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

PURPOSE: 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). METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Stepwise reduction of bone mineral density increases the risk of cage subsidence in oblique lumbar interbody fusion patients biomechanically: an in-silico study.

BACKGROUND: Cage subsidence causes poor prognoses in patients treated by oblique lumbar interbody fusion (OLIF). Deterioration of the biomechanical environment initially triggers cage subsidence, and patients with low bone mineral density (BMD) suffer a higher risk of cage subsidence. However, whether low BMD increases the risk of cage subsidence by deteriorating the local biomechanical environment has not been clearly identified. METHODS: OLIF without additional fixation (stand-alone, S-A) and with different additional fixation devices (AFDs), including anterolateral single rod screws (ALSRs) and bilateral pedicle screws (BPSs) fixation, was simulated in the L4-L5 segment of a well-validated finite element model. The biomechanical effects of different BMDs were investigated by adjusting the material properties of bony structures. Biomechanical indicators related to cage subsidence were computed and recorded under different directional moments. RESULTS: Overall, low BMD triggers stress concentration in surgical segment, the highest equivalent stress can be observed in osteoporosis models under most loading conditions. Compared with the flexion-extension loading condition, this variation tendency was more pronounced under bending and rotation loading conditions. In addition, AFDs obviously reduced the stress concentration on both bony endplates and the OLIF cage, and the maximum stress on ALSRs was evidently higher than that on BPSs under almost all loading conditions. CONCLUSIONS: Stepwise reduction of BMD increases the risk of a poor local biomechanical environment in OLIF patients, and regular anti-osteoporosis therapy should be considered an effective method to biomechanically optimize the prognosis of OLIF patients.

Predictive ability of pharyngeal inlet angle for the occurrence of postoperative dysphagia after occipitocervical fusion.

BACKGROUND: PIA has been proven to be a predictor for postoperative dysphagia in patients who undergo occipitospinal fusion. However, its predictive effect for postoperative dysphagia in patients who undergo OCF is unknown. The aim of this study was to evaluate the predictive ability of the pharyngeal inlet angle (PIA) for the occurrence of postoperative dysphagia in patients who undergo occipitocervical fusion (OCF). METHODS: Between 2010 and 2018, 98 patients who had undergone OCF were enrolled and reviewed. Patients were divided into two groups according to the presence of postoperative dysphagia. Radiographic parameters, including the atlas-dens interval (ADI), O-C2 angle (O-C2a), occipital and external acoustic meatus to axis angle (O-EAa), C2 tilting angle (C2Ta), C2-7 angle (C2-7a), PIA and narrowest oropharyngeal airway space (nPAS), were measured and compared. Simple linear regression and multiple regression analysis were used to evaluate the radiographic predictors for dysphagia. In addition, we used PIA = 90° as a threshold to analyze its effect on predicting dysphagia. RESULTS: Of the 98 patients, 26 exhibited postoperative dysphagia. Preoperatively, PIA in the dysphagia group was significantly higher than that in the nondysphagia group. We detected that O-C2a, O-EAa, PIA and nPAS all decreased sharply in the dysphagia group but increased slightly in the nondysphagia group. The changes were all significant. Through regression analyses, we found that PIA had a similar predictive effect as O-EAa for postoperative dysphagia and changes in nPAS. Additionally, patients with an increasing PIA exhibited no dysphagia, and the sensitivity of PIA <90° in predicting dysphagia reached 88.5%. CONCLUSIONS: PIA could be used as a predictor for postoperative dysphagia in patients undergoing OCF. Adjusting a PIA level higher than the preoperative PIA level could avoid dysphagia. For those who inevitably had decreasing PIA, preserving intraoperative PIA over 90° would help avert postoperative dysphagia. TRIAL REGISTRATION: This trial has been registered in the Medical Ethics Committee of West China Hospital, Sichuan University. The registration number is 762 and the date of registration is Sep. 9 th, 2019.

Clinical and radiographic outcome of dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease: a minimal five-year follow-up.

