Accelerated development of cervical spine instabilities in rheumatoid arthritis: a prospective minimum 5-year cohort study.

OBJECTIVE: To clarify the incidence and predictive risk factors of cervical spine instabilities which may induce compression myelopathy in patients with rheumatoid arthritis (RA). METHODS: Three types of cervical spine instability were radiographically categorized into "moderate" and "severe" based on atlantoaxial subluxation (AAS: atlantodental interval >3 mm versus ≥10 mm), vertical subluxation (VS: Ranawat value <13 mm versus ≤10 mm), and subaxial subluxation (SAS: irreducible translation ≥2 mm versus ≥4 mm or at multiple). 228 "definite" or "classical" RA patients (140 without instability and 88 with "moderate" instability) were prospectively followed for >5 years. The endpoint incidence of "severe" instabilities and predictors for "severe" instability were determined. RESULTS: Patients with baseline "moderate" instability, including all sub-groups (AAS(+) [VS(-) SAS(-)], VS(+) [SAS(-) AAS(±)], and SAS(+) [AAS(±) VS(±)]), developed "severe" instabilities more frequently (33.3% with AAS(+), 75.0% with VS(+), and 42.9% with SAS(+)) than those initially without instability (12.9%; p<0.003, p<0.003, and p = 0.061, respectively). The incidence of cervical canal stenosis and/or basilar invagination was also higher in patients with initial instability (17.5% with AAS(+), 37.5% with VS(+), and 14.3% with SAS(+)) than in those without instability (7.1%; p = 0.028, p<0.003, and p = 0.427, respectively). Multivariable logistic regression analysis identified corticosteroid administration, Steinbrocker stage III or IV at baseline, mutilating changes at baseline, and the development of mutilans during the follow-up period correlated with the progression to "severe" instability (p<0.05). CONCLUSIONS: This prospective cohort study demonstrates accelerated development of cervical spine involvement in RA patients with pre-existing instability--especially VS. Advanced peripheral erosiveness and concomitant corticosteroid treatment are indicators for poor prognosis of the cervical spine in RA.

Incidence and aggravation of cervical spine instabilities in rheumatoid arthritis: a prospective minimum 5-year follow-up study of patients initially without cervical involvement.

STUDY DESIGN: A prospective minimum 5-year follow-up study of the cervical spine in patients with rheumatoid arthritis (RA) initially without cervical involvement. OBJECTIVE: To clarify the incidence and aggravation of cervical spine instabilities and their predictive risk factors in patients with RA. SUMMARY OF BACKGROUND DATA: Many reports have shown the progression of cervical spine involvement in RA. However, few articles have described comprehensive evaluation of its prognostic factors. METHODS: A total of 140 patients with "definite" or "classical" RA initially without cervical involvement were prospectively followed for more than 5 years. Radiographical cervical findings were classified into 3 instabilities: atlantoaxial subluxation (AAS: atlantodental interval >3 mm), vertical subluxation (VS: Ranawat value <13 mm), and subaxial subluxation (SAS: irreducible translation ≥ 2 mm). "Severe" extents were defined as AAS with atlantodental interval 10 mm or more, VS with Ranawat value 10 mm or less, and SAS with translation 4 mm or more or at multiple levels. Incidence of these developments and predictors for "severe" instabilities were investigated. RESULTS: During 6.0 ± 0.5 years, 43.6% of 140 patients developed cervical instabilities: AAS in 32.1%, VS in 11.4%, and SAS in 16.4% with some combinations. "Severe" instabilities were exhibited in 12.9% of patients: AAS in 3.6%, VS in 6.4%, and SAS in 5.0%. Furthermore, 4.3% presented canal stenosis, with 13 mm or less space available for the spinal cord (SAC) due to "severe" AAS or "severe" VS in 2.9% and 12 mm or less SAC due to "severe" SAS in 2.1%. Multivariable logistic regression analysis identified corticosteroid administration, mutilating changes at baseline, and the development of nonmutilating into mutilating changes during the follow-up period correlated with "severe" instabilities (P < 0.05). CONCLUSION: A minimum 5-year follow-up reveals the occurrence of cervical instabilities in 43.6%, "severe" aggravation in 12.9%, and decreased SAC in 4.3% of patients with RA. Characteristics of severe disease activity-established mutilating changes, progressive development into mutilating changes, and potentially concomitant corticosteroid treatment-are indicators for poor prognosis of the cervical spine in RA.

