Previously held under moratorium from 23 November 2016 until 23 November 2021Correct positioning of the acetabular cup is critical for success within Total
Hip Arthroplasty. Malpositioning of the acetabular cup contributes to many
complications, all of which lead to revision surgery. Despite recognition of the
importance of correct orientation, there is no consensus on what the optimum
orientation of the acetabular cup should be. The suggested orientations in the
literature are contradictory and comparison between studies is difficult due to
variations in angle definitions, measurement systems and reference systems. These
contradictions, the lack of consensus in the literature and results from studies
suggest that acetabular orientation must be patient specific.
Mechanical guides are the most commonly used device to assist surgeons in
positioning the acetabular cup, both in cemented and uncemented arthroplasties.
However, these devices have many limitations one of which is a fixed acetabular
orientation which does not allow for any patient variability.
Using a combination of quantitative and qualitative product design
techniques, Harrison User Centred Methodology was developed. This new
methodology was adopted to design and develop a device to aid surgeons with
positioning the acetabular cup in total hip arthroplasty. The aim was to design a
device which could be used for both cemented and uncemented hip arthroplasty.
The final device design was a novel positioning guide which addressed the lack of
patient variability in current mechanical guides. The device simplified the positioning
and limited the movement of the introducer. Feedback from surgeons demonstrated
a positive response and with further development, a willingness to try the product.
Proof of concept testing was carried out to measure the accuracy of the
device. An available (uncemented) introducer was used for testing which
demonstrated the device can accurately position the acetabular cup. The accuracy
of the developed device and current techniques was compared. The study showed
less variation in the position over time using the novel device which highlights an
added benefit for cemented procedures demonstrating stability as the cement cures.Correct positioning of the acetabular cup is critical for success within Total
Hip Arthroplasty. Malpositioning of the acetabular cup contributes to many
complications, all of which lead to revision surgery. Despite recognition of the
importance of correct orientation, there is no consensus on what the optimum
orientation of the acetabular cup should be. The suggested orientations in the
literature are contradictory and comparison between studies is difficult due to
variations in angle definitions, measurement systems and reference systems. These
contradictions, the lack of consensus in the literature and results from studies
suggest that acetabular orientation must be patient specific.
Mechanical guides are the most commonly used device to assist surgeons in
positioning the acetabular cup, both in cemented and uncemented arthroplasties.
However, these devices have many limitations one of which is a fixed acetabular
orientation which does not allow for any patient variability.
Using a combination of quantitative and qualitative product design
techniques, Harrison User Centred Methodology was developed. This new
methodology was adopted to design and develop a device to aid surgeons with
positioning the acetabular cup in total hip arthroplasty. The aim was to design a
device which could be used for both cemented and uncemented hip arthroplasty.
The final device design was a novel positioning guide which addressed the lack of
patient variability in current mechanical guides. The device simplified the positioning
and limited the movement of the introducer. Feedback from surgeons demonstrated
a positive response and with further development, a willingness to try the product.
Proof of concept testing was carried out to measure the accuracy of the
device. An available (uncemented) introducer was used for testing which
demonstrated the device can accurately position the acetabular cup. The accuracy
of the developed device and current techniques was compared. The study showed
less variation in the position over time using the novel device which highlights an
added benefit for cemented procedures demonstrating stability as the cement cures