Humeral trochlear morphology does not influence coronoid fractures in elbow dislocation

Area of Science:

• Orthopedic surgery
• Radiology
• Biomechanics

Background:

• Traumatic elbow dislocation is common despite the elbow's inherent stability.
• Individual variations in elbow joint anatomy and their relation to instability are not well understood.
• Previous research has not extensively explored the link between trochlear morphology and dislocation complexity.

Purpose of the Study:

• To analyze trochlear morphology in simple (SED) and complex elbow dislocations (CED).
• To determine if humeroulnar joint congruence influences coronoid fracture incidence in elbow dislocations.
• To evaluate the association between trochlear morphology and coronoid fracture patterns.

Main Methods:

• Retrospective analysis of 62 elbow CT scans from patients with SED or CED and isolated coronoid fractures.
• Exclusion of skeletally immature patients, those with concomitant fractures, or prior elbow surgery.
• Measurement of trochlear coverage using angles and ratios, with assessment by four readers and repeated measurements for reproducibility.

Main Results:

• No statistically significant differences were found in humeral trochlear morphology between SED and CED groups.
• No association was identified between morphometric measurements and coronoid fracture patterns.
• High intra- and inter-reader reproducibility confirmed the reliability of the CT analysis protocol.

Conclusions:

• This study is the first to investigate the impact of trochlear morphology on elbow instability.
• Variables such as trauma energy and ligamentous hyperlaxity may be more significant contributors to coronoid bone damage.
• Capsuloligamentous structures are likely crucial for maintaining elbow joint stability.