Anterior Subcutaneous Internal Fixator Research Articles

Progress of anterior subcutaneous internal fixation in the treatment of anterior pelvic ring injury

Anterior subcutaneous internal fixation (INFIX) is one of the current representatives of minimally invasive fixation of injuries to the anterior pelvic ring. The nail insertion point of this technique is located at the anterior inferior iliac spinous screw, with an angle of 30° outward and 20° backward. Screw in at an angle, and note that the screw head should be above the deep fascia and maintain a safe distance of 20 to 25 mm from the bone surface. Its improved versions include 3 or 4 nails INFIX with added pubic tubercle screws, unilateral INFIX, short-rod INFIX, and double INFIX. These improvements further enhance stability. The lateral femoral cutaneous nerve (LFCN) is relatively easy to be damaged during anatomy, so special attention should be paid during the operation. Biomechanical stability has advantages over external fixation, and its application is flexible. It is not limited to pubic ramus fracture, symphyseal separation, etc. It also plays an important role in combined anterior and posterior ring fixation. It can be combined with posterior sacroiliac screws, iliac lumbar screws, etc. Fixed etc. Good clinical results have also been reported in children, pregnant women, and people with contraindications for subcutaneous connecting rods. In addition, the current application of robots, reduction frames and other technologies has greatly reduced the difficulty of reduction and improved the quality of closed reduction, making it possible to fix complex pelvic fracture. This technique has high reduction quality and is as effective as traditional steel plates. A common complication is LFCN injury. Careful exposure and adjustment of the position and depth of internal fixation during surgery can effectively avoid this complication.

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.

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

ObjectiveThe 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 methodsA 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.ResultsThere 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).ConclusionThis 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.

USAGE OF ANTERIOR SUBCUTANEOUS INTERNAL FIXATOR FOR TREATMENT OF PELVIC FRACTURES (INFIX): OUR EXPERIENCE

Abstract Introduction Anterior subcutaneous internal fixator(INFIX) was proposed to treat anterior pelvic ring injury. INFIX was initially designed as an alternative to the external fixator, but recently its indications have been expanded, using it as a definitive treatment, and multiple complications have been reported. Methods Retrospective study of 11 polytrauma patients with pelvic fractures treated with anterior subcutaneous internal fixator after a high energy trauma between January (2018)-September (2021) Results 11 polytrauma patients. The average age was 50,5 years old. The mechanism of injury was precipitation, 5 run over and 2 vehicle accidents. According to Tile classification: type B:6 and type C:5, according to Young classification: lateral compression:3, anteroposterior compression:6 and vertical shear:2. The average time of implantation of INFIX was 4,3 days (0–17). In 10 cases a sacroiliac screw was associated at the same time of surgery and in one patient spinopelvic fixation. The patients sitting was allowed 24 hours after surgery and partial weight-bearing 6 weeks later. The average time until removal was 5 months and the average follow up was 10 months. Complications rate was 63,63%(n=7):3 Lateral femoral cutaneous nerve(LFCN) paresthesia:two of them temporary and another persistant one, 1 supracetabular screw osteolysis. 2 implant infections, 1 of them treated with implant removal and reosteosynthesis with symphysis plates. 1 common iliac vein thrombosis resolved with antithrombotic treatment. Conclusions Anterior subcutaneous internal fixator provides initial stability in pelvic fractures with a fast and simple technique. However, some complications have been reported. The main complication is LFCN paresthesia, especially during implantation and removal of the fixator.

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

IntroductionThe incidence of the fragility fractures of the pelvis (FFPs) has been increasing in recent years. Operative treatment is effective in patients who are unable to ambulate due to pain. Anterior subcutaneous internal fixation (ASIF) is a minimally invasive and stable fixation used to treat the FFPs, with few reported vascular complications. However, we experienced a case in which the rod directly pressed the common femoral artery (CFA). ObjectivesThe purpose of this study was to examine the relationship between the rod position as defined by ASIF and the CFA in the FFPs patients, and between BMI and the rod-to-CFA distance. Materials and methodsPelvic measurements were performed in 47 patients with FFPs using trauma CT. We identified the anterior inferior iliac spine (AIIS) on both sides in axial CT images. Next, we performed a simulation study using the CT images, in which the virtual fixation rod was bent according to the shape of the patients’ abdomen in the supine position. The shortest rod-to-CFA distance when the virtual rod was positioned directly above the AIIS in the CT image was measured. The correlation between body mass index (BMI) and the rod-to-CFA distance was measured. ResultsThe average shortest rod-to-CFA distance was 18.4 ± 11.1 mm, and the simulated rod compressed the CFA in three of the 47 cases (6.4%). A statistically significant positive correlation between BMI and the rod-to-CFA distance was found (r = 0.47, p = 0.001). ConclusionsThe course of the CFA should be confirmed before ASIF surgery, and if there is danger of compression of the CFA such as in patients with low BMI, the rod-to-AIIS distance should be adjusted to the optimal distance. However, considering the disadvantages, such as decreased stability of the fixation, when adjusting the rod-to-AIIS distance, and skin irritation and abrasion by the rod, ASIF is not recommended in cases in which the rod is close to the CFA.

