Application of Rapid Prototyping Pelvic Model for Patients with DDH to Facilitate Arthroplasty Planning: A Pilot Study

Conformity of Three Pre-Contoured Clavicular Plates Compared Using Personalized 3D-Printed Models of Clavicles from Patients

The human clavicle's unique S-shaped, three-dimensional structure complicates fracture management. This study evaluated the anatomical conformity of pre-contoured anatomical plates using 3D-printed clavicle models. CT scans from 30 patients (15 males and 15 females) were used to create these models. Three brands of distal clavicle plate systems (Acumed, Synthes, and Arthrex) were tested for fit. Measurements included the distance from the distal end of the clavicle to the plate's lateral end, the gap between the clavicle and the plate, and the overhang distance. Results showed significant differences in clavicle length between sexes, with men having a mean length of 156.1 ± 7.6 mm and women 138.4 ± 4.3 mm, both with normal distribution (p > 0.05). The mean lateral distance was 7.9 ± 1.7 mm, and the mean medial gap was 3.6 ± 3.0 mm, showing no significant differences between products or sexes. The mean overhang distance was 5.8 ± 4.6 mm, with larger values in women for the Acumed (p = 0.037) and Arthrex (p = 0.000) plates. Overall, pre-contoured plates exhibited notable discrepancies, especially in shorter clavicles.

Intraoperative application of three-dimensional printed guides in total hip arthroplasty: A systematic review

BACKGROUND

Acetabular component positioning in total hip arthroplasty (THA) is of key importance to ensure satisfactory post-operative outcomes and to minimize the risk of complications. The majority of acetabular components are aligned freehand, without the use of navigation methods. Patient specific instruments (PSI) and three-dimensional (3D) printing of THA placement guides are increasingly used in primary THA to ensure optimal positioning.

AIM

To summarize the literature on 3D printing in THA and how they improve acetabular component alignment.

METHODS

PubMed was used to identify and access scientific studies reporting on different 3D printing methods used in THA. Eight studies with 236 hips in 228 patients were included. The studies could be divided into two main categories; 3D printed models and 3D printed guides.

RESULTS

3D printing in THA helped improve preoperative cup size planning and post-operative Harris hip scores between intervention and control groups (P = 0.019, P = 0.009). Otherwise, outcome measures were heterogeneous and thus difficult to compare. The overarching consensus between the studies is that the use of 3D guidance tools can assist in improving THA cup positioning and reduce the need for revision THA and the associated costs.

CONCLUSION

The implementation of 3D printing and PSI for primary THA can significantly improve the positioning accuracy of the acetabular cup component and reduce the number of complications caused by malpositioning.

Clinical Applications of "In-Hospital" 3D Printing in Hip Surgery: A Systematic Narrative Review

Introduction: Interest in 3D printing for orthopedic surgery has been increasing since its progressive adoption in most of the hospitals around the world. The aim of the study is to describe all the current applications of 3D printing in patients undergoing hip surgery of any type at the present time. Materials and Methods: We conducted a systematic narrative review of publications indexed in MedLine through the search engine PubMed, with the following parameters: 3D printing AND (orthopedics OR traumatology) NOT tissue engineering NOT scaffold NOT in vitro and deadline 31 July 2023. After reading the abstracts of the articles, papers were selected according to the following criteria: full text in English or Spanish and content related to hip surgery. Those publications involving experimental studies (in vitro or with anatomical specimens) or 3D printing outside of hospital facilities as well as 3D-printed commercial implants were excluded. Results are presented as a reference guide classified by disease, including the used software and the steps required for the development of the idea. Results: We found a total of 27 indications for in-house 3D printing for hip surgery, which are described in the article. Conclusions: There are many surgical applications of 3D printing in hip surgery, most of them based on CT images. Most of the publications lack evidence, and further randomized studies should be encouraged to assess the advantages of these indications.

Using Three-Dimensional Printing Technology to Solve Complex Primary Total Hip Arthroplasty Cases: Do We Really Need Custom-Made Guides and Templates? A Critical Systematic Review on the Available Evidence

The burden of osteoarthritis (OA) is around 300 million people affected worldwide, with the hip representing a commonly affected joint. Total hip arthroplasty (THA) has been used with notable success as a definitive treatment to improve pain and function in hip OA patients. The recent advent of new technologies, such as 3D printing, has pushed the application of these new concepts toward applications for the well-known THA. Currently, the evidence on the use of 3D printing to aid complex primary THA cases is still scarce.

METHODS

An extensive literature review was conducted to retrieve all articles centered on the use of 3D printing in the setting of primary THA.

