A Geometric Model to Determine Patient-Specific Cup Anteversion Based on Pelvic Motion in Total Hip Arthroplasty
Table 2
Clinical scenarios comparing a patient’s calculated standing, sitting, and change in functional anteversion to the population-based averages and the respective guidance provided by the mobile application.
Standing Anteversion
Sitting Anteversion
Change in Anteversion
Clinical Outcome
Tool Guidance
Greater than average
Appropriate
Appropriate
Potential for posterior impingement when standing
Decrease intra-operative anteversion
Greater than average
Less than average
Appropriate
Unlikely scenario as appropriate pelvic mobility should provide adequate seated anteversion when standing anteversion is increased
This patient has good pelvic mobility and adjustments may cause instability or impingement, maintain anteversion
Appropriate
Less than average
Appropriate
Low sitting anteversion may lead to posterior instability when sitting
Increase intra-operative anteversion
Appropriate
Less than average
Less than average
Low sitting and change in anteversion may lead to posterior instability when sitting
Increase intra-operative anteversion by greater discrepancy
Appropriate
Appropriate
Less than average
Low change in anteversion may lead to posterior instability when sitting
Increase intra-operative anteversion
Greater than average
Appropriate
Less than average
Decreased pelvic mobility and potential for impingement when standing, but patient can achieve normal sitting anteversion
Decrease intra-operative anteversion (stop if decrease leads to decreased sitting anteversion below average)
Greater than average
Less than average
Less than average
Patient has very limited pelvic mobility
Cup anteversion adjustments could be detrimental. Consider additional articulation options
