A Study Investigating the Effect of Patient Pelvic Positioning and Method of Acetabular Component Insertion on Acetabular Component Inclination During Total Hip Arthroplasty (THA)

Musgrave Park Hospital

Status: Completed

Conditions: THA; Total Hip Arthroplasty; THR; Total Hip Replacement

Treatments: Device: Standard straight acetabular component introducer without alignment guide.; Procedure: Operating table position Y° head down; Device: Modified 35° acetabular component introducer.; Procedure: Operating table position 0° head down (Horizontal); Device: Inclinometer-assisted acetabular component introducer.; Procedure: Operating table position 7° head down.

Study type: Interventional

Funder types: Other

Identifiers

NCT01831401

12080DB-SW

Details and patient eligibility

About

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:

• Operative version
• Operative inclination
• 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).

Enrollment: 270 patients

Sex: All

Ages: 16 to 100 years old

Volunteers: No Healthy Volunteers

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.

Trial design

270 participants in 9 patient groups

0° Head Down (horizontal) & Standard Introducer.

Experimental group

Description:

Operating table position 0° head down (horizontal) \& standard straight acetabular component introducer without alignment guide.

Treatment:

Device: Standard straight acetabular component introducer without alignment guide.

Procedure: Operating table position 0° head down (Horizontal)

0° Head Down (horizontal) & Modified 35° Introducer.

Experimental group

Description:

Operating table position 0°head down (horizontal) \& modified 35° acetabular component introducer.

Treatment:

Procedure: Operating table position 0° head down (Horizontal)

Device: Modified 35° acetabular component introducer.

0°Head Down (horizontal) & Inclinometer-assisted Introducer.

Experimental group

Description:

Operating table position 0°head down (horizontal) \& standard straight acetabular component introducer without alignment guide.

Treatment:

Device: Inclinometer-assisted acetabular component introducer.

Procedure: Operating table position 0° head down (Horizontal)

7° Head Down & Standard Introducer.

Experimental group

Description:

Operating table position 7° head down \& standard straight acetabular component introducer without alignment guide.

Treatment:

Procedure: Operating table position 7° head down.

Device: Standard straight acetabular component introducer without alignment guide.

7° Head Down & Modified 35° Introducer.

Experimental group

Description:

Operating table position 7° head down \& modified 35° acetabular component introducer.

Treatment:

Procedure: Operating table position 7° head down.

Device: Modified 35° acetabular component introducer.

7° Head Down & Inclinometer-assisted Introducer.

Experimental group

Description:

Operating table position 7° head down \& inclinometer-assisted acetabular component introducer.

Treatment:

Device: Inclinometer-assisted acetabular component introducer.

Procedure: Operating table position 7° head down.

Y° Head Down & Standard Introducer.

Experimental group

Description:

Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) \& standard straight acetabular component introducer without alignment guide.

Treatment:

Device: Standard straight acetabular component introducer without alignment guide.

Procedure: Operating table position Y° head down

Y° Head Down & Modified 35° Introducer.

Experimental group

Description:

Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) \& modified 35°acetabular component introducer.

Treatment:

Device: Modified 35° acetabular component introducer.

Procedure: Operating table position Y° head down

Y° Head Down & Inclinometer-assisted Introducer.

Experimental group

Description:

Operating table position Y° head down (angle required to obtain vertical Transverse Pelvis Lines) \& inclinometer-assisted acetabular component introducer.

Treatment:

Device: Inclinometer-assisted acetabular component introducer.

Procedure: Operating table position Y° head down