[Conservative treatment of acetabular fractures: epidemiology and medium-term clinical and radiological results]

The vast majority of studies on fractures of the acetabulum are concerned with surgical treatment. All displaced fractures are presented as surgically treated. The purpose of this study was to evaluate the results of surgical and conservative treatment of patients with acetabular fractures in relation to the degree of fracture displacement.

We analysed 140 fractures of the acetabulum treated in our institution by different methods between 2009 and 2013. In addition to the use of Letournel´s classification, we allocated each fracture to one of six groups: 1. Sixty displaced fractures treated surgically, 2. Twenty three fractures with a displacement of more than 6 mm, 3. Eighteen slightly displaced fractures (2-3 mm in the acetabular roof or 4-5 mm in other parts of the acetabulum), 4. Twenty non-displaced fractures, 5. Six pelvic fractures involving the acetabulum and 6. Thirteen fractures of old people, mostly displaced but not examined by CT. Groups 2 to 6 were treated conservatively. In all patients, demographic and epidemiologic factors were analysed in relation to the patient's group assignment. In 107 patients, hip function was assessed using the Matta clinical grading system at a minimum follow-up of 12 months (average 3.16 years). Radiological status, time of admission, start of weight-bearing after the accident, working ability, mortality and complications were also evaluated.

Non-displaced fractures were often associated with serious injury or polytrauma in 20 patients; not all of them had excellent functional outcome. (mean score, 17.25). Excluding two patients who developed avascular necrosis, fourteen slightly displaced fractures had a fixal score of 16.92. Sixteen patients with displaced fractures were managed conservatively due to their poor medical condition and other circumstances. Their functional outcome (mean score, 15.25) was significantly worse than that of the patients with non-displaced fractures (p=0.02) and worse than the outcome in patients with slightly displaced fractures, but the difference was not significant (p=0.32). No occurrence of accelerated post-traumatic arthritis was observed in these groups. The mean clinical score of 14.80 and 60% of excellent and good results were achieved in surgically treated patients. Eight of them were treated by primary hip arthroplasty and osteosynthesis. A total of 11 patients required total hip arthroplasty because of post-traumatic osteoarthritis, but only one from the group of slightly displaced fractures, all others from the group of surgically treated patients.

Displaced fractures of the acetabulum are best treated by open reduction and internal fixation. The type of fracture and the quality of reduction influence the functional outcome. There are a few studies reporting long-term outcomes in conservatively treated acetabular fractures. Although conservative treatment continues to be the mainstay of treatment in most centres in the developing countries, it is obvious that not all of acetabular fractures can or must be treated surgically or identically. We found that, in many cases, surgery was too dangerous for the patient and his/her medical condition or that the result of surgery was doubtful, mostly because of a late presentation. In some cases, primary hip arthroplasty is a solution. Secondary total hip replacement is technically more demanding and has a higher rate of failure.

Conservative treatment is the method of choice for the treatment of non-displaced acetabular fractures. Excellent or very good results can also be expected in slightly displaced fractures if acetabular roof involvement is minor. In displaced fractures, if the result of surgery is doubtful under various circumstances or if high-risk medical conditions are present in the patient, conservative treatment can be the method of choice with satisfying results. Key words: acetabular fractures, conservative treatment, degree of displacement, epidemiology of acetabular fractures.