of common femoral artery injury with anterior subcutaneous internal fixation in patients with fragility fractures of the pelvis

INTRODUCTION

The incidence of the fragility fractures of the pelvis (FFPs) has been increasing in recent years. Operative treatment is effective in patients who are unable to ambulate due to pain. Anterior subcutaneous internal fixation (ASIF) is a minimally invasive and stable fixation used to treat the FFPs, with few reported vascular complications. However, we experienced a case in which the rod directly pressed the common femoral artery (CFA).

OBJECTIVES

The purpose of this study was to examine the relationship between the rod position as defined by ASIF and the CFA in the FFPs patients, and between BMI and the rod-to-CFA distance.

MATERIALS AND METHODS

Pelvic measurements were performed in 47 patients with FFPs using trauma CT. We identified the anterior inferior iliac spine (AIIS) on both sides in axial CT images. Next, we performed a simulation study using the CT images, in which the virtual fixation rod was bent according to the shape of the patients' abdomen in the supine position. The shortest rod-to-CFA distance when the virtual rod was positioned directly above the AIIS in the CT image was measured. The correlation between body mass index (BMI) and the rod-to-CFA distance was measured.

RESULTS

The average shortest rod-to-CFA distance was 18.4 ± 11.1 mm, and the simulated rod compressed the CFA in three of the 47 cases (6.4%). A statistically significant positive correlation between BMI and the rod-to-CFA distance was found (r = 0.47, p = 0.001).

CONCLUSIONS

The course of the CFA should be confirmed before ASIF surgery, and if there is danger of compression of the CFA such as in patients with low BMI, the rod-to-AIIS distance should be adjusted to the optimal distance. However, considering the disadvantages, such as decreased stability of the fixation, when adjusting the rod-to-AIIS distance, and skin irritation and abrasion by the rod, ASIF is not recommended in cases in which the rod is close to the CFA.

Therapeutic effect of an external fixator in the treatment of unstable pelvic fractures in children

BACKGROUND

Unstable pelvic fractures in children are serious and complex injuries, and the optimal method to manage these injuries is controversial.

HYPOTHESIS

We hypothesized that an external fixator would be a satisfactory method of treating unstable pelvic fractures in children.

PATIENTS AND METHODS

We retrospectively reviewed 40 pediatric patients with unstable pelvic fractures who were treated with an external fixator in Beijing Children's Hospital from June 2006 to June 2016. Postoperative follow-up was 12 to 108 months, with an average of 26 months. One year after the operation, fracture healing, pelvic asymmetry, and deformity index were assessed by X-ray. Pelvic function was evaluated with the Cole evaluation standard, and daily cognitive and motor functions were evaluated by weeFIM. Patient complications were recorded.

RESULTS

The average age of the 40 patients was 5.9±3.1 years (2 to 14.5), including 25 boys and 15 girls. Among these cases, 37 (92.5%) had injuries caused by traffic accidents and 3 (7.5%) had injuries caused by falling from height. Based on the Tile classification, there were 18 cases of class B (14 class B2 and 4 class B3) and 22 cases of class C (15 class C1, 6 class C2, and 1 class C3). The X-rays showed good fracture healing at the 1-year postoperative follow-up. The pelvic asymmetry was reduced from 1.13cm before the operation to 0.88cm after (p<0.05), and the deformity index was decreased from 0.09 before to 0.05 after the operation (p<0.05). At the 1-year postoperative follow-up, 36 patients had excellent Cole scores, and 4 had good Cole scores, with a good or excellent rate of 100%. According to the weeFIM, 28 patients had complete independence, 11 had basic independence, and 1 had conditional independence. Three patients (7.5%) had complications, all of which were postoperative pin-site infections.

DISCUSSION

For children with horizontally unstable pelvic fractures, an external fixator can be used alone. For children with horizontally and vertically unstable pelvic fractures, after external fixator placement and reduction, lower extremity traction can be performed to achieve better reduction and maintain stability, and the therapeutic effect is satisfactory.

LEVEL OF EVIDENCE

IV, retrospective observational cohort study.

Biomechanical study of anterior and posterior pelvic rings using pedicle screw fixation for Tile C1 pelvic fractures: Finite element analysis

Objective

The purpose of this study was to analyse the biomechanical characteristics of pedicle screws with different placement methods and diameters in the treatment of Tile C1 pelvic fractures by finite element simulation technology and to compare them with the plate fixation model to verify the effectiveness of pedicle screw fixation.

Methods

A three-dimensional digital model of a normal pelvis was obtained using computed tomography images. A finite element model of a normal pelvis containing major ligaments was built and validated (Model 1). Based on the verified normal pelvis finite element model, a Tile C1 pelvic fracture model was established (Model 2), and then a plate fixation model (Model 3) and a pedicle screw fixation model with different screw placement methods and diameters were established (Models 4–15). For all pelvic fracture fixation models, a vertical load of 500 N was applied on the upper surface of the sacrum to test the displacement and stress distribution of the pelvis in the standing state with both legs.

Results

The finite element simulation results showed the maximum displacement of Model 1 and Models 3–15 to be less than 1 mm. The overall maximum displacement of Models 4–15 was slightly larger than that of Model 3 (the maximum difference was 177.91×10⁻³ mm), but the maximum displacement of iliac bone and internal fixation in Models 4–15 was smaller than that of Model 3. The overall maximum stress (maximum stress of the ilium) and maximum stress of internal fixation in Models 4–15 were less than those in Model 3. The maximum displacement difference and maximum stress difference at the fracture of the pubic ramus between each fixed model were less than 0.01 mm and 1 MPa, respectively. The greater the diameter and number of pedicle screws were, the smaller the maximum displacement and stress of the pelvic fracture models were.The maximum displacement and stress of the pelvic fracture models of the screws placed on the injured side of the pubic region were smaller than the screws on the healthy side.

Conclusion

Both the anterior and posterior pelvic rings are fixed with a pedicle screw rod system for treatment of Tile C1 pelvic fractures, which can obtain sufficient biomechanical stability and can be used as a suitable alternative to other implants.The greater the diameter and number of pedicle screws were, the greater the pelvic stability was, and the greater was the stability of the screws placed on the injured side of the pubic region than the screws on the healthy side.

Supraacetabular osseous corridor: defining dimensions, sex differences, and alternatives

INTRODUCTION

The supraacetabular (SA) corridor extends from the anterior inferior iliac spine to the posterior ilium and can safely accommodate implants to stabilize pelvic and acetabular fractures. However, quantitative analysis of its dimensions and characteristics have not been thoroughly described. This study seeks to define the dimensions, common constriction points, and any alternative trajectories that would maximize the corridor diameter.

METHODS

Computed tomography of 100 male and 100 female hemipelves without osseous trauma were evaluated. The corridor boundaries were determined through manual best-fit analysis. The largest intercortical cylinder within the pathway was created and measured. Alternative trajectories were tested within the SA boundaries to identify another orientation that maximized the diameter of the intercortical cylinder.

