Femoral nerve palsy after pelvic fracture treated with INFIX: a case series

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.

Iliacus hematoma causing late femoral nerve palsy

Femoral nerve palsy is rare and may progress insidiously, leading to late clinical presentation. Identifying the underlying cause is very important for treatment. An iliacus hematoma causing nerve palsy is perhaps the most innocent etiology. However, this hematoma sometimes causes only abdominal pain and may even be misdiagnosed as a late intra-abdominal pathology.

Do we need to fix the anterior fracture component in insufficiency fractures of the pelvis? A biomechanical comparison on an FFP type IIIc fracture in an osteoporotic pelvic bone model

There is a growing understanding of the specific characteristics of insufficiency fractures of the pelvis and of general requirements for the treatment of affected patients with focus on early mobilization and effective pain reduction as the main goals of therapy. While there is consensus on the significance of achieving stability of the dorsal pelvic ring structures there is still an open discussion about the potential benefits of additional stabilization of an anterior fracture component. Within a biomechanical test setup, two established methods of dorsal fracture fixation were tested under axial loading (25-1200 N; 1000 test cycles) on an explicit osteoporotic bone model (n = 32) with a standardized FFP type IIIc fracture with and without additional fixation of the anterior fracture component. Dorsal fixation was performed with and long and a short 7.3 mm cannulated screw in S1 in one group (n = 16), and a trans sacral bar with an additional short 7.3 mm cannulated screw in S1 in the other group (n = 16). Half of the samples received a 7.3 mm cannulated retrograde transpubic screw for anterior fixation. The fixation with the trans sacral bar and the additional anterior screw fixation showed the highest rate of stability (p = 0.0014), followed by the double SI-screw fixation with stabilization of the anterior fracture (p = 0.0002). During testing, we observed the occurrence of new sacral fractures contralateral to the initial fracture in 22/32 samples. The results let us assume that stabilization of an additional anterior fracture component relevantly improves the stability of the entire ring construct and might prevent failure of the dorsal stabilization or further fracture progression.

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.

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.

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.

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.

Midterm follow-up of elderly patients with fragility fractures of the pelvis: A prospective cohort-study comparing operative and non-operative treatment according to a therapeutic algorithm

INTRODUCTION

The treatment of fragility fractures of the pelvis (FFP) is a challenge. The variations of non-operative- and of operative treatment are manifold and a structured treatment algorithm is lacking. The purpose of this study was to evaluate the outcome of elderly patients with a FFP who were treated with a therapeutic algorithm based on the FFP-classification.

PATIENTS AND METHODS

In a prospective cohort study 154 patients (mean age: 81.8 ±.61 (65-96); female: (86.8%; 131/154). BMI: 23.7 ±.34 (15-43)) with a FFP after inadequate mono trauma were treated according to a strict therapeutic algorithm between 04/2016 and 12/2018. According to a classification based on CT-scans either a standardized operative treatment or conservative therapy was induced and the outcome regarding objective measurements of mobility, pain, need for analgesics and mortality during hospital stay and after one year was analyzed.

RESULTS

82/154 participants (53.2%) were assigned to the conservative treatment group and 72 participants (46.8%) to the operative treatment group. The overall one-year survival rate was 78.1% (118/151). The survival of the operative treatment group was 90.7% (49/54) and significantly higher than the survival of the conservative treatment group (74.7%; 56/75; p=.023). The one-year follow up showed a high dispersion of the pain level in the operatively treated patients and a significantly higher mean in comparison to conservatively treated patients. Both treatment groups showed increasing numbers of patients with unlimited mobilization but also immobile patients. Overall in 31.0% (18/58) of the operative participants and in 14.9% (14/93) of the non-operatively treated participants complications occurred (p=.04).

CONCLUSION

The strict compliance to the presented treatment algorithm of FFP with an operative strategy starting from FFP IIc leads to a significantly lower mortality within one year in comparison to the conservatively treated patients. The worst outcome and the highest mortality was seen in patients who refused the recommendation of operative stabilization. The results of this study justify to proceed with the strict classification dependent treatment algorithm and also support the early switch-over to operative treatment of patients with failed conservative therapy in FFP I to FFP IIb.

Fragility Fractures of the Pelvis and Sacrum: Current Trends in Literature

Fragility fractures of the pelvis (FFP) and fragility fractures of the sacrum (FFS), which are emerging in the geriatric population, exhibit characteristics that differ from those of pelvic ring disruptions occurring in the younger population. Treatment of FFP/FFS by a multidisciplinary team can be helpful in reducing morbidity and mortality with the goal of reducing pain, regaining early mobility, and restoring independence for activities of daily living. Conservative treatment, including bed rest, pain therapy, and mobilization as tolerated, is indicated for treatment of FFP type I and type II as loss of stability is limited with these fractures. Operative treatment is indicated for FFP type II when conservative treatment has failed and for FFP type III and type IV, which are displaced fractures associated with intense pain and increased instability. Minimally invasive stabilization techniques, such as percutaneous fixation, are favored over open reduction internal fixation. There is little evidence regarding outcomes of patients with FFP/FFS and more literature is needed for determination of optimal management. The aim of this article is to provide a concise review of the current literature and a discussion of the latest recommendations for orthopedic treatment and management of FFP/FFS.

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.

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.

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.

[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.

