Severe Thoracolumbar Kyphosis Research Articles

A Femoral Neck Osteotomy for the Patients with Ankylosing Spondylitis and Thoracolumbar Kyphosis Combined with Hip Flexion Contracture.

The surgical treatment of patients with ankylosing spondylitis and severe thoracolumbar kyphosis combined with hip flexion contracture is very difficult for all the surgeons. The femoral neck osteotomy (FNO) is the first step to break the ice. The evaluation of a new modified FNO method is very important to improve the curative effect. Five male patients with nine bone-fused hips who underwent the new femoral neck osteotomy were included from October 2021 to March 2022. The FNO was designed that the saw blade was manipulated from the lateral femoral neck base to the inferior part of the femoral head, keeping Pauwels' angle less than 30° on the coronal plane. On the transverse plane, the angle between the saw blade and the coronal plane was more than 15°. On the sagittal plane, the saw blade cut through the femoral neck. They accepted pedicle subtraction osteotomy (PSO) after FNO according to the patient' recovery. Then, 2 weeks later, the patients underwent total hip arthroplasty (THA). The visual analogue scale (VAS), Harris hip score (HHS) and passive hip flexion-extension range of motion (ROM) were used to evaluate hip function. The data were analyzed by paired t-test. The average operation time and blood loss of FNO, the average interval between FNO and THA were collected. The average angle of the trunk and lower limb (ATL) was 36.33° ± 16.36° pre-FNO, 82.89° ± 13.51° post-FNO and 175.22° ± 3.42° post-THA. The average VAS scores were 0 pre-FNO, 5 ± 1.58 post-FNO and 2.6 ± 0.55 post-THA. The average HHS was 43.56 ± 1.59 preoperatively and 83.89 ± 2.21 postoperatively. The average hip extension ROM was 23.89° ± 12.69° pre-FNO, -22.67° ± 14.18° post-FNO and - 3.33° ± 2.50 post-THA°. The average hip flexion ROM was 23.89° ± 12.69° pre-FNO, 35.56° ± 12.11° post-FNO and 104.44° ± 5.27° post-THA. The differences among them were significant (p < 0.05). Only one hip (11.11%) displaced completely after FNO. A new modified FNO was developed, which can provide osteotomy with a certain degree of stability and greater ease for performing PSO and THA.

Orientation of Osteotomized Vertebrae in 2-Level Pedicle Subtraction Osteotomy Plays a Crucial Role in the Remodeling of Harmonious Sagittal Curve for Severe Thoracolumbar Kyphotic Deformity Caused by Ankylosing Spondylitis.

Few studies reported the remodeling of harmonious sagittal curve after 2-level pedicle subtraction osteotomy (PSO) for severe thoracolumbar kyphosis in ankylosing spondylitis (AS). To investigate how the orientation of osteotomized vertebrae (OV) affects the remodeling of harmonious sagittal curve in patients with AS undergoing 2-level PSO. Twenty-six patients treated with 2-level PSO were reviewed. Plumb lines of thoracic apex and lumbar apex, the superior/inferior endplate angle of OV, and OV tilt were measured. Patients with AS were grouped based on the postoperative lumbar lordotic apex (LLA, L3 or L4 vs L5 or others). The level of thoracic kyphotic apex was positively correlated with that of superior OV postoperatively. Larger sacral slope, L1-L3 lordotic angle, and plumb lines of lumbar apex could be obtained in patients with LLA at L3 or L4, accompanied with larger superior endplate angle of OV and OV tilt of inferior OV ( P < .05). Besides, larger lumbar lordotic angle (LL) was observed in these patients (marginally significant, P = .057). For patients with relocated LLA at L5 or others, lower pelvic incidence was observed, accompanied with significant loss of correction ( P < .05) and worse Visual Analog Scale scores (marginally significant, P = .054) during follow-up. Ventrally leaning inferior OV combined with dorsally leaning superior OV contributed to the most harmonious sagittal curve defined as thoracic kyphotic apex at T8 or above and LLA at L3 or L4. Sagittal curve with LLA at L5 could be acceptable in patients with more severe kyphosis, especially those with low pelvic incidence.

Global realignment after posterior vertebral column resection in severe thoracolumbar post-tubercular kyphosis: correlation with patient-reported outcomes.

