Minimally invasive treatment for pubic ramus fractures combined with a sacroiliac joint complex injury

Determinants for successful medullary fixation of the superior ramus

OBJECTIVES

The purpose of this study is to determine what demographic and anatomical variables affect successful placement of a superior medullary ramus screw, and how they affect the maximal diameter of that screw.

METHODS

Design: Prognostic Level IV SETTING: Level I Trauma Center Patients/Participants: Two hundred consecutive patients underwent computed tomography (CT) of the pelvis. We included those patients aged 18 and older without osseous injury or abnormalities precluding measurement.

INTERVENTION

3D reconstructions of the pelvis were created, and a virtual 3.5 mm cylindrical implant was placed from the pubic tubercle to the lateral cortex of the ilium. Success was defined as a bicortical virtual screw path from the ramus to the lateral ilium without cortical perforation. The cylinder was then expanded to model varying screw diameters. We then repeated this same process for unicortical retrograde screw insertion ending medial to the acetabular joint.

MAIN OUTCOME MEASURES

Successful screw placement and maximum screw diameter.

RESULTS

A 3.5 mm screw was successfully placed in 187 patients (93.5 %). One male (1/107, 0.9 %) and 12 females (12/93, 12.9 %) could not accommodate a 3.5 mm screw. All cases of perforation occurred lateral to the obturator foramen. Increasing height was associated with success, and male gender was associated with the ability to accommodate screws with a diameter 6.5 mm and larger.

CONCLUSIONS

Most patients can accommodate a 3.5 mm screw from the pubic tubercle to the ilium. Height and gender should be noted when planning medullary ramus fixation.

Antegrade anterior column acetabulum fracture fixation with cannulated compression headless screws-A biomechanical study on standardized osteoporotic artificial bone

PURPOSE

Due to the increase in life expectancy and high-energy traumas, anterior column acetabular fractures (ACFs) are also increasing. While open reduction and internal fixation (ORIF) is still the standard surgical procedure, minimally invasive, percutaneous fixation of osteoporotic acetabulum fractures (AF) are growing in popularity. The aim of this biomechanical study was to evaluate the biomechanical competence following antegrade fixation with a standard screw versus a cannulated compression headless screw.

METHODS

Eight anatomical osteoporotic composite pelvises were given an anterior column fracture. Two groups of eight specimens each (n = 8) for fixation with either a 6.5 mm cannulated compression headless screw in group Anterior Acetabulum Canulated Compression Headless Screw (AACCH), or with a 6.5 mm partially threaded cannulated screw in group Anterior Acetabulum Standard Screw (AASS) where compared. Each specimen was biomechanically loaded cyclically at a rate of 2 Hz with monotonically increasing compressive load until failure. Motions were assessed by means of optical motion tracking.

RESULTS

Initial construct stiffness trended higher in group AACCH at 152.4 ± 23.1 N/mm compared to group AASS at 118.5 ± 34.3 N/mm, p = 0.051. Numbers of cycles and corresponding peak load at failure, were significantly higher in group AACCH at 6734 ± 1669 cycles and 873.4 ± 166.9 N versus group AASS at 4440 ± 2063 cycles and 644.0 ± 206.3 N, p = 0.041. Failure modes were breakout of the screws around the proximal entry point.

CONCLUSION

From a biomechanical perspective, group AACCH was associated with superior biomechanical competence compared to standard partially threaded cannulated screws and could therefore be considered as valid alternative for fixation of anterior acetabulum fractures.

Finite Element Analysis of Channel Screw and Conventional Plate Technique in Tile B2 Pelvic Fracture

