Joint replacement surgery in the treatment of arthritic disease is now commonplace and on the whole very successful. Research into the design and development of prostheses has made major advances since the 1940s resulting in complex devices for almost all articulating joints of the body. In this thesis, a programme of work to design and test a surface replacement prosthesis for the metacarpophalangeal joint is presented. The anatomy and kinematics of the MCP joint are discussed for both normal and abnormal joint function and, based on these considerations, the design of a new surface replacement prosthesis is described. Various materials are explored with respect to their biocompatibility, durability and ease of fabrication with special attention being paid to one material - a new cross linked ultra-high molecular weight polyethylene - which is tested for wear and assessed for durability in long-term prototype tests. A finger function simulator is detailed which was designed and developed during this research programme, and results of tests on bone replicas, Swanson Silastic implants and prototypes of the new design are presented. The simulator can be easily modified to accept any MCP joint prosthesis for bench testing. Finally the stress response of the prototype design is studied using finite element analysis and modifications to the implant design and bone preparation are suggested.

BACKGROUND: One of the most recurrent complaints after total joint replacement is difficulty sleeping. Sleep disturbance after major surgery is common. The “stress response” to surgery, personal factors and environmental factors can affect quality and quantity of sleep in the hospital setting. Occupational therapy intervention for individuals that have problems with function as a result of sleep insufficiency is an emerging practice area. However, there are few occupational therapy practitioners who have addressed the important occupation of sleep in acute care settings. There is a need to develop science-driven research and establish evidence to support acute care occupational therapy interventions that address sleep hygiene, a set of behavioral and environmental practices designed to improve both quality and quantity of sleep. In response to this need, the author designed and carried out a non- randomized controlled study to evaluate the effectiveness of a non-pharmacological occupational therapy intervention to improve quality and quantity of clients’ sleep in a fast track joint replacement center. OBJECTIVE: In the author’s study, the aim was to compare sleep quality, sleep quantity, and activities of daily living (ADL) performance before and after fast track total joint replacement surgery for clients who received an occupational therapy intervention targeted at improving sleep hygiene, in addition to conventional acute care occupational therapy, compared to those that received only conventional acute care occupational therapy. The project focused on 1) identifying evidence-based literature to support the benefit of non-pharmacological interventions for joint replacement surgery clients, 2) designing a program that represented best practice while incorporating the holistic and occupation-based theoretical base of occupational therapy, 3) implementing the program, 4) conducting summative program evaluation, and 5) developing a dissemination plan and implementation budget. RESULTS: There were no initial significant differences between the control and experimental groups. The quality of sleep in the experimental group at discharge was significantly better than in the controls and this group reported significantly improved quality of sleep at discharge compared to 2 weeks before surgery. At discharge the experimental group reported significantly longer sleep duration compared to the control group and the increase in duration from 2 weeks before surgery to discharge was significant. CONCLUSION: The results of this study demonstrated that improvement in sleep quality and quantity can be achieved in clients undergoing fast track joint replacement surgery who receive an occupation-based intervention that incorporates implementation of sleep hygiene practices. Moreover the change appears to persist after the client returns home. More research examining the effectiveness of this intervention with other surgical populations and the persistence of learned sleep hygiene practices over time after hospital discharge are warranted. / 2018-11-07T00:00:00Z