Objective: To examine the effect of posterior atlanto-axial intraarticular distraction technique as revision surgery for failed posterior fossa decompression in patients with basilar invagination(BI) and atlanto-axial dislocation(AAD). Methods: The clinical data of 13 cases of AAD accompanied with BI treated at Department of Neurosurgery, Xuanwu Hospital, Capital Medical University were retrospectively analyzed. There were 3 males and 10 females,aged (42.6±9.5) years (range:30 to 63 years). All cases had assimilation of atlas and once underwent posterior fossa decompression. Anterior tissue was released through posterior approach followed by cage implantation into facet joint and occipital-cervical fixation with cantilever technique. The clinical results were evaluated using Japanese Orthopedic Association scale(JOA) and the main radiological measurements including atlantodental interval (ADI), the distance of odontoid tip above Chamberlain line(DCL),clivus-canal angle(CCA) and the length of syrinx were collected. Paired sample t test was used to compared the data before and after operation. Results: All patients underwent surgery successfully, the mean surgical time was (187.7±47.4) minutes (range from 116 to 261 minutes). Twenty occipital condyle screws, 26 C2 pedicle screws and 3 occipital plates were implanted. Clinical symptoms improved in all patients. Twelve patients had complete reduction of basilar invagination and atlanto-axial dislocation, 1 achieved near completely reduction of basilar invagination. The postoperative ADI, DCL and CCA significantly improved((4.3±1.1) mm vs. (1.8±0.8) mm, (11.7±5.0) mm vs. (6.4±2.8) mm, (142.4±7.9)° vs. (133.3±7.9)°, all P<0.01).There were 5 cases with syringomyelia before surgery, and shrinkage of syrinx was observed 1 week after surgery in all cases. Eight patients achieved bone fusion 3 months after surgery, all patients achieved bone fusion 6 months after surgery. The JOA score increased from 12.8±2.3 before surgery to 14.8±1.3 one year after surgery, with statistically significant difference (t=4.416, P<0.01).No implant failure, spacer subsidence and infection were observed. Conclusion: In cases of failure posterior fossa decompression of basilar invagination and atlanto-axial dislocation, using posterior atlanto-axial intraarticular distraction and cantilever technique with cage implantation could achieve complete reduction and symptomatic relief.
Atlanto-Axial Joint/surgery* ; Female ; Humans ; Joint Dislocations/surgery* ; Male ; Pedicle Screws ; Platybasia/surgery* ; Reoperation ; Retrospective Studies ; Spinal Fusion/methods*

Atlantoaxial dislocation (AAD) is a kind of life-threatening atlantoaxial structural instability and a series of neurological dysfunction caused by common multidisciplinary diseases. The operation risk is extremely high because it is adjacent to the medulla oblongata and the location is deep. With the increase of the number of operations in the upper cervical region, postoperative complications such as failure of internal fixation, non fusion of bone graft and poor prognosis gradually increase.Incomplete primary operation, non fusion of bone graft, infection and congenital malformation are the potential causes. In addition, considering the objective factors such as previous graft, scar formation and anatomical marks changes, revision surgery is further difficult. However, there is currently no standard or single effective revision surgery method. Simple anterior surgery is an ideal choice in theory, but it has high risk and high empirical requirements for the operator;simple posterior surgery has some defects, such as insufficient reduction and decompression;anterior decompression combined with posterior fixation fusion is a more reasonable surgical procedure, but many problems such as posterior structural integrity and multilevel fusion need to be considered.This article reviews the causes and strategies of AAD revision surgery.
Atlanto-Axial Joint/surgery* ; Humans ; Joint Dislocations/surgery* ; Joint Instability/surgery* ; Reoperation/adverse effects* ; Spinal Fusion/methods* ; Treatment Outcome

OBJECTIVE: To explore the treatment strategy and clinical efficacy for os odontoideum complicated with atlantoaxial dislocation. METHODS: The clinical data of 17 patients with os odontoideum complicated with atlantoaxial dislocation surgically treated from January 2006 to January 2015 were retrospectively analyzed, including 7 males and 10 females, aged 17 to 53 (43.1±11.3) years old;course of disease was 3 to 27(10.2±6.9) months. All patients received cranial traction before operation, 12 of 14 patients with reducible dislocation were treated by posterior atlantoaxial fixation and fusion, and 2 patients with atlantooccipital deformity were treated by posterior occipitocervical fixation and fusion;3 patients with irreducible alantoaxial dislocation were treated by transoral approach decompression combined with posterior atlantoaxial fixation and fusion. The operation time, intraoperative blood loss and perioperative complications were recorded. Visual analogue scale (VAS) and Japanese Orthopaedic Association (JOA) score were used to evaluate the change of neck pain and neurological function. Atlantoaxial joint fusion rate was evaluated by CT scan. RESULTS: The operation time of posterior fixation and fusion ranged from 86 to 170 (92.2±27.5) min, and the intraoperative blood loss was 200-350 (250.7±65.2) ml. No vertebral artery injury and spinal cord injury were recorded. Among the patients underwent atlantoaxial fixation and fusion, 1 patient with reducible dislocation fixed by C CONCLUSION Surgical treatment of os odontoideum complicated with atlantoaxial dislocation can achieve satisfactory results, improve the patient's neurological function and improve the quality of life, however the surgical options needs to be individualized.
Adolescent ; Adult ; Atlanto-Axial Joint/surgery* ; Axis, Cervical Vertebra ; Female ; Humans ; Joint Dislocations/surgery* ; Male ; Middle Aged ; Quality of Life ; Retrospective Studies ; Spinal Fusion ; Treatment Outcome ; Young Adult

