[Multiplanar reconstruction with mobile 3D image intensifier. Surgical treatment of proximal humerus fractures]

3D C-arm navigated acromioclavicular joint stabilization

INTRODUCTION

Surgical treatment options for acromioclavicular joint separations are varied. Frequently, suspension devices (SD) are inserted for stabilization under arthroscopic view. This study investigates the feasibility and accuracy of three-dimensional (3D) digital-volume-tomography (DVT) C-arm navigated implantation with regard to the general trend toward increasingly minimally invasive procedures.

MATERIALS AND METHODS

The implantation of a TightRope® suture button system (SD) via a navigated vertical drill channel through the clavicle and coracoid was investigated in 10 synthetic shoulder models with a mobile isocentric C-arm image intensifier setup in the usual parasagittal position. Thereby, in addition the placement of an additive horizontal suture cerclage via a navigated drill channel through the acromion was assessed.

RESULTS

All vertical drill channels in the Coracoclavicular (CC) direction could be placed in a line centrally through the clavicle and the coracoid base. The horizontal drill channels in the Acromioclavicular (AC) direction ran strictly in the acromion, without affecting the AC joint or lateral clavicle. All SD could be well inserted and anchored. After tensioning and knotting of the system, the application of the horizontal AC cerclage was easily possible. The image quality was good and all relevant structures could be assessed well.

CONCLUSION

Intraoperative 3D DVT imaging of the shoulder joint using a mobile isocentric C-arm in the usual parasagittal position to the patient is possible. Likewise, DVT navigated SD implantation at the AC joint in CC and AC direction on a synthetic shoulder model. By combining both methods, the application in vivo could be possible. Further clinical studies on feasibility and comparison with established methods should be performed.

Intraoperative 3D imaging in plate osteosynthesis of proximal humerus fractures

INTRODUCTION

Proximal humerus fractures are common and often associated with osteoporosis in the elderly. Unfortunately, the complication and revision rate for joint-preserving surgical treatment using locking plate osteosynthesis is still high. Problems include insufficient fracture reduction and implant misplacement. Using conventional intraoperative two dimensional (2D) X-ray imaging control in only two planes, a completely error-free assessment is not possible.

MATERIALS AND METHODS

The feasibility of intraoperative three-dimensional (3D) imaging control for locking plate osteosynthesis with screw tip cement augmentation of proximal humerus fractures was retrospectively studied in 14 cases with an isocentric mobile C-arm image intensifier set up parasagittal to the patients.

RESULTS

The intraoperative digital volume tomography (DVT) scans were feasible in all cases and showed excellent image quality. One patient showed inadequate fracture reduction in the imaging control, which then could be corrected. In another patient, a protruding head screw was detected, which could be replaced before augmentation. Cement distribution in the humeral head was consistent around the screw tips with no leakage into the joint.

CONCLUSION

This study shows that insufficient fracture reduction and implant misplacement can be easily and reliably detected by intraoperative DVT scan with an isocentric mobile C-arm set up in the usual parasagittal position to the patient.

Intraoperative 3D imaging in intraarticular tibial plateau fractures - Does it help to improve the patients' outcomes?

BACKGROUND

In tibial plateau fractures (TPF) the restoration of an anatomical joint surface as well as an exact subchondral screw position for postoperative stability is crucial for the outcome. The aim of this study was to determine whether the additional use of an intraoperative 3D imaging intensifier (3D) might help to improve the outcome of complex TPF.

METHODS

We performed a retrospective case-control study of a level 1 trauma center. Patients with AO/OTA 41 B3 and C-TPF operated on using a 3D imaging intensifier between November 2015 and December 2018 (3D group) were included. The outcomes of this patients were compared to patients operated without 3D imaging between January 2005 to December 2014 (2D group). The comparison of the groups was performed by matched pair analysis. The functional outcome of both groups was measured by KOOS and Lysholm Score after a follow-up period of at least 12 months. Operation time, infections and postoperative revisions were registered.

RESULTS

In total, 18 patients were included in the 3D group (mean age: 51.0± 16.4 years; 12 females) and an equal number of matching partners from the 2D group (mean age: 50.3± 15.2 years; 11 females) were found (p=0.82; p=0.79). We found 9x B3, 2x C1, 1x C2, 6x C3 fractures according to AO/OTA for each group (p=1.00) with comparable ASA score (p=0.27). The mean operation time was 127.9± 45.9 min and 116.1± 45.7 min for the 3D and 2D group (p=0.28). The mean follow-up time was 20.9± 10.7 months for the 3D and 55.5± 34.7 months for the 2D group (p< 0.001). For the 3D group a mean Lysholm overall score of 67.4± 26.8 and KOOS overall score of 72.6± 23.5 could be assessed. In contrast, a mean Lysholm overall score of 62.0± 21.4 and KOOS overall score of 65.8± 21.6 could be measured in the 2D group (p=0.39; p=0.31). Thereby, functional outcome of the 3D group showed a significant higher KOOS Sport/Rec sub score of 54.7± 35.0 in comparison to the 2D group with 26.7± 31.6 (p= 0.01). Postoperative revisions had to be performed in 27.8% of cases in both groups (p=1.00). Due to the 3D imaging an intraoperative revision was performed in 33.3% (6/18).

