Abstract
Background
Extensive research has been conducted concerning the epidemiology of fractures of the calcaneus and ankle. However, less work has characterized the population sustaining talus fractures, necessitating the analysis of a large, national sample to assess the presentation of this important injury.
Methods
The current study included adult patients from the 2011 through 2015 National Trauma Data Bank (NTDB) who had talus fractures. Modified Charlson Comorbidity Index (CCI), mechanism of injury (MOI), Injury Severity Score (ISS), and associated injuries were evaluated.
Results
Out of 25,615 talus fracture patients, 15,607 (61%) were males. The age distribution showed a general decline in frequency as age increased after a peak incidence at 21 years of age. As expected, CCI increased as age increased. The mechanism of injury analysis showed a decline in motor vehicle accidents (MVAs) and an increase in falls as age increased. ISS was generally higher for MVAs compared to falls and other injuries.
Overall, 89% of patients with a talus fracture had an associated injury. Among associated bony injuries, non-talus lower extremity fractures were common, with ankle fractures (noted in 42.7%) and calcaneus fractures (noted in 27.8%) being the most notable. The most common associated internal organ injuries were lung (noted in 19.0%) and intracranial injuries (noted in 14.9%).
Conclusion
This large cohort of patients with talus fractures defined the demographics of those who sustain this injury and demonstrated ankle and calcaneus fractures to be the most commonly associated injuries. Other associated orthopaedic and non-orthopaedic injuries were also defined. In fact, the incidence of associated lumbar spine fracture was similar to that seen for calcaneus fractures (14%) and nearly 1 in 5 patients had a thoracic organ injury. Clinicians need to maintain a high suspicion for such associated injuries for those who present with talus fractures.
Level of Evidence
Level II, retrospective study
Keywords: Talus fracture, Talus, Associated injuries, Mechanism of injury
1. Introduction
Understanding injury patterns is useful for physicians, especially for orthopaedic surgeons, as it allows them to directly evaluate areas of likely injury once a primary injury is identified. Especially with distracting injuries, multiple surveys of the trauma patients and focused workups are critical.1
There are many examples of defined injury associations that help guide clinical management. Worsham et al. analyzed 62 patients with an open calcaneus fracture and were able to inform practitioners about the high percentages of local injuries (23% having an ipsilateral ankle fracture and 19% having a talus fracture) as well as distant trauma (24% of patients had upper extremity fracture and 15% of patients had spinal fractures).2 Moreover, lumbar spine injuries have been noted to occur with calcaneus fractures,3 scapular fractures have been shown to be associated with thoracic injuries,4 and ipsilateral fractures of the femoral neck and shaft have been demonstrated as well.5
Talus fractures are often caused by high-energy impacts, classically with forced dorsiflexion of the foot. If not recognized and treated properly, talus injuries can cause foot deformities, lead to chronic pain, and interfere with walking.6 With the above said, talus fractures are relatively uncommon (comprising less than 1% of all fractures), which can limit the size of the patient populations that are available for study.7
Several cohort studies have assessed the epidemiology of talus injuries. Elgafy et al. examined the incidence and pattern of 58 patients with talar fractures that were collected from two level I trauma centers and found that 86% of patients had multiple injuries.8 Furthermore, Kirkpatrick et al. examined injuries from 12 Colorado ski resorts for 7 years and found that 2.3% of all snowboarding injuries were fractures of the lateral process of the talus.9
Despite the well-defined demographic and associated injury patterns of other orthopaedic injuries, such data is not as robust for talus fractures. The current study was thus defined to explore such considerations in a large nationwide sample. The National Trauma Data Bank (NTDB),10 which was created by the American College of Surgeons to be a source of trauma related data collected voluntarily from trauma centers, was utilized for this purpose.
2. Methods
The NTDB is the largest multi-center trauma database in the country, containing information from over 900 trauma centers.10 The following inclusion criteria were used on the NTDB to select patients for this study: (1) adult patients (over age 18) who were admitted to the hospital between years 2011 and 2015, and (2) an International Classification of Disease (ICD), 9th Revision code for either closed or open talus fractures (825.21, 825.31).
For the years studied, NTDB contains ICD-9 codes and chart-abstracted data. The variables used in this study were age, comorbidities, injury severity score (ISS),10,11 mechanism of injury, and associated injuries (as defined by ICD-9 codes).