RESULTS

The traditional SA corridor had a mean diameter of 8.3 mm in men and 6.2 mm in women. This difference in diameter is due to a more S-shaped ilium in women. A larger alternative SA corridor was found that had a less limited path through the ilium and measured 11.3 mm in men and 9.9 mm in women. These dimensions are significantly different compared to those of the traditional SA corridor in both men and women.

CONCLUSIONS

In men, the SA corridor allows for the safe passage of most hardware used in pelvic and acetabular fractures. However, in women, the SA corridor is restricted by a more S-shaped ilium. An alternative trajectory was found that has a significantly larger mean diameter in both sexes. Ultimately, the trajectory of hardware will be dictated by the clinical scenario. When large implants are needed, especially in women, we recommend considering the alternative SA corridor.

Identification of safe channels for screws in the anterior pelvic ring fixation system

Background

Minimally invasive surgery for pelvic fracture using anterior ring internal fixator system is increasing gradually, and the way to insert the fixation screws in the fixation system is the key technical points of the method. However, there have been few studies on insertion of fixation screws for the anterior pelvic ring internal fixator system.

Objective

To identify safe channels for fixation screws in the anterior pelvic fixator system and provide the anatomical basis for insertion of fixation screws in clinical operation.

Methods

Screw insertion was simulated into a total of 40 pelvic finite element models as well as 16 fresh pelvic specimens, and the channel parameters were measured.

Results

Finite elements (male, female) include: screws in ilium: length 114.4 ± 4.1 and 107.6 ± 8.3 mm, respectively; diameter 11.7 ± 0.5 and 10.0 ± 0.6 mm, distance between screw and anterior inferior iliac spine: 5.5 ± 1.0 and 5.6 ± 1.0 mm, angle of coronal plane 55.8° ± 2.4° and 50.6° ± 3.1°, angle of sagittal plane 26.6° ± 1.0° and 24.5° ± 1.9° and angle of horizontal plane 64.9 ± 3.7 and 58.1 ± 3.1; screws in pubis: length 47.0 ± 2.0 and 39.8 ± 3.9 mm, diameter 7.1 ± 0.4 and 6.1 ± 0.4 mm. Specimens (male, female) include: distance between screw and anterior inferior iliac spine: 5.5 ± 0.5 and 5.6 ± 0.7 mm, angle of coronal plane 55.9° ± 1.3° and 50.7° ± 1.5°, angle of sagittal plane 26.7° ± 0.5° and 24.1° ± 0.9° and angle of horizontal plane 64.8° ± 0.6° and 58.8° ± 0.8°. In the comparison between female and male in each group, differences in distances between screws and anterior inferior iliac spine and median line of symphysis pubis (P > 0.05) were not statistically significant; differences in the remaining parameters were statistically significant (P < 0.05).

Conclusions

If surgeons paid attention to sex differences, select screws of appropriate diameter and length and hold the insertion position and direction, screws in the anterior pelvic ring fixation system could be safely inserted.

Variability in rod to bone distance needed in pelvic subcutaneous internal fixation to avoid nerve compression: A tridimensional population-based study

INTRODUCTION

Pelvic internal fixation has become a popular method for treatment of unstable pelvic ring injuries. Although successful, one complication is femoral nerve palsy from compression of the connecting rod. In light of this complication, this study was designed to evaluate sagittal inclinations of the rod and the feasibility of using a rod with a constant curvature.

HYPOTHESIS

It is hypothesized that that there is a connection between the sagittal inclination of the rod and the rod to bone distance, as well as single rod can be contoured with a constant curvature to be used in the majority of all patients.

METHODS

Three dimensional models of pelvis CTs from a single level 1 trauma center were created and imported into a program where software superimposed a pre-contoured rod in the sagittal planes upon the pelvic slices. The sagittal inclination was deemed acceptable is no interference occurred between the area of compression risk and the rod. For each pelvis and considered sagittal rod inclination, the rod radius of curvature (ROC), minimal rod to bone distance (RTB) and transverse inclinations (φ_L and φ_R) were measured at which the pedicle screws should be inserted to follow the direction of the smallest RTB.

RESULTS

The sagittal inclinations feasible for all subjects were between 15° to 30°. In this sagittal range, the average RTB varied in values ranging from 4.0±0.9mm to 25.4±11.4mm (p<0.01). Only 46% of subjects allowed a rod with constant curvature.

DISCUSSION AND CONCLUSION

Our study found that a rod to bone distance of 15mm was not safe for all models. As well, many subject models did not allow placement of pre-contoured rod. Patient specific templating of pelvic subcutaneous internal fixation is strictly needed to limit complications.

LEVEL OF EVIDENCE

VII; Basic Science.

A clinical and biomechanical comparison of INFIX plus single versus double sacroiliac screw fixation for unstable pelvic ring injury

BACKGROUND

The aim of this study is to compare the clinical and biomechanical outcome of INFIX plus single with two sacroiliac screw fixation for unstable pelvic fractures of Type C.

METHODS

Sixteen cadavers were randomly subjected to INFIX plus single or double sacroiliac screw fixations and then mounted onto the ElectroForce loading machine under different vertical loads. To investigate the clinical outcomes of the two techniques, nineteen patients were retrospectively analyzed. The main outcome measures were postoperative radiographic reduction grading (using the Tornetta and Matta grading system), functional outcome (using the Majeed scoring system), and incidence of complications.

RESULTS

In the biomechanical study, INFIX plus double sacroiliac screw fixation showed better biomechanical stability than fixation with a single sacroiliac screw (p < 0.05). In our clinical case series, all 19 patients had bony union 6 months after the operation. INFIX plus double sacroiliac screw fixation also demonstrated a better functional outcome and a higher radiographic satisfactory rate than INFIX plus single sacroiliac screw fixation (79.25 ± 5.47; 91.33 ± 4.97; p < 0.05), (77.78% vs. 60%; p = 0.05). One patient in INFIX plus single-screw fixation group had screw loosening at 6-month follow-up postoperatively. One case in each group suffered heterotopic ossification and the lateral femoral cutaneous nerve paralysis, and one patient suffered from infection.

CONCLUSION

INFIX plus double sacroiliac screw fixation demonstrated more stability in cadaveric biomechanical analysis and better clinical outcomes than INFIX plus single sacroiliac screw fixation.

Outcomes and complications of the INFIX technique for unstable pelvic ring injuries with high-velocity trauma: a systematic review and meta-analysis

BACKGROUND

The pelvic INFIX technique has been proposed as a useful alternative to symphyseal plating for management of unstable pelvic ring injuries. The minimally invasive nature of the procedure, shorter operative time and less perioperative blood loss have been purported as potential advantages.

QUESTIONS/PURPOSES

This systematic review and meta-analysis were conducted to determine the outcomes and complications of the INFIX technique for unstable pelvic ring injuries.