Objective: This study aims to analyze the biomechanical characteristics of tile B2 pelvic fractures using finite element analysis when the superior ramus of the pubis was fixed by a plate or hollow screws in standing and sitting positions, respectively. Methods: A three-dimensional digital model of the tile B2 pelvic fracture was obtained by CT scanning the patient. The main ligament structure was then reconstructed based on the anatomical characteristics to create a finite element model of the tile B2 pelvic fracture. The posterior pelvic ring was fixed by sacroiliac joint screws, while the anterior ring injury of the superior ramus of the pubis was fixed by plates and hollow compression screws, respectively. The degrees of freedom of the bilateral acetabulum or two sides of the ischial tuberosity were constrained in the two models. A vertical load of 600 N was applied to the upper surface of the sacrum to measure the displacement and stress distribution of the pelvis in the standing and sitting positions. Results: The displacement distribution of both the healthy and the affected side of the pelvis was relatively uniform in both the plate group and the hollow screw group according to the finite element simulation results. The maximum displacement value in the sitting position was greater than the standing position, and the maximum displacement value of the hollow screw fixation was greater than that of the plate fixation. In the four groups of fixation models, the maximum displacement value of the pelvis in the hollow screw sitting position group was 1616.80 × 10−3 mm, which was greater than that of the other three groups, and in this group the total displacement value of the hollow screw in the anterior ring was 556.31 × 10−3 mm. The stress distribution of the pelvis in the various models was similar in the four groups of models, in which the maximum stress of the pelvis in the hollow screw sitting position group was the largest, which was 201.33 MPa, while the maximum stress in the standing position was 149.85 MPa greater than that in the sitting position of the hollow screw fixation. Conclusion: The anterior ring of patients with Tile B2 pelvic fractures fixed with hollow screws or plates in both standing and sitting positions can achieve satisfactory biomechanical results with significant safety margins for plates and screws.

Three-dimensional (3D) Printing Technology Assisted by Minimally Invasive Surgery for Pubic Rami Fractures

The feasibility of three-dimensional (3D) printing technology combined with minimally invasive surgery in the treatment of pubic rami fractures was explored. From August 2015 to October 2017, a series of 30 patients who underwent surgical stabilization of their anterior pelvic ring (all utilizing the 3D printing technology) by one surgeon at a single hospital were studied. The minimally invasive incisions were made through anterior inferior cilia spine and pubic nodule. Data collected included the operative duration, the blood loss, the damage of the important tissue, the biographic union and the recovery of the function after the operation. Measurements on inlet and outlet pelvic cardiograph were made immediately post-operation and at all follow-up clinic visits. The scores of reduction and function were measured during follow-up. Results showed that the wounds of 30 patients were healed in the first stage, and there was no injury of important structures such as blood vessels and nerves. According to the Matta criteria, excellent effectiveness was obtained in 22 cases and good in 8 cases. According to the functional evaluation criteria of Majeed, excellent effectiveness was obtained in 21 cases and good in 9 cases. It was suggested that the 3D printing technology assisted by minimally invasive surgery can better evaluate the pelvic fracture before operation, which was helpful in plate modeling, and can shorten surgery duration and reduce intraoperative blood loss and complications. The positioning accuracy was improved, and better surgical result was finally achieved.

Minimally invasive treatment for anterior pelvic ring injuries with modified pedicle screw-rod fixation: a retrospective study

Background

Pelvic ring injuries constitute only 2 to 8% of all fractures; however, they occur in 20% of polytrauma patients. High-energy pelvic fractures often result in mechanical instability of the pelvic ring. Successful treatment of unstable pelvic ring fractures remains a challenge for orthopedic surgeons. This study presents a novel internal fixation method for stabilizing unstable anterior pelvic ring fractures using a minimally invasive modified pedicle screw-rod fixation (MPSRF) technique.

Methods

This retrospective study included six patients with unstable pelvic ring injuries who underwent MPSRF, with or without posterior fixation. Intraoperative parameters such as blood loss, operative time, complications, and quality of reduction (Matta criteria) were recorded and evaluated by a blinded reviewer.

Results

In the present clinical series, the mean operative times and mean blood loss for unilateral versus bilateral anterior ring fixations were 176.0 min versus 295.6 min, and 153.3 mL versus 550.0 mL, respectively. No iatrogenic neuropraxia of the lateral femoral cutaneous nerve or femoral nerve palsy occurred. The reduction quality, graded by the Matta criteria, was excellent in five patients and good in one patient.

Conclusions

There were no infections, delayed unions, nonunions, or loss of reductions during the follow-up period. Only one patient suffered from a broken rod at 4 months postoperatively. The modified technique represents a novel, minimally invasive procedure for the treatment of anterior pelvic ring fractures and offers a reliable and effective alternative to currently available surgical techniques.

