Musculoskeletal Injuries in the Military: Parachute, Marches, and Sports Injuries

Yong Jae Kwon, MD, Jeongyun Kim, MD, Seung Gwi Park, MD, and Sangun Kim, MD

Department of Radiology, Aerospace Medical Center, Cheongju, Republic of Korea

Introduction

• Musculoskeletal (MSK) injuries are highly prevalent among military personnel due to heavy mechanical stress, repetitive physical training, and unique operational activities such as parachute jumps and long-distance marches

​

• Early recognition and proper rehabilitation of these injuries are crucial for the timely return of soldiers to active duty

​

• Familiarity with the characteristic patterns of MSK injuries that emerge during periods of intensive training and specialized military tasks is essential for effective management

​

• Therefore, this study reviews the common patterns of MSK injuries observed in military personnel, highlighting cases that occurred during high-intensity training phases and special operations

Case 1, right foot pain after paratrooper landing

A

B

C

D

A, B: right foot AP and lateral radiographs showed no definite fracture. The gap between C1-M2 is less than 2mm (within normal limit)

C, D: CT scan at the metatarsal base level reveals a fracture at the base of the 2nd metatarsal, along with cortical fractures at the bases of the 3rd and 4th metatarsals

A: intact Lisfranc ligament between C1-M2 (white arrow)

B: suspicious partial tear of C1-M3 plantar Lisfranc ligament (red arrow) and bone marrow edema at presumed fracture at M2, 3 base

A

B

Review : Lisfranc injury, initial evaluation and normal value on radiograph

How to diagnostic order?

- Unilateral AP, LAT and 30’ internally rotated oblique radiograph

- Sensitivity : weight bearing > non-weight bearing

​

What to see?

- AP : M1-C1 lateral border and M2-C2 medial border aligns each

<2mm gap between C1-M2

- LAT : continuity of dorsal M1-C1 border

superior location of plantar surface of M1 base to plantar surface M5 base

Normal anatomy of Lisfranc joint

Key anatomic structures

- Dorsal Lisfranc lig : no connection between dorsal M1-M2 base, therefore the dorsal ligamentous complex have been found to be weakest

- Plantar and interosseous Lisfranc lig : primary ligamentous stability for the Lisfranc joint

- Injury to the interosseous and plantar Lisfranc ligaments is the primary cause of transverse midfoot instability that results in tarsometatarsal

widening of C1-M2.

Case 2-1, left ankle pain after paratrooper landing

A

B

A, B: non displaced fracture of fibular at the tibial plafond level

​

🡪SER stage 2

Case 2-2, left ankle pain after paratrooper training

A

B

C

A, B, and C:

​

AP, lateral radiograph and CT volume rendering images showed widening of tibiofibular space and spiral fracture with minimal displacement at distal fibula.

🡪 SER stage 2

Case 2-3, left ankle pain after paratrooper training, pronation injury

A

B

C

D

A, B : AP, and lateral radiographs showed oblique fracture at mid to distal fibular shaft, 6cm above from the the tibial plafond.

C, D : axial and coronal CT scan showed additional findings of avulsion bone fragment at deep deltoid ligament and subcutaneous edema at medial and lateral aspect of the ankle. 🡪 PER stage 3

Case 2-4, right ankle pain after paratrooper training

-- injury mechanism : dorsiflexion

A

B

C

D

A, B : AP and lateral radiographs showed no definite fracture.

​

C, D : sagittal and axial CT scans revealed a posterior malleolar fracture that was not clearly visible on the radiographs.

​

Unclassifiable by Lauge-Hansen system

Review : ankle fracture

Position : pronation

Direction of force : abduction

Position : supination

Direction of force : adduction

Direction of force : external rotation

Injury mechanism of SER

Injury mechanism of SAD

Oblique/spiral fracture

anterior, low

posteiror, high

​

SER stage 2

Below the tibial plafond

SAD stage 1

Review : ankle fracture

Position : pronation

Direction of force : abduction

Position : supination

Direction of force : adduction

Direction of force : external rotation

Injury mechanism of PER

Injury mechanism of PA

Medial injury first

High fibular fracture

​

PER stage 3

Widening of medial mortise

Low medial

High lateral fibular fx

​

PA stage 3

Case 3-1, right ankle pain after paratrooper training

- P/E : ATFL Td+, syndesmosis Td+

A, B : AP and mortise radiographs demonstrated widening of the distal tibiofibular joint, raising suspicion for anterior inferior tibiofibular (AITFL) injury (red arrows).

​

An oblique lucent line with marginal sclerosis was also noted, initially suspected to represent a fracture by the emergency department clinician (white arrows).

​

C: The suspected tibial fracture line is not seen on the lateral radiograph.

