Comparison of Fusion Rate and Clinical Outcomes in Minimally Invasive and Conventional Posterior Fusion for Lumbar Degenerative Disease: A Network Meta-Analysis.

BACKGROUND: The fusion rate, clinical efficacy, and complications of minimally invasive fusion surgery and open fusion surgery in the treatment of lumbar degenerative disease are still unclear. METHODS: We conducted a literature search using PubMed, Embase, Cochrane Library, CNKI, and WANFANG databases. RESULTS: This study included 38 retrospective studies involving 3097 patients. Five intervention modalities were considered: unilateral biportal endoscopic-lumbar interbody fusion (UBE-LIF), percutaneous endoscopic-lumbar interbody fusion (PE-LIF), minimally invasive-transforaminal lumbar interbody fusion (MIS-TLIF), transforaminal lumbar interbody fusion (TLIF), and posterior lumbar interbody fusion (PLIF). Quality assessment indicated that each study met acceptable quality standards. PE-LIF demonstrated reduced low back pain (Odds Ratio = 0.50, Confidence Interval: 0.38-0.65) and lower complication rate (Odds Ratio = 0.46, Confidence Interval: 0.25-0.87) compared to PLIF. However, in indirect comparisons, PE-LIF showed the lowest fusion rates, with the ranking as follows: UBE-LIF (83.2%) > MIS-TLIF (59.6%) > TLIF (44.3%) > PLIF (39.8%) > PE-LIF (23.1%). With respect to low back pain relief, PE-LIF yielded the best results, with the order of relief as follows: PE-LIF (96.4%) > MIS-TLIF (64.8%) > UBE-LIF (62.6%) > TLIF (23.0%) > PLIF (3.2%). Global and local consistency tests showed satisfactory results, and heterogeneity tests indicated good stability. CONCLUSIONS: Compared to conventional open surgery, minimally invasive fusion surgery offered better scores for low back pain and Oswestry Disability Index, lower complication rates, reduced bleeding, and shorter hospital stays. However, minimally invasive fusion surgery did not show a significant advantage in terms of fusion rate and had a longer operative time.

[Channel-assisted fixation and interbody fusion in treating recurrent lumbar disc herniation by muscle-splitting approach].

OBJECTIVE: To explore the clinical value and safety of unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion by muscle-splitting approach treatment of recurrent lumbar disc herniation. METHODS: The clinical data of 51 patients with recurrent lumbar disc herniation treated from June 2012 to December 2017 were retrospectively analyzed. There were 32 males and 19 females, aged 34 to 64 years with an average of (51.11± 7.28) years. Lesions invoved L4,5 in 38 cases and L5S1 in 13 cases. All patients had a history of lower back pain and radiation pain of lower limbs(3 bilateral and 48 unilateral)and underwent unilateral pedicle screw combined with contralateral translaminar facet screw fixation and interbody fusion, among which 24 patients were treated through median incision approach (median incision group);other 27 patients were treated through muscle-splitting approach with channel-assisted exposure(muscle-splitting approach group). Operation time, intraoperative blood loss, postoperative drainage and incision length of the two groups were recorded. Visual analogue scale (VAS) was used to score the pain of lumbar incision at 72 h after operation, and JOA low back pain scoring system was used to evaluate the lumbar function preoperatively and at final follow-up. Imaging data were analyzed, including the changes in the height of intervertebral space of diseased segment before operation, 3 to 5 days after operation, and at final follow-up;Cobb angle changes in the coronal and sagittal planes of lumbar spine preoperatively and at final follow-up;multifidus area and multifidus fatty tissue deposition grade before and 12 months after operation; postoperative pedicle screw and laminar process screw position and intervertebral fusion condition. The complications of the two groups were compared. RESULTS: There was no statistical difference in operation time between two groups (P>0.05). Muscle-splitting approach group was better than median incision group in light of incision length, intraoperative blood loss and postoperative drainage volume (P<0.05). VAS score of lumbar incision pain at 72 h after operation was 1.61±0.54 in median incision group and 0.76±0.28 in muscle-splitting approach group(P<0.05). All patients were followed up for 12 to 84 (43.50±15.84) months. At final follow-up, the JOA scores of the two groups were significantly improved compared with those before operation(P<0.05). The rate of pedicle screw malposition was 6.25%(3/48) in medianincision group and 9.26%(5/54) in muscle-splitting approach group, there was no statistically significant difference between two groups (P>0.05). Rate of translaminar facet screw malposition in median incision group (12.50%) was significant less than the muscle-splitting approach group (18.52%)(P< 0.05). The height of the intervertebral space of the two groups was significantly restored 3 to 5 days after operation (P<0.05), and there was also a significant loss of height at final follow-up (P<0.05). At final follow-up, the balance of lumbar coronal plane and sagittal plane in two groups were improved very well (P<0.05). The comparison of the area and grade of the multifidus muscle in two groups 12 months after operation showed that obvious damage to the multifidus muscle were present in the median incision, while the multifidus muscle was less damaged by muscle-splitting approach (P<0.05). The fusion rate was 91.7%(22/24) in the median incision group and 92.6%(25/27) in muscle-splitting approach group(P>0.05). In median incision group, there were 1 case of intraoperative pedicle entry point fracture, 1 case of intraoperative dural tear and 1 case of postoperative nerve root injury;in muscle-splitting approach group, there were 1 case of intraoperative pedicle entry point fracture, 2 cases of intraoperative dural tear, 1 case of postoperative nerve root injury, 2 cases of incision epidermal necrosis and 1 case of poor incision healing. Nerve root injuries in the two groups were caused by incorrect positions of pedicle screws, the screws were immediately adjusted upon discovery. The nerve root symptoms were completely recovered 3 and 6 months after surgery. No incision infection was occurred in two groups. During the follow-up, no pedicle screw and laminar facet screw were loosened, displaced, broken, or intervertebral fusion cage moved forward and backward. The complication rate of 25.93% in muscle-splitting approach group was higher than 12.50% in the median incision group (P<0.05). CONCLUSION: Muscle-splitting approach is feasible for thetreatment of recurrent lumbar disc herniation with pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion. Compared with the median incision approach, the muscle-splitting approach has the advantages of small incision, less trauma, less bleeding, rapid recovery. Also it can protect multifidus and do not increase the incidence of serious complications. Thus, it can be used as a choice for fixation and fusion of recurrent lumbar disc herniation.