Minimally invasive plate osteosynthesis on anterior pelvic ring injury and anterior column acetabular fracture

INTRODUCTION

In performing surgery for fractures of the pelvis and acetabulum, various surgical approaches have been introduced with their own advantages and drawbacks. The extensile nature of ilioinguinal approach gives excellent exposure but was related to wound healing problems. Modified stoppa has a higher difficulty and poses a risk for neurovascular injury. In this study, we elaborate our experience using the Modified Stoppa approach with additional lateral window while adding few modifications to simplify the procedure and facilitate future implant removal.

METHODS

A prospective-retrospective cohort involving 30 anterior pelvic ring and/or anterior column acetabulum fracture patients were conducted from 2012-2016. Fifteen cases were prospectively treated using the modified approach since 2014, while the remaining fifteen cases that were treated using Ilioinguinal approach were retrospectively reviewed. Intraoperative parameters such as blood loss, duration of surgery, quality of reduction (Matta) and postoperative functional outcome (Majeed and Hannover score) at 12 months period were recorded and evaluated by a blinded reviewer.

RESULT

There were no significant differences between the two groups in mean age, sex and fracture type. The mean blood loss in the MIPO group were 325 ± 225 mL versus 710.67 ± 384.51 mL in the control group (p = 0.002). Duration of surgery were 149.33 ± 91.92 minutes in MIPO group versus 235.71 ± 65.79 minutes in ilioinguinal group (p = 0.014). There were no significant differences noted between the two groups in the quality of reduction and postoperative functional outcome, either by using Majeed or Hannover pelvic score. No complications were found after a 12-months follow up period. Two modified cases already had their implant removed and during the procedure, fibrotic tissue were minimal making the implant removal was less complicated and easier.

CONCLUSIONS

Modified stoppa and lateral window technique can be used as a safe and effective alternative approach for anterior pelvic ring fracture and/or anterior column acetabulum fracture. This approach decreased the duration of surgery and blood loss without compromising the quality of reduction and functional outcome in patients.

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.

Midterm radiologic and functional outcomes of minimally-invasive fixation of unstable pelvic fractures using anterior internal fixator(INFIX) and percutaneous iliosacral screws

BACKGROUND

Anterior pelvic external fixation is associated with pin site infections, aseptic loosening with loss of reduction, frame bulkiness hindering patient mobilization and consequent difficulties in inpatient nursing. We performed a single-center prospective series to evaluate the feasibility, safety, limitations and midterm radiologic and functional outcomes of an alternative minimally invasive pelvic internal fixation technique using an anterior subcutaneous pelvic internal fixator (INFIX) and percutaneous iliosacral screws in unstable pelvic ring fractures.

METHODS

Fifteen consecutive patients with vertically and/or rotationally unstable pelvic fractures, presenting to a Level-1 trauma center were treated with closed reduction, appropriate posterior stabilization with percutaneous iliosacral screws and anterior INFIX application. Outcomes were analyzed with respect to the quality of fracture reduction (Matta's radiologic criteria), ease of inpatient nursing, patient mobility and comfort, functional outcomes at final follow-up (Majeed score, SF-12 score), social reintegration and complications.

RESULTS

Most common injury pattern was AO/OTA type 61-C pelvic fracture in thirteen patients. Mean procedure time and intra-operative blood loss were, 57.1+/-4.9 min (range,51-68 min) and 115.3+/-26.7 ml (range,80-170 ml) respectively. Mean follow-up was 34.9+/-4.1 months (range,31-42 months). Fracture reduction was excellent in twelve and good in three patients (Matta's criteria). Functional outcomes were excellent in eight and good in seven patients (Majeed score). Mean SF-12 scores for physical and mental health were 48.58+/-5.61 and 50.89+/-3.97 respectively. Thirteen patients returned to their pre-injury jobs. All fifteen patients reintegrated into society without any restrictions. INFIX was removed at a mean post-operative period of 7.3+/-1.5 months (range,5.5-11 months). Complications included, lateral femoral cutaneous nerve irritation(n = 1), superficial wound infection(n = 1) and loss of reduction(n = 2).

CONCLUSION

Minimally invasive pelvic stabilization using INFIX and percutaneous iliosacral screws is easy to learn and apply, achieves good fracture reduction and definitive stabilization with minimum complications and offers excellent functional outcomes at a minimum follow-up of 31 months.

LEVEL OF EVIDENCE

Level IV.

