Efficacy of Posterior Cervical Decompression and Fusion for atlanto-axial instability due to a Periodontoid Pannus in Rheumatoid Arthritis A Case Report and Systematic Review of the Literature

Introduction: Patients with rheumatoid arthritis (RA) may develop a retrodental lesion known as periodontoid pannus, which can lead to cervical instability and potential neurological complications. Various techniques have been suggested for managing cervical spine instability associated with RA. However, there is scarcity of reported cases as well as of systematic reviews within the past decade. We conducted a systematic review to assess the effectiveness of posterior decompression and fusion in relieving compression caused by periodontoid pannus in individuals with RA.

Methods: A systematic review on cervical pannus caused by RA and treated by posterior cervical fusion and decompression was conducted on PubMed, Embase and Scopus for articles in English. The authors excluded literature reviews, pediatric studies, and articles where the periodontoid pannus was not caused by RA and/or the treatment was not a posterior cervical decompression and fusion.

Results: We followed the PRISMA protocol, reviewing 1,215 papers, and ultimately included 6 studies with a total of 48 patients in our analysis. The average patient age was 70 years, with 30 (63%) being females. Neck pain, myelopathy signs, and limb weakness constituted 30%, 25%, and 25% of the reported symptoms, respectively. Among the patients, 69% were classified as Ranawat IIIa, and 31% as IIIb. The average Atlanto-Dental Interval (ADI) measured 5.5 mm, and all patients exhibited atlanto-axial instability (AAI). Vertical subluxation was present in 33% of cases. Following a posterior decompression and fusion, clinical improvement was observed in 41 patients (85%), with 73% of them achieving a post-operative Ranawat score of I or II. Complete pannus resolution was reported in 67% of patients.

Conclusion : Posterior cervical decompression and fusion is effective for relieving symptoms and resolving periodontoid pannus in cases of Rheumatoid Arthritis. A current and comprehensive review on this topic confirms that second stage anterior approaches are rarely warranted.