Greater increase in femoral offset with use of collum femoris-preserving stem than Tri-Lock stem in primary total hip arthroplasty

Objective This study was performed to compare the clinical outcomes and performance of the collum femoris-preserving (CFP) stem (Waldemar Link GmbH & Co., Hamburg, Germany) and the Tri-Lock stem (DePuy Orthopaedics, Warsaw, IN, USA) in terms of femoral offset (FO) and leg length reconstruction. Methods Clinical and radiographic data of patients who underwent total hip arthroplasty with either a CFP stem or Tri-Lock stem from January 2016 to March 2017 were compared (65 and 57 patients, respectively). The Harris hip score and Western Ontario and McMaster Universities Osteoarthritis Index were recorded. The FO, femoral vertical offset, and neck–shaft angle were measured at the last follow-up. The occurrence of dislocation and periprosthetic fracture during the follow-up period was recorded. Results The CFP stem induced significantly more FO than did the Tri-Lock stem on the operated side than contralateral side (3.63 ± 4.28 vs. 0.83 ± 5.46 mm). Significantly fewer patients had a >5-mm decrease in FO on the unaffected side in the CFP stem group ( n = 1) than Tri-Lock stem group ( n = 10). Conclusion Both stems similarly improved hip function and reconstructed the leg length, but the CFP stem was superior to the Tri-Lock stem in reconstructing FO.