METHODS

A systematic review of literature was performed on the PubMed, EMBASE and Scopus databases. Prospective and retrospective studies in all languages, whether comparative or non-comparative, pertaining to the use of INFIX in pelvic fractures were included. Studies which did not evaluate INFIX, case reports, conference abstracts and those with less than 10 cases were excluded. Cadaveric studies, technique papers and studies that did not describe the prespecified outcome measures were also excluded. Meta-analysis consisted of two different arms: a comparative arm, to compare INFIX to symphyseal plating, and a non-comparative meta-analysis arm, to determine pooled rates of outcomes and complications. Risk of bias was determined by the Methodological Index for Non-Randomised Studies (MINORS) tool.

RESULTS

A total of 22 studies were included in the systematic review, of which 7 were comparative and 15 were non-comparative. 746 patients were included for qualitative analysis and pooled analysis done for 589 patients. The average follow-up of these studies ranged from a minimum of 5.4 months to a maximum of 54 months. Comparative meta-analysis (n = 3 studies) of plating and INFIX showed significantly lesser blood loss (mean difference = 176.46 mL; 95% CI - 207.54 to - 145.38) and shorter operative time (mean difference = 26.43 min, 95% CI - 31.79 to - 21.07) with INFIX, but no significant difference in the overall complication rates (OR 1.59, 95% CI 0.83-3.05) and functional outcome scores (mean difference = - 2.51, 95% CI - 5.73 to 0.71). Pooled analysis showed overall good radiological (mean percentage of excellent to good reduction = 91.4%, 95% CI 0.860-0.969) and functional outcomes (mean Majeed score = 86.48, 95% CI 83.34-89.61) with INFIX. The most common complications were lateral femoral cutaneous nerve (LFCN) injury (overall rate 28%, 95% CI 15.1-41%) and heterotopic ossification (HO) (overall rate 9.4%, 95% CI 5.5-13.3%); rates of other complications were low. Significant heterogeneity was noted in the pooled analysis of blood loss, operative time, functional outcome, HO and LFCN injury. The overall strength of evidence was found to be weak.

CONCLUSION

The INFIX technique can be considered as a viable alternative to symphyseal plating for unstable pelvic ring injuries. It has the advantages of shorter operative times and less blood loss, along with comparable functional outcomes, when compared to plating. Overall, good functional outcomes can be expected. However, well-designed, multi-center randomized controlled trials are needed to conclusively prove the benefit of this technique.

Is unrestricted weight bearing immediately after fixation of rotationally unstable pelvic fractures safe?

INTRODUCTION

Rotationally unstable pelvic fractures treated with surgical fixation have traditionally been treated with restricted weight bearing on the affected side for 6-8 weeks post operatively. We have been developing pelvic fixation standards to allow for unrestricted weight bearing immediately post operatively in type B rotationally unstable pelvic fractures.

AIMS

To assess for safety and efficacy of allowing unrestrictive weight bearing in this cohort of patients, we have clinically and radiologically monitored outcomes up to two years post operatively.

METHODS

Through retrospective review, two cohorts of patients with Tile Type B pelvic fractures were identified that were treated at the Royal Adelaide Hospital, South Australia. Patient demographics, injury classification, surgical fixation and weight bearing status post operatively was recorded. One cohort of patients was allowed to fully weight bear post operatively, whilst the other was treated with 6 weeks of restricted post op weight bearing. At clinical follow up, post-operative x-rays were assessed for loss of reduction, screw or plate breakage and reoperation.

RESULTS

Between January 2018 and January 2021, 53 patients with rotationally unstable pelvic fractures that underwent surgical fixation were included in this study. One group of patents were allowed to immediately weight bear as tolerated (WBAT) post operatively (n = 28) and the other with restricted weightbearing (RWB) (n = 25). There was 1 re operation for failure of fixation in each group. Metalwork breakage was more common in the WBAT group than in the RWB group and this was seen only in APC fractures. This increase in metalwork failure was not associated with loss of reduction.

CONCLUSIONS

With surgical fixation, Tile type B rotationally unstable pelvic fractures can be allowed immediate weight bearing post operatively. We found this to be safe and effective, employing surgical strategies to address both anterior and posterior injuries to allow immediate unrestricted weight bearing. Broken metalwork was more commonly seen in the WBAT group but this was not associated with loss of reduction or reoperation.

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.

Starr frame-assisted and minimally invasive internal fixation for pelvic fractures: Simultaneous anterior and posterior ring stability

OBJECTIVE

We aimed to investigate the surgical techniques, efficacy, and safety of Starr frame-assisted and minimally invasive internal fixation for simultaneous anterior and posterior ring stability in pelvic fractures.

METHODS

The clinical data of 22 patients with anterior and posterior pelvic ring injuries who underwent Starr frame-assisted and minimally invasive internal fixation were retrospectively collected. The anterior pelvic ring was fixed with an anterior subcutaneous internal fixator (INFIX), and the posterior pelvic ring was fixed with sacroiliac screws. The operative time, intraoperative blood loss, fluoroscopy times, number of assistants, complications, and weight-bearing time were analyzed. The Matta score was used to evaluate the fracture reduction. The Majeed score was used to evaluate clinical efficacy, and Gibbon's classification was used to estimate the occurrence of sacral nerve injury.

RESULTS

All 22 patients were treated with sacroiliac screws for posterior ring injuries, including 12 cases with single sacroiliac screws, nine with two sacroiliac screws, and one with three sacroiliac screws. INFIX was used for all anterior ring fixation, including two screws in seven cases, three screws in 13 cases, and four screws in two cases. The fracture reduction quality was excellent in 15 cases, good in four cases, and moderate in three cases by Matta scores. All patients were followed up for 6-20 (12.5 ± 5.7) months. Callus-formation time based on postoperative X-ray was 3-8 (4.3 ± 1.2) weeks. Weight-bearing time was 3-12 (6.3 ± 2.8) weeks after surgery. At the last follow-up, 15 patients were evaluated as excellent, five as good, and two as fair according to the Majeed score. Gibbons' classification showed that one of the three patients with sacral nerve injury recovered completely and two did not recover. Complications occurred in six patients, including one with internal fixation loosening, two with anterolateral thigh paresthesia, one with malunion, one with nonunion, and one with heterotopic ossification.

CONCLUSIONS

Starr frame-assisted and minimally invasive internal fixation could stabilize the anterior and posterior pelvic rings simultaneously, overcoming the difficulty of fracture reduction. This technique can help patients with early postoperative weight-bearing and improved functional outcomes, providing a novel modality for the minimally invasive treatment of pelvic ring injuries.

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

Background

The subcutaneous screw rod system, commonly known as the internal pelvic fixator (INFIX), is useful in managing unstable pelvic ring fractures. Conventional INFIX and transiliac–transsacral (TITS) screw techniques are performed using C-arm fluoroscopy. There have been problems with medical exposure and screw insertion accuracy with these techniques. This work describes new INFIX and TITS techniques using intraoperative computed tomography (CT) navigation and C-arm fluoroscopy for pelvic ring fracture.

