The Association of Fecal Microbiota in Ankylosing Spondylitis Cases with C-Reactive Protein and Erythrocyte Sedimentation Rate.

The purpose of this work was to identify the features of the gut microbiome in cases of ankylosing spondylitis (AS) testing positive for human leukocyte antigen- (HLA-) B27 and healthy controls (HCs) as well as to determine how bacterial populations were correlated with C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Fecal DNA extracted from fecal samples from 10 AS cases and 12 HCs was subjected to 16S rRNA gene sequencing. The two research groups did not differ significantly regarding alpha diversity. By comparison to HCs, AS cases displayed a lower relative level of Bacteroidetes (P < 0.05), but a higher level of Firmicutes and Verrucomicrobia (P < 0.05). Furthermore, the correlation between the specific gut bacteria and ESR or CRP was investigated. At the phylum level, Firmicutes and Verrucomicrobia had a positive association with ESR and CRP, while Bacteroidetes exhibited an inverse correlation with ESR and CRP. Meanwhile, in terms of genus, Bacteroides had a positive association with ESR and CRP, whereas Ruminococcus and Parasutterella had an inverse correlation with ESR and CRP, and Helicobacter also displayed an inverse correlation with CRP. Such findings indicated dissimilarities between AS cases and HCs regarding the gut microbiome, as well as the existence of correlations between bacterial populations and both ESR and CRP.

[Transforaminal lumbar intervertebral fusion in the treatment of thoracolumbar disc herniation: technique feasibility and radiological outcomes].

OBJECTIVE: To explore the feasibility, safety and efficacy of treating thoracolumbar disc herniation with transforaminal lumbar intervertebral fusion (TLIF). METHODS: From December 2009 to May 2013, 15 consecutive patients with one-level thoracolumbar disc herniation underwent TLIF. There were 9 males and 6 females with an average age of 41.2 (25-72) years. According to the Japanese Orthopedic Association (JOA) criteria and Frankel grading system, it was evaluated for the clinical effects of all patients. RESULTS: The average operative duration was 140 (115-180) min and mean blood loss volume 329 (100-500) ml. The symptoms improved all greatly over an average follow-up period of 19 (3-44) months. According to the JOA criteria system, the outcomes were excellent (n = 9, 60%), good (n = 4, 26.6%) and fair (n = 2, 13.4%). Based on the Frankel grading system, 2 cases were classified as A (n = 2), 2 as B (n = 2), 4 as C (n = 4) and 7 as D (n = 7) preoperatively versus B (n = 1), C (n = 1), D (n = 4) and E (n = 9) postoperatively. CONCLUSION: The combined approach of TLIF plus posterior laminectomy is anatomically simple, visually distinct, relatively safe, reliable and efficacious in treatment of thoracolumbar disc herniation.

[Lateral position one-stage combined anteroposterior approach versus posterior approach with subtotal corpectomy, decompression, and reconstruction of spine in the treatment of thoracolumbar burst fractures].

OBJECTIVE: To compare the medium and long-term outcomes of lateral position one-stage plus anteroposterior versus posterior approach with subtotal corpectomy, decompression, and reconstruction of spine in the treatment of thoracolumbar burst fractures. METHODS: A total of 47 patients with thoracolumbar burst fractures were divided into 2 groups according to surgical approaches. Group A underwent lateral position one-stage plus anteroposterior approach while group B had posterior approach with subtotal corpectomy, decompression and reconstruction of spine. During a follow-up period of 36-68 months, their clinical and radiological outcomes were retrospectively evaluated. The perioperative volume of blood loss, operative duration, complications, pulmonary functions, Frankel scale and American Spinal Injury Association (ASIA) motor scores were recorded and analyzed. And the heights of anterior edge of vertebral body and Cobb angle were examined for radiological outcomes. RESULTS: At the latest follow-up, all patients achieved solid fusion with significant neurological improvements. The perioperative volumes of blood loss were less, operative duration was shorter and postoperative pulmonary functions were better in the group B (P < 0.05). The ASIA motor score and radiological outcomes were not significantly different at all timepoints between two groups (P < 0.05). But the neurological functions of two groups improved by approximately 1.4 Frankel grade (group A) versus 1.41 (group B) at the final follow-up. CONCLUSION: Lateral position one-stage plus anteroposterior and posterior approaches with subtotal corpectomy, decompression, and reconstruction of spine are adequate surgical treatments for thoracolumbar burst fractures. But the latter has the major advantages of less perioperative volume of blood loss, fewer complications, shorter operative duration and better pulmonary functions.

