Association between distal ulnar morphology and extensor carpi ulnaris tendon pathology

Area of Science:

• Orthopedic Surgery
• Radiology
• Anatomy

Background:

• The extensor carpi ulnaris (ECU) tendon is crucial for wrist stability and function.
• Pathology of the ECU tendon, including tenosynovitis, tendinopathy, and tears, can lead to wrist pain and dysfunction.
• Distal ulnar morphology is increasingly recognized as a potential factor in various wrist pathologies.

Purpose of the Study:

• To investigate the association between specific distal ulnar morphological parameters and the presence of ECU tendon pathology or subluxation.
• To determine if anatomical variations of the distal ulna contribute to the development of ECU tendon abnormalities.

Main Methods:

• Retrospective review of 71 adult wrist MRI studies with ECU tendon pathology or subluxation.
• Inclusion criteria excluded patients with trauma, surgery, infection, or inflammatory arthritis.
• Measurement of distal ulnar parameters: ulnar variance, ulnar styloid process length, and ECU groove dimensions. Comparison with 46 control subjects.

Main Results:

• A significant correlation was found between negative ulnar variance and ECU tendon pathology (P < 0.0001).
• Negative ulnar variance was also significantly associated with ECU tendon subluxation (P < 0.0001).
• A trend towards a shorter and shallower ECU groove was observed in subjects with ECU subluxation, though not all findings reached statistical significance after correction.

Conclusions:

• Distal ulnar morphology, particularly negative ulnar variance, appears to be associated with ECU tendon abnormalities.
• These findings suggest that anatomical variations in the distal ulna may predispose individuals to ECU tendon pathology and subluxation.
• Further research could explore the clinical implications of these morphological associations.