Minimally invasive 3D data registration in computer and robot assisted total knee arthroplasty

Accurate and robust registration method for computer-assisted high tibial osteotomy surgery

PURPOSE

Computer-assisted high tibial osteotomy (HTO) is a frequently used treatment technique for lower extremity orthopedics, and its small incision and low exposure area are major limitations in tibial registration. This work combines skin surface features and gives a suitable registration algorithm based on Iterative Closest Points (ICP) algorithm to improve registration results. Furthermore, the precision, stability and efficiency of the described method is evaluated.

METHODS

After the initialization stage, the bone surface and skin surface data are combined to construct registration features. Then, a steepest perturbation search method is performed after the ICP algorithm (SPS-ICP) to obtain the optimal transformation through several iterations. Finally, the registration result is evaluated by establishing ground-truth through manual landmarks.

RESULTS

Phantom experiments including simulated human tissue show that the proximal fiducial registration error (FRE) of our method can reach 0.80 ± 0.30 mm (mean ± SD) with an overall rotational error < 1° and translational error < 1.5 mm. Furthermore, it remains stable when the point set is sparse. The average registration time is less than 40 s to ensure the high efficiency of surgical operation.

CONCLUSIONS

The approach fully describes a well-defined framework without additional imaging acquisition equipment for Computer-assisted HTO. By the experiment on the basis of a phantom with simulated soft tissue, the proposed method enables the accurate and robust registration of the tibia, and its computation time meets the demands of surgery.

A Bibliometric Analysis of the Field of Computer-Assisted Orthopedic Surgery during 2002–2021

Background

This study aimed to investigate the characteristics of research articles and research trends in computer-assisted orthopedic surgery (CAOS) by conducting bibliometric analyses.

Methods

CAOS-related research articles published in international journals from 2002 to 2021 were collected using the PubMed database and analyzed using the bibliometric method. Their publication year, journal name, corresponding author's country name, and the number of citations of all collected articles were noted. Contents of the articles were analyzed to evaluate the time point and anatomical site at which the digital technique was applied. Further, the 20-year period was divided into two halves of 10 years each to analyze the research trends.

Results

A total of 639 CAOS-related articles were identified. An average of 32.0 CAOS-related articles were published annually, with an average of 20.6 and 43.3 published in the first half and second half, respectively. Of all articles, 47.6% were published in the top 10 journals, and 81.2% were written in the top 10 countries. The total numbers of citations were 11.7 and 6.3 in the first and second halves, respectively, but the average annual number of citations was higher in the second half than in the first one. Articles on application of digital techniques during surgery were 62.3% and those on pre-surgery application were 36.9%. Further, articles in the knee (39.0%), spine (28.5%), and hip and pelvis (21.5%) fields accounted for 89.0% of the total publications. But the increase in publications in the said period was highest in the fields of the hand and wrist (+1,300.0%), ankle (+466.7%), and shoulder (+366.7%).

Conclusions

Over the last 20 years, the publication of CAOS-related research articles in international journals has grown steadily. Although the knee, spine, hip, and pelvis fields account for most CAOS-related research, research in new fields is also increasing. This study analyzed the types of articles and trends in CAOS-related research and provided useful information for future research in the field of CAOS.

Robotic-Assisted Knee Arthroplasty (RAKA): The Technique, the Technology and the Transition

BACKGROUND

There has been an exponential increase in knee arthroplasty over the past 20 years. This has led to a quest for improvement in outcomes and patient satisfaction. While the last decade of last century proved to be the decade for Computer-Assisted Surgery (CAS) or Computer Navigation wherein the technology demonstrated a clear benefit in terms of improving mechanical axis alignment and component positioning, this decade is likely to belong to Robotics. Robotics adds an independent dimension to the benefits that CAS offers. The article deals with the generation of robots, technical steps in robotics, advantages and downsides of robotics and way forward in the field of knee arthroplasty.

MATERIALS AND METHODS

The review article was designed and edited by six different authors reviewing 32 relevant pubmed-based articles related to robotics in arthroplasty and orthopaedics. The concept, design and the definition of the intellectual content were based on the internationally published literature and insightful articles. The review is also based on the clinical experimental studies published in the literature.