BACKGROUND: To evaluate the mid- to long-term clinical and radiographic outcomes of anterior cervical discectomy and dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease. METHODS: From April 2010 to October 2010, 38 patients with single- or double-level cervical disc herniation underwent anterior cervical discectomy and DCI arthroplasty. The clinical results and radiographic outcomes of these 38 patients (42 levels) were retrospectively evaluated. The clinical results included the visual analogue scale, Japanese Orthopaedic Association score, Neck Disability Index score, 36-item short form health survey questionnaire, and incidences of complications and neurological deterioration. Radiographic results including cervical alignment, intervertebral height, cervical range of motion (ROM), ROM of the functional spinal unit, adjacent intervertebral ROM, migration, subsidence, and heterotopic ossification (HO) were assessed on plain radiography, three-dimensional computed tomography, and magnetic resonance imaging. RESULTS: The mean follow-up period was 72.3 months (range 68-78 months). During follow-up, all patients showed significant improvements in the visual analogue scale score, Japanese Orthopaedic Association score, Neck Disability Index score, 36-item short form health survey physical component summary score and mental component summary score. The ROM of the functional spinal unit was partly reduced. The DCI migrated forward in 10 of 42 (23.8%) cases, and HO was detected in 24 of the 42 (57.1%) DCI segments. Subsidence was observed in 14 of 42 (33.3%) DCI segments. Two patients experienced symptom recurrence, and were treated conservatively. CONCLUSIONS: The clinical efficacy of DCI arthroplasty was maintained during mid- to long-term follow-up. HO formation is a common phenomenon, leading to a substantial decrease in ROM at the index level and recurrence of neurological symptoms. The incidence of implant subsidence and migration is relatively high, leaving a potential risk of symptoms at the index level and adjacent segment degeneration. We consider that the first choice for patients with degenerative cervical disc disease should still be total disc replacement or anterior cervical discectomy and fusion, rather than DCI arthroplasty.

Negative pressure pulmonary edema after percutaneous endoscopic interlaminar lumbar discectomy-a case report.

BACKGROUND: Negative pressure pulmonary edema (NPPE) is a rare complication that is more prevalent in young patients. NPPE usually results from acute upper airway obstruction, which is most commonly caused by laryngospasm during extubation. NPPE is characterized by the sudden onset of coughing, hemoptysis, tachycardia, tachypnea, and hypoxia, and is dramatically improved with supportive care, which prevents severe sequelae. To our knowledge, there is no report of a patient developing NPPE after percutaneous endoscopic interlaminar lumbar discectomy. CASE PRESENTATION: Herein, we report the case of a 22-year-old amateur basketball player with L5/S1 disc herniation who developed NPPE during extubation after general anesthesia for a minimally invasive spinal surgery (percutaneous endoscopic interlaminar lumbar discectomy). The NPPE was treated by maintaining the airway patency, applying positive-pressure ventilation, administering dexamethasone and antibiotics, and limiting the volume of fluid infused. The patient had an uneventful postoperative course, and was discharged to his home on postoperative day 3. CONCLUSIONS: Although NPPE is an infrequent complication, especially in patients undergoing percutaneous endoscopic interlaminar lumbar discectomy, this case report highlights the importance of early diagnosis and prompt treatment of NPPE to prevent the development of potentially fatal complications.

Comparison of two temporary fixation techniques for the treatment of type II odontoid fracture.

To evaluate and compare the clinical and radiographic results between temporary C1-C2 pedicle screw fixation and cable-dragged reduction and cantilever beam internal fixation. Between 2010 and 2013, temporary C1-C2 pedicle screw fixation (Group P, 28 patients) and cable-dragged reduction following cantilever beam internal fixation (Group C, 33 patients) were performed on type II odontoid fracture cases. Implants were removed after fracture union. All of the 61 surgeries were performed successfully with no iatrogenic neurological worsen. One patient in Group P detected intra-operative vertebral artery injury. All patients gained fracture union. Among the observed indexes, only blood loss in Group P (128.9 ± 73.9ml) is statistically higher than in Group C (97.3 ± 5 4.2ml). Pedicle screw fixation carries the risk of vertebral artery injury, especially in patients with high-riding vertebral artery. Cable-dragged reduction following cantilever beam internal fixation could avoid the potential risk of vertebral injury, but it prolonged the fixed segments. We thought cable-dragged reduction following cantilever beam internal fixation could be an alternative method for treating type II odontoid fracture.

A rare case of osteoblastoma combined with severe scoliosis deformity, coronal and sagittal imbalance.