Short-term outcome of finger joint synovectomy in rheumatoid arthritis.

Rheumatoid arthritis (RA) frequently affects finger joints, and persistent synovitis is believed to cause not only bone destruction but also various deformities of the fingers in the long run. Synovectomy of the finger joints is carried out when chronic swelling of the synovium does not respond to any conservative treatment with medication and rehabilitation. In the present study the short-term results of finger joint synovectomy in RA were reviewed in 49 finger joints. The subjects were evaluated at two time points, with average follow-up periods of 14 and 62 months, and the results were compared between the two follow-up time points. In regard to results, pain relief, swelling abatement, and only a little loss of motion were observed in most fingers. Moreover, only a few patients demonstrated progression of bone destruction, suggesting that synovectomy has a retarding effect and tends to be effective especially in the early stages of the disease. In conclusion, we recommend synovectomy for finger joints in RA patients before bone changes occur, and when chronic synovitis of the finger joints does not respond to any other conservative treatment.

Progression of cervical spine instabilities in rheumatoid arthritis: a prospective cohort study of outpatients over 5 years.

STUDY DESIGN: A 5-year prospective cohort study of cervical spine instabilities in rheumatoid arthritis (RA). OBJECTIVE.: To clarify the natural course of cervical instabilities in RA patients and to determine predictors for the prognosis of RA cervical spine. SUMMARY OF BACKGROUND DATA: Although several previous studies investigating the natural history of RA cervical spine have been reported, few of them have described radiological predictive factors for the aggravation of these instabilities. METHODS: Two hundred sixty-seven outpatients with "definite" or "classical" RA initially assigned were prospectively followed for over 5 years. Radiographic cervical findings were classified into three representative instabilities: atlantoaxial subluxation (AAS), vertical subluxation (VS), and subaxial subluxation (SAS). The aggravations of these instabilities were identified in the cases with a decrease of at least 2 mm in the Ranawat value of VS, an increase of at least 1 mm in translation of SAS, or a new development of respective instabilities. RA stages and mutilating changes were assessed in the hand radiograms. RESULTS: Fifty-two point four percent of 267 patients, without any cervical instability at the beginning of follow-up, decreased to 29.6% at the end (P < 0.01), whereas VS and SAS increased significantly (P < 0.01). The aggravation of VS was observed at statistically higher rates in patients with pre-existing instabilities as follows; 25.7% of AAS (P = 0.01), 49.1% of VS (P < 0.01), and 41.2% of SAS (P = 0.06). The aggravation of SAS was also detected in 47.2% of VS and 64.7% of SAS (P < 0.01). Patients with pre-existing mutilating changes exhibited the aggravations of VS and SAS in significantly higher incidences (P < 0.01). Furthermore, the cases with development into mutilating changes during the follow-up showed significantly higher tendencies for the aggravations of these instabilities (P < 0.01). CONCLUSION: The incidences of VS and SAS significantly increased during the minimum 5-year follow-up. Prognostic factors of these instabilities were revealed to be the initial radiological findings of VS, SAS, and mutilating changes.

Total knee arthroplasty for rheumatoid knee with bilateral, severe flexion contracture: report of three cases.

The treatment of patients with severe flexion contracture of the rheumatoid knee, deprived of ambulation for long periods of time, is challenging. Based on three cases, we indicate the potential risks of posterior dislocation of the knee after total knee arthroplasty. In this pathological condition, surgeons must carefully select the type of implant in order to avoid this serious complication. We also emphasize the importance of working on disuse muscle atrophy of trunk (back, abdominal) and lower limbs, both of which play an integral role in ambulation. The personality of each rheumatoid patient should be carefully considered when considering surgical and rehabilitation options.