Posterior Occipitocervical Fusion Research Articles

Perioperative Cerebrovascular Accidents in Spine Surgery: A Retrospective Descriptive Study and A Systematic Review with Meta-Analysis.

Perioperative cerebrovascular accidents (CVAs) related to spine surgery, although rare, can lead to significant disabilities. More studies on spine surgeries are required to identify those at risk of perioperative CVAs. The characteristics and outcomes of patients that experienced CVAs during spine surgery were assessed through a retrospective descriptive study and meta-analysis. Patients aged ≥18 years who underwent spine surgery under general anesthesia at a hospital between April 2011 and March 2023 were examined. Of the 2,391 initially identified patients, 2,346 were included after excluding 45 who underwent debridement for surgical site infections. Subsequently, a meta-analysis including the present retrospective descriptive study was conducted. Databases such as PubMed and Google Scholar were searched for original peer-reviewed articles written in English. Of the 2,346 patients, 4 (0.17%) (three men, one woman) exhibited perioperative CVAs associated with spine surgery. The CVAs were diverse in nature: one case of cerebral hemorrhage resulting from dural injury during posterior occipitocervical fusion, two cases of cerebral infarctions after lumbar laminectomy and anterior thoracic fusion due to anticoagulant discontinuation, and one case of posterior reversible encephalopathy syndrome following microscopic lumbar discectomy due to gestational hypertension. The subsequent meta-analysis included three studies (n=186,860). It showed several risk factors for perioperative CVAs, including cervical level (pooled odds ratio [OR]=1.33), hypertension (pooled OR=2.27), atrial fibrillation (pooled OR=8.78), history of heart disease (pooled OR=2.47), and diabetes (pooled OR=2.13). It was speculated that the potential risk factors for the four perioperative CVA cases of spine surgery in this retrospective descriptive study were intraoperative dural injury, preoperative anticoagulant discontinuation, and gestational hypertension history. The meta-analysis revealed that cervical spine surgery, hypertension, atrial fibrillation, heart disease, and diabetes increased the CVA risk. This highlights the need for risk assessment, preoperative optimization, and postoperative care to reduce spine surgery-associated perioperative CVAs.

Failed reintubation during resuscitation after posterior occipito-cervical spinal fusion: A case report.

Posterior occipito-cervical spinal fusion (OCF) is a common surgical method for atlantoaxial dislocation, but postoperative airway complications may occur. Reintubation has been reported in the past, but the failure of reintubation is rare. A 54-year-old woman who underwent OCF due to rheumatoid cervical spondylosis and atlantoaxial dislocation. In the postanesthesia care unit, the patient developed upper respiratory tract obstruction after extubation. It is an upper respiratory tract obstruction due to anatomical changes because of surgery. Emergency airway management was activated, but it did not work. Emergency reintubation failed, and the patient was finally saved after tracheotomy. For patients who underwent OCF due to cervical spondylosis caused by rheumatoid arthritis, great attention should be paid to the perioperative airway management, especially during the recovery period. And more important, adequate reintubation preparatory work should be done before extubation.

Surgical Treatment of Cervical Kyphosis and Atlantoaxial Dislocation in a Child With Loeys-Dietz Syndrome: A Case Report and Literature Review.

We report the case of a 3-year-old child with Loeys-Dietz syndrome, a rare genetic connective tissue disorder. The young girl had concurrent cervical kyphosis, atlantoaxial dislocation (AAD), and spinal cord compression. Posterior occipitocervical fusion was performed. Postoperative examination and clinical manifestations confirmed that all pedicle screws were satisfactorily placed, cervical kyphosis and AAD were corrected, and spinal cord compression was relieved. At the 1-year postoperative follow-up, the patient had recovered well, indicating that our operation was successful. To the best of our knowledge, this is the first reported surgical case of cervical kyphosis and AAD caused by Loeys-Dietz syndrome.

Incidences, causes and risk factors of unplanned reoperation within 30days of craniovertebral junction surgery: a single-center experience.

