60 Fig. 1 a AP pre-revision radiograph. b Post operative radiograph of revision right THA using Zweymuller stem. Notice the fractured greater trochanter. c, d 8-year follow-up radiographs. e ,f 14-year follow- up radiographs showing solid ingrowth, minimal proximal bony resorption, and no evidence of loosening J Orthopaed Traumatol (2008) 9:57–62 [5 mm within the ﬁrst month after surgery. This patient did not have a calcar fracture. The stem stabilized, and has since gone on to show radiographic evidence of bony ingrowth with good clinical outcome. This case illustrated the utility of a tapered stem geometry in that subsidence could result in greater axial and rotational stability leading to durable stem ﬁxation. Distal cortical hypertrophy (Gruen zone 4) was observed in ten patients (42%). Proximal stress-related bone remodeling (stress shielding) was observed in six patients (25%). No quantitative measure- ment of stress shielding was done. No femoral or pelvis osteolysis was observed. We elected to analyze the data further by breaking the patients into two groups based upon mean follow-up time. One group (long-term) included 8 hips with a mean follow- up of 12.4 years (range 10–15 years). The other group (medium-term) included 16 hips with a mean follow-up of 5.7 years (range 2–9 years). We were especially interested in determining if there was a difference between the 2 groups with regard to clinical outcome, and bone remodeling changes. Tables 3 and 4 show the results for these 2 groups. There was no difference in the Harris hip scores between the groups, pre- or post-op (P = 0.091 and P = 0.056, respectively). There was no difference in ﬁx- ation stability, distal cortical hypertrophy, or proximal stress shielding between the groups. 123 Discussion Recent data from the National Hospital Discharge Survey showed both the total number and rate of primary and revision total hip arthroplasty (THA) procedures are increasing [13]. In addition to the increase in number of procedures, analysis of this data by age groups showed this trend to continue across both young and elderly patients. The annual revision burden remained relatively constant at 17.5% per year over the study period. It is expected that the total number of revision THAs will continue to rise with increasing primary THAs being done, especially in younger and more active patients. Moreover, increases in revision THAs are at least in part due to longer patient life expectancy and more active life style. Improvements in implant design and surgical techniques for revision THAs have led to much better clinical outcome over the past three decades. There are however limitations and suboptimal results of the existing techniques. Efforts in developing and evaluating the efﬁcacy and durability of newer and alter- native designs and techniques must be continued. Cementless ﬁxation has evolved to be the predominant technique in femoral revisions. The commonly used stems include: (1) extensively-coated cylindrical design; (2) proximally-coated cylindrical or anatomically-shaped designs; and (3) modular designs with a variety of