Management of Pelvic Ring Injury Patients With Hemodynamic Instability

Pelvic ring injuries (PRI) are among the most difficult injuries to deal with in orthopedic trauma. When these injuries are accompanied by hemodynamic instability their management becomes significantly more complex. A methodical assessment and expeditious triage are required for these patients followed by adequate resuscitation. A major triage decision is whether these patients should undergo arterial embolization in the angiography suit or prompt packing and pelvic stabilization in the operating room. Patient characteristics, fracture type and injury characteristics are taken into consideration in the decision-making process. In this review we discuss the acute evaluation, triage and management of PRIs associated with hemodynamic instability. An evidence based and protocol driven approach is necessary in order to achieve optimal outcomes in these patients.

Transfer of Sciatic Nerve Motor Branches in High Femoral Nerve Injury: A Cadaver Feasibility Study and Clinical Case Report

BACKGROUND

Femoral nerve injury causes knee dysfunction, and high femoral nerve injury is difficult to repair.

OBJECTIVE

To evaluate the anatomic feasibility of transferring the sciatic nerve motor branches in high femoral nerve injury.

METHODS

The femoral nerve was exposed in both lower extremities of 3 adult fresh-frozen cadavers; each branch was noninvasively dissected to its proximal nerve fiber intersection point and distal muscle entry point. The branches of the sciatic nerve were also exposed. The length, diameter, and number of myelinated fibers were measured in each femoral and sciatic nerve branch. The feasibility of tension-free direct suture between the femoral and sciatic nerve branches was evaluated. One patient was treated with transfer of a nerve branch innervating the semitendinosus muscle to the femoral nerve branch and was followed up for 18 mo.

RESULTS

The diameters and numbers of myelinated fibers in the femoral nerve branches matched those of the sciatic nerve branches. In the single patient, a combined femoral nerve bundle (comprising the rectus femoris and vastus lateralis branches) was used as a graft. The branch of the sciatic nerve was sutured with the muscle branch of the femoral by using a sural nerve as a nerve graft. The knee joint straightening strength reached medical research council grade 4+.

CONCLUSION

The proximal motor branches of the sciatic nerve may be transferred as donor nerves to repair high femoral nerve injury. A femoral nerve bundle comprising the rectus femoris and vastus lateralis branches may be used as the receptor nerve.

Stabilization of a Type B1.1 Injury in a Morbidly Obese Patient Using an Internal Fixator in a Minimally Invasive Technique: A Case Report

CASE

In this case report, we present a novel stabilization technique of the pubic symphysis using an internal spinal fixator in a 78-year-old morbidly obese woman having a pelvic disruption type B1.1 (AO classification). We treated the disruption using an internal fixator to reduce the extent of the incision and soft-tissue damage.

CONCLUSIONS

The use of an internal fixator, known from percutaneous spinal fixation, for the stabilization of the pubic symphysis in cases of disruption ("open book" injuries) may be an alternative to the standard plate fixation as a novel minimally invasive stabilization 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.

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.

[Anterior subcutaneous internal fixation combined with posterior percutaneous iliosacral screw for treatment of unstable pelvic fractures]

OBJECTIVE

To assess the effectiveness of anterior subcutaneous internal fixation (INFIX) combined with posterior percutaneous iliosacral screw for the treatment of unstable pelvic fractures.

METHODS

Between August 2016 and November 2017, 19 cases of unstable pelvic fractures were treated with anterior subcutaneous INFIX combined with posterior percutaneous iliosacral screw. There were 14 males and 5 females, with an average age of 40.6 years (range, 17-69 years). Causes of injury included traffic accident injury in 11 cases, falling from height in 5 cases, bruise injury by heavy object in 3 cases. According to Tile classification, there were 2 cases of type B1, 6 cases of type B2, and 11 cases of type C. Anterior ring injuries included bilateral pubic ischial ramus fractures in 12 cases, unilateral pubic ischial ramus fractures in 5 cases, and symphysis pubis separation in 2 cases. Posterior ring injuries included sacroiliac ligament injuries in 2 cases, unilateral iliac bone fractures in 3 cases, unilateral sacral fractures in 11 cases, unilateral sacroiliac joint dislocation in 2 cases, and bilateral sacral fracture in 1 case. The intraoperative blood loss and operation time were recorded, and the fracture healing and postoperative complications were observed. Matta score was used to evaluate the reduction of fracture, and Majeed score was used to evaluate the postoperative function of patients.

RESULTS

The operation time was 47-123 minutes (mean, 61.4 minutes) and the intraoperative blood loss was 50-115 mL (mean, 61.1 mL). One case had superficial infection at the site of screw implantation, and 1 case had unilateral cutaneous nerve stimulation, which were cured after corresponding treatment. There was no damage of urinary system, reproductive system, and intestine. All cases were followed up 12-25 months (mean, 18.1 months). All the fractures healed after operation, the average healing time was 9.5 weeks (range, 8-13 weeks); no nonunion, delayed healing, internal fixation loosening, fracture, and other situations occurred. Of the 2 patients with lumbosacral plexus injury before operation, 1 recovered completely and 1 had residual mild claudication. At last follow-up, the reduction of fracture was evaluated by Matta scoring standard, the results were excellent in 13 cases and good in 6 cases, with an excellent and good rate of 100%; the function was evaluated by Majeed scoring standard, the results were excellent in 15 cases and good in 4 cases, with an excellent and good rate of 100%.

CONCLUSION

Minimally invasive pelvic stabilization by using anterior subcutaneous INFIX and posterior percutaneous iliosacral screw for treatment of unstable pelvic fractures, can achieve good fracture reduction and definitive stabilization with minimum complications and obtain excellent functional outcomes.

