Injuries in outdoor climbing: a retrospective single-centre cohort study at a level 1 emergency department in Switzerland

Climbing disciplines

Climbing can be subdivided into indoor climbing, which takes place on special facilities on artificial walls, and outdoor climbing. Outdoor climbing can further be subdivided into ice climbing (ice axes and crampons are used to climb ice formations), bouldering (rock faces are ascended with restricted height without belaying), outdoor sports climbing (permanent or preplaced protective bolts are attached), clean climbing (bolts are attached and removed by the climber himself) and traditional mountaineering (mountain ascent).8 We decided to focus on all aspects of outdoor climbing for our research.

Current studies

With increasing popularity and more participants, climbing-related injuries might be seen more frequent.9 In order to analyse patterns of injury in climbing, it is useful to differentiate between acute traumatic injuries, atraumatic injuries (supraphysiological loading, for example, a strain), and chronic overuse injuries.10 Acute injuries are caused by a specific identifiable event like a fall, whereas overuse injuries result from multiple micro traumata, where no triggering event can be named.11

In general, climbing is considered a relatively safe sport and the risk of injury is lower than with other popular sports like basketball or soccer.12 A study on the risk of injuries and fatalities found that incidences are greater for alpine and ice climbing, as the risks are more objective and external than for sport climbing, indoor climbing and bouldering.12 Bouldering and sports climbing are associated with lower injury rates, minor injury severity and few fatalities, irrespective of whether they are performed indoors or on natural rock outdoors.12 In Switzerland, an average of four climbers, and one ice climber annually died between 2000 and 2018.13 This number is relatively low compared with the average of 184 fatal sports accidents that occur annually in Switzerland.13

In a survey by an Austrian mountain rescue service, the overall mortality was low. Many climbers were uninjured, but acute traumatic injuries were often severe or fatal.10 Likewise the International Alpine Trauma Registry suggests that climbing accidents are generally rare but potentially fatal events.14 Inconsistent conclusions have been reached about the effects of age, increasing years of climbing, lead climbing, skill level and high Climbing Intensity Score, all potential risk factors for climbing accidents.14 15 Current studies use heterogeneous definitions, scores and methodologies, which makes interstudy comparison difficult or impossible.16 17 To counteract this problem, the Medical Commission of the International Mountaineering and Climbing Federation UIAA introduced classifications for analysing climbing and mountaineering accidents and illnesses in 2011, including definitions for injury location, injury classification and fatality risk.17

Settings

The Department of Emergency Medicine (ED) of the University Hospital of Bern, Switzerland, is a level 1 trauma centre with approximately 50 000 patients per year. The University Hospital of Bern is one of five University Hospitals in Switzerland and part of the Swiss trauma network. This network consists of 12 hospitals in total that are specialised and assigned for the care of seriously injured patients and provide highly specialised trauma medicine.18 The catchment area includes various parts of the Alps, as well as climbing gardens, viae ferratae and high ropes courses.

Data collection

The clinical reporting system E.care (BVBA-beslotet vennootschap, Turnhout, Belgium) was searched for the German keywords ‘climbing’ and ‘boulder’. A total of 222 cases could be found during the period from 15 April 2012 to 31 December 2018. All 222 medical records were anonymised, then fully read.All patients with evidence for an outdoor climbing accident in the medical report were included. Exclusion criteria were indoor climbing accidents, incomplete information, and lack of a direct correlation between injury and climbing accident. Patients aged under 16 were treated in the Department for children and adolescents and were therefore not included in this study. Information about demographics, mechanism of injury, diagnosis, treatment and hospital stay were collected. The full cost of the care in the emergency department (ED) and the hospital stay were compiled for each case in an additional search.

The Injury Severity Score (ISS), a score based on the Abbreviated Injury Scale, was used to retrospectively classify injuries based on the diagnosis, on a scale from 0 (uninjured) to 75 (worst outcome). A score greater than 15 is defined as a polytrauma. In addition, the UIAA MedCom Score was used to classify the injuries as 0 (uninjured), 1 (mild injury), 2 (moderate injury), 3 (major injury), 4 (alive with permanent damage), 5 (death due to injury), and 6 (immediate death). Injury location was classified with the Orchard Sports Injury Classification System (OSICS) 10, as proposed by the UIAA-medical commission.17 Patients were divided into a rock and ice fall group and a group with other mechanisms of injury. A retrospective, descriptive data analysis (percentage and mean) was performed with Microsoft Excel.