BACKGROUND: Osteoblastoma is a rare and benign tumor which requires early diagnosis and surgical excision. Scoliosis is a common presentation following osteoblastoma. It is considered due to pain-provoked muscle spasm on the side of the lesion. Few researches about osteoblastoma combined with severe scoliosis have been reported. CASE PRESENTATION: A 14-year-old girl presents with progressive scoliosis deformity for 3 years, with gradually appeared low back pain and numbness of left leg. Radiographic results showed osteoblastic mass at the left side of L3-L4 with severe scoliosis deformity, pelvic obliquity and spinal imbalance. The patient underwent posterior tumor excision, spinal decompression, scoliosis correction, spinal fusion with auto-graft and instrumentation from T8-S1. The mass was found to be osteoblastoma. The patient had a full neurological recovery with no aggravate of scoliosis or spinal imbalance during the follow-up. CONCLUSIONS: This case emphasizes the importance of early diagnosis and surgical treatment of osteoblastoma. Early surgical excision will not only prevent neurological deficit but also the progression of scoliosis. Atypical scoliosis presence without pain requires carefully examination of whether a tumor exists.

Clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy: a five-year follow-up study.

INTRODUCTION: To evaluate the five year clinical and radiographic outcome of unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation for cervical compressive myelopathy. METHODS: From August 2009 to June 2010, 56 patients with cervical compressive myelopathy underwent unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation with a mean age of 64.8 years. Clinical results were investigated including Japanese Orthopedic Association (JOA) scores, Neck Dysfunction Index (NDI), occurrences of complications and neurological deterioration. Radiographic results including cervical alignments, cervical range of motion (ROM), spinal canal enlargement and spinal cord decompression were assessed on X-ray, three-dimensional CT and MRI. RESULTS: The mean follow-up period was 59.2 months (range 53∼64 months), and all patients achieved osseous fusion at hinge side at an average of 6.8 months after operation. The average cost from admission to discharge is $9817.9. Compared to previous all-level fixation, the cost decreased nearly 40 %. During the follow-up, all patients showed a significant improvement in the JOA score and NDI score. A 23.2 % incidence of axial neck pain were also observed; Significant enlargement of the spinal canal and spinal cord drift was achieved and well maintained, overall cervical ROM decreased by 27.1 % (mean 12.9° loss) at the final follow-up and cervical lordosis decreased slightly in all patients without statistic difference. No instrumentation failure or lamina reclosure was observed in our study. Comparing mini-plate segments and suture segments, the mean AP diameter and Pavlov's ratio at the final follow-up showed no statistic difference, only open angle at the final follow-up showed significant decrease. CONCLUSIONS: Unilateral open-door laminoplasty with alternative levels centerpiece mini-plate fixation is a safe, effective and economical surgical method for cervical compressive myelopathy and the five year result is satisfactory.

Clinical and radiographic outcomes of dynamic cervical implant replacement for treatment of single-level degenerative cervical disc disease: a 24-month follow-up.

PURPOSE: To determine the role of dynamic cervical implant (DCI) replacement for single-level degenerative cervical disc disease in Chinese patients. METHODS: Thirty patients with single-level degenerative cervical disc disease were prospectively enrolled between April 2010 and August 2010 (12 women, 18 men; mean age 56.5 years). All patients underwent anterior cervical decompression, DCI replacement, clinical and radiological assessments preoperatively and at 1, 6, 12, and 24 months postoperatively, and Japanese Orthopaedic Association (JOA), Visual Analogue Scale (VAS), Neck Disability Index (NDI), and Short Form 36 (SF-36) scores. Lateral neutral radiographs provided the intervertebral space height. Lateral dynamic radiographs were taken to measure the range of motion (ROM) of the cervical spine and functional spinal unit (FSU) of the treated segment. We compared the amount of motion of the adjacent vertebral endplate and the intrinsic motion of the implant and calculated a correlation analysis. RESULTS: DCI showed good clinical and radiographic outcomes. At the final follow-up, JOA, VAS, NDI, and SF-36 average scores improved significantly. The intervertebral space height increased slightly after operation and was maintained during follow up. The ROM of the cervical spine and FSU decreased at early follow-up, but recovered to the preoperative level within 1-2 years. There was a high index of linear correlation between the motion of the adjacent vertebral endplate and the intrinsic motion of the implant. CONCLUSIONS: DCI provided elastic dynamic stability for the targeted segment, and restored and sustained intervertebral space height and ROM of the cervical spine.

Management of limb fractures in a teaching hospital: comparison between Wenchuan and Yushu earthquakes.

