Cervicothoracic Kyphosis Research Articles

Surgical Treatment of Lower Cervical TuberculosisWith Kyphosis Deformity

The objective of this paper was to investigate the outcome of the patients with lower cervical tuberculosis with kyphosis deformity who underwent 1-stage anterior debridement, autograft fusion combined anterior or posterior fixation. From January 2007 to December 2012, 10 cases were enrolled in this retrospective study. There were 7 patients with cervical deformity and 3 with cervicothoracic kyphosis. Seven patients underwent anterior debridement and reconstruction, using iliac crest or cage with autograft, while 3 patients with cervicothoracic kyphosis received single-stage kyphosis correction and posterior fixation combined anterior debridement and autograft fusion. Neurologic function of all the patients was evaluated by JOA score and visual analogue scale (VAS) score. Patients were followed up for 26 months on average. The mean preoperative focal kyphotic angle was 49.1° (range, 25–90°), reducing to −4.9° (range, −15 to 13°) postoperatively at the last follow-up visit. Neurologic assessment of all the patients using the JOA and VAS score was improved significantly after surgery. All patients had solid fusion and no major complications were observed in the follow-up. One-stage anterior debridement, autograft fusion combined anterior or posterior fixation was demonstrated to be a safe and effective method to achieve spinal decompression and kyphosis correction in patients with lower cervical tuberculosis.

Surgical strategies for cervical spine fracture combined with ankylosing spondylitis and cervicothoracic junction kyphosis

Objective To discuss the operative strategies for cervical spine fracture combined with ankylosing spondylitis and the deformity of cervicothoracic kyphosis. Methods Retrospectively analyzed 21 cases of cervical spine fracture combined with ankylosing spondylitis and the deformity of cervicothoracic kyphosis, who underwent surgeries from January, 2007 to August, 2014. Twenty males and 1 female were included. Mean age was (48.6±7.5) years (range, 36-65 years). The preoperative American Spine Injury Association (ASIA) classification distribution: 2 cases of Grade A, 6 cases of Grade B, 7 cases of Grade C, 5 cases of Grade D, and 1 case of of Grade E. The investigative surgical methods including posterior cervical open reduction, internal fixation and bone graft fusion; posterior cervical open reduction/decompression, internal fixation and bone graft fusion; or combined posterior and anterior cervical decompression, bone graft fusion and instrumentation. The operative time and blood loss were recorded, the clinical therapeutic effect was evaluated by visual analogue scale (VAS) score, ASIA grade improvement, cervical curvature (the angle between a line drawn parallel to the inferior endplate of C2 and a line drawn parallel to the inferior endplate of C7 in the lateral plane of an X-ray image) and radiological assessment (including bone graft fusion condition and internal fixation position). Results One case died from severe pulmonary infection and respiratory failure at the 45th day after operation. All the other 20 patients obtained complete follow-up with a mean time of (39.4±8.76) months (range, 25-59 months). 7 cases received posterior cervical open reduction, internal fixation and bone graft fusion, average operative time was (92.1±5.4) minutes and average blood loss was (96.1+23.7) ml. 9 cases received the posterior cervical open reduction and decompression, internal fixation and bone graft fusion, mean operation time was (121.4±14.0) minutes and blood loss was (250.0±38.9) ml. 3 cases experienced combined posterior and anterior cervical decompression, bone graft fusion and fixation, average operative time was (222.4±14.9) minutes and average blood loss was (354.3+46.7) ml. Mean of VAS scores at the 3th month postoperatively was 2.76±0.46, significantly lower than the preoperatively VAS scores (8.95±0.36). Mean of VAS scores at the 24th month postoperatively was 1.77±0.39, significantly lower than those at the 3th month postoperatively. The neurological function of spinal cord achieved significant improvement after operations and continued recovered gradually in the subsequent follow up. ASIA Classification distribution at the 24th month postoperatively was: 0 case of Grade A, 0 case of Grade B, 3 cases of Grade C, 8 cases of Grade D, 9 case of Grade E. Mean of the cervical curvature after operation was -7.1°±1.9°, significantly higher than preoperatively(-13.4°±3.3°) and did not have any loss of Cobb's angles at 24th month after operation. All the surviving cases achieved solid bone graft fusion. Mean bone graft fusion time was 5.8 months (range, 4-9 months). There was no internal fixation loose, fracture and dislocation occurred during follow up. Conclusion All procedures can significantly relieve the painful symptoms, effectively restore the normal cervical alignment and stability, and remarkably improve the neural function of the patients suffering cervical spine fracture combined with ankylosing spondylitis and the deformity of cervicothoracic junction kyphosis. Key words: Spondylitis, ankylosing; Cervical vertebrae; Spinal fractures; Thoracic vertebrae; Kyphosis

Variations in Occipitocervical and Cervicothoracic Alignment Parameters Based on Age: A Prospective Study of Asymptomatic Volunteers Using Full-Body Radiographs.

