title: A low-cost solution for the restoration of femoral head centre during total hip arthroplasty.
abstract: Restoration of joint centre during total hip arthroplasty is critical. While computer-aided navigation can improve accuracy during total hip arthroplasty, its expense makes it inaccessible to the majority of surgeons. This article evaluates the use, in the laboratory, of a calliper with a simple computer application to measure changes in femoral head centres during total hip arthroplasty. The computer application was designed using Microsoft Excel and used calliper measurements taken pre- and post-femoral head resection to predict the change in head centre in terms of offset and vertical height between the femoral head and newly inserted prosthesis. Its accuracy was assessed using a coordinate measuring machine to compare changes in preoperative and post-operative head centre when simulating stem insertion on 10 sawbone femurs. A femoral stem with a modular neck was used, which meant nine possible head centre configurations were available for each femur, giving 90 results. The results show that using this technique during a simulated total hip arthroplasty, it was possible to restore femoral head centre to within 6 mm for offset (mean 1.67 ± 1.16 mm) and vertical height (mean 2.14 ± 1.51 mm). It is intended that this low-cost technique be extended to inform the surgeon of a best-fit solution in terms of neck length and neck type for a specific prosthesis.
authors: Primary Joint Unit, Musgrave Park Hospital, Belfast, UK. janet.hill@belfasttrust.hscni.net
authors: Janet C
authors: JC
authors: Hill
authors: Jose J
authors: JJ
authors: Salazar-Torres
authors: John F
authors: JF
authors: Orr
authors: H A Pooler
authors: HA
authors: Archbold
authors: David E
authors: DE
authors: Beverland
mesh_terms: D000886:Anthropometry / Q000295:instrumentation* / Q000379:methods; D019644:Arthroplasty, Replacement, Hip / Q000295:instrumentation* / Q000379:methods*; D003198:Computer Simulation; D005270:Femur Head / Q000033:anatomy & histology* / Q000601:surgery*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008953:Models, Anatomic; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D025321:Surgery, Computer-Assisted / Q000379:methods*
keywords: Total hip arthroplasty; calliper; femoral head restoration