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Snowblower injuries to the hand
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ScienceDirect www.sciencedirect.com Chirurgie de la main 33 (2014) 272–278
Original article
Snowblower injuries to the hand Traumatismes de la main par déneigeuse E. Jardin a,*,b, J. Uhring a,b, P.-B. Rey a,b, M. Ferrier a,b, L. Obert a,b a
Service d’orthopédie, de traumatologie, de chirurgie plastique, reconstructrice et assistance main & CIC IT 808, CHU Jean-Minjoz, 3, boulevard Fleming, 25000 Besançon, France b EA 4268 Innovation, imagerie, ingénierie et intervention en santé « I4S », IFR 133 Inserm, faculté de médecine et de pharmacie, université de Franche-Comté, Franche-Compté, France Received 27 January 2014; received in revised form 25 April 2014; accepted 12 June 2014 Available online 25 June 2014
Abstract The aim of this study was to describe the nature and incidence of hand injuries caused by snowblowers, as well as the accident conditions and accident prevention. We conducted a retrospective evaluation over ten consecutive winters. Nine patients were included. All were men with an average age of 49.7 years (17–71). The accidents occurred at home in seven out of nine patients. The machine was running in 50% of the injury events. In most cases, the injuries occurred when the patient tried to unclog snow from the lateral discharge chute. Only four out of the nine patients had read the instructions or received instructions from the salesperson. The dominant hand was injured in 7 out of 9 patients. An average of 2.7 fingers were injured. The longest fingers were most commonly injured: 8 middle fingers, 7 ring fingers, 4 little fingers, 2 indexes and 1 thumb. All the fractures were open. Three patients were operated on several times. In 7 out of 9 cases, the patients had sequelae such as amputation. The mean time off work was 11.4 weeks (3–24). All the patients were experienced snowblower users (9 years and 57th use on average). Snowblower accidents are very mutilating. Prevention must include protected access to blades and better verbal and written safety warnings. # 2014 Elsevier Masson SAS. All rights reserved. Keywords: Mutilation; Hand; Snowblower; Prevention
Résumé L’objectif de ce travail était d’évaluer la nature et la fréquence des traumatismes de la main par déneigeuse, les conditions de survenue des accidents et leur prévention. Dans ce but, nous avons réalisé une évaluation rétrospective durant dix hivers consécutifs. Neuf patients ont été inclus. Tous les patients étaient des hommes, d’âge moyen 49,7 ans (17–71). Il s’agissait d’accidents de loisirs dans sept cas sur neuf. La machine était en marche une fois sur deux lors de l’accident. Les lésions étaient dues en majorité à un essai de déblocage de la neige dans le conduit d’évacuation latéral. Seuls quatre patients sur neuf avaient lu la notice d’utilisation ou avaient eu des explications lors de l’achat. La main dominante était lésée chez sept des neuf patients. Deux ou trois doigts (2,7 en moyenne) étaient atteints. Les lésions intéressaient préférentiellement les doigts longs: huit majeurs, sept annulaires, quatre auriculaires, deux index et un pouce. Il s’agissait de fractures ouvertes plus ou moins complexes chez tous les patients. Trois patients ont été opérés à plusieurs reprises. Dans sept cas sur neuf, les patients présentaient des séquelles à type d’amputation. L’arrêt de travail moyen était de 11,4 semaines (3–24). Tous les patients avaient une expérience de l’utilisation de la déneigeuse (9 ans et 57e utilisation en moyenne). Les accidents de déneigeuse sont des accidents mutilants. La prévention doit inclure un accès plus sécurisé vis à vis des lames, et une meilleure prévention orale et écrite. # 2014 Elsevier Masson SAS. Tous droits réservés. Mots clés : Mutilation ; Main ; Déneigeuse ; Prévention
* Corresponding author. E-mail address: [email protected] (E. Jardin). http://dx.doi.org/10.1016/j.main.2014.06.002 1297-3203/# 2014 Elsevier Masson SAS. All rights reserved.
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
273
1. Introduction Snowblower-related hand injuries have been described by several North American authors over the past 20 years [1–5]. Snowblowers, also called snow-throwers, consist of front auger blades that collect snow. This snow is ejected from the side chute with or without an impeller fan (Fig. 1). Because of the nature of the auger’s rotating blades, these machines cause severe mutilation injuries that are challenging to repair. These accidents seem to be rarer in France, but since records are not kept, they may go unreported or underreported. For the first time in France, this article describes the initial evaluation performed on nine patients treated, followed and evaluated from the winter of 2002 through the winter of 2012. A review of literature provides context for our findings. 2. Material and methods
Fig. 1. Self-propelled snowblower: front auger blades pull in snow while lateral impeller blades eject snow from the discharge chute.