DISCUSSION

The robotic arm is actively involved with surgeon to achieve the precision and outcomes that the surgeon aims for. With the concept of haptic boundaries and augmented reality being incorporated in most systems, Robotic Assisted Arthroplasty (RAA) is likely to offer several advantages. The potential advantages of these systems may include accuracy in gap balancing, component positioning, minimal bone resection, reduced soft tissue handling and trauma, patient anatomy specific resection, and real time feedback. They, however, come with their own downsides in terms of capital cost, learning curve, time consumption and unclear advantages in term of long-term clinical outcomes.

CONCLUSION

To conclude, this review article offers a balanced view on how the technology is impacting current arthroplasty practice and what can be expected in coming years. The commitment of almost all major implant manufacturers in investing in robotics likely means that the evolution of Robotic technology and this decade will be exciting with rapid strides revealing paradigm shift and evolution of technology with significant reductions of cost enabling it to be available universally. For technology to populate in operating room, I think it will be result of exposure of young surgeons to these computers and robotics, as they grow in with confidence with technology from residency days to offer better precision in future.

Innovations in Total Knee Arthroplasty: Improved Technical Precision, But Unclear Clinical Benefits

Total knee arthroplasty has been an effective treatment for advanced degenerative joint disease. Traditional knee designs and surgical approaches have resulted in consistently high performance, but some patients may remain dissatisfied after their surgery. Several surgical innovations, including accelerometer-based navigation, patient-specific instrumentation, and robotic-assisted total knee arthroplasty, have been developed to improve the accuracy and precision of total knee arthroplasty surgery, with anticipated secondary benefits of improved functional outcomes and implant survivorship. This article reviews the current status of these technologies as reported in contemporary orthopedic literature. [Orthopedics. 2016; 39(4):217-220.].

A bounded iterative closest point method for minimally invasive registration of the femur

This article describes a novel method for image-based, minimally invasive registration of the femur, for application to computer-assisted unicompartmental knee arthroplasty. The method is adapted from the well-known iterative closest point algorithm. By utilising an estimate of the hip centre on both the preoperative model and intraoperative patient anatomy, the proposed 'bounded' iterative closest point algorithm robustly produces accurate varus-valgus and anterior-posterior femoral alignment with minimal distal access requirements. Similar to the original iterative closest point implementation, the bounded iterative closest point algorithm converges monotonically to the closest minimum, and the presented case includes a common method for global minimum identification. The bounded iterative closest point method has shown to have exceptional resistance to noise during feature acquisition through simulations and in vitro plastic bone trials, where its performance is compared to a standard form of the iterative closest point algorithm.

A perspective on robotic assistance for knee arthroplasty

Knee arthroplasty is used to treat patients with degenerative joint disease of the knee to reduce pain and restore the function of the joint. Although patient outcomes are generally quite good, there are still a number of patients that are dissatisfied with their procedures. Aside from implant design which has largely become standard, surgical technique is one of the main factors that determine clinical results. Therefore, a lot of effort has gone into improving surgical technique including the use of computer-aided surgery. The latest generation of orthopedic surgical tools involves the use of robotics to enhance the surgeons' abilities to install implants more precisely and consistently. This review presents an evolution of robot-assisted surgical systems for knee replacement with an emphasis on the clinical results available in the literature. Ever since various robotic-assistance systems were developed and used clinically worldwide, studies have demonstrated that these systems are as safe as and more accurate than conventional methods of manual implantation. Robotic surgical assistance will likely result in improved surgical technique and improved clinical results.

Computer-assisted surgery for subtalar arthrodesis. A study in cadavers

BACKGROUND

Despite considerable recent interest in computer navigation for orthopaedic surgery, few investigations of computer-assisted surgery for foot and ankle operations have been reported. The purpose of the present study was to compare subtalar arthrodesis with and without computer navigation in a cadaver model.

METHODS

Subtalar arthrodesis was performed on thirty-six matched-pair cadaver lower extremities with intact soft tissues, with an attempt being made to orient two screws in the optimal configuration based on unpublished data from a preceding biomechanical study. Each matched pair was randomly assigned either to a group of surgeons who were experienced in subtalar arthrodesis or to a group of inexperienced operators. Neither surgical group was experienced in computer-assisted surgery. We compared optimal first-pass guidewire placement, fluoroscopic time, total operative time, screw placement accuracy, and adverse screw placement events between conventional (fluoroscopically guided) and computer-assisted subtalar arthrodesis.