Use of INFIX for managing unstable anterior pelvic ring injuries: A systematic review

INTRODUCTION

Subcutaneous screw rod system which is popularly known as Pelvic internal fixator (INFIX) has emerged as an alternative to external fixators in management of unstable pelvic injuries. INFIX has shown various advantages over external fixation such as reduced infection rate and patient morbidity. However, it has its own set of complications such as lateral femoral cutaneous nerve injury, heterotopic ossification, femoral nerve palsy etc. We intended to conduct a systematic review of the current literature to assess outcomes and complications with INFIX technique of fixation.

METHODS

A comprehensive search of literature was performed based on Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines and online database of EMBASE, PubMed, Medline and Scopus was searched for all studies in English language till March 2020. Included studies were reviewed for demographic data, fracture type/classification, radiological outcome and functional outcomes. The inclusion criteria were: 1. Studies in English language 2. Clinical studies reporting use of INFIX technique in pelvis fracture where clinical and radiological outcomes were reported.

RESULTS

Twenty-two studies fulfilling inclusion and exclusion criteria were included in this systematic review with total of 619 patients. Radiographic parameters and outcome measures were infrequently reported. Fixation with INFIX in these fractures leads to 87% excellent to good radiological results and 84% excellent to good functional results. Complications include lateral femoral cutaneous nerve irritation (25.3%), heterotopic ossification (24.7%), infection (3%), and femoral nerve palsy (1.6%); which is likely related to placing the bar and screws too deep.

CONCLUSION

This analysis supports the use of INFIX in management of unstable pelvis fractures where anterior fixation is required.

[Three-point buttressing with internal fixator for minimally invasive stabilization of the anterior pelvic ring : Operative technique and first clinical results]

BACKGROUND

The changing age distribution in society inevitably leads to a percentage increase in osteoporotic and fatigue fractures as well as the absolute number of insufficiency fractures of the pelvic ring. Due to pain these fractures lead to a loss of mobility and autonomy. To prevent these consequences surgical treatment is increasingly being performed.

OBJECTIVE

This article presents a new configuration of an internal fixator on the anterior pelvic ring, the principle of which correlates to a three-point buttressing.

METHODS

In addition to a description of the configuration of the internal fixator on the anterior pelvic ring and the surgical technique, the article presents the results after the first 23 applications.

RESULTS

The first results after application of the new internal fixator on the pelvic ring show a low risk, sufficient and minimally invasive stabilization with an encouraging clinical and radiological outcome.

CONCLUSION

Missing long-term results, also taking into account a higher number of patients, as well as the biomechanical examination of the presented fixator configuration still have to be evaluated.

[Research progress in internal fixation for treatment of pelvic anterior ring injury]

Objective

To review the research progress of the application of internal fixation (INFIX) in the treatment of pelvic anterior ring injuries.

Methods

The recent literature about INFIX in the treatment of pelvic anterior ring injury concerning the surgery technique, biomechanical characteristics, indications, contraindications, advantages, complications, and effectiveness was extensively consulted, reviewed, and summarized.

Results

INFIX is a relatively novel technique for the treatment of pelvic anterior ring injuries at present. The advantages include good biomechanical properties, extensive indications, minimally invasion, convenient nursing, less complications, and excellent effectiveness.

Conclusion

It is a clinical method with obvious advantages and development potential for treatment of pelvic anterior ring injuries using INFIX, and further study is needed to improve its effectiveness.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Fixation of Anterior Pelvic Ring Injuries

Treatment of anterior pelvic ring injuries involves both acute stabilization during the initial resuscitation and definitive fixation. Definitive management has evolved substantially over the past 40 years with improved patient mobilization and long-term outcomes. Although its use has recently declined, external fixation remains a favorable option in certain situations. Symphyseal plating is the preferred technique for stabilization of symphyseal diastasis because of superior stability and low morbidity. Ramus screws can be effective for simple ramus fractures but require a careful technique because of the proximity of neurovascular structures. The subcutaneous internal fixator provides a good option for obese patients in whom external fixation would be poorly tolerated. Regardless of fixation strategy, posterior ring reduction and stabilization is crucial.

The use of anterior subcutaneous internal fixation (INFIX) for treatment of pelvic ring injuries in major trauma patients, complications and outcomes

Purpose: Pelvic anterior internal fixators (INFIX) are a relatively new alternative in the treatment of unstable pelvic fractures. The authors wanted to review the use of complications and outcomes of this method of pelvic fixation at our institution.

Method: Patients over the age of 18 who had an INFIX used in treatment of their pelvic ring injury were identified. Patient demographics, fracture type, injury severity score, morbidity, complications and time until removal were recorded. All available patients were followed up following the removal of the INFIX and completed an Iowa Pelvic Score (IPS) at this time.

Results and Discussion: 24 patients (19 male) with a mean age of 38.5 (range 18–71) met the inclusion criteria with an average injury severity score of 29.8 (10–66). The most common complication following insertion was a lateral femoral cutaneous nerve (LFCN) injury, which occurred in 11 patients (bilaterally in two), 6 patients (25%) had ongoing numbness 6 months post removal. Two patients had an infection, one of which prompted the removal of the INFIX. One INFIX was removed for implant failure. All other removals were planned electively. Heterotopic ossification was noted to have occurred in five cases. The mean IPS following removal of the INFIX was 79.2 (52–100). INFIX is a safe and successful treatment for unstable pelvic ring injuries. Overall, patients tolerate the INFIX well with good outcome scores. The main concern being the high rate of LFCN injuries, although many resolved after removal of the INFIX.

Modified internal fixator for anterior pelvic ring fractures versus conventional two-screw fixation

PURPOSE

The present study aims to evaluate the short-term clinical effects and complications of modified three-screw fixation and conventional two-screw fixation for treating anterior pelvic ring fractures.

