title: Remodelling of the sacrum in high-grade spondylolisthesis: a report of two cases.
abstract: Two young patients are described, who were operated on for high-grade spondylolisthesis. A good posterolateral fusion was achieved, without decompression and without reduction. The clinical course was favourable, the tight hamstring syndrome resolved. Disappearance of the posterior-superior part of the sacrum and of the posterior part of the L5-S1 disc was observed on comparing pre- and postoperative magnetic resonance (MR) images. This resulted in normalisation of the width of the spinal canal. Around the L5 nerve roots in the L5-S1 foramina some fat reappeared. These anatomical changes on MRI could play a role in the disappearance of clinical symptoms.
authors.affiliation: Department of Orthopaedic Surgery, University Hospital Maastricht, Postbox 5800, 6202 AZ Maastricht, The Netherlands. avoo@sort.azm.nl
authors.forename: André
authors.initials: A
authors.lastname: van Ooij
authors.forename: René
authors.initials: R
authors.lastname: Weijers
authors.forename: Lodewijk
authors.initials: L
authors.lastname: van Rhijn
mesh_terms: D000293:Adolescent; D016723:Bone Remodeling / Q000502:physiology*; D002648:Child; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D008160:Lumbosacral Plexus / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D008297:Male; D018908:Muscle Weakness / Q000209:etiology / Q000473:pathology / Q000503:physiopathology; D012447:Sacrum / Q000473:pathology* / Q000503:physiopathology / Q000601:surgery; D013123:Spinal Fusion; D013126:Spinal Nerve Roots / Q000293:injuries / Q000473:pathology / Q000503:physiopathology; D013168:Spondylolisthesis / Q000473:pathology* / Q000503:physiopathology* / Q000601:surgery; D016896:Treatment Outcome