Proposal of a New Treatment-Oriented Classification System for Spinal Deformity in Ankylosing Spondylitis.

OBJECTIVE: To describe and apply an optimal classification system for the management of ankylosing spondylitis (AS) that may be appropriate to make a preoperative surgical plan. BACKGROUND: The treatment choices of ankylosing spondylitis kyphosis remain controversial. The lack of a widely accepted classification system contributes to the variation in surgical decision making. METHODS: The classification is mainly based on radiographic findings. The sagittal deformity of spine in ankylosing spondylitis is classified according to three criteria: the location of the apex, the lumbar modifier (A, lumbar lordosis <0°, and B, lumbar kyphosis >0°) and the thoracic/thoracolumbar kyphosis severity modifier (- or +). RESULTS: The ankylosing spondylitis kyphosis can be divided into 4 types according to the location of the apex: Type I (lumbar), Type II (thoracolumbar), Type III (thoracic), Type IV (cervical or cervicothoracic junction). Either Type II or Type III is further divided into four subtypes based on the lumbar modifier and the thoracic/thoracolumbar kyphosis severity modifier: Type IIA-, Type IIA+, Type IIB-, Type IIB+, Type IIIA-, Type IIIA+, Type IIIB-, and Type IIIB+. Surgical decision making for AS kyphosis can be made according to the new classification. CONCLUSION: This new classification system can be used effectively to classify AS kyphosis, which can be used to guide surgical decision making, including determining the site and the levels of osteotomies. Further research may be needed to validate the classification.

[Case control study on two different surgical approaches combined fixation with lumbar interbody fusion for the treatment of single segmental lumbar vertebra diseases].

OBJECTIVE: To discuss the advantages and disadvantages of two different surgical approaches combined fixation with lumbar interbody fusion in treating single segmental lumbar vertebra diseases. METHODS: The clinical data of 86 patients with single segmental lumbar vertebra diseases treated from June 2011 to June 2013 was retrospectively analyzed. There were 33 males and 53 females, aged from 28 to 76 years old with an average of 53.0 years. Among them, there were 39 cases of lumbar disc degeneration, 22 cases of lumbar disc herniation complicated with spinal canal stenosis, 9 cases of huge lumbar disc herniation and 16 cases of lumbar degenerative spondylolisthesis (Meyerding degree I ). Lesion sites contained L3, 4 in 5 cases, L4, 5 in 70 cases and L5S1 in 11 cases. All the patients were treated with internal fixation and lumbar interbody fusion with 45 cases by midline incision approach (median incision group) and the other 41 cases by channel-assisted by muscle-splitting approach(channel group). Incision length, operation time, intraoperative bleeding and postoperative drainage were recorded in two groups. Visual analogue scale(VAS) was used to assess lumbar incision pain 72 h after operation. Depended on imaging results to compare the changes of the disc space height in lesion in preoperative, postoperative and final follow-up, the coronal and sagittal Cobb angle in preoperative and final follow-up, the area of multifidus and the degree of multifidus fat deposition before and after operation between two groups. Loosening or fragmentation of internal fixation, displacement of intervertebral cage and interbody fusion were observed in each group. Japanese Orthopedic Association (JOA) scoring system was used to evaluate the function before operation and at the final follow-up. RESULTS: The channel group was superior to the median incision group in incision length and postoperative drainage while the median incision group was less than the channel group in the operation time and intraoperative bleeding. The average VAS score of lumbar incision 72 h after operation was 1.50 points in median incision group and 0.97 points in channel group, and there was significant difference between two groups(P<0.05). No incision infection was found, but there were 4 cases of incisional epidermal necrosis, 1 case of incision healed badness, and 3 cases of nerve injury in channel group. The incidence of cacothesis of pedicle screw were 5.0% and 3.6% in median incision group and channel group respectively, and there was no significant difference between two groups(P>0.05). The incidence of cacothesis of translaminar facet screw were 6.6% and 12.2% in median incision group and channel group respectively, and there was significant difference between two groups(P<0.05). All the patients were followed up for 12 to 36 months with a mean of 22.8 months. The changes of disc space height had statistical difference between preoperative and postoperative(P<0.05) in all patients, but there was no significant difference between postoperative and final follow-up(P>0.05), however, there was no significant difference 3 days after operation and final follow-up between two groups(P>0.05). At final follow-up, coronal and sagittal Cobb angle were obviously improved in all patients(P<0.05), but there was no significant difference between two groups(P>0.05). One year after operation, the area of multifidus in median incision group was (789.00±143.15) mm² less than preoperative(1 066.00±173.55) mm² (P<0.05), and in channel group, was(992.00±156.75) mm² at 1 year after operation and(1 063.00±172.13) mm² preoperatively, there was no significant difference between them(P>0.05), however, there was significant difference one year after operation between two groups (P<0.05) . About the degree of multifidus fat deposition, there was significant difference between one year after operation and preoperation in median incision group (P<0.05), but there was no significant difference between one year after operation and preoperation in channel group (P>0.05), and there was significant difference at one year after operation between two groups(P<0.05). During the follow-up period, neither pedicle screw and/or translaminar facet screw loosening, displacement or fragmentation nor displacement of intervertebral cage were found. The lumbar interbody fusion rate was 95.6% in median incision group and was 95.1% in channel group, and there was no significant difference between two groups(P>0.05). No obvious adjacent segmental degeneration was observed in fixed position. JOA score in median incision group was significantly increased from 8-16 points (average: 12.77±2.56) preoperative to 21-29 points (average: 25.20±2.43) at final follow-up(P<0.05); and in channel group was significantly increased from 8-16 points (average: 12.64±2.37) preoperative to 23-29 points(average: 26.7±1.82) at final follow-up(P<0.05); there was also significant difference between two groups at final follow-up. CONCLUSIONS: Compared to the median incision approach, unilateral pedicle screw combined with contralateral translaminar facet screw fixation using channel-assisted by muscle-splitting approach has advantages of small incision, less trauma, fast recovery and so on. However, it also has shortages such as high surgical complications incidence, especially in cases that.

