PURPOSE OF THE STUDY Continuous epidemiologic data on changes in the spectrum of acetabular fractures is rare. The purpose of this study is to evaluate changes in the types of acetabular fractures over the last two decades.
MATERIAL AND METHODS In the period between 2007 and 2016, a total of 522 patients were treated at the authors department (Traumacentre Level I) for acetabular fractures. 15 patients sustained bilateral fractures. The group consisted of 361 men and 161 women, with the mean age of 49 years (the range of 10-96 years).
Standard procedure was applied to diagnose the fractures (X-ray and CT scan). Non-operative treatment was opted for in fractures without displacement, fractures with minimum displacement of acetabular weight bearing area less than 2 mm, confirmed by the CT scan (e.g. low fractures of anterior column, low transverse fractures), fractures with secondary congruence in patients over the age of 70, and fractures in patients contraindicated for surgery due to their serious overall medical condition or severe osteoporosis.
A surgery was indicated in case of instability or incongruent acetabular joint space due to the displacement of weight bearing area fragments, or a bone fragment or soft tissue interposition. A surgery was indicated also in a non-displaced acetabular injury with concurrent femoral head injury.
AO/ASIF classification was used to classify the fractures. The following data was monitored in the referred to group of patients: gender, age, mechanism of injury, associated injuries, type of fracture, and treatment method.
RESULTS Type A fracture was reported in 293 patients (56%), type B fracture in 150 patients (29%) and type C fracture in 79 patients (15%). A high-energy trauma occurred in 334 patients (64%), namely 254 men and 50 women, with the mean age of 41 years.
A low-energy trauma was sustained by 188 patients (36%), namely 77 men and 111 women, with the mean age of 69 years (56-91). This difference in the share of men and women with respect to the seriousness of the mechanism of injury was statistically significant (p < 0.0001).
Non-operative treatment was used in 248 patients (48%), of whom 167 were men and 81 were women. The mean age in this sub-group was 60 years, namely 58 years in men and 62 years in women.
Operative treatment was opted for in 272 patients (52%), of whom 206 were men and 50 were women, with the mean age of 45 years in women as well as in men. The statistical processing of differences between the non-operative and operative treatment in dependence on the type of fractures revealed a significantly higher percentage of operative treatment in type C fractures compared to type A and B fractures (p < 0.0001, or p = 0.0009).
In the group of patients treated by the authors in the 1996-2002 period, type A fractures constituted 45% of all fractures, where A1 fractures prevailed with 29%, A2 fractures represented 9% and A3 fractures only 6 %. In the recent group of patients, type A fractures constituted 56%, but A3 fracture were seen in 29% of patients, which was a significant increase (p < 0.0001).
A3 fractures (anterior wall or anterior column fractures) were associated with a low-energy mechanism of injury and occurred in 48% of patients (73, mostly elderly women). DISCUSSION When compared to the published groups of other authors, the monitored group showed no difference in the mean age and gender ratio.
There was an obvious increase in the number of patients with a low-energy mechanism of injury. The authors believe that this is the result of population ageing.
It is also related to the growing share of patients treated non-operatively. The number of patients with a high-energy mechanism injury increased to a lesser degree.
The spectrum of fractures significantly changed over the last 20 years. It was caused by an increase in low-energy injuries and partly also by improved diagnostics.
CONCLUSIONS In the last 20 years, the authors noticed a rise in some types of acetabular fractures. It was caused by a statistically significantly higher number of fractures with a low-energy mechanism of injury, especially in elderly patients, the so-called "fragility fractures".
Therefore, the share of non-operatively treated acetabular fractures increased as well. The number of acetabular fractures in young patients as a result of a high-energy injury grew more slowly, and it was only the share of posterior-wall acetabular fractures that was significantly higher.
Key words: epidemiology of acetabular fractures, mechanism of injury, types of acetabular fractures.