To investigate spinal realignment in patients with severe post-tubercular kyphosis (PTK) who underwent posterior vertebral column resection (PVCR) and its correlation with patient-reported outcomes (PROs). Eighty-two patients were included in this study. Spinopelvic parameters (focal scoliosis (FS), coronal balance (CB), sagittal vertical axis (SVA), focal kyphosis (FK), C2-7 lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL), sacral slope (SS), pelvic tilt (PT), pelvic incidence (PI), and pelvic incidence minus lumbar lordosis (PI-LL)) and PROs (Visual Analog Scale (VAS) and Oswestry Disability Index (ODI)) were analyzed. The correlation between spinopelvic parameters and PROs was evaluated. FK, FS, CL, TK, LL, and PI-LL significantly changed after surgery. FK decreased from pre-operative 108.5 ± 16.4° to 31.8 ± 4.5° at threemonths after surgery and increased to 38.7 ± 6.6° at final follow-up (P < 0.001). FS decreased from pre-operative 20.9 ± 2.2° to 5.1 ± 2.2° at final follow-up (P < 0.001). CL decreased from pre-operative 7.2 ± 7.3° to 3.3 ± 8.3° at final follow-up (P = 0.002). TK improved from pre-operative - 5.6 ± 7.1° to 12.9 ± 8.2° at final follow-up (P < 0.001). LL decreased from pre-operative 75.5 ± 12.6° to 45.5 ± 7.9° at final follow-up (P < 0.001). PI-LL improved from pre-operative - 24.8 ± 13.4° to 4.8 ± 9.9° at final follow-up (P < 0.001). The improvement of PROs was found to be significantly correlated with the variations of FK, CL, TK, LL, and PI-LL. The multiple regression analysis revealed that FK was an independent predictor for the improvement of VAS and ODI. PVCR is effective in treating severe PTK, which can significantly improve patients' clinical and radiographic outcomes. Spine surgeons should pay more attention to reducing the residual kyphosis.

Pedicle Subtraction Osteotomy in Lateral Position: A New Strategy for Correcting Severe Thoracolumbar Kyphosis Combined with Hip Flexion Contracture in Ankylosing Spondylitis.

ObjectiveTo describe spinal osteotomy in lateral position, which might be a new strategy for correcting thoracolumbar kyphotic deformity combined with severe hip flexion contracture, and to present two cases in which this method was successfully performed.MethodsSpinal osteotomies in lateral position were performed in two patients with severe thoracolumbar kyphosis combined with hip flexion contracture, which was not suitable for operation in the prone position. Case 1: a 33‐year‐old female AS patient still had severe hip flexion contracture due to poor rehabilitation after total hip replacement (THR). The range of movement of the hip was only about 15° in right and 10° in left. Pre‐operativethoracic kyphosis (TK), thoracolumbar kyphosis (TLK), lumbar lordosis (LL), and sagittal vertical axis (SVA) were 52.4°, 49.1°, 42.7°, and 315 mm, respectively. Pedicle subtraction osteotomy (PSO) at L3 was performed in the lateral position. The eggshell procedure was used during osteotomy. Case 2: a 45‐year‐old male AS patient presented coexisting rigid thoracolumbar kyphosis and hip flexion contracture. The range of movement of the hip was only about 20° in right and 25° in left. Pre‐operativeTK, TLK, LL and SVA were 34.9°, 66.8°, 58.8° and 290.8 mm, respectively. PSO at L2 was performed in lateral position. The eggshell procedure was also used.ResultsSagittal malalignments of both patients were greatly improved. For case 1, the total operation time was 5.5 h. The blood loss was 1500 mL and the amount of allogeneic blood transfusion was 1580 mL during the operation. SVA was reduced to 127 mm and LL decreased from preoperative 42.7° to −28.4°. The correction angle through L3 was 34.7° and the correction angle through the osteotomy segment was 62.9°. For case 2, the duration of surgery was 6.5 h. The operative blood loss was 2000 mL and the total amount of blood transfusion was 2020 mL. SVA was reduced to 209.8 mm and LL decreased from preoperative 58.8° to 9.2°.The correction angle through L2 was 37.1° and the correction angle through the osteotomy segment was 55°. No intra‐operative or post‐operative complications were observed. Six months after PSO, case 1 had good posture for standing and sitting. The case 2 underwent bilateral THRs nine months after PSO.ConclusionPSO could be performed in the lateral position successfully. For AS patients who cannot be placed in the prone position due to coexisting severe thoracolumbar kyphosis and hip flexion contracture, performing spinal osteotomy in the lateral position as the first step is an alternative.

