Predictability of the spontaneous lumbar curve correction after selective thoracic fusion in idiopathic scoliosis

In this study we tried to achieve a better understanding of the biodynamic mechanism of balance in the scoliotic spine. Therefore we focused on the pre- and postoperative spine of patients with idiopathic scoliosis with a primary thoracic curve and a secondary lumbar curve. Several studies showed that the lumbar curve spontaneously corrects and improves after selective thoracic fusion. We try to understand and describe this spontaneous compensatory lumbar curve correction after selective thoracic correction and fusion. We performed a retrospective examination of pre- and postoperative radiographs of the spine of 38 patients with idiopathic scoliosis King type II and III. Frontal Cobb angles of the thoracic and lumbar curves were assessed on pre- and postoperative antero-posterior and side bending radiographs. We determined the postoperative corrections of the thoracic and lumbar curves. Relative (%) corrections and correlations of the postoperative corrections were calculated. The group was divided in three subgroups, depending on lumbar curve modifier, according to Lenkes classification system. The calculations were done for the whole group as for each subgroup. As expected, significant correlations were present between the relative correction of the main thoracic and the lumbar curve (mean R = 0.590; P = 0.001). The relation between relative thoracic and lumbar correction decreased with the lumbar modifier type. This study shows a highly significant correlation between the relative corrections of the main thoracic curve and the lumbar curve after selective thoracic fusion in idiopathic scoliosis. This correlation depends on lumbar curve modifier type. This new classification system seems to be of great predictable value for the spontaneous correction of the lumbar curve. Depending on the curve-type, a different technique for predicting the outcome should be used. The lumbar curve correction does not occur throughout the whole lumbar curve. Most correction is achieved in the upper part of the curve. The distal lumbar curve seems to be more rigid and less important in the spontaneous curve correction

Juvenile idiopathic scoliosis treated with posterior arthrodesis and segmental pedicle screw instrumentation before the age of 9 years: a 5-year follow-up

<p>Abstract</p> <p>Study design</p> <p>Retrospective study.</p> <p>Objective</p> <p>To evaluate the radiological results of fusion with segmental pedicle screw fixation in juvenile idiopathic scoliosis with a minimum 5-year follow-up.</p> <p>Summary of background data</p> <p>Progression of spinal deformity after posterior instrumentation and fusion in immature patients has been reported by several authors. Segmental pedicle screw fixation has been shown to be effective in controlling both coronal and sagittal plane deformities. However, there is no long term study of fusion with segmental pedicle screw fixation in these group of patients.</p> <p>Methods</p> <p>Seven patients with juvenile idiopathic scoliosis treated by segmental pedicle screw fixation and fusion were analyzed. The average age of the patients was 7.4 years (range 5–9 years) at the time of the operation. All the patients were followed up 5 years or more (range 5–8 years) and were all Risser V at the most recent follow up. Three dimensional reconstruction of the radiographs was obtained and 3DStudio Max software was used for combining, evaluating and modifying the technical data derived from both 2d and 3d scan data.</p> <p>Results</p> <p>The preoperative thoracic curve of 56 ± 15° was corrected to 24 ± 17° (57% correction) at the latest follow-up. The lumbar curve of 43 ± 14° was corrected to 23 ± 6° (46% correction) at the latest follow-up. The preoperative thoracic kyphosis of 37 ± 13° and the lumbar lordosis of 33 ± 13° were changed to 27 ± 13° and 42 ± 21°, respectively at the latest follow-up. None of the patients showed coronal decompensation at the latest follow-up. Four patients had no evidence of crankshaft phenomenon. In two patients slight increase in Cobb angle at the instrumented segments with a significant increase in AVR suggesting crankshaft phenomenon was seen. One patient had a curve increase in both instrumented and non instrumented segments due to incorrect strategy.</p> <p>Conclusion</p> <p>In juvenile idiopathic curves of Risser 0 patients with open triradiate cartilages, routine combined anterior fusion to prevent crankshaft may not be warranted by posterior segmental pedicle screw instrumentation.</p

Comparative analysis between shape memory alloy-based correction and traditional correction technique in pedicle screws constructs for treating severe scoliosis