OBJECTIVE: To comparatively analyze the medical records of patients with limb fractures as well as rescue strategy in Wenchuan and Yushu earthquakes so as to provide references for post-earthquake rescue. METHODS: We retrospectively investigated 944 patients sustaining limb fractures, including 891 in Wenchuan earthquake and 53 in Yushu earthquake, who were admitted to West China Hospital (WCH) of Sichuan University. RESULTS: In Wenchuan earthquake, WCH met its three peaks of limb fracture patients influx, on post-earthquake day (PED) 2, 8 and 14 respectively. Between PED 3-14, 585 patients were transferred from WCH to other hospitals outside the Sichuan Province. In Yushu earthquake, the maximum influx of limb fracture patients happened on PED 3, and no one was shifted to other hospitals. Both in Wenchuan and Yushu earthquakes, most limb fractures were caused by blunt strike and crush/burying. In Wenchuan earthquake, there were 396 (396/942, 42.0%) open limb fractures, including 28 Gustilo I, 201 Gustilo II and 167 Gustilo III injuries. But in Yushu earthquake, the incidence of open limb fracture was much lower (6/61, 9.8%). The percent of patients with acute complications in Wenchuan earthquake (167/891, 18.7%) was much higher than that in Yushu earthquake (5/53, 3.8%). In Wenchuan earthquake rescue, 1 018 surgeries were done, composed of debridement in 376, internal fixation in 283, external fixation in 119, and vacuum sealing drainage in 117, etc. While among the 64 surgeries in Yushu earthquake rescue, the internal fixation for limb fracture was mostly adopted. All patients received proper treatment and survived except one who died due to multiple organs failure in Wenchuan earthquake. CONCLUSION: Provision of suitable and sufficient medical care in a catastrophe can only be achieved by construction of sophisticated national disaster medical system, prediction of the injury types and number of injuries, and confirmation of participating hospitals?exact role. Based on the valuable rescue experiences after Wenchuan earthquake, the rescue was faster, more orderly and effective in Yushu earthquake. Nevertheless, there is still a long way to go in the development of a stronger emergent response to the disasters.

[Comparative analysis of the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquakes].

OBJECTIVE: To systematically analyze and compare the clinical characteristics of orthopedic inpatients in Lushan and Wenchuan earthquake, so as to provide useful references for future earthquakes injury rescue. METHODS: Based on the orthopedic inpatients in Lushan and Wenchuan earthquakes, the data of the age, gender, injury causes, body injured parts and speed of transport were classified and compared. RESULTS: The duration of patients admitted to hospital lasted long and the peak appeared late in Wenchuan earthquake, which is totally opposed to Lushan earthquake. There was no significant difference in the patient's age and gender between the two earthquakes. However, the occurrence rate of crush syndrome, amputation, gas gangrene, vascular injury and multiple organ dysfunction syndrome (MODS) in Wenchuan earthquake was much higher than that in Lushan earthquake. Blunt traumas or crush-related injuries (79.6%) are the major injury cause in Wenchuan earthquake, however, high falling injuries and falls (56.8%) are much higher than blunt trauma or crush-related injuries (39.2%) in Lushan earthquake. The incidence rate of foot fractures, spine fractures and multiple fractures in Lushan earthquake was higher than that in Wenchuan earthquake, but that of open fractures and lower limb fractures was lower than that in Wenchuan earthquake. CONCLUSION: The rapid rescue scene is the cornerstone of successful treatment, early rescue and transport obviously reduce the incidence of the wound infection, crush syndrome, MODS and amputation. Popularization of correct knowledge of emergency shelters will help to reduce the damage caused by blindly jumping or escaping while earthquake happens.

[The mid-term follow-up of Coflex non-fusion internal fixation in the treatment of degenerative lumbar disease].

