Although several risk factors have been reported for cervical ossification of the longitudinal ligament (opLL), most evaluations made in the past were based on plain X-ray, not on computed tomography (ct) scan. in this study, we aimed to clarify novel risk factors for cervical opLL in asymptomatic subjects undergoing CT scan as their routine medical checkups. A total of 1789 Japanese asymptomatic subjects who underwent ct scan for the whole body as their routine medical checkups were retrospectively reviewed. the medical checkup also included laboratory examinations, bone mineral status, and ultrasound of the carotid artery. As a result, cervical OPLL was seen in 120 subjects (6.7%). As we compared the demographic and clinical data between subjects with and without opLL, opLL group showed older age, higher proportion of male sex, higher BMi, higher incidence of hypertension, higher levels of blood HbA1c and triglyceride, and higher incidence of plaques in the carotid artery. A multivariate logistic regression analysis revealed that age (Odds ratio (OR):1.03), male sex (OR: 1.91), and the presence of plaque in the carotid artery (OR: 1.71) were risk factors for OPLL. To the best of our knowledge, this is the first report to reveal an association between OPLL and arteriosclerotic lesions. Ossification of the posterior longitudinal ligament (OPLL) is a disorder characterized by progressive ectopic OPLL. Although the precise mechanisms of OPLL remain uncertain, it is considered a multifactorial disease with both environmental and genetic factors; in addition, several risk factors have been reported, including age, male sex, ethnicity, presence of diabetes mellitus, obesity, diet, sleeping time, and mechanical stimulation 1-9. Most OPLL patients are diagnosed by X-ray or computed tomography (CT) scanning when they present with radiculopathy or myelopathy. When symptoms are severe with evidence of compression to the nerve root or spinal cord, surgical intervention is often required. However, past epidemiological studies revealed that the incidence of OPLL may be higher in the general population because some patients do not present with clinical symptoms regardless of the presence of OPLL 4,10. Most epidemiological studies of OPLL have used X-rays for diagnosis; importantly, CT scans can provide more accurate diagnoses of OPLL than X-rays. There has been one study comparing the incidence of OPLL among various ethnic groups by using CT scans 11 ; however, there have been no previous reports regarding risk factors of OPLL based on diagnosis through CT scans. In this study, we aimed to investigate novel risk factors for cervical OPLL in asymptomatic subjects undergoing their routine medical checkups, which included laboratory examinations, bone mineral status evaluation, carotid artery ultrasound, and whole-body CT scans. To the best of our knowledge, this is the first study to assess the association between OPLL and arteriosclerosis.

OBJECTIVEThe incidence and risk factors for the progression of ossification of the posterior longitudinal ligament (OPLL) have been previously reported in surgically and nonsurgically treated symptomatic patients. However, the correlates of OPLL progression in asymptomatic subjects with OPLL are not well characterized. This study aimed to clarify the incidence and risk factors for OPLL progression in asymptomatic subjects based on whole-body CT.METHODSThe authors retrospectively reviewed 2585 healthy subjects who underwent whole-body CT at a single health center from September 2007 to December 2011. This study included asymptomatic subjects with OPLL who underwent CT scans twice with an interval of at least 5 years. Progression of OPLL was assessed based on initial and final CT scan. Subjects were divided into two groups: nonprogression (OPLL-NP) and progression (OPLL-P) groups. Clinical characteristics, bone mineral density status, OPLL types, and OPLL involvement of multiple vertebral levels between the two groups were compared. Risk factors for progression of OPLL were identified by logistic regression analysis after propensity score adjustment.RESULTSOf the 109 subjects with OPLL (91 men and 18 women), 20 (18.3%) exhibited OPLL progression (OPLL-P group). Subjects in the OPLL-P group were significantly younger (p = 0.031), had higher prevalence of multilevel OPLL involvement (p = 0.041) and continuous type of OPLL (p = 0.015), and had higher uric acid (UA) levels (p = 0.004) at the time of initial CT examination compared to the OPLL-NP group. Younger age (adjusted odds ratio [aOR] 0.95, 95% CI 0.90–0.99), OPLL involvement of multiple vertebral levels (aOR 2.88, 95% CI 1.06–7.83), continuous type of OPLL (aOR 4.21, 95% CI 1.35–13.10), and higher UA levels (aOR 2.09, 95% CI 1.24–3.53) were significant risk factors for OPLL progression.CONCLUSIONSYounger age, OPLL involvement of multiple vertebral levels, continuous type of OPLL, and higher UA levels are significant risk factors for OPLL progression in asymptomatic subjects.

