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Purpose: The objective of this study was to compare the safety and efficacy of minimally invasive discectomy (MID) with standard discectomy (SD) and determine whether the use of the MID technique could decrease the recurrence of lumbar disc herniation (LDH) after the surgery., Methods: In February 2014, a comprehensive search was performed in PubMed, EMBASE, Web of Science, Cochrane Library and the Chinese Biological Medicine Database. Only randomised controlled trials (RCT) that compared MID with SD for the surgical management of LDH were included. These trials were carefully picked out following the inclusion and exclusion criteria. Using the Cochrane Collaboration guidelines, two authors independently extracted data and assessed these trials' quality. The age of the patients, size of incision, surgical time, blood loss, visual analogue scale (VAS) score after the surgery, hospital stay, disc herniation recurrence, X-ray exposure and surgical costs in these studies were abstracted and synthesised by a meta-analysis with RevMan 5.2.0 software, and the main results (VAS score after the surgery and disc herniation recurrence) of publication bias were examined by Stata 12.0., Results: Overall, 16 trials involving 2,139 patients meeting our criteria were included and analysed. Comparing MID and SD, the former was more likely to increase disc herniation recurrence [relative risk (RR) = 1.95, 95 % confidence interval (CI) 1.19-3.19, p = 0.008], and it involved a smaller size of incision [mean difference (MD) = -1.91, 95 % CI -3.33 to -0.50, p = 0.008], shorter hospital stay, longer operating time (MD = 11.03, 95 %C I 6.62-15.44, p < 0.00001) and less blood loss (MD = -13.56, 95 % CI -22.26 to -4.87, p = 0.002), while no statistical difference appeared with regard to the age of the patients, VAS score after the surgery, X-ray exposure, hospital stay and surgical costs., Conclusions: Based on available evidence, MID results in less suffering for patients during the hospital course with a similar clinical efficacy compared to SD. This makes MID a promising procedure for patients with LDH; however, to popularise it greater effort is required to reduce disc herniation recurrence.

Study Design: Retrospective analysis of the clinical outcomes of 15 patients with the old thoracolumbar junction fracture treated by minimally invasive surgery (MIS) transforaminal interbody fusion surgery., Objective: To investigate the efficacy and safety of MIS for the old fracture of the thoracolumbar junction in a pilot study., Summary of Background Data: MIS have demonstrated efficacy in the treatment of lumbar degenerative diseases. There is some controversy regarding the ideal management of thoracolumbar fractures, especially those without an associated neurologic deficit. Reports concerning MIS for old thoracolumbar junction fracture with chronic pain are quite rare., Methods: A total of 15 MIS fusion, performed between October 2006 and May 2011, were examined in a retrospective study. The clinical and radiological data were collected and analyzed. Fusion levels were T10–T11 (2 patients), T11–T12 (5 patients), T12–L1 (6 patients), L1–L2 (2 patients). Clinical outcome was assessed using the visual analogue scale and the Oswestry disability index. Radiographic evaluation of the lumbar spine was performed at the second day and 12 months postoperatively., Results: The average follow-up period was 26.3 months, with a minimum of 17 months. The mean operating time, intraoperative blood loss, and x-ray exposure time were 125±31 minutes, 226±45 mL, and 47±12 seconds, respectively. At last followup,the visual analogue scale for back pain and the Oswestry disability index decreased significantly postoperatively from 7.4±2.3 to 1.8±0.6 (P<0.01) and from 38.9±7.1 to 13.5±4.5 (P<0.01), respectively. The average Cobb angle was improved from 19.1–15.1 degrees in this series. No significant correction of local kyphosis was found postoperatively (P>0.05). Radiographic evaluation showed satisfactory bony union at the fixed level in all cases except for 2 patients. There were no other major complications at last follow-up., Conclusions: MIS transforaminal interbody fusion is a safe and effective procedure for old thoracolumbar junction fracture with chronic pain. Improvement of kyphosis is limited and occurrence of nonunion is relatively high.

