[Effectiveness of nano-hydroxyapatite/polyamide 66 cage in anterior spinal reconstruction: a mid-term study].

OBJECTIVE: To evaluate the mid-term effectiveness of nano-hydroxyapatite/polyamide66 (n-HA/PA66) cage in the anterior spinal reconstruction. METHODS: There were 177 patients who undergone the anterior decompression and fusion with n-HA/PA66 cage and internal fixation between January 2008 and January 2010 included in this study. There were 117 male and 60 female patients aged from 18 to 74 years. The diagnoses included cervical fracture in 47 patients, thoracic or lumbar fracture in 50 patients, cervical spondylopathy in 58 patients, spinal tuberculosis in 17 patients and spinal tumor in 5 patients. The X-ray and three-dimensional CT were followed up in all these patients to observe the spinal alignment, the rate of fusion and the rate of n-HA/PA66 cage subsidence and translocation. The neurological functions of patients with spinal fracture were evaluated by Frankel grading; the improvement of the clinical symptoms of the other patients were assessed by visual analogue scale (VAS) scores and Japan Orthopaedic Association (JOA) scores or SF-36 scores. RESULTS: All the 177 patients had been followed-up for 36 to 70 months after surgery (average 51 months). Except the slight cage translocation been found in the only one patient with cervical fracture, no cage prolapsed or breakage was exist in our patients up to the last follow-up. In the patients with spinal fracture, the mean time for fusion was 4.5 months, the rate of fusion was 95.9% and the rate of cage subsidence was 5.2%; while in the patients with cervical spondylopathy, the mean time for fusion was 4.4 months, the fusion rate was 96.5% and the subsidence rate was 5.2%; while in patients with spinal tuberculosis, the mean fusion time was 5.5 months, the rate of fusion was 94.0%, the rate of subsidence was 5.9%; and in the patients with tumor, the mean time for fusion was 6.0 months, the fusion rate was 100%, and the cage subsidence was found in only one patient. The preoperative symptoms of each patient were improved to varying degrees after surgery. At the last follow-up, the Frankel grading of patients of spinal fracture with incomplete paralysis improved 0 to 2 classes; the VAS, JOA or SF-36 scores of the other patients were improved significantly than their respective scores before surgery (t = 2.982, 4.126 and 3.980, P < 0.05). CONCLUSIONS: The n-HA/PA66 cage has much higher rate of osseous fusion and lower cage subsidence, it is an ideal cage which can provide effective restoring and maintaining for the spinal alignment and intervertebral height. Moreover, the mid-term clinical results of anterior reconstruction with this cage in the patients with spinal trauma, degeneration, tuberculosis or tumor are well content.

Comparison of anterior cervical fusion by titanium mesh cage versus nano-hydroxyapatite/polyamide cage following single-level corpectomy.

PURPOSE: The titanium mesh cage (TMC) is a typical metal cage device which has been widely used in cervical reconstruction for decades. Nano-hydroxyapatite/polyamide-66 (n-HA/PA66) cage is a novel biomimetic non-metal cage device growing in popularity in many medical centres in recent years. There has been no comparison of the efficacy between these two anterior reconstructing cages. The purpose of this study was to compare the radiographic and clinical outcomes of these two different devices. METHODS: Sixty-seven eligible patients with single-level ACCF using TMC or n-HA/PA66 cage for cervical degenerative diseases, with four-year minimum follow-up, were included in this prospective non-randomised comparative study. Their radiographic (cage subsidence, fusion status, segmental sagittal alignment [SSA]) and clinical (VAS and JOA scales) data before surgery and at each follow-up was recorded completely. RESULTS: The fusion rate of the n-HA/PA66 group was higher than TMC at one year after surgery (94% vs. 84%) though their finial fusion rates were similar (97% vs. 94%). Finial n-HA/PA66 cage subsidence was 1.5 mm with 6% of severe subsidence over three millimetres, which was significantly lower than the respective 2.9 mm and 22% of TMC (P < 0.0001). Lastly, SSA, VAS and JOA in TMC group were worse than in the n-HA/PA66 group (P = 0.235, 0.034 and 0.007, respectively). CONCLUSIONS: The n-HA/PA66 cage is associated with earlier radiographic fusion, less subsidence and better clinical results than TMC within four years after one-level ACCF. With the added benefit of radiolucency, the n-HA/PA66 cage may be superior to TMC in anterior cervical construction.

