No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Outcome and safety analysis of 3D printed patient specific pedicle screw jigs for complex spinal deformities: A comparative study
Abstract
Background context:
Spinal deformities are very challenging to treat and have a great risk of neurological complications due to hardware placement during corrective surgery. Various techniques have been introduced to ensure safe and accurate placement of pedicle screws. Patient-specific screw guides with pre-drawn and pre-validated trajectory seems to be an attractive option.
Purpose:
We have focused on developing 3D printing technique for complex spinal deformities in India. This study also aimed to compare the placement of pedicle screw with 3D printing and free hand technique.
Study design/settings:
This is a retrospective comparative clinical study at an academic institutional setting.
Patient sample:
A total of 20 patients were enrolled during the study, 10 were operated with the help of 3D printing (group 1) and 10 were operated with freehand technique (group 2). Group 1 included 6 congenital, 3 adolescent idiopathic scoliosis (AIS), one post tubercular kyphosis and Group 2 included 5 congenital, 4 AIS and one post tubercular kyphosis patient.
Outcome measures:
Primary outcomes were measured in terms of screw violation and secondary outcome were measured in terms of Surgical time, Blood loss, Radiation exposure (no. of shoots required) and complications.
Methods:
MIMICS v18.0 Software was used for 3D reconstruction from CT scan images of all the patients. 3-Matic software was used to create drill guide. 3-D printer from Stratasys Mojo ABS P 430 model material cartilage (a thermoplastic material) was used for printing of vertebrae model and jigs. Two sample test of proportion was used to compare correctly and wrongly pedicle screw placement with 3D printing and freehand technique. T-test with equal variance was used for operating surgical time and blood loss. This work was carried out by collaboration of Orthopaedics Department, All India Institute of Medical Sciences (AIIMS), New Delhi and Biomedical Engineering Department, Indian Institute of Technology (IIT) Delhi. This project received the grant of USD 60000 from Department of Biotechnology (DBT), Government of India under DBT Innovative young Biotechnologist Award. No study-specific conflicts of interest-associated biases is declared by the authors.
Results:
No superior or inferior screw violation was observed in any of our patients in either group. We found significant (p=0.03) difference between 2 groups regarding perfect screw placement in favour of 3D printing. There were 13 grade 2 medial perforations in free hand group and 3 in 3D printing group. There was no grade 3 medial perforation in either group. There were 6 grade 2 lateral perforations in free hand group and 7 in 3D printing group were observed. There were 3 grade 3 lateral perforation in free hand group and 2 in 3D printing group were observed. Analysis showed a statistically significant (p-value: 0.005) medial violation in free hand group. Surgical time was significantly (p-value: 0.03) less in 3D printing group as compared to free hand group. Mean Blood loss was higher in free hand group, however it was not statistically significant (p-value: 0.3) in 3D printing group. Fluoroscopic shots required were less in number in 3D printing group in comparison to free hand group. There was no neurological deficit in any of the patient in any group.
Conclusions:
In our study, focusing on spinal deformities statistically significant higher rate of accurate screw positioning and higher number of inserted screws with 3D printing was possible due to enhanced safety particularly at apical levels. As such, spinal deformities are difficult to treat worldwide. In India, these deformities are often neglected and present at a very late and much more deformed state when their treatment becomes even more challenging. Developing these patient specific drill templates will enable an average spine surgeon to treat these patients with much ease and safety.
... Since the 1990s, 3DP, also commonly known as rapid prototyping, additive manufacturing, or solid free form technology, has been used for pre-operative planning, patient, and resident education, manufacturing surgical guides, as well as patient specific implants. 1,2 3DP utilizes 3D digital imaging data (eg from computerized tomography or magnetic resonance imaging) which is subsequently sliced into 2D cross sections that are 3D printed in layers. These slices are layered on top of each other and fused into a full prototype. ...
... These slices are layered on top of each other and fused into a full prototype. 1,[3][4][5] This method of additive manufacturing is more efficient in terms of both cost and material use compared to other methods such as subtractive manufacturing, which consists of the removal of excess material in order to fabricate the final product. 5 While there are various techniques within the realm of 3DP, there are 3 main techniques that are most popular in medical applications. ...
... 5 While there are various techniques within the realm of 3DP, there are 3 main techniques that are most popular in medical applications. 1,5 Stereolithography (SLA) involves a light curable resin which is cured prior to the addition of successive layers via photopolymerization to create a final polymerized prototype. Selective Laser Sintering (SLS) utilizes an electron beam or laser focused energy source to sinter a fine powder bed. ...
Study design:
Systematic Review.
Objective:
3DP technology use has become increasingly more common in the field of medicine and is notable for its growing utility in spine surgery applications. Many studies have evaluated the use of pedicle screw placement guides and spine models in adult spine patients, but there is little evidence assessing its efficacy in pediatric spine patient populations. This systematic review identifies and evaluates the current applications and surgical outcomes of 3-Dimensional Printing (3DP) technology in pediatric spinal surgery.
Methods:
A search of publications was conducted using literature databases and relevant keywords in concordance with PRISMA guidelines. Inclusion criteria consisted of original studies, and studies focusing on the use of 3DP technology in pediatric spinal surgery. Studies with a focus on adult populations, non-deformity surgery, animal subjects, systematic or literature reviews, editorials, or non-English studies were excluded from further analysis.
Results:
After application of inclusion/exclusion criteria, we identified 25 studies with 3DP applications in pediatric spinal surgery. Overall, the studies found significantly improved screw placement accuracy using 3DP pedicle screw placement guides but did not identify significant differences in operative time or blood loss. All studies that utilized 3D spine models in preoperative planning found it helpful and noted an increased screw placement accuracy rate of 89.9%.
Conclusions:
3DP applications and techniques are currently used in pre-operative planning using pedicle screw drill guides and spine models to improve patient outcomes in pediatric spinal deformity patients.
... Different techniques have been used to design such trajectory guides with varying success as the breach rates ranged from 1.5-19%. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] These guides may prove to be an asset in complex spinal deformity cases involving the cervical and thoracic spine. The higher breach rates in some studies may be attributed to the inept design of the template. ...
... [21,29] The trajectory guide, which is based on the spinous process, transverse process, and lamina, enables a good lock-and-key type of fit, and provides good stability; however, it requires extensive soft-tissue dissection. [19,20,25,26,30,32,34] Some of these designs have large contact areas that may extend up to the adjacent vertebra, which can hinder the placement of trajectory guide, once the pedicle screws are inserted in the adjacent vertebra. [30,31] Sugawara et al. designed their template where they did not use the whole spinous process but only used the base of the spinous process for anchoring. ...
... Though sufficient studies are not available to prove its efficacy over the other newer methods (such as navigation or robotic technique), there are enough studies to demonstrate its superiority over the conventional free-hand technique. [25,[28][29][30][31][32]34] Two meta-analyses concluded that the trajectory guide significantly improves the accuracy of the pedicle screw and reduces the operative time and intra-operative blood loss compared with those of the free-hand technique. [36,37] Various cadaveric and clinical studies have shown high accuracy of pedicle screws at all levels and pathologies such as fracture-dislocation, myelopathy, infections, tumor, and complex deformities. ...
Background:
Conventional methods of pedicle-screw placement have higher breach rates due to variations in pedicle trajectories.
Objective:
We studied the accuracy of patient-specific, three-dimensional (3D)-printed laminofacetal-based trajectory guide for pedicle-screw placement in the subaxial-cervical and thoracic spine.
Materials and methods:
We enrolled 23 consecutive patients who underwent subaxial cervical and thoracic pedicle-screw instrumentation. They were divided into two groups: group A (cases without spinal deformity) and group B (cases with pre-existing spinal deformity). Patient-specific, 3D-printed laminofacetal-based trajectory guide for each instrumented level was designed. The accuracy of screw placement was assessed on postoperative computed tomography (CT) using the Gertzbein-Robbins grading.
Results:
A total of 194 pedicle screws (114 cervical and 80 thoracics) were placed using trajectory guides, of which 102 belonged to group B (34 cervical and 68 thoracics). Out of a total of 194 pedicle screws, 193 had clinically acceptable placement (grade A: 187; grade B: 6; and grade C: 1). In the cervical spine, 110 pedicle screws out of a total of 114 had grade A placement (grade B: 4). In the thoracic spine, 77 pedicle screws out of a total of 80 had grade A placement (grade B: 2; grade C: 1). Out of a total of 92 pedicle screws in group A, 90 had grade A placement, and the rest 2 had grade B breach. Similarly, 97 out of a total of 102 pedicle screws in group B were placed accurately, 4 had grade B and another had a grade C breach.
Conclusions:
Patient-specific, 3D-printed laminofacetal-based trajectory guide may help in accurate placement of subaxial cervical and thoracic pedicle screws. It may help reduce surgical time, blood loss, and radiation exposure.
... Высокая точность транспедикулярной имплантации при использовании персонифицированных навигационных шаблонов подтверждается многочисленными современными исследованиями [1][2][3][4][5]. Изготовление таких шаблонов требует определенных финансовых, технических и временных ресурсов [6][7][8][9]. ...
... Так как пациенты контрольной группы отобраны ретроспективно, послеоперационная КТ у 5 из них не была доступна для анализа. В связи с этим сравнительную оценку корректности стояния транспедикулярных винтов между группами не проводили, тем более что эти вопросы неоднократно освещались в ранее опубликованных работах [1][2][3][4][5]. ...
... Большинство исследователей, применяющих 3D-печать при протяженной транспедикулярной фиксации, использует навигационные шаблоны для установки всех винтов в ходе одной операции [2][3][4][5][16][17][18][19][20], обеспечивая при идиопатическом сколиозе их корректное стояние для 92,5-97,6 % винтов [17,19]. В сравнительных исследованиях показаны такие преимущества тотальных навигационных шаблонов перед методикой free-hand, как меньшая частота мальпозиций [2][3][4][5], меньшая продолжительность операции [3], меньшее время, необходимое для установки одного винта [4]. ...
Objective. To evaluate short-term result of selective navigation templates application in idiopathic scoliosis surgery.