This was a descriptive study of snowblower-related accident in an area with a continental climate (Franche-Comté, France). Over 10 winters, nine patients presented with finger mutilation caused by snowblowers. The surgeon recorded the preoperative epidemiological variables, nature of the injuries and postoperative assessment. At the last follow-up of 67.2 months on average (range 4–123), we were able to review and talk with seven of the nine patients; two were lost to follow-up. The assessment consisted of the patient’s progression during postoperative recovery, total time off work and sequelae. 3. Results All the patients were men; the average age was 49.7 years (range 17–71). Five of the patients were manual workers, one was a marketing representative and three were retirees. Six of the seven accidents occurred during snow removal at home. At the time of the accident, patients had been using the snowblower
for an average of 25 minutes (range 15–45) and it was on average the 57th time they had used their machine (range 12– 120). They had owned the snowblower for an average of nine years (range 4–15). Six of the seven patients were injured while trying to unclog snow from the discharge chute. Only three patients had turned off the machine before attempting to unclog it. On the prevention front, only three patients had read the safety guidelines and only three had received verbal safety instructions when they bought their snowblower (Table 1). The right hand was injured in six patients and the left in three. Seven of the nine patients had their dominant hand injured. A total of 25 fingers were injured: 1 thumb (4%), 5 index (20%), 8 middle (32%), 7 ring (28%) and 4 little (16%). Patients had an average of 2.7 fingers injured. Loss of finger vascularization occurred in 28% of cases (7/25 affected fingers). These finger mutilations, along with skin, bone, tendon, nerve and sometimes vascular wounds, could be either
Table 1 Summary of conditions under which snowblower was used at time of hand injury. Case No.
Accident context
Length of snowblower ownership
Number of uses
Time elapsed before accident occurred
Machine completely turned off
Location where hand was placed
Safety warnings Read instructions
Provided by salesperson
1
Recreational
4 years
15 times
20 min
No
In front
No
No
4
Recreational
6 years
70 times
25 min
Yes
Discharge chute
Yes
Yes
5
Recreational
12 years
100 times
20 min
No
Discharge chute
No
No
6
Work-related
Employer’s
20 times
15 min
No
Discharge chute
No
Yes
7
Recreational
15 years
120 times
45 min
Yes
Discharge chute
No
No
8
Recreational
Borrowed
12 times
20 min
No
Discharge chute
Yes
No
9
Recreational
8 years
60 times
30 min
Yes
Discharge chute
Yes
Yes
Overall
6/7 recreational
9 years
57th use
25 min
4/7 with machine still on
6/7 discharge chute
3/7 cases
3/7 cases
274
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
Fig. 2. Clinical case: AP X-ray and photograph on arrival.
reconstructed or preserved in 68% of cases (17/25). Finger amputation was performed in 32% of cases (8/25). Six of the nine patients required amputation of at least one phalanx; one patient needed five amputations (Figs. 2–4 and Table 2). An open fracture was present in every case. The tendons and neurovascular bundles were intact in only three of nine cases. Three patients required more than one surgical procedure. One patient was operated a second time using Masquelet’s induced membrane technique due to a bone defect in the middle phalanx. Two patients required secondary amputations: one for secondary necrosis of the middle and distal phalanges in an arthritic patient and the other for osteitis due to methicillin-sensitive S. aureus (MSSA) in a middle phalanx.
Fig. 3. Number of patients according to the injured finger.
In the 8 of 9 cases where more than one finger was injured, chronic discomfort or function deficit was present: paresthesia in three cases, grasping deficit in two cases, strength deficiency in two cases, or pain estimated at an average of 1.7/10 on the VAS (visual analogue scale) at the longest follow-up. The average QuickDASH functional score at the longest follow-up, after body image had been recovered post-amputation, was 20.45/100. Employed patients returned to work an average of 11.4 weeks (range 3–24) after their injury. The three retirees were not included in this calculation; one patient was reassigned to a new job (Table 2).
Fig. 4. Amputation level. Trans-P1: through the proximal phalanx; Trans-P2: through the middle phalanx.
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
275
Table 2 Overview of patient injuries. Age
Simple wound
Years
Clinical observation
Preserved
Clinical observation
Amputated
1
35
D2: pad wound D4: P3 fracture
D2: skin suture D4: fixation
D3: trans DIP amputation
D3: DIP surgical amputation
2
17
D2: superficial wounds D4: dorsal skin defect D5: superficial wounds
D2: skin suture D4: skin graft using banked 3rd finger D5: skin suture
D3: P3 degloving with proximal dorsal defect and pedicle avulsion over 6 cm
D3: DIP surgical amputation
3
49
D1: pad wound D4: volar wound over DIP and PIP; P2 comminuted fracture
D1: skin suture D4: skin suture, P2 non-surgical treatment
D2: devascularisation with bone defect in all 3 phalanges, along with flexors and ulnar neurovascular bundle D3: P1, P2 bone defect; extensor laceration; skin defect on volar side of P1
D2: trans-P1 surgical amputation D3: K-wire for realignment, cement spacer, pedicle flap from volar skin using banked 2nd finger
4
68
D3: quasi-circular trans-P2 crease; tendon and vascularization intact D5: trans-P3 subtotal amputation; vascularization intact
D3: skin suture D5: pad repositioned, P3 pinned
D2: trans-P1 devascularisation (only flexor remained) D4: trans-DIP traumatic amputation with distal defect
D2: trans-P1 surgical amputation D4: trans-DIP surgical amputation
5
61
D3: P3 comminuted fracture with distal defect D4: P3 comminuted fracture and P2 distal fracture with distal defect
D3: trans-DIP surgical amputation D4: trans-P2 surgical amputation
6
63
D2: comminuted fractur of distal P2 with DIP and nail destruction
D2: fixation of P3 to P2; removal of nail matrix
7
71
D3: wound on dorsal side of P3 D4: open P2 fracture D5: open P3 fractures with nail avulsion; tendons and pedicle intact
D3: lavage, skin suture, no bone fixation D4: lavage, skin suture, no bone fixation D5: reinsertion of nail
8
27
D4: nail avulsion D5: open P3 fracture, matrix wound and nail avulsion
D4: reinsertion of nail D5: needle fixation, matrix suture and reinsertion of nail
9
57
D3: open P3 fracture
D3: lavage, skin suture, no bone fixation
Case
Complex wounds
D3: trans-P2 traumatic amputation D3: trans-P2 surgical with partial distal fragment amputation D4: trans-P2 secondary amputation due to osteitis
D1: thumb; D2: index; D3: middle; D4: ring; D5: little finger.