Selecting proper distal fusion level in severe thoracolumbar kyphosis secondary to late osteoporotic vertebral compression fracture to limit distal complications

BackgroundSurgical treatment of severe thoracolumbar kyphosis (TLK) secondary to late osteoporotic vertebral compression fracture (OVCF) presents several challenges to spine surgeons. Proper selection of distal fusion level is an important issue in surgical planning to decrease the likelihood of distal mechanical complications. This study was designed to compare the clinical and radiographic outcomes in elderly patients suffering from severe TLK related with late OVCF between different distal fusion strategies and to recommend a superior distal fusion level for these patients. MethodsA total of 57 consecutive subjects with a minimum follow-up of two years were retrospectively reviewed. TLK was defined as the hyperkyphosis with an apex below T10. Severe TLK was defined as the Cobb angle of kyphosis ≥60°. Patients fused to sagittal stable vertebra (SSV) were assigned to Group SSV, while those fused to the vertebra above and below SSV were assigned to Groups SSV- and SSV+, respectively. Bone cement was used to enhance pedicle screw fixation. Clinical and radiographic results were collected and compared between different groups. ResultsDeformity corrections and living quality improvements at the latest follow-up were superior in Group SSV than Group SSV- with shorter fusion levels, while to the equal extent with Group SSV+ with longer fusion levels. 7 cases of distal complications were observed in Group SSV-. Negatively balanced lowest instrumented vertebra was revealed to be the independent factor predicting distal complications. Patients’ satisfaction of their surgical management was greater in Group SSV than Group SSV- (83.2 ± 4.4% vs. 70.5 ± 10.9%, P = 0.024), while comparable with Groups SSV + SSV+ (84.8 ± 5.7%). ConclusionsFusion to SSV with cement-augmented pedicle screws could limit the development of distal junctional mechanical complications after surgical treatment for severe TLK secondary to late OVCF in elderly patients, while achieves satisfactory deformity correction with the preservation of necessary lumbar motility.

RETRACTED ARTICLE: Osteotomy in lateral position for correcting severe thoracolumbar kyphosis combined with hip flexion contracture in ankylosing spondylitis: a case report and literature review.

The purpose of this case study and literature review is to describe the successful spinal osteotomy in the lateral position performed on ankylosing spondylitis (AS) patients with thoracolumbar kyphotic deformity combined with severe hip flexion contracture. The case study and literature review aim to determine alternative surgical methods for patients who are inoperable in the prone position. A 33-year-old female AS patient with a prior total hip replacement (THR) is later diagnosed with severe thoracolumbar kyphosis and hip flexion ankylosis. The patient developed hip flexion contracture due to the excessive anteversion angle of the acetabular cup and poor rehabilitation from the THR. Due to the patient's compounding medical conditions and THR, it was determined that she was inoperable in the prone position; therefore, the Smith-Petersen osteotomy (SPO) and pedicle subtraction osteotomy (PSO) at L3 was performed in the lateral position, not the prone position. The patient's sagittal malalignment was significantly improved. Through the osteotomy segment, the correction angle was 60°. There were no intraoperative or postoperative complications. At six-month follow-up, the osteotomy site demonstrated complete fusion. The PSO + SPO could be performed successfully in a lateral position. For those AS patients unable to be positioned prone due to coexisting severe thoracolumbar kyphosis and hip flexion contracture, performing spinal osteotomy in the lateral position as the first step is an alternative and gives comparable results to an operation performed in the prone position.

Posterior Vertebral Column Resection (pVCR) for Severe Thoracolumbar Kyphosis in Patients With Achondroplasia.

Study Design:Retrospective cohort study.Objective:We aimed to evaluate the safety and validity of posterior vertebral column resection (pVCR) for severe thoracolumbar kyphosis (TLK) in the achondroplasia (ACH) patients.Methods:Seven ACH patients (male: female = 6:1) who underwent pVCR procedures due to severe TLK from December 2008 to December 2017 in the authors’ hospital were included in this retrospective study. Their mean follow-up duration was 67 ± 35 months. Their clinical characteristics, radiologic characteristics, surgical characteristics and surgical complications were reviewed.Results:A total of 8 vertebrae were removed with an average of 5 ± 2 levels of decompression and 9 ± 2 segments instrumented. The mean correction rates of TLKs and the main curves were 73 ± 15% and 87 ± 6%, respectively. Five patients (71%) had preoperative neurological symptoms with a mean Japanese Orthopedic Association (JOA) score of 8 ± 3 points. Their neurological functions were all improved, with a recovery rate of 78 ± 32% for the JOA score at the last follow-up. Four patients (57%) suffered from surgical complications, including rod breakages (43%), neurological complications (28%), dural tears (14%), cerebrospinal fluid leaks (14%) and proximal junction kyphosis (14%).Conclusions:pVCR can offer a good correction for TLK and improve neurological function with extensive laminectomies in ACH patients. But the morbidity of surgical complications is relatively high. Therefore, it is a reserved surgical option for severe TLK in ACH patients by experienced spinal surgeons, especially with apical markedly hypoplastic vertebrae.