Objective: To examine disc degeneration at levels adjacent and next adjacent to the fractured vertebra and to analyses, if the disc degeneration is determined by the endplate fracture. Thoracolumbar burst fracture is one of the most common spinal injuries. The diagnostic (clinical and imaging) approach and treatment of a fractured vertebra is well established; however, some controversy remains. The associated disc degeneration is less well known after 9-12 months of the short segment pedicle screw fixations. There is a major controversy whether spinal trauma with vertebral endplate fractures can result in posttraumatic disc degeneration. No study to date, however, has assessed disc degeneration of the AO type A3 thoracolumbar fractures without neurologic deficits after pedicle screw fixations., Methods: Twenty-six patients with single-level AO type A3 thoracolumbar fractures and no neurological deficit were treated by using postural reduction and short segment percutaneous pedicle screw fixation. No laminectomy and fusion were performed. Implants were removed 9-12 months after the first operation. The thoracolumbar magnetic resonance imaging (MRI) was used to assess disc degeneration at levels adjacent and next adjacent to the fractured vertebra before the first operation and after the second operation in a retrospective study., Results: After the instrumentation removal, new disc degeneration was usually found at level adjacent to the cranial endplate of fractured vertebra by MRI examination in 24 patients. The average Pfirrmann grade of degenerative discs adjacent to the cranial fractured endplates deteriorated from 2.1 pre-operatively to 3.4 after the second operation. No change of disc degeneration was seen at the caudal disc space adjacent to the fractured vertebra and the levels next adjacent to the fractured vertebra. The discs next adjacent to the fractured vertebra were showed to be relatively normal without changes of degeneration during the study period., Conclusions: Disc degeneration usually occurs at level adjacent to the fractured endplate of thoracolumbar burst fractures. Endplate fracture is strongly associated with disc degeneration. No correlation between fixation level and disc degeneration is seen in this study.

Introduction: Only 12 cases of musculoskeletal tuberculosis (TB) that occurred at the site of recent blunt trauma have been previously described., Materials and Methods: A 43-year-old previously healthy man experienced an uncomplicated bursting fracture at the L2 vertebra without any spinal tuberculosis (ST)-associated evidence. During the conservative treatment, he was in good physical condition with back pain totally subsiding and occasional ambulation in a spinal brace, whereas 7 months after the original trauma, he presented with a characteristic manifestation of ST at the same vertebra., Results: Intraoperatively, biopsy confirmed ST of the L2 vertebra and radical debridement with an anterior fusion was performed. The patient received an 18-month course of anti-TB regimen. Excellent clinical outcomes were achieved., Conclusion: In developing countries, where TB is still widely prevalent, there must be a heightened awareness of the risk of ST at recently fractured vertebrae, as demonstrated in this case.

Introduction: Cartilage endplate (CEP) degeneration is usually accompanied by loss of cellularity, and this loss may be a crucial key factor in initiation and development of degenerative disc disease. The study of cell types in degenerated CEP could help in understanding CEP etiopathogenesis, and may help in devising new treatments, especially if the presence of progenitor cells could be demonstrated. The aim of this study was to determine if progenitor cells existed in degenerated human CEP., Materials and Methods: Cells isolated from CEP were cultured in a three-dimensional agarose suspension to screen for proliferative cell clusters. Cell clusters were then expanded in vitro and the populations were analyzed for colony forming unit, immunophenotype, multilineage induction, and expression of stem cell-related genes., Results: The presence of progenitor cells in degenerated human CEP is indicated by the results of CFU, immunophenotype, multilineage induction, and expression of stem cell-related genes., Conclusions: We believe that this is the first study which has conclusively shown the presence of progenitor cells in degenerated CEP. The finding of this study may influence the clinical management of degenerative disc disorder.

