Minimally invasive surgery (MIS) for total hip arthroplasty and hemiarthroplasty is performed through anterior or anterolateral approach from April 2006. Appropriate stem insertion is often difficult by conventional approach. Retractor for MIS stem insertion is used from February 2007 and initial stem position is measured. Forty-four hemiarthroplasty and 20 total hip arthroplasty were performed from April 2006 until December 2007 with mean age of 79.7. Retractor for MIS stem insertion has been used for 36 hips from February 2007. Stem was cemented for more than 13mm at femoral isthmus. Stem position was measured in rentogenographs of hip after operation about adduction or abduction, extension or flexion, and anteversion of stem in proximal femur. The average abduction/adduction was 1.75 degree abduction in conventional method and 1.38 degree abduction from February 2007. The average extension/flexion was 1.10 degree flexion in conventional method and 0.25 degree flexion from February 2007. The average anteversion was 30.3 degree in conventional method and 28.4 degree from February 2007. Two cases in conventional method and one case from February 2007 complicated femoral fracture during operation. In conventional method, cement cap in one case was undersized and proximal major trochanteric fracture was happened in one case. Ectopic ossification at medial gluteal muscle in one case was observed and one case was dislocated among conventionally operated cases during follow-up period. Care of femoral exposure though gluteal muscles is needed in anterior and anterolateral MIS. More exact and safe stem insertion procedure is available by using retractor for MIS of the hip.