The three-dimensional correction of severe rigid scoliosis has been improved by segmental pedicle screw instrumentation. However, there can be significant difficulty related to the use of a rigid rod, especially in the apex region of severe scoliosis. This study is a retrospective matched cohort study to evaluate the advantages of Nitinol shape memory alloy (SMA) rod-based correction by comparing the clinical and radiographic results obtained from using a temporary SMA rod and those from a standard rod in the correction of severe scoliosis. From May 2004 to September 2006, patients with matched curve type, ages at surgery, operative methods and fusion levels in our institute and instrumented with either SMA rods (n = 14) or traditional correction techniques (n = 16) were reviewed. In SMA group, the SMA rods served as a temporary intraoperative tool for deformity correction and were replaced by standard rods. The blood loss at surgery averaged 778 ± 285 ml in the traditional group and 585 ± 188 ml in the SMA group (P < 0.05). Operative time averaged 284 ± 53 min in the SMA group and 324 ± 41 min in the traditional group (P < 0.05). In the SMA group, the preoperative major curve was 92.6° ± 13.7° with a flexibility of 25.5 ± 7.3% was corrected to 29.4° ± 5.7° demonstrating a 68.4% immediate postoperative correction. In the traditional group, the preoperative major curve was 88.6° ± 14.6° with a flexibility of 29.3 ± 6.6% was corrected to 37.2° ± 7.3° demonstrating a 57.8% immediate postoperative correction. There was a statistic difference between the SMA group and traditional group in correction rate of the major thoracic curve. In the SMA group, one case suffered from deep infection 2 months postoperatively. In the traditional group, 6 of 16 cases suffered pedicle screw pull out or loosening during placement of the standard rod at the apex vertebrae on the concave side. In three cases, the mono-axial pedicle screws near the apex were abandoned and in five cases replaced with poly-axial pedicle screws. This study shows that the temporary use of SMA rod may reduce the operative time, blood loss, while improve the correction of the coronal plane when compared with standard techniques

Why do we treat adolescent idiopathic scoliosis? What we want to obtain and to avoid for our patients. SOSORT 2005 Consensus paper

BACKGROUND: Medicine is a scientific art: once science is not clear, choices are made according to individual and collective beliefs that should be better understood. This is particularly true in a field like adolescent idiopathic scoliosis, where currently does not exist definitive scientific evidence on the efficacy either of conservative or of surgical treatments. AIM OF THE STUDY: To verify the philosophical choices on the final outcome of a group of people believing and engaged in a conservative treatment of idiopathic scoliosis. METHODS: We performed a multifaceted study that included a bibliometric analysis, a questionnaire, and a careful Consensus reaching procedure between experts in the conservative treatment of scoliosis (SOSORT members). RESULTS: The Consensus reaching procedure has shown to be useful: answers changed in a statistically significant way, and 9 new outcome criteria were included. The most important final outcomes were considered Aesthetics (100%), Quality of life and Disability (more than 90%), while more than 80% of preferences went to Back Pain, Psychological well-being, Progression in adulthood, Breathing function, Scoliosis Cobb degrees (radiographic lateral flexion), Needs of further treatments in adulthood. DISCUSSION: In the literature prevail outcome criteria driven by the contingent treatment needs or the possibility to have measurement systems (even if it seems that usual clinical and radiographic methods are given much more importance than more complex Disability or Quality of Life instruments). SOSORT members give importance to a wide range of outcome criteria, in which clinical and radiographic issues have the lowest importance. CONCLUSION: We treat our patients for what they need for their future (Breathing function, Needs of further treatments in adulthood, Progression in adulthood), and their present too (Aesthetics, Disability, Quality of life). Technical matters, such as rib hump or radiographic lateral alignment and rotation, but not lateral flexion, are secondary outcomes and only instrumental to previously reported primary outcomes. We advocate a multidimensional, comprehensive evaluation of scoliosis patients, to gather all necessary data for a complete therapeutic approach, that goes beyond x-rays to reach the person and the family

Selective thoracic surgery in the Lenke type 1A: King III and King IV type curves