Methods

A typical case is presented in this study. An 86-year-old woman suffered from an unstable pelvic ring fracture due to a fall from a height. INFIX and TITS screw fixation with intraoperative CT navigation were selected to optimize surgical invasiveness and proper implant placement.

Results

The patient was placed in a supine position on a Jackson table. An intraoperative CT navigation was imaged, and screws were inserted under the navigation. Postoperative X-rays and CT confirmed that the screw was inserted correctly. This technique was less invasive to the patient and had little radiation exposure to the surgeon. Rehabilitation of walking practice was started early after the surgery, and she was able to walk with the assistance of a walker by the time of transfer.

Conclusions

The technique employed in our case study has the cumulative advantages of safety, accuracy, and reduced radiation exposure, together with the inherent advantages of functional outcomes of previously reported INFIX and TITS screw techniques. Further experience with this approach will refine this technique to overcome its limitations and facilitate its wider use.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-02920-0.

Clinical application of anterior ring internal fixator system combined with sacroiliac screw fixation in Tile C pelvic fracture treatment

Background

How to perform minimally invasive surgery for Tile C pelvic fracture is a major problem in clinical practice. We performed minimally invasive surgery for Tile C pelvic fracture using anterior ring internal fixator systems combined with sacroiliac screw fixation.

Objective

To investigate the advantages and efficacy of anterior ring internal fixator systems combined with sacroiliac screw fixation in the treatment of Tile C pelvic fracture.

Methods

From May 2017 to May 2020, 27 patients with Tile C pelvic fracture who underwent anterior ring internal fixator system combined with sacroiliac screw fixation (group A) and 21 patients with Tile C pelvic fracture who underwent plate-screw system combined with sacroiliac screw fixation (group B) were retrospectively analyzed.

Results

All 48 patients were followed up for more than 12 months, all fractures healed within 3–6 months. The operative time, intraoperative bleeding volume, blood transfusion volume, incision length, hospital stay, complication rate and Majeed score were 63.5 ± 10.7 min, 48.3 ± 27.9 ml, 0 ml, 4.5 ± 0.8 cm, 10.2 ± 2.7 d, 3.7% and 89.7 ± 4.6 points, respectively, in group A and 114.8 ± 19.1 min, 375 ± 315.8 ml, 266.7 ± 326.6 ml, 9.2 ± 3.9 cm, 20.9 ± 5.7 d, 23.8% and 88.7 ± 4.9 points, respectively, in group B. Combined excellent and good rates of the Matta evaluation and Majeed score were 100% in both groups. There were no significant differences in the Matta evaluation or Majeed score between the two groups (both P > 0.05), whereas the operative time, intraoperative bleeding volume, blood transfusion volume, incision length and hospital stay were significantly less in group A (all P < 0.05).

Conclusion

An anterior ring internal fixator system combined with sacroiliac screw fixation can effectively treat Tile C pelvic fracture, and has advantages, including minimal invasiveness, simple operation, short operative time, safe and reliable features, fewer complications, short hospital stay and a good curative effect.

Treatment of unstable pelvic ring injury with a dual internal anterior subcutaneous fixator using spinal instrumentation called "dual INFIX": A case report

Introduction

External fixation, various subcutaneous screw fixations, and plate fixation can be considered as fixation methods for unstable pelvic ring fractures. We describe a first case of treated unstable pelvic ring injury using a dual internal anterior subcutaneous fixator we called "dual INFIX," comprising four screws, two subcutaneous rods, and two cross-link connectors, without posterior fixation.

Case Report

An 81-year-old man sustained an unstable pelvic injury (AO type B2) with fracture of the left ilium and pubis. Dual INFIX was used to stabilize the pelvic ring injury. Polyaxial screws were introduced along a path between the anterior inferior iliac spine and ipsilateral posterior superior iliac spine until the head of the screw lay immediately above the fascia. Bilateral cranial screws were connected by a rod passed subcutaneously, and caudal screws were connected by the other rod. Finally, cross-link connectors connected cranial and caudal rods on the right and left. One year after the first operation, the patient could walk without a cane and had no limitation of daily living and bony fusion was achieved.

Conclusion

The stability of the pelvic ring of dual INFIX was sufficient to achieve bony fusion in this case. The stability of dual INFIX should be stronger than that of INFIX. Dual INFIX as with INFIX has other advantages such as ease of management compared with external fixation, and nonnecessity of strict anatomical reduction compared with various percutaneous screw fixation. Furthermore, this technique is simple and minimally invasive compared with plate fixation because it does not require open surgery. However, because the type C fracture with an unacceptable position of reduction by closed reduction has the possibility to become a symptomatic malunion, such cases should not be treated by this method. Furthermore, it is necessary for pelvic stabilization using dual INFIX that the contralateral pelvis is intact because dual INFIX stabilizes the fracture side with the other side of the pelvis. Dual INFIX can be considered as an option of fixation methods for type B-1 or 2 pelvic ring injuries.

Endoscopically assisted implant removal of a symphyseal pelvic plate - A case report

Introduction

The approach-related morbidity rate in the care of pelvic fractures is still high. Endoscopic procedures are known to significantly reduce access-related complications. Recently, a new endoscopically assisted implantation technique for plate osteosynthesis on the anterior pelvic ring has been described as the “Endoscopic Approach to the Symphysis”.

Case report

We present a case of a 29-year old male with a pelvic injury (AO type 61B2.3a) initially treated with a supraacetabular external fixator. After one week the definitive stabilization was performed by an endoscopically assisted symphyseal plating as well as a percutaneous iliosacral screw on the right side. One year after primary surgery, we performed an endoscopically assisted removal of the symphyseal plate using standard laparoscopic instruments.

Results

We demonstrate the feasibility of an endoscopically assisted implant removal at the anterior pelvic ring. No complications occurred during the procedure. The patient was discharged after a regular time of surveillance and with an adequate decline of pain.

Discussion

While we were able to show that the endoscopically assisted implantation as well as the removal of a plate osteosynthesis on the anterior pelvic ring is possible, there is still further research necessary, especially regarding the development of specific endoscopic instruments. This should enable operating times similar to the standard open procedures.

Infection after the use of INFIX in Pelvic Ring Injuries

INTRODUCTION

The purpose of this study is to report on infection with anterior subcutaneous internal pelvic fixation (INFIX) for pelvic ring injuries and the outcomes of treatment.

METHODS

An IRB-approved retrospective study was performed using trauma databases of a level one and level two trauma center from 2012-2018. Infection after the INFIX procedure was diagnosed in 10 of 179 cases. Treatment included formal irrigation and debridement, removal of the hardware, and culture-specific antibiotics. Patients were followed for a minimum of 12 months. Recorded outcomes include X-rays, Majeed scores, and the presence of any loss of reduction using reduction parameters.

RESULTS

Time to detect the infection was 54.2 ± 24.3 days (range 24-90, median 56 days). Staphylococcus aureus was the most common bacteria isolated. The average follow-up was 830 ± 170 days (range 575-1088 days). All patients went on to the radiographic union. There were no recurrent infections or osteomyelitis at the latest follow-up. Patients maintained their reduction after INFIX removal (KI), and Majeed scores ranged from 72 to 96 (seven good, three excellent).