[Surgical options and clinical outcomes in patients of lumbar disc herniation with Modic changes].

OBJECTIVE: To retrospectively evaluate medium and long-term outcomes of conventional fenestration discectomy versus posterior lumbar interbody fusion in lumbar disc herniation with Modic changes. METHODS: From January 2002 to January 2007, a total of 486 patients of lumbar disc herniation with Modic changes were analyzed retrospectively. They were divided into fenestration group (n = 215) and fusion group (n = 271) according to the operative approaches. The scores of Oswestry disability index (ODI) and visual analog scale (VAS) pre-and post-operative 3, 6, 12 month and annually were recorded and analyzed. RESULTS: All of them had complete records during a mean follow-up period of 88.9 (60-120) months. At the end of the latest follow-up, all symptoms were relieved postoperatively. Significantly difference existed in the improvement rate of back pain VAS between two groups (77.9% vs 68.0%). In the fenestration group, the improvement rate of VAS (back pain) of Modic type I I was better than that of Modic type I (72.8% vs 64.9%). And the difference was statistically significant. For those with Modic type I changes, the improvement rate of ODI and VAS (back pain) of the fusion group were better than those of the fenestration group (78.3% vs 70.4% and 77.4% vs 64.9%). And the differences were statistically significant (P < 0.05). CONCLUSION: The patients with Modic I and II changes were recommended to undergo lumbar fusion and undergo fenestration discectomy respectively.

[Influences of clinical symptoms on the selection of surgical options for adult degenerative scoliosis].

OBJECTIVE: To retrospectively analyze the interactions between the clinical symptoms and surgical options and evaluate the surgical efficacies for adult degenerative scoliosis (DS). METHODS: A total of 35 adult DS patients underwent operations at Tianjin hospital from May 1996 to December 2008. There were 23 females and 12 males with a mean age of 59.1 years (range: 45 - 74). Clinical symptoms, physical examinations and radiological findings for all patients were recorded at different stages, at 1 week, 3 months, 6 months, 1 year post-operation and per year respectively. According to different surgical options, they were classified into 3 groups: A: limited decompression; B: selective decompression & short-segment fusion; C: selective decompression & long-segment correction & fusion. RESULTS: All patients had complete records with a mean follow-up period of 42.4 months (range: 24 - 168). Firstly, 9 patients in group A had no complaint of a low-back pain at pre-operation. The average coronal Cobb's angles were 15.6 ± 2.3° at pre-operation and 17.1 ± 3.3° at the latest follow-up. The radicular symptoms became greatly relieved at 1 year. Three cases complained of the aggravation of back pain. Secondly, 15 patients in group B mainly complained of a low-back pain at pre-operation. It was combined with lower-limb radiation pain in 6 patients and nerve claudication in 9 cases. The average coronal Cobb's angles were 14.1 ± 4.6° at pre-operation and 24.4 ± 6.7° at the latest follow-up. However, 12 patients experienced the progression of scoliosis. Thirdly, 11 patients in group C experienced a low-back pain at pre-operation while 5 cases with lower-limb radiation pain and 6 with claudication. The mean coronal Cobb's angles were 22.3 ± 9.2° at pre-operation and 12.2 ± 4.7° at the latest follow-up. Among 4 patients with residual pains, none required revision. CONCLUSIONS: For the DS patients, it is quite important for the surgical options to comprehensively analyze the neurological signs, imaging data and clinical symptoms. However, the fusion end vertebrae should always avoid the vicinity or apex of curve if the short-segment fusion is selected.

