Rod fracture after long construct fusion for spinal deformity: clinical and radiographic risk factors

Background

No reports have been published on detailed risk factors for rod fracture after spinal deformity correction and fusion. The purpose of this study was to analyze clinical and radiographic risk factors of rod fracture after long construct fusion for spinal deformity.

Methods

The survey subjects were 155 cases who were diagnosed with spinal deformity and underwent correction and fusion surgery with long construct instrumentation (>3 levels, average 10.3 levels) between July 2004 and June 2010. The subjects comprised 32 males and 123 females with a mean age of 19.0 (range 8–78) years. The mean Cobb angle was 61.0 ± 16.1° preoperatively and 25.7 ± 16.9° postoperatively. Univariate analysis and logistic regression analysis were performed.

Results

Rod fracture occurred in 8 of 155 cases (5.2 %). The mean period from surgery to rod fracture was 18.1 months (range 2–37). The level of fracture ranged from the thoracolumbar junction to the lumbosacral vertebrae. Six patients had fracture near the fused lower end and two patients had fracture at the thoracolumbar junction. Univariate analysis revealed that non-ambulatory status, preoperative kyphosis, small-diameter rods, multiple surgery, and use of iliac screws were significant risk factors for rod fracture. Sex, obesity, severity of preoperative scoliosis, and rod material were not significant risk factors. Logistic regression analysis revealed that use of iliac screws (odds ratio: 81.9, 95 % confidence interval: 7.2–935.0, p < 0.001) and small-diameter (<6 mm) rods (odds ratio: 16.3, 95 % confidence interval: 1.7–152.6, p = 0.015) were risk factors for rod fracture.

Conclusions

The incidence of rod fracture after long construct fusion for spinal deformity was 5.2 %. Iliac screw fixation and small-diameter rods were risk factors for rod fracture.     

Posterior short-segment instrumentation and limited segmental decompression supplemented with vertebroplasty with calcium sulphate and intermediate screws for thoracolumbar burst fractures

Purpose

Thoracolumbar burst fractures treated with short-segment posterior instrumentation without anterior column support is associated with a high incidence of implant failure and correction loss. This study was designed to evaluate the clinical and radiographic results following posterior short-segment instrumentation and limited segmental decompression supplemented with vertebroplasty with calcium sulphate and intermediate screws for patients with severe thoracolumbar burst fractures.

Methods

Twenty-eight patients with thoracolumbar burst fractures of LSC point 7 or more underwent this procedure. The average follow-up was 27.5 months. Demographic data, radiographic parameters, neurologic function, clinical outcomes and treatment-related complications were prospectively evaluated.

Results

Loss of vertebral body height and segmental kyphosis was 55.3 % and 20.2° before surgery, which significantly improved to 12.2 % and 5.4° at the final follow-up, respectively. Loss of kyphosis correction was 2.2°. The preoperative canal encroachment was 49 % that significantly improved to 8.8 %. The preoperative pain and function level showed a mean VAS score of 9.2 and ODI of 89.9 % that improved to 1.4 and 12.9 % at the final follow-up, respectively. No implant failure was observed in this series, and cement leakage occurred in two cases without clinical implications.

Conclusions

Excellent reduction and maintenance of thoracolumbar burst fractures can be achieved with short-segment pedicle instrumentation supplemented with anterior column reconstruction and intermediate screws. The resultant circumferential stabilization combined with a limited segmental decompression resulted in improved neurologic function and satisfactory clinical outcomes, with a low incidence of implant failure and progressive deformity.     

One-stage anterior debridement,bone grafting and posterior instrumentation vs. single posterior debridement,bone grafting,and instrumentation for the treatment of thoracic and lumbar spinal tuberculosis

Purpose

The aim of this study was to compare single posterior debridement, interbody fusion and instrumentation with one-stage anterior debridement, interbody fusion and posterior instrumentation for treating thoracic and lumbar spinal tuberculosis.

Method

From January 2006 to January 2010, we enrolled 115 spinal tuberculosis patients with obvious surgical indications. Overall, 55 patients had vertebral body destruction, accompanied by a flow injection abscess or a unilateral abscess volume greater than 500 ml. The patients underwent one-staged anterior debridement, bone grafting and posterior instrumentation (group A) or single posterior debridement, bone grafting and instrumentation (group B). Clinical and radiographic results for the two groups were analyzed and compared.