Oblique lumbar interbody fusion combined with stress end plate augmentation and anterolateral screw fixation for degenerative lumbar spinal stenosis with osteoporosis: a matched-pair case-controlled study.

BACKGROUND CONTEXT: Oblique lumbar interbody fusion (OLIF) has been proven to be effective in treating degenerative lumbar spinal stenosis (DLSS). Whether OLIF is suitable for treating patients with DLSS with osteoporosis (OP) is still controversial. Bone cement augmentation is widely used to enhance the internal fixation strength of osteoporotic spines. However, the effectiveness of OLIF combined with bone cement stress end plate augmentation (SEA) and anterolateral screw fixation (AF) for DLSS with OP have not confirmed yet. PURPOSE: To evaluate the clinical, radiological, and functional outcomes of OLIF-AF versus OLIF-AF-SEA in the treatment of DLSS with OP. STUDY DESIGN: Retrospective case-control study. PATIENT SAMPLE: A total of 60 patients with OP managed for DLSS at L4-L5. OUTCOME MEASURES: Visual analog scale (VAS) score of the lower back and leg, Oswestry Disability Index (ODI), disk height (DH), lumbar lordosis (LL), segmental lordosis (SL), cage subsidence and fusion rate. METHODS: The study was performed as a retrospective matched-pair case‒controlled study. Patients with OP managed for DLSS at L4-L5 between October 2017 and June 2020 and completed at least 2 years of follow-up were included, which were 30 patients treated by OLIF-AF and 30 patients undergoing OLIF-AF-SEA. The demographics and radiographic data, fusion status and functional outcomes were therefore compared to evaluate the efficacy of the two approaches. RESULTS: Pain and disability improved similarly in both groups at the 24-month follow-up. However, the SEA group had lower pain and functional disability at 3 months postoperatively (p<.05). The mean postoperative disc height decrease (△DH) was significantly lower in the SEA group than in the control group (1.17±0.81 mm vs 2.89±2.03 mm; p<.001). There was no significant difference in lumbar lordosis (LL) or segmental lordosis (SL) between the groups preoperatively and 1 day postoperatively. However, a statistically significant difference was observed in SL and LL between the groups at 24 months postoperatively (p<.05). CS was observed in 4 cases (13.33%) in the SEA group and 17 cases (56.67%) in the control group (p<.001). A nonsignificant difference was observed in the fusion rate between the SEA and control groups (p=.347) at 24 months postoperatively. CONCLUSIONS: This study revealed that OLIF-AF-SEA was safe and effective in the treatment of DLSS with OP. Compared with OLIF-AF, OLIF-AF-SEA results in a minor postoperative disc height decrease, a lower rate of CS, better sagittal balance, and no adverse effect on interbody fusion.

[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.

Novel biodegradable α-TCP/poly(amino acid) composite artificial lamina following spinal surgery for prevention of intraspinal scar adhesion.

Biodegradable copolymer α-TCP/poly(amino acid) composite artificial lamina was prepared and used in goat cervical vertebra resection repair. Cervical 4 was removed by laminectomy, and a vertebra defect of 27 × 9 mm was made. α-TCP/poly(amino acid) composite artificial lamina was inserted in the test group. The efficiency of the copolymer during repair and reconstruction of the goats' vertebra was tested by using X-ray, CT scanning, and histological and biomechanical measurements. In the 24 weeks following the operation, the artificial lamina refrained from shifting, and no dural adhesion pressure was observed. In contrast, the control group suffered from infiltration of soft tissue in the spinal canal, dural pressure and α-TCP/poly(amino acid) degradation. In conclusion, α-TCP/poly(amino acid) composite artificial lamina can significantly prevent scar tissue from infiltrating the spinal canal.

[Effectiveness of combined Pregabalin and Celecoxib for treatment of neuropathic pain after percutaneous endoscopic lumbar discectomy].