4. Discussion Snowblower-related accidents are rare. In 1977, Waller estimated their frequency at 5.3 accidents/1000 machines/year and 4.1 accidents per 10,000 uses in the United States [1]. In 1980, 3000 accident were reported in the United States and 5000 in 2004; of these 5000 accidents, 1000 led to amputation [7]. These numbers point to an increase in the severity of snowblower-related accidents, despite improvements in the equipment and more explicit safety warnings. Barry and Linton [2] described snowblower-related hand injuries as resulting from the momentum of the impeller blades, even after the machine is turned off. In the current study, all of the accidents were the result of attempts to remove snow by hand when the blades had locked up. Clogging occurs when the snow being removed is too deep and dense. This accident mechanism was reported by several other authors, including the Center for Disease Control and Prevention in the United States [5,8–10].
Various authors [5,6,8,10–13] found the same type of injury characteristics as in our study: men between 40 and 50 years of age with injuries distal to the metacarpophalangeal joints. In six of the seven reviewed patients, snow removal was not part of their occupation and the accidents occurred at home with personal machines. This is consistent with Chin’s finding of only one work-related accident among 22 [8]. One study [12] reported that the accident occurred after 21 minutes of use, while the average was 25 minutes in the current study. Bowen et al. [3] found that inexperience increased the risk of an accident. However, Millea et Hansen [4] found that patients with snowblower injuries had an average of 5.7 years of experience and Master et al. found 15.2 years [12]. Thus even experienced operators were injured. In the current study, patients had an average of 9 years’ experience with snowblowers and were using their machine for the 57th time. The dominant hand was injured in 78% of cases. This is consistent with published findings [4,8,9,12]. The observed
276
Table 3 Review of published studies. No. of patients
Gender
Average age (years)
Current study
9
100% men 49.7 (17–71)
Millea & Hansen, 1989 [4]
13
Istre et al., 1989 [5]
27
Hammig & Jones, 2002 [6]
20,049 90% men (over 6 yr period)
43.7% between 40 & 59
Chin et al., 1998 [8]
22
39.7 (20–68)
Dietzel et al., 1997 [9]
62
CDC Colorado, 1983 [10]
26
100% men 44
CDC New York, 1983 [10]
17
94% men 47 (14–73) 16 M, 1 W
Proano & Partridge, 2002 [11]
11
100% men 40
% dominant hand injury
Most frequently injured fingers
Average number Simple of fingers injured injury per patient
Complex injury requiring amputation
Comments
78%
D3: 32% D4: 28% D2: 20%
2.7 fingers
Phalanx fractures: 100%
Amputations: 78% (1–5 phalanges per patient)
85% not work-related Experience with machine: 57th use (1-40) Time elapsed before accident occurred: 25 min Safety warnings: 43% written, 43% verbal
Phalanx fractures: 100%
Amputations: 14%
Experience with machine: Average of 5.7 years
Skin defects: 48%
Amputations: 52%
Experience with machine: 4th use Time elapsed before accident occurred: 11 min 48% had read safety warnings 32% had received instructions from salesperson
Skin lacerations: 29% Fractures/avulsions: 42%
Amputations: 20%
Phalanx fractures: 29.2% Nail injuries: 22.9% Tendon injuries: 14.6% Skin defects: 6.3% Nerve injuries: 4.2%
Amputations: 22.9% 96% not work-related
100% men 44 (15–63)
77% men
D3: 76% D2: 46% D4: 32%
86%
D3: 39.6% D4: 33.3% D2: 16.7%
1.6 fingers
2.3 fingers
2.4 fingers D3: 45% D2: 30% D4: 20%
72%
D3: 72% D2: 45% D4: 18%
1.6 fingers
Most often after putting hand into discharge chute Skin lacerations: 46%
Amputations: 54%
Skin lacerations: 65% Phalanx fractures: 41%
Amputations: 24%
Phalanx fractures: 81% Tendon injuries: 72% Skin defects: 18% Skin lacerations: 27%
Amputations: 36%
70% with machine still running
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
Lead author [Ref. No.]
Table 3 (Continued ) Lead author [Ref. No.]