OBJECTIVE: To evaluate the effect of bilateral atlantoaxial lamina hook and atlantoaxial joint space screw combined with autologous iliac bone graft on atlantoaxial dislocation caused by acute type I transverse ligament injury in school-age children. METHODS: From February 2006 to February 2019, 8 school-age children with atlantoaxial dislocation caused by acute type I transverse ligament injury were systematically reviewed, including 6 males and 2 females; aged 9 to 12 years old; 8 acute injuries included 4 high-level falls, 2 car accidents and 2 sports injuries; the atlantoaxial interval(ADI) was 5 to 8 mm. Eight cases presented with pain, stiffness, numbness and cervical spine dysfunction in different degrees. Two of them were accompanied by nerve compression and ASIA grade D. The preoperative C₁,₂ angle averaged 20.7° to 23.4°. All patients received cranial traction and surgical treatment after complete reduction or atlantoaxial reduction. The changes of Japanese Orthopaedic Association(JOA) score, space available for the cord(SAC), neck disability index(NDI), ADI, ASIA classification(ASIA) injury classification(1992) and C₁,₂ angle before and after treatment were observed. RESULTS: The average follow-up time was 8 to 156 months. Clinical and radiological follow-up showed that the atlantoaxial joint was completely relieved, the reduction was satisfactory and the arthrodesis was stable. Nerve and vascular injuries associated with this technique were not observed. JOA score, SAC, NDI, C₁,₂ angle of the last follow-up of the children were significantly improved. Two children of ASIA grade D recovered to grade E. CONCLUSIONS Bilateral atlantoaxial lamina hook and atlantoaxial joint space screw combined with autologous iliac bone graft is simple, less bleeding, strong stability and high fusion rate. It is an ideal surgical procedure for acute type I transverse ligament injury with atlantoaxial dislocation in school-age children.
Atlanto-Axial Joint ; surgery ; Bone Screws ; Child ; Female ; Humans ; Joint Dislocations ; Ligaments ; Male ; Spinal Fusion ; Treatment Outcome

OBJECTIVETo explore the clinical effects of cervical posterior pedicle screw internal fixation and interbody fusion for the treatment of atlanto-axial vertebral instability fractures.

METHODSFrom July 2008 to July 2013, 21 patients with atlanto-axial vertebral instability fractures were treated with vertebral pedicle screw internal fixation and interbody fusion through posterior approach. There were 14 males and 7 females, aged from 20 to 55 years old with an average of 32 years. Lifted and guided the atlanto-axial vertebral pedicle screw to reduce atlanto-axial vertebral displacement.

RESULTSAll patients were followed up from 6 to 24 months with an average of 12.5 months. Wounds got healed without complication of infection. Clinical symptoms were relieved at 6 months after operation. According to ASIA score standard to assess at 6 months after operation, the items of motion, light touch and needle score had obviously improved, and respectively were 99.45 ±0.27, 111.09 ± 0.47,111.11 ± 0.58. VAS and NDI scores also had obviously improved, and respectively were 1.04 ± 0.38 and 12.56 ± 2.24. Imaging examinations showed internal fixation locations were good, without atlanto-axial joint instability.

CONCLUSIONCervical posterior pedicle screw internal fixation and interbody fusion can effectively restore the stability of atlanto-axial joint, reduce complication and obtain satisfactory effects.

