Single-plane rotational osteotomy for cubitus varus deformity based on preoperative computer simulation

Clinical applications and prospects of 3D printing guide templates in orthopaedics

Background

With increasing requirements for medical effects, and huge differences among individuals, traditional surgical instruments are difficult to meet the patients' growing medical demands. 3D printing is increasingly mature, which connects to medical services critically as well. The patient specific surgical guide plate provides the condition for precision medicine in orthopaedics.

Methods

In this paper, a systematic review of the orthopedic guide template is presented, where the history of 3D-printing-guided technology, the process of guides, and basic clinical applications of orthopedic guide templates are described. Finally, the limitations of the template and possible future directions are discussed.

Results

The technology of 3D printing surgical templates is increasingly mature, standard, and intelligent. With the help of guide templates, the surgeon can easily determine the direction and depth of the screw path, and choose the angle and range of osteotomy, increasing the precision, safety, and reliability of the procedure in various types of surgeries. It simplifies the difficult surgical steps and accelerates the growth of young and mid-career physicians. But some problems such as cost, materials, and equipment limit its development.

Conclusions

In different fields of orthopedics, the use of guide templates can significantly improve surgical accuracy, shorten the surgical time, and reduce intraoperative bleeding and radiation. With the development of 3D printing, the guide template will be standardized and simplified from design to production and use. 3D printing guides will be further sublimated in the application of orthopedics and better serve the patients.

The translational potential of this paper

Precision, intelligence, and individuation are the future development direction of orthopedics. It is more and more popular as the price of printers falls and materials are developed. In addition, the technology of meta-universe, digital twin, and artificial intelligence have made revolutionary effects on template guides. We aim to summarize recent developments and applications of 3D printing guide templates for engineers and surgeons to develop more accurate and efficient templates.

3D-printed model and osteotomy template technique compared with conventional closing-wedge osteotomy in cubitus varus deformity

Cubitus varus deformity is the most common late complication of malunited supracondylar fracture that requires corrective osteotomy and fixation. From 2009 to 2017, 40 consecutive patients with cubitus varus deformity were included. Twenty patients underwent the conventional closing-wedge osteotomy (conventional group), while the other twenty patients underwent the 3D-printed model and osteotomy template osteotomy (3D-printed template group). The functional outcome was evaluated using the Mayo Elbow Performance Index (MEPI) Score and Flynn criteria. There were no statistically significant differences were observed regarding the humerus-elbow-wrist angle and tilting angle between the two groups, both preoperatively and postoperatively at 24 months. No statistically significant differences were observed regarding the elbow ROM (127.0 ± 4.7° VS 128.9 ± 3.8°) and MEPI score (93.5 ± 3.3 VS 94.3 ± 4.1) between the groups. All patients were satisfied both cosmetically and functionally as per the Flynn criteria and MEPI score. The conventional osteotomy and 3D-printed model and osteotomy template techniques both met the treatment requirements of cubitus varus deformity. The 3D-printed template technique showed better osteotomy accuracy, but no significant advantage regarding the functional and cosmetic results than conventional osteotomy.

The effect of three-dimensional (3D) printing on quantitative and qualitative outcomes in paediatric orthopaedic osteotomies: a systematic review

Three-dimensional (3D) printing technology is increasingly being utilized in various surgical specialities. In paediatric orthopaedics it has been applied in the pre-operative and intra-operative stages, allowing complex deformities to be replicated and patient-specific instrumentation to be used. This systematic review analyses the literature on the effect of 3D printing on paediatric orthopaedic osteotomy outcomes.A systematic review of several databases was conducted according to PRISMA guidelines. Studies evaluating the use of 3D printing technology in orthopaedic osteotomy procedures in children (aged ≤ 16 years) were included. Spinal and bone tumour surgery were excluded. Data extracted included demographics, disease pathology, target bone, type of technology, imaging modality used, qualitative/quantitative outcomes and follow-up. Articles were further categorized as either 'pre-operative' or 'intra-operative' applications of the technology.Twenty-two articles fitting the inclusion criteria were included. The reported studies included 212 patients. There were five articles of level of evidence 3 and 17 level 4.A large variety of outcomes were reported with the most commonly used being operating time, fluoroscopic exposure and intra-operative blood loss.A significant difference in operative time, fluoroscopic exposure, blood loss and angular correction was found in the 'intra-operative' application group. No significant difference was found in the 'pre-operative' category.Despite a relatively low evidence base pool of studies, our aggregate data demonstrate a benefit of 3D printing technology in various deformity correction applications, especially when used in the 'intra-operative' setting. Further research including paediatric-specific core outcomes is required to determine the potential benefit of this novel addition. Cite this article: EFORT Open Rev 2021;6:130-138. DOI: 10.1302/2058-5241.6.200092.

[Application of three-dimensional navigation template in adult cubitus varus osteotomy]

OBJECTIVE

To investigate the effectiveness of three-dimensional (3D) navigation template in the adult cubitus varus osteotomy.

