We reviewed 34 consecutive patients (18 female-16 male) with
isthmic spondylolysis and grade I to II lumbosacral spondylolisthesis
who underwent in situ posterolateral arthodesis between the L5 transverse
processes and the sacral ala with the use of iliac crest autograft.
Ten patients had an associated scoliosis which required surgical correction
at a later stage only in two patients with idiopathic curves unrelated
to the spondylolisthesis. No patient underwent spinal decompression or instrumentation
placement. Mean surgical time was 1.5 hours (1 to 1.8) and intra-operative
blood loss 200 ml (150 to 340). There was one wound infection treated
with antibiotics but no other complication. Radiological assessment
included standing posteroanterior and lateral, Ferguson and lateral flexion/extension
views, as well as CT scans. Aims
Methods
It has been noted that bony union of a pars defect can be achieved in children if they wear a trunk brace. Our aim was to evaluate how the stage of the defect on CT and the presence or absence of high signal change in the adjacent pedicle on T2-weighted MRI were related to bony healing. We treated 23 children conservatively for at least three months. There were 19 boys and four girls with a mean age of 13.5 years (7 to 17). They were asked to refrain from sporting activity and to wear a Damen soft thoracolumbosacral type brace. There were 41 pars defects in 23 patients. These were classified as an early, progressive or terminal stage on CT. The early-stage lesions had a hairline crack in the pars interarticularis, which became a gap in the progressive stage. A terminal-stage defect was equivalent to a pseudarthrosis. On the T2-weighted MR scan the presence or absence of high signal change in the adjacent pedicle was assessed and on this basis the defects were divided into high signal change-positive or -negative.
