Comparison of Tri-Lock Bone Preservation Stem and the Conventional Standard Corail Stem in Primary Total Hip Arthroplasty

Objective To compare the clinical and radiographic outcomes between the Tri-Lock Bone Preservation Stem (BPS) and the conventional standard Corail stem in primary total hip arthroplasty (THA). Methods From March 2012 to May 2014, we retrospectively reviewed 84 patients (104 hips) who received Tri-Lock (BPS) and 84 patients (115 hips) who received conventional standard Corail stem in THA. Their mean ages were 53.12 +/- 2.32 years and 52.00 +/- 2.11 years, respectively. The clinical outcomes were assessed by Western Ontario and McMaster University Osteoarthritis Index (WOMAC), Pain Visual Analogue Scale (VAS) and Harris Hip Score (HHS). The radiological outcomes were evaluated by the radiological examination. Accordingly, Intraoperative and postoperative complications were observed as well. Results The mean follow-up time was 48.23 +/- 2.91 months in the Tri-Lock (BPS) group and 49.11 +/- 2.11 months in the Corail group, respectively. The bleeding volumes in two groups were comparable (169.22 +/- 58.11 mL vs 179.30 +/- 59.14 mL, P = 0.003), with more bleeding volume in Corail group patients, while no statistically significance with respect to operation time was observed (65.41 +/- 6.24 min vs 63.99 +/- 6.33 min, P = 0.567). The rates of intraoperative fracture was 8% for the Corail group while 1% for the Tri-Lock (BPS) group (8% vs 1%, P = 0.030). At final follow-up, no statistical differences in regard to HHS, WOMAC, and Pain VAS were revealed between the two groups (P > 0.05). The rate of thigh pain was higher in Corail group than in Tri-lock (BPS) group (5% vs 0%, P = 0.043). However, incidence of stress shielding in grade 1 was higher in Tri-Lock (BPS) than in the Corail group (76% vs 23%, P < 0.01), while those in grade 2 and 3 were lower compared to the Corail stem (15% vs 28%, P < 0.01; 9% vs 16%, P = 0.008, respectively). Intriguingly, other assessments in relation to radiographic outcomes and postoperative complications were not comparable between the two groups. The Kaplan-Meier survival rate (revision surgery performed for any reason was defined as the end point) was similar between the two groups (P = 0.57), with 98.8% (95% confidence interval, 92.3%-100%) in Tri-lock (BPS) group and 97.6% (95% confidence interval, 94.6%-100%) in Corail group. Conclusions The Tri-Lock (BPS) has similar clinic performances compared to the Corail stem. Furthermore, the Tri-lock (BPS) stem has some advantages in achieving lower incidence of thigh pain, stress shielding and intra-operative fracture. Therefore, we recommend the Tri-lock (BPS) stem as a good alternative in primary total hip arthroplasty, especially taking into account patient factors, including bone deficiency and convenience of extraction of the stem in hip revision.