Restoration of Femoral Condylar Anatomy for Achieving Optimum Functional Expectations: Continuation of an Earlier Study At 5-Year Minimum Follow-Up

Abstract

BACKGROUND: Studying and reporting the continuous, prospective outcomes of a post-surgical orthopaedic population without loss to follow-up at various standard landmarks over time is rarely achieved in total knee arthroplasty (TKA) literature. Small case series populations reported at an early follow-up time is common, and usually not beyond any initial publication for further reporting. The purpose of this study was to advance the knowledge base of the performance of Freedom Knee system through the continuous monitoring of a previously reported early series TKA patient population. METHODS: A prospective, continuous series of 176 primary posterior stabilized (PS) TKAs were performed in 172 patients by a single surgeon. Femoral component size distribution was assessed and all patients were followed for a minimum of five-years post-operatively. Total Hospital for Special Surgery (HSS) scores and range of motion (ROM) was assessed for the entire cohort and by gender. RESULTS: There were no patients lost to follow-up. Two patients required incision and drainage for superficial wound infection of the indicated knees. One patient required tibial component and polyethylene insert revision following a motor vehicle accident resulting in a proximal tibial fracture and component loosening. There was no radiographic evidence of component failure. As expected, femoral component size frequency use was skewed by gender with the larger sizes in males. There were no pre- or post-operative clinical or functional differences by gender and at the recent follow-up (avg. 6.9 years). In addition, there was an average significant increase in change of HSS score (p<0.001) and ROM (P<0.001) when compared to pre-operative baseline but no significant difference in HSS or ROM between the two and five-year outcome results. CONCLUSIONS: The design characteristic for component sizing and functional expectations were re-confirmed in the reported Western population cohort series, and observed optimum safety, performance and efficacy through five-years. Further continued study efforts of this primary TKA system is warranted across multiple surgeons and all ethnic cultures.

Keywords

• total knee
• condylar anatomy