Cross-Sectional Cohort Study OBJECTIVE.: To describe age-stratified normative values of novel occipitocervical, cervical, and cervicothoracic alignment parameters. Full-body radiographic images obtained without stitching or vertical distortion represent an ideal method to evaluate occipitocervical alignment and horizontal gaze. One hundred twenty adults with no back or neck symptoms were recruited. Age, sex, body mass index, Neck Disability Index (NDI), and Oswestry Disability Index scores were recorded. Radiographic parameters measured included: center sacral vertebral line, chin brow vertical angle (CBVA), orbital tilt (OrT), orbital slope, occipital slope (OS), occipital incidence, occiput-C2 (O-C2) lordosis, cervical lordosis (C2-C7, CL), T1 slope (TS), neck tilt, thoracic inlet angle (TIA), cervicothoracic kyphosis (C6-T4), and C2-C7 sagittal vertical axis (C2-7 SVA). Interobserver reliability was calculated for all measurements (intraclass correlation coefficient, ICC). A Pearson correlation was used to determine relationships between variables. A total of 115 patients were analyzed; average age as 50.1 years (range 22-78). All measured variables had an ICC >0.6. CL (r = -0.33, P < 0.001), TS (r = 0.42, P < 0.001), TIA (r = 0.24, P = 0.010), and C7 SVA (r = 0.48, P < 0.001) all increased with age. OrT (r = -0.88, P < 0.001) and OS (r = 0.73, P < 0.001) were both strongly correlated with CBVA and each other (r = -0.83, P ≤ 0.001). Both measures were also correlated with the C2-C7 SVA (OrT, r = 0.41, P < 0.001; OS, r = -0.29, P = 0.002) and O-C2 angle (OrT, r = 0.46, P < 0.001; OS, r = -0.28, P = 0.003). C6-T4 angulations was negatively correlated with NDI scores in this population (r = -0.25, P = 0.007). We present age-based normative values for occipitocervical, cervicothoracic, and cervical alignment parameters using a novel biplanar radiographic imaging technique. We introduce measures of craniocervical alignment that might provide surgeons with an intuitive way to account for the position of the orbit when planning cervical deformity correction. 4.

Spine malformation complex in 3 diverse syndromic entities: Case reports.

Rationale:Clinical and radiographic phenotypic characterizations were the base line tool of diagnosis in 3 syndromic disorders in which congenital cervico-thoracic kyphosis was the major deformity.Patients concerns:Directing maximal care toward the radiographic analysis is not only the axial malformation but also toward the appendicular abnormalities was our main concern. We fully documented the diversity of the spine phenotypic malformation complex via the clinical and radiographic phenotypes.Diagnoses:We established the diagnosis via phenotypic/genotypic confirmation in 3 diverse syndromic entities namely acampomelic campomelic dysplasia, Larsen syndrome and Morquio syndrome type A (mucopolysaccharidosis type IV A).Interventions:Surgical interventions have been carried out in the Larsen syndrome and Morquio syndrome type A, resepectively.Outcomes:The earliest the diagnosis is, the better the results are. The necessity to diagnose children in their first year of life has many folds, firstly the management would be in favor of the child's growth and development and secondly, the prognosis could be clearer to the family and the medical staff as well. Our current paper is to sensitize paediatricians, physicians and orthopedic surgeons regarding the necessity to detect the aetiological understanding in every child who manifests a constellation of malformation complex.Lesons:Scoliosis and kyphosis/kyphoscoliosis are not a diagnosis in themselves. Such deformities are mostly a symptom complex correlated to dozens of types of syndromic associations. The rate curve progression and the final severity of congenital spine tilting are related to 3 factors: (a) the type of vertebral malformation present, (b) the patient's phenotype, and (c) the diagnosis.