METHODS

A retrospective study of 51 patients with type B fractures was performed. 25 patients (modified group) were treated with modified three-screw fixation and the other 26 patients (conventional group) with conventional two-screw fixation. Outcome measures included operation time, intraoperative blood loss, hospital stays, postoperative complications and the Majeed score at postoperatively 2 months, 3 months, 1 year and the time of implant removal.

RESULTS

The mean operative times and mean blood loss for modified three-screw fixation versus conventional two-screw fixation bilateral were 54.8 ± 10.7 min versus 32.3 ± 9.9 min, and 153.3 mL versus 550.0 mL (p < 0.001), respectively. However, the Majeed score was better in modified group at postoperatively 2 months (75.6 ± 9.5 vs. 69.7 ± 8.3, p = 0.008) and 3 months (80.3 ± 10.7 vs. 75.1 ± 11.9, p = 0.014). There was no statistical difference between two groups at the time of implant removal (82.1 ± 9.3 vs. 80.9 ± 8.8, p = 0.272) and postoperatively 1 year (83.5 ± 7.8 vs 82.6 ± 8.2, p = 0.723). No patients experienced surgical wound infection, deep vein thrombosis, delayed union or nonunion, implant loosening or rupture. One patient complained of tardive unilateral thigh pain at postoperatively 4 months in conventional group.

CONCLUSIONS

Both modified three-screw fixation and conventional two-screw fixation could ultimately afford satisfactory clinical and radiological outcomes with less complication for anterior pelvic ring fractures. The modified three-screw fixation might have better biomechanical strength and faster pelvic rehabilitation.

Effectiveness of surgical fixation for lateral compression type one (LC-1) fragility fractures of the pelvis: a systematic review

OBJECTIVES

To undertake a systematic review of the evidence base for the effectiveness of surgical fixation of lateral compression (LC-1) fragility fractures of the pelvis compared with non-surgical approaches.

SEARCHES

MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials and two international trials registers were searched up to January 2017 (MEDLINE to February 2019) for studies of internal or external fixation of fragility fractures of the pelvis.

PARTICIPANTS

Patients with lateral compression pelvic fractures, sustained as the result of a low-energy mechanism, defined as a fall from standing height or less.

INTERVENTIONS

Surgery using either external or internal fixation devices. Conservative non-surgical treatment was the defined comparator.

OUTCOME MEASURES

Outcomes of interest were patient mobility and function, pain, quality of life, fracture union, mortality, hospital length of stay and complications (additional operative procedures, number and type of adverse events and serious adverse events).

QUALITY ASSESSMENT AND SYNTHESIS

The Joanna Briggs Institute Checklist for Case Series was used to assess the included studies. Results were presented in a narrative synthesis.

RESULTS

Of 3421 records identified, four retrospective case series met the inclusion criteria. Fixation types were not consistent between studies or within studies and most patients had more than one type of pelvic fixation. Where reported, mobility and function improved post-surgery, and a reduction in pain was recorded. Length of hospital stay ranged from 4 days to 54 days for surgical fixation of any type. Reported complications and adverse outcomes included: infections, implant loosening, pneumonia and thrombosis. Use of analgesia was not reported.

CONCLUSIONS

There is insufficient evidence to support guidance on the most effective treatment for patients who fail to mobilise after sustaining an LC-1 fragility fracture.

TRIAL REGISTRATION NUMBER

CRD42017055872.

Minimally invasive internal fixator for unstable pelvic ring injuries with a pedicle screw-rod system: a retrospective study of 23 patients after 13.5 months

PURPOSE

Pelvic ring fractures are challenging injuries and require effective treatment due to the frequently compromised patient condition. The aim of this study was to evaluate the outcome of unstable pelvic ring injuries treated with a minimally invasive pedicle screw-rod system.

METHODS

Retrospective analysis was performed for patients with an unstable pelvic ring injury that were treated with a minimally invasive anterior internal pelvic fixator (INFIX) with or without a posterior pedicle screw-rod fixator (6/2012-4/2015). The quality of reduction was evaluated by the Tornetta and Matta criteria and the clinical outcome was evaluated by the Majeed scores. Further evaluation included the operation time, intraoperative blood loss, and complication rate.

RESULTS

A total of 23 patients (12 males and 11 females) with a mean age of 37.6 years (range 10-65 years) and a follow-up of 13.5 months (6-27 months) were evaluated. The Tile classification showed 13 type B (B1 = 6, B2 = 4, and B3 = 3) and 10 type C (C1 = 7 and C2 = 3) fractures. Mean operation time and intraoperative blood loss were 24.8 min (20-30 min) and 20.4 ml (16-29 ml) for an anterior INFIX (n = 13), and 60 min (45-70 min) and 150 ml (115-168 ml) when combined with a posterior pedicle screw-rod fixator (n = 10). Quality of reduction was excellent in 13, good in 6, and fair in 4 patients, with no signs of heterotopic ossification. Clinical results after 6 months were excellent in 14 patients, good in 6, fair in 2, and poor in 1. Unilateral thigh paresthesia was seen in 2 patients which resolved after implant removal.

CONCLUSIONS

The INFIX appears to be a safe and minimally invasive surgical technique which can effectively be combined with posterior pedicle screw-rod fixation. It also can be applied for the definitive treatment of vertically and/or rotationally unstable pelvic ring injuries, especially in severely compromised patients with a high mortality risk.

A biomechanical study comparing minimally invasive anterior pelvic ring fixation techniques to external fixation

INTRODUCTION

INFIX and Pelvic Bridge are two new minimally invasive surgical techniques for unstable pelvic ring injuries, and they have demonstrated early clinical success in small, single-center case-series. The primary objective of this study is to gather evidence speaking to the biomechanical stability of internal bridging methods relative to external fixation, with the expectation of biomechanical equivalence.

