Short-stem total hip arthroplasty (THA) has primarily been recommended for young and active patients, mainly due to its bone preserving philosophy. Elderly patients, however, may also benefit of a minimally invasive technique due to the short and curved implant design. The purpose of this study was to compare the clinical and radiological outcomes as well as perioperative complications of a calcar-guided short stem between a young (75 years) population.

Data were collected in a total of 5 centers, and 400 short stems were included as part of a prospective multicentre observational study between 2010 and 2014 with a mean follow-up of 49.2 months. Clinical and radiological outcomes were assessed in both groups. Secondary outcomes such as perioperative complications, rates and reasons for stem revision were also investigated.

No differences were found for the mean visual analogue scale (VAS) values of rest pain, load pain, and satisfaction. Harris Hip Score (HHS) was found to be slightly better in the young group. Comparing both groups, no statistically significant differences ere found in the radiological parameters that were assessed (stress-shielding, cortical hypertrophy, radiolucency, osteolysis). Aseptic loosening was the main cause of implant failure in younger patients whereas in elderly patients, postoperative periprosthetic fractures due to accidental fall was found to be the main cause for stem revision.

These short-term results are encouraging towards the use of a cementless short stem in the geriatric population. According to our findings, advanced age and potentially reduced bone quality should not necessarily be considered as contra-indications for calcar-guided short-stem THA but careful and reasonable selection of the patients is mandatory. Longer follow up is necessary in order to draw safer conclusions.

Introduction: The non-cemented CBC femoral stem has been used in total hip arthroplasty (THA) since 1997. This shaft exists in a standard and a lateralised version. The concept behind the design of the implant focuses on proximal anchoring and load introduction. Migration within the first two years after surgery is confirmed to be a good predictive value for early failure of the femoral component in THA. With respect to the different load transformation of the two stem types clinical outcome and migration were investigated.

Material and Methods: Prospective follow-up study of 170 patients (52% female) who received 172 non-cemented CBC femoral stems. THA was performed in eight European clinics between March 2001 and April 2005. 127 standard and 45 lateral CBC stems were implanted. 106 cases fulfilled the criteria having a series of four X-rays during a minimum period of two years. After a mean follow-up of 32.1 months in 106 patients migration was analysed using the EBRA system. The mean age at surgery was 66.9 years (range, 39.1–85.2 years). Mean body mass index was 27.8 kg/m2 (range, 16.3–42.6 kg/m2).

Results: The average subsidence is − 0.63 mm (− 0.36 mm lateral, − 0.75 mm standard group), 7.6% of the stems showed a subsidence of > 2 mm. None of the lateralised stems migrated > 3 mm, but there is no statistical significance between the groups. There is no evidence of association of high stem migration (> 2 mm) and lower scores. The HHS increased from a preoperative mean of 51 to 96 points after 5 years follow-up. At last follow-up patients with a standard stem had a flexion, external rotation and total ROM value of 105°, 29°, and 220°, respectively. Patients with a lateralised stem reached values of 115°, 36°, and 237°, respectively. Interestingly, 93% of patients with a lateral stem indicated putting on socks “easy”, compared to 81% in the standard group, although the BMI of patients with a lateralised stem was significantly (p=0.014) higher. No thigh pain was reported after 5 years follow-up. No revisions had taken place.

Conclusion: The prism-shaped geometry of the ribs promotes good osteointegration. The standard stems showed higher migration values compared to the lat-eralised stem, statistically not significant. Patients with a lateralised femoral component showed better results for ROM, flexion, external rotation, putting on socks. Putting on socks “easy” was positively correlated with a higher flexion angle. All patients undergoing THA showed significant improvements in postoperative functioning and activity level after the implantation of a CBC stem. None of the stems had to be revised.