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

Percutaneous hollow nail internal fixation treatment for fractures of the pubic symphysis and its adjacent areas

Purpose

To explore the percutaneous minimally invasive treatment of pubic symphysis and its adjacent fractures.

Method

Since May 2021, 13 cases of fractures involving the pubic symphysis and its adjacent parts were treated with x-ray fluoroscopic localization and percutaneous cannulated screw fixation across the symphysis pubis, the guide pin pierced the symphysis pubis and the fracture end and stopped at the inner edge of the acetabulum. Visual analogue scale (VAS) was used to evaluate the effect of the operation, and the patients were followed up.

Result

The screw insertion operation time was 25-40 min, with an average of 31.45 min; The number of perspectives is 20-40, with an average of 28.75. The average intraoperative blood loss was 10 ml, and there were no puncture complications such as nerve or vascular damage. The initial stability of the fractured end of the patient after surgery was good. The VAS score decreased from preoperative 8-10 points to postoperative 1-2 points (average of 1.5 points). The follow-up time was 3-25 months, with an average of 8.5 months. At the last follow-up, the excellent and good rate of pelvic function according to Majeed pelvic function scoring system was 100%. One patient had screws removed 1.5 years after surgery, while the remaining twelve patients did not have screws removed. All patients did not experience any discomfort symptoms caused by pubic symphysis fixation.

Conclusion

Percutaneous hollow nail internal fixation is an effective method for treating fractures of the pubic symphysis and its adjacent parts.

Lower abdominal cyst complicated with suspected infection following INFIX internal fixation for pelvic fracture: a report of two rare cases

BACKGROUND

The Internal Fixator (INFIX) is a popular method, known for its minimal invasiveness and short operation time, for treating anterior pelvic ring fractures. Studies have shown that postoperative complications may occur, including anterolateral femoral cutaneous nerve injury, the femoral nerve paralysis, and delayed fracture healing. These complications are believed to be related to surgical stimulation, an excessively long lateral end of the connecting rod, a small distance between the screw and bone surface, insufficient pre-bending of the connecting rod, and difficulties in fracture reduction.

CASE PRESENTATION

We report two unique cases of lower abdominal pseudocyst complicated with suspected infection after INFIX treatment of pelvic fractures at our trauma center. Following surgical removal of the internal fixation, resolution of the cysts was observed in both patients, and subsequent postoperative follow-up revealed the absence of any residual sequelae. These cases have not been reported in previous literature reviews.

DISCUSSION

The lower abdominal cysts, potentially arising from the dead space created during intraoperative placement of the INFIX rod, may increase infection risk. The etiology remains uncertain, despite the presence of abnormal inflammation markers in both cases, and staphylococcus aureus found in one. These cysts were confined to the lower abdomen, not involving the internal fixation, and hence, only the INFIX was removed. Postoperative oral cefazolin treatment was successful, with resolved pseudocysts and no subsequent discomfort.

CONCLUSION

We report two unprecedented cases of post-INFIX abdominal cysts, with a suspected link to intraoperative dead space. Despite uncertain etiology, successful management involved INFIX removal and oral cefixime therapy. These findings necessitate further exploration into the causes and management of such complications.

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.

Comparison of ESIN and other minimally invasive techniques for anterior pelvic ring injury: a finite element analysis and case-control study

OBJECT

A novel technique, percutaneous elastic stable intramedullary nail fixation (ESIN), proposed by our team for the treatment of anterior pelvic ring injury. Finite element analysis and retrospective case-control study were used to compare biomechanical properties and clinical outcomes between ESIN and other techniques.

METHODS

Four groups of finite element models of pelvic anterior ring injury were simulated, including ESIN (model A), retrograde transpubic screw fixation (RTSF, model B), subcutaneous internal fixator (model C), and external fixator (model D), and a vertical downward load of 500 N was applied to the S1 vertebral endplate. Stress and displacement distributions of intact pelvis, displacement distributions of pubic fracture fragments, and stress distributions of fixation devices were analysed. Then 31 patients with anterior pelvic ring injury (15 in the ESIN group and 16 in the RTSF group) were reviewed. Clinical outcomes were evaluated at the final follow-up. Postoperative complications were also recorded.