METHODS

Ten human cadaveric pelvic specimens were dissected free of all skin, fat, organs, and musculature and were prepared with a partially unstable pelvic ring injury (OTA/AO 61-B). The specimens were randomized to two groups and were repaired and tested with anterior pelvic external fixation (APEF) and INFIX sequentially, or APEF and Pelvic Bridge sequentially. Testing was performed with each specimen mounted onto a servo-hydraulic testing frame with axial compression applied to the superior base of the sacrum under five axial loading/unloading sinusoidal cycles between 10 N and 1000 N at 0.1 Hz. Relative translational motion and rotation across the osteotomy site was reported as our primary outcome measures. Outcome measures were further analyzed using a Wilcoxon signed-rank test to determine differences between non-parametric data sets with significance defined as a p value < 0.05.

RESULTS

We found no statistical difference in translation (p = 0.237, 0.228) or rotation (p = 0.278, 0.873) at the fracture site when comparing both new constructs to external fixation. Under the imposed loading protocol, no episodes of implant failure or failure at the bone-implant interface occurred.

DISCUSSION

Our study provides the biomechanical foundation necessary to support future clinical trial implementation for pelvic fracture patients. While biomechanical stability of these newer, subcutaneous techniques is equivalent to APEF, the surgeon must take into account their technical abilities and knowledge of pelvic anatomy, patient-specific factors including body habitus, and the potential complications associated with each implant and the ability to avoid them.

Complications Following Internal Fixator in the Treatment of Pelvic Fracture

The aim of this systematic review was to investigate the incidence of complications of the internal fixator in the treatment of anterior pelvic ring injury. The literature was comprehensively searched from 1980 to January 2017 to identify potential studies. Six studies involving 272 cases of anterior pelvic ring injury treated with the internal fixator were included in this meta-analysis. The rates of wound infection, heterotopic ossification, nerve paresthesia, pain, and fracture dislocation were 5.7%, 35.1%, 28.2%, 3.7%, and 3.0%, respectively. This new technique should be prudently used to treat pelvic fractures. [Orthopedics. 2019; 42(1):e7-e13.].

When and How to Operate Fragility Fractures of the Pelvis?

Fragility fractures of the pelvis (FFP) are an entity with an increasing frequency. The characteristics of these fractures are different from pelvic ring fractures in younger adults. There is a low energy instead of a high energy trauma mechanism. Due to a specific and consistent decrease of bone mineral density, typical fractures in the anterior and posterior pelvic ring occur. Bilateral sacral ala fractures are frequent. A new classification system distinguishes between four categories with increasing loss of stability. The subtypes represent different localizations of fractures. The primary goal of treatment is restoring mobility and independency. Depending on the amount of instability, conservative or surgical treatment is recommended. The operative technique should be as less invasive as possible. When the broken posterior pelvic ring is fixed operatively, a surgical fixation of the anterior pelvic ring should be considered as well. FFP Type I can be treated conservatively. In many cases, FFP Type II can also be treated conservatively. When conservative treatment fails, percutaneous fixation is performed. FFP Type III and FFP Type IV are treated operatively. The choice of the operation technique is depending on the localization of the fracture. Iliosacral screw osteosynthesis, transsacral bar osteosynthesis, transiliac internal fixation, and iliolumbar fixation are alternatives for stabilization of the posterior pelvic ring. Plate osteosynthesis, retrograde transpubic screw, and anterior internal fixation are alternatives for stabilization of the anterior pelvic ring. Postoperatively, early mobilization, with weight bearing as tolerated, is started. Simultaneously, bone metabolism is also analyzed and its defects compensated. Medical comorbidities should be identified and treated with the help of a multidisciplinary team.

Clinical and radiological short-term outcomes of pubic symphysis diastasis treated with modified pedicle screw-rod fixation

PURPOSE

Pubic symphysis diastasis with an incidence of approximately 20% in pelvic fractures is a severe lesion which needs to be treated properly. The objective of this retrospective study was to describe and evaluate the clinical and radiological outcomes including its advantages and limitations of this modified minimal invasive technique.

METHODS

Totally 29 patients with pubic symphysis diastasis, with or without posterior ring instability, were treated by modified pedicle screw-rod fixation (modified PSRF) between January 2010 and December 2016. The duration from injury to surgery, operation time, intraoperative blood loss as well as complications were recorded. During follow-up, the functional outcomes were assessed according to the Majeed evaluation criteria 1 year postoperatively. The evaluation of the postoperative reduction quality was carried out according to Matta criteria.

RESULTS

According to Tile classification, there were 9 cases of Type B1 underwent only anterior-modified PSRF and 20 cases of Type C1 experienced anterior-modified PSRF combined with posterior fixation. The duration from injury to operation, operation time and intraoperative blood loss were 3.27 days (range 1-6 days), 42.07 min (range 38-45 min), and 46.14 ml (range 40-55 ml). The results of reduction quality were rated as excellent in 16, good in 11 and fair in 2 based on Matta criteria. The Majeed functional scores ranged from 68 to 95 and there were excellent in 15, good in 12 and fair in 2. No patients experienced incision infection. Slight loosening of middle-two screws was verified during follow-up in one patient. Two patients underwent femoral nerve palsy. Irritation to the LFCN was detected in four patients.

CONCLUSIONS

Modified PSRF can be performed as an alternative to manage pubic symphysis diastasis due to its merits of minimal invasive, less blood loss, less soft tissue injuries as well as shorter operation time, even with the early weight-bearing.