RESULTS

A total of seven studies were included in the present systematic review. Four studies investigated the use of 3D-printed surgical guides to be used during surgery. The remaining three studies investigated the benefit of the use of 3D-printed templates of the pelvis to simulate the surgery.

CONCLUSIONS

The use of 3D printing could be a promising aid to solve difficult primary total hip arthroplasty cases. However, the general enthusiasm in the field is not supported by high-quality studies, hence preventing us from currently recommending its application in everyday practice.

Artificial intelligence planning and 3D printing augmented modules in the treatment of a complicated hip joint revision: a case report

Total hip revision with osseous defects can be very difficult. Artificial intelligence offers preoperative planning, real-time measurement, and intraoperative judgment, which can guide prothesis placement more accurately. Three-dimensional printed metel augment modules which are made according to the individualized osseous anatomy, can fit the osseous defects well and provide mechanical support. In this case, we used AI to plan the size and position of the acetabular cup and 3D-printed augmented modules in a complicated hip revision with an acetabular bone defects, which achieved stable fixation and relieved hip pain postoperatively.

3D Printing Technology for Smart Clothing: A Topic Review

Clothing is considered to be an important element of human social activities. With the increasing maturity of 3D printing technology, functional 3D printing technology can realize the perfect combination of clothing and electronic devices while helping smart clothing to achieve specific functions. Furthermore, the application of functional 3D printing technology in clothing not only provides people with the most comfortable and convenient wearing experience, but also completely subverts consumers' perception of traditional clothing. This paper introduced the progress of the application of 3D printing from the aspect of traditional clothing and smart clothing through two mature 3D printing technologies normally used in the field of clothing, and summarized the challenges and prospects of 3D printing technology in the field of smart clothing. Finally, according to the analysis of the gap between 3D-printed clothing and traditionally made clothing due to the material limitations, this paper predicted that the rise in intelligent materials will provide a new prospect for the development of 3D-printed clothing. This paper will provide some references for the application research of 3D printing in the field of smart clothing.

Early Emergent and Progressive Aberrant Subchondral Bone Remodeling Coupled with Aggravated Cartilage Degeneration in Developmental Dysplasia of the Hip

OBJECTIVE

Developmental dysplasia of the hip (DDH) is the most common skeletal development in children and could result in secondary osteoarthritis. This study aims to clarify the alternations of subchondral trabecular bone remodeling and microstructural properties during the development of DDH, and the potential influence of these alternations on the overlying cartilage degeneration and DDH progression.

DESIGN

Traditional straight-leg swaddling method was adopted to establish DDH model in newborn Sprague Dawley rats. Hip joint specimens from normal or DDH rats were used. Typical features of DDH in radiological examination were observed by x-ray analysis. Micro-computed tomography analysis was applied to evaluate the microstructural properties of subchondral bone at postnatal weeks 2, 4, and 6. Histological and immunohistochemical analyses were adopted to appraise subchondral bone remodeling activity and cartilage degeneration. The associations among subchondral bone, articular cartilage, and DDH severity were analyzed via multiple linear regression analysis.

RESULTS

Compared with control group, the subchondral bone in DDH group displayed a gradual trend of deteriorated microstructure and worsening biomechanical properties along with aberrant bone remodeling, which might be responsible for the inhibition of stress transmission from the articular cartilage to the subchondral bone and thus leading to the cartilage degeneration and accelerated DDH progression.

CONCLUSIONS

Our findings indicate that alternations of subchondral trabecular bone in a time-dependent manner could contribute to the DDH progression and the amelioration on subchondral bone might be a favorable therapeutic candidate for DDH.

Restoring Rotation Center in Total Hip Arthroplasty for Developmental Dysplasia of the Hip with the Assistance of Three Dimensional Printing Technology: A Pilot Study

Objective

To develop a new method to restore hip rotation center exactly and rapidly in total hip arthroplasty (THA) with the assistance of three dimensional (3D) printing technology and evaluate its clinical and radiological outcomes.

Methods

From March 2014 to July 2018, a total of 17 patients (five hips of four men and 16 hips of 13 women) with end‐stage osteoarthritis secondary to developmental dysplasia of the hip who underwent THA were analyzed and followed up retrospectively. The average age is 58.00 ± 8.12 years (range from 45 to 71 years). Simulated operations were performed on 3D printed hip models for preoperative planning. The morphology of Harris fossa and acetabular notches were recognized and restored to locate the acetabular center. The size of bone defect was measured by the bone wax method. The agreement on the size of acetabular cup and bone defect between simulated operations and actual operations were analyzed. Harris Hip Score (HHS) was used to evaluate the recovery of hip joint function. The vertical distance and horizontal distance of the rotation center on the pelvis plain radiograph were measured, which were used to assess the efficacy of restoring hip rotation center and acetabular cup migration.

