Comparison of push-prone and lateral-bending radiographs for predicting postoperative coronal alignment in thoracolumbar and lumbar scoliotic curves

STUDY DESIGN: A comparative evaluation of supine right and left lateral-bending radiographs and push-prone radiographs in patients with thoracolumbar and lumbar scoliosis to determine postoperative correction of the curve. OBJECTIVES: To determine the difference in the ability of the push-prone radiograph and the supine lateral-bending radiograph to predict postoperative coronal alignment for primary thoracolumbar and lumbar curves managed with an anterior spinal instrumentation and fusion. SUMMARY OF BACKGROUND DATA: Right and left supine side-bending radiographs are the standard means of evaluating curve flexibility before surgery in idiopathic scoliosis. A push-prone radiograph also has been obtained at the authors' institution as a single dynamic radiographic assessment of forced correction of the primary curve and resultant effects on compensatory curves above and below the fusion. METHODS: Preoperative standing, supine right and left lateral-bending, and push-prone radiographs were performed in 40 patients who underwent anterior spinal instrumentation and fusion. Postoperative standing radiographs of the spine were obtained at 3 months after surgery. Measurements on all the radiographs included the coronal Cobb angle, the angle of the lowest instrumented vertebra to the horizontal, the rotation of the lowest instrumented vertebra, and the distance of the midpoint of the lowest instrumented vertebra from the center sacral line. RESULTS: The lateral-bending and the push-prone radiographs predicted less correction of the Cobb angle and the angle of the lowest instrumented vertebra to the horizontal than was achieved after surgery. However, the push-prone radiograph was superior to the lateral-bending radiograph in accurately predicting the postoperative correction of the rotation of the lowest instrumented vertebra as well as the translation of the lowest instrumented vertebra from the center sacral line. CONCLUSIONS: The push-prone and lateral-bending radiographs are similar in predicting less correction of the Cobb angle after anterior spinal surgery. The push-prone radiograph helps in determining the effects that correction of the primary curve has on the curves above and below the level of fusion by better predicting the translational correction of the lowest instrumented vertebra and the rotation of the lowest instrumented vertebra.     

Loss of sagittal plane correction after removal of spinal implants

STUDY DESIGN: A retrospective review of a clinical series was performed. OBJECTIVES: To evaluate the incidence of adult patients who experienced spinal collapse after spinal implant removal after a long spinal arthrodesis, and to assess the various factors that may influence the likelihood of collapse after implant removal. SUMMARY OF BACKGROUND DATA: Published reports describing the benefits or complications of spinal implant removal do not exist. Spinal implant removal, often considered a benign procedure, is even required by the Food and Drug Administration (FDA) for certain implants. METHODS: The medical records and radiographs of 116 consecutive adult patients with long posterior instrumented fusions (>5 segments) were reviewed. The information obtained included original diagnosis, patient age, number of previous surgeries before implant removal, levels of anterior and posterior fusion, time from fusion to implant removal, time from implant removal to failure, and reason for hardware removal. Radiographs also were assessed including scoliosis, lordosis, and kyphosis measurements before implant removal, after hardware removal, after failure, and after revision surgery. RESULTS: Of 116 patients, 14 underwent spinal implant removal. Most of these patients reported prominent implants either proximally in the thoracic spine or distally in the ilium (Galveston technique). Of these 14 patients, 4 experienced increased pain and collapse after implant removal despite thorough intraoperative explorations demonstrating solid fusion. CONCLUSIONS: Spinal implant removal after long posterior fusion in adults may lead to spinal collapse and further surgery. Removal of instrumentation should be avoided or should involve partial removal of the prominent implant.     

内置物保留治疗脊柱内固定术后细菌感染8例报告

目的探讨脊柱内固定术后细菌感染发生时在保留内固定物的情况下手术联合药物治疗的效果。方法对来自滨州医学院附属医院的458例脊柱疾患采用脊柱内固定治疗,8例（1．75％）确诊术后感染接受治疗。结果在保留内固定物的情况下,所有确诊感染的患者接受外科彻底清创、抗感染及VSD辅助治疗,感染均得以根治,平均随访时间2．1年（1-2．5年）。结论脊柱内固定术后发生的细菌感染通过积极的手术清创、应用抗生素并联合VSD辅助治疗均可得到控制。结果显示术后细菌感染在不取出内固定物的情况下,可以成功治愈。     

Is there a need for anterior release for 70–90° thoracic curves in adolescent scoliosis?

