Changes of Bone Mineral Density in Total Hip Arthroplasty

Changes of Bone Mineral Density in Total Hip Arthroplasty - A Prospective Comparison of Isoelastic and Metal-backed Cup Designs

The study was performed as a prospective, single center study at the Department of Orthopedics, Sacred Heart of Jesus Hospital Vienna, Austria. 117 patients were enrolled in a from January 2016 to May 2017. 53 patients received an isoelastic monoblock cup (RM Pressfit vitamys® Mathys) and 64 patients received a metal- backed modular cup (ANA.NOVA® ImplanTec). Dual-energy x-ray absorptiometry scans according to DeLee and Charnley Zones were performed at time points 0, 3, 6, 12, and 24 months after surgery. The aim of thise study was to compare changes in BMD between an isoelastic monoblock cup and a titanium modular cup. We hypothesized that the more elastic monoblock cup performs better than the more rigid modular cup with regard to changes in BMD.

Study Overview

• Status: Completed
• Conditions: Bone Mineral Density

Detailed Description

The study was performed as a prospective, single center study at the Department of Orthopedics, Sacred Heart of Jesus Hospital Vienna, Austria.

Inclusion criteria were as follows: any patient aged from 18 years onwards undergoing primary cementless THA for degenerative joint disease, including osteoarthritis, post-traumatic arthritis, congenital hip dysplasia and avascular necrosis. Excluded were all patients with malignant diseases and pregnant women, additionally, patients were excluded if severe complications such as fracture or revision surgery occurred during the study period.

Patients were enrolled from January 2016 to May 2017, a total of 117 patients were included. All patients underwent uncemented THA, patients either received a monoblock cup (RM Pressfit vitamys®; Mathys Ltd. Bettlach, Switzerland), or a titanium shell (ANA.NOVA® Implantec, Mödling, Austria). DEXA measurements according to the DeLee and Charnley Zones were performed postoperatively, 3, 6, 12 and 24 months after primary hip arthroplasty. Bone mineral density (BMD) was measured by using the bone densiometer (Lunar, Prodigy, GE Medical Sytsems). A special legholder was used to fix the leg to ensure the same rotation and avoid measurement errors. DEXA measurements were performed and analyzed by two trained authors. Statistical analysis focused on differences in BMD between monoblock cup and modular cup after 3, 6, 12 and 24 months as well as changes in BMD in relation to cup inclination. In order to gain valid results, the nonparametric Wilcoxon rank-sum test was used. We used t-Test to evaluate differences to the baseline. A probability value of p ≤0.05 was considered as statistically significant. Data was analyzed using Microsoft Excel® and SPSS® (version 26.0, SPSS Inc., Chicago, IL, USA) representing standard statistical software. We hypothesized that the more elastic monoblock cup performs better than the more rigid modular cup with regard to changes in BMD.

• Study Type: Observational
• Enrollment (Actual): 117

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients who either received a monoblock cup (RM Pressfit vitamys®; Mathys Ltd. Bettlach, Switzerland), or a titanium shell (ANA.NOVA® Implantec, Mödling, Austria) between January 2016 and May 2017. 117 patients (female 69, male 48), mean age was 68 years (range, 43 to 89 years)

Description

Inclusion Criteria:

• any patient aged from 18 years onwards undergoing primary cementless THA for degenerative joint disease, including osteoarthritis, post-traumatic arthritis, congenital hip dysplasia and avascular necrosis.

Exclusion Criteria:

• patients with malignant diseases and pregnant women, additionally, patients were excluded if severe complications such as fracture or revision surgery occurred during the study period.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

2

Cohorts and Interventions

Group / Cohort
Monoblock Cup; 53 patients received a monoblock cup (RM Pressfit vitamys®)
Modular Cup; 64 patients received a modular cup (ANA.NOVA® Implantec)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Dexa meassurments	Changes in BMD according to DeLee and Charnley Zones	24 Months

Collaborators and Investigators

• Sponsor: St. Vincent Hospital, Vienna

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2016
• Primary Completion (Actual): May 9, 2019
• Study Completion (Actual): April 1, 2021

Study Registration Dates

• First Submitted: July 10, 2021
• First Submitted That Met QC Criteria: July 10, 2021
• First Posted (Actual): July 15, 2021

Study Record Updates

• Last Update Posted (Actual): July 15, 2021
• Last Update Submitted That Met QC Criteria: July 10, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Keywords: Total Hip Arthroplasty; DEXA
• Other Study ID Numbers: DEXA THA

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No