Health-related quality of life in patients undergoing cervicothoracic osteotomies for fixed cervicothoracic kyphosis in patients with ankylosing spondylitis

Health-related quality of life in patients undergoing cervicothoracic osteotomies for fixed cervicothoracic kyphosis in patients with ankylosing spondylitis

Safety and Efficacy of Reconstruction of Complex Cervical Spine Pathology Using Pedicle Screws Inserted with Stealth Navigation and 3D Image-Guided (O-Arm) Technology.

Retrospective analysis. To determine safety and efficacy of cervical pedicle screw placement using O-Arm and Stealth Navigation in patients with cervicothoracic spinal deformities and revision subaxial cervical pathology. Cervical pedicle screws are biomechanically advantageous to other posterior cervical fixation techniques; however, their use is limited by concerns for neurovascular injury. Few clinical reports exist on their placement safety and efficacy using modern navigation systems. Adults who had cervical pedicle screws inserted using O-Arm and Stealth Navigation between November 2007 and January 2014 and with a minimum 1-year follow-up were retrospectively studied. Screw insertion safety, surgical complications, need for reoperation, and clinical outcomes [Neck Disability Index, EQ-5D, numeric pain rating scales] were evaluated. 21 patients (female-10; male-11; average age 63 yr [32-83 yr]) met inclusion criteria. Average follow-up was 29.8 months (12-81.6 mo). Reconstruction of C2 and the subaxial cervical spine included 8 primary operations for cervicothoracic kyphosis and 13 revision operations. 121 pedicle screws were placed (C2: 4, C3: 20, C4: 22, C5: 23, C6: 18, C7: 34) using Stealth Navigation. The average number of screws placed per case was 6 (1-12). Greater than 99% of screws were placed safely without neurovascular injury. 1 screw (0.8%) was noted postoperatively to critically breach the medial wall and was associated with an acute C5 nerve root palsy. 2 patients required revisions for postoperative iatrogenic foraminal stenosis and associated C8 radiculopathies. No vascular complications due to aberrant screw placement occurred. There were significant improvements (P < 0.05) in EQ-5D utility scores and neck and arm pain. Neck Disability Index scores decreased on average by 10 points (P = 0.12). Placement of cervical pedicle screws using O-Arm/Stealth Navigation in this series was a safe and effective method for posterior stabilization in cervicothoracic deformity and revision operations of the subaxial cervical spine. 4.

Dural Ectasia in a Child With Larsen Syndrome

We present a case of an incidental finding of dural ectasia in a child diagnosed with Larsen syndrome. Larsen syndrome is a rare inherited disorder of connective tissue characterized by facial dysmorphism, congenital joint dislocations of the hips, knees and elbows, and deformities of the hands and feet. Dural ectasia is as an abnormal expansion of the dural sac surrounding the spinal cord and may result in spinal morphologic changes, instability, and spontaneous dislocation. To the best of our knowledge, the presence of dural ectasia in Larsen syndrome has not previously been reported. A 6-year-old boy diagnosed with Larsen syndrome presented with an upper thoracic curve measuring 74 degrees, a right thoracic curve measuring 65 degrees, and significant cervicothoracic kyphosis with 50% anterior subluxation of C6 on C7 and C7 on T1. Advanced imaging studies showed dural ectasia (evidenced by spinal canal and dural sac expansion), thinning of pedicles and lamina, and C4 and C6 pars defects with cervical foramen enlargement. The patient received growing rod instrumentation (attached to cervical spine fixation) by a combined anterior/posterior surgical approach using intraoperative halo. Complications included intraoperative medial breach (fully resolved), wound dehiscence, 2 instances of bilateral broken rods, and a broken cervical rod. Following 7 lengthening procedures, the patient underwent definitive fusion. Surgeons should be aware of the potential for dural ectasia in patients with Larsen syndrome. Its presence will cause difficulties in the surgical intervention for spinal deformity. Multiple factors must be considered, and surgical approach and technique will require modification to avoid complications. Although dural ectasia confounds surgical intervention in these patients, surgery still appears to outweigh the risks associated with delayed intervention. The presence of dural ectasia should not preclude surgical decompression and stabilization. This report adds to the body of knowledge on the treatment of Larsen syndrome by demonstrating the potential existence of dural ectasia and highlights the importance of careful and thorough preoperative evaluation and diagnostic imaging.