Results

The mean sizes of bone defect in simulated operations and THA were 4.58 ± 2.47 cm² and 4.55 ± 2.57 cm² respectively. There was no significant difference statistically between the sizes of bone defect in simulated operations and the actual sizes of bone defect in THA (t = 0.03, P = 0.97). The sizes of the acetabular cup of simulated operations on 3D print models showed a high rate of coincidence with the actual sizes in the operations (ICC = 0.93). All 17 patients were available for clinical and radiological follow‐up. The average follow‐up time was 18.35 ± 6.86 months (range, 12–36 months. The average HHS of the patients was improved from (38.33 ± 6.07) preoperatively to the last follow‐up (88.61 ± 3.44) postoperatively. The mean vertical and horizontal distances of hip rotation center on the pelvic radiographs were restored to 15.12 ± 1.25 mm and 32.49 ± 2.83 mm respectively. No case presented dislocation or radiological signs of loosening until last follow‐up.

Conclusions

The application of 3D printing technology facilitates orthopedists to recognize the morphology of Harris fossa and acetabular notches, locate the acetabular center and restore the hip rotation center rapidly and accurately.

Patient-specific total hip arthroplasty is superior to conventional methods for Crowe III and IV adult developmental hip dysplasia: a randomized controlled trial

Background

Restoration of the acetabulum during total hip arthroplasty in adults with developmental dysplasia of the hip (DDH-THA) and resumption of hip function remain major challenges. Herein, a new patient-specific instrument (PSI) was developed that uses the superolateral rim of the acetabulum as a positioning marker to assist surgeons in adult DDH-THA.

Methods

From January 2017 to October 2018, 104 adult DDH patients were randomized to either the PSI group or conventional operation (CO) group, and further divided into eight subgroups by stratified random sampling using Crowe's classification. Complications, Harris hip scores (HHS), and X-ray results were recorded at 3 and 12 months after surgery.

Results

With the exception of anteversion in CO-Crowe II group patients, there was no difference in the accuracy of cup placement and orientation between the PSI and CO groups in Crowe I and II DDH patients. With the exception of percentage of acetabular cup coverage (PACC) and the qualification rate of Crowe IV PACC patients, among all Crowe III and IV DDH groups, all postoperative indexes of cup orientation and positioning exhibited significant differences between the PSI and CO groups; however, no significant differences were observed in Crowe I and II DDH patients.

Conclusions

Compared with conventional methods, the new PSI-assisted surgical method improved the accuracy of placement and orientation of the acetabulum and cup prosthesis, optimized the surgical process, reduced complications, and contributed to quicker recovery of hip function after surgery in adults with Crowe III and IV DDH-THA, but little difference was noted for those with Crowe I and II DDH.

Clinical evaluation of rapid 3D print-formed implants for surgical reconstruction of large cranial defects

BACKGROUND

To clinically evaluate 3D print-formed implant process, using cranioplasty as a proof of concept, to examine its effectiveness and utility as a method of intraoperative implant fabrication.

METHODS

Twelve patients had a 3D print-formed template created for patient-specific implant manufacture. Of these patients, 10 received intraoperatively formed polymethylmethacrylate cranioplasty implants between 2013 and 2019. The 3D print-formed implant templates produced to manufacture these patient-specific implants were generated using patient computed tomography scans and 3D printed using fused deposition modelling technology. Cosmetic and functional results were determined by participating surgeons, in conjunction with a patient questionnaire.

RESULTS

The functional results and stability of the implants were deemed to be favourable by participating surgeons. Three of the 10 patients completed a post-cranioplasty survey, all of whom judged their cosmetic results as good or excellent. At time of writing, the rate of surgical revision was zero and without clinically adverse outcomes.

CONCLUSIONS

3D print-formed implants are an effective method of patient-specific implant formation.

A Comparative Study of Patients' Subjective Feelings Toward Total Hip Arthroplasty with Patient-Specific Instruments and Traditional Total Hip Arthroplasty

OBJECTIVE

To determine whether differences exist in patients' subjective feelings, daily life, and surgical satisfaction between those who underwent surgery for developmental dysplasia of the hip (DDH) using patient-specific instruments (PSIs) and those who underwent traditional surgical total hip arthroplasty (THA).