Results

Patients were followed 12–36 months (mean 21.3 months), Fusion occurred at 4–12 months (mean 7.8 months). There were significant differences between groups regarding the post-operative kyphosis angle, angle correction and angle correction rate, especially if pathology is present in thoracolumbar and lumbar regions. Operative complications affected five patients in group A, and one patient in group B. A unilateral psoas abscess was observed in three patients 12 months postoperatively. In one of them, interbody fusion did not occur, and there was fixation loosening and interbody absorption. All of them were cured by an anterior operation.

Conclusion

Anterior debridement and bone grafting with posterior instrumentation may not be the best choice for treating patients with spinal tuberculosis. Single posterior debridement/bone grafting/instrumentation for single-segment of thoracic or lumbar spine tuberculosis produced good clinical results, except in patients who had a psoas abscess.     

Indication for preoperative MRI of neural axis abnormalities in patients with presumed thoracolumbar/lumbar idiopathic scoliosis

Purpose

The purpose of this study was to investigate the incidence of neural axis abnormalities in patients with presumed “idiopathic” thoracolumbar or lumbar scoliosis by magnetic resonance imaging (MRI) and try to determine which clinical and radiographic characteristics correlate with neural axis abnormalities on MRI in these patients.

Methods

The database of a single spinal deformity center was retrospectively reviewed to identify all patients with a primary diagnosis of idiopathic scoliosis (IS) between January 2003 and August 2011. A total of 446 patients with main thoracolumbar or lumbar curves were identified. Radiographic parameters including main curve Cobb angles, location of curve apex, span of main curve, thoracic kyphosis (T5–T12), thoracolumbar junction kyphosis (T10–L2), lumbar lordosis (L1–S1), and sagittal and coronal balance were measured.

Results

Neural axis abnormalities were detected in 35 (7.8 %) patients. For patients with neural axis abnormalities, a higher proportion of male gender and long thoracolumbar curves were presented. In these patients, the mean age was smaller and the mean Cobb angle of main curve was larger. Greater thoracic kyphosis (≥30°) was more frequently found in those with neural axis abnormalities. The incidences of thoracolumbar junction hyperkyphosis were similar between two groups (P > 0.05). There was no difference between two groups as to lumbar lordosis and coronal and sagittal balance.

Conclusion

We recommend the routine use of MRI in the patients with one or more of the following characteristics: right curves, long curve span, apex at thoracolumbar spine and hyperthoracic kyphosis.     

Two-level pedicle subtraction osteotomy for severe thoracolumbar kyphotic deformity in ankylosing spondylitis

Study design

A retrospective clinical study.

Objective

To evaluate the outcomes of two-level (T12 and L3) pedicle subtraction osteotomy (PSO) for severe thoracolumbar kyphosis in ankylosing spondylitis (AS), and to discuss the surgical strategies of this surgery.

Background

Cases were limited on the results of two-level PSO for correction of severe kyphosis caused by AS, nor on surgical strategies of this type of surgery.

Methods

From March 2006 to December 2010, nine consecutive AS patients with severe kyphotic deformity, underwent T12 and L3 PSOs. Chin-brow vertical angle (CBVA) and radiographic assessments which contain thoracic kyphosis (TK), lumbar lordosis (LL), global kyphosis (GK), and sagittal vertical axis were carefully recorded pre and postoperatively to evaluate the sagittal balance. Intra and postoperative complications were also registered. All patients were asked to fill out Oswestry Disability Index before surgery and at the last follow-up visit.

Results

All nine patients (8M/1F), averaged 41.4 years old (range 35–51 years), were received two-level (T12 and L3) PSO, and were followed up after surgery for a mean of 39.9 months (range 24–68 months). Good cosmetic results were achieved in all patients. Mean correction at two-level PSO was 67.9 ± 5.5°. All CBVA, TK, LL, and GK were changed significantly after surgery (P < 0.05), the mean amount of correction of which were 59.5 ± 13.8, 34.7 ± 3.8, 33.2 ± 2.4, and 54.0 ± 14.8 degrees, respectively, and with a small loss of correction at the last follow-up visit. Sagittal imbalance was significantly improved from 27.3 ± 4.4 to 3.4 ± 0.7 cm postoperatively. Neither mortalities nor any major neurological complications were found. The mean ODI score was significantly improved from 53.4 ± 15.5 before surgery to 8.2 ± 4.7 at the last visit.