Comparison of Posterior Unilateral Vertebral Column Resection Versus Posterior Vertebral Column Resection for Severe Thoracolumbar Angular Kyphosis as a Revision Surgical Modality: A Retrospective Cohort Study.

Objective:The objective of this study was to determine the safety and efficacy of posterior unilateral vertebral column resection (PUVCR) as revision surgery for severe thoracolumbar angular kyphosis.Patients and Methods:This is a retrospective cohort study. Adult patients undergoing revision surgery for severe thoracolumbar angular kyphosis in 2010–2016 with ≥2-year follow-up at our institution were assessed. Perioperative complications and clinical outcomes, including blood loss, operation time, Visual Analog Scale score, Oswestry Disability Index, and preoperative and postoperative kyphotic angles, were analyzed.Results:This study included 58 patients who were divided into the PUVCR group and the posterior vertebral column resection (PVCR) group. Age (P=0.810), sex distribution (P=0.500), and vertebrae that underwent surgery (P=0.638) were similar in the 2 groups. Shorter mean operation time was observed in the PUVCR group as compared with the PVCR group (P<0.001). In addition, less blood loss was recorded in the PUVCR group as compared with the PVCR group (P=0.001). There were no significant differences between the 2 groups in a change of Visual Analog Scale scores postoperation versus preoperation (P=0.961), and at postoperative 3 months (P=0.906), 12 months (P=0.752), and 24 months (P=0.811) versus postoperation, respectively. There were no significant differences between the 2 groups in Oswestry Disability Index changes postoperation versus preoperation (P=0.157), and at postoperative 3 months (P=0.899), 12 months (P=0.947), and 24 months (P=0.811) versus postoperation, respectively. PUVCR and PVCR were comparable in deformity correction (P=0.434) and final angle correction (P=0.790). Complication rates in the PUVCR and PVCR groups were 7.1% and 36.7%, respectively.Conclusion:PUVCR has comparable safety and efficacy to PVCR in treating severe thoracolumbar angular kyphosis, with the advantages of the shorter operation time, less blood loss, and fewer complications.

Severe thoracolumbar congenital kyphosis treated with single posterior approach and gradual "in situ" correction.

Congenital kyphosis results from the failed formation of the vertebrae during the embryonic period and may be associated with cardiac, urogenital, or spinal cord anomalies. Surgical treatment is the best choice through anterior, posterior, or both approaches. This study aims to evaluate the effect of posterior gradual correction using the "in situ" bender to correct severe thoracolumbar congenital kyphosis with or without osteotomy or excision of the vertebra. Twenty-five patients with an age range of 2-23 (mean ± SD = 12.58 ± 6.03) years with severe thoracolumbar kyphosis were treated surgically at our institution between 2004 and 2013. Pedicle screwing, osteotomy, and gradual "in situ" bending through the single posterior approach were the choices of treatment. Cobb's angle, patient's height, and SRS-22r were used to evaluate the patients preoperatively and postoperatively. Follow-up periods were 35-136 months. Cobb's angle pre-surgery range was 35-180 (81.48 ± 39.1) degrees improved post-surgery to 0-45 (21.72 ± 13.47) degrees (p-value <0.0001). The range of patients' standing height pre-surgery was 79-170 (142.42 ± 24.85) centimeters increased after surgery to 81-175 (147.76 ± 26.33) centimeters (p-value <0.0001). SRS-22r pre-surgery range was between 2.12 and 3.904 (3.2 ± 0.77) and improved post-surgery to 4.16 and 4.96 (4.59 ± 0.29) (p-value = 0.046). Gradual correction with the "in situ" bender with or without osteotomy through the single posterior approach can give satisfying clinical (patients' standing height and SRS-22r scores) and radiological (Cobb's angle) results to treat severe congenital thoracolumbar kyphosis.

Staged cervical osteotomy:a new strategy for correcting ankylosing spondylitis thoracolumbar kyphotic deformity with fused cervical spine

