To observe the clinical effect and safety of the nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composite in repairing the bone defects due to benign bone tumors. Methods From January 2003 to May 2005, 38 patients (21 males, 16 females; age, 19-58 years, averaged 38.5 years) with the bone defects due to benign bone tumors were treated with the n-HA/PA66 grains. Among the 37 patients, 11 had fibrous dysplasia, 14 had bone cyst, 10 had giant cell tumor of the bone (Grade Ⅰ), and 2 had enchondroma. The tumors ranged in size from 1.0 cm×0.7 cm×0.4 cm to 10.0 cm×4.0 cm×3.0 cm, with the location of the proximal femur in 12 patients, the distal femur in 7, the proximal tibia in 9, the proximal humerus in 5, the phalanges of the finger in 2, the metacarpal bone in 1,and the calcaneus in 1. Allthe benign bone tumors underwent the curettage treatment, and then the tumor cavities were filled up with the n-HA/PA66 grains. The incision healing, local inflammatory reaction, rejection, toxic reaction, tumor cavity healing, and function recovery of the limbs were all observed after operation. Results All the patients were followed up for 5-33 months, and all the incisions healed by the first intention except 1 incision, which developed infection. The inflammatory reaction was mild, with no reection or general toxic reaction. At 3 to 5.5 months(mean 4 months) after operation, osteogenesis wasfound in the space filled with the n-HA/PA66 grains. Eight months after operation, the patients’ lower limbs could bear weights; 5 months after operation, the upper limbs could complete daily work. Conclusion The n-HA/PA66 grains have great biological safety, good biocompatibility, and good bone conduction, which aregood materials for the bone repair and reconstruction, and can be safely, andeffectively used for repairing the bone defects due to benign bone tumors．
Objective To investigate the safety of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) bioactive support in bone grafting and fusion for elderly patients with lumbar tuberculosis, and to analyze its effectiveness and advantages by comparing with autologous iliac bone grafting. Methods A retrospective analysis was performed on 48 elderly patients with lumbar tuberculosis who met the selection criteria between January 2017 and January 2020. The patients all underwent one-stage posterior pedicle screw internal fixation combined with anterior lesion removal and bone grafting and fusion, of which 23 cases applied n-HA/PA66 bioactive support+allogeneic bone graft (n-HA/PA66 group) and 25 cases applied autologous iliac bone graft (autologous iliac bone group). There was no significant difference between the two groups in gender, age, bone density, disease duration, lesion segment, and preoperative pain visual analogue scale (VAS) score, Japanese Orthopaedic Association (JOA) score, and Cobb angle (P>0.05). The operation time, intraoperative blood loss, and postoperative complications, as well as the VAS score, JOA score, American Spinal Injury Association (ASIA) spinal cord injury grading, Cobb angle, and bone fusion were recorded and compared between the two groups. Results The operations were completed successfully in both groups. n-HA/PA66 group had significantly less operation time and intraoperative blood loss than the autologous iliac bone group (P<0.05). All patients were followed up 12-24 months, with an average of 15.7 months. And the difference in follow-up time between the two groups was not significant (P>0.05). Postoperative complications occurred in 3 cases (13%) in the n-HA/PA66 group and 10 cases (40%) in the autologous iliac group, and the difference in the incidence of complications between the two groups was significant (χ2=4.408, P=0.036). The postoperative VAS scores and JOA scores significantly improved when compared with the preoperative scores in both groups (P<0.05), and the difference was significant (P<0.05) between 2 weeks after operation and the last follow-up. The difference in VAS score at 2 weeks after operation was significant between the two groups (P<0.05), and there was no significant difference (P>0.05) at the other time points. At last follow-up, according to the ASIA grading, the effective improvement rate was 86% (18/21) in the n-HA/PA66 group and 90% (18/20) in the autologous iliac group, with no significant difference (χ2=0.176, P=0.675). Imaging review showed that grade Ⅰ bony fusion was obtained in both groups, and the fusion time of bone graft in the n-HA/PA66 group was significantly longer than that in the autologous iliac bone group (P<0.05). There was no significant difference in the Cobb angle at each time point between the two groups (P>0.05). No recurrence of tuberculosis, loosening or fracture of the internal fixator, or displacement of the bone graft was observed during follow-up. Conclusion In elderly patients with lumbar spine tuberculosis, the n-HA/PA66 bioactive support combined with allogeneic bone graft can effectively restore and maintain the fusion segment height and physiological curvature of the lumbar spine, and the fusion rate of bone graft is similar to that of autologous iliac bone, which can achieve better effectiveness.
