Ultrasonic Osteotome Assisted Full-Endoscopic en Block Resection of Thoracic Ossified Ligamentum Flavum: Technical Note and 2 Years Follow-up.

BACKGROUND: Conventional open laminectomy is considered to be the standard procedure for the treatment of thoracic ossified ligamentum flavum, but multi-segment thoracic laminectomy extensively removes the facet joints and ligamentous tissue, destroying the thoracic spine biomechanics and stability, may lead to delayed thoracic spine kyphosis deformities, which in turn can lead to potential neurological deterioration and local intractable pain. OBJECTIVE: To introduce the technical notes and clinical outcome of ultrasonic osteotome assisted full-endoscopic en block resection of thoracic ossified ligamentum flavum. STUDY DESIGN: A prospective cohort study. SETTING: Hospital and outpatient surgery center. METHODS: From January 2017 to March 2018, 15 patients with 1 - 2 segment thoracic ossified ligamentum flavum were treated with ultrasonic osteotome assisted full-endoscopic en block resection of thoracic ossified ligamentum flavum under local anesthesia. The magnetic resonance imaging and computed tomography of the thoracic spine was reexamined after the operation to evaluate the completeness of ossified ligamentum flavum resection and spinal cord decompression. The patients were followed up on the visual analog scale of back pain and radicular pain, Nurick score and mJOA score of neurological function, and Oswestry Disability Index at 1 week, 3 months, 6 months, one year, and 2 years after operation. RESULTS: All operations of 17 segments thoracic ossified ligamentum flavum in 15 patients were successfully completed without intraoperative conversion to open surgery. There were no intraoperative spinal cord injuries, dura tears, postoperative cerebrospinal fluid leakage, postoperative infections, and postoperative spinal cord injury aggravated symptoms. Postoperative thoracic spine magnetic resonance imaging and computed tomography examinations of all patients showed that the spinal cord was fully decompressed without any residual pressure. Back pain and radicular pain were relieved significantly, and spinal cord function (Nurick, mJOA, and Oswestry Disability Index scores) was obviously restored. The mJOA recovery rate at the 2-year follow-up was 78.3% in average. LIMITATIONS: This is an observational cohort study with relative small sample and short-term follow-up. CONCLUSIONS: Ultrasonic assisted full-endoscopic en block resection of ossified ligamentum flavum is a safe and effective minimally invasive spine surgery for thoracic myelography caused by thoracic ossified ligamentum flavum.

A Pilot Study of Full-Endoscopic Annulus Fibrosus Suture Following Lumbar Discectomy: Technique Notes and One-Year Follow-Up.

BACKGROUND: An annulus fissure or defect will inevitably be left on the posterior annulus fibrosus after almost all kinds of lumbar discectomy, which may lead to unsatisfying postoperative pain relief and recurrence of the disc herniation. OBJECTIVE: The objective of this research is to introduce the technique of full-endoscopic annulus fibrosus suture following lumbar discectomy through the transforaminal or interlaminar approach, and to analyze the clinical outcome of full-endoscopic lumbar discectomy and annulus fibrosus suture. STUDY DESIGN: This study used a prospective cohort design. SETTING: The research was conducted in a hospital and outpatient surgery center. METHODS: A total of 50 patients with noncontained lumbar disc herniation treated with full-endoscopic lumbar discectomy and annulus fibrosus suture were treated in our department between January 2018 and November 2018. Full-endoscopic single-stitch suture via the transforaminal approach (Group T) or double-stitch suture via the interlaminar approach (Group I) was selected according to the level of lesion. Lumbar magnetic resonance imaging (MRI) was reexamined on the second day and 3 months after operation to evaluate the completeness of the discectomy and the adequacy of nerve decompression. Patients were followed up on the second day, 3 months, 6 months, and one year after operation to evaluate the relief of low back pain and leg pain, using a visual analog scale (VAS, 100-point scale). At 3 months, 6 months, and one year after operation, the patients were followed up for recovery of lumbar spine function, using the Oswestry Disability Index (ODI). At the one-year follow-up, the MacNab score was used to evaluate the clinical outcome, and the recovery of nerve root function (sensation, muscle strength, and reflex) was recorded. RESULTS: All operations were successfully completed, including 27 cases in Group T and 23 cases in Group I. There were no surgical complications and no recurrence of lumbar disc herniation. Lumbar MRI reexaminations of all patients showed that the herniated disc was completely removed and the nerves were fully decompressed. Postoperative low back pain and leg pain were significantly relieved, and the ODI score was significantly improved (P < .01) in both groups. At the one-year follow-up, the excellent and good rates as measured by the MacNab score were 92.6% in Group T and 91.3% in Group I with no significant difference between the 2 groups (P > .05). The impaired sensation and muscle strength in the low extremities of evolved nerve root of the 2 groups of patients recovered significantly at the one-year follow-up (P < .01), but the tendon reflex did not recover significantly (P > .05). LIMITATIONS: This is an observational cohort study with relatively small sample sizes and short-term follow-up. CONCLUSIONS: Full-endoscopic lumbar discectomy and annulus fibrosus suture through either the transforaminal or interlaminar approach are safe and effective minimally invasive spinal surgery techniques that can reduce the recurrence rate of lumbar disc herniation after full-endoscopic lumbar discectomy.

