Page 48 - JSOM Fall 2024

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Most of the spinal deviations described (lateral deviations and criteria can be added : weather conditions (mainly wind speed
scoliosis) were at the thoracolumbar level (96.9%; 1,258), with and temperature), initial jump speed (varying from fixed-wing
equal repartition between the two territories. When measuring aircraft to helicopter to balloon), type of landing zone, para-
the Cobb angle, 42% (545) were between 8° and 10° (inclu- trooper sex and body weight, absence of ankle brace, simulta-
sive). At hip level, 46% of pelvic tilts (545) were of less than neous jumps from both side doors, and lack of experience. An
11mm, equally deviated to the left or to the right. Of the other Australian publication on preventing injury during static-line
8
findings, more than half (58.2%; 103) of the listheses were an- jumps confirms these data. Scoliosis or spine deformation
terior and at the L5–S1 segment, and 5.6% of airborne candi- is never mentioned as a risk factor for injury, even though it
dates (223) had radiological sequelae of juvenile epiphysitis. seems to be a strong selection factor in the French Army. 5

Of the 3,993 candidates deemed medically acceptable for ser- Anatomical Distribution of Injuries
vice who underwent full-spine X-rays, 97.5% (3,893) were Static-line jump injuries have identical anatomic distribution
fit for static-line jumps, and 2.5% (100) were unfit. Sixty-six regardless of the country in which the studies are conducted,
(1.6%) were deemed unfit because of findings that did not and regardless of the selection standards. Half of the injuries
meet the MI 700 standard on the full-spine X-ray: 53 enlisted concern lower limbs (32.8% ankles and 21.2% knees), while
6
personnel had scoliosis greater than 15° and 13 had spondylo- spinal injuries represent 18.5% of the injuries. A French study
listhesis (grade II or III). finds similar results, which could mean that restrictive stan-
dards do not modify the incidence of spine injuries. 9
Follow-up of Waivered Paratroopers
Of the 3,893 enlisted personnel who were deemed medically Spine Fractures Induced by Static-Line Jumps
acceptable, 23 received waivers for airborne selection after Many French military studies focus on fractures induced by
a second consultation with an orthopedic surgeon. Initially, static lines. A retrospective descriptive study conducted in
these 23 enlisted personnel were not considered medically fit Corsica from 2008 to 2011 analyzed almost 44,000 jumps.
for airborne training (MI 700). They were deemed unfit be- Ninety-six patients suffered fractures; 29 (30.2%) fractures
cause of spine X-ray findings: 17 had scoliosis with an angle were located on vertebrae and 8 (8.3%) were hip fractures.
1
between 16° and 21°; 4 had thoracic kyphosis of 50°; 1 pre- Most of the spinal fractures were of the compression type.
sented with severe degenerative disc disease, and one presented To our knowledge, there is a lack of studies evaluating the
with an anterior listhesis of grade 2. links between pre-existing scoliosis and spinal fracture risk.
Apart from external causes, such as collisions, entanglements,
At the end of the 5-year study period, we conducted a review or stealing air (sudden closure of the parachute due to lack of
of the medical files of the 23 personnel considered medically air) near the ground, spinal injuries seem to most commonly
unacceptable according to the MI 700 fitness standard, which result from badly performed landings, with knees or feet apart,
was subsequently waived; 17 were still in airborne units and or incorrect parachute landing falls. 10
fit for jump duty on 1 January 2018.
A meta-analysis from 2015 that focused on the links between
Of the 17 participants with scoliosis who received waivers, radiological findings and clinical expressions of low back pain
82.3% (14) were still fit for airborne units and had not declared showed that the only significant association is the presence
any back pain as of 1 January 2018. Of the three enlisted person- of spondylolisthesis on X-rays. Another study from 2008
12
11
nel who had scoliosis at spinal X-ray but were discharged, one showed a possible correlation between scoliosis and low back
went for a second spinal X-ray in a civilian clinic, which found pain when the scoliosis, as measured by the Cobb method, is
that his scoliosis was less than 15°, but was then discharged at around 30°. More recently, a similar study regarding fitness
his request for low back pain; the second was discharged for ab- for airborne units at the French cadet and officers’ school, con-
normal thoracic pain during exertion (with no back pain); and ducted over a 4-year period, showed that, in a population of
the third was discharged for a nonmedical reason. 643 cadets, 41 spinal X-rays did not meet airborne standards,
including 14 that displayed scoliosis with an angles between
Of the four enlisted personnel displaying kyphosis above 50°, 16° and 20°. Half of these cadets (21) were accepted for static-
two remain on duty with no back pain reported, one was dis- line jump training after a second full-spine X-ray. 13
charged after a year for a nonmedical reason, and one is on
medical leave for a psychiatric reason. We compared French medical standards to those of other
armies in order to gain a broader perspective. The U.S. Army
The enlisted serviceman who presented with severe degenera- declares applicants unfit for airborne service if there is lum-
tive disc disease had a medical history of low back pain, but he bar scoliosis greater than 20° and thoracic scoliosis greater
was still medically acceptable for airborne operations. than 30°. Kyphosis and lordosis are tolerated up to 55° when
measured by the Cobb method. Our study is in line with
14
The enlisted person with an anterior listhesis of grade 2 re- the American standard, with a tolerance of up to 20°. Indeed,
quested an invalidity pension for low back pain. 82.3% (14) of those enrolled with scoliosis between 16° and
20° had no accidents or chronic low back pain within 5 years.
In the German Army, full-spine X-rays are not systematic and
Discussion
requested only as a result of clinical findings; meanwhile, scoli-
Factors Leading to Injury During Parachute Jumps osis with an angle up to 30° is accepted. For the Belgian Army,
Knapik and Steelman’s 2016 meta-analysis of factors leading standards are mostly clinical and focus on pathology that in-
to injury during static-line parachute jumps identifies two terferes with some movements or with the proper wearing of
main risks: jumping at night and jumping with an additional a uniform or military equipment or that prevents action re-
load (e.g., a leg bag). To these two main factors, many other quired by the duty or mission.
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46 | JSOM Volume 24, Edition 3 / Fall 2024