Large and stiff thoracic scoliotic curves in the adolescent represent a classic indication of anterior release followed by posterior instrumentation. However, third-generation segmental spinal instrumentations have shown increased correction of thoracic curves. Indication for an anterior release may therefore not be required even in large and stiff thoracic curves. The objective of the study was, therefore, to analyze retrospectively the results of third-generation segmental posterior instrumentation in large and stiff thoracic curves and to compare our results with the current literature of anterior release followed by posterior instrumentation. An independent observer, who had not participated in any of the case, reviewed our electronic database of adolescent scoliosis surgery (Scolisoft) with the following query: thoracic curves, Cobb angle between 70° and 90° and posterior surgery only. He was able to identify 19 patients whose thoracic curves were measured between 70° and 90°. Out of these, four had convex-side bending Cobb angle values of less than 45° and were not included in the study, as they were judged too flexible. Fifteen patients (aged 11–18 years, mean 13.6 years) with thoracic scoliosis were left for the study (average Cobb angles 78.5° with a flexibility index of 32.5% (range, 19–42%). The mean follow-up period was 32 months (range 18–64 months). Classic parameters of deformity correction were analysed. The average operative time was 314 min and the mean total blood loss was 1,875 ml. Average level of instrumented vertebrae was 12 (Range, 10–14). Postoperatively, the thoracic Cobb angle was measured at 34.8° (range, 25–45°), which represents a correction rate of 54% (range, 40.0–67.1%) and remained unchanged at the last follow-up (35°). Patients with thoracic hypokyphosis improved from an average 11° to 18°. There were three complications (one excessive bleeding, one early infection and one late infection). One case showed an add-on phenomenon at the last follow-up. Coronal balance was improved from 1.8 cm (Range 0–4cm) down to 0.75 cm (range 0–2.5 cm). Shoulder balance was improved from 1.3 cm (range 0–4cm) down to 0.75 (0–2.5 cm). All patients reported satisfactory results except the patient with an adding-on phenomena. In the literature, most of the results of anterior thoracoscopic release and posterior surgery give a percentage of Cobb angle correction similar or inferior to our series for an average initial Cobb angle of less magnitude. Therefore, with adequate posterior release, and the use of third-generation segmental instrumentation there is no need for anterior release even for curves in the 70 –90° range.     

Surgical treatment of infantile and juvenile scoliosis--a retrospective analysis of 21 patients]

PROBLEM: We carried out a retrospective analysis of 21 patients with infantile or juvenile scoliosis (9 boys, 12 girls) who underwent surgical treatment between 1985 and 1997. 13 patients underwent primary dorsal instrumentation without fusion (growing-rod group). In contrast, 8 patients received already in this young age an instrumented spondylodesis (fusion-group). PATIENTS AND METHODS: The initial examination was performed at an age of 6 years (median; range 29 years), and first surgery was performed at an age of 8 years (median, range 310 years). The patients have been followed-up clinically and radiologically at an age of 16 years (median; range 1021 years). RESULTS: The preoperative measurement showed no significant differences between both groups (thoracic Cobb angle 77 degrees versus 66 degrees [median], lumbar Cobb angle 40 degrees versus 51 degrees [median]). At follow-up we measured significantly better results in the fusion-group than in the growing-rod group (thoracic Cobb angle 24 degrees versus 60 degrees [median; p < 0.01]), lumbar Cobb angle 21 degrees versus 34 degrees [median, p < 0.05]). The fusion-group also showed significantly better results with respect to the parameters (median values given): duration of hospital stay (14 versus 150 days), number of operations per patient (2 versus 3) and number of complications (0 versus 26). CONCLUSION: Based on the results of this small patient group we no longer see an indication to treat infantile and juvenile scoliosis by dorsal instrumentation without fusion. In contrast, we find the principle of short instrumented anterior fusion to be more promising.     

