Open reduction and internal fixation aided by intraoperative 3-dimensional imaging improved the articular reduction in 72 displaced acetabular fractures

[Imaging examination procedures, navigation and minimally invasive procedures in acetabular surgery]

Acetabular fractures still pose a special challenge even today. Considering the increasing case numbers, especially in the geriatric patient group, modern imaging examination procedures represent an essential pillar of the diagnostics. Especially in this vulnerable patient group, minimally invasive methods are necessary, which can be guaranteed by intraoperative navigation; however, the choice of surgical access and implants is also made based on the existing morphological characteristics of fractures, which highlights the importance of an imaging modality that is as detailed as possible. Last but not least, new developments concerning the surgical treatment of these injuries are also based on this. This article summarizes the current state of the techniques and the available literature.

Intraoperative revision rates due to three-dimensional imaging in orthopedic trauma surgery: results of a case series of 4721 patients

PURPOSE

Intraoperative 3D imaging has become a valued tool in assessing the quality of reduction and implant placement in orthopedic trauma surgery. In our institution, 3D imaging is used routinely since 2001. To evaluate the intraoperative findings and consequences of this technique, intraoperative revision rates in cases with 3D imaging were analyzed.

METHODS

All operative procedures carried out with intraoperative 3D imaging between August 2001 and December 2016 were included. The scans were assessed intraoperatively and documented thereafter. In case of malreduction or misplaced implants, an immediate revision was performed. The number of scans per case as well as the findings and consequences drawn regarding the anatomical region were analyzed.

RESULTS

4721 cases with 7201 3D scans were included in this study. The most common anatomical regions were the ankle (22.3%), the calcaneus (14.8%) and the tibial head (9.5%). In 19.1% of all cases, an intraoperative revision was performed. The highest revision rates were found with 36.0% in calcaneal fractures, 24.8% in fractures of the tibial plateau, 22.3% in injuries of the ankle. In 52.0% of revisions, the reduction was improved regarding intra-articular steps or joint congruency. In 30.5% an implant was corrected.

CONCLUSION

Intraoperative revision due to results of 3D imaging was performed in almost one-fifth of cases. This illustrates the improved possibilities to detect malreduction and implant misplacements intraoperatively and thus the abilities to improve surgical outcome.

LEVEL OF EVIDENCE

III.

Low interobserver and intraobserver reliability using the Matta radiographic system for intraoperative assessment of reduction following acetabular ORIF

INTRODUCTION

The system described by Matta for rating acetabular fracture quality of reduction following ORIF has been used extensively throughout the literature. However, the reliability of this system remains to be validated. We sought to determine the interobserver and intraobserver reliability of this system when used by fellowship-trained pelvic and acetabular surgeons to evaluate intraoperative fluoroscopy.

METHODS

This is a retrospective evaluation of a prospectively collected acetabular fracture database at an academic level I trauma center. The quality of reduction of all acetabular fractures treated with open reduction internal fixation (ORIF) between May 2013 and December 2015 was assessed using three standard intraoperative fluoroscopic views (anteroposterior and two 45˚ oblique Judets). Displacement of ≤1 mm was considered to be an anatomic reduction, 2-3 mm imperfect, and >3 mm poor according to the system described by Matta. A total of 107 acetabular fractures treated with ORIF with complete intraoperative fluoroscopic images during that time period were available for review. Acetabular fracture reductions were reviewed by the operative surgeon at the time of surgery and subsequently reviewed by two fellowship-trained pelvic and acetabular surgeons. All reduction assessments were performed in a blinded fashion. The primary outcome measure was interobserver reliability for assessing reduction quality. This was evaluated using a weighted kappa (κ_w) statistic between each evaluator and the operative surgeon and a generalized kappa (κ_g) for all 3 surgeons. After a 6-week "washout interval," the surgeons reviewed the images again and intraobserver agreement was calculated using a weighted kappa statistic.

RESULTS

Interobserver reliability based on the initial assessment was low (κ_g = 0.09); however, did slightly improve with the second assessment to fair (κ_g = 0.24). Intraobserver reliability ranged from slight (κ_w = 0.20) to moderate (κ_w = 0.53) among the surgeons.

DISCUSSION

Low interobserver and intraobserver reliability was found when quality of reduction was assessed with intraoperative fluoroscopic images by the operative and two other pelvic and acetabular surgeons using the Matta system. Given the importance of an anatomic reduction on functional and radiographic outcomes, an accurate and reliable system for assessing intraoperative quality of reduction is essential.

