Reinforcing the role of the conventional C-arm--a novel method for simplified distal interlocking

Endoscopy-assisted distal locking of an intramedullary nail: A new experimental technique to reduce radiation exposure during distal locking of the intramedullary nails

Objectives

In this study, we aimed to introduce a new technique in which distal locking step was easier and safer for orthopedic trauma surgeons involving in the treatment of long bone fractures using an intranail endoscopic visualization and illumination method.

Materials and methods

A total of 20 fresh bovine hind limbs derived from healthy adults and killed for sale were dissected to obtain tibial bones. Two equal groups including 10 samples in each were prepared. We applied a standard nailing process in both groups: the study group (n=10) was locked by the new technique, intranail endoscopic illumination guidance and intranail visualization assistance locking technique and the control group (n=10) was locked by the classical free-hand fluoroscopic guidance technique. We measured the surgical period time and the radiation exposure time required for the distal locking in both groups.

Results

The radiation exposure time was statistically significantly lower in the study group compared to the control group. Also, the time period required for distal locking in the study group were statistically significantly lower than the control group. With the use of the intranail endoscopic illumination guidance and visualization assistance technique, the median period time required for the distal locking procedure reduced from 477.5 to 223.5 sec (p<0.001). The median time for radiation exposure dramatically reduced from 13.5 to 2 sec (p<0.001). The median attempt number reduced from 6.5 to 2 times (p<0.001).

Conclusion

This experimental study indicates that the endoscopic illumination and intranail visualization assistance technique can reduce the radiation exposure time and the period time required for distal locking compared to the free-hand fluoroscopic guidance.

Intramedullary nail holes laser indicator, a non-invasive technique for interlocking of intramedullary nails

Interlocking of intramedullary nails is a challenging procedure in orthopedic trauma surgery. Numerous methods have been described to facilitate this process. But they are exposed patient and surgical team to X-rays or involves trial and error. An accurate and non-invasive method has been provided to easily interlocking intramedullary nails. By transferring a safe visible light inside the nail, a drilling position appears which use to drilling bone toward the nail hole. The wavelength of this light was obtained from ex-vivo spectroscopy on biological tissues which has optimal transmission, reflectance, and absorption properties. Moreover, animal and human experiments were performed to evaluate performance of the proposed system. Ex-vivo performance experiments were performed successfully on two groups of cow and sheep samples. Output parameters were procedure time and drilling quality which there were significant differences between the two groups in procedure time (P < 0.05). But no significant differences were observed in drilling quality (P > 0.05). Moreover, an In-vivo performance experiment was performed successfully on a middle-aged man. To compare the provided method, targeting-arm, and free-hand techniques, two human experiments were performed on a middle-aged and a young man. The results indicate the advantage of the proposed technique in the procedure time (P < 0.05), while the drilling quality is equal to the free-hand technique (P = 0.05). Intramedullary nail holes laser indicator is a safe and accurate method that reduced surgical time and simplifies the process. This new technology makes it easier to interlocking the intramedullary nail which can have good clinical applications.

A novel dynamic electromagnetic tracking navigation system for distal locking of intramedullary nails

BACKGROUND

The accurate distal locking of intramedullary (IM) nails is a clinical challenge for surgeons. Although many navigation systems have been developed, a real-time guide method with free radiation exposure, better user convenience, and high cost performance has not been proposed.

METHODS

This paper aims to develop an electromagnetic navigation system named TianXuan-MDTS that provides surgeons with a proven surgical solution. And the registration method with external landmarks for IM nails and calibration algorithm for guiders were proposed. A puncture experiment, model experiments measured by 3D Slicer and cadaver experiments (2 cadaveric leg specimens and 6 drilling operations) are conducted to evaluate its performance and stability.

RESULTS

The registration deviations (TRE) is 1.05± 0.13 mm. In the puncture experiment, a success rate of 96% can be achieved in 45.94 s. TianXuan-MDTS were evaluated on 3 tibia model. The results demonstrated that all 9 screw holes were successfully prepared at a rate of 100% in 91.67 s. And the entry point, end point, and angular deviations were 1.60±0.20 mm, 1.47±0.18 mm, and 3.10±0.84°, respectively. Postoperative fluoroscopy in cadaver experiments showed that all drills were in the distal locking holes, with a success rate of 100% and the average time 143.17± 18.27 s.