The following comorbidities were abstracted: hypertension, alcoholism, diabetes, respiratory disease, obesity, congestive heart failure, coronary artery disease, prior cerebrovascular accident, liver disease, functionally dependent status, cancer, renal disease dementia, and peripheral vascular disease. From these, a modified Charlson Comorbidity Index (CCI), a measure of overall comorbidity burden, was computed, as previously described.12
Patients were categorized into “fall”, motor vehicle accident (“MVA”), or “other” for mechanism of injury. Patients with a fall mechanism of injury were determined based on the following ICD-9 e-code ranges: 880.00–889.99, 833.00–835.99, 844.7, 881, 882, 917.5, 957.00–957.99, 968.1, 987.00–987.99. For MVA mechanism of injury, the following ICD-9 e-code ranges were used: 800–826, 829–830, 840–845, 958.5, and 988.5. Motor vehicle drivers, motorcyclists, bicyclists, and pedestrians were included in this category. All other e-codes were counted as “other”. Associated bony and internal organ injuries were identified by diagnosis codes as shown in Appendix 1, Appendix 2.
The associated injury shadings on the skeleton and internal organ figures were created using Adobe® Photoshop® CS3. Increasing injury frequency is noted by darker shades on the grayscale images. Stata® 13.0 statistical software (StataCorp LP, College Station, TX), specifically the “tabulate” function for quantification, was used for all statistical analyses.
3. Results
3.1. Patient demographics
A total of 25,615 patients (15,607 males and 10,008 females) who had talus fractures and were over 18 years old were identified in the NTDB (Table 1). Fig. 1 shows the distribution of these patients by age. There is a general decline in incidence of talus fractures with increasing age, although there are local peaks at around ages 21 and 52. Most patients were below 65 years of age, with only 2355 patients (9.2%) who were older than 65. Of the 25,615 patients, 20,934 (81.7%) had closed fractures, while 4681 (18.3%) had open fractures.
Table 1.
Distribution of patients by age and sex.
| Age | Male | Female | Total |
|---|---|---|---|
| 18–39 | 8619 | 4856 | 13,475 |
| 40–65 | 6100 | 3685 | 9785 |
| 65+ | 888 | 1467 | 2355 |
| Total | 15,607 | 10,008 | 25,615 |
Fig. 1.
Distribution of ages of all talus fracture patients by gender.
3.2. Comorbidity index and injury severity
Table 2 shows modified Charlson Comorbidity Index (CCI) for age categories 18–39, 40–64, and 65+. The medians were 0, 2, and 4, respectively.
Table 2.
Distribution of modified Charlson Comorbidity Index (CCI) by Age.
| CCI | Age |
|||
|---|---|---|---|---|
| 18–39 | 40–64 | 65+ | Total | |
| 0 | 12,606 | 387 | 0 | 12,993 |
| 1 | 798 | 3756 | 0 | 4554 |
| 2 | 48 | 3550 | 0 | 3598 |
| 3 | 10 | 1482 | 714 | 2206 |
| 4 | 3 | 381 | 1051 | 1435 |
| >=5 | 10 | 229 | 590 | 829 |
| Total | 13,475 | 9785 | 2355 | 25,615 |
Note: Median values are underlined in each column.
The Injury Severity Score (ISS) distributions for these age categories were relatively flat with a predominance of injuries with ISS between 0 and 9, as shown in Table 3. An isolated talus fracture could have an ISS of 9 or below if it were considered to be an injury below the threshold denoted as severe. Overall, 11% of the injuries were from isolated talus fractures and 89% had an additional injury. The overall mean ISS score was 12.57.
Table 3.
Distribution of injury severity score (ISS) by Age.
| ISS | Age |
|||
|---|---|---|---|---|
| 18–39 | 40–64 | 65+ | Total | |
| 0–9 | 7285 | 5280 | 1199 | 13,764 |
| 10–19 | 3380 | 2617 | 637 | 6634 |
| 20–29 | 1887 | 1331 | 388 | 3606 |
| 30+ | 923 | 557 | 131 | 1611 |
| Total | 13,475 | 9785 | 2355 | 25,615 |
Note: Median values are underlined in each column.
Although most patients had an ISS between 0 and 9 regardless of mechanism, ISS was higher for MVAs, compared to other mechanisms. Mean ISS scores were 7.89, and 14.98, and 8.93 for patients with falls, MVAs, and other mechanisms, respectively. In general, this demonstrates that many patients with talus fractures present with other injuries and have injury severity scores that suggest that the injury was not isolated to the talus.
3.3. Mechanism of injury
Fig. 2 shows the mechanism of injury distribution by age. Overall, MVAs were far more common than falls or other injury mechanisms. As expected, MVAs were more common in younger patients, while falls were more common in older patients. Table 4 demonstrates that MVAs had a higher ISS compared to falls and other injury mechanisms. Of all male patients, 27.2% suffered falls, while 62.7% suffered MVAs. Of all female patients, 17.1% suffered falls, while 78.2% suffered MVAs.