BackgroundIn patients with cervical ankylosis, the chin-brow vertical angle (CBVA) should be taken into consideration. Usually, the correction of sagittal balance is sacrificed to ensure the patient has a horizontal visual field. To our knowledge, a staged osteotomy strategy for ankylosing spondylitis kyphotic deformity with an ankylosed cervical spine has not been reported before. The aim of this study was to describe a new surgical strategy with emphasis on sagittal balance and gaze angle in correction of kyphotic deformity with a rigid cervical spine in ankylosing spondylitis thoracolumbar kyphotic deformity.MethodsA 36-year-old man has severe thoracolumbar kyphosis accompanied with cervical hyperlordosis caused by ankylosing spondylitis. A two-stage surgery planning was managed. For the first stage, an interrupted two-level osteotomy was performed at the thoracolumbar area. After surgery, sagittal imbalance was corrected but the CBVA was − 21.7°. Cervical osteotomy was performed for the second stage. A flexion osteotomy was performed at C7, using anterior-posterior-anterior approaches.ResultsBoth sagittal imbalance and gaze angle of the patient were improved markedly. The osteotomy sites were documented fused. Complications were not observed during and after operation.ConclusionsThe aim of osteotomy for ankylosing spondylitis is to reestablish sagittal balance and improve forward gaze and the visual field. A staged cervical osteotomy is an alternative to reduce cervical lordosis to obtain a normal gaze angle. An anterior-posterior-anterior approach is recommended.

Spinal manifestations in 12 patients with musculocontractural Ehlers-Danlos syndrome caused by CHST14/D4ST1 deficiency (mcEDS-CHST14).

Musculocontractural Ehlers-Danlos syndrome caused by mutations in CHST14 (mcEDS-CHST14) is a recently delineated disorder, characterized by craniofacial, skeletal, visceral, and ocular malformations; and progressive cutaneous, skeletal, vascular, and visceral fragility-related manifestations. Spinal lesions, though one of the most serious complications, have not been investigated systematically. In this study, we report detailed and comprehensive information about spinal lesions of 12 patients with a mean age at the first visit of 13.4 years. Eight patients (66.7%) had scoliosis with a Cobb angle ≥10°, including one with severe scoliosis with a Cobb angle ≥45°. Five patients (41.7%) had kyphosis at the thoracolumbar junction with a kyphotic angle ≥20°. Three patients (25%) developed severe thoracolumbar kyphosis with a kyphotic angle ≥50° accompanied by thoracic lordosis with a wedge-like vertebral deformity and anterior vertebral osteophyte at the thoracolumbar junction, and two of them underwent surgical correction: complicated by fistula formation in one and performed safely and effectively through two-staged operation in the other. Six patients (50.0%) had cervical kyphosis, all of whom except one had kyphosis ≥20° at the thoracolumbar level. Two patients (16.7%) had atlantoaxial subluxation, and 10 patients (83.3%) had cervical vertebral malformations. Patients with mcEDS-CHST14 are susceptible to develop scoliosis, thoracolumbar kyphosis, and cervical kyphosis; and are recommended to have regular surveillance including total spine radiology. The present findings also suggest the critical role of dermatan sulfate in the development and maintenance of the spine.

Face-to-face intubation using a lightwand in a patient with severe thoracolumbar kyphosis: a case report

BackgroundSevere deformity of the thoracolumbar spine may cause difficulty in airway management during induction of anesthesia. Therefore, special attention must be devoted to patient safety.Case presentationA 65-year-old male with severe thoracolumbar kyphosis was scheduled to undergo posterior spinal fusion under general anesthesia. Due to his inability to lie supine, conventional tracheal intubation under direct laryngoscopy was difficult. Alternatively, face-to-face tracheal intubation using a lightwand in the semi-recumbent position was performed. Intubation was successful on the first attempt without any complications.ConclusionsThe face-to-face intubation technique using a lightwand is one of several alternative techniques for tracheal intubation in patients who cannot lie supine.

Computer Simulation of Two-level Pedicle Subtraction Osteotomy for Severe Thoracolumbar Kyphosis in Ankylosing Spondylitis.

Background:Advanced ankylosing spondylitis is often associated with thoracolumbar kyphosis, resulting in an abnormal spinopelvic balance and pelvic morphology. Different osteotomy techniques have been used to correct AS deformities, unfortunnaly, not all AS patients can gain spinal sagittal balance and good horizontal vision after osteotomy.Materials and Methods:Fourteen consecutive AS patients with severe thoracolumbar kyphosis who were treated with two-level PSO were studied retrospectively. All were male with a mean age of 34.9 ± 9.6 years. The followup ranged from 1–5 years. Preoperative computer simulations using the Surgimap Spinal software were performed for all patients, and the osteotomy level and angle determined from the computer simulation were used surgically. Spinal sagittal parameters were measured preoperatively, after the computer simulation, and postoperatively and included thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence, pelvic tilt (PT), and sacral slope (SS). The level of correlation between the computer simulation and postoperative parameters was evaluated, and the differences between preoperative and postoperative parameters were compared. The visual analog scale (VAS) for back pain and clinical outcome was also assessed.Results:Six cases underwent PSO at L1 and L3, five cases at L2 and T12, and three cases at L3 and T12. TK was corrected from 57.8 ± 15.2° preoperatively to 45.3 ± 7.7° postoperatively (P < 0.05), LL from 9.3 ± 17.5° to −52.3 ± 3.9° (P < 0.001), SVA from 154.5 ± 36.7 to 37.8 ± 8.4 mm (P < 0.001), PT from 43.3 ± 6.1° to 18.0 ± 0.9° (P < 0.001), and SS from 0.8 ± 7.0° to 26.5 ± 10.6° (P < 0.001). The LL, VAS, and PT of the simulated two-level PSO were highly consistent with, or almost the same as, the postoperative parameters. The correlations between the computer simulations and postoperative parameters were significant. The VAS decreased significantly from 6.1 ± 1.9 to 2.0 ± 1.1 (P < 0.001). In terms of clinical outcome, 10 cases were graded “excellent” and 4 cases were graded “good.”Conclusion:Two-level PSO using a preoperative computer simulation is a feasible, safe, and effective technique for the treatment of severe thoracolumbar kyphosis in AS patients with normal cervical motion.

