Article, Surgery

Avocado-related knife injuries: Describing an epidemic of hand injury

a b s t r a c t

Introduction: Recent media reports have described knife injuries sustained while preparing avocados; however, this rise has not been reported in the literature. The purpose of this study is to describe, quantify, and trend emer- gency department (ED) encounters associated with avocado-related knife injuries.

Methods: The National Electronic Injury surveillance System (NEISS) was queried for avocado-related knife inju- ries from 1998 to 2017. Patient demographic and injury data was collected and analyzed to describe trends in in- cidence, patient demographics, and Injury patterns associated with an ED encounter for an avocado-related knife injury.

Results: There were an estimated 50,413 (95% Confidence Interval: 46,333-54,492) avocado-related knife inju- ries from 1998 to 2017. The incidence of avocado-related knife injuries increased over this time period (1998-2002 = 3143; 2013-2017 = 27,059). This increase correlated closely with a rise in avocado consumption in the U.S. (Pearson’s Correlation: 0.934, p b 0.001) Women comprised 80.1% of injuries. The most common de- mographic injured were 23 to 39-year old females (32.7%), while the least common was males under the age of 17 (0.9%). Most ED presentations occurred on Saturdays (15.9%) or Sundays (19.9%) and the majority occurred during the months of April through July (45.6%). Injuries were much more common on the left (and likely non-dominant) hand.

Conclusion: Avocado-related knife injuries are a preventable cause of hand injury. The incidence has risen signif- icantly in recent years, possibly due to an increased consumption of avocados in the United States. Education on safe avocado preparation techniques and public safety initiatives, such as warning labels, could help prevent se- rious injuries in the future.

(C) 2019

Introduction

The avocado is an increasingly popular food in American cuisine [1,2]. It consists of a sturdy outside skin, a soft edible interior, and a hard center pit. Macronutritionally, it is comprised of predominantly fats, with the rest consisting mostly of soluble and insoluble fibers [2]. Likely a result of its nutritional composition, the avocado has become exceedingly popular. From 1998 to 2017, avocado consumption in the United States (U.S.) has nearly tripled [3].

Recently, knife injuries sustained while preparing avocados have emerged in media reports, citing injury to the palm or digits [4-6]. The media and the emergency department (ED) physicians that treat this

? This work has not been presented at a conference or meeting.

* Corresponding author at: 59 Executive Park S, Atlanta, GA, 30329, USA

E-mail addresses: [email protected] (K.X. Farley), [email protected] (M. Aizpuru), [email protected] (E.R. Wagner), [email protected] (M.B. Gottschalk), [email protected] (C.A. Daly).

pattern of injury have named this phenomenon “avocado hand” [7]. The avocado fruit’s unique composition may explain its predilection for injury. The soft fat-filled interior contributes to a slippery exterior of the center pit. With the avocado placed in the non-cutting hand, a downward slicing motion into the fruit with excessive force can result in knife slippage over the pit and into the hand. Furthermore, injury can also result if one uses the cutting technique cautioned by Greminger et al.; a perpendicular puncture by the knife tip into a half-sliced fruit in an attempt to remove the pit [8].

Despite anecdotal reports of an “avocado hand” epidemic [4], there remains a paucity of scientific data on the national incidence of avocado-related knife injuries. The purpose of this study was to describe trends in incidence, injury patterns, and patient demographics for avocado-related knife injuries over the last 20 years (1998-2017). Given the increase in media coverage, we hypothesized there would be a significant rise in avocado-related knife injuries in the last two de- cades. Additionally, we sought to describe safe avocado cutting prac- tices, with a focus on hand protection [8,9].

https://doi.org/10.1016/j.ajem.2019.06.051

0735-6757/(C) 2019

Table 1

Trends in avocado-related knife injuries and consumption, 1998-2017.

Year

Estimate (95% CI)

Counta

Consumption

1998

647 (516-779)

12

1.52

1999

267 (231-303)

7

1.92

2000

327 (251-404)

9

2.21

2001

709 (557-860)

20

2.50

2002

1193 (536-1850)

24

2.43

2003

703 (509-897)

18

2.67

2004

1255 (567-1942)

24

3.17

2005

1117 (771-1463)

33

3.46

2006

2767 (1945-3590)

55

3.50

2007

1318 (923-1712)

45

3.50

2008

1539 (993-2085)

34

3.83

2009

2300 (1342-3257)

64

4.25

2010

3258 (2205-4312)

77

4.00

2011

1655 (1317-1993)

51

5.10

2012

4298 (3093-5503)

107

5.61

2013

4286 (2835-5738)

101

6.11

2014

4716 (3688-5744)

119

6.97

2015

5324 (4052-6596)

143

7.18

2016

6735 (4995-8476)

176

6.87

2017

5998 (4267-7730)

157

7.47

Total

50,413 (46,333-54,492)

1276

4.22 (average)

a Unweighted count.