Adult ; Atlanto-Axial Joint ; injuries ; surgery ; Female ; Fracture Fixation, Internal ; methods ; Humans ; Joint Instability ; physiopathology ; surgery ; Male ; Middle Aged ; Pedicle Screws ; Spinal Fractures ; physiopathology ; surgery ; Spinal Fusion ; methods ; Young Adult

The present of atlanto-axial pedicle screw fixation through posterior approach provide a new remedy for treating instability of pillow and cervical. A lot of researches have reported feasibility of atlanto-axial pedicle screw fixation, the results showed that it had advantages of easily exposure, less blood loss, shorter operative time, especially in treating as remedy fixation for atlanto-axial joint screw, atlas lateral mass screws and pedicle screw caused by injuries of tumor,inflammation and trauma. If not done properly, it can cause serious complications, such as iatrogenic fracture,injuries of vertebral artery and cervical spinal cord. Therefore,the safty and effectiveness of atlanto-axial pedicle screw fixation may be focus of research.
Atlanto-Axial Joint ; surgery ; Bone Screws ; utilization ; Cervical Atlas ; surgery ; Fracture Fixation, Internal ; instrumentation ; methods ; trends ; Humans ; Spinal Fractures ; surgery

OBJECTIVETo investigate the surgical outcome and its influencing factors in patients of congenital basilar invagination (BI) with atlanto-axial dislocation (AAD).

METHODSFrom May 2004 to August 2010, 120 patients who had BI with AAD were surgically treated with direct posterior intraoperative distraction-reduction and fixation technique, 93 patients were successfully followed up by means of questionnaire survey, telephone and clinical evaluation. Pre- and postoperative dynamic cervical X-rays, computed tomographic scans, 3-dimentional reconstruction views and magnetic resonance imaging were performed. Pre- and postoperative Japanese Orthopaedic Association (JOA) score, distance between odontoid tip and Chamberlain's line and atlantodental interval were measured to evaluate the surgical result. Statistical analysis was performed by means of paired t test and Pearson Correlation analysis.

RESULTSThere were 93 cases were followed up for 24-99 months with an average of 46.5 months. Until the final follow-up, clinical symptoms were improved in 79 patients (84.9%), and were stable in 7 patients (7.5%) and deteriorated in 4 patients (4.3%). Three patients died postoperatively (3.2%). Patients without intramedullary signal intensity change (ISIC) had better surgical outcome. Patients with compression from anterior odontoid tip and posterior bone margin of occipital foramen had the worst surgical outcome (F = 3.987, P < 0.01). Overall, good decompression and bone fusion were shown on postoperative image in 87 patients (93.5%). There were 3 deaths in this series because of basilar artery thrombosis, posterior fossa hematoma and unknown reasons each.

CONCLUSIONSThe direct posterior intraoperative distraction-reduction and fixation technique is an effective simple and safe method for the treatment of BI with AAD. Anterior compression from odontoid tip and posterior compression from bone margin of occipital foramen-atlantal posterior arch play important roles in its developing mechanism. ISIC on MRI is a predictive factor for the worse surgical outcome.

Adolescent ; Adult ; Atlanto-Axial Joint ; surgery ; Bone Screws ; Child ; Decompression, Surgical ; Female ; Follow-Up Studies ; Humans ; Joint Dislocations ; complications ; surgery ; Male ; Middle Aged ; Platybasia ; complications ; surgery ; Root Cause Analysis ; Spinal Fusion ; methods ; Young Adult

OBJECTIVESTo analyze the clinical characteristics of the atlantoaxial dislocation (AAD) in craniovertebral junction (CVJ) abnormalities and to study the setup of its surgery strategy.

METHODSFrom April 2009 to November 2011, 56 patients of AAD and CVJ abnormalities including 22 male and 34 female patients who had received surgery were analyzed. There were 2 cases of reducible AAD and 54 cases of irreducible AAD. The age of the patients ranged from 9 to 56 years (mean 34 years). Among them, 14 cases achieved reduction/partial reduction via direct posterior fixation, 41 cases had transoral anterior deconpression and occipito-cervical/C₁-C₂ fusion and 1 case had the posterior odontoidectomy and spinal fusion.

RESULTSFifty-three cases had a follow-up between 6 months and 36 months (mean 20 months) and 3 cases lost follow-up (had improvement at discharge). Seven cases had complications as follows: 1 case had irreversible spinal cord injury and muscle weakness of extremities, 2 cases had cerebrospinal leak, 2 cases had pulmonary infection, 1 case had local granuloma hyperplasia and 1 case had delayed healing of the incision. The later 6 cases all got recovery after reasonable treatments. The grades of Nurick at last follow-up were as follows: 6 cases (11.3%) improved by 3 grades, 30 cases (56.6%) improved by 2 grades, 13 cases (24.5%) improved by 1 grade, 3 cases (5.7%) without change, 1 case (1.9%) get worse.

CONCLUSIONSReducible AAD could achieve direct reduction and fixation via posterior pathways. Irreducible AAD needs individualized treatment. To choose the direct reduction and fixation or transoral odontoidectomy and posterior fixation and fusion should consider the pathogenetic condition, the image data and personal clinical experience.