Background: Far lateral lumbar disc herniation (FLLDH) accounts for 2.6% to 11.7% of all lumbar herniated discs. Numerous surgical approaches have been described for treating this condition. The purpose of this study was to evaluate minimally invasive surgical techniques for the treatment of FLLDH., Methods: From June 2000 to March 2006, 52 patients with FLLDH were treated with minimally invasive procedures. All patients were assessed by anteroposterior and lateral roentgenography and computed tomography (CT). Some patients underwent myelography, discography, and magnetic resonance imaging. Procedures performed included Yeung Endoscopy Spine System (YESS) (n = 25), METRx MicroDiscectomy System (n = 13), and X-tube (n = 14). Patients were followed up for a mean of 13.5 months. Clinical outcomes were assessed using a visual analog scale (VAS) and Nakai criteria., Results: All 3 procedures significantly improved radiating leg symptoms (P < 0.005). After surgery, 84.0%, 84.6%, and 92.8% of patients in the YESS, METRx, and X-tube groups had excellent or good outcomes. There were no statistically significant differences of VAS scores between the groups. The YESS procedure was associated with the shortest operation time, simplest anesthesia, and least trauma compared with the other 2 procedures, especially for type I herniations. The METRx procedure was the most suitable for type II herniations and posterior endoscopic facetectomy. Posterior lumbar interbody fusion and unilateral pedicle screw instrumentation with X-tube was the most suitable for herniations combined with degenerative lumbar instability (type III)., Conclusion: Minimally invasive strategies and options should be determined with reference to the type of FLLDH.

Objectives: To retrospectively analyze the treatment of lumbar spondylolisthesis using minimally invasive and open transforaminal lumbar interbody fusion (TLIF), and compare the clinical results of two techniques., Methods: From June 2006 to May 2010, 371 patients with lumbar spondylolisthesis grade 1 and 2 were treated with TLIF, pedicle screw fixation and followed up. The mean age was 50.4 years (range, 37 - 85 years). There were 172 patients who underwent minimally invasive TLIF and percutaneous pedicle screw fixation were set as the MIS-TLIF group, 199 patients who underwent open TLIF and pedicle screw fixation were set as the OTLIF group. The operative time, blood loss, X-ray exposure time and complications were compared between the two groups. Clinical outcome was assessed using the visual analog scale (VAS) and the Oswestry disability index (ODI). Fusion rates were determined by using CT scan reconstruction and dynamic lumbar radiography in last fellow-up., Results: The average follow-up duration was 32.7 months with a range of 12-58 months. The gender, age, classification of spondylolisthesis and level of fusion showed a identical pattern in both groups. The mean intra-operative blood loss (310 ± 75) ml and postoperative blood loss (38 ± 13) ml in MIS-TLIF group were significantly superior to the intra-operative blood loss (623 ± 156) ml and postoperative blood loss (184 ± 72) ml in OTLIF group (t = 2.836 and 3.274, P < 0.01). Comparing with the OTLIF group (20 ± 10) s, the MIS-TLIF group had a significantly longer radiation time (51 ± 19) s (t = 2.738, P < 0.01). There was no statistical difference in operating time, lower back pain VAS scores, ODI scores and incidence of complication between the two groups., Conclusions: Comparing with open TLIF, minimally invasive TLIF is a safe and reliable procedure for treatment of lumbar spondylolisthesis grade 1 and 2 with potential advantages.

Minimally invasive lumbar fusion techniques have been developed in recent 20 years. The goals of these procedures are to reduce approach-related soft tissue injury, postoperative pain, and disability while allowing the surgery to be conducted in an effective manner. There have been no prospective clinical reports published on the comparison of minimally invasive transforaminal lumbar interbody fusion as revision surgery for patients previously treated by open discectomy and decompression or a traditional open approach. A prospective clinical study was performed by evaluating the clinical and radiographic results of minimally invasive transforaminal lumbar interbody fusion as an alternative new technique in the revision surgery for patients previously treated by open procedure. 52 patients (28 M, 24 F) with an average age of 55.7 (31-76) were prospectively evaluated. All patients who had previous discectomy (n = 13), hemilaminectomy (n = 16), laminectomy (n = 12) and facetectomy (n = 11) underwent monosegmental and bisegmental minimally invasive transforaminal lumbar interbody fusion (MiTLIF) (n = 25) or open transforaminal lumbar interbody fusion (OTLIF) (n = 27) by two experienced surgeons at one hospital, from March 2006 to October 2008 (minimum 12-month follow-up). The following data were compared between the two groups: the clinical and radiographic results, operative time, blood loss, X-ray exposure time, postoperative back pain, and complications. Clinical outcome was assessed using the visual analogue scale and the Oswestry disability index (ODI). The operative time and clinical and radiographic results were basically identical in both groups. Comparing with the OTLIF group, the MiTLIF group had significantly less blood loss and less postoperative back pain at the second day postoperatively. The radiation time was significantly longer in the MiTLIF group. Complications included three cases of small dural tear in the MiTLIF group. There were five cases of dural tear and two cases of superficial wound infection in the OTLIF group. One case of nonunion was observed from each group. Minimally invasive TLIF is a safe and effective procedure for treatment of selected revision patients previously treated by open surgery with some potential advantages. However, this technique needs longer X-ray exposure time.