No. of patients
Gender
Average age (years)
Master et al., 2008 [12]
22
100% men 41.86 (12–75)
Tetz & Aghababian, 1995 [13]
37
100% men
% dominant hand injury
Most frequently injured fingers
Average number Simple of fingers injured injury per patient
Complex injury requiring amputation
Comments
68.2%
D3: 43.5% D2: 26.0% D4: 21.8%
2.0 fingers
Amputations: 41%
82% with machine still running 77% were aware of safety warnings Experience with machine: 15.17 years on average Time elapsed before accident occurred: 21 min
D3: 49% D4: 23% D2: 20%
Phalanx fractures: 100% Skin defects: 82%
95% with machine still running
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E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
injuries mainly affected the longest fingers. This is also consistent with published studies [5,6,8,10–12]. All of these studies have found that the longest finger (middle finger) is the most commonly injured. The second most injured finger was either the ring finger [3,4,8,13] or the index finger [2,5,9,11,12]. Injury to the middle finger, which almost always occurs in combination with index or ring finger injury, is likely due to the hand position during snow removal (pronation or supination). Master et al. [12] reported that two fingers were injured in most cases. In the current study more than two fingers were involved (average of 2.7), which is consistent with the Dietzel et al. study [9] (average of 2.4) and Chin et al. study [8] (average of 2.3). These finger injuries were highly heterogeneous, ranging from superficial wounds to amputations. In seven of our nine patients, devascularization of multiple tissues led to amputation of at least one phalanx, with five phalanges being amputated in one patient (Tables 2 and 3). Based on our experience, the lack of isolated nail injuries, as reported by Chin et al. [8], is surely due to recruitment bias. Patients with more benign injuries were likely not referred to us or were treated in hospital emergency departments and walk-in clinics. In all of our patients, the phalanx fractures were comminuted, which is consistent with published studies [4,12]. Various types of injuries are reported by different authors, but the most common ones are bone and skin injuries, following by nail, tendon and vascular or nerve injuries [5,8,11]. Only two of our nine patients had their injured hand fully restored. It must be noted that, other than for simple lacerations, every patient had functional deficits with pain, paresthesia, areas of anesthesia, loss of strength or stiffness. All of these affections had an impact on their professional and personal lives. In the Master et al. study, 77.3% knew the safety precautions, but 82% had their accident while the machine was still running and only 18% had their accident with the machine turned off [12]. Other authors have reported that 70-95% of accidents occurred while the machine was still running [11,13]. In the Istre et al. study, 48% of patients had read the instruction manual and 32% had received training and instructions from the person who sold them the snowblower. In the current study, only 43% of patients had read the safety warnings or received them verbally. Two studies [1,5] emphasized the importance of experience and user training on the occurrence of injuries; however these factors were not significantly predictive of injury. The user’s experience does not seem to be a risk-reduction factor; if anything, it was the opposite. It is logical to think that these patients were injured when they placed their hand in the snowblower’s front auger blades. But in the current study, more than 85% of injuries occurred when the user tried to remove snow from the discharge chute. These patients seemed to be aware of the danger associated with placing a hand near the front blades (visible part of
blades), but are not aware that it is also dangerous to place a hand in the discharge chute (hidden impeller blades). Snowblowers should be redesigned so that a user cannot access the discharge chute when the machine is running. 5. Conclusion The current study and review of literature (Table 3) reveal that snowblower-related injuries lead to multiple types of trauma, mainly to the longer fingers. These multifinger injuries are challenging to treat because the bone fractures occur in combination with nerve and vascular injuries, and often skin and tendon wounds, as well. The sequelae of these accidents are often significant. Prevention and proper use of this type of machine are the only ways to avoid these serious accidents. Any snow clogged in the discharge chute should be cleared with a stick once the machine has been turned off. However, until the option to remove snow by hand is eliminated, the risk of finger injuries remains high, despite preventative measures [6,12]. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Waller JA. Snowblower injuries. J Trauma 1977;17:122–5. [2] Barry TP, Linton PC. Biophysics of rotary mower and snowblower injuries of the hand: high vs low velocity ‘‘missile’’ injury. J Trauma 1977;17: 211–4. [3] Bowen V, Loback D, Tokaryk R. Snowblower injuries to the hand. Can J Surg 1987;30:111–2. [4] Millea TP, Hansen RH. Snowblower injuries to the hand. J Trauma 1989;29:229–33. [5] Istre GR, Tinnell C, Ouimette D, Gunn RA, Shillam P, et al. Surveillance for injuries: cluster of finger amputations from snowblowers. Public Health Rep 1989;104:155–7. [6] Hammig B, Jones C. Injuries related to snowblowers in the United States: 2002 through 2008. Acad Emerg Med 2010;17:566–9. [7] Consumer Product Safety Alert. Snow Thrower Safety Alert. Washington DC: US: Consumer Product Safety Commission; 2004. [8] Chin G, Weinzweig N, Weinzweig J, Geldner P, Gonzalez M. Snowblower injuries to the hand. Ann Plast Surg 1998;41:390–6. [9] Dietzel DP, Gorosh J, Burke EF, Singer RM. Snowblower injuries to the hand. Am J Orthop 1997;26:863–7. [10] Centers for Disease Control (CDC). Snowblower injuries – Colorado, New York. MMWR Morb Mortal Wkly Rep 1983;32:77–8. [11] Proano L, Partridge R. Descriptive epidemiology of a cluster of hand injuries from snowblowers. J Emerg Med 2002;22:341–4. [12] Master D, Piorkowski J, Zani S, Babigian A. Snowblower injuries to the hand: epidemiology, patterns of injury, and strategies for prevention. Ann Plast Surg 2008;61:613–7. [13] Tetz DJ, Aghababian R. Hand injuries from snowblowers: a report of an epidemic. Prehosp Disaster Med 1995;10:265–7.