Fig. 2.
Mechanism of Injury distribution of talus fracture patients by age.
Table 4.
Distribution of injury severity score (ISS) by Mechanism of injury (MOI).
| ISS | MOI |
|||
|---|---|---|---|---|
| Fall | MVA | Other | Total | |
| 0–9 | 4698 | 7559 | 1507 | 13,764 |
| 10–19 | 881 | 5408 | 345 | 6634 |
| 20–29 | 282 | 3191 | 133 | 3606 |
| 30+ | 106 | 1448 | 57 | 1611 |
| Total | 5967 | 17,606 | 2042 | 25,615 |
Note: Median values are underlined in each column.
3.4. Associated injuries
Overall, 89% of patients with a talus fracture had an associated injury. Ankle fractures (42.7%) and calcaneus fractures (27.8%) were the most common bony associated injuries. Ribs/sternum fractures (24.5%), lumbar spine injuries (14.0%), pelvic fractures (12.1%), and radius/ulna fractures (12.0%) were relatively common as well.
Lung (19.0%) and intracranial (14.9%) injuries were the most common internal organ injuries. Abdominal organ injuries appeared in 13.2% of patients, with dominant subcategories being liver (5.7%) and spleen (5.1%) injuries.
Table 5 summarizes the associated injury frequencies by age category. Fig. 3, Fig. 4 show the overall incidences of select bony and internal organ associated injuries, respectively, in different body regions. Darker shadings on grayscale correspond to higher frequencies.
Table 5.
Associated injury incidences by age.
| Associated Injuries | Age |
||
|---|---|---|---|
| 18–39 | 40–64 | 65+ | |
| Head Injury | 24.28 | 20.33 | 19.58 |
| Skull Fracture | 12.97 | 9.93 | 6.88 |
| Intracranial Injury | 15.64 | 13.91 | 15.07 |
| Spinal Injury | 20.25 | 24.59 | 26.96 |
| Cervical Spine | 4.36 | 6.38 | 9.13 |
| Thoracic Spine | 5.73 | 7.43 | 9.64 |
| Lumbar Spine | 12.71 | 15.45 | 15.20 |
| Sacral Spine | 4.41 | 3.77 | 3.44 |
| Ribs/Sternum | 19.52 | 28.80 | 35.41 |
| Pelvic Fracture | 12.78 | 11.61 | 10.19 |
| Acetabulum | 8.21 | 7.07 | 4.80 |
| Pubis | 4.06 | 3.87 | 3.91 |
| Ilium | 1.44 | 1.28 | 1.61 |
| Ischium | 0.31 | 0.30 | 0.51 |
| Upper Extremity Fracture | 23.84 | 26.75 | 26.96 |
| Clavicle Fracture | 3.32 | 3.64 | 3.99 |
| Scapula Fracture | 2.37 | 2.54 | 2.34 |
| Humerus Fracture | 4.07 | 4.18 | 4.33 |
| Proximal Humerus | 1.33 | 2.06 | 2.00 |
| Humeral Shaft | 1.43 | 1.04 | 1.19 |
| Distal Humerus | 1.25 | 1.00 | 1.02 |
| Radius/Ulna Fracture | 11.11 | 13.00 | 13.16 |
| Proximal Radius/Ulna | 2.40 | 2.66 | 2.17 |
| Radial/Ulnar Shaft | 3.01 | 2.84 | 2.68 |
| Distal Radius/Ulna | 6.02 | 8.04 | 8.58 |
| Hand Fracture | 9.31 | 10.70 | 10.96 |
| Other Lower Extremity Fracture | 73.02 | 81.32 | 83.91 |
| Femur Fracture | 8.42 | 9.91 | 11.17 |
| Proximal Femur | 4.13 | 4.79 | 5.73 |
| Femoral Shaft | 8.51 | 4.94 | 2.97 |
| Distal Femur | 3.73 | 5.14 | 5.48 |
| Patella Fracture | 5.25 | 5.43 | 6.28 |
| Tibia/Fibula Fracture | 52.51 | 61.85 | 68.83 |
| Proximal Tibia/Fibula | 7.62 | 12.20 | 11.38 |
| Tibial/Fibular Shaft | 10.81 | 13.36 | 12.36 |
| Ankle Fracture | 38.18 | 45.71 | 55.75 |
| Medial Malleolus | 15.66 | 16.50 | 17.88 |
| Lateral Malleolus | 9.18 | 12.11 | 13.33 |
| Bimalleolar | 5.78 | 8.41 | 14.14 |
| Trimalleolar | 2.37 | 4.63 | 8.83 |
| Other Foot Fractures | 40.54 | 46.40 | 43.10 |
| Navicular | 8.18 | 8.23 | 7.43 |
| Cuboid | 11.42 | 11.83 | 9.85 |
| Cuneiforms | 4.31 | 4.60 | 3.57 |
| Metatarsals | 14.04 | 16.30 | 15.67 |
| Phalanges | 3.09 | 4.52 | 4.03 |
| Thoracic Organ Injury | 21.07 | 17.57 | 19.92 |
| Heart | 0.59 | 0.82 | 1.15 |
| Lung | 20.53 | 16.81 | 19.07 |
| Pneumothorax | 12.88 | 11.51 | 13.76 |
| Diaphragm | 0.35 | 0.46 | 0.55 |
| Abdominal Organ Injury | 14.92 | 11.71 | 9.98 |
| GI Tract | 3.48 | 3.62 | 3.14 |
| Liver | 7.25 | 4.29 | 2.97 |
| Spleen | 6.19 | 4.07 | 3.27 |
| Kidney | 2.27 | 1.44 | 1.02 |
| Pelvic Organ Injury | 0.78 | 0.63 | 0.30 |
Note: All values are percentages of talus fracture patients in the column-specified age range with the associated injury.
