Tensile characteristics of the acromioclavicular joint: a systematic review and meta-analysis.
Genevieve M Fraipont, Ryan S Beyer, Claire G Olivas et al.
✦ AI-curated · Sources linked
In 30 seconds
This systematic review and meta-analysis pooled cadaveric evidence on the tensile properties of intact acromioclavicular joint ligaments, including 26 studies and 374 shoulders. The combined acromioclavicular–coracoclavicular complex and isolated coracoclavicular ligaments had significantly higher ultimate failure loads than the isolated acromioclavicular, conoid, or trapezoid ligaments (P < 0.05). Failure load did not differ significantly between the combined complex and isolated coracoclavicular ligaments. The acromioclavicular ligament showed greater deformation and energy absorption at failure than the isolated coracoclavicular group.
Key findings
- The combined ligament complex and isolated coracoclavicular ligaments had higher ultimate failure loads than isolated acromioclavicular, conoid, or trapezoid ligaments (P < 0.05).
- Failure load did not differ significantly between the combined complex and isolated coracoclavicular ligaments.
- The combined complex and isolated acromioclavicular ligament had greater deformation and energy absorption at failure than the isolated coracoclavicular group (P < 0.05).
- Midsubstance tears were the most common failure mode.
Why it matters
The findings distinguish the ligaments’ mechanical contributions: the coracoclavicular ligaments provide substantial resistance to failure, while the acromioclavicular ligament contributes to deformation and energy absorption. This helps frame joint stability as involving more than failure strength alone and provides biomechanical context for understanding ligament injury and reconstruction.
What to keep in mind
The evidence comes from cadaveric studies of intact joints, so it does not directly establish clinical outcomes or the effectiveness of surgical techniques.