Three-Dimensional Printing in Hand Surgery

A 3-Dimensional Printed Dynamic External Fixator for the Treatment of Proximal Interphalangeal Fracture-Dislocations: A Biomechanical Study

PURPOSE

This study evaluated the efficacy of a 3-dimensional printed dynamic external fixator for treating proximal interphalangeal (PIP) fracture-dislocations. The null hypothesis was that there would be no difference in maintaining PIP joint reduction between a 3-dimensional printed dynamic external fixator (3DPDEF) and the pins and rubbers traction system (PRTS).

METHODS

Ten cadaveric fingers underwent an oblique osteotomy at the base of the middle phalanx, recreating an unstable dorsal PIP fracture-dislocation. The percentages of compromised articular surface and middle phalanx dorsal displacement were measured. Both fixators were randomly placed on each digit and underwent 1,400 flexion-extension cycles. Efficacy, determined by joint reduction and maintenance of dorsal translation correction, was assessed using fluoroscopy before and after the cycles.

RESULTS

The mean compromised articular surface was 50.8%. After osteotomy, PIP joint subluxation occurred at 37.8° flexion. Dorsal translation after osteotomies was 2.8 mm. After applying the 3DPDEF and the PRTS, it was 0 mm and 0.1 mm, respectively. During the cycles, all the joints remained stable and reduced. Dorsal displacement after cycles was -0.1 mm for the 3DPDEF and 0 mm for the PRTS. The mean translation difference between both fixators was 0.1 and 0 mm before and after the cycles. The translation differences before and after the cycles were 0.1 mm for both dynamic fixators.

CONCLUSIONS

The 3DPDEF is a suitable option for PIP fracture-dislocations, providing stability comparable to that of the PRTS while offering benefits, such as easy placement, controlled distraction, and clear visualization of the articular surface.

CLINICAL RELEVANCE

This external fixator, characterized by its efficacy, low cost, and simplicity of application, broadens the options available to address PIP fracture-dislocations.

Three-Dimensionally Planned and Printed Patient-Tailored Plates for Corrective Osteotomies of the Distal Radius and Forearm

PURPOSE

We evaluated the 1-year postoperative clinical and patient-reported outcomes in patients who had a 3-dimensional planned corrective osteotomy of their distal radius, radial shaft, or ulnar shaft using a printed, anatomical, patient-tailored plate to determine the feasibility and effectiveness of this methodology.

METHODS

Simulations in computer-assisted preoperative planning of corrective osteotomies resulted in 3-dimensionally printed surgical guides, surgical models, and anatomically customized plates for application at the distal radius and forearm. Patients with malunions of the distal radius or forearm who underwent fixation with the custom-made plates were documented in our registry. Grip strength and range of motion assessments were made before surgery (baseline), as well as at 6 weeks and 3 and 12 months. Additionally, patients rated their wrist-related pain and disability using the Patient-Rated Wrist Evaluation.

RESULTS

Fifteen patients underwent corrective surgery, and the 1-year follow-up data of 14 patients with a median age of 56 years (interquartile range, 24-64 years) were available for analysis. The median baseline Patient-Rated Wrist Evaluation score improved from 47 to 7 after 1 year. The flexion-extension arc of motion of the wrist increased from 90° at baseline to 130° at 1 year and the pronation-supination arc of motion of the wrist increased from 135° to 160° in the same time period. Differences in radiological measurements for palmar and radial inclinations, as well as for ulnar variance between the affected and contralateral wrists, were reduced with the osteotomy. In 1 case, the plate was removed 11 months after the osteotomy. No severe adverse events were reported.

CONCLUSIONS

Three-dimensionally planned and printed patient-tailored plates offer a reliable method for correcting even complex malunions of the distal radius and forearm.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Bone Graft Substitutes-What Are My Options?

We examine the range of available bone graft substitutes often used in nonunion and malunion surgery of the upper extremity. Synthetic materials such as calcium sulfate, beta-calcium phosphate ceramics, hydroxyapatite, bioactive glass, and 3D printed materials are discussed. We delve into the advantages, disadvantages, and clinical applications for each, considering factors such as biocompatibility, osteoconductivity, mechanical strength, and resorption rates. This review provides upper extremity surgeons with insights into the available array of bone graft substitutes. We hope that the reviews helps in the decision-making process to achieve optimal outcomes when treating nonunion and malunion of the upper extremity.

