Correlation between Disc Imaging Observations and Clinical Efficacy after Percutaneous Endoscopic Lumbar Discectomy: A 1-Year Follow-up Study.

OBJECTIVE: The connection between alterations in the disc structure following percutaneous endoscopic lumbar discectomy (PELD) and symptoms in patients postsurgery has not been reported yet. The purpose of the present study was to discuss the potential correlation between the changes in the morphological characteristics of various reference surfaces of the intervertebral disc after percutaneous endoscopic lumbar discectomy (PELD) and clinical outcomes, to identify the morphological parameters that affect efficacy and provide an evidence-based foundation for assessing postoperative efficacy. METHODS: From October 2019 to October 2021, after percutaneous endoscopic lumbar discectomy (PELD), 98 individuals were enrolled. MRI DICOM data of the lumbar spine were obtained before and after surgery, specifically around 3 months. The morphological parameters of the operated and adjacent segments of the discs were measured using T2-weighted images from three reference planes. Outcomes were assessed using the Oswestry disability index (ODI), visual analogue pain scores for the back and leg (VAS-back/VAS-leg), Japanese Orthopaedic Association (JOA) scores, and recovery rates. Postoperative changes in disc parameters and outcomes were compared between patients with different severity and types of LDH based on the MSU staging. Patients completed the questionnaire during outpatient follow-up appointments 3, 6, and 12 months after the surgery. The follow-up period was 14.69 ± 4.21 months, ranging from 12 to 24 months. RESULTS: Parameters such as area and circumference of intervertebral discs in the cross-section were not associated with the change in the efficacy index. Postoperatively, a negative correlation between the variation of the disc height, disc height index, and protrusion distance and the difference in VAS scores for low back pain at 3 and 6 months was observed among the two sagittal change parameters. Differences between changes in disc imaging parameters and postoperative efficacy were not statistically significant between various types of lumbar disc herniation. CONCLUSION: For the patients after percutaneous endoscopic lumbar discectomy, the changes in parameters such as disc area and circumference in the cross-sectional plane are not associated with efficacy, and the changes in disc height and herniation distance in the sagittal plane provide a morphologic basis for the assessment of short-term postoperative efficacy. In addition, the changes in disc morphologic parameters and postoperative efficacy do not differ between various types of lumbar disc herniation.

A simple, universal and multifunctional template agent for personalized treatment of bone tumors.

Bone tumors occur in bone or its accessory tissues. Benign bone tumors are easy to cure and have good prognosis, while malignant bone tumors develop rapidly and have poor and high mortality. So far, there is no satisfactory treatment method. Here, we designed a universal template vector for bone tumor therapy that simultaneously meets the needs of bone targeting, tumor killing, osteoclast suppression, and tumor imaging. The template is composed of a polydopamine (PDA) core and a multifunctional surface. PDA has excellent biosafety and photothermal performance. In this study, alendronate sodium (ALN) is grafted to enable its general bone targeting function. PDA core can carry a variety of chemotherapy drugs, and the rich ALN group can carry a variety of metal ions with an imaging function. Therefore, more personalized treatment plans can be designed for different bone tumor patients. In addition, the PDA core enables photothermal therapy and enhanced chemotherapy. Through template drug Doxorubicin (DOX) and template imaging ion Fe (Ⅱ), we systematically verified the therapeutic effect, imaging effect, and inhibition of bone dissolution of the agent on Osteosarcoma (OS), a primary malignant bone tumor, in vivo. In conclusion, our work provides a more general template carrier for the clinical treatment of bone tumors, through which personalized treatment of bone tumors can be achieved.

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

OBJECTIVE: To 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. METHODS: Spinal 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. RESULTS: Sagittal 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. CONCLUSION: PSO 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.

Correlation of Acetabular Anteversion and Thoracic Kyphosis Postoperatively with Proximal Junctional Failure in Adult Spinal Deformity Fused to Pelvis.

