The existence of intravertebral cleft impact on outcomes of nonacute osteoporotic vertebral compression fractures patients treated by percutaneous kyphoplasty: a comparative study.

STUDY DESIGN: A retrospective comparative study. OBJECTIVE: The purpose of this study is to assess radiologic features of intravertebral cleft (IVC) in nonacute osteoporotic vertebral compression fractures (OVCFs) patients, and analyze the existence of IVC impact on outcomes of percutaneous kyphoplasty (PKP). SUMMARY OF BACKGROUND DATA: The IVC sign is regarded as vertebral instability and the cause of persisting pain. It is more likely to happen at nonacute OVCFs patients. Patients with IVC sign have different outcomes from these without IVC treated by percutaneous vertebroplasty. There were rare reports about the outcomes of patients with IVC sign treated by PKP. MATERIALS AND METHODS: We divided 92 nonacute OVCFs patients (total of 113 vertebrae) into 2 groups according to the existence of IVC. Preoperative and postoperative Visual Analogue Scales, Oswestry Disability Index, kyphotic angulation (KA), and anterior vertebral height were recorded; the incidence and radiologic features of IVC were analyzed. RESULTS: The diagnostic sensitivity of IVC on plain radiograph, computed tomography, and magnetic resonance imaging were 35.4%, 89.3%, and 83.3%, respectively. The IVC group had an average correction KA of 9.14 degrees and reduction of ratio of compression of 20.09%, and the non-IVC group was 8.76 degrees and 20.23%, respectively. Cleft pattern of cement accounted for 64.6% in IVC group and 27.7% in non-IVC group. Five/7 of cement leakage in IVC group was intradiscal leakage, whereas 7/9 of cement leakage in non-IVC group was perivertebral leakage. CONCLUSIONS: Computed tomography and magnetic resonance imaging were more sensitivity to diagnose IVC sign than X-ray. PKP could improve pain, functional activity, KA, and anterior height of both IVC and non-IVC groups, however, there was more cleft pattern of cement and higher intradiscal cement leakage in the IVC group.

Microendoscopic anterior approach for irreducible atlantoaxial dislocation: surgical techniques and preliminary results.

STUDY DESIGN: Surgical techniques and preliminary results. OBJECTIVE: To describe and evaluate the safety and efficacy of a new minimal invasive technique for the irreducible atlantoaxial dislocation (IADD). SUMMARY OF BACKGROUND DATA: Endoscope has been widely used in minimal invasive spinal surgery. However, there are no clinical reports regarding anterior approach for IADD in the literature. METHODS: Ten consecutive patients with IADD were treated by anterior release with microendoscopic aide and subsequently reduction, anterior transarticular screw fixation and morselized autologous bone grafts. There were 3 cases of odontoid dysplasia, 4, chronic odontoid fracture, 1, odontoid absence, 1 fasilar impression, and 1 malunion of odontoid fracture. According to Symon and Lavender's classification of disability, 6 cases were moderate disability, 3 severe nonbedbound, and 1 severe bedridden. The procedure was performed by the same surgeon (Yong-Long Chi). RESULTS: The new technique was performed successfully in all cases. All the patients underwent transarticular screw fixation and anterior morselized autograft fusion. The average operation time was 120 min (range, 90 to 150 min) and the mean estimated blood loss was 150 mL (range, 100 to 250 mL). Postoperative radiographs demonstrated that 9 cases restored anatomic position and 1 had partial reduction. According to the postoperative computed tomography all the screws were appropriately placed. Follow-up after surgery, longest is 16 months and minimal 8 months with a mean of 12 months, neurologic status was improved in all patients. There was no loss of fixation and solid fusion was achieved in all cases. CONCLUSIONS: Surgical technique of microendoscopic anterior release, reduction, fixation, and fusion is safe and reliable minimally invasive for treating IADD.

[Percutaneous microendoscopic anterior release, fixation and fusion for irreducible atlanto-axial dislocation].