A

B

C

A, B : on follow up CT, the suspected distal fibular fracture noted at the emergency department was confirmed to be a nutrient foramen rather than an actual fracture (white arrows).

​

C, D : on MRI, complete tear of AITFL (white arrowhead) and ATFL (red arrowhead) were found.

A

B

C

D

Case 3-2, left lower leg pain after landing on a rock during high-altitude parachute training

Left distal leg radiograph showed a linear lucent line along the lateral cortex of the mid-shaft tibia, which was not observed on the contralateral side.

​

As this area correlated with the patient’s pain, a CT scan was performed under suspicion of a fracture at emergency department.

A : left distal leg radiograph showed a linear lucent line along the lateral cortex of the mid-shaft tibia, which was not observed on the contralateral side.

​

As this area correlated with the patient’s pain, a CT scan was performed under suspicion of a fracture at emergency department.

​

B, C : on CT, it was a nutrient foramen of the tibia, and no fracture was demonstrated.

A

C

B

Review : fracture mimic, nutrient foramen of long bones

Distribution of nutrient foramen in human long bones

Typical location per lower extremity bones

Case 4, left thigh pain after tree collision during paragliding landing

A : right knee lateral radiograph showed no demonstrable abnormal findings

​

B: left knee lateral radiograph showed increased opacity at suprapatellar recess, suggesting knee joint effusion (white arrows)

​

C: magnification view of B showed suspicious fracture line at tibial plateau

A

B

C

A, B : sagittal and axial CT scan showed fracture line (arrows) at lateral tibial plateau which extended to anterolateral aspect tibia

A

B

A : sagittal T1 weight image showed fracture at lateral femoral condyle (arrowhead) with indentation and lateral tibial plateau (arrow) with cortical depression. B : sagittal proton density image showed bone marrow edema and lipohemarthrosis (red arrow).

A

B

Review : tibial plateau fracture and Schatzker fracture classification

Energy ↑

Severity ↑

Prognosis ↓

I

II

III

IV

V

VI

Case 5-1, lower back pain after paragliding landing

A : lateral x ray showed anterior wedging and transverse fracture line

​

B : sagittal CT scan showed compression fracture of anterior column of L1 vertebral body

A

B

Case 5-2, lower back pain after falling on buttocks during paragliding landing

A : sagittal CT scan showed anterior wedging, sclerotic trabecular compression line (white arrow) while intact posterior vertebral height

B : coronal CT scan showed cortical step off (arrowhead) and angulation deformity

C : axial CT scan showed no demonstrable retropulsion

D : MR image showed transverse fracture of vertebral body with surrounding bone marrow edema. No demonstrable injury on posterior element and other vertebral level

A

B

C

D

Case 5-3, lower back pain after paragliding landing

A, B : sagittal and axial CT scan showed anterior wedging, retropulsion of fracture fragment (arrow) and comminuted fracture and centripetal displaced fracture fragment

​

Due to the retropulsion of fracture fragment more than 50% central canal stenosis occurred

A

B

Review : spine fracture, ThoracoLumbar Injury Classification and Severity score (TILICS) and Three-column Concept by Denis

TLICS score 0~3 ->non-operative/ 4 -> optional / 5 and above -> surgical

Three-column concept-Denis

Case 6, left shoulder pain and numbness immediately after jumping from the aircraft

A, B : AP and scapular Y view radiographs showed comminuted fracture at humeral surgical neck with displacement (arrows).

​

No demonstrable concomitant gleno-humeral joint dislocation.

A

B

Comminuted fracture at humeral surgical neck (arrows) and greater tuberosity (arrowheads) with severe displacement and angulation deformity.

​

No gleno-humeral joint dislocation nor articular surface fracture was noted.

Review : proximal humerus fracture

Fractures are classified by the number of displaced segments, including the greater tuberosity, lesser tuberosity, articular surface, and humeral diaphysis.

**Any anatomic neck fracture is associated with increased risk of avascular necrosis

Case 6-1, right knee pain after march

Both knee AP and LAT radiograph showed no demonstrable abnormal findings on bone, soft tissue structures. No remarkable knee joint effusion.

Pain was aggravated during activity, and MRI was performed for further evaluation

A : on T1-weighted imaging, a linear low-signal fracture line (arrows) was identified at the lateral femoral condyle

B : on fat-suppressed PD-weighted imaging, surrounding bone marrow edema (arrowheads) was observed

A

B

Case 6-2, 21/M Ankle swelling 7 days ago

-CRP and D-dimer elevation

On AP radiographs, no definite fracture was identified. A linear sclerotic line near the tibial plafond was considered a normal epiphyseal scar.

On lateral radiographs, no definite fracture was identified. A linear sclerotic line near the tibial plafond and posterior calcalneus was considered normal epiphyseal scar.