Minimally invasive lumbar fusion techniques have only recently been developed. The goals of these procedures are to reduce approach-related soft tissue injury, postoperative pain and disability while allowing the surgery to be conducted in an effective manner. There have been no prospective clinical reports published on the comparison of one-level transforaminal lumbar interbody fusion in low-grade spondylolisthesis performed with an independent blade retractor system or a traditional open approach. A prospective clinical study of 85 consecutive cases of degenerative and isthmic lower grade spondylolisthesis treated by minimally invasive transforaminal lumbar interbody fusion (MiTLIF) or open transforaminal lumbar interbody fusion (OTLIF) was done. A total of 85 patients suffering from degenerative spondylolisthesis (n = 46) and isthmic spondylolisthesis (n = 39) underwent one-level MiTLIF (n = 42) and OTLIF (n = 43) by two experienced surgeons at one hospital, from June 2006 to March 2008 (minimum 13-month follow-up). The following data were compared between the two groups: the clinical and radiographic results, operative time, blood loss, transfusion needs, X-ray exposure time, postoperative back pain, length of hospital stay, and complications. Clinical outcome was assessed using the visual analog scale (VAS) and the Oswestry disability index. The operative time, clinical and radiographic results were basically identical in both groups. Comparing with the OTLIF group, the MiTLIF group had significantly lesser blood loss, lesser need for transfusion, lesser postoperative back pain, and shorter length of hospital stay. The radiation time was significantly longer in MiTLIF group. One case of nonunion was observed from each group. Minimally invasive TLIF has similar surgical efficacy with the traditional open TLIF in treating one-level lower grade degenerative or isthmic spondylolisthesis. The minimally invasive technique offers several potential advantages including smaller incisions, less tissue trauma and quicker recovery. However, this technique needs longer X-ray exposure time.