[Analysis of the technical key points and clinical effect of full-endoscopic lumbar annulus fibrosus suture].

OBJECTIVE: To introduce the technical key points of lumbar annulus fibrosus suture under full-endoscope and analyze the clinical efficacy of full-endoscopic lumbar discectomy and annulus fibrosus suture. METHODS: A total of 50 patients with non contained lumbar disc herniation treated with full-endoscopic lumbar discectomy and annulus fibrosus suture in our department between January 2018 and November 2018 were included. Full-endoscopic single-stitch suture through transforaminal approach or double-stitch suture through interlaminar approach was selected according to lesion level. The lumbar MRI and CT were reexamined on the second day and 3 months after surgery to evaluate the completeness of the discectomy and the adequacy of nerve decompression respectively. The patients were followed up on the second day, 3 months, 6 months, and 1 year after surgery for pain relief using visual analogue scale (VAS, 100 -point scale). The patients were followed up at 3 months, 6 months, and 1 year postoperatively for the recovery of lumbar spine function using Oswestry Disability Index(ODI). At the 1-year follow-up, the Macnab standard of lumbar spine function was evaluated, and the recovery of nerve root function (sensory, muscular and reflex) was recorded. RESULTS: All operations were successfully completed, of which 27 patients were treated with transforaminal approach(including 8 cases of L3, 4 and 19 cases of L4, 5), and 23 patients(including 11 cases of L4, 5 and 12 cases of L5S1) with interlaminar approach. The average operation time was 43.2 minutes. There were no surgical complications and no recurrence of lumbar disc herniation. Postoperative lumbar MRI and CT examinations of all patients showed that the herniated disc was completely removed and the nerveswere fully decompressed. All patients had significant relief of low back pain and lower extremity radiation pain, and the ODI score improved significantly(P<0.01). At 1 year postoperative follow up, 17 patients got an excellent result, 29 good and 4 fair according to Macnab evaluation system. On the first year after surgery, the sense of damaged nerve roots and muscle strength were significantly restored (P<0.01), but tendon reflexes were not significantly restored (P>0.05). CONCLUSION: Full-endoscopic lumbar discectomy and annulus fibrosus suture are safe and effective techniques for minimally invasive spinal surgery, which can reduce the recurrence rate of lumbar disc herniation after full endoscopic lumbar discectomy.

Modified Percutaneous Lumbar Foraminoplasty and Percutaneous Endoscopic Lumbar Discectomy: Instrument Design, Technique Notes, and 5 Years Follow-up.