RESULTS

Under 500N loading, the intact stability of the pelvis was compared as follows: model B (20.58 mm, 121.82 MPa), model A (20.80 mm, 129.97 MPa), model C (22.02 mm, 141.70 MPa), and model D (22.57 mm, 147.06 MPa). The regional stability of superior pubic ramus was compared as follows: model B (9.48 mm), model A (10.16 mm), model C (10.52 mm), and model D (10.76 mm). All 31 patients received follow-up at least 12 months postsurgery (range 12-20 months). Age, sex, injury mechanism, fracture type, time between the injury and operation, American Society of Anesthesiologists score, intraoperative blood loss, hospital stay, follow-up period, time to union, and Majeed scores did not differ significantly between the two groups ( P >0.05). However, the differences in the duration of unilateral surgery, unilateral intraoperative fluoroscopy and one-time success rate were significant ( P <0.05).

CONCLUSIONS

With sufficient biomechanical stability and minimally invasive advantage, the percutaneous technique using ESIN can be used to successfully treat anterior pelvic ring injuries. In addition, advantages over RTSF include a shorter duration of surgery, reduced requirement for intraoperative fluoroscopy, and a higher one-time success rate. ESIN therefore constitutes a good alternative to RTSF.

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.

Causes and associations with mortality in patients with pelvic ring injuries with haemorrhagic shock

BACKGROUND

High energy pelvic ring injuries are associated with significant morbidity and mortality and can be accompanied by haemorrhagic shock following associated vascular injury. This study evaluated the causes and predictors of mortality in haemodynamically unstable pelvic fractures.

METHODS

This retrospective observational study at a Major Trauma Centre reviewed 938 consecutive adult patients (≥ 18yrs) with pelvic ring injuries between December 2014 and November 2018. Patients with features of haemorrhagic shock were included, defined as: arrival Systolic BP < 90 mmHg, Base Deficit ≥ 6.0 mmol/l, or transfusion of ≥ 4 units of packed red blood cells within 24 h.

RESULTS

Of the 102 patients included, all sustained injuries from high energy trauma, and 47.1% underwent a haemorrhage control intervention (Resuscitative Endovascular Balloon Occlusion of the Aorta-REBOA, Interventional Radiology-IR, or Laparotomy). These were more often required following vertical shear injuries (OR 10.7, p = 0.036). Overall, 33 patients (32.4%) died; 16 due to a head injury, and only 2 directly from acute pelvic exsanguination (6.1%). Multivariable logistic regression demonstrated that increasing age, Injury Severity Score, Abbreviated Injury Scale (AIS) Head ≥ 3 and open pelvic fracture were all independent predictors of mortality, and IR was associated with reduced mortality. Lateral Compression III (LC3) injuries were associated with mortality due to multiple organ dysfunction syndrome (MODS).

CONCLUSION

Haemodynamically unstable patients with pelvic ring injuries have a high mortality rate, but death is usually attributed to other injuries or later complications, and not from acute exsanguination. This reflects improvements in resuscitative care, transfusion protocols, and haemorrhage control techniques.

Bony Sacral Volume after Sacro-Iliac Screw Fixation of Pelvic Fractures Is Dependent on Reduction of the Anterior Pelvic Ring

Pelvic ring injuries are uncommon but serious injuries. Percutaneous sacro-iliac screw fixation (SSF) is the standard treatment for posterior stabilization of pelvic fractures. Compression forces of the SSF might cause deformity of the sacrum and the pelvic ring. The aim of this radio-volumetric study is to evaluate the morphometry of the sacrum and pelvic ring in SSF for posterior pelvic fractures. (1) Methods: We conducted a radio-volumetric study measuring the bony sacral volume before and after SSF for a pelvic fracture based on a three-dimensional reconstruction of the pre- and postoperative computed tomography scan of 19 patients with a C-type pelvic fracture. In addition to the bony sacral volume, we assessed the pelvic deformity and the load bearing axis. We compared the results of patients without anterior stabilization (Group A) to patients who had additional ORIF of the anterior pelvic ring. (2) Results: Median age of the patients was 41.2 years (±17.8). All patients received percutaneous SSF with partially threaded 7.3 mm screws. The sacral volume decreased from 202.9 to 194.3 cm³ in group A (non-operative treatment anterior, n = 10) and an increase of sacral volume from 229.8 to 250.4 cm³ in group B (anterior ORIF; n = 9). Evaluation of the pelvic deformity also reflected this trend by a decrease of the ipsilateral load-bearing angle in group A (37.0° to 36.4°) and an increase of this angle in group B (36.3 to 39.9°). (3) Conclusions: Bony sacral volume and pelvic deformity after sacro-iliac screw fixation in pelvic fractures depend on treatment of the anterior pelvic ring. Reduction and fixation of the anterior fracture shows an increase of the bony sacral volume and the load bearing angle leading to a closer to normal reconstruction of the pelvic anatomy.