Pedicle screw fixation enables enhanced three-dimensional correction of spinal deformities and effectively shortens the distal fusion level. However, the choice of distal fusion level is still controversial in single thoracic idiopathic scoliosis with the lumbar compensatory curve not crossing the middle line (Lenke type 1 with modifier A or King type III and IV curves).The authors retrospectively analyzed 31 patients treated by segmental pedicular instrumentation alone, affected by a single thoracic adolescent idiopathic scoliosis with a compensatory lumbar curve not crossing the midline (Lenke 1A), with an average age of 16.3 years (range 10–22 years). The patients with regard to the King classification were also assessed. A statistical analysis was performed to determine whether the two groups (King III, King IV) presented differences concerning the level of the stable vertebra (SV), end vertebra (EV), and neutral vertebra (NV) and were also analyzed the results at follow-up regarding the relationships between the SV, EV, and lowest instrumented vertebra (LIV). The statistical analysis showed a significant difference between the two curve types. In the King III type curve the SV, EV, and NV appeared to be more proximal than those of the King IV type curve and the segments between the SV, EV, and NV appeared to be reduced in King III curves compared with King IV curves. At a follow-up of 3.2 years (range 2.2–5) the thoracic curve showed a correction of 58.4% (from 62.3° to 26.6°) and compensatory lumbar curve an average spontaneous correction of 52.4% (from 38.1° to 18.1°).The position of the LIV was shorter than the position of the SV in 30 patients (97%) with an average “salvage” of 2.1 (from 1 to 4) distal fusion levels. Four cases (13%), all affected by a King IV type curve, presented at follow-up an unsatisfactory results due to an “adding on” phenomenon. The statistical analysis confirmed that this phenomenon was correlated with The King IV curve (P = 0.043; Chi-square test) and that the only predictive parameter for its onset was the LIV–SV difference (odds ratio = 0.093; with a confidence interval of 0.008–1): every time that in King IV curve type the LIV was three or more levels shorter than the stable vertebra at follow-up the “adding on” phenomenon was present. The authors conclude that Lenke’s type 1 with modifier A includes two kinds of curves, King III and King IV and that the Lenke’s type 2 curves and King V with the lumbar curve not crossing the middle line have a similar behavior. Therefore, it is of authors’ opinion that “the adding on phenomenon” could be prevented by more rigidly defining K. IV versus K. III curves. In Lenke’s 1/2 A-K. IV/V type with the rotation of the first vertebra just below the thoracic lower EV in the same direction as the thoracic curve, and when SV and EV show more than two levels of difference, it is necessary to extend the lower fusion down to L2 or L3 (not more than two levels shorter than the SV). Whereas in Lenke’s 1/2 A-K. III/V with the rotation of the first proximal vertebra of lumbar curve in the opposite direction to the thoracic apex and when SV and EV show not more than two level gap differences, the position of the lowest instrumented vertebra can be two or three levels shorter than the stable vertebra with satisfactory postoperative spinal balance. Therefore, the stable vertebra and the rotation of lumbar curve are considered to be a reliable guide for selecting the lower level of fusion

Fixed lumbar apical vertebral rotation predicts spinal decompensation in lenke type 3c adolescent idiopathic scoliosis after selective posterior thoracic correction and fusion

Retrospective radiographic review of surgically treated double major curves (Lenke type 3C) in adolescent idiopathic scoliosis. To evaluate the role of selective posterior thoracic correction and fusion in double major curves with third generation instrumentation and to identify preoperative radiographic parameters that predict postoperative coronal spinal decompensation. Traditionally the surgical treatment of double major curves consists of fusion of both the thoracic and the lumbar curve. Few attempt to perform selective thoracic fusion in this curve pattern because of the potential to create spinal imbalance. Thirty-six patients with Lenke type 3C curves underwent a selective posterior thoracic correction and fusion with either Cotrel–Dubousset instrumentation or the Universal Spine System. Radiographs were evaluated to assess coronal and sagittal balance, curve flexibility, and curve correction at a minimum follow up of 2 years. Postoperative coronal spinal decompensation was investigated with respect to preoperative radiographic parameters on standing anteroposterior (AP), standing lateral radiographs, thoracic and lumbar supine side-bending radiographs. Coronal spinal decompensation was defined as plumbline deviation of C7 of more than 2 cm with respect to the centre sacral vertical line (CSVL) within 2 years of surgery. Twenty-six patients (72%) showed satisfactory frontal plane alignment patients (28%) showed coronal spinal decompensation. Significant group differences, however, were identified for lumbar apical vertebral rotation, measured according to Perdriolle (La scoliose. Son êtude tridimensionnelle. Maloine, Paris, pp 179, 1979) (A 16°, B 22°, P = 0.02), percentage correction (derotation) of lumbar apical vertebrae in lumbar supine side-bending films in comparison to standing AP radiographs (A 49%, B 27%, P = 0.002) and thoracic curve flexibility (A 43%, B 25%, P = 0.03). High correlation was noted between postoperative decompensation and derotation of lumbar apical vertebrae in pre-operative lumbar supine side-bending films with a critical value of 40% (Pearson correlation coefficient; P = 0.62, P < 0.001). Ten of 36 patients (28%) with Lenke type 3C adolescent idiopathic scoliosis showed coronal spinal decompensation of more than 2 cm after selective posterior thoracic correction and fusion. Lumbar apical vertebral derotation of less than 40% provided the radiographic prediction of postoperative coronal spinal imbalance. We advise close scrutiny of the transverse plane in the lumbar supine bending film when planning surgical strategy

Parafuso pedicular: método para correção da deformidade na escoliose idiopática do adolescente Tornillo pedicular: método para corregir la deformidad en la escoliosis idiopática del adolescente Pedicular screw: method to correct the deformity in adolescent idiopatic scoliosis