OBJECTIVE: To evaluate the safety and efficacy of one-stage percutaneous microendoscopic anterior release, trans-articular fixation and fusion to reduce and stabilize for irreducible atlanto-axial dislocation. METHODS: Eight consecutive patients were treated by percutaneous microendoscopic anterior release, trans-articular C(1-2) fixation and bone graft fusion. The mean age was 33 years (range, 28-52 years). The pathology included odontoid dysplasia in 3 patients, chronic odontoid fractures in 2, odontoid absence in 1, fasilar impression in 1 and malunion of odontoid fracture in 1. The classification of disability was that proposed by Symon and Lavender. There were moderate disability in 4, severe non-bedbound in 3, and severe bedridden in 1. RESULTS: The new technique was performed successfully in all cases. All patients underwent trans-articular C(1-2) screw fixation and anterior bone graft fusion. The average operation time was 120 min (90-150 min), and the average estimated blood loss was 150 ml (100-250 ml). Seven cases resulted in anatomic reduction, 1 had partial reduction. The follow-up period was 8-16 months. The effective rate was 100%, and the excellent rate was 51.25%; the average improvement rate for the spinal canal decompression was 76.5%. There was no instrument failure or pseudarthrosis, and solid fusion was achieved in the all cases. The loss of axial rotation of cervical spine was 30-40 degrees . CONCLUSION: Percutaneous microendoscopic anterior release, fixation and fusion is an effective, reliable, and safe procedure for the treatment of irreducible atlanto-axial dislocation.

[Therapeutic effects and complications of percutaneous anterior screw fixation for odontoid fractures].

OBJECTIVE: To investigate the therapeutic effects and complications of percutaneous anterior screw fixation for odontoid fractures. METHODS: Twenty-eight patients with odontoid fractures, 21 males and 7 females, aged 38.6 (21-72), 12 with type II fractures and 16 with type III fractures, including 10 cases with shallow type III fractures, according to Anderson's classification system, underwent percutaneous anterior odontoid screw fixation with one screw implant. Five to seven days after the operation the patients got out of bed to conduct dirigation. Prostheses were used for 8-12 weeks post-operationally. The patients were followed up for 43.2 months (26-62 months). Radiological examination, including X-ray and CT examinations, and clinical examinations were carried out to observe the therapeutic effects. RESULTS: Radiological examination showed bony union in 25 cases (89.3%), and non-union developed in 2 cases, 1 case was switched to posterior fusion surgery because of redisplaced fracture. The union rate was 83.3% in the type II fracture, and was 93.8% in the type III. Majority of the patients resumed an excellent cervical motion. No severe complication such as esophagus and carotid artery injury related with puncture was found. One patient had temporary superior laryngeal nerve paralysis, The screw tail was detained at the superior margin of C3 vertebral body in 5 cases, the screw penetrate the tip of odontoid process in 1 case, and the screw thread failed to pass the fracture site entirely in 1 case. CONCLUSION: An innovative alternative method with the advantages of convenient procedure, less bleeding, gentle injury for surrounding tissue, and rapid recovery, percutaneous anterior odontoid screw fixation is similarly effective as open anterior odontoid screw fixation, for the treatment of odontoid fractures. Related complication is rare and not severe. The surgery has.

[The classification and its clinical value for extravertebral cement leakage complicated by percutaneous vertebral augmentation].

OBJECTIVE: To explore the category and its clinical value of extravertebral cement leakage complicated by percutaneous vertebroplasty and kyphoplasty. METHODS: After collecting clinical data of 56 patients underwent surgery of PVP or PKP between August 2001 and March 2005, extravertebral cement leakage was classified according to anatomical position, and its clinical value was analysed. RESULTS: Eighteen vertebraes presented cement leakage in all 43 vertebraes in PVP group. There were 15 vertebraes with one-place leakage, 6 vertebraes with perivertebral leakage, 5 spinal canal leakage, 2 intraforaminal leakage, 1 intradical leakage and 1 paravertebral soft tissues leakage respectively among them; and there were 3 vertebraes with two-place leakage. Four vertebraes presented cement leakage in all 22 vertebraes in PKP group. All 4 vertebraes had one-place leakage including 2 vertebraes with perivertebral leakage, 1 spinal canal leakage and 1 intraforaminal leakage. Five patients with cement leakage presented new symptoms including peritoneal irritation signs and spinal cord or nerve root injury, 3 patients recovered after conservative treatment, whereas the other 2 patients need decompression surgery. CONCLUSIONS: The types of perivertebral leakage and spinal canal leakage are common among extravertebral cement leakage followed by percutaneous vertebroplasty and kyphoplasty. The minority of patients with cement leakage presents new symptoms, and the majority of them has the same therapeutic effect except patients with spinal canal leakage on one day after surgery.

[Instability of C1,2 treated with transcutaneous anterior lateral mass fixation and bone grafting].

