Patient-specific instrumentation (PSI) Referencing High Tibial Osteotomy Technological Transfer and Education: protocol for a double-blind, randomised controlled trial (PROTECTED HTO Trial)

Application of image recognition-based tracker-less augmented reality navigation system in a series of sawbone trials

BACKGROUND

This study introduced an Augmented Reality (AR) navigation system to address limitations in conventional high tibial osteotomy (HTO). The objective was to enhance precision and efficiency in HTO procedures, overcoming challenges such as inconsistent postoperative alignment and potential neurovascular damage.

METHODS

The AR-MR (Mixed Reality) navigation system, comprising HoloLens, Unity Engine, and Vuforia software, was employed for pre-clinical trials using tibial sawbone models. CT images generated 3D anatomical models, projected via HoloLens, allowing surgeons to interact through intuitive hand gestures. The critical procedure of target tracking, essential for aligning virtual and real objects, was facilitated by Vuforia's feature detection algorithm.

RESULTS

In trials, the AR-MR system demonstrated significant reductions in both preoperative planning and intraoperative times compared to conventional navigation and metal 3D-printed surgical guides. The AR system, while exhibiting lower accuracy, exhibited efficiency, making it a promising option for HTO procedures. The preoperative planning time for the AR system was notably shorter (4 min) compared to conventional navigation (30.5 min) and metal guides (75.5 min). Intraoperative time for AR lasted 8.5 min, considerably faster than that of conventional navigation (31.5 min) and metal guides (10.5 min).

CONCLUSIONS

The AR navigation system presents a transformative approach to HTO, offering a trade-off between accuracy and efficiency. Ongoing improvements, such as the incorporation of two-stage registration and pointing devices, could further enhance precision. While the system may be less accurate, its efficiency renders it a potential breakthrough in orthopedic surgery, particularly for reducing unnecessary harm and streamlining surgical procedures.

Custom-Made Devices Represent a Promising Tool to Increase Correction Accuracy of High Tibial Osteotomy: A Systematic Review of the Literature and Presentation of Pilot Cases with a New 3D-Printed System

Background: The accuracy of the coronal alignment corrections using conventional high tibial osteotomy (HTO) falls short, and multiplanar deformities of the tibia require consideration of both the coronal and sagittal planes. Patient-specific instrumentations have been introduced to improve the control of the correction. Clear evidence about customized devices for HTO and their correction accuracy lacks. Methods: The databases PUBMED and EMBASE were systematically screened for human and cadaveric studies about the use of customized devices for high tibial osteotomy and their outcomes concerning correction accuracy. Furthermore, a 3D-printed customized system for valgus HTO with three pilot cases at one-year follow-up was presented. Results: 28 studies were included. The most commonly used custom-made devices for HTO were found to be cutting guides. Reported differences between the achieved and targeted correction of hip-knee-ankle angle and the posterior tibial slope were 3° or under. The three pilot cases that underwent personalized HTO with a new 3D-printed device presented satisfactory alignment and clinical outcomes at one-year follow-up. Conclusion: The available patient-specific devices described in the literature, including the one used in the preliminary cases of the current study, showed promising results in increasing the accuracy of correction in HTO procedure.

[Effect of knee suspension on posterior tibial slope after medial opening-wedge high tibial osteotomy]

OBJECTIVE

To investigate the effect of knee suspension during titanium plate fixation on postoperative posterior tibial slope (PTS) in knee osteoarthritis (KOA) with medial opening-wedge high tibial osteotomy (OWHTO).

METHODS

The clinical data of 47 patients with KOA treated by OWHTO between January 2019 and December 2020 was retrospectively analyzed. In 24 cases, the knee joint was suspended when titanium plate was fixed (research group), and in 23 cases, the knee joint was naturally straightened when titanium plate was fixed (control group). There was no significant difference in gender, age, side, body mass index, disease duration, preoperative visual analogue scale (VAS) score, American Hospital for Special Surgery (HSS) score, Western Ontario and McMaster University Osteoarthritis Index (WOMAC) score, Lysholm score, and preoperative PTS between the two groups ( P>0.05). PTS were measured at 1 day after operation and last follow-up, and were compared with that before operation. Before operation and at last follow-up, VAS score was used to evaluate the knee pain, HSS score, WOMAC score, and Lysholm score were used to evaluate the knee function.

RESULTS

The patients in both groups were followed up 13-24 months, with an average of 19.9 months. There was no complication such as incision infection, screw fracture, and deep venous thrombosis of lower limbs in two groups. At last follow-up, the VAS score, HSS score, WOMAC score, and Lysholm score in two groups were significantly improved when compared with those before operation ( P<0.05), but there was no significant difference between the two groups in the each score difference of before and after operation ( P>0.05). There was no significant difference in PTS at each time point before and after operation in the research group ( P>0.05), but PTS in the control group significantly increased at 1 day after operation and last follow-up ( P<0.05). PTS of the research group at 1 day after operation and last follow-up were significantly lower than those of the control group ( P<0.05).

CONCLUSION

OWHTO can effectively relieve knee pain and improve knee function in KOA, and the increase of postoperative PTS can be effectively avoided by suspending knee joint.

Preoperative Planning Using 3D Printing Technology in Orthopedic Surgery

The applications of 3D printing technology in health care, particularly orthopedics, continue to broaden as the technology becomes more advanced, accessible, and affordable worldwide. 3D printed models of computed tomography (CT) and magnetic resonance image (MRI) scans can reproduce a replica of anatomical parts that enable surgeons to get a detailed understanding of the underlying anatomy that he/she experiences intraoperatively. The 3D printed anatomic models are particularly useful for preoperative planning, simulation of complex orthopedic procedures, development of patient-specific instruments, and implants that can be used intraoperatively. This paper reviews the role of 3D printing technology in orthopedic surgery, specifically focusing on the role it plays in assisting surgeons to have a better preoperative evaluation and surgical planning.