Material and Methods. A total of 12 patients aged 14–17 years with idiopathic scoliosis were included in the study. Group A included 6 patients treated with selective application of navigation templates for pedicle screws insertion in the most difficult zones. Group B (control) included 6 patients in whom all the pedicle screws were placed with free-hand technique. Number of screws inserted was 16–20 per patient. There was no significant difference between the groups in sex, age, Cobb angle, number of vertebrae instrumented, number of pedicle screws and laminar hooks. Surgery duration, blood loss, absolute and relative correction were compared. In Group A, duration of the 3D-objects fabrication and printing, as well as pedicle screw accuracy based on 2-mm increment grading system were evaluated.
Results. Selective application of navigation templates as compared with total free hand screws placement significantly reduced surgery duration. Difference in blood loss and deformity correction was not significant. A total of 107 pedicle screws were placed in Group A, 48 of them with navigation templates and 59 by free-hand technique. Average pedicle width in screw installation with navigation templates was 4.28 ± 1.43 mm, and in that with free-hand technique 6.53 ± 1.72 mm, with significant difference. Accurate screw placement with navigation templates and by free-hand technique were 93.7 % and 88.0 %, respectively, with no significant difference. Duration of 3D-objects manufacturing was 1419 ± 190 minutes. Active operator’s involvement was required in about 10 % of the while.
Conclusion. Selective application of a pair of two-level navigation templates for most difficult pedicles in idiopathic scoliosis significantly reduces surgery duration. Difference in blood loss and deformity correction is insignificant. Refusal of total templates usage for combination of navigation templates for selected difficult pedicles and free-hand technique for the rest is an option for shortening the preoperative preparation, but provides screw placement accuracy comparable with total templates usage (92.5–97.6 % as reported).
... Only one study had a high risk of selection bias due to random sequence generation. 20 There was one study with a high risk of reporting bias due to selective reporting, 18 and one study with a high risk of other bias. 13 As shown in ►Fig. ...
... Data on complication rates were reported in four studies. 18,19,21,22 A fixed-effect model was used to summarize the results because little heterogeneity was found among the four studies (I 2 ¼ 0%; p ¼ 0.69). Compared with the freehand technique group, the 3D-printed navigation template group showed a lower incidence of complications (OR ¼ 0.21; 95% CI: 0.06-0.78; ...
... Three studies 18,21,22 reported data on blood loss, and all of them reported the mean and standard deviation. The heterogeneity regarding blood loss among the three studies was moderate (I 2 ¼ 69%; p ¼ 0.04), so the results were summarized using a random-effect model. ...
Background There is a lack of attention to screw placement techniques for surgical treatment of scoliosis in children and adolescents. This meta-analysis aims to compare the accuracy and safety of pedicle screw placement between the 3D-printed navigation template technique and the freehand technique during corrective surgery for scoliosis in children and adolescents.
Methods A comprehensive search was conducted for relevant articles up to December 2021 in databases including PubMed, Embase, MEDLINE, Cochrane, and Web of Science. The systematic meta-analysis compared the efficacy of pedicle screw placement between the two techniques, including accuracy of pedicle screw placement, complication rate, operation time, blood loss, mean placement time per screw, and mean times for fluoroscopy.
Results The seven articles analyzed in this study involved 229 patients altogether. A total of 2,805 pedicle screws were placed by the two methods. Our results revealed that the 3D-printed guide template technique was more accurate than the freehand technique in pedicle screw placement (odds ratio [OR] =2.96; 95% confidence interval [CI]: 2.24–3.91; p < 0.000) with a lower complication rate (OR = 0.21; 95% CI: 0.06–0.78; p = 0.02). The operation time (mean difference [MD] = –34.37; 95% CI: –67.47 to –1.28; p = 0.04) and mean placement time per screw (MD = –3.11; 95% CI: –6.13 to –0.09; p = 0.04) and mean times for fluoroscopy (MD = –6.60; 95% CI: –8.66 to –4.55; p < 0.000) significantly decreased among patients in the 3D-printed navigation template group compared with those in the freehand technique group. In addition, the two techniques had no significant statistical difference in blood loss.
Conclusions Compared with the traditional freehand technique, the 3D-printed guide template is a promising technique with higher accuracy and safety in screw placement for surgical treatment of scoliosis in children and adolescents, and is worth popularizing and validating through more prospective clinical studies.
... The latter becomes key to surgical scenarios that require patient-specific devices [16,19]. In this sense, from cranioplasty implants [20] and screw guides for spine surgery [21] to chest wall reconstruction devices [22], FDM has been successfully tested in the clinical setting. Likewise, FDM-printed PLA anatomical models have been evaluated for effective preoperative planning, yielding promising results for cranial and spinal surgery [23,24]. ...
... The latter becomes key to surgical scenarios that require patient-specific devices. In this sense, from cranioplasty implants [20] and screw guides for spine surgery [21] to chest wall reconstruction devices [22], FDM has been successfully tested in the clinical setting. Likewise, FDM-printed PLA anatomical models have been evaluated for effective preoperative planning, yielding promising results for cranial and spinal surgery [23,24]. ...
To successfully implement additive manufacturing (AM) techniques for custom medical device (MD) production with low-cost resources, it is imperative to understand the effect of common and affordable sterilization processes, such as formaldehyde or steam sterilization, on pieces manufactured by AM. In this way, the performance of low-risk MDs, such as biomodels and surgical guides, could be assessed for complying with safety, precision, and MD delivery requirements. In this context, the aim of the present work was to evaluate the effect of formaldehyde and steam sterilization on the dimensional and mechanical stability of standard polylactic acid (PLA) test pieces produced by fused deposition modeling (FDM). To achieve this, PLA samples were sterilized according to the sterilization protocol of a public hospital in the city of Bucaramanga, Colombia. Significant changes regarding mechanical and dimensional properties were found as a function of manufacturing parameters. This research attempts to contribute to the development of affordable approaches for the fabrication of functional and customized medical devices through AM technologies, an issue of particular interest for low- and middle-income countries.
... The use of the 3D navigation template technique was first proposed in the 1990s [18], and the clinical application of templates has recently become more popular in the surgical treatment of different spine disorders [19]. Several studies have demonstrated that the 3D navigation templates improve the accuracy of screw placement, reduce the time taken for screw insertion and lower the frequency of intraoperative radiographs in scoliotic corrective surgeries [20][21][22]. Nevertheless, how 3D navigation templates affect rotational vertebrae is not well understood. ...
... A previous comparative study found a significant difference between the template group and the free-hand group in the accuracy of pedicle screw placement (91.2% vs. 82.6%) [21]. In that study, five Grade 3 screws in two groups were recorded, which were not seen in our study; additionally, eleven congenital scoliotic patients and two kyphotic patients were recruited, and the difference in samples might lead to the discrepancy of the results between the study and ours. ...
This study compares the accuracy and safety of pedicle screw placement using a 3D navigation template with the free-hand fluoroscopy technique in scoliotic patients. Fifteen scoliotic patients were recruited and divided into a template group (eight cases) and a free-hand group (seven cases). All patients received posterior corrective surgeries, and the pedicle screw was placed using a 3D navigation template or a free-hand technique. After surgery, the positions of the pedicle screws were evaluated using CT. A total of 264 pedicle screws were implanted in 15 patients. Both the two techniques were found to achieve satisfactory safety of screw insertion in scoliotic patients (89.9% vs. 90.5%). In the thoracic region, the 3D navigation template was able to achieve a much higher accuracy of screw than the free-hand technique (75.3% vs. 60.4%). In the two groups, the accuracy rates on the convex side were slightly higher than on the concave side, while no significance was seen. In terms of rotational vertebrae, no significant differences were seen in Grades I or II vertebrae between the two groups. In conclusion, the 3D navigation template technique significantly increased the accuracy of thoracic pedicle screw placement, which held great potential for extensively clinical application.
... However, these technologies have some problems, such as increased operative time, radiation exposure to the patient, and high cost. A 3D-printed patient-specific guide was developed to facilitate PS placement [6][7][8][9][10][11][12]. In 2014, a novel 3D-printed patient-specific guide system (MySpine™, Medacta) for AIS was introduced [9]. ...
... The major perforation rate using other patient-specific guide systems for AIS has been reported to be 3.3-8.8%, which is lower than that in the freehand technique [7,8,11,12,19]. Our perforation rate results tended to be lower than those of previous reports using a drill template. Several advantages of the low-profile MySpine system were considered: (1) planning software provides an accurate screw trajectory and length. ...
Purpose
This study aimed to compare the accuracy of pedicle screw (PS) placement between a low-profile three-dimensional (3D) printed patient-specific guide system and freehand technique for adolescent idiopathic scoliosis (AIS) surgery.
Methods
Patients with AIS who underwent surgery between 2018 and 2023 at our hospital were included in the study. The 3D-printed patient-specific guide was used since 2021 (guide group). PS perforation was classified using Rao and Neo’s classification (grade 0, no violation; grade 1, < 2 mm; grade 2, 2–4 mm; grade 3, > 4 mm). Major perforations were defined as grades 2 or 3. The major perforation rate of PS, operative time, estimated blood loss (EBL), and correction rate were compared between the two groups.
Results
A total of 576 PSs were inserted in 32 patients (20 patients in the freehand (FH) group and 12 patients in the guide group). The major perforation rate was significantly lower in the guide group than in the FH group (2.1% vs. 9.1%, p < 0.001). Significantly fewer major perforations were observed in the guide group than in the FH group in the upper thoracic (T2-4) region (3.2% vs. 20%, p < 0.001) and lower thoracic (T10-12) region (0% vs. 13.8%, p = 0.001). The operative time, EBL, and correction rate were equivalent between the two groups.
Conclusion
The 3D-printed patient-specific guide notably reduced the major perforation rate of PS without increasing EBL and operative time. Our findings indicate that this guide system is reliable and effective for AIS surgery.
... They have also been used in complex cases, such as patients with deformity or as compression screws in spondylolysis. [9][10][11][12][13][14] A more recent development is the shift to utilization of patient specific implants which includes development of interbody fusion cages, 3D printed vertebral body in patients with malignancies J o u r n a l P r e -p r o o f and lately even implantable intervertebral disc. [15][16][17][18][19] Now focus has also shifted to usage of more biological material coated around the implants which can decrease failures especially in the form of pseudarthrosis and subsidence. ...
... 3D printed guides also provide a cheaper alternative to those setups where access to high end technology like image-guided navigation and intra-operative CT scans is lacking. 9,43,44 ...