To investigate the incidences, causes, and risk factors for unplanned reoperation within 30days of craniovertebral junction (CVJ) surgery. From January 2002 to December 2018, a retrospective analysis of patients who underwent CVJ surgery at our institution was conducted. The demographics, history of the disease, medical diagnosis, approach and type of operation, surgery duration, blood loss, and complications were recorded. Patients were divided into the no-reoperation group and the unplanned reoperations group. Comparison between two groups in noted parameters was analyzed to identify the prevalence and risk factors of unplanned revision and a binary logistic regression was performed to confirm the risk factors. Of 2149 patients included, 34(1.58%) required unplanned reoperation after the initial surgery. The causes for unplanned reoperation contained wound infection, neurologic deficit, improper screw placement, internal fixation loosens, dysphagia, cerebrospinal fluid leakage, and posterior fossa epidural hematomas. No statistical difference was found in demographics between two groups (P > 0.05). The incidence of reoperation of OCF was significantly higher than that of posterior C1-2 fusion (P = 0.002). In terms of diagnosis, the reoperation rate of CVJ tumor patients was significantly higher than that of malformation patients, degenerative disease patients, trauma patients, and other patients (P = 0.043). The binary logistic regression confirmed that different disease, fusion segment (posterior) and surgery time were independent risk factors. The unplanned reoperation rate of CVJ surgery was 1.58% and the major causes were implant-related failures and wound infection. Patients with posterior occipitocervical fusion or diagnosed with CVJ tumors had an increased risk of unplanned reoperation.

Surgical treatment of craniovertebral junction instability in children with Down syndrome: a systematic review.

Down syndrome (DS) affects 1 in 700 live births and approximately one-third of patients develop craniovertebral junction (CVJ) instability, diagnosed by clinical examination and radiological measures such as the atlantodens interval (ADI) and space available for the cord (SAC). Patients with symptomatic CVJ instability are at increased risk for spinal cord injury. There are no guidelines for surgical management of CVJ instability in DS, the existing literature is sparse, and there is a lack of consistent pediatric data. This systematic review aimed to synthesize practice patterns of the surgical management of CVJ stability in pediatric DS patients to facilitate future standardization of care. Peer-reviewed studies reporting surgical management of CVJ instability in pediatric DS patients were systematically reviewed. Inclusion criteria were studies reporting primary data on patients younger than 18 years with DS, who had CVJ instability evaluation and underwent surgical treatment. Bias risk was assessed. Descriptive statistics of the independent patient data were presented. Interval variables were analyzed using the Wilcoxon rank-sum test. Of 1056 records, 38 studies were included. Of the included patients, 169 (6%) underwent surgery. The surgical indication was symptomatic, radiologically confirmed CVJ instability in 81% of the patients, presenting with myelopathy (30%), weakness (25%), abnormal gait (24%), torticollis (15%), and neck pain (14%). A cutoff of ADI ≥ 4 mm or SAC ≤ 14 mm, cord compression, cord signal change, and anomalous bony anatomy were used in diagnosing CVJ instability. Surgical approaches focused on internal fixation with posterior occipitocervical or atlantoaxial instrumented fusion in 57% and 44% of patients, respectively. Autograft, wiring, and allograft constructs were used in 48%, 45%, and 9% of patients. Anterior cervical approaches were performed in 6% of patients. Preoperative and postoperative external orthoses were used in approximately 50% of patients. The surgical mortality rate was 3%, and the complication rate was 36%. Assessment of CVJ instability in DS is based on radiographic and clinical factors. Surgery is recommended if symptoms are present, and the procedure type depends on patient factors, degree of instability, anomalous bony anatomy, and reduction results to relieve cord compression. Most commonly, posterior instrumented fusion is used. However, further research is required to determine the strength of evaluation methods, create standardized guidelines for evaluation and surgical treatment, and investigate the long-term results of different surgical techniques.

Bow hunter’s syndrome: temporary obstruction of blood flow in the affected vertebral artery during posterior occipitocervical fusion. Illustrative case

Bow hunter's syndrome (BHS) is a rare condition characterized by mechanical impingement of a vertebral artery (VA) during neck rotation followed by vertebrobasilar insufficiency. Posterior fusion is a typical surgical method for BHS. The case of a 70-year-old Japanese man who presented with presyncope that occurred during right cervical rotation is reported. Given the possibility of vertebrobasilar insufficiency, digital subtraction angiography and computed tomography angiography were performed and showed a hypoplastic right VA and severe stenosis of the left VA over the occiput (O)-C2 level. The blood flow of the left VA was interrupted by right cervical rotation, with resumption of blood flow on left cervical rotation. BHS was diagnosed, and posterior fusion at the O-C2 level was performed. Immediately after implant fixation, selective arteriography confirmed disruption of blood flow in the left VA. The rods were removed immediately; resumption of blood flow was confirmed; and the rods were refixed, anatomically bent with slight left cervical rotation. Then, sustained blood flow in the left VA was confirmed. Posterior fixation for BHS can induce VA occlusion due to minor changes in cervical spine alignment. Intraoperative selective arteriography is a necessary tool to identify occlusion of the affected VA.