RESULTS

The number of passes needed to achieve optimal guidewire placement decreased with the use of computer assistance for both experienced surgeons and inexperienced operators (p < 0.001), with ideal placement occurring on the first attempt in 95% of the procedures performed with use of computer assistance. While the experienced surgeons required less time and fewer guidewire passes during conventional subtalar arthrodesis than the inexperienced operators did (p < 0.001), both groups used less fluoroscopy with computer assistance (p < 0.001). There was no significant difference in operative time between the two techniques when performed by the inexperienced operators, yet the total procedure time doubled for the experienced surgeons when the procedure was performed with use of computer assistance (p < 0.001). There was no significant difference between experienced surgeons and inexperienced operators or between conventional and computer-assisted subtalar arthrodesis with respect to adverse screw placement events or the ability to accurately place both screws.

CONCLUSIONS

Computer-assisted subtalar arthrodesis resulted in screw placement accuracy that was equivalent to that of conventional (fluoroscopically guided) subtalar arthrodesis while decreasing the number of suboptimal guidewire passes and fluoroscopic time. The computer-assisted surgery technique increased the operative time for surgeons who were more experienced in conventional subtalar arthrodesis, but there was no difference in operative time for the group of operators who were inexperienced in subtalar arthrodesis.

How correctly does an intramedullary rod represent the longitudinal tibial axes?

In a robot-assisted procedure for preparing the tibia in total knee arthroplasty, developed in the authors' laboratory, an intramedullary rod is used to register the tibia. In 18 formalin-fixed tibias, the difference in orientation was calculated between the intramedullary rod and several longitudinal tibial axes used in clinical practice. This was done using roentgenstereophotogrammetric analysis. Three tibial axes and two insertion techniques were considered. In three-dimensional space, small differences between the axes are observed. The results showed a high standard deviation, indicating the importance of anatomic differences. In the frontal plane, the difference in orientation between rod and tibial axes never exceeded +/- 2 degrees. In the sagittal plane, the observed differences were larger. Significant differences between the considered axes appeared. The results of the two insertion techniques were not significantly different. Because an intramedullary rod frequently is used for alignment of the tibia in conventional surgery, these results also are valuable for conventional surgery. In the current study, the accuracy of the intramedullary alignment is examined, without influences of the sawing procedure. Moreover, the study is not limited to the frontal plane; the total accuracy in three-dimensional space, and the accuracy in the frontal and the sagittal planes were studied.

Image-guided endoscopic spine surgery: Part II: clinical applications

STUDY DESIGN

Endoscopic spinal procedures were performed under computed-tomography-based, image-guided assistance.

OBJECTIVE

To assess the clinical feasibility of applying a methodology that allows image-guided assistance in endoscopic spinal surgery.

SUMMARY OF BACKGROUND DATA

Endoscopic spinal procedures have become a part of the minimal invasive approaches to the spine. The main disadvantage of these techniques is the long learning curve and the lack of peroperative monitoring. Fluoroscopy does have disadvantages, such as positioning during surgery and the risk for radiation exposure. Fluoroscopy-based navigation has many advantages, however it is still based on preselected fluoroscopic images. There is no method that allows computed-tomography-based navigation in endoscopic conditions.

METHODS

Two patients have been operated on using endoscopic approaches assisted by computed-tomography-based navigational system. One had a thoracoscopic approach for median calcified disc herniation and another one had an endoscopic posterior approach for resection of a sacro-iliac osteophyte. For each patient, a frame of reference had been placed percutaneously and scanned. The computed tomography images were registered to the anatomy using the geometry of the frame as fiducials. Navigation through endoscopic approaches was possible in both cases.

RESULTS

In both cases navigation was reliable and a helpful monitoring to achieve the surgical goals through endoscopic approaches.

CONCLUSIONS

There are some factors that make endoscopic spine surgery a difficult start. Image-guided spine surgery is technically feasible and clinically applicable in endoscopic approaches.