Clin Orthop Surg.  2010 Jun;2(2):98-104. 10.4055/cios.2010.2.2.98.

Prognostic Factors That Affect the Surgical Outcome of the Laminoplasty in Cervical Spondylotic Myelopathy

• Ahn JS
• Lee JK
• Kim BK

• KMID: 1719336
• DOI: http://doi.org/10.4055/cios.2010.2.2.98

Abstract

BACKGROUND
This study examined the prognostic factors that affect the surgical outcome of laminoplasty in cervical spondylotic myelopathy patients by comparative analysis.
METHODS
Thirty nine patients, 26 males and 13 females, who were treated with laminoplasty for cervical myelopathy from September 2004 to March 2008 and followed up for 12 months or longer, were enrolled in this study. The mean age of the subjects was 62.4 years (range, 37 to 77 years). The patients' age, number of surgical segments, spinal cord compression ratio, segment number, level, localized marginal pattern of high signal intensity within the spinal cord in the T2 image, preoperative Japanese Orthopaedic Association Scoring System (JOA) score with the recovery ratio were compared respectively. The JOA score was used for an objective assessment of the patients' preoperative and postoperative clinical status. The recovery ratios of surgery were graded using the Hirabayashi equation. Statistical analysis was carried out using Pearson correlation analysis.
RESULTS
The patients' JOA score increased from a preoperative score of 11.1 (range, 5 to 16) to a postoperative score of 14.9 (range, 7 to 17). The average recovery ratio was 65.8% (range, 0 to 100%). The number of segments with high signal changes in the T2 image, a localized marginal pattern with high signal change, signal intensity changes in the upper cervical spinal cord were inversely associated with the recovery ratio, whereas the spinal cord compression ratio showed a significant positive correlation. However, the currently known prognostic factors, such as number of surgical segment, age, and preoperative JOA score, showed no statistically significant correlation.
CONCLUSIONS
The number of segments, localized marginal pattern, rostral location of signal intensity c hanges with a high signal change in the T2 image and a low spinal cord compression ratio in cervical spondylotic myelopathy patients treated by laminoplasty can indicate a poor prognosis.

Keyword

Cervical spondylosis; Myelopathy; Laminoplasty; Prognostic factor

MeSH Terms

Adult
Aged
*Cervical Vertebrae/pathology
Female
Humans
*Laminectomy
Magnetic Resonance Imaging
Male
Middle Aged
Prognosis
Spinal Cord Compression/diagnosis/etiology/*surgery
Spondylosis/*complications

Figure

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  Fig. 1 (A) Compression ratio of the spinal cord = anteroposterior diameter/transverse diameter × 100. (B) Method for drawing "A" (anteroposterior diameter) and "B" (transverse diameter) in the compression ratio of this patient. "A" and "B" are the widest anteroposterior and transverse diameter of the spinal cord, respectively.

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