Radiographic and functional outcome of posterolateral lumbosacral fusion for low grade isthmic spondylolisthesis in children and adolescents

Abstract

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. A solid posterolateral fusion was confirmed in all patients at mean latest follow-up of 4.7 years (3.4 to 9.8) beyond skeletal maturity into early adult life. Fusion of the isthmic lesion was documented in nine patients bilaterally and eight patients unilaterally. The poor fusion rate across the spondylolysis has not affected the excellent functional results of the procedure, which in our series depended on achieving a stable lumbosacral junction. Quality of life assessment demonstrated significant improvement in all functional scores and high patient satisfaction with 28 patients returning to previous sports activities at an elite competitive level. Posterolateral arthrodesis in situ with autologous iliac crest bone without instrumentation has achieved a solid fusion between the L5 transverse processes and the sacral ala in patients with grade I to II isthmic lumbosacral spondylolisthesis and this has produced excellent clinical outcomes and high patient satisfaction.