BACKGROUND: Conventional percutaneous endoscopic lumbar discectomy (PELD) with an "inside-outside" technique has 4.3% - 10.3% surgical failure rate, especially in central herniated discs (HDs), migrated HDs, and axillary type HDs. PELD with foraminoplasty has been used for complex HDs. Percutaneous lumbar foraminoplasty (PLF), which is performed with a trephine or bone reamer introduced over a guidewire without a protective working cannula in the original Tessys technique, can quickly cut the hypertrophied bony structure under fluoroscopic guidance, and risk injury to the exiting and traversing nerve roots. STUDY DESIGN: A prospective cohort study. SETTING: Hospital and outpatient surgical center. OBJECTIVE: To evaluate the outcome and safety of modified PLF-PELD with a specially designed instrument for complex uncontained lumbar HDs. METHOD: From April of 2007 to April of 2009, 148 patients with uncontained lumbar HDs were treated with modified PLF-PELD. Magnetic resonance imaging (MRI) checkup was performed the next morning after the operation. Outcomes of symptoms were evaluated by follow-up interviews at 3 months, 6 months, one year, and 5 years after surgery. Low back pain and leg pain were measured by visual analog scale (VAS) score (1 - 100). Functional outcomes were assessed by using the Oswestry Disability Index (ODI) and modified MacNab criteria. RESULTS: Follow-up data were obtained from 134 cases, including 14 cases on L3-4, 78 cases on L4-5, and 42 cases on L5-S1. One hundred-eight cases were prolapse type, while 26 cases were sequestration type. Pre-operative symptoms and deficits included nerve root dermatome hypoesthesia in 98 patients (73%), nerve root myotome muscle weakness in 32 patients (23%), and weakening or disappearance of tendon reflex in 43 patients (32%). No case required conversion to an open procedure during the surgery. Low back pain and leg pain were significantly relieved immediately after surgery in all patients. MRI examination showed adequate removal of HD in all patients. VAS scores and ODI values were significantly lower at all time points after surgery than before surgery. The percentage of pain relief in leg pain was significantly higher than that in low back pain (P < 0.01). But there was no significant correlation between duration of the preoperative symptoms and the percentage of pain relief. MacNab scores at 5 years after surgery were obtained from 134 patients. Seventy-five cases were rated "excellent"; 49 were rated "good," Five patients experienced heavier low back pain, thus being classified as "fair." Five cases with recurrence were rated "poor." Preoperative and postoperative (5 years follow-up) related nerve root function status was compared. Sensation and muscle strength recovered significantly (P < 0.01), while tendon reflex was not changed (P = 0.782). No patients had infections. Five patients were complicated with dysesthesia in distribution of the exiting nerve that was all operated at L5-S1. Complaints were reduced one week after treatment with medium frequency pulse electrotherapy. Five cases required a revision surgery after recurrence. LIMITATIONS: This is an observational clinical case series study without comparison. CONCLUSION: Modified PLF-PELD with a specially designed instrument is a less invasive, effective and safe surgery for complex uncontained lumbar DH.Key words: Lumbar disc herniation, minimally invasive treatment, foraminoplasty, percutaneous endoscopic lumbar discectomy.

Percutaneous lumbar foraminoplasty and percutaneous endoscopic lumbar decompression for lateral recess stenosis through transforaminal approach: Technique notes and 2 years follow-up.

OBJECTIVE: To evaluate the outcome and safety of percutaneous lumbar foraminoplasty (PLF) and percutaneous endoscopic lumbar decompression (PELD) with specially designed instrument for lumbar lateral recess stenosis with/without herniated discs (HDs). METHOD: From August of 2011 to August of 2013, 96 patients met the inclusion criteria were treated with PLF-PELD and 85 cases were followed up to 2 years postoperatively. MRI or CT checkup performed in the next morning after operation. Outcomes of symptoms were evaluated by follow-up interviews at 3 months, 6 months, 1 year and 2 years after surgery. Low back pain and leg pain were measured by Visual Analog Scale (VAS) score (1-100). Functional outcomes were assessed by using Oswestry Disability Index (ODI) and modified MacNab criteria. RESULT: Two years follow-up data were obtained from 85 cases, including 14 cases on unilateral L3-4, 1 case on bilateral L3-4, 49 cases on unilateral L4-5, 3 cases on bilateral L4-5, 12 cases on unilateral L5S1, 1 case on bilateral L5S1, 3 cases on unilateral L3-5 and 2 cases on unilateral L4-S1. So totally 95 lumbar lateral recesses were decompressed. Patients ranged in age from 46-78 years (mean age, 56.7 years), including 36 males and 49 females. 56 cases combined with HDs. Low back pain and leg pain were significantly relieved after surgery in all patients. 3 patients were complicated with dysesthesia in distribution of exiting nerve that was all operated at L5S1. Postoperative MRI/CT examination showed adequate decompression of lateral recess and removal of combined HDs in all patients. No patient had postoperative infection, dysfunctional nerve root injury or iatrogenic segmental instability. 2 cases experienced recurrence of combined HDs (2.4%), but could not undertake further revision surgery because of infirm condition. All the 85 cases were analyzed with complete follow-up data. VAS scores and ODI values were significantly lower in all time-points after surgery than before surgery. MacNab scores at 2 years after surgery were obtained from all the 85 patients. 29 cases were given "excellent"; 48 were given "good". 6 patients experienced heavier low back pain, thus being classified as "fair". 2 cases with recurrence were given "poor". CONCLUSIONS: PLF-PELD with specially designed instrument is a less invasive, effective and safe surgery for lumbar lateral recess stenosis with/without combined HDs.