3D printing (3DP) has been brought to medical use since the early part of this century- but it has been widely researched on and publicized only in the last few years. Amongst patients with spinal disorders, 3DP has been utilized in various facets of patient care. These include pre-operative aspects - such as patient education, resident training, pre-operative planning and simulations, intra-operative assistance in the form of customized jigs for pedicle screw insertion, patient specific interbody cages and vertebral body substitutes in complex malignancies and spinal infections. It has also been utilized in deformity surgeries and has opened new avenues in minimally invasive spine care. Guidelines have now been drafted by various organizations including the FDA with a prime focus on quality control measures applicable to this new technology. There has been a recent surge in publications supporting the use of 3DP in spinal disorders, reporting an improvement in various aspects of patient care. As the technology spreads out its wings further, more innovations and applications are expected to unfold in the coming years. Considering the rapid advances that 3DP has made, having a basic understanding of this technology is imperative for all spine surgeons. Despite promising preliminary results, there still exist a few pitfalls of the technology which have hindered the universal application of 3DP. Most importantly, there is a dearth of data related to long term outcomes supporting its clinical use. The prohibitive cost of 3D models, the specialized manpower it necessitates and the need for specific instrumentation are major deterrents to widespread use of this technology, particularly in small-scale healthcare setups. With further advancements in technology, the goal must be to make it more accurate and affordable to hospitals and patients so that the benefits of the technology can reach a wider patient population.
... In addition to building individual models, 3D software can use preoperative images to create patient-specific instrumentation (PSI), such as screw templates, that can guide the sizing and positioning of pedicle screw placement during surgery [32][33][34]. Several recent studies have shown significant improvement in accuracy when placing screws using 3D-guided templates compared to free-handed screw placement [32,35]. In another study, the use of 3D templates decreased the frequency of misplaced screws in patients with complex deformities to the same level as in patients with simple deformities [36]. ...
... Furthermore, the placement of screws using a 3D-guided template has been shown to result in significantly fewer post-operative complications compared to freehand placement [32]. These results suggest that 3D-guided templates are safe and may provide superior screw placement accuracy and decreased post-operative complications compared to traditional free-hand placement [32,35,37]. ...
Purpose
Spine surgery entails a wide spectrum of complicated pathologies. Over the years, numerous assistive tools have been introduced to the modern neurosurgeon’s armamentarium including neuronavigation and visualization technologies. In this review, we aimed to summarize the available data on 3D printing applications in spine surgery as well as an assessment of the future implications of 3D printing.
Methods
We performed a comprehensive review of the literature on 3D printing applications in spine surgery.
Results
Over the past decade, 3D printing and additive manufacturing applications, which allow for increased precision and customizability, have gained significant traction, particularly spine surgery. 3D printing applications in spine surgery were initially limited to preoperative visualization, as 3D printing had been primarily used to produce preoperative models of patient-specific deformities or spinal tumors. More recently, 3D printing has been used intraoperatively in the form of 3D customizable implants and personalized screw guides.
Conclusions
Despite promising preliminary results, the applications of 3D printing are so recent that the available data regarding these new technologies in spine surgery remains scarce, especially data related to long-term outcomes.
... High-quality fluoroscopy equipment is essential, but a hybrid technique using both fluoroscopy and CT has been described by some authors. PVP and BKP can be carried out under local or epidural anesthesia, sedation or general anesthesia depending on the spine level and number of vertebrae treated (62) . ...
University, my God father , for his continuous interest, helpful cooperation and effective advice throughout the entire work. He guided me patiently, provided me generously with his valuable experience, which kept me on the right way, from all my heart thanks for being my most powerful support and the light in my journey Dear prof and father you are an angel and whatever I say will never be enough.
... When combined with stereotactic navigation systems, AR has been shown to enhance pedicle screw accuracy and reduce surgeon fatigue [80]. Studies have also explored the efficacy and safety of 3D templates and patientspecific rods [81][82][83]. While these technologies are particularly beneficial for complex deformities, their use will likely increase for AIS patients. ...
Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of unknown etiology that commonly affects adolescents, imposing significant socioeconomic burdens. Effective management necessitates a comprehensive approach that takes into account multiple factors, including growth potential and psychological issues. Despite significant advancements in AIS management, several questions regarding optimal treatment strategies persist. Recent technological advancements are transforming the treatment landscape, encompassing advancements in bracing, robotic-assisted deformity corrections, and other interventions. This review explores current issues debated in the literature concerning the treatment of AIS, focusing on contemporary high-level evidence (e.g., meta-analyses and randomized controlled trials). Furthermore, this review explores cutting-edge developments and future directions in AIS management, including the integration of artificial intelligence and augmented reality.
... They help determine the surgical approach and enable simulations to ensure optimal screw trajectories and precise implant placement, 41 reducing intraoperative risks and enhancing surgical success rates. 42,43 3D-printed pedicle screw guides improve the accuracy and number of screw placements, 44 define safe screw trajectories, reduce vascular or nerve damage, shorten surgery time, and lessen radiation exposure, 45 and are suitable for upper, middle, and lower cervical spine surgeries. [46][47][48] In cases of cervical spine disease with cancer, preoperative use of 3D models to assess the extent of the tumor and its proximity to critical structures is highly valuable. ...
In the context of the digital revolution, 3D printing technology brings innovation to the personalized treatment of cervical spondylosis, a clinically common degenerative disease that severely impacts the quality of life and increases the economic burden of patients. Although traditional surgeries, medications, and physical therapies are somewhat effective, they often fail` to meet individual needs, thus affecting treatment adherence and outcomes. 3D printing, with its customizability, precision, material diversity, and short production cycles, shows tremendous potential in the treatment of cervical spondylosis. This review discusses the multiple applications of 3D printing in the treatment of cervical spondylosis, including the design, manufacture, and advantages of 3D-printed cervical collars, the role of 3D models in clinical teaching and surgical simulation, and the application of 3D-printed scaffolds and implants in cervical surgery. It also discusses the current challenges and future directions.
... 3 The emergence of 3D-printed pedicle screw guides (3DPSG) offers a promising solution for enhancing the accuracy and speed of pedicle screw placement while minimizing disruptions to a conventional open ASD surgical workflow. 4,5 However, the efficacy and safety of using 3DPSG in patients with small or entirely cortical pedicles has not previously been evaluated. ...
Background:
Adult spinal deformity (ASD) surgery often involves the placement of pedicle screws using various methods, including freehand technique, fluoroscopic guidance, and computer-assisted intraoperative navigation, each with distinct limitations. Particularly challenging is the instrumentation of pedicles with small or absent cancellous channels (Watanabe types C and D pedicles), commonly found at the apex of large curves where precise screw placement is crucial for effective deformity correction. 3D-printed pedicle screw drill guides (3DPSG) may assist in accurately placing pedicle screws while minimally disrupting the standard ASD surgery workflow. This study aims to evaluate the safety and efficacy of 3DPSG in ASD patients with Watanabe types C and D pedicles, where the safe corridor for screw placement is limited.
Methods:
3DPSG were designed using fine cut (≤1.25 mm) computed tomography scans. Preoperative screw trajectory planning and guide manufacturing were conducted using computer-aided design software (Mighty Oak Medical, Englewood, CO). Four ASD surgeons with varying experience levels placed the guides. Data on patient demographics, pedicle morphology, number of levels instrumented, and implant-related complications were collected.
Results:
The study included 115 patients (median age 67, range 18-81 years) with 2210 screws placed from T1 to L5. The median number of levels instrumented per case was 11 (range 7-12). Diagnoses included adult degenerative scoliosis (n = 62), adult idiopathic scoliosis (n = 30), Scheuermann's kyphosis (n = 2), and other complex conditions (n = 21). The overall accuracy rate for pedicle screw placement was 99.5%, with a 0% malposition rate in type C and D pedicles. No vascular or neurological complications or reoperations related to screw placement were reported.
Conclusion:
3DPSG facilitates safe and accurate pedicle screw placement regardless of pedicle morphology in ASD surgeries. This includes the challenging Watanabe types C and D pedicles, typically found at curve apices, enabling surgeons to achieve high implant density and optimal spinal fixation in ASD patients.
... An ideal surgical template should allow for the minimal removal of soft tissues, while maintaining maximal stability on the vertebrae throughout the drilling procedure. Covering templates are designed to conform to the vertebral surface, hence requiring the removal of all soft tissue from the bone (Garg et al., 2019;Pijpker et al., 2021). These templates have appropriate stability on their underlying vertebrae and provide great accuracy (Ribera-Navarro et al., 2021). ...
Background
Cervical spinal fusion surgeries require accurate placement of the pedicle screws. Any misplacement/misalignment of these screws may lead to injuries to the spinal cord, arteries and other organs. Template guides have emerged as accurate and cost-effective tools for the safe and rapid insertions of pedicle screws.
Questions/Purposes
Novel patient-specific single- and multi-level non-covering templates for cervical pedicle screw insertions were designed, 3D-printed, and evaluated.
Methods
CT scans of two patients were acquired to reconstruct their 3D spine model. Two sets of single-level (C3-C7) and multi-level (C4-C6) templates were designed and 3D-printed. Pedicle screws were inserted into the 3D-printed vertebrae by free-hand and guided techniques. For single-level templates, a total of 40 screws (2 patients × 5 vertebrae × 2 methods × 2 screws) and for multi-level templates 24 screws (2 patients × 3 vertebrae × 2 methods × 2 screws) were inserted by an experienced surgeon. Postoperative CT images were acquired to measure the errors of the entry point, 3D angle, as well as axial and sagittal plane angles of the inserted screws as compared to the initial pre-surgery designs. Accuracy of free-hand and guided screw insertions, as well as those of the single- and multi-level guides, were also compared using paired t-tests.
Results
Despite the minimal removal of soft tissues, the 3D-printed templates had acceptable stability on the vertebrae during drillings and their utilization led to statistically significant reductions in all error variables. The mean error of entry point decreased from 3.02 mm (free-hand) to 0.29 mm (guided) using the single-level templates and from 5.7 mm to 0.76 mm using the multi-level templates. The percentage reduction in mean of other error variables for, respectively, single- and multi-level templates were as follows: axial plane angle: 72% and 87%, sagittal plane angle: 56% and 78%, and 3D angle: 67% and 83%. The error variables for the multi-level templates generally exceeded those of the single-level templates. The use of single- and multi-level templates also considerably reduced the duration of pedicle screw placements.
Conclusion
The novel single- and multi-level non-covering templates are valuable tools for the accurate placement of cervical pedicle screws.