CONCLUSIONS

The experimental results indicate that our system with novel registration and calibration methods could serve as a feasible and promising tool to assist surgeons during distal locking.

Generic Implant Positioning Technology Based on Hole Projections in X-Ray Images

Implant placement plays a key role in trauma and orthopedics. In this paper, a generic technological concept for implant positioning assistance is outlined. The system utilizes conventional radiographic devices for imaging and tracking and embeds into surgical workflows without the need for complex navigation equipment. It is based on feature extraction from cylindrical hole-projections in X-ray images for determining spatial alignment of implant and anatomy. Basic performance of a prototype system was experimentally verified in terms of tracking accuracy and robustness under varying conditions. In a second step, the system was developed into a set of application modules, each serving a pressing clinical need: Plating of the proximal humerus, cephalic nail and dynamic hip-screw placement, general anatomic plating, distal nail interlocking with adjustment of femoral anteversion and corrective osteotomies. Module prototypes were tested according to their degree of maturity from feasibility assessment in wet-labs to clinical handling tests. Orientation tracking of reference objects yielded an accuracy and precision of 0.1±0.71 deg (mean±standard deviation) with a maximum error of 4.68 deg at unfavorable conditions. This base-performance translated, e.g., into a precision of ±1.2 mm (standard deviation) screw-tip to joint distance at proximal humerus plating, or into a precision of lag screw positioning in the femoral head of ±0.6 mm in craniocaudal and ±1.6 mm in anterioposterior direction. The concept revealed strong potential to improve surgical outcomes in a broad range of orthopedic applications due to its generic and simplistic nature. Comprehensive validation activities must follow for clinical introduction.

In vivo test of a radiography-based navigation system for control of derotational osteotomies

Malalignment of the femur is a frequently encountered problem in orthopaedics entailing manifold consequences for the affected patients. Corrective osteotomies, necessary to restore the physiological and anatomical relationships, face great challenges due to no existing reliable gold standard for intraoperative control of torsional malalignment. The aim of this study was to test a novel radiography-based navigation tool for control of derotational osteotomies in a clinical environment. In a first-and preliminary-case-controlled study on 12 patients (level 3 of evidence), the achieved torsional correction measured with implementation of the navigation tool was compared with measurements from pre- and postoperative computed tomography (CT) scans. The navigation tool was able to acquire and process all relevant data and capture possible malrotation during surgery with only little deviations of 1.61° ± 0.86° (mean ± standard deviation) from the measurements based on CT scans. Next, the system will be used to assist surgeons for more precise treatment avoiding maltorsion after derotational osteotomies.

Reduced Surgical Time and Higher Accuracy of Distal Locking with the Electromagnetic Targeting System in Humeral Shaft Intramedullary Nailing

Objective

To evaluate the efficacy of the electromagnetic distal targeting system in the treatment of humeral shaft fractures.

Methods

From January 2012 to December 2018, we retrospectively reviewed 60 patients with humeral shaft fractures treated by intramedullary nailing. Among 60 cases, 41 were men and 19 were women. The average age at surgery was 48.5 years (range, 21–81 years). We performed the same surgical procedure for all patients. According to the different distal locking technique used, all patients were divided into two groups. The standard fluoroscopic freehand technique was used for Group FH, while the electromagnetic real‐time targeting technique was used for Group EM. All procedures were performed by two senior surgeons. Overall surgical time, cases of complications, failure of distal locking, union time, and shoulder function assessment were recorded intraoperatively and during follow‐up.

Results

Twenty‐seven patients in Group FH and 33 patients in Group EM met the inclusion criteria. No significant difference was found in the demographic data of the two groups. The mean surgical time was 76.48 ± 10.73 min in Group FH and 65.61 ± 8.91 min in Group EM (P < 0.05), showing significant difference. Seven failures occurred in Group FH and two failures occurred in Group EM (P < 0.05). No relevant complications were noted. The average union time was 3.37 ± 0.49 months in Group FH and 3.39 ± 0.50 months in Group EM (P = 0.855). The mean follow‐up was 14.30 ± 2.28 months in Group FH and 15.27 ± 2.83 months in Group EM (P = 0.153). The disabilities of the arm, shoulder and hand score (DASH) score, the range of motion (checked with the constant score), and the degree of functionality were, respectively, 21.52 ± 3.23, 27.04 ± 1.84, and 81.31% ± 3.88% in Group FH and 19.09 ± 2.40, 26.18 ± 1.70, and 77.97% ± 3.91% in Group EM (P = 0.233, 0.971, and 0.607).

