Utilising 3D-printed ex vivo biomimetics to improve open reduction and internal fixation (ORIF) simulation training for hand fractures.

Background: Surgery for hand trauma accounts for a significant proportion of the plastic surgery training curriculum. The aim of this article is to create a standardised simulation training module for hand fracture fixation on open reduction and internal fixation (ORIF) techniques for residents in order to create a standardised hand-training framework that universally hones their skill and prepares them for their first encounter in a clinical setting. Methods: A step-ladder approach training using three-dimensional (3D)-printed ex vivo hand biomimetics was employed on a cohort of 15 plastic surgery residents (n = 15). Assessment of skills using a score system (global rating scale) was performed in the beginning and the end of the module by hand experts in our unit. Results: The overall average score of the cohort pre- and post-assessment were 22.08/50 (44.16%) and 41.54/50 (83.08%) respectively. Significant (p < 0.01) difference of improvement of skills was noted on all trainees. All trainees confirmed that the simulated models provided in this module were akin to the patient scenario and noted that it helped them improve their skills with regards to ORIF techniques including improvement of their understanding of the 3D bone topography. Conclusion: We demonstrate a standardised simulation training framework that employs 3D-printed ex vivo hand biomimetics proven to improve the skills of residents and which paves the way to more universal, standardised and validated training across hand surgery. This is, to our knowledge, the first standardised method of simulated training on such hand-surgical cases.Level of Evidence: Not ratable.

Response to a letter: "Plastic surgery in a student-run free clinic".

N/A.

The successful use of a bespoke OssDsign cranial plate to reconstruct an occipital defect following excision of a recurrent epithelioid sarcoma.

A cranioplasty has a number of known associated complications including infection for non-biological implants and bone flap resorption where autologous grafts are used. In recent years, bioactive ceramic cranial implants have been developed as a new reconstructive option. The OssDsign cranial plate (OssDsign AB, Uppsala, Sweden) was first introduced in 2010 and consists of an interconnected mosaic of hydroxyapatite tiles mounted onto a 3D-printed titanium mesh. Each tile is composed of a monetite, beta-calcium pyrophosphate, beta-tricalcium phosphate and brushite compound designed to mimic the process of coupled bone formation once implanted. This case presents a patient's journey from diagnosis of an epithelioid sarcoma over the posterior scalp and its management in the following 7 years. Initial excision of the lesion was reconstructed with a tissue expander and local rotational flap. Recurrence of the disease 3 years later was treated with a course of radical radiotherapy. Persistent osteomyelitis over the next 3 years resulted in chronic ulceration and exposed bone in the treated area. As the first part of a 3-stage treatment plan, two separate tissue expanders became infected. The multidisciplinary team therefore chose to use a bespoke OssDsign cranial plate combined with a deep inferior epigastric perforator (DIEP) free flap to provide a definitive single operative solution. The advantages over other reconstruction options include that the plate can be removed should further excision be required, greater potential for long-term integration with surrounding tissues and the ability to be soaked in antibiotic to reduce the risk of infection.

A model to evaluate Pauwels type III femoral neck fractures.

While many femoral neck fractures can be reliably treated with surgical intervention, Pauwels III femoral neck fractures in the young adult population continue to be a challenging injury, and there is no consensus on optimal treatment. As such, there are past and ongoing biomechanical studies to evaluate the fixation provided by different constructs for this inherently unstable fracture. While many investigations rely on cadavers to evaluate the biomechanical performance of a construct, significant inter-subject variability can confound the analysis. Biomechanical femur analogs are being used more frequently due to more consistent mechanical properties; however, they have not been stringently evaluated for morphology or suitability for instrumentation. This study sought to determine the variability among composite femoral analogs as well as consistently create a Pauwels III injury and instrument the analogs without the need for fluoroscopic guidance. In total, 24 fourth-generation composite femoral analogs were evaluated for femoral height, neck-shaft angle, anteversion, and cortical thickness. A method was developed to simulate a Pauwels III fracture and to prepare three different constructs: an inverted triangle of cannulated screws, a sliding hip screw, and a hybrid inverted triangle with cannulated screws and a sliding hip screw. Radiographs were utilized to evaluate the variation in implant position. All but one of the morphological parameters varied by <1%. The tip-to-apex distance for all sliding hip screw hardware was 18.8 ± 3.3 mm, and all relevant cannulated screw distances were within 5 mm of the adjacent cortex. All screws were parallel, on average, within 1.5° on anterior-posterior and lateral films. Fourth-generation composite femora were found to be morphologically consistent, and it is possible to consistently instrument the analogs without the use of fluoroscopy. This analog and hardware implantation model could serve as a screening model for new fracture repair constructs without the need for cadaveric tissues or radiologic technology.