ObjectiveTo explore the effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) Cage in interbody fusion for degenerative lumbar scoliosis.MethodsA retrospective analysis was designed and conducted for 43 patients, who underwent posterior decompression and n-HA/PA66 Cage interbody fusion with correction of deformity between January 2013 and June 2016. Eighteen cases were single-level fusion (single-level group) and 25 cases were double-level fusion (double-level group). There was no significant difference in gender, age, body mass index, direction of convex, degree of apical rotation, fusion level, the number of osteoporotic patients, pre-operative intervertebral height of fusion segments, coronal Cobb angle, visual analogue score (VAS), and modified Oswestry Disability Index (ODI) between 2 groups (P>0.05). The operation time, intraoperative blood loss, postoperative drainage, hospital stay, and complications of the operation were recorded. Modified ODI, VAS score, and MacNab criteria were adopted to assess clinical outcomes. Radiographic indexes, including intervertebral height of fusion segments, coronal Cobb angle, disc insertion depth, and the bone graft fusion rate, were also evaluated.ResultsThere was no significant difference in operation time, intraoperative blood loss, postoperative drainage, and hospital stay between 2 groups (P>0.05). All patients were followed up 18-62 months (mean, 30.9 months). Wound complications, postoperative delirium, and Cage retropulsion occurred in 4 cases (2 cases in single-level group, 2 cases in double-level group), 1 case of single-level group, and 1 case of double-level group, respectively. The intervertebral height of fusion segments after operation significantly improved compared with preoperative ones in both groups (P<0.05). At last follow-up, the intervertebral height in double-level group was superior to which in single-level group (P<0.05). The coronal Cobb angles after operation significantly improved compared with preoperative ones (P<0.05), and no significant difference was found between 2 groups at each time point (P>0.05). The disc insertion depth showed no significant difference between different time points after operation in 2 groups (P>0.05) and between 2 groups at each time point after operation (P>0.05). Bony fusion was obtained in all patients at last follow-up. The VAS score and modified ODI after operation in both groups were superior to those before operation (P<0.05). The VAS score in double-level group was higher than that in single-level group (P<0.05) at last follow-up, and no significant difference was found in VAS score and modified ODI between 2 groups at other time points (P>0.05). According to the MacNab criteria, the excellent and good rates at last follow-up were 94.4% and 84.0% in single-level group and double-level group, respectively.ConclusionThe n-HA/PA66 Cage can effectively restore and maintain the disc height of fusion segment, normal sequence, and biomechanical stability of the spine, and gain favorable effectivenss for degenerative lumbar scoliosis. And double-level fusion is superior to single-level fusion in maintaining disc height of fusion segment.
Objective To evaluate the security and effectiveness of nano-hydroxyapatite/polyamide 66 (n-HA/PA66) cage in reconstruction of spinal stabil ity after resection of spinal tumor. Methods Between January 2008 and December2009, 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 osteoblastsarcoma, 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 compl ication 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 stabil ity 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 differenecs when compared with the preoperative height [(97.5 ± 15.4) mm, P lt; 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 stabil ity without increasing the risk of recurrence and compl ications during the surgical treatment of spinal tumors. It is an idealselection for reconstruction of spinal stability.
ObjectiveTo compare the biomechanical differences between the kidney-shaped nano-hydroxyapatite/polyamide 66 (n-HA/PA66) Cage and the bullet-shaped n-HA/PA66 Cage. MethodsL2-L5 spinal specimens were selected from 10 adult male pigs. L2, L3 and L4, L5 served as a motor unit respectively, 20 motor units altogether. They were divided into 4 groups (n=5):no treatment was given as control group (group A); nucleus pulposus resection was performed (group B); bullet-shaped Cage (group C), and kidney-shaped Cage (group D) were used in transforaminal lumbar interbody fusion (TLIF) through left intervertebral foramen and supplemented by posterior pedicle screw fixation. The intervertebral height (IH) and the position of Cages were observed on the X-ray films. The range of motion (ROM) was measured. ResultsThere was no significant difference in the preoperative IH among 4 groups (F=0.166, P=0.917). No significant change was found in IH between at pre- and post-operation in group B (P>0.05); it increased after operation in groups C and D, but difference was not statistically significant (P>0.05). There was no significant difference in the postoperative IH among groups B, C, and D (P>0.05). The distance from Cage to the left margin was (3.06±0.51) mm in group C (close to the left) and (5.68±0.69) mm in group D (close to the middle), showing significant difference (t=6.787, P=0.000). The ROM in all directions were significantly lower in groups C and D than in groups A and B (P<0.05), and in group A than in group B (P<0.05). The right bending and compression ROM of group C were significantly higher than those of group D (P<0.05), but no statistically significant difference was found in the other direction ROM (P>0.05). ConclusionThe bullet-shaped and kidney-shaped Cages have similar results in restoring IH and maintaining the stability of the spine assisted by internal fixation. Kidney-shaped Cage is more stable than bullet-shaped Cage in the axial compression and the bending load opposite implant, it can be placed in the middle and back of the vertebral body more ideally.
