Abstract
This study was undertaken to evaluate the efficacy and reliability of posterior intra-operative reduction and fusion by pedicle screw fixation in the treatment of children and adolescents for severe lumbosacral spondy-lolisthesis.Researchers identified 21 patients who underwent reduction of their high-grade spondylolisthesis at our Institution between 1993 and 2000. Recent clinical and radiograph data were available for all patients. Indications for surgery were severe back pain in 21 patients, leg pain in 17, cosmetic appearance in 16 and progression of slippage in 15. There were 11 females and 10 males, aged 16 years on average (range, 11–18 years). Seven patients had grade III slippage, nine grade IV and five grade V. The slippage was at L4-L5 level in one patient and at L5-S1 in the remaining cases. The instrumented levels were 2 (L4-S1) in 12 patients and 1 in nine (L5-S1). The patients underwent surgery using a single posterior surgical procedure. After removal of the loosened arch and complete discectomy, gradual distraction and posterior translation of the anteriorly displaced vertebral body were performed using a temporary device (Harrington rod) placed bilaterally between L1 and the sacral wings. Reduction was followed by a posterior interbody strut graft or placement of titanium cages and pedicle segmental fixation.
At a mean follow-up of 5 years (range, 1–10 years) a complete remission of back pain was observed in 18 cases and incomplete in three; all presented solid fusion radiographically. The mean correction of the slippage was 33.1%.(from 78.3% to 41%) and that of the slippage angle 51% (from 35.2° to 17°). Complications included two skin protrusions of a sacral screw, two transitory neurological deficit (L5-S1). Two patients with screw pullout underwent instrumentation revision and reinsertion of screws; another two patients underwent anterior interbody fusion since slippage exceeded 50% after posterior reduction.
Reduction of high-grade spondylolisthesis may be considered for patients with a high degree of lumbosacral kyphosis, an unacceptable clinical appearance, and/or neurological deficit. With the advent of pedicle screw fixation, posterior instrumentation and reduction appears feasible. We found that using the gradual reduction by temporary Harrington rod incurs less risk than other options for treating high-grade spondylolisthesis. This procedure provides a controlled method of reduction where continuous visualisation of nerve roots is possible and internal fixation is achieved.