ScienceDirect www.sciencedirect.com Chirurgie de la main 33 (2014) 272–278
Original article
Snowblower injuries to the hand Traumatismes de la main par déneigeuse E. Jardin a,*,b, J. Uhring a,b, P.-B. Rey a,b, M. Ferrier a,b, L. Obert a,b a
Service d’orthopédie, de traumatologie, de chirurgie plastique, reconstructrice et assistance main & CIC IT 808, CHU Jean-Minjoz, 3, boulevard Fleming, 25000 Besançon, France b EA 4268 Innovation, imagerie, ingénierie et intervention en santé « I4S », IFR 133 Inserm, faculté de médecine et de pharmacie, université de Franche-Comté, Franche-Compté, France Received 27 January 2014; received in revised form 25 April 2014; accepted 12 June 2014 Available online 25 June 2014
Abstract The aim of this study was to describe the nature and incidence of hand injuries caused by snowblowers, as well as the accident conditions and accident prevention. We conducted a retrospective evaluation over ten consecutive winters. Nine patients were included. All were men with an average age of 49.7 years (17–71). The accidents occurred at home in seven out of nine patients. The machine was running in 50% of the injury events. In most cases, the injuries occurred when the patient tried to unclog snow from the lateral discharge chute. Only four out of the nine patients had read the instructions or received instructions from the salesperson. The dominant hand was injured in 7 out of 9 patients. An average of 2.7 fingers were injured. The longest fingers were most commonly injured: 8 middle fingers, 7 ring fingers, 4 little fingers, 2 indexes and 1 thumb. All the fractures were open. Three patients were operated on several times. In 7 out of 9 cases, the patients had sequelae such as amputation. The mean time off work was 11.4 weeks (3–24). All the patients were experienced snowblower users (9 years and 57th use on average). Snowblower accidents are very mutilating. Prevention must include protected access to blades and better verbal and written safety warnings. # 2014 Elsevier Masson SAS. All rights reserved. Keywords: Mutilation; Hand; Snowblower; Prevention
Résumé L’objectif de ce travail était d’évaluer la nature et la fréquence des traumatismes de la main par déneigeuse, les conditions de survenue des accidents et leur prévention. Dans ce but, nous avons réalisé une évaluation rétrospective durant dix hivers consécutifs. Neuf patients ont été inclus. Tous les patients étaient des hommes, d’âge moyen 49,7 ans (17–71). Il s’agissait d’accidents de loisirs dans sept cas sur neuf. La machine était en marche une fois sur deux lors de l’accident. Les lésions étaient dues en majorité à un essai de déblocage de la neige dans le conduit d’évacuation latéral. Seuls quatre patients sur neuf avaient lu la notice d’utilisation ou avaient eu des explications lors de l’achat. La main dominante était lésée chez sept des neuf patients. Deux ou trois doigts (2,7 en moyenne) étaient atteints. Les lésions intéressaient préférentiellement les doigts longs: huit majeurs, sept annulaires, quatre auriculaires, deux index et un pouce. Il s’agissait de fractures ouvertes plus ou moins complexes chez tous les patients. Trois patients ont été opérés à plusieurs reprises. Dans sept cas sur neuf, les patients présentaient des séquelles à type d’amputation. L’arrêt de travail moyen était de 11,4 semaines (3–24). Tous les patients avaient une expérience de l’utilisation de la déneigeuse (9 ans et 57e utilisation en moyenne). Les accidents de déneigeuse sont des accidents mutilants. La prévention doit inclure un accès plus sécurisé vis à vis des lames, et une meilleure prévention orale et écrite. # 2014 Elsevier Masson SAS. Tous droits réservés. Mots clés : Mutilation ; Main ; Déneigeuse ; Prévention
* Corresponding author. E-mail address: [email protected] (E. Jardin). http://dx.doi.org/10.1016/j.main.2014.06.002 1297-3203/# 2014 Elsevier Masson SAS. All rights reserved.
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
273
1. Introduction Snowblower-related hand injuries have been described by several North American authors over the past 20 years [1–5]. Snowblowers, also called snow-throwers, consist of front auger blades that collect snow. This snow is ejected from the side chute with or without an impeller fan (Fig. 1). Because of the nature of the auger’s rotating blades, these machines cause severe mutilation injuries that are challenging to repair. These accidents seem to be rarer in France, but since records are not kept, they may go unreported or underreported. For the first time in France, this article describes the initial evaluation performed on nine patients treated, followed and evaluated from the winter of 2002 through the winter of 2012. A review of literature provides context for our findings. 2. Material and methods
Fig. 1. Self-propelled snowblower: front auger blades pull in snow while lateral impeller blades eject snow from the discharge chute.