[Unilateral pedicle screw fixation versus its combination with contralateral translaminar facet screw fixation for the treatment of single segmental lower lumbar vertebra diseases].

OBJECTIVE: To compare the advantages and disadvantages of unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion in treating single segmental lower lumbar vertebra diseases. METHODS: Sixty-two patients with single segmental lower lumbar vertebra disease who received treatment between January 2008 and June 2009. These patients were consisted of 16 males and 46 females, ranging in age from 27 to 72 years old, with a mean age of 51.6 years old. Among these patients, lumbar degenerative disease had in 22 patients, recurrence of lumbar intervertebral disc protrusion in 13 patients, lumbar intervertebral disc protrusion accompany with spinal canal stenosis in 12 patients, massive lumbar intervertebral disc protrusion in 5 patients and lumbar degenerative spondylolisthesis with degree I in 10 patients. The lesions occurred at L3,4 segment in 5 patients, at L4,5 segment in 42 patients, and at L5S1 segment in 15 patients. Thirty patients underwent unilateral pedicle screw fixation (unilateral screw fixation group, group A) and thirty-two patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation (bilateral screw fixation group, group B). Lumbar interbody fusion with intervertebral cages was also performed in all patients. Incision length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Loosening or breakage of internal fixations, displacement of intervertebral cages and interbody fusion conditions were observed in each group. Preoperative and postoperative intervertebral height, coronal and sagittal Cobb angle and wound pain at 72 h after operation were compared between two groups. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the cinical effects. RESULTS: Neither wound infection, skin necrosis, nerve root or cauda equia injury, nor worsened neurological dysfunction in the lower limb occurred in each group. There were no significant differences in incision length, intraoperative blood loss and postoperative wound drainage between two groups. The operation time in group A was significantly shorter than that of group B (P < 0.05). There were no significant differences in visual analogue scale value of the wound pain at postoperative 72 h between two groups (P > 0.05). All patients were followed up for 12-48 months,with a mean of 27.5 months. The intervertebral height of all patients had obviously recovered at 5 days after operation, furthermore, at the final follow-up, it still had well maintained. During follow-up, no pedicle screw and/or translaminar facet screw loosening, displacement or breakage and displacement of intervertebral cages were found. The lumbar interbody fusion rate was 96.7% and 96.9% in group A and group B, respectively, and there was no significant difference between two groups (P > 0.05). JOA score of all patients got obviously improved after operation (P < 0.05) and there was no significant difference between two groups (P > 0.05). CONCLUSION: Both unilateral pedicle screw fixation plus lumbar interbody fusion and unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation plus lumbar interbody fusion have advantages of small incision, minimal invasion, simple operation, reliable stability, high interbody fusion rate,rapid recovery, encouraging clinical effects and less complications. Compared with unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation, the operation of unilateral pedicle screw fixation is simpler and can avoid using special equipments. Therefore, unilateral pedicle screw fixation plus lumbar interbody fusion can be used in treating single-segmental lower lumbar vertebra diseases under the precondition of strictly grasping indications for surgery and improving surgical skills.