Software-Automated Implant Detection for Intraoperative 3D Imaging-First Clinical Evaluation on 214 Data Sets

Previous studies have demonstrated a frequent occurrence of screw/K-wire malpositioning during surgical fracture treatment under 2D fluoroscopy and a correspondingly high revision rate as a result of using intraoperative 3D imaging. In order to facilitate and accelerate the diagnosis of implant malpositioning in 3D data sets, this study investigates two versions of an implant detection software for mobile 3D C-arms in terms of their detection performance based on comparison with manual evaluation. The 3D data sets of patients who had received surgical fracture treatment at five anatomical regions were extracted from the research database. First, manual evaluation of the data sets was performed, and the number of implanted implants was assessed. For 25 data sets, the time required by four investigators to adjust each implant was monitored. Subsequently, the evaluation was performed using both software versions based on the following detection parameters: true-positive-rate, false-negative-rate, false-detection-rate and positive predictive value. Furthermore, the causes of false positive and false negative detected implants depending on the anatomical region were investigated. Two hundred fourteen data sets with overall 1767 implants were included. The detection parameters were significantly improved (p<.001) from version 1 to version 2 of the implant detection software. Automatic evaluation required an average of 4.1±0.4 s while manual evaluation was completed in 136.15±72.9 s (p<.001), with a statistically significant difference between experienced and inexperienced users (p=.005). In summary, version 2 of the implant detection software achieved significantly better results. The time saved by using the software could contribute to optimizing the intraoperative workflow.

First experiences with intraoperative CT in navigated sacroiliac (SI) instrumentation: An analysis of 25 cases and comparison with conventional intraoperative 2D and 3D imaging

BACKGROUND

Intraoperative imaging is regularly used for intraoperative reduction control and evaluation of the implant position in trauma surgery. 2D imaging is limited, especially in complex anatomical regions such as the pelvis. The introduction of mobile 3D C-arms (CBCT: cone-beam computed tomography) has significantly improved intraoperative assessment. Nevertheless, there are still limitations regarding the field of view and metal artifacts. The purpose of this study was to evaluate the potential of intraoperative computed tomography (iCT) in surgical treatment of sacroiliac (SI) injuries.

METHODS

Twenty-five cases with injuries of the posterior pelvic ring involving the SI region that were surgically treated with navigated SI screws using the mobile iCT Airo (Brainlab, Munich, Germany) were analysed. Subsequently, the data were compared with historical control groups (CBCT with and without navigation; 2D fluoroscopy only).

RESULTS

The average score for subjective image quality achieved using the Likert scale is significantly higher for the iCT (4.48 ± 0.65) than for the CBCT (3.04 ± 0.69) with p = 0.00. The average duration of surgery using iCT was 189.32 ± 88.64 min, which was not significantly different from the control groups (p = 0.14 - 0.70). The average fluoroscopy time using iCT was 81.96 ± 97.34 s, which was significantly shorter than in all of the control groups (p = 0.00 - 0.03). The rate for postoperatively detected complications after using iCT was 0% (n = 0). Compared with the 2D-only control group (25%; n = 1), there is a significant difference (p = 0.01). The remaining two control groups showed no significant differences (p = 0.09 - 0.19).

CONCLUSIONS

The iCT provides excellent image quality that allows reliable assessment of fracture reduction and implant placement even in complex anatomical regions. The radiation exposure for the medical staff is reduced by decreasing the fluoroscopy time without significantly prolonging the surgical time. Overall, the possibility of intraoperative correction improves clinical outcome and patient treatment in the long term.

Utility of 3-Dimensional Intraoperative Imaging in Pelvic and Acetabular Fractures: A Network Meta-Analysis

BACKGROUND

Successful surgical management of pelvic ring and acetabular fractures requires technical expertise to achieve an accurate reduction and stable fixation. The use of 3-dimensional (3D) intraoperative imaging (3DIOI) as an assessment tool has led to improved reduction and placement of implants. The purpose of this study was to assess the utility of using 3DIOI in the management of acetabular and pelvic fractures on the basis of outcomes reported in the literature.

METHODS

A literature search was performed using PubMed, the Cochrane Database of Systematic Reviews (CDSR), and Google Scholar using key terms. A network meta-analysis conducted using the frequentist approach allowed for statistical analysis of reported outcomes regarding screw position (in mm), fracture reduction (in mm), and complications.