This was a descriptive study of snowblower-related accident in an area with a continental climate (Franche-Comté, France). Over 10 winters, nine patients presented with finger mutilation caused by snowblowers. The surgeon recorded the preoperative epidemiological variables, nature of the injuries and postoperative assessment. At the last follow-up of 67.2 months on average (range 4–123), we were able to review and talk with seven of the nine patients; two were lost to follow-up. The assessment consisted of the patient’s progression during postoperative recovery, total time off work and sequelae. 3. Results All the patients were men; the average age was 49.7 years (range 17–71). Five of the patients were manual workers, one was a marketing representative and three were retirees. Six of the seven accidents occurred during snow removal at home. At the time of the accident, patients had been using the snowblower
for an average of 25 minutes (range 15–45) and it was on average the 57th time they had used their machine (range 12– 120). They had owned the snowblower for an average of nine years (range 4–15). Six of the seven patients were injured while trying to unclog snow from the discharge chute. Only three patients had turned off the machine before attempting to unclog it. On the prevention front, only three patients had read the safety guidelines and only three had received verbal safety instructions when they bought their snowblower (Table 1). The right hand was injured in six patients and the left in three. Seven of the nine patients had their dominant hand injured. A total of 25 fingers were injured: 1 thumb (4%), 5 index (20%), 8 middle (32%), 7 ring (28%) and 4 little (16%). Patients had an average of 2.7 fingers injured. Loss of finger vascularization occurred in 28% of cases (7/25 affected fingers). These finger mutilations, along with skin, bone, tendon, nerve and sometimes vascular wounds, could be either
Table 1 Summary of conditions under which snowblower was used at time of hand injury. Case No.
Accident context
Length of snowblower ownership
Number of uses
Time elapsed before accident occurred
Machine completely turned off
Location where hand was placed
Safety warnings Read instructions
Provided by salesperson
1
Recreational
4 years
15 times
20 min
No
In front
No
No
4
Recreational
6 years
70 times
25 min
Yes
Discharge chute
Yes
Yes
5
Recreational
12 years
100 times
20 min
No
Discharge chute
No
No
6
Work-related
Employer’s
20 times
15 min
No
Discharge chute
No
Yes
7
Recreational
15 years
120 times
45 min
Yes
Discharge chute
No
No
8
Recreational
Borrowed
12 times
20 min
No
Discharge chute
Yes
No
9
Recreational
8 years
60 times
30 min
Yes
Discharge chute
Yes
Yes
Overall
6/7 recreational
9 years
57th use
25 min
4/7 with machine still on
6/7 discharge chute
3/7 cases
3/7 cases
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E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
Fig. 2. Clinical case: AP X-ray and photograph on arrival.
reconstructed or preserved in 68% of cases (17/25). Finger amputation was performed in 32% of cases (8/25). Six of the nine patients required amputation of at least one phalanx; one patient needed five amputations (Figs. 2–4 and Table 2). An open fracture was present in every case. The tendons and neurovascular bundles were intact in only three of nine cases. Three patients required more than one surgical procedure. One patient was operated a second time using Masquelet’s induced membrane technique due to a bone defect in the middle phalanx. Two patients required secondary amputations: one for secondary necrosis of the middle and distal phalanges in an arthritic patient and the other for osteitis due to methicillin-sensitive S. aureus (MSSA) in a middle phalanx.
Fig. 3. Number of patients according to the injured finger.
In the 8 of 9 cases where more than one finger was injured, chronic discomfort or function deficit was present: paresthesia in three cases, grasping deficit in two cases, strength deficiency in two cases, or pain estimated at an average of 1.7/10 on the VAS (visual analogue scale) at the longest follow-up. The average QuickDASH functional score at the longest follow-up, after body image had been recovered post-amputation, was 20.45/100. Employed patients returned to work an average of 11.4 weeks (range 3–24) after their injury. The three retirees were not included in this calculation; one patient was reassigned to a new job (Table 2).
Fig. 4. Amputation level. Trans-P1: through the proximal phalanx; Trans-P2: through the middle phalanx.
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
275
Table 2 Overview of patient injuries. Age
Simple wound
Years
Clinical observation
Preserved
Clinical observation
Amputated
1
35
D2: pad wound D4: P3 fracture
D2: skin suture D4: fixation
D3: trans DIP amputation
D3: DIP surgical amputation
2
17
D2: superficial wounds D4: dorsal skin defect D5: superficial wounds
D2: skin suture D4: skin graft using banked 3rd finger D5: skin suture
D3: P3 degloving with proximal dorsal defect and pedicle avulsion over 6 cm
D3: DIP surgical amputation
3
49
D1: pad wound D4: volar wound over DIP and PIP; P2 comminuted fracture
D1: skin suture D4: skin suture, P2 non-surgical treatment
D2: devascularisation with bone defect in all 3 phalanges, along with flexors and ulnar neurovascular bundle D3: P1, P2 bone defect; extensor laceration; skin defect on volar side of P1
D2: trans-P1 surgical amputation D3: K-wire for realignment, cement spacer, pedicle flap from volar skin using banked 2nd finger
4
68
D3: quasi-circular trans-P2 crease; tendon and vascularization intact D5: trans-P3 subtotal amputation; vascularization intact
D3: skin suture D5: pad repositioned, P3 pinned
D2: trans-P1 devascularisation (only flexor remained) D4: trans-DIP traumatic amputation with distal defect
D2: trans-P1 surgical amputation D4: trans-DIP surgical amputation
5
61
D3: P3 comminuted fracture with distal defect D4: P3 comminuted fracture and P2 distal fracture with distal defect
D3: trans-DIP surgical amputation D4: trans-P2 surgical amputation
6
63
D2: comminuted fractur of distal P2 with DIP and nail destruction
D2: fixation of P3 to P2; removal of nail matrix
7
71
D3: wound on dorsal side of P3 D4: open P2 fracture D5: open P3 fractures with nail avulsion; tendons and pedicle intact
D3: lavage, skin suture, no bone fixation D4: lavage, skin suture, no bone fixation D5: reinsertion of nail
8
27
D4: nail avulsion D5: open P3 fracture, matrix wound and nail avulsion
D4: reinsertion of nail D5: needle fixation, matrix suture and reinsertion of nail
9
57
D3: open P3 fracture
D3: lavage, skin suture, no bone fixation
Case
Complex wounds
D3: trans-P2 traumatic amputation D3: trans-P2 surgical with partial distal fragment amputation D4: trans-P2 secondary amputation due to osteitis
D1: thumb; D2: index; D3: middle; D4: ring; D5: little finger.
