Orthopedics

Feature Article 

Population-Based Epidemiology of Tibial Plateau Fractures

Rasmus Elsoe, MD; Peter Larsen, MR; Nina Pil Hostrup Nielsen, MD; Johanna Swenne, BM; Sten Rasmussen, MD; Svend Erik Ostgaard, PhD, MD

Abstract

Although epidemiologic studies of tibial plateau fractures have been conducted, none have included geographically defined populations or a validated fracture classification based on computed tomography (CT). The goals of this study were to provide up-to-date information on the incidence and basic epidemiology of tibial plateau fractures in a large unselected patient population and to report the mechanisms of injury involved and the distribution of fractures according to a validated CT-based fracture classification. The authors conducted a population-based epidemiologic study of all patients treated for tibial plateau fracture over a 6-year period from 2005 to 2010. The study was based on an average background population of 576,364 citizens. A retrospective review of hospital records was performed. During this time, a total of 355 patients were treated for tibial plateau fracture. This group included 166 men and 189 women, and mean age was 52.6 years (SD, 18.3). The most common fracture type was AO type 41-B3, representing 35% of all tibial plateau fractures. The second most common fracture type was AO type 41-C3, representing 17% of all tibial plateau fractures. The incidence of tibial plateau fractures was 10.3 per 100,000 annually. Compared with women, men younger than 50 years had a higher incidence of fractures. The incidence of fractures increased markedly in women older than 50 years but decreased in men older than 50 years. In both sexes, the highest frequency was between the ages of 40 and 60 years. [Orthopedics. 2015; 38(9):e780–e786.]

The authors are from the Department of Orthopaedic Surgery (RE, NPHN, JS, SR, SEO), the Department of Occupational Therapy and Physiotherapy (PL), and the Department of Clinical Medicine (SR), Aalborg University Hospital, Aalborg University, Aalborg, Denmark.

The authors have no relevant financial relationships to disclose.

This study was supported by unrestricted grants from the Department of Orthopaedic Surgery and the Department of Occupational Therapy and Physiotherapy, Aalborg University Hospital, Aalborg University, Aalborg, Denmark.

Correspondence should be addressed to: Rasmus Elsoe, MD, Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg University, 18-22 Hobrovej, DK-9000 Aalborg, Denmark ( rae@rn.dk).

Received: September 26, 2014
Accepted: December 29, 2014

Abstract

Although epidemiologic studies of tibial plateau fractures have been conducted, none have included geographically defined populations or a validated fracture classification based on computed tomography (CT). The goals of this study were to provide up-to-date information on the incidence and basic epidemiology of tibial plateau fractures in a large unselected patient population and to report the mechanisms of injury involved and the distribution of fractures according to a validated CT-based fracture classification. The authors conducted a population-based epidemiologic study of all patients treated for tibial plateau fracture over a 6-year period from 2005 to 2010. The study was based on an average background population of 576,364 citizens. A retrospective review of hospital records was performed. During this time, a total of 355 patients were treated for tibial plateau fracture. This group included 166 men and 189 women, and mean age was 52.6 years (SD, 18.3). The most common fracture type was AO type 41-B3, representing 35% of all tibial plateau fractures. The second most common fracture type was AO type 41-C3, representing 17% of all tibial plateau fractures. The incidence of tibial plateau fractures was 10.3 per 100,000 annually. Compared with women, men younger than 50 years had a higher incidence of fractures. The incidence of fractures increased markedly in women older than 50 years but decreased in men older than 50 years. In both sexes, the highest frequency was between the ages of 40 and 60 years. [Orthopedics. 2015; 38(9):e780–e786.]

The authors are from the Department of Orthopaedic Surgery (RE, NPHN, JS, SR, SEO), the Department of Occupational Therapy and Physiotherapy (PL), and the Department of Clinical Medicine (SR), Aalborg University Hospital, Aalborg University, Aalborg, Denmark.

The authors have no relevant financial relationships to disclose.

This study was supported by unrestricted grants from the Department of Orthopaedic Surgery and the Department of Occupational Therapy and Physiotherapy, Aalborg University Hospital, Aalborg University, Aalborg, Denmark.

Correspondence should be addressed to: Rasmus Elsoe, MD, Department of Orthopaedic Surgery, Aalborg University Hospital, Aalborg University, 18-22 Hobrovej, DK-9000 Aalborg, Denmark ( rae@rn.dk).