TRIAL REGISTRATION

Researchregistry3905.

Anterior Subcutaneous Internal Pelvic Fixation/INFIX: A Systemic Review

INTRODUCTION

The purpose of this article is to review the available literature on anterior subcutaneous internal pelvic fixation (ASIPF) to identify indications, clinical and radiographic outcomes, and compare these with alternative fixation methods.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic search on PubMed and Google Scholar was performed. Articles included were in the English language or English translations and published between 2007 and 2018. Studies included were appraised with narrative data synthesis.

RESULTS

Twenty-five articles with 496 patients were included. These included 17 case series, with 3 case reports reporting adverse events.

CONCLUSIONS

ASIPF and the appropriate posterior fixation resulted in healing of pelvic ring injuries in 99.5% of cases. Indications include unstable pelvic ring injuries with the appropriate posterior fixation. Radiographic parameters and outcome measures were infrequently reported. ASIPF is a valuable tool for reduction and fixation in unstable pelvic ring injuries. Complications include lateral femoral cutaneous nerve irritation (26.3%); heterotopic ossification (36%); infection (3%); and femoral nerve palsy (1%), which is likely related to placing the bar and screws too deep.

Minimally invasive anterior pelvic internal fixation: An anatomic study comparing Pelvic Bridge to INFIX

OBJECTIVES

Anterior external fixation for pelvic ring fractures has shown to effectively improve stability and reduce mortality. However, these fixators can be associated with substantial morbidity such as pin tract infection, premature loss of fixation, and decreased quality of life in patients. Recently, two new methods of subcutaneous anterior pelvic internal fixation have been developed; the INFIX and the Pelvic Bridge. These methods have the purported advantages of lower wound complications, less surgical site pain, and improved quality of life. We sought to investigate the measured distances to critical anatomic structures, as well as the qualitative and topographic differences notable during implantation of both devices in the same cadaveric specimen.

MATERIALS AND METHODS

The Pelvic Bridge and INFIX were implanted in eleven fresh cadavers. Distances were then measured to: the superficial inguinal ring, round ligament, spermatic cord, lateral femoral cutaneous nerve (LFCN), femoral nerve, femoral artery, and femoral vein. Observations regarding implantation and topography were also recorded.

RESULTS

The INFIX had greater measured distances from all structures except for the LFCN, in which its proximity placed this structure at risk. Neither device appears to put other critical structures at risk in the supine position. Significant implantation and topographic differences exist between the devices. The INFIX application lacked "safety margins" concerning the LFCN in 10/11 (90.9%) specimens, while Pelvic Bridge placement lacked "safety margins" with regard to the right superficial ring (1/11, 9%) and the right spermatic cord (1/11, 9%).

CONCLUSIONS

Both the Pelvic Bridge and INFIX lie at safe distances from most critical pelvic structures in the supine position, though INFIX application places the LFCN at risk.

Management of the open book APC II pelvis: Survey results from pelvic and acetabular surgeons in the United Kingdom

The results of this questionnaire show that the opinion of pelvic and acetabular surgeons in the UK and Republic of Ireland vary as to the best method of fixation for APC II pelvic injuries. A single anterior plate and single sacroiliac joint (SIJ) screw was the most popular fixation method, chosen by 34%. 74% favour a single, opposed to two orthogonal anterior plates. Posterior fixation supplementing anterior plating is preferred by 63% of surgeons, 58% use a single versus 42% two SIJ screws. Case by case assessment and intraoperative screening to assess stability is essential when considering whether to stabilise the SIJ.

Complications Associated With Pelvic External Fixation

An external fixator is an essential tool for treating unstable pelvic ring injuries but its use carries risks, including pin-site infections and injury to the lateral femoral cutaneous nerve (LFCN). Surgeons currently lack data regarding these risks for patient counseling. This study aimed to identify the incidence of and risk factors for superficial and deep pin-site infection and LFCN damage. Fifty-two patients who underwent pelvic external fixation with anterior pin placement as part of definitive treatment for unstable pelvic ring disruption were retrospectively evaluated to identify factors associated with the development of infection. Ten (19%) patients developed superficial pin-site infections, with none developing a deep infection. Five were treated with oral antibiotics alone, 5 with additional intravenous antibiotics, and 1 underwent superficial surgical debridement at the time of external fixator removal. Three (6%) patients had temporary symptoms consistent with irritation to their LFCN that all resolved by 3 months. One (2%) patient had residual mild and intermittent LFCN dysesthesias at the 6-month follow-up. Adjusted logistic regression models identified no specific factors that were associated with increased risk of infection. The incidence of superficial infections related to pelvic external fixation was 19%, which can usually be treated with antibiotics with low risk of deep infection. In addition, there remains a low risk of long-term LFCN damage. Patients should be counseled on these risks during the perioperative period. [Orthopedics. 2017; 40(6):e959-e963.].

Bladder incarceration following anterior pelvic infix of a traumatic pubic symphysis diastasis treated with immediate open reduction and internal fixation

Stabilization after a pelvic fracture can be accomplished using multiple techniques. The anterior external fixator has been traditionally used in variety of unstable pelvis either singly or in combination of posterior screws. These devices are cumbersome and restrict side turning and sitting particularly in obese patients. An alternative, anterior subcutaneous pelvic internal fixation technique (ASPIF) was developed which is well tolerated by patients for mobility and comfort and biomechanically more stable construct Complications of this construct included irritation of the lateral femoral cutaneous nerve, femoral nerve palsy &heterotypic ossification with reduced rates of infections and aseptic loosening as compared to external fixator. Bladder incarceration following treatment has never been reported and we encountered such a problem during management which we want to highlight.