Long fusion from sacrum to thoracic spine for adult spinal deformity with sagittal imbalance: upper versus lower thoracic spine as site of upper instrumented vertebra.

Despite increasing numbers of patients with adult spinal deformity, it is unclear how to select the optimal upper instrumented vertebra (UIV) in long fusion surgery for these patients. The purpose of this study was to compare the use of vertebrae in the upper thoracic (UT) versus lower thoracic (LT) spine as the upper instrumented vertebra in long fusion surgery for adult spinal deformity. Patients who underwent fusion from the sacrum to the thoracic spine for adult spinal deformity with sagittal imbalance at a single medical center were studied. The patients with a sagittal vertical axis (SVA) ≥ 40 mm who had radiographs and completed the 12-item Short-Form Health Survey (SF-12) preoperatively and at final follow-up (≥ 2 years postoperatively) were included. Eighty patients (mean age of 61.1 ± 10.9 years; 69 women and 11 men) met the inclusion criteria. There were 31 patients in the UT group and 49 patients in the LT group. The mean follow-up period was 3.6 ± 1.6 years. The physical component summary (PCS) score of the SF-12 significantly improved from the preoperative assessment to final follow-up in each group (UT, 34 to 41; LT, 29 to 37; p = 0.001). This improvement reached the minimum clinically important difference in both groups. There was no significant difference in PCS score improvement between the 2 groups (p = 0.8). The UT group had significantly greater preoperative lumbar lordosis (28° vs 18°, p = 0.03) and greater thoracic kyphosis (36° vs 18°, p = 0.001). After surgery, there was no significant difference in lumbar lordosis or thoracic kyphosis. The UT group had significantly greater postoperative cervicothoracic kyphosis (20° vs 11°, p = 0.009). The UT group tended to maintain a smaller positive SVA (51 vs 73 mm, p = 0.08) and smaller T-1 spinopelvic inclination (-2.6° vs 0.6°, p = 0.06). The LT group tended to have more proximal junctional kyphosis (PJK), although the difference did not reach statistical significance. Radiographic PJK was 32% in the UT group and 41% in the LT group (p = 0.4). Surgical PJK was 6.4% in the UT group and 10% in the LT group (p = 0.6). Both the UT and LT groups demonstrated significant improvement in clinical and radiographic outcomes. A significant difference was not observed in improvement of clinical outcomes between the 2 groups.

Cervicothoracic Myelopathy in Children With Morquio Syndrome A

Craniovertebral junction anomalies and C1-C2 instability resulting in myelopathy have been well described in the literature on mucopolysaccharidosis IV (MPS-IV). Spinal involvement in MPS-IV patients, with neurological impairment, other than atlanto-axial instability and thoracolumbar kyphosis, has been scarcely mentioned in the literature. Retrospective clinical and radiologic review of the medical records and imaging studies of 4 individuals with Morquio A syndrome, who had undergone decompression and fusion of the cervicothoracic spine for myelopathy secondary to cervicothoracic stenosis between 1990 and 2009. Data regarding the presence of kyphosis at the cervicothoracic and upper thoracic spine, and neurological symptoms and signs were obtained. There were 3 girls and 1 boy with an average age of 5 years and 11 months at presentation with neurological symptoms. Half of the patients had previously undergone occipitocervical fusion for atlanto-axial instability, whereas the other half were noted to have spinal cord compression at both the upper cervical and cervicothoracic regions, and underwent decompression and fusion at both levels concomitantly. All patients showed postoperative neurological improvement. All patients presented with the classical Morquio syndrome vertebral morphology. Cervicothoracic kyphosis was found in all of our patients in a varying severity (10 to 35 degrees). Levels of stenosis were similar in 3 patients, C7-T2; and occurred at a lower spinal level, T1-T4, in the remaining patient. Posterior disk bulging and thecal sac indentation were found in all 4 patients. Neurological problems secondary to progressive kyphosis and stenosis at the cervicothoracic and upper thoracic spine are seen in children with Morquio syndrome. Early detection with a careful neurological assessment, whole spine MR imaging, and appropriate surgical treatment can prevent permanent neurological sequelae.

Analysis of the cervical spine sagittal alignment in young idiopathic scoliosis: a morphological classification of 120 cases.

