A novel 3D-printed patient-specific instrument based on "H-point" for medial opening wedge high tibial osteotomy: a cadaver study

Is Previously Implanted Osteosynthesis Material an Obstacle for the Use of Customized Guides?: A Case Report

CASE

We present the case of a 46-year-old patient with asymmetric deformity in the posterior tibial slope after previous high tibial osteotomy surgeries with the presence of a medial osteotomy plate. A customized cutting guide was designed to fit on the plate to perform a single surgery and avoid possible soft-tissue complications after multiple surgeries.

CONCLUSIONS

The presence of a previous internal fixation device may affect the manufacture of 3-dimensional cutting guides. However, in this case, the previously placed osteosynthesis plate was used as an aid for creating the guide.

Personalised opening wedge high tibial osteotomy with patient-specific plates and instrumentation accurately controls coronal correction and posterior slope: Results from a prospective first case series

BACKGROUND

Patient specific devices represent a promising tool to improve accuracy and simplify high tibial osteotomy (HTO) procedures. The current study aims to assess accuracy of the correction of alignment and posterior tibial slope (PTS), and provide patient reported outcomes (PROMs) of a new personalised cutting guide and fixation plate (TOKA) system for HTO in patients with medial osteoarthritis (OA) and varus knee.

METHODS

25 patients (mean age 54.4 years) with medial OA and varus knee malalignment who underwent HTO with the TOKA system were prospectively evaluated pre-operatively, 1, 3, 6 and 12-months follow-up. Standing long-leg and lateral radiographs of the knee were used to assess the hip-knee-ankle (HKA) angle and the PTS, respectively. Accuracy was defined as the difference in planned minus achieved correction. The patient reported outcomes collected were the KOOS score, EQ5D, KSS score, and VAS pain scores. All statistical analyses were performed using IBM SPSS Statistics for Windows.

RESULTS

The mean preoperative HKA was 170.7° (SD ± 3.2°); the mean postoperative HKA was 177.4° (SD ± 2.9°). The overall mean difference between planned and achieved correction in terms of HKA was 2.1° (SD ± 2.0°). The mean difference between planned and achieved PTS was 0.2° (SD ± 0.4°). All the assessed PROMs had a significant (p < 0.001) increase from the pre-operative value to postoperative evaluation and showed a significant (p < 0.001) improvement with follow-up time.

CONCLUSIONS

TOKA personalised HTO system showed accurate correction in terms of both coronal and sagittal alignment, and excellent patient reported outcomes.

LEVEL OF EVIDENCE

4, prospective case series. Registration in public trial registry: registered at ClinicalTrial.gov [NCT04574570].

[Application status of open-wedge high tibial osteotomy assisted by three-dimensional printing patient-specific cutting guides]

Objective

To review the application of three-dimensional (3D) printing patient-specific cutting guides (PSCG) in open-wedge high tibial osteotomy (OWHTO).

Methods

The domestic and foreign literature about the use of 3D printing PSCG to assist the OWHTO in recent years was reviewed, and the effectiveness of different types of 3D printing PSCG to assist OWHTO was summarized.

Results

Many scholars design and use different 3D printing PSCGs to confirm the precise positioning of the osteotomy site (the bone surface around the cutting line, the "H" point of the proximal tibia, the internal and external malleolus fixators, etc.) and the correction angle (the pre-drilled holes, the wedge-shaped filling blocks, the angle-guided connecting rod, etc.) during operation, and all of them achieve good effectiveness.

Conclusion

Compared with conventional OWHTO, 3D printing PSCG assisted OWHTO has many obvious advantages, such as shortening the operation time, and the frequency of fluoroscopy, and being closer to the expected preoperative correction, etc. However, the effectiveness between different 3D printing PSCGs still need to be discussed in the follow-up studies.

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.