This study suggests that preoperative segmental instability may be a criterion determining whether an additional PLIF would be beneficial in the treatment of lumbar DS.

PI increased in all patients with surgically corrected, adult sagittal deformity, following surgical correction of fixed LL. The disparity of PI after surgery was significantly higher in non-sacropelvic fixation, and showed a significant correlation with follow-up period without influence on sagittal alignment at last follow-up.

Reduction of intervertebral height and loss of sagittal profile occurred in both groups. Complications relating to the bone graft were more common in Group I than in Group II. Despite loss of correction, both groups had a high fusion rate without recurrence of infection. The reduction of intervertebral graft height appears to be the result of destruction of the endplate either due to surgical debridement or the infective process.

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Study DesignSenescence-related markers were assessed in surgically obtained human nucleus pulposus (NP) specimens.PurposeTo demonstrate the mechanism and signaling pathway involved in the senescence of NP chondrocytes.Overview of LiteratureThe population of senescent disc cells has been shown to be increased in degenerated or herniated discs. However, the mechanism and signaling pathway involved in the senescence of NP chondrocytes are unknown.MethodsWe examined cell senescence markers [senescence-associated β-galactosidase (SA-β-gal), telomere length, telomerase activity, p53, p21, pRB and p16] and the hydrogen peroxide (H2O2) content in human NP specimens.ResultsThe percentage of SA-β-gal-positive NP chondrocytes increased with age, while the telomere length and telomerase activity declined. However, there was no significant correlation between age and H2O2 content. The NP specimens with grade III or IV degeneration showed significantly higher percentages of SA-β-gal-positive NP chondrocytes than those with grade II degeneration. Immunohistochemistry showed that senescent NP chondrocytes in all specimens expressed p53, p21, and pRB, while a few NP chondrocytes in only two specimens expressed p16.ConclusionsThe present study demonstrates that, with increasing age and advancing disc degeneration, senescent NP chondrocytes increase or accumulate in the NP. Furthermore, the telomere-based p53, p21, pRB pathway, rather than the stress-based p16, pRB pathway, plays a more important role in the senescence of NP chondrocytes in in vivo conditions. Our results suggest that prevention or reversal of senescence of NP chondrocytes can be a novel mechanism by which to prevent human disc degeneration.

Study DesignA retrospective radiographic study.PurposeTo verify the correlation of sagittal and coronal plane changes after selective thoracic fusion in main thoracic (MT) adolescent idiopathic scoliosis (AIS).Overview of LiteratureSagittal plane deformity is known to be essential in the evolution of scoliosis.MethodsTwenty-eight MT AIS patients treated by anterior selective thoracic fusion were evaluated after minimal follow-up of two years. The unfused lumbar area was divided into proximal and distal parts by the lumbar apex in the coronal plane, and into proximal and distal lumbar lordosis by L2 in the sagittal plane. Surgical motion (the difference between preoperative and postoperative values) and follow-up motion (the difference between postoperative and the last follow-up values) were compared.ResultsImmediately after surgery, as thoracic kyphosis increased, lumbar lordosis decreased (r=0.734); proximal lumbar lordosis increased, and distal lumbar lordosis decreased. The proximal lumbar area was mobilized in the sagittal plane, and was straightened in the coronal plane. However, the distal lumbar area was stabilized in the sagittal plane, and showed resistant motion against MT translation in the coronal plane. The surgical motion was correlated to the follow-up motion, i. e., was regulated during follow-up, and the regulatory motion was more precise in the distal than proximal lumbar area in both sagittal and coronal planes.ConclusionsSagittal and coronal motions were co-related; optimal sagittal motions were necessary for optimal coronal motions after anterior selective thoracic fusion for MT AIS. Proximal and distal lumbar motions were different for different roles; the proximal lumbar area played a role as a bumper to absorb the MT translatory force, and the distal lumbar area played a role of resistance against MT translation.

Study DesignRetrospective comparative study.PurposeTo compare the progression of the kyphotic angle (KA) in a surgically treated group with the predicted outcome of a conservatively treated group.Overview of LiteratureLate onset kyphosis is a complication of tuberculous spondylitis making its prevention a major goal of surgery.MethodsTwenty six consecutive patients underwent an anterior reconstruction and posterior instrumented fusion in conjunction with antituberculous chemotherapy. The mean follow up was 56 months (range, 28 to 112 months). The patients were divided into subgroups based on the involved region of the thoracic and the thoracolumbar spine, initial KA, and the initial vertebral body loss (VBL(x)). The predicted KA (KAPd) was calculated using the formula, KAPd=5.5+30.5 VBL(x), to predict the final gibbus deformity. Kyphotic angle progression (ΔKA) based on the radiographic measurements after surgery (ΔKAR), and the predicted outcome of conservative treatment (ΔKAP) with chemotherapy were compared.ResultsAmong the subgroups of the regions involved and initial KA, the ΔKA was radiographically superior with a reduced amount of kyphogenesis in the surgery group than the predicted outcome of the conservatively treated patients (p<0.05). The radiographic ΔKA was similar (p>0.05) with VBL(x)≤0.5 in the VBL(x) subgroup.ConclusionsThese results showed that in the VBL(x) subgroup, an initial VBL(x)≤0.5 is an indication of conservative antituberculous chemotherapy without surgery.

Study DesignRetrospective radiographic study.PurposeTo evaluate the efficacy of the proximal lumbar curve flexibility compared with the traditional whole lumbar curve flexibility in patients with main thoracic adolescent idiopathic scoliosis (MT-AIS).Overview of LiteratureTraditionally the flexibility of the whole lumbar curve was measured, and the flexibility of the proximal lumbar curve was not analyzed in any study.MethodsTwenty-eight MT-AIS patients treated by anterior selective thoracic fusion (STF) were evaluated after mean follow-up of 50.1 months (range, 25 to 116 months). The male : female ratio was in 5 : 23. The man age at surgery was 14 years and 8 months (range, 11.4 to 18.4 years). The lumbar curve was divided into the proximal and distal curves by the lumbar apex.ResultsThe mean final correction rates (CR)/(flexibilities) of the MT, lumbar, proximal lumbar, and distal lumbar curves were 65.2%/(50.5%), 61.9%/(92.8%), 65.3%/(90.9%), and 36.4%/(134%), respectively. With the final lumbar CR, the lumbar flexibility (r = 0.267, p > 0.05) and the proximal lumbar flexibility (r = 0.327, p > 0.05) was similarly correlated. The mean lumbar CR was similar to the proximal lumbar CR (61.9% vs. 65.3%, p = 0.305). And the correlation between the flexibility and the CR was significant only in the proximal lumbar curve (r = 0.457, p < 0.05), but not in the lumbar curve (r = 0.267, p > 0.05) or the distal lumbar curve (r = 0.175, p > 0.05).ConclusionsThe proximal lumbar curve flexibility may be an alternative method of measuring the lumbar flexibility in MT-AIS patients treated by STF.