METHODS

We selected 30 adult patients with various types of DDH who underwent surgery during 2016-2017 at our hospital. The patients were divided into PSI surgery group and the traditional surgery group. All patients underwent follow-up, and we collected data on the Harris Hip Score, Oxford University Hip Score (OHS), Forgotten Joint Score (FJS-12), Visual Analogue Scale (VAS) score, patient satisfaction score, intraoperative surgical time, amount of bleeding and postoperative complications incidence for both groups. We then performed statistical analyses on the data.

RESULTS

The Harris Hip Score, OHS, VAS score, patient satisfaction score, and mean bleeding volume did not differ statistically significantly (t-tests, P > 0.05). No statistically significant differences were found between surgical groups in the incidence of complication and sub-trochanteric osteotomy, or in the surgical side (chi-square tests, P > 0.05). For the experimental group, the FJS-12 score was 80.0 ± 12.0, and for the control group the score was 68.5 ± 16.1. The operative time of the experimental group was 138.4 ± 32.2 min, while that of the control group was 88.9 ± 26.8 min. The values of these data differed significantly (t-tests, P < 0.05).

CONCLUSIONS

The novel PSI designed by our group has certain advantages for the short-term subjective feelings of patients after THA, but it may cause prolonged operative times.

Three-dimensional-printing Technology in Hip and Pelvic Surgery: Current Landscape

The use of three-dimensional (3D) printing is becoming more common, including in the field of orthopaedic surgery. There are currently four primary clinical applications for 3D-printing in hip and pelvic surgeries: (i) 3D-printed anatomical models for planning and surgery simulation, (ii) patient-specific instruments (PSI), (iii) generation of prostheses with 3D-additive manufacturing, and (iv) custom 3D-printed prostheses. Simulation surgery using a 3D-printed bone model allows surgeons to develop better surgical approaches, test the feasibility of procedures and determine optimal location and size for a prosthesis. PSI will help inform accurate bone cuts and prosthesis placement during surgery. Using 3D-additive manufacturing, especially with a trabecular pattern, is possible to produce a prosthesis mechanically stable and biocompatible prosthesis capable of promoting osseointergration. Custom implants are useful in patients with massive acetabular bone loss or periacetabular malignant bone tumors as they may improve the fit between implants and patient-specific anatomy. 3D-printing technology can improve surgical efficiency, shorten operation times and reduce exposure to radiation. This technology also offers new potential for treating complex hip joint diseases. Orthopaedic surgeons should develop guidelines to outline the most effective uses of 3D-printing technology to maximize patient benefits.

3D-printed pelvis model is an efficient method of osteotomy simulation for the treatment of developmental dysplasia of the hip

Developmental dysplasia of the hip (DDH) is a congenital or developmental deformation of the hip joint, which may require a high number of surgical interventions. It has been indicated that 3D printing may be used to simulate a fractured pelvis to facilitate the fixation of plates during the surgical procedure. In the present double-blinded randomized clinical trial, the utility of the 3D-printed pelvis model, comprising 3D reconstruction, reverse engineering and rapid prototyping, in the treatment of DDH was evaluated with 3D CT as control. The value of the 3D-printed pelvis model in the surgical management and development of a strategy for an individualized operation for DDH using osteotomy simulation was also assessed. The results indicated that use of the 3D-printed pelvis model increased the success rate of the operation with a shortened surgery time and post-operative recovery time for DDH patients. In addition, the application of the 3D-printed pelvis model allowed for more efficient surgical management of DDH than 3D CT and promoted post-operative recovery of the DDH patients. Pre-operative planning using the 3D-printed pelvis model was feasible for DDH patients. Furthermore, few patients exhibited delayed incision healing, wound infection or nonunion in the DDH group with osteotomy simulation using the 3D-printed pelvis model or 3D-CT. In conclusion, the present study indicated that the 3D-printed pelvis model, including 3D reconstruction, reverse engineering and rapid prototyping, constitutes an efficient tool for pelvic osteotomy simulation, which improves personalized pre-operative planning by providing a visual and accurate osteotomy model for patients with DDH (Chinese Trial Registry No. KCT0012374).

Different subchondral trabecular bone microstructure and biomechanical properties between developmental dysplasia of the hip and primary osteoarthritis

Objective

Developmental dysplasia of the hip (DDH) is recognized as a frequent cause of secondary osteoarthritis (OA). The purpose in this study was to compare structural and biomechanical properties of subchondral trabecular bone ​and its relationship with cartilage damage between patients with DDH and patients with primary hip OA.