Due to elevated D-dimer levels and severe edema, deep vein thrombosis was suspected by the internist, and CT angiography was performed.

​

On CT angiography of the lower extremities, no evidence of deep vein thrombosis or fracture was observed. However, marked soft tissue edema was noted in both distal legs.

Due to elevated CRP levels, an infectious or inflammatory condition was suspected, and MRI was performed.

​

On fat-suppressed PD-weighted images, diffuse bone marrow edema was observed in the distal tibia and calcaneus, along with adjacent soft tissue edema. On T1-weighted images, fracture lines were noted at the posterior aspect of the distal tibia and calcaneus (white arrows). A diagnosis of stress fracture was made, and considering the elevated CRP level with suspected concomitant cellulitis, conservative treatment was initiated.

Axial FS PD

Sag FS PD

Sag T1

Review : stress fracture

• Pathophysiology

Repetitive cyclical loading

Micro-damage > Remodeling capacity

​

• Common Sites
• Tibia (m/c)
• Calcaneus
• Metatarsals
• Proximal femur

​

• Different radiographic finding
• Cortical bone : grey cortex sign
• Cancellous bone : blurring and sclerosis

​

​

**Earliest radiographic feature of bone fatigue

Cortical bone : grey cortex” sign, which refers to subtle cortical lucency

Cancellous bone : subtle blurring and faint sclerosis of the trabeculae

linear sclerosis along the fracture line (arrowheads)

subtle lucency (black arrow)

adjacent smooth periosteal reaction (white arrows)

Role of imaging in managing stress fracture

• Managed with activity modification and continued weight bearing
• Posteromedial tibia
• Calcaneus
• Third and fourth metatarsals
• Medial femoral neck

Low risk

• Managed with cessation of the offending activity, protected weight bearing, and in some cases, surgery
• Superolateral femoral neck
• Patella
• Anterior tibial cortex
• Medial malleolus
• Talar neck
• Dorsal navicular cortex
• Proximal metaphysis of the fifth metatarsal
• Sesamoids of the great toe

• Anterior tibial cortex

• Talar neck

High risk

MRI grading in stress fracture

↑Fredericson classification grades for medial tibial stress syndrome at MRI

←A, B: FS PD image showed periosteal edema and subtle bone marrow which was not definite on T1 WI

​

↓C: follow up CT after 1w showed fracture and callus formation at posterior tibial cortex

B

C

A

Case 7, left knee pain, aggravated on walking on stair or downhill ambulation

A :edema presented medial to the iliotibial tract that extend into the fatty layer distal to the vastus lateralis muscle (curved arrow).

​

B :Soft tissue edema (arrows) between the ITT (arrowheads) and the femur.

B

A

Review : iliotibial band friction syndrome

• Clinical presentation

Pain at the lateral knee joint with point tenderness 1-2 cm above the lateral joint line

Worse with downhill running and increases throughout an episode of activity

​

• Pathophysiology

Knee flexed the ITT moves posteriorly and comes in contact with the lateral femoral epicondyle

Case 8, dislocation while playing foot volleyball

A, B : Lower extremity angiography showed a lateral patellar dislocation with an avulsion fracture of the medial patellofemoral ligament (MPFL), visualized as a bony fragment at the medial patellar facet. The popliteal artery was intact.

​

C, D : axial T1-weighted and fat-suppressed PD images showed an avulsion fracture of MPFL, with typical bone marrow edema at the medial patellar facet and lateral femoral condyle. A large amount of knee joint effusion was noted, and an osteochondral lesion was identified at the medial patellar facet.

A

B

C

D

Review : patellofemoral Instability

Inclination angle

Facet asymmetry

Trochlea depth

Patella alta

Tibial tuberosity lateralization

• Risk factor and assessment

Trochlea dysplasia

-- lateral trochlea inclination (< 11 degree), trochlea facet asymmetry (M/L of <40%), trochlea depth (<3mm)

Patella alta (reference >1.3)

Tibial tubercle to trochlea groove distance (reference 15mm, >20mm indicate tibial tuberosity lateralization)

• Common MRI finding after lateral patellar dislocation

1. Medial patellofemoral ligament and medial patellar retinaculum

-- 50-90% patellar insertion site

-- 25% femoral attach site

2. Bone contusion edema at medial patellar and lateral femoral condyle

3. Medial patellar osteo-chondral lesion

-- present in more than 60% of patient

4. Lateral femoral condyle defect

-- 40% at anterolateral or mid-lateral

5. Effusion

6. Vastus medialis injury

Complete MPFL disruption

Medial patellar osteochondral lesion

Lateral condyle defect

Case 9, knee pain during soccer

A, B : PCL complete tear on T2 and FS PD images (white arrows)

C : bone marrow edema at anteromedial tibial plateau (arrowhead)

