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A contribution to the calculation of a safe deltoid split
Gulihar Abhinav1, Balasubramanian Sivaraman, Nixon Matthew
1Leicester Medical School and Glenfield Hospital, Leicester, UK.
International Journal of Shoulder Surgery
|March 20, 2010
Summary
The traditional 5 cm deltoid split is too generous. A safer limit of 4.2 cm is recommended to protect the axillary nerve during shoulder surgery, avoiding abduction splits.
Area of Science:
- Orthopedic surgery
- Anatomy
Background:
- Traditional deltoid split guidelines may not adequately protect the axillary nerve.
- Nerve proximity necessitates a re-evaluation of surgical safety margins.
Purpose of the Study:
- To redefine the safe maximum deltoid split distance.
- To assess the influence of arm length and position on nerve proximity.
Main Methods:
- Cadaveric shoulder dissection (n=30) to measure axillary nerve distance.
- Measurements taken in neutral, abducted, and adducted positions.
- Correlation with upper arm length and intraoperative split measurements.
Main Results:
- Mean axillary nerve distance: 6.0 cm; abduction moved nerve 1.5 cm closer.
- Strong correlation between nerve distance and arm length (r=0.82).
- Mean intraoperative deltoid split was 3.4 cm.
Conclusions:
- A 4.2 cm deltoid split is recommended to protect 99.7% of axillary nerves.
- Avoid splitting the deltoid in abduction due to increased nerve proximity.
- The 4.2 cm limit is safer than the traditional 5 cm guideline.
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