Mineralized Collagen: Rationale, Current Status, and Clinical Applications.

This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.

[Two different fixation methods combined with lumbar interbody fusion for the treatment of two-level lumbar vertebra diseases: a clinical comparison study].

OBJECTIVE: To investigate the advantages and disadvantages of unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion with cages in the treatment of two-level lumbar vertebra diseases, by comparing bilateral pedicle screw fixation and interbody fusion with cages. METHODS: Forty-nine patients with two-level lumbar diseases who received treatments from June 2009 to December 2011 were included in this study. Among these patients, 23 patients received unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and interbody fusion with cages (combined fixation group) and the remaining 26 patients underwent bilateral pedicle screw fixation and interbody fusion with cages (bilateral fixation group). These patients consisted of 17 males and 32 females, ranging in age from 29 to 68 years old. Among these patients, lumbar intervertebral disc herniation accompanied by the spinal canal stenosis was found in 29 patients, degenerative lumbar disc diseases in 17 patients and lumbar degenerative spondylolisthesis (degree I) in 3 patients. The lesions occurred at L2,3 and L3,4 segments in 1 patient, at L3,4 and L4,5 segments in 30 patients, and at L4,5 segment and L5S1 segment in 18 patients. Wound length, operation time, intraoperative blood loss and postoperative wound drainage were compared between two groups. Intervertebral space height in the lesioned segment before and during surgery and at the latest follow up was also compared between two groups. Before surgery and at the latest follow-up, the Cobb angle of the coronal plane and sagittal plane of the lumbar spine, loosening or breakage of internal fixations, the dislocation of intervertebral cages, and interbody fusion were all evaluated in each group. The visual analogue scale (VAS) was used to measure lumbar incision pain. The Japanese Orthopedic Association (JOA) scoring system was used to evaluate the function before surgery and at the latest follow-up. RESULTS: No wound infection or skin necrosis was observed after surgery in all patients. No cerebrospinal fluid leakage, nerve root injury, cauda equia injury or worsened neural function in the lower limb occurred in all patients during and after surgery. Wound length, operation time, intraoperative blood loss and postoperative wound drainage in the combined fixation group were superior to those in the bilateral fixation group. At postoperative 72 hours, the VAS score in the combined fixation group (1 to 4 points, mean 2.35±1.20) was significantly lower than that in the bilateral fixation group (2 to 5 points, mean 3.11±1.00; P<0.05). All the patients were followed up for 12 to 48 months, with a mean of 29 months. After surgery, intervertebral space height was well recovered in each patient and it was well maintained at the latest follow-up, and there was no significant difference between two groups (P>0.05). During follow-up, pedicle screw and translaminar facet screw loosening, dislocation or breakage and dislocation of intervertebral cages were all not found. At the latest follow-up, the Cobb angle of the coronal plane and sagittal plane of the lumbar spine was obviously improved and was not significantly different between two groups (P>0.05). The lumbar interbody fusion rate was 93.5% and 96.2% in the combined fixation group and bilateral fixation group, respectively, and there was no significant difference between them (P>0.05). There was a significant difference in JOA score between before surgery and at the latest follow-up in each patient (P<0.05), and at the latest follow-up, significant difference in JOA score was found between two groups (P<0.05). CONCLUSION: Compared to bilateral pedicle screw fixation and lumbar interbody fusion with cages, unilateral pedicle screw fixation combined with contralateral translaminar facet screw fixation and lumbar interbody fusion with cages shows advantages including small skin incision, minimal invasion, ease of operation, highly reliable stability, high interbody fusion rate, rapid recovery in the treatment of two-level lumbar vertebra diseases and therefore can be preferred as a treatment method of this disease.

Two-level spinal osteotomy for severe thoracolumbar kyphosis in ankylosing spondylitis. Experience with 48 patients.

STUDY DESIGN: A retrospective study. OBJECTIVE: To report surgical results for severe thoracolumbar kyphosis secondary to ankylosing spondylitis (AS) corrected with 2-level spinal osteotomy. SUMMARY OF BACKGROUND DATA: Transpedicular osteotomy in the lumbar spine is the major approach to correct kyphosis in AS. Most surgical procedures were performed at 1 level and only few literature report 2-level osteotomy in 1 patient. METHODS: From January 2003 to June 2011, we reviewed 48 patients experiencing AS with severe thoracolumbar kyphosis who underwent stage 2-level spinal osteotomy in our hospital. The osteotomies were performed at T12 and L2 or L1 and L3, according to the apex of kyphosis. Preoperative and postoperative height, chin-brow vertical angle, sagittal balance, and the sagittal Cobb angle of the vertebral osteotomy segment were documented. Intraoperative, postoperative, and general complications were recorded. RESULTS: The chin-brow vertical angle improved from 65.0° ± 28.0° to 5.0°± 10.0° (P = 0.000) and the sagittal imbalance distance improved from 26.9 ± 10.4 cm to 10.6 ± 5.6 cm (P = 0.000). The mean amount of correction was 24.9° at the superior site of the osteotomy and 38.1° at the inferior site of the osteotomy. Postoperatively, all patients could walk with horizontal vision and lie on their backs. No major acute complications such as death or complete paralysis occurred. Five patients experienced complications such as infections (n = 1) and cerebrospinal fluid leaks (n = 4). Both Oswestry Disability Index and Scoliosis Research Society scores improved largely. Fusion at the osteotomy site was achieved in each patient, and no implant failures were noted. CONCLUSION: Single-stage 2-level osteotomy can effectively and safely correct kyphotic deformities of the thoracolumbar spine caused by AS. LEVEL OF EVIDENCE: 3.