To analyze the relationship between the cervical spine and global spinal-pelvic alignment in young patients with idiopathic scoliosis based on a morphological classification, and to postulate the hypothesis that cervical kyphosis is a part of cervico-thoracic kyphosis in them. 120 young patients with idiopathic scoliosis were recruited retrospectively between 2006 and 2011. The following values were measured and calculated: cervical angles (CA), cervico-thoracic angles (CTA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), spinal sacral angle (SSA), hip to C7/hip to sacrum, thoracic kyphosis (TK), lumbar lordosis (LL), Roussouly sagittal classification, Lenke Type Curve and Lumbar Modifier. The cervical curves were classified as lordosis, straight, sigmoid and kyphosis. They were categorized into four groups as cervical non-kyphosis group (CNK Group), cervical kyphosis group (CK Group), cervical-middle-thoracic kyphosis group (CMTK Group), and cervical-lower-thoracic kyphosis group (CLTK Group) according to their morphological characters of sagittal alignments. All parameters were compared and analyzed among groups. The incidence of cervical kyphosis was 40 % (48/120). The CA and the CTA were in significant correlation (r = 0.854, P = 0.00). The cervical spine alignments were revealed to be significantly different among groups (r = 85.04, P = 0.00). Significant differences among groups in CA, CTA and TK were also detected. A strong correlation between the group type and Lenke Lumbar Modifier was still seen (P < 0.05). Fisher's exact test revealed that the individual vertebral body kyphosis and wedging were directly related to the overall cervical kyphosis (P = 0.00, respectively). The cervical kyphosis is correlated with global sagittal alignment, and is a part of cervico-thoracic sagittal deformity in young patients with idiopathic scoliosis. Despite the deformity in cervical alignment, the global spine could still be well-balanced with spontaneous adjustment. The correlation between our grouping based on the morphological characteristics of the sagittal alignments and Lenke Lumbar Modifier suggests that the coupled motion principle be appropriate to explain the modifications both in coronal and sagittal planes.

Relationship of Cervicothoracic Curvature with Muscle Strength and Endurance in Subjects with Neck Pain

Purpose: The purpose of the study is to determine the changes seen in cervicothoracic curvature with increasing age in normal and neck pain subjects and also to study, relationship of cervicothoracic curvature with deep neck flexor muscle function and pain level. Material & Method: A group of 10 normal subjects were recruited for reliability study of photographic method. Age and sex matched 30 normal and 30 neck pain subjects were also recruited. Both the groups were divided into three age groups i.e.31-40, 41-50 and 51-60 years with 10 subjects in each. To determine cervicothoracic curvature, lateral profile photographs were taken for both the groups and using AutoCAD software cervicothoracic kyphosis angles were measured at C6 (C4 - C6- T4), C7 (C4 - C7- T4) and T1 (C4 - C6- T4) levels. For neck pain subjects, the angle average (of all the 3 levels) was compared with deep flexor muscle strength, endurance and pain level. Results : The intraclass correlation coefficients for Interrater reliability indicated high reliability with ICC at C6=0.86, at C7=0.80 and at T1=0.88. Statistical analysis was done using one-way ANOVA & Tukey's HSD at all three levels for both the groups. Cervicothoracic kyphosis was increased with age and the increase was more prominent in subjects with neck pain. At C7, angle showed early changes i.e. in forth decade in neck pain subjects compared to normal. The pain intensity and muscle functions were correlated with average cervicothoracic angle using Pearson's co-relation in neck pain subjects. There was statistically significant positive correlation between cervicothoracic angle average and deep flexor muscle strength (r=.598, p=.000). However, no statistically significant relationship was established for muscle endurance and pain intensity. Conclusion: It was concluded that degenerative changes at C7 vertebra were progressed early in neck pain subjects and their deep flexors strength reduces as the cervicothoracic kyphosis increases.

