Collared versus collarless femoral stems for primary total hip replacement

Comparing Collared and Collarless Femoral Stems in Total Hip Arthroplasty

Not applicable Interventional Medstar Health Research Institute · NCT07337642

This trial will test whether adding a collar to a femoral stem reduces sinking (subsidence) and lowers fracture risk in adults having an uncemented total hip replacement for osteoarthritis.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment100 (estimated)
Ages18 Years to 99 Years
SexAll
SponsorMedstar Health Research Institute Academic / other
Locations1 site (Washington D.C., District of Columbia)
Trial IDNCT07337642 on ClinicalTrials.gov

What this trial studies

This is a prospective, randomized comparison of two femoral stem options—one with a collar and one without—that share the same triple-taper design, used in primary uncemented total hip arthroplasty. Participants are adults with non-inflammatory degenerative hip disease who are randomized to receive either the collared or collarless stem, with serial clinical assessments and radiographs scheduled after surgery. The study will quantify subsidence on serial radiographs and record intraoperative and postoperative periprosthetic fractures and aseptic loosening rates. Results will compare clinical outcomes and radiographic behavior between the two implant groups at prespecified follow-up intervals.

Who should consider this trial

Good fit: Adults aged 18 or older scheduled for a primary, uncemented total hip arthroplasty for non-inflammatory degenerative joint disease who can give informed consent and complete follow-up are ideal candidates.

Not a fit: Patients who need cemented or hybrid components, have prior surgery on the same hip, active or prior hip infection, severe osteoporosis, revision/conversion THA, or cannot complete follow-up are unlikely to benefit from this comparison.

Why it matters

Potential benefit: If successful, the collared design could reduce implant sinking and fracture risk, improving early stability and potentially prolonging implant survival.

How similar studies have performed: Biomechanical and observational studies have suggested collars may reduce subsidence and certain fracture risks, but high-quality randomized data comparing identical stem designs with and without collars are limited.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Adults (≥ 18 years old) scheduled for primary, uncemented THA using a cementless femoral stem
* Diagnosis of primary osteoarthritis or other non-inflammatory degenerative joint disease.
* Ability and willingness to comply with study procedures and follow-up schedule.
* Ability to provide written informed consent

Exclusion Criteria:

* Patients not indicated for a cementless THA
* Prior surgery on the ipsilateral hip (e.g., prior THA, internal fixation, osteotomy)
* Use of cemented or hybrid femoral components.
* Revision THA or conversion THA
* Active or prior infection of the hip joint.
* Severe osteoporosis (T-score ≤ -2.5) or known metabolic bone disease.
* Inability to complete follow-up or anticipated relocation out of the area.

Where this trial is running

Washington D.C., District of Columbia

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Primary Total Hip Arthroplasty
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.