We considered three different device systems for the treatment of lumbar and lumbosacral instability. From a prospective database in use in our Institution, we obtained a 45-patient cohort of individuals who received a one-level lumbar or lumbosacral fusion procedure between 1995 and 1998. All patients had presented with disabling back and/or radicular pain and severe degenerative changes at one disc level or low-grade spondylolisthesis. First group: 15 patients, six male and nine female, with an average age of 41 years, were treated by an interbody fusion using cylindrical threaded cages; the levels fused were L5-S1 in 10 patients and at L4-L5 in five. Second group: 15 patients, eight male and seven female, with an average age of 39 years were treated by nine cylindrical, threaded cages and seven square cages, combined with posterior pedicle screws; the levels fused were L5-S1 in 11 and L4-L5 in four. Third group: 15 patients, eight male and seven female, with an average age of 40 years, underwent posterolateral fusion with posterior pedicle screws instrumentation alone; the levels fused were L5-S1 in 10 and L4-L5 in the remaining five. At a mean follow-up of 8 years in the first group, eight patients (53%) required a second operation (five posterior instrumentation, two root decompression and one repair of dural tear). The clinical results were fair in six patients (40%) and poor in three (20%); five patients (33%) presented uncertain fusion signs. In the second group, two patients (13%) required a second operation (one root decompression and one dural repair). All patients (100%) presented definite fusion signs. The clinical results 6.5 years after primary surgery were fair in two (13%) patients and poor in two (13%). In the third group, two patients (13%) required a second operation (one dural repairand one implant removal). The clinical results were fair in two cases (13%) and no poor results were seen. At a mean follow-up of 6.5 years, 14 patients (93%) showed definite fusion signs. According to the present data, we can conclude that in terms of fusion success, clinical outcome and complication rates, the use of posterior interbody cages alone is not as safe and effective for the management of one level degenerative disc disease or low-grade spondylolisthesis as the posterior pedicle screw instrumentation combined with two posterior cages or the stand-alone pedicle screw instrumentation.
Homoplastic bone has been produced and used at the Rizzoli Orthopaedic Institute since 1998. Bone grafts are treated following the “freeze-dry” technique developed by the Rizzoli Bone Bank. Up to now, 111 patients have been surgically managed by using lyophilised bone grafts at the Division of Spine Surgery. With a follow-up of more than 12 months, the authors reviewed 81 subjects affected with scoliosis (45 cases – group A), lumbar diseases (34 cases – group B) and segmental cervical degenerative stenosis (two cases – group C). Group A consisted of 20 patients, mean age 14 years, affected with progressive or congenital idiopathic scoliosis; 12 patients, mean age 34.5 years, affected with adult symptomatic scoliosis; 10 patients, mean age 14.4 years, affected with neuromuscular scoliosis; and the remaining three, mean age 37 years, who had already undergone surgery) presenting with pseudarthrosis. Surgical technique was circumferential arthrodesis in paediatric congenital scoliosis and posterior arthrodesis in adult and adolescent idiopathic scoliosis. Fusion was extended to the sacrum and iliac crests in five cases of neuromuscular scoliosis. Patients of group B (16 spondylolisthesis and 18 degenerative lumbar instability), aged 42 years on average, underwent posterior arthrodesis with pedicle fixation. Only two patients in group C were treated with bone graft anteriorly placed at the cervical level to supplement the intersomatic fusion with cage. At a mean follow-up of 28 months, solid fusion was observed in 79 cases (97%); a clearly visible pseudarthrosis was seen only in two cases (3%) (an infantile scoliosis and reintervention for neuromuscular scoliosis in an adult patient). A deep infection with Staphlylococcus aureus was encountered in one patient (1.2%) with degenerative lumbar instability treated with arthrodesis and L2-S1 pedicle fusion: the infection resolved after surgical reintervention (leaving the instrumentation in situ) and drainage. Lyophilised bone, either used as wedge grafts anteriorly or morcellised grafts posteriorly, provides good resistance and integration. Safety, ready availability and possibility to be stored at environmental temperature are further advantages offered by these bone grafts, which make them particularly suitable for application in spinal surgery, above all when surgical times are long and the risk of complications is high.
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.