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

ObjectiveWe aimed to investigate the surgical techniques, efficacy, and safety of Starr frame-assisted minimally invasive internal fixation for simultaneous anterior and posterior ring stability in pelvic fractures. MethodsThe clinical data of 22 patients with anterior and posterior pelvic ring injuries who underwent Starr frame-assisted minimally invasive internal fixation were retrospectively collected. The anterior pelvic ring was fixed with an anterior subcutaneous internal fixator (INFIX), and the posterior pelvic ring was fixed with sacroiliac screws. The operative time, intraoperative blood loss, fluoroscopy times, number of assistants, complications, and weight-bearing time were analyzed. The Matta score was used to evaluate the fracture reduction. The Majeed score was used to evaluate clinical efficacy, and Gibbon's classification was used to estimate the occurrence of sacral nerve injury. ResultsAll 22 patients were treated with sacroiliac screws for posterior ring injuries, including 12 cases with single sacroiliac screws, nine with two sacroiliac screws, and one with three sacroiliac screws. INFIX was used for all anterior ring fixation, including two screws in seven cases, three screws in 13 cases, and four screws in two cases. The fracture reduction quality was excellent in 15 cases, good in four cases, and moderate in three cases by Matta scores. All patients were followed up for 6–20 (12.5 ± 5.7) months. Callus-formation time based on postoperative X-ray was 3–8 (4.3 ± 1.2) weeks. Weight-bearing time was 3–12 (6.3 ± 2.8) weeks after surgery. At the last follow-up, 15 patients were evaluated as excellent, five as good, and two as fair according to the Majeed score. Gibbons’ classification showed that one of the three patients with sacral nerve injury recovered completely and two did not recover. Complications occurred in six patients, including one with internal fixation loosening, two with anterolateral thigh paresthesia, one with malunion, one with nonunion, and one with heterotopic ossification. ConclusionsStarr frame-assisted minimally invasive internal fixation could stabilize the anterior and posterior pelvic rings simultaneously, overcoming the difficulty of fracture reduction. This technique can help patients with early postoperative weight-bearing and improved functional outcomes, providing a novel modality for the minimally invasive treatment of pelvic ring injuries.

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

BackgroundThis 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.MethodsIntraoperative 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.ResultsTwenty-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.ConclusionINFIX with or without sacroiliac screws can achieve satisfactory radiographic and functional outcomes in the treatment of unstable pelvic ring fractures.Trial registrationChiCTR2000038812. Registered 04 October 2020. Retrospectively registered.

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

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

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

To investigate the effectiveness of anterior subcutaneous internal fixator combined with posterior plate in the treatment of unstable pelvic fractures. Between January 2015 and January 2019, 26 cases of unstable pelvic fractures were treated with anterior subcutaneous internal fixator combined with posterior plate. There were 16 males and 10 females, with an average age of 42.8 years (range, 25-66 years). According to the Tile classification, 9 of them belonged to type B2, 6 to type B3, 7 to type C1, 3 to type C2, 1 to type C3. The injury severity score (ISS) was 6-43 (mean, 18.3). Four cases combined with brain injury, 7 with limb fractures, 3 with hemopneumothorax, 1 with sciatic nerve injury. The time from injury to operation was 4-12 days (mean, 6.4 days). The intraoperative blood loss, operation time, and the complications were recorded. The fracture reduction and the postoperative function of patients were evaluated. All patients were followed up 12-26 months (mean, 16.8 months). The operation time was 65-142 minutes (mean, 72.5 minutes) and the intraoperative blood loss was 42-124 mL (mean, 64.2 mL). There were 2 cases of unilateral lateral femoral cutaneous nerve stimulation, 1 case of femoral nerve paralysis, and 1 case of superficial infection of incision, which were cured after corresponding treatment. X-ray films showed that all fractures healed at 3 months after operation. At last follow-up, according to Matta criteria for fracture reduction, the results were excellent in 8 cases, good in 15 cases, fair in 2 cases, and poor in 1 case, with an excellent and good rate of 88.5%. According to Majeed scoring system for pelvic function, the results were excellent in 10 cases, good in 12 cases, and fair in 4 cases, with an excellent and good rate of 84.6%. For unstable pelvic fractures, the anterior subcutaneous internal fixator combined with posterior plate has fewer operative complications, high security, and achieve good effectiveness.