Fig. 3.
Schematic representation of percentages of talus fracture patients who are over 18 years old with incidence of associated bony injuries in different body regions. Darker shadings in grayscale correspond to higher frequencies of associated injuries.
Fig. 4.
Schematic representation of percentages of talus fracture patients who are over 18 years old with incidence of associated internal organ injuries in different body areas. Darker shadings in grayscale correspond to higher frequencies of associated injuries.
4. Discussion
Understanding the epidemiology and injuries associated with specific orthopaedic fractures is of known clinical importance. Calcaneus, scapula, and femoral shaft fractures have known associations with lumbar spine, thoracic, and ipsilateral femoral neck injuries, respectively.3, 4, 5 Though talus fractures are less common, demographic, injury characteristics, and associated injuries are not as well these fractures.7 In this context, the goals of the current paper were to explore these characteristics for talus fractures from a large national dataset.
The current study identified over 25,000 talus fractures between 2011 and 2015 in the NTDB. These were predominantly in males with peak incidence noted in the 18–38 age group. These demographics are similar to the level 1 trauma cohort study by Elgafy et al.8 As could be expected comorbid medical conditions increased with increasing patient age.
Injury severity decreased with patient age but was greatest in those who sustained their injuries from MVA (as opposed to from falls). The lower mechanism fall injuries leading to talus fractures in the older may be associated with lower bone density.13 The association of talus fracture with MVAs is consistent with the prior data.8
Overall, 89% of patients with a talus fracture had an associated injury. This high fraction suggests that associated injuries should be suspected in these patients. The injury pattern of patients with talus fractures was assessed by first analyzing specific associated skeletal injuries. The present study is the first, to our knowledge, to complete such an analysis.
Local associated injuries were common, with over 77% of patients having a concurrent lower extremity fracture. Of these, the most common were adjacent injuries, especially ankle fractures (42.7%). The most common foot fracture was a calcaneus fracture occurring in 27.8% of patients with talus fracture. These high rates of local fracture confirm the need for physicians to continue to closely evaluate the bony anatomy of this region for patients sustaining a talus fracture, via physical exam and/or imaging.
There were also significant rates of distant fractures as well: for example, upper extremity fractures (25%) as well as spine injuries (23%). The spine injuries were mostly lumbar spine with 14% of all patients with talus fractures having lumbar injury. The incidence of injuries at distant sites, while echoing the results of a previous calcaneus injury study by Worsham et al., has not previously been reported with respect to talus injury.2 Physicians treating talus fracture patients should assess the distant skeleton and also should have a low threshold for ordering upper extremity and spine imaging.
Internal organ injuries were also assessed. Nearly one in five patients had concurrent thoracic organ injury followed closely by 15% of the population sustaining intracranial injury and 13% of patients suffering abdominal injury. These percentages may guide emergency care providers to lower their threshold to examine and imaging these areas of the body, which have never been taught as areas of associated injury with talus fracture.
Overall, the current study is limited by the general limitations of database studies. Specifically, it only includes patients that were admitted to a trauma center after the initial accident, and does not include patients who died on scene or were taken to a facility that does not participate in NTDB. Further, the talus fractures could not be sub-classified. However, the large dataset that the NTDB allowed for a large scale study of a less common fracture. Lastly, another limitation is that the NTDB does not delineate whether a there were pre-existing injuries in patients or whether patients suffered injuries on multiple occasions.