4. Discussion Snowblower-related accidents are rare. In 1977, Waller estimated their frequency at 5.3 accidents/1000 machines/year and 4.1 accidents per 10,000 uses in the United States [1]. In 1980, 3000 accident were reported in the United States and 5000 in 2004; of these 5000 accidents, 1000 led to amputation [7]. These numbers point to an increase in the severity of snowblower-related accidents, despite improvements in the equipment and more explicit safety warnings. Barry and Linton [2] described snowblower-related hand injuries as resulting from the momentum of the impeller blades, even after the machine is turned off. In the current study, all of the accidents were the result of attempts to remove snow by hand when the blades had locked up. Clogging occurs when the snow being removed is too deep and dense. This accident mechanism was reported by several other authors, including the Center for Disease Control and Prevention in the United States [5,8–10].
Various authors [5,6,8,10–13] found the same type of injury characteristics as in our study: men between 40 and 50 years of age with injuries distal to the metacarpophalangeal joints. In six of the seven reviewed patients, snow removal was not part of their occupation and the accidents occurred at home with personal machines. This is consistent with Chin’s finding of only one work-related accident among 22 [8]. One study [12] reported that the accident occurred after 21 minutes of use, while the average was 25 minutes in the current study. Bowen et al. [3] found that inexperience increased the risk of an accident. However, Millea et Hansen [4] found that patients with snowblower injuries had an average of 5.7 years of experience and Master et al. found 15.2 years [12]. Thus even experienced operators were injured. In the current study, patients had an average of 9 years’ experience with snowblowers and were using their machine for the 57th time. The dominant hand was injured in 78% of cases. This is consistent with published findings [4,8,9,12]. The observed
276
Table 3 Review of published studies. No. of patients
Gender
Average age (years)
Current study
9
100% men 49.7 (17–71)
Millea & Hansen, 1989 [4]
13
Istre et al., 1989 [5]
27
Hammig & Jones, 2002 [6]
20,049 90% men (over 6 yr period)
43.7% between 40 & 59
Chin et al., 1998 [8]
22
39.7 (20–68)
Dietzel et al., 1997 [9]
62
CDC Colorado, 1983 [10]
26
100% men 44
CDC New York, 1983 [10]
17
94% men 47 (14–73) 16 M, 1 W
Proano & Partridge, 2002 [11]
11
100% men 40
% dominant hand injury
Most frequently injured fingers
Average number Simple of fingers injured injury per patient
Complex injury requiring amputation
Comments
78%
D3: 32% D4: 28% D2: 20%
2.7 fingers
Phalanx fractures: 100%
Amputations: 78% (1–5 phalanges per patient)
85% not work-related Experience with machine: 57th use (1-40) Time elapsed before accident occurred: 25 min Safety warnings: 43% written, 43% verbal
Phalanx fractures: 100%
Amputations: 14%
Experience with machine: Average of 5.7 years
Skin defects: 48%
Amputations: 52%
Experience with machine: 4th use Time elapsed before accident occurred: 11 min 48% had read safety warnings 32% had received instructions from salesperson
Skin lacerations: 29% Fractures/avulsions: 42%
Amputations: 20%
Phalanx fractures: 29.2% Nail injuries: 22.9% Tendon injuries: 14.6% Skin defects: 6.3% Nerve injuries: 4.2%
Amputations: 22.9% 96% not work-related
100% men 44 (15–63)
77% men
D3: 76% D2: 46% D4: 32%
86%
D3: 39.6% D4: 33.3% D2: 16.7%
1.6 fingers
2.3 fingers
2.4 fingers D3: 45% D2: 30% D4: 20%
72%
D3: 72% D2: 45% D4: 18%
1.6 fingers
Most often after putting hand into discharge chute Skin lacerations: 46%
Amputations: 54%
Skin lacerations: 65% Phalanx fractures: 41%
Amputations: 24%
Phalanx fractures: 81% Tendon injuries: 72% Skin defects: 18% Skin lacerations: 27%
Amputations: 36%
70% with machine still running
E. Jardin et al. / Chirurgie de la main 33 (2014) 272–278
Lead author [Ref. No.]
Table 3 (Continued ) Lead author [Ref. No.]