Traumatic posterior atlantoaxial dislocation without fracture of the odontoid process: illustrative case.

Traumatic posterior atlantoaxial dislocation without fracture of the odontoid process is extremely rare. Only 24 cases have been documented since the first patient was reported by Haralson and Boyd in 1969. Although various treatment strategies are reported, no consensus has been yielded. A 58-year-old man experienced loss of consciousness and breathing difficulties after being struck by a car from behind. An immediate computed tomography scan showed subarachnoid hemorrhage, a posterior atlantoaxial dislocation without C1-2 fracture, and a right tibiofibular fracture. After the patient's respiration and hemodynamics were stabilized, closed reduction was attempted. However, this strategy failed due to unbearable neck pain and quadriplegia, resulting in surgical intervention with transoral odontoidectomy and posterior occipitocervical fusion. The patient developed postoperative central nervous system infection. After anti-infective and drainage treatment, the infection was controlled. At 1-year follow-up, the patient did not complain of special discomfort and was generally in good condition. The authors report their experience with transoral odontoidectomy and concomitant posterior occipitocervical fusion in a case of posterior atlantoaxial dislocation without related fracture. Although these procedures are highly feasible and effective, particular attention should be paid to their complications, such as postoperative infection.

Research on effectiveness of occipito-odontoid angle in predicting dysphagia after occipitocervical fusion in patients with C 2, 3 Klippel-Feil syndrome

To introduce a new occipitocervical angle parameter, occipito-odontoid angle (O-Da), for predicting dysphagia after occipitocervical fusion (OCF) in patients with C 2, 3 Klippel-Feil syndrome (KFS) and analyze its effectiveness. A total of 119 patients met selective criteria between April 2010 and November 2019 were retrospectively included as the study subjects. There were 56 males and 63 females. The age ranged from 14 to 76 years, with a median age of 51 years. There were 44 cases of basilar invagination and 75 cases of atlantoaxial subluxation. Forty patients were combined with C 2, 3 KFS. Seven patients underwent anterior decompression combined with posterior OCF and 112 patients underwent posterior OCF. The fixed segments were O-C 2 in 36 cases, O-C 3 in 51 cases, O-C 4 in 25 cases, and O-C 5 in 7 cases. All patients were followed up 21-136 months, with a median time of 79 months. The lateral cervical X-ray films before operation and at last follow-up were used to measure the occipital to C 2 angle (O-C 2a), the occipital and external acoustic meatus to axis angle (O-EAa), the occipital protuberance to axial angle (Oc-Axa), the O-Da, and the narrowest oropharyngeal airway space (nPAS). The differences of the above parameters between the last follow-up and the preoperative values were calculated (represented as dO-C 2a, dO-EAa, dOc-Axa, dO-Da, and dnPAS). Patients were divided into two groups according to whether they suffered dysphagia after operation, and the differences in clinical data and radiographic parameters were compared between the two groups. The correlation between occipitocervical angle parameters and nPAS in 40 patients with C 2, 3 KFS was analyzed respectively. In addition, sensitivity and specificity analyses were used to assess the effectiveness of dO-Da≤-5° for the prediction of postoperative dysphagia. Thirty-one patients (26.1%) suffered dysphagia after OCF (dysphagia group), including 10 patients with C 2, 3 KFS; no dysphagia occurred in 88 patients (non-dysphagia group). There was no significant difference in age, follow-up time, fixed segment, proportion of patients with rheumatoid arthritis, proportion of patients with atlantoaxial subluxation, and proportion of patients with C 2, 3 KFS between the two groups ( P>0.05). The proportion of female patients was significantly higher in dysphagia group than in non-dysphagia group ( χ 2=7.600, P=0.006). The difference in preoperative O-C 2a between the two groups was significant ( t=2.528, P=0.014). No significant differences were observed in preoperative O-EAa, Oc-Axa, O-Da, and nPAS ( P>0.05). There was no significant difference in dO-C 2a, dO-EAa, dOc-Axa, dO-Da, and dnPAS between the two groups ( P>0.05). The dO-C 2a, dO-EAa, dOc-Axa, and dO-Da were positively correlated with dnPAS in 40 patients with C 2, 3 KFS ( r=0.604, P<0.001; r=0.649, P<0.001; r=0.615, P<0.001; r=0.672, P<0.001). Taking dO-Da≤-5° as the standard, the sensitivity and specificity of dO-Da to predict postoperative dysphagia in patients with C 2, 3 KFS were 80.0% (8/10) and 93.3% (28/30), respectively. The dO-Da is a reliable indicator for predicting dysphagia after OCF in patients with C 2, 3 KFS.

