Introduction

Thoracic pedicle screws have been proven to be safe and effective in the treatment of adolescent idiopathic scoliosis (AIS). However, the effect of the instrumentation alloy has not yet been investigated. We aimed to compare segmental versus non segmental thoracic pedicle screw instrumentation in patients with AIS.

Introduction

Posterior spinal arthrodesis with thoracoplasty and an open anterior approach, with respect to a posterior only fusion, have a deleterious effect on pulmonary function for up to 5 years after surgical treatment of adolescent idiopathic scoliosis. We aimed to compare two groups of adolescents surgically treated for their spinal deformity either by posterior segmental fusion alone (PSF) or by posterior spinal fusion and thoracoplasty (PSF+T). We focused on the long-term effects of thoracoplasty on pulmonary function in the surgical treatment of adolescent idiopathic scoliosis.

Introduction

We aimed to determine the midterm effect of pedicle screw instrumentation on sagittal plane alignment, compared with a hybrid alignment, in the treatment of thoracic adolescent idiopathic scoliosis (AIS).

Introduction: Adolescent idiopathic scoliosis (IS) is the most common spine deformity arising during childhood, but the aetiology of IS remains unknown. A large proportion (75%) of structural scoliosis is clinically classified as idiopathic. Idiopathic scoliosis often appears in several members of the same family, this strongly suggesting a genetic transmission. Clinical studies indicate that approximately 1:4 of the total scoliosis cases and 1:3 of idiopathic scoliosis cases are familial. Also studies on twins showing that concordance of monozygotic twins is greater than that of dizygotic twins suggest a genetic basis for the idiopathic scoliosis. A series of candidate genes, including FBN1, COL1A1, COL1A2, COL2A1 and elastin genes, have already been examined by linkage studies, with negative results, and, at present, the particular mode of inheritance of the idiopathic scoliosis still remains unclear. There are conflicting data in the existing literature. Some reports show that the disorder has many of the characteristics of a complex trait, indicating the presence of a multifactorial inheritance pattern, while other studies indicate a major autosomal dominant gene effect. Even more, not all the linkage studies, which demonstrate that the inheritance pattern of idiopathic scoliosis is based on a major autosomal dominant gene effect, did identify a unique locus responsible for idiopathic scoliosis. A linkage with idiopathic scoliosis has been found at locus 17p11 in a three generation Italian family and at locus 19p13.3 in a Chinese family. Therefore, it is possible that idiopathic scoliosis is caused by alterations in different genes.

Study Design: This study aimed at investigating the loci responsible for susceptibility to idiopathic scoliosis in all the population and not only in single families. For this reason, we chose to perform an association study on parent-offspring trios. A genetic study and statistical linkage analysis of a population of 81 trios, each consisting of a daughter/son affected by idiopathic scoliosis (IS) and both parents.

Objectives: The objective of this study was to assess a linkage disequilibrium between the matrilin-1 (MATN1) gene and the idiopathic scoliosis (IS).

Summary of Background Data: In a previous study (Giampietro et al., 1999), a number of genes, associated with spine musculoskeletal deformity phenotypes in mouse and in synteny between mouse and man, were identified as candidate genes for IS. Among these genes, MATN1, which carries a polymorphic micro-satellite marker within its sequence, was selected for a linkage analysis. MATN1 is localised at 1p35 and is mainly expressed in cartilage.

Methods: In all trios components, the region of MATN1 gene containing the microsatellite marker was amplified by a polymerase chain reaction. The amplicons were analysed by a DNA sequencer-genotyper. The statistical analysis was performed using the extended transmission/disequilibrium test.

Results: Three microsatellite polymorphisms, respectively consisting of 103 bp, 101 bp and 99 bp, were identified. ETDT evidenced a significant preferential transmission for the 103 bp allele (2 = 5.058, df=1, P=0.024).

Main Conclusions: The results suggest that the familial idiopathic scoliosis is linked to the MATN1 gene.

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.

The purpose of this review is to evaluatei the clinical and surgical aspects of lumbar disc herniation in paediatric and adolescent patients. Between 1975 and 1991, a total of 5,160 lumbar disc operations were performed at the Rizzoli Orthopaedic Institutes. We included in this study only 129 patients (2.5%), aged from 9 to 18 years, with a mean age of 16.2 years (S.D. 1.7). Almost half of the patients (66 cases) ranged from 17 to 18 years of age and 49% (63 cases) from 9 to 16. Only three subjects were aged 9, 11 and 12 years.

This group consisted of 84 boys and 45 girls. Eleven had noted the onset of symptoms after a trauma and 15 during athletic activities or after lifting heavy objects. Almost all of the patients (106 cases, 82%) had low-back pain with radiculopathy, 13% (17 cases) complained of lumbar pain alone, 5% (six cases) had sciatica and 16% (21 cases) presented with a radicular neurological deficit.

Posterior discectomy by conventional procedure without fusion was performed in all patients, except for three cases with associated spondylolisthesis, treated by a posterolateral artrodesis, supplemented in two cases by pedicle screw fusion. Patients were followed in a short-term assessment using medical records. Long-term follow-up was conducted by a mailed, self-report questionnaire that quantified leg and back pain and scored the ability to return to normal activities and satisfaction.

Short-term results were excellent for 120 patients (93%) and postoperative complications included one superficial wound infection and one discitis. A total of 98 (76%) long-term responses were obtained with a mean follow-up time of 12.4 years (range, 6-19.4 years). Mean age at long-term follow-up was 28.7 years whereas the functional outcomes were excellent in 56%, good 30% and poor 14%. Eight patients (6.2%) required additional surgical treatment at a mean interval from the first surgery of 9 years (range 2 to 16). Three of them had a re-exploration for a herniated disc at the same level, five at a different level.

Our results have confirmed, as in adult patients, a negative trend between the short-term and long-term functional outcomes in young patients treated by discectomy. Furthermore, they have suggested that young individuals with lumbar Scheuermann-type changes are at great risk of experiencing herniation of intervertebral discs (10% in our series).

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.

Introduction: Pedicle screw instrumentation as a part of scoliosis surgery has been shown to provide a better correction in lumbar deformities. The purpose of this retrospective study was to verify if segmental screw fixation has the same efficacy in correcting hypokyphotic thoracic deformities.

Methods and results: We considered 40 cases with AIS treated posteriorly by segmental fixation (CDI, Colorado or similar instrumentations) from 1987 to 1998. All patients presented with a predominant hypokyphotic thoracic curve and were divided into two groups (20 cases each) according to the fixation method selected: multiple, hook fixation (MHF) or segmental pedicle screw fixation (SPSF). In the PSF group, the pedicle screws were inserted at every other or every third vertebra in lumbar and thoracic areas, and correction was achieved by translation technique and derotation manoeuvre without distraction and compression on the concavity and convexity of the curve, respectively. At a follow-up longer than two years and in all of the cases, the average frontal correction in the PSF group decreased from 61.3° to 27.6°, and in the MHF group from 57.5° to 28°; the average hypokyphosis value improved from 12.9° to 25.6° in the PSF group, and from 15.3° to 17° in the MHF group. There were no major, visceral or neurological complications related to hook or pedicle screw placement.

Conclusion: According to the present results, segmental pedicle screws are more effective than multiple hooks in restoring thoracic kyphosis in AIS: pedicle screw fixation may play a role in reducing the need for the two-stage surgery.