The optimal fluoroscopic views to rule out intra-articular screw penetration during acetabular fracture fixation

PURPOSE

To determine the ideal view(s) and the minimum number of intraoperative fluoroscopic views required to rule out any intra-articular screw violation in acetabular fractures fixation.

METHODS

This study was conducted using a series of fluoroscopic examinations of pelvic synthetic models with screws positioned in different planes around the acetabulum. Ten screws were placed in the synthetic pelvis models in different planes of the acetabulum. Seven views were taken for each screw. Radiographic images were evaluated by 14 orthopaedic surgeons who were asked to assess joint violation and the view(s) required for assessment.

RESULTS

The observers' accuracy rate in identifying joint violation was 82.1% for the anterior part of the anterior column and the superior part of the posterior column, 89.3% for the posterior part of the anterior column and the inferior part of the posterior column, and 92.9% for the quadrilateral plate. The sensitivity was 100% for the anterior and posterior parts of the anterior column and the inferior part of the posterior column, 87.5% for the superior part of the posterior column, and 85.7% for the quadrilateral plate. The specificity was 100% for the quadrilateral plate, 80% for the superior part of the posterior column and the posterior part of the anterior column, 78.6% for the inferior part of the posterior column, and 66.7% for the anterior part of the anterior column. There was a strong overall interobserver and intra-observer agreement with intraclass correlation coefficient (ICC) of 0.709 and 0.86, respectively.

CONCLUSIONS

This study confirms the hypothesis that in a concave surface/joint fixation, such as the acetabulum, the probability of joint violation is unlikely if there is no evidence of it within a single fluoroscopic view. In acetabulum fracture fixation with a screw violating the joint, the screw's presence was evident within the joint space in all fluoroscopic views. However, the absence of joint violation in one fluoroscopic view was adequate to rule out joint penetration.

Intraoperative three-dimensional imaging in the treatment of distal radius fractures

INTRODUCTION

In operative treatment of distal radius fractures satisfying outcome mainly relies on anatomical fracture reduction and correct implant placement. Examination with two-dimensional fluoroscopy may not provide reliable information about this. The aim of this study was to determine the effectiveness of additional intraoperative three-dimensional imaging in the operative treatment of comminuted distal radius fractures.

MATERIALS AND METHODS

From August 2001 to June 2015, patients with a distal radius fracture who were treated operatively and received intraoperative three-dimensional scan were included. The findings of the three-dimensional scan were documented by the operative surgeon and analyzed retrospectively with regard to incidence and the need for intraoperative revisions. Clinical evaluation included the patient's medical history, the injury pattern of the affected wrist (according to the OTA/AO fracture classification) and concomitant injuries. Intraoperative and postoperative complications and revision surgeries were evaluated as well.

RESULTS

Of 4515 operatively treated distal radius fractures, 307 (6.8%) received additional intraoperative three-dimensional imaging during surgery. 263 of 307 patients (85.7%) had a distal radius fracture type C. Intraoperative three-dimensional imaging revealed findings in 125 patients (40.7%) that were not detected on conventional two-dimensional fluoroscopy. In 54 patients (17.6%) these findings led to an immediate revision. Most commonly, revision was done in the case of remaining steps in the articular surface ≥ 1 mm (n = 25, 8.1%) followed by intra-articular screw placement (n = 23, 7.5%).

CONCLUSIONS

Intraoperative three-dimensional imaging can provide additional information compared to conventional two-dimensional fluoroscopy in the operative treatment of distal radius fractures with the possibility of immediate intraoperative revision.