Abstract
The purpose of this study was to evaluate the application of CAD CAM in the production of temporary trans-tibial prostheses. The CAD CAM system was assessed based on the number of socket attempts, number of prosthetic appointments, and temporary prosthesis rehabilitation time. These parameters were considered to be related to the quality of socket fit and were influenced by the entire interdisciplinary team including the patient. A concurrent prospective comparison between the CAD CAM system and an established fibreglass/pelite liner technique was also performed. Patients (n=30), were fitted with either a conventional or a CAD CAM socket. Records were kept before and after discharge until the interdisciplinary team considered the patient ready for definitive prosthesis casting. After approximately 90 postoperative days, patients were deemed fit to proceed from their initial plaster cast prostheses to their temporary prostheses. The group fitted with conventional sockets had an in-patient rehabilitation phase of 10.5+/−60 days and required 2.9+/−1.1 prosthetic appointments. In-patients fitted with CAD CAM sockets required 5.1+/−1.8 appointments and were hospitalised for 23.6+/−15.0 days. The significantly increased rehabilitation duration and number of appointments (p=0.01), were generally due to incorrect socket volume and/or inadequately modified relief/loading areas. In this study 67% of the patients fitted with CAD CAM sockets required at least one additional attempt. The clinical evaluation and modification of the temporary prostheses, including the decision to remake a particular socket, were camed out by the same prosthetist who cast the patients. During the out-patient phase, the type of socket design was not observed to influence either duration of out- patient rehabilitation or frequency of appointments. Out-patient rehabilitation included on average 4 appointments and ended after 90 days. Multidisciplinary discharge criteria and standardised follow-up procedures rendered the measured parameters less relevant to this study's purpose in the out-patient phase.