Maintaining lumbar lordosis with anterior single solid-rod instrumentation in thoracolumbar and lumbar adolescent idiopathic scoliosis.

STUDY DESIGN: A prospective radiographic evaluation of 20 consecutive patients with primary lumbar or thoracolumbar adolescent idiopathic scoliosis who were treated with anterior convex compressive single solid-rod spinal instrumentation and structural titanium mesh (Harms) cages. OBJECTIVES: To evaluate a lordosis-preserving anterior single solid-rod instrumented fusion technique for these specific adolescent idiopathic curves. SUMMARY OF BACKGROUND DATA: Maintaining instrumented segmental lumbar lordosis after anterior fusion and instrumentation for thoracolumbar and lumbar curves has been difficult. Twenty consecutive patients who underwent anterior single solid-rod fusion, aged 18 or younger with a primary thoracolumbar or lumbar curve, were observed for preservation of lordosis for a minimum of 2 years. METHODS: All patients underwent an identical anterior surgical technique, involving discectomies and anulectomies of all convex discs, structural titanium mesh (Harms) cages placed in the anterior half of all disc spaces below T12, morselized rib autograft packed in all disc spaces to be fused and inside the cages, and anterior single solid-rod (5.0-mm or 5.5-mm diameter) convex compressive spinal instrumentation with appropriate lordotic rod contour and rod rotation as necessary. The anterior rod was placed just posterior to the cages to optimize lordotic contouring of the spine during compression. None of the patients was braced after surgery. The lowest instrumented vertebrae (LIV) were L2 (n = 3), L3 (n = 15), and L4 (n = 2), typically the lower end vertebra of the Cobb measurement. RESULTS: Measurements for the primary coronal Cobb before surgery, 1 week after surgery, and 2 years after surgery were 48 degrees, 11 degrees, and 12 degrees; for C7 plumb line deviation from the midline: 3.6 cm, 1.9 cm, and 1.2 cm; for lowest instrumented vertebra translation: 31 mm, 15 mm, and 15 mm; and for LIV tilt: 29 degrees, 6 degrees and 6 degrees, respectively. Sagittal measurements before surgery, 1 week after surgery, and 2 years after surgery were: T12-L2: -1 degree, -6 degrees, and -6 degrees; T12-LIV: -8 degrees, -13 degrees, -9 degrees; T12-S1: -61 degrees, -56 degrees, -60 degrees; and entire instrumented levels: -6 degrees, -9 degrees, and -6 degrees, respectively. Coronal plane correction improved: 75% in the primary Cobb, 66% in the plumb line, 50% in LIV translation, and 80% in LIV tilt. Sagittal plane alignment improved in T12-L2 lordosis (P < 0.01) with preservation of physiologic lordosis in the instrumented levels, T12-LIV, and T12-sacrum. There were no instrumentation failures, pseudarthroses, or reoperations. CONCLUSIONS: Coronal plane correction with preservation of thoracolumbar and lumbar lordosis 2 years after anterior convex compressive spinal instrumentation was accomplished using a lordotically contoured single solid rod with structural cages placed anteriorly in the disc spaces of patients with primary thoracolumbar or lumbar adolescent idiopathic scoliosis.     

Vacuum-assisted wound closure of deep infections after instrumented spinal fusion in six children with neuromuscular scoliosis.

BACKGROUND CONTEXT: The rate of infection after spinal fusion in neuromuscular scoliosis is reported to range from 4% to 20%. Infection persists in about 50% after traditional treatment including debridement and closure. Instrumentation removal is necessary in up to 28%. PURPOSE: To analyze the outcome of vacuum-assisted wound closure (VAC) in combination with antibiotics for the treatment of deep wound infection after instrumented spinal fusion in pediatric neuromuscular scoliosis. STUDY DESIGN: Six prospective consecutive neuromuscular patients with scoliosis. PATIENT SAMPLE: Between 2001 and 2005, six consecutive pediatric patients (average age, 12.6 years) with neuromuscular scoliosis with a postoperative deep wound infection after instrumented spinal fusion were included in the study. OUTCOME MEASURES: Measurement of the duration of wound closure and infection parameters during treatment. METHODS: The patients were treated with a VAC system in combination with antibiotics. RESULTS: Wound closure averaged 3 months. Infection parameters were normalized within 6 weeks. Removal of the instrumentation was not necessary in any patient, and there were no signs of infection at follow-up ranging from 9 to 42 months. CONCLUSION: The VAC system, in combination with antibiotic therapy, seems to be a useful method for treatment of deep wound infections after spinal fusion in pediatric neuromuscular scoliosis. It may prevent removal of the instrumentation and multiple surgery for irrigation and closure of the wound.     