Objective To study the clinical effects of artificial vertebral laminae of the biomimetic nano-hydroxyapatite/polyamide 66 (n-HA/PA66) composites in prevention of the scar formation in lumbar spinal canal and the reconstruction of posterior vertebral laminae structure. Methods From January 2003 to December 2005, 23 patients were treated with artificialvertebral laminae of the biomimetic n-HA/PA66 composites. There were 16 males and 7 females, aging from 48 to 76 years with an average of 59 years. Of 23 cases,11 cases had spinal stenosis, 7 cases had spinal stenosis with spondylolysis, 3 cases had lumbar disk herniation and 2 cases had spinal tumor. Twenty cases of vertebral laminae were reconstructed by 1 artificial vertebral laminae and 3 cases by 2.The affected locations were C5,6,L1 and L2 in 1 case respectively; L4,5 in 5 cases; L4-S1 in 9 cases; and L5, S1 in 6 cases. Results First intension was achieved in 22 cases and infection occured in 1 case.In the period of follow-up for all cases lasted from 5 to 24 months,the postoperative CT showed that the nHA/PA66 artificial vertebral laminae enlarged the spinal canal. MRI showed little scar formation and adhesion in the lumbar spinal canal. CT showed illdefined boundary between artificial vertebral laminae and recipient vertebral laminae. No neural symptoms occured in all cases except onebecause of stretch injury of nerve root in operation. Also no rejection reaction was observed. Conclusion The artificial vertebral laminae of the biomimetic nHA/PA66 composites can effectively prevent the compression to the nerve root and dural sac from the scar and restore the vertebral laminae.
Selective recognition of double strands DNA (dsDNA) has been a research hot spot in molecular biology and biomedicine for a couple decades. Based on the selective interaction between natural nucleic acid/synthetic molecular ligands and dsDNA, gene diagnosis, gene therapy and gene editing would be realized. Hairpin oligopolyamide is a molecular ligand with excellent cellular permeability and nucleases-resistance which can target dsDNA sequence with high affinity and specificity at minor groove. This paper reviews the binding properties and biomedical applications of hairpin oligopolyamide targeting dsDNA, which provide references for further design and application of hairpin oligopolyamide.
The present study is aimed to investigate the early clinical effects of nano-hydroxyapatite/polyamide 66 intervertebral fusion cage (n-HA/PA66 cage) for the treatment of lumbar degenerative diseases. We selected 27 patients with lumbar degenerative diseases who were managed by posterior decompression or reset operation combined with n-HA/PA66 cage intervertebral fusion and internal fixation from August 2010 to January 2012. The oswestry disability index (ODI), low back and leg pain visual analogue score (VAS), and intervertebral height (IH) were evaluated at preoperation, 1 week postoperation and the last follow-up period, respectively. Intervertebral bony fusion was evaluated at the last follow-up time. The patients were followed up for 12-24 months (averaged 19 months). The ODI, VAS and IH were significantly improved at 1 week postoperation and the last follow-up time compared with those at preoperative period (P<0.05). But there was no significant difference between 1 week postoperative and the last follow-up time (P<0.05). Brantigan's standard was used to evaluate fusion at the last follow-up time. There were 19 patients with grade 5 fusion, 8 with grade 4 fusion, with a fusion rate of 100%, and none with grade 1-3 fusions. There was no cage translocation and internal fixation breakage. These results suggested that n-HA/PA66 cage was an ideal biological material in the posterior lumbar interbody fusion and internal fixation operation for treatment of lumbar degenerative diseases. It can effectively maintain the intervertebral height and keep a high rate of bony fusion. The early clinical effect has been satisfactory.