D : intact ACL

A

B

C

D

Review : PCL tear

→resulting in bone marrow edema at anterior tibia

→produce kissing contusions of the femur and tibia anteromedially or anterolaterally

→may result in multi-ligamentous injuries involving the PCL, ACL, PLC, or PMC structures

• Incidence

PCL injuries are relatively uncommon, with isolated PCL injuries accounting for 4% of all knee ligamentous injuries

​

Over 60% of PCL injuries are associated with additional capsuloligamentous lesions

​

• Injury mechanism

①

②

③

④

Case 10, popping sound and knee pain during soccer

A : ACL complete tear (white arrows)

B : bone marrow edema at lateral femoral condyle and posterior lateral tibial plateau suggesting pivot shift injury (white arrowheads). Also posterior horn of lateral meniscus peripheral vertical tear was noted (yellow arrow).

C : MCL complete tear (red arrow)

A

B

C

Review : ACL tear, primary and secondary finding

A: bone contusion

B: deep sulcus sign

C: Segond fracture (white arrowhead), avulsion fracture of ACL tibial attach site (black arrowhead) and LCL avulsion fracture (arrow)

A

B

C

Lateral condylopatellar sulcus (middle ½)

Medial condylopatellar sulcus (ant 1/3)

Normal LAT radiograph

References

1. Siddiqui NA, Galizia MS, Almusa E, Omar IM (2014) Evaluation of the tarsometatarsal joint using conventional radiography, CT, and MR imaging. Radiographics 34(2):514-531

2. Tartaglione JP, Rosenbaum AJ, Abousayed M, DiPreta JA (2015) Classifications in Brief: Lauge-Hansen Classification of Ankle Fractures. Clin Orthop Relat Res 473(10):3323-3328

3. Okanobo H, Khurana B, Sheehan S, Duran-Mendicuti A, Arianjam A, Ledbetter S (2012) Simplified diagnostic algorithm for Lauge-Hansen classification of ankle injuries. Radiographics 32(2):E71-84

4. Kizilkanat E, Boyan N, Ozsahin ET, Soames R, Oguz O (2007) Location, number and clinical significance of nutrient foramina in human long bones. Ann Anat 189(1):87-95

5. Yun HH, Choi GW, Kim WT, Yoon JR (2019) Differentiating Nutrient Artery Canals of the Femur versus Fracture Lines in Patients with Total Hip Arthroplasty on Plain Radiographs. Indian J Orthop 53(5):622-629

6.Bryson WN, Fischer EJ, Jennings JW, Hillen TJ, Friedman MV, Baker JC (2021) Three-Column Classification System for Tibial Plateau Fractures: What the Orthopedic Surgeon Wants to Know. Radiographics 41(1):144-155

7. Markhardt BK, Gross JM, Monu JU (2009) Schatzker classification of tibial plateau fractures: use of CT and MR imaging improves assessment. Radiographics 29(2):585-597

8. Raniga SB, Skalski MR, Kirwadi A, Menon VK, Al-Azri FH, Butt S (2016) Thoracolumbar Spine Injury at CT: Trauma/Emergency Radiology. Radiographics 36(7):2234-2235

References

9. Cibulas A, Leyva A, Cibulas G, 2nd et al (2019) Acute Shoulder Injury. Radiol Clin North Am 57(5):883-896

10. Marshall RA, Mandell JC, Weaver MJ, Ferrone M, Sodickson A, Khurana B (2018) Imaging Features and Management of Stress, Atypical, and Pathologic Fractures. Radiographics 38(7):2173-2192

11. Muhle C, Ahn JM, Yeh L et al (1999) Iliotibial band friction syndrome: MR imaging findings in 16 patients and MR arthrographic study of six cadaveric knees. Radiology 212(1):103-110

12. Diederichs G, Issever AS, Scheffler S (2010) MR imaging of patellar instability: injury patterns and assessment of risk factors. Radiographics 30(4):961-981

13. Winkler PW, Zsidai B, Wagala NN et al (2021) Evolving evidence in the treatment of primary and recurrent posterior cruciate ligament injuries, part 1: anatomy, biomechanics and diagnostics. Knee Surg Sports Traumatol Arthrosc 29(3):672-681

14. Naraghi AM, White LM (2016) Imaging of Athletic Injuries of Knee Ligaments and Menisci: Sports Imaging Series. Radiology 281(1):23-40

15. Shelbourne KD, Clark M, Gray T (2013) Minimum 10-year follow-up of patients after an acute, isolated posterior cruciate ligament injury treated nonoperatively. Am J Sports Med 41(7):1526-1533

16. Fracture of ankle and foot, 김지나, 2023년 대한근골격영상의학회 정기 연수강좌

Thank you

for your attention