... This period marked a significant increase in scientific publications from the Indian dataset in the following years. The primary focus of research in the Indian Orthopaedic community has been on patient-specific instrumentation, complex trauma, revision arthroplasty, spine surgery, and bio-printable implants [4,[9][10][11][12][13]. Surgical teams in the country have been supported by professionals with engineering backgrounds [14,15], who have published significant work on the application of additive manufacturing to advance emerging surgical technologies. ...
Editorial on 3D Printing applications in Orthopaedics in India
... This period marked a significant increase in scientific publications from the Indian dataset in the following years. The primary focus of research in the Indian Orthopaedic community has been on patient-specific instrumentation, complex trauma, revision arthroplasty, spine surgery, and bio-printable implants [4,[9][10][11][12][13]. Surgical teams in the country have been supported by professionals with engineering backgrounds [14,15], who have published significant work on the application of additive manufacturing to advance emerging surgical technologies. ...
Surgical innovations have driven advancements in patient care, leading to improved surgical results and decreased patient morbidity. The integration of new technical advancements in orthopedic surgery is linked to the clinical advantages, ethical challenges, financial factors, and its broader influence on the global health-care sector [1]. 3D printing in orthopedic surgery is a developing technique that is rapidly gaining recognition and positively impacting patient results. The widespread influence and usefulness of 3D printing in orthopedics have been confirmed through reports detailing its application in complex trauma, complex hip revision surgeries, and various other areas such as complex spine deformity for pedicle screw trajectory guides, 3D printed implants, and bio-scaffolds [2-5]. The amount of scientific literature on the use of 3D printing in orthopedics has significantly increased in the past decade, both internationally and in India [6]. However, it has this quickly rising trend in the field of orthopedic surgery “really arrived in India.”
... With varying degrees of effectiveness, personalized 3D-printed drill guides in four distinct designs were utilized on cadaveric specimens during the first pedicle screw guide study, which was published in 2005 by Berry et al. Subsequent to its inception, 3D printed pedicle screw guides have significantly enhanced their accuracy and precision through design modifications and manufacturing process advancements, thereby broadening their utility in the field of spine surgery [23] . ...
... Further advantages of patient-specific guides include shorter surgical time, less radiation exposure, and decreased blood loss than the free-hand technique [34]. Shortcomings are the need of a more meticulous dissection of the soft-tissue from the bone for proper guide placement and the longer production time of the guides, which might be problematic in emergency cases [21,35]. ...
Purpose
Hypoplastic pedicles of the thoracolumbar spine (<5 mm diameter) are often found in syndromic deformities of the spine and pose a challenge in pedicle screw instrumentation. 3D-printed patient-specific guides might help overcome anatomical difficulties when instrumenting pedicles with screws, thereby reducing the necessity for less effective fixation methods such as hooks or sublaminar wires. In this study, the surgical feasibility and clinical outcome of patients with hypoplastic pedicles following pedicle screw instrumentation with 3D-printed patient-specific guides were assessed.
Methods
Hypoplastic pedicles were identified on preoperative computed tomography (CT) scans in six patients undergoing posterior spinal fusion surgery between 2017 and 2020. Based on these preoperative CT scans, patient-specific guides were produced to help with screw instrumentation of these thin pedicles. Postoperatively, pedicle-screw-related complications or revisions were analyzed.
Results
93/105 (88.6%) pedicle screws placed with patient-specific guides were instrumented. 62/93 (66.7%) of these instrumented pedicles were defined as hypoplastic with a mean width of 3.07 mm (SD ±0.98 mm, 95% CI [2.82–3.32]). Overall, 6 complications in the 62 hypoplastic pedicles (9.7%) were observed and included intraoperatively managed 4 cerebrospinal fluid leaks, 1 pneumothorax and 1 delayed revision due to 2 lumbar screws (2/62, 3.3%) impinging the L3 nerve root causing a painful radiculopathy. The mean follow-up time was 26.7 (SD ±11.7) months. Complications were only noted when the pedicle-width-to-screw-diameter ratio measured less than 0.62.
Conclusion
Patient-specific 3D-printed guides can aid in challenging instrumentation of hypoplastic pedicles in the thoracolumbar spine, especially if the pedicle-width-to-screw-diameter ratio is greater than 0.62.
... Physical spine models printed from virtual three-dimensional reconstructions have also been shown to improve operative planning, especially in cases with complex or anomalous anatomy [27]. Three-dimensional printing has further enabled the creation of patient-specific hardware guides, thus im proving screw placement accuracy and reducing surgical time [28,29]. ...
Background:
Surgical intervention is a critical tool to address adult spinal deformity (ASD). Given the evolution of spinal surgical techniques, we sought to characterize developments in ASD correction and barriers impacting clinical outcomes.
Methods:
We conducted a literature review utilizing PubMed, Embase, Web of Science, and Google Scholar to examine advances in ASD surgical correction and ongoing challenges from patient and clinician perspectives. ASD procedures were examined across pre-, intra-, and post-operative phases.
Results:
Several factors influence the effectiveness of ASD correction. Standardized radiographic parameters and three-dimensional modeling have been used to guide operative planning. Complex minimally invasive procedures, targeted corrections, and staged procedures can tailor surgical approaches while minimizing operative time. Further, improvements in osteotomy technique, intraoperative navigation, and enhanced hardware have increased patient safety. However, challenges remain. Variability in patient selection and deformity undercorrection have resulted in heterogenous clinical responses. Surgical complications, including blood loss, infection, hardware failure, proximal junction kyphosis/failure, and pseudarthroses, pose barriers. Although minimally invasive approaches are being utilized more often, clinical validation is needed.
Conclusions:
The growing prevalence of ASD requires surgical solutions that can lead to sustained symptom resolution. Leveraging computational and imaging advances will be necessary as we seek to provide comprehensive treatment plans for patients.
... These can effectively form an alternative to the costlier intra-operative imaging systems that are now used in all centres where complex deformity corrections are undertaken. 20 ...
Background:
Three-dimensional printing (3D Printing) has emerged as a new technology in the early part of the 21st century, with promising applications in various industries, including the medical field. Spine care is a complex sub-specialty that has shown rapid inculcation of 3D printing. This technology is being used in pre-operative planning, patient education, and simulations, as well as intra-operatively for assistance in the form of patient specific jigs for pedicle screw placement and as implantable material in the form of vertebral body substitutes and patient-specific interbody cages.
Applications:
3DP in spine care has broadened the scope of minimally invasive and spine deformity surgeries. It has also enabled the production of patient-specific implants for complex spinal malignancies and infections. The technology has been embraced by various government organizations, including the US-FDA, which has drafted guidelines for the medical use of 3DP.
Drawbacks:
Despite these promising advances and results, there still exist some significant drawbacks to the universal application of 3D printing technology. One of the main limitations is the dearth of long-term data describing the advantages and drawbacks in its clinical use. The widespread adoption of 3D models in small-scale healthcare setups is impeded by significant factors such as the high cost associated with their production, the requirement for specialized human resources, and specific instrumentation.
Conclusion:
As technological understanding increases, newer applications and innovations in spine care are expected to unravel in the near future. With the expected surge in 3DP applications in spine care, it is imperative for all spine surgeons to possess a rudimentary understanding of this technology. Although there are still limitations to its universal use, 3DP in spine care has shown promising results and has the potential to revolutionize the field of spine surgery.
... При выборе методик трехмерной печати для конкретной задачи оцениваются несколько показателей: время, необходимое для завершения печати, доступность принтера и материалов, свойства материалов (цвет, прозрачность, влагостойкость, биосовместимость, температурные характеристики). Из известных методик 3D-печати в медицине в настоящее время находят применение стереолитография Роль 3D-печати не ограничивается использованием в образовании и планировании хирургических вмешательств, она также может быть использована в изготовлении индивидуальных средств иммобилизации (лонгет, шин и ортезов) [13,15,[32][33][34]. ...
In the last decade, the range of applications of three-dimensional printing (3D printing) in surgery has been expanding. In traumatology, orthopedics and rehabilitation of injuries of the upper limbs, there is growing interest in creating splints and orthoses that can take into account the individual anatomical features of the human body. Traditional orthoses and splints are not always convenient and can lead to undesirable consequences such as pain, swelling, pressure, or even lack of therapeutic effect. The prospects of 3D printing technology in medicine from the beginning of its mass introduction, the features of modeling, manufacturing and application of means for immobilization of injuries and diseases of the upper extremities according to domestic and foreign publications over the past 5 years are considered. The data on the functionality of 3D-printed tire structures and orthoses used to immobilize the upper limb are analyzed in comparison with traditional methods of fixation. Three-dimensional images of patients with injuries obtained using computed tomography, magnetic resonance imaging or using a 3D scanner can be used to create virtual 3D models of the forearm, wrist, fingers of the patient, and 3D printing with these anatomical models allows you to create personalized tires and orthoses. Thanks to an individual approach and the use of various solutions, three-dimensional printing can be widely used in traumatology and orthopedics. As a result of this approach, it becomes possible to implement and effectively use a variety of solutions that will find support in healthcare.
... By creating specific 3D printed anatomical models, surgeons can better understand the anatomical structure details of patients' fractures, including trauma bone, surrounding soft tissue, and normal areas. Thus 3D printing technology is helping to make accurate preoperative plans [6][7][8][9][10]. ...
Purpose
This study aims to examine the use of 3D printing technology to treat clavicular fractures by skilled and inexperienced surgeons.
Methods
A total of 80 patients with clavicle fractures (from February 2017 to May 2021) were enrolled in this study. Patients were divided randomly into four groups: group A: Patients underwent low-dose CT scans, and 3D models were printed before inexperienced surgeons performed surgeries; group B: Standard-dose CT were taken, and 3D models were printed before experienced surgeons performed surgeries; group C and D: Standard-dose CT scans were taken in both groups, and the operations were performed differently by inexperienced (group C) and experienced (group D) surgeons. This study documented the operation time, blood loss, incision length, and the number of intraoperative fluoroscopies.
Results
No statistically significant differences were found in age, gender, fracture site, and fracture type ( P value: 0.23–0.88). Group A showed shorter incision length and fewer intraoperative fluoroscopy times than groups C and D ( P < 0.05). There were no significant differences in blood loss volume, incision length, and intraoperative fluoroscopy times between group A and group B ( P value range: 0.11–0.28). The operation time of group A was no longer than those of groups C and D ( P value range: 0.11 and 0.24).
