The Design and Development of Breed Specific Hip Replacement Implants for Dogs

Kongphan, Phanphong
(2019) The Design and Development of Breed Specific Hip Replacement Implants for Dogs. PhD thesis, University of Liverpool.

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This thesis describes work performed to developed canine cementless hip re-placement implants with breed specific basis. Existing commercial cementless hip replacement systems offer a range of implants to fit all dog breeds, but the effectiveness of this system is questionable due to a high complication rate re-ported by many prior studies and a record of hip registries. To develop a novel cementless hip system, three breeds of dogs, including German Shepherd Dog, Retriever (Labrador) and Spaniel (a mixture of Cocker and Springer) were se-lected as studied breeds based on the prevalence of the hip diseases. A novel measuring method used to determine the anatomical parameters of the proximal femur and acetabulum from CT scans was developed using a commer-cial software package, and then the database of canine femoral and acetabular morphologies for three selected breeds of dogs was established. In order to de-velop a range of implants for each selected breeds, linear regression analyses were carried out to define Transfer Functions (TFs), which are necessary for the design and development of the implants. As the implants were developed for cementless, in which short-term and long-term stability of the implants are achieved through press-fit and bone in-growth, respectively, the porous struc-ture used to promote bone in-growth was included in the design. The develop-ment of the relevant instruments that are required for the implantation of the prosthesis, including drill bit, reamers and broaches, is also included within this study. Additional surgical guides, including drilling, neck-section and milling guides, were developed in order to reduce or eliminate surgical errors, which would result in a lower rate of complications compared with the other hip re-placement systems currently available on the veterinary market. The prototypes of the implants and relevant instruments for further trials were manufactured using Laser Powder Bed Fusion (L-PBF) followed by machining process if nec-essary. A surgical procedure was developed from a sequence of phased steps generated using sawbones trials with additional steps to fulfil the requirement of the ca-daveric trials. The results of the cadaveric trials revealed that the surgical pro-cedure in conjunction with the current generation of instruments could not pro-vide the ideal outcome as the femoral stem cannot be located in the appropriate position with correct angulation without the use of specific drilling and milling guides. The outcomes will be improved when these custom guides are available.

Item Type: Thesis (PhD)
Divisions: Faculty of Science and Engineering > School of Engineering
Depositing User: Symplectic Admin
Date Deposited: 13 Aug 2020 13:46
Last Modified: 01 Sep 2022 07:42
DOI: 10.17638/03069671
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