Demographics

Table 1 For the period from 15 April 2012 to 31 December 2018, a total of 78 patients could be included who were treated at the University Hospital of Bern due to an injury related to outdoor climbing. Between 8 and 14 patients were admitted annually, which accounts for about 1 per 3571 (0.028%) of all ED visits during that period. Age distribution was between 18 and 68 years, with a mean age of 35.8±10.4 (SD) years, median of 34 and IQR of 11.75 years. 76% (n=59) of all patients were male. Most accidents occurred during the summer (n=37; 47%). Rock and icefall accidents accounted for 0 to 5 patients annually. Over the years, injuries due to rock and ice fall were accounted for an increasing proportion of the visits to the ED. In 2018, five of nine patients were injured due to falling rock or ice.

Climbing-specific parameters

Sixty-six patients (85%) participated in outdoor rock climbing, and 12 patients (15%) were ice climbers.

Mechanism, severity and localisation of injury

Table 2 Eighteen (23%) patients were included in the rock and ice fall group. The mechanisms of injury in the other patients included fall, hit and slip, distortion and others (n=60; 77%). Direct falls accounted for 64% (n=50) of all injuries, followed by injuries provoked by falling rock or ice with 23% (n=18), hit and slip (n=4), distortions (n=4), and others (n=2). In three cases, rock and ice fall was followed by a fall of the patient.

Table 2

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Analysis by mechanism of injury

Fall height was registered in 47 cases (60%) and varied from 1 m to 50 m, with most falls occurring between 1–10 metres (41%). In seven records, information about the fall height was missing. Through the anatomical site analysis with OSICS 10, we found that head injuries were most frequent (n=33; 42%), followed by injuries to the chest (n=15; 19%), lumbar spine (n=13; 17%) and foot/toe (n=11; 14%) (figure 1). In this analysis, multiple and isolated injuries were included. When it is divided, in 38% (n=30) of injuries, multiple body regions were affected, the rest were isolated lower limbs (n=17), head and neck (n=16), upper limbs (n=9) and trunk injuries (n=6).

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Figure 1

Anatomical sites according to Orchard Sports Injury Classification System 10 and mechanism of injury.

Injury severity as based on the ISS had an overall mean of 7.5 points (range 1–38) (figure 2). Patients injured through rock and ice fall had a mean ISS Score that was 1.9 points lower (6.1 and 8.0) than other patients. Polytrauma occurred in 14% of patients (n=11). All patients with polytrauma were male. The patient with the highest ISS (ISS 38) died 2 days after hospital admission. He suffered from haemorrhagic shock, multiple fractures and severe traumatic brain injury (TBI) with multiple intracranial haemorrhages and shearing injuries. Due to the very poor prognosis, therapy was discontinued. No patient died in the ED.

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Figure 2

Injury Severity Score by mechanism of injury.

Severity of injury as based on the UIAA MedCom Score was similarly distributed in all groups for grade 2, 3 and 4 injuries, with grade 3 injuries being the most common with 45% (n=35). Climbers injured by rock and ice fall had more grade 1 injuries (11%) than in the other subgroups (1.7%). There was one grade 5 injury (fatal). No grade 0 or grade 6 injuries were registered.

Fractures were the most common type of injury (n=53; 68%), and the trunk was most often affected (n=27; 35%), followed by head and neck (n=20; 26%) and lower limbs (n=14; 18%). Lacerations (n=29; 37%), soft tissue injuries (n=20; 26%), were among the most common injuries. TBI accounted for 24% of reported injuries with 14 mild, 2 moderate and 3 severe brain injuries. Intracranial haemorrhage occurred in six patients (8%).

Mechanism of injury

According to various studies, falls are the most common mechanism of injury in outdoor rock climbing and ice climbing, and cause between 55% and 77.5% of all accidents.1 14 19–24 This is consistent with our result of 64.1%. We found that a surprisingly high proportion of injuries (23.1%) were caused by rock or ice falling on the victim. In contrast, retrospective analysis from American EDs identified only a few such injuries (3% or 6.4% of all injuries) . Both studies analysed data from the National Electronic Injury Surveillance System registry, a register of ED presentations collected from around 100 hospitals in the USA.1 19 The reason for this discrepancy could be that the cited studies also included indoor climbing activities. Presumably less experience and less risk averse people could participate in indoor climbing, as the ropes and harnesses are a requirement and therefore the injury patterns may differ.