ODONTOİD FRAKTÜR YÖNETİMİ: KLİNİK DENEYİM

Amaç&#x0D; Kliniğimize başvuran odontoid kırıklı hastalara uyguladığımız&#x0D; tedavi yaklaşımlarını literatür eşliğinde sunmayı&#x0D; amaçladık.&#x0D; Gereç ve Yöntem&#x0D; Kliniğimize başvuran odontoid kırıklı 18 hasta retrospektif&#x0D; olarak değerlendirildi. Hastaların 6’sı kadın,&#x0D; 12’si erkek ve yaş ortalamaları 45,5 (16-87) idi. 7 hastada&#x0D; Tip 1, 4 hastada Tip 2, 7 hastada Tip 3 kırık tespit&#x0D; edildi. Tip 1 kırık tespit edilen hastaların %86’sı (n=6),&#x0D; tip 3 kırık tespit edilen hastaların %57’si (n=4) konservatif&#x0D; takip edilirken, tip 2 kırıkların tümüne anterior&#x0D; odontoid vidalama, tip 3 kırıklı 1 hastaya posterior&#x0D; artrodez uygulandı. Konservatif tedavi edilen hastaların&#x0D; 6’sında Halo-Vest, 3’ünde Philadelphia boyunluk,&#x0D; 2’sinde sterno-oksipito-mandibüler immobilizasyon&#x0D; (SOMİ) kullanıldı.&#x0D; Bulgular&#x0D; Konservatif takip edilen 11 hastadan 7’sinde (%64)&#x0D; füzyon izlenirken, 4’ünde (%36) füzyon gelişmemesi&#x0D; üzerine cerrahi planlandı. Hastalardan 2’si şikayetlerinin&#x0D; olmaması nedeni ile cerrahiyi kabul etmedi.&#x0D; Anterior cerrahi yapılan 1 hastada vida malpozisyonu&#x0D; görülerek posterior oksipitoservikal füzyon yapıldı.&#x0D; Sonuç&#x0D; Odontoid kırıklarında tedaviye karar verirken fraktür&#x0D; tipi ve hasta yaşı dikkate alınmalıdır. Cerrahi teknik&#x0D; belirlenirken klinik iyileşmenin yanısıra füzyon oranı&#x0D; da önemlidir. Anterior vidalama hareketin daha iyi korunabilmesi&#x0D; için genç hastalarda; mekanik yetmezlikle&#x0D; karşılaşmamak ve diğer komplikasyonları en aza&#x0D; indirebilmek amacıyla posterior füzyon ileri yaşlı hastalarda&#x0D; tercih edilmelidir. Ancak halen uygun tedavi&#x0D; stratejisi net değildir.

Digital and anatomical study of posterior atlantooccipital joint-occipital condyle-clivus screw technique