Conclusion

The outcomes of follow-up showed that two-level (T12 and L3) PSO can effectively and safely correct severe thoracolumbar kyphosis in AS.     

Thoracolumbar spinal tuberculosis with psoas abscesses treated by one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage

Purpose

Retrospective analysis of the clinical efficacy and feasibility of patients with thoracolumbar spinal tuberculosis with psoas abscesses treated by one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage.

Method

A total of 18 patients with thoracolumbar tuberculosis (TB), between February 2007 and February 2011, underwent one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage. And the clinical efficacy was evaluated based on surgery duration time, the blood loss, the postural drainage of time, neurological status that was recorded by American Spinal Injury Association (ASIA) Impairment Scale, the fate of bone graft fusion, kyphosis angle, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP), which were collected at certain time.

Results

The average follow-up period was 34 months (range 18–48 months). 18 patients suffered from seriously neurological deficits pre-operatively, of which 16 patients returned to normal at final follow-up. The surgery duration time was 197 ± 37.9 min, and the blood loss was 815 ± 348.5 ml. The postural drainage of time was 7.2 ± 2.7 days. The psoas abscesses disappeared in all cases, within the time range of 6–9 months (mean 7.4 ± 1.2 months). All patients of the grafted bones were thoroughly fused, with a fusion time ranging from 4 to 12 months (mean 7.8 months). Kyphosis angle was 44.32 ± 7.26° on average pre-operative and returned to 11.72 ± 2.85° at 6 weeks after operation; kyphosis angle was 13.10 ± 2.39° at final follow-up. The values of ESR and CRP were significant declined at 6 weeks post-operative, and returned to normal levels at final follow-up.

Conclusion

With standardized anti-TB chemotherapy, thoracolumbar spinal tuberculosis with psoas abscesses could be effectively treated by one-stage posterior transforaminal lumbar debridement, interbody fusion, posterior instrumentation, and postural drainage.     

Thoracoscopic interbody fusion with percutaneous posterior stabilization for thoracic and thoracolumbar injuries

Background context

Traumatic thoracolumbar discoligamentous injuries and partial burst fractures are commonly managed through posterior-only stabilization. Many cases present later with failure of posterior implant and progressive kyphotic deformities that necessitates major surgeries. Anterior interbody fusion saves the patients unnecessary long-segment fixation and provides a stable definitive solution for the injured segment.

Purpose

The purpose of this study is to assess the clinical and radiographic outcomes of combined minimal invasive short-segment posterior percutaneous instrumentation and anterior thoracoscopic-assisted fusion in thoracolumbar partial burst fractures or discoligamentous injuries.

Study design

Prospective observational study.

Patient sample

Thirty patients with acute thoracic or thoracolumbar injuries operated upon between December 2007 and January 2009.

Outcome measures

Oswestry Disability Index (ODI), clinical and neurological examination for clinical assessment. Plain X-ray for radiological evaluation.

Methods

Preoperative evaluation included clinical and neurological examination, plain X-rays, computed tomography (CT), and magnetic resonance imaging (MRI). Posterior short-segment percutaneous stabilization plus anterior thoracoscopically assisted fusion in prone position were done. The minimum follow-up period was 2 years (range 24–48 months).

Results

The mean age was 44 years. The commonest affected segment was between T10 and L1 (22 patients, 73 %). The mean total operative time was 103 min. The mean operative blood loss was 444 ml. Interbody fusion cage was used in 28 patients while iliac graft in two cases. Fusion rate at the final follow-up was 97 % (29 patients); one patient did not show definitive fusion although he was clinically satisfied. The mean final follow-up ODI was 12 %. The mean preoperative kyphosis angle was 22° improved to 6.5° postoperatively and was 7.5° at final follow-up. There were no major intraoperative or postoperative complications.