OBJECTIVE: Creating the method of transcutaneous anterior lateral mass fixation for instability of C(1,2). METHODS: The regular and safe angle and the distance between the median margin of vertebral artery and median line of superior and inferior margin of axis were measured with computerized tomography. Fifteen cases of C(1,2) instability including 7 cases atlanto-axial dislocation, 3 cases of Jefferson's fracture, 1 case of dental fracture and dislocation and 4 cases of fractures of anterior arch of C1 were treated with pertacuneous anterior lateral mass screws and bone grafting with new-designed hole instrumentations according to the measurement of 40 normal atlanto-axial vertebrae. RESULTS: In posterior-anterior ray the regular angle was 24.0 degrees +/- 3.7 degrees (right side), and 23.8 degrees +/- 1.8 degrees (left side); safe angle is 15.2 degrees - 30.3 degrees (left side) and 14.8 degrees - 32.1 degrees (right side), respectively. The distance between the median margin of vertebral artery and median line of superior and inferior margin of vertebral artery and median line of superior and inferior margin of lateral mass was (5.6 +/- 2.2) mm (right) and (5.8 +/- 1.9) mm (left). In lateral ray the regular angle was 24.1 degrees +/- 1.8 degrees, and safe angle 12.6 degrees - 26.8 degrees. All cases reach a satisfactory result of fixation without the injury of vertebral artery, spinal cord and esophagus. The acupuncture point recovers without infection. CONCLUSIONS: This operation procedure for instability of C(1,2) has the advantage of less trauma and bleeding, simply operation and bone grafting at the same time. The operation procedure is safe with reasonable instrument and selecting the correct puncture point, angle and depth.

[Application of anterior percutaneous screw fixation in treatment of odontoid process fractures in aged people].

OBJECTIVE: To explore the efficacy of anterior percutaneous screw fixation in the treatment of odontoid process fractures in aged people. METHODS: From February 2001 to April 2009, 15 elderly patients with odontoid fracture were treated with anterior percutaneous screw fixation,including 13 males and 2 females; the average age was 69.3 years (ranged, 60 to 86 years). According to Anderson classification, there were 10 patients with type II fractures (type II A in 7 cases, type II B in 3 cases, based on Eysel and Roosen classification), 4 patients with shallow type III fractures, 1 patient with deep type III fractures. Thirteen patients were fresh fractures, 2 patients were obsolete fractures. All patients had varying degrees of neck or shoulder pain, and limit activity of neck. There were 4 patients with neural symptoms including 2 grade D and 2 grade C according to Frankel classification. All the patients were followed up and were assessed by radiology. Clinical examination included neck activity, neurological function and the degree of neck pain. Radiology examinations including anteroposterior, lateral, open mouth position and flexion-extension radiographs of cervical vertebra were performed. RESULTS: After surgery, all patients were followed up,and the duration ranged from 6 to 60 months (averaged 31.3 months). Two patients died of other diseases during the follow-up period (18 and 22 months after surgery respectively). All patients got satisfactory results, and all screws were in good position. As the screw was too long, esophagus was compressed by screw tail in one case. One case showed fibrous union, 12 cases had achieved solid bony union, 2 cases showed nonunion without clinical symptoms. The rotation of neck in 3 cases was mildly limited,the neck function of the remaining patients were normal. Four patients with symptoms nerve injuries improved after operation (Frankel E in 3 cases, Frankel D in 1 case). The symptom of neck pain had a significant improvement after surgery (P < 0.001). The VAS score decreased from preoperative (6.07 +/- 1.44) (4 to 8 scores),to postoperative (1.13 +/- 0.92) (0 to 3 scores). And there were no severe postoperative complications. CONCLUSION: The anterior percutaneous screw fixation is less traumatic than conventional approaches for aged people in dealing with odontoid process fractures. Most patients will achieve satisfactory clinical results, as long as the general conditions of them are comprehensively assess. However, this procedure should not be used in patients with comminuted odontoid fractures or severe osteoporosis.

Management of odontoid fractures with percutaneous anterior odontoid screw fixation.

Minimally invasive techniques have revolutionized the management of a variety of spinal disorders. The authors of this study describe a new instrument and a percutaneous technique for anterior odontoid screw fixation, and evaluate its safety and efficacy in the treatment of patients with odontoid fractures. Ten patients (6 males and 4 females) with odontoid fractures were treated by percutaneous anterior odontoid screw fixation under fluoroscopic guidance from March 2000 to May 2002. Their mean age at presentation was 37.2 years (with a range from 21 to 55 years). Six cases were Type II and four were Type III classified by the Anderson and D'Alonzo system. The operation was successfully completed without technical difficulties, and without any soft tissue complications such as esophageal injury. No neurological deterioration occurred. Satisfactory results were achieved in all patients and all of the screws were in good placement. After a mean follow-up of 15.7 months (range 10-25 months), radiographic fusion was documented for 9 of 10 patients (90%). Neither clinical symptoms nor screw loosening or breakage occurred. Our preliminary clinical results suggest that the percutaneous anterior odontoid screw fixation procedure using a new instrument and fluoroscopy is technically feasible, safe, useful, and minimally invasive.