Direct repair of defect in lumbar spondylolysis and mild isthmic spondylolisthesis by bone grafting, with or without facet joint fusion

Forty-six patients with lumbar spondylolysis and mild isthmic spondylolisth esis were managed with direct repair of the defect with or without facet jo int fusion in the affected segment. There were 24 males and 22 females, ran ging in age from 15 to 56 years (average, 38.2 years). These patients had e xperienced clinical symptoms due to spondylolysis for between 4 months and 20 years (average, 5.3 years). Of 46 patients, 28 had no spondylolisthesis, 11 had Meyerding grade I vertebral slippage and 7 had grade II. Direct rep air of 98 defects was performed on these patients. Twenty-six patients, in whom the disc adjacent to the defect was determined as degenerative by magn etic resonance imaging (MRI), simultaneously underwent facet joint fusion; 17 in one segment and 9 in two segments. The average period of follow-up wa s 50 months (24-92 months). Ninety-four defects achieved bony healing. As a result, 28 patients were graded as having an excellent outcome, 15 good, a nd 3 fair. Bone grafting in the defects achieves union between the loose la mina and the anterior element of lumbar vertebrae, and reconstructs the ana tomic structure and physiologic functions of the lumbar vertebrae. There wa s no significant difference in outcome between the spondylolytic/spondyloli sthetic patients with non-degenerative disc, who were treated with direct r epair of defect only, and those with degenerative disc, who additionally un derwent a fusion procedure (P >0.05). The present series demonstrates a sat isfactory result and a high rate of bony healing of the pars defect by this operative procedure in patients with lumbar spondylolysis and mild isthmic spondylolisthesis. Preoperative assessment of the disc degeneration with M RI is of great assistance in making the protocol choice of whether to opt f or fusion.