Conclusion
The surgical effectiveness of inexperienced surgeons who applied 3D printing technology before clavicular fracture operation was better than those of inexperienced and experienced surgeons who did not use preoperative 3D printing technology.
... Also, it is less prone to manual human errors by using anatomy-based guides in the 3D model (Figure 6 (A)) of the patient-specific vertebra in virtual screen. This ultimately reduces the operation time, less bleeding, fewer screw misalignments, and cheaper treatment [82][83][84][85]. The whole process of printing the patientspecific pedicles is shown in the flow chart (Figure 6 (B)). ...
Additive manufacturing technologies are expected to disrupt the majority of the traditional way of manufacturing methods, particularly in the field of medical and healthcare. Bones and teeth are vital organs that are susceptible to various disorders due to environmental, traumatic, genetic factors, and inherent malignant disorders. Most of the implants/prostheses normally used are cast and have a standard size and shape. Additive manufacturing has opened opportunities to replace these hard tissues with customized implants, prostheses, or the whole additive manufactured organ itself while considering anatomical/structural parts and functional aspects of the body. It helps to visualize and mimic internal organs/models, pre-planning via simulation, anatomical demonstration, treatments, and surgical teaching/training to technical staff by medical professionals. The current review covers additive manufacturing applications for the possible treatment of osteosarcoma, bone tumors, traumatic fracture, congenital anomalies, dental diseases, vertebral and cranial abnormalities, etc. from toe to head highlighting printing of long bones, short bones, cartilages, teeth, and more based on the general classification of bones shape i.e. the external shape and size of different bones with some case studies. The article has also touched upon the additive manufacturing competitive edge over the conventional methods in terms of complexity, easiness, cost-effectiveness, reduced time. However, the internal structures have not been addressed so far in additive manufacturing which could be a new corner to enhance the properties of bones and teeth in the future.
... PSGs have been used as surgical templates during pedicle cannulation in patients with spinal deformities. PSGs have been shown to provide superior PS placement accuracy, reduced placement time, decreased blood loss, and lower cost and radiation exposure compared with the free-hand technique [5][6][7][8][9][10]. ...
Purpose Pedicle screw (PS) placement in thoracic scoliotic deformities can be challenging due to altered vertebral anatomy;
malposition can result in severe functional disability or inferior construct stability. Three-dimensional (3D) printed patient�specifc guides (PSGs) have been recently used to supplement other PS placement techniques. We conducted a single-center,
retrospective observational study to assess the accuracy of PS placement using PSGs in a consecutive case series of pediatric
and adult patients with thoracic scoliosis.
Methods We analyzed the data of patients with thoracic scoliosis who underwent PS placement using 3D-printed PSG as
a vertebral cannulation aid between June 2013 and July 2018. PS positions were determined via Gertzbein–Robbins (GR)
and Heary classifcations on computed tomography images. We determined the concordance of actual and preoperatively
planned PS positions and defned the technique learning curve using a receiver-operating characteristic (ROC) curve.
Results We performed 362 thoracic PS placement procedures in 39 consecutive patients. We classifed 352 (97.2%), 2
(0.6%), and 8 (2.2%) screws as GR grades 0 (optimal placement), I, and II, respectively. The average instrumented PS entry
point ofsets on the X- and Y-axes were both 0.8 mm, and the average diferences in trajectory between the planned and the
actual screw placements on the oblique sagittal and oblique transverse planes were 2.0° and 2.4°, respectively. The learning
process was ongoing until the frst 12 PSs were placed.
Conclusions The accuracy of PS placement using patient-specifc 3D templates in our case series exceeds the accuracies of
established thoracic PS placement techniques.
... Application of 3D printing technology makes it possible to anticipate and prepare for the challenges that need to be addressed during Am J Transl Res 2022;14(9):6341-6348 planning of screw placement, osteotomy and bone fusion avoided excessive trauma and hemorrhage from excessive exposure during surgery, leaving more time for accurate osteotomy and screw positioning. As consistent with our results, Garg et al. [28] found that 3D printing-aided surgery can significantly decrease the intraoperative time, hemorrhage, x-ray exposure, and achieve more accurate screw placement than the control group. ...
Objective:
To test if preoperative planning with 3 dimensional (3D)-printed spine models can increase the effectiveness and safety of spinal deformity surgery.
Methods:
A total of 53 patients who were treated in our center for spinal deformities from January 2010 to January 2018 were included in the current study. They were divided into two groups based on whether 3D-printed models were used in the surgical planning. A total of 28 patients who were treated with 3D-printed models were assigned to the experimental group, and 25 patients who were treated with conventional methods were assigned to the control group. Duration of surgery, intraoperative hemorrhage, incidence of surgery related complications, Oswestry disability index (ODI), visual analogue scale (VAS), and Cobb's angle were compared between the two groups before and after surgery.
Results:
There were significant differences in the duration of surgery, intraoperative hemorrhage and intraoperative x-ray exposure between the two groups (P<0.01). Cobb's angle was smaller in the experimental group than in the control group when measured three days and a year after surgery (P<0.01). Although there was no significant difference between the experimental and control groups (P>0.05), Oswestry disability index and VAS pain scores were lower a month and a year after the surgery than before the surgery (P<0.01).
Conclusion:
Surgical planning using 3D-printed spine models can decrease the operation time, intraoperative hemorrhage, and x-ray exposure, and help achieve satisfactory structural restoration in patients with severe spinal deformity.
... Compared with conventional placement, screw insertion with the 3DP guide had higher placement accuracy, decreased pedicle cortex perforation, and reduced operative duration and fluoroscopic frequency [23]. Drill templates and trajectories that can be improved before surgery would help traverse this complex anatomical environment and might reduce the chance of vertebral artery damage, a potentially fatal complication [24]. ...
Purpose
Although numerous publications on three-dimensional printing (3DP) in spine surgery have been published, bibliometric analysis studies are scarce. Thus, this study aimed to present a bibliometric analysis of the status, hot spots, and frontiers of 3DP in spine surgery and associated research disciplines.
Methods
All publications relating to the utilization of 3DP in spine surgery from 1999 to May 9, 2022, were retrieved from the Web of Science. The bibliometric analysis was performed using CiteSpace software, and information on the country, institution, author, journal, and keywords for each publication was collected.
Results
A total of 270 articles were identified. From 2016 onward, a significant increase in publications on spinal surgery was observed. China was the most productive and influential country (98 publications) and H-index (22), followed by the USA and Australia. The most productive institution was Capital Medical University (9 publications). P. S. D’urso (8 publications, 46 citations) and R. J. Mobbs (8 publications, 39 citations) were the most prolific authors. European Spine Journal contributed the highest number of publications. The eight main clusters were: “rapid prototyping” #0, “3D printed” #1, “spine fusion” #2, “scoliosis” #3, “spine surgery” #4, “patient-specific” #5, “nervous system” #6, and “neuronavigation” #7. The strongest keyword bursts in 3DP in spine surgery were “fixation,” “drill template,” “instrumentation,” “fusion,” “complication,” and “atlantoaxial instability.”
Conclusion
This analysis provides information on research trends and frontiers in the application of 3DP in spine surgery, as well as research and collaboration partners, institutions, and countries.
... Their study, however, did not specifically examine the intraoperative use of 3D printed guides. Garg et al. (13) compared 10 patients treated with patient-specificguides with 10 patients treated using freehand technique for screw placement and found greater accuracy and shorter operative times when using patient-specific guides. ...
Background: Three-dimensional (3D) printed guides are finding increasing applications in the field of orthopaedic surgery and more recently spine surgery. This retrospective cohort study compares benefits and costs of 3D printed guides in surgical treatment of adolescent idiopathic scoliosis (AIS) compared to freehand techniques.
Methods: Intraoperative screw placement was conducted either with 3D printed guides (3D cohort) or traditional freehand technique (freehand cohort) for AIS patients undergoing spinal fusion at a single institution. Patient and perioperative data include: screw placement time, length of surgery, blood loss, hospital stay, spinal curvature correction, total implant costs and training level of surgical assist. Multivariate analysis assessed for confounding and effect modification. P-values <0.05 were considered significant.
Results: There were 29 patients included in analyses, 18 in the 3D and 11 in the freehand (FH) cohort, for a total of 263 3D and 307 freehand screws. Between cohorts, there were no significant differences in patient age (P=0.93), gender (P=0.15), height (P=0.18) or weight (P=0.40). The 3D cohort (mean 6,374) had significantly higher implant costs than FH (mean 5,587, P=0.003) with significantly reduced intraoperative blood loss (mean 559 mL, SD =273 FH; vs. mean 357 mL, SD =123 3D; P=0.01). On multivariate analysis, surgical residents had significantly faster screw placement times when using 3D guides (P<0.001) than when placing screws freehand. There were no significant differences between cohorts in length of postoperative hospitalization, spinal levels fused, or coronal or sagittal curve correction.
Conclusions: At significant cost, 3D printed guides reduce intraoperative blood loss compared to freehand pedicle screw placement and reduce screw placement time for surgical residents.
... The use of pedicle screw guides was first reported in 2005 in a cadaveric study by Berry et al. He tested 3D printing drill templates in cadaveric specimens with varying degrees of success [63]. Subsequently, the professors conducted a large number of experiments for spine pedicle screw placement, vertebral screw placement, cortical bone trajectory (CBT) screw placement, etc [64]. ...
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.
... For spinal surgery, pedicle screws that run from posterior to anterior are currently the most used fixation technique. Since the groundbreaking work of Suk et al. in 1995 [12], spine surgeons also adopted its use for challenging locations such as the scoliotic thoracic spine [13,14]. Although the pedicle screw trajectory seems dangerous, as it passes immediately next to the spinal canal (Figure 1), its use has been demonstrated to be safe in experienced hands, even when the screws are not positioned perfectly. ...
For decades, the advantages of rapid prototyping for clinical use have been recognized. However, demonstrations of potential solutions to treat spinal problems that cannot be solved otherwise are scarce. In this paper, we describe the development, regulatory process, and clinical application of two types of patient specific 3D-printed devices that were developed at an in-house 3D point-of-care facility. This 3D lab made it possible to elegantly treat patients with spinal problems that could not have been treated in a conventional manner. The first device, applied in three patients, is a printed nylon drill guide, with such accuracy that it can be used for insertion of cervical pedicle screws in very young children, which has been applied even in semi-acute settings. The other is a 3D-printed titanium spinal column prosthesis that was used to treat progressive and severe deformities due to lysis of the anterior column in three patients. The unique opportunity to control size, shape, and material characteristics allowed a relatively easy solution for these patients, who were developing paraplegia. In this paper, we discuss the pathway toward the design and final application, including technical file creation for dossier building and challenges within a point-of-care lab.