How to Calculate the Exact Angle for Two-level Osteotomy in Ankylosing Spondylitis?

A prospective case series study. To describe and assess a two-level osteotomy method for the management of severe thoracolumbar kyphosis (TLK) in patients with ankylosing spondylitis (AS). To achieve better postoperative outcomes in these patients, a sophisticated preoperative surgical plan is required. Most deformities are managed using a one-level osteotomy and a two-level osteotomy is seldomly reported. Till date, no study has described a two-level osteotomy for these cases. From January 2011 to December 2012, 10 consecutive patients with ankylosing spondylitis who underwent two-level spinal osteotomy were studied. Pre- and postoperative full-length free-standing radiographs, including the whole spine and pelvis, were available for all patients. Pre- and postoperative radiological parameters, including T5-S1 Cobb angles, TLK, lumbar lordosis, pelvic incidence, pelvic tilt, sacral slope, and sagittal vertical axis were measured. Health related quality of life , including Oswestry Disability Index and Scoliosis Research Society-22 surveys were administered before surgery and at 1-year follow up. The preoperative and postoperative T5-S1 Cobb angles was 51.3° and -7.1°, respectively (P < 0.001). All patients demonstrated changes in postoperative radiographic parameters including decreased pelvic tilt (from 37.1° to 14.3°, P < 0.001), TLK (from 36.9° to 12.6°, P < 0.001), and sagittal vertical axis (from 21.4 cm to 7.1 cm, P < 0.001), increased lumbar lordosis (from -5.1° to -47.1°, P < 0.001), sacral slope (from 13.4° to 37.7°, P < 0.001), but no significant change in pelvic incidence. Health related quality of life scores at 1-year follow up were significantly improved compared to those before surgery. This calculation of two-level osteotomy provides an accurate and reproducible method for ankylosing spondylitis correction. By which, we can obtain satisfactory radiological parameters and clinical outcomes. 4.

Thoracolumbar kyphosis in patients with mucopolysaccharidoses

Aims Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses (MPS) with thoracolumbar kyphosis managed non-operatively or operatively in our institution. Methods In all 16 patients were included (eight female: eight male; 50% male), of whom nine had Hurler, five Morquio and two Hunter syndrome. Six patients were treated non-operatively (mean age at presentation of 6.3 years; 0.4 to 12.9); mean kyphotic progression +1.5o/year; mean follow-up of 3.1 years (1 to 5.1) and ten patients operatively (mean age at presentation of 4.7 years; 0.9 to 14.4); mean kyphotic progression 10.8o/year; mean follow-up of 8.2 years; 4.8 to 11.8) by circumferential arthrodesis with posterior instrumentation in patients with flexible deformities (n = 6). Results In the surgical group (mean age at surgery of 6.6 years; 2.4 to 16.8); mean post-operative follow-up of 6.3 years (3.5 to 10.3), mean pre-operative thoracolumbar kyphosis of 74.3o (42o to 110o) was corrected to mean of 28.6o (0o to 65o) post-operatively, relating to a mean deformity correction of 66.9% (31% to 100%). Surgical complications included a deep wound infection treated by early debridement, apical non-union treated by posterior re-grafting, and stable adjacent segment spondylolisthesis managed non-operatively. Thoracolumbar kyphosis &gt; +38o at initial presentation was identified as predicting progressively severe deformity with 90% sensitivity and 83% specificity. Discussion This study demonstrates that severe thoracolumbar kyphosis in patients with MPS can be effectively treated by circumferential arthrodesis. Severity of kyphosis at initial presentation may predict progression of thoracolumbar deformity. Patients with MPS may be particularly susceptible to post-operative complications due to the underlying connective tissue disorder and inherent immunological compromise. Take home message: Clinical and radiological data were reviewed for all patients with mucopolysaccharidoses with thoracolumbar kyphosis managed non-operatively or operatively in our institution. Cite this article: Bone Joint J 2016;98-B:229–37.

