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Clinical Neurology and Neurosurgery Sep 2023In economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet...
PURPOSE
In economically undeveloped areas, surgery for basilar invagination (BI) is still a serious economic burden for people. This study introduces a modified interfacet technique for the treatment of BI using shaped autologous occipital bone mass to reduce BI and to save economical expenditure.
METHODS
The data of 6 patients with BI who underwent modified interfacet technique using shaped autologous occipital bone mass in our hospital from April 2020 to February 2021 were retrospectively analyzed. During the operation, osteotomy at the external occipital protuberance was performed using ultrasonic osteotome, followed by interfacet release and implantation of shaped autologous occipital bone mass to complete vertical reduction. The atlantodental interval (ADI), Chamberlain's line violation (CLV), clivo-axial angle (CXA) and cervico-medullary angle (CMA) were compared before and after surgery. Additionally, we observed implant stability during the follow-up period to assess the long-term success of the modified interfacet technique.
RESULTS
The surgical procedure was successful in all six patients, with no reported incidents of vascular injury, spinal cord injury, or dural tear. Following the operation, improvements were observed in the ADI, CLV, CXA, and CMA. Throughout the follow-up period, the implants remained stable, demonstrating no complications such as bone resorption of the autologous occipital bone mass, implant fracture, or displacement.
CONCLUSION
The utilization of shaped autologous occipital bone mass in atlantoaxial interfacet bone grafting has demonstrated effectiveness and feasibility. This technique offers simplicity, ease of preparation, and cost-effectiveness, making it a viable option for treating BI.
Topics: Humans; Retrospective Studies; Joint Dislocations; Atlanto-Axial Joint; Platybasia; Occipital Bone; Spinal Fusion
PubMed: 37419081
DOI: 10.1016/j.clineuro.2023.107848 -
World Neurosurgery: X Oct 2023Chiari malformation type 1 (CM-1) is characterized by cerebellar tonsil herniation through the foramen magnum and can be associated with additional craniovertebral...
BACKGROUND
Chiari malformation type 1 (CM-1) is characterized by cerebellar tonsil herniation through the foramen magnum and can be associated with additional craniovertebral junction anomalies (CVJA). The pathophysiology and treatment for CM-1 with CVJA (CM-CVJA) is debated.
OBJECTIVE
To evaluate the trends and outcomes of surgical interventions for patients with CM-CVJA.
METHODS
A systematic review of the literature was performed to obtain articles describing surgical interventions for patients with CM-CVJA. Articles included were case series describing surgical approach; reviews were excluded. Variables evaluated included patient characteristics, approach, and postoperative outcomes.
RESULTS
The initial query yielded 403 articles. Twelve articles, published between 1998-2020, met inclusion criteria. From these included articles, 449 patients underwent surgical interventions for CM-CVJA. The most common CVJAs included basilar invagination (BI) (338, 75.3%), atlantoaxial dislocation (68, 15.1%) odontoid process retroflexion (43, 9.6%), and medullary kink (36, 8.0%). Operations described included posterior fossa decompression (PFD), transoral (TO) decompression, and posterior arthrodesis with either occipitocervical fusion (OCF) or atlantoaxial fusion. Early studies described good results using combined ventral and posterior decompression. More recent articles described positive outcomes with PFD or posterior arthrodesis in combination or alone. Treatment failure was described in patients with PFD alone that later required posterior arthrodesis. Additionally, reports of treatment success with posterior arthrodesis without PFD was seen.
CONCLUSION
Patients with CM-CVJA appear to benefit from posterior arthrodesis with or without decompressive procedures. Further definition of the pathophysiology of craniocervical anomalies is warranted to identify patient selection criteria and ideal level of fixation.
PubMed: 37456684
DOI: 10.1016/j.wnsx.2023.100221 -
Operative Neurosurgery (Hagerstown, Md.) Apr 2024Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and...
BACKGROUND AND OBJECTIVES
Patients with basilar invagination (BI) can be treated with several surgical options, ranging from simple posterior decompression to circumferential decompression and fusion. Here, we aimed at examining the indications and outcomes associated with these surgical strategies to devise a staged algorithm for managing BI.
