Clinical experience
A clinical safety and efficacy trial, including 100 patients and 9 surgeons, was performed over three phases in the period September 2011 – September 2014. Of important results can be mentioned:
- 50% decrease in operations where supplementing screw fixation was used
- Number of cups fully seated increased from 90% to 100%
- 77% more cups with accumulated anterior and posterior overhang
(protrution) less than 10 degrees
These results are not statistically significant due to small population size in this phase of the trial (phase three – see below). Results of the evaluations given by the surgeons involved, of the X-pander version used in phase three of the trial, included that in.
a) 93.6% of the operations it vas evaluated that X-pander can provide useful knowledge
about the reamed acetabulum’s geometry
b) 93.6% of the operations it vas evaluated that X-pander can provide useful knowledge
about the reamed acetabulum’s stiffness
c) 97.8% of the operations it vas evaluated that X-pander can provide useful knowledge
concerning choice of cup size
d) 74.5% of the operations it vas evaluated that X-pander can provide useful information
about positioning of the cup
Overall conclusion of the trial was:
X-pander is a safe clinical device that meets requirements for efficacy as set fourth in the Clinical Investigation Plan. The results and sub-conclusions indicates that the use of X-pander is likely to lead to real clinical improvements and it is therefore the ultimate conclusion, that X-pander should be marketed and recommended as standard equipment when performing total hip arthroplasty.
Objective and design
The purpose of the clinical investigation was to evaluate the ergonomic design, functionality, safety and efficacy of X-pander in clinical use. The method used was a consecutive, prospective, historic comparative, non-randomized and non-blinded investigation.
The investigation took place at Aalborg University Hospital, Denmark and as the mechanical design of X-pander was updated on two occasions during the trial, to meet with surgeons’ input for usability, the investigation was divided into three phases:
- Phase 1 with the first design of X-pander commenced from September 2011 to March 2012. In this phase a total of 30 patients was operated with the use of X-pander.
- Phase 2 with the second design of X-pander commenced from August to December 2012. In this phase a total of 22 patients was operated with the use of X-pander.
- Phase 3 with the third and final design of X-pander commenced from May to September 2014. In this phase a total of 48 patients was operated with the use of X-pander.
The results 1), 2) and 3) above is comprised by 20 X-pander operations performed by two surgeons during phase 3, compared to 30 operations performed by the same two surgeons using the same cup type before taking X-pander into use. The results a) – d) are based on surgeon evaluations from all 48 X-pander operations performed during phase 3.