[Anterior cervical discectomy and fusion in the treatment of Hangman's fracture].

OBJECTIVE: To evaluate the efficacies and features of treating Hangman's fracture by anterior cervical discectomy and fusion (ACDF). METHODS: Since June 2005 to December 2008, 36 cases with Hangman's fracture were analyzed with their clinical data including history, symptoms, signs, radiological findings and treatments. According to the classification system designed by Levine and Edwards depending on the radiological manifestations of Hangman's fractures, they were subdivided into type I (n = 9) (conservative therapy), type II (n = 17) and type IIA (n = 10). Conservative therapy was offered to type I in 9 cases, while ACDF with cervical gear protection for 4 weeks after surgery was performed to type II in 17 cases and type IIA in 10 cases. A combination of operation time, days of hospitalization, complications, neurological improvement and fusion rate was assessed. RESULTS: An average follow-up of 15 months (range: 10 - 36) was achieved. No vertebral redisplacement and angulation deformity occurred. Axial pain was relieved in each case. The preoperative neurological deficits in all patients got improvements. No spinal cord injury, vertebral artery injury or cerebrospinal fluid leakage occurred. No complication related to internal fixator was found. Average operative time and hospitalization were similar to those of ACDF for lower cervical spine (98 minutes vs. 9 days). Fusion was achieved within 6 months in all cases. CONCLUSION: ACDF at C2-C3 may be an effective and safe way to treat Hangman's fracture.

[Surgical options and result analyses in adult degenerative lumbar scoliosis].

OBJECTIVE: To investigate the clinical and radiographic outcomes for varying degrees of degenerative lumbar scoliosis using different surgical options with a minimal 5-year follow-up. METHODS: From May 1998 to November 2002, 31 patients with degenerative lumbar scoliosis underwent operations at our hospital. The mean age of 19 females and 12 males was 55.8 years old (range: 45 to 71). All patients were divided into 4 groups: Group A, mild coronal deformity with obvious sagittal deformity, 13 cases; Group B, obvious coronal deformity with mild sagittal deformity; Group C, both significant coronal and sagittal deformities; Group D, both mild coronal and sagittal deformities. Posterior decompression, internal fixation and bone graft fusion were performed in Groups A, B and C. And posterior decompression was performed in Group D. All patients were followed up for at least 5 years. Patients answered the Oswestry low back pain disability questionnaire at pre-operation, and 1 year, 5 year post-operation. RESULTS: Thirty patients were followed up for the whole process. According to Cobb's angle methods, there was great post-operative improvement for patients with internal fixation (Groups A, B, C) while there was no significant difference for patients with posterior decompression at pre-and post-operation. After surgery, the average Oswestry Disability Index score in the patients with internal fixation (Groups A, B, C) was significantly lower than the preoperative score (25.8 vs 58.0; P < 0.001). However there was statistical difference for patients with internal fixation between 1 year and 5 year postoperatively. No perioperative death or major medical complications occurred. Ten patients had adjacent segment degeneration. CONCLUSIONS: The surgical aim for adults with a spinal deformity is to achieve a stable, balanced and pain-free spine. Surgical treatments should consist of decompression and fusion with segmental instrumentation to avoid instability and curb progression. Despite the complexity of adult lumbar degenerative scoliosis, it might improve the quality of life for patients by choosing an appropriate operation option on the basis of varying degrees of lumbar deformity.

Comparison of the Biomechanical Changes After Percutaneous Full-Endoscopic Anterior Cervical Discectomy versus Posterior Cervical Foraminotomy at C5-C6: A Finite Element-Based Study.