DISCUSSION

Infections after using the INFIX procedure were dealt with by irrigating and debriding the wounds, removing the INFIX with culture-specific antibiotics for 2-6 weeks. Implants were maintained for at least 25 days, and there was no loss of reduction. There were no long-term sequelae noted in this small series or the literature review included in this paper.

Modified pedicle screw-rod versus anterior subcutaneous internal pelvic fixation for unstable anterior pelvic ring fracture: a retrospective study and finite element analysis

Objectives

This study compared the stability and clinical outcomes of modified pedicle screw-rod fixation (MPSRF) and anterior subcutaneous internal pelvic fixation (INFIX) for the treatment of anterior pelvic ring fractures using the Tornetta and Matta grading system and finite element analyses (FEA).

Methods

In a retrospective review of a consecutive patient series, 63 patients with Orthopaedic Trauma Association (OTA)/Arbeitsgemeinschaft für Osteosynthesefragen (AO) type B or C pelvic ring fractures were treated by MPRSF (n = 30) or INFIX (n = 33). The main outcome measures were the Majeed score, incidence of complications, and adverse outcomes, and fixation stability as evaluated by finite element analysis.

Results

Sixty-three patients were included in the study, with an average age of 34.4 and 36.2 in modified group and conventional group, respectively. Two groups did not differ in terms of the injury severity score, OTA classification, cause of injury, and time to pelvic surgery. However, the MPSRF group had a rate of higher satisfactory results according to the Tornetta and Matta grading system than the conventional group (73.33% vs 63.63%) as well as a higher Majeed score (81.5 ± 10.4 vs 76.3 ± 11.2), and these differences were statistically significant at 6 months post-surgery. FEA showed that MPSRF was stiffer and more stable than INFIX and had a lower risk of implant failure.

Conclusions

Both MPSRF and INFIX provide acceptable biomechanical stability for the treatment of unstable anterior pelvic ring fractures. However, MPSRF provides better fixation stability and a lower risk of implant failure, and can thus lead to better clinical outcomes. Therefore, MPSRF should be more widely applied to anterior pelvic ring fractures

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-021-02618-9.

Functional outcomes of the anterior subcutaneous internal pelvic fixator (INFIX) technique for pelvic ring injuries: A case series

INTRODUCTION

Anterior external fixation is a well-established technique for treating pelvic ring injuries, but many complications are associated with it. The subcutaneous anterior internal fixator (INFIX) technique is associated with reduced complication rates and is less uncomfortable for patients.

OBJECTIVE

This study evaluated functional outcomes among patients with pelvic ring injuries treated using the INFIX method.

PATIENTS AND METHODS

In this retrospective case series, patients treated using the INFIX technique were reviewed for functional outcomes, using the Iowa Pelvic Score (IPS). Thirty-four patients, of mean age 39.2 years, were evaluated after a mean follow-up of 1.2 years.

RESULTS

Twenty-three of the 34 patients experienced reduction classified as excellent, and eleven as good, with no instances of moderate or poor reduction. One patient developed implant exposure and infection during follow-up. Twenty-six ultimately experienced an excellent or good functional result. The average final IPS was 79.4 (range: 48-100).

CONCLUSION

Our results reinforce prior evidence that the INFIX method is safe for fixating pelvic ring lesions. Most of our patients also experienced excellent or good functional recovery, suggesting that this technique is a viable option for treating certain pelvic ring injuries.

The role of anterior supra-acetabular external fixator as definitive treatment for anterior ring fixation in unstable pelvic fractures

PURPOSE

Management of anterior ring injuries is still a matter of discussion, and there are only few studies reporting anterior external fixator as definitive treatment for unstable pelvic injuries. This study aimed to describe the clinical and radiological outcomes of a consecutive series of mechanically unstable pelvic injuries that were treated with definitive anterior supra-acetabular external fixator for the anterior ring, and to identify risk factors for failure.

METHODS

We included a consecutive series of patients with unstable pelvic ring fractures who underwent anterior supra-acetabular external fixation for definitive treatment, between January 2012 and January 2020. All demographics, associated injuries and procedures, injury mechanism, and complications were analysed. Pelvic fracture was classified based on Orthopaedic Trauma Association/Tile AO (OTA/AO) and Young-Burgess classifications. Complications associated with the external fixator were revised. All patients were functionally evaluated at final follow-up and asked to report their clinical outcomes using the Majeed score.

RESULTS

A total of 47 patients were included, of which 25 were females. The median age was 44 years (interquartile range 23-59). Median follow-up duration was 14 months (interquartile range 6-31). The most frequent aetiology was motor vehicle accident (35), followed by fall from height (8). All fractures required posterior pelvic ring fixation. The median time during which patients had external fixation in situ was 11 weeks (interquartile range 9-13). All patients achieved healing of pelvic fracture at median time of 10 weeks (interquartile range 8-12). At final follow-up, the median displacement of the anterior pelvis was 6 mm (interquartile range 0-11). Superficial infection was the most common complication (n = 7). No washout procedures were needed. No major complication was reported. No patient required reoperation for anterior ring fracture. The median Majeed score was 88 points (range 60-95; interquartile range 80-90) at final follow-up.

CONCLUSION

Our findings suggest that the use of supra-acetabular external fixator is safe and effective for definitive treatment of the anterior ring in unstable pelvic fractures. It is a method with high proportion of excellent results, regardless of the type of fracture. The rate of complications is low, and it does not compromise functional results.

Minimally invasive internal fixation for unstable pelvic ring fractures: a retrospective study of 27 cases

Background

This study aimed to evaluate the radiographic and clinical outcomes of anterior subcutaneous internal fixation (INFIX) with or without posterior fixation for the treatment of unstable pelvic fractures.

Methods

Intraoperative blood loss, operation time, and duration of hospital stay were recorded, and fracture union and postoperative complications were evaluated. The fracture reduction quality was evaluated using the Matta score, pelvic deformity index (PDI), and pubic symphyseal width (PSW). In addition, the functional recovery and general quality of life were evaluated using the Majeed score and the 12-Item Short-Form Survey (SF-12), respectively. Furthermore, sacral nerve injury was evaluated using the Gibbons classification.

Results

Twenty-seven patients (14 males and 13 females) with an average age of 37.4 years were followed up for a mean of 22 months. The average operation time, median intraoperative blood loss, and average duration of hospital stay were 129 ± 47 min, 100 mL, and 22 ± 13 days, respectively. All patients achieved bony union with an average union time of 13.3 weeks. Furthermore, the average PDI and PSW were 0.07 ± 0.04 vs. 0.04 ± 0.03 (P = 0.009) and 1.15 ± 1.36 vs. 0.54 ± 0.17 (P = 0.048) before and after the operation, respectively. In 78% of the patients, the Matta or Majeed scores were excellent or good. The SF-12 physical and mental health scores were 45.1 ± 10.2 and 53.2 ± 6.3, respectively. Furthermore, one superficial surgical site infection, one loosening of INFIX, one lateral femoral cutaneous nerve irritation, one femoral nerve injury, and two implant discomforts due to the bar were noted. Among five patients with sacral nerve injuries, four were asymptomatic, and one just had paresthesia at the last follow-up.