Non-instrumented correction of cervicothoracic kyphosis in ankylosing spondylitis: a critical analysis on the results of open-wedge osteotomy C7-T1 with gradual Halo-Thoracic-Cast based correction

With progression of cervicothoracic kyphosis (CTK), ankylosing spondylitis (AS) patients suffer functional disability. Surgical correction still poses neurologic risks, while evidence of an ideal technique preventing its complications is weak. We report our results with non-instrumented correction in perspective of a review of literature, serving as an important historical control. Database review identified 18 AS patients with CTK correction. After application of a Halo-Thoracic-Cast (HTC) patients underwent posterior non-instrumented open-wedge osteotomy at C7/T1 and osteotomy closure by threaded HTC-rod adjustments. Postoperative gradual HTC correction was continued for 2-4 weeks. Patients were invited for follow-up and medical charts were reviewed for demographics, surgical details, complications and outcomes. The patients' preoperative, postoperative, before HTC removal and follow-up photographs were analyzed for the Chin-Brow-Vertical-Angle (CBVA), radiographs for the CTK angle. Patients' age was 50 ± 11 years, follow-up was 37 ± 47 months and CBVA correction was 25° ± 9° (p < 0.000001). The final radiographic correction at follow-up was 20° ± 11° (p = 0.00002). At the latest follow-up, three patients judged their outcome as excellent, nine good, three moderate and one poor. Upon invitation, seven patients appeared with follow-up averaging 87 months. Neck-pain disability index was 8 ± 14 %. Two patients died, three were lost, one had revision elsewhere and five just had a routine follow-up. Six patients sustained a minor and ten a major complication. Revisions were indicated in five patients including infection, C8-radiculopathy and neurologic events by translation at the osteotomy. A total of 44 % of patients showed translation at the osteotomy indicating acute surgery with instrumentation twice after osteotomy closure, three patients had a revision posterior decompression and instrumented fusion for sequels related to translation. With the non-instrumented HTC-based technique, average CBVA correction of 25° was achieved and all patients were ambulatory at follow-up. However, regarding translation at the osteotomy, loss of correction, morbidity of the HTC and lack of control at the osteotomy instrumentation-based correction and instrumented fusion seem to be preferable.

The surgical treatment and related management for post-tubercular kyphotic deformity of the cervical spine or the cervico-thoracic spine

The outcomes of surgical treatment and related complications of post-tubercular kyphotic (PTK) deformity of the cervical spine or the cervico-thoracic spine were evaluated. From January 2005 to October 2010, 12 cases with PTK (7 males, 5 females) with an average age of 30 years (range 21-43 years) formed the study group. There were ten patients with cervical deformities and two with cervico-thoracic kyphosis. Neurological function of all the patients was evaluated by the Japanese Orthopaedic Association (JOA) score and visual analogue scale (VAS) score. Two patients with severe cervico-thoracic deformity received modified skeleton traction pre-operatively. Ten patients underwent anterior debridement and reconstruction, using iliac crest or cages with autografts, while two patients with cervico-thoracic kyphosis received posterior instrumentation and fusion. The mean pre-operative focal kyphotic angle was 42.58° (range 30-67°), reducing to -8° (range -15-11°) postoperatively (at the last follow-up visit). The average operating time was 117.50 min (80-200 min) with an average blood loss of 110 ml (range 50-300 ml). Neurological assessment of all the patients, using the Japanese Orthopaedic Association (JOA) score and visual analogue scale (VAS) score, was improved significantly after surgery. All patients had solid fusion and no major complication was observed in the follow-up. One-stage anterior debridement, instrumentation and fusion for cervical spinal TB and single posterior instrumentation for cervico-thoracic spinal TB followed by chemotherapy is practical to correct PTK. The procedure has the advantage of lower blood loss, effective kyphosis correction and minimal complications. To patients with severe deformity, skeletal traction seemed indispensible.

Biomechanical Analysis of Osteotomy Type and Rod Diameter for Treatment of Cervicothoracic Kyphosis

