Early clinical and radiological results of total knee arthroplasty using patient-specific guides in obese patients

Total knee arthroplasty (TKA) is a challenging procedure in patients with a high body mass index (BMI). The aim of our study was to assess the outcome and accuracy of restoration of mechanical alignment in TKA using patient-specific guides (PSG) involving patients with high BMI. Patients with BMI of 30 or above were enrolled in the study. The mean age of the patients was 65.15 years. The study comprised of 46 males and 54 females. Total knee arthroplasty was planned after a pre-operative MRI and long leg x-ray films using customized PSG. Of the 105 knees (100 patients) in the study, average BMI was 35.42 kg/m(2) (30-56). Twenty patients (20 %) had class III obesity (a parts per thousand yen40 kg/m(2)). The average blood loss and operative time were 236.1 ml (range 50-700 ml) and 92.2 min (65-130 min), respectively. The average post-operative mechanical axis was noted to be 1.85A degrees varus (range 4A degrees valgus to 6A degrees varus). Eighty-eight patients (86.27 %) had mechanical alignment within 3A degrees of neutral. There were no adverse intraoperative events. One patient had deep infection that required a two-stage revision. The average post-operative range of motion at 1-year follow-up was 105.8A degrees (range 80A degrees-130A degrees). Patient-specific guides technology restores the coronal mechanical axis reliably in obese patients without adversely affecting outcomes. Our short-term follow-up has shown favorable outcomes. Surgeons should use these customized jigs as a guide and adjust the size of components, alignment and rotation according to normal surgical principles.