Anatomical Cadaver Study of the Hotchkiss Over-the-Top Approach for Exposing the Anteromedial Facet of the Ulnar Coronoid Process: Critical Measurements and Implications for Protecting the Median Nerve.
OBJECTIVE
To measure distances from anatomical landmarks to the median nerve, and estimate the length of the flexor-pronator/flexor carpi ulnaris (FCU) detachment necessary to expose the anteromedial facet of the ulnar coronoid process (UCP) using the Hotchkiss over-the-top approach.


METHODS
Dissections were made of 20 fresh-frozen cadaveric upper limbs. Measurements were made of the shortest distance from the medial epicondyle to the median nerve, the distance from the medial epicondyle to the median nerve in line with the flexor-pronator/FCU interval, the shortest distance from the apex of the UCP to the median nerve, and the length of the flexor-pronator/FCU detachment necessary to expose the anteromedial facet of the UCP. Measurements were also made of the length of the ulnar insertion of the brachialis muscle and the shortest distances from the proximal and distal insertions of the brachialis muscle to the median nerve.


RESULTS
The distances and lengths were as follows: medial epicondyle to median nerve, 31 ± 3 mm; in line with the flexor-pronator/FCU interval, 43 ± 5 mm; from the apex of the UCP to the median nerve, 7 ± 2 mm; the detachment necessary to expose the UCP, 47 ± 6 mm; the ulnar insertion of the brachialis muscle, 27 ± 4 mm; and the proximal and distal insertions of the brachialis muscle to the median nerve, 14 ± 2 mm and 5 ± 1 mm, respectively.


CONCLUSIONS
The length of the flexor-pronator/FCU detachment necessary to expose the anteromedial facet of the UCP was similar to the distance from the medial epicondyle to the median nerve in line with the flexor-pronator/FCU interval. The distance from the distal insertion of the brachialis muscle to the median nerve was 5 mm.


CONCLUSIONS
The results of our study provide information on important points for surgeons to consider when performing distal exposure using the Hotchkiss over-the-top approach.
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan. Electronic address: helpandriver502@gmail.com.
Koji
K
Sukegawa
Department of Bioenvironmental Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan.
Takane
T
Suzuki
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Yasufumi
Y
Ogawa
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Tomoko
T
Kobayashi
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Yusuke
Y
Matsuura
Department of Orthopedic Surgery, Graduate School of Medicine, Chiba University, Chiba, Japan.
Kazuki
K
Kuniyoshi
D000368:Aged; D000369:Aged, 80 and over; D002102:Cadaver; D004210:Dissection; D004551:Elbow Joint / Q000033:anatomy & histology* / Q000601:surgery*; D005260:Female; D006801:Humans; D057072:Intra-Articular Fractures / Q000601:surgery*; D008297:Male; D008475:Median Nerve / Q000033:anatomy & histology* / Q000293:injuries; D059348:Peripheral Nerve Injuries / Q000517:prevention & control*; D014457:Ulna / Q000033:anatomy & histology; D014458:Ulna Fractures / Q000601:surgery; D034941:Upper Extremity
Anteromedial facet fracture; Hotchkiss over-the-top approach; cadaver study; median nerve; ulnar coronoid process