OrthopedVR: clinical assessment and pre-operative planning of paediatric patients with lower limb rotational abnormalities in virtual reality

Rotational abnormalities in the lower limbs causing patellar mal-tracking negatively affect patients' lives, particularly young patients (10-17 years old). Recent studies suggest that rotational abnormalities can increase degenerative effects on the joints of the lower limbs. Rotational abnormalities are diagnosed using 2D CT imaging and X-rays, and these data are then used by surgeons to make decisions during an operation. However, 3D representation of data is preferable in the examination of 3D structures, such as bones. This correlates with added benefits for medical judgement, pre-operative planning, and clinical training. Virtual reality can enable the transformation of standard clinical imaging examination methods (CT/MRI) into immersive examinations and pre-operative planning in 3D. We present a VR system (OrthopedVR) which allows orthopaedic surgeons to examine patients' specific anatomy of the lower limbs in an immersive three-dimensional environment and to simulate the effect of potential surgical interventions such as corrective osteotomies in VR. In OrthopedVR, surgeons can perform corrective incisions and re-align segments into desired rotational angles. From the system evaluation performed by experienced surgeons we found that OrthopedVR provides a better understanding of lower limb alignment and rotational profiles in comparison with isolated 2D CT scans. In addition, it was demonstrated that using VR software improves pre-operative planning, surgical precision and post-operative outcomes for patients. Our study results indicate that our system can become a stepping stone into simulating corrective surgeries of the lower limbs, and suggest future improvements which will help adopt VR surgical planning into the clinical orthopaedic practice.