Robots and Tools for Remodeling Bone

Progress in Computer-Assisted Navigation for Total Knee Arthroplasty in Treating Knee Osteoarthritis with Extra-Articular Deformity

Total knee arthroplasty (TKA) is a well-established treatment for end-stage knee osteoarthritis. However, in patients with concomitant extra-articular deformities, conventional TKA techniques may lead to unsatisfactory outcomes and higher complication rates. This review summarizes the application of navigated TKA for treating knee osteoarthritis with extra-articular deformities. The principles and potential benefits of computer navigation systems, including improved component alignment, soft tissue balancing, and restoration of mechanical axis, are discussed. Research studies demonstrate that navigated TKA can effectively correct deformities, relieve pain, and improve postoperative joint function and quality of life compared with conventional methods. The advantages of navigated TKA in terms of surgical precision, lower complication rates, and superior functional recovery are highlighted. Despite challenges like the learning curve and costs, navigated TKA is an increasingly indispensable tool for achieving satisfactory outcomes in TKA for knee osteoarthritis patients with extra-articular deformities.

Advancements in Robotic-Assisted Spine Surgery

Applications and workflows around spinal robotics have evolved since these systems were first introduced in 2004. Initially approved for lumbar pedicle screw placement, the scope of robotics has expanded to instrumentation across different regions. Additionally, precise navigation can aid in tumor resection or spinal lesion ablation. Robot-assisted surgery can improve accuracy while decreasing radiation exposure, length of hospital stay, complication, and revision rates. Disadvantages include increased operative time, dependence on preoperative imaging among others. The future of robotic spine surgery includes automated surgery, telerobotic surgery, and the inclusion of machine learning or artificial intelligence in preoperative planning.

A scientometric analysis of bone cutting tools & methodologies: Mapping the research landscape

This study undertakes a Scientometric analysis of bone-cutting tools, investigating a corpus of 735 papers from the Scopus database between 1941 and 2023. It employs bibliometric methodologies such as keyword coupling, co-citation, and co-authorship analysis to map the intellectual landscape and collaborative networks within this research domain. The analysis highlights a growing interest and significant advancements in bone-cutting tools, focusing on their design, the materials used, and the cutting processes involved. It identifies key research fronts and trends, such as the emphasis on surgical precision, material innovation, and the optimization of tool performance. Further, the study reveals a broad collaboration among researchers from various disciplines, including engineering, materials science, and medical sciences, reflecting the field's interdisciplinary nature. Despite the progress, the analysis points out several gaps, notably in tool design optimization and the impact of materials on bone health. This comprehensive review not only charts the evolution of bone-cutting tool research but also calls attention to areas requiring further investigation, aiming to inspire future studies that address these identified gaps and enhance surgical outcomes.

Robot-assisted implantation of additively manufactured patient-specific orthopaedic implants: evaluation in a sheep model

PURPOSE

Bone tumours must be surgically excised in one piece with a margin of healthy tissue. The unique nature of each bone tumour case is well suited to the use of patient-specific implants, with additive manufacturing allowing production of highly complex geometries. This work represents the first assessment of the combination of surgical robotics and patient-specific additively manufactured implants.

METHODS

The development and evaluation of a robotic system for bone tumour excision, capable of milling complex osteotomy paths, is described. The developed system was evaluated as part of an animal trial on 24 adult male sheep, in which robotic bone excision of the distal femur was followed by placement of patient-specific implants with operative time evaluated. Assessment of implant placement accuracy was completed based on post-operative CT scans.

RESULTS

A mean overall implant position error of 1.05 ± 0.53 mm was achieved, in combination with a mean orientation error of 2.38 ± 0.98°. A mean procedure time (from access to implantation, excluding opening and closing) of 89.3 ± 25.25 min was observed, with recorded surgical time between 58 and 133 min, with this approximately evenly divided between robotic (43.9 ± 15.32) and implant-based (45.4 ± 18.97) tasks.

CONCLUSIONS

This work demonstrates the ability for robotics to achieve repeatable and precise removal of complex bone volumes of the type that would allow en bloc removal of a bone tumour. These robotically created volumes can be precisely filled with additively manufactured patient-specific implants, with minimal gap between cut surface and implant interface.

Automated elaborate resection planning for bone tumor surgery

PURPOSE

Planning for bone tumor resection surgery is a technically demanding and time-consuming task, reliant on manual positioning of planar cuts in a virtual space. More elaborate cutting approaches may be possible through the use of surgical robots or patient-specific instruments; however, methods for preparing such a resection plan must be developed.

METHODS

This work describes an automated approach for generating conformal bone tumor resection plans, where the resection geometry is defined by the convex hull of the tumor, and a focal point. The resection geometry is optimized using particle swarm, where the volume of healthy bone collaterally resected with the tumor is minimized. The approach was compared to manually prepared planar resection plans from an experienced surgeon for 20 tumor cases.

RESULTS

It was found that algorithm-generated hull-type resections greatly reduced the volume of collaterally resected healthy bone. The hull-type resections resulted in statistically significant improvements compared to the manual approach (paired t test, p < 0.001).

CONCLUSIONS

The described approach has potential to improve patient outcomes by reducing the volume of healthy bone collaterally resected with the tumor and preserving nearby critical anatomy.

A New Accurate, Simple and Less Radiation Exposure Device for Distal Locking of Femoral Intramedullary Nails

Background

Due to the metal elasticity of intramedullary nails (IMs) and irregularities of the long bone marrow cavity and other reasons, one of the greatest challenges for surgeons is to position the distal locking screw. Therefore, a novel laser guiding navigation device was designed for the distal locking of femoral IMs. The purpose of this study was to compare the effectiveness of the novel device and freehand technique for distal locking of IMs in the femoral model.

Methods

The laser guiding navigation device (laser group) and freehand technique (freehand group) were used in the distal locking of the IMs in the femoral model. All operations were performed by surgeons of the same level. The differences between the two groups were compared in terms of operative time, radiation exposure time, first success rate, deviation angle between ideal trajectory and actual trajectory, and learning curve.

Results

The distal locking of the IMs in the femoral model was performed 40 times in each group. The results showed that the laser group was better than the freehand group in terms of operative time (345±165 VS 212±105 seconds, t=4.27, P<0.001), radiation exposure time (164±57 VS 41±15 seconds, t=13.15, P<0.001) and first successrate (χ ²=21.36, P<0.001). Compared with the freehand group, the actual trajectory of the laser group was closer to the ideal trajectory in coronal and horizontal planes. Furthermore, the learning curve time of the laser group was shorter.

Conclusion

Compared with traditional freehand technique, the novel laser guiding navigation device can shorten the operative time and reduce radiation exposure invitro. In addition, it is easy to master with more accuracy and a higher first success rate in vitro.