Postoperative Medial Gutter Impingement Following Primary Total Ankle Arthroplasty: A Retrospective Case-Control...

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering
• Radiology

Background:

• Medial gutter impingement can negatively impact total ankle arthroplasty (TAA) success.
• Predisposing factors for medial impingement after TAA have not been previously identified.
• This study investigates risk factors and the role of talar component downsizing in preventing medial impingement.

Purpose of the Study:

• To identify predisposing radiographic factors for medial gutter impingement following TAA.
• To evaluate the effectiveness of talar component downsizing in reducing the incidence of medial impingement.
• To compare radiographic parameters between patients with and without medial impingement.

Main Methods:

• Retrospective case-control study involving 149 patients (34 reoperated for medial impingement, 115 controls).
• Radiographic analysis included pre- and post-TAA coronal alignment, talar center of migration ratio (TCMr), joint line height ratio (JLHR), and absolute talar component rotation (aTR).
• Logistic regression was used to assess correlations between medial impingement, radiographic parameters, and talar component downsizing.

Main Results:

• Talar component downsizing was significantly less frequent in the medial impingement group (29.4% vs. 70.4% in controls).
• Medial impingement was associated with postoperative varus alignment, elevated joint line, increased medial talar translation (TCMr), and internal talar rotation (aTR).
• Talar downsizing showed a strong negative correlation with medial impingement probability (OR=0.18).

Conclusions:

• Talar component downsizing is a key factor in reducing medial gutter impingement after TAA, correlating with an 82% reduction in impingement probability.
• Postoperative varus alignment, elevated joint line, and medial/internal talar component positioning are prevalent in patients requiring reoperation for medial impingement.