Conclusion

Combined anterior thoracoscopic fusion and short-segment posterior percutaneous instrumentation showed good clinical and radiographic outcomes in cases of thoracolumbar injuries through limiting the instrumented levels and preventing progress of posttraumatic kyphosis.     

Preoperative halo-gravity traction with and without thoracoscopic anterior release for skeletal dysplasia patients with severe kyphoscoliosis

Purpose

Recent work has shown the safety and efficacy of halo-gravity traction as an operative adjunct. However, there are no reports specifically looking at halo-gravity traction in patients with skeletal dysplasia. Our purpose was to assess the safety and efficacy of traction in children with skeletal dysplasia who present with severe kyphoscoliosis.

Methods

We retrospectively reviewed eight consecutive children with skeletal dysplasia who were treated with halo-gravity traction preoperatively. Six of the patients had a thoracoscopic anterior release prior to the halo-gravity traction. All patients were ambulatory and presented with severe, rigid kyphoscoliosis.

Results

The mean duration of traction was 32 days. There were no neurologic complications with traction or after posterior spinal instrumentation. The majority of kyphoscoliosis correction was with the halo-gravity traction alone: major curve (MC) Cobb angle improved 41 %; C7–center sacral vertical line, 75 %; C7–MC apex, 21 %; and T2–T12 kyphosis, 35 %. Trunk height increased 37 % and thoracic height 44 %. An additional amount of correction was obtained with posterior spinal instrumentation (±fusion), decreasing MC Cobb angle an additional 23 %; C7–apex, 16 %; and T2–T12 kyphosis, 10 %. There was no additional correction of thoracic height. Two years after posterior spinal instrumentation (±fusion), a mild-to-moderate amount of correction was lost: MC Cobb angle decreased 23 %; compensatory Cobb angle, 28 %; C7–CSVL, 24 %; C7–S1, 22 %; regional kyphosis, 31 %; thoracic kyphosis, 29 %; and trunk height, 27 %.

Conclusions

Among children with skeletal dysplasia and severe kyphosis, halo-gravity traction is well tolerated and safe. Most of the corrections in radiographic parameters were achieved with traction alone. Traction improves coronal balance, apical translation, thoracic height, and kyphosis. In this specific population, the potential for neurologic injury during corrective surgery is high. However, preoperative halo-gravity traction provides slow, progressive correction in a safe manner and avoided neurologic injury in these patients. This study did not compare patients without halo-gravity traction to patients with halo-gravity traction, therefore it cannot be concluded that going straight to instrumentation without traction will give a poorer radiographic result.

Level of evidence

IV.

     

The results of closing wedge osteotomy with posterior instrumented fusion for the surgical treatment of congenital kyphosis

Purpose

There exist not much data regarding the surgical treatment of pure congenital kyphosis (CK) in the literature. The purpose of this study was to evaluate the results of closing wedge osteotomy with posterior instrumented fusion in patients with congenital kyphotic deformity.

Methods

We retrospectively evaluated the radiographical results of 10 patients who were subject to closing wedge vertebral osteotomy and posterior instrumented fusion due to CK. The mean age of the patients at surgery was 12.6 ± 3.72 years (range 8–18 years). Radiographical measurements including local kyphosis, correction loss, global kyphosis and sagittal balance values were noted for the preoperative, postoperative and final follow up periods, respectively. The data obtained from those periods underwent statistical analysis.

Results

Average follow-up period was 51.8 ± 29.32 months (range 26–96 months). The mean local kyphosis angle was 67.7° ± 15.64° (range 42°–88°) prior to the surgery, 31.5° ± 17.12 (range 14°–73°) following the surgery and 31.9° ± 15.98° (range 14°–71°) during the follow up-period, respectively (p < 0.05). A correction rate of 53.5 % was reported at the final follow up. Average sagittal balance was measured as 33.1 ± 24.48 mm (range 2–77 mm) prior to the surgery, 20.8 ± 15.46 mm (range 5–46 mm) following the surgery (p < 0.05) and 14.1 ± 9.2 mm (range 0–30 mm) during follow-up period (p > 0.05). Complications consisted of a rod fracture due to pseudoarthrosis, an implant failure with loosening of screws and a proximal junctional kyphosis. No neurological deficit or deep infection were encountered in any of the patients in the study group.