Received: September 26, 2014
Accepted: December 29, 2014

The incidence of fractures of the lower limb is reported with variation over time and between countries.1–3 Fractures of the proximal articular surface of the tibia are uncommon injuries. Tibial plateau fractures constitute approximately 1% of all bone fractures.1,4

Epidemiologic studies of tibial plateau fractures have been reported, but not in a geographically defined and unselected patient population. In addition, earlier studies did not use a computed tomography (CT)-based validated fracture classification or provide complete information on the mechanism of injury.

The current study reported up-to-date information on the incidence and basic epidemiology of tibial plateau fractures in a large and unselected population, including the mechanism of injury and the distribution of fractures according to a validated fracture classification based on CT scans.

Materials and Methods

The authors performed a population-based epidemiology study of all patients treated for tibial plateau fracture over a 6-year period from 2005 to 2010.

The study was conducted at Aalborg University Hospital, Denmark, in the North Denmark Region, and was based on an average background population of 576,364 citizens (Figure 1). The region is served by Aalborg University Hospital, which is a Level I trauma center, as well as by 6 smaller hospitals. The study included all patients in the region who were treated for tibial plateau fracture between 2005 and 2010.

Average population between 2005 and 2010 by sex and age.

Figure 1:

Average population between 2005 and 2010 by sex and age.

Denmark provides a unique opportunity to conduct population-based studies. Danish law requires all patient contacts with a hospital or clinic in Denmark to be recorded in the Danish National Patient Registry.5 A Civil Registration Number is given to all residents of Denmark and recorded in the Civil Registration System. For each hospital or clinic visit, specific information is recorded, including hospital identification, date and time of activity, and patient’s municipality.6 This system provides researchers with complete records on all health-related issues on both individual and population levels.

A retrospective review of clinical and radiologic records obtained from this system was performed in April 2014.

Clinical information about patient age, sex, mechanism of injury, and high- or low-energy trauma was obtained. High-energy trauma was defined as a fall from more than 3 m or a fracture as a result of a traffic or road accident at more than 30 km/h. Information recorded included length of hospital stay, time to surgery after admission, use of conservative or operative treatment, additional bone injury, and the presence of multiple injuries.

All patients with suspected or confirmed tibial plateau fracture underwent CT scans to classify the fracture and plan operative or conservative treatment. All fractures were categorized according to the AO classification.7

This study was conducted in accordance with the ethical standards of the responsible committee and within the ethical principles of the 1975 Declaration of Helsinki. The study was approved by the Danish Data Protection Agency (J. nr. 2010-41-4354).

Statistics

Mean values and SDs are given for continuous variables. Frequencies and percentages are used for categorical data. Normal distribution was checked visually by QQ plots. Statistical analysis was performed with SPSS software (PAWStatistic, version 21.0; IBM Corporation, Armonk, New York).

Results

A total of 355 patients were treated for tibial plateau fracture between 2005 and 2010. Mean age was 52.6 years (SD, 18.3 years). Mean age was 57.7 years (SD, 18.3 years) for women and 46.8 years (SD, 16.4 years) for men. The study included 166 men (46.8%) and 189 women (53.2%). Of these patients, 57% had a left-sided fracture and 43% had a right-sided fracture.

Conservative treatment with a cast was used in 28 patients (7.9%), and 327 patients (92.1%) were treated surgically.

Patients treated conservatively were primarily patients with small articular depression or small nondisplaced pure split fractures (AO type 41-B1 and AO type 41-B2, N=18). The remaining patients were treated conservatively because of late recognition of the fracture or comorbidity. Of the patients treated conservatively, 20 (71%) were women and 8 (29%) were men. Mean age of the conservatively treated patients was 66.5 years (SD, 16.2) vs 51.4 years (SD, 18.0) for patients treated operatively.

Of the 355 patients, 310 (87.3%) had a single traumatic injury, and 42 patients (11.8%) were admitted to the hospital with multiple traumatic injuries. Additional bone injuries were present in 51 patients (Table 1).

Additional Bone Injuries

Table 1:

Additional Bone Injuries

Average length of hospital stay was 10.6 days (SD, 11.0 days) for patients treated surgically. Average time from hospital admission to surgery was 2.5 days (SD, 2.0 days).

The AO classification of fractures is shown in Table 2. The most common fracture type was AO type 41-B3, representing 35% of all tibial plateau fractures. The second most common fracture type was AO type 41-C3, representing 17% of all tibial plateau fractures.