Objective: To prospectively evaluate the feasibility, safety and efficacy of the percutaneous pedicle screw fixation through the pedicle of fractured vertebra in the treatment of type A thoracolumbar fractures using Sextant system in the retrospective non-randomized case-control study., Methods: A total of 38 consecutive non-randomized patients with type A thoracolumbar fractures, which had been stabilized posteriorly from December 2006 to March 2009, were examined retrospectively more than 9 months after surgery. Twenty-one patients had been treated conventionally with open pedicle screw fixation (OPSF) and 17 patients received minimally invasive treatment with Sextant percutaneous pedicle screw fixation (SPPSF). As a method of evaluation, the incision size, the intraoperation and postoperative volume of blood loss, operation time, postoperative hospital stay, blood transfusion, the radiological assessment of the sagittal Cobb;s angle, vertebral body angle and vertebral body height were recorded and compared., Results: All patients were followed up for 8-24 months (average 11.6 months). There were significant differences in the incision size, surgical blood loss, surgical draining loss, operation time, hospital stay after operation, blood transfusion, the proportion of antalgic supplement and postoperative incisional VAS between the two groups (P less than 0.05). Mean preoperative kyphotic deformity was 16.0 degree and improved by 9.3 degree after surgery in OPSF group, but 15.2 degree and 10.3 degree respectively in SPPSF group. Mean preoperative angle of the fractured vertebral body was 15.9 degree and improved by 7.9 degree after surgery in OPSF group, but 14.9 degree and 6.6 degree respectively in SPPSF group. Mean anterior vertebral body height (% of normal) was 67.3% before surgery and 95.8% after surgery, but 69.1% and 90.1% respectively in SPPSF group. Mean posterior vertebral body height (% of normal) was 93.3% before surgery and 99.5% after surgery, but 88.9% and 93.3% respectively in SPPSF group. Among the patients whose 9-month follow-up films were available, 3.0 degree of kyphosis correction was lost in OPSF group, but 3.2 degree in SPPSF group. And 1.0 degree of the angle of the fractured vertebral body correction was lost in OPSF group, but 1.5 degree in SPPSF group. Then 3.0% of the anterior vertebral body height correction was lost in OPSF group, but 2.2% in SPPSF group. And 3.0% of the posterior vertebral body height correction was lost in OPSF group, but 2.5% in SPPSF group. The sagittal Cobb's angle, vertebral body angle and anterior height of the fractured vertebra were all significantly different in each group before and after operation (P less than 0.05). There were no significant differences in the postoperative sagittal Cobb's angle, vertebral body angle and the improvement of the vertebral body height and the kyphotic deformity correction between OPSF and SPPSF groups (P larger than 0.05), but there was significant difference in the postoperative anterior height of the fractured vertebra between the two groups (P less than 0.05)., Conclusion: The percutaneous pedicle screw fixation through the pedicle of fractured vertebra using Sextant system is a good minimally-invasive surgical therapeutic choice for patients with type A thoracolumbar fracture except for that the SPPSF has a little insufficiency in resuming the anterior height of the fractured vertebra compared with OPSF.

Primary non-Hodgkin lymphoma (PHL) of the spine is very rare. A case of a 44-year-old patient with PHL originating from a single lumbar vertebra was initially misdiagnosed as tuberculous spondylitis. After surgical decompression and biopsy, the patient was confirmed as primary B-cell non-Hodgkin lymphoma of the lumbar vertebrae and was further treated with chemotherapy. It warrants attention that PHL from the spine may be misdiagnosed as tuberculous spondylitis.

Objective: To investigate the efficacy of microendoscopic discectomy (MED) for the treatment of lumbar disc herniation over a five-year follow-up period., Methods: Between January 2000 and December 2002, 275 patients were accepted for MED in our hospital. A retrospective review was carried out on 151 of these cases with a mean of five years follow-up. The study helped us to assess the efficacy of this technique in the treatment of lumbar disc diseases. Modified MacNab criteria were used to assess the clinical outcome, and the disc-height ratio was assessed radiographically according to the Mochida's method., Results: According to the modified MacNab criteria, 78.8% of patients were rated as excellent, 13.2% as good, 4.6% as fair, and 3.3% as poor. Complications included five revision surgeries due to recurrence of herniation, five dural lacerations during operation, and three cases of vertebral/disc infection. The average disc-height ratio was 76.25%. Approximately 57% of the patients maintained their primary engagement., Conclusion: MED is both feasible and efficacious for the management of lumbar disc disease. On the basis of the present study it is concluded that MED is better than open discectomy (OD)., (© 2009 Tianjin Hospital and Blackwell Publishing Asia Pty Ltd.)

Objective: To evaluate the clinical results of, and surgical techniques for, microendoscopic (METRx) decompression of extraforaminal entrapment of the L5 spinal nerve at the lumbosacral tunnel., Methods: Five patients with extraforaminal entrapment of the L5 spinal nerve in the lumbosacral tunnel were treated in our department, including three men and two women. The average age was 65.6 years. All patients suffered severe leg pain and neurological deficits compatible with L5 radiculopathy. Minimally invasive decompression of the L5 spinal nerve was performed under METRx intertransverse decompression., Results: With an average follow-up of 17.8 months, clinical results were assessed based on Nakai criteria and Visual Analogue scale (VAS). All patients experienced immediate pain relief postoperatively. Clinical outcomes were excellent in three patients and good in two. The average intraoperative blood loss was 59 ml, with an average operative time of 103 min. Average post-operative stay in bed was 7 days, and average cost was $1860., Conclusion: Extraforaminal entrapment of the L5 spinal nerve in the lumbosacral tunnel can cause L5 radiculopathy. METRx partial resection of the L5 transverse processes, sacral ala and osteophytes of L5-S1 vertebral bodies to relieve extraforaminal entrapment of the L5 spinal nerve is a very effective and minimally invasive surgical option., (© 2009 Tianjin Hospital and Blackwell Publishing Asia Pty Ltd.)

