Retrospective comparative study. To analyze changes in the clinical and radiological factors related to cervical sagittal balance, relative to preoperative T1 slope, in patients with cervical myelopathy after laminoplasty (LP). T1 slope is an important factor that should be considered before LP. However, until now, there have been no studies on how preoperative T1 slope affects the sagittal balance of cervical spine and various functional outcomes after LP. Seventy-six patients with cervical myelopathy (M:F ratio = 50:26; mean age = 64.7 ± 9.1 yr) underwent a cervical LP and were followed for more than 2 years. Radiological measurements were performed to analyze the following parameters: (1) C2-C7 sagittal vertical axis; (2) T1 slope; (3) C2-C7 lordosis; and (4) thoracic kyphosis. The visual analogue scale, Japanese Orthopedic Association, neck disability index, and 36-Item Short-Form Health Survey were also investigated. Patients were divided into 2 groups according to preoperative T1 slope, with the cutoff value being the median preoperative T1 slope. Changes in clinical and radiological parameters were compared between the preoperative evaluation and final visit. Overall, C2-C7 sagittal vertical axis increased from 21.2 to 24.5 mm (P = 0.004) and C2-C7 lordosis decreased from 13.9° to 10.3° (P = 0.007) postoperatively. The T1 slope did not show any postoperative differences. Preoperative C2-C7 lordosis was larger in the high-T1 group (19.1°) than in the low-T1 group (9.0°). However, postoperative changes in C2-C7 sagittal vertical axis and C2-C7 lordosis did not show any between-group differences. Clinical outcomes (except neck pain) demonstrated overall improvement in both groups. Comparing changes in both groups showed no differences in neck pain, arm pain, neck disability index, or 36-Item Short-Form Health Survey physical component score between groups. Cervical sagittal balance is compromised after cervical LP. However, the degree of aggravation does not correlate with the preoperative T1 slope. Most clinical parameters demonstrate overall improvement regardless of preoperative T1 slope. 3.

Retrospective review of radiographsObjective. The objective of this study was to (1) determine the prevalence of LSTV with computed tomography (CT) and (2) correlate LSTV presence with lumbar disc degeneration at each level by magnetic resonance imaging (MRI).Lumbosacral transitional vertebra (LSTV) is a frequently observed abnormality. Although its prevalence in adolescent idiopathic scoliosis (AIS) patients has been shown, no studies have yet examined the clinical importance of LSTV in AIS patients.This study included 385 consecutive patients who underwent surgery for AIS at a single center. Plain radiographs and CT scans were used to detect LSTV. Disc degeneration was analyzed at the L3-4, L4-5, and L5-S1 disc levels with MRI. The difference in disc degeneration at each level by the presence of LSTV was also analyzed. The effect of lumbar curve type on the disc degeneration of each level was then determined. To minimize confounding factors, logistic regression analysis was performed.The overall prevalence of LSTV in AIS patients confirmed by CT scans was 12.2% (47/385). The proportion of grade II or more disc degeneration at the L4-5 level was higher in the LSTV(+) group than in the LSTV(-) group (29.8% vs. 19.2%) although it was not statistically significant (p = .093). Large lumbar curves showed a positive correlation with disc degeneration at the L5-S1 level (p = .022).The prevalence of LSTV in AIS patients was 12.2%. A trend of early degeneration in L4-5 level discs was found in AIS patients with LSTV although it was not statistically confirmed. Disc degeneration at the L5-S1 level is related to a large lumbar curve. If AIS patients with large lumbar curves have LSTV, consideration should be given to stopping the distal fusion at L3 instead of L4.

Dung Chul Lee, MD, Oog Jin Shon, MD, Byung Hoon Kwack, MD, and Sung Jun Lee, MD. Knee Surg Relat Res 2013;25:126-32. https://doi.org/10.5792/ksrr.2013.25.3.126

Retrospective analysis. To compare the rates and types of a surgical site infection according to the surgical options in spine surgeries. Scant literatures exist on the difference of surgical site infection according to the surgical methods. We presumed that the incidence of infection after posterior lumbar interbody fusion (PLIF) was higher than posterior or posterolateral fusion (PF, PLF) due to several reasons. A retrospective analysis was made on the patients who received instrumented spinal fusion surgeries from 2000 to 2009. The differences of surgical site infection rates and characteristics were compared between the patients who received PF or PLF (group I) and PLIF (group II). In addition, the infection rate according to the graft options and number of cages was compared in group II. A significant difference (P = 0.003) of infection rate between group I (0.3%, 3 cases out of 974) and group II (1.37%, 29 cases out of 2110) was observed. In group I, 67% of infections were wound infections and 33% were osteomyelitis. In group II, 23% were wound infections, 73% were osteomyelitis, and 4% were osteomyelitis combined with wound infection. Significant increase of infection rate was observed in the single cage group (P = 0.001) and mainly local bone grafted group (P = 0.030). The infection rate of PLIF was higher than that of PF or PLF. Considering the increased infection rate in local bone grafted group and 52% of the infection cases after interbody fusion was osteomyelitis around interbody space, contaminated local bones and interbody space were suspected as major routes of contamination. The higher infection rate in single cage group than that of double cage group was attributed to vulnerability of remained avascular disk materials to infection.

Choi CH, et al. Clin Orthop Surg. 2017 Mar;9(1):83-90. https://doi.org/10.4055/cios.2017.9.1.83