METHODS
We conducted a retrospective cohort study in 2 neurosurgical centers and included patients with a BI, as defined by a position of the dens tip at least 5 mm above the Chamberlain line. Other craniovertebral junction anomalies, such as atlas assimilation, platybasia, and Chiari malformations, were documented. C1-C2 stability was assessed with a dynamic computed tomography scan.
RESULTS
We included 30 patients with BI with a mean follow-up of 56 months (min = 12, max = 166). Posterior decompression and fusion (n = 8) was only performed in cases of obvious atlanto-axial instability (eg, increased atlanto-dental interval or hypermobility on flexion/extension), while anterior decompression (transoral or transnasal) was reserved to patients with lower cranial nerves deficits (eg, swallowing dysfunction) and irreducible anterior compression (n = 9). Patients with posterior signs (eg, Valsalva headaches) or myelopathy but without C1-C2 instability nor anterior signs were managed with an isolated foramen magnum decompression, with or without duraplasty (n = 13). Complications were more frequent for combined procedures, including neurological deterioriation (n = 4) and tracheostomy (n = 2), but reinterventions were more likely in patients undergoing posterior decompression alone (n = 3).
CONCLUSION
Patient selection is key to determine the appropriate surgical strategy for BI: In our experience, combined approaches are only needed for patients with irreducible and symptomatic anterior compression, while fusion should be restricted to patient with obvious signs of atlanto-axial instability. Other BI patients can be managed by foramen magnum decompression alone to minimize surgical morbidity.
PubMed: 38869484
DOI: 10.1227/ons.0000000000001152 -
British Journal of Neurosurgery Dec 2023Sleep apnoea is common in patients with Basilar Invagination with Arnorld Chiari Malformation (ACM). Various studies have shown its incidence in the range of 60-70%... (Review)
Review
Sleep apnoea is common in patients with Basilar Invagination with Arnorld Chiari Malformation (ACM). Various studies have shown its incidence in the range of 60-70% among such patients. Most of the studies have shown improvement in sleep disturbances after decompressive surgeries for Chiari Malformations. There is no report of postoperative deterioration due to sleep apnoea in these patients. Authors report two cases of basilar invagination associated with ACM and Platybasia, who deteriorated probably due to worsening of pre-existing sleep disorders on 3rd and 7th postoperative days after their surgeries, despite clinico-radiological improvements during their early post-operative courses. Authors discuss literature related to sleep apnoea in basilar invagination associated with Chiari Malformations and share precautions, which are relevant and should be undertaken in such patients especially during early post-operative periods to avoid alarming complication which may occur even in experienced hands.
Topics: Humans; Platybasia; Arnold-Chiari Malformation; Sleep Apnea Syndromes; Decompression, Surgical; Sleep
PubMed: 34251945
DOI: 10.1080/02688697.2021.1947981 -
Spine Jun 2024Retrospective study.
STUDY DESIGN
Retrospective study.
OBJECTIVE
To evaluate the feasibility of C2 pedicle screw fixation with the "in-out-in" technique in patients with basilar invagination (BI).
SUMMARY OF BACKGROUND DATA
The "in-out-in" technique is a fixation technique in which the screw enters the vertebrae through the parapedicle. The technique has been used in upper cervical spine fixation. However, anatomic parameters associated with the application of this technique in patients with BI are unclear.
MATERIALS AND METHODS
We measured the C2 pedicle width (PW), the distance between the vertebral artery (VA) and the transverse foramen (VATF), the safe zone, and the limit zone. The lateral safe zone is the distance from the medial/lateral cortex of the C2 pedicle to the VA (LPVA/MPVA), and the medial safe zone is the distance from the medial/lateral cortex of the C2 pedicle to the dura (MPD/LPD). The lateral limit zone is the sum of LPVA/MPVA and VATF (LPTF/MPTF), and the medial limit zone is the distance from the medial/lateral cortex of the C2 pedicle to the spinal cord (MPSC/LPSC). PW, LPVA, MPVA, and VATF were measured on the reconstructed CT angiography. PW, MPD, LPD, MPSC, and LPSC were measured on MRI. We define a width greater than 4 mm as safe for screw. The t -test was used to compare the parameters between male and female, left and right sides in all patients, and PW in CTA and MRI data in the same patient. For intrarater reliabilities, interclass correlation coefficients were calculated.