Conclusion

INFIX with or without sacroiliac screws can achieve satisfactory radiographic and functional outcomes in the treatment of unstable pelvic ring fractures.

Trial registration

ChiCTR2000038812. Registered 04 October 2020. Retrospectively registered.

Bilateral vertical shear sacroiliac joint dislocations treated with bilateral triangular osteosynthesis in a young female: A case report

Case

Type C pelvic ring fractures account for only 0.34% of all pelvic fractures (Zhang, 2012 [1]). Anterior and posterior pelvic fixation is necessary in these injuries and can be accomplished using a variety of techniques. This study presents a case of bilateral vertical shear sacroiliac joint dislocations with an associated hip dislocation and pubic rami fractures that was treated with bilateral triangular osteosynthesis and INFIX.

Conclusion

This is the first reported case of bilateral vertical shear sacroiliac joint dislocation treated with triangular osteosynthesis. Anterior pelvic fixation with INFIX and posterior fixation with lumbopelvic and percutaneous sacroiliac screws resulted in excellent radiographic and clinical outcomes.

Biomechanical Analysis of Retrograde Superior Ramus Screw Fixation Constructs

OBJECTIVE

To investigate the biomechanical performance of different size and length retrograde superior ramus screws.

MATERIALS AND METHODS

A vertical superior ramus fracture was created in osteoporotic composite hemipelvis bone models (Sawbones, Vashon Island, WA). After reduction, 4 fixation groups were created by inserting either a solid 4.5 mm (Depuy Synthes, Paoli, PA) or cannulated 7.0 mm screw (Zimmer, Warsaw, IN) of either 80 mm (short) or 140 mm (long) in length. An intact and an unstabilized osteotomy group were also created. Samples underwent cyclic loading for 5000 cycles with data acquisition at regular intervals. At the end of cyclic loading, load to failure was performed.

RESULTS

The displacement after 5000 cycles for 4.5 mm short screws was significantly greater than 4.5 mm long and 7.0 mm short screws. At 5000 cycles, the 4.5-mm short screws had a significantly lower stiffness and lower load to failure than all other screws and were not different from the osteotomy model.

CONCLUSIONS

Short 4.5-mm screws demonstrated increased displacement, lower stiffness, and decreased load to failure compared with all other screws. The biomechanical performance of 4.5-mm short screws was no different than unstabilized controls. Longer bicortical screw fixation is suggested when possible. Additional biomechanical and clinical studies are needed to fully understand the significance of these findings.

Biomechanical study of Tile C3 pelvic fracture fixation using an anterior internal system combined with sacroiliac screws

Background

How to perform minimally-invasive surgery on Tile C pelvic fractures is very difficult, and it is also a hot topic in orthopedic trauma research. We applied minimally-invasive treatment using an anterior internal fixator combined with sacroiliac screws.

Objectives

To compare the biomechanical properties of different fixation models in pelvic facture specimens, using an internal fixation system or a steel plate combined with sacroiliac screws.

Methods

Sixteen fresh adult cadaver pelvic specimens were randomly separated into four groups named A, B, C, and D. The four groups were respectively stabilized using a two-screwed, three-screwed, or four-screwed anterior internal fixator or a steel plate with sacroiliac screws. All models were tested in both standing and sitting positions. Vertical loads of 600 N were applied increasingly. Shifts of bilateral sacroiliac joints and pubis rupture were measured.

Results

The shifts in sacroiliac joints and pubis rupture in the standing position were all less than 3.5 mm, and the shifts in the sitting position were all less than 1 mm. In the standing position, the results of shifts in the sacroiliac joints were group C < group D < group B < group A. For comparisons between A:B and C:D, P > 0.05. For comparisons between A, B:C, and D, P < 0.05. The results of shifts in pubis ruptures were group D < group C < group B < group A. In the comparison between C:D, P > 0.05; for comparisons between A:B, A:C, A:D, B:C, and B:D, P < 0.05. In the sitting posture, the results of shifts in the sacroiliac joints were group C < group D < group B < group A, and the shifts in the pubis ruptures were group D < group C < roup B < group A. For comparison between C:D, P > 0.05. For comparisons between A:B, A:C, A:D, B:C, and B:D, P < 0.05.

Conclusion

Use of an anterior internal fixator combined with sacroiliac screws effectively stabilized Tile C3 pelvic fractures. The stability of specimens increased as the number of screws in the internal fixator increased.

INFIX-safe and effective surgical option for complex fracture patterns of the anterior pelvic ring: A prospective single center study

Background

Complex fracture patterns of anterior pelvic ring are a challenge and usually needs extensive surgeries. The purpose of this study was to evaluate INFIX as a minimally invasive procedure for such injuries in terms of feasibility, outcomes and complications in the Indian population.

Methods

Patients with complex fracture patterns of anterior pelvic ring were selected for anterior INFIX application along with standard posterior stabilization. Outcomes were assessed radiographically by Matta's criteria and amount of displacement. Post-operative CT scan for relation of implant to vital structures and Doppler at varying hip flexion for possible vascular occlusion was used. Functional outcomes included both disease specific scores (Majeed score, IOWA pelvic score) and quality of life scores (SMFA, SF-12). Complications were also noted.

Results

12 cases out of 112 patients had complex fracture pattern of the anterior ring. Most common injury pattern were LC-3 and VS (n = 6 and 3) Young and Burgess type. The average follow up was 6 months. Fracture reduction as per Matta's criteria was excellent in 10 (83.3%) cases and good in 2 (16.6%) cases with functional outcomes excellent in 11 cases, and a mean Majeed score of 92.67 ± 5.8. The average SMFA score was 51 ± 4.39 and mean SF-12 scores for physical and mental health were 48.493 ± 6.74 and 56.370 ± 4.04 respectively. Complications noted were lateral femoral cutaneous nerve palsy (1/24 nerves), skin dehiscence (n = 2), infection (n = 2) and sacral nonunion (n = 1).

Conclusion

INFIX is a safe and effective minimally invasive technique for addressing complexfracture patterns involving the anterior half of pelvic ring with excellent fracture reduction, radiological and functional outcomes and predictable fracture healing.

[Comparison of effectiveness of anterior subcutaneous internal fixator and plate internal fixation for unstable anterior pelvic ring fractures]

Objective

To compare the effectiveness of anterior subcutaneous pelvic internal fixator (INFIX) and plate internal fixation in treatment of unstable anterior pelvic ring fractures.