Methods

Forty-three femoral head specimens obtained from patients who underwent total hip arthroplasty [DDH, n ​= ​17; primary OA, n ​= ​16; and normal control (NC), n ​= ​10] were scanned by microcomputed tomography and analyzed by individual trabecula segmentation to obtain the microstructural types of subchondral trabecular bone. The biomechanical properties were analyzed by micro-finite element analysis, and cartilage damage was evaluated by histology. The linear regression analysis was used to indicate the association between microstructures, biomechanical property, and articular cartilage.

Results

The DDH group showed the lowest total bone volume fractions (BV/TV) and plate BV/TV in the three groups (p ​< ​0.05). There were also different discrepancies between the three groups in plate/rod trabecular number, plate/rod trabecular thickness, trabecular plate surface area/trabecular rod length, and junction density with different modes (plate-plate, rod-rod, and plate-rod junction density). The micro-finite element analysis, histology, and linear regression revealed that the subchondral trabecular bone in the DDH group had inferior biomechanical properties ​and cartilage damage of patients with DDH was more serious with different subchondral trabecular bone microstructures.

Conclusion

Our findings detected deteriorating subchondral trabecular bone microstructures in patients with DDH. The mass and type of subchondral trabecular bone play a key role in mechanical properties in DDH, which might be related to cartilage damage.

The translational potential of this article

Our findings suggested that changes of subchondral trabecular bone play a critical role ​in DDH progression and that the improvement on subchondral trabecular bone may be a sensitive and promising way in treatment of DDH.

Clinical Applications of 3-Dimensional Printing Technology in Hip Joint

Three‐dimensional (3D) printing is a digital rapid prototyping technology based on a discrete and heap‐forming principle. We identified 53 articles from PubMed by searching “Hip” and “Printing, Three‐Dimensional”; 52 of the articles were published from 2015 onwards and were, therefore, initially considered and discussed. Clinical application of the 3D printing technique in the hip joint mainly includes three aspects: a 3D‐printed bony 1:1 scale model, a custom prosthesis, and patient‐specific instruments (PSI). Compared with 2‐dimensional image, the shape of bone can be obtained more directly from a 1:1 scale model, which may be beneficial for preoperative evaluation and surgical planning. Custom prostheses can be devised on the basis of radiological images, to not only eliminate the fissure between the prosthesis and the patient's bone but also potentially resulting in the 3D‐printed prosthesis functioning better. As an alternative support to intraoperative computer navigation, PSI can anchor to a specially appointed position on the patient's bone to make accurate bone cuts during surgery following a precise design preoperatively. The 3D printing technique could improve the surgeon's efficiency in the operating room, shorten operative times, and reduce exposure to radiation. Well known for its customization, 3D printing technology presents new potential for treating complex hip joint disease.

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

Three-dimensional printing is a valuable modality with broad clinical applications. Hip preservation surgery outcomes are dependent on correction of morphological abnormalities that may be optimally visualized with three-dimensional models. To assess the efficacy of three-dimensional models for patient and trainee education and to determine its benefits during pre-operative planning in hip preservation surgery. Sixteen patients with hip pathology were selected. Computed tomography was utilized to generate three-dimensional models. Customized Likert-style questionnaires were given to 10 hip preservation surgeons, 11 orthopedic surgery residents and 10 patients. All residents strongly agreed or agreed that the three-dimensional hip models helped them to understand patients’ pathology. All but one patient agreed that the models assisted in their understanding of the treatment plan. Surgeons concurred that although they do not routinely order three-dimensional models, their use would improve trainee and patient education, especially when treating atypical osseous pathomorphologies. Three-dimensional models are tools that can help surgeon, trainee and patient understanding and participation in treatment of complex hip disorders. Patients and trainees agree that the prototypes enhanced their educational experience, as the surgeon can directly demonstrate complex morphological abnormalities. Trainees can therefore gain a better understanding of hip pathologies and treatment. As patients better understand their hip disorder, they can more fully participate in shared treatment decision-making.

Level of Evidence

Level IV, Retrospective Case Series

Accuracy and practicability of a patient-specific guide using acetabular superolateral rim during THA in Crowe II/III DDH patients: a retrospective study

Background

It is challenging to create an ideal artificial acetabulum during total hip arthroplasty (THA) in adult DDH. Our team developed a new patient-specific instrument (PSI) that uses the superolateral rim of the acetabulum as a positioning mark to assist in the production of an artificial acetabulum in adult Crowe II/III DDH patients. The purpose of this retrospective study is to verify whether this new PSI can be used to implement the preoperative plan accurately and quickly to create an ideal artificial acetabulum during THA in adult Crowe II/III DDH patients.