RESULTS
A total of 154 patients (49 CTA, 143 MRI) were included. The average PW, LPVA, MPVA, LPTF, MPTF, MPD, LPD, MPSC, and LPSC were 5.30 mm, 1.28 mm, 6.60 mm, 2.45 mm, 8.94 mm, 2.09 mm, 7.07 mm, 5.51 mm, and 10.48 mm, respectively. Furthermore, in patients with PW <4 mm, 53.6% of MPVA, 86.2% of LPTF, and all limit zones were larger than 4 mm.
CONCLUSIONS
In patients with BI, there is sufficient space medially and laterally to the C2 pedicle for partial screw encroachment to achieve "in-out-in" fixation, even if the pedicle is small.
LEVEL OF EVIDENCE
Level-4.
Topics: Humans; Male; Pedicle Screws; Female; Feasibility Studies; Retrospective Studies; Adult; Middle Aged; Cervical Vertebrae; Spinal Fusion; Aged; Platybasia; Young Adult; Treatment Outcome; Vertebral Artery
PubMed: 37339267
DOI: 10.1097/BRS.0000000000004757 -
World Neurosurgery Aug 2023
Topics: Humans; Foramen Magnum; Platybasia; Arnold-Chiari Malformation
PubMed: 37550925
DOI: 10.1016/j.wneu.2023.03.124 -
World Neurosurgery Oct 2023To analyze the anatomical changes of the IV ventricle and cisterna magna in the Chiari malformation I (CMI) and basilar invagination (type B).
OBJECTIVE
To analyze the anatomical changes of the IV ventricle and cisterna magna in the Chiari malformation I (CMI) and basilar invagination (type B).
METHODS
This is a controlled study with 161 exams of magnetic resonance imaging (MRI) of adults grouped into control (n = 37), basilar invagination (BI; n = 31), Chiari malformation I (CMI; n = 37), and CMI+BI (n = 56). The MRIs were analyzed using the visualization software Osirix (Pixmeo, Bernex, Geneva, version 3.8.2). The morphometric variables were: distance from the obex to the McRae line; length of the IV ventricle floor; and the area and volume of the cisterna magna. The univariate ANOVA followed by Tukey's post-hoc test was applied to evaluate the difference between the groups. The difference between sexes was evaluated by the t test for each group.
RESULTS
Alterations in the cisterna magna and IV ventricle were more evident only in the CMI and CMI+BI groups. For both sexes, the CMI and CMI+BI groups showed: a reduction in the CSF space (P < 0.001), cisterna magna with volume reduction (P < 0.001), low position of the obex (P < 0.001), and IV ventricle more elongated (male P = 0.007 and female P < 0.001). The BI group had no significant change in the analysis by sex.
CONCLUSIONS
The CMI (isolated and associated with BI) showed a low obex position and elongation of the IV ventricle due to traction towards the spinal canal. The reduction of cisterna magna volume added to the occupation of the cerebellar tonsils can impact in the cerebrospinal fluid dynamics. The BI when isolated was not related to alterations in the parameters of cerebrospinal fluid spaces studied.
Topics: Adult; Humans; Male; Female; Cisterna Magna; Platybasia; Arnold-Chiari Malformation; Magnetic Resonance Imaging; Fourth Ventricle
PubMed: 37562686
DOI: 10.1016/j.wneu.2023.07.154 -
Orthodontics & Craniofacial Research Apr 2024Cranio-cervical anomalies are significant complications of osteogenesis imperfecta (OI), a rare bone fragility disorder that is usually caused by mutations in collagen...
INTRODUCTION
Cranio-cervical anomalies are significant complications of osteogenesis imperfecta (OI), a rare bone fragility disorder that is usually caused by mutations in collagen type I encoding genes.
OBJECTIVE
To assess cranio-cervical anomalies and associated clinical findings in patients with moderate-to-severe OI using 3D cone beam computed tomography (CBCT) scans.