Conclusion

Closing wedge osteotomy with posterior instrumented fusion is an efficient method of surgical treatment in terms of sagittal balance restoration and deformity correction in patients with congenital kyphosis.     

Reciprocal changes in cervical spine alignment after corrective thoracolumbar deformity surgery

Purpose

To identify changes in cervical alignment parameters following surgical correction of thoracolumbar deformity and then assess the preoperative parameters which induce changes in cervical alignment following corrective thoracolumbar deformity surgery.

Methods

A retrospective study of 49 patients treated for thoracolumbar deformity with preoperative planning of an acceptably aligned coronal and sagittal plane in each case. We compared cervical spine parameters in two distinct low [preoperative C7 sagittal vertical axis (SVA) ≤6 cm] and high (preoperative C7 SVA ≥9 cm) C7 SVA groups. Multilinear regression analysis was performed and revealed the relationship between postoperative cervical lordosis and preoperative spinopelvic parameters and surgical plans.

Results

In the lower C7 SVA group, cervical lordosis was significantly increased after thoracic/lumbar deformity correction (p < 0.01). In contrast, the high C7 SVA group showed decreased cervical lordosis postoperatively (p < 0.01). Multilinear regression analysis demonstrated the preoperative parameters (preoperative C2–7 angle, T1 slope, surgical plan for PT and C7 SVA), which determine the postoperative cervical lordosis.

Conclusion

In spinal deformity procedures, preoperative spinal alignment parameters, and surgical plans could affect postoperative cervical spine alignment.     

Extreme Lateral Interbody Fusion (XLIF) in the Thoracic and Thoracolumbar Spine: Technical Report and Early Outcomes

Background

Previous studies have demonstrated the distinct advantages of thoracoscopically assisted spinal fusion compared to traditional open thoracotomy. However, these techniques are limited by a steep learning curve, prolonged operative time, and lack of three-dimensional visualization of the surgical field.

Objective

The objective of this study was to describe our initial experience with an adaptation of the extreme lateral interbody fusion (XLIF) technique allowing access to the anterior aspect of the thoracic and thoracolumbar spine with specific reference to (1) early pulmonary complications, (2) non-pulmonary complications, and (3) ability of this technique to successfully achieve spinal decompression and fusion at the operative level.

Methods

Clinical and radiographic data were reviewed for the entire perioperative period. A total of 18 patients (72% females; mean age, 56.8 years) underwent a thoracic XLIF procedure for spinal pathologies including disc herniation, fracture, tumor, pseudoarthrosis, and proximal junctional kyphosis. A total of 32 levels were treated, with the majority located at the thoracolumbar junction. Twelve of the procedures were done as part of a combined anterior/posterior surgery.

Results

The mean estimated blood loss was 577 ml and the mean length of stay was 12 days. At a mean follow-up of 14 months, all patients except for one (who died of widely metastatic disease) had achieved radiographic evidence of fusion. Two patients developed pulmonary effusions requiring medical intervention. Six patients had seven non-pulmonary complications: incidental durotomy (two), infection (one), instrumentation pullout (one), cardiac arrhythmia (two), and death from metastatic disease (one).

Conclusions

The XLIF technique can be utilized for access to the anterior column of the thoracic and thoracolumbar spine. The advantages of this minimally invasive technique include avoidance of the need for an access surgeon and for lung deflation during surgery as well as excellent visualization of the spinal pathology.     

Posterior vertebral column resection in early onset spinal deformities

Purpose

Early onset spinal deformities (EOSD) can be life-threatening in very young children. In the growing spine, surgical intervention is often unavoidable and should be carried out as soon as possible. A deformed section of the spine not only affects the development of the remaining healthy spine, but also that of the chest wall (which influences pulmonary function), the extremities and body balance. Posterior vertebral column resection (PVCR) represents an effective surgical solution to address such problems. However, reports in the literature concerning PVCR are mostly limited to its use in adolescents or adults. The purpose of this study was to illustrate our experience with PVCR in EOSD and to describe the surgical technique with respect to the unique anatomy of young children.