OBJECTIVES: To investigate whether the immediate thoracic kyphosis (TK) and acetabular anteversion (AA) postoperatively are correlated with proximal junctional failure (PJF) in adult spinal deformity (ASD) patients underwent surgical treatment. METHODS: This is a retrospective study. Following institutional ethics approval, a total of 57 patients (49 Female, eight Male) with ASD underwent surgery fused to sacroiliac bone (S1, S2, or ilium) from March 2014 to January 2019 were included. All of those patients were followed up for at least 2 years. Demographic, radiographic and surgical data were recorded. The maximum range of flexion motion (F-ROM) and extension motion (E-ROM) actively of hip joints was measured and recorded at pre- and postoperation. The sum of F-ROM and E-ROM was defined as the range of hip motion (H-ROM). Receiver operating characteristic (ROC) curve analysis was used to obtain the cut off value of parameters for PJF. A Kaplan-Meier curve and log-rank test were used to analyze the differences in PJF-free survival. RESULTS: In all, 14 patients developed PJF during follow-up. Comparisons between patients with and without PJF showed significant differences in immediate TK (P < 0.001) and AA (P = 0.027) postoperatively. ROC curve analysis determined an optimal threshold of 13° for immediate AA postoperatively (sensitivity = 74.3%, specificity = 85.7%, area under the ROC curve [AUC] = 0.806, 95% CI [0.686-0.926]). Nineteen patients with post-AA ≤13° were assigned into the observational group, and 38 patients with post-AA >13° were being as the control group. Patients in the observational group had smaller H-ROM (P = 0.016) and F-ROM (P < 0.001), but much larger E-ROM (P < 0.001). There were 10 patients showing PJF in the observational group and four in the control group (10/9 vs 4/34, P < 0.001). PJF-free survival time significantly decreased in the observational group (P = 0.001, log-rank test). Furthermore, patients in the observational group had much larger TK (post-TK, P = 0.015). The optimal threshold for post-TK (sensitivity = 85.7%, specificity = 76.7%; AUC = 0.823, 95% CI [0.672-0.974]) was 28.1° after the ROC curve was analyzed. In the observational group, those patients with post-TK ≥28.1° had significantly higher incidence of PJF (9/2 vs 1/7, P < 0.001) than those with post-TK < 28.1°. Moreover, PJF-free survival time in those patients significantly decreased (P = 0.001, log-rank test). CONCLUSIONS: ASD patients with acetabular anteversion of ≤13° at early postoperation may suffer significantly restricted hip motion and much higher incidence of PJF during follow-up, moreover, in those patients, postoperative TK ≥28.1° would be a significant risk factor for PJF developing.

Spine-Pelvis-Hip Alignments in Degenerative Spinal Deformity Patients and Associated Procedure of One-Stage Long-Fusion with Multiple-Level PLIF or Apical-Vertebra Three Column Osteotomy-a Clinical and Radiographic Analysis Study.

