Atlantoaxial fixation for failed foramen magnum decompression in patients with Chiari formation

Abstract

Background: Relationship of atlantoaxial instability with Chiari formation is further analyzed in the report. Objective: The outcome of 25 patients who had failed conventional treatment for Chiari formation that included foramen magnum decompression surgery and were treated by atlantoaxial fixation is analyzed. Materials and Methods: During the period January 2010 to November 2019, we treated 25 patients who had undergone conventionally described surgical procedures; all included foramen magnum decompression for Chiari formation. None of the patients had any craniovertebral junction anomaly. All patients had syringomyelia. All patients had worsened in their neurological condition following surgery either in the immediate or in the delayed postoperative phase. Atlantoaxial instability was diagnosed on the basis of facetal alignment and on the basis of direct observation of joint status by bone manipulation during surgery. The patients were treated by atlantoaxial fixation. Goel clinical grading scale and Japanese Orthopedic Association Score assessed the clinical status both before and after surgery. Results: Following surgery, all patients improved in the clinical condition. The improvement began in the immediate postoperative period and progressed. During the follow-up period that ranged from 4 to 123 months, “significant” neurological recovery and amelioration of presenting symptoms were observed. During the period of follow-up, reduction in the size of syrinx was observed in 14 out of 18 cases where postoperative magnetic resonance imaging was possible. Conclusions: Clinical results reinforce the belief that atlantoaxial instability is the nodal point of pathogenesis of Chiari formation. Atlantoaxial fixation is the treatment.

Central or axial atlantoaxial dislocation and craniovertebral junction alterations: a review of 393 patients treated over 12 years

“…Reversal of musculoskeletal abnormalities, including short neck, torticollis, and dorsal kyphoscoliosis, was observed as early as during the immediate postoperative period. [5][6][7][8][9][10][11][12][13][14][23][24][25][26][27][28][29][30] In our previous articles, we have also detailed the rate of regression of tonsils in more than 65% of cases and resolution of the syrinx in more than 85% cases when im- aging was done after 6 months of surgery. Reduction in syrinx size was observed in 100% of cases when follow-up was done 1 year after surgery.…”

“…Surgical procedures that involve decompression by bone or softtissue resection were not used in any of these cases. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][23][24][25][26][27][28][29][30][31][32][33][34][35] The articles that have been included were all published in peer-reviewed journals and are indexed in the Medline and PubMed databases. Selected editorials on the subject are also included for the sake of discussion.…”

Letter: Congress of Neurological Surgeons Systematic Review and Evidence-Based Guidelines for Patients With Chiari Malformation: Surgical Interventions

“…We, and recently others, have reported remarkable or “magical” clinical recovery from symptoms after atlantoaxial stabilization. 2-9…”

“…I believe that it was responsibility of the authors to identify from the "published literature" the altered views on pathogenesis and changing paradigm of management of Chiari malformation. [2][3][4][5][6][7] In this respect, I believe that the authors have done injustice to the readers of Neurosurgery in entirely ignoring the concept that atlantoaxial instability can be the basis of Chiari formation and atlantoaxial stabilization can be the treatment. The authors might not agree with this concept, but to put it under the carpet and selectively ignoring it, might not be in the spirit of scientific evaluation of an important clinical issue, such as Chiari malformation.…”

“…I find it difficult to understand the reasons for ignoring my "multiple" articles published in major neurosurgery journals over the past 3 decades that analyze probably the largest patient cohort on the subject of Chiari malformation. [2][3][4][5][6][7] The concept proposed in my articles is that chronic or longstanding atlantoaxial instability forms the nodal point of pathogenesis of Chiari malformation. We, and recently others, have reported remarkable or "magical" clinical recovery from symptoms after atlantoaxial stabilization.…”