Computer simulations of patellofemoral joint surgery. Patient-specific models for tuberosity transfer.

Abstract

Variable clinical outcomes of tibial tuberosity transfer surgery have been reported. The biomechanical outcome of surgery is patient-specific; no single procedure produces superior results for all patients. Use of patient-specific computer models can optimize choice of procedure. Computer simulation study using clinical data. We used patient-specific multibody models of the patellofemoral joints of 20 patients with a diagnosis of patellar subluxation and osteoarthritis. Four tibial tuberosity transfer procedures (two anterior and two anteromedial) were simulated for each patient and compared with their preoperative model. When results for all patients were averaged, all simulated operations produced a statistically significant decrease in surface-wide mean contact stress, although no significant difference was found among them. The simulated surgical outcomes were patient-specific: no single procedure was consistently superior at decreasing peak or mean stress and each procedure produced a potentially detrimental outcome, an increase in either mean stress or peak stress, in at least one patient. Computer simulation may serve as a valuable tool for tailoring procedures to specific patients.