What do we get from navigation in primary THA?

Abstract

Navigation in primary total hip arthroplasty has a history of over 20 years. During this process, imageless computer navigation can be particularly helpful in optimally restoring the hip’s biomechanics. This involves the accurate placement of the acetabular component with the determination of the anteversion and abduction, whereby the navigated femur-first technique also allows for a calculation of the combined anteversion. Additional critical parameters such as the reconstruction of the rotation centre, as well as the femoral and acetabular offset, can also be optimally adjusted. Last but not least, an intra-operative evaluation and equalisation of the leg length is possible.Nonetheless, the disadvantages of this surgical technique in terms of the high costs in the acquisition and preservation of the necessary devices, as well as the longer operation time, must be taken into account. However, economic aspects are not the only thing preventing widespread use of the navigation technique. Determining the plane of reference (APP) for the optimal orientation of the implants is based on palpation of the bony landmarks – and this is influenced by the thickness of the soft tissue layer. Furthermore, the experience of the surgeon constitutes a variable that influences the accuracy of navigation.In summary, hip navigation certainly offers an interesting technique for the optimisation of total hip arthroplasty with reconstruction of proper biomechanics. At the same time, there is currently a lack of high-quality randomised controlled long-term trials that evaluate the clinical advantage for the patients, together with cost utility and survival rates.Cite this article: Renner L, Janz V, Perka C, Wassilew GI. What do we get from navigation in primary THA? EFORT Open Rev 2016;1:205-210. 10.1302/2058-5241.1.000034.

Advances in hip arthroplasty surgery: what is justified?

“…The recent reviews 68 , 69 agree that computer-navigation and even robotic-assisted surgery have disadvantages that may limit their routine use, including high costs and longer surgery time. Randomised controlled studies with long-term follow-up and future research are needed to prove a cost-effective long term clinical benefit to patients.…”

Virtual trial to evaluate the robustness of cementless femoral stems to patient and surgical variation

“…Fibrotic tissue formation is likely due to large micromotion between the stem and the hosting bone (Pilliar et al, 1986b), while peri-prosthetic bone damage is likely due to excessive strains on the host bone (Morgan and Keaveny, 2001). There is evidence that patient and surgical factors, including anatomy (Heller et al, 2001;Renner et al, 2016;Umeda et al, 2003), bone material properties (Wong et al, 2005), stem position (Bah et al, 2009;Bah et al, 2011;Dopico-Gonzalez et al, 2009), size (Al-Dirini et al, 2018) and the extent of the cortical contact (Viceconti et al, 2001b) influence micromotion, peri-prosthetic bone strains and hence, the primary stability of femoral stems.…”

Leg length correction in computer assisted primary total hip arthroplasty: A collective review of the literature

“…The accuracy of the navigation system relies on the surgeons ability to accurately define these planes. 2 , 4 , 5 To calculate the 3D relationship between the implants and the patient's anatomy, the surgeon controls instruments which have an optical tracking array attached to them (dynamic reference frames). The interaction between the static reference frame, and the dynamic reference frames is what allows the surgeon to adjust the leg length, femoral offset, inclination angle and anteversion of the cup with dynamic live values displayed on a computer monitor.…”