Objective: To investigate the effectiveness of combined Pregabalin and Celecoxib for neuropathic pain after percutaneous endoscopic lumbar discectomy. Methods: Between January and June 2014, 178 patients with lumbar disc herniation underwent percutaneous endoscopic interlaminar discectomy (PEID). Ninety patients who met the inclusion criteria were recruited in this study. Every case in group A was recruited to match its counterpart in group B and group C according to gender, disease duration, herniated level, smoking history, preoperative Leeds assessment of neuropathic symptoms and signs (LANSS), and Oswestry disability index (ODI). Nine patients were excluded due to incomplete study or loss of follow-up. In each group, 27 cases were included in the final analysis. There was no significant difference in gender, age, height, body mass index, herniated level, disease duration, smoking history, preoperative LANSS, ODI, and visual analogue scale (VAS) between groups ( P>0.05). All patients of 3 groups received oral administration of Celecoxib from preoperative 3rd day to postoperative 14th day. Pregabalin was taken orally from preoperative 3rd day to postoperative 14th day in group A, and from postoperative 1st to 14th day in group B. Adverse drug reactions were observed during medication. The LANSS score and VAS score in rest state and active state were conducted before operation and at 1 day, 1 month, and 3 months after operation. ODI was conducted before operation and at 1, 3 months after operation. The number of neuropathic pain cases was recorded, and the effectiveness was evaluated by modified Macnab criteria at 3 months after operation. Results: During period of increasing Pregabalin dose, 1 patient of group A suffered severe dizziness, and 1 patient of group B suffered sleepiness, who were eliminated from this research. Another 2 cases (1 case of group A and 1 case of group C) suffered dry mouth, and 1 case of group B suffered muscle weakness. At 1 day after operation, the LANSS score and VAS in rest state and active state of group A were significantly lower than those of groups B and C ( P<0.05). At 1 month after operation, the LANSS score, ODI, and VAS in rest state and active state of group A and group B were significantly lower than those of group C ( P<0.05). At 3 months after operation, the LANSS score, ODI, and VAS in active state of group A and group B were significantly lower than those of group C ( P<0.05). There was no significant difference in the above indicators at the other time points between groups ( P>0.05). Neuropathic pain occurred at 3 months after operation in 1 case (3.7%) of group A and 6 cases (22.2%) of group C, showing significant differences in incidence of neuropathy pain between groups A, B and group C ( P<0.05), but no significant difference was found between group A and group B ( P>0.05). The excellent and good rate of modified Macnab criteria was 92.6% in group A, was 88.9% in group B, and was 85.2% in group C at 3 months after operation, showing no significant difference between groups ( P>0.05). Conclusion: Combined use of Pregabalin and Celecoxib during perioperative period can reduce postoperative pain and incidence of postoperative neuropathic pain. Preoperative oral Pregabalin can reduce the incidence of acute postoperative neuropathic pain.

[PRELIMINARY EFFECTIVENESS OF POLYAMINOACID/NANO-HYDROXYAPATITE/CALCIUM SULFATE CAGE IN LUMBAR FUSION SURGERY].

OBJECTIVE: To discuss the early effectiveness of polyaminoacid/nano-hydroxyapatite/calcium sulfate (PAA/HA/CS) Cage (PHC Cage) in lumbar fusion surgery. METHODS: Thirty cases undergoing lumbar fusion of single segment between March and September 2014 were enrolled in this study. The patients were randomly divided into the trial group (n = 20) and the control group (n = 10). The PHC Cage was implanted in the trial group, while the polyetheretherketone (PEEK) Cage was implanted in the control group. The patients of 2 groups mainly presented lumbocrural pain and lower limb radiation pain or numbness. There was no significant difference in gender, age, type, affected segment, disease duration, preoperative intervertebral height, the lordosis angle of fusion segments, and the Oswestry Disability Index (ODI) between 2 groups (P > 0.05). Lateral lumbar X-ray films and three dimensional CT were taken preoperatively and at 1 week and 3, 6, and 12 months postoperatively. The intervertebral height and the lordosis angle of fusion segments at 1 week and 3, 6, and 12 months after operation and ODI at 3, 6, and 12 months after operation were measured; and the bone graft fusion rate was evaluated according to Brantigan criteria. RESULTS: There was no significant difference in operation time, intraoperative blood loss, and the amount of autologous blood transfusion between 2 groups (P > 0.05). Healing by first intention as obtained in 30 cses. All patients were followd up 12 months. The intervertebral height of fusion segments, the lordosis angle of fusion segments, and ODI at each time point after operation were significantly improved when compared with preoperative ones (P < 0.05). The ODI showed significant difference between 3 months and 6, 12 months (P < 0.05), but there was no significant difference between the other time points after operation (P > 0.05). There was no significant difference in the intervertebral height and the lordosis angle of fusion segments between groups at different time points (P > 0.05). There was no significant difference in the above indexes between the trial group and the control group at each time point (P > 0.05). At last follow-up, 5 cases were rated as Brantigan grade E, 13 cases as grade D, and 2 cases as grade C in the trial group; 4 cases were rated grade E, 5 cases as grade D, and 1 case as grade C in the control group. The bone fusion rate was 90% in 2 groups. CONCLUSION: The PHC Cage can effectively restore and maintain the disc height of fusion segment, normal sequence and biomechanical stability of the lumbar spine. The PHC Cage is similar to the PEEK Cage and has good clinical outcome in short-term follow-up.