Objective: To evaluate the results of micro-endoscopic revision surgery for recurrent disc herniation, and compare the results of disc excision with and without interbody fusion., Methods: A total of 32 patients included who had undergone micro-endoscopic revision discectomy for recurrent disc herniation with or without interbody fusion has been surveyed to assess their clinical outcome. The 27 patients who had been followed were divided into two groups; the micro-endoscopic discectomy alone 14 cases, the micro-endoscopic discectomy with interbody fusion 13 cases. With an average follow-up of 25.5 months. Clinical symptoms were assessed based on the VAS scores and Nakai criteria. All medical and surgical records were examined and analyzed, including intraoperative blood loss, length of surgery, and postsurgery hospital stay et al., Results: The statistical difference in the postoperative back pain and leg pain score compared with preoperative score were significant (P < 0.05) or very significant (P < 0.01). Clinical outcomes were excellent or good in 92.8% of patients undergoing a micro-endoscopic discectomy alone, and in 85.5% of patients with interbody fusion. The statistical difference between the fusion and non-fusion groups was insignificant (P = 0.793). But the two groups intraoperative blood loss, length of surgery, length of hospitalization and expenses were significantly less in patients undergoing discectomy alone than in patients with interbody fusion., Conclusions: Micro-endoscopic revision surgery for recurrent disc herniation is very effective and safety. Micro-endoscopic discectomy alone is first choice for managing recurrent disc herniation.

Objective: To investigate the surgical procedures, options and surgical indications for far-lateral lumbar disc herniation between three different minimally invasive procedures., Methods: From January 2000 to October 2006, 52 patients with far-lateral lumbar disc herniation (29 males and 23 females, with the average age of 41.5 years) were treated with minimally invasive procedures. All the patients were assessed by X-ray and CT. Some were given additional myeography, discography, Computerized tomography mye-lography (CTM) and MRI examination. Yeung Endoscopy Spine System (YESS), METRx and X-tube procedures were performed in 25, 13 and 14 cases, respectively. All patients were followed up for a mean period of 13.5 months. Clinical outcomes were assessed by visual analog score (VAS) and Nakai criteria., Results: The results indicated that the three procedures could significantly improve the radiating leg symptoms (P less than 0.05). The postoperative overall excellent and good rates of YESS, METRx and X-tube procedures were 84.0%, 84.6% and 92.8% respectively, with no statistical difference among three groups (P larger than 0.05). The YESS procedure had several advantages including shortest operation time, simplest anesthesia and least trauma as compared with the other two procedures, especially for simple type I far-lateral lumbar disc herniation. METRx procedure was specially suitable for simple type II. And the procedure of posterior endoscopic facetectomy, posterior lumbar interbody fusion and unilateral pedicle screw instrumentation with X-tube was designed for far-lateral disc herniation combined with degenerative lumbar instability., Conclusion: Minimally invasive strategies and options should be determined by different types of far-lateral lumbar disc herniation.