Structural vertebral changes in the horizontal plane in idiopathic scoliosis and the long-term corrective effect of spine instrumentation

Summary The rotation and structural changes of the apex vertebra in the horizontal plane as well as of the thoracic cage deformity were quantified by measurements on computed tomography (CT) scans from patients with right convex thoracic idiopathic scoliosis (IS). The CT scans were obtained from 12 patients with moderate scoliosis (mean Cobb angle 25.8°, r 13°–30°) and from 33 with severe scoliosis (mean Cobb angle 46.2°, r 35°–71°). In addition, CT scans of thoracic vertebrae from 15 patients without scoliosis were used as reference material. Ten of the scoliotic cases had had Cotrel-Dubousset instrumentation (CDI) and posterior fusion and had entered a longitudinal study on the effect of operative correction on the re-modelling of the apical vertebra. An increasingly asymmetrical vertebral body, transverse process angle, pedicle width and canal width were found in the groups with scoliosis as compared with the reference material. Vertebral rotation and rib hump index were significantly larger in patients with early and advanced scoliosis than in normal subjects. The modelling angle of the vertebral body, the transverse process angle index and the vertebral rotation in relation to the middle axis of the thoracic cage were significantly greater in patients with severe than with moderate scoliosis. The results of this longitudinal study suggest that the structural changes of the apical vertebra regress 2 years or more after CD instrumentation.     

伴有侧凸畸形的腰椎管狭窄症的外科治疗

目的总结后路一期减压、内固定、融合手术治疗伴有腰椎侧凸畸形的腰椎管狭窄症患者的效果。方法自1998年1月-2005年10月,治疗伴有腰椎侧凸畸形的腰椎管狭窄症患者38例,腰椎侧凸畸形角度平均31°,术前 JOA评分平均11分,均采用腰椎后路一期减压、矫形、内固定、融合治疗。结果 32例得到随访,随访时间1-4年,平均2．5年,矫正角度平均13°。矫正角度丧失1°-5°,平均3°。截骨融合率100％。随访时JOA评分平均23分,患者对手术效果满意。结论后路一期减压、内固定、融合手术是治疗伴有腰椎侧凸畸形的腰椎管狭窄症的有效手段。     

顶椎置钉与否对Lenke 1型青少年特发性脊柱侧凸矫形效果的影响

目的:探讨顶椎置钉与否对Lenke 1型青少年特发性脊柱侧凸(AIS)患者矫形效果的影响。方法:回顾性分析从2009年6月～2010年1月采用全椎弓根螺钉后路矫形内固定融合术治疗的69例Lenke 1型AIS患者,年龄12～20岁,平均15.0岁,主弯Cobb角50°～70°,平均53.7°。根据顶椎置钉与否分为:顶椎凸凹侧均未置入螺钉组(A组,35例)和至少一侧置入螺钉固定组(B组,34例)。记录两组患者术前年龄、性别、主弯Cobb角、柔韧度、顶椎旋转度和固定节段数、置入物密度、术后Cobb角、主弯Cobb角矫正率、顶椎去旋转率等指标并进行两组间的比较分析。B组病例在CT图像上统计顶椎不良置钉率。结果:两组患者年龄、性别比、术前主弯Cobb角、柔韧度和顶椎旋转度等资料均无统计学差异(P>0.05)。所有病例矫形术后均未发生冠状面与矢状面的失代偿。随访24～30个月,平均27.7个月,两组患者无内固定松动及断钉断棒,植骨融合牢固,均未出现明显的矫正丢失。A、B两组置入物密度分别为63.4%、65.3%,平均固定节段数分别为11.3和11.6,主弯Cobb角矫正率分别为73.9%和72.6%。两组在置入物密度、内固定节段数和主弯Cobb角矫正率方面均无统计学差异(P>0.05)。术后顶椎去旋转率A组为18.4%,显著低于B组的34.8%(P<0.05)。B组顶椎置入的41枚螺钉中,有5枚为不良置钉(12.2%)。结论:对于Cobb角在50°～70°非严重的Lenke 1型青少年特发性脊柱侧凸,顶椎置钉尽管并不能显著提高侧凸矫正率,但可以明显矫正顶椎旋转,因此,在注意置钉安全性的前提下,应尽量在顶椎置入椎弓根螺钉。     