No. of patients
Gender
Average age (years)
Master et al., 2008 [12]
22
100% men 41.86 (12–75)
Tetz & Aghababian, 1995 [13]
37
100% men
% dominant hand injury
Most frequently injured fingers
Average number Simple of fingers injured injury per patient
Complex injury requiring amputation
Comments
68.2%
D3: 43.5% D2: 26.0% D4: 21.8%
2.0 fingers
Amputations: 41%
82% with machine still running 77% were aware of safety warnings Experience with machine: 15.17 years on average Time elapsed before accident occurred: 21 min
D3: 49% D4: 23% D2: 20%
Phalanx fractures: 100% Skin defects: 82%
95% with machine still running
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injuries mainly affected the longest fingers. This is also consistent with published studies [5,6,8,10–12]. All of these studies have found that the longest finger (middle finger) is the most commonly injured. The second most injured finger was either the ring finger [3,4,8,13] or the index finger [2,5,9,11,12]. Injury to the middle finger, which almost always occurs in combination with index or ring finger injury, is likely due to the hand position during snow removal (pronation or supination). Master et al. [12] reported that two fingers were injured in most cases. In the current study more than two fingers were involved (average of 2.7), which is consistent with the Dietzel et al. study [9] (average of 2.4) and Chin et al. study [8] (average of 2.3). These finger injuries were highly heterogeneous, ranging from superficial wounds to amputations. In seven of our nine patients, devascularization of multiple tissues led to amputation of at least one phalanx, with five phalanges being amputated in one patient (Tables 2 and 3). Based on our experience, the lack of isolated nail injuries, as reported by Chin et al. [8], is surely due to recruitment bias. Patients with more benign injuries were likely not referred to us or were treated in hospital emergency departments and walk-in clinics. In all of our patients, the phalanx fractures were comminuted, which is consistent with published studies [4,12]. Various types of injuries are reported by different authors, but the most common ones are bone and skin injuries, following by nail, tendon and vascular or nerve injuries [5,8,11]. Only two of our nine patients had their injured hand fully restored. It must be noted that, other than for simple lacerations, every patient had functional deficits with pain, paresthesia, areas of anesthesia, loss of strength or stiffness. All of these affections had an impact on their professional and personal lives. In the Master et al. study, 77.3% knew the safety precautions, but 82% had their accident while the machine was still running and only 18% had their accident with the machine turned off [12]. Other authors have reported that 70-95% of accidents occurred while the machine was still running [11,13]. In the Istre et al. study, 48% of patients had read the instruction manual and 32% had received training and instructions from the person who sold them the snowblower. In the current study, only 43% of patients had read the safety warnings or received them verbally. Two studies [1,5] emphasized the importance of experience and user training on the occurrence of injuries; however these factors were not significantly predictive of injury. The user’s experience does not seem to be a risk-reduction factor; if anything, it was the opposite. It is logical to think that these patients were injured when they placed their hand in the snowblower’s front auger blades. But in the current study, more than 85% of injuries occurred when the user tried to remove snow from the discharge chute. These patients seemed to be aware of the danger associated with placing a hand near the front blades (visible part of
blades), but are not aware that it is also dangerous to place a hand in the discharge chute (hidden impeller blades). Snowblowers should be redesigned so that a user cannot access the discharge chute when the machine is running. 5. Conclusion The current study and review of literature (Table 3) reveal that snowblower-related injuries lead to multiple types of trauma, mainly to the longer fingers. These multifinger injuries are challenging to treat because the bone fractures occur in combination with nerve and vascular injuries, and often skin and tendon wounds, as well. The sequelae of these accidents are often significant. Prevention and proper use of this type of machine are the only ways to avoid these serious accidents. Any snow clogged in the discharge chute should be cleared with a stick once the machine has been turned off. However, until the option to remove snow by hand is eliminated, the risk of finger injuries remains high, despite preventative measures [6,12]. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Waller JA. Snowblower injuries. J Trauma 1977;17:122–5. [2] Barry TP, Linton PC. Biophysics of rotary mower and snowblower injuries of the hand: high vs low velocity ‘‘missile’’ injury. J Trauma 1977;17: 211–4. [3] Bowen V, Loback D, Tokaryk R. Snowblower injuries to the hand. Can J Surg 1987;30:111–2. [4] Millea TP, Hansen RH. Snowblower injuries to the hand. J Trauma 1989;29:229–33. [5] Istre GR, Tinnell C, Ouimette D, Gunn RA, Shillam P, et al. Surveillance for injuries: cluster of finger amputations from snowblowers. Public Health Rep 1989;104:155–7. [6] Hammig B, Jones C. Injuries related to snowblowers in the United States: 2002 through 2008. Acad Emerg Med 2010;17:566–9. [7] Consumer Product Safety Alert. Snow Thrower Safety Alert. Washington DC: US: Consumer Product Safety Commission; 2004. [8] Chin G, Weinzweig N, Weinzweig J, Geldner P, Gonzalez M. Snowblower injuries to the hand. Ann Plast Surg 1998;41:390–6. [9] Dietzel DP, Gorosh J, Burke EF, Singer RM. Snowblower injuries to the hand. Am J Orthop 1997;26:863–7. [10] Centers for Disease Control (CDC). Snowblower injuries – Colorado, New York. MMWR Morb Mortal Wkly Rep 1983;32:77–8. [11] Proano L, Partridge R. Descriptive epidemiology of a cluster of hand injuries from snowblowers. J Emerg Med 2002;22:341–4. [12] Master D, Piorkowski J, Zani S, Babigian A. Snowblower injuries to the hand: epidemiology, patterns of injury, and strategies for prevention. Ann Plast Surg 2008;61:613–7. [13] Tetz DJ, Aghababian R. Hand injuries from snowblowers: a report of an epidemic. Prehosp Disaster Med 1995;10:265–7.