The more frequent rock and ice falls in our catchment area might be due to climate change and melting of the permafrost. As we only have a limited sample of patients, further investigation is required. Nearly all injuries were caused by an acute trauma. We only registered one injury due to overexertion: A medianus lesion was suspected due to the heavy load while climbing. Nelson et al and Buzzacott et al registered between 3% and 15% of overexertion injuries.1 19

Classification based on case narratives may be subjective and therefore another reason for the difference in distribution of mechanisms of injury.19 For instance, in our study three patients additionally fell after the ice/rock fall, and these were classified as part of the ice and rock fall mechanism, whereas they could also be classified as falls.

Due to a lack of information, the fall height was difficult to analyse since it was presumably based mainly on an estimation. For example, five patients reported falling more than 30 metres and in these patients, severity of injury varied greatly between ISS 1–38 and UIAA MedCom Score 2–5. Furthermore, in most cases it remained unclear whether the fall was decelerated by a rope and how steep the terrain was.

In non-impact acute injuries and chronic overuse injuries, the upper limbs seem to be mostly affected, especially the fingers.25–28 Injuries in alpine climbing mostly occur through falls and affect the lower extremity.16 With 46.3%–47%, the lower extremity was mostly affected in two analysis of patient data from American ED.1 19 In another analysis of American EDs and similarly to our results, Forrester et al found that multiple body regions were often affected.9 Rugg et al reported that in fatal accidents multiple body injuries were most frequent and that injuries to the lower extremities predominated in severe accidents.10 Neuhof et al29 found that injuries in sport climbing were equally distributed between upper and lower limbs.

Severity of injury

Various studies have analysed the severity of injury using the UIAA MedCom score (Union Internationale des Associations d'Alpinisme Score).10 19 29–31 It is difficult to compare the studies, due to the differences in study design. In a study conducted during an ice climbing festival, most injuries were mild (UIAA 1).30 Most injuries were moderate (grade 2) in a case series in a German hospital with elective outpatient and emergency treatment, and in an internet survey of sport climbing injuries.29 32 In a study in an indoor climbing hall, grade 1 injuries were excluded, but grades 2 and 3 were about equally common (15 grade 2 and 13 grade 3 injuries) hall.31 In an analysis of rescue services in Austria, most patients (n=1469) were uninjured, followed by grade 3–5 injuries (n=703).10 In contrast to our results, Buzzacott et al found more moderate injuries and fewer UIAA grade 3–5 injuries in US EDs.19 Likewise, the number of patients requiring inpatient treatment in our cohort was high at 56.4%, in contrast to other studies in EDs, in which 8%–11.3% of patients were hospitalised.1 9 19 This could be explained by the fact that indoor climbing accidents were not included in our study and are presumed to lead to injuries of minor severity and with fewer fatalities.12 As in our analysis, fractures accounted for the majority of injuries in patients treated in EDs.1 9 19 During the 6-year period, we only identified one inpatient fatality, so we suggest that climbing related deaths mostly occurred at the site of injury, and these cases, were not included in our study. This is in accordance with Forrester et al.9 Injury prevention is essential and should include careful planning, appropriate equipment, checking weather and environmental conditions as well as checking the anchors and the partners’ equipment.33

Costs

To our knowledge, the multicentre, retrospective ED-analysis by Forrester et al, is the only study that has reported costs for climbing related hospital treatment.9 With a median of US$65 000 for inpatient treatment, their costs were much higher than ours, where mean costs were 1328 CHF (Swiss franc) for outpatient treatment and 20 746 CHF for inpatient treatment. This must be interpreted in the context of the different cost structures in the different countries. Inability to work was frequent and caused additional financial burdens that were not included in our analysis.

Limitations

As the University Hospital Bern is a level 1 trauma centre and part of the Swiss trauma network, it is more likely to treat severe accidents, which might cause a selection bias. Furthermore, as this was a single-centre study, only accidents in the catchment area of the trauma centre were registered, whereas a nationwide analysis could provide more information about prevalence and injury trends. A systematic data collection on climbing specific parameters, like climbing discipline, belaying technique, climbing level and use of a helmet, could not be performed due to the lack of structured data. Standardised questionnaires for climbing parameters could be completed in the ED and would enable more accurate analysis.