The Presence of a Negative Sacral Slope in Patients with Ankylosing Spondylitis with Severe Thoracolumbar Kyphosis

Pelvic retroversion is one of the mechanisms for regulating sagittal balance in patients with a kyphotic deformity. This retroversion is limited by hip extension, which prevents the pelvis from becoming excessively retroverted, achieving a sacral slope of <0°. However, a negative sacral slope can be found in some patients with ankylosing spondylitis with thoracolumbar kyphosis. The purpose of this study was to analyze this finding. We performed a retrospective review of 106 consecutive Chinese Han patients with ankylosing spondylitis with thoracolumbar kyphosis treated at our center from October 2005 to October 2012. Forty-one patients in whom the upper third of the femur was clearly visualized on lateral radiographs were analyzed. Seventeen had a sacral slope of <0° (group A) and twenty-four had a sacral slope of ≥0° (group B). Eight sagittal parameters were measured and compared between the two groups. Correlations among sacral slope, the femoral obliquity angle, and the other sagittal parameters were analyzed. Mean global kyphosis, lumbar lordosis, pelvic tilt, the sagittal vertical axis, and the femoral obliquity angle were significantly larger in group A than in group B, whereas mean pelvic incidence and sacral slope were significantly smaller in group A (p < 0.05 for all). Global kyphosis, lumbar lordosis, pelvic tilt, and the sagittal vertical axis were significantly negatively associated with sacral slope but positively associated with the femoral obliquity angle, whereas pelvic incidence was significantly positively associated with sacral slope but negatively associated with the femoral obliquity angle (p < 0.05 for all). The femoral obliquity angle was significantly negatively associated with sacral slope (p < 0.05). Negative sacral slope does exist in Chinese Han patients with ankylosing spondylitis with thoracolumbar kyphosis. This appears to be caused by severe kyphosis, an initially small sacral slope, and pronounced tilting of the femoral shaft as a result of knee flexion, resulting in the pelvis becoming further retroverted.

Two-level spinal osteotomy for severe thoracolumbar kyphosis in ankylosing spondylitis. Experience with 48 patients.

A retrospective study. To report surgical results for severe thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) corrected with 2-level spinal osteotomy. Transpedicular osteotomy in the lumbar spine is the major approach to correct kyphosis in AS. Most surgical procedures were performed at 1 level and only few literature report 2-level osteotomy in 1 patient. From January 2003 to June 2011, we reviewed 48 patients experiencing AS with severe thoracolumbar kyphosis who underwent stage 2-level spinal osteotomy in our hospital. The osteotomies were performed at T12 and L2 or L1 and L3, according to the apex of kyphosis. Preoperative and postoperative height, chin-brow vertical angle, sagittal balance, and the sagittal Cobb angle of the vertebral osteotomy segment were documented. Intraoperative, postoperative, and general complications were recorded. The chin-brow vertical angle improved from 65.0° ± 28.0° to 5.0°± 10.0° (P = 0.000) and the sagittal imbalance distance improved from 26.9 ± 10.4 cm to 10.6 ± 5.6 cm (P = 0.000). The mean amount of correction was 24.9° at the superior site of the osteotomy and 38.1° at the inferior site of the osteotomy. Postoperatively, all patients could walk with horizontal vision and lie on their backs. No major acute complications such as death or complete paralysis occurred. Five patients experienced complications such as infections (n = 1) and cerebrospinal fluid leaks (n = 4). Both Oswestry Disability Index and Scoliosis Research Society scores improved largely. Fusion at the osteotomy site was achieved in each patient, and no implant failures were noted. Single-stage 2-level osteotomy can effectively and safely correct kyphotic deformities of the thoracolumbar spine caused by AS. 3.

