Lawnmower Injuries Kyle Kenoyer PGY-1 Madigan Army Medical Center

Demographics • 60000 ED visits per year • 75 deaths annually • 7% require hospitalization • 2-5 surgeries per injury • 64% require amputation • $457 million annually • Prosthetic costs of $73140 to $116040 from the time of injury

to the age of 18 • 18.9% of all injuries are to the lower extremities • 50% of amputation from lawn mower injuries occur in the foot

Demographics • 58-77% males • Age <14 and >44 years old • 20% are in children under 18 years old • 11.9/100000 children • 2000 children permanently impaired per year.

Recommendations • American Academy of Pediatrics and the United States

Consumer Product Safety Commission. • Children less than 14 years of age should not be allowed to

operate ride-on lawn mowers • Adolescents should be trained in the use of these tools

before independent use. • Young children, especially those 5 years or younger, should be

kept indoors when a lawn mower is in use. • Continue to develop safety devices that will reduce the risk of

injury to all lawn mower users.

Regulations • Deadman’s switch

• Required in July of 1982 • Decreased lawn mower related injury by 40%

• Riding mower

• Operator presence control • Higher seat back

Mechanism of Injury • Blade spins at 3000 RPM • Equivalent of dropping 211 lb weight 100 ft

• 3x the power of a .357

• 51% pulling mower backwards • 24% pulling mower up a slope

Types of injury • Laceration 41%

• 71% occurring on the hands or feet • Soft tissue 21.4% • Burn 15.5% • Fracture 10.3% • Missile injury 5-9%

Types of injury • Anger DM

• 33 patients • 40 open fractures • 20 amputations • 18 lacerations involving skin and nail bed • 9 tendon lacerations • 2 closed fx • 2 segmental loss of bone • 1 segmental achilles

Complex soft tissue wounds Types • Degloving injuries • Soft tissue avulsion • Mutilation

Zones of injury • Corcoran

Evaluation • Soft tissue • Osseous involvement • Thorough exam (may need to use local anesthesia) • Remove debris and contaminates

Tetanus • Tetanus immune globulin is administered in the event a child

has not received a minimum of three doses of tetanus toxoid, or if the immunization status is unknown. Tetanus toxoid (dT, DT, or DTaP) also is given in this situation.

• A booster dose should be administered if the child has not received a dose of tetanus toxoid in the last 5 years.

Treatment • Intraoperative cultures

• Aerobic, anaerobic, fungal, and acid-fast organisms • Open fractures -> bone biopsy

• Immediate and vigorous surgical debridement • Pulse lavage as soon after the injury as possible

Infection • Campbell • Meta-analysis • 9 studies, 355 cases • 5-60% of injuries became infected

• Anger • Mean of 3 infecting organisms

Organisms • Harkness • Fertilizer • Enterobacter spp, E. coli, Klebsiella spp, Serratia spp, Citrobacter spp

• Environmental gram negative • Enterobacter spp, E. coli, Klebsiella spp, Serratia spp, Citrobacter spp

• Gram Positive • Enterococcus , coagulase negative Staphylococcus Staphylococcus

aureus

• Soil related anaerobes • Clostridium spp and Bacteroides spp

• Fungal infection has also been reported

Antibiotics • Traumatic contaminated wounds • Danger

• Ciprofloxacin first line • Bactrim second line • Ceftazidime in children

• Anaerobes • Penicillin G or Clindamycin

• Absence of infection • Abx course for 5-10 days

Antibiotics cont. • Therapeutic Guidelines: Antibiotic • Initiate monotherapy with zosyn or timentin

• or clindamycin combined with either gentamicin or ciprofloxacin

• For heavily soiled wounds: recommend initial therapy with vancomycin, imipenem and an aminoglycoside

• Fungal infection amphotericin B or voriconazole

• Modify once cultures become available.

Antibiotics cont. • Gustillo and Anderson • I. Clean Wound <1cm in diameter

-Abx choice: 1st generation cephalosporin (Ancef) • II. Wound 1.0-5.0cm in diameter with minimal soft tissue

damage -Abx choice: Ancef, Clindamycin • III. Wound >5cm in diameter with extensive soft tissue

damage -Abx choice: Ancef (or high dose PCN), Clindamycin and Aminoglycoside

Treatment cont. • Love

• 2nd intra-operative debridement 24-72 hours after injury. • Planned delayed closure

• Graham • 28 Pts • “multiple debridement with irrigation”

• Peterson • Multiple debridement necessary

• Ryan and Hume • 6 cases • Primary closure is contraindicated

• Myerson 1991 • under no circumstances should the skin be closed before 5-7 days

Treatment cont. • Corcoran

• 96 wounds in 70 patients • Primary closure does not increase chance of infection

• Anger • No difference between primary closure and secondary closure in

regards to infection • Goldsmith

• 9 patients • Advocated for primary closure of digits and NWB surfaces.