[A feasibility research of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using hybrid internal fixation for recurrent lumbar disc herniation].

OBJECTIVE: To investigate the feasibility of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using hybrid internal fixation of pedicle screws and a translaminar facet screw for recurrent lumbar disc herniation. METHODS: From January 2010 to December 2011, 16 recurrent lumbar disc herniation patients, 10 male and 6 female patients with an average age of 45 years (35-68 years) were treated with unilateral incision MIS-TLIF through working channel. After decompression, interbody fusion and fixation using unilateral pedicle screws, a translaminar facet screw was inserted from the same incision through spinous process and laminar to the other side facet joint. The results of perioperative parameters, radiographic images and clinical outcomes were assessed. The repeated measure analysis of variance was applied in the scores of visual analogue scale (VAS) and Oswestry disablity index (ODI). RESULTS: All patients MIS-TLIF were accomplished under working channel including decompression, interbody fusion and hybrid fixation without any neural complication. The average operative time was (148 ± 75) minutes, the average operative blood loss was (186 ± 226) ml, the average postoperative ambulation time was (32 ± 15) hours, and the average hospitalization time was (6 ± 4) days. The average length of incision was (29 ± 4) mm, and the average length of translaminar facets screw was (52 ± 6) mm. The mean follow-up was 16.5 months with a range of 12-24 months. The postoperative X-ray and CT images showed good position of the hybrid internal fixation, and all facets screws penetrate through facets joint. The significant improvement could be found in back pain VAS, leg pain VAS and ODI scores between preoperative 1 day and postoperative follow-up at all time-points (back pain VAS:F = 52.845, P = 0.000;leg pain VAS:F = 113.480, P = 0.000;ODI:F = 36.665, P = 0.000). CONCLUSION: Recurrent lumbar disc herniation could be treated with MIS-TLIF using hybrid fixation through unilateral incision, and the advantage including less invasion and quickly recovery.

[Preliminary application of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws].

OBJECTIVE: To study the clinical effects and application value of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws. METHODS: Thirty-two cases of severe scoliosis were retrospectively analysed in our hospital from June 2009 to June 2011,which were treated by posterior total pedicle screws with intraoperative CT including 12 males and 20 females with an average age of 16.8 years ranging from 10 to 38 years. There were 19 cases combined with thoracic kyphosis among 32 cases. Multiple planar reconstruction technology of intraoperative CT was applied to assess screw position. The numbers (rates) of pedicle screws were calculated and evaluated as different grades in upper thoracic vertebra (T1-T4) ,middle thoracic vertebra (T5-T8), lower thoracic vertebra (T9-T12) and lumbar vertebra. The pedicle screws of 2 grade and 3 grade were defined as malpositioned screws. Times of applicating intraoperative CT were calculated. Cobb angle of all cases and kyphosis angle of the cases combined with thoracic kyphosis were measured before and after surgery. Scoliosis correction rates and kyphosis correction rates were calculated. RESULTS: There were 686 pedicle screws placed in thoracolumbar of 32 patients (including 544 thoracic pedicle screws,142 lumbar pedicle screws) and 14 patients underwent osteotomy. The rate of malpositioned screws in thoracolumbar was 7.3% by evaluating with intraoperative CT,and it respectively was 5.6%,11.1%, 6.7% and 4.3% in upper thoracic vertebra, middle thoracic vertebra,lower thoracic vertebra and lumbar vertebra. The malpositioned screws were amended in surgery. The mean times of intraoperative CT was 2.6 times (ranged from 2 times to 4 times). The mean preoperative Cobb angle was 95 degrees (ranged from 78 degrees to 123 degrees) and the mean postoperative Cobb angle was 340 (ranged from 19 degrees to 53 degrees). The mean correction rate of Cobb angle was 64%. The mean preoperative kyphosis angle of the patients combined with thoracic kyphosis was 69 degrees (ranged from 46 degrees to 82 degrees) and the mean postoperative kyphosis angle was 32 degrees (ranged from 22 degrees to 45 degrees). The mean correction rate of kyphosis angle was 54%. Four patients suffered cerebrospinal fluid leak after surgery. No infection, vascular lesion and nervous lesion were found. All patients had an average 18-month follow-up (ranged from 12 to 26 months). No broken nails, broken rods and pseudarthrosis were founded. CONCLUSION: Application of in traoperative CT in severe scoliosis with posterior total pedicle screws can detect and amend malpositioned screws timely in surgery, to avoid secondary surgery for malpositioned screws and protect the safety of surgery. The effects of surgery is satisfactory.

