Objective To review the current development of the dynamic stabilization devices and their biomechanics as well as clinical application.Methods The related biomedical research papers at home and abroad were consulted and analyzed Results There were obvious advances in the theoretic foundation and the clinical application in treatment of the degenerative lumbar disorders with the dynamic stabilization devices, especially with the nonfusion dynamic stabilization devices. Conclusion The effectiveness of the dynamic stabilization devices have attracted more and more biomedical researchers, especially the posterior dynamic stabilization device, which has provided a new approach to treatment of the degenerative lumbar disorders.
Objective To explore the feasibil ity and efficacy of percutaneous kyphoplasty (PKP) for the treatment of severe osteoporotic vertebral compression fracture (OVCF), and to assess the cl inical result of the PKP technique. Methods From May 2006 to October 2007, 12 patients with severe OVCF affecting more than 2/3 of the original vertebral body height were treated by using domestic PKP and percutaneous vertebroplasty (PVP) tool systems. There were 3 malesand 9 females, with the age of 56-82 years and a mean disease course of 4.2 months (1-49 months). Eleven thoracic vertebra and 4 lumbar vertebra suffered from severe vertebral compression fractures, which included 3 extremely severe thoracic OVCF. Four thoracic vertebra and 3 lumbar vertebra had not severe OVCF. There were 4 cases of single vertebral compression fracture, 6 cases of double fractures, and 2 cases of triple fractures. Only single side PKP and PVP were performed via extrapedicular approach in thoracic vertebra, and via transpedicular approach in lumbar spine under fluoroscopic control. Eight patients with severe thoracic compression fractures and 4 with severe lumbar fractures were treated by PKP. Four patients with relatively mild thoracic compression fractures and 3 with lumbar fractures were treated by PVP. Results The operation was successfully, 3 patients with extremely severe thoracic compression fractures received no intervention. The maximum expansion pressure of balloon was (1 068 ± 298) kPa, and the volume was (3.1 ± 1.2) mL during operation. The average operative time of PKP was (44.9 ± 10.6) minutes per vertebra, while the average operative time of PVP was (36.5 ± 6.8) minutes per vertebra. The average volume of injected bone cement was (2.5 ± 0.6) mL per thoracic vertebra, and (3.6 ± 1.2) mL per lumbar vertebra. The mean hospitalization time were (3.7 ± 1.6) days. Twelve cases were followed up 5-18 months (mean 8.6 months). The visual analogue scale scoreswere (2.35 ± 0.61) points 2 days after operation and (2.89 ± 1.07) points at last follow-up, there were statistically significant differences when compared with before operation (8.27 ± 1.36) points (P lt; 0.01). Extravertebral leakage of the bone cement into the paravertebral tissue and/or disc occurred in 6 patients (9 vertebra) without significant symptom. Conclusion One side approach PKP is a safe and effective technique for treatment of severe OVCF with markedly rel ief of pain.
ObjectiveTo measure L1-L5 lumbar isthmus thickness and to construct Chinese adult male lumbar (L1-L5) 3D model by Micro CT 3D reconstruction technique, in order to provide micro-anatomical data for clinical treatment of L1-L5 lumbar spondylolysis. MethodsDry, non-damaged specimens of L1-L5 lumbar isthmus from 60 Chinese adult males were randomly selected from September 2013 to January 2014. Micro CT scanning was carried out, followed by corresponding 3D model construction. The microscopic anatomical parameters such as superior, inferior, inner and outer edge thickness of left and right L1-L5 lumbar isthmus were measured. ResultsL1-L5 lumbar isthmus superior edge thickness was in the order of L1> L2> L3> L5> L4, with the variation ranging from (4.31±0.95) mm to (4.88±0.75) mm. L1-L5 lumbar isthmus inferior edge thickness was in the order of L1< L2< L3< L4< L5, gradually thickened with the variation ranging from (6.03±1.01) mm to (7.27±1.27) mm. L1-L5 lumbar isthmus inner edge thickness amplitude was not obvious, ranging from (6.33±1.21) mm to (6.57±1.27) mm. L1-L5 lumbar isthmus outer edge thickness was in the order of L1< L2< L3< L4< L5, gradually thickened with the variation ranging from (8.44±1.21) mm to (10.27±1.28) mm. ConclusionThere are certain rules within superior, inferior, inner and outer edge thickness of adult L1-L5 lumbar isthmus:the inferior and outer edge thickness of L1-L5 lumbar isthmus gradually becomes thicker, while superior edge gradually becomes thinner. From L1 to L5 lumbar isthmus, the outer edge of the lumbar isthmus is the thickest, followed by inner and inferior edge, and the upper edge is the thinnest.