The strategy and early clinical outcome of full-endoscopic L5/S1 discectomy through interlaminar approach.

OBJECTIVE: To analyze the surgical strategy, safety and clinical outcome of full-endoscopic discectomy through interlaminar approach in the case of L5/S1 intervertebral disc excision. METHODS: From April 2011 to December 2011, 72 cases of intracanalicular non-contained disc herniations at L5/S1 level were treated with full-endoscopic discectomy through interlaminar approach. L5/S1 disc herniation was divided into three types according to position of herniated disc related to S1 nerve root: axilla type, ventral type and shoulder type. Axilla approach was selected for axilla type while shoulder approach was selected for ventral type and shoulder type. After operation, MRI was reexamined to evaluate the resection completeness of prolapsed disc material. Visual analog scales (VAS) of low back pain and sciatica, and Oswestry disability index (ODI) were recorded in certain preoperative and postoperative time points. MacNab scores were evaluated at the 12-month follow-up. RESULTS: All operations were completed without conversion to other surgical techniques. Average operation time was 45 min (20-80 min). Only one reoccurrence was revised with microendoscopic discectomy. No nerve injury and infection were complicated. Postoperative ODI and VAS of low back pain and sciatica were significantly decreased in each time point (P < 0.05). MacNab scores of 12-month follow-up include 44 excellent, 26 good, 1 fair and 1 poor. CONCLUSION: With proper selection between axilla approach and shoulder approach according to the sites of prolapsed or sequestered disc materials, full-endoscopic L5/S1 discectomy through interlaminar approach is a safe, rational and effective minimally invasive spine surgery technique with excellent clinical short-term outcomes.

Evaluation of endoscopic dorsal ramus rhizotomy in managing facetogenic chronic low back pain.

OBJECTIVE: To study the effectiveness of surgical dorsal endoscopic rhizotomy for the treatment of facetogenic chronic low back pain. METHODS: From April 2011 to November 2011, 58 patients who were diagnosed with lumbar facetogenic chronic low back pain (CLBP) and thereafter experienced >80% reliefs of pain with two comparative lumbar medial branch blocks were recruited in the study. Of those 58 patients, 45 cases (the operation group) received dorsal endoscopic rhizotomy, and the remaining 13 cases (the conservative group) received conservative treatment. Patients' preoperative and postoperative VAS score, percentage of pain relief and the MacNab score were analyzed and compared. Anatomic variations and any possible complications were recorded. RESULTS: In the operation group, VAS scores of pain (low back/referred) at any time point postoperatively were significantly lower than that before MBB (P<0.05), which, however, showed no significant difference as compared to the scores after MBB (P>0.05). In the conservative group, VAS scores of pain (low back/referred) at any time point postoperatively with conservative treatment decreased significantly compared with that before MBB (P<0.05) and were significantly higher than that after MBB (P<0.05). Percentage of pain relief in the operation group at any time point postoperatively were significantly higher than that in the conservative group (P<0.01). The MacNab scores of 1 year follow-up in the operation group were higher than that in the conservative group. In addition, four separate newly identified anatomical variations of medial branch anatomy were observed and reported. CONCLUSION: Dorsal endoscopic rhizotomy is safe and effective for the facetogenic CLBP, and can achieve better clinical outcome than the conservative treatment.

[Laminectomy and extraction of nucleus pulposus for treatment of lumbar disc herniation: effect evaluation of over 10-year-followed-up].

