Polyethylene Wear between Farming and Non-Farming Patients after Total Knee Arthroplasty

ABSTRACT

PURPOSE: We evaluated the polyethylene wear rate between patients from farming and non-farming communities to determine whether active life styles, knee scores, and occupations could affect outcomes. MATERIALS AND METHODS: 201 knee replacements were performed in 105 patients who were an average of 68.7 years old. 30 non-farming patients(59 cases) and 75 farming patients(142 cases) who had operation between 1989 and 1996 were reviewed retrospectively. Mean follow-up period was 12.1 years(range 10~16 years). The difference of clinical, radiographic, and functional results of total knee replacement were assessed by Knee Society scores and activity levels. RESULTS: The non-farming group had lesser activity levels(non-farming group 82.5, farming group 89.7), higher knee scores(non-farming group 88.4, farming group 81.1) and functional scores(non-farming group 87.9, farming group 80.4) than the farming group(p<0.05). Farming patients showed 33 cases(23%) of polyethylene wear and non-farming patients showed 7 cases(12%) which is statistically significant(p<0.001). CONCLUSION: Primary osteoarthritic patients from farming communities had higher activity levels and polyethylene wear rate with lower Knee Society scores which were expected to participate in more activities involving impact on knee joint. We assume that the increase rate of complication is due to the overuse of the prosthesis. Therefore, working condition and life style modification will be needed.