Combined anterior and posterior instrumentation in severe and rigid idiopathic scoliosis

A prospective clinical and radiographic evaluation of 33 consecutive patients with severe and rigid idiopathic scoliosis (average Cobb angle 93°, flexibility on bending films 23%) were treated with combined anterior and posterior instrumentation with a minimum follow-up of 2 years. All patients underwent anterior release and VDS-Zielke Instrumentation of the primary curve. In highly rigid scoliosis, this was preceded by a posterior release. Finally, posterior correction and fusion with a multiple hook and pedicle screw construct was performed. Thirty patients were operated in one stage, three patients in two stages. Preoperative curves ranged from 80 to 122° Cobb angle. Frontal plane correction of the primary curve averaged 67% with an average loss of correction of 2°. The apical vertebral rotation of the primary curve was corrected by 49%. In all but three patients, sagittal alignment was restored. There were no neurological complications, deep wound infections or pseudarthrosis. Combined anterior and posterior instrumentation is safe and enables an effective three-dimensional curve correction in severe and rigid idiopathic scoliosis.     

全椎弓根螺钉与钉钩混合系统治疗青少年特发性脊柱侧凸的疗效分析

目的 通过临床病例回顾,对后路全椎弓根螺钉系统和钉钩混合系统治疗青少年特发性脊柱侧凸的疗效进行对比分析研究.方法 从2000年至2004年进行手术治疗的青少年特发性脊柱侧凸患者中选取60例配对分为两组(A、B两组,各30例),A组采用后路钉钩混合系统固定,B组采用后路全椎弓根螺钉系统固定,配对患者年龄相似、融合节段相仿、Lenke分型相近.通过比较手术前后影像学改变、手术时间、术中出血等,对两种手术方法的疗效进行对比分析研究.结果 A组患者术前冠状面主弯Cobb角平均为61°,术后为25°,平均矫正率为59%;B组患者术前冠状面主弯Cobb角平均为60°,术后为18°,平均矫止率为70%.两组患者主弯矫正率差异有统计学意义(P=0.002),随访2年两组间主弯矫正率差异仍有统计学意义(A、B两组分别为49%、67%,P<0.001).矢状面上,与术前相比,术后2年A组的胸椎后凸角平均减少了1°,而B组则减少了6°,差异有统计学意义(P=0.026).随访结果 提示,两组在下端椎远端融合椎体数、平均失血量方面差异均无统计学意义.两组患者术后均未出现神经系统并发症.结论 全椎弓根螺钉系统较钉钩混合系统能提供更好的主弯矫止率,而在最下端固定椎体的选择、术中失血量方面,两种内固定系统未见明显差异.     

Spinal deformity progression after posterior segmental instrumentation and fusion for idiopathic scoliosis

Study design

Retrospective chart and radiographic review.

Purpose

To assess the incidence of and variables associated with spinal deformity progression after posterior segmental instrumentation and fusion at a single institution. Progression of the scoliotic deformity after posterior instrumented spinal fusion has been described. Recent studies have concluded that segmental pedicle screw constructs are better able to control deformity progression.

Methods

Retrospective review of a consecutive series of idiopathic scoliosis patients (n = 89) with major thoracic curves (Lenke types 1–4) treated with posterior segmental instrumentation and fusion. Deformity progression was defined as a 10° increase in Cobb angle between the first-erect and 2-year post-operative radiographs. Clinical and radiographic data between the two cohorts (deformity progression versus stable) were analyzed to determine the variables associated with deformity progression.