[Effects of wide posterior release on the correction of severe and rigid thoracic scoliosis in sagittal plane].

OBJECTIVE: To explore the effects of wide posterior release on the correction of severe and rigid thoracic scoliosis in sagittal plane. METHODS: A total of 37 idiopathic scoliosis patients (26 females and 11 males) with severe and rigid thoracic curves corrected with posterior pedicle screw system between 2006 and 2009 were recruited. Their average age was 17.3 years (range: 14 - 22) at operation and the thoracic Cobb angle was between 70 - 100°. They were separated into 2 groups: group A (n = 15) with wide posterior release and group B (n = 22) with posterior soft tissue release alone. The preoperative, postoperative and latest standing posteroanterior and lateral radiographs during follow-ups were reviewed. RESULTS: All patients were operated successfully. No statistic difference existed in the average operative duration between two groups (P > 0.05). The average volume of blood loss was 874 ml in Group A versus 712 ml in Group B (P < 0.05). The average coronal Cobb angle on postoperative standing photograph was 27.4° (68.1% correction) in Group A and 35.6° (56.9% correction) in Group B. For comparing sagittal correction results in patients with similar thoracic sagittal deformities, we distinguished subgroup A1 (preoperative TKA < 40°) from subgroup A2 (preoperative TKA > 40°) in group A and subgroup B1 (preoperative TKA < 40°) from subgroup B2 (preoperative TKA > 40°) in group B. The postoperative TKA was 26.8° (> 9.2° than preoperation) in subgroup A1 and 12.5° (3.1° < preoperation) in subgroup B1 (P < 0.05). The postoperative TKA was 28.4° (24.9° < preoperation) in subgroup A2 and 39.1° (10.3° < preoperation) in subgroup B2 (P < 0.05). There was one case of dural leakage in group A. A leakage of cerebrospinal fluid was cured with a prone position and wound compression. One case of infection in superficial part of wound in group B was cured after debridement. No nerve system injury, deep infection or instrumentation failure was found. During a follow-up period of 2 years, there was no obvious correction loss or trunk decompensation. CONCLUSION: In idiopathic scoliosis patients with severe and rigid thoracic curves, wide posterior release via a posterior approach may help to correct the deformity in sagittal plan and achieve more coronal correction in these curves.

[Clinical efficacies of skipping two-level transpedicular wedge osteotomy for correction of severe kyphosis in ankylosing spondylitis].

OBJECTIVE: To explore the clinical efficacies of skipping two-level transpedicular wedge osteotomy in the correction of severe kyphotic deformity in ankylosing spondylitis (AS). METHODS: From January 2003 to December 2009, a total of 38 consecutive patients with AS and severe kyphosis (chin-brow vertical angle (CBVA) or global thoraco-lumbar kyphosis angle (TLKA) over 70°) undergoing skipping two-level transpedicular wedge osteotomy at the Department of Orthopedics of Chinese PLA General Hospital were reviewed retrospectively. There were 32 males and 6 females with an average age of 38.0 years (range: 22 - 65). The preoperative parameters of TLKA, T11-L2 kyphotic angle, L1-S1 lordosis angle, sagittal imbalance and CBVA were obtained from the total spine radiography or computed tomography and clinical lateral photograph. According to the characteristic curves and normal spinal alignment, their profiles of osteotomy location and angle were determined and confirmed by computer simulations. Improvement in postoperative parameters was observed and treatment satisfaction evaluated RESULTS: The average operating duration was 309 minutes and the average volume of blood loss was 2050 ml. The parameters of TLKA, T11-L2 kyphotic angle and L1-S1 lordosis angle improved from 101.0° ± 21.3°, 45.2° ± 13.6°, -28.2° ± 23.3° at preoperation to 26.0° ± 12.1°, 2.8° ± 11.6°, 28.9° ± 13.3° postoperation respectively (P < 0.01). CBVA improved from 79.4° ± 15.9° to 13.6 ° ± 10.9° (P < 0.01). The sagittal imbalance distance improved from (49 ± 13) to (15 ± 7) cm (P < 0.01). All patients could walk with orthophoria and lie horizontally postoperatively. The average follow-up was 32 months (range: 24 ∼ 78 months). Fusion of osteotomy was achieved in all patients and there was no event of loss of correction or implant failure. The SRS-22 average score improved from 1.8 to 4.2. CONCLUSION: For severe kyphosis in AS, skipping two-level transpedicular wedge osteotomy is a satisfactory and reliable approach for the correction of kyphotic deformity and it may improve appearance and function significantly.

[A feasibility research of unilateral incision minimally invasive transforaminal lumbar interbody fusion using pedicle screws and a translaminar screw hybrid fixation].

