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Screening of Axonal Degeneration in Carpal Tunnel Syndrome Using Ultrasonography and Nerve Conduction Studies
Published on: January 11, 2019
Association between lunate morphology and carpal collapse patterns in scaphoid nonunions
Steven C Haase1, Richard A Berger, Alexander Y Shin
1Department of Surgery, University of Michigan Health System, Ann Arbor, MI, USA. shaase@med.umich.edu
The Journal of Hand Surgery
|September 11, 2007
Summary
Type II lunate morphology significantly reduces dorsal intercalated segment instability (DISI) in scaphoid nonunions. This finding highlights lunate shape as a key factor in carpal instability following scaphoid fractures.
Area of Science:
- Orthopedic surgery
- Hand and wrist anatomy
- Biomechanics of the wrist
Background:
- Scaphoid nonunions can lead to carpal instability.
- Lunate morphology, specifically the presence of a hamate facet, may influence carpal alignment.
- Dorsal intercalated segment instability (DISI) is a common complication.
Purpose of the Study:
- To investigate the association between lunate morphology and carpal instability in patients with scaphoid nonunions.
- To determine if lunate morphology correlates with the location of the scaphoid fracture (proximal vs. waist).
Main Methods:
- Retrospective review of radiographs from 45 patients with established scaphoid nonunions.
- Classification of lunate morphology into Type I (single distal facet) and Type II (additional hamate facet).
- Assessment of carpal instability using the radiolunate angle and determination of scaphoid fracture location.
Main Results:
- Type I lunates were observed in 21 patients, with 15 exhibiting DISI (radiolunate angle > 15 degrees).
- Only 4 patients with Type II lunates showed the DISI pattern.
- No significant association was found between lunate morphology and scaphoid fracture location.
Conclusions:
- Type II lunate morphology is significantly associated with a lower incidence of DISI deformity in scaphoid nonunions.
- Lunate morphology does not appear to be significantly associated with the fracture location in scaphoid nonunions.
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