Repair of pars interarticularis defect. The prognostic value of pars infiltration.

Ten patients with symptomatic spondylolysis or Grade I spondylolisthesis were treated with the Buck method. At follow-up, nine patients were graded as successful. All patients fused. Pain relief, level of function, and likelihood of return to work were higher in patients preoperatively selected by lidocaine infiltration of the pars defect. Pars infiltration gives an accurate prediction of successful outcome following pars repair.