Recurrent postdiskectomy low back pain: MR-surgical correlation

Time-dependent scar enhancement in magnetic resonance imaging of the postoperative lumbar spine

“…With MRI specificity and accuracy are greater than with unenhanced CT scanning [14] although results were approximately equal in one report [13], Several authors have documented the usefulness of unenhanced MRI in evaluating the postoperative spine [2,5,8,13]. Morphologic features that suggest scar as opposed to recurrent disc herniation include the presence of aberrant soft tissue in the spinal canal without mass effect upon the thecal sac, absence of continuity of mass with the parent disc, presence of abnormal soft tissue above or below the disc level, retraction of the thecal sac at the level of the mass, and irregular configuration [2,5]. The signal features of scar in unenhanced MRI of the spine are somewhat more variable.…”

“…The signal features of scar in unenhanced MRI of the spine are somewhat more variable. Hochhauser et al [5] have suggested that reliable differentiation of scar from disc herniation is not possible if signal intensity alone is used as a criterion; topography must always be considered as well. In their 11 patients, signal intensity of epidural fibrosis was variable on both T1-and T/-weighted sequences and had no correlation with the time from the original surgery.…”

“…Magnetic resonance imaging (MRI) has facilitated the evaluation of patients with the failed back surgery syndrome [1,2,5,6,8,9,13]. Differentiation between recurrent disc herniation and postoperative scarring is of crucial importance in these patients, because only those individuals with recurrent disc herniation can be expected [4,7].…”

“…Distinguishing features of recurrent disc herniation as opposed to postoperative scarring can be identified on both unenhanced [2,5,8, 23] and enhanced [1,6,10,12,14] MR images. Morphologic criteria such as an anterior location, lack of mass effect, lack of continuity with the parent disc, and the presence of hyperintense or heterogeneously intense material tend to indicate scarring on unenhanced MR scans.…”

Resonancia magnética nuclear en el postoperatorio de discectomía lumbar en pacientes asintomáticos y con síndrome de cirugía lumbar fallida

“…El saco tecal mantiene o recupera regular contorno redondeado y es frecuentemente desplazado, posteriormente, hacia el sitio de la laminectomía, al tiempo que protruye dentro del tejido del lecho 13,14 . Dentro de los hallazgos anormales comunes en el postoperatorio de la patología lumbar, tenemos: estenosis espinal lateral, herniación discal residual o recurrente, fibrosis postoperatoria, aracnoiditis, pseudoartrosis, lesión neural durante la cirugía, infección posquirúrgica, calcificación distrófica y osificación, las cuales se asocian en mayor parte de los casos con una evolución tórpida del paciente [15][16][17][18] . Las causas del síndrome de cirugía lumbar fallida han sido enumeradas por diferentes autores, las dividiendo en dos grupos:…”