OBJECTIVE: To summarize the mid-term effectiveness of Coflex non-fusion internal fixation treatment of degenerative lumbar disease. METHODS: From October 2008 to December 2010, a retrospective analysis was carried out on 39 patients (29 males and 10 females) diagnosed as degenerative lumbar disease and treated with Coflex interspinous dynamic device, who had been followed up for 1 year at least, the average age was 45.5 years (range, 23 - 67 years). The results were assessed by Japanese Orthopedic Association (JOA) scores, visual analogue scale (VAS) scores, Oswestry disability index (ODI) scores and SF-36 scores; and the range of mobility (ROM), intervertebral disc height of the responsible and adjacent segments were measured on X-film before the operation and at last follow-up. Observed the therapeutic effect of the patients and compared the effect on the patients of different body mass index (BMI) and different age by the One-way analysis of variance and paired t test. RESULTS: The 39 patients were followed up for 30.9 months (range, 12 - 37 months). At the last follow-up, JOA, ODI, VAS and SF-36 scores were improved by 70% ± 12%, 54% ± 12%, 77% ± 10% and 51% ± 9%, and were statistically significant (t = -33.289, 26.448, 26.596 and -20.772, P = 0.00). Patients with BMI ≥ 25 kg/m(2) had lower improvement rates in the scores than those with BMI < 25 kg/m(2) (F = 10.561, 5.850, 5.651 and 6.519, P < 0.05). The patients were 50 years older or younger couldn't affected the improvement rates in the scores statistically (P > 0.05). There were no significant difference in remaining disc height (P > 0.05), except that the intervertebral disc height of L4-5 increased slightly compared with the preoperative (t = -2.819, P = 0.008). In addition to the ROM of L3-4, L5-S1 and L1-S1 were not significantly different from the preoperative(P > 0.05), the ROM of L4-5 were decreased (t = 12.598, P = 0.000). CONCLUSIONS: The mid-term effectiveness of Coflex non-fusion interspinous fixation in treatment of degenerative lumbar disease is worthy of recognition, and Coflex combined with Isobar has advantages in the treatment of multi-segment degenerative lumbar disease.

Preoperative Skull Traction, Anterior Debridement, Bone Grafting, and Internal Fixation for Cervical Tuberculosis with Severe Kyphosis.

OBJECTIVE: Cervical tuberculosis (CTB) readily causes local kyphosis, and its surgical strategy remains controversial. Although some previous studies suggested that the anterior approach could effectively treat CTB, patients in these studies only suffered mild to moderate kyphosis. Therefore, little is known about whether the anterior approach can achieve satisfactory outcomes in CTB patients with severe kyphosis. This study was performed to evaluate the safety and efficacy of preoperative skull traction combined with anterior surgery for the treatment of CTB patients with a severe kyphosis angle of more than 35°. METHODS: In this retrospective study, we enrolled 31 CTB patients with severe kyphosis who underwent preoperative skull traction combined with anterior surgery from April 2015 to January 2021. Patients were followed up for at least 2 years. Clinical data, such as operative time, blood loss, and postoperative hospital stay, were collected. The clinical outcomes included American Spinal Injury Association (ASIA) spinal cord injury grade, Japanese Orthopaedic Association (JOA) score, visual analog scale (VAS) score, and related complications. The radiological outcomes included the Cobb angle of cervical kyphosis at each time point and the bony fusion state. Clinical efficacy was evaluated by paired Student's t-test, Mann-Whitney U-test, and others. RESULTS: Six patients had involvement of one vertebra, 21 had involvement of two vertebrae, and four had involvement of three vertebrae. The most common level of vertebral involvement was C4-5, whereas the most common apical vertebra of kyphosis was C4. The mean kyphosis angle was 46.1° ± 7.7° preoperatively, and the flexibility on dynamic extension-flexion X-rays and cervical MRI was 17.5% ± 7.8% and 43.6% ± 11.0%, respectively (p = 0.000). The kyphosis angle significantly decreased to 13.2° ± 3.2° after skull traction, and it further corrected to -6.1° ± 4.3° after surgery, which was well maintained at the final follow-up with a mean Cobb angle of -5.4° ± 3.9°. The VAS and JOA scores showed significant improvement after surgery. The erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) levels normalized at 3 months after surgery. All patients achieved solid bone fusion, and no complications related to the instrumentation or recurrence were observed. CONCLUSION: Preoperative skull traction combined with anterior debridement, autologous iliac bone grafting, and internal plate fixation can be an effective and safe surgical method for the treatment of cervical tuberculosis with severe kyphosis. Skull traction can improve the safety and success rate of subsequent anterior corrective surgery.

Characteristics of Sagittal Alignment in Patients with Severe and Rigid Scoliosis.