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

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

Minimally Invasive Screw Fixation of Unstable Pelvic Fractures Using the "Blunt End" Kirschner Wire Technique Assisted by 3D Printed External Template.

Objective This study aimed to determine the accuracy and safety of the “blunt end” Kirschner wire (KW) technique for the minimally invasive treatment of unstable pelvic fractures with the assistance of a 3D printed external template. Methods Clinical data of 28 patients with unstable pelvic fractures between January 2016 and January 2018 were retrospectively analyzed. There were 6 cases of B1, 10 of B2, 8 of C1, and 4 of C2 fractures, all of which received surgical treatment. The “blunt end” KW technique with a 3D template was adopted for the minimally invasive placement of the iliosacral (IS) or superior ramus screws. The number of intraoperative fluoroscopies, surgical time, and complications were recorded. Postoperative reduction was assessed using the Matta criteria, and the Majeed score system was used to evaluate postoperative functional recovery. Results The average number of fluoroscopies was 35 per patient, and the average surgical time was 85.2 min. A total of 19 S1 and 28 S2 IS screws were inserted. Eleven antegrade superior ramus screws and 4 retrograde screws were placed in 11 patients, and anterior subcutaneous internal fixation (INFIX) was used to fix the anterior pelvic ring in 17 patients. All patients were followed up for an average of 18 months. Postoperative reduction was evaluated by Matta's criteria: excellent in 16 cases, good in 9 cases, and fair in 3 cases. The Majeed score was used in the last follow-up to evaluate functional recovery: excellent in 13 cases, good in 10 cases, fair in 4 cases, and poor in 1 case. There were no cases of operative vascular injury. Conclusion The “blunt end” KW technique with a 3D printed external template is a safe and effective method for the placement of IS and superior ramus screws in unstable pelvic fractures with minimized surgical duration and radiation exposure.

Anterior subcutaneous internal fixator (INFIX) versus plate fixation for pelvic anterior ring fracture

The aim of this study was to compare the clinical outcomes in patients with unstable anterior pelvic ring fractures after treatment with anterior subcutaneous internal fixator (INFIX) or plate fixation. We performed a retrospective study from August 2015 to October 2017. A consecutive series of 74 patients who underwent surgical treatment of their anterior pelvic ring (35 treated with INFIX and 39 treated with plates) were studied. Data collected included patients’ demographic data, injury severity score (ISS), AO/OTA classification, injury mechanism, time to surgery, procedure time, and blood loss. The quality of postoperative reduction were assessed by postoperative radiographs using the Tornetta and Matta method. Functional outcome was evaluated using Majeed scoring system. In the INFIX group, ten patients developed LFCN paralysis, one patient suffered from superficial infection. Three screw loosening cases and two wound infection cases occurred in the plate group. INFIX is relatively minimally invasive and time-saving than the reconstruction plate in the treatment of anterior pelvic ring fracture. However, plate fixation increases the rate of anatomic reduction of the pelvic anterior ring fracture. Plates also provide a higher functional outcome compared with INFIX. INFIX is especially suitable in patients with urological injury, which can also decrease the wound infection rate.

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.

Anterior subcutaneous internal fixation of the pelvis − what rod-to-bone distance is anatomically optimal?