METHODS

Between April 2013 and September 2015, 17 patients with cubitus varus were admitted. There were 6 males and 11 females, aged from 19 to 38 years, with an average age of 26.9 years. There were 10 cases of left elbow joints and 7 cases of right elbow joints. The disease duration was 9-30 years (mean, 18 years). Based on the preoperative X-ray film, the humerus-elbow-wrist (HEW) angle was (-13.2 ±3.3)°, the anteversion angle was (-10.5±2.3)°. The preoperative range of motion (ROM) of flexion was (127.3±7.3)° and ROM of extension was (-10.0±2.5)°. Based on the CT 3D reconstruction, the osteotomy navigation template was designed and printed by 3D printing technique. The cubitus varus osteotomy was assisted by 3D navigation template. The postoperative HEW angle, anteversion angle, and ROMs of the elbow joints of both sides were measured. The elbow function was evaluated based on the Oppenheim elbow function score at 1 year after operation.

RESULTS

All cubitus varus osteotomies succeeded with the assist of 3D navigation template. All incisions healed by first intention. All patients were followed up 12-15 months (mean, 13 months). X-ray films showed that all osteotomies healed after 9-12 weeks (mean, 11 weeks). At 1 year after operation, the HEW angle was (9.7±1.9)°, the anteversion angle was (20.7±4.3)°, the ROM was (2.6±3.5)° in extension and (139.2±4.8)° in flexion of affected side. The HEW angle, anteversion angle, and ROMs significantly increased compared with preoperative values ( P<0.05). And there was no significant difference between affected and normal elbow joints ( P>0.05). The elbow functions were excellent in 13 cases and good in 4 cases based on the Oppenheim elbow function score at 1 year after operation. There was no complication such as the nerve injury or osteomyositis of elbow joint during follow-up.

CONCLUSION

The 3D navigation template can provide a personalized and precise osteotomy treatment for adult cubitus varus deformity and obtain a satisfactory effectiveness.

Clinical application of individualized 3D-printed navigation template to children with cubitus varus deformity

Background

Cubitus varus deformity is a common sequela of elbow fractures in children. Cubitus varus deformity treatment is tending toward 3D correction, which is challenging for orthopedic surgeons. This study aims to explore whether individualized 3D-printed navigation templates can assist with accurate and effective corrective treatment of children with cubitus varus deformity.

Methods

Thirty-five patients were treated for cubitus varus deformity from June 2015 to April 2017, including 21 boys and 14 girls, aged 4.6–13.2 years (average, 7.5 years). Of these cases, 17 deformities were on the left side and 18 were on the right side. All were treated with wedge osteotomy of the lateral distal humerus. 3D-printed navigation templates were used in 16 cases, while traditional surgery was used in 19 cases. All patients underwent computed tomography scans before surgery. Computer software was used to analyze the measurements and design and print individualized navigation templates. The navigation templates were matched, and surgery was initially simulated. Intraoperative individualized navigation templates were used to assist with accurate osteotomy and Kirschner wire fixation. Operation times were recorded in all cases, the carrying angles before and after surgery were assessed by computer, and postoperative elbow joint function was evaluated using Bellemore criteria. All measurement data were presented as means ± SD, and Student’s t test was used to examine differences between groups. All count data between both groups were compared using the chi-square test or Fisher’s exact test analysis.

Results

All individualized navigation templates matched well with the corresponding anatomical markers and were consistent with preoperative planning, simulated surgery, and intraoperative procedures. Average operation times from clear exposure to fixed Kirschner wire were 11.69 min (9.6–13.5 min) for the individualized navigation template group and 22.89 min (17.7–26.8 min) for the traditional operation group (p < 0.001). Average differences in postoperation carrying angles between affected and healthy sides were 1.13° (0–2.0°) and 4.21° (0–7.5°), respectively (p < 0.001). Follow-up 6–12 months postoperation showed that elbow function did not differ significantly between groups using the Bellemore criteria (p > 0.05).

Conclusions

Individualized navigation templates simplify procedures, reduce operation time, and improve accuracy when used in orthopedic surgery to treat children with cubitus varus deformity.

Morphology and kinematics studies of the upper extremity and its clinical application in deformity correction

Morphological and kinetic studies using computer-generated bone models are helpful for determining normal articular movements and various pathological conditions of the wrist joints, forearms, and elbow joints. Previous studies consisted of kinetic analyses that were carried out by superimposing three-dimensional bone models created on a computer on the basis of CT data obtained by scanning the limbs in several different positions. We applied the techniques used in such studies and have discovered a method for carrying out surgical procedure simulations aimed at correcting upper limb deformities. In addition, we have developed a system aimed at assisting surgical procedures conducted in accordance with simulations by using patient-matched guides (patient-matched instruments, PMI) and custom-made osteosynthesis plates. Our system has allowed for accurate anatomical corrections to be carried out three-dimensionally during a simple surgical procedure. The system was clinically used in the treatment of cubitus varus as well as malunited distal radial fractures and forearm fractures. As a result, accurate correction and favorable clinical outcomes have been achieved. Together with the development of therapeutic techniques, we have also simultaneously developed the related technological system, which consists of imaging protocols aimed at reducing the amount of radiation exposure and creating statistical shape models, as well as web-based tools for communication between physicians and engineers.