Biomechanical comparison of supraacetabular external fixation and anterior pelvic bridge plating

Unstable pelvic ring injuries are complex and risky injuries due to high morbidity and mortality. Although anterior pelvic external fixator is a suitable method for rapid stabilization of an injured pelvic ring, due to some disadvantages such as high complication rate, nerve damage, and difficulties of patient's mobility and comfort, there has recently been increased searching for alternative methods for stabilization of the pelvic ring. Pubic symphysis zone freely moves in pelvic models. This study aims to evaluate the biomechanical stability of anterior pelvic bridge plating and compare it with supraacetabular external fixators in an untreated unstable pelvic fracture model. Samples were loaded statically with 2-mm/min loading rate in single leg standing position. Maximum load was 2.3 kN. When loading the samples, photographs were taken continuously. Stiffness values were calculated from the load displacement curves. Some reference parameters were described and were measured from unloaded and 2.3-kN-loaded photographs of the test. The mean stiffness values were 491.14 ± 52.22, 478.55 ± 41.44, and 470.25 ± 44.51 N/mm for anterior pelvic bridge plating group, supraacetabular external fixator group, and Control group, respectively. According to the measured parameters from photographs, the mean displacement at the pubic symphysis was 4.7 ± 0.32, 15.8 ± 2.01, and 18.2 ± 0.47 mm for anterior pelvic bridge plating, supraacetabular external fixator, and Control group, respectively. The highest displacement in the pubic symphysis was found in Control group, and minimum displacement was observed in anterior pelvic bridge plating group. When the perpendicular distance between the right and left lower end of ischium was examined, it was observed that displacement was minimum in anterior pelvic bridge plating group compared to other two groups, regarding to the high stability of pubic symphysis. In conclusion, this study revealed superiority of anterior subcutaneous plate fixation with biomechanical results.

Minimally invasive treatment of unstable pelvic ring injuries with modified pedicle screw-rod fixator

Objective

To evaluate the clinical application of the minimally invasive modified pedicle screw–rod fixator for unstable pelvic ring injuries, including its feasibility, merits, and limitations.

Methods

Twenty-three patients (13 males, 10 females; average age, 36.3 years) with unstable pelvic ring injuries underwent anterior fixation using a modified pedicle screw–rod fixator with or without posterior fixation using a transiliac internal fixator. The clinical findings were assessed using Majeed scores. The quality of reduction was evaluated using the Matta criteria.

Results

Clinical results at 1 year postoperatively were excellent in 14 patients, good in 7, and fair in 2. The two patients with fair results had intermittent pain at the sacroiliac joint because of the posterior implant. One woman complained of persistent pain at the pubic tubercle during sexual intercourse. Iatrogenic neuropraxia of the unilateral lateral femoral cutaneous nerve occurred in three patients. Unilateral femoral nerve palsy occurred in one patient. The quality of fracture reduction was excellent in 12 patients, good in 8, and fair in 3. Heterotopic ossification occurred in eight patients; all were asymptomatic.

Conclusions

Minimally invasive modified pedicle screw-rod fixation is an effective alternative treatment for pelvic ring injuries.

Modified pedicle screw-rod fixation as a minimally invasive treatment for anterior pelvic ring injuries: an initial case series

Background

Unstable pelvic ring injuries often involve high mortality and morbidity. This study was aimed to evaluate the modified minimally invasive pedicle screw–rod fixation for anterior pelvic ring injuries, in the respects of its feasibility, merits, and limitations.

Methods

Twenty-three patients with unstable pelvic ring injuries underwent the modified anterior pedicle screw–rod fixation, with or without posterior fixation. The clinical outcomes were assessed using Majeed scores, and the quality of reduction was evaluated according to the criteria of Matta.

Results

Majeed scores showed that the clinical outcomes at postoperatively 1 year were excellent in 14 patients, good in 7, and fair in 2. One woman complained of persistent pain at the pubic tubercle during sexual intercourse. Iatrogenic neuropraxia of the unilateral lateral femoral cutaneous nerve occurred in 3 patients. Unilateral femoral nerve palsy occurred in 1 patient. The reduction was found to be excellent in 12 patients, good in 8, and fair in 3. Heterotopic ossification occurred in 8 patients, all being asymptomatic.

Conclusions

The modified pedicle screw–rod fixation with the minimally invasive technique offered an effective alternative for unstable anterior pelvic ring injuries.

The use of external fixators in the definitive stabilisation of the pelvis in polytrauma patients: Safety, efficacy and clinical outcomes

OBJECTIVES

To analyse the complications and outcomes (functional/radiographic) of Pelvic External Fixators applied as part of the definitive fixation in polytrauma patients.

DESIGN

A single center retrospective chart review.

SETTING

A level-1 trauma center.

PATIENTS AND METHODS

We reviewed all the polytrauma patients (ISS>16) between 2007 and 2012 that had a PEF applied more than 30days. Complications including infection, aseptic loosening, neurological injury, loss of reduction, non-union and mal-union were recorded. Pelvic asymmetry and Deformity Index (DI) were measured at the immediate postoperative radiographs and final follow-up. The functional outcome at final follow up was estimated using a scale previously reported by Chiou et al.

RESULTS

59 patients with mean age of 38.4 (16 - 81) years and mean ISS score 28 (16- 66) were included. The PEFs were applied for mean duration of 56 (30-104) days. The average follow-up was 403days. 22 injuries were type B and 37 type C (AO/OTA). The most common symptomatic complications were pin site infection in 11 (18.6%) and loosening in 5 (8.5%) cases. 44 (74.5%) patients had satisfactory functional outcome. The immediate post-operative and final asymmetry and DI were compared between the two pelvic injury groups (type B and C fractures). The difference in displacement progression was more for type C injuries (p=0.034) but no correlation to the functional outcome was evident.