AO Fracture Type Classification

Table 2:

AO Fracture Type Classification

The incidence of tibial plateau fractures was 10.3 per 100,000 annually. The incidence was 9.6 per 100,000 annually in men and 11.0 per 100,000 annually in women. Figure 2 shows the yearly incidence between 2005 and 2010. A large variation over the years is evident, ranging from 7 to 13 per 100,000 annually. This study showed no decrease in incidence from 2005 to 2010. Analysis of seasonal variation showed equal distribution among seasons.

Incidence of tibial plateau fractures between 2005 and 2010.

Figure 2:

Incidence of tibial plateau fractures between 2005 and 2010.

Compared with women, men younger than 50 years had a higher incidence of fractures. The incidence of fractures in women older than 50 years increased markedly, whereas a major decrease in incidence was noted in men older than 50 years (Figure 3A).

Incidence of tibial plateau fracture by age and sex (number per 100,000 annually) (A). Frequency of high-energy trauma by age and sex (B). Percentage of high-energy trauma by age and sex (C). Frequency of low-energy trauma by age and sex (D). AO classification by age (E). AO classification for women by age (F). AO classification for men by age (G).

Figure 3:

Incidence of tibial plateau fracture by age and sex (number per 100,000 annually) (A). Frequency of high-energy trauma by age and sex (B). Percentage of high-energy trauma by age and sex (C). Frequency of low-energy trauma by age and sex (D). AO classification by age (E). AO classification for women by age (F). AO classification for men by age (G).

Figure 3B shows the age and sex distribution of high-energy trauma. This type of fracture was more common in men than in women. In both men and women, the highest frequency of fractures was between the ages of 40 and 60 years. In men, 64% of fractures were the result of high-energy trauma compared with 35% in women. Figure 3C shows the percentage of high-energy trauma by age and sex. Both younger men and younger women had a high proportion of high-energy fractures. After the age of 40 years, the incidence of high-energy fractures in women declined, whereas the incidence in men remained relatively high.

Figure 3D shows the age and sex distribution of low-energy trauma. Men and women had a similar low frequency of low-energy trauma until the age of 40 years. In older age groups, an increase in frequency was seen in women but not in men.

Figure 3E shows the relationship between age group and AO classification. Both AO type A and AO type C fractures were evenly distributed among the age groups. The incidence of AO type B fractures showed a peak between the ages of 40 and 70 years, representing more than 50% of total fractures. The distribution of AO classification between age and sex is shown in Figure 3F for women and Figure 3G for men. A similar pattern was seen with regard to AO classification in men and women.

The distribution according to AO classification and mechanism of injury showed a weak tendency toward AO type 41-B and AO type 41-C fractures in the high-energy trauma group and toward AO type 41-B fractures in the low-energy trauma group. Men had an increased frequency of injuries as a result of motorcycle or other motorized vehicle accidents and also as a result of falls from a height, both of which show a tendency toward an increase in the frequency of AO type B3 and AO type C3 fractures. Women had an increase in injuries as a result of bicycling, walking, indoor activity, and falls from a height, with a tendency toward AO type B2 and AO type B3 fractures (Tables 35).

Mechanism of Injury and Fracture Classification

Table 3:

Mechanism of Injury and Fracture Classification

Mechanism of Injury and Fracture Classification in Men

Table 4:

Mechanism of Injury and Fracture Classification in Men

Mechanism of Injury and Fracture Classification in Women

Table 5:

Mechanism of Injury and Fracture Classification in Women

Discussion

This was the first study to show the incidence of tibial plateau fractures and fracture distribution according to AO classification based on CT scans and mechanism of injury in a large unselected and well-defined cohort.

Reports on the incidence of fractures of the lower limb showed variation over time and in different countries.1–3 In 2000, Court-Brown and Caesar1 concluded that the incidence of fractures is changing quickly as a result of changes in mechanism of injury and aging of the population.