Methods

We selected suitable adult Crowe II/III DDH patients from the registration system for artificial joint surgery at our hospital during April 2016 to March 2018 who underwent THA assisted by a PSI using the superolateral rim of the acetabulum as a positioning mark. We retrospectively analyzed data, including preoperative and postoperative anteversion, inclination, postoperative bilateral rotator center discrepancy (BRCD), surgery time, and the incidence of neurovascular injury. All patients underwent follow-up, and their Harris hip score (HHS) and X-ray data were recorded. Then, we performed statistical analyses on the data described above.

Results

A total of 20 hip surgeries from 17 patients were included in our study. All patients underwent a successful operation assisted by the PSI. The mean anteversion of the cup in our preoperative plan was 15.1° (range, 10.0° to 20.0°), while the mean postoperative anteversion of the cup was 15.3° (range, 7.0° to 28.6°). The mean inclination of the cup in our preoperative plan was 44.7° (range, 40.0° to 50.0°), while the mean postoperative inclination of the cup was 45.6° (range, 35.0° to 57.6°). Paired-samples t test revealed no significant differences in anteversion and inclination between pre- and postoperation times (P > 0.05). The mean BRCD was 3.38 ± 3.0 mm (range, 0.5 to 11.0 mm). The average operation time was 105.1 ± 15.4 min, and no patients had neurovascular injury complications. All patients’ acetabular components appeared clinically and radiologically stable after surgery. The mean HHS values were significantly improved at 12 weeks (P < 0.05) and 24 weeks (P < 0.05) postoperatively compared to the preoperative mean scores.

Conclusions

The new PSI is accurate and practical to create an ideal artificial acetabulum during THA in adult Crowe II/III DDH patients.

Electronic supplementary material

The online version of this article (10.1186/s13018-018-1029-1) contains supplementary material, which is available to authorized users.

Radiological Society of North America (RSNA) 3D printing Special Interest Group (SIG): guidelines for medical 3D printing and appropriateness for clinical scenarios

Medical three-dimensional (3D) printing has expanded dramatically over the past three decades with growth in both facility adoption and the variety of medical applications. Consideration for each step required to create accurate 3D printed models from medical imaging data impacts patient care and management. In this paper, a writing group representing the Radiological Society of North America Special Interest Group on 3D Printing (SIG) provides recommendations that have been vetted and voted on by the SIG active membership. This body of work includes appropriate clinical use of anatomic models 3D printed for diagnostic use in the care of patients with specific medical conditions. The recommendations provide guidance for approaches and tools in medical 3D printing, from image acquisition, segmentation of the desired anatomy intended for 3D printing, creation of a 3D-printable model, and post-processing of 3D printed anatomic models for patient care.

Publication trends and knowledge mapping in 3D printing in orthopaedics

PURPOSE

Three dimensional (3D) printing, also called 'rapid prototyping' and 'additive manufacturing' is considered as a "second industrial revolution." With this rapidly emerging technology, CT or MR images are used for the creation of graspable objects from 3D reconstituted images. Patient-specific anatomical models can be, therefore, manufactured efficiently. These can enhance surgeon's understanding of their patients' patho-anatomy and also help in precise preoperative planning. The 3D printed patient-specific guides can also help in achieving accurate bony cuts, precise implant placement, and nice surgical results. Customized implants, casts, orthoses and prosthetics can be created to match an individual patient's anatomy. The 3D printing of individualized artificial cartilage scaffolds and 3D bioprinting are some other areas of growing interest. We aim to study the publication trends in 3D printing as applied to the field of orthopaedics.

MATERIALS AND METHODS

A literature search was performed to extract all papers related to 3D printing applications in orthopaedics and allied sciences on the Pubmed, Web of Science and SCOPUS databases. Suitable keywords and boolean operators ("3D Printing" OR "3-dimensional printing" OR "3D printed" OR "additive manufacturing" OR "rapid prototyping") AND (''Orthopaedics" OR "Orthopaedics'') were used, in May 2018. Search was attempted in Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Database of Abstracts of Review of Effectiveness (DARE) databases, using keywords 3d printing orthopaedics. A similar search was repeated in pubmed and SCOPUS to get more specific papers.No limits were set on the period or evidence level, as 3D printing in orthopaedics is relatively new and evidence available is usually limited to low-level studies. Trends in a publication on these topics were analyzed, focussing on publications, type of research (basic science or clinical), type of publication, authors, institution, and country. Some citations received by these papers were also analyzed in SCOPUS and Web of Science. MS Excel (2008 - Mac version) and VOS Viewer1.6.8 (2018- Mac version) software were used to analyze the search results and for citation mapping respectively. We also identified top 10 most cited articles in the field.

