Predicting reduction loss risk after acromioclavicular joint dislocation treated with the endobutton device.

Area of Science:

• Orthopedic Surgery
• Biomedical Engineering

Background:

• Acromioclavicular (AC) joint dislocation is a common shoulder injury.
• The Endobutton device is frequently used for AC joint reconstruction.
• Reduction loss can negatively impact patient outcomes.

Purpose of the Study:

• To identify risk factors for reduction loss after Endobutton fixation for AC joint dislocation.
• To develop a nomogram to predict the probability of reduction loss.
• To evaluate clinical outcomes in patients with reduction loss.

Main Methods:

• Retrospective review of 250 patients treated with Endobutton device.
• Logistic regression analysis to identify risk factors for reduction loss.
• Nomogram construction and validation for prediction accuracy.
• Assessment of Visual Analogue Scale (VAS) and Constant scores for clinical outcomes.

Main Results:

• Reduction loss occurred in 25.6% of patients.
• Independent risk factors for reduction loss included conoid/trapezoid tunnel ratios, coracoid button position, additional pin fixation, and weight-bearing time.
• The nomogram achieved a predictive accuracy of 0.896.
• Patients with >100% distal clavicle displacement had significantly worse VAS and Constant scores.

Conclusions:

• Displacement >100% of distal clavicle thickness correlates with poorer outcomes.
• Reduction loss is associated with tunnel malposition, lack of additional fixation, and premature weight-bearing (<5 weeks).
• The developed nomogram effectively identifies high-risk patients, guiding close follow-up and potential surgical intervention to decrease reduction loss rates.