Methods

The clinical data of 48 patients with unstable anterior pelvic ring fractures who met the selection criteria between June 2014 and December 2019 were retrospectively analyzed. Among them, 21 cases were treated with INFIX (INFIX group), and 27 cases were treated with plate (plate group). There was no significant difference in gender, age, body mass index, cause of injury, time from injury to operation, Injury Severity Score (ISS), and fracture type between the two groups ( P>0.05). The operation time, intraoperative blood loss, fracture healing time, partial weight-bearing time, and complete weight-bearing time were recorded and compared between the two groups. Matta standard was used to evaluate the quality of fracture reduction, and Majeed score system was used to evaluate the functional recovery of pelvic fracture after operation.

Results

The patients in both groups were followed up for an average of 12.5 months (range, 6-16 months). The operation time and intraoperative blood loss in INFIX group were significantly lower than those in plate group ( t=-11.965, P=0.000; t=-20.105, P=0.000). There was no significant difference in the quality of fracture reduction, fracture healing time, partial weight-bearing time, and complete weight-bearing time between the two groups ( P>0.05). At 14 weeks after operation, there was no significant difference in the scores of pain, working, standing and walking, and total scores between INFIX group and plate group ( P>0.05), but there were significant differences in sitting and sexual intercourse scores ( t=-4.250, P=0.003; t=-6.135, P=0.006). The incidences of lateral femoral cutaneous nerve injury, femoral nerve injury, and heterotopic ossification were significantly higher in INFIX group than in plate group ( P<0.05), while the incidence of incision infection was lower in INFIX group than in plate group ( P<0.05).

Conclusion

Compared with the plate internal fixation, the INFIX internal fixation can obtain the similar effectiveness for the unstable anterior pelvic ring fracture and has the advantages of shorter operation time, less blood loss, and lower risk of infection.

Stability of internal versus external fixation in osteoporotic pelvic fractures - a biomechanical analysis

INTRODUCTION

Osteoporosis-related fragility fractures of the pelvic ring (FFP) differ fundamentally from pelvic fractures in younger patients. However, very little is known about biomechanical stability of different osteosynthesis procedures addressing the anterior pelvic ring in these fractures. The aim of this study was to compare standard external fixation with internal fixation using a novel screw-and-rod system in osteoporotic fractures of the pelvic ring in terms of stiffness, plastic deformation and maximum load under cyclic loading in a human cadaveric model.

MATERIALS AND METHODS

A total of 18 embalmed osteoporotic cadaver pelvis specimens were randomized based on the T-score into a group for external fixation and a group for internal fixation. FFP type-IIB fractures were created. In addition to the external or internal fixator, a cement-augmented sacroiliac screw was implanted. Afterwards, axial cyclic loading was performed in a testing setup simulating one-leg stand.

RESULTS

Mean plastic deformation and stiffness both were significantly better in the internal fixation group than in the external fixation group (plastic deformation: 0.37 mm (SD: 0.23) versus 0.71 mm (SD: 0.26), p = 0.011; stiffness: 43.69 N/mm (SD: 18.39) versus 26.52 N/mm (SD: 9.76), p = 0.029). Maximum load did not differ significantly between internal fixator (506.3 N; SD: 129.4) and external fixator (461.1 N; SD: 147.4) (p = 0.515).

CONCLUSIONS

Submuscular internal fixation might be an interesting alternative to external fixation in clinical practice because of better biomechanical properties as well as several advantages in clinical use.

Biomechanical comparison of three minimally invasive fixations for unilateral pubic rami fractures

BACKGROUND

To compare the mechanical characteristics of a percutaneous superior pubic intramedullary screw, percutaneous bridging plate and percutaneous screw-rod system of the anterior ring for the treatment of unilateral vertical pubic fractures to provide a reference for clinical application.

METHODS

A finite element model of pelvic anterior ring injury (unilateral vertical pubic fracture) was produced. The fractures were fixed with a percutaneous superior pubic intramedullary screw, percutaneous bridging plate and percutaneous screw-rod system of the anterior ring and their combinations in 5 types of models. The fracture stabilities under vertical, bilateral and anterior-posterior load were quantified and compared based on the displacement of the hip joints' midpoint as quantificational index of fracture stability.

RESULTS

In the condition of bilateral and anterior-posterior load, the vertical, bilateral and anterior-posterior displacements of the hip joints' midpoint of different models were significantly different respectively. In general, the displacements of the 5 pelvic anterior ring fixations were ranked from maximum to minimum as follows: bridging plate, pelvic anterior screw-rod system, combination of bridging plate and pelvic anterior screw-rod system, superior pubic intramedullary screw and combination of superior pubic intramedullary screw and pelvic anterior screw-rod system.

CONCLUSION

For the fixation in unilateral pubic fractures of pelvic ring injury, the percutaneous superior pubic intramedullary screw is optimal, the percutaneous pelvic anterior screw-rod system is the second choice, and percutaneous bridging plate ranks the third. The percutaneous pelvic anterior screw-rod system can significantly increase fixation stability of the percutaneous superior pubic intramedullary screw and the percutaneous bridging plate.

[Application of anterior subcutaneous internal fixator combined with posterior plate in treatment of unstable pelvic fractures]

OBJECTIVE

To investigate the effectiveness of anterior subcutaneous internal fixator combined with posterior plate in the treatment of unstable pelvic fractures.

METHODS

Between January 2015 and January 2019, 26 cases of unstable pelvic fractures were treated with anterior subcutaneous internal fixator combined with posterior plate. There were 16 males and 10 females, with an average age of 42.8 years (range, 25-66 years). According to the Tile classification, 9 of them belonged to type B2, 6 to type B3, 7 to type C1, 3 to type C2, 1 to type C3. The injury severity score (ISS) was 6-43 (mean, 18.3). Four cases combined with brain injury, 7 with limb fractures, 3 with hemopneumothorax, 1 with sciatic nerve injury. The time from injury to operation was 4-12 days (mean, 6.4 days). The intraoperative blood loss, operation time, and the complications were recorded. The fracture reduction and the postoperative function of patients were evaluated.

RESULTS

All patients were followed up 12-26 months (mean, 16.8 months). The operation time was 65-142 minutes (mean, 72.5 minutes) and the intraoperative blood loss was 42-124 mL (mean, 64.2 mL). There were 2 cases of unilateral lateral femoral cutaneous nerve stimulation, 1 case of femoral nerve paralysis, and 1 case of superficial infection of incision, which were cured after corresponding treatment. X-ray films showed that all fractures healed at 3 months after operation. At last follow-up, according to Matta criteria for fracture reduction, the results were excellent in 8 cases, good in 15 cases, fair in 2 cases, and poor in 1 case, with an excellent and good rate of 88.5%. According to Majeed scoring system for pelvic function, the results were excellent in 10 cases, good in 12 cases, and fair in 4 cases, with an excellent and good rate of 84.6%.

CONCLUSION

For unstable pelvic fractures, the anterior subcutaneous internal fixator combined with posterior plate has fewer operative complications, high security, and achieve good effectiveness.

What's New in Percutaneous Pelvis Fracture Surgery?