OBJECTIVE: There has been increasing concern about the importance of sagittal alignment in the evaluation and treatment of spinal scoliosis. However, recent studies have only focused on patients with mild to moderate scoliosis. To date, little is known about the sagittal alignment in patients with severe and rigid scoliosis (SRS). This study was performed to evaluate the sagittal alignment in patients with SRS, and to analyze how it was altered after corrective surgery. METHODS: In this retrospective cohort study, we included 58 patients with SRS who underwent surgery from January 2015 to April 2020. Preoperative and postoperative radiographs were reviewed, and the sagittal parameters mainly included thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), sacrum slope (SS), and sagittal vertical axis (SVA). The sagittal balance state was evaluated according to whether the PI minus the LL (PI-LL) was less than 9°, and the patients were divided into thoracic hyperkyphosis and normal groups based on whether the TK exceeded 40°. The Student's t test, Pearson's test, and Receiver operating characteristic (ROC) curve analysis were used to compare related parameters between the different groups. RESULTS: The mean follow-up duration was 2.8 years. Preoperatively, the mean PI was 43.6 ± 9.4°, and the mean LL was 65.2 ± 13.9°. Sixty-nine percent of patients showed sagittal imbalance, and they showed larger TK and LL values and smaller PI and SVA values than those with sagittal balance. Additionally, most patients (44/58) presented with thoracic hyperkyphosis; this group had smaller PI and SVA values than the normal patients. Patients with syringomyelia-associated scoliosis were more likely to present with thoracic hyperkyphosis. The TK and LL values were significantly decreased, and 45% of patients with preoperative sagittal imbalance recovered after surgery. These patients had a larger PI (46.4 ± 9.0° vs 38.3 ± 8.8°, P = 0.003) and a smaller TK (25.5 ± 5.2° vs 36.3 ± 8.0°, P = 0.000) at the final follow-up. CONCLUSION: Preoperative sagittal imbalance appears in the majority of SRS patients, accounting for approximately 69% of our cohort. Patients with small PI values or syringomyelia-associated scoliosis were more likely to present with thoracic hyperkyphosis. Sagittal imbalance can generally be corrected by surgery, except in patients with a PI less than 39°. To achieve good postoperative sagittal alignment, we recommend controlling the TK to within 31°.

Comparison of Long-Term Clinical and Radiographical Outcomes between the Anterior and Combined Anterior and Posterior Approaches for Treating Lumbosacral Tuberculosis.

OBJECTIVE: Both anterior and combined anterior and posterior approaches have been used to treat lumbosacral tuberculosis. However, long-term follow-up studies of each approach have not been conducted. We aimed to compare the long-term clinical and radiographical outcomes between the two approaches. METHODS: In this retrospective cohort study, we included 49 patients with a minimum 6-year follow-up between January 2008 and March 2012. Twenty-four patients underwent the anterior approach (anterior group), and 25 underwent the combined anterior and posterior approach (anterior-posterior group). Student's t test, Mann-Whitney U test, and Pearson's chi-square test were used to compare the two groups regarding clinical data, such as visual analogue scale scores, Oswestry disability index scores and neurological status, and radiographical data, such as lumbosacral angle, lumbar lordosis, and L5-S1 height. Furthermore, operative time, length of stay, and intraoperative and postoperative blood loss (IBL, PBL) were recorded. RESULTS: Both groups had satisfactory clinical and radiographical outcomes until the final follow-up. All patients achieved bony fusion, and no group differences were found in any of the clinical indices. Both groups corrected and maintained the lumbosacral angle, lumbar lordosis, and L5-S1 height. However, the operative time, length of stay, maximum Hb drop, IBL, and PBL of the anterior group (140.63 ± 24.73 min, 12.58 ± 2.45 days, 28.33 ± 9.70 g/L, 257.08 ± 110.47 ml, and 430.60 ± 158.27 ml, respectively) were significantly lower than those of the anterior-posterior group (423.60 ± 82.81 min, P < 0.001; 21.32 ± 3.40 days, P < 0.001; 38.48 ± 8.03 g/L, P < 0.001; 571.60 ± 111.04 ml, P < 0.001; and 907.01 ± 231.99 ml, P < 0.001). CONCLUSION: This retrospective study demonstrated long-term efficacy of the anterior approach with a single screw fixation, which was as effective as that of the combined anterior and posterior approach, with the advantage of less trauma.

Incidence and Risk Factors for Postoperative Ileus after Posterior Surgery in Adolescent Idiopathic Scoliosis.