Results

Patients in the deformity progression group (n = 13) tended to be younger (median 13.7 vs. 14.7 years) and experienced a significant change in height (p = 0.01) during the post-operative period compared to the stable group (n = 76). At 2-years post-op, the patients in the deformity progression group had experienced a significantly greater change in upper instrumented vertebra (UIV) angulation, lower instrumented vertebra (LIV) angulation, and apical vertebral translation (AVT). Two-year post-op Scoliosis Research Society questionnaire (SRS-22) scores in the appearance domain were also significantly worse in the deformity progression group. Patients in the deformity progression group had a significantly greater difference between the lowest instrumented vertebra and stable vertebra compared to patients in the stable group (p = 0.001).

Conclusions

Deformity progression after posterior spinal fusion does occur after modern segmental instrumentation. Segmental pedicle screw constructs do not prevent deformity progression. Skeletally immature patients with a significant growth potential are at the highest risk for deformity progression. In immature patients, extending the fusion distally to the stable vertebra may minimize deformity progression.

Level of evidence

Level III.     

单中心8818例脊柱畸形矫形术后深部感染的处理策略

目的探讨脊柱畸形矫形术后深部感染的发生率及其相应的处理策略。方法回顾性分析1998年1月至2017年12月接受脊柱畸形矫形术治疗8818例患者的病历资料,根据患者术后的临床症状、影像学检查及实验室检查判断是否发生深部感染。将初次手术后3个月之内发生的感染定义为早发性感染,初次手术3个月后发生的感染定义为迟发性感染。所有感染患者行清创灌洗、术后引流冲洗,并静脉应用敏感抗生素。若感染无法根除,如手术后时间不足2年,暂予伤口换药保留内固定;如手术后时间达到2年,评估融合情况满意后可在伤口清创的同时取出内固定。摄站立位全脊柱正、侧位X线片测量冠状面和矢状面参数,评估取出内固定者矫正丢失情况。结果共有60例(0.68%,60/8818)术后发生深部感染,早发性感染11例(发生率为0.12%,11/8818),迟发性感染49例(发生率为0.56%,49/8818)。两组患者在年龄、性别、手术入路及融合节段数方面的差异均无统计学意义。术后2~5年是深部感染发生的高峰期。特发性脊柱侧凸及强直性脊柱炎患者术后感染的发生率最低,综合征性及神经肌源性脊柱侧凸术后感染的发生率较高。初次培养阴性率较高,早发性感染中金黄色葡萄球菌和大肠埃希菌居多;迟发性感染中痤疮丙酸杆菌和凝固酶阴性葡萄球菌占比明显增高。经治疗后早发性感染组中9例保留内固定,2例换药至术后2年取出内固定。迟发性感染组中5例保留内固定,10例换药至术后2年取出内固定,34例手术时间超过2年直接取出内固定;其中1例患者取出内固定后1个月重新植入内固定;另有1例患者因矫正丢失在取出内固定3年后重新植入内固定。末次随访时取出内固定的患者出现了明显的冠状面矫正丢失。结论脊柱畸形矫形术后深部感染的发生率为0.68%,早发性感染发生率较低,迟发性感染较高;神经肌源性脊柱侧凸与综合征性脊柱侧凸患者有着较高的感染风险。如果感染在反复清创后无法根除,推荐在术后2年骨融合后取出内固定,但仍存在矫正丢失的风险。     

Short anterior instrumented fusion and posterior convex non-instrumented fusion of hemivertebra for congenital scoliosis in very young children