Conclusion

The electromagnetic real‐time targeting system reduced surgical time and improved accuracy, and there was no radiation exposure in the distal locking procedure for humeral shaft fractures.

C-Arm Image-Based Surgical Path Planning Method for Distal Locking of Intramedullary Nails

Due to the curvature of the bone marrow cavity, the intramedullary nail used in long bone fracture fixation can be deformed, causing displacement of the locking holes. In this study, an algorithm using only one C-arm image to determine the center positions and axial directions of locking holes was developed for drilling guidance. Based on conventional method that the axial direction of locking hole would be identified when locking hole contour is presented as a circle, the proposed method can locate the circle contour centroid by using one C-arm image including two elliptical contours. Then the two distal locking holes' axial direction and centers would be determined. Three experiments were conducted to verify the performance of the proposed algorithm, which are (1) computer simulation, (2) use of real intramedullary nails, and (3) actual drilling test with the bone model. The experimental results showed that the average error of the axial direction and center position were 0.62 ± 0.6°, 0.73 ± 0.53 mm (simulation) and 3.16 ± 1.36°, 1.10 ± 0.50 mm (actual nail), respectively. The last ten drilling test sets were completed successfully (with an average duration of 48 seconds). Based on the experimental results, the proposed algorithm was feasible for clinic applications.

Fluoroscopic freehand and electromagnetic-guided targeting system for distal locking screws of humeral intramedullary nail

PURPOSE

The current techniques used to lock distal screws for the nailing of long bone fractures expose the surgeons, radiologists and patients to a hearty dose of ionizing radiation. The Sureshot™ Distal Targeting System is a new technique that, with the same results, allows for shorter surgery times and, consequently, less exposure to radiation.

MATERIALS AND METHODS

The study was performed on 59 patients (34 males and 25 females) with a simple humerus fracture diagnosis, type 1.2.A according to the AO classification, who were divided into two groups. Group 1 was treated with ante-grade intramedullary nailing with distal locking screws inserted with a freehand technique. Group 2 was treated with the intramedullary nail using the Sureshot™ Distal Targeting System. Two intra-operative time parameters were evaluated in both groups: the time needed for the positioning of the distal locking screws and the time of exposure to ionizing radiations during this procedure.

RESULTS

Group 2 showed a lower average distal locking time compared to group 1 (645.48″ vs. 1023.57″) and also a lower average time of exposure to ionizing radiation than in group 1 (4.35″ vs. 28.96″).

CONCLUSION

The Sureshot™ Distal Targeting System has proven to be equally effective when compared to the traditional techniques, with the added benefits of a significant reduction in both surgical time and risk factors related to the exposure to ionizing radiation for all the operating room staff and the patient.

Intra-operative augmented reality in distal locking

PURPOSE

To design an augmented reality solution that assists surgeons during the distal locking of intramedullary nailing procedures.

METHOD

Traditionally, the procedure is performed under X-ray guidance and requires a significant amount of time and radiation exposure. To absolve these complications, we propose video guidance that allows surgeons to achieve both the down-the-beam position of the intramedullary nail and its subsequent locking. For the down-the-beam position, the IM nail pose in X-ray is calculated using a 2D/3D registration scheme and later related to the patient leg pose which is calculated using video-tracked AR markers. For the distal locking, surgeons use an augmented radiolucent drill in which its tip position is detected and tracked in real-time under video guidance.

VALIDATION

To evaluate the feasibility of our solution, we performed a preclinical study on dry bone phantom with the participation of four clinicians.

RESULTS

Participants achieved 100 % success rate in the down-the beam positioning and 93 % success rate in distal locking using only two X-ray images in 100 s.

CONCLUSIONS

We confirmed that intra-operative navigation using augmented reality provides an alternative way to perform distal locking in a safe and timely manner.