Purpose
The objective of this systematic review is to present a comprehensive summary of existing research on the use of 3D printing in spinal surgery.
Methods
The researchers conducted a thorough search of four digital databases (PubMed, Web of Science, Scopus, and Embase) to identify relevant studies published between January 1999 and December 2022. The review focused on various aspects, including the types of objects printed, clinical applications, clinical outcomes, time and cost considerations, 3D printing materials, location of 3D printing, and technologies utilized. Out of the 1620 studies initially identified and the 17 added by manual search, 105 met the inclusion criteria for this review, collectively involving 2088 patients whose surgeries involved 3D printed objects.
Results
The studies presented a variety of 3D printed devices, such as anatomical models, intraoperative navigational templates, and customized implants. The most widely used type of objects are drill guides (53%) and anatomical models (25%) which can also be used for simulating the surgery. Custom made implants are much less frequently used (16% of papers). These devices significantly improved clinical outcomes, particularly enhancing the accuracy of pedicle screw placement. Most studies (88%) reported reduced operation times, although two noted longer times due to procedural complexities. A variety of 3DP technologies and materials were used, with STL, FDM, and SLS common for models and guides, and titanium for implants via EBM, SLM, and DMLS. Materialise software (Mimics, 3-Matic, Magics) was frequently utilized. While most studies mentioned outsourced production, in-house printing was implied in several cases, indicating a trend towards localized 3D printing in spine surgery.
Conclusions
3D printing in spine surgery, a rapidly growing area of research, is predominantly used for creating drill guides for screw insertion, anatomical models, and innovative implants, enhancing clinical outcomes and reducing operative time. While cost-efficiency remains uncertain due to insufficient data, some 3D printing applications, like pedicle screw drill guides, are already widely accepted and routinely used in hospitals.
Spine surgery has evolved significantly over the years with advancements in technology, including the use of three-dimensional (3D) printing. 3D printing is being utilized in a new cutting-edge way that allows for the creation of patient-specific surgical guides for spine surgery. These guides are designed based on the patient’s anatomy, providing precise guidance to the surgeon during the surgical procedure. In this chapter we provide a review of the clinical results related to the use of 3D printing in spine surgery using articles published in the last 10 years (2013–2023) to ensure the most up-to-date information.
3D printing, also known as rapid additive manufacturing, adds materials layer by layer to construct the final product and offers many potential advantages including increased flexibility in the design process as well as efficient production that accommodates patient’s unique anatomy and needs. In spinal surgery, 3D printing has been shown to improve surgical dissection, accuracy of implant placement, and execution of spinal osteotomies. 3D-printed anatomic models improve communication in the perioperative setting. 3D-printed non-custom implants may allow for model refinement (such as geometries not previously attainable with traditional manufacturing modalities). Additionally, 3D-printed customized implants may allow for improved surgical management in complex spinal pathology. This review outlines the history and basics of 3D printing technology, its current applications in spinal surgery, and its associated advantages and disadvantages.
Pedicle screws are the primary method of vertebral fixation in scoliosis surgery, but there are lingering concerns over potential malposition. The rates of pedicle screw malposition in pediatric spine surgery vary from 10% to 21%. Malpositioned screws can lead to potentially catastrophic neurological, vascular, and visceral complications. Pedicle screw positioning in patients with neuromuscular scoliosis is challenging due to a combination of large curves, complex pelvic anatomy, and osteopenia. This study aimed to determine the rate of pedicle screw malposition, associated complications, and subsequent revision from screws placed with the assistance of machine vision navigation technology in patients with neuromuscular scoliosis undergoing posterior instrumentation and fusion.
A retrospective analysis of the records of patients with neuromuscular scoliosis who underwent thoracolumbar pedicle screw insertion with the assistance of machine-vision image guidance navigation was performed. Screws were inserted by either a staff surgeon, orthopaedic fellow, or orthopaedic resident. Post-operative ultra-low dose CT scans were used to assess pedicle screw accuracy. The Gertzbein classification was used to grade any pedicle breaches (grade 0, no breach; grade 1, <2 mm; grade 2, 2–4 mm; grade 3, >4 mm). A screw was deemed accurate if no breach was identified (grade 0).
25 patients were included in the analysis, with a mean age of 13.6 years (range 11 to 18 years; 13/25 (52.0%) were female. The average pre-operative supine Cobb angle was 90.0 degrees (48–120 degrees). A total of 687 screws from 25 patients were analyzed (402 thoracic, 241 lumbosacral, 44 S2 alar-iliac (S2AI) screws). Surgical trainees (fellows and orthopaedic residents) inserted 46.6% (320/687) of screws with 98.8% (4/320) accuracy. The overall accuracy of pedicle screw insertion was 98.0% (Grade 0, no breach). All 13 breaches that occurred in the thoracic and lumbar screws were Grade 1. Of the 44 S2AI screws placed, one screw had a Grade 3 breach (2.3%) noted on intra-operative radiographs following rod placement and correction. This screw was subsequently revised. None of the breaches resulted in neuromonitoring changes, vessel, or visceral injuries.
Machine vision navigation technology combined with careful free-hand pedicle screw insertion techniques demonstrated high levels of pedicle screw insertion accuracy, even in patients with challenging anatomy.
Objective Surgical stabilization to treat fractures, luxations, and congenital malformations in the thoracic spine can be difficult due to its unique anatomy and surrounding structures. Our objective was to document the morphometrics of the thoracic vertebrae relating to an ideal trajectory for dorsolateral implant placement in a variety of dog sizes and to assess proximity to important adjacent critical anatomical structures using computed tomography (CT) studies.
Study Design Medical records for 30 dogs with thoracic CT were evaluated. Implantation corridor parameters for thoracic vertebrae (T1–T13) were measured, including the length, width, angle from midline, and allowable deviation angle for corridors simulated using an ideal implant trajectory. The distances from each vertebra to the trachea, lungs, aorta, subclavian artery, and azygos vein were also measured.
Results Implantation corridor widths were often very narrow, particularly in the mid-thoracic region, and allowable deviation angles were frequently small. Distances to critical anatomical structures were often less than 1 mm, even in larger dogs.
Conclusion Thoracic implantation requires substantial precision to avoid breaching the canal, ineffective implant placement, and potential life-threatening complications resulting from invasion of surrounding anatomical structures.
Objective
To compare vertebral implant placement in the canine thoracolumbar spine between 3D‐printed patient‐specific drill guides (3DPG) and the conventional freehand technique (FH).
Study design
Ex vivo study.
Animals
Cadaveric canine spines ( n = 24).
Methods
Implant trajectories were established for the left and right sides of the T10 through L6 vertebrae based on computed tomography (CT) imaging. Customized drill guides were created for each vertebra of interest. Each cadaver was randomly assigned to one of six veterinarians with varying levels of experience placing vertebral implants. Vertebrae were randomly assigned a surgical order and technique (3DPG or FH) for both sides. Postoperative CT images were acquired. A single, blinded observer assessed pin placement using a modified Zdichavsky classification.
Results
A total of 480 implants were placed in 240 vertebrae. Three sites were excluded from the analysis; therefore, a total of 238 implants were evaluated using the FH technique and 239 implants using 3DPG. When evaluating implant placement, 152/239 (63.6%) of 3DPG implants were considered to have an acceptable placement in comparison with 115/248 (48.32%) with FH. Overall, pin placement using 3DPG was more likely to provide acceptable pin placement ( p < .001) in comparison with the FH technique for surgeons at all levels of experience.
Conclusion
The use of 3DPG was shown to be better than the conventional freehand technique regarding acceptable placement of implants in the thoracolumbar spine of canine cadavers.
Clinical significance
Utilizing 3DPG can be considered better than the traditional FH technique when placing implants in the canine thoracolumbar spine.
Three-dimensional (3D) printing technology has proven to have many advantages in spine and sacrum surgery. 3D printing allows the manufacturing of life-size patient-specific anatomic and pathologic models to improve preoperative understanding of patient anatomy and pathology. Additionally, virtual surgical planning using medical computer-aided design software has enabled surgeons to create patient-specific surgical plans and simulate procedures in a virtual environment. This has resulted in reduced operative times, decreased complications, and improved patient outcomes. Combined with new surgical techniques, 3D-printed custom medical devices and instruments using titanium and biocompatible resins and polyamides have allowed innovative reconstructions.
Objective:
The main objective of this study has been to demonstrate why additive printing allows to make complex surgical pathological processes that affect the spine more visible and understandable, increasing precision, safety and reliability of the surgical procedure.
Methods:
A systematic review of the articles published in the last 10 years on 3D printing-assisted spinal surgery was carried out, in accordance with PRISMA 2020 declaration. Keywords «3D printing» and «spine surgery» were searched in Pubmed, Embase, Cochrane Database of Systematic Reviews, Google Scholar and Opengrey databases, which was completed with a manual search through the list of bibliographic references of the articles that were selected following the defined inclusion and exclusion criteria.
Results:
From the analysis of the 38 selected studies, it results that 3D printing is useful in surgical planning, medical teaching, doctor-patient relationship, design of navigation templates and spinal implants, and research, optimizing the surgical process by focusing on the patient, offering magnificent support during the surgical procedure.
Conclusions:
The use of three-dimensional printing biomodels allows: making complex surgical pathological processes that affect the spine more visible and understandable; increase the accuracy, precision and safety of the surgical procedure, and open up the possibility of implementing personalized treatments, mainly in tumor surgery.