Objective: To investigate the screw placement parameters, feasibility and safety of posterior atlantooccipital joint-occipital condyle-clivus screw technique in Chinese people. Methods: Upper cervical spine CT images of 46 patients, including 24 males and 22 females, were collected with random number table from June 2019 to May 2020 in Ningbo No.6 Hospital. The patients aged 20-55 years, with a mean age of (39±9) years. Total of 92 sides of upper cervical spine models were obtained by Mimics 19.0 digital three-dimensional reconstruction, and screw placement was conducted simulately. The midpoint of transition zone between the posterior arch of atlas and the inferior articular process of lateral mass was selected as the screw entry point. The diameter and length of screws was 3.5 mm and 50 mm, respectively. Detailed morphometric measurements of the 92 atlantooccipital joint-occipital condyle-clivus screws were conducted. The distance between the screw and its surrounding important structures, screw inside and upper tilting angles, the length of screw trajectory in atlas and the length of screw trajectory on occipital side (occipital condyle-clivus) were all measured. Paired t test was performed on the parameters of left and right screw placement to confirm whether there was difference between the two sides. Results: In the 46 cases of upper cervical spine digital three-dimensional models, 92 posterior atlantooccipital joint-occipital condyle-clivus screws were implanted. All the screws were completely fixed in the clivus, without breaking through the upper sphenoid sinus, entering into the canalis spinalis and foramen magnum, and damaging the surrounding structures such as hypoglossal canal. The screw trajectory parameters between the left and right sides were slightly different, but there was no statistical differences between the two sides (P>0.05). The vertical distance between the screw entry point and the upper edge of atlas was (12.6±1.0) mm, the vertical distance between the screw entry point and the lower edge of atlas was (6.5±0.6) mm, the distance between the screw and the medial border of atlas vertebral artery foramen was (6.7±0.6) mm, the distance between the screw entry point and the medial wall of atlas was (6.6±0.7) mm, the distance between the screw outer margin and the hypoglossal canal was (5.5±0.6) mm, screw inside tilting angle was 21.2°±2.5°, screw upper tilting angle was 52.0°±3.4°, the length of screw trajectory in atlas was (12.1±0.9) mm, the length of screw trajectory on occipital side (occipital condyle-clivus) was (37.9±0.9) mm. Conclusion: The posterior atlantooccipital joint-occipital condyle-clivus screw technique can serve as a feasible and safe treatment for instability of the occipitocervical junction, which can be used as a new posterior occipitocervical fusion technique.

Odontoid Resorption After Posterior Occipitocervical Fusion in Rheumatoid Basilar Invagination

Background Context: Inflammatory arthritis of the cervical spine is common and begins early after the onset of rheumatoid arthritis. Atlantoaxial instability is the most common pattern followed by cranial settling or basilar invagination, with subaxial subluxation being least common. Vertical migration of the odontoid (basilar invagination) poses an increased risk of sudden death from compression of the brain stem. A combination of transoral decompression and posterior occipitocervical fusion has been described, although a single posterior approach stabilization may suffice and avoid the associated comorbidities with an anterior/posterior surgery in a high-risk rheumatoid patient. Purpose: To report a case of odontoid resorption and cervicomedullary angle improvement after occipitocervical fusion. Study Design: A retrospective case report. Methods: Radiographic analysis. Results: After posterior occipitocervical fusion alone for basilar invagination there was a reduction of cervicomedullary angle to 127 degrees at 3 years follow up. This was improved from an initial 115 degrees through odontoid remodeling. Conclusions: Basilar invagination treated with posterior alone occipitocervical stabilization may suffice in providing stability and long term decompression of the cervicomedullary junction through resorption and remodeling of the odontoid. This case study supports the viability of avoiding a transoral resection for an irreducible severely migrated odontoid.

Treatment strategy and curative effect analysis of os odontoideum complicated with atlantoaxial joint dislocation

To explore the treatment strategy and clinical efficacy for os odontoideum complicated with atlantoaxial dislocation. 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. 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 C2 laminar screw lost reduction after primary operation, and received anterior release again and finally occipitocervical fusion. All patients were followed up for 15 to 58 (32.0±12.2) months. VAS score was decreased from preoperative 4.2±0.9 to 1.3±0.7 at final follow up and the JOA score was improved from preoperative 11.2±1.2 to 16.9±0.8 at final follow-up. CT scan confirmed that the atlantoaxial or occipitocervical fusion wasgood, and the fusion time was 5 to 9 (6.7±0.6) months. 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.

Transoral release to realign postoperative loss of reduction following occipitocervical fixation for congenital basilar invagination.

Revision surgery in an irreducible atlantoaxial dislocation (IAAD) previously operated with a posterior approach is challenging. Multiple modalities using anterior, posterior, and dual approaches have been described. We report a so far unreported technique of revision surgery by posterior implant removal and decompression with anterior transoral release followed by posterior instrumentation. 14-year male with basilar invagination (BI) with IAAD, previously operated with posterior decompression and instrumented occipitocervical fusion presented three months later with post-traumatic recurrence of myelopathy with quadriparesis with Di Lorenzo grade 4 and loss of reduction. He was operated with a posterior implant and early fusion mass removal with extended foramen magnum decompression (FMD), followed by anterior transoral release with a satisfactory reduction on traction, and finally, a posterior revision instrumented occipitocervical fusion. At 2-year follow-up, the patient was symptom-free with Di Lorenzo grade 1 and cervicomedullary angle improvement from 97.4° to 141.2°; achieving bony fusion. Single-stage posterior-anterior transoral-posterior approach can be used to achieve satisfactory reduction for a revision BI with IAAD with prior posterior instrumentation.