OBJECTIVE: Postoperative ileus (POI) is a relatively common complication after spinal fusion surgery, which can lead to delayed recovery, prolonged length of stay and increased medical costs. However, little is known about the incidence and risk factors of POI after corrective surgery for patients with adolescent idiopathic scoliosis (AIS). This study was performed to report the incidence of POI and identify the independent risk factors for POI after postoperative corrective surgery. METHODS: In this retrospective cohort study, A total of 318 patients with AIS who underwent corrective surgery from April 2015 to February 2021 were enrolled and divided into two groups: those with POI and those without POI. The Student's t test, Mann-Whitney U test, and Pearson's chi-square test were used to compare the two groups regarding patient demographics and preoperative characteristics (age, sex and the major curve type), intraoperative and postoperative parameters (lowest instrumented vertebra [LIV], number of screws, and length of stay), radiographic parameters (T5-12 thoracic kyphosis [TK], T10-L2 thoracolumbar kyphosis and height [TLK and T10-L2 height], L1-S1 lumbar lordosis [LL], and L1-5 height). Then, a multivariate logistic regression analysis was used to identify independent risk factors for POI, and a receiver operating characteristic (ROC) curve was performed to assess the predictive values of these risk factors. RESULTS: Forty-two (13.2%) of 318 patients who developed POI following corrective surgery were identified. The group with POI had a significantly longer length of stay, more lumbar screws, higher proportions of a major lumbar curve and lumbar anterior screw breech, and a lower LIV. Among radiographic parameters, the mean lumbar Cobb angle at baseline, the changes in the lumbar Cobb angle, and T10-L2 and L1-5 height from before to after surgery were significantly larger in the group with POI than in the group without POI. Multivariate logistic regression analysis showed that large changes in T10-L2 (odds ratio [OR] =2.846, P = 0.007) and L1-5 height (OR = 31.294, p = 0.000) and lumbar anterior screw breech (OR = 5.561, P = 0.006) were independent risk factors for POI. The cutoff values for the changes in T10-L2 and L1-5 height were 1.885 cm and 1.195 cm, respectively. CONCLUSION: In this study, we identified that large changes in T10-L2 and L1-5 height and lumbar anterior screw breech were independent risk factors for POI after corrective surgery. Improving the accuracy of pedicle screw placement might reduce the incidence of POI, and greater attention should be given to patients who are likely to have large changes in T10-L2 and L1-5 height after corrective surgery.

Comparison of Long-Term Outcomes between the n-HA/PA66 Cage and the PEEK Cage Used in Transforaminal Lumbar Interbody Fusion for Lumbar Degenerative Disease: A Matched-Pair Case Control Study.

OBJECTIVE: The nanohydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel bioactive nonmetal cage that is now used in some medical centers, while the polyetheretherketone (PEEK) cage is a typical device that has been widely used for decades with excellent clinical outcomes. This study was performed to compare the long-term radiographic and clinical outcomes of these two different cages used in transforaminal lumbar interbody fusion (TLIF). METHODS: In this retrospective and matched-pair case control study, we included 200 patients who underwent TLIF from January 2010 to December 2014 with a minimum 7-year follow-up. One hundred patients who used n-HA/PA66 cages were matched with 100 patients who used PEEK cages for age, sex, diagnosis, and fusion level. The independent student's t-test and Pearson's chi-square test were used to compare the two groups regarding radiographic (fusion status, cage subsidence rate, segmental angle [SA], and interbody space height [IH]) and clinical (Oswestry Disability Index [ODI], and Visual Analog Scale [VAS] for back and leg) parameters preoperatively, postoperatively, and at the final follow-up. RESULTS: The n-HA/PA66 and PEEK groups had similar fusion rates of bone inside and outside the cage at the final follow-up (95.3% vs 91.8%, p = 0.181, 92.4% vs 90.1%, p = 0.435). The cage union ratios exposed to the upper and lower endplates of the n-HA/PA66 group were significantly larger than those of the PEEK group (p < 0.05). The respective cage subsidence rates in the n-HA/PA66 and PEEK groups were 10.5% and 17.5% (p = 0.059). There were no significant differences between the two groups in the SA, IH, ODI scores, or VAS scores at any time point. The n-HA/PA66 group showed high fusion and low subsidence rates during long-term follow-up. CONCLUSION: Both n-HA/PA66 and PEEK cages can achieve satisfactory long-term clinical and radiographic outcomes in TLIF. However, the n-HA/PA66 group showed significantly larger cage union ratios than the PEEK group. Therefore, the results indicated that the n-HA/PA66 cage is an ideal alternative material comparable to the PEEK cage in TLIF.

Misdiagnosis and management of iatrogenic pseudoaneurysm of vertebral artery after Harms technique of C1-C2 fixation.