Objective: To evaluate the surgical procedure of endoscopic transforminal discectomy, bone grafting and Dynalok pedicle screw fixation under X-Tube operation system in the treatment of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis., Methods: From June 2004 to May 2006, 42 patients with classic features of lumbar disc herniation combined with segmental instability and/or pars defected spondylolithesis underwent endoscopic transforminal lumbar interbody fusion (TLIF). Under the guidance of fluoroscopy, a 2.8 to 3.0 cm incision with 4.5 to 5.0 cm apart from the posterior middle line was made on the symptomatic side and the working portal (X-Tube) was docked unilaterally on the facet joint. A total facetectomy was then performed to expose neural foramina and nerve root. Discectomy and endplate preparation were completed through the tube. A Telamon cage was placed obliquely into the intervertebral space after interbody grafting, and then the Dynalok pedicle screw fixation system was performed. This procedure was accomplished on the lateral side when it is necessary., Results: Clinical outcomes were determined using the Oswestry Disability Index (ODI) which revealed that 62.2% of patients got excellent results, 29.2% good and 8.6% fair. The average hospital stay was 12.5 days (5-25 days). Operation time averaged 240 min (110-320 min), blood loss averaged 140 ml (80-420 ml) and incision length averaged 3 cm (2.8-3.2 cm). Five patients had complications including wound infection in 1 case, incision dehiscence and focal skin necrosis in 1, progressive radicular pain of contralateral leg in 1 and residual radicular numbness after transient radicular pain in 2., Conclusions: This surgical procedure of endoscopic transforminal diskectomy, bone grafting, cage placement and pedicle screw fixation can be effectively accomplished under X-Tube operation system with predominant benefits such as small incision, less stripping of paraspinal muscles, minimal blood loss and rapid postoperative recovery.

Objective: To evaluate the surgical procedure of unilateral transforaminal discectomy, bone grafting, cage (Telamon) insertion and Dylanok pedicle screw fixation using X-tube operation system for the treatment of lumbar disc herniation combined with segmental instability and Spondylolysis with pars defect., Methods: From 2004 to 2006, 42 patients including 17 male and 25 female were treated in our department. The age range from 22 to 77 (mean: 51.6). Etiologies including lumbar disc herniation combined with segmental instability and Spondylolysis with pars defect., Result: Of these 42 patients, the mean operation time was 240 min (110 - 320 min), the average blood loss was 140 ml (80 - 420 ml), the average incision length was 3 cm (2.8 - 3.2 cm) and the average hospitalization time was 12.5 days (5 - 25 days). Nakai criteria, Excellent in 23 cases (62.2%), good in 11 cases (29.2%) and fair in 3 cases (8.6%). 5 patients had postoperative complication (complication rate: 16.3%)., Conclusions: The surgical procedure has shown predominant benefits: small incision, less stripping of paraspinal muscles, minimal blood loss and rapid postoperative recovery which makes it a valuable alternative to conventional surgical procedures.

Objective: To study the effects of unilateral graded facetectomy on lumbar stability through biomechanical analysis. The primary clinical results of unilateral facetectomy, posterior lumbar interbody fusion and unilateral pedicle screw instrumentation using X-tube system were also evaluated., Methods: 5 functional spinal units (FSU) from fresh cadavers of 5 adults were made, divided into 5 groups to remain intact, or with the lateral 1/4, 1/2, or 3/4 or the whole of the left L4/5 articular process, and then put in the biomechanical testing apparatus to evaluate the effects of operation on the lumbar motion range of flexion, extension, lateral bending and axial rotation. Twenty-three patients, 16 males and 7 females, aged 47.7 (32 - 74), underwent unilateral facetectomy, posterior lumbar interbody fusion, and unilateral pedicle screw instrumentation using X-tube system. The clinical outcomes of the 23 patients were assessed by use of the visual analog score (VAS), Oswestry disability index (ODI), and Nakai criteria., Result: The experiment of the 5 FSUs showed that no significantly negative effects on the change in lumbar motion range of flexion, extension after unilateral graded facetectomy (all P > 0.05), and the stability of lateral bending and axial rotation had been greatly affected with the range of graded facetectomy exceeding 1/2 (P < 0.05). According to the Nakai criteria, the clinical effect was excellent in 15 cases (65.2%), good in 6 cases (26.1%), and fair in 2 cases (8.7%). The excellent and good cases accounted for 91.3% with a fusion rate of 95.6%., Conclusion: The lumbar stability is significantly affected if the range of graded facetectomy exceeds 1/2. The use of procedures of unilateral facetectomy, diskectomy, spinal nerve root decompression, autologous bone grafting, and unilateral pedicle screw fixation using X-tube is an optional strategy for minimally invasive spine technique.