Application of three-dimensional printing for pre-operative planning in hip preservation surgery

Enhancing Hip Arthroplasty Outcomes: The Multifaceted Advantages, Limitations, and Future Directions of 3D Printing Technology

In the evolving field of orthopedic surgery, the integration of three-dimensional printing (3D printing) has emerged as a transformative technology, particularly in addressing the rising incidence of degenerative joint diseases. The integration of 3D printing technology in hip arthroplasty offers substantial advantages throughout the surgical process. In preoperative planning, 3D models enable meticulous assessments, aiding in accurate implant selection and precise surgical strategies. Intraoperatively, the technology contributes to precise prosthesis design, reducing operation duration, X-ray exposures, and blood loss. Beyond surgery, 3D printing revolutionizes medical equipment production, imaging, and implant design, showcasing benefits such as enhanced osseointegration and reduced stress shielding with titanium cups. Challenges include a higher risk of postoperative infection due to the porous surfaces of 3D-printed implants, technical complexities in the printing process, and the need for skilled manpower. Despite these challenges, the evolving nature of 3D printing technologies underscores the importance of relying on existing orthopedic surgical practices while emphasizing the need for standardized guidelines to fully harness its potential in improving patient care.

Improving Patient Understanding of Femoroacetabular Impingement Syndrome With Three-Dimensional Models

INTRODUCTION

Three-dimensional (3D) printed models may help patients understand complex anatomic pathologies such as femoroacetabular impingement syndrome (FAIS). We aimed to assess patient understanding and satisfaction when using 3D printed models compared with standard imaging modalities for discussion of FAIS diagnosis and surgical plan.

METHODS

A consecutive series of 76 new patients with FAIS (37 patients in the 3D model cohort and 39 in the control cohort) from a single surgeon's clinic were educated using imaging and representative 3D printed models of FAI or imaging without models (control). Patients received a voluntary post-visit questionnaire that evaluated their understanding of the diagnosis, surgical plan, and visit satisfaction.

RESULTS

Patients in the 3D model cohort reported a significantly higher mean understanding of FAIS (90.0 ± 11.5 versus 79.8 ± 14.9 out of 100; P = 0.001) and surgery (89.5 ± 11.6 versus 81.0 ± 14.5; P = 0.01) compared with the control cohort. Both groups reported high levels of satisfaction with the visit.

CONCLUSION

In this study, the use of 3D printed models in clinic visits with patients with FAIS improved patients' perceived understanding of diagnosis and surgical treatment.

Computer-Aided Design and 3D Printing of Hemipelvic Endoprosthesis for Personalized Limb-Salvage Reconstruction after Periacetabular Tumor Resection

3D-printed hemipelvic endoprosthesis is an emerging solution for personalized limb-salvage reconstruction after periacetabular tumor resection. Further clinical studies are still required to report its surgical characteristics, outcomes, benefits and drawbacks. Sixteen consecutive patients underwent periacetabular tumor wide resection and pelvic reconstruction with a 3D-printed hemipelvic endoprosthesis from 2018 to 2021. The surgical characteristics and outcomes are described. The mean follow-up duration was 17.75 months (range, 6 to 46 months). Five patients underwent surgery for type I + II resection and reconstruction, seven for type II + III resection and reconstruction, three for type II resection and reconstruction, and one for type I + II + IV resection and reconstruction. The incidence of postoperative complication was 12.5% (2/16) for deep venous thrombosis (DVT), 12.5% (2/16) for pneumonia, and 12.5% (2/16) for would deep or superficial infection. During follow-up, two patients (12.5%) suffered hip dislocation and underwent revision surgery. CT demonstrated an obvious prosthetic porous structure–bone fusion after follow-up of at least 6 months. At the final follow-up, 12 lived with no evidence of disease while four lived with disease; no patients experienced pain; and 15 had independent ambulation, with a mean Musculoskeletal Tumor Society (MSTS) score of 85.8% (range, 26.7% to 100%). 3D-printed hemipelvic endoprosthesis facilitates wide resection of periacetabular tumor and limb-salvage reconstruction, thus resulting in good oncological and functional outcomes. The custom-made nature is able to well mimic the skeletal anatomy and microstructure and promote osseointegration. Perioperative complications and rehabilitation exercise still need to be stressed for this engineering technology-assisted major orthopedic surgery.

