Symax International Study

Not Applicable

Completed

• Conditions: Prosthesis Durability; Hip Osteoarthritis
• Interventions: Device: Symax uncemented hip stem

• Registration Number: NCT03469687
• Lead Sponsor: Maastricht University Medical Center

Brief Summary

The uncemented Symax hip stem is developed through optimization of the uncemented Omnifit hip stem. The Symax stem design combines an anatomical anteverted proximal geometry with a straight distal section. The proximal part is coated with a biomimetic hydroxyapatite (HA) coating for improved osseointegration to enhance load transfer and to minimize proximal bone loss. The distal part is treated with an anodization surface treatment in order to prevent distal bone apposition, which is expected to prevent distal loading and reduce proximal stress shielding. Aim of this study is to report mid-term clinical performance and evaluate whether the radiographic features are in line with the design principles of the Symax hip in an international clinical study with 5 years of follow-up.

Detailed Description

Not available

Study Timeline

• Study Start: 2004-11-02
• Primary Completion: 2010-10-11
• Study Completion: 2010-10-11
• Status Verified: 2018-01
• Study First Submitted: 2018-01-15
• Study First Submitted QC: 2018-03-16
• Last Update Submitted: 2018-03-16
• Study First Posted: 2018-03-19
• Last Update Posted: 2018-03-19

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 80

Inclusion Criteria

• Patients requiring uncemented primary total hip arthroplasty (osteoarthritis, avascular necrosis and/or post-traumatic arthritis), age between 18-70 years, BMI less or equal to 35.

Exclusion Criteria

• Patients with bilateral hip complaints, impaired cognitive function and use of medication or illness influencing bone metabolism.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Symax uncemented hip stem	Symax uncemented hip stem	The Symax hip stem is an uncemented design forged from Ti6Al4V alloy (Stryker EMEA). Primary mechanical stability is provided by anatomical metaphyseal geometry. The hip stem features a size dependent anteversion, neck length and offset, with a CCD angle of 128°. Secondary biological stability is accomplished by fast osseous integration due to the BONIT-HA coating on the metaphyseal part of the stem.

Primary Outcome Measures

Name	Time	Method
Change of Harris Hip Score (HHS) during follow-up	Preoperative HHS and postoperatively change in HHS at 6 months, 1 year, 2 years, 3 years and 5 years	A hip specific functional score

Secondary Outcome Measures

Name	Time	Method
Radiographic evaluations	Immediately postoperative radiograhpic evaluation as baseline and changes in radiography at follow-up 6 months, 1 year, 2 years, 3 years and 5 years we evaluated the radiograhip evaluations again	Radiographic evaluations per Gruen zone and comparison between two assessment teams