Symax International Study

Maastricht University Medical Center80 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

Purpose

TREATMENT

Masking

NONE

Enrollment

Conditions

Hip Osteoarthritis Prosthesis Durability

Interventions

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Change of Harris Hip Score (HHS) during follow-up

A hip specific functional score

Time frame: Preoperative HHS and postoperatively change in HHS at 6 months, 1 year, 2 years, 3 years and 5 years

Secondary Outcomes

Radiographic evaluations

Radiographic evaluations per Gruen zone and comparison between two assessment teams

Time frame: 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