Periprosthetic Bone Mineral Density Changes After Implantation Of A Short Hip Stem Compared To A Straight Stem

University Hospital Ulm

Status: Unknown

Conditions: Osteoarthritis, Hip

Treatments: Procedure: Total Hip Arthroplasty

Study type: Interventional

Funder types: Other

Identifiers

NCT03147131

D.3067-244/10

Details and patient eligibility

About

The aim of this study is to evaluate periprosthetic bone mineral density (BMD) changes in the proximal femur after implantation of the Fitmore compared to the CLS stem.

Full description

After power analysis, 140 consecutive patients were prospectively included in the randomisation protocol receiving either a Fitmore short or a CLS straight stem. The short stem was assigned in 57 (37% females) cases and the straight stem in 83 (38% females) hips. Periprosthetic bone mineral density was measured before surgery, 7 days, 3, 12 and 60 months postoperatively, using dual energy x-ray absorptiometry (DEXA). The results of the first postoperative measurement served as the baseline value. Because of the different length of the two prostheses we used adapted Gruen zones to divide the periprosthetic bone in seven regions of interest (ROI) with equal length in the proximal zones 1,2,6 and 7, only the regions 3 and 5 featured different sizes. Clinical results were recorded using the WOMAC and the Harris hip score (HHS).

Enrollment: 126 estimated patients

Sex: All

Ages: 18 to 75 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Primary or secondary osteoarthritis of the hip
• written informed consent
• indication for cementless total hip arthroplasty

Exclusion criteria

• previous surgery in the same hip
• femoral fracture
• metabolic bone disease
• drugs affecting bone quality
• contralateral THA within the study period
• infectious disease or bony tumor

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Single Blind

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126 participants in 2 patient groups

Fitmore short stem

Active Comparator group

Description:

Intervention: Total hip arthroplasty with an uncemented femoral short stem, the Fitmore short stem (Zimmer, Warsaw, USA). Furthermore, an uncemented cup (Allofit, Zimmer, Warzaw, USA). Device: Fitmore Short Stem

Treatment:

Procedure: Total Hip Arthroplasty

CLS straight stem

Active Comparator group

Description:

Intervention: Total hip arthroplasty with an uncemented femoral straight stem, the CLS short stem (Zimmer, Warsaw, USA).Furthermore, an uncemented cup (Allofit, Zimmer, Warzaw, USA). Device: CLS Straight Stem

Treatment:

Procedure: Total Hip Arthroplasty