Three-dimensional printing in paediatric orthopaedic surgery

Three-dimensional (3D) printing is a rapidly evolving and promising field to improve outcomes of orthopaedic surgery. The use of patient-specific 3D-printed models is specifically interesting in paediatric orthopaedic surgery, as limb deformity corrections often require an individual 3D treatment. In this editorial, various operative applications of 3D printing in paediatric orthopaedic surgery are discussed. The technical aspects and the imaging acquisition with computed tomography and magnetic resonance imaging are outlined. Next, there is a focus on the intraoperative applications of 3D printing during paediatric orthopaedic surgical procedures. An overview of various upper and lower limb deformities in paediatrics is given, in which 3D printing is already implemented, including post-traumatic forearm corrections and proximal femoral osteotomies. The use of patient-specific instrumentation (PSI) or guiding templates during the surgical procedure shows to be promising in reducing operation time, intraoperative haemorrhage and radiation exposure. Moreover, 3D-printed models for the use of PSI or patient-specific navigation templates are promising in improving the accuracy of complex limb deformity surgery in children. Lastly, the future of 3D printing in paediatric orthopaedics extends beyond the intraoperative applications; various other medical applications include 3D casting and prosthetic limb replacement. In conclusion, 3D printing opportunities are numerous, and the fast developments are exciting, but more evidence is required to prove its superiority over conventional paediatric orthopaedic surgery.

THREE-DIMENSIONAL PRINTING IN ORTHOPEDICS: WHERE WE STAND AND WHERE WE ARE HEADING

Three-dimensional printing is a technology in expansion in the medical field. It also presents many applications in orthopedics. Our review article aims to describe 3D printing, types of 3D printers, and its use in the orthopedic field. 3D models can be created using tomography scans. Those models can then be manipulated, even simulating surgeries. It is possible to print biomodels, which will help us understand deformities and plan surgeries. Orthopedic surgeons must be updated in these disruptive technologies that may help their daily practice. Level of Evidence V, Expert opinion.

DICOM 3D viewers, virtual reality or 3D printing - a pilot usability study for assessing the preference of orthopedic surgeons

As standard practice in orthopedic surgery, the information gathered by analyzing Computer Tomography (CT) 2D images is used for patient diagnosis and planning surgery. Lately, these virtual slices are the input for generating 3D virtual models using DICOM viewers, facilitating spatial orientation, and diagnosis. Virtual Reality (VR) and 3D printing (3DP) technologies are also reported for use in anatomy visualization, medical training, and diagnosis. However, it has not been yet investigated whether the surgeons consider that the advantages offered by 3DP and VR outweigh their development efforts. Moreover, no comparative evaluation for understanding surgeon's preference in using these investigation tools has been performed so far. Therefore, in this paper, a pilot usability test was conducted for collecting surgeons' opinions. 3D models of knee, hip and foot were displayed using DICOM 3D viewer, two VR environments and as 3D-printed replicas. These tools adequacy for diagnosis was comparatively assessed in three cases scenarios, the time for completing the diagnosis tasks was recorded and questionnaires filled in. The time for preparing the models for VR and 3DP, the resources needed and the associated costs were presented in order to provide surgeons with the whole context. Results showed a preference in using desktop DICOM viewer with 3D capabilities along with the information provided by Unity-based VR solution for visualizing the virtual model from various angles challenging to analyze on the computer screen. 3D-printed replicas were considered more useful for physically simulating the surgery than for diagnosis. For the VR and 3DP models, the lack of information on bone quality was considered an important drawback. The following order of using the tools was preferred: DICOM viewer, followed by Unity VR and 3DP.

Unusual apical femoral head deformity treated by hip arthroscopy and tunnel drilling through femoral head: a case report

Femoro-acetabular impingement (FAI), is the result of an abnormal morphology of the hip joint. On the femoral side, asphericity of the head can be highlighted by an alpha angle measurement >50° on computed tomography or MRI. However, some particular cephalic asphericities can make it difficult to measure the alpha angle, leading to a diagnostic pitfall. While in the classic cam effect, the deformity is peripheral and can be treated by arthroscopic femoroplasty, an apical head deformity remains a therapeutic challenge. We present the case of a 17-year-old male patient with a femoral head deformity, corresponding to an ISHA zone 6 overhang, significantly improved in everyday and sports life by arthroscopic trapdoor technique to resect the focal central deformity while enabling concomitant treatment of central compartment pathology, in this case, a hypertrophic ligamentum teres and femoral head chondral flap. Etiology of this femoral head deformity remains uncertain but could be a particular cam deformity, sequelae to pediatric disease or instability with repeated traction of the ligament teres on the femoral head apical insertion during cephalic growth.