Treatment Cont. • Laing • Split skin grafting in 17 patients, • Local fasciocutaneous flap reconstruction in 3 patients • Microvascular free tissue transfer in 3 patients to reconstruct

amputated heels • 2 free latissimus dorsi flaps and • 1 free thoracodorsal artery perforator flap.

Case • 19 year old active duty male presents to the ED with right

hallux wound secondary to a lawnmower injury. Pt was wearing military boots while mowing on a hill and slipped with his right foot ending up under the mower.

History • PMH: denies

• Meds: denies

• Social History

• Current smoker 1 pack year hx • Denies alcohol • 11 Bravo (infantry)

• ROS unremarkable except what was mentioned above

Physical exam

Plan • Irrigation • Wound dressed and posterior splint applied • NWB to right lower extremity • Ancef 1gm q8h • Surgery in the AM

OR • Debridement • Pulse lavage • Application of wound vac

Discharge • Augmentin 125/875 BID • Gram stain – no organisms seen • Pre-irrigation cultures – results unavailable • Post-irrigation cultures showed no growth

2nd OR visit (6 days s/p injury) • Debridement • Graft application

Follow up • 1 month • Applied dermacell graft

Follow up • 1 month + 1 week • Reapplied dermacell

Follow up • 2 month • Pt still in CAM boot • Prescribed orthotic

with Morton's extension.

8 month follow up

References • Anger DM, Ledbetter BR, Stasikelis PJ, Calhoun JH. Injuries of the foot related to the use of

lawn mowers. J Bone Joint Surg Am. 1995;77(5):719-25. • Brook I. Recovery of anaerobic bacteria from wounds after lawn-mower injuries. Pediatr

Emerg Care. 2005;21(2):109-10. • Campbell JR. Infectious complications of lawn mower injuries. Pediatr Infect Dis J.

2001;20(1):60-2. • Corcoran J, Zamboni WA, Zook EG. Management of lawn mower injuries to the foot and

ankle. Ann Plast Surg. 1993;31(3):220-4. • Costilla V, Bishai DM. Lawnmower injuries in the United States: 1996 to 2004. Ann Emerg

Med. 2006;47(6):567-73. • Erdmann D, Lee B, Roberts CD, Levin LS. Management of lawnmower injuries to the lower

extremity in children and adolescents. Ann Plast Surg. 2000;45(6):595-600. • Goldsmith JR, Massa EG. Primary closure of lawn mower injuries to the foot: a case series. J

Foot Ankle Surg. 2007;46(5):366-71. • Greenhagen RM, Raspovic KM, Crim BE, Ryan MT, Gruen GG. Lawn mower injuries to the

lower extremity: a 10-year retrospective review. Foot Ankle Spec. 2013;6(2):119-24. • Gustilo RB, Anderson JT. Prevention of infection in the treatment of one thousand and

twenty-five open fractures of long bones: retrospective and prospective analyses. J Bone Joint Surg Am. 1976;58(4):453-8.

• Hammig B, Childers E, Jones C. Injuries associated with the use of riding mowers in the United States, 2002-2007. J Safety Res. 2009;40(5):371-5.

References cont • Harkness B, Andresen D, Kesson A, Isaacs D. Infections following lawnmower and farm

machinery-related injuries in children. J Paediatr Child Health. 2009;45(9):525-8. • Loder RT, Dikos GD, Taylor DA. Long-term lower extremity prosthetic costs in children with

traumatic lawnmower amputations. Arch Pediatr Adolesc Med. 2004;158(12):1177-81. • Lau ST, Lee YH, Hess DJ, Brisseau GF, Keleher GE, Caty MG. Lawnmower injuries in children:

a 10-year experience. Pediatr Surg Int. 2006;22(3):209-14. • Laing TA, O'sullivan JB, Nugent N, O'shaughnessy M, O'sullivan ST. Paediatric ride-on mower

related injuries and plastic surgical management. J Plast Reconstr Aesthet Surg. 2011;64(5):638-42.

• Mullins J. Lawn mower injuries: a review. J Emerg Nurs. 2010;36(1):83-4. • Nugent N, Lynch JB, O'shaughnessy M, O'sullivan ST. Lawnmower injuries in children. Eur J

Emerg Med. 2006;13(5):286-9. • Park WH, Demuth WE. Wounding capacity of rotary lawn mowers. J Trauma. 1975;15(1):36-

8. • Ren KS, Chounthirath T, Yang J, Friedenberg L, Smith GA. Children treated for lawn mower-

related injuries in US emergency departments, 1990-2014. Am J Emerg Med. 2017; • Robertson WW. Power lawnmower injuries. Clin Orthop Relat Res. 2003;(409):37-42. • Vollman D, Smith GA. Epidemiology of lawn-mower-related injuries to children in the

United States, 1990-2004. Pediatrics. 2006;118(2):e273-8.