[Navigated or conventional acetabular surgery : Comparison of positional accuracy exemplified by the infra-acetabular screw].

BACKGROUND

The principle of joint-preserving treatment of acetabular fractures is the anatomic reduction of joint-bearing elements and internal osteosynthesis. For stabilization of the anterior and posterior columns against each other, the infra-acetabular screw (IAS) is regularly used in the clinical routine.

OBJECTIVE

The aim of this study was to compare the position of the IAS in the infra-acetabular corridor after navigated placement and after freehand placement.

MATERIAL AND METHOD

The position of the screw was evaluated in 42 patients using multiplanar reconstructions. The screw was placed freehand in 30 patients and using image-guided navigation in 12 patients. In addition to measurement of the position of the screw, demographic data, operating time, radiation exposure and blood loss were recorded.

RESULTS

The vast majority of the patients were male (86%), the median age was 67 years and the median body mass index (BMI) was 25 kg/m. The median operating time was 166 min and the median blood loss was 900 ml. The adjusted values in the whole sample considering the position of the screw were: distance of screw to cartilage mean value (m) = 3.8 mm, distance of screw to corridor center m = 3.5 mm and angle of screw to corridor m = 1.4°. There were no differences between the groups in the demographic parameters and the accuracy of positioning of the screw (p-value > 0.05). There was a longer irradiation time and a higher radiation dose in the navigated group compared to the group without navigation (p-value < 0.001).

CONCLUSION

With appropriate experience both procedures are comparable taking into account the accuracy. Taking into consideration other perioperative parameters, such as radiation exposure and planned operating time, patient-related factors should be taken into consideration.