Channel-assisted fixation and interbody fusion in treating recurrent lumbar disc herniation by muscle-splitting approach / 中国骨伤

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 L@*RESULTS@#There was no statistical difference in operation time between two groups (@*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.

Evaluation methodology of cellular uptake of magnetic nanoparticles / 中国组织工程研究

BACKGROUND: Magnetic nanoparticles have attracted tremendous attention for their diverse biomedical applications involving tumor hyperthermia, drug controlled release and magnetic resonance angiography. The interaction between biomaterials and cells is the major part in the in vitro study, and the evaluation of cellular uptake of magnetic nanoparticles is indispensable for tumor hyperthermia and drug delivery. OBJECTIVE: To review the progress of evaluation methodology of cellular uptake of magnetic nanoparticles. METHODS: The articles about magnetic nanoparticles and cellular uptake were retrieved from PubMed, SCI and Embase databases published during January 2010 to June 2017 by the first author using computer. The Mesh terms were "magnetic nanoparticles", and the key words were "cellular uptake", "internalization" or "endocytosis". The logical operator between them was "AND". RESULTS AND CONCLUSION: Qualitative quantitative assessment methods for cellular uptake of magnetic nanoparticles include Prussian blue staining, fluorescence microscopy, confocal microscopy,transmission electron microscopy. Quantitative assessment methods for cellular uptake of magnetic nanoparticles include inductively coupled plasma, magnetization measurements, colorimetry of Prussian blue staining. The development direction of the evaluation methodology is from qualitative to quantitative. As each method has its own merits and demerits, we should choose the right evaluation method based on the function and application of magnetic nanoparticles and then supply the right experimental basis for the biomedical application of magnetite nanoparticles.

Case control study on two different surgical approaches combined fixation with lumbar interbody fusion for the treatment of single segmental lumbar vertebra diseases / 中国骨伤

<p><b>OBJECTIVE</b>To discuss the advantages and disadvantages of two different surgical approaches combined fixation with lumbar interbody fusion in treating single segmental lumbar vertebra diseases.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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(<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(>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(<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(<0.05) in all patients, but there was no significant difference between postoperative and final follow-up(>0.05), however, there was no significant difference 3 days after operation and final follow-up between two groups(>0.05). At final follow-up, coronal and sagittal Cobb angle were obviously improved in all patients(<0.05), but there was no significant difference between two groups(>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 (<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(>0.05), however, there was significant difference one year after operation between two groups (<0.05) . About the degree of multifidus fat deposition, there was significant difference between one year after operation and preoperation in median incision group (<0.05), but there was no significant difference between one year after operation and preoperation in channel group (>0.05), and there was significant difference at one year after operation between two groups(<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(>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(<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(<0.05); there was also significant difference between two groups at final follow-up.</p><p><b>CONCLUSIONS</b>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.</p>

Unilateral pedicle screw fixation versus its combination with contralateral translaminar facet screw fixation for the treatment of single segmental lower lumbar vertebra diseases / 中国骨伤

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>

Two different fixation methods combined with lumbar interbody fusion for the treatment of two-level lumbar vertebra diseases: a clinical comparison study / 中国骨伤

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>

Setting property and compressive strength of nHA/α-CSH combined bone grafts / 医用生物力学

Objective To develop a new type of combined bone grafts mainly including nanometer hydroxyapatite (n-HA) and α-calcium sulphate hemihydrate (α-CSH), and investigate its setting property and compressive strength. Methods The setting time and compressive strength of nHA/α-CSH combined bone grafts with different liquid-to-solid (L/S) ratio or calcium sulphate dehydrate (CSD) amount were measured and observed by the X-ray diffraction (XRD) and the scanning electron microscope (SEM). Results The setting time of combined bone grafts was increased along with the increase of L/S ratio or nHA amount, and reduced with the increase of CSD amount. The setting time of the compound with 20% of nHA, 80% of α-CSH was (169±36) min, while that of the compound with 5% of nHA, 20% of CSD, 75% of α-CSH was (6±1.1) min. The compressive strength of combined bone grafts reduced along with the increase of nHA amount. The average compressive strength of pure α-CSH was (12.3±2.4) MPa, while that of the compound with 20% of nHA, 80% of CSH was (4.8±0.6) MPa. The XRD results showed that no other materials were produced except that α-CSH was transformed to CSD during the setting process. The SEM results indicated that nHA was filled in the crystal structure of the CSD, presenting two-phase structure. Conclusions The setting time and compressive strength of nHA/α-CSH combined bone grafts can be adjusted by the different proportion of nHA, CSD amount and L/S ratio, which provides an appropriate condition for clinical application.