A Case Report of Complete Dislocation of Atlantoaxial Joint due to a Traumatic and Pathological Axial Lesion.

Atlantoaxial dislocation usually results in sudden death. The patient had never found any axial lesion before, and the atlantoaxial joint dislocation was caused by rotation of the neck due to discomfort of the neck. The patient was given surgical treatment after the rescue of respiratory and cardiac arrest during transportation, which was extremely rare and rarely reported. A 62-year-old male patient presented with limited cervical mobility after a violent rotation of the neck due to neck discomfort. X-ray and computed tomography (CT) scan suggested atlantoaxial dislocation. Sudden respiratory and cardiac arrest during transportation was immediately followed by continuous cranial traction and successful occipital and neck fusion operation. After the successful rescue of endotracheal intubation, the patient was given continuous cranial traction. After the completion of CT scan, the patient was given occipital neck fusion, and 6 days after the surgery, the patient wore the skull-neck-thorax brace and walked freely. Continuous cranial traction and posterior occipitocervical fusion are effective methods for treating axial pathological fracture with atlantoaxial dislocation. 5.

Nasoseptal flap revision in endoscopic endonasal odontoidectomy for acute atlantoaxial osteomyelitis with atlantoaxial subluxation

Vertebral osteomyelitis compromises approximately 1%–7% of all cases of osteomyelitis, whereas the cervical region is affected in 3%–10% of all cases. Not surprisingly, osteomyelitis at the craniocervical junction is a rare occurrence that poses certain challenge to surgeons. With the advancement of antibiotics, most patients with vertebral osteomyelitis can be successfully treated by conservative treatment. However, surgical intervention is indicated in cases presented with neurological deficits, spinal deformity, or instability. We present one case of retropharyngeal abscess involving the craniocervical junction that led to irreducible atlantoaxial rotatory dislocation and significant ventral cord compression. Staged procedures with endoscopic endonasal odontoidectomy assisted by nasoseptal flap reconstruction for decompression and posterior occipitocervical fusion were arranged in sequence. Nevertheless, postoperative magnetic resonance imaging revealed incomplete decompression at C2 level of the cervical spine. Prompt revision surgery with nasoseptal flap takedown and reuse performed uneventfully. The patient recovered well and was able to ambulate 5 weeks later. This case illustrated long-term radionecrosis complicated with osteomyelitis and craniocervical instability. An aggressive surgical decompression followed by staged spinal fusion would be beneficial in such complex osteomyelitis cases.

Endoscopic Endonasal Transclival Odontoidectomy for Basilar Invagination: Operative Video and Technical Nuances.

Basilar invagination is a congenital or acquired craniovertebral junction abnormality where the tip of the odontoid process projects through the foramen magnum which can cause severe symptomatic compression of the brainstem and spinal cord. If left untreated, patients can develop progressive quadriparesis. Traditionally, basilar invagination can be treated with cervical traction and posterior stabilization. However, in irreducible cases, anterior decompression via a transoral or endonasal approach may be necessary. In this operative video, we demonstrate an endoscopic endonasal transclival approach for odontoidectomy to successfully treat a 37-year-old female with severe basilar invagination causing symptomatic compression on the cervicomedullary junction resulting in unsteady gait and motor weakness. The patient had Klippel–Feil syndrome where the C1 arch was assimilated to the foramen magnum and transclival drilling was needed to adequately access the odontoid process for removal. A second-stage posterior occipitocervical stabilization and fusion was performed the following day. Immediate postoperative imaging showed excellent decompression of the cervicomedullary junction. Postoperatively, the patient had significant improvement in gait and motor strength in all extremities, and was ambulating independently without assistance at 1 year after surgery. The endoscopic endonasal transclival odontoidectomy is a useful strategy to treat severe irreducible basilar invagination causing symptomatic neural compression. The surgical technique and nuances are described in a step-by-step fashion in this illustrative operative video.The link to the video can be found at: https://youtu.be/HL4K7KqJEJM.