Multi-modal intra-operative navigation during distal locking of intramedullary nails

The interlocking of intramedullary nails is a technically demanding procedure which involves a considerable amount of X-ray acquisitions; one study lists as many as 48 to successfully complete the procedure and fix screws into 4-6 mm distal holes of the nail. We propose to design an augmented radiolucent drill to assist surgeons in completing the distal locking procedure without any additional X-ray acquisitions. Using an augmented reality fluoroscope that coregisters optical and X-ray images, we exploit solely the optical images to detect the augmented radiolucent drill and estimate its tip position in real-time. Consequently, the surgeons will be able to maintain the down the beam positioning required to drill the screws into the nail holes successfully. To evaluate the accuracy of the proposed augmented drill, we perform a preclinical study involving six surgeons and ask them to perform distal locking on dry bone phantoms. Surgeons completed distal locking 98.3% of the time using only a single X-ray image with an average navigation time of 1.4 ± 0.9 min per hole.

Integration of fluoroscopy-based guidance in orthopaedic trauma surgery - a prospective cohort study

INTRODUCTION

Computer-assisted guidance systems are not used frequently for musculoskeletal injuries unless there are potential advantages. We investigated a novel fluoroscopy-based image guidance system in orthopaedic trauma surgery.

MATERIALS AND METHODS

The study was a prospective, not randomised, single-centre case series at a level I trauma centre. A total of 45 patients with 46 injuries (foot 12, shoulder 10, long bones seven, hand and wrist seven, ankle seven and spine and pelvis four) were included. Different surgical procedures were examined following the basic principles of the Arbeitsgemeinschaft für Osteosynthesefragen/Association for the Study of Internal Fixation (AO/ASIF). Main outcome measurements were the number of trials for implant placement, total surgery time, usability via user questionnaire and system failure rate.

RESULTS

In all cases, the trajectory function was used, inserting a total of 56 guided implants. The system failed when used in pelvic and spinal injuries, resulting in a total failure rate of 6.5% (n=3) of all included cases. The overall usability was rated as good, scoring 84.3%.

CONCLUSION

The novel image-guidance system could be integrated into the surgical workflow and was used successfully in orthopaedic trauma surgery. Expected advantages should be explored in randomised studies.

Radiation-free distal locking of intramedullary nails: evaluation of a new electromagnetic computer-assisted guidance system

Distal locking of intramedullary nails (IMNs) is a difficult part of intramedullary nailing (IMN) that could be time-consuming and expose the surgeon, the surgery personnel and the patient to a considerable amount of radiation as fluoroscopy is usually guiding the procedure. Utilization of electromagnetic fields for that purpose offers an attractive alternative. The SURESHOT™ Distal Targeting System (Smith & Nephew, Inc., Memphis, TN, USA) is a novel commercially available radiation-free aiming system that utilizes computerized electromagnetic field tracking technology for the distal locking of IMNs. In order to evaluate the efficacy of the system we conducted the present study. Nineteen patients (six females-thirteen males, mean age 39.5 years, range 17-85 years) with closed diaphyseal fracture of the femur (eight patients) or the tibia (eleven patients) were treated with IMN using the SURESHOT™ Distal Targeting System for the distal interlocking. All targeting attempts were successful at first try and followed by correct positioning of the screws. Mean time for distal locking of tibial IMNs (two screws) was 219sec (range 200-250sec). Mean time for distal locking of femoral IMNs (two screws) was 249 (range 220-330sec). In the current study the SURESHOT™ Distal Targeting System proved to be accurate, fast and easy to learn.

Diagnostic medical imaging radiation exposure and risk of development of solid and hematologic malignancy

Limiting patients' exposure to ionizing radiation during diagnostic imaging is of concern to patients and clinicians. Large single-dose exposures and cumulative exposures to ionizing radiation have been associated with solid tumors and hematologic malignancy. Although these associations have been a driving force in minimizing patients' exposure, significant risks are found when diagnoses are missed and subsequent treatment is withheld. Therefore, based on epidemiologic data obtained after nuclear and occupational exposures, dose exposure limits have been estimated. A recent collaborative effort between the US Food and Drug Administration and the American College of Radiology has provided information and tools that patients and imaging professionals can use to avoid unnecessary ionizing radiation scans and ensure use of the lowest feasible radiation dose necessary for studies. Further collaboration, research, and development should focus on producing technological advances that minimize individual study exposures and duplicate studies. This article outlines the research used to govern safe radiation doses, defines recent initiatives in decreasing radiation exposure, and provides orthopedic surgeons with techniques that may help decrease radiation exposure in their daily practice.