Proximal sacral deformity: a common element in lytic isthmic spondylolisthesis at L5 and in degenerative spondylolisthesis at L4-L5 segment. Two apparently very different etiopathogenic entities. / Deformidad sacra proximal: elemento común a la espondilolistesis ístmica lítica de L5 y a la degenerativa del segmento L4-L5, 2 entidades de etiopatogenia muy diferente, aparentemente.

A radiographic study was carried out to investigate the relationship between proximal sacral sagittal anatomy (either kyphosis or lordosis) and either isthmic or degenerative spondylolisthesis. In addition, we studied whether there is a relationship between proximal sacral kyphosis and the degree of such listhesis in the case of L5 isthmic spondylolisthesis. Lateral standing x-rays were used from 173 patients, ninety of whom had degenerative spondylolisthesis L4-L5, and eighty-three an isthmic spondylolisthesis of L5 (67 low-grade and 16 high-grade) and compared with a control group of 100 patients adjusted by age and gender, without any type of spondylolisthesis. Listhesis was graded using Meyerding's classification and the proximal sacral kyphosis angle (CSP) was measured between S1 and S2 posterior walls, according to Harrison's method. In our series, there was a proximal sacral kyphosis in both types of spondylolisthesis, greater in the lytic type. By contrast, the control group had a proximal sacral lordosis. The differences were statistically significant. Therefore, we concluded that there was a proximal sacral kyphosis in patients with both degenerative and isthmic lytic spondylolisthesis, but with our results, we were not able to ascertain whether it is a cause or a consequence of this listhesis.

Prognostic value of an immediate lateral standing X-ray with a TLSO in patients with a thoracolumbar burst fracture.

UNLABELLED: The final collapse of a "stable" thoracolumbar burst fracture is difficult to predict. This collapse was prospectively studied radiologically in patients with T12 or L1 burst fractures who, after evaluating the admission x-rays and the CT scan with the patients themselves, opted for a rigid thoracolumbar brace with support in the sternal manubrium (TLSO). On the other hand, patients with rigid braces sometimes have low back pain on follow-up (due to overload of the L5-S1 joints). HYPOTHESIS: the standing lateral x-ray with only a TLSO for support (intrinsic mechanical stability) provides information on the final collapse and could also provide information on the low back pain. The study included 50 patients (20 males and 30 females, age: 63+14 years) admitted during 2011 and 2012, with 2 losses to follow-up. VARIABLES: Farcy index and local kyphosis (Cobb at 3 vertebrae). X-Rays: admission, with TLSO (immediate: Rx0), and at 3 and 6 months. They were compared with the final clinical and radiological results. It was decided to surgically intervene in 4 patients after Rx0. There were no painful sequelae at the fracture level, and 16/44 (31%) had low back pain. Using linear regression mathematical models, the increase in the Farcy index (Rx0-Rx admission) was associated with the appearance of low back pain and with local kyphosis (Rx0-Rx admission), and with the final kyphosis. It is advisable to perform a lateral standing X-ray after TLSO for information on the final collapse of the fracture and the appearance of accompanying low back pain.

[Inveterate subaxial cervical dislocations: a discussion on the best therapeutic strategy]. / Luxación subaxial cervical inveterada. Discusión de cuál es la mejor estrategia terapéutica.

It is difficult to decide the appropriate treatment for inveterate cervical dislocations because of the difficulty of their reduction, as well as due to the risk of inducing iatrogenic injuries during this reduction. The literature on the most appropriate surgical strategy for their management is also limited as well as controversial. We report one clinical case treated in the Spine Unit of the Orthopedic Surgery and Trauma Service of the University Hospital of Santiago de Compostela, discussing the currently most used treatment options, the anterior-posterior-anterior and the posterior-anterior-posterior approach. After analyzing the results, it could be concluded that the surgical approach to these lesions is generally difficult, with any of two techniques described above being suitable, but always with the precaution to remove the entire affected intervertebral disc before axial correction maneuvers, thus avoiding the risk of extrusion into the medullary canal. After the surgical procedure, a proper release and reduction of the joint facets should be performed, sometimes with the need to add osteotomies in them.