A variety of treatments has been described in the literature for the treatment of HV. We report the results of early surgical anterior instrumented fusion with partial preservation of the HV and posterior non-instrumented fusion in the treatment of progressive congenital scoliosis in children below the age of six. Between 1996 and 2006, 31 consecutive patients with 33 lateral HV and progressive scoliosis underwent short segment fusions. Mean age at surgery was 2 years and 10 months. Mean follow-up period was 6.1 years. The major scoliotic curve improved from 41° preoperatively to 17° on follow-up. Preoperative segmental Cobb angle averaging 39° was corrected to 15° after surgery, being 15° at the last follow-up (62% of improvement). Compensatory cranial and caudal curves corrected by 47 and 45%, respectively. The angle of segmental kyphosis averaged 16° before surgery, 11° after surgery, and 11° at follow-up. There were two wound infections requiring surgical debridment, one intraoperative fracture of the vertebral body and one case lost correction due to implant failure. All went on to stable bony union. There were no neurological complications. Early diagnosis and early and aggressive surgical treatment are mandatory for a successful treatment of congenital scoliosis and prevention of the development of secondary compensatory deformities. Anterior instrumentation is a safe and effective technique capable of transmitting a high amount of convex compression allowing short segment fusion, which is of great importance in the growing spine. Study conducted at the Great Ormond Street Hospital for Children and the Royal National Orthopaedic Hospital, Stanmore, London, UK.     

Analysis of instrumentation/fusion survivorship without reoperation after primary posterior multiple anchor instrumentation and arthrodesis for idiopathic scoliosis

BackgroundDuring the past 25 years, spinal instrumentation systems and surgical techniques used to treat idiopathic scoliosis have evolved, achieving fewer patient restrictions during arthrodesis healing, shorter constructs, and better correction. The purposes of this retrospective comparative study were to determine the survivorship of the implant/fusion without reoperation and the risk factors influencing such survival.MethodsFrom 1989 through 2002, 208 consecutive patients (index patient included, age 10–20 years) underwent primary posterior instrumentation and arthrodesis with the same multiple anchor implant system by one surgeon, a co-designer of the system. Two hundred seven were followed for more than 2 years; reoperation status was available for them at an average follow-up of 8.3 years. Twenty-one independent demographic, deformity, instrumentation, and process variables possibly influencing the need for reoperation were studied by comparing the reoperated group with the unreoperated group.ResultsNineteen patients (9.2%) had reoperation; 16 (7.7%) were for indications related to posterior spine instrumentation. Survival of the implant/fusion without reoperation for spine instrumentation–related indications was 96% (95% confidence interval [CI], 93.2–98.7%) at 5 years, 91.6% (95% CI, 86.9–96.3%) at 10 years, 87.1% (95% CI, 79.5–94.6%) at 15 years, and 73.7% (95% CI, 48.6–98.6%) at 16 years, when the number at risk was nine. Reoperation need was significantly influenced by two implant variables: transverse connector design (p=.0012) and the lower instrumented vertebra anchors used (p=.0004). At 9 years, the longest interval allowing comparison, survival of the implant/fusion without reoperation for these two variables was 100% (six subjects at risk) compared to 82% (95% CI, 74.2–90.3%) with 59 patients still at risk for reoperation for those who did not have them, p=.0014.ConclusionsThe most stable lower instrumented vertebra anchor configuration, bilateral pedicle screws, and the stronger transverse connector design, closed drop entry, provided the best survival of the implant/fusion without reoperation with this system and the techniques used at 9-year follow-up. We hope that this post-market study using survivorship techniques will be a guide for studies of other spinal implants.     

MW construct in fusion for neuromuscular scoliosis

A retrospective case control review was conducted to determine if the MW construct offers a superior means of correction of Cobb angles and pelvic obliquity in neuromuscular scoliosis. Posterior spinal fusion (PSF) in patients with neuromuscular scoliosis presents a surgical challenge. Particularly difficult is the correction of pelvic obliquity. Numerous instrumentation techniques have sought to address these difficulties. Most recently Arlet et al have introduced the MW construct. (in Eur Spine 8(3):229–231, 1999). They theorize that this construct may allow for superior spinopelvic fixation. Six patients with neuromuscular scoliosis who underwent PSF with the MW construct were compared with six subjects undergoing PSF utilizing the Galveston technique. Subjects were matched on the basis of preoperative Cobb angles and similar amounts of preoperative pelvic obliquity. Individuals who underwent PSF utilizing the MW construct obtained nearly 30% better correction of pelvic obliquity than did those who received a Galveston construct. A trend toward superior correction of Cobb angles with the MW construct was also observed. The MW construct may be a superior construct for curve correction in PSF for neuromuscular scoliosis, particularly those cases with excessive pelvic obliquity.     

