Clinical Outcomes of Atlantoaxial Dislocation Combined with Osteoporosis Using Posterior Atlantoaxial Rod, Screw Fixation, and Posterior Interfacet Fusion: A Retrospective Study of 21 Cases

Abstract

Background Surgical procedures on atlantoaxial dislocation combined with osteoporosis remain controversial. This study was established to assess the mid-term clinical outcomes of atlantoaxial dislocation combined with osteoporosis using posterior atlantoaxial rod, screw fixation and posterior interfacet fusion. Material/Methods From January 2017 to January 2020, 21 patients (4 males and 17 females) with coexisting atlantoaxial dislocation and osteoporosis who underwent posterior atlantoaxial rod and screw fixation were included in our study with an average age of 64±8.1 years (range, 57–74 years). The subjective and objective symptoms, together with the neurological function of the patients were measured. Radiography and magnetic resonance imaging (MRI) were performed, Japanese Orthopaedic Association (JOA) score for spinal cord function and VAS score for pain recovery was assessed. Results JOA and visual analog scale (VAS) score were significantly improved at 14±5.9 month follow-up compared with pretreatment values. Complete or almost complete anatomical reduction was observed in all 21 patients. All patients had good bony fusion at the final follow-up. No screw-loosening or atlantoaxial redislocation occurred in 21 cases. The only complication was mild numbness in the C2 innervation area of the posterior occipital region in 6 cases, which had no effect on life. Conclusions The results suggested that posterior atlantoaxial rod, screw fixation system, and posterior interfacet fusion could achieve satisfactory initial results for the treatment of atlantoaxial dislocation combined with osteoporosis.

Early Outcomes of Bone Autografting in the Bilateral Atlantoaxial Joints Applied in Posterior Fusion Surgery

“…The removal of cartilage and roughing up of the atlantoaxial joints bilaterally provide an ideal environment for postoperative fusion. Besides, the contact area of the bone‐graft bed in the atlantoaxial joints is large enough for the placement of bone autograft, which make it more conducive to the fusion of the autograft 5,29,30 . Additionally, the bone autograft acts as a stimulus for living bone growth and maintains structural strength immediately.…”

“…However, bone graft fusion is key to achieving long‐term maintenance of stability. 1 , 2 Regarding fusion, although several studies have shown that the rate of bone graft fusion with internal fixation was higher, 1 , 2 , 5 some patients still experience unsatisfactory bone graft healing and postoperative complications resulting from postoperative nonunion of bone grafts. 19 It has been reported that the rates of instrumentation failure after nonunion were about 6.7% during atlantoaxial fusion.…”

“…Therefore, decompressing the neurological structures, realignment of the cervical spine, and stabilizing the unstable atlantoaxial complex are necessary for patients suffering from atlantoaxial dislocation or instability. [4][5][6] Posterior surgical procedures have been considered effective treatment strategies for atlantoaxial dislocation or instability, and the fusion rates ranged from 89%-100%. [7][8][9] The bone graft is usually placed across C1-C2 for fusion in these procedures.…”

“…Given the particular anatomical location, such dysfunction could threaten the brain stem and upper spinal cord. Therefore, decompressing the neurological structures, realignment of the cervical spine, and stabilizing the unstable atlantoaxial complex are necessary for patients suffering from atlantoaxial dislocation or instability 4–6 …”

“…Therefore, decompressing the neurological structures, realignment of the cervical spine, and stabilizing the unstable atlantoaxial complex are necessary for patients suffering from atlantoaxial dislocation or instability. 4 , 5 , 6 …”