OBJECTIVE: To investigate retrospectively the clinical effects and recurrence rate of 143 cases who underwent one level discectomy and followed up more than 10 years. To evaluate the outcome of patients in groups of different operating age and extents of disc herniation, and analyse whether difference exists in each group. METHODS: There were 143 patients (operation time from January 1996 to December 2000) including 80 males and 63 females, aged from 18 to 66 years old with an average of 37.85 years. The followed-up time was 10 to 15 years with an average of 12.7 years. Patients were divided into 3 groups depends on operating age: < 30 years old, 30 to 50 years old and > 50 years old; 87 patients who's pre-operative CT scan could be collected among 143 cases were divided into 3 groups depends on extents of disc herniation: I degree, II degrees, and III degrees. The final followed-up was obtained in 2011, to evaluate each group and the holistic clincal outcome with JOA scores and ODI scores, and observe whether there were difference between every groups; to judge the effects by patient himself with modified Macnab Criteria. RESULTS: (1) JOA scores pre-operation and final followed-up was 5.11 +/- 2.02 and 12.51 +/- 2.35 respectively; ODI scores pre-operation and final followed-up was 33.98 +/- 7.42 and 13.39 +/- 6.79 respectively. There were significant differences between pre-operative and final followed-up in JOA and ODI (P < 0.01). The excellent-good rate was 83.2% (119/143 ) according to modified Macnab Classification with recurrence rate of 6.3% at final follow-up. (2) Obvious difference was found in JOA scores in group who's age at operation less than 30 years old compared with other 2 groups at followed-up time, and no significant difference was found in JOA scores between other two groups ; no significant difference was found in ODI scores among the three groups. (3) Significant difference was found in JOA and ODI scores in group with III degrees lumbar disc herniation group compared with other 2 groups, and no statistical difference was found in clincal scores between other 2 groups. CONCLUSION: (1) Long-term followed-up of 143 cases prove mono-level lumbar discectomy is an option for disc herniation with good curative effect and lower recurrent rate, the technique should be the prior selection in dealing with patients with lumbar disc herniation. (2) 51% patients (19/37) in group under 30 years old endure persistent low back pain. (3) The long-term clinical effects in patients with severe disc protrution who underwent lumbar discectomy is worse than those patients with mild lumbar disc herniation.

Sirt1 overexpression protects murine osteoblasts against TNF-α-induced injury in vitro by suppressing the NF-κB signaling pathway.

AIM: Sirtuin 1 (Sirt1) is the class III histone/protein deacetylase that interferes with the NF-κB signaling pathway, thereby has anti-inflammatory function. This study was undertaken to investigate whether Sirt1 could protect osteoblasts against TNF-α-induced injury in vitro. METHODS: Murine osteoblastic cell line, MC3T3-E1, was used. Overexpress of Sirt1 protein in MC3T3-E1 cells was made by transfection the cells with Sirt1-overexpressing adenovirus. The levels of mRNAs and proteins were determined with qRT-PCR and Western blotting, respectively. The activity of NF-κB was examined using NF-κB luciferase assay. The NO concentration was measured using the Griess method. RESULTS: Treatment of MC3T3-E1 cells with TNF-α (2.5-10 ng/mL) suppressed Sirt1 protein expression in a concentration-dependent manner. TNF-α (5 ng/mL) resulted in an increase in apoptosis and a reduction in ALP activity in the cells. Overexpression of Sirt1 in the cells significantly attenuated TNF-α-induced injury through suppressing apoptosis, increasing ALP activity, and increasing the expression of Runx2 and osteocalcin mRNAs. Furthermore, overexpression of Sirt1 in the cells significantly suppressed TNF-α-induced NF-κB activation, followed by reducing the expression of iNOS and NO formation. Sirt1 activator resveratrol (10 µmol/L) mimicked the protection of the cells by Sirt1 overexpression against TNF-α-induced injury, which was reversed by the Sirt1 inhibitor EX-527 (5 µmol/L). CONCLUSION: Overexpression of Sirt1 protects MC3T3-E1 osteoblasts aganst TNF-α-induced cell injury in vitro, at least in part, via suppressing NF-κB signaling. Sirt1 may be a novel therapeutic target for treating rheumatoid arthritis-related bone loss.

Simvastatin protects osteoblast against H2O2-induced oxidative damage via inhibiting the upregulation of Nox4.