RESULTS

A total of 9 studies were included in this analysis. When compared with conventional radiography, the mean radiation dose (in cGy·cm2) was significantly higher in 3DIOI (mean difference, 82.72; 95% confidence interval [CI], 21.83 to 143.61; p = 0.007). Use of 3DIOI yielded a 93% lower risk of developing medical complications (odds ratio [OR], 0.07; 95% CI, 0.02 to 0.35; p = 0.014). Use of 3DIOI yielded higher odds of achieving accurate screw placement (OR, 4.21; 95% CI, 1.44 to 12.32; p = 0.008) and perfect reduction (OR, 2.60; 95% CI, 1.19 to 5.68; p = 0.016). In ranking the imaging modalities, 12 of the 13 parameters analyzed were in favor of 3DIOI over conventional fluoroscopy and 2D navigation imaging.

CONCLUSIONS

Current literature supports the use of 3DIOI because of the decreased rates of misplaced implants, malreduced fractures, complications, and subsequent revision operations. The use of 3DIOI allows for improved visualization of pelvic anatomy when repairing pelvic and acetabular fractures, and helps surgeons to achieve favorable surgical outcomes.

LEVEL OF EVIDENCE

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

Clinical impact of intraoperative cone beam tomography and navigation for displaced acetabular fractures: a comparative study at medium-term follow-up

INTRODUCTION

The use of per-operative cone beam tomography imaging for displaced acetabular fractures yields increased post-operative articular reduction accuracy. This study evaluates the need for total hip replacement (THR) and hip-related functional outcomes in patients with displaced acetabular fractures treated with O-ARM guidance compared to those treated under C-ARM guidance.

MATERIALS AND METHODS

This is a prospective matched cohort study. Adult patients (35) with acetabular fractures operated under O-ARM guidance were included. These were matched (age, fracture type) to classically treated patients (35) from our data base. The primary outcome was the need for THR during three year follow-up period. Secondary outcomes were functional scores [Harris Hip score (HHS), Postel-Merle d'Aubigné (PMA)] and hip osteoarthritis grade at three year follow-up. Correlation between reduction gap and THR was evaluated.

RESULTS

At three years, five patients were lost to follow-up in O-ARM group and four in control group. Two patients (6.66%) in the O-ARM group needed THR compared to eight patients in controls (25.80%) (p = 0.046). Hip X-ray osteoarthritis grade averaged 0.00 in patients without THR in O-ARM group compared to 0.22 in patients without THR in controls (p = 0.008). HHS averaged 95.79 in patients without THR in O-ARM group, compared to 93.82 in patients without THR in the control group (p = 0.41%). PMA averaged 17.25 in patients without THR in the O-ARM group compared to 17.04 in patients without THR in group 2 (p = 0.37). Evaluation of correlation between reduction gap and THR rate yielded OR = 1.22 (1.06-1.45).

DISCUSSION

Increased accuracy in articular reduction, with per-operative three-dimensional control of impaction, in acetabular fractures led to significantly less need for THR in patients treated under O-ARM. Patients in both groups are comparable for functional outcomes because those with the lowest scores were offered THR. Per-operative cone beam guidance and navigation use are recommended in tertiary referral centres for acetabular trauma.

Evolution of imaging in surgical fracture management

Intraoperative imaging has been advanced substantially over the last decades. It supports localization of the region of interest, verification of the preoperatively classified fracture pattern, identification of correct insertion point of the implant, placement of instruments and fixation material, and verification of correct fracture reduction and implant positioning. While conventional fluoroscopic 2D imaging remains the gold standard in intraoperative imaging, critical anatomical regions are predestined for intraoperative 3D imaging. Additional options such as perioperative virtual planning, simulation, and surgical training, 3D printing techniques and 3D augmented reality visualization may potentially open new windows to improve surgical results in fracture care. This manuscript presents an update on current and upcoming imaging techniques in orthopaedic and trauma surgery focusing on technical advances for decreasing malreduction, malalignment, and malposition, as well as tips and tricks for daily surgical practice in order to improve clinical outcomes and patients' and surgeons' safety.

Minimizing Posttraumatic Osteoarthritis After High-Energy Intra-Articular Fracture

This article serves to provide an overview of molecular and surgical interventions to minimize the progression of posttraumatic arthritis following high-energy intra-articular fractures. The roles of cartilage and the microcellular environment are discussed, as well as the response of the joint and cartilage to injury. Molecular therapies, such as glucocorticoids, mesenchymal stem cells, and bisphosphonates, are presented as potential treatments to prevent progression to posttraumatic arthritis. High-energy intra-articular fractures of the elbow, hip, knee, and ankle are discussed, with emphasis on restoring anatomic alignment, articular reduction, and stability of the joint.