Materials and methods

Four children [mean age 3.7 (range 2.5–5.2) years] with severe spinal deformity underwent PVCR through a single approach. Multimodal intraoperative monitoring was used in all cases. Surgery included one stage posterior circumferential resection of one vertebral body along with the adjoining intervertebral discs and removal of all posterior elements. A transpedicular screw-rod system was used for correction and stabilisation. Fusion was strictly limited to the resection site, allowing for later conversion into a growing rod construct at the remaining spine, if necessary. Relevant data were extracted retrospectively from patient charts and long spine radiographs.

Results

The mean operation time was 500 (range 463–541) min, with an estimated blood loss of 762 (range 600–1,050) ml. Mean follow-up time was 6.3 (range 3.5–12.4) years. After PVCR, the mean Cobb angle for scoliosis was reduced from 69° (range 50–99°) to 29° (5–44°) and the sagittal curvature (kyphosis) from 126° (87–151°) to 61° (47–75°). The mean correction of scoliosis was 57 % (18–92°) and of kyphosis, 51 % (44–62°). There were no spinal cord-related complications. In three patients, spinal instrumentation for growth guidance (fusion less growing rod technique) was applied. Two patients had complications: one patient had a complication of anesthesia, halo pin failure, and revision surgery with extension of the instrumentation cranially due to loss of correction; the second patient had a postoperative infection, which required plastic reconstructive measures.

Conclusion

PVCR appears to be an effective technique to treat severe EOSD. There are important differences in its use in young children when compared with older patients. In patients with EOSD, additional surgical procedures are often necessary during growth, and hence non-fusion instrumentation beyond the vertebral resection site is advantageous, as it permits spinal growth and the later addition of fusion.     

Adolescent idiopathic scoliosis treated with posteromedial translation: radiologic evaluation with a 3D low-dose system

Purpose

Computed tomography can be used for three-dimensional (3D) evaluation of adolescent idiopathic scoliosis (AIS) patients, but at the expense of high radiation exposure, and with the limitation of being performed in the supine position. These drawbacks can now be avoided with low-dose stereoradiography, even in routine clinical use. The purpose of this study was to determine the 3D postoperative correction of AIS patients treated by posteromedial translation.

Methods

Forty-nine consecutive patients operated for AIS (Lenke 1–4) using posteromedial translation were included. Corrections were evaluated preoperatively, postoperatively and after at least 2 years using the EOS imaging system. 3D angles were measured in the plane of maximum deformity.

Results

Mean number of levels fused and operative time were 13.5 ± 1 and 215 ± 25 min, respectively. Main thoracic, proximal thoracic, and lumbar curves corrections averaged 64.4 ± 18, 31 ± 10 and 69 ± 20 %, respectively. Mean T4–T12 kyphosis increased 18.8° ± 9° in the subgroup of hypokyphotic patients. Mean apical vertebral rotation reduction was 48.3 ± 20 %. Trunk height gain averaged 27.8 ± 14 mm. There was no pseudarthrosis or significant loss of correction in any plane during follow-up. Two patients (4 %) developed asymptomatic proximal junctional kyphosis, despite having normal thoracic kyphosis. Their sagittal balance was shifted posteriorly by 36 and 47 mm, respectively, by the operation, but revision surgery was not performed.

Conclusions

Low-dose stereoradiography provided 3D reconstructions of the fused and unfused spine in routine clinical use. Postoperative 3D analysis showed that posteromedial translation enhanced sagittal balance correction, without sacrificing frontal or axial correction of the deformity.     

Non-fusion and growing instrumentation in the correction of congenital spinal deformity associated with split spinal cord malformation: an early follow-up outcome

Study design

A retrospective case review.

Introduction

To evaluate the safety and efficacy of the non-fusion technique in achieving and maintaining the proper correction for congenital spinal deformity (CSD) and allowing normal spinal growth in patients with split spinal cord malformation (SSCM).

