Computer-Assisted Mosaic Arthroplasty: A Femur Model Trial

Abstract

Computer assisted mosaic arthroplasty (CAMA) is a surgical technique that transplants cylindrical osteochondral grafts to repair damaged cartilage. An earlier in vivo study on sheep showed that short-term clinical outcomes are improved with the use of computer assistance, as compared to the conventional technique.

This thesis reports on a study comparing three mosaic arthroplasty techniques -- one conventional and two computer assisted -- on human anatomy. This in vitro study used solid foam femur models modified to incorporate simulated cartilage defects. There were five participating surgeons ranging from a third year resident to a senior orthopedic surgeon. Each of the five participating surgeons performed a total of nine trials. There were three distinct sets of identical solid foam femur models with simulated cartilage defects. Three surgical techniques (conventional, opto-electronic, and patient-specific template) were performed on each.

Several measures were made to compare surgical techniques: operative time; surface congruency; defect coverage; graft surface area either too high or too low; air volume below the grafts; and distance and angle of the grafts from the surgical plan. The patient-specific template and opto-electronic techniques resulted in improved surface congruency, defect surface coverage, graft surface within 0.50mm recessed and 0.25mm proud of the original surface, and below-graft air gap volume in comparison to the conventional technique. However, the conventional technique had a shorter operative time. The patient-specific template technique had less variance in surface congruency and shorter operative time than did the opto-electronic technique.