First experiences with the Airo mobile intraoperative CT scanner in acetabular surgery-An analysis of 10 cases

BACKGROUND

Being a proven method in trauma and spine surgery, intraoperative 3D imaging (CBCT) has intrinsic deficits in difficult anatomy and with artifacts because of metal implants. The purpose of this study was to evaluate the use of intraoperative computed tomography (iCT) in acetabular surgery.

METHODS

Ten cases of acetabular fractures that were operated with intraoperative use of the mobile CT scanner Brainlab Airo were analyzed. Data were compared with a historical group of 17 patients.

RESULTS

Additional fluoroscopy time was 24.2 seconds (6-91), which was significantly lower than in the control group where it was 211.4 seconds (77-446; P < 0.000). Operation time did not differ significantly (iCT group 196.8 min [122-288], control group 240.8 min [71-411], P = 0.234).

CONCLUSION

iCT provides images of a reliable high quality and assessability. Radiation exposure to the staff is reduced while surgery time is not altered significantly. Quality of intraoperative imaging and thus patient care can substantially improve patient outcome.

Accuracy and safety of percutaneous periacetabular screw insertion using screw view model of navigation in acetabular fracture: A case report

RATIONALE

The purpose of this study was to estimate the efficacy and safety of percutaneous periacetabular screw (PPS) insertion assisted by screw view model of navigation (SVMN) to treat fracture of acetabulum.

PATIENT CONCERNS

A 61-year-old male patient was injured in a motorcycle accident, which caused pain, swelling, deformity and limited mobility on his right hip.

DIAGNOSES

He was diagnosed with fracture of acetabulum.

INTERVENTIONS

We used PPS insertion assisted by SVMN to treat fracture of acetabulum in this patient.

OUTCOMES

The follow up lasted 24 months. Totally 2 screws were inserted into anterior and posterior column of acetabulum respectively and both of them displayed grade 0. Compared with the preoperative gap and step of fracture displacement, the postoperative ones were significantly reduced. It took 11.7 minutes for designing the screws, 6.7 minutes for implanting the guide wire, and 45.5 minutes for placing the screws. Intraoperative blood loss was 29 mL and total fluoroscopic time was 4.1 minutes. No clinical complications such as nerve vascular injury, infection and screw loosening were found after the operation.

LESSONS

The study indicated that SVMN is favorable to the PPS insertion for acetabular fracture. Our lesson is that the relative position between the acetabular and the patient tracker must be static to ensure the accuracy of the entire system throughout the operation.

Intraoperative assessment of reduction and implant placement in acetabular fractures-limitations of 3D-imaging compared to computed tomography

Background

In acetabular fractures, the assessment of reduction and implant placement has limitations in conventional 2D intraoperative imaging. 3D imaging offers the opportunity to acquire CT-like images and thus to improve the results. However, clinical experience shows that even 3D imaging has limitations, especially regarding artifacts when implants are placed. The purpose of this study was to assess the difference between intraoperative 3D imaging and postoperative CT regarding reduction and implant placement.

Methods

Twenty consecutive cases of acetabular fractures were selected with a complete set of intraoperative 3D imaging and postoperative CT data. The largest detectable step and the largest detectable gap were measured in all three standard planes. These values were compared between the 3D data sets and CT data sets. Additionally, possible correlations between the possible confounders age and BMI and the difference between 3D and CT values were tested.

Results

The mean difference of largest visible step between the 3D imaging and CT scan was 2.0 ± 1.8 mm (0.0–5.8, p = 0.02) in the axial, 1.3 ± 1.4 mm (0.0–3.7, p = 0.15) in the sagittal and 1.9 ± 2.4 mm (0.0–7.4, p = 0.22) in the coronal views. The mean difference of largest visible gap between the 3D imaging and CT scan was 3.1 ± 3.6 mm (0.0–14.1, p = 0.03) in the axial, 4.6 ± 2.7 mm (1.2–8.7, p = 0.001) in the sagittal and 3.5 ± 4.0 mm (0.0–15.4, p = 0.06) in the coronal views. A positive correlation between the age and the difference in gap measurements in the sagittal view was shown (rho = 0.556, p = 0.011).

Conclusions

Intraoperative 3D imaging is a valuable adjunct in assessing reduction and implant placement in acetabular fractures but has limitations due to artifacts caused by implant material. This can lead to missed malreduction and impairment of clinical outcome, so postoperative CT should be considered in these cases.