Biomechanical laboratory research. To characterize the structural stiffness of opening and closing wedge osteotomies and the independent effect of rod diameter. Traditionally, C7 opening wedge osteotomy (OWO) has been performed for patients with ankylosing spondylitis. For patients without ankylosing spondylitis, closing wedge osteotomy (CWO) may be considered for more controlled closure. Biomechanical characteristics of the two osteotomy alternatives have not yet been analyzed. Nondestructive pure moment flexion/extension (FE), lateral bending (LB), and axial rotation (AR) tests were conducted to 4.5 Nm on cadaveric specimens (C4-T3). All specimens underwent posterior bilateral screw-rod fixation with 3.5 mm and 4.5 mm Ti rods, whereas half received OWO and half received CWO. Independent of osteotomy type, constructs with 4.5 mm rods exhibited a significant increase in stiffness compared to 3.5 mm rods in all bending modes (P < 0.01). Relative to 3.5 mm rods, 4.5 mm constructs showed an increase in stiffness of 31 ± 12% for FE, 37 ± 39% for LB, and 31 ± 11% for AR. At the osteotomy site, there was a 43 ± 23% increase in FE stiffness, 45 ± 36% in LB, and 41 ± 17% in AR. Independent of rod diameter, CWO was significantly stiffer than OWO (42% for the construct and 56% across the osteotomy) in FE bending only (P < 0.05). The surgeon can expect a similar increase in stiffness in switching from 3.5 mm to 4.5 mm rod independent of osteotomy type. The increased stiffness of CWOs has an anatomic basis. OWOs disrupt the anterior longitudinal ligament (ALL) and leave a significant anterior gap whereas CWOs create a wedge through the vertebral body and leave the ALL and the discs above and below the osteotomy intact. The closure in CWOs leaves no anterior gap providing greater axial loading stability. This greater bone on bone contact in CWOs is likely a significant reason for the anterior stiffness and may provide greater fusion rates in the nonankylosing spondylitis patient population.

A Safe Controlled Instrumented Reduction Technique for Cervical Osteotomy in Ankylosing Spondylitis

A retrospective review of clinical and radiologic outcome in 13 consecutive patients with Ankylosing Spondylitis (AS) who underwent cervical osteotomy for correction of fixed cervicothoracic kyphotic deformity (CTKD) using an innovative technique. To report further refinements to an existing technique for instrumented reduction of cervical osteotomy and assess the safety and efficacy of this procedure in 13 patients. Cervical osteotomy in AS has been used for correction of CTKD, but is associated with significant risks. We have previously reported a novel technique to perform this procedure safely. Even with this technique, there was a small risk of subluxation, and this risk has been further reduced with our new technique. Between 1993 and 2008, the senior author (SMHM) performed cervical osteotomy for severe CTKD in 13 AS patients. There were 11 male and two female patients, the average age being 56 (40-74) years. The main surgical indication was restricted frontal visual field. The average symptom duration was 2.7 (1-5) years. All patients had a general anesthetic and underwent cervical osteotomy and instrumentation from C3 to T5 in prone position. The average duration of surgery was 4.7 (3-6.5) hours. The calculated blood loss was 1938 mL (1000-3600). The mean follow-up period was 6.5 (1.5-16) years. The mean preoperative chin brow vertical angle was found to be 54° (20°-70°). After surgery, this improved to 7° (2°-12°). The preoperative kyphotic angle measured was 19.2° (14°-28°). This improved after surgery to -34° (-21° to -39°). There were no instances of a neurologic deficit. At a mean follow-up of 6.5 years (18 months-6 yr), no instances of loss of correction or implant failure were noted. This innovative new technique provides for a safe, controlled reduction for cervical osteotomy for fixed cervicothoracic kyphosis in AS. The technique reliably renders rigid immobilization that obviates the risk of intra- and postoperative junctional subluxation, eliminates the need for postoperative halo-vest immobilization, and achieves satisfactory fusion.

Cervico-thoracic kyphosis in a girl with Pierre Robin sequence.

Congenital cervico-thoracic kyphosis has been encountered in a girl with Pierre Robin sequence. The constellation of the spine malformation complex such as incomplete development of the vertebral bodies associated with defective ossification of the cervico-thoracic pedicles causing effectively the development of complete spinal cord injury at the kyphotic level of C7/T1 were present. Congenital kyphosis secondary to vertebral body hypoplasia has not been reported in connection with Pierre Robin sequence.

Impact of multimodal intraoperative monitoring during correction of symptomatic cervical or cervicothoracic kyphosis

