A stature-specific concept for uncemented, primary total hip arthroplasty

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Reconstructive Surgery

Background:

• Standard uncemented hip stems face challenges with femoral canal fit, leading to leg length discrepancies and offset issues in total hip arthroplasty (THA).
• These anatomical fit issues can result in impingement, dislocation, and wear, compromising THA outcomes.
• Modular stems and neck options offer potential solutions for improved fit and reconstruction.

Purpose of the Study:

• To evaluate the efficacy of an uncemented modular neck, dual-stem system in primary total hip arthroplasty (THA).
• To assess the system's ability to achieve accurate joint reconstruction, addressing femoral canal fit, leg length discrepancy, and offset.
• To determine the medium-term clinical and radiological outcomes and implant survival rates.

Main Methods:

• A prospective study involving 173 patients (190 hips) undergoing uncemented THA with a modular neck, dual-stem system.
• Two different stem shapes were used for canal fit, combined with modular necks for patient-specific reconstruction.
• Clinical and radiological outcomes were evaluated at a median follow-up of 9 years, with 155 hips available for assessment.

Main Results:

• High implant survival rates at 10 years: 100% for stems, 99% for modular necks, and 94% for cups.
• Excellent reconstruction accuracy: 96% achieved no leg length discrepancy and 98% achieved accurate offset.
• Positive functional outcomes with high median Harris hip scores (94) and Merle d'Aubigné scores (16), with no significant radiolucent lines or osteolysis.

Conclusions:

• The uncemented modular neck, dual-stem system facilitates precise anatomical reconstruction in THA.
• This adaptability to patient-specific needs may lead to improved outcomes and reduced complications in primary THA.
• Medium-term results support the effectiveness of this modular implant system for total hip arthroplasty.