The incidence of patients with tibial plateau fractures in the North Denmark Region was 10.3 per 100,000 annually between 2005 and 2010. This finding was lower than the incidence of 13.3 per 100,000 annually in 2000 reported by Court-Brown and Caesar1 in the United Kingdom. The reason for this difference may be inaccuracy in estimating population size, exclusion of children younger than 12 years, the use of different time periods, and regional differences. Further, the current authors used a 6-year study period and showed considerable year-to-year variation in incidence. In contrast, in 1990, Donaldson et al2 reported an average incidence of 26 per 100,000 annually for the 3 years surrounding the 1981 census. The variation in incidence in their report vs the current results may be the result of inclusion of all fractures of the upper end of the tibia and fibula. In contrast, the current study included only tibial plateau fractures. Furthermore, Donaldson et al2 used an approximated population size to calculate incidence. Most studies of tibial plateau fractures lack accurate information on population size.1,2,8 In the current study, incidence was calculated based on an unselected and well-defined population.

Distribution of fractures according to sex and age groups in this study showed a bimodal distribution among women and a unimodal distribution among men. Men had an increasing incidence of fractures until 50 to 60 years of age, followed by a decline in incidence. Women showed a peak incidence between 20 and 30 years of age. After the age of 40 years, they had an increase in incidence throughout life compared with men. This is in contrast to the findings of Court-Brown and Caesar,1 who reported a bimodal distribution for both sexes.

Tibial plateau fractures are most common between the ages of 30 and 60 years, a finding reported in a number of studies.8,9 Albuquerque et al8 reported a male predominance (70%) in tibial plateau fractures, in contrast to the findings of the current study, which showed a female predominance of 53%. This difference may be related to variations in geography, demography, mechanism of injury, and exclusion of nonsurgically managed fractures.

The current study was the first to show classification of fractures based on CT scans and the distribution of tibial plateau fractures according to AO classification and mechanism of injury in a large unselected cohort. The most common fracture type was AO type 41-B3, representing 35% of all tibial plateau fractures. The next most common type was AO type 41-C3, representing 17% of all tibial plateau fractures. These findings were similar to those of Albuquerque et al8 from a comparable time, although they included only surgically treated fractures at a single trauma center. Further, CT scans were not used in the classification of fractures.

The current findings showed that AO type 41-B fractures were primarily present in women and that AO type 41-C fractures were primarily present in men. Albuquerque et al8 did not discuss the sex-specific distribution of fractures in their study, but calculation based on their tables showed that AO type 41-B and AO type 41-C fractures were both more common in men (AO type 41-B, 69%; AO type 41-C, 73%).

No clear association was seen between type of AO fracture and high- or low-energy trauma. However, the results showed a weak tendency toward high-energy trauma resulting in AO type 41-B3 and AO type 41-C3 fractures. More research on this association is needed.

In general, younger and middle-aged men tend to have fractures as a result of high-energy trauma, whereas older women have low-energy fractures. The distribution of high-energy trauma between men and women was equal in younger age groups. After the age of 30 years, however, high-energy fractures were still common in men, whereas in women, the incidence of these fractures decreased throughout life. This finding may be related to the mechanism of injury, which showed that women are primarily injured during bicycling, walking, indoor activities, and falls from a height. In contrast, men are injured primarily as a result of accidents involving motorcycles and other motorized vehicles and as a result of falls from a height. Further, men had a higher frequency of multiple traumatic injuries compared with women (76%).

The reason for the increase in the frequency of low-energy trauma with older age and female sex may be related to the increasing prevalence of osteoporotic bone.1,10

Conclusion

This study showed an incidence of 10.3 per 100,000 annually for tibial plateau fractures. The most common type of fracture was AO type 41-B3, representing 35% of all tibial plateau fractures, followed by AO type 41-C3, representing 17% of all tibial plateau fractures. In both men and women, the highest frequency of fractures was between the ages of 40 and 60 years. Men younger than 50 years had a higher incidence of fractures, but after the age of 50 years, the incidence of fractures increased markedly in women and decreased in men. Men were predominantly injured as a result of falls from a height or because of accidents involving cars, motorcycles, or other motorized vehicles. Women were injured primarily while bicycling, while walking, and during indoor activity.

