Sung-Woo Roh

The Time Course of Range of Motion Loss After Cervical Laminoplasty: A Prospective Study With Minimum Two-Year Follow-up

Study Design. A prospective study. Objective. To identify the time-dependent change in range of motion (ROM) after cervical laminoplasty. Summary of Background Data. Although numerous studies have reported on the loss of flexion/extension ROM associated with laminoplasty, few have reported on the time course of this loss of motion. Methods. Twenty-three patients who received unilateral open-door laminoplasties, including miniplate fixation over 2 levels, were serially evaluated at regular set intervals after surgery. The mean follow-up period was 26.78 months (range: 24–41 months). Twelve patients had OPLL and 11 patients had cervical spondylotic myelopathy. Enrolled patients were divided into 2 groups (ossification of posterior longitudinal ligament [OPLL] and cervical spondylotic myelopathy) to compare the ROM between the OPLL and the spondylosis patients. We evaluated the time-dependent neck ROM changes by taking neutral, flexion, and extension radiographs before surgery and at 1, 3, 6, 9, 12, 18, and 24 months after surgery. Postoperative neck and arm pain was evaluated using a numerical rating scale. Results. The preoperative, and 1-, 3-, 6-, 9-, 12-, 18-, and 24-month postoperative ROM figures were 37.8° ± 14.6°, 34.1° ± 12.9°, 35.0° ± 12.3°, 30.3° ± 13.0°, 28.6° ± 15.1°, 27.3° ± 12.4°, 26.1° ± 14.8°, and 25.9° ± 13.2°, respectively, and at the most recent follow-up, ROM was 25.8 ± 15.2°. Thus, the mean ROM decreased by 10.1° ± 9.5° (31.66%) after surgery (P = 0.002). In OPLL group, we observed a more limited cervical ROM than in cervical spondylotic myelopathy group (35.3% vs. 29.2%). However, the rate of ROM reduction slowed with time in both groups (P = 0.000). Postoperative axial pain did not correlate with the degree of serial cervical ROM. Conclusion. The results suggest that the loss of cervical ROM is time-dependent and plateaus by18 months after surgery, with no further decreases thereafter.

A haplotype at the COL9A2 gene locus contributes to the genetic risk for lumbar spinal stenosis in the Korean population.

Study Design. We conducted a cross-sectional, genotyping study in patients with lumbar spinal stenosis (LSS) and controls. Objective. To determine the contribution of COL9A2 polymorphisms to LSS development in the Korean population. Summary of Background Data. Because congenital spinal stenosis is typically associated with chondrodysplasias, which are genetic disorders, genetic factors may also play a role in degenerative LSS. A recent Finnish study reported a splice site mutation in COL9A2, leading to premature translation termination. However, a few studies on the genetic association of single nucleotide polymorphisms (SNPs) or haplotypes with LSS have appeared. Methods. We studied 205 symptomatic patients with radiographically proven LSS and 101 volunteers with no history of back problems from our institution. Magnetic resonance images were obtained for all the patients and controls. Quantitative image evaluation for LSS was performed to evaluate the severity of LSS. All patients and controls were genotyped for COL9A2 allele variations, using a polymerase chain reaction–based technique. Results. We found no causal SNPs in COL9A2 that were significantly associated with LSS, even after phenotypic subgrouping. Haplotype analysis showed that the “GCAGCG” haplotype (HAP2) was overrepresented in LSS patients (P = 0.023, odds ratio [OR] = 1.86), especially in those with severe stenosis (P = 0.018, OR = 1.98). In addition, the “TCAGCG” haplotype (HAP4) was overrepresented in controls (P = 0.042, OR = 0.52). Conclusion. Although no SNPs in COL9A2 were associated with LSS, a COL9A2 haplotype (HAP2) was significantly associated with LSS in the Korean population, whereas another haplotype (HAP4) may play a protective role against LSS development. However, the genetic functions of COL9A2 haplotypes in LSS remain to be determined.

Prognostic factor analysis after surgical decompression and stabilization for cervical spinal-cord injury

Abstract Introduction: Several studies have demonstrated the role of decompression surgery in preventing secondary injury and improving the neurological outcome after spinal cord injury (SCI). We retrospectively analyzed the prognostic factors affecting the outcomes of decompression surgery in patients with SCI. Methods: We performed one-level decompression and fusion surgery on 73 patients with cervical SCI. We classified all patients based on their interval to decompression, sex, age, surgical level, presence of high signal intensity, American Spinal Injury Association Impairment scale (AIS) before surgery, blood pressure at admission, the amount of cord compression, surgical time, estimated blood loss during surgery, and steroid use. We considered an improvement to have occurred if the patient showed an AIS improvement of ≥1 grade. Results: Among the 73 patients with SCI we analyzed, 27 and 35 showed ≥1 grade of AIS improvement immediately and 3 months after surgery, respectively. Using multivariate analysis, the mean arterial blood pressure (MAP) was a significant prognostic factor affecting recovery in the SCI patients during the immediate post-operative period. In the late recovery period at 3 months after surgery, the AIS before surgery and the MAP were significant prognostic factors affecting recovery. Conclusions: Prognostic factors for AIS improvement include the initial neurological status before surgery and hemodynamic MAP at admission. The interval between decompression surgery and trauma does not affect the neurological outcome.