Benefit of Orthopedic Navigation in the ARThroplasty of the Hip

Study Overview
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Brief Summary
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This study was initiated to investigate the impact of the computer based image free navigation on the precision of the cup implantation. The implantation of the acetabular component (cup) is known to be a critical step in hip endoprosthetics. The cup position influences significantly the function, the absence of pain and the longevity of the artificial hip joint. The image free navigation system OrthoPilot is used to control the positioning of the cup during surgery.

Official Title
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Randomised Controlled Double-blind Monocenter Therapy Study Validating the Benefit From Information Provided by Image Free Navigation System on the Precision of the Placement of Acetabular Component in Patients Undergoing Primary THA

Conditions
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Osteoarthritis, Hip, Arthritis, Rheumatoid, Femur Head Necrosis

Intervention / Treatment
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* Procedure: Manual Intervention
* Procedure: Navigated Intervention


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Indication for primary cementless total hip endoprosthesis implantation with Bicontact stem and Plasmacup Diagnoses: primary or secondary coxarthrosis, rheumatoid arthritis, femoral head necrosis Age ≥ 50 Years ASA score <4 Patient signed the informed consent Exclusion Criteria: Excessive damage to the hip joint (e.g. dysplasia) Severe deformities of the pelvis, femoral bone or knee Unfeasibility of landmark palpation (e.g. due to adiposity) Acute or chronic infection Pregnancy Patients not available for follow-up-examination at the center Patients exceeding 10 mSv effective radiation dose because of previous scientific or clinical exposition during the past 10 years

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Sham Comparator: Manual<br>Manual Implantation of THA | Procedure: Manual Intervention<br>* Implantation of acetabular component without the use of the navigation system information<br>* Other names: Conventional THA;|
| Experimental: Navigated<br>Navigated Implantation of THA | Procedure: Navigated Intervention<br>* Navigated implantation of acetabular component using OrthoPilot image free navigation system<br>* Other names: Computer assisted orthopedic surgery;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Evaluation of improvement of the implantation accuracy of acetabular component by navigation compared to manual implantation | The ratio of implantations within the intraoperatively adjusted safe zone of Lewinnek (target anteversion +/-10°, target inclination +/-10°), proved by a CT-scan control measurement. | 3 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Comparison of implantation precision, postoperative function and complication rates with vs. without gaining information from navigation system. | The ratio of implantations within the intraoperatively determined safe zone of 5° (target anteversion +/-5°, target inclination +/- 5°) Geometric deviation from the target implantation position Range of Motion Harris hip score 3 months postoperative Complication rate until 3 months Correlation of manual and ultrasound registration of the anterior pelvic plane (independent from therapy group) Proposal and validation of a combined Hip Alignment Score for navigated implantation | 3 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Navigation OrthoPilot Hip TEP THA