Treatment of symptomatic spondyloptosis in an adult previously treated with in situ fusion and instrumentation by L5 vertebrectomy and L4-S1 instrumented reduction

Background context: One traditional treatment for spondylolisthesis is fusion. However, for high-grade spondylolisthesis and spondyloptosis, posterior fusion has had high rates of nonunion, progression, and persistent physical deformity. Thus, some surgeons have recommended reduction and instrumentation. One such technique (Gaines procedure) entails a two-stage procedure: L5 vertebrectomy anteriorly, followed by resection of the L5 posterior elements and instrumented reduction of L4 onto S1. However, to our knowledge, there is no report of reversing the fusion and deformity reduction in a symptomatic patient with previous solid fusion of the spondyloptosis at L5-S1. Purpose: To present the first reported revision via the Gaines procedure for failed fusion secondary to spondyloptosis. Study design: Patient report. Methods: A 24-year-old woman, who had undergone multiple procedures for L5-S1 spondylolisthesis and a final fusion and instrumentation attempt, presented with continued urinary retention, leg and back pain, and inability to stand. She subsequently underwent posterior hardware removal, followed by anterior L5 vertebral body resection. In the second stage, she had posterior osteotomy of the previous L5-S1 fusion, resection of the posterior elements of L5, and reduction and instrumentation of L4 to S1. Results: At the 2-year follow-up, she had full resolution of symptoms, full return of motor strength, and resolution of urinary retention. Conclusions: The Gaines procedure has been performed successfully in patients without previous fusions at the level of spondylolisthesis or spondyloptosis. Patients for whom the traditional posterior fusion fails still may be candidates for this procedure, albeit at increased risk of neurologic injury.