Pseudarthrosis after instrumented and nonstrumented fusion: clinical status and reoperation rate

Several studies have shown that in patients undergoing lumbar fusion, satisfactory results may be obtained even if solid fusion is not achieved. It may be hypothesized that in patients with failed instrumented fusion the rate of satisfactory results may be even greater, since spinal instrumentation may significantly reduce vertebral motion at the operated level.This study was aimed at analysing the clinical and functional outcome in patients with pseudarthrosis after instrumented and non-instrumented fusion. Material and Methods: Fifteen patients with pseudoarthrosis after failed non-instrumented fusion (group I) and 15 who had failed instrumented (pedicle screw) fusion (group II) were followed prospectively. Thirty patients matched for age and sex, who had solid fusion were analysed as a control group (group III). A self-reported questionnaire assesssing patient satisfaction, pain severity, psychological status and functional outcome were administered. Fusion status was evaluated on standard and flexion-extension radiographs. Follow-up was carried out a minimum of two years after fusion. Results: Clinical results were rated as satisfactory in seven patients of group I and in three of group II (p<0.05); in group III 25 patients reported satisfactory results (p<0.05). Six patients in group I were fully employed compared with 4 of group II (p>0.05) and with 23 of those in group III (p<0.01). Seven patients of group I and 13 of group II underwent repeat fusion (p