Study Design: A retrospective observational study. Objective: To clarify the association of the paraspinal muscle area and composition with clinical features in patients with cervical ossification of the posterior longitudinal ligament (OPLL). Methods: Consecutive patients with cervical OPLL who underwent cervical magnetic resonance imaging (MRI) before surgery were reviewed. The cross-sectional area (CSA) and fatty infiltration ratio (FI%) of deep posterior cervical paraspinal muscles (multifidus [MF] and semispinalis cervicis [SCer]) were examined. We assessed the association of paraspinal muscle measurements with the clinical characteristics and clinical outcomes, such as Neck Disability Index (NDI) score. Moreover, we divided the patients into 2 groups according to the extent of the ossified lesion (segmental and localized [OPLL-SL] and continuous and mixed [OPLL-CM] groups) and compared these variables between the 2 groups. Results: 49 patients with cervical OPLL were enrolled in this study. The FI% of the paraspinal muscles was significantly associated with the number of vertebrae ( ρ = 0.283, p = 0.049) or maximum occupancy ratio of OPLL ( ρ = 0.397, p = 0.005). The comparative study results indicated that the NDI score was significantly worse (OPLL-SL, 22.9 ± 13.7 vs. OPLL-CM, 34.4 ± 13.7) and FI% of SCer higher (OPLL-SL, 9.1 ± 1.7% vs. OPLL-CM, 11.1 ± 3.7%) in the OPLL-CM group than those in the OPLL-SL group. Conclusions: Our results suggest that OPLL severity may be associated with fatty infiltration of deep posterior cervical paraspinal muscles, which could affect neck disability in patients with cervical OPLL.

Introduction: Patients with rheumatoid arthritis (RA) tend to be immunosuppressed due to RA itself and the therapeutic drugs administered. The management of surgical site infection (SSI) following upper cervical spinal instrumented fusion in RA patients is challenging; however, literature on the treatment for such conditions is scarce. We report 3 consecutive patients with RA, who developed deep SSI following upper cervical posterior fusion and were treated using antibiotic-loaded bone cement (ALBC). Patient Concerns: All 3 patients reported in the current study experienced compression myelopathy with upper cervical spinal deformity and received prednisolone and methotrexate for controlling RA preoperatively. The patient in Case 1 underwent C1–2 posterior fusion and developed deep SSI due to methicillin-sensitive Staphylococcus aureus at 3 months postoperatively; the patient in Case 2 underwent occipito-C2 posterior fusion and developed deep SSI due to methicillin-sensitive Staphylococcus aureus at 2 weeks postoperatively; and the patient in Case 3 underwent occipito-C2 posterior instrumented fusion and laminoplasty at C3–7, and developed deep SSI due to methicillin-resistant coagulase negative staphylococci at 3 weeks postoperatively. Diagnosis: All patients developed deep staphylococcal SSI in the postoperative period. Interventions: All 3 patients were treated using ALBC placed on and around the instrumentation to cover them and occupy the dead space after radical open debridement. Outcomes: The deep infection was resolved uneventfully after the single surgical intervention retaining spinal instrumentation. Good clinical outcomes of the initial surgery were maintained until the final follow-up without recurrence of SSI in all 3 cases. Conclusion: ALBC embedding spinal instrumentation procedure can be a viable treatment for curing SSI in complex cases, such as patients with RA who undergo high cervical fusion surgeries without implant removal.

Study Design: A retrospective cohort study. Objective: To investigate whether the Japanese Orthopaedic Association (JOA) score can be used for patients with degenerative cervical myelopathy as a patient-reported outcome (PRO) through the JOA written questionnaire. Methods: A total of 75 patients who underwent posterior decompression surgery for degenerative cervical myelopathy were reviewed. Patients responded to questionnaires including PRO-JOA, EuroQOL-5D, Neck Disability Index, and Short Form-12 preoperatively and at >12 months postoperatively. Spearman’s rho and Bland-Altman analyses were used to investigate the correlations. Results: Preoperative JOA and PRO-JOA scores were 10.8 and 10.6, respectively, with Spearman’s rho of 0.74. Similarly, postoperative JOA and PRO-JOA scores were 13.3 and 12.9, respectively, with Spearman’s rho of 0.68. However, the recovery rates for JOA and PRO-JOA scores were 42% and 27%, respectively, with Spearman’s rho of 0.45. Compared with other PROs, JOA and PRO-JOA scores were moderately correlated. The minimum clinically important difference was 2.5 for JOA score, 3.0 for PRO-JOA score, 42% for JOA recovery rate, and 33% for PRO-JOA recovery rate. Bland-Altman analyses revealed that limits of agreement were −4.3 to 4.7, −3.4 to 4.3, and −75% to 106% for the preoperative score, postoperative score, and recovery rate, respectively. Conclusion: PRO-JOA score can also be used as a disease-specific scoring measure instead of JOA score. However, although both measures demonstrate a similar trend as a group analysis, PRO-JOA and JOA scores should be regarded as different outcomes.