Materials and methods

As a review of de-identified, publicly available data, this study was exempt from our Institutional Review Board. The U.S. Consumer Product Safety Commission, National Electronic Injury Surveillance System is a nationally representative probability sample of all ED en- counters associated with a consumer product. The NEISS has been used extensively for examining injury trends and patterns associated with consumer products in the U.S., including hand-related injuries [10-14]. Each year, approximately 100 hospital EDs are sampled, includ- ing children’s hospitals [15]. Sampling weights are provided with each case to estimate national incidence. Each case also contains a narrative of the event which can be used to elucidate data that would not other- wise be captured with coding provided by the NEISS.

The NEISS was used to query all knife-related avocado injuries oc- curring from 1998 to 2017. Incident date, patient demographics, diag- nosis, injury location, narrative description of incident, and disposition data were collected from incident ED encounters. On initial query, the product codes 464 (Knives, Not Elsewhere Classified), 218 (Electric or Battery Powered Knives), and 838 (Knives with Replaceable Blades) were utilized to capture all knife-related injuries in the database. The search term “avocado” was subsequently used to identify avocado- related knife injuries from the patient narrative. Common misspellings were also queried to ensure capture of all related principal events. The narrative text was manually reviewed to specify distribution of injury to the digits and to determine left or right handedness of injury. Further- more, data from the U.S. Department of Agriculture was queried to com- pare estimates in avocado-related knife injuries to consumption patterns in the U.S. [3]. Consumption in Table 1 and Fig. 1 is defined as the average per-capita utilization of the avocado per year (in pounds). After applying provided weights to estimate national incidence, de- scriptive analyses were performed to describe patterns of presentation, Patient dispositions, and injury pattern and location. All national inci- dence estimates were calculated with the Complex Samples function of SPSS to account for clustering and to produce 95% confidence inter- vals (CI) around estimates. Injury location data was queried from the patient narrative, and was not available for every patient. Linear regres- sion analysis was performed to describe change in incidence over time. Pearson’s correlation was used to compare trends. Non-overlapping 95%

CIs were used to determine significance.

Results

National estimates of avocado-related knife injuries and consumption

There were an estimated 50,413 (95% CI: 46,333-54,492; Table 1) avocado-related knife injuries from 1998 to 2017. The incidence of these injuries rose over time, from an estimated 3143 cases between 1998 and 2002 to 27,059 cases between 2013 and 2017 (R2 = 0.84, P

b 0.001; Fig. 1). Incidence reached an all-time high in 2016 and 2017 (Table 1). Avocado-related knife injuries are more frequent on weekend days (Sunday [19.9%], Saturday [15.9%]; Fig. 2) and in the summer

7,000 8.00

R2 = 0.9507

R2 = 0.8402

6,000

Estimeated Incidence of Avocado-Related Knife Injuries (No.)

7.00

5,000

6.00

4,000

3,000

5.00

4.00

3.00

2,000

2.00

1,000

Per Capita Avocado Consumption (Pounds)

1.00

0

1995 1997 1999 2001 2003 2005 2007 2009 2011 2013 2015 2017 2019

Avocado-Related Knife Injuries Per-Capita Avocado Consumption

0.00

Fig. 1. Trends in avocado-related knife injuries presenting to emergency departments and avocado consumption in the United States, 1998-2017.

14,000

12,000

10,000

8,000

6,000

4,000

2,000

0

Sunday Monday Tuesday Wednesday Thursday Friday Saturday

Fig. 2. Estimated avocado-related knife injuries by day of the week, 1998-2017.

months (April through July [45.6%]; Fig. 3). The increase in avocado- related knife injuries correlated with an increase in avocado consump- tion in the U.S. (1989: 1.52 pounds consumed per person, 2017: 7.47 pounds consumed per person; Pearson’s Correlation: 0.934, p b 0.001).

Patient characteristics associated with injury

Demographic characteristics of avocado-related knife injury patients are described in Table 2. 4 out of 5 injuries (80.1%) occurred in women and the most affected population subgroup were 23 to 39-year old fe- males (32.7%). The least affected demographic were males under the age of 17 years (0.9%). Race was available for 58.0% of patients. 83.2%

were White, 7.7% were Hispanic, 3.5% were Black, 2.5% were Asian, and 3.2% were classified as ‘other’.

