Thoracolumbar Junction Kyphosis Research Articles

Thoracolumbar/Lumbar Degenerative Kyphosis-The Importance of Thoracolumbar Junction in Sagittal Alignment and Balance.

To conduct a more comprehensive study of sagittal alignment in patients with thoracolumbar/lumbar (TL/L) degenerative kyphosis. A total of 133 consecutive patients from September 2016 to March 2019 with degenerative spinal kyphosis were enrolled. These patients were divided into different types according to sagittal alignment, including thoracolumbar junctional kyphosis (TLJK). Then, we divided the patients with TLJK into two groups: the Sagittal Balance group (C7-SVA < 50 mm) and the Sagittal Imbalance group (C7-SVA ≥ 50 mm). The sagittal parameters of each type or group were compared and correlation analysis was conducted. Thoracolumbar/lumbar degenerative kyphosis consists of four types: Type I, lumbar kyphosis; Type II, degenerative flat back; Type III, thoracolumbar junctional kyphosis; and Type IV, global kyphosis. According to different sagittal alignments, Type III can further be divided into three subtypes: IIIA, with smooth kyphosis of thoracic and upper lumbar; IIIB, like a clasp knife, with a flat thoracic and lumbar angle; and IIIC, with bigger thoracic kyphosis and lumbar lordosis. The thoracolumbar kyphosis angle (°) of the three subtypes were -23.61 ± 5.37, -25.40 ± 7.71, and -40.01 ± 8.40, respectively. Lumbar lordosis was correlated with thoracic kyphosis (IIIA, r = -0.600, p = 0.005; IIIB, r = -0.312, p = 0.046; IIIC, r = -0.657, p = 0.015), and correlated with sacral slope (IIIA, r = 0.537, p = 0.015; IIIB, r = 0.654, p = 0.000; IIIC, r = 0.578, p = 0.039). All spinopelvic parameters were compared between the Sagittal Balance group and the Sagittal Imbalance group, and only the thoracolumbar kyphosis angle showed statistical difference (t = -2.247, p = 0.028). The common characteristics of thoracolumbar junctional kyphosis were found to be a bigger thoracolumbar junctional angle and vertex of kyphosis located in the thoracolumbar junction (T10-L2). Despite TLJK, a change in the thoracic angle was still important to maintain sagittal balance. The thoracolumbar junction plays an important role in sagittal alignment and balance.

Lumbar lordosis restoration by minimally invasive short-segment fusion with anterior column realignment for adult spinal deformity: minimum 2-year follow-up.

The efficacy of anterior column realignment (ACR) remains relatively unclear, possibly because some safety concerns have limited its adoption and extensive evaluation. The authors aimed to study whether a minimally invasive surgery (MIS) triad consisting of ACR, lateral lumbar interbody fusion, and percutaneous pedicle screw fixation in a select group of adult spinal deformity (ASD) patients helps shorten fusion length without compromising clinical and radiographic outcomes over a minimum 2-year follow-up period. A series of 61 ASD patients (mean age 72.8 years) with pelvic incidence (PI) - lumbar lordosis (LL) (PI-LL) mismatch > 10° underwent the short-segment MIS triad (mean fusion length 3.0 levels) as a single-stage operation with a mean operative time and estimated blood loss of 157 minutes and 127 mL, respectively. Exclusion criteria were 1) thoracic scoliosis as the main deformity, 2) thoracolumbar junction kyphosis > 25°, 3) ankylosed facet joints, and 4) previous spinal fusion surgery. Seven patients, who needed fusion to be extended to S1, underwent mini-open transforaminal lumbar interbody fusion at L5-S1. The segmental disc angle at the ACR level more than quintupled, averaging from 2.9° preoperatively to 18.9° at the latest follow-up (p < 0.0001). LL, in turn, nearly doubled from 17.0° to 32.8° (p < 0.0001) and PI-LL decreased by nearly half from 28.8° to 13.2° (p < 0.0001). At the same time, other spinopelvic deformity parameters as well as Oswestry Disability Index (ODI) scores significantly improved. Patients were divided into two groups at the latest postoperative evaluation: 36 patients whose PI-LL improved to < 10° and 25 patients who maintained a PI-LL mismatch > 10°. Binary logistic regression revealed preoperative PI-LL mismatch as the only factor that significantly influenced this dichotomous separation postoperatively. Receiver operating characteristic curve analysis identified the critical preoperative mismatch of 26.4° with 68% sensitivity and 84% specificity. Despite this different radiographic consequence, the two groups had an equally successful clinical outcome with no significant difference in ODI scores. As long as the ASD characteristics are consistent with the authors' exclusion criteria, the short-segment MIS triad served as an excellent surgical option in the patients with preoperative PI-LL mismatch < 26.4°, but the technique also worked well even in those with a mismatch > 26.4°, although ideal spinopelvic alignment targets were not necessarily achieved in these patients.