RESULTS

An increasing trend in publications in 3D printing-related work in orthopedic surgery and related fields was observed in the recent past. A search on Pubmed using the above strategy revealed 389 documents. A similar search revealed 653 documents on SCOPUS, many (314) of which were from an engineering background and only 271 were related to medicine. No papers were found in the Cochrane database. Search on TRIP database revealed 195 papers. A similar search revealed 237 papers on orthopedic applications on Pubmed and 269 documents on SCOPUS, whereas a search on Web of Science revealed only 23 papers. Publication trends were then analyzed on data derived from SCOPUS database. Overall, most papers were published from China, followed by United States, United Kingdom, and India.

CONCLUSION

There has been an upsurge of interest in 3D printing in orthopedic surgery, as is evident by an increasing trend in research and publications in this area in the recent years. Presently, 3D printing is in a primitive stage in the field of orthopedic surgery as our knowledge is still insufficient, and costs and learning curve are somewhat high. However, looking at latest publication trends, we are enthusiastic that it holds the key to future in orthopaedics and trauma cases.

Computed Tomographic Evaluation of Bone Stock in Patients With Crowe Type III Developmental Dysplasia of the Hip: Implications for Guiding Acetabular Component Placement Using the High Hip Center Technique

BACKGROUND

We evaluated acetabular cup coverage (CC) and rim contact (RC) to evaluate the bone stock above the acetabulum for guiding acetabular component placement using the high hip center technique in patients with Crowe type III developmental dysplasia of the hip.

METHODS

Using hip computed tomography and image processing software, pelvises were reconstructed digitally in 20 hips with Crowe type III developmental dysplasia of the hip. Mimicked cup was placed with anteversion angles of 0° (group I), 5° (group II), and 10° (group III) respectively. In each group, the cup was placed at the anatomical hip center at first, and then the cup was moved up to 40 mm vertically about the native rotation center with an increment of 2.5 mm at each step. CC and RC were calculated and documented with each movement.

RESULTS

CC was 65.87%, 67.77%, and 68.98% for group I, group II, and group III at the native rotation center, and increased progressively to 86.45%, 85.85%, and 84.71% at 25 mm above. RC was 49.17%, 50.25%, and 51.92% for group I, group II, and group III at the native rotation center, and increased progressively to 86.87%, 86.39%, and 84.94% at 22.5 mm above. CC and RC were positively correlated, despite the different anteversion angles (r = 0.687 at 0°, 0.683 at 5°, and 0.645 at 10°; P < .001).

CONCLUSION

Computed tomography analysis and computer stimulation demonstrate that it is feasible to use high hip center technique in Crowe type III hips.

Morphological Analysis of True Acetabulum in Hip Dysplasia (Crowe Classes I-IV) Via 3-D Implantation Simulation

BACKGROUND

The purpose of this study was to investigate the 3-dimensional (3D) morphological features of the true acetabulum in patients with developmental dysplasia of the hip (DDH).

METHODS

Seventy-nine hips-53 in patients with developmental dysplasia of the hip (DDH) and 36 normal hips-were included in the present study. According to the Crowe classification, 26 hips were graded as Class I, 31 were Class II or III, and 22 were Class IV. The anterior pelvic plane was defined to standardize the measurements in the study. A selected virtual cup component was implanted into the true acetabulum of a 3D pelvic model of each hip. The acetabular anteversion angle, effective center-edge (CE) angle, effective Sharp angle, and thickness of the medial wall were measured to provide morphological indices of the true acetabulum. Acetabular sector angles and the component coverage ratio were measured to provide coverage indices.

RESULTS

The acetabular anteversion angle increased with the severity of the DDH. Crowe-II/III hips had the smallest effective CE angle and the largest effective Sharp angle. The mean medial wall thickness was greatest in the Crowe-II/III hips (8.72 mm; 95% confidence interval [CI] = 7.52 to 9.92 mm), intermediate in the Crowe-I hips (7.17 mm; 95% CI = 6.24 to 8.11 mm), and smallest in the Crowe-IV hips (6.05 mm; 95% CI = 4.78 to 7.32 mm). The integrated coverage ratio of the Crowe-II/III hips was significantly less than that of the Crowe-I and IV hips.

CONCLUSIONS

The morphological features of the true acetabulum in patients with DDH can be evaluated comprehensively by using 3D implantation simulation. Segmental bone deficiency was prevalent in the dysplastic hips, especially those in the Crowe-II/III group. Both the severity and the individual morphology of the acetabular dysplasia should be carefully considered in preoperative planning.