OBJECTIVE: To explore the spine-pelvis-hip alignments in degenerative spinal deformity (DSD) patients, and compare the outcomes in the procedure of long-fusion with posterior lumbar inter-body fusion (PLIF) or single-level three-column osteotomy (STO) at lower lumbar level (LLL, L3 -S1 ) and thoracolumbar levels (TLL, T10 -L2 ) for those patients. METHODS: This is a retrospective study. Following institutional ethics approval, a total of 83 patients (Female, 67; Male, 16) with DSD underwent long-fusion with PLIF or STO surgery between March 2015 and December 2017 were reviewed. All of those patients were assigned into LLL and TLL groups. The average age at surgery was 65.2 years (SD, 8.1). Demographic (age, gender, BMI, and comorbidities), radiographs (both coronal and sagittal parameters) and health-related quality of life (HRQOL) assessments were documented. The radiographic parameters and HRQOL-related measurements at pre- and post-operation were compared with paired-samples t test, and those variables in the two groups were analyzed using an independent-sample t test. The relationships between pelvic incidence (PI) and other sagittal parameters were investigated with Pearson correlation analysis. The Pearson χ2 or Fisher's exact was carried out for comparison of gender, incidence of comorbidities and post-operative complications. RESULTS: There were 53 and 30 patients in the LLL and TLL groups respectively. Those spino-pelvic radiographic parameters had significant improvements after surgeries (P < 0.001). The patients in the two group with different pre-operative thoracolumbar kyphosis (TLK, P = 0.003), PI (P = 0.02), and mismatch of PI minus lumbar lordosis (PI-LL, P = 0.01) had comparable post-operative radiographic parameters except PI (P = 0.04) and pelvic-femur angle (PFA, P = 0.02). Comparing the changes of those spine-pelvic-hip data during surgeries, the corrections of TLK in TLL group were significant larger (P = 0.004). Pearson correlation analysis showed that there were negative relationship between PI and TLK (r = -0.302, P = 0.005), positive relationship between PI and LL (r = 0.261, P = 0.016) at pre-operation. Those patients underwent the surgical procedure that long-segment instrumentation and fusion with STO would have higher incidence of complications involving longer operative timing (P = 0.018), more blood loss (P < 0.001), revision surgery (P = 0.008), and cerebrospinal fluid leakage (P = 0.001). All the HRQOL scores significantly improved at final follow-up (P < 0.001), with no difference of intra-group. CONCLUSION: Patients suffered de-novo scoliosis or hyper-kyphosis with low PI would be vulnerable to significant thoracolumbar degeneration, and have more changes of spine-pelvis-hip data after long-fusion surgery, however, those with high PI would be closed to significant lumbar degeneration. Although spine-pelvis-hip alignments in DSD patients can be restored effectively after long-fusion with PLIF or STO, the incidence of complications in patients underwent STO was significant higher than that in patients performed multi-level PLIF.

Association of Sagittal Spinopelvic Realignment with Correction in Lower Lumbar Lordosis after Surgical Treatment in Degenerative Lumbar Scoliosis.

OBJECTIVE: To assess the effect that correction of lower lumbar lordosis (3L) has on global spine realignment due to the key role of 3L for scoliosis surgery in patients with degenerative lumbar scoliosis (DLS). METHODS: This study is a retrospective review performed between June 2018 and January 2020, including consecutive patients with DLS. Only patients age ≥ 45 years who had already undergone a selective root block operation and had the procedure of long-fusion extending to pelvis and posterior lumbar interbody fusion (PLIF) at lower lumbar spine (L4 -S1 ) were retained for analysis. Spinopelvic parameters measured included thoracic kyphosis (TK), lumbar lordosis (LL), 3L, pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), T1 pelvic angle (TPA), and sagittal vertical axis (SVA) at pre-operation and the third month follow-up. The mismatch (PI-LL) was calculated subsequently. Pearson correlation and linear regression analysis were performed to explore the association of the changes in global spinopelvic parameters with 3L correction. RESULTS: Thirty-nine patients (five males, 34 females) with the average age of 63.84 years (SD 7.53; range, 45-75 years) at the time of surgery were identified. All patients had the surgical procedure of long-fusion (≥4 vertebras) with PLIF at lower lumbar spine between L4 and S1 spine. Lower instrumented vertebras (LIV) fused to pelvis (S1 , 14; S2 , 18; ilium, 7) were operated in all patients. Seventeen patients were with upper instrumented vertebras (UIV) at thoracolumbar spine (L2 -T11 ), and 22 patients at thoracic spine (T10 and above). The median of instrumented segments was 10 (5-14). 3L significantly increased (P = 0.02) after surgical treatment by mean change of 4.21° (range, -19.7° to +22.2°). Perioperatively, all spinopelvic parameters regarding to TK, LL, SS, PT, TPA, SVA, and mismatch (PI-LL) had significant changes (P < 0.001). The change in 3L correlated significantly with the changes in spinopelvic parameters (r = 0.772 for LL, -0.589 for SVA, -0.439 for TPA, and -0.428 for PI-LL). After linear regression analysis, the formulas were obtained: d-LL = 14.977 + 0.636 × d-3L, (R2 = 0.596); d-(PI-LL) = 16.575 + 0.62 × d-3L, (R2 = 0.183); d-TPA = -7.284 to 0.358 × d-3L, (R2 = 0.193); d-SVA = -30.556-2.639 × d-3L (R2 = 0.347). CONCLUSIONS: Correction in lower lumbar lordosis, following the surgical procedure of long-fusion with PLIF at lower lumbar spine, could result in significant changes in full-spine parameters. The significant association of changes in each of global spine parameter with the correction of 3L perioperatively could provide important information for surgeons to make a surgical plan for spinal correction.