Metacarpophalangeal Joint Reconstruction of a Complex Hand Injury with a Vascularized Lateral Femoral Condyle Flap Using an Individualized 3D Printed Model-A Case Report

This case report describes the surgical management of a patient with a complex hand trauma. This injury included tendon, vascular, and nerve injuries, a partial amputation of the index finger, fractures of the third proximal phalanx, and destruction of the metacarpophalangeal joint of the fifth finger. Firstly, the acute treatment of a complex hand injury is described. Secondly, the planning and execution of a joint reconstruction using a vascularized lateral femoral condylar flap, assisted by an individual 3D model, is illustrated. Precise reconstruction of the affected structures resulted in good revascularization as well as an anatomical bone consolidation. Intensive physical therapy, including autonomous proprioceptive range-of-motion exercises by the patient, resulted in significant functional improvement of the hand in daily life. Overall, we report on the successful reconstruction of a metacarpophalangeal joint by using a vascularized flap from the lateral femoral condyle. Furthermore, this case report highlights the efficacy of integrating individualized 3D printing technology to plan complex reconstructions, opening up promising opportunities for personalized and optimized interventions.

Biomechanics of the proximal interphalangeal joint after total joint replacement

Introduction Small joints arthroplasty of the hand including the proximal interphalangeal joint (PIPJ) is associated with the need to create anatomically adapted structures using optimal materials. Introduction of a new medical device requires comprehensive preclinical testing.

The objective was to determine a range of loads allowed for the proximal interphalangeal joint after arthroplasty through analyzing the biomechanics to prevent critical conditions and complications.

Methods A full-ceramic non-constrained anatomically adapted proximal interphalangeal joint implant was developed between 2016 and 2021 using an integrated approach with preclinical trials and a clinical study of 42 patients (25 males, 17 females) with PIPJ arthritis. A digital endoprosthesis was created with 3D-modelling. Critical conditions for the digital model imitating typical joint movements were explored with the use of finite element method and the findings to be employed in clinical practice.

Results A stable biomechanical construct was intact with loads of 5 kilograms and a motion ranging from 0 to 60 degrees, with loads of 20 kilograms and a motion ranging between 0 and 30 degrees. Cortical bone could sustain loads up to 20 kilograms with a motion ranging between 0 and 60 degrees. Discussion Load capacity of the implant was explored considering the strength of bone tissue and zirconium ceramics as a material. The study set a vector for the development of the optimal mode of motor activity early after surgery and indicated the optimal range of motion to be applied after PIPJ arthroplasty.

Conclusion The load up to 5 kg was optimal for the patient to be applied early after surgery with the range of flexion measuring less that 90°. The patient could use a load of 5 to 20 kg with flexion in the proximal interphalangeal joint measuring less than 30°. Endoprosthetic components were likely to get dislocated with a load of 20 kg and flexion angle of greater than 30°. Periprosthetic fracture could occur with flexion angle of greater than 60°.

Insights and trends review: the role of three-dimensional technology in upper extremity surgery

The use of three-dimensional (3-D) technology in upper extremity surgery has the potential to revolutionize the way that hand and upper limb procedures are planned and performed. 3-D technology can assist in the diagnosis and treatment of conditions, allowing virtual preoperative planning and surgical templating. 3-D printing can allow the production of patient-specific jigs, instruments and implants, allowing surgeons to plan and perform complex procedures with greater precision and accuracy. Previously, cost has been a barrier to the use of 3-D technology, which is now falling rapidly. This review article will discuss the current status of 3-D technology and printing, including its applications, ethics and challenges in hand and upper limb surgery. We have provided case examples to outline how clinicians can incorporate 3-D technology in their clinical practice for congenital deformities, management of acute fracture and malunion and arthroplasty.

Meta-analyzing the efficacy of 3D printed models in anatomy education

Three-dimensional printing models (3DPs) have been widely used in medical anatomy training. However, the 3DPs evaluation results differ depending on such factors as the training objects, experimental design, organ parts, and test content. Thus, this systematic evaluation was carried out to better understand the role of 3DPs in different populations and different experimental designs. Controlled (CON) studies of 3DPs were retrieved from PubMed and Web of Science databases, where the participants were medical students or residents. The teaching content is the anatomical knowledge of human organs. One evaluation indicator is the mastery of anatomical knowledge after training, and the other is the satisfaction of participants with 3DPs. On the whole, the performance of the 3DPs group was higher than that of the CON group; however, there was no statistical difference in the resident subgroup, and there was no statistical difference for 3DPs vs. 3D visual imaging (3DI). In terms of satisfaction rate, the summary data showed that the difference between the 3DPs group (83.6%) vs. the CON group (69.6%) (binary variable) was not statistically significant, with p > 0.05. 3DPs has a positive effect on anatomy teaching, although there are no statistical differences in the performance tests of individual subgroups; participants generally had good evaluations and satisfaction with 3DPs. 3DPs still faces challenges in production cost, raw material source, authenticity, durability, etc. The future of 3D-printing-model-assisted anatomy teaching is worthy of expectation.

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

Background

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

Methods

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

Results

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

Conclusions

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

The translational potential of this paper

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