[Novel artificial lamina for prevention of epidural adhesions after posterior cervical laminectomy].

OBJECTIVE: To evaluate the application of artificial lamina of multi-amino-acid copolymer (MAACP)/nano-hydroxyapatite (n-HA) in prevention of epidural adhesion and compression of scar tissue after posterior cervical laminectomy. METHODS: Fifteen 2-year-old male goats [weighing, (30 +/- 2) kg] were randomly divided into experimental group (n=9) and control group (n=6). In the experimental group, C4 laminectomy was performed, followed by MAACP/n-HA artificial lamina implantations; in the control group, only C4 laminectomy was performed. At 4, 12, and 24 weeks after operation, 2, 2, and 5 goats in the experimental group and 2, 2, and 2 goats in the control group were selected for observation of wound infection, artificial laminar fragmentation and displacement, and its shape; Rydell's degree of adhesion criteria was used to evaluate the adhesion degree between 2 groups. X-ray and CT images were observed; at 24 weeks after operation, CT scan was used to measure the spinal canal area and the sagittal diameter of C3, C4, and C5 vertebrea, 2 normal goats served as normal group; and MRI was used to assess adhesion and compression of scar tissue on the dura and the nerve root. Then goats were sacrificed and histological observation was carried out. RESULTS: After operation, the wound healed well; no toxicity or elimination reaction was observed. According to Rydell's degree of adhesion criteria, adhesion in the experimental group was significantly slighter than that in the control group (Z= -2.52, P=0.00). X-ray and CT scan showed that no dislocation of artificial lamina occurred, new cervical bone formed in the defect, and bony spinal canal was rebuilt in the experimental group. Defects of C4 vertebral plate and spinous process were observed in the control group. At 24 weeks, the spinal canal area and sagittal diameter of C4 in the experimental group and normal group were significantly larger than those in the control group (P < 0.05), but no significant difference was found between experimental group and normal group (P > 0.05). MRI showed cerebrospinal fluid signal was unobstructed and no soft tissue projected into the spinal canal in the experimental group; scar tissue projected into the spinal canal and the dura were compressed by scar tissue in the control group. HE staining and Masson trichrome staining showed that artificial lamina had no obvious degradation with high integrity, some new bone formed at interface between the artificial material and bone in the experimental group; fibrous tissue grew into defect in the control group. CONCLUSION: The MAACP/n-HA artificial lamina could maintaine good biomechanical properties for a long time in vivo and could effectively prevent the epidural scar from growing in the lamina defect area.

Novel biodegradable lamina for lamina repair and reconstruction.

BACKGROUND CONTEXT: Posterior laminectomy is an effective spinal surgical procedure. The adhesion of postoperative scar tissue to surgically exposed dura and, occasionally, to nerve roots can cause failed back surgery syndrome. The establishment of a barrier between scar tissue and dura that is made of hard material may prevent scar adhesions. PURPOSE: To evaluate the efficacy of a novel biodegradable multi-amino acid copolymer/nanohydroxyapatite composite artificial lamina. METHODS: A cervical laminectomy animal model in goats was used, and the animals were randomly divided into three groups. In the test group, cervical 4 was removed by laminectomy and the artificial lamina was inserted (n=12). In the control group, the incision was closed directly without implantation (n=9). The goats in the normal group did not undergo any procedure or treatment. Copolymer efficiency was tested by using X-ray, computed tomography scanning, magnetic resonance imaging, scanning electronic microscope, and histologic and biomechanical measurements 4, 12, and 24 weeks postoperation. RESULTS: No shifting of the artificial lamina or dural adhesion pressure was observed. New cervical natural bone formed in the defect and the bony spinal canal was rebuilt. In the control group, fibrous scar tissue filled the defect and exerted pressure on the dura. No paralysis was observed, and gait was normal in all test and control goats. CONCLUSIONS: Artificial lamina can prevent the epidural adhesions surrounding the defect and promote effectively bone tissue repair and new bone formation.