Statins, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, have been used clinically as a cholesterol-lowering drug to treat hyperlipidemia. In recent years, accumulating evidence indicates the possible beneficial effect of statins on osteoporosis. However, the underlying molecular mechanism remains to be elucidated. In the present study, we investigated the therapeutic effects of simvastatin on cell viability, apoptosis, and alkaline phosphatase activity in murine osteoblastic MC3T3-E1 cells treated by hydrogen peroxide (H(2)O(2), 100 µM). It was shown that simvastatin suppressed H(2)O(2)-induced oxidative stress and attenuated H(2)O(2)-induced cell injury including increasing osteoblastic viability, inhibiting apoptosis, and promoting differentiation. Then, we examined the effects of simvastatin (10(-7) M) on Nox1, Nox2, and Nox4 expressions in osteoblastic cells treated by H(2)O(2) (100 µM). We found that in MC3T3-E1 cells, H(2)O(2)-induced upregulation of Nox4 expression was inhibited by simvastatin, which was restored by farnesyl pyrophosphate (5 µM) as well as geranylgeranyl pyrophosphate (5 µM). RNAi approach was used to reduce Nox4 protein levels in osteoblastic cells to explore its biological effects against H(2)O(2)-induced oxidative damage. When Nox4 expression was reduced in osteoblastic cells, H(2)O(2)-induced cell injury was attenuated markedly. We concluded that simvastatin protected osteoblast against H(2)O(2)-induced oxidative damage, at least in part, via inhibiting the upregulation of Nox4.

[Surgical treatment of thoracolumbar single compression fracture by using in situ rod rotation reduction].

OBJECTIVE: To evaluate the efficacy and clinical outcome of the treatment of thoracolumbar single compression fracture by using in situ rod rotation reduction and short segment pedicle screw at the fracture level. METHODS: From December 2008 to May 2010,12 cases of traumatic thoracolumbar single compression fracture (T11-L2) were treated, including 9 males and 3 females, with an average age of 35.8 years old (ranging from 24 to 52). There were 2 case with T11 fracture, 2 cases with T12, 6 cases with L1 and 2 cases with L2, without osteoporosis,pathological fractures or neurologic deficits. Radiographic data were collected preoperatively, 5 days postoperatively and at last follow-up (at least 12 months). Cobb's angle, vetebral compression ratio, internal fixation state were observed. RESULTS: All patients were followed up from 12 to 30 months postoperatively,with an average of 19 months. There was no pseudoarticulation and solid bone fusion was achieved in all cases. There were no complications such as loosening or rupturing of internal fixation and so on. Sagittal kyphotic Cobb angle was corrected from preoperative (25.8 +/- 9.4) degrees to postoperative (6.7 +/- 2.3) degrees and (6.9 +/- 2.6) degrees at last follow-up. The percentage of vertebral compression was corrected from preoperative (42.5 +/- 10.4)% to postoperative (7.5 +/- 3.9)% and (8.4 +/- 4.5)% at last follow-up.There was significant difference between the postoperative data and preoperative data (P < 0.05), while the difference was not significant between the postoperative data and the last follow-up (P > 0.05). CONCLUSION: The thoracolumbar single compression fracture can obtain and maintain a good restoration by using the technic of in situ rod rotation reduction and short segment pedicle screw at the fracture level. The technique should be highly recommended.

Cervical myelopathy caused by anomalies at the level of atlas.

STUDY DESIGN: Case report. OBJECTIVE: To report a case of cervical myelopathy due to simultaneous anomalies at the level of atlas involving hypoplasia of the posterior arch of the atlas, partial ossification of the transverse atlantal ligament, and hypertrophy of the dens. SUMMARY OF BACKGROUND DATA: Hypoplasia of the posterior arch of the atlas, ossification of the transverse atlantal ligament, and hypertrophy of the dens are all individually very rare clinical entities. We are not aware of previous reports describing the association of hypoplasia of the posterior arch of the atlas, partial ossification of the transverse atlantal ligament, and hypertrophy of the dens. METHODS: The patient's medical history, physical examination, and radiographic evaluation are examined. Surgical treatment and clinical outcome are reported. In addition, available literature is also reviewed. RESULTS: The patient's neurologic symptoms significantly improved after posterior decompressive surgery. CONCLUSION: We believe this is the first case of cervical myelopathy caused by simultaneous anomalies at the level of atlas involving hypoplasia of the posterior arch of the atlas, partial ossification of the transverse atlantal ligament, and hypertrophy of the dens. Surgical intervention improved the neurologic impairment.