Surgical outcomes of posterior occipito-cervical decompression and fusion for basilar invagination: A prospective study

Study designA Prospective Study. ObjectiveTo assess results of posterior occipito-cervical decompression and fusion operated with intra-operative traction/manipulation and instrumented reduction in cases of Basilar Invagination(BI). MethodsTotal 22 patients of 8–65 years with diagnosed BI were operated for posterior occipito-cervical fusion by intra-operative traction/manipulation and instrumented reduction. Fusion was done using autologous bone graft taken from iliac crest. Immediate post-operative, first month and then every 3 months’ follow-up examination were done for minimum period of 2 years. Results22 patients (10 males,12 females) with mean age of 23.9 years having BI were included. 11 patients had C1 occipitalization, 4 had platybasia and 9 had atlanto-axial dislocation (AAD). 1 patient with os odontoideum with kyphotic deformity expired on 4th postoperative day due to respiratory insufficiency (mortality rate 4.54%). Neurological improvement by at least by one grade according to RANAWAT’s and/or NURICK’S scale was observed in 17/21 patients (80.95%). 3 patients remained static and 1 had neuro-worsening. Mean mJOA score of 13.14 improved to 16.24. All had reduction of dens below foramen magnum according to McRae, chamberlain line and Ranawat index. Bone graft fused in all patients as confirmed with CT scan and dynamic X-rays. 1 wound dehiscence and 1 asymptomatic implant loosening were seen on follow-up. ConclusionSurgical treatment of BI with intra-operative traction/manipulation, instrumented reduction and posterior occipito-cervical fusion can achieve good correction of radiology, functional performance and clinical neurology as well as excellent fusion rates without adverse effects of trans-oral surgery.

Transoral intraarticular cage distraction and C-JAWS fixation for revision of basilar invagination with irreducible atlantoaxial dislocation

BackgroundThe revision surgery of basilar invagination (BI) with irreducible atlantoaxial dislocation (IAAD) after a previous occipitocervical fusion (OCF) is challenging. Transoral revision surgery has more advantages than a combined anterior and posterior approach in addressing this pathology. The C-JAWS is a cervical compressive staple that has been used in the lower cervical spine with many advantages. Up to now, there is no report on the application of C-JAWS in the atlantoaxial joint. We therefore present this report to investigate the clinical outcomes of transoral intraarticular cage distraction and C-JAWS fixation for revision of BI with IAAD.MethodsFrom June 2011 to June 2015, 9 patients with BI and IAAD were revised by this technique after previous posterior OCF in our department. Plain cervical radiographs, computed tomographic scans and magnetic resonance imaging were obtained pre- and postoperatively to assess the degree of atlantoaxial dislocation and compression of the cervical cord. The Japanese Orthopedic Association (JOA) score was used to evaluate the neurological function.ResultsThe revision surgeries were successfully performed in all patients. The average follow-up duration was 18.9 ± 7.3 months (range 9–30 months). The postoperative atlas-dens interval (ADI), cervicomedullary angle (CMA), distance between the top of the odontoid process and the Chamberlain line (CL) and JOA score were significantly improved in all patients (P < 0.05). Bony fusion was achieved after 3–9 months in all cases. No patients developed recurrent atlantoaxial instability.ConclusionsTransoral revision surgery by intraarticular cage distraction and C-JAWS fixation could provide a satisfactory outcome for BI with IAAD after a previous unsuccessful posterior operation.