Restoring the ideal Roussouly sagittal alignment in Lenke 5 adolescent idiopathic scoliosis patients: a method for decreasing the risk of proximal junctional kyphosis.

Although the Roussouly classification has been widely used in surgical planning for adult scoliosis patients, little is known about whether it can be used to guide sagittal correction for adolescent idiopathic scoliosis (AIS) patients. The purpose of this study was to explore whether the Roussouly classification could be used to help surgeons restore the ideal sagittal alignment for AIS patients to avoid the development of proximal junctional kyphosis (PJK). In this retrospective cohort study, eighty-seven patients with Lenke 5 AIS who underwent surgery from January 2010 to August 2020 were enrolled and divided into two groups: the PJK group and the non-PJK group. All patients were classified into "current types" and "ideal types" according to two versions of the Roussouly classification, and the mismatch rate was evaluated in terms of the consistency between their current type and ideal type. Student's t test, Mann‒Whitney U test, Pearson's Chi-square test, and others were used to compare the two groups regarding patient demographic characteristics (age, sex, Risser sign, etc.) and radiographic parameters (sagittal vertical axis [SVA]; thoracic kyphosis [TK]; thoracolumbar junctional kyphosis [TLK]; lumbar lordosis [LL]; pelvic incidence [PI]; pelvic tilt [PT]; sacral slope [SS]; upper instrumented vertebra [UIV]; lower instrumented vertebra [LIV]; etc.). Multivariate logistic regression with backwards stepwise selection was performed to identify the risk factors for PJK. PJK was observed in 16 out of 87 patients (18.4%) until the final follow-up. The incidence of PJK was significantly higher in the patients not matching their ideal type than in those who did after surgery (60.9% vs. 3.1%, p = 0.000). The patients with ideal Type 1 had the highest incidence of PJK, while the lowest incidence was observed in patients with ideal Type 2 (50.0% vs. 5.1%, p = 0.000). The PJK group had greater TK, LL, and PI-LL than the non-PJK group before and after surgery. The postoperative PJA in the PJK group was also larger than that in the non-PJK group. Multivariate logistic regression revealed that postoperative Roussouly type mismatch was significantly associated with the occurrence of PJK (OR = 64.2, CI = 9.6-407.1, p = 0.000). The Roussouly classification could serve as a prognostic tool for PJK in Lenke 5 AIS patients. Corrective surgery should restore sagittal alignment with respect to the patient's ideal sagittal profile (according to the Roussouly classification based on the PI) to decrease the incidence of PJK in AIS patients.

Use of multiple rods and proximal junctional kyphosis in adult spinal deformity surgery.

Multiple rods are utilized in adult spinal deformity (ASD) surgery to increase construct stiffness. However, the impact of multiple rods on proximal junctional kyphosis (PJK) is not well established. This study aimed to investigate the impact of multiple rods on PJK incidence in ASD patients. ASD patients from a prospective multicenter database with a minimum follow-up of 1 year were retrospectively reviewed. Clinical and radiographic data were collected preoperatively, at 6 weeks postoperatively, at 6 months postoperatively, at 1 year postoperatively, and at every subsequent year postoperatively. PJK was defined as a kyphotic increase of > 10° in the Cobb angle from the upper instrumented vertebra (UIV) to UIV+2 as compared with preoperative values. Demographic data, radiographic parameters, and PJK incidence were compared between the multirod and dual-rod patient cohorts. PJK-free survival analysis was performed using Cox regression to control for demographic characteristics, comorbidities, level of fusion, and radiographic parameters. Overall, 307/1300 (23.62%) cases utilized multiple rods. Cases with multiple rods were more likely to be revisions (68.4% vs 46.5%, p < 0.001), to be posterior only (80.7% vs 61.5%, p < 0.001), involve more levels of fusion (mean 11.73 vs 10.60, p < 0.001), and include 3-column osteotomy (42.9% vs 17.1%, p < 0.001). Patients with multiple rods also had greater preoperative pelvic retroversion (mean pelvic tilt 27.95° vs 23.58°, p < 0.001), greater thoracolumbar junction kyphosis (-15.9° vs -11.9°, p = 0.001), and more severe sagittal malalignment (C7-S1 sagittal vertical axis 99.76 mm vs 62.23 mm, p < 0.001), all of which corrected postoperatively. Patients with multiple rods had similar incidence rates of PJK (58.6% vs 58.1%) and revision surgery (13.0% vs 17.7%). The PJK-free survival analysis demonstrated equivalent PJK-free survival durations among the patients with multiple rods (HR 0.889, 95% CI 0.745-1.062, p = 0.195) after controlling for demographic and radiographic parameters. Further stratification based on implant metal type demonstrated noninferior PJK incidence rates with multiple rods in the titanium (57.1% vs 54.6%, p = 0.858), cobalt chrome (60.5% vs 58.7%, p = 0.646), and stainless steel (20% vs 63.7%, p = 0.008) cohorts. Multirod constructs for ASD are most frequently utilized in revision, long-level reconstructions with 3-column osteotomy. The use of multiple rods in ASD surgery does not result in an increased incidence of PJK and is not affected by rod metal type.

Distal junctional failure after corrective surgery without pelvic fixation for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture

BackgroundThoracolumbar junctional kyphosis (TLJK) due to osteoporotic vertebral fracture (OVF) negatively impacts patients’ quality of life. The necessity of pelvic fixation in corrective surgery for TLJK due to OVF remains controversial. This study aimed to: 1) evaluate the surgical outcomes of major corrective surgery for thoracolumbar junctional kyphosis due to osteoporotic vertebral fracture, and 2) identify the risk factors for distal junctional failure to identify potential candidates for pelvic fixation. MethodsPatients who underwent surgical correction (fixed TLJK>40°, OVF located at T11–L2, the lowermost instrumented vertebra at or above L5) were included. Sagittal vertical axis, pelvic tilt, pelvic incidence, thoracic kyphosis, lumbar lordosis (L1-S1), local kyphosis, and lower lumbar lordosis (L4-S1) were assessed. Proximal and distal junctional kyphosis (P/DJK) and failures (P/DJF) were evaluated. Pre/postoperative spinopelvic parameters were compared between DJF and non-DJF patients. ResultsThirty-one patients (mean age: 72.3 ± 7.9 years) were included. PJK was observed in five patients (16.1%), while DJK in 11 (35.5%). Twelve cases (38.7%) were categorized as failure. Among the patients with PJK, there was only one patient (20%) categorized as PJF and required an additional surgery. Contrary, all of eleven patients with DJK were categorized as DJF, among whom six (54.5%) required additional surgery for pelvic fixation. In comparisons between DJF and non-DJF patients, there was no significant difference in pre/postoperative LK (pre/post, p = 0.725, p = 0.950). However, statistically significant differences were observed in the following preoperative alignment parameters: SVA (p = 0.014), LL (p = 0.001), LLL (p = 0.006), PT (p = 0.003), and PI-LL (p < 0.001). ConclusionsSpinopelvic parameters, which represent the compensatory function of lumbar hyperlordosis and pelvic retroversion, have notable impacts on surgical outcomes in correction surgery for TLJK due to OVF. Surgeons should consider each patient's compensatory function when choosing a surgical approach.

Spinopelvic sagittal compensation in adult cervical deformity.

The objective of this study was to evaluate spinopelvic sagittal alignment and spinal compensatory changes in adult cervical kyphotic deformity. A database composed of 13 US spine centers was retrospectively reviewed for adult patients who underwent cervical reconstruction with radiographic evidence of cervical kyphotic deformity: C2-7 sagittal vertical axis > 4 cm, chin-brow vertical angle > 25°, or cervical kyphosis (T1 slope [T1S] cervical lordosis [CL] > 15°) (n = 129). Sagittal parameters were evaluated preoperatively and in the early postoperative window (6 weeks to 6 months postoperatively) and compared with asymptomatic control patients. Adult cervical deformity patients were further stratified by degree of cervical kyphosis (severe kyphosis, C2-T3 Cobb angle ≤ -30°; moderate kyphosis, ≤ 0°; and minimal kyphosis, > 0°) and severity of sagittal malalignment (severe malalignment, sagittal vertical axis T3-S1 ≤ -60 mm; moderate malalignment, ≤ 20 mm; and minimal malalignment > 20 mm). Compared with asymptomatic control patients, cervical deformity was associated with increased C0-2 lordosis (32.9° vs 23.6°), T1S (33.5° vs 28.0°), thoracolumbar junction kyphosis (T10-L2 Cobb angle -7.0° vs -1.7°), and pelvic tilt (PT) (19.7° vs 15.9°) (p < 0.01). Cervicothoracic kyphosis was correlated with C0-2 lordosis (R = -0.57, p < 0.01) and lumbar lordosis (LL) (R = -0.20, p = 0.03). Cervical reconstruction resulted in decreased C0-2 lordosis, increased T1S, and increased thoracic and thoracolumbar junction kyphosis (p < 0.01). Patients with severe cervical kyphosis (n = 34) had greater C0-2 lordosis (p < 0.01) and postoperative reduction of C0-2 lordosis (p = 0.02) but no difference in PT. Severe cervical kyphosis was also associated with a greater increase in thoracic and thoracolumbar junction kyphosis postoperatively (p = 0.01). Patients with severe sagittal malalignment (n = 52) had decreased PT (p = 0.01) and increased LL (p < 0.01), as well as a greater postoperative reduction in LL (p < 0.01). Adult cervical deformity is associated with upper cervical hyperlordotic compensation and thoracic hypokyphosis. In the setting of increased kyphotic deformity and sagittal malalignment, thoracolumbar junction kyphosis and lumbar hyperlordosis develop to restore normal center of gravity. There was no consistent compensatory pelvic retroversion or anteversion among the adult cervical deformity patients in this cohort.

Comparison of sagittal spinal alignment on standing plain x-rays and supine MRI in degenerative lumbar disease.

The purpose of the present study is to examine the possible correlation between standing plain x-rays and supine magnetic resonance imaging (MRI) for evaluating spinal sagittal alignment in degenerative lumbar disease (DLD). The characteristics and images of 64 patients with DLD were reviewed retrospectively. The thoracolumbar junction kyphosis (TJK), lumbar lordosis (LL) and sacral slope (SS) were measured on lateral plain x-rays and by MRI. Inter- and intra-observer reliability was tested using intra-class correlation coefficients. The results suggested that TJK measurements obtained from MRI tended to underestimate the radiographic measures by 2°, whereas SS measurements obtained from MRI tended to overestimate the radiographic measures by 2°. The LL measurements obtained from MRI were approximately equal to the radiographic measures, and the x-ray and MRI measurements were linearly related. In conclusion, supine MRI can be directly translated into sagittal alignment angle measurements obtained from standing x-rays with an acceptable degree of accuracy. This can avoid the impaired view caused by the overlapping ilium, while reducing the patient's exposure to radiation.

Use of an exoscope for enhanced visualization of a Schwab grade 5 osteotomy to correct kyphotic deformity.

The development of the 3D exoscope has advanced intraoperative visualization by providing access to visual corridors that were previously difficult to obtain or maintain with traditional operating microscopes. Favorable ergonomics, maneuverability, and increased potential for instruction provide utility in a large range of procedures. Here, the authors demonstrate the exoscope system in a patient with progressive thoracolumbar junctional kyphosis with bony retropulsion of a T12–L1 fracture requiring a Schwab grade 5 osteotomy and fusion. The utilization of the exoscope provides visual access to the ventrolateral dura for the entire surgical team (surgeons, learners, and scrub nurse).The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21190

PI and T9-SPI: New Predictive Factors for Increased Kyphosis of the Thoracolumbar Junction in Thoracolumbar/Lumbar Adolescent Idiopathic Scoliosis.

Objectives: Studies have demonstrated that there is an increased thoracolumbar junction sagittal Cobb angle (TLJS) in thoracolumbar/lumbar adolescent idiopathic scoliosis (AIS) patients. The objectives were to ascertain the correlations between the spinopelvic alignments and TLJS and to explore potential predictive factors for hyperkyphotic TLJS in the sagittal plane in thoracolumbar/lumbar AIS.Methods: A total of 114 AIS patients with thoracolumbar/lumbar curve were included. Cobb angle, apical vertebrae rotation (AVR), thoracic kyphosis (TK), TLJS, lumbar lordosis (LL), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), T1-spinopelvic inclination (T1-SPI), and T9-spinopelvic inclination (T9-SPI) were measured. After patients were organized into two subgroups based on TLJS, all parameters were compared between the two groups. Correlation analysis and multiple linear regression analysis were performed between the radiologic measurements and TLJS in all patients.Results: There was a significant difference between the non-kyphotic group and kyphotic group in mean Nash-Moe grade, TK, T9-SPI, PI, and SS. Correlation analysis showed that LL, PI, and SS were inversely associated with TLJS. TK, T9-SPI, and Nash-Moe grade were positively related to TLJS. The multiple linear regression analysis showed that TLJS could be predicted by the equation TLJS = −2.322 + 5.585 × Nash-Moe grade + 0.687 × T9-SPI – 0.208 × PI, with an adjusted R2 of 0.410.Conclusion: TLJS was positively correlated with greater AVR in the coronal plane, greater T9-SPI in the sagittal plane and inversely associated with PI among patients with thoracolumbar/lumbar scoliosis. Spine surgeons should pay more attention to the degree of AVR, T9-SPI, and PI when dealing with thoracolumbar/lumbar scoliosis with thoracolumbar junction kyphosis.

Coronal and sagittal spinal alignment in lumbar disc herniation with scoliosis and trunk shift

BackgroundTo investigate the incidence of scoliosis and trunk shift in patients with LDH (lumbar disc herniation) and analyze the differences in spinopelvic alignment among patients with or without trunk shift and non-symptom controls.Materials and methodsAll included subjects had standard upright antero-posterior and lateral radiographs of the whole spine taken. Evidence of disc herniation was confirmed by computed tomography or magnetic resonance imaging. The parameters measured included trunk shift and Cobb angle, TK (thoracic kyphosis), TLK (thoraco-lumbar junction kyphosis), LL (lumbar lordosis), PI (pelvic incidence), SS (sacral slope), PT (pelvic tilt) and SVA (sagittal vertical axis).ResultsSixty-eight patients with LDH and 61 controls were included. There were significantly more male patients with trunk shift than the patients without trunk shift. Forty-two patients had curve magnitudes ranging from 5 to 38°. The trunk shift ranged from 0.5 to 7.3 cm. A total of 54.76% of patients had a disc herniation on the concave side of the main curve. Fifty percent of patients showed a trunk shift towards the opposite side of disc herniation. There were significant differences in spinopelvic parameters among groups. Significant correlations were also observed between several spinopelvic parameters in the three groups. However, the degrees of correlations among the spinopelvic parameters differed among the three groups.ConclusionSpinal sagittal morphology in LDH patients with trunk shift exhibits a more anterior shift of the C7 plumb line, less LL, and a more horizontal sacrum. Correlation analysis indicated a disharmonious spinopelvic interaction and a change in the compensatory model in patients with LDH.

Short-Segment Fixation With Percutaneous Pedicle Screws in the Treatment of Unstable Thoracolumbar Vertebral Body Fractures.

Clinical care of patients with unstable thoracolumbar vertebral body fractures may be challenging, especially in the setting of polytrauma patients who require other acute intervention. Compared with the traditional open approach, percutaneous short-segment fixation constructs place less surgical burden on patients regarding operative time and blood loss. Between 2008 and 2012, 32 patients with a mean age of 49 years (range, 19-80 years) underwent percutaneous short-segment fixation at the authors' institution and had a minimum of 6 months of complete clinical and radiographic follow-up. Load-sharing classification scores were determined. Outcomes evaluated included anterior body height, posterior body height, local kyphosis, regional kyphosis, thoracolumbar junctional kyphosis, mean operative time, and total blood loss. Standard binomial and categorical comparative analyses were performed. All load-sharing classification scores were 7 or less, and 11 of the 32 patients were polytrauma patients requiring surgery. No difference was seen between preoperative and late measurements of anterior body height, posterior body height, local kyphosis, regional kyphosis, or thoracolumbar junctional kyphosis. There were no complications, revisions, or anterior corpectomies. Only 2 patients (6%) underwent elective removal of hardware at 1 year. Mean operative time was 43 minutes (range, 33-56 minutes), and mean estimated blood loss was less than 50 mL. Percutaneous short-segment fixation prevented loss of vertebral body height and progression of kyphosis in the treatment of unstable thoracolumbar fractures with load-sharing classification scores of 7 or less. This study shows that these fractures with a load-sharing classification score of 6 and 7 may be stabilized using fewer screws than traditional methods in some patients and allow polytrauma patients to undergo other acute treatment. [Orthopedics. 2018; 41(6):e802-e806.].

Surgical Management of Progressive Thoracolumbar Kyphosis in Mucopolysaccharidosis: Is a Posterior-only Approach Safe and Effective?

According to the current literature, the recommended surgical treatment is circumferential spinal fusion, including both anterior and posterior procedures, for progressive thoracolumbar kyphosis in mucopolysaccharidosis (MPS). The purpose of this study was to report our experience with the posterior-only approach and instrumented fusion for MPS kyphosis. Six consecutive patients with MPS and thoracolumbar junctional kyphosis managed with the posterior-only approach were included. Demographic data, the type of MPS, medical comorbidities, and accompanying clinical manifestations were recorded. Measurements recorded on radiographs for the study included the presence of any coronal-plane deformity, fusion levels, changes in the local kyphosis angle (LKA), proximal and distal junctional kyphosis angles, and the apical vertebral wedge angle. The average age at the time of surgery was 6.6 (range, 4 to 12) years. The average follow-up duration was 52.6 (range, 44 to 64) months. The mean preoperative LKA of 63.1±15.8 (range, 48 to 92) degrees decreased to a mean of 16.6±8.4 (range, 5 to 30) degrees immediately after surgery. At the latest follow-up, the mean LKA was 19.6±8.8 (range, 8 to 34) degrees. Apical vertebral listhesis was reduced in all patients with surgical correction. The average apical vertebral wedge angle of 15 (range, 11 to 19) degrees at the early postoperative period decreased to 4.6 (range, 2 to 7) degrees at the latest follow-up. Adjacent-segment problems occurred in 2 patients. There were no neurological complications or implant failures in any of the patients. Posterior-only corrective techniques and instrumented fusion with pedicle screws for progressive thoracolumbar junctional kyphosis in MPS patients are safe and effective methods. Its results are comparable to those achieved with conventional circumferential fusion. However, patients should be monitored closely for adjacent-segment problems. Level IV-retrospective case series.

Selective Fusion in Lenke 5 Adolescent Idiopathic Scoliosis

To compare the clinical and radiographic outcomes on the sagittal plane between anterior and posterior selective fusion (ASF and PSF) in patients with Lenke 5 adolescent idiopathic scoliosis (AIS) for a minimum of 5 years of follow-up. We included 77 patients with Lenke 5 AIS who underwent ASF (n= 40) with a single rod with structural cages or PSF (n= 37) with pedicle screw instrumentation. Radiographic parameters were compared preoperatively, 3 months and 2 years postoperatively, and at final follow-up. The mean follow-up duration was 93.9 ± 21.4 months in the ASF group and 80.4 ± 15.2 in the PSF group (P=0.002). The correction rate of the coronal curve was comparable between the 2 groups at final follow-up. There was a significant time trend for lumbar lordosis (LL), thoracic kyphosis, thoracolumbar junctional kyphosis, instrumented segmental angle (ISA), proximal junctional angle, and sagittal vertical axis (P < 0.001) and significant group effects for LL (P= 0.0065) and ISA (P= 0.0325). At 3 months postoperatively, LL decreased in the ASF group and increased in the PSF group (-3.1° ± 6.6° vs. 1.3° ± 5.5° change, P= 0.002) and increased in both groups at final follow-up (2° ± 2.9° vs. 4.3° ± 4.9° change, P= 0.070). ISA increased in both groups 3 months postoperatively but decreased significantly in the ASF group compared with the PSF group at 2-year follow-up (4.0° ± 3.9° vs. 0.7° ± 1.9° change, P < 0.001) and final follow-up (8.1° ± 5.8° vs. 0.8° ± 3.4° change, P < 0.001). LL, ISA, and proximal junctional angle were significantly larger at final follow-up in the PSF group (P < 0.05). The incidence of proximal junctional kyphosis was higher in the PSF group (5/37) than in the ASF group (1/40). A significant and continuous loss of lordosis in ISA was observed after ASF in patients with Lenke 5 AIS. A larger LL was obtained with a higher incidence of proximal junctional kyphosis at long-term follow-up after PSF.

Clinical and radiographic presentation and treatment of patients with cervical deformity secondary to thoracolumbar proximal junctional kyphosis are distinct despite achieving similar outcomes: Analysis of 123 prospective CD cases

CD development secondary to PJK was recently documented in adult spinal deformity patients after surgical correction for thoracolumbar ASD. This study analyzes surgical management of patients with CD secondary to proximal junctional kyphosis (PJK) versus patients with primary CD. Retrospective review of multicenter cervical deformity (CD) database. CD defined as at least one of the following: C2–C7 coronal Cobb > 10°, cervical lordosis (CL) > 10°, cervical sagittal vertical axis (cSVA) > 4cm, CBVA > 25°. Patients were grouped into those with PJK (UIV +2 < −10°) prior to cervical surgery versus who don’t (Non-PJK). Independent t-tests and chi-squared tests compared radiographic, clinical, and surgical metrics between PJK and non-PJK groups. Of 123 eligible CD patients, 26(21.1%) had radiographic PJK prior to cervical surgery. PJK patients had significantly greater T2–T12 thoracic kyphosis (−58.8° vs −45.0°, p = 0.002), cSVA (49.1 mm vs 38.9 mm, p = 0.020), T1 Slope (42.6° vs 28.4°, p < 0.001), TS-CL (44.1° vs 35.6°, p = 0.048), C2-T3 SVA (98.8 mm vs 75.8 mm, p = 0.015), C2 Slope (45.4° vs 36.0°, p = 0.043), and CTPA (6.4° vs 4.6°, p = 0.005). Comparing their surgeries, the PJK group had significantly more levels fused (10.7 vs 7.4, p = 0.01). There was significantly greater blood loss in PJK patients (1158 ± 1063vs 738 ± 793 cc, p = 0.028); operative time, surgical approach, and BMP-2 use were similar (all p > 0.05). PJK patients experienced higher rates of complications 30 and 90 days post-operatively (23.1% vs. 5.2%, p = 0.004; 30.8% vs. 19.6%, p = 0.026), and more instrumentation failure 30 days postoperatively (7.8% vs. 1.0%, p = 0.004). Patients with cervical deformity secondary to PJK had worse baseline CD, despite no differences in HRQL or demographics. Surgical correction of CD associated with PJK required more invasive surgery and had higher complication rates than non-PJK patients, despite achieving similar clinical outcomes.

Junctional kyphosis: how can we detect and monitor it during growth?

BackgroundDespite its importance in affecting adult pain, and disability, there is a lack of universal criteria for the diagnosis and evaluation of thoraco-lumbar Junctional Kyphosis (JK) and a gold standard measurement and diagnostic system does not exist.This study aims to verify the sensibility and specificity of clinical, and Formetric surface topography (FST) data in identifying Junctional Kyphosis in respect to the radiographical standard references.MethodsDesign: This is a cross sectional study from a prospective database started in March 2003.Participants: 38 subjects.Inclusion criteria: Patients selected by age according to Risser score 1, at first visit with lateral x-rays and FST. Diagnostic test used to detect JK:FST criteria: level of thoraco-lumbar inflexion point in percentage compared to the total height of the spine.X-ray criteria: lower limit of thoracic kyphosis below T12. Statistics: sensitivity, specificity, positive (PPV) and negative predictive values (NPV), ROC curve.ResultsFST showed a good reliability in detecting JK: with a threshold of 75 %, PPV was 100 %, NPV was 86 % and the Area Under the Curve was 83 %.ConclusionThe need for a useful criteria able to characterize JK to allow diagnosis and monitoring of the deformity is still lacking, and further studies will deepen this issue.

Sagittal spinopelvic alignment in adolescent thoracic scoliosis secondary to Chiari I malformation: a comparison between the left and the right curves

To investigate whether the sagittal morphology differs between the left and right thoracic curves in patients with Chiari malformation-associated scoliosis (CMS). Thirty-four patients with a left thoracic curve constituted the CM-L group, whereas 44 patients with a right thoracic curve were assigned into the CM-R group. Another cohort of 90 age- and gender-matched asymptomatic adolescents was enrolled to serve as the control group. Seven sagittal parameters were evaluated on standing lateral radiographs, including thoracic kyphosis (TK), lumbar lordosis (LL), thoracolumbar junctional kyphosis (TJK), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT) and sacral slope (SS). Compared to the normal controls, the TK, LL and SS were significantly greater in the CM-L group, along with a significantly decreased PT. Similar changes in SS and PT were also demonstrated in the CM-R group, while the TK and LL were found to be relatively normal compared with the control group. Concerning CMS patients with different curve directions, significantly increased TK and LL were observed in the CM-L group, whereas all three pelvic parameters were similar for the two groups. In addition, no significant differences were noted between the three groups in PI, TJK or SVA. Moreover, the LL was strongly related to the TK and SS in all three groups, but to the PI only in the control and CM-R groups. A significant correlation was also noted between TK and SS in the CM-L group. Significant differences in sagittal profiles indeed exist between CMS patients and healthy adolescents, as well as between CMS patients with different curve directions. In CMI patients with a left thoracic curve, compensatory alterations appear to occur in LL in response to the increased TK to maintain a balanced posture.