Objective To evaluate the reliability and the advantageof canal laminoplasty with laminoplasty over laminectomy for treatment of lumbar spinal stenosis.Methods From June 2000 to September 2004, the titanium miniplate fixation technique was applied to re-implantation of the vertebral lamina in the lumbar spine. The vertebral lamina was made with a specially made osteotome and a special technique in 18 patients with lumbar spinal stenosis. Results The patients were followed up for 1 yr and 8 mon on average (range, 3 mon4 yr and 3 mon) and were observed to have a bony fusion of the re-implanted lamina 3-9 months postoperatively. There was no nonunion, displacement of the re-implanted lamina, overgrowth of the anterior bone edge of osteotomy, recompression of the nerves or instability of the lumbar spine. Conclusion The result demonstrates that canal laminoplasty with the titanium miniplate re-implantation of the vertebral lamina in lumbar spine can restore the normal anatomy, keep stability of the spine, and avoid adhesion and scar in the canal.
To evaluate the appl ication value of internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement for the treatment of tuberculosis of lumbosacral vertebral body. Methods From March 2000 to February 2005, 16 cases of spinal tuberculosis in L3-S1 were treated with internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement. Sixteen cases included 11 males and 5 females, and the age was 21-56 years. The locations of spinal tuberculosis were L3 in 4 cases, L4 in 6, L5 in 4, and S1 in 2. The course of disease averaged 13 monthes (range 6 monthes to 6 years). The ESR of all cases was greater than 20 mm/h (average40 mm/h); WBC was normal in 14 cases, and a l ittle high in 2 cases. The X-ray picture showed narrow intervertebral space in 5 cases, compressed body of vertebra in 7 cases, and destroyed 2 consecutive vertebra and its sclerotin was condupl icate in 1 case. All cases were abscess in major psoas muscle. The CT showed destruction of bone, abscess-formation and dead bone in body of vertebra of 16 cases. The abscess were found in vertebral canal in 5 cases and dura mater of spinal cord and spinal nerve root crushed in 2 cases. The MRI showed destruction of bone, abscess-formation and hibateral abscess in major psoas muscle in 11 cases. The abscess were found in vertebral canal and dura mater of spinal cord and spinal nerve root crushed in 6 cases. The therapy of pasid was treated after operation in all the cases. Results Incision healed by first intention in 16 cases; and disruption of wound occurred and heal ing was achieved after symptomatic treatment in 1 case. Sixteen cases were followed up 2-5 years (29 months on average). Among all the cases, anaesthesia in double thigh was found in 3 cases, adynamia of dorsiflexion in foot in 1 case, gatism in 1 case; after 2 weeks the symptoms were vanished. Indirect hernia of fold inguen were found in 1 case after 2 years, and the patient refused operation for age and was no longer followed up. Fuzzy, exsic and acerb in eyes were foundin 6 cases, hearing disturbance were found in 2 cases, and symptoms were vanished after medication adjustment. Low-grade fever and lumbar myalgia were found in 1 case and cured after staying in bed and medication adjustment. All ESR were normal, synostosis of lumbosacral vertebral body was found in 13 cases, kyphosis in 1 case. Conclusion Internal fixation of spinal column by posterior approach and extraperitioneal bilateral focal debridement is safe and available way for the treatment of tuberculosis of lumbosacral vertebral body, it can save the times of operation, shorten period and enhance effect of treatment.
