A screw-view model of navigation aid retrograde transpubic screw fixation for anterior pelvic ring fracture: A case report with 28 months follow-up and technical note

Identifying safe corridors for anterior pelvic percutaneous instrumentation using computed tomography-based anatomical relationships

INTRODUCTION

Percutaneous anterior pelvic ring instrumentation is performed for retrograde screw fixation of ramus fractures, as well as for repair of pubic symphysis diastasis. The anatomic relationships of critical structures around the anterior pelvic ring, such as the spermatic cord and round ligament, have been described in only a few studies regarding the risk of iatrogenic injury during surgery. Our goal is to further describe these relationships, as well as provide radiographic information on safe corridors for percutaneous fixation.

METHODS

Eighty (80) axial computed tomography scans of the abdomen, obtained for non traumatic diagnostic purposes and screened for prior abdominal trauma or procedures, were evaluated by 3 fellowship trained radiologists. Mid-symphyseal cuts were used to obtain several measurements relative to the spermatic cords (SC) or round ligaments (RL): inter-cord or inter-ligament distance, skin to cortex of symphysis distance (vertical), skin to cortex of symphysis distance (oblique), safe corridor distance (between SC/RL and femoral triangle), center safe angle (relative to bilateral ischia), maximal safe angle, and minimal safe angle.

RESULTS

There were 41 male and 39 female scans included in the final analysis. The average inter-cord distance was 50.2 mm, skin to cortex vertical distance of 43.0 mm, skin to cortex oblique distance of 83.5 mm, safe corridor distance 26.3 mm, center safe angle 19.3˚, maximal safe angle 32.3˚, and minimal safe angle 13.6˚. These were further broken down by range and gender in Table 1. Agreement between radiologists was high for these different measurements with the exception of the skin to cortex oblique distance in female patients and the maximal safe angle in female patients, due to absence of round ligament in a majority of the scans. The round ligament was only present at the mid-symphyseal level for our three reviewers in 37/39, 36/39, and 24/39 of female patient scans.

CONCLUSIONS

We have identified defined safe corridors for instrumentation of the anterior pelvic ring that can assist the surgeon in percutaneous application of fixation for fracture care.

A novel computer navigation model guided unilateral percutaneous vertebroplasty for vertebral compression fracture: A case report

RATIONAL

Vertebral compression fracture (VCF) is one of the most common diseases in spinal surgery. Traditional percutaneous vertebroplasty (PVP) under fluoroscopy is an effective method to treat vertebral compression fracture. However, there is still a risk of vascular nerve injury and infection caused by inaccurate or repeated puncture. Therefore, the purpose of this paper was to assess the accuracy of unilateral PVP guided by screw view model of navigation (SVMN) for VCF.

PATIENT CONCERNS

A 59-year-old female patient suffered high falling injury, and with back pain as its main clinical symptom.

DIAGNOSES

The patient was diagnosed with a L1 VCF.

INTERVENTIONS

We placed the puncture needle under the guidance of SVMN to reach the ideal position designed before operation, and then injected the bone cement to complete the percutaneous kyphoplasty (PKP).

OUTCOMES

The operative time was 29.5 minutes, the puncture time was 1 time, the fluoroscopy time was 2.9 minutes, and the bone cement distribution was satisfactory. VAS and ODI scores were significant improved postoperatively. No surgical complications, including neurovascular injury and infection, were observed during 28-month follow up.

LESSONS

The SVMN guided percutaneous puncture needle insertion in PKP operation for VCF is an effective and safety technique. Besides, the SVMN has also been a contributor to reduce radiation doses and replace conventional fluoroscopy.

A screw view model of navigation guided minimal invasive percutaneous pelvic screws insertion for lateral compression pelvic ring injuries: A case report

RATIONALE

The objective of the present study was to evaluate the accuracy, effectiveness, and safety of screw view model of navigation (SVMN) guided minimal invasive percutaneous pelvic screws (PPSs) insertion for lateral compression pelvic ring injuries (PRI).

PATIENT CONCERNS

A female patient experienced a high falling injury, and presented with pain, swelling, deformity, and movement limitation of the left hip for 3 hours.

DIAGNOSES

She was diagnosed with pelvic fractures, left iliac fracture, left pubic branch fracture, left ischial branch fracture, and lumbar transverse process fracture.

INTERVENTIONS

We used a SVMN technique to guide PPSs insertion, including a percutaneous anterior inferior iliac spine screw, a percutaneous iliac screw (PIS), and a percutaneous sacroiliac screw (PSIS).

OUTCOMES

In total, 3 PPSs were inserted and all were presented with excellent position postoperatively. The designing time of all screws was 11.7 minutes, the time of all guide needles insertion was 18.1 minutes, the time of all screws insertion was 32.8 minutes, blood loss was 21 mL, and the time of radiation exposure lasted 7.2 minutes. Moreover, surgical complications, including neurovascular compromise, wound infection, fracture nonunion, and screw loosening, were not observed during the 12 months follow up visit.

LESSONS

SVMN technique guided PPSs insertion is an effective and safety approach for the treatment of PRI in selected patients. Besides, it is necessary for surgeons to master the rationale of computer navigation, to familiar with the anatomy of pelvis and to select suitable patients.

Computer navigation-assisted minimally invasive percutaneous screw placement for pelvic fractures

Pelvic fractures are often caused by high-energy injuries and accompanied by hemodynamic instability. Traditional open surgery has a large amount of bleeding, which is not suitable for patients with acute pelvic fracture. Navigation-guided, percutaneous puncture-screw implantation has gradually become a preferred procedure due to its advantages, which include less trauma, faster recovery times, and less bleeding. However, due to the complexity of pelvic anatomy, doctors often encounter some problems when using navigation to treat pelvic fractures. This article reviews the indications, contraindications, surgical procedures, and related complications of this procedure for the treatment of sacral fractures, sacroiliac joint injuries, pelvic ring injuries, and acetabular fractures. We also analyze the causes of inaccurate screw placement. Percutaneous screw placement under navigational guidance has the advantages of high accuracy, low incidence of complications and small soft-tissue damage, minimal blood loss, short hospital stays, and quick recovery. There is no difference in the incidence of complications between surgeries performed by new doctors and experienced ones. However, computer navigation technology requires extensive training, and attention should be given to avoid complications such as screw misplacement, intestinal injury, and serious blood vessel and nerve injuries caused by navigational drift.