Pre-operative digital templating in cemented hip hemiarthroplasty for neck of femur fractures.

Pre-operative digital templating allows the surgeon to foresee any anatomical anomalies which may lead to intra-operative problems, and anticipate appropriate instruments and implants required during surgery. Although its role is well-established in successful elective total hip arthroplasty, little work has been done on its use in hip hemiarthroplasty in neck of femur fractures. We describe our initial experience of digital templating in 40 consecutive patients who have undergone cemented hip hemiarthroplasty, assessing templating accuracy between templated implant sizes to actual implant sizes. 81% of implanted heads were templated to within two head sizes, and 89% of implanted stems were templated to within two sizes. Although there was a moderately strong correlation of 0.52 between templated and actual head sizes, this correlation was not demonstrated in femoral stem sizes. Mean leg length discrepancy was -2.5mm (S.D. 8.5), and the mean difference in femoral offset between the operated and non-operated hip was -1mm (S.D. 4.4). Digital templating is a useful adjunct to the surgeon in pre-operative planning of hip hemiarthroplasty in the restoration of leg length and femoral offset. However, its accuracy is inferior to that of elective total hip arthroplasty.