Navigated correction operation of the pelvis

Abstract

Non unions or clinical relevant posttraumatic mal-unions of the pelvis are rare entities due to the application of standardized treatment protocols. However, these problems may occur also with an optimal primary treatment [17, 19]. After instable pelvic ring fractures type B and C Tile gives an estimation of about five percent post traumatically mal unions of the pelvis [22]. Other authors report 55 to 75% non unions and mal unions after non operative treatment of pelvic C type fractures [4, 6, 18]. Pain, instabilities and persistent and relevant problems during daily activities are the indication for a correction operation of the pelvis. Pain is the most frequent symptom, which is related to the instability or the displacement within the sarco-iliacal region [21]. After a correction operation of a mal united pelvic fracture the pain within the posterior pelvic ring can be reduced significantly (16). The clinical diagnosis of a pelvic ring fracture may be quite visible in severe instabilities; the diagnosis of a non union is very difficult with clinical examination only. Instability with compression can not be provoked frequently by the examiner of the pelvic ring. Weight bearing radiographs with left or right leg standing may be helpful in documentation instability. In our own experience a fluoroscopy controlled infiltration of painful regions of the pelvic ring with local anesthesia may help also for a more precise diagnosis. Limping or sitting incongruence are other typical symptoms. Frequently cranial or posterior displacements rotational displacements are to be seen according to the initial pelvic ring fracture (16). With the initial clinical examination these displacements can be diagnosed. Another typical symptom is sitting incongruence as the patient complains about having pain while sitting or lying on the back. An internal rotation of one hemipelvis leading to external rotation of the spina iliaca posterior superior becoming more prominent is the reason therefore is. The sacrum or coccygeum might be prominent as well if one hemipelvis is shifted cranially and may lead to pain while sitting. Limping is due to a cranial displacement of the hemi pelvis, which leads to functional shortening of the leg. 3 to 6 cm have been described in the literature due to leg differences (16). Internal or external displacements may lead to limping, too. AP, inlet and outlet views and with acetabular involvements the Judet views as well are the standard radiological examination. These conventional radiographs allow an initial quantitative analysis of the displacement. The cranial displacement is visible in the AP-view and posterior displacements are diagnosed best with the inlet view. For further thorough analysis the spiral computer tomography is the most important examination. The three dimensional views provide the surgeon with an excellent whole overview of the problem. The reformations in axial sagittal and coronar planes allow an excellent analysis in all planes. The software allows measurements of angles and distances within one millimeter. A model of the pelvis («rapid prototyping») may be helpful in special cases. A thorough neurological examination is essential to exclude other problems according to fresh pelvic ring injuries. Huittinen found 50% neurological lesions with instable pelvic fractures (3). The nerval routes L5 and S1 are most frequently damaged. The other sacral roots may be involved, too. Further neurophysiologic examinations as EMG and ENG may be necessary. © 2007 Springer Medizin Verlag Heidelberg.