(1) Background: The three-dimensional printing (3DP) technique has been reported to be of great utility in spine surgery. The purpose of this study is to report the clinical application of personalized preoperative digital planning and a 3DP guidance template in the treatment of severe and complex adult spinal deformity. (2) Methods: eight adult patients with severe rigid kyphoscoliosis were given personalized surgical simulation based on the preoperative radiological data. Guidance templates for screw insertion and osteotomy were designed and manufactured according to the planning protocol and used during the correction surgery. The perioperative, and radiological parameters and complications, including surgery duration, estimated blood loss, pre- and post-operative cobb angle, trunk balance, and precision of osteotomy operation with screw implantation were collected retrospectively and analyzed to evaluate the clinical efficacy and safety of this technique. (3) Results: Of the eight patients, the primary pathology of scoliosis included two adult idiopathic scoliosis (ADIS), four congenital scoliosis (CS), one ankylosing spondylitis (AS), and one tuberculosis (TB). Two patients had a previous history of spinal surgery. Three pedicle subtraction osteotomies (PSOs) and five vertebral column resection (VCR) osteotomies were successfully performed with the application of the guide templates. The main cobb angle was corrected from 99.33° to 34.17°, and the kyphosis was corrected from 110.00° to 42.00°. The ratio of osteotomy execution and simulation was 97.02%. In the cohort, the average screw accuracy was 93.04%. (4) Conclusions: The clinical application of personalized digital surgical planning and precise execution via 3D printing guidance templates in the treatment of severe adult rigid deformity is feasible, effective, and easily generalizable. The preoperative osteotomy simulation was executed with high precision, utilizing personalized designed guidance templates. This technique can be used to reduce the surgical risk and difficulty of screw placement and high-level osteotomy.
Three-dimensional printing opens up many opportunities for use in traumatology and orthopedics, because it takes into account personal characteristics of the patients. Modern methods of high-resolution medical imaging can process data to create threedimensional images for printing physical objects. Today, three-dimensional printers are able to create a model of any complexity of shape and geometry. The article provides a review of the literature about three-dimensional digital modeling in shaping implants for osteosynthesis. Data search was carried out on the Scopus, Web of Scince, Pubmed, RSCI databases for the period 2012–2022. The effectiveness of three-dimensional printing for preoperative modeling of bone plates has been confirmed: implants perfectly corresponds with the unique anatomy of the patient, since the template for it is based on the materials of computed tomography. Individual templates can be useful when the geometry of patients' bones goes beyond the standard, and when improved results of surgery are expected due to better matching of implants to the anatomical needs of patients.
Background:
Advances in three-dimensional (3D) printing technology have enabled the development of customized instrumentation and surgical training platforms. However, no existing studies have assessed how patient-specific 3D-printed spine models can facilitate patient education and operative planning in complex spinal deformity correction.
Objective:
To present a cost-effective technique for constructing personalized 3D-printed spine models for patients with severe spinal deformities and to outline how these models can promote informed consent, trainee education, and planning for instrumentation placement and alignment correction.
Methods:
We present 2 patients who underwent surgical correction of progressive thoracolumbar deformities. Full-scale 3D-printed models of each patient's spine were produced preoperatively and used during clinic evaluations, surgical planning, and as intraoperative references.
Results:
Each model took 9 days to build and required less than 60 US dollars of material costs. Both patients were treated with a posterior approach and contiguous multilevel osteotomies. Postoperatively, their alignment parameters and neurological deficits improved.
Conclusion:
Personalized 3D-printed spine models can aid in patient education, surgical training, visualization, and correction of complex spinal deformities.
Introduction:
Scoliosis is a complex deformity that affects all three planes of the axis of the spine. The association between neuromuscular pathology and vertebral alignment was initially described in 1960. Neuromuscular pathology is progressive and results in postural abnormalities. Surgical goals in patients with neuromuscular deformity include anatomical correction for sedation and ambulation, as well as functional improvement. The gold standard of treatment is by posterior approach with transpedicular screws. The "hands-free" technique saves surgical time, decreases radiation by reducing the use of fluoroscopy. The advent of 3D printing technology allows precise study of the anatomical area and detail of the deformity in its three planes. This model can be sterilized for transoperative guidance. A 13-year-old female patient who develops thoracolumbar neuromuscular scoliosis secondary to spastic cerebral palsy (CP), with previous instrumentation T11-L3 of which he develops severe proximal curve. After the segmentation of the three-dimensional model, pedicle violation greater than 2 mm towards bilateral medullary canal was detected in the pedicles of L1 and L2 of previous instrumentation, pedicle dysplasia and the morphological characteristics of the pedicles were observed. Three-dimensional planning and the use of surgical guides represent a tool for surgical planning, especially in severe cases and with pedicle dysplasia. It helps as a surgical guide for the placement of hands-free transpedicular screws with possible reduction of radiation and anesthetic time.
Introducción:
La escoliosis es una deformidad compleja que afecta los tres planos del eje de la columna vertebral. La asociación entre patología neuromuscular y la alineación vertebral fue descrita inicialmente en 1960. La patología neuromuscular es progresiva y resulta en anormalidades posturales. Las metas quirúrgicas en pacientes con deformidad neuromuscular engloban la corrección anatómica para la sedestación y deambulación, así como mejoría funcional. El estándar de oro de tratamiento es por vía posterior con tornillos transpediculares. La técnica de «manos libres» ahorra tiempo quirúrgico, disminuye la radiación al reducir el uso de fluoroscopía. El advenimiento de la tecnología de impresión 3D permite estudio preciso del área anatómica y detalle de la deformidad en sus tres planos. Este modelo puede ser esterilizado para guía transoperatoria. Paciente femenino de 13 años de edad que desarrolla escoliosis neuromuscular toracolumbar secundario a parálisis cerebral infantil (PCI) espástica, con instrumentación previa T11-L3 de la cual desarrolla curva severa proximal. Finalizada la segmentación del modelo tridimensional se detectó violación pedicular mayor a 2 mm hacia canal medular bilateral en los pedículos de L1 y L2 de instrumentación previa, displasia pedicular y se observaron las características morfológicas de los pedículos. La planeación tridimensional y el uso de guías quirúrgicas representan una herramienta para la planeación quirúrgica, sobre todo en casos severos y con displasia pedicular. Ayuda como guía quirúrgica para la colocación de tornillos transpediculares a manos libres con posible reducción de radiación y tiempo anestésico.
Objective The aim of this study was to compare the accuracy of pedicle screw placement at the canine lumbosacral junction using a novel unilateral three-dimensional printed patient-specific guide (3D-PSG) versus a freehand drilling technique. Additionally, accuracy of screw placement between a novice and an experienced surgeon was determined.
Study Design Preoperative computed tomography images from 20 lumbosacral cadaveric specimens were used to design a novel unilateral 3D-PSG for the L7 and sacral vertebrae which was printed in acryl-nitrile butadiene styrene plastic. A novice and an expert surgeon each placed 3.5mm cortical screws in 10 cadavers; on the left using the unilateral 3D-PSG and by the freehand (anatomic landmark) technique on the right.
Results Sixty screws were placed using the unilateral 3D-PSG and 60 using the freehand technique. There was no statistical difference in accuracy for the comparison between methods performed by the expert (p = 0.679) and novice (p = 0.761) surgeon, nor between an expert and novice surgeon overall (p = 0.923). Unexpectedly, the use of a unilateral 3D-PSG increased variability for the expert surgeon in our study (p = 0.0314).
Conclusion Using a novel unilateral 3D-PSG did not improve the accuracy of screw placement for lumbosacral stabilization by a novice surgeon compared with an expert surgeon in lumbar spine surgery. This may reflect a suboptimal PSG design.
Objective:
The aim of this study was to compare duration of surgery, intraoperative fluoroscopy exposure, blood loss and the accuracy of pedicular screw placement between 3D model-assisted surgery and conventional surgery for AO spinal C-type injuries.
Methods:
In this study 32 patients who were admitted with thoracolumbar AO spinal C-type injuries were included. These patients were divided randomly into two groups of 16 where one group was operated on using conventional surgery and the other group was operated on using 3D model-assisted surgery. During surgery, instrumentation time, amount of blood loss and intraoperative fluoroscopy exposure were recorded. Moreover, the status of the screws in the pedicles was assessed as described by Learch and Wiesner's and regional sagittal angles (RSA) were measured preop and postoperatively.
Results:
It was found that there was a statistically significant difference in instrumentation time, blood loss and intraoperative fluoroscopy exposure in the 3D model-assisted surgery group (61.9 ± 4.7 min, 268.4 ± 42.7 ml, 16.3 ± 1.9 times) compared to the conventional surgery group (75.5 ± 11.0 min, 347.8 ± 52.2 mL, 19.7 ± 2.4 times) (t=4.5325, P < 0.0001 and t=4.7109, P < 0.0001 and t=4.4937, P < 0.0001, respectively) Although the screw misplacement rate of the conventional surgery group was higher than that of the 3D model-assisted surgery group, the only statistically significant difference was in the medial axial encroachment (t=5.101 P=0.02) . There was no severe misplacement of pedicle screws in either group. There were no statistically significant differences between postoperative RSA angles and were in both groups restored significantly.
Conclusion:
The results of this study have shown us that the 3D model helps surgeons see patients' pathoanatomy and determine rod lengths, pedicle screw angles and lengths preoperatively and peroparatively, which in turn shortens operative time, reduces blood loss and fluoroscopy exposure.
Level of evidence:
Level I, Therapeutic Study.
The importance of 3D printing applications in the surgery of musculoskeletal tumors has increased in recent years. Even prior to the era of 3D printing, computer-assisted techniques, such as navigation, have proved their utility. Due to the variable appearance of bone tumors, there is a need for individual solutions. The 3D printing can be used for the development of anatomical demonstration models, the construction of patient-specific instruments and custom-made implants. For these three applications, different regulatory hurdles exist. Especially for the resection of pelvic tumors, 3D printing technologies seem to provide advantages due to the complicated anatomy and the proximity to relevant neurovascular structures. With the introduction of titanium printing, construction of individualized implants that fit exactly into the defect became feasible.
The technique of 3D printing offers a high potential for further optimization of spinal surgery. This new technology has been published for different areas in the field of spinal surgery, e.g. in preoperative planning, intraoperative use as well as to create patient-specific implants. For example, it has been demonstrated that preoperative 3‑dimensional visualization of spinal deformities is helpful in planning procedures. Moreover, insertion of pedicle screws seems to be more accurate when using individualized templates to guide the drill compared to freehand techniques. This review summarizes the current literature dealing with 3D printing in spinal surgery with special consideration of the current applications, the limitations and the future potential.