CONCLUSION

In our study we could show that re-reduction of the fracture or implant re-positioning were performed in relevant numbers based on the 3D imaging. This was associated with a midterm clinical benefit in regard to better KOOS Sport/Rec scores.

TRIAL REGISTRATION

AZ 488 /20-ek.

Detection of primary screw perforation in locking plate osteosynthesis of proximal humerus fracture by intra-operative 3D fluoroscopy

PURPOSE

The purpose of this study was to identify the rate of primary screw perforations after osteosynthesis of proximal humerus fractures with intra-operative 3D fluoroscopy and to analyse the rate of secondary screw perforations as well as complications, outcome, and revision surgeries after a minimum of 12 months.

MATERIALS AND METHODS

Thirty-three patients (20 female, 13 male, median age 67 years, range 35-85 years) with displaced proximal humerus fractures were included. After reduction and fixation, an intra-operative 3D fluoroscopy was performed to evaluate primary screw perforations (PS) and screws with "near perforation" (nPS). These screws were changed intra-operatively. Patients were followed-up for a minimum of 12 months. Clinical and radiological parameters, such as secondary screw perforation, secondary loss of reduction, or functional outcome, were investigated.

RESULTS

In six patients (18.2%), humeral head screws were changed due to primary PS (n = 2) or nPS (n = 4) after the intra-operative 3D fluoroscopy. Follow-up revealed an adapted constant score (%CMS) of 76.2% after a mean follow-up of 17.7 months. Two secondary screw perforations were observed (6%). Loss of reduction was observed in eight patients (24.2%).

CONCLUSION

The intra-operative 3D reveals a high rate of primary screw perforations or near perforations. Immediate change of these screws may lead to a lower rate of secondary screw perforations and, therefore, reduce post-operative complications.

Detection of articular perforations of the proximal humerus fracture using a mobile 3D image intensifier - a cadaver study

Background

The purpose of this study was to investigate the accuracy of perforation detection with multiplanar reconstructions using a mobile 3D image intensifier.

Methods

In 12 paired human humeri, K-wires perforating the subchondral bone and placed just below the cartilage level were directed toward five specific regions in the humeral head. Image acquisition was initiated by a fluoroscopy scan. Within a range of 90°, 45° external rotation (ER) and 45° internal rotation (IR). The number and percentage of detected perforating screws were grouped and analyzed. Furthermore, the fluoroscopic images were converted into multiplanar CT-like reconstructions. Each K-wire perforation was characterized as “detected” or “not detected”.

Results

In the series of fluoroscopy images in the standard neutral position at 30° internal rotation, and 30° external rotation, the perforations of all K-wires (n = 56) were detected. Twenty-nine (51.8%) of them were detected in one AP view, 22 (39.3%) in two AP views, and five (8.9%) in three AP views. All K-wire perforations (100%, n = 56) were detected in multiplanar reconstructions.

Conclusion

In order to reveal all of the intraoperative and postoperative screw perforations in a “five screw configuration”, conventional AP images should be established in both the neutral positions (0°), at 30° internal rotation and 30° external rotation. Alternatively, the intraoperative 3D scan with multiplanar reconstructions enables a 100% rate of detection of the screw perforations.

[Treatment of proximal humeral fractures in Germany: Influence of the level of hospital care and the frequency of treatment]

BACKGROUND

Various treatment options exist for displaced proximal humeral fractures. The impact of the level of hospital care and frequency of treatment on current treatment regimens in Germany was analyzed.

MATERIAL AND METHODS

A total of 576 hospitals were included. The survey covered questions on frequency, diagnostics, classification, therapy, complications, and clinical scenarios.

RESULTS

In all, 48% of the hospitals returned the questionnaire: 73% treat more than 60% of the fractures surgically, mainly with angle-stable implants. The angle-stable plate is the treatment of choice for young patients, but older patients are treated using other treatment options. Problems and complications included malreduction, secondary displacement, screw perforation, avascular necrosis, and impingement. According to treatment indication, implant choice, and common complications, no significant differences between the level of hospital care and frequency of treatment were observed.

CONCLUSION

Independent of the level of hospital care and frequency of treatment, there is a trend for head-preserving angular-stable surgery with a homogenous level of treatment in Germany.