surgical correction of symptomatic cervical or cervicothoracic kyphosis involves the potential for significant neurological complications. Intraoperative monitoring has been shown to reduce the risk of neurological injury in scoliosis surgery, but it has not been well evaluated during surgery for cervical or cervicothoracic kyphosis. In this article, the authors review a cohort of patients who underwent kyphosis correction with multimodal intraoperative monitoring (MIOM). twenty-nine patients were included in the study. Preoperative and postoperative Cobb angles were measured to determine the extent of correction. Multimodal intraoperative monitoring consisted of somatosensory evoked potentials, transcranial motor evoked potentials (tMEPs), and electromyography activity. Sensitivity, specificity, positive predictive values (PPVs), and negative predictive values (NPVs) were assessed for each monitoring modality. the mean patient age was 58.0 years, and 20 patients were female. The mean pre- and postoperative sagittal Cobb angles were 41.3° and 7.3°, respectively. A total of 8 intraoperative monitoring alerts were observed. Transcranial MEPs yielded a sensitivity of 75%, specificity of 84%, PPV of 43%, and NPV of 95%. Somatosensory evoked potentials had a sensitivity of 25%, specificity of 96%, PPV of 50%, and NPV of 88%. Electromyography resulted in a sensitivity of 0%, specificity of 93%, PPV of 0%, and NPV of 96%. Changes in tMEPs led to successful intervention in 2 cases. There was 1 case in which a C-8 palsy occurred without any changes in MIOM. in contrast to sensitivity and PPV, specificity and NPV were generally high in all 3 monitoring modalities. Both false-positive and false-negative results occurred. Transcranial MEP monitoring was the most useful modality and appeared to allow successful intervention in certain cases. Larger, prospective comparative studies are necessary to determine whether MIOM truly decreases the rate of neurological complications and is therefore worth the added economic cost and intraoperative time.

Biomechanical Analysis of Osteotomy Type (OWO, CWO) and Rod Diameter for Treatment of Cervicothoracic Kyphosis

Sagittal imbalance of the cervicothoracic spine often causes severe pain and loss of horizontal gaze. Traditionally, C7 opening wedge osteotomy (OWO) has been performed for patients with ankylosing spondylitis. For patients without ankylosing spondylitis, closing wedge osteotomy (CWO) may be considered for more controlled closure. Biomechanical characteristics of the two osteotomy alternatives have not yet been analyzed.

Treatment of scoliosis in patients affected with Prader-Willi syndrome using various techniques

BackgroundThe incidence of spinal deformity in children with Prader-Willi syndrome (PWS) is high, with 86% of these patients found to have a significant structural scoliosis; however, there are very few case reports describing surgical treatment for this deformity.MethodsThe authors reviewed a case series consisting of 6 patients who underwent spine surgery for scoliosis. Children's mean age at index surgery was 12 years and 10 months (range, 10 to 15 yrs). Clinical evaluation revealed the typical phenotypic features of the PWS in all of the patients; 4 subjects had a karyotype confirmation of PWS. Major structural curves showed preoperative mean Cobb angles of 80.8° (range, 65° to 96°). Hybrid instrumentation with sublaminar wires, hooks and screws was used in the first 2 patients, while the remaining 4 were treated with titanium pedicle screw constructs.ResultsThe mean clinical and radiological follow-up was 3 years and 10 months (range, 2 years to 9 years). Major complication rate was 50%. One patient who developed a major intraoperative complication (paraparesis) prevented spinal fusion to be obtained: the neurologic deficit resolved completely after instrumentation removal. Solid arthrodesis and deformity correction in both coronal and sagittal plane was, however, achieved in the other 5 cases and no significant curve progression was observed at follow-up. Another major short-term complication was encountered 3 months after surgery in a patient who experienced the detachment of a distally located rod and required correction through revision surgery and caudal extension by one level. Cervico-thoracic kyphosis was seen in 1 patient who did not require revision surgery.ConclusionsSpine reconstructive surgery in patients with PWS is rare and highly demanding.The best method of reconstruction is posterior multilevel pedicle screw fixation. Moreover, even with modern techniques, the risk of complications is still high. These new techniques, however, have shown to improve the postoperative course by allowing for immediate mobilization without any brace or cast. The use of the growing rod techniques, requiring repeated surgeries, should be carefully evaluated in each single case.

Translaminar screw fixation of a kyphosis of the cervical and thoracic spine in neurofibromatosis

The spinal manifestations of neurofibromatosis include cervicothoracic kyphosis, in which scalloping of the vertebral body and erosion of the pedicles may render conventional techniques of fixation impossible. We describe a case of cervicothoracic kyphosis managed operatively with a vascularised fibular graft anteriorly across the apex of the kyphus, followed by a long posterior construct using translaminar screws, which allow segmental fixation in vertebral bodies where placement of the pedicle screws was impracticable.