ABSTRACT

Osteoarthritis, which is one of the most common causes of pain and motion loss, is an important medical disease that particularly affects elderly people. Unicondylar knee arthroplasty treatment is still a challenge for obese and/or ACL deficient patients. In addition, surgeons face a challenge of deciding whether to perform either fixed or mobile insert design prosthesis. The objective of this study was to evaluate the effect of fixed or mobile insert design prosthesis on the mid-term results of patients that we followed up for 8 years or more.

Between 2003 and 2014, 293 patients were treated with unicondylar knee arthroplasty due to medial gonarthrosis, and 239 patients that we followed up for at least 18 months were included in the study. Nine of the patients (3.7%) underwent bilateral operation, 193 (77.8%) patients were operated with the fixed insert design, and 55 (22.2%) patients were operated with the mobile insert design. A total of 248 knees were evaluated retrospectively.

The mean age was 59.3 (53–71) years. Of the patients, 156 (65.2%) were female and 83 (34.8%) were male (female/male ratio: 1.87). The mean follow up period was 101 months (18–126). The mean body mass index was 29.4 kg/m2 (25–33 kg/m2). The preoperative mean Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) value was 72.64±5.32 (68–78), and the mean Knee Society Knee Scoring System (KSS) score was 70.6±3.9 (66–89). The postoperative mean WOMAC value was 97.23±4.02 (92–100) (p<0.05), and the mean KSS score was 92.3±3.94 (85–100) (p<0.05).

When we compared the fixed and mobile insert design prosthesis, there was no statistically significant difference between the knee scores, but the mobile insert design prosthesis had better flexion degrees. We have observed 97.2% prosthesis survival rates over 8 years. In conclusion, unicondylar knee prosthesis is a good treatment option, with a high success rate for medial knee osteoarthritis. (JAREM 2016; 6: 31-4)

Keywords: Survival, osteoarthritis, knee