Percutaneous reduction and fixation of pelvic ring fractures is now widely accepted as a safe and effective treatment method. The only exception remains reduction and fixation of pubic symphyseal injuries. Several units from China and one from Spain have published clinical and biomechanical studies supporting percutaneous reduction and fixation of the pubic symphysis with various screw configurations. The initial clinical results are promising. Biomechanical data show there is little difference between plate and screw fixation. We review the current literature and also present a case performed by ourselves using this novel technique.

[Comparison study of minimally invasive percutaneous bridge internal fixator and traditional external fixator in treatment of unstable pelvic fractures]

Objective

To evaluate the effectiveness of unstable pelvic fractures treated with minimally invasive percutaneous bridge internal fixator or traditional external fixator.

Methods

The clinical data of 45 patients with unstable pelvic fractures who met the selection criteria between January 2013 and February 2018 were retrospectively analyzed. According to the different surgical methods, they were divided into two groups. In the observation group (25 cases), minimally invasive percutaneous bridge internal fixators were used, and three-dimensional printing pelvic models were used to simulate the reduction and fixation before operation to develop individual reduction strategies. In the control group (20 cases), external fixators were used. There was no significant difference between the two groups in gender, age, cause of injury, fracture type (according to Tile classification), and time from injury to operation ( P>0.05). The operation time, intraoperative blood loss, fracture healing time, and complications were recorded and compared between the two groups. The reduction quality was evaluated according to the Matta standard, and functional recovery was evaluated according to the Majeed scoring standard.

Results

All patients were followed up 12-20 months (mean, 15 months). The operation time of the observation group was significantly longer than that of the control group ( t=2.719, P=0.009); no significant difference in intraoperative blood loss was found between the two groups ( t=0.784, P=0.437). There was no significant difference between the two groups in fracture healing time ( t=0.967, P=0.341). According to the Matta standard, the excellent and good rate of the observation group was 92%, and that of the control group was 70%, showing no significant difference between the two groups ( χ ² =3.748, P=0.053). At last follow-up, according to the Majeed scoring standard, the excellent and good rate of the observation group was 88%, and that of the control group was 60%, showing significant difference between the two groups ( χ ² =4.717, P=0.030). The incidences of incision and nailway infection, secondary displacement of fracture, and malunion in the observation group were significantly lower than those in the control group ( P<0.05); the differences in incidences of iatrogenic injury of lateral femoral cutaneous nerve, deep vein thrombosis, and loosening of fixation between the two groups were not significant ( P>0.05).

Conclusion

Minimally invasive percutaneous bridge internal fixator is a safe and effective method for the treatment of unstable pelvic fractures. It has the advantages of minimal trauma, stable fixation, less interference to patients' daily life, early functional exercise, and quickly recovery after operation.

[Research progress on minimally invasive treatment of anterior pelvic ring fracture]

OBJECTIVE

To summarize the related research results of minimally invasive treatment of anterior pelvic ring fracture, and to improve the understanding of minimally invasive treatment of anterior pelvic ring fracture.

METHODS

The literature of minimally invasive treatment of anterior pelvic ring fracture at domestic and overseas in recent years was reviewed, and the reduction and fixation methods of minimally invasive treatment were summarized and analyzed.

RESULTS

The pelvic reduction frame may be an effective auxiliary method for minimally invasive reduction of pelvis. The fixation methods of anterior pelvic ring include percutaneous screw fixation, stent fixation, and percutaneous plate fixation.

CONCLUSION

One kind of fixation is not applicable to all types of anterior pelvic ring fracture, and the fixation method should be selected according to the type of fracture and the patient's condition to minimize the complications.

Biomechanics of Anterior Ring Internal Fixation Combined with Sacroiliac Screw Fixation for Tile C3 Pelvic Fractures

Background

Despite the development of minimally invasive techniques for pelvic fractures, performing minimally invasive surgery for Tile C3 pelvic fractures remains challenging. Thus, we propose use of anterior ring internal fixation combined with sacroiliac screw fixation for Tile C3 pelvic fractures.

Material/Methods

A normal pelvic finite element model (model 1) was established. Two-screw, three-screw, and four-screw anterior ring internal fixators and plate combined with sacroiliac screw Tile C3 pelvic fracture models (models 2, 3, 4, and 5, respectively) were also established. A vertical load of 600 N was applied on S1. The distribution of displacement and stress in the standing and sitting positions was compared.

Results

Models 2, 3, 4, and 5 can provide effective fixation. Compared with model 1, in the erect position, the maximum displacement of models 2, 3, 4, and 5 increased by 66.51%, 65.36%, 35.16%, and 35.47% and the maximum stress increased by 201.78%, 130.65%, 100.82%, and 99.03%, respectively. Compared with model 1, in sitting position, the maximum displacement of models 2, 3, 4, and 5 increased by 9.1%, 11.04%, 5.57%, and 8.59% and the maximum stress increased by 157.73%, 118.02%, 98.32%, and 93.16%, respectively.

Conclusions

Anterior ring internal fixators combined with sacroiliac screws can effectively fix Tile C3 pelvic fractures.

Comparison of Biomechanical Performance of Five Different Treatment Approaches for Fixing Posterior Pelvic Ring Injury

Background

A large number of pelvic injuries are seriously unstable, with mortality rates reaching 19%. Approximately 60% of pelvic injuries are related to the posterior pelvic ring. However, the selection of a fixation method for a posterior pelvic ring injury remains a challenging problem for orthopedic surgeons. The aim of the present study is to investigate the biomechanical performance of five different fixation approaches for posterior pelvic ring injury and thus provide guidance on the choice of treatment approach in a clinical setting.

Methods

A finite element (FE) model, including the L3-L5 lumbar vertebrae, sacrum, and full pelvis, was created from CT images of a healthy adult. Tile B and Tile C types of pelvic fractures were created in the model. Five different fixation methods for fixing the posterior ring injury (PRI) were simulated: TA1 (conservative treatment), TA2 (S1 screw fixation), TA3 (S1 + S2 screw fixation), TA4 (plate fixation), and TA5 (modified triangular osteosynthesis). Based on the fixation status (fixed or nonfixed) of the anterior ring and the fixation method for PRI, 20 different FE models were created. An upright standing loading scenario was simulated, and the resultant displacements at the sacroiliac joint were compared between different models.

Results

When TA5 was applied, the resultant displacements at the sacroiliac joint were the smallest (1.5 mm, 1.6 mm, 1.6 mm, and 1.7 mm) for all the injury cases. The displacements induced by TA3 and TA2 were similar to those induced by TA5. TA4 led to larger displacements at the sacroiliac joint (2.3 mm, 2.4 mm, 4.8 mm, and 4.9 mm), and TA1 was the worst case (3.1 mm, 3.2 mm, 6.3 mm, and 6.5 mm).

Conclusions

The best internal fixation method for PRI is the triangular osteosynthesis approach (TA5), followed by S1 + S2 screw fixation (TA3), S1 screw fixation (TA2), and plate fixation (TA4).