The case of 'A Rhino Horn': case report and proposal for modification to the Hetsroni and Kelly classification

Subspine impingement syndrome by definition involves a prominent antero-inferior iliac spine (AIIS) which can lead to impingement on the femoral neck thereby causing symptoms. We present the case of a 22-year-old semi-professional athlete who presented with a Type III AIIS morphology leading to subspine impingement syndrome and was managed via a mini open anterior approach. Radiological examination revealed a fairly prominent left AIIS resembling the 'horn of a rhino' extending to the trochanteric region anteriorly. A mini-anterior surgical approach was utilized for the resection of the 'rhino horn' and the rectus femoris was reattached. The patient remained asymptomatic at the one-year follow-up and had resumed weightlifting. Following this case, we propose a new classification of the type III AIIS morphology in view of the clinical presentation. The AIIS type III-Standard represents an extension from the acetabular rim to less than 1 cm (type III-S) and type III-Large, with an extension from the acetabular rim beyond 1 cm (type III-L). The type III-L will further be divided into two groups based on its relation to the ilium, type III-Lr ('rib shape') and type III-Lrh ('rhino horn').

In-House, Fast FDM Prototyping of a Custom Cutting Guide for a Lower-Risk Pediatric Femoral Osteotomy

Three-dimensional printed custom cutting guides (CCGs) are becoming more and more investigated in medical literature, as a patient-specific approach is often desired and very much needed in today’s surgical practice. Three-dimensional printing applications and computer-aided surgical simulations (CASS) allow for meticulous preoperatory planning and substantial reductions of operating time and risk of human error. However, several limitations seem to slow the large-scale adoption of 3D printed CCGs. CAD designing and 3D printing skills are inevitably needed to develop workflow and address the study; therefore, hospitals are pushed to include third-party collaboration, from highly specialized medical centers to industrial engineering companies, thus increasing the time and cost of labor. The aim of this study was to move towards the feasibility of an in-house, low-cost CCG 3D printing methodology for pediatric orthopedic (PO) surgery. The prototype of a femoral cutting guide was developed for its application at the IOR—Rizzoli Orthopedic Institute of Bologna. The element was printed with an entry-level 3D printer with a high-temperature PLA fiber, whose thermomechanical properties can withstand common steam heat sterilization without bending or losing the original geometry. This methodology allowed for extensive preoperatory planning that would likewise reduce the overall surgery time, whilst reducing the risks related to the intervention.

Creation of a Three-Dimensional Printed Model for the Preoperative Planning of Hip Arthroscopy for Femoral Acetabular Impingement

We describe a technique that creates a 3-dimensional (3D) printed model from a patient's own computed tomography scan. This introduces an adjunct to conventional imaging for the surgical management of femoral acetabular impingement. The creation of a tactile 1:1 scale model with patient-specific anatomy allows for free manipulation and inspection. This is compared to planar imaging and 3D-reconstructed computer tomography scans, which are limited in their degrees of movement. With a minimal learning curve because of a highly iterative process, no prior experience in 3D printing is required to successfully complete this technique. The primary barrier of entry is the initial start-up cost of a 3D printer; however, the price per print is minimal. These models are valuable clinical tools that can be used in preoperative planning, patient education, and medical trainee learning.

3D-printed models for periacetabular osteotomy surgical planning

The purpose of this study was to determine the feasibility and clinical benefits of using 3D-printed hemipelvis models for periacetabular osteotomy preoperative planning in the treatment of hip dysplasia. This retrospective study included 28 consecutive cases in 26 patients, with two bilateral cases, who underwent periacetabular osteotomy between January 2017 and February 2020 and had routine radiographs, CT and MR imaging. Of these, 14 cases [mean patient age 30.7 (SD 8.4) years, 11 female] had routine preoperative imaging, and 14 cases [mean patient age 28.0 (SD 8.7) years, 13 female] had routine preoperative imaging and creation of a full-scale 3D-printed hemipelvis model from the CT data. The expected surgical cuts were performed on the 3D-printed models. All patients underwent Bernese periacetabular osteotomy. Operative times, including time to achieve proper acetabular position and total periacetabular osteotomy time, fluoroscopy radiation dose and estimated total blood loss were compiled. ANOVA compared outcome variables between the two patient groups, controlling for possible confounders. On average, patients who had additional preoperative planning using the 3D-printed model had a 5.5-min reduction in time to achieve proper acetabular position and a 14.5-min reduction in total periacetabular osteotomy time; however, these changes were not statistically significant (P = 0.526 and 0.151, respectively). No significant difference was identified in fluoroscopy radiation dose or total blood loss. Detailed surgical planning for periacetabular osteotomy using 3D-printed models is feasible using widely available and affordable technology and shows promise to improve surgical efficiency.

