Figure 2
Classification of patients with LSTV according to Castellvi12 Dysplastic enlargement of the transversal process > 19 mm was classified as Castellvi Ia (a) if it appeared unilateral and as Castellvi Ib if it was detected bilateral. Patients with unilateral (IIa) (b) or bilateral (IIb) pseudarthrosis of the transversal process with the sacral ala were classified as Castellvi II. Patients with unilateral (IIIa) (c) or bilateral (IIIb) osseous fusion of the transversal process with the sacral ala were classified as Castellvi III. Patients with unilateral pseudarthrosis and contralateral osseous fusion were classified as Castellvi IV (d).
