Development of patient-specific knee joint prostheses for unicompartmental knee replacement (UKR)

[摘要] ENGLISH ABSTRACT: The knee is the largest, most complicated and incongruent joint in the humanbody. It sustains very high forces and is susceptible to injury and disease.Osteoarthritis is a common disease prevalent among the elderly and causessoftening or degradation of the cartilage and subcondral bone in the joint, whichleads to a loss of function and pain. This problem can be alleviated through asurgical intervention commonly termed a 'knee replacement. The aim of a kneereplacement procedure is to relieve pain and restore normal function. Ideally, theknee replacement prosthesis should have an articulating geometry similar to thatof the patient's healthy knee, and must allow for normal motion. Unfortunately,this is often problematic since knee prostheses are supplied in standard sizes froma variety of manufacturers and each one has a slightly different design.Furthermore, commercial prostheses are not always able to restore the complexgeometry of an individual patient's original articulating surfaces. This dissertationshows that there is a significant variation between knee geometries, regardless ofgender and race. This research aims to resolve the problem in two parts: Firstly bypresenting a method for preoperatively selecting the optimal knee prosthesis typeand size for a specific patient, and secondly by presenting a design procedure fordesigning and manufacturing patient-specific unicompartmental kneereplacements. The design procedure uses mathematical modelling and an artificialneural network to estimate the original and healthy articulating surfaces of apatient's knee. The models are combined with medical images from the patient tocreate a knee prosthesis that is patient-specific. These patient-specific implants arethen compared to conventional implants with respect to contact stresses andkinematics. The dissertation concludes that patient-specific implants can havecharacteristics that are comparable to or better than conventional prostheses. Theunique design methodology presented in this dissertation introduces a significantadvancement in knee replacement technology, with the potential to dramaticallyimprove clinical outcomes of knee replacement surgery.

[发布机构] Stellenbosch University