Injury pattern and location

The vast majority of wounds were lacerations (94.4% of total). Punc- ture wounds occurred in 5.6% of the sample. 281 patients (95% CI: 23-534) were admitted into the hospital. Injuries were almost equally distributed between the digits (46.9%) and the palm (52.8%) (Table 3). Specific digit injury data was available for 28.8% of patients on review of the narrative (14,540/50,413). The most common digit injured was the index finger (34.4%), followed by the thumb (18.6%), and the ring

8,000

7,000

6,000

5,000

4,000

3,000

2,000

1,000

0

Fig. 3. Estimated avocado-related knife injuries by month, 1998-2017.

Table 2

Incidence of avocado-related knife injury by sex and age groups.

Age groups

Female (80.12% of all injuries)

Male (19.88% of all injuries)

% of Total (Female and Male)

Estimate

Counta

Estimate

Counta

b17 yrs.

2122 (1437-2807)

60

472 (122-821)

18

5.1

18-22 yrs.

5610 (4350-6869)

138

1740 (1085-2396)

43

14.6

23-39 yrs.

16,470 (14,430-18,509)

459

2188 (1451-2924)

56

42.5

40-59 yrs.

11,619 (9850-13,389)

249

4977 (3912-6041)

135

27.4

60+ yrs.

4353 (3326-5380)

95

863 (424-1301)

23

10.3

Total

40,174 (36,786-43,561)

1001

10,239 (8593-11,885)

275

100%

a Unweighted counts.

finger (17.1%) (Table 3). Injuries to the web-spaces occurred in 5.3% of all digit-related injuries (Table 3). Handedness of injury (left or right) was available for 46.1% of all patients (23,247/50.413), in which the vast majority were injuries to the left hand (90.1%) (Table 3). There were an estimated 124 infections (95% CI: 1-287), 612 nerve injuries (95% CI: 225-999), 289 tendon injuries (95% CI: 73-504), and 70 ampu- tations (95% CI: 1-210).

Discussion

The epidemic of avocado-related knife injuries

Our data confirms the widely popularized notion that avocado- related knife injuries to the hand have been increasing in recent years. This increase in avocado-related hand injuries corresponds with the popularization of the avocado in the American diet, which has more than tripled since 1998 (Fig. 1) [3].

We clarify which populations are most at risk for ED visits secondary to avocado-related knife injuries. Most injuries occurred in women (80.1%), with young women between the ages of 23 and 39 years of age being the most affected. This is in contrast to previous knife injury literature, which has found the majority of knife injuries occur in males [10]. People under 18 years of age sustained the fewest avocado related knife injuries. These differences are likely due to differences in the demographic of patients that prepare and consume avocados across the U.S.

Seasonal and Weekly variations in ED presentations for avocado- related knife injuries likely represent fluctuations in consumption pat- terns. A greater proportion of avocado-related knife injury presenta- tions occurred on the weekend. This is consistent with previous literature which has found increased weekend ED visits for all causes [16]. The reason for this is likely multifactorial, including less access to

urgent care and walk-in clinics, thus driving people to seek care in the ED. In addition, people may prepare and consume more avocados on weekends, thus increasing their risk of hand injury and presentation to the ED. Seasonal trends in avocado related knife injury likely stem from similar variations in avocado consumption and human behavior at large. Previous literature has found increased rates of trauma presen- tations in the summer months relative to the winter months [17-20]. In addition, preparation and consumption is likely more frequent in the summer months when the avocado is in season in the U.S., and thus more available for purchase [21].

Most injuries involved the left hand, implying that the non- dominant (and non-cutting) hand is injured in the vast majority of cases [22]. The majority of injuries were lacerations, implying that inju- ries occurred with the blade edge, as opposed to the knife tip. Lacera- tions were found at a similar rate compared to all-cause knife injuries [10]. These results suggest that common avocado cutting techniques in- adequately protect the non-cutting hand from slicing motions during preparation. Additionally, lacerations may be more likely to present to the ED, while patients sustaining puncture wounds do not seek care. Most patients were treated in the ED and discharged without admission, at a rate similar to other knife injuries [10].

Several patients presented with infection associated with their avocado-related knife injury, suggesting that delayed infection after in- jury is common. These results emphasize the importance of adequate ir- rigation and wound care of Penetrating injuries contaminated with food. Additionally, several patients in this study injured critical struc- tures, emphasizing the importance of ED physicians to consider Vascular injury, nerve injury, and tendon injury in any patient with an avocado- related knife injury to the hand. Given the serious and often subtle na- ture of tendon and nerve injuries, providers should have a low threshold to consult a hand surgeon for evaluation of injury to these critical structures.

