Intraoperative Angle Measurement of Anatomical Structures: A Systematic Review.

Ensuring precise angle measurement during surgical correction of orientation-related deformities is crucial for optimal postoperative outcomes, yet there is a lack of an ideal commercial solution. Current measurement sensors and instrumentation have limitations that make their use context-specific, demanding a methodical evaluation of the field. A systematic review was carried out in March 2023. Studies reporting technologies and validation methods for intraoperative angular measurement of anatomical structures were analyzed. A total of 32 studies were included, 17 focused on image-based technologies (6 fluoroscopy, 4 camera-based tracking, and 7 CT-based), while 15 explored non-image-based technologies (6 manual instruments and 9 inertial sensor-based instruments). Image-based technologies offer better accuracy and 3D capabilities but pose challenges like additional equipment, increased radiation exposure, time, and cost. Non-image-based technologies are cost-effective but may be influenced by the surgeon's perception and require careful calibration. Nevertheless, the choice of the proper technology should take into consideration the influence of the expected error in the surgery, surgery type, and radiation dose limit. This comprehensive review serves as a valuable guide for surgeons seeking precise angle measurements intraoperatively. It not only explores the performance and application of existing technologies but also aids in the future development of innovative solutions.

Case Report of an Osteochondral Lesion of the First Metatarsal Head in an Adolescent Patient Treated by Autograft Mosaicplasty: Surgical Technique and Decision-Making Rationale.

Introduction: First metatarsophalangeal (MTP) joint mobility is critical to a normal gait pattern; therefore, osteochondral defects (OCDs) of the first metatarsal head should be treated promptly to avoid functional limitation and progression to hallux rigidus. <15 cases of OCDs of the first MTP joint in the pediatric population, predominantly adolescents, have been published so far. The purpose of this article is to present a rare case of an adolescent first MTP joint OCD treated by the technique of autograft osteochondral mosaicplasty, which has been commonly used for OCDs of the knee and talus but scarcely described for the first MTP joint. Case Report: The case of a 13-year-old male futsal player with a post-traumatic 50 mm2 OCD of the first metatarsal head is presented. The Osteochondral Autograft Transfer System® (Arthrex Inc™, Naples, FL) was used to harvest a 10-mm diameter donor plug from the medial ipsilateral femoral condyle, then delivered to the first metatarsal head. At the 6-month follow-up, physical activity had been resumed with no pain or significant mobility limitation and an improvement of the American Orthopedic Foot and Ankle Society hallux score of 54-95 points. At the same time, a follow-up magnetic resonance showed complete incorporation of the osteochondral graft without bone edema or subchondral osteonecrosis. Conclusion: Treatment for osteochondral lesions, regardless of their location, aims to restore function by recreating the articular congruity reducing the potential for a progressive degenerative process. Multiple surgical treatment options exist for OCDs of the first metatarsal head. The treatment decision must take into consideration both patient factors and lesion factors. Based on this, a literature revision and treatment decision rationale are presented. This case demonstrated that an osteochondral transplant could be a reasonable treatment option for a traumatic, full-thickness OCD of the first metatarsal head in adolescent patients.

On the utility of 3D hand cursors to explore medical volume datasets with a touchless interface.

Analyzing medical volume datasets requires interactive visualization so that users can extract anatomo-physiological information in real-time. Conventional volume rendering systems rely on 2D input devices, such as mice and keyboards, which are known to hamper 3D analysis as users often struggle to obtain the desired orientation that is only achieved after several attempts. In this paper, we address which 3D analysis tools are better performed with 3D hand cursors operating on a touchless interface comparatively to a 2D input devices running on a conventional WIMP interface. The main goals of this paper are to explore the capabilities of (simple) hand gestures to facilitate sterile manipulation of 3D medical data on a touchless interface, without resorting on wearables, and to evaluate the surgical feasibility of the proposed interface next to senior surgeons (N=5) and interns (N=2). To this end, we developed a touchless interface controlled via hand gestures and body postures to rapidly rotate and position medical volume images in three-dimensions, where each hand acts as an interactive 3D cursor. User studies were conducted with laypeople, while informal evaluation sessions were carried with senior surgeons, radiologists and professional biomedical engineers. Results demonstrate its usability as the proposed touchless interface improves spatial awareness and a more fluent interaction with the 3D volume than with traditional 2D input devices, as it requires lesser number of attempts to achieve the desired orientation by avoiding the composition of several cumulative rotations, which is typically necessary in WIMP interfaces. However, tasks requiring precision such as clipping plane visualization and tagging are best performed with mouse-based systems due to noise, incorrect gestures detection and problems in skeleton tracking that need to be addressed before tests in real medical environments might be performed.