The use of three-dimensional printing technology in orthopaedic surgery

Three-dimensional (3-D) printing or additive manufacturing, an advanced technology that 3-D physical models are created, has been wildly applied in medical industries, including cardiothoracic surgery, cranio-maxillo-facial surgery and orthopaedic surgery. The physical models made by 3-D printing technology give surgeons a realistic impression of complex structures, allowing surgical planning and simulation before operations. In orthopaedic surgery, this technique is mainly applied in surgical planning especially revision and reconstructive surgeries, making patient-specific instruments or implants, and bone tissue engineering. This article reviews this technology and its application in orthopaedic surgery.

3D-printing techniques in a medical setting: a systematic literature review

BACKGROUND

Three-dimensional (3D) printing has numerous applications and has gained much interest in the medical world. The constantly improving quality of 3D-printing applications has contributed to their increased use on patients. This paper summarizes the literature on surgical 3D-printing applications used on patients, with a focus on reported clinical and economic outcomes.

METHODS

Three major literature databases were screened for case series (more than three cases described in the same study) and trials of surgical applications of 3D printing in humans.

RESULTS

227 surgical papers were analyzed and summarized using an evidence table. The papers described the use of 3D printing for surgical guides, anatomical models, and custom implants. 3D printing is used in multiple surgical domains, such as orthopedics, maxillofacial surgery, cranial surgery, and spinal surgery. In general, the advantages of 3D-printed parts are said to include reduced surgical time, improved medical outcome, and decreased radiation exposure. The costs of printing and additional scans generally increase the overall cost of the procedure.

CONCLUSION

3D printing is well integrated in surgical practice and research. Applications vary from anatomical models mainly intended for surgical planning to surgical guides and implants. Our research suggests that there are several advantages to 3D-printed applications, but that further research is needed to determine whether the increased intervention costs can be balanced with the observable advantages of this new technology. There is a need for a formal cost-effectiveness analysis.

Three-dimensional printing for preoperative planning of total hip arthroplasty revision: case report

Three dimensional (3D) printing can be used to create material models to aid preoperative planning of complex orthopedic procedures as exemplified by this case of total hip arthroplasty failure due to infection with resulting severe acetabular bone stock deficiency. The 3D model allowed for trialing of the acetabular component to determine cup size, position, and screw placement. Most importantly, the model confirmed that there was not a pelvic discontinuity and the revision shell would be sufficient for the reconstruction. Previously, the cost and complexity of utilization of 3D printers were prohibitive. Recent improvements in commercially available 3D printers have made rapid prototype model creation a realistic option, which can facilitate difficult surgery.

Comparison of Clinical Efficacy Between Modular Cementless Stem Prostheses and Coated Cementless Long-Stem Prostheses on Bone Defect in Hip Revision Arthroplasty

Background

The aim of this study was to investigate and compare the clinical efficacy of modular cementless stem and coated cementless long-stem prostheses in hip revision arthroplasty.

Material/Methods

Sixty-five patients with complete hip revision surgery data during January 2005 to March 2015 were selected from the People’s Hospital of Linyi City and randomly divided into a S-ROM group (implanted with cementless modular stem prostheses, n=32) and a SLR-PLUS group (implanted with cementless coated long-stem prostheses, n=33). Harris score was used to evaluate the hip function of the patients in order to measure the clinical efficacy of the prostheses in total hip arthroplasty. Anteroposterior pelvic radiographs and lateral pelvic radiographs were taken and each patient’s hip arthroplasty condition was recorded. Kaplan-Meier method was applied to compare the cumulative 5-year non-revision rate between the 2 prostheses and log-rank method was used to inspect the statistical data.

Results

The Harris scores of both the S-ROM group and the SLR-PLUS group were significantly higher at 12 months after the operation than those before the operation (both P<0.05). The Harris scores of the patients with type I/II bone defects in the S-ROM group were not significantly different from those of the same types in the SLR-PLUS group at all time points (all P>0.05), while the Harris scores of the patients with type IIIA/IIIB in the S-ROM group were both significantly higher than those of the same types in the SLR-PLUS group at 3 months, 6 months, and 12 months after the operation (all P<0.05). No significant difference was found in the cumulative 5-year non-revision rate between the type I/II patients in the S-ROM group (92.31%) and the patients of the same types in the SLR-PLUS group (85.71%) (P>0.05). However, the cumulative 5-year non-revision rate of the type IIIA/IIIB patients in the S-ROM group (89.47%) was significantly different from the patients of the same types in the SLR-PLUS group (42.11%) (P<0.05).

Conclusions

The modular stem prostheses in hip revision arthroplasty were clinically more effective in the treatment of type IIIA and IIIB bone defects than the coated long-stem prostheses according to the Harris score and the cumulative 5-year non-revision rate.