METHODS
Cross-sectional analysis of CBCT scans in 52 individuals with OI (age 10-37 years; 32 females) and 40 healthy controls (age 10-32 years; 26 females). Individuals with a diagnosis of OI type III (severe, n = 11), type IV (moderate, n = 33) and non-collagen OI (n = 8) were recruited through the Brittle Bone Disorders Consortium. Controls were recruited through the orthodontic clinic of the University of Missouri-Kansas City (UMKC).
RESULTS
OI and control groups were similar in mean age (OI: 18.4 [SD: 7.2] years, controls: 18.1 [SD: 6.3] years). The cranial base angle was increased in the OI group (OI: mean 148.6° [SD: 19.3], controls: mean 130.4° [SD: 5.7], P = .001), indicating a flatter cranial base. Protrusion of the odontoid process into the foramen magnum (n = 7, 14%) and abnormally located odontoid process (n = 19, 37%) were observed in the OI group but not in controls. Low stature, expressed as height z-score (P = .01), presence of DI (P = .04) and being male (P = .04) were strong predictors of platybasia, whereas height z-score (P = .049) alone was found as positive predictor for basilar impression as per the Chamberlain measurement.
CONCLUSION
The severity of the phenotype in OI, as expressed by the height z-score, correlates with the severity of cranial base anomalies such as platybasia and basilar impression in moderate-to-severe OI. Screening for cranial base anomalies is advisable in individuals with moderate-to-severe OI, with special regards to the individuals with a shorter stature and DI.
Topics: Female; Humans; Male; Adolescent; Child; Young Adult; Adult; Osteogenesis Imperfecta; Platybasia; Cross-Sectional Studies; Genotype; Phenotype; Mutation; Collagen Type I
PubMed: 37642979
DOI: 10.1111/ocr.12707 -
Medicina (Kaunas, Lithuania) Apr 2024: To present a novel technique of treatment for a patient with basilar invagination. Basilar invagination (BI) is a congenital condition that can compress the... (Review)
Review
: To present a novel technique of treatment for a patient with basilar invagination. Basilar invagination (BI) is a congenital condition that can compress the cervicomedullary junction, leading to neurological deficits. Severe cases require surgical intervention, but there is debate over the choice of approach. The anterior approach allows direct decompression but carries high complication rates, while the posterior approach provides indirect decompression and offers good stability with fewer complications. : A 15-year-old boy with severe myelopathy presented to our hospital with neck pain, bilateral upper limb muscle weakness, and hand numbness persisting for 4 years. Additionally, he experienced increased numbness and gait disturbance three months before his visit. On examination, he exhibited hyperreflexia in both upper and lower limbs, muscle weakness in the bilateral upper limbs (MMT 4), bilateral hypoesthesia below the elbow and in both legs, mild urinary and bowel incontinence, and a spastic gait. Radiographs revealed severe basilar invagination (BI). Preoperative images showed severe BI and that the spinal cord was severely compressed with odontoid process. : The patient underwent posterior surgery with the C-arm free technique. All screws including occipital screws were inserted into the adequate position under navigation guidance. Reduction was achieved with skull rotation and distraction. A follow-up at one year showed the following results: Manual muscle testing results and sensory function tests showed almost full recovery, with bilateral arm recovery (MMT 5) and smooth walking. The cervical Japanese Orthopedic Association score of the patient improved from 9/17 to 16/17. Postoperative images showed excellent spinal cord decompression, and no major or severe complications had occurred. : Basilar invagination alongside Klippel-Feil syndrome represents a relatively uncommon condition. Utilizing a posterior approach for treating reducible BI with a C-arm-free technique proved to be a safe method in addressing severe myelopathy. This novel navigation technique yields excellent outcomes for patients with BI.
Topics: Humans; Male; Adolescent; Klippel-Feil Syndrome; Decompression, Surgical; Platybasia; Treatment Outcome; Spinal Cord Compression
PubMed: 38674263
DOI: 10.3390/medicina60040616 -
Neurosurgical Focus Mar 2024
Topics: Humans; Spinal Diseases; Joint Instability; Atlanto-Axial Joint; Decompression, Surgical; Platybasia; Joint Dislocations
PubMed: 38428006
DOI: 10.3171/2023.11.FOCUS23789