OBJECTIVE: Percutaneous full-endoscopic anterior cervical discectomy (PEACD) and posterior cervical foraminotomy (PCF) have been reported as effective treatments for the cervical spondylosis radiculopathy (CSR), but the biomechanical effects on the discs and facet joints of PEACD and PCF remain largely unclear. The purpose of this paper is to investigate and compare the biomechanical changes on cervical spine after PECAD and PCF procedures, thus providing evidences for surgeons to select a more appropriate approach. METHODS: An intact cervical C5-C6 digital model was constructed and then modified to obtain the PCF and PEACD models using finite element method. All the models were subjected to a 73.6N preload accompanied by a 1.8 Nm moment during flexion, extension, axial rotation, lateral bending. The range of motion (ROM), intervertebral disc pressure (IDP), facet joint contact area, and contact pressure were calculated under different loading conditions. RESULTS: The ROM of the PCF model changed slightly (0.28%), whereas that of the PEACD model increased significantly (20.49%) compared with intact model. The trend of IDP changes in these 2 surgical models were similar to ROM in the corresponding motion state. The contact pressure on the facet joint of the PEACD model increased by 20.53%, 33.38%, and 17.46% during extension, lateral bending, and axial bending, respectively, compared with the intact model, and the PCF increased by 33.53% and 16.16% during extension and lateral bending, respectively, whereas it decreased 0.97% in axial rotation. The facet joint contact area of the PCF model increased by 85.71%, 1.54%, and 2.17% during extension, lateral bending, and axial rotation, respectively, and the area of the PEACD model increased by 157.14% and 36.96% during extension and axial rotation, whereas it decreased by 13.85% during lateral bending. CONCLUSIONS: This is the first biomechanical finite element study comparing PEACD with PCF for the treatment of CSR. Our results showed that PEACD led to hypermobility with high IDP within the cervical segment undergone surgery, whereas the ROM and IDP changed slightly after PCF. The variations of the contact stress indicated that both procedures changed the transmission path of the force on the facet joint and may accelerate the degeneration of the facet joint. PCF may be a better choice for the treatment of CSR compared with PEACD.

miR-221 alleviates the inflammatory response and cell apoptosis of neuronal cell through targeting TNFAIP2 in spinal cord ischemia-reperfusion.

This study aimed to examine the role of miR-221 in inflammatory response and apoptosis of neuronal cells after spinal cord ischemia/reperfusion (I/R) injury. Blood samples were obtained from 20 I/R patients and that of 20 healthy individuals were used as a control. AGE1.HN and SY-SH-5Y neuronal cell lines subjected to oxygen-glucose deprivation (OGD) stress were used in cell experiments. Real-time PCR and western blot were used to evaluate the expression of miR-221, tumor necrosis factor-α, and TNFAIP2. TUNEL assay analyzed cell apoptosis. I/R patients had lower serum levels of miR-221 than healthy controls. In OGD-AGE1.HN and SY-SH-5Y cells, miR-221 was significantly downregulated and TNFAIP2 mRNA and protein were upregulated; meanwhile, both proinflammatory cytokine tumor necrosis factor-α and anti-inflammation cytokine interleukin-6 were elevated and the percentage of apoptotic cells was increased. This inflammatory response and cell apoptosis induced by OGD stress were attenuated by miR-221 overexpression and enhanced by miR-221 knockdown. TNFAIP2 is a target gene for miR-221 and could be regulated negatively by the miR-221 mimic or the miR-221 inhibitor with or without OGD stress. Accordingly, TNFAIP2 overexpression reversed the inflammatory response and cell apoptosis induced by miR-221 under OGD stress. Downregulation of miR-221 occurs in spinal cord I/R injury and in cell lines subjected to oxygen-glucose deprivation. miR-221 regulates the inflammatory response and apoptosis of neuronal cells through its impact on TNFAIP2.

Vancomycin microspheres reduce postoperative spine infection in an in vivo rabbit model.