[The role of capsaicin-sensitive primary afferents in experimental sciatic pain].

OBJECTIVES: To determine the effect of destroying capsaicin-sensitive primary afferents (CSPA) fibers on paw withdrawal mechanical threshold (PWMT) induced by the direct compression of L5 nerve root with autologous disc. METHODS: The procedure used autologous disc of the rats from the coccygeal intervertebral discs to apply direct pressure to the L5 dorsal root. PWMT was measured at the different time points post-surgery and pre-surgery. The changes in spatial expression pattern of c-fos protein in the spinal cord were also determined at 3 weeks when PWMT decreased to the peak. RESULTS: The pretreatment with capsaicin produced a complete prevention of mechanical hyperalgesia induced by disc compression. The direct compression of L5 nerve root produced an obvious expression of fos-like immunoreactivity neurons in the dorsal horn of the spinal cord, which was significantly decreased by pretreatment with capsaicin. CONCLUSIONS: The study shows that CSPA fibers, which mainly terminated in superficial layers of dorsal horn, may play a key role in mechanical hyperalgesia in the new sciatica model.

[Studying the influence of age and short or long segments of pedicle screw instrumentation to the clinical efficacy of early single thoracolumbar fracture].

OBJECTIVE: To study the influence of different age and short or long segments of pedicle screw fixation to the clinical efficacy of early single thoracolumbar fracture. METHODS: From June 2005 to June 2008, 27 patients of early single thoracolumbar fracture were treated using short or long segments pedicle screw instrumentation, fracture vertebral (AO classification: type A1 or A2) was between T11 or L2. All patients were divided into A or B group according to age. A group: 12 cases mean age (32.6+/-10.7) years old (range, 16-55 years old). B group: 15 cases mean age (66.8+/-9.2) years old (range, 56-78 years old). All patients were treated with bony autograft by transpedicular of fracture vertebral and internal fixation by pedicle instrumentation. Pedicle screws were inserted in the pedicles of above and lower adjacent vertebral body of fracture vertebral, and others were inserted in the pedicles of above and lower two vertebral bodies of injured vertebral. Recorded operation time, blood loss and occurrence of complications. All patients took X radiograph plane examination (anterior-posterior position and lateral position) before operation and during 1 week of post operation and more than 1 year of follow up. Measured percentage of anterior compression vertebral high and kyphosis angle of the fracture vertebral by the same one group doctors. RESULTS: Mean follow up time was (29.6+/-9.1) months (range, 10 - 34 months). The patients using short segments pedicle screw fixation in A and B group, mean operation time were (102+/-16) min and (118+/-24) min (P=0.072), mean volume of loss blood were (315+/-87) ml and (331+/-87) ml (P=0.064) respectively. The patients using long segments pedicle screw fixation in A and B group, Mean operation time were (138+/-22) min and (159+/-31) min (P=0.052), Mean volume of loss blood were (446+/-102) ml and (482+/-148) ml (P=0.055) respectively. There was no statistic different significantly between A and B group. The patients using short segments fixation, preoperative, during one week of post operation, one year of follow up, in A group the percentage of anterior compression vertebral high were 41.3+/-14.0, 5.4+/-1.0, 13.6+/-1.1, and 38.5+/-11.2, 8.3+/-2.1, 21.4+/-5.2 in B group. The patients using long segments fixation, at some time of preoperative, during one week of post operation and one year of follow up the percentage of anterior compression vertebral high were 40.8+/-11.5, 4.6+/-1.2, 8.3+/-1.0 in group A, and 44.3+/-10.2, 9.7+/-2.1, 11.2+/-3.0 in group B. In group A and B the kyphosis angle of fracture segment was 17.5 degrees+/-1.0 degrees and 16.3 degrees+/-3.1 degrees before operation, 4.2 degrees+/-1.0 degrees and 6.0 degrees+/-1.1 degrees in one week of postoperation and 11.5 degrees+/-1.0 degrees, 13.4 degrees+/-3.0 degrees in one year later postoperation. All the compression vertebral high was recovered and kyphosis was corrected significantly during one week and one year after operation (P<0.05), but there was some loss of kyphosis correction rate in follow up. CONCLUSION: There is better clinical efficacy of short segments pedicle instrumentation for treating early thoracolumbar fracture in the young group, but long segments fixation of pedicle instrumentation is more suitable for the older group.