Primary thoracoplasty and pedicle screw instrumentation in thoracic idiopathic scoliosis

Thoracoplasty in combination with spine fusion is an established method to address the rib cage deformity in idiopathic scoliosis. Most reports about thoracoplasty and scoliosis correction focused on Harrington or CD instrumentation. We report a retrospective analysis of 21 consecutive patients, who were treated with pedicle screw instrumentation for idiopathic thoracic scoliosis and concomitant thoracoplasty. Minimal follow up was 24 (24–75) months. Indication for thoracoplasty was clinical rib prominence of more than 15°. In average there was a 44% correction of clinical rib hump, from 18 (15–25°) to 10° (0–18°) (p<0.0001) and a 40% correction of radiological rib hump, from 15 (5–20°) to 9°(2–15°) (p<0.0001). The preoperative pulmonary function, accessed by forced vital capacity (FVC) and one-second forced expiratory volume (FEV1), remained unchanged at the last follow up. The distal end of fusion was the end vertebra of the curve in 83.3% and the end vertebra plus one in 16.7% of the patients. There was a 68% correction of instrumented primary thoracic curves, from 60 (45–85°) to 19°(5–36°) (p<0.0001), and a 45% correction of non-instrumented secondary lumbar curves, from 40 (28–60°) to 22°(8–38°) (p<0.0001). Apical vertebral rotation (AVR) of the thoracic curves improved 54%, from 24 (10–35°) to 11° (5–20°) (p<0.0001). The tilt of lowest instrumented vertebra (LIV) improved 68%, from 28 (20–42°) to 9°(3–20°) (p<0.0001). There was no significant change in sagittal profile of the spine. Analysis with SRS-24 questionnaire showed that the majority of the patients were very satisfied with the outcome. A matched control group (n=21) operated by the same surgeon with the same operation technique but without concomitant thoracoplasty was chosen for comparison. The scoliosis correction in the two groups was comparable. The patients without thoracoplasty had 37% spontaneous improvement of the clinical rib hump.     

The comparison of the results after spinal fusion with or without iliac screw insertion in the treatment of neuromuscular scoliosis

Introduction

Neuromuscular scoliosis leads to a wide range of spinal disorders which disturb the musculoskeletal system. The aim of this study is to compare the clinical and radiological results of posterior spinal fusion with and without extending the instrumentation to iliac bones in treatment of neuromuscular scoliosis.

Transpedicular hemiepiphysiodesis and posterior instrumentation as a treatment for congenital scoliosis

Anterior and posterior hemiepiphysiodesis using a transpedicular approach is an effective alternative treatment when compared with the traditional convex hemiepiphysiodesis or hemivertebrae excision. No study has reported the results of instrumentation with transpedicular hemiepiphysiodesis. Our study was a retrospective radiographic evaluation to assess the efficacy of transpedicular convex hemiepiphysiodesis with short segment instrumented posterior spinal fusion for congenital scoliosis. Ten hemivertebrae in 9 patients were evaluated. The average patient age was 10.5 years (range, 2.9-14.5 years). The average follow-up was 29.7 months. Cobb angles were recorded for the instrumented segment (segmental main curve) and the global or entire curve (total main curve). These values were compared preoperatively, postoperatively, and at 2-year follow-up. The average total main curve improved in 6 of 10 curves, from 35.0 to 29.6 degrees (15.4%). The average segmental main curve improved in 8 of 10 curves, from 30.0 to 21.5 degrees (28.3%). Seven of 10 curves demonstrated either no progression or improvement at the average 2-year follow-up. Two curves in older patients (greater than 9 years, 10 months) progressed until a comprehensive posterior spinal fusion was required. Multiple surgical techniques have been developed to provide treatment for progressive congenital scoliosis. Transpedicular hemiepiphysiodesis with a short segment instrumented posterior spinal fusion is a safe and effective treatment method to halt the progression of congenital scoliosis due to a hemivertebra in patients who are skeletally immature.