Virtual Hip Replacement Simulator for 3D Printed Implants
Authors: Vaughan Neil , Dubey Venketesh N. 
Published: October 2017

This research presents a virtual reality simulator for total hip replacement surgery. The simulator supports a library of 3D hip stem models for different sizes and manufacturers. The 3D hip stems can be adjusted in size and shape by parametric software and sent for 3D printing. Biocompatible materials such as titanium enable the 3D printed stems to be directly implanted on patients.

Currently surgical simulation for orthopaedic procedures is not as advanced as other surgical disciplines. As a result there are only limited training simulators available for orthopaedic surgery such as total hip replacement, hip resurfacing or knee replacement. This is demanding since 66,000 hip replacements are performed annually in the UK.

One area which is neglected in VR orthopaedic simulation is the digital library generation of implants. Currently orthopaedic surgeons have limited choice in terms of an exact identification of implant specific to patient requirements. We conducted a literature review of orthopaedic training simulators which found no simulators catering for this [9].

Orthopaedic surgeons generally have a positive opinion for the use of virtual reality (VR) training systems. A survey amongst all orthopaedic surgeons in New Zealand found that 77% of qualified surgeons believe simulation is effective for practicing and learning surgical procedures [1]. A separate review from the American Academy of Orthopaedic Surgeons (AAOS) showed that over 80% agreed that surgical skills simulations should become a required part of orthopaedic training, based on views from 185 program directors and 4549 residents. There was a strong agreement that simulation technology should be a required component of orthopaedic resident training [2].

The hip replacement procedure has been considered as the most successful and influential orthopaedic surgery of the twentieth century. Currently over 66,000 total hip replacements (THR) are performed each year in England and Wales by the National Health Service (NHS) and around 75,000 hip fractures are treated each year in the UK. Knee arthroscopy has increased 49% from 1996–2006 and now over 1 million are performed each year [3].

Each year there are an increasing number of orthopaedic procedures due to the aging population. Currently 247,000 hip fractures occur yearly in the United States, with the majority occurring in the population over 45 years old [4]. The incidence of hip fracture is also on the rise, partly due to the aging population, with over half a million hip fractures annually expected by 2040. The cost of these fractures is also expected to rise from $7 billion per year [4], to nearly $16 billion per year by 2040 [5]. Each hip fracture is estimated at costing between $39,555 and $40,600 in the first year after surgery [6]. Hip fractures have the highest cost of any orthopaedic procedure after surgery, and also incur $11,241 each year following surgery in extra health costs. Due to increased life expectancy, worldwide by 2050, it is projected that 6.26 million hip fractures will occur annually [7].

A paradigm shift is underway toward use of surgical training simulations [8]. The conventional master-apprentice learning model for surgical training of ‘see one, do one, teach one’ has recently been seen as inefficient. Due to orthopaedics being heavily dependent on technical skill, orthopaedic VR simulation holds potential to have great impact for improving surgical skill. The transition to VR simulation is relatively new compared to cadaver training which has been the gold standard for several centuries.