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<0.05).
Conclusions: In contrast with our hypothesis we found that
pseudarthrosis is more likely to be associated with a poor
outcome after instrumented than non-instrumented fusion.
Moreover, a higher reoperation rate was found in patients
with failed instrumented fusion than in those with no
instrumentation. These findings suggest that in patients
with pseudarthrosis showing persistent mobility at the operated levels the presence of pedicle screws may be an
additional source of pain
