Page 75 - 2022 Spring JSOM

TABLE 1 Amputation Time per Extremity in Seconds, Amputation Location, Success Rate, and Extremity Diameter
Distal Proximal Distal Proximal Distal Proximal Distal Proximal
Knife Tool Forearm Forearm Humerus Humerus Tib/Fib Tib/fib Femur Femur
Leatherman Multitool 102 s 62 s 62 s 108 s 70 s, 94 s 94 s Fail Fail
Tree Hopper
Field knife 118 s 94 s 50 s 68 s 44 s 119 s, Fail Fail Fail
Victorinox Rescue tool 42 s,102 s 119 s 65 s Fail 83 s Fail Fail Fail
SOG Fixed blade 27 s Fail 108 s, Fail 118 s 83 s Fail Fail Fail
Location success rate 100% 75% 80% 75% 100% 40% 0% 0%
Mean Limb
Diameter cm 5.7 (SD 0.4) 8.5 (SD 0.3) 8.5 (SD 0.3) 10.4 (SD 0.5) 7.4 (SD 0.8) 10.8 (SD 0.5) 12.7 (SD 0.4) 15.2 (SD 0.4)
The amputation time is shown for each amputation site in seconds and tool used, success rates are shown in percentages, and limb diameter is in
centimeters (cm) with standard deviation in cm (SD).

amputation success rate was with the Leatherman Super Tool On the postamputation questionnaire, the Leatherman multi-
300, followed by the TreeHopper 3-in-1 Field Dress Knife, the tool received a statistically significant higher score for the
Swiss Army Rescue Tool, and finally, the SOG Pentagon fixed questions, “Which knife performed the complete amputation
blade knife (Table 2). the best?” and “Which knife saw cut through the bone the
best?” (p = .001). For the remaining two questions (“Which
TABLE 2 Amputation Success and Fail Rates With Odds Ratio and knife cut through the soft tissue the best?” and “Which knife
95% Confidence Intervals was the most ergonomically comfortable to amputate with?”),
Success Odds there was no clear preference (Table 3).
Successful Fail Rate Ratio 95% CI
Leatherman 7 2 78% 3.5 [0.727–16.85] TABLE 3 Subjective Instrument Rankings by Five Amputators
Tree Hopper 6 3 67% 2 [0.5–7.996] Knife/Tool Points Rank p Value
Victorinox 5 4 56% 1.25 [0.336–4.65] Which knife performed the complete amputation the best?
SOG 4 5 44% 0.8 [0.2148–2.979] Leatherman multitool 1.4 1 .001
Treehopper hunting knife 2.2 2
The success of amputation was associated with the limb tested:
83% (15/18) of amputation attempts on the upper limbs were Victorinox Rescue tool 2.4 3
successful compared with a 39% (7/18) success rate in the SOG Fixed blade 4 4
lower limbs. None of the knives was successful in severing the Which serrated saw blade cut through bone the best?
femur in 2 minutes. In contrast, the distal tibia/fibula and the Leatherman multitool 1.4 1 .001
distal radius/ulna were amputated successfully 100% (5/5) of Treehopper hunting knife 2.0 2
the time regardless of the tool used. The proximal radius/ulna Victorinox Rescue tool 2.8 3
and proximal humerus were amputated in 75% of attempts SOG Fixed blade 4 4
(3/4 each). The distal humerus was amputated in 80% of at- Which knife was the most ergonomically comfortable to amputate
tempts (4/5). The proximal tibia/fibula was amputated in 40% with?
of attempts (2/5). Victorinox Rescue tool 2.2 1 .73
SOG fixed blade 2.2 1
Of the extremity locations amputated, the Leatherman mul-
titool and the Tree Hopper folding field hunting knife were Leatherman multitool 2.8 2
able to complete all six amputations; however, the Tree Hop- Treehopper hunting knife 2.8 2
per failed in a second attempt to amputate the proximal tibia/ Which knife cut through soft tissue the best?
fibula. The Victorinox Swiss Rescue Knife also failed in the at- Victorinox Rescue tool 2.4 1 .98
tempt on the proximal tibia/fibula and the proximal humerus. Treehopper hunting knife 2.6 2
The SOG Pentagon fixed blade failed on the proximal tibia/ Leatherman multitool 2.6 2
fibula, the proximal forearm, and on a second attempt of the SOG fixed blade 2.6 2
distal humerus.
Which knife performed the complete amputation the best?
Leatherman multitool 1.4 1 .001
Success and failure appear to be related to the cadaver’s limb
diameter and not to the operators’ abilities, sex, or body hab- Treehopper hunting knife 2.2 2
itus/height. The Leatherman multitool amputated all limbs Victorinox Rescue tool 2.4 3
< 10.8 cm (SD, 0.5 cm) in diameter. The TreeHopper success- SOG Fixed blade 4 4
fully amputated limbs < 10.8 cm (SD, 0.5 cm) in diameter but
failed on the proximal tibia/fibula on a second amputation at- Discussion
tempt. The Victorinox Swiss Army Rescue Tool amputated all
limbs measuring < 8.5 cm (SD, 0.3 cm) in diameter. The SOG A field surgical amputation can be a life-saving procedure
fixed-blade knife amputated limbs < 7.4 cm (SD, 0.8 cm) in for a patient requiring extrication and extraction. Our study
diameter and was variable with larger diameters, amputating demonstrates that human cadaver distal limb (radius/ulna and
in one of three attempts limbs 8.5 cm (SD, 0.3 cm) in diameter. tibia/fibula) amputations are possible with select hand tools
None of the tools was able to amputate the distal or proximal within 2 minutes. The diameter of the limb was the strongest
femur. determinate regarding successful amputation versus failure.

Knives and Multitools for Cadaveric Limb Amputation | 73