IntroductionAnterior fixation of the pelvis using subcutaneous supra-acetabular pedicle screw internal fixation (INFIX) has proven to be a useful tool by avoiding the downsides of external fixation in patients where open fixation is not suited.The purpose of this study was to find a rod-to-bone distance for the INFIX that allows for minimal hazard to the inguinal neuro-vascular structures and, at the same time, as little as possible interference with the soft tissues of the proximal thigh when the patient is sitting. MethodsAn INFIX was applied to 10 soft-embalmed cadaver pelvises with three different rod-to-bone distances. With each configuration, the relations of the rod to the neuro-vascular and the muscular surroundings were measured in supine and sitting position. ResultsExcept for the femoral artery, vein and nerve, all investigated anatomical structures of the groin were under compression with a rod-to-bone distance of 1cm. With a rod-to-bone distance of 2cm most of the anatomical structures were safe in supine position, although less than with 3cm. With hip flexion some structures got under compression, especially the lateral femoral cutaneous nerve (LFCN, 80%) and the anterior cutaneous branches of the femoral nerve (ACBFN, 35%). With a rod-to-bone distance of 3cm almost all anatomical structures were safe in supine position, while with hip flexion most superficial structures of the proximal thigh got under compression, especially the LFCN (75%) and the ACBFN (60%). ConclusionsAiming for a rod-to-bone distance of 2cm is the safest way with regard to compression of the femoral neuro-vascular bundle and at the same time leads to the least compression of more superficial structures like the LFCN, the ACBFN, or the sartorius and the rectus femoris muscles in sitting position.

Treatment of type B pelvic fracture using anterior subcutaneous internal fixator with triple pedicle screws: a new surgical technique.

To evaluate the clinical outcomes of anterior subcutaneous internal fixator using triple pedicle screws (ASIF/TPS) in the treatment of unstable type B pelvic fracture compared with open reduction internal fixation (ORIF). This was a retrospective cohort study of 26 patients with type B unstable fractures that underwent ASIF/TPS and 26 similar patients that underwent ORIF using plates and screws. Intraoperative blood loss, operating time, and post operation hospitalization duration were compared. Anteroposterior, inlet, and outlet X-rays and 3D computed tomography were obtained. Pain, numbness, sexual dysfunction, and activity were evaluated at every follow-up visit until the implants were removed. The Majeed score was used to assess the clinical and radiological outcomes. Blood loss, operating time, and hospitalization duration were less (all P<0.001) in the ASIF/TPS group compared with the ORIF group. The clinical and radiological outcomes of the ASIF/TPS group after a mean follow-up of 6months were excellent and good in 80.8%, and moderate in 19.2%. In comparison, the results of the ORIF group were excellent and good in 65.4%, moderate in 29.0%, and poor in 5.6%. No patient experienced nonunion, delayed union, superficial infection, or deep surgical wound infection. No urethral injury or dysuria occurred in the ASIF/TPS group. Two patients had temporary lateral femoral cutaneous nerve numbness after operation. There were two superficial wound infections in the ORIF group. The use of ASIF/TPS with triple pedicle screws could be a reasonable option for the treatment of type B unstable pelvic fractures.

Anterior subcutaneous internal fixation with triple pedicle screws for treatment of Tile type B pelvic fractures

Objective To evaluate the clinical outcome of anterior subcutaneous internal fixator (ASIF) system with triple pedicle screws in stabilizing Tile type B pelvic fractures. Methods From August 2013 to April 2015, 38 cases of pelvic fractures were stabilized with the ASIF system using triple pedicle screws. There were 24 male and 14 female cases, with the age range of 16-74 years [(41.5±5.5)years]. Causes of injury were traffic accidents (n=28), crushing injury (n=6) and fall from height (n=4). All cases had Tile type B fractures, including 5 cases of type B1, 29 type B2 and 4 type B3. Intraoperative blood loss, operation time, length of hospitalization and complications were detected. Postoperative function evaluation was done using the Majeed score. Results All cases were available for follow-up of 6.5-13.5 months (mean, 10.5 months). Intraoperative blood loss was (30.8±7.1)ml, operation time was (51.5±9.2)minutes, and length of hospitalization was (5.0±3.1)days. Among them, 34 cases showed bilateral hip flexion over 95 degrees after operation, and 24 cases were able to squat fully 1.5 months after operation. No cases experienced nonunion, delayed union, superficial or deep surgical wound infection, urethral injury and dysuresia. Two cases developed temporary lateral femoral cutaneous nerve numbness. According to the Majeed score, excellent results were found in 32 cases (84%) and good results in 6 cases (16%). Conclusion ASIF system with triple pedicle screws results in high healing rate and few complications in the treatment of Tile type B pelvic fractures, and hence deserves popularization in clinic. Key words: Pelvis; Fracture fixation; Surgical procedures, minimally invasive