Adolescent ; Adult ; Atlanto-Axial Joint ; surgery ; Child ; Decompression, Surgical ; Female ; Humans ; Joint Dislocations ; surgery ; Male ; Middle Aged ; Postoperative Complications ; epidemiology ; Spinal Fusion ; methods ; Young Adult

OBJECTIVETo explore radiographic results and clinical effects of posterior atlanto axial vertebra internal fixation in treating instability of occipitocervical.

METHODSThe clinical data of 155 patients with instability of occipitocervical treated by posterior atlanto axial vertebra internal fixation were respectively analyzed from September 2005 to January 2011. There were 68 males and 87 females, ranging in age from 6 to 75 years old with an average of 45.6 years old. Of them, 53 cases were fresh odontoid fractures(Aderson type II C), 30 cases were os odontoideum, 20 cases were old odontoid fractures, 18 cases were unstable atlas fractures, 12 cases were atlanto axial rotatory dislocation, 11 cases were atlanto axial dislocation after rheumatoid arthritis, and 11 cases were basilar invagination. Radiographic results were evaluated in terms of atlas pedicle screw fixation, bone healing and bone graft fusion. Clinical effect evaluation included relief of pain in the occipital-cervical region by VAS score and JOA score.

RESULTSTotally 300 screws were set through atlas pedicle screw fixation in 150 patients. Five patients receivde hook fixation. Postoperative CT showed ideal nailing were 275 (91.7%),acceptable nailing were 14 (4.7%) and unacceptable nailing were 11 (3.6%). All patients were followed up, and the duration ranged from 16 to 40 months with an average of 25.4 months. The fresh fractures healed and 140 cases got bone graft fusion. Preoperative VAS and JOA score were respectively improved from (7.2 +/- 1.1), (7.3 +/- 2.4) to (3.2 +/- 1.1), (13.3 +/- 2.4) at the latest follow-up.

CONCLUSIONPosterior atlanto axial vertebra internal fixation in treating instability of occipitocervical can effectively recover physiological curvature of cervical, provide mechanical stability, and obtain good clinical effect. For the young patients who require further activity, posterior fixation and non-fusion technology is a good choose, which can avoid bone graft.

Adolescent ; Adult ; Aged ; Atlanto-Axial Joint ; surgery ; Bone Screws ; Cervical Atlas ; surgery ; Child ; Female ; Fracture Fixation, Internal ; Humans ; Internal Fixators ; Joint Instability ; surgery ; Male ; Middle Aged ; Retrospective Studies ; Treatment Outcome ; Young Adult

OBJECTIVETo discuss the therapeutic effects of the atlantoaxial pedicle screw system fixation in treatment of atlantoaxial instability.

METHODSFrom June 2003 to March 2010, 32 patients with atlantoaxial instability were treated by atlantoaxial pedicle screw system fixation, included 21 males and 11 females wiht an average age of 42.5 years old ranging from 28 to 66 years. Among them, 18 cases were odontoid process fractures, 7 were congenital dissociate odontoid process, 4 were Jefferson fracture combined with odontoid fracture, 3 were rheumatic arthritis causing atlantoaxial instability. All patients suffered from the atlantoaxial subluxation and atlantoaxial instability. The JOA score ranged from 4 to 14 (means 9.1 +/- 0.3) before operation. The patients had some image examination including the X-ray of cervical vertebrae (include of dynamic position film), spiral CT 3D reconstruction and/or MRI. The position of pedicle screw system implantation,the angle of pedicle screw system implantation and screw length were measured. Operating skull traction. Operation undewent general anesthesia, implanted the pedicle screw, reduction and bone fusion under direct vision. The bone was fixated between posterior arch of atlas and lamina of axis by the lateral combination bended to posterior.

RESULTSOne hundred and twenty-eight atlantoaxial pedicle screws were implanted in 32 patients. No patient had the injure of spinal cord, nerve root and vertebral artery. All patients were followed-up from 6 to 48 months (averaged 16 months). After operation, the JOA score ranged from 11 to 17 (averaged 15.9 +/- 0.2), improvement rate was 86.1%. The fracture of odontoid process were healing completely. All fusion bone were combinated. The internal fixation wasn't loosening and breaking.

CONCLUSIONThe atlantoaxial pedicle screw system fixation was effective method to treat atlantoaxial instability. The method had many advantages, such as provide rigid and short segment fixation, safe and simple, high fusion rate. The method was worth in clinical application.

Adult ; Aged ; Atlanto-Axial Joint ; diagnostic imaging ; injuries ; surgery ; Biomechanical Phenomena ; Bone Screws ; Female ; Humans ; Joint Instability ; surgery ; Male ; Middle Aged ; Tomography, X-Ray Computed