ABSTRACT: A prospective comparative study about the incidence of postoperative C5 palsy and multivariate analysis of the risk factors of C5 palsy.
To clarify the risk factors of occurrence of C5 palsy after laminoplasty (LP) by comparing the 2 surgical procedures of open-door and double-door LP prospectively.
The incidence of C5 palsy has been reported to average 4.6%, and there has been no difference of the incidence among surgical procedures. However, there were only indirect retrospective studies.
A total of 146 patients who underwent the LP procedure between 2006 and 2007 were studied prospectively. In 2006, the patients were assigned to undergo the open-door LP, and in 2007, they were assigned to undergo the double-door LP. The incidence of postoperative C5 palsy was compared prospectively between these 2 LP procedures, and the risk factors of C5 palsy were detected with multivariate logistic regression analysis.
Postoperative C5 palsy occurred in 7 of 73 cases after open-door LP (9.6%) and in 1 of 73 cases after double-door LP (1.4%). The incidence of C5 palsy after open-door LP was statistically higher than the one after double-door LP (P = 0.029), and open-door LP was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 69.6, P = 0.043). In addition, ossification of posterior longitudinal ligament (OPLL) was recognized as a significant risk factor for postoperative C5 paralysis (odds ratio: 43.8, P = 0.048).
This study showed significant evidence indicating the higher risk of postoperative C5 palsy in open-door LP than double-door LP. Because OPLL as well as open-door LP were recognized as the risk factors of C5 palsy, asymmetric decompression by open-door LP might introduce imbalanced rotational movement of spinal cord and result in C5 palsy. We recommend double-door LP to minimize the postoperative C5 palsy, in particularly, if the patient has OPLL.
Spine 12/2010; 35(26):E1553-8. · 2.08 Impact Factor
ABSTRACT: 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.
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.
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.
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).
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.
Spine 12/2010; 36(8):647-53. · 2.08 Impact Factor
ABSTRACT: Case report.
Cervical myelopathy caused by osteophyte formation appearing at the pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis is extremely rare. To our knowledge, only 2 cases in non-Klippel-Feil syndrome have been reported so far.
A 61-year-old man, who was diagnosed as Klippel-Feil syndrome with assimilation between C2 and C3 vertebrae, which were fused in hyperlordosis, suffered cervical myelopathy. Complete bipartition of the atlas was also demonstrated. Massive osteophytes, which severely compressed the spinal cord at the pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis, were seen. Surgical resection of the osteophytes was performed.
The patient had significant clinical improvement after posterior resection of the osteophytes.
Coincidence of several bony anomalies such as assimilation of C2 and C3, which were fused in hyperlordosis, and the bipartition of the atlas may biomechanically influence the formation of pseudoarthrosis between the posterior arch of the atlas and the lamina of the axis. Because symptoms appeared in the patient's 60s despite congenital bony anomaly, degeneration might contribute to the formation of massive osteophytes. Posterior decompression was effective in this case.
Journal of Spinal Disorders & Techniques 06/2008; 21(3):225-8. · 1.50 Impact Factor
American Journal of Roentgenology 10/2002; 179(3):667-9. · 2.78 Impact Factor