Effect of body mass index on the conventional method of templating in uncemented total hip arthroplasty: A prospective study

Abstract

BACKGROUND: Preoperative templating is an important step in total hip arthroplasty (THA). Results of traditional as well as digital method of templating are well established in various studies. Very few studies have evaluated the effect of body mass index (BMI) and gender on templating. Our study was undertaken to evaluate the effect of BMI and gender in accurate size estimation in uncemented THA components by conventional method of templating. MATERIALS AND METHODS: Preoperative radiographs were templated for 60 patients who underwent primary uncemented THA. BMI and gender of patients were noted during preoperative evaluation. Patients were grouped as per gender and divided into three groups as per BMI (underweight <18.5, normal 18.5-24.9, overweight >25). The estimated preoperative template size was compared with the actual implant size used. P-value of <0.05 was considered to be significant. RESULTS: Acetabular component was exactly templated in 63.33% and femoral component in 76.6% cases. Gender and BMI had no statistical difference in component size prediction. Post-operative analysis of THA performed showed statistically significant association between high BMI and limb length discrepancy and restoration of femoral offset. CONCLUSION: In our study, we found that femoral component is more accurately predicted. No statistically significant effect of gender and BMI was seen in accuracy of conventional method of templating in implant size estimation. However, BMI is found to affect limb length assessment during surgery and restoration of femoral offset.