CONCLUSION

PEF can be used as definitive alternative stabilization method in specific situations at polytrauma setting. Radiological displacement occurred in both type B and C injuries but the clinical outcome was not correlated to this displacement. Complications related to PEF do not affect the final clinical outcome.

LEVEL OF EVIDENCE

Therapeutic Level III.

Midterm Radiographic and Functional Outcomes of the Anterior Subcutaneous Internal Pelvic Fixator (INFIX) for Pelvic Ring Injuries

OBJECTIVE

To describe our experience using the anterior internal pelvic fixator (INFIX) for treating pelvic ring injuries.

DESIGN

Case Series.

SETTING

Level 1 Trauma Center.

PATIENTS

Eighty-three patients with pelvic ring injuries were treated with INFIX. Follow-up average was 35 months (range 12-80.33).

INTERVENTION

Surgical treatment of pelvic ring injuries included reduction, appropriate posterior fixation, and INFIX placement.

OUTCOME MEASUREMENTS

Reduction using the pelvic deformity index and pubic symphysis widening, Majeed functional scores, complications; infection, implant failure, heterotopic ossification (HO), nerve injury, and pain.

RESULTS

All patients healed in an appropriate time frame (full weight bearing 12 weeks postoperation). The average pelvic deformity index reduction (injury = 0.0420 ± 0.0412, latest FU = 0.0254 ± 0.0243) was 39.58%. The average reduction of pubic symphysis injuries was 56.92%. The average Majeed score of patients at latest follow-up was 78.77 (range 47-100). Complications were 3 infections, 1 case of implant failure, 2 cases implantation too deep, 7 cases of lateral femoral cutaneous nerve irritation, and 3 cases of pain associated with the device. HO was seen in >50% of the patients, correlated with increased age (P < 0.007), injury severity score (P < 0.05) but only 1 case was symptomatic.

CONCLUSIONS

The pelvic injuries had good functional and radiological outcomes with INFIX and the appropriate posterior fixation. The downside is removal requiring a second anesthetic, there is a learning curve, HO often occurs, the lateral femoral cutaneous nerve may get irritated which often resolves once the implants are removed. Surgery-specific implants need to be developed.

LEVEL OF EVIDENCE

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

[Percutaneous internal fixation of pelvic fractures. German version]

BACKGROUND

Percutaneous internal fixation of pelvic fractures is increasing in popularity with multiple new techniques reported.

OBJECTIVES

The purpose of this article is to outline the imaging, indication, planning, equipment, surgical technique and complications of these methods.

METHODS

A review of the literature is provided and the techniques for anterior and posterior pelvic stabilization are discussed.

RESULTS

High-quality preoperative CT scans are essential in planning for this technique. The anterior internal fixator ("InFix") is an effective method for stabilizing the anterior ring and should be usually used in conjunction with posterior fixation. Good technique avoids neurovascular injury, which can be a devastating complication. The retrograde anterior column screw (RACS) is a technique that can be used in most patients, although in smaller patients smaller screw diameters may be needed. The entry point for the screw is more lateral in women than men. Iliosacral screws (ISS) are an effective method of posterior stabilization and can be placed using 2D or 3D fluoroscopy, computer navigation or CT navigation.

CONCLUSION

Percutaneous fixation of pelvic fractures requires high-quality imaging and can be aided by computer navigation. Safe techniques are reproducible; however, not all patients and fracture patterns can be treated using these techniques.

Vascular occlusion following application of subcutaneous anterior pelvic fixation (INFIX) technique

We report a case of bilateral external iliac artery compression after application of subcutaneous anterior pelvic fixation (INFIX) technique in a 51-year-old male with an unstable pelvic fracture sustained following a motor vehicle accident. This has not been previously reported in the literature. The management of this complication is discussed in detail, along with key precautions and technical steps to consider while utilizing the 'INFIX' technique for pelvic fractures.

"Anterior subcutaneous pelvic internal fixator (INFIX), Is it safe?" A cadaveric study

INTRODUCTION

Anterior pelvic internal fixator (INFIX) is used to treat unstable pelvic ring injuries. Nerve injury complications with this procedure have been reported.

OBJECTIVES

This anatomic study attempted to identify structures at risk after application of INFIX.

MATERIALS AND METHODS

INFIX was applied in fifteen fresh, frozen, anatomical specimens using polyaxial pedicular screws and subcutaneous rods. Surgical dissection was done to identify the structures at risk including the femoral nerve (FN), femoral artery (FA), femoral vein (FV) and the lateral femoral cutaneous nerve (LFCN) related to which are potentially affected by the implant.

RESULTS

All structures at risk were closer to the rod than to the pedicular screw. Measurements were made between the rod and the structures at risk. The LFCN was an average of 13.49±1.65mm (95% CI 12.871-14.103) from the lateral end of the rod. The FN was an average of 12.43±3.42mm (95% CI 11.151-13.709), the FA was an average of 12.80±3.67 (95% CI 11.430-14.173) and the FV was an average of 13.48±3.73 (95% CI 12.082-14.871) below the rod. No direct compression of the rod to the structure at risk was observed.

CONCLUSIONS

The femoral nerve is the structure most at risk of compression by the INFIX rod. Careful surgical technique is required in every step of this surgery. We suggest using polyaxial screws and recommend that during screw insertion the surgeon should leave some space between the screw and rectus fascia. The the rod should be trimmed as short as possible to reduce LFCN irritation.