Anterior reconstruction with nano-hydroxyapatite/polyamide-66 cage after thoracic and lumbar corpectomy.

Cages are used to regain stability of the anterior spinal column following vertebrectomy, which could prevent significant donor-site morbidity from the iliac autograft harvesting and the risk of disease transmission associated with the allograft. The hollow, porous, cylindrical nanohydroxyapatite/polyamide 66 (n-HA/PA66) cage is a new nonmetallic cage device made by combining nanohydroxyapatite with polyamide 66. Few studies have examined its effectiveness and outcomes over a follow-up >2 years.We retrospectively studied 51 consecutive patients with acute traumatic thoracic or lumbar burst fracture who underwent anterior reconstruction with the n-HA/PA66 cage following single-level corpectomy. Radiologic parameters (radiographs and 3-dimensional computed tomography scans) preoperatively and at 1 week and >2 years postoperatively, as well as clinical outcome parameters (SF-36 scores), were analyzed. Mean kyphosis correction in the segment within the cage was 11.8°±7.1°, and mean loss of correction at last follow-up was 1.9°±2.1°. Osseous fusion was achieved in 90.2% of patients, and severe cage subsidence (settling >2 mm) was observed in 19.6% of patients at final follow-up. Significant differences were found in 7 of 8 health dimensions of the SF-36 between neurologically intact patients and neurologically injured patients. Our clinical results indicate that the n-HA/PA66 cage is an effective device for reconstruction after anterior thoracic and lumbar vertebral resection, resulting in a high rate of successful osseous fusion and a low proportion of severe cage subsidence.

[Application of nano-hydroxyapatite/polyamide 66 cage in reconstruction of spinal stability after resection of spinal tumor].

OBJECTIVE: To evaluate the security and effectiveness of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage in reconstruction of spinal stability after resection of spinal tumor. METHODS: Between January 2008 and December 2009, 11 patients with spinal tumor underwent surgical resection and strut graft with n-HA/PA66 cage. There were 6 males and 5 females with an average age of 44.5 years (range, 16-61 years). The average disease duration was 6.8 months (range, 2-14 months). The locations of lesions included cervical spine (2 cases), thoracic spine (6 cases), and lumbar spine (3 cases). Among them, there were 5 metastatic carcinomas, 2 giant cell tumors, 1 osteoblastoma osteosarcoma, 1 chondrosarcoma, and 2 non-Hodgkin lymphoma. According to Frankel criteria for nerve function classification, there were 1 case of grade A, 3 cases of grade B, 2 cases of grade C, 2 cases of grade D, and 3 cases of grade E. RESULTS: Incisions healed by first intention in all patients, no operative or postoperative complication occurred. Four cases of metastatic carcinoma died of primary disease during 5-9 months after operation. Seven cases were followed up 14.4 months on average (range, 10-18 months). All patients gained significant improvement of the neurological function at 3 months after operation. All cases obtained bone fusion and good spinal stability without displacement and subsidence of the n-HA/PA66 cage. The intervertebral height of the adjacent segments was (110.5 +/- 16.1) mm at 3 months after operation and (109.4 +/- 16.2 ) mm at the final follow-up, showing significant differences when compared with the preoperative height [(97.5 +/- 15.4) mm, P < 0.05], but no significant difference between 3 months after operation and the final follow-up. In 2 patients undergoing surgery via anterior approach, bilateral pleural effusion on both sides occurred and were cured after closed thoracic drainage. During the follow-up, 2 cases (1 chondrosarcoma and 1 giant cell tumor) relapsed and underwent reoperations. CONCLUSION: n-HA/PA66 cage can provide satisfactory bone fusion and ideal spinal stability without increasing the risk of recurrence and complications during the surgical treatment of spinal tumors. It is an ideal selection for reconstruction of spinal stability.