Table 3

Location of injury.

Estimate (95% CI) Count Percentage (%)

Safe cutting practices and future direction

Best practices for safely cutting an avocado have been described in

Location on person (reported for all patients)

Digits

24,351 (21,652-27,050)

599

48.3% case report of 18 patients in the European Journal of Hand Surgery,

Palm

26,014 (23,453-28,576)

674

51.6%

Leg

16 (1-46)

1

0.0% have described several injury patterns associated with avocado-

Wrist

31 (1-75)

2

0.1% related knife injuries [7,8]. In all cases reported, the non-dominant

Digital injury (reported for 14,540 patients)a hand (otherwise, the non-cutting hand) has been injured, mostly over

Thumb 2709 (1855-3563) 61 18.6% the radial palm or radial digits. In these series, all injuries involved a sin-

Index

5008 (3603-6413)

97

34.4%

gle penetrative site [8]. This mimics our data, where the left, and likely

Middle

2385 (1674-3096)

61

16.4%

non-dominant hand, was injured in the majority of avocado-related

Ring

Pinky

Web space (1st, 2nd) Web space (2nd, 3rd)

2482 (1707-3258)

1196 (636-1755)

185 (1-386)

156 (1-332)

55

30

5

5

17.1%

8.2%

1.3%

1.1%

knife injuries. These reports urge for safe cutting methods for avocado

preparation and dissection. However, techniques and Safety measures to do so remain debated [8,9].

Web space (3rd, 4th)

240 (52-428)

9

1.7%

We recommend that avocado dissection be performed with a focus

Web space (4th, 5th)

178 (1-386)

4

1.2%

on technique that can provide protection to the hand, including hand

Handedness of injury (reported for 23,247 patients)a protection with a thick towel in the non-cutting hand, dissecting the

Left

20,936 (18,216-23,657)

486

90.1%

fruit on a cutting board with the non-cutting hand a safe distance

Right

2311 (1568-3053)

53

9.9%

from the knife, and to avoid dissecting the pulp of the fruit with the av-

a Handedness and specific digit location not available for all ED encounters. ocado held in hand. Furthermore, knife-alternative dissection tools

the lay literature. In addition, recently published articles, including a

exist, that can safely aid in the fruit’s dissection, including a spoon to scoop the pulp from the exterior skin.

In addition to safe-avocado dissection techniques, public health ini- tiatives could be considered to warn and mitigate the spate of knife in- juries related to the fruit. One such proposal, made by physicians in the United Kingdom, is a warning label placed on the exterior of the skin [23]. In addition, warning labels, pamphlets, or other visual modes of communication could be placed near avocado stands in supermarkets. There are also other initiatives to make the fruit easier to dissect. One such strategy, which went on sale in the fall of 2018, are avocados with skin that is easy to pull away once cut in half [24]. These initiatives could potentially help mitigate future avocado-related knife injuries.

Limitations

This study likely underestimates the true national incidence of avocado-related knife injuries, as it only includes patients that pre- sented to the ED with their injury. Patients may self-treat or present to their primary care provider, an urgent care center, or a hand surgeon with their injury, which would not be included in this database. Patients with minor injuries or poor access to care may not seek medical atten- tion at all. Also, data in the NEISS is limited to the patients’ record on their initial encounter into the ED, and the detail entered into the pa- tient narrative by NEISS coders. As a result, the NEISS narrative may have lacked the search term “avocado” (and its common misspellings) that we used to query for all avocado-related knife injuries. Further- more, it is not clear whether the same 100 hospitals were queried over time, or whether there were any changes in the surveyed hospitals that could impact the accuracy of the estimates. This is especially rele- vant for this analysis, as the study period extended 20 years. Addition- ally, a large portion of the estimated sample did not capture race. Differences in NEISS coders may account for differences in the classifica- tion of an injury as a “puncture” or “laceration”. Additionally, there is potential for misclassification of the injuries. Furthermore, tendon, nerve, or vascular injury could not be reliably tracked, and thus are likely underestimated. Finally, not every patient had specified location data recorded and individual patients could not be tracked over time.

Conclusion

Avocado-related knife injuries are a preventable cause of hand in- jury, increasing significantly in recent years due to increased consump- tion and preparation of the fruit in the U.S.

Education on safe avocado preparation techniques and public safety initiatives, such as warning labels and avocados engineered for safe preparation, could help prevent Serious injuries in the future.

Funding

No funding was received for this study.

Declaration of Competing Interest

No disclosures relevant to the current research.

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