Objective To analyze the cl inical effects of modified transforaminal lumbar interbody fusion (TLIF) for the treatment of lumbar degenerative disease. Methods From October 2003 to December 2006, 33 patients with lumbar degenerative disease (L3-S1) were treated by modified TLIF. There were 14 males and 19 females with an average age of 52.2 years(33 to 70 years). The median disease course was 1.8 years (4 months to 15 years). A total of 42 levels were fused, including 24 cases of single level and 9 cases of double levels. The results of preoperative diagnosis were lumbar degenerative spondylol isthesis with stenosis (8 cases), isthmic spondylol isthesis (5 cases), degenerative lumbar stenosis (16 cases), huge herniated disc with segmental instabil ity (3 cases) and failed back surgery syndrome (1 case). During the modified TLIF procedure, total inferior facet process and inner half summit of superior facet process of TLIF side were resected to make the posterior wall of foramen opened partly. After the bone graft (3 to 5 mL) was placed into the interbody space, a single rectangle Cage was inserted obl iquely from 30° to 40° toward the midl ine. Combined with pedicle screw instrumentation, TLIF was accompl ished. Middle canal and opposite side nerve root decompression were performed simultaneously when necessary. Results Intraoperative dura mater rupture, postoperative cerebral spinal fluid leakage, deep wound infection and transient nerve root stimulation occurredin 1 case respectively, and were all recovered after treatment. No patients had permanent neurologic deficit or aggravation. All patients were followed up for 20 to 58 months (mean 27.2 months). At the follow-up after 1 year postoperatively, all the operated segments achieved fusion standard and no broken screw or Cage dislocation occurred. All 13 cases of spondylol isthesis were reduced thoroughly and maintained satisfactorily. Nineteen patients remained sl ight chronic back pain. There was significant difference (P lt; 0.05) in JOA score between preoperation (14.9 ± 5.1) and postoperation (25.9 ± 3.0). The rate of cl inical improvement was 80.5% (excellent in 24 cases, good in 7 cases, and fair in 2 cases). Conclusion The modified TLIF carries out the less invasive principles in opening operations, simpl ifies the manipulation and expands the indication of TLIF to some extent, and the cl inical results for the treatment of lumbar degenerative disease is satisfactory.
Objective To explore an improved surgical approach to the superior posterior partial resection of the fractured vertebral body followed by the single segmental fusion to treat lumbar burst fracture and to evaluate its preliminary clinical application. Methods From June to October 2006, 4 patients (2 males, 2 females; age, 17-39 years) with Denis B type lumbar burst fracture underwent the superior posterior partial resection of the fractured vertebral body followed by the single segmental fusion. The fracture occurred in 2 patients at L1 and 2 at L2. According to the Frankel scales assessment, before operation, 2patients were at Grade B and the other 2 at Grade C, and the visual analogue scale (VAS) was 7.00±0.82. Radiological evaluation was performed, which revealed the kyphosis Cobb angel of 22.94±11.21°, the adjacent superior and the inferiorintervertebal disc heights of 12.78±1.52 mm and 11.68±1.04 mm, espectively, and the vertebral canal sagittal diameter of 9.56±2.27 mm on the computer tomography (CT) scan. The neurological and the radiological evaluations were also made immediately and 3 months after operation. Results The anterior single segmental decompression and fusion operations were performed successfully in all the patients. The average operating time was 166±29 min and the average amount of blood loss was 395± 54 ml. The Frankel scales assessment showed that at the time immediately after operation, one of the 2 Grade B patients had an improvement to Grade C, but the other patient had no improvement. One of the 2 Grade C patientshad an improvement to Grade D, but the other patient had no improvement. Three months after operation, the 2 Grade B patients had an improvement to Grade C. The 2 grade C patients had an improvement to Grade D or E. The VAS score was significantly decreased to 3.50±1.29 after operation and to 1.25±0.50 3 months later （P＜0.05）. The vertebral canal sagittal diameter was significantly increased to 19.76±3.82 mm (Plt;0.01), but it was maintained to 19.27±3.41 mm3 months later, with no significant difference（Pgt;0.05）. The patients’ kyphosis Cobb angle was significantly improved to 8.71±5.41° (P＜0.05) , but it was maintained to 9.52±5.66° 3 months later, with no significant difference（Pgt;0.05）. The heights of the adjacent discs remained unchanged. No complication was observedduring and after operation, and the radiological and the CT scanning evaluations 3 months later showed no failure of the internal fixation. Conclusion The superior and posterior partial resection of the fractured vertebral body followedby the single segmental fusion can effectively decompress the vertebral canal and maintain the spine stability in treatment of the Denis B type fracture thoughthe longterm effectiveness requires a further follow-up.