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

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

What can we learn from surveys? A systematic review of survey studies addressing femoroacetabular impingement syndrome

The purpose of this study was to systematically review the methodology, response rate and quality of survey studies related to femoroacetabular impingement (FAI) syndrome. A search was conducted on three databases (PubMed, EMBASE, MEDLINE) for relevant studies from database inception to 27 January 2020. Data extracted included study and survey characteristics, as well as response rates. The quality of the included studies was also assessed using a previously published quality assessment tool. Data were analysed with means, ranges, standard deviations, 95% confidence intervals and bivariate analysis. Eleven studies (13 surveys) were included in this review out of a total of 1608 initial titles found. Surveys were most often administered via the Internet (72%) to orthopaedic surgeons (54%). The mean response rate was 70.4%. The mean quality score was moderate 13.3/24 (SD ±4.3). The criterion that most often scored high was ‘clearly defined purpose and objectives’ (11/11). The most common survey topic investigated surgeons’ knowledge regarding FAI diagnosis and management (n = 7). In addition, bivariate analysis between quality score and response rate showed no significant correlation (Spearman’s rho = −0.090, P = 0.85). Overall, survey studies related to FAI syndrome most often use Internet-based methods to administer surveys. The most common target audience is orthopaedic surgeons. The topics of the surveys most often revolve around orthopaedic surgeons’ knowledge and opinions relating to the diagnosis and management of FAI syndrome. The response rate is high in patient surveys and lower in larger surgeon surveys. Overall, the studies are of moderate quality.

Are We Involving Patients in Shared Decision-Making in Young Adult Hip Surgery? A Systematic Review of Patient Engagement Initiatives in Hip Preservation

There are limited published studies on patient engagement, including shared decision-making, in adolescents and young adults with complex congenital or post-traumatic hip disorders. Despite the limited number of papers, we aim to clearly summarize what is currently available in the literature using a systematic review approach. We hope this serves as a call to action and catalyst for more work in this field. Future research must focus on awareness of what matters most to patients (values), and the development, implementation, and barriers to the use of decision aids and patient engagement optimization specific to hip disease in young adults.

Assessment of three-dimensional acetabular coverage angles

The purpose of this article is to report the inter- and intra-observer reliability of a computerized objective technique to quantify patient-specific acetabular morphology. We describe the use of and provide the software code for a technique to better define the location and magnitude of acetabular pathology. We have developed software code that allows the end user to obtain detailed measurements of the acetabulum using traditional computed tomography data. We provide the code and detailed instructions on how to use it in this article. The methodology was validated by having an unbiased observer (that was not involved in this project but has been trained in this software measurement methodology) to perform the entire acquisition, reconstruction and analysis procedure and compare their measurements to the measurements of one of the authors. The author then repeated the procedure 2 months later to determine intra-observer reliability. Inter- and intra-observer reliability for version, tilt, surface area and total acetabular coverage angles ranged from an intra-class correlation coefficient of 0.805 to 0.997. The method provided in this manuscript gives a reproducible objective assessment of three-dimensional (3D) acetabular morphology that can be used to assist in the diagnosis of hip pathology and to compare the morphological parameters of subjects with and without hip pathology. It allows a surgeon to understand the 3D shape of each individual’s acetabulum, share these findings with patients and their parents to demonstrate the magnitude and location of the clinical abnormality and perform patient-specific surgical corrections to optimize the shape and coverage of the hip.

Computer-Aided Surgical Simulation for Correcting Complex Limb Deformities in Children

This work aims to present an in-house low-cost computer-aided simulation (CASS) process that was recently implemented in the preoperative planning of complex osteotomies for limb deformities in children. Five patients admitted to the Unit of Paediatric Orthopaedics and Traumatology from April 2018 to December 2019, for correcting congenital or post-traumatic limb deformities were included in the study. Three-dimensional (3D) digital models were generated from Computed Tomography (CT) scans, using free open-source software, and the surgery was planned and simulated starting from the 3D digital model. 3D printed sterilizable models were fabricated using a low-cost 3D printer, and animations of the operation were generated with the aim to accurately explain the operation to parents. All procedures were successfully planned using our CASS method and the 3D printed models were used during the operation, improving the understanding of the severely abnormal bony anatomy. The surgery was precisely reproduced according to CASS and the deformities were successfully corrected in four cases, while in one case, the intraoperative intentional undersizing of the bone osteotomy produced an incomplete correction of a congenital forearm deformity. Our study describes the application of a safe, effective, user-friendly, and low-cost CASS process in paediatric orthopaedics (PO) surgery. We are convinced that our study will stimulate the widespread adoption of this technological innovation in routine clinical practice for the treatment of rare congenital and post-traumatic limb deformities during childhood.