Anterior Subcutaneous Internal Fixation of the Pelvis: Placement of the INFIX

The treatment of displaced or unstable pelvic fractures involves surgical stabilization. Traditional methods of fixation for the anterior pelvic ring include plate fixation, screw fixation, or external fixation. Recently, a technique for using spinal pedicle screws to create an anterior subcutaneous internal fixator, also termed an “INFIX,” has been reported with some success. Although no technique has proved clinically superior, the subcutaneous technique offers significant advantages over traditional pelvic external fixation. These advantages include obviating the risk of pin tract irritation or infection, decreasing postoperative pain, and increasing the biomechanical stability of the fixation construct. Here, we review the anatomical considerations, imaging, and surgical technique for placing an anterior subcutaneous internal fixator. In addition, the surgical outcomes and complications of this specialized technique are discussed. Surgical management of pelvic ring injuries is complex, and this technique is a valuable tool in the armamentarium of pelvic surgeons.

Anterior subcutaneous internal fixation of unstable pelvic ring fracture

Objective To determine the curative effect of stabilizing unstable pelvic ring fracture using the anterior subcutaneous internal fixator (INFIX). Methods From July 2013 to June 2014, 15 cases who suffered from anterior pelvic ring fracture were treated with the device. There were 11 males and 4 females, with mean age of 38. 5 years (range, 23-65 years). Eight cases sustained fracture in traffic accidents, 4 in high falls, and 3 in crush injury. According to the Young-Burgess and AO/OTA classification systems, type APC2 or 61-B1 was noted in one case, LC1 or 61-B2.1 in 4 cases, LC2 or 61-B2. 2/61-B2. 3 in 6 cases, and VS or 61-C1/61-C2 in 4 cases. Basic method in anterior ring fixation was one pedicle screw was respectively inserted into the area between the anterior superior iliac spine and anterior inferior iliac spine of both sides. The precontoured rod was then tunneled subcutaneously from one screw to the other. For the stable posterior injury in pelvic ring fracture, the anterior pelvic ring was stabilized only using the technique. For the unstable posterior injury in pelvic ring fracture, the anterior and posterior ring were both fixed using the technique.During follow-up visits, patients' tolerance to the device, wound infection, myositis ossificans, internal fixation lessening, and lateral femoral cutaneous nerve injury were evaluated. Results Follow-up ranged from 6-12 months (mean, 7. 5 months). The device was well tolerated by the patients for comfort. None had surgical site infection and internal fixation loosening. Injuries healed without loss of reduction at the 3-month follow-up. Injury of the lateral femoral cutaneous nerve at the both side was reported in 4 cases and at one side in 2 cases, but all restored 3 month after operation. Conclusion The reported technique is minimally invasive with few complications and reliable results, hinting an ideal method to stabilize the anterior pelvic ring fracture. Key words: Pelvis; Fracture fixation, internal; Surgical procedures, minimally invasive

The anterior subcutaneous internal fixator (ASIF) for unstable pelvic ring fractures. Clinical and radiological mid-term results

The purpose of this study was to determine the outcome of unstable type C pelvic fractures treated with posterior stabilisation and the anterior subcutaneous internal fixator (ASIF). Altogether, 36 consecutive patients were treated for unstable type C pelvic ring fractures using posterior stabilisation and ASIF. After a minimum of 18 months, the clinical and radiological outcome was retrospectively investigated. Overall, three patients (8.3%) died, and 31 patients (86%) were available for follow-up after a mean of 4.5 years. Thirty of 31 patients (97%) showed radiographic bone consolidation of both the posterior and anterior pelvic ring. Only one non-union and two infections due to the anterior device were observed. The total German pelvic outcome score showed an excellent or good rating for 64.5% of the patients, and a fair or poor for 35.5%. The SF-12 questionnaire showed a significantly reduced total score for physical and mental health compared to a general reference population. The ASIF represents an innovative surgical procedure for the treatment of type C pelvic ring fractures. In the medium term, patient satisfaction was high and the complication rate was low, despite the small number of patients. More cases must be investigated before the procedure can be recommended in general, possibly replacing the external fixator for the treatment of pelvic ring fractures in the future.