Materials and methods

Seven patients who had CSD and SSCM were adopted, with a mean age of 8 years. All the patients in this study received Halo-gravity traction (HGT) prior to expansion of the spine and instrumentation with vertical expandable titanium prosthetic rib, growing rod or their hybrid. Five of them underwent opening wedge thoracoplasty simultaneously. And the two patients with type I SSCM underwent bony spur excision in the initial surgery before corrective manipulation. Then all the patients received a lengthened operation every six months. Changes of their major curve and length of T1–S1 spine were measured, and complications, neurological status were recorded. All the patients were followed up with an average of 32.6 months.

Results

Their mean major curve improved from 90.1° to 58.6° with a correction rate of 34.9 %. The T1–S1 length increased from 26.3 to 34.7 cm at final follow-up. Especially, one of the type I SSCM patients whose neurological deterioration was found preoperatively was significantly improved.

Conclusion

Preoperative Halo-gravity traction followed by non-fusion and growing instrumentation may be effective and safe for young children of CSD associated with SSCM. But it is an ongoing study and additional large multicenter studies are necessary to further assess the safety and efficacy of non-fusion and growing instrumentation.     

Proximal junctional kyphosis following adult spinal deformity surgery

Purpose

Proximal junctional kyphosis (PJK) is a common radiographic finding following long spinal fusions. Whether PJK leads to negative clinical outcome is currently debatable. A systematic review was performed to assess the prevalence, risk factors, and treatments of PJK.

Methods

Literature search was conducted on PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials using the terms ‘proximal junctional kyphosis’ and ‘proximal junctional failure’. Excluding reviews, commentaries, and case reports, we analyzed 33 studies that reported the prevalence rate, risk factors, and discussions on PJK following spinal deformity surgery.

Results

The prevalence rates varied widely from 6 to 61.7 %. Numerous studies reported that clinical outcomes for patients with PJK were not significantly different from those without, except in one recent study in which adult patients with PJK experienced more pain. Risk factors for PJK included age at operation, low bone mineral density, shorter fusion constructs, upper instrumented vertebrae below L2, and inadequate restoration of global sagittal balance.

Conclusions

Prevalence of PJK following long spinal fusion for adult spinal deformity was high but not clinically significant. Careful and detailed preoperative planning and surgical execution may reduce PJK in adult spinal deformity patients.     

Posterior instrumentation, anterior column reconstruction with single posterior approach for treatment of pyogenic osteomyelitis of thoracic and lumbar spine

Purpose

Surgical treatment of thoracolumbar osteomyelitis consists of radical debridement, reconstruction of anterior column either with or without posterior stabilization. The objective of present study is to evaluate a case series of patients with osteomyelitis of thoracic and lumbar spine treated by single, posterior approach with posterior instrumentation and anterior column reconstruction.

Methods

Seventeen patients underwent clinical and radiological evaluation pre and postoperatively with latest follow-up at 19 months (8–56 months) after surgery. Parameters assessed were site of infection, causative organism, angle of deformity, blood loss, duration of surgery, ICU stay, deformity correction, time to solid bony fusion, ambulatory status, neurologic status (ASIA impairment scale), and functional outcome (Kirkaldy-Willis criteria).

Results

Mean operating time was 207 min and average blood loss 1,150 ml. Patients spent 2 (1–4) days in ICU and were able to walk unaided 1.6 (1–2) days after surgery. Infection receded in all 17 patients postoperatively. Solid bony fusion occurred in 15 out of 17 patients (88 %) on average 6.3 months after surgery. Functional outcome was assessed as excellent or good in 82 % of cases. Average deformity correction was 8 (1–18) degrees, with loss of correction of 4 (0–19) degrees at final follow-up.

Conclusions

Single, posterior approach addressing both columns poses safe alternative in treatment of pyogenic vertebral osteomyelitis of thoracic and lumbar spine. It proved to be less invasive resulting in faster postoperative recovery.     

Reversing the concept: correction of adolescent idiopathic scoliosis using the convex rod de-rotation maneuver

Purpose

To show the radiological results of adolescent idiopathic scoliosis (AIS) patients treated with posterior fusion using all-pedicle-screw construct with correction carried out using a convex rod reduction technique.

Methods

Between October 2004 and June 2007, 42 AIS patients were treated with posterior fusion using all-pedicle-screw construct with correction done through the convex side. Two patients were lost to follow-up and were not included in the study. Forty patients had a minimum follow-up of 2 years. Patients were evaluated for the deformity correction in coronal and sagittal planes and for spinal balance.

