Short stems reproduce femoral offset better than standard stems in total hip arthroplasty: a case-control study

International audienceIntroduction: In total hip arthroplasty (THA), altering the original offset can lead to poor outcome or even complications or revision when the changes are too great. The aim of the present study was to compare femoral offset between short and standard stems. The hypothesis was that the short stems studied provide better control of postoperative femoral offset. Patients and methods: We retrospectively reviewed 100 consecutive THAs using uncemented optimys™ short stems (Mathys, Bettlach, Switzerland), matched to 100 standard-stem THAs performed during the same period. The primary endpoint was femoral offset; secondary endpoints were limb length and cervico-diaphyseal angle. Results: Mean femoral offset increased by 6.0 +/-7.2 mm overall (p< 0.0001): 4.7 +/-6.7 mm in the short-stem group (p<0.0001), and 7.2 +/-7.5 mm in the standard-stem group (p<0.0001), with a significant inter-group difference (p=0.0152). Limb length showed no significant inter-group difference (p=0.8425). Cervico-diaphyseal angle was increased by surgery overall, and more by standard than by short stems (p