A feasibility research of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) using hybrid internal fixation for recurrent lumbar disc herniation / 中华外科杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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).</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSION</b>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.</p>

Preliminary application of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws / 中国骨伤

<p><b>OBJECTIVE</b>To study the clinical effects and application value of intraoperative CT in treatment of severe scoliosis with posterior total pedicle screws.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

A feasibility research of unilateral incision minimally invasive transforaminal lumbar interbody fusion using pedicle screws and a translaminar screw hybrid fixation / 中华外科杂志

<p><b>OBJECTIVE</b>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).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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).</p><p><b>CONCLUSIONS</b>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.</p>

The clinical outcomes of surgical treatment for adult idiopathic scoliosis using pedicle subtraction osteotomy / 中华外科杂志

<p><b>OBJECTIVE</b>to evaluate the clinical outcomes of transpedicular lumbar wedge resection osteotomy in treating adult idiopathic scoliosis.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>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.</p>

Study on the setting property and compressive strength of β-TCP/α-CSH combined bone graft / 医用生物力学

Objective To investigate the setting property and compressive strength of β-TCP (β-tricalcium phosphate)/α-CSH (α-calcium sulphate hemihydrate) combined bone graft. Method β TCP/α CSH combined bone graft and distilled water were mixed with different ratio: 1 g∶0.1 mL、1 g∶0.2 mL、1 g∶0.3 mL、1 g∶0.4 mL、1 g∶0.5 mL, respectively. The initial setting time (Ti), final setting time (TF), compressive strength were recorded, and the X-ray diffraction (XRD) and the scanning electron microscope (SEM) were examined. Results The initial and final setting time of combined bone graft increased along with the increase of solid/liquid ratio. The Ti and TF were (4.6±1.3) min and (13.1±2.9) min respectively when the solid/liquid ratio was 1 g∶0.2 mL. The average compressive strength was 7.86 MPa in one day after setting, which was about two times higher than that of β-TCP alone. The XRD results showed that no other materials were produced except that α-CSH was transformed to CSD in the setting process. The SEM results indicated that thick CSD granules were adhered to the porous surfaces of β-TCP granules after setting. Conclusions The setting time and compressive strength of β-TCP/α-CSH combined bone graft could be adjusted by the different solid/liquid ratio.

Modified posterior closing wedge osteotomy in patients of posttraumatic thoracic lumbar kyphosis / 中华外科杂志

<p><b>OBJECTIVE</b>To evaluate the outcome of posterior trans-pedicle + disc osteotomy in patients with post-traumatic thoracolumbar kyphosis.</p><p><b>METHODS</b>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).</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>Single posterior trans-pedicle + disc osteotomy technique is suitable to thoracolumbar post-traumatic kyphosis.</p>

A method to avoid the fixator failure by using pedicle screw combined vertebroplasty for spine fractures / 中华外科杂志

<p><b>OBJECTIVE</b>To study a new implant material (carbonated hydroxyapatite, CHA) united pedicle screw to cure spine fracture.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSIONS</b>The pedicle screw fixation united vertebroplasty is an efficient way to prevent the failure of the treatment of spine fracture.</p>

A pilot study of repair of periodontal bone defects with carbonated phosphate bone cement modified with synthesized peptides in dogs / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To explore the possibility of repairing periodontal defects with carbonated calcium phosphate bone cement (CCPBC) modified with synthesized peptides.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>