A Study Investigating the Effect of Patient Pelvic Positioning and Method of Acetabular Component Insertion on Acetabular Component Inclination During Total Hip Arthroplasty (THA)
Study Details
Study Description
Brief Summary
Total Hip Arthroplasty (THA) is one of the most commonly performed orthopaedic operations worldwide. The main aim is overall improvement in levels of patient pain and mobility. Such surgery involves implantation of both an acetabular and femoral component. With the patient in the lateral decubitus position, the Orthopaedic Surgeon assumes that the pelvis is in a neutral position with respect to all three body planes at the time of acetabular component implantation.
With regard to THA, the current orthopaedic literature demonstrates a clear relationship between acetabular component positioning, polyethylene wear and risk of dislocation. Problems with edge loading, stripe wear and squeaking are also associated with higher acetabular inclination angles, particularly in hard-on-hard bearing implants.
The important parameters of acetabular component positioning are depth, height, version and inclination.
Control of acetabular component inclination, particularly in the lateral decubitus position, is difficult and remains a challenge for the Orthopaedic Surgeon.
Accurate implantation of the acetabular component within the 'safe zone' of radiological inclination is dependent on:
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Operative version
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Operative inclination
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Pelvic position (Primarily, but not exclusively, abduction / adduction.)
This study aims to investigate the effect of patient pelvic positioning and method of acetabular component insertion on acetabular component inclination during Total Hip Arthroplasty (THA).
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: 0° Head Down (horizontal) & Standard Introducer. Operating table position 0° head down (horizontal) & standard straight acetabular component introducer without alignment guide. |
Procedure: Operating table position 0° head down (Horizontal)
Device: Standard straight acetabular component introducer without alignment guide.
|
| Experimental: 0° Head Down (horizontal) & Modified 35° Introducer. Operating table position 0°head down (horizontal) & modified 35° acetabular component introducer. |
Procedure: Operating table position 0° head down (Horizontal)
Device: Modified 35° acetabular component introducer.
|
| Experimental: 0°Head Down (horizontal) & Inclinometer-assisted Introducer. Operating table position 0°head down (horizontal) & standard straight acetabular component introducer without alignment guide. |
Procedure: Operating table position 0° head down (Horizontal)
Device: Inclinometer-assisted acetabular component introducer.
|
| Experimental: 7° Head Down & Standard Introducer. Operating table position 7° head down & standard straight acetabular component introducer without alignment guide. |
Procedure: Operating table position 7° head down.
Device: Standard straight acetabular component introducer without alignment guide.
|
| Experimental: 7° Head Down & Modified 35° Introducer. Operating table position 7° head down & modified 35° acetabular component introducer. |
Procedure: Operating table position 7° head down.
Device: Modified 35° acetabular component introducer.
|
| Experimental: 7° Head Down & Inclinometer-assisted Introducer. Operating table position 7° head down & inclinometer-assisted acetabular component introducer. |
Procedure: Operating table position 7° head down.
Device: Inclinometer-assisted acetabular component introducer.
|
| Experimental: Y° Head Down & Standard Introducer. Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) & standard straight acetabular component introducer without alignment guide. |
Procedure: Operating table position Y° head down
Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines).
Device: Standard straight acetabular component introducer without alignment guide.
|
| Experimental: Y° Head Down & Modified 35° Introducer. Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) & modified 35°acetabular component introducer. |
Procedure: Operating table position Y° head down
Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines).
Device: Modified 35° acetabular component introducer.
|
| Experimental: Y° Head Down & Inclinometer-assisted Introducer. Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) & inclinometer-assisted acetabular component introducer. |
Procedure: Operating table position Y° head down
Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines).
Device: Inclinometer-assisted acetabular component introducer.
|
Outcome Measures
Primary Outcome Measures
- Radiological acetabular component inclination. [Radiological acetabular component inclination will be measured on the routine post-operative pelvic x-ray, usually within 48 hrs from time of surgery.]
The study has two primary aims, each with a different primary outcome. The first primary aim is to investigate the effect of adjusting patient pelvic position in the transverse plane by using a head down position of the operating table. This is to determine, when aiming for 35° of operative inclination, which operating table position most accurately achieves a target radiological inclination of 42° on the post-operative x-ray: 0° head down (Horizontal), 7° head down, or Y° head down (Angle required to obtain vertical Transverse Pelvic Lines).
- Operative Acetabular Component Inclination. [Operative acetabular component inclination will be measured intra-operatively.]
The study has two primary aims, each with a different primary outcome. The second primary aim is to determine which of the three methods of acetabular component insertion most accurately allows the Orthopaedic Surgeon to obtain the desired operative inclination of 35° during THA when using a cementless cup: Standard straight introducer without any alignment guide, Modified 35° introducer with horizontal alignment guide, or Digital inclinometer assisted introducer.
Secondary Outcome Measures
- Proportion of cases in which the target radiological inclination of 42 +/- 5° is actually obtained. [Radiological acetabular component inclination will be measured on the routine post-operative pelvic x-ray, usually within 48 hrs from time of surgery.]
Eligibility Criteria
Criteria
Inclusion Criteria:
- All patients between the ages of 16 and 100 years awaiting primary Total Hip Arthroplasty the care of Professor D Beverland and Mr D Molloy in Musgrave Park Hospital will initially be invited to participate.
Exclusion Criteria:
- Patients unable to provide fully informed consent.
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Musgrave Park Hospital | Belfast | County Antrim | United Kingdom | BT9 7JB |
Sponsors and Collaborators
- Musgrave Park Hospital
- Belfast Arthroplasty Research Trust (BART)
- Belfast Health and Social Care Trust
- Queen's University, Belfast
Investigators
- Principal Investigator: David E Beverland, MD FRCS(Orth), Musgrave Park Hospital / Belfast Health & Social Care Trust
Study Documents (Full-Text)
None provided.More Information
Publications
- 12080DB-SW