BACKGROUND: Surgical site infections are common and devastating complications after implants related surgeries. Staphylococcus aureus contamination is a leading cause of surgical site infections. This study aims at assessing the effect of vancomycin microspheres on reducing Staphylococcus aureus infection in an in vivo rabbit model. METHODS: Sixty surgical sites of 20 New Zealand White rabbits underwent spinal implant were randomly divided to three groups: the control group, the vancomycin group and vancomycin microspheres group. The surgical sites were incubated with 100 µl 1 × 107 CFU S. aureus ATCC 25923. Prior to closure, vancomycin and vancomycin microspheres were placed into the wounds of the rabbits in the vancomycin group and the vancomycin microspheres group, respectively. The rabbits were killed on postoperative day 7. Standard quantification techniques were used to analyze biomaterial centered and soft tissue bacterial growth. The bacteria were further confirmed by PCR with primers from the thermostable nuclease gene of S. aureus. RESULTS: All the rabbits survived the surgery and no postoperative wound complications or systemic illness occurred. Results showed that the bacterial cultures were 76.9, 30.8, and 15.4% in the control group, vancomycin group, and vancomycin microspheres group. Vancomycin microspheres treatments significantly decreased the infection rate compared to the control group (p < 0.05). CONCLUSION: Vancomycin microspheres combined with preoperative ceftriaxone is effective to reduce postoperative S. aureus infection compared with the control group.

Association of follistatin-like 3 concentrations in serum and synovial fluid with the radiographic severity of knee osteoarthritis.

OBJECTIVE: Follistatin-like 3 (FSTL3), a circulating glycoprotein, is correlated with obesity and inflammation, which are potential mechanisms of osteoarthritis (OA). This study aims to determine the correlation of FSTL3 concentrations in serum and synovial fluid (SF) with the radiographic severity of OA. METHODS: This study consisted of 200 patients with knee OA and 148 healthy controls. The radiological grading of OA in the knee was performed in accordance with Kellgren-Lawrence (KL) grading system. RESULTS: Knee OA patients had higher serum FSTL3 concentrations compared with healthy controls. Knee OA patients with KL grade 4 showed significantly elevated FSTL3 concentrations in serum and SF compared with those with KL grades 2 and 3. Moreover, knee OA patients with KL grade 3 had significantly higher FSTL3 concentrations in serum and SF compared with those with KL grade 2. FSTL3 concentrations in serum and SF of knee OA patients were significantly correlated with KL grading criteria. CONCLUSIONS: FSTL3 concentrations in serum and SF are correlated with the radiographic severity of OA.

[Using of transforaminal lumbar interbody fusion in lumbar revision surgery].

OBJECTIVE: To analyze the effectiveness of transforaminal lumbar interbody fusion (TLIF) for failed back surgery syndrome (FBSS). METHODS: Between October 2003 and December 2007, 36 patients with FBSS were treated with TLIF. There were 19 males and 17 females with an average age of 52.6 years (range, 46-68 years) and an average disease duration of 1.6 years (range, 3 months-15 years). Of 36 patients, reoperation was performed in 25, 10 received 3 operations, and 1 had 5 operations. A total of 50 segments were involved in fusion, including L4,5 in 12 cases, L5, S1 in 10 cases, L3, 4 and L4, 5 double segments in 8 cases, and L4, 5 and L5, S1 double segments in 6 cases. According to X-ray films, CT, and MRI examination, 12 patients were diagnosed as having lumbar instability secondary to total laminectomy, 18 as having recurrence of lumbar disc protrusion, and 6 as having recurrence of lumbar spondylolisthesis. RESULTS: Dural rupture occurred in 1 case and was repaired by suturing without cerebrospinal fluid leakage was observed; 1 had deep incision infection of Staphylococcus; and 1 had transient single irritation sign because of hematoma formation and was cured after symptomatic treatment. The other incisions healed by first intention. No patients had permanent nerve injury or deterioration. Thirty-three cases were followed up 18-72 months (mean, 35.2 months). At 12 months, all the operated segments reached interbody fusion, and no breakage of screw or Cage dislocation occurred. Japanese Orthopaedic Association (JOA) scores showed significant difference (t = 2.45, P = 0.01) between before operation (14.2 +/- 4.1) and 18 months after operation (23.9 +/- 2.6). The rate of clinical improvement was 90.9% (23 cases of excellent, 7 cases of good, 3 cases of acceptable). CONCLUSION: The TLIF simplifies the manipulation of lumbar revision surgery and decreases the operation risk and the operative complications for the treatment of FBSS.