Results

The mean preoperative Cobb angle of the major curve and secondary minor curves was 60° and 41°, respectively. Immediate postoperative mean Cobb angle of the major curve and secondary minor curves was 17° and 13°, respectively. Postoperative 2-year average major curve loss of correction was 7 %. Postoperative 2-year average minor curve loss of correction was 5 %. Preoperative thoracic kyphosis of 28° was changed to 22° in 2-years follow-up. The loss of thoracic kyphosis was most noted in hyperkyphotic patients.

Conclusions

The correction of AIS by convex-sided pedicular screws yields a coronal correction comparable to what is described in the literature for segmental concave-sided screws.     

The use of posterior vertebral column resection in the management of severe posttuberculous kyphosis: a retrospective study and literature review

Purpose

We present a retrospective study of 15 cases with severe posttuberculous kyphosis of thoracolumbar region that underwent posterior vertebral column resection.

Methods

From 2004 to 2009, 15 consecutive patients with posttubercular kyphotic deformity underwent posterior vertebral resection osteotomy. Six subjects were females and nine were males with an average age of 35.8 years (range 20–60 years) at the time of surgery. None of the patients had neurological deficits. The mean preoperative visual analogue scale was 8.7 (range 3–9), and the average preoperative Oswestry Disability Index was 46.5 (range 40–56).

Results

The average duration of postoperative follow-up was 36.1 ± 10.7 months (range 24–62 months). The number of vertebra resected was 1.3 (range 1–2) on average. There were ten patients with one-level osteotomy and five patients with two-level osteotomy. The average operation time was 446.0 ± 92.5 min (range 300–640 min) with an average blood loss of 1,653.3 ± 777.9 ml (range 800–3000 ml). The focal kyphosis before surgery averaged 92.3 ± 8.9° (range 74–105°), and the kyphotic angle decreased to 34.5 ± 8.7° on average after the surgical correction. The average kyphotic angle at the last follow-up was 36.9 ± 8.5°, loss of correction was 2.4 ± 1.4° on average. All patients postoperatively received bony fusion within 6–9 months.

Conclusions

Our results showed that although posterior vertebral resection is a highly technical procedure, it can be used safely and effectively in the management of severe posttuberculous kyphosis. It is imperative that operations be performed by an experienced surgical team to prevent operation-related complications.     

Surgical treatment of thoracic spinal tuberculosis with adjacent segments lesion via one-stage transpedicular debridement, posterior instrumentation and combined interbody and posterior fusion, a clinical study

Purpose

To investigate the clinical efficacy and feasibility of one-stage surgical treatment for thoracic spinal tuberculosis with adjacent segments lesion by internal fixation, transpedicular debridement, and combined interbody and posterior fusion via a posterior-only approach.

Materials and methods

Twenty-one patients (thirteen males, eight females) with thoracic tuberculosis whose lesions were confined to two adjacent segments were studied retrospectively. All patients were treated with one-stage surgical treatment by internal fixation, transpedicular debridement, and combined interbody and posterior fusion via a posterior-only approach. The American Spinal Injury Association (ASIA) impairment scale was used to assess neurological function. Thoracic Cobb angle was used to assess thoracic kyphosis. Operating time, blood loss, complications, neurological function, deformity correction and interbody fusion were investigated.

Results

Average mean operating time was 231.4 ± 31.9 min, and evaluated blood loss during operation was 880.2 ± 112.7 ml. All patients were followed up for 22–41 months postoperatively (average 29.8 ± 5.4 months). All patients had significant postoperative improvement in ASIA classification scores. The thoracic kyphotic angles were significantly decreased to 9°–25° postoperatively (average 16.7° ± 4.4°), and at final follow-up were 10°–27°(average 17.7° ± 4.4°). No severe complications or spinal cord injury occurred. The erythrocyte sedimentation rate recovered to normal within 3 months postoperatively in all patients. All patients got bony fusion within 6–9 months after surgery.

Conclusions

One-stage transpedicular debridement, posterior instrumentation and combined interbody and posterior fusion via a posterior-only approach can be an effective and feasible treatment method for thoracic spinal tuberculosis.