Clinical Outcome of IM-Guided Total Knee Arthroplasty with Inappropriate Femoral Resection in Coronal Plane

PURPOSE: The purpose of this study was to evaluate clinical results and accuracy of femoral cutting in the coronal plane in total knee arthroplasty (TKA) using a fixed length intramedullary guide. MATERIALS AND METHODS: From 2005 to 2008, 101 patients (154 knees) underwent TKA (NexGen LPS implant). The minimal follow-up period was 3 years (mean, 4.4 years). The patients were divided into two groups (group 1, 94≤α angle<98; group 2, 94>α, 98≤α). Mechanical axis deviation (MAD), patellar tilting angle (PTA), Knee Society Knee Score (KSKS), and Knee Society Function Score (KSFS) were measured in both groups. RESULTS: There were 120 knees in group 1 and 34 knees in group 2. There was no significant intergroup difference in the postoperative MAD (group 1, 1.59°; group 2, 1.91°). The number of outliers with ≥2° MAD was 65 in group 1 and 24 in group 2. The mean PTA, KSKS, and KSFS were 10.17°, 96.0, and 96.6, respectively, in group 1 and 11.58°, 84.5, and 85.5, respectively, in group 2. CONCLUSIONS: The percentage of coronal alignment outliers was relatively high (34 in 154 cases, 22%) after TKA using a fixed length intramedullary guide. However, there was no statistically significant intergroup difference in clinical results (KSKS, p=0.67; KSFS, p=0.56).