[Modified transforaminal lumbar interbody fusion for the treatment of lumbar degenerative disease].

OBJECTIVE: To analyze the clinical effects of modified transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disease. METHODS: From October 2003 to December 2006, 33 patients with lumbar degenerative disease (L3-S1) were treated by modified TLIF. There were 14 males and 19 females with an average age of 52.2 years (33 to 70 years). The median disease course was 1.8 years (4 months to 15 years). A total of 42 levels were fused, including 24 cases of single level and 9 cases of double levels. The results of preoperative diagnosis were lumbar degenerative spondylolisthesis with stenosis (8 cases), isthmic spondylolisthesis (5 cases), degenerative lumbar stenosis (16 cases), huge herniated disc with segmental instability (3 cases) and failed back surgery syndrome (1 case). During the modified TLIF procedure, total inferior facet process and inner half summit of superior facet process of TLIF side were resected to make the posterior wall of foramen opened partly. After the bone graft (3 to 5 mL) was placed into the interbody space, a single rectangle Cage was inserted obliquely from 30 degrees to 40 degrees toward the midline. Combined with pedicle screw instrumentation, TLIF was accomplished. Middle canal and opposite side nerve root decompression were performed simultaneously when necessary. RESULTS: Intraoperative dura mater rupture, postoperative cerebral spinal fluid leakage, deep wound infection and transient nerve root stimulation occurred in 1 case respectively, and were all recovered after treatment. No patients had permanent neurologic deficit or aggravation. All patients were followed up for 20 to 58 months (mean 27.2 months). At the follow-up after 1 year postoperatively, all the operated segments achieved fusion standard and no broken screw or Cage dislocation occurred. All 13 cases of spondylolisthesis were reduced thoroughly and maintained satisfactorily. Nineteen patients remained slight chronic back pain. There was significant difference (P < 0.05) in JOA score between preoperation (14.9 +/- 5.1) and postoperation (25.9 +/- 3.0). The rate of clinical improvement was 80.5% (excellent in 24 cases, good in 7 cases, and fair in 2 cases). CONCLUSION: The modified TLIF carries out the less invasive principles in opening operations, simplifies the manipulation and expands the indication of TLIF to some extent, and the clinical results for the treatment of lumbar degenerative disease is satisfactory.

[Design and experimental study of internal fixator for the reconstruction of lumbar isthmus].