Vascularized Rib Grafts to Augment Spinal Fusion: A Novel Approach

BACKGROUND: Pseudoarthrosis is a well-known complication following spinal fusion. Rates range from 5% to 40% and are influenced by both patient factors and technical factors. Patients with pseudoarthrosis may experience a return or worsening of their preoperative pain, which can significantly decrease quality of life. For patients with complex posterior column defects with either anterior or posterior columnar insufficiency, especially those receiving chemotherapy, radiation, predisposed to recurrent pseudarthrosis or infection, vascularized bone grafts (VBGs) have been shown to provide better outcomes than nonvascularized bone grafts (N-VBGs).1–5 The purpose of this study is to present an innovative pedicled rib VBG (R-VBG) that can be utilized to augment instrumented spinal fusion. METHODS: Following hardware placement for spinal fusion, an incision is made over the target rib. The intercostal muscle attachments to the superior border of the R-VBG are released, and the rib with its blood supply intact is bluntly dissected from the underlying pleura and inferior intercostal muscle attachments, protecting the subcostal vessels. Particular care is taken when separating the intercostal nerve from the subcostal vessels to prevent postoperative numbness and radicular pain. At the lateral limit of the dissection, the subcostal vessels were controlled, and the rib is cut distally and proximally. The R-VBG is then tunneled under the paraspinous muscles and placed along the posterolateral gutters of the spinal levels being augmented. The natural curvature of the rib is used to match the patients kyphosis/lordosis. The rib is cut down to size and fixated. RESULTS: To date, 7 R-VBGs have attempted. Of these 6 (86%) have been successfully harvested, all of which (100%) went on to achieve at least probable radiologic evidence of graft site fusion. CONCLUSION: The technique described for rotating a vascularized rib bone graft into the posterolateral space for spinal fusion as far as the L4/L5 joint space is an effective method for augmentation of spinal fusion in patients with complex spinal pathologies. Although additional data needs to be collected before true indications can be elucidated for this procedure, our preliminary prospective results suggest that this approach is relatively low risk, especially compared to free tissue transfer, and it has the benefit of providing well-vascularized, healthy bone to augment the fusion bed. REFERENCES: 1. Eastlack R, Dekutoski M, Bishop A, et al. Vascularized pedicled rib graft: a technique for posterior placement in spinal reconstruction. Spinal Disord Tech. 2007;20:610–615. 2. Bohl M, Mooney M, Catapano J, et al. Pedicled vascularized bone grafts for posterior occipitocervical and cervicothoracic fusion: a cadaveric feasibility study. Oper Neurosurg. 2018;15:318–324. 3. Bradford DS. Anterior vascular pedicle bone grafting for the treatment of kyphosis. Spine. 1980;5:318–323. 4. Bradford DS, Daher YH. Vascularised rib grafts for stabilisation of kyphosis. J Bone Joint Surg. 1986;68B:357–361. 5. Wilden JA, Moran SL, Dekutoski MB, et al. Results of vascularized rib grafts in complex spinal reconstruction. J Bone Joint Surg. 2006;88A:832–839.

Posterior Occipitocervical Fusion for Unstable Upper Cervical Trauma in Old and Elderly Population, Although Decreases Upper Cervical Rotation, Does Not Significantly Increase Neck Disability Index.

Background Despite the research progress in the thoraco-lumbo-pelvic balance, cervical spine balance has only recently gained increasing interest. To our knowledge, there is a lack of research regarding sagittal occipitocervical spine balance restoration following posterior occipitocervical fusion (POCF). Purpose The primary outcome measure is the evaluation of sagittal cervical alignment roentgenographic parameters and the secondary is the functional outcome (NDI), following POCF for upper (C1 & C2) cervical trauma (UCT) in coexistence with upper cervical spine degeneration. Patients and Methods. Twenty old and elderly patients aged 62 ± 12 years with evident upper cervical degeneration, who received POCF for upper C1 & C2 unstable cervical spine injuries, were included. C2-C7 lordosis, C2-C7 SVA, spinocranial angle (SCA), T1-slope, neck tilt (NT), thorax inlet angle (TIA), cervical tilt (CT), cranial tilt (CrT), and C0-C1 angle were measured. The subfusion angle was used to study the behavior of the unfused cervical segments below fusion. The Neck Disability Index (NDI) was used for the functional outcome evaluation. 29 age-matched individuals were used as controls for radiographic analysis and self-reported functional status comparison. Results The roentgenographic data were measured 3 and 39 ± 12 months postoperatively. Twelve patients showed no disability, and eight showed mild disability. Postoperatively, the patients stood with less C2-C7 lordosis, SCA, and CT (P < 0.02) but with higher NT (P < 0.02) in comparison to the controls. The patient's neck disability (NDI) was increasing as TIA increases (P=0.023). Subfusion angle seems to adapt to C2-C7 lordosis (P < 0.0033) and C0-C2 angle (P < 0.003) without any changes till the last evaluation. Conclusions POCF sufficiently restored occipitocervical sagittal balance along with functional outcome similar to controls in adult and elderly individuals with evident upper cervical degeneration. We do not recommend POCF for young active individuals without occipitocervical pathology, but in contrary, we recommend the removal of the spinocranial connection hardware after cervical fusion is completed.