Clinical and imaging outcomes of self-locking stand-alone cages and anterior cage-with-plate in three-level anterior cervical discectomy and fusion: a retrospective comparative study.

BACKGROUND: Anterior cervical discectomy and fusion has been considered standard management for cervical myelopathy and radiculopathy. However, the option of using self-locking stand-alone cages or cage-with-plate in three-level anterior cervical discectomy and fusion still remains controversial. The aim of this study was to evaluate the clinical and imaging outcomes of the two procedures in multilevel anterior cervical discectomy and fusion. METHODS: Sixty-seven patients who underwent three-level anterior cervical discectomy and fusion were enrolled in this study, of which 31 patients underwent surgery using self-locking stand-alone cages (group cage) and 36 patients using cage-with-plate (group plate). For the evaluation of clinical outcomes, modified Japanese Orthopedic Association scores, visual analogue scale for neck pain, neck disability index, Odom's criteria and dysphagia status were measured. Imaging outcomes were evaluated by cervical sagittal angle, fusion segmental Cobb's angle, fusion segmental height, range of motion, cage subsidence rate, fusion rate and adjacent segment degeneration. Statistical analyses were performed using the SPSS software (version 19.0). RESULTS: Both groups showed improvement in modified Japanese Orthopedic Association scores, visual analogue scale for neck pain and neck disability index, after surgery, and there was no significant difference between the groups. The occurrence rate of dysphagia is significantly lower in the group cage compared with the group plate (p < 0.05). The postoperative cervical sagittal angle, fusion segmental Cobb's angle, fusion segmental height and cage subsidence rate in the group plate were significantly superior to that in the group cage (p < 0.05). However, the rate of adjacent segment degeneration was significantly lower in the group cage compared with the group plate (p < 0.05). Both groups showed no significant difference in terms of fusion rate (p > 0.05). CONCLUSIONS: The self-locking stand-alone cages are effective, reliable and safe in anterior cervical discectomy and fusion for the treatment of cervical myelopathy and radiculopathy. Self-locking stand-alone cages showed a significantly lower rate of dysphagia and adjacent segment degeneration, while anterior cervical cage-with-plate could provide stronger postoperative stability and maintain better cervical spine alignment.

DEPDC1B regulates the progression of human chordoma through UBE2T-mediated ubiquitination of BIRC5.

Chordoma is a rare bone malignancy with a high rate of local recurrence and distant metastasis. Although DEP domain-containing protein 1B (DEPDC1B) is implicated in a variety of malignancies, its relationship with chordoