Thoracolumbar Kyphosis Research Articles

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.

Postoperative Changes of Spinopelvic Sagittal Parameters After Cervical Laminoplasty for Cervical Spondylotic Myelopathy.

A retrospective analysis of prospectively collected data. To investigate postoperative changes of spinopelvic sagittal parameters after laminoplasty for cervical spondylotic myelopathy (CSM) accompanying postoperative cervical kyphotic deformity or cervical regional sagittal imbalance. To the best of our knowledge, no study has been reported concerning postoperative changes of spinopelvic sagittal parameters accompanying postoperative deterioration of cervical sagittal alignment or balance after cervical laminoplasty. Forty-five CSM patients without preoperative cervical kyphosis who underwent laminoplasty were included. None of the 45 patients had a medical history of previous spine surgery, hip joint surgery, or knee joint surgery. The patients were divided into 2 groups (kyphosis and lordosis groups) according to postoperative C2-7 angle, and they were also divided into 2 other groups (imbalance and balance groups) according to postoperative C1-7 sagittal vertical axis. Postoperative changes (Δ) of T1 slope (T1S), thoracic kyphosis, thoracolumbar kyphosis (TLK), lumbar lordosis (LL), Pelvic tilt, and C7 sagittal vertical axis were measured comparing lateral radiographs of the whole spine in the standing position taken at 1 year postoperatively with those before surgery. Both T1S and TLK significantly decreased after cervical laminoplasty in the kyphosis group compared with the lordosis group. On the other hand, both T1S and TLK increased significantly, and LL significantly decreased after surgery in the imbalance group compared with the balance group. At 1 year after laminoplasty for CSM, both T1S and TLK significantly decreased accompanying postoperative cervical kyphotic deformity as a compensatory action for postoperative cervical kyphosis to maintain the global sagittal balance of the spine, whereas both T1S and TLK increased significantly, and LL significantly decreased accompanying postoperative cervical reginal sagittal imbalance which resulted in postoperative forward inclination of the whole spine.

Impact of Surgical Resection Without Spinal Fusion for Thoracic Dumbbell Tumors on Postoperative Global Spinal Sagittal Alignment and Clinical Outcomes.

A retrospective comparative study. This study investigated radiographical changes in global spinal sagittal alignment (GSSA) and clinical outcomes after tumor resection without spinal fusion in patients with thoracic dumbbell tumors. Thirty patients with thoracic dumbbell tumors who were followed up for at least 3 years were included in this study. Variations in the outcome variables were analyzed using individual GSSA parameters measured on radiography. Clinical outcomes were assessed using the modified McCormick scale (MMCS), Japan Orthopaedic Association (JOA) score, and visual analog scale (VAS). To assess the impact of the affected levels on these outcomes, we divided the patients into three groups according to the location of the tumor (upper [T1-4], middle [T5-8], or lower [T9-12] thoracic spine). The GSSA parameters (cervical lordosis, T1 slope, thoracic kyphosis [global, upper, middle, and lower], thoracolumbar kyphosis, lumbar lordosis, sacral slope, pelvic incidence, and pelvic tilt) of all the patients did not change significantly after surgery. Eleven of thirty patients had preoperative gait disturbances but they could walk without support (MMCS grade I or II) at the final follow-up. The JOA score and VAS showed significant postoperative improvements. No statistically significant differences were observed in each postoperative sagittal profile or clinical outcome between the upper, middle, and lower groups. Tumor resection without spinal fusion did not affect the various GSSA parameters and resulted in satisfactory clinical outcomes, indicating that spinal fusion may not always be necessary when resecting thoracic dumbbell tumors.

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.

Risk factors for distal junctional kyphosis after posterior spinal surgery in adolescent idiopathic scoliosis: a meta-analysis.

Distal junctional kyphosis (DJK) is a serious complication after posterior spinal surgery in managing adolescent idiopathic scoliosis (AIS). Our study aims to investigate the predictors of DJK in AIS patients. We searched the English databases of PubMed, Embase, and the Cochrane Library for clinical research studies on AIS. To identify the risk factors for DJK, we collected demographic data, such as age, gender, and body mass index (BMI), and sagittal parameters, including preoperative pelvic tilt (PT), sagittal vertical axis (SVA), lumbar lordosis (LL), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK), distal junctional angle (DJA), lowest instrumented vertebrae (LIV) relative to sagittal stable vertebrae (SSV), and postoperative DJA. Data were analyzed by RevMan (5.3 version) and STATA (12.0 version). Finally, six included articles (1,240 patients) showed 9% (98 of 1,240 patients) of patients suffering from DJK. Our findings indicated that preoperative TK [p = 0.007, OR = 0.35, 95% CI (0.10, 0.61)], TLK [p < 0.0001, OR = 5.99, 95% CI (3.33, 8.65)], and postoperative DJA [p = 0.002, OR = 0.56, 95% CI (0.21, 0.91)] in the DJK group were markedly higher than those in the non-DJK group. Moreover, patients with LIV above SSV [p < 0.0001, OR = 7.95, 95% CI (4.16, 15.22)] were more likely to develop DJK. No discernible difference was found in age, sex, BMI, preoperative PT, SVA, LL, or DJA between the two groups. Regarding the AIS patients, factors such as higher preoperative TK and TLK, higher postoperative DJA, and LIV above the SSV were related to an increased rate of DJK.

Correlation between Degenerative Thoracolumbar Kyphosis and Lumbar Posterior Muscle.

A case-control study was conducted comparing 126 patients with DTLK and LSS against 87 control patients. The lumbar crossing indentation value (LCIV) was introduced as a novel measurement for paraspinal muscle content, and its relationship with thoracolumbar kyphosis (TLK), BMI, and LL was assessed. LCIV in DTLK patients was found to be lower than in the control group, with a progressive increase from the upper to lower lumbar spine. In the control group, paraspinal muscle content was observed to increase with age and BMI, and LCIV was higher in males. However, the DTLK group showed no gender difference. LCIV in the DTLK group was more pronounced in patients with increased LL. The degree of TLK was not influenced by BMI but was associated with the content of the paravertebral muscle. Paraspinal muscle content, as measured by LCIV, is significantly associated with DTLK and LSS. The study emphasizes the importance of considering paraspinal muscle health in DTLK patients and offers valuable insights for diagnosis and therapeutic interventions.

A novel uniplanar clamp-hinge correction system for vertebral column resection of severe angular kyphosis: an experimental study using a sawbone model.

To introduce a novel uniplanar clamp-hinge (Uni-CH) correction system designed for vertebral column resection (VCR) of severe angular kyphosis and test its efficacy using a sawbone simulating model. The Uni-CH was introduced and its functionality was demonstrated on a sawbone model simulating severe angular kyphosis. An 83° thoracolumbar angular kyphosis with the apex at T11 was simulated in the sawbone spine model. The deformity was then corrected using the Uni-CH to identify the optimal hinge position for VCR reduction of severe angular kyphosis. The thoracolumbar angular kyphosis, initially measuring a mean of 82.7 ± 0.5°, was corrected to 0°, achieving a 100% correction rate. The optimal hinge position was identified to be at the level of the posterior vertebral body wall (PVBW), which allowed for the maintenance of the spinal cord with a slight shortening of 3%. In contrast, hinge positions located more posteriorly to the PVBW resulted in a greater 42% lengthening of the spinal cord, while positions located more anteriorly led to a greater 27% shortening of the spinal cord. The Uni-CH proves its efficacy in providing consistent stability to the spinal segments and acts as an adjustable and controllable hinge for VCR correction of severe angular kyphosis in the sawbone model. Placing the hinge pivot at the level of the PVBW preserves the spinal cord, preventing excessive shortening or lengthening during VCR reduction of severe angular kyphosis.

Incidence and Potential Risk Factors of Superior Mesenteric Artery Syndrome After Spinal Corrective Surgery in Patients with Adult Spinal Deformity

This study aimed to determine the incidence and potential risk factors of superior mesenteric artery syndrome (SMAS) after corrective spinal surgery in patients with adult spinal deformity (ASD). In total, 102 patients (67.6 ± 8.4years; 8 male/94 female; body mass index (BMI); 22.4 ± 3.6kg/m2) with ASD treated by spinal correction surgery were enrolled. Preoperative and postoperative spinal parameters, including thoracolumbar kyphosis (TLK: T10-L2) and upper lumbar lordosis (ULL: L1-L4) were measured. To evaluate the potential risk factors of SMAS, the angle and the distance between the superior mesenteric artery and aorta, the aortomesenteric angle (AMA) and aortomesenteric distance (AMD), were evaluated pre- and postoperatively. Based on the postoperative AMA, AMD, and abdominal symptoms, the patients were diagnosed with SMAS. Correlations between demographic data or spinal parameters and AMA and AMD were assessed. Two (2.0%) patients were diagnosed with SMAS. Postoperative TLK significantly correlated with postoperative AMA (P= 0.013, 0.046). Postoperative ULL was significantly correlated with postoperative AMD (β=-0.27; P= 0.014). The incidence of SMAS after corrective spinal surgery in patients with ASD was 2.0%. Postoperative smaller TLK and greater ULL can be risk factors for developing SMAS. Spine surgeons should avoid overcorrection of the upper lumbar spine in the sagittal plane to prevent SMAS.

Risk factors of proximal junctional kyphosis after surgical correction of spinal deformities caused by Scheuermann’s disease

Objective. To identify risk factors for the development of Proximal Junctional Kyphosis (PJK) in patients with Scheuermann’s kyphosis operated on using segmental instrumentation.Material and Methods. The study group consisted of 43 patients (13 females, 30 males), mean age was 17 years, and mean postoperative follow-up was 6 years. Spondylograms with a patient in a standing position performed before surgery, a week after surgery, and at the end of the follow-up period were analyzed. Radiological parameters were studied: cervical lordosis, absolute rotation angle, thoracic entry angle, T1 vertebral body tilt, neck tilt, skull tilt, thoracic kyphosis, thoracolumbar kyphosis, lumbar lordosis, vertebral and pelvic parameters (Pelvic Incidence, Pelvic Tilt, Sacral Slope), sagittal vertical axis, proximal junctional angle (PJA), and length of the posterior spinal fusion.Results. The mean PJA before surgery was 7° [3°; 8°], immediately after surgery – 10° [8°; 13°], by the end of the follow-up period – 25°[19°; 32°]. The incidence of PJK by the end of the follow-up period was 79.1 % (in 34 out of 43 patients). The initial value of thoracic kyphosis was 77° [72°; 86°], after surgery – 41° [31°; 46°], at the last examination – 43° [35°; 53°]. The inclination of the T1 vertebral body in the sagittal plane before surgery was 39° [30°; 45°], at the stages of follow-up – 33° [22°; 37°] and 39° [27°; 45°]. Some significant predictors were identified. An increase in the inclination of the T1 vertebral body (p = 0.005) by k° is associated with an increase in the risk of PJK by 1.19k [1.08k; 1.37k] times, and an increase of thoracic kyphosis by k° (p = 0.023) – by 1.12k (1.03k; 1.27k) times. The formula for preoperative predicting the likelihood of this complication is: P (PJK) = 1 - 1/(1 + exp (-23.14 + 0.26 × T1 + 0.21 × TK)), where P(PJK) is the probability of proximal junctional kyphosis; exp(z) is the exponential function to the power of z; T1 (T1 vertebral body tilt) and TK (thoracic kyphosis) are preoperative values of variables. Using ROC analysis, the threshold value for predicting PJK was determined to be 74.2 %, that is, the development of PJK was predicted in patients with a PJK probability greater than the threshold value calculated by the model formula. The predictive ability of the multivariate model was tested on the basis of the available initial data with a known final result. The prediction was correct in 41 cases out of 43.Conclusion. Using the multivariate logistic regression method, two mutually independent multiplicative indicators were determined for predicting PJK with high accuracy (sensitivity 94.1 %, specificity 100.0 %) – inclination of the T1 vertebral body and thoracic kyphosis.

Risk Factors for Distal Junctional Problems Following Long Instrumented Fusion for Degenerative Lumbar Scoliosis: Are they Related to the Paraspinal Muscles.

Although the incidence of distal junctional problems (DJPs) following long construct-based treatment for degenerative lumbar scoliosis (DLS) is lower, affected patients are more likely to require revision surgery when they occur. So the aim of this study is to identify risk factors associated with DJPs to avoid its occurrence by at least 1-year follow-up. A total of 182 DLS patients undergoing long instrumented fusion surgery (≥4 levels) between February 2011 and March 2022 were retrospectively analyzed. Patients were placed into the DJP group if a DJP occurred at the final follow-up; patients without mechanical complications were matched 1:2 according to age, sex and BMI as the control group. Patient characteristics, surgical variables, radiographic parameters, lumbar muscularity and fatty degeneration were analyzed statistically. The statistical differences in the results between the two groups (p values <0.05) and other variables selected by experts were entered into a multivariate logistic regression model, and the forwards likelihood ratio method was used to analyze the independent risk factors for DJPs. Twenty-four (13.2%) patients suffered a DJP in the postoperative period and the reoperation rate was 8.8%. On univariate analysis, the lowest instrumented vertebra (LIV) CT value (p = 0.042); instrumented levels (p = 0.030); preoperative coronal vertical axis (CVA) (p = 0.046), thoracolumbar kyphosis (TLK) (p = 0.006), L4-S1 lordosis (p = 0.013), sacral slop (SS) (p = 0.030), pelvic tilt (PT) classification (p = 0.004), and sagittal vertical axis (SVA) (p = 0.021); TLK correction (p = 0.049); post-operative CVA (p = 0.029); Overall, There was no significant difference in the paraspinal muscle parameters between the two groups. On multivariate analysis, instrumented levels (OR = 1.595; p = 0.035), preoperative SVA (OR = 1.016; p = 0.022) and preoperative PT (OR = 0.873; p = 0.001) were identified as significant independent risk factors for DJP. Longer instrumented levels, a greater preoperative SVA and a smaller PT were found to be strongly associated with the presence of DJPs in patients treated for DLS. The degeneration of the paraspinal muscles may not be related to the occurrence of DJPs. For DLS patients, the occurrence of DJP can be reduced by selecting reasonable fusion segments and evaluating the patient's sagittal balance and spino-pelvic parameters before operation.

Is the pelvic incidence a determinant factor for kyphosis curve patterns of ankylosing spondylitis patients?

To investigate the influence of pelvic incidence (PI) on the kyphosis curve patterns and clinical outcomes in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis and to construct a classification of AS according to the PI value for surgical decision-making. 107 AS patients underwent single-level lumbar pedicle subtraction osteotomy (PSO) and finished a minimal of 2-year follow-up. All patients were divided into three groups: low PI (PI ≤ 40°), moderate PI (40° < PI ≤ 60°), and high PI (PI > 60°). Standing lateral radiographs were taken to evaluate the location of kyphotic apex, thoracic kyphosis (TK), lumbar lordosis (LL), C7 sagittal vertical axis (SVA), spino-sacral angle (SSA), global kyphosis (GK), PI, sacral slope (SS), and pelvic tilt (PT). Visual Analogue Scale (VAS) score, Oswestry Disability Index (ODI) and Bath Ankylosing Spondylitis Functional Index (BASFI) were used to evaluate quality of life. Before surgery, a significant difference was shown in the average LL and the mean GK in high PI group was the largest among the three groups. Correction of SVA, GK and LL in high PI group was the smallest among the three group. No significant difference in clinical outcomes was found among the three groups before surgery and at the final follow-up. Regarding the preoperative sagittal profile, the kyphosis curve pattern of moderate PI group is similar to that of low PI group. For AS patients in these two groups, harmonious sagittal alignment can be restored by a single-level PSO. However, the sagittal imbalance is insufficiently realigned by a single-level PSO in a patient with high PI.

Operative strategies for ankylosing spondylitis-related thoracolumbar kyphosis: focus on the cervical stiffness, coronal imbalance and hip involvement

BackgroundCervical stiffness, coronal imbalance and limited hip movement all play crucial roles in designing the corrective surgery for ankylosing spondylitis-related thoracolumbar kyphosis (AS-TLK). However, a comprehensive classification and tailored strategies for directing clinical work are lacking. This study aims to investigate the types and surgical strategies for AS-TLK that consider cervical stiffness, coronal imbalance and hip involvement as the key factors.Methods25 consecutive AS-TLK patients were divided into three types according to their accompanying features: Type I: with a flexible cervical spine; Type IIA: with a stiff cervical spine; Type IIB: with coronal imbalance; Type IIC: with limited hip movement. Type III is the mixed type with at least two conditions of Type II. Individual strategies were given correspondingly. Spinal-pelvic-femoral parameters were measured, Scoliosis Research Society outcome instrument-22 (SRS-22) was used and complications were recorded and analysed.ResultsAll patients (Type I 10, Type II 8 and Type III 7) underwent surgery successfully. 13 cases with 16 complications were recorded and cured. The patients were followed up for 24–65 months with an average of 33.0 ± 9.6 months. Both the sagittal and coronal parameters were corrected and decreased significantly (all, p < 0.05). SRS-22 scores showed a satisfactory outcome.ConclusionThoracolumbar kyphosis secondary to ankylosing spondylitis are complex and variable. Considering the factors of cervical stiffness, coronal imbalance and hip involvement assists in making decisions individually and achieving a desired surgical result.

Camptocormia and drop head syndrome secondary to myotonic dystrophy type 1: a case series and literature review

Camptocormia and drop head syndrome (DHS) is an abnormal flexion of the spine (kyphosis) caused by paraspinal muscle weakness. Camptocormia is used when the kyphosis is at the thoracolumbar levels and DHS is used when the kyphosis is in the cervical area. This manifestation can be seen in different populations including myotonic dystrophy type 1 (DM1). The purpose of this article is to present a case series of patients with DM1 developing camptocormia or DHS in addition to a literature review about pathophysiology, diagnosis, and treatment. The case series are 2 patients diagnosed with camptocormia and 1 patient diagnosed with DHS secondary to DM1 evaluated at a neuromuscular outpatient clinic. Physical examination showed flexible thoracolumbar kyphosis in 2 patients, and 1 patient presented with a flexible kyphotic cervical spine. Imaging studies showed atrophy of the paraspinal muscles (magnetic resonance imaging and computed tomography scan). Physical therapy was prescribed with poor results. The orthotic recommendation was given to patients with camptocormia with marked functional improvement. The DHS patient showed no improvement with an orthosis. In conclusion, camptocormia and DHS are possible long-term complications in patients with DM1. Clinically they present with flexible cervical and thoracic kyphosis due to atrophic changes with fatty infiltration at the paraspinal muscles. Physical therapy has poor results, and orthosis use has mixed results.

Selecting the Vertebra above Sagittal Stable Vertebra as the Distal Fusion Level in Scheuermann's Kyphosis: A Prospective Study with a Minimum of 2-Year Follow-Up.

The proper selection of the lower instrumented vertebra (LIV) remains controversial in the surgical treatment of Scheuermann's disease and there is a paucity of studies investigating the clinical outcomes of fusion surgery when selecting the vertebra one level proximal to the sagittal stable vertebra (SSV-1) as LIV. The purpose of this study is to investigate whether SSV-1 could be a valid LIV for Scheuermann kyphosis (SK) patients with different curve patterns. This was a prospective study on consecutive SK patients treated with posterior surgery between January 2018 and September 2020, in which the distal fusion level ended at SSV-1. The LIV was selected at SSV-1 only in patients with Risser >2 and with LIV translation less than 40 mm. All of the patients had a minimum of 2-year follow-up. Patients were further grouped based on the sagittal curve pattern as thoracic kyphosis (TK, n = 23) and thoracolumbar kyphosis (TLK, n = 13). Radiographic parameters including global kyphosis (GK), lumbar lordosis (LL), sagittal vertical axis (SVA), LIV translation, pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) were measured preoperatively, postoperatively, and at the latest follow-up. The intraoperative and postoperative complications were recorded. The Scoliosis Research Society (SRS)-22 scores were performed to evaluate clinical outcomes. A total of 36 patients were recruited in this study, with 23 in the TK group and 13 in the TLK group. In TK group, the GK was significantly decreased from 80.8° ± 10.1° to 45.4° ± 7.7° after surgery, and was maintained at 45.3° ± 8.6° at the final follow-up. While in the TLK group, GK was significantly decreased from 70.7° ± 9.2° to 39.1° ± 5.4° after surgery (p < 0.001) and to 39.3° ± 4.5° at the final follow-up. Meanwhile, despite presenting with different sagittal alignment, significant improvement was observed in LL, SVA, and LIV translation for both TK and TLK groups (p < 0.05). Self-reported scores of pain and self-image in TK group and scores of self-image and function in TLK group showed significant improvement at the final follow-up (all p < 0.05). Distal junctional kyphosis (DJK) was observed in two patients (8.7%) in TK group, and one patient (7.7%) in TLK group. No revision surgery was performed. Selecting SSV-1 as LIV can achieve satisfactory radiographic and clinical outcomes for SK patients with different curve patterns without increasing the risk of DJK. This selection strategy could be a favorable option for SK patients with Risser sign >2 and LIV translation less than 40 mm.

The Association Between Corrective Surgery for Adult Spinal Deformity and Serum Levels of Hepatobiliary Enzymes.

Background and objective The surgery to correct adult spinal deformity (ASD) is associated with a rare, but life-threatening complication called acute celiac artery compression syndrome (ACACS). To our knowledge, there is currently no study in the literature regarding the abnormal elevation of serum levels of hepatobiliary enzymes after surgery to correct the deformity. In light of this, the purpose of this study was to investigate this potential association. Materials and methods We collected data on 74 patients with ASD who underwent correction surgery at our institution. A Spearman's rank-order correlation was used to assess the association between serum levels of hepatobiliary enzymes and spinal parameters. Factors showing a correlation coefficient of 0.2 or more were combined in a stepwise multiple regression analysis. Results The mean age of the patientswas 68.4 ± 7.7 years; the study comprisedsix men and 68 women. In our stepwise multiple regression analysis, there were two valid models that included spinal parameters as independent variables: changes in lactate dehydrogenase (LDH) - changes in thoracolumbar kyphosis (TLK) (B -0.0025 ± 0.0007, p<0.01), and changes in LDH - preoperative T12-L1 kyphosis (B 0.0031 ± 0.001, p<0.01). Additionally, both valid models contained median arcuate ligament (MAL) overlap defined as MAL crossing the base of the celiac artery (CA) as a significant independent variable. Conclusions Greater sagittal correction of TLK, larger preoperative T12-L1 kyphosis, and MAL overlap were factors associated with an elevated serum level of LDH. Although few patients werereported to have clinically severe symptoms, "potential" ACACS due to a temporary blood flow disturbance can occur in this patient population.

E40 Chronic recurrent multifocal osteomyelitis: management disease in Tunisian child population

Abstract Introduction Chronic recurrent multifocal osteomyelitis (CRMO) is a rare disease especially in Tunisian population and occurs more often in children. It is a bone non-microbial inflammatory disease that frequently involves long bones, pelvis and spine. The autoimmune origin seems to be the most suggested pathogenic theory. It often manifests by multifocal bone pain with insidious onset and recurrent course Objectives The aim of the study was to highlight specific symptoms, frequent localization, investigations, imaging and multidisciplinary management of CRMO Methods We retrospectively reviewed five children on follow up for CRMO in our institution on both pediatric orthopedic and rheumatology department between 2012 and 2022. We have noted epidemiology features, symptoms, clinical manifestations, medical and orthopedic management, sequallae and outcome at last follow up for each case in order to identify specificities and correlations Results Five children, including 3 female and 2 males, were treated for such disease during this period. The mean age at diagnosis was 13.2 years (9–16). Duration of symptoms prior to diagnosis was 1–6 months. Inflammatory bone pain was present in all cases and isolated swelling in one case (clavicle). CRMO involves spine, femur, foot, humerus and clavicle and only two children present more than two locations. No correlation between age and location was noted. Radiographs were normal at presentation in four cases and showed reactive hyperostosis during the course of the disease in two cases. Whole-body MRI revealed some clinically non symptomatic localizations in three cases. The differential diagnoses were osteomyelitis, inflammatory arthritis, vertebral fracture and Ewing's sarcoma in one case. Microbiological examinations were negative in all cases. Biopsy, performed in two cases (spine, clavicle) showed non-specific inflammatory bone involvement. Non-steroidal anti-inflammatory drugs were used in four cases and salazopyrine in one case with durable remission at last follow up. CRMO involved spine in two cases where brace has been used for a 6-month period. A mild progression of thoraco-lumbar kyphosis was noted in one case (local kyphosis from 6 to 10°). Conclusion Even if CRMO remains diagnosis of exclusion, it should be managed early to prevent functional sequellae especially in spine where orthosis is essential to prevent kyphosis and vertebrae collapses. Asymptomatic bone involvement can be revealed by whole body MRI. Non steroid anti-inflammatory drugs and salazopyrin in second intention seems to be effective to stabilize bone lesion. Ethics Informed consent was obtained for each patient for diffusing their imaging file in scientific congress

The Role of Thoracic Tilt in Identifying Thoracic Compensation and Predicting Proximal Junctional Kyphosis in Degenerative Lumbar Scoliosis.

A retrospective cohort study of consecutive patients. To investigate the clinical value of thoracic tilt (TT) in characterizing thoracic compensation and predicting proximal junctional kyphosis (PJK) in degenerative lumbar scoliosis (DLS). Thoracic compensation has been shown to be associated with the development of PJK, while thoracic shape and morphology in patients with DLS remain understudied. Patients with DLS who underwent long-segment fusion were divided into a PJK group and a non-PJK group. Asymptomatic elderly volunteers were recruited as healthy controls. Thoracic parameters were measured in both cohorts, including the TT, T1-L1 pelvic angle (TLPA), T12 slope, thoracic kyphosis (TK, T4-T12), global thoracic kyphosis (GTK, T1-T12), and thoracolumbar kyphosis (TLK, T10-L2). Multivariate logistic regression was used to assess the association between TT and the development of PJK, adjusting for confounders. Multivariate linear regression was used to establish the predictive formula for TT. A total of 126 patients with DLS were enrolled, of which 37 (29.4%) developed PJK. Compared with 110 healthy controls, DLS patients had significantly greater TT, TLPA, T12 slope, and TLK as well as smaller TK and GTK (all P <0.001). Preoperatively, the PJK group showed significantly greater TT ( P =0.013), TLPA ( P <0.001), and TLK ( P =0.034) than the non-PJK group. No significant differences were found in TK and GTK before surgery. Postoperatively, the PJK group showed significantly greater TT ( P <0.001), TLPA ( P <0.001), TLK ( P <0.001), and proximal junctional angle ( P <0.001). Multivariate logistic regression analysis showed that greater postoperative TT was associated with the development of PJK. Multivariate linear regression analysis suggested that the regression formula was postoperative TT=0.675×T12slope+0.412×TK+0.158×TLK-4.808 ( R2 =0.643, P <0.001). The novel sagittal parameter TT can be used for the evaluation of thoracic compensation. Greater preoperative TT might represent a decompensated state of TK. Rebalancing the TT in a sagittal neutral position might help to prevent PJK in patients with DLS.

Walking status and spinopelvic parameters in young children with achondroplasia: 10-year follow-up.

Thoracolumbar kyphosis (TLK) is common in children with achondroplasia and resolves in 90% by 10years of age. Our purpose was to describe the natural progression of TLK in a cohort of pre-walking children with achondroplasia. A single-center, retrospective review identified 62 children (32 male, 30 female) with achondroplasia. Clinical information and sagittal spinopelvic parameters were collected. The children were divided into positive pelvic tilt (PT) and negative PT. All parents were routinely counseled about unsupported sitting. Spontaneous resolution rate was 64.5% at 1-year post-walking, 74.2% at 5years of age, and 88.7% at 10years of age. None of the children required posterior spinal decompression and fusion for progressive deformity or symptomatic spinal stenosis. At 1-year post-walking, the negative PT group had a higher sacral slope (p = 0.006), higher lumbar lordosis (p < 0.001), and lower pelvic incidence (p < 0.001). This relationship remained constant up to 10years of age, and there was no association with TLK. In this largest series to date, spontaneous resolution of TLK in children with achondroplasia was 64.5% at 1-year post-walking, 74.2% at 5years of age, and 88.7% in children followed to 10years of age. With early identification and regular follow-up with patient education, no patient in this series required treatment or developed symptomatic spinal stenosis. While not predictive of resolution of TLK, the dichotomous presentation of PT in young children with achondroplasia persists at 5 and 10years of age and reliably predicts the spinopelvic parameters. III-retrospective comparative study.

Effect of morphological changes in the sagittal plane of vertebrae and discs on degenerative kyphodeformity

To explore the effects of morphological changes such as vertebral wedge deformation and disc degeneration (collapse) on adult thoracolumbar/lumbar degenerative kyphosis(TL/LDK) deformity. A retrospective analysis of 32 patients with spinal TL/LDK deformity admitted from August 2015 to December 2020, including 8 males and 24 females, aged 48 to 75(60.3±12.4) years old. On the long-cassette standing upright lateral radiographs, the coronal Cobb angle, sagittal thoracic lumbar/lumbar kyphosis angle(KA) of spine were measured, and the height and wedge parameters of apex vertebral(AV) and two vertebrae(AV-1, AV-2, AV+1, AV+2) above and below AV and the intervertebrae and the intervertebral disc(AV-1D, AV-2D, AV+1D, AV+2D) were evaluated, involving anterior vertebral body height(AVH), posterior vertebral body height(PVH), vertebral wedge angle(VWA), ratio of vertebral wedging(RVW), anterior disc height(ADH), posterior disc height(PDH), disc wedge angle(DWA), ratio of disc wedging(RDW), and DWA/KA. The average angle of kyphosis was (44.2±19.1)°. A significant decrease in anterior height of vertebral was observed compared to the posterior height of vertebral(P<0.005). There was no significant difference in anterior and posterior height of discs. The vertebral wedging ratio/contribution ratio:AV-2(14.98±10.95)%/(14.21±8.08)%, AV-1(21.08±12.39)%/(18.09±7.38)%, AV(26.94±11.94)%/(25.52±8.64)%, AV+1(24.19±8.42)%/(20.82±8.69)%, AV+2(20.56±7.80)%/(15.60±9.71)%, total contribution(94.23±22.25)%, the disc wedging ratio/contribution ratio:AV-2D(2.88±2.57)%/(5.27±4.11)%, AV-1D(1.98±1.41)%/(2.29±2.16)%, AV+1D(-5.54±3.75)%/(-0.57±0.46)%, AV+2D(-8.27±4.62)%/(-1.22±1.11)%, total contribution (5.77±4.79)%. And the contribution rate of AV was significantly higher than that of adjacent vertebral(P<0.05). The vertebral body and intervertebral disc shape both have influence on thoracolumbar kyphosis. However, the contribution of vertebral morphometry to the angle of TL/LDK deformity is relatively more important than the disc. The contribution of the wedge change of the AV to the TL/LDK deformity is particularly significant.

The Correlation of Global Spinal Realignment With the Quality of Life After Corrective Surgery for Delayed Thoracolumbar Osteoporotic Fracture-Related Kyphosis.

Few studies have been conducted to evaluate the precise impact of corrective surgery on sagittal spinal realignment and clinical outcomes in cases of delayed thoracolumbar osteoporotic fracture-related kyphosis. To assess the efficacy of corrective surgery on sagittal spinal alignment and investigate the relationship between spinal alignment and health-related quality of life (HRQoL) in patients with delayed thoracolumbar osteoporotic fracture-related kyphosis. A total of 78 patients were enrolled. The characteristics and surgical variables were meticulously documented. The sagittal spinal parameters were measured, and the HRQoL was evaluated using Oswestry Disability Index (ODI), SF-12 Physical Component Score (SF-12 PCS), and Scoliosis Research Society-22 Patient Questionnaire (SRS-22) before and after surgery. The changes in spinal parameters and HRQoL were analyzed through the paired t -test. The Pearson correlation analysis was performed to analyze the correlation of parameters with HRQoL. Then, a multiple stepwise regression analysis was performed with HRQoL scores as the dependent variable and spinal parameters as the independent variable. The operative time was 185.9 ± 33.2 min, and the estimated blood loss was 782.8 ± 145.2 mL. The results of the paired t -test revealed a significant difference preoperatively and at the final follow-up in the thoracic kyphosis, thoracolumbar kyphosis (TLK), lumbar lordosis, T9 tilt, pelvic tilt, sacral slope, sagittal vertical axis, and spinosacral angle as well as the ODI, SF-12 PCS, and SRS-22 ( P < .05). Multiple stepwise regression analysis revealed that TLK and pelvic tilt, TLK and sagittal vertical axis, and TLK were the primary parameters affecting the ODI, SF-12 PCS, and SRS-22, respectively. Corrective surgery can effectively realign the global spine and improve HRQoL in patients with delayed thoracolumbar osteoporotic fracture-related kyphosis. The change of TLK is a driving factor to realign the global spine.