Precision insertion of percutaneous sacroiliac screws using a novel augmented reality-based navigation system: a pilot study

PURPOSE

Augmented reality (AR) enables superimposition of virtual images onto the real world. The aim of this study is to present a novel AR-based navigation system for sacroiliac screw insertion and to evaluate its feasibility and accuracy in cadaveric experiments.

METHODS

Six cadavers with intact pelvises were employed in our study. They were CT scanned and the pelvis and vessels were segmented into 3D models. The ideal trajectory of the sacroiliac screw was planned and represented visually as a cylinder. For the intervention, the head mounted display created a real-time AR environment by superimposing the virtual 3D models onto the surgeon's field of view. The screws were drilled into the pelvis as guided by the trajectory represented by the cylinder. Following the intervention, a repeat CT scan was performed to evaluate the accuracy of the system, by assessing the screw positions and the deviations between the planned trajectories and inserted screws.

RESULTS

Post-operative CT images showed that all 12 screws were correctly placed with no perforation. The mean deviation between the planned trajectories and the inserted screws was 2.7 ± 1.2 mm at the bony entry point, 3.7 ± 1.1 mm at the screw tip, and the mean angular deviation between the two trajectories was 2.9° ± 1.1°. The mean deviation at the nerve root tunnels region on the sagittal plane was 3.6 ± 1.0 mm.

CONCLUSIONS

This study suggests an intuitive approach for guiding screw placement by way of AR-based navigation. This approach was feasible and accurate. It may serve as a valuable tool for assisting percutaneous sacroiliac screw insertion in live surgery.

Minimally-invasive fixation for anterior pelvic ring disruptions

Pelvic fractures are usually the result of high-energy trauma. In addition to the underlying disruption of the pelvic ring extensive damage to the surrounding soft tissue envelope might be present. Different fixation techniques have been developed including open plating, external fixation and transramus intraosseous screw fixation. Recently another method has been reported the so called pelvic Bridge or Infix technique. In this short review article the different techniques of pelvic fixation are described.

Treatment of pelvic fractures through a less invasive ilioinguinal approach combined with a minimally invasive posterior approach

BACKGROUND

Unstable pelvic fractures usually result from high-energy trauma. There are several treatment modalities available. The purpose of this study was to evaluate the clinical application of a new less invasive ilioinguinal approach combined with a minimally invasive posterior approach technique in patients with unstable pelvic fractures. We also address the feasibility, validity, and limitations of the technique.

METHODS

Thirty-seven patients with unstable pelvic fractures were treated with our minimally invasive technique. The anterior pelvic ring fractures were treated with a less invasive ilioinguinal approach, and the sacral fractures were treated with a minimally invasive posterior approach. The clinical outcome was measured using the Majeed scoring system, and the quality of fracture reduction was evaluated. The patients were followed up for 13 to 60 months (mean, 24 months).

RESULTS

Anatomical or near to anatomical reduction was achieved in 26 (70.3 %) of the anterior pelvic ring fractures and a satisfactory result was obtained in another 11(29.7 %). For the posterior sacral fractures, excellent reduction was obtained in 33 (89.2 %) of the fractures, with a residual deformity in the other 4 patients. One superficial wound infection and two deep vein thromboses occurred, all of which resolved with conservative treatment. The clinical outcome at one year was "excellent" in 29 patients and "good" in 8 patients (Majeed score).

CONCLUSIONS

The satisfactory results showed that a reduction and fixation of unstable pelvic fractures is possible through a combination of a limited ilioinguinal approach and posterior pelvic ring fixation. We believe our method is a new and effective alternative in the management of pelvic fractures.

Minimally invasive surgery (MIS) of anterior ring fracture combined with pubic symphysis separation

Background

The aim of this study was to evaluate the reliability of open reduction and minimally invasive plate osteosynthesis (MIPO) for anterior ring fracture combined with pubic symphysis separation and to explore the operative techniques and therapeutic efficacy.

Material/Methods

We used minimally invasive plate osteosynthesis (MIPO) to treat anterior ring fracture combined with pubic symphysis separation.

Results

During postoperative follow-up, all patients recovered well, with no fat liquefaction, infection, femoral nerve or iliac blood vessels injury, deep vein thrombosis, heterotopic ossification, or any and other complications.

Conclusions

The MIS or MIPPO for anterior ring fracture combined with pubic symphysis separation has the advantages of short operation time and less blood loss. This clinical operation is safe and feasible, with therapeutic efficacy.