OBJECTIVE: To investigate the feasibility and safety of unilateral incision hybrid fixation using pedicle screws and a translaminar screw in minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF). METHODS: From January to June 2010, 18 patients with single-level lumbar disc disease were treated with MIS-TLIF under METRx(TM) X-tube. After decompression and fixation using unilateral pedicle screws, a translaminar screw was inserted from the same incision to the other side. The results of perioperative parameters, radiographic images and clinical outcomes were assessed. RESULTS: All patients underwent MIS-TLIF were accomplished unilateral hybrid fixation without any neural complication. The average operative time was (107 ± 19) min, the average operative blood loss was (62 ± 21) ml, and the average postoperative ambulation time was (21 ± 5) h. The average length of translaminar facets screw was (52 ± 2) mm, and the postoperative images showed all screws penetrate through facets joint. During the follow-up the visual analogue scale and Oswestry disability index scores were significant improved compared with preoperative (F = 42.221 - 259.833, P < 0.01). CONCLUSIONS: Bilateral hybrid fixation could be completed through unilateral incision by pedicle screws and a translaminar screw in MIS-TLIF, and the advantage including less invasion, quickly recovery, short operative time, and saving fixation cost.

[The clinical outcomes of surgical treatment for adult idiopathic scoliosis using pedicle subtraction osteotomy].

OBJECTIVE: to evaluate the clinical outcomes of transpedicular lumbar wedge resection osteotomy in treating adult idiopathic scoliosis. METHODS: twenty-five adult idiopathic scoliosis patients treated with transpedicular lumbar wedge resection osteotomy from July 2001 to November 2007 were included, among whom 18 were female and 7 were male. Nine of 25 were with double major curve in thoracic and thoracolumbar/lumbar spine, and 16 were with single curve in thoracolumbar/lumbar spine. The average age was 35 years (29 - 48 years) at operation. Osteotomy were performed at T(11), T(12), L(1) or L(2). The motion evoked potential monitoring system and awaking test were used during surgery. The preoperative, postoperative immediately and latest standing posteroanterior and lateral radiographs were reviewed. RESULTS: all patients were operated successfully. The average operation time was 274 min (range, 220 - 380 min) and the average blood loss were 2328 ml (range, 1500 - 5000 ml). The average coronal Cobb angle of all patients in thoracolumbar/lumbar curves was 88° (range, 70° - 121°) before operation, which was corrected to 43° (range, 35° - 70°). The coronal correction rate was 44%. The average kyphosis angle of all in thoracolumbar/lumbar curves was 63° (range, 50° - 90°) before operation, which was corrected to 10° (range, -40° - 21°). The sagittal correction rate was 86%. Nerve root injury occurred in 3 of all patients who complained about postoperative radicular pain. No spine cord injury, delayed paralysis, infection and instrumentation failure were found. With a follow-up of 2 - 4 years, no correction loss or decompensation happened. The back pain existing before operation was relieved in large measure. The cosmetic appearance were all promoted significantly. CONCLUSIONS: the transpedicular thoracolumbar/lumbar wedge osteotomy is efficient and safe in the correction of adult idiopathic scoliosis. The correction is much better on the sagittal plane than that on the coronal plane.

[Modified posterior closing wedge osteotomy in patients of posttraumatic thoracic lumbar kyphosis].

OBJECTIVE: To evaluate the outcome of posterior trans-pedicle + disc osteotomy in patients with post-traumatic thoracolumbar kyphosis. METHODS: Between June 2000 and June 2003, 26 adult patients, 16 male and 10 female, average 30.6 years old (21 - 42 y), of post-traumatic thoracolumbar kyphosis were corrected by means of single posterior trans-pedicle + disc osteotomy technique. Operation time, blood loss, and surgical complication were counted. Back pain Visual Analog Scale (VAS) Oswestry score and Frankel neurological grade were used to for clinical evaluation. All the radiographic and clinical data were requested at 3 time points (before operation, directly postoperatively, and at final follow-up). RESULTS: No severe complications were found in this group. Local kyphosis (T(10)-L(2) Cobb angle) was corrected from average 22.3 degrees +/- 3.5 degrees to 2.2 degrees +/- 2.1 degrees (corrective rate 90.1%). Intraoperative average blood loss was (680.0 +/- 31.5) ml and average operational time was (186.0 +/- 22.8) min. All the patients finished at least 3 - 5 years follow-up, Neural improvement achieved in this group (before operation Frankel D 12 cases, Frankel C 6 cases and Frankel B2 cases; 3 years postoperation Frankel E 14 cases, Frankel D 2 cases Frankel C1 case and Frankel B 1 case), postoperative back pain was reduced from preoperative 8.6 +/- 1.3 to 2.2 +/- 0.5 in VAS and Oswestry score improved from (62.5 +/- 8.6)% to (16.2 +/- 4.3)% at last follow up. CONCLUSION: Single posterior trans-pedicle + disc osteotomy technique is suitable to thoracolumbar post-traumatic kyphosis.

[Selective posterior fusion of single thoracic curve adolescent idiopathic scoliosis: experience in 72 cases].