Harms technique of C1-C2 fixation for atlantoaxial complex becomes more popular due to good fusion rate and low vertebral artery injury (VAI) rate. But considering the unique and variable anatomy of atlantoaxial complex, iatrogenic VAI will result in catastrophic consequences and provides particular surgical challenges for surgeons. To our knowledge, comparing with iatrogenic VAI in the screw hole, iatrogenic VAI in the "open space" is much rarer during the Harms technique of C1-C2 fixation. In this article, we present a case of iatrogenic vertebral artery pseudoaneurysm after Harms technique of posterior C1-C2 fixation. This case of iatrogenic VAI effectively treated by endovascular coil occlusion and external local compression was initially misdiagnosed as VAI by pedicle screw perforation. It can be concluded that intraoperative or postoperative computed angiography is very helpful to diagnose the exact site of VAI and the combination of endovascular coil occlusion as well as external local compression can further prevent bleeding and abnormal vertebral artery flow in the pseudoaneurysm. However, patients treated require further follow-up to confirm that there is no recurrence of the pseudoaneurysm.

[Application of n-HA/PA66 composite artificial vertebral body in anterior reconstruction of lower cervical spine fracture and dislocation].

OBJECTIVE: To initially evaluate the application of artificial vertebra of n-HA/PA66 in anterior reconstruction of lower cervical spine fracture and dislocation. METHODS: In this study, 84 patients with lower cervical spine fracture and dislocation received anterior cervical discectomy, spinal canal decompression or subtotal corpectomy, spinal canal decompression and reconstruction by n-HA/PA66 composite artificial vertebral body combined with plate instrumentation. Neurological function was followed up by improvement rate of Frankel and situations of the supporting body was observed by X ray and 3D-CT in 3, 12, 24 months postoperatively. The intervertebral height, physical arc (reflected by Cobb angle) and the locations and fusion rate of the supporting body were assessed in order to evaluate the stability of the cervical spine and alignment improvements. RESULTS: All the patients underwent operation successfully and were followed up for 6 to 24 months with an average of 12 months. The preoperative symptoms were improved to varying degrees. Imaging studies showed that in all cases graft fusion were achieved, and cervical alignments, intervertebral height, cervical spine stability and the locations of the artificial vertebral body were well maintained. No displacement and subsidence of the artificial vertebral body occurred. Postoperative immediate intervertebral height (2.4 ± 0.2) cm, preoperative intervertebral height (1.9 ± 0.1) cm, comparisons of the two groups was statistically significant (q = 2.48, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group intervertebral height was not statistically significant (P > 0.05). Preoperative Cobb angle was 9.8° ± 1.2°, postoperative immediate Cobb angle was 16.6° ± 1.2°, comparisons of the two groups was statistically significant (q = 14.25, P < 0.001). The immediate, 3 month, 1 year, 2 year period follow-up group Cobb angle was not statistically significant (P > 0.05). CONCLUSIONS: n-HA/PA66 artificial vertebral body can provide early cervical spine support and stability and effectively maintain the biological alignment and cervical intervertebral height. It has high rate of graft fusion and is convenient to observe by X-ray. Therefore, n-HA/PA66 can be taken as an ideal graft for anterior lower cervical spine fracture and dislocation operation, but further follow-up study is still required to evaluate the long-term effects.

Case report: Thoracolumbar spinal stenosis associated with alkaptonuria.

Background: Alkaptonuria is a rare autosomal genetic disorder with an incidence of about 1 in 1 million per year. Spinal involvement often manifests in the later stages of the disease. However, this is the first report of the presentation of thoracolumbar spinal stenosis. Case presentation: We report the case of a 61-year-old female patient with significant thoracolumbar stenosis symptoms. The patient had obvious kyphosis with preoperative lower extremity muscle strength grade 2/5. Symptoms and imaging signs initially suggested ankylosing spondylitis. This patient was classified into motor incomplete injury (ASIA C). However, the patient was found to have melanin deposits on the sclera and skin, and the urine was darkened at rest. CT and MRI both suggested no bone bridge connection between vertebrae, which was the key difference between ankylosing spondylitis and alkaptonuria in imaging. Most importantly, urine specimen testing and intraoperative pathology demonstrated alkaptonuria. The patient underwent spinal decompression and vertebral body fixation. Postoperative recovery was good: the patient had significantly relieved pain and could stand and walk. Conclusion: This case is the first report of thoracolumbar spinal stenosis associated with alkaptonuria involving the spine.