OBJETIVO: avaliar retrospectivamente o poder de correção da deformidade escoliótica em pacientes tratados cirurgicamente com instrumental de terceira geração sendo utilizados exclusivamente parafusos pediculares tanto nas curvas torácicas quanto nas lombares. MÉTODOS: dezessete pacientes com escoliose idiopática do adolescente (EIA) foram submetidos a tratamento cirúrgico, com correção da deformidade e artrodese via posterior com parafusos pediculares em todas as vértebras. Foram analisados sexo, idade, linha de Risser e classificação da escoliose pelo sistema de Lenke. As curvas foram comparadas entre si no pré e pós-operatório em relação ao grau da curvatura pelo método de Cobb, sua flexibilidade por meio de radiografias em inclinação, translação vertebral apical (AVT, do inglês apical vertebral translation) e rotação vertebral apical (AVR, do inglês apical vertebral rotation). A porcentagem de correção pós-operatória foi analisada por meio do "índice de correção de Cincinnati" (ICC). RESULTADOS: houve correção significativa no ângulo de Cobb nas curvas maiores (p<0,0001) e nas curvas menores (p<0,0001). O ICC obtido para as curvas maiores (2,89) e menores (1,21) foi significativamente diferente do zero (p=0,0143 e p<0,0001, respectivamente). Em relação ao AVT, houve correção significativa nas curvas maiores (p=0,0007), porém não-significativa nas curvas menores (p=0,1082). O AVR foi corrigido significativamente tanto nas curvas maiores (p=0,0001) quanto nas menores (p=0,0033). CONCLUSÃO: o tratamento cirúrgico da EIA por artrodese via posterior com instrumental de terceira geração apresentou elevado poder de correção das deformidades, além de ter se mostrado técnica segura.<br>OBJETIVO: evaluar retrospectivamente la facultad de corregir la deformidad de escoliosis en los pacientes tratados quirúrgicamente con instrumento de tercera generación se utilizando exclusivamente los tornillos de pedículo, tanto en las curvas torácicas como en las lumbares. MÉTODOS: diecisiete pacientes con escoliosis idiopática del adolescente fueron tratados quirúrgicamente, con la corrección de la deformidad y artrodesis posterior con tornillos pediculares en todas las vértebras. Se analizaron sexo, edad, línea de Risser y clasificación de la escoliosis por el sistema de Lenke. Las curvas fueron comparadas antes y después de la cirugía en relación con el grado de curvatura por el método de Cobb, su flexibilidad con las radiografías en la pendiente, la traslación vertebral apical (AVT, sigla del inglés apical vertebral translation) y la rotación vertebral apical (AVR, del inglés apical vertebral rotation). El porcentaje de corrección postoperatoria fue analizado con el "índice de corrección de Cincinnati" (CPI). RESULTADOS: se observó una corrección significativa en el ángulo de Cobb en las curvas de mayor (p<0,0001) y en las curvas de menor (p<0,0001). El CPI logrado para las curvas de mayor (2,89) y menor (1,21) era significativamente diferente de cero (p=0,0143 y p<0,0001, respectivamente). En relación con la AVT, hubo corrección significativa de las curvas de mayor (p=0,0007), pero no significativa en las curvas de menor (p=0,1082). El AVR se corrigió significativamente tanto en las curvas de mayor (p=0,0001) como en la curva de menor (p=0,0033). CONCLUSIÓN: el tratamiento quirúrgico de la EIA por artrodesis posterior con la tercera generación de alta potencia instrumental presentó grande poder para corregir las deformidades, y ha demostrado ser una técnica segura.<br>OBJECTIVE: to evaluate retrospectively the power of scoliotic deformity in patients that were submitted to surgical treatment with third generation instrumentation using exclusively pedicle screws in both thoracic and lumbar curves. METHODS: seventeen patients with adolescent idiopathic scoliosis (AIS) were submitted to surgical treatment with deformity correction and fusion by posterior approach with pedicle screws in all vertebral bodies. Sex, age, Risser line and Lenke system of classification were analyzed. The curves were compared between pre and postoperatory in relation to Cobb angle, curve flexibility by the bending radiographs, apical vertebral translation (AVT) and apical vertebral rotation (AVR). The postoperative correction percentage was expressed by the Cincinnati correction index (CCI). RESULTS: the Cobb angle had significant correction in the major curves (p<0.0001) and the minor curves (p<0.0001). The CCI of the major curves (2.89) and minor curves (1.21) differ significantly from zero (p=0.0143 and p<0.0001, respectively). The AVT had significant correction in the major curves (p=0007), but not significant in the minor curves (p=1.082). The AVR was significantly corrected in both major (p=0.0001) and minor (p=0.0033) curves. CONCLUSION: the surgery treatment of AIS with posterior fusion using third generation instrumentation has proved to be powerful in correcting the deformities besides shown to be a safe technique