OBJECTIVE: To investigate the clinical applicability and value of internal fixator for the reconstruction of lumbar isthmus in the treatment of lumbar vertebral spondylolysis and to lay a foundation for its clinical application. METHODS: Six teen healthy goats weighing 22.65-31.22 kg were selected to establish the models of vertebral spondylolysis at L5, which thereafter were randomized into two groups (n=8): bone graft group in which 0.8-1.1 g fresh autogenous bone was transplanted into the isthmus spondylolysis area, and internal fixation with bone graft group in which internal fixator was installed before transplanting 0.8-1.1 g fresh autogenous bone into the isthmus spondylolysis area. All animals were killed 8 weeks after operation to receive imaging, topographic anatomy and histology detection. Meanwhile, biomechanics test was performed by using 5 donated vertebral body specimens (4 males and 1 female aged 35-51 years old). The left isthmus of Ls vertebra was transected to serve as lumbar vertebral spondylolysis model. A mini-displacement sensor was put at the transected ends of the isthmus. Then loading was conducted with a constant velocity of 2 mm/min by electronic omnipotent tester simulating the direction of fixation force of the internal fixator, and the deformation value of the transected ends was collected by a dynamic data collector and analyzer. The loading was continued until the vertebra specimens were damaged. The deformation of displacement sensor and the closure of transected ends of the lumbar isthmus were observed. RESULTS: All the goats behaved normally shortly after operation, and no nerve injury induced by operation and no wound infection occurred. Bilaterally oblique X-ray films of lumbar vertebra and topographic anatomy 8 weeks after operation showed the fusion rate of the internal fixation and bone graft group and the bone graft group was 100% and 62.5%, respectively, indicating there was a significant difference (P < 0.05). Histology observation showed 3 goats in the bone graft group presented empty bone trabecula, empty bone lacuna and the disappearance of osteocytes at the transected ends of lumbar isthmus; while in the internal fixation and bone graft group, the bone trabecula grew into cancellous structures with hematopoietic and fatty bone marrow tissue inside, and parts of the bone trabecula had various degrees of mosaic-like pattern. During the upload, the biomechanics test and data processing results showed when the external load was 40 N, the deformation of displacement sensor was identified and the gap between the transected ends of lumbar isthmus started to close; then with the increase of external load, the displacement sensor tended to ascend in a linearity manner; while when the external load was 212 N, the displacement sensor had no further deformation, the gap between the transected ends of lumbar isthmus was completely closed, and the pressor effect appeared. CONCLUSION: The internal fixator for the reconstruction of lumbar isthmus has mechanical effects of stabilizing and elevating pressure with a high fusion rate.

Thoracic ossification of ligamentum flavum caused by skeletal fluorosis.

Thoracic ossification of ligamentum flavum (OLF) caused by skeletal fluorosis is rare. Only six patients had been reported in the English literature. This study reports findings from the first clinical series of this disease. This was a retrospective study of patients with thoracic OLF due to skeletal fluorosis who underwent surgical management at the authors' hospital between 1993 and 2003. Diagnosis of skeletal fluorosis was made based on the epidemic history, clinical symptoms, radiographic findings, and urinalysis. En bloc laminectomy decompression of the involved thoracic levels was performed in all cases. Cervical open door decompression or lumbar laminectomy decompression was performed if relevant stenosis was present. Neurological status was evaluated preoperatively, at the third day postoperatively, and at the end point of follow-up using the Japanese Orthopaedic Association (JOA) scoring system of motor function of the lower extremities. A total of 23 cases were enrolled, 16 (69.6%) males and 7 (30.4%) females, age ranging from 42 to 72 years (mean 54.8 years). All patients came from a high-fluoride area, and 22 (95.7%) had dental fluorosis. Medical imaging showed OLF together with ossification of many ligaments and interosseous membranes, including interosseous membranes of the forearm (18/23 patients 78.3%), leg (14/23 patients 60.9%), and ribs (11/23 patients 47.8%). OLF was classified into five types based on MRI findings: localized (4/23 patients 17.4%), continued (12/23 patients 52.2%), skip (3/23 patients 13.0%), combining with anterior pressure (2/23 patients 8.7%), and combining with cervical and/or lumbar stenosis (2/23 patients, 8.7%). Urinalysis showed a markedly high urinary fluoride level in 14 of 23 patients (60.9%). Patients were followed up for an average duration of 4 years, 5 months. Paired t-test showed that the JOA score was slightly but nonsignificantly increased relative to preoperative measurement 3 days after surgery (P = 0.0829) and significantly increased at the end of follow-up (P = 0.0001). In conclusion, Fluorosis can cause ossification of thoracic ligamentum flavum, as well as other ligaments. Comparing with other OLF series, a larger number of spinal segments were involved. The diagnosis of skeletal fluorosis was made by the epidemic history, clinical symptom, imaging study findings, and urinalysis. En bloc laminectomy decompression was an effective method.