References

  1. Court-Brown CM, Caesar B. Epidemiology of adult fractures: a review. Injury. 2006; 37(8):691–697. doi:10.1016/j.injury.2006.04.130 [CrossRef]
  2. Donaldson LJ, Cook A, Thomson RG. Incidence of fractures in a geographically defined population. J Epidemiol Community Health. 1990; 44(3):241–245. doi:10.1136/jech.44.3.241 [CrossRef]
  3. Madadi F, Vahid Farahmandi M, Eajazi A, Daftari Besheli L, Madadi F, Nasri Lari M. Epidemiology of adult tibial shaft fractures: a 7-year study in a major referral orthopedic center in Iran. Med Sci Monit. 2010; 16(5):CR217–CR221.
  4. McDonald E, Chu T, Tufaga M, et al. Tibial plateau fracture repairs augmented with calcium phosphate cement have higher in situ fatigue strength than those with autograft. J Orthop Trauma. 2011; 25(2):90–95. doi:10.1097/BOT.0b013e3181e3e28f [CrossRef]
  5. Lynge E, Sandegaard JL, Rebolj M. The Danish National Patient Register. Scand J Public Health. 2011; 39(suppl 7):30–33. doi:10.1177/1403494811401482 [CrossRef]
  6. Thorlund JB, Hare KB, Lohmander LS. Large increase in arthroscopic meniscus surgery in the middle-aged and older population in Denmark from 2000 to 2011. Acta Orthop. 2014; 85(3):287–292. doi:10.3109/17453674.2014.919558 [CrossRef]
  7. Marsh JL, Slongo TF, Agel J, et al. Fracture and dislocation classification compendium—2007: Orthopaedic Trauma Association Classification, Database and Outcome Committee. J Orthop Trauma. 2007; 21(suppl 10):S1–S133. doi:10.1097/00005131-200711101-00001 [CrossRef]
  8. Albuquerque RP, Hara R, Prado J, Schiavo L, Giordano V, do Amaral NP. Epidemiological study on tibial plateau fractures at a level I trauma center. Acta Ortop Bras. 2013; 21(2):109–115. doi:10.1590/S1413-78522013000200008 [CrossRef]
  9. Schulak DJ, Gunn DR. Fractures of tibial plateaus: a review of the literature. Clin Orthop Relat Res. 1975; (109):166–177. doi:10.1097/00003086-197506000-00025 [CrossRef]
  10. Luria S, Liebergall M, Elishoov O, Kandel L, Mattan Y. Osteoporotic tibial plateau fractures: an underestimated cause of knee pain in the elderly. Am J Orthop (Belle Mead NJ). 2005; 34(4):186–188.

Additional Bone Injuries

FractureNo.
Clavicle4
Colles’/ulna9
Columna lumbalis5
Femur9
Costa1
Patella3
Humerus5
Maxilla1
Metacarpal2
Calcaneus3
Lower leg1
Acetabulum2
Malleolus3
Metatarsal3
Total51

AO Fracture Type Classification

AO TypeNo. (%)
41-A14 (1.1)
41-A222 (6.2)
41-A34 (1.1)
41-B130 (8.5)
41-B259 (16.6)
41-B3123 (34.6)
41-C128 (7.9)
41-C223 (6.5)
41-C362 (17.5)
Total355 (100.0)

Mechanism of Injury and Fracture Classification

AO TypeaNo.
High EnergybLow EnergybMultiple Traumatic InjuriesCarMotorcycleOther Motorized VehicleBicycleWalkingIndoorFall From Height
41-A12100010101
41-A2814310503112
41-A34011000002
41-B1141433124983
41-B2193923063201016
41-B349741687920291534
41-C1151362145871
41-C215870372650
41-C34120433148101112
Total1671834221154842866771
Total women64 (38%)123 (67%)10 (24%)7 (33%)2 (13%)7 (15%)30 (71%)56 (65%)54 (81%)32 (45%)
Total men103 (62%)60 (33%)32 (76%)14 (67%)13 (87%)41 (85%)12 (29%)30 (35%)13 (19%)39 (55%)

Mechanism of Injury and Fracture Classification in Men

AO TypeNo.
High EnergyLow EnergyMultiple Traumatic InjuriesCarMotorcycleOther Motorized VehicleBicycleWalkingIndoorFall From Height
41-A11100000101
41-A25220040012
41-A34011000002
41-B19633121522
41-B211722061306
41-B32825945758221
41-C111562142430
41-C210350360220
41-C32411423123735
Total103603214134112301339

Mechanism of Injury and Fracture Classification in Women

AO TypeNo.
High EnergyLow EnergyMultiple Traumatic InjuriesCarMotorcycleOther Motorized VehicleBicycleWalkingIndoorFall From Height
41-A11000010000
41-A2312110103100
41-A30000000000
41-B15800003461
41-B283201002171010
41-B32149742215211313
41-C14800003441
41-C25520012430
41-C317901025387
Total641231072730565432

10.3928/01477447-20150902-55

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