Unilateral external fixator in the treatment of lower third humeral shaft fractures.

OBJECTIVE: To retrospectively analyze the effect of unilateral external fixators in the treatment of lower third humeral shaft fractures. METHODS: From October 1997 to October 2003, 33 patients aged 15 -70 years (average 31 years) with lower third humeral shaft fractures were treated with unilateral external fixators. There were 9 spiral fractures (type A1), 1 oblique fracture (type A2), 3 transverses fractures (type A3) and 20 comminuted fractures (11 type B1, 9 type B2) according to AO classification. Fifteen cases were treated with open reduction and limited internal fixation and fixation with external fixators, 10 cases treated with open reduction and fixation with external fixators, and 8 cases treated with closed reduction and fixation with external fixators. Nerve exploration was undertaken in 9 cases with preoperative radial nerve injury. External fixators were removed after bone healing. The average follow-up was 18 months with a range from 8 to 24 months. RESULTS: The time of bone healing ranged 11-22 weeks (average 14 weeks). The latest follow-up showed the functions of 9 cases of preoperative radial nerve injury and of 2 cases postoperative radial nerve injury and the function of elbow were recovered to normal. There were only 7 cases of superficial infection at pin hole, which was subsided by using oral antibiotics and pin-hole care with mild disinfectants. CONCLUSIONS: Fixation with unilateral external fixators combined with open reduction and limited internal fixation has a good effect in the treatment of lower third humeral shaft fractures.

[The use of dynamic axial external fixator with modified technique in Pilon fractures of tibial].

OBJECTIVE: To retrospectively analyses the results of dynamic axial external fixator with modified technique in the treatment of severely Pilon fractures. METHODS: From July 2000 to February 2003, 14 patients with severely Pilon fractures were treated with dynamic axial external fixator inserted with modified technique combined with limited open reduction and internal fixation with screws and Kirschner wires, with two distal external pins inserted into talus and calcaneus respectively so that the rotation axis of distal clamp was coincided with that of ankle joint. All patients were young or middle-aged people from 20 y to 52 y (average 38 y). All fractures were Rüedi-Allg were type II or type III. External fixators were removed after bone healing. Duration of follow-up was 5 - 36 m (average 18 m). RESULTS: The time of bone healing was 12 - 24 weeks (average 14 weeks). At the latest follow-up, results include 5 excellent, 6 good and 3 fair according to ankle scoring system (ASS). There was only one case of superficial pin site infection settled with oral antibiotics and pin site care with mild disinfectants. There was no wound breakdown, superficial and deep infection, osteomyelitis, fracture fragments redisplacement and collapse. CONCLUSION: Dynamic axial external fixator with modified technique combined with limited internal fixation is an effective method for the treatment of severely Pilon fractures.

[The diagnosis and treatment of lumbar internal disc disruption].

OBJECTIVE: To study the diagnosis and treatment of lumbar internal disc disruption (IDD). METHODS: Thirty-six patients with chronic disabling low back pain proved by discography as IDD were treated with disc excision and lumbar interbody fusion, and 8 cases were treated with PLIF, 28 with ALIF. The clinical results were evaluated by pre- and post-operative VAS, and the fusion results were evaluated by X-ray studies of the lumbosacral spine. RESULTS: The average period of follow-up was 18 months, ranging from 6 to 26 months. Six patients treated with PLIF basically disappeared low back pain, 2 complained of mild back pain; the VAS after operation was decreased significantly in comparison with that of pre-operation (P < 0.01). Twenty-seven treated with ALIF basically disappeared low back pain; the VAS after operation was decreased significantly in comparison with that of pre-operation (P < 0.01). Fusion rate was 88% in patients who were treated with PLIF, and 97% in patients with ALIF. CONCLUSION: Disc excision and interbody fusion is an effective method for the treatment of IDD, but the operation indications should be known well.