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.

Objective: Dislocation is a well known complication after total hip arthroplasty (THA), and the second cause of revision surgery. Our objective was to assess the effect of a pre-operative patient education session on the occurrence of hip dislocation within 6 months after primary THA.

Methods: Between 1998 and 2007 we conducted a prospective cohort study at the University Hospital Department of Orthopaedic Surgery including all primary THAs performed via a transgluteal approach and with use of a 28mm diameter head. The preoperative education session was introduced in June 2002 and included advice on muscle strengthening exercises and postoperative restrictions of range of motion as means of preventing dislocation. Main outcome was the incidence of dislocation within 6 months of surgery. The following potentially confounding factors were assessed: age, sex, body mass index, number of co-morbidities, presence of a neurological disorder, history of alcohol abuse, American Society of Anaesthesiologists (ASA) score, diagnosis (primary or secondary osteoarthritis), previous surgery of the hip, surgeon experience, preoperative functional status, pain level, and motion (Harris Hip Score), preoperative general health status (SF-12), and private or public health care insurance (as proxy for socioeconomic status). Multivariable logistic regression was used for adjustment.

Results: 597 patients who underwent 656 THAs between June 2002 and June 2007 participated in the education session, while 1641 patients who underwent 1945 procedures did not. Forty-six dislocations occurred over the study period, 5 (0.8%) in participants and 41 (2.1%) in non-participants (risk difference 1.3%; 95% CI 0.4; 2.3), with the time interval between surgery and dislocation being significantly shorter among participants (0.2 vs. 1.2 months, p=0.016). Preoperative counselling of 77 patients allowed for preventing one dislocation (number needed to treat). Non-participants had a 2.8 times higher risk of dislocation than participants (unadjusted odds ratio 2.80, 95% CI 1.10; 7.13). Adjustment for age, sex, co-morbidities and prior surgery did not change the results (adjusted odds ratio 2.79, 95% CI 1.09; 7.15).

Conclusion: Preoperative patient education reduced the dislocation risk within 6 months after THA, and particularly after the patient had returned home. Other peri-operative benefits from patient education have been reported and should be considered in a cost-effectiveness analysis.