TiRobot‑assisted versus conventional fluoroscopy-assisted percutaneous sacroiliac screw fixation for pelvic ring injuries: a meta‑analysis

BACKGROUND

The TiRobot is the only robot that has been reported in the literature for posterior pelvic injuries. We aim to compare TiRobot-assisted pelvic screw fixation with the conventional fluoroscopy-assisted percutaneous sacroiliac screw fixation.

METHODS

We conducted a meta-analysis to identify studies involving TiRobot‑assisted versus conventional percutaneous sacroiliac screw fixation for pelvic ring injuries in electronic databases, including Web of Science, Embase, PubMed, Cochrane Controlled Trials Register, Cochrane Library, Highwire, CBM, CNKI, VIP, and WanFang database, up to April 2022. The following keywords were used: "TiRobot," "robot," "robotic," "pelvic fracture," "screw fixation," "percutaneous," and "pelvic ring injury." Pooled effects of this meta-analysis were calculated using STATA SE version 15.0.

RESULTS

Compared with conventional fluoroscopy-assisted percutaneous sacroiliac screw fixation, TiRobot will result in less radiation exposure time of screw implantation (P = 0.000), less frequency of intraoperative fluoroscopy (P = 0.000), fewer guide wire attempts (P = 0.000), less intraoperative blood loss (P = 0.005), better screw accuracy (P = 0.011), better Majeed score (P = 0.031), and higher overall excellent and good rates of Majeed score (P = 0.018). However, there were no significant differences in terms of operative time (P = 0.055), fracture healing time (P = 0.365), and overall excellent and good rate of reduction accuracy (P = 0.426) between the two groups.

CONCLUSION

TiRobot-assisted fixation has less intraoperative fluoroscopy and intraoperative blood loss, superior screw accuracy, and Majeed score compared with conventional percutaneous sacroiliac screw fixation. TiRobot has no significant effect on operative time, fracture healing time, and reduction accuracy. Given the relevant possible biases in our meta-analysis, we required more adequately powered and better-designed RCT studies with long-term follow-up to reach a firmer conclusion.

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.

Posterior INFIX for Treating Unilateral Unstable Sacral Fractures

Objective

To evaluate the clinical outcomes of the treatment of unilateral unstable sacral fractures by fixation with the posterior INFIX (posterior pelvic ring screw‐rod internal fxation).

Methods

Data of 60 patients with unilateral unstable sacral fractures who underwent surgery from March 2013 to March 2020 were retrospectively analyzed according to the selection criteria. All patients were associated with anterior pelvic ring injuries, and the operations were performed by the same team of surgeons. According to the different types of internal fixation, the patients were divided into two groups, which both included 30 patients: the posterior INFIX group and iliosacral screw fixation group. The demographic and clinical data of the two patient groups, such as age, sex, sacral fracture types based on the Denis classification, operation time, amount of intraoperative bleeding, intraoperative fluoros copy time, Majeed pelvic score at final follow‐up, and quality of fracture reduction based on Mears and Velyvis's imaging classification criteria were collected by the same researcher and compared statistically.

Results

All patients were continuously followed up for 23.17 ± 3.34 months (range, 12 to 46 months). All sacral fractures healed with an average healing time of 9.3 ± 2.24 months (range, 6 to 18 months). None of the patients had re‐displacement of the fracture or fixation failure. Compared to the iliosacral screw group, the posterior INFIX group patients had more intraoperative bleeding (t = 3.59, P < 0.001), shorter operation time (t = 4.49, P < 0.001), and shorter intraoperative fluoroscopy time (t = 6.26, P < 0.001). There were no statistical differences between the two groups in terms of age, sex, fracture type, Majeed score, and quality of fracture reduction (P > 0.05). In the posterior INFIX group, one patient had a superficial wound infection and one patient complained of discomfort due to a prominent fixation. In the iliosacral screw fixation group, one patient had intraoperative iatrogenic S1 nerve injury and vessel injury. The posterior INFIX fixation was a simpler manipulation with higher safety, shorter time of operation and intraoperative fluoroscopy, and similar clinical outcomes compared to iliosacral screw fixation.

Conclusion

For the treatment of unilateral unstable sacral fractures, the posterior INFIX fixation can be recommended in clinic application.