Low pelvic incidence is associated with Andersson lesions in ankylosing spondylitis patients with kyphosis.

INTRODUCTION/OBJECTIVES: This study was to investigate the role of pelvic incidence (PI) in the development of Andersson lesions (ALs) in ankylosing spondylitis (AS) patients with kyphosis and to evaluate the difference in sagittal spinopelvic parameters between inflammatory ALs and mechanical ALs. METHOD: A total of 135 AS patients with kyphosis were reviewed. The patients were classified into AL group and non-AL group based on the presence or absence of ALs. Additionally, AS patients with ALs were also classified as either inflammatory or mechanical lesions depending on the radiological features of the lesions. The sagittal spinopelvic parameters of all these AS patients were measured and compared. Logistic regression analysis was performed to determine the powerful variables for predicting ALs in AS patients. RESULTS: ALs were detected in 34 patients (25.2%) of the total 135 AS patients. The mean PI of the AL group was 40.0°, which was significantly lower than that (48.3°) of the non-AL group (P < 0.001). No statistically significant difference was observed in PI (P = 0.350) between the inflammatory lesion group and the mechanical lesion group. Logistic regression analysis showed that only PI was a statistically significant risk factor for ALs (P < 0.001) and was negatively correlated with ALs (odds ratio = 0.76). CONCLUSIONS: These data suggest that low PI is closely associated with ALs in AS patients with kyphosis and that it might be a possible risk factor for the development of ALs. Moreover, both inflammatory and mechanical ALs patients had similarly low PI.Key Points• Low PI was closely associated with ALs in AS patients with kyphosis and might be a possible risk factor for development of ALs.• Either inflammatory or mechanical ALs patients had similar low PI.

Positioning thoracic pedicle screw entry point using a new landmark: a study based on 3-dimensional computed tomographic scan.

STUDY DESIGN: A novel method to identify the entry point. OBJECTIVE: To quantify the position of thoracic pedicle screw entry points on the lamina at various segments of the thoracic vertebrae in normal subjects and patients with adolescent idiopathic scoliosis and propose a new technique to select entry points using a new landmark. SUMMARY OF BACKGROUND DATA: Thoracic pedicle screws have been widely used in thoracic surgery, and the placement of pedicle screws has been studied extensively. However, there are only qualitative studies on selecting the entry point, and no study has quantified the position of entry points. METHODS: A retrospective study using 3-dimensional computed tomographic reconstruction techniques were used to study the morphology of thoracic vertebrae in 110 adolescents (56 cases of adolescent idiopathic scoliosis and 54 normal subjects). A quantitative area was used to select the entry point. Thoracic pedicle screw entry point was determined using the new landmark as reference and thoracic pedicle screws were placed in 21 patients. Postoperative computed tomographic scanning was performed to assess the safety and effectiveness of this entry point selection technique. RESULTS: We determined that the accuracy of pedicle screw placing after positioning entry point using the quantitative area was significantly superior to that after positioning entry point using the traditional method (P < 0.05). CONCLUSION: The new technique quantifies the position of each thoracic pedicle screw entry point and it is convenient, easy to operate, and has relatively high accuracy of screw placement. This positioning technique can provide safe and accurate clinical guidance for selecting thoracic pedicle screw entry point.