The intertransverse ‘ligament’ consists of sheets of connective tissue extending from the upper border of one transverse process to the lower border of the one above. It lacks a distinct border medially or laterally, with less densely packed and more irregular collagen fibres than is found in a true ligament. It probably forms part of a complex fascial system separating the paravertebral compartments ¹⁾.

The membrane extends to the lateral aspect of the pars interarticularis and the facet. It can be incised safely provided that the underlying neural structures are protected after identification by tracing the posterior prim- ary ramus into the intertransverse space ²⁾