Objective To evaluate the short-term effectiveness of nano-hydroxyapatite/polyamide-66 (n-HA/PA66) intervertebral cage for lumbar interbody fusion in the patients with lower lumbar degenerative diseases. Methods Between January and October 2011, 20 patients with lower lumbar degenerative diseases underwent transforaminal lumbar interbody fusion with n-HA/PA66 intervertebral cage. There were 8 males and 12 females, aged 22-80 years (mean, 51 years). The disease duration was 1 to 24 months (mean, 4 months). L4, 5 fusion was performed in 8 cases, L5, S1 fusion in 9 cases, and L4-S1 fusion in 3 cases. Among 20 cases, 3 were diagnosed as having recurrent lumbar disc protrusion, 5 as having lumbar degenerative spondylolisthesis, 9 as having lumbar isthmic spondylolisthesis, and 3 as having lumbar spinal stenosis. The intervertebral height and lordosis were measured on X-ray film to assess the surgical correction and postoperative sustain while osseous fusion was observed on 3-dimensional CT. The Oswestry disability index (ODI) and short-form 36 health survey scale (SF-36) scores were obtained to assess the status of clinical recovery. Results All patients had incision healing by first intention. The pain and numb were relieved in varying degrees after operation. No cerebrospinal leakage, nerve root injury, or wound infection was occurred. All patients were followed up 6-9 months (mean, 7 months). No cage displacement or collapse was found. The intervertebral height and lordosis of single fusion segment were significantly improved at 3 days and 3, 6 months after operation when compared with those at preoperation (P lt; 0.01); there was no significant difference among each time point after operation (P gt; 0.05). The fusion rate was 74% at 3 months after operation and 96% at 6 months after operation, with an average of 4 months (range, 3-9 months) for interbody fusion. The ODI and SF-36 scores were significantly improved at 3 days and 6 months after operation when compared with the scores at preoperation (P lt; 0.01); there was no significant difference among each time point after operation (P gt; 0.05). Conclusion The interbody fusion with n-HA/PA intervertebral cage is effective and safe to treat the lower lumbar degenerative diseases. The n-HA/PA66 intervertebral cage is an ideal device of interbody fusion with high fusion rate, low subsidence rate, and high transmission X-ray, but the long-term effectiveness need further observation.
Objective To study the clinical effects of the artificial vertebral body of the biomimetic nanohydroxyapatite/polyamide 66 (nHA/PA66) compositefor the structural reconstruction and the height restoring of the vertebral body in the thoracolumbar fractures by the anterior surgical procedures. Methods From December 2003 to January 2006, 42 patients with thoracolumbar fractures received the anterior surgical procedures to decompress and reconstruct the spinal vertebral structure with the artificial vertebral body of the nHA/PA66 composite. Among the patients, there were 28 males and 14 females, aged 1767 years, averaged 43.6 years. The thoracolumbar fractures developed at T12 in 5 patients, at L1 in 17, at L2 in 14, and at L3 in 6. The height of the anterior border of thevertebral body amounted to 29%-47% of the vertebral body height, averaged 40.6%.The Cobb angle on the sagittal plane was 2138° averaged 27.6°. According tothe Frankel grading scale, the injuries to the nerves were as the following: Grade A in 7 patients, Grade B in 19, Grade C in 8, Grade D in 6, and Grade E in 2. Results All the 42 patients were followed up for 625 months. Among the patients, 36 were reconstructed almost based on the normal anatomic structure, and 6 were well reconstructed. The mean height of the anterior border of the vertebralbody was 40.6% of the vertebral body height before operation but 91.7% after operation. And the reconstructed height of the vertebra was maintained. The mean Cobb angle on the sagittal plane was 27.6°before operation but 13.4° after operation. All the patients had a recovery of the neurological function that had a 1grade or 2grade improvement except 7 patients who were still in Grade A and 2 patients who were in Grade D. The implant was fused 35 months after operation. No infection, nail break, bar/plate break or loosening of the internal fixation occurred. Conclusion The artificial vertebral body of the biomimetic nHA/PA66 composite can effectively restore the height and the structure of the vertebra, can be fused with the vertebral body to reconstruct the spinal structural stability effectively, and can be extensively used in the clinical practice.