Correction of Spine Deformity in Patients With Melnick-Needles Syndrome

Melnick-Needles syndrome (MNS) is a rare X-linked dominant disorder affecting the skeletal system and connective tissue. To date, < 70 cases with MNS have been documented. Although few reports in the literature have shown that these patients might develop kyphoscoliosis, there is no report regarding long-term follow-up of patients with MNS undergo spine surgery. The aim of this study is to describe 2 unique cases of MNS with long-term follow-up after instrumented posterior spinal fusion, multiple-level Ponte osteotomies, and pedicle subtraction osteotomies. A 17-year-old female patient (patient 1) was evaluated for the first time at our institution. She was diagnosed with MNS, severe kyphoscoliosis, and restrictive lung disease. After pulmonary function improvement, she underwent posterior spinal fusion. Halo-femoral traction with gradual weight increase was used a week before spinal surgery. Surgical correction of her spinal deformity was achieved through a hooks-and-wires construct. The second patient was an 18-year-old female (patient 2) who carried the diagnosis of MNS when she was first seen at our institution. She had a significant thoracolumbar junction kyphosis and gibbous. She also suffered from significant pulmonary disease with a stent in her right main stem bronchus. A posterior procedure consisting of multiple-level Ponte osteotomies and pedicle subtraction osteotomy at L2 was carried out. Eight- and 5-year follow-up of patients 1 and 2, respectively, demonstrated solid fusion, a well-maintained correction, and no evidence of implant breakage. The reported cases add to the literature of excellent long-term results of spinal deformity correction with instrumented posterior spinal fusion in patients with MNS. Patients with this condition should be closely monitored from early childhood for the development of spine deformity so that early referral to a spine surgeon can be made followed by appropriate treatment, if necessary.

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

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. 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. 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. 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.

A Comparison of Anterior and Posterior Instrumentation for Restoring and Retaining Sagittal Balance in Patients With Idiopathic Adolescent Scoliosis

Retrospective, comparative study. To compare the effects of anterior rod-screw instrumentation and posterior pedicle screw instrumentation on sagittal balance in patients with Lenke type 5 adolescent idiopathic scoliosis (AIS). Lenke type 5 AIS is treated by anterior or posterior spinal fusion surgery. Most studies comparing anterior and posterior fusion surgery have focused on assessing improvement in coronal balance. Studies comparing the effects of anterior and posterior surgery on sagittal balance are lacking. The records of 49 patients diagnosed with Lenke type 5 AIS were examined. A total of 21 patients underwent anterior surgery between 2000 and 2003, while 26 underwent posterior surgery between 2004 and 2006. Preoperative, postoperative, and follow-up thoracic kyphosis (T5-T12 and T2-T12), lumbar lordosis, thoracolumbar junction kyphosis, and spinal vertical axis measurements were made by examining radiographs. Quality of life was assessed using the Scoliosis Research Society-22 questionnaire. All patients were followed up for at least 2 years. There were no significant between group differences in coronal alignment, thoracic kyphosis, or T11-L2 alignment after surgery. Sagittal alignment improvement was significantly more pronounced in the anterior surgery group compared with the posterior surgery group. The fusion segment was also significantly shorter in the anterior surgery compared with the posterior surgery group. Quality of life scores were significantly higher in the anterior surgery group compared with the posterior surgery group. Anterior solid rod-screw instrumentation results in shorter fusion segments, and better sagittal alignment and quality of life than posterior pedicle screw instrumentation in patients with Lenke type 5 AIS.

Spinal alignment in surgical, multisegmental, transpedicular correction of adolescent idiopathic scoliosis

SummaryThe objective of this study was to discuss the variables influencing alignment mechanisms of the spine, with particular consideration of post-surgical alignment in adolescent idiopathic scoliosis. The analysis is based on information currently available in the literature, and on the authors’ own experience, which includes surgical material from over 2200 cases of idiopathic scoliosis.Over 50% of cases of adolescent idiopathic scoliosis are decompensated before surgical treatment. Spinal alignment is most significantly influenced by the position of the pelvis. Surgical restoration of lumbar lordosis is more important than attempting to restore thoracic kyphosis in the sagittal plane. The sagittal profile has an essential impact on spinal alignment. The same curves in the coronal plane can have various 3-dimensional configurations. Clinical difficulties in the assessment of thoracic kyphosis and lumbar lordosis result from the fact that they undergo constant change with age. Thoracic hypokyphosis diagnosed before surgery is a very frequent symptom of curve progression. The presence of proximal (thoraco-thoracic) and distal (thoraco-lumbar) junctional kyphosis is very important for planning the scope of spondylodesis.The natural tendency of the spine for alignment (compensation) after surgery nowadays occurs more naturally by applying derotational forces through pedicle screws, compared to the distraction devices (eg, Harrington rod) used in the past.