OBJECTIVE: To prospectively evaluate the strategy of surgery and choice of the fusion segments in thoracic adolescent idiopathic scoliosis (AIS) treatment. METHODS: Selective posterior fusion was used on 72 AIS patients, 13 male and 59 female, aged 14.3 (12 - 18), 50 being of Lenke-type IA, 8 Lenke-type IB, and 14 Lenke-type IC. In principle the upper neutral vertebrae were selected as upper instrumented vertebrae. The lower neutral vertebrae, the vertebrae 1 level proximal to the neutral vertebrae, or stable vertebrae were chosen as the lower instrumented vertebrae based on the analysis of the correlation among the lower end vertebrae, neutral vertebrae and stable vertebrae's locations. Standing anteroposterior and lateral and side-bending radiographs were taken preoperatively, postoperatively and during the follow-up. The coronal and sagittal Cobb angle, translation and rotation of apical vertebrae, and trunk translation were evaluated to observe the curve correction and trunk balance. The patients underwent spinal fusion of 7.3 segments (4 - 10 segments) on average. Follow-up was conducted for 15.9 months (12 - 39 months). RESULTS: The thoracic curves' coronal Cobb angle before the operation was 56.7 degrees +/- 14.5 degrees (40 degrees - 98 degrees), and was 18.5 degrees +/- 8.3 degrees (3 degrees - 40 degrees) after the operation. The lumbar curves' coronal Cobb angle before operation was 33.9 degrees +/- 10.4 degrees (25 degrees - 69 degrees), and was 11.1 degrees +/- 6.4 degrees (0 degrees - 30 degrees ) after operation. The spontaneous correction rate was 66.9% +/- 16% (44% - 100%). The trunk translation before operation was 16.1 +/- 10.2 mm (4 - 43 mm), and was 8.2 +/- 6.1 mm (0 - 25 mm) after operation. Two patients were found with slight trunk decompensation postoperatively, but with no progression during a 2-year follow-up. CONCLUSION: Determination of the fusion levels based on the analysis of the correlation among the end vertebrae, neutral vertebrae and stale vertebrae's location helps obtain the satisfying curative effect in the management of single thoracic curve AIS.

[A method to avoid the fixator failure by using pedicle screw combined vertebroplasty for spine fractures].

OBJECTIVE: To study a new implant material (carbonated hydroxyapatite, CHA) united pedicle screw to cure spine fracture. METHODS: Thirty-two cases of spine compressed fracture were used with pedicle screw fixator and vertebroplasty. Before operation, patients' vertebral body were compressed (46 + 21)% (20% approximately 70%) on average. In operation, broken vertebral body was reposition through pedicle screw technique, then used self-made syringe to inject CHA into anterior and central column of broken vertebral body through pedicle. And all of patients were not given any bone-graft. RESULTS: In 6 - 26 months followed-up, no immunologic rejection was found about hydroxyapatite, and no any broken of the screws and shafts was found, no loosing and other complications either. All the patients could move in 3 - 5 days after operation. The height of the broken vertebral body were reduced 97% compared with pre-operation. And CHA in vertebral body was degraded gradually, and at the same time it was replace by new bone in vertebral body. After operation, VAS score was 61 +/- 32, and there was significant difference compared with pre-operation. CONCLUSIONS: The pedicle screw fixation united vertebroplasty is an efficient way to prevent the failure of the treatment of spine fracture.

[Safety and efficacy of resection of hemivertebrae by posterior approach in treatment of thoracolumbar kyphoscoliosis in adolescents].

OBJECTIVE: To investigate the safety and efficacy of resection of hemivertebrae by posterior approach in treatment of thoracolumbar kyphoscoliosis in adolescents. METHODS: twenty-eight patients of kyphoscoliosis, 19 male and 9 female, aged 12 approximately 16, 12 cases with the hemivertebra located in T(12), 10 cases in L(1), and 6 cases in T(11), and with a mean angle of 75 degrees in kyphosis and 48 degrees in scoliosis by the Cobb measurement, underwent resection of the hemivertebrae via the posterior approach and were followed up for 3.5 years. RESULTS: The mean surgical time was 3.7 hours and the average blood loss was 900 ml. Intercostal neuralgia occurred in one patient and relieved automatically without treatment. Hemothorax and pneumothorax were found in two cases during the operation and were healed after 1 week. Solid fusion was obtained in all the patients. The Cobb measurement was 19 degrees in kyphosis and 14 degrees in scoliosis on average at the final follow-up. No neurological deficit and infection was noted in the late stage. Clinically, no spinal imbalance or trunk shift was observed in all patients. CONCLUSION: Resection of hemivertebrae via posterior approach is safe and effective in the treatment of thoracolumbar kyphoscoliosis in adolescents.

[A pilot study of repair of periodontal bone defects with carbonated phosphate bone cement modified with synthesized peptides in dogs].

OBJECTIVE: To explore the possibility of repairing periodontal defects with carbonated calcium phosphate bone cement (CCPBC) modified with synthesized peptides. METHODS: Periodontal bone defects in 4 dogs were surgically created and then restored directly with hydroxyapatite (HA), Perioglass, CCPBC and CCPBC modified with peptides. The results were compared at different levels. RESULTS: Bone replacement materials were lost in HA and Perioglass groups. In the HA group defects were restored with connective tissue. Perioglass group had only a little new bone around materials by alveolar bone. CCPBC could firmly stay in bone defects to maintain the space of bone defects even without membrane use. CCPBC modified with peptides was superior to HA, Perioglass, and CCPBC, surrounded by a great deal of new bone. CONCLUSION: Under limitation of this study, CCPBC modified with peptides has some osteoinuctive activity and may have good prospect for the clinical application in periodontal defect repair.