Combined spinal arthrodesis with instrumentation for the management of progressive thoracolumbar kyphosis in children with mucopolysaccharidosis

To evaluate the outcome and complications of a novel technique for the treatment of progressive thoracolumbar kyphosis in children with mucopolysaccharidosis (MPS). The medical records and spinal imaging of four consecutive paediatric patients who underwent a single stage anteroposterior spinal fusion with segmental pedicle screw instrumentation were reviewed. Patients underwent spinal deformity correction at the mean age of 3 years (2.4-3.7) with mean clinical follow-up of 3.2 years (2.1-4.5) and mean postoperative radiographic follow-up was 2.4 years (0.8-3). Preoperative kyphosis was corrected from a mean angle of 65º (63º-70º) to 6.5º (-12º-13º). Vertebral subluxation at the apex of the deformity was corrected from an average 64% (56-83%) to 12% (0-24%). Spinal cord monitoring with somatosensory evoked potentials (SSEP) was successfully obtained and stable throughout surgery. No instrumentation failure, loss of correction or junctional problems occurred at final follow-up. Anterior and posterior spinal arthrodesis with segmental pedicle screw instrumentation is a safety and reliable technique for the treatment of severe thoracolumbar kyphosis in children with MPS. This technique achieves excellent correction of the deformity with adequate decompression of the spinal canal. The fusion is limited to the thoracolumbar junction and interferes minimally with the longitudinal growth of the thorax. No neurological complications or intraoperative spinal cord monitoring events occurred. No loss of correction or junctional kyphosis was observed.

Change of Aortic Length After Closing-Opening Wedge Osteotomy for Patients With Ankylosing Spondylitis With Thoracolumbar Kyphosis

A computed tomographic study. To investigate the change in aortic length in patients with ankylosing spondylitis (AS) with thoracolumbar kyphosis after closing-opening wedge osteotomy (COWO). Several previous studies reported that COWO can effectively correct severe thoracolumbar kyphosis caused by AS. However, one disadvantage of COWO is elongation of the aorta, which increases the risk of aortic injury. To date, no studies have analyzed the alteration in aortic length in patients with AS undergoing COWO for thoracolumbar kyphosis. A total of 21 consecutive patients with AS with a mean age of 38.9 years undergoing COWO for the correction of thoracolumbar kyphosis were retrospectively studied. Radiographical measurements included global kyphosis, thoracic kyphosis, lumbar lordosis, angle of fusion levels, local kyphosis, and anterior height of the osteotomized vertebra. The computed tomographic scans of the spine were used to measure the aortic diameter (at the site of the osteotomy) and length (the length between the superior endplate of the upper instrumented vertebra and the inferior endplate of L4). The aortic length increased by an average of 2.2 cm postoperatively. Significant changes in global kyphosis, local kyphosis, angle of fusion levels, lumbar lordosis, anterior height of the osteotomized vertebra, and aortic diameter at the site of the osteotomy were observed (P < 0.01). Significant correlation was noted between aortic length and changes in global kyphosis (r = 0.525, P = 0.015), local kyphosis (r = 0.654, P = 0.001), angle of fusion levels (r = 0.634, P = 0.002), and lumbar lordosis (r = 0.538, P = 0.012). Aortic lengthening after COWO for correction of kyphosis was quantitatively confirmed by this study. Spine surgeons should be aware of the potential risk for the development of aortic injury in patients with AS undergoing COWO for the correction of thoracolumbar kyphosis. 4.

An exon polymorphism of programmed cell death 1 gene is associated with both the susceptibility and thoracolumbar kyphosis severity of ankylosing spondylitis in a Chinese Han population

BackgroundAlthough human leukocyte antigen (HLA)-B27 gene is the major susceptible gene associated with ankylosing spondylitis (AS), it has been recognized that non-HLA-B27 genes also play key roles in the development of AS. The purpose of this study is to investigate whether a single nucleotide polymorphism (SNP) in the exon region of the programmed cell death 1 (PDCD-1) gene is associated with the susceptibility or the thoracolumbar kyphosis severity of AS in a Chinese Han population. MethodsA total of 255 AS patients between January 2008 and October 2012 were recruited in this study. Two hundred and three healthy patients were recruited as normal controls. According to the severity of thoracolumbar kyphosis, the AS patients were further divided into group A (patients with kyphosis <70°, n=135) and group B (patients with kyphosis ≥70°, n=120). One exon polymorphism, rs2227982 (C/T) of PDCD-1 gene, was selected for analysis. Genotyping was performed by TaqMan probe assays in all the subjects. ResultsThere were significant differences of genotype distributions of rs2227982 between AS patients and normal controls. The frequency of the T allele was significantly higher in AS patients when compared with normal controls. The frequency of the T allele in group B was significantly higher than that in group A. Carriage of the TT genotype increased the risk of severe thoracolumbar kyphosis 1.9-fold in AS patients. ConclusionsOur study confirms a significant association between the SNP rs2227982 of PDCD-1 gene and the susceptibility of AS in a Chinese Han population. Moreover, the TT genotype is suggested to be associated with the severity of thoracolumbar kyphosis secondary to AS.