Objective To review the research progress of stress fracture of the lumbar pedicle. Methods The literature about the stress fracture of the lumbar pedicle was reviewed extensively and summarized. Results There are two types of stress fracture: fatigue and structure insufficient. Stress fracture of lumbar pedicle occurred mainly in the crowd with repetitive and large activities of spine, contralateral spondylolysis, or previous surgery of lumbar vertebra. The main stresses causing stress fracture of the lumbar pedicle are shear stress and twisting stress, followed by sudden hyperflexion or hyperextension of the spine. Stress fracture of lumbar pedicle was easily missed by conventional X-ray examination, usually XCT, MRI, or bone scan was needed to confirm the diagnosis. It is divided into 4 types or 4 periods according to MRI findings: stress reaction, incomplete fracture, complete fracture, and pseudarthrosis. For patients with incomplete, complete, and juvenile stress fractures of the lumbar pedicle without nerve root irritation, the majority of claims preferred conservative treatment and the healing rate of fracture was high; for patients with bilateral pseudarthrosis and with nerve root irritation as well as patients who failed to the conservative treatment, surgical management was advocated and the operation result is good. Conclusion Stress fracture of the lumbar pedicle as one of the causes of low back pain is extremely rare, and is easily missed clinically. Surgery or conservative management should be selected based on type of fracture and specific condition of the patient, the treatment results are satisfactory.
ObjectiveTo analyze the relationship between the bone mineral density (BMD) and lumbar intervertebral disc degeneration in rhesus macaques by using T1ρ-MRI. MethodsTwenty female rhesus macaques at the age of 10.9 years on average (rang, 4-20 years) were selected. The lumbar intervertebral discs were classified by Pfirrmann grading system and the T1ρ relaxation time (T1ρ value) was examined by using MRI (Philips 1.5 Tesla), and then BMD values of the L4,5 vertebrae and femoral ward's triangle were detected by using Osteocore dual energy X-ray absorptiometry. Finally, the relationship of T1ρ value of the lumbar intervertebral discs and Pfirrmann grading with age, weight, BMD of lumbar vertebrae and femoral ward's triangle was analyzed. ResultsThe BMD values of lumbar vertebrae and femoral ward's triangle were (0.64±0.17) g/cm2 and (0.67±0.19) g/cm2 respectively, showing no significant difference (t=2.893, P=0.128). According to Pfirrmann grading system, there were 7 cases of grade I, 8 cases of grade Ⅱ, and 5 cases of grade Ⅲ at L4,5 intervertebral discs. The T1ρ value of the lumbar intervertebral disc was (104.08±18.65) ms; the T1ρ values of grades I, Ⅱ, and Ⅲ were (121.31±13.44), (104.73±15.01), and (77.41±11.87) ms, respectively. There was a negative correlation between T1ρ value and the age and the BMD of lumbar vertebrae and femoral ward's triangle. There was a positive correlation between Pfirrmann grading and the variables as listed above. Significant negative linear correlation was also observed between T1ρ value and Pfirrmann grading. ConclusionThe T1ρ value is a reliable index when quantifying lumbar intervertebral disc degeneration, and there is a significant positive correlation between BMD and lumbar intervertebral disc degeneration in rhesus macaques.
ObjectiveTo analyze the relative position between lumbar plexus and access corridor of minimally invasive lateral transpsoas approach based on magnetic resonance imaging distribution of lumbar plexus by three dimensional reconstruction technique, so as to evaluate approach safety. MethodsThree-dimensional fast imaging employing steady-state acquisition sequences of lumbar spine were performed on 71 patients with lumbar degenerative diseases between July 2012 and January 2015. The axial image distance between the anterior edge of lumbar plexus and sagittal central perpendicular line (SCPL) of disc was determined using the distance formula at the mid-disc space from L1, 2 to L4, 5 level. SCPL was drawn perpendicularly to the sagittal plane of intervertebral disc and it passed through its central point, which is initial dilator trajectory for transpsoas approach. With respect to the SCPL of disc, the distance with a positive value indicated neural tissue posterior to it whereas anterior to it represented by a negative value. ResultsVarious branches of lumbar plexus which passed through the psoas major anterior to the SCPL of disc were identified in 42 (59.2%), 58 (81.7%), and 70 (98.6%) patients at L2, 3, L3, 4, and L4, 5 levels, respectively. It is possible to infer the presence of genitofemoral nerve in accordance with relevant anatomic research. A ventral migration of intrapsoas nerves is identified from L1, 2 to L4, 5 level. All differences between levels were statistically significant (P < 0.05). ConclusionWith respect to the SCPL of disc, a pass way of guide wire or a radiographic reference landmark to place working channel, lumbar plexus lie posterior to it from L1, 2 to L3, 4 level and shift anteriorly to it at L4, 5 level, while genitofemoral nerve locate anterior to the SCPL from L2, 3 to L4, 5 level. Neural retraction may take place during sequential dilation of working channel especially at L4, 5 level.