5. Conclusion
In summary, the current study examined a nationwide sample of 25,615 talus fractures and reports demographics, mechanisms of injury and injury severity scores that were in line with previously published cohort studies. It also contributes the first known analysis of specific bony and internal organ associated injuries in patients with talus fractures. The results of this study suggest that there should be a low threshold for evaluation of given bony and internal injuries that have defined associations with talus fractures in the trauma patient population.
IRB approval
A waiver was issued for this study by our institution's Human Investigations Committee.
Appendix 1. International Classification of Disease, Ninth Revision (ICD-9) diagnosis codes for bony injuries associated with talus fracture
| Injury | ICD-9 diagnosis codes |
|---|---|
| Skull fracture | 800.00–804.99 |
| Spinal injury (cord or vertebrae) | All subcategories listed below |
| Cervical spine injury | 805.00–805.19, 806.00–806.19, 952.00–952.09 |
| Thoracic spine injury | 805.2, 805.3, 806.20–806.39, 952.1 |
| Lumbar spine injury | 805.4, 805.5, 806.4, 806.5, 952.2 |
| Sacral spine injury | 805.6, 805.7, 806.60–806.62, 806.69, 806.70–806.72, 806.79, 952.3, 952.4 |
| Rib/Sternum injury | 807.0, 807.00–807.19, 807.1, 807.2, 807.3, 807.4 |
| Pelvic fracture | 808.40–808.59, 808.8, 808.9 + All subcategories listed below |
| Acetabulum fracture | 808.0, 808.1 |
| Pubis fracture | 808.2, 808.3 |
| Ilium fracture | 808.41, 808.51 |
| Ischium fracture | 808.42, 808.52 |
| Upper extremity fracture | 818.0, 818.1, 819.0, 819.1828.0, 828.1 + All subcategories listed below |
| Clavicle fracture | 810.00–810.19 |
| Scapula fracture | 811.00–811.19 |
| Humerus fracture | 812.2, 812.3 + All subcategories listed below |
| Proximal humerus fracture | 812.00–812.19 |
| Midshaft humerus fracture | 812.21, 812.31 |
| Distal humerus fracture | 812.40–812.59 |
| Radius/Ulna fracture | 813.80–813.83, 813.90–813.93 + All subcategories listed below |
| Proximal radius/ulna fracture | 813.00–813.19 |
| Midshaft radius/ulna fracture | 813.20–813.39 |
| Distal radius/ulna fracture | 813.40–813.59 |
| Hand fracture | 814.00–817.19 |
| Lower extremity fracture | 819.0, 819.1, 827.0, 827.1, 828.0, 828.1 + All subcategories listed below |
| Femur fracture | 821.00, 821.10 + All subcategories listed below |
| Proximal femur fracture | 820.00–820.99 |
| Midshaft femur fracture | 821.01, 821.11 |
| Distal femur fracture | 821.20–821.39 |
| Patella fracture | 822.0, 822.1 |
| Tibia/fibula fracture | 823.80, 823.81, 823.82, 823.90, 823.91, 823.92 + All subcategories listed below |
| Proximal tibia/fibula fracture | 823.00–823.19 |
| Midshaft tibia/fibula fracture | 823.20–823.39 |
| Ankle fracture | 824.0–824.9 |
| Foot fracture | 825.20, 825.26–825.29, 825.30, 825.36–825.39 + All subcategories listed below |
| Calcaneus fracture | 825.0, 825.1 |
| Talus fracture | 825.21, 825.31 |
| Navicular fracture | 825.22, 825.32 |
| Cuboid fracture | 825.23, 825,33 |
| Cuneiform fracture | 825.24, 825.34 |
| Metatarsal fracture | 825.25, 825.35 |
| Phalanx fracture | 826.0, 826.1 |
Appendix 2. International Classification of Disease, Ninth Revision (ICD-9) diagnosis codes for internal organ injuries associated with talus fracture
| Injury | ICD-9 diagnosis codes |
|---|---|
| Intracranial injury | 850.00–854.19 |
| Thoracic organ injury | 862.10–862.99 + All subcategories listed below |
| Heart injury | 861.00–861.19 |
| Lung injury | 861.20–861.39 |
| Diaphragm injury | 862.0, 862.1 |
| Abdominal organ injury | 868.00–868.19 + All subcategories listed below |
| Liver injury | 864.00–864.19 |
| Spleen injury | 865.00–865.19 |
| Kidney injury | 866.00–866.19 |
| GI tract injury | 863.00–863.99 |
| Pelvic organ injury | 867.00–867.99 |
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