[Our Experience with RM Pressfit Vitamys Cup and Cementless Optimys Short Stem]

Area of Science:

• Orthopedic Surgery
• Biomaterials Engineering
• Radiology

Background:

• Cementless total hip arthroplasty (THA) relies on primary fixation and component positioning for long-term success.
• Understanding bone remodeling and implant integration is crucial for predicting clinical outcomes and implant survivorship.

Purpose of the Study:

• To evaluate clinical outcomes and bone tissue remodeling around RM Pressfit Vitamys cementless elastic cups and Optimys short cementless stems at 3-6 years post-implantation.
• To assess implant stability, femoroacetabular offset, and signs of complications such as aseptic loosening or osteolysis.

Main Methods:

• Retrospective evaluation of 49 THA cases (2012-2015) using RM Pressfit Vitamys cups and Optimys stems.
• Postoperative assessment included implant position, femoroacetabular offset, osseointegration, bone remodeling, and aseptic loosening via X-ray.
• Functional status was evaluated using the Harris Hip Score (HHS).

Main Results:

• Excellent osseointegration was observed for all Vitamys cups.
• No radiolucent lines or osteolysis were detected around components; minimal stem migration occurred in 2 cases.
• Mean HHS increased from 53 to 97, with 44 excellent results (100 points in 28 cases).
• 100% survival rate for both components (Kaplan-Meier analysis).
• Minimal stress shielding observed in 2 stems; no polyethylene wear.

Conclusions:

• The RM Pressfit Vitamys cup's elasticity promotes symmetrical stress distribution, mimicking bone tissue.
• The Optimys stem facilitates anatomical reconstruction, contributing to favorable hip joint function.
• Achieving good primary fixation and minimizing wear are key for long-term implant survivorship and successful reimplantation outcomes.