Pedicle screw instrumentation has been used to stabilize the thoracolumbar spine for several decades. Although pedicle screws were originally placed via a free-hand technique, there has been a movement in favor of pedicle screw placement with the aid of imaging. Such assistive techniques include fluoroscopy guidance and stereotactic navigation. Imaging has the benefit of increased visualization of a pedicle's trajectory, but can result in increased morbidity associated with radiation exposure, increased time expenditure, and possible workflow interruption. Many institutions have reported high accuracies with each of these three core techniques. However, due to differing definitions of accuracy and varying radiographic analyses, it is extremely difficult to compare studies side-by-side to determine which techniques are superior. From the literature, it can be concluded that pedicles of vertebrae within the mid-thoracic spine and vertebrae that have altered morphology due to scoliosis or other deformities are the most difficult to cannulate. Thus, spine surgeons would benefit the most from using assistive technologies in these circumstances. All other pedicles in the thoracolumbar spine should theoretically be cannulated with ease via a free-hand technique, given appropriate training and experience. Despite these global recommendations, appropriate techniques must be chosen at the surgeon's discretion. Such determinations should be based on the surgeon's experience and the specific pathology that will be treated.
Thoracic pedicle screws have superior anchoring strength compared with other available fixation techniques. However, these are not universally accepted in many developing countries because of the concerns regarding safety and complications. In addition, there is evidence that pedicle morphology is unique in Chinese patients. The goal of this study was to analyze the complications seen at our institution, while using thoracic pedicle screws for the treatment of thoracic deformity, and to determine the safety of our techniques for the treatment of thoracic deformity in a Chinese population. From 1998 to 2005, there were 208 thoracic deformity patients treated at our institution, 70 of whom were male and 138 were female. Their age ranged from 11 to 55 years (mean of 14.9 years). All of them underwent corrective deformity surgery using posterior pedicle screw systems and follow-up was available for at least 3 years. Etiologic diagnoses included adolescent idiopathic scoliosis in 119 patients, congenital kyphoscoliosis in 38, adult scoliosis in 37 and undetermined in 14. Screw positions were evaluated using intraoperative and postoperative radiographs and a CT scan was performed when a concern for screw malposition was present. All radiographic evaluations were carried out in a double-blinded fashion. A total of 1,123 thoracic pedicle screws were inserted (5.4 thoracic screws/patient). The deformity correction rate was 81, 65 and 62% for idiopathic, congenital and adult scoliosis patients, respectively. The overall complication rate was 16.5% at the final follow-up. Complication rates directly and indirectly related to pedicle screws were 7.2 and 9.3%, respectively. There were no significant screw-related neurologic or visceral complications that adversely affected long-term results. The complications seen with thoracic pedicle screws in a Chinese population were similar to other populations and could be utilized safely for the treatment of thoracic deformity in this population.
With the rapid increase in the use of thoracic pedicle screws in scoliosis, accurate and safe placement of screw within the pedicle is a crucial step during the scoliosis surgery. To make thoracic pedicle screw placement safer various techniques are used, Patient-specific drill template with pre-planned trajectory has been thought as a promising solution, it is critical to assess the efficacy, safety profile with this technique. In this paper, we develop and validate the accuracy and safety of thoracic transpedicular screw placement with patient-specific drill template technique in scoliosis. Patients with scoliosis requiring instrumentation were recruited. Volumetric CT scan was performed on each desired thoracic vertebra and a 3-D reconstruction model was generated from the CT scan data. The optimal screw size and orientation were determined and a drill template was designed with a surface that is the inverse of the posterior vertebral surface. The drill template and its corresponding vertebra were manufactured using rapid prototyping technique and tested for violations. The navigational template was sterilized and used intraoperatively to assist with the placement of thoracic screws. After surgery, the positions of the pedicle screws were evaluated using CT scan and graded for validation. This method showed its ability to customize the placement and the size of each pedicle screw based on the unique morphology of the thoracic vertebra. In all the cases, it was relatively very easy to manually place the drill template on the lamina of the vertebral body during the surgery. This method significantly reduces the operation time and radiation exposure for the members of the surgical team, making it a practical, simple and safe method. The potential use of such a navigational template to insert thoracic pedicle screws in scoliosis is promising. The use of surgical navigation system successfully reduced the perforation rate and insertion angle errors, demonstrating the clear advantage in safe and accurate pedicle screw placement of scoliosis surgery.
The objective of this study was to develop a novel, patient-specific, navigational template for thoracic pedicle screw placement.
Twenty thoracic cadaver specimens were randomly divided into two groups of 10: the navigational template group and the free-hand group. A volumetric CT scan was performed on each thoracic vertebra, and a three-dimensional reconstruction model was generated. A drill template was designed with a surface that was the inverse of the posterior vertebral surface. Each drill template and its corresponding vertebra were manufactured using a rapid prototyping technique and tested for violation. Two hundred and forty screws were implanted into the thoracic spines and the positions of the screws were evaluated.
Two hundred and forty thoracic screws were inserted using either the navigational template method or the free-hand method. The accuracy rate and incidence of risk for setting thoracic pedicle screws differed statistically between the two methods (P < 0.05): The navigational template method had a higher accuracy rate and a lower incidence of risk than the free-hand method. Moreover, the free-hand method had a significant learning curve, whereas a learning curve for the navigational template method was not obvious.
We have developed a novel, patient-specific, navigational template for thoracic pedicle screw placement with good applicability and high accuracy.
To develop and validate the efficacy and accuracy of a novel drill template for cervical pedicle instrumentation.
A CT scan of the cervical vertebrae was performed, and a 3D model of the vertebrae was reconstructed using MIMICS 10.01 software. The 3D vertebral model was then exported in STL format, and opened in a workstation running UGS Imageware 12.0 software to determine the optimal pedicle screw size and orientation. A virtual navigational template was established according to the laminar anatomic trait, and physical navigational templates were manufactured using rapid prototyping. The navigational templates were used intraoperatively to assist in the placement of cervical pedicle screws.
In all, 84 pedicle screws were placed, and the accuracy of screw placement was confirmed with postoperative X-rays and CT scans. Eighty-two screws were rated as Grade 0, 2 as Grade 1, and no screws as Grade 2 or 3. Hence, safer screw positioning was accomplished with the drill template technique.
This study demonstrates a patient-specific template technique that is easy to use, can simplify the surgical act, and generates highly accurate cervical pedicle screw placement. The advantages of this technology over traditional techniques are that it enables planning of the screw trajectory to be completed prior to surgery, and that the screw can be sized to fit the patient's anatomy.
STUDY DESIGN.: Prospective trial. OBJECTIVE.: To develop and validate a novel, patient-specific navigational template for cervical pedicle placement. SUMMARY OF BACKGROUND DATA.: Owing to the narrow bony anatomy and the proximity to the vertebral artery and the spinal cord, cervical instrumentation procedures demand the need for a precise technique for screw placement. PATIENT.: Specific drill template with preplanned trajectory has been thought as a promising solution for cervical pedicle screw placement. METHODS.: Patients with cervical spinal pathology (n = 25) requiring instrumentation were recruited. Volumetric CT scan was performed on each desired cervical vertebra and a 3-dimensional reconstruction model was generated from the scan data. Using reverse engineering technique, the optimal screw size and orientation were determined and a drill template was designed with a surface that is the inverse of the posterior vertebral surface. The drill template and its corresponding vertebra were manufactured using rapid prototyping technique and tested for violations. The navigational template was sterilized and used intraoperatively to assist with the placement of cervical screws. In total, 88 screws were inserted into levels C2-C7 with 2 to 6 screw in each patient. After surgery, the positions of the pedicle screws were evaluated using CT scan and graded for validation. RESULTS.: This method showed its ability to customize the placement and the size of each screw based on the unique morphology of the cervical vertebra. In all the cases, it was relatively very easy to manually place the drill template on the lamina of the vertebral body during the surgery. The required time between fixation of the template to the lamina and insertion of the pedicle screws was about 80 seconds. Of the 88 screws, 71 screws had no deviation and 14 screws had deviation <2 mm, 1 screw had a deviation between 2 to 4 mm and there were no misplacements. Fluoroscopy was used only once for every patient after the insertion of all the pedicle screws. CONCLUSION.: The authors have developed a novel patient-specific navigational template for cervical pedicle screw placement with good applicability and high accuracy. This method significantly reduces the operation time and radiation exposure for the members of the surgical team. The potential use of such a navigational template to insert cervical pedicle screws is promising. This technique has been clinically validated to provide an accurate trajectory for pedicle screw placement in the cervical spine.
The present method of C2 laminar screw placement relies on anatomical landmarks for screw placement. Placement of C2 laminar screws using drill template has not been described in the literature. The authors reported on their experience with placement of C2 laminar screws using a novel computer-assisted drill guide template in nine patients undergoing posterior occipito-cervical fusion. CT scan of C2 vertebrae was performed. 3D model of C2 vertebrae was reconstructed by software MIMICS 10.01. The 3D vertebral model was then exported in STL format, and opened in a workstation running software UG imageware12.0 for determining the optimal laminar screw size and orientation. A virtual navigational template was established according to the laminar anatomic trait. The physical vertebrae and navigational template were manufactured using rapid prototyping. The navigational template was sterilized and used intraoperative to assist the placement of laminar screw. Overall, 19 C2 laminar screws were placed and the accuracy of screw placement was confirmed with postoperative X-ray and CT scanning. There were not complications of related screws insertion. Average follow-up was 9 months (range 4-13 months), 77.8% of the patients exhibited improvement in their myelopathic symptoms; in 22.2% the symptoms were unchanged. Postoperative computed tomographic (CT) scanning was available for allowing the evaluation of placement of thirteen C2 laminar screws, all of which were in good position with no spinal canal violation. This study shows a patient-specific template technique that is easy to use, can simplify the surgical act and generates highly accurate C2 laminar screw placement. Advantages of this technology over traditional techniques include planning of the screw trajectory is done completely in the presurgical period as well as the ability to size the screw to the patient's anatomy.
Rates and causes of mortality associated with spine surgery based on 108,419 procedures: a review of the Scoliosis Research Society Morbidity and Mortality Database
- J S Smith
- D Saulle
- C J Chen
- L G Lenke
- D W Polly
- M K Kasliwal
Smith JS, Saulle D, Chen CJ, Lenke LG, Polly DW Jr, Kasliwal MK,
et al. Rates and causes of mortality associated with spine surgery based
on 108,419 procedures: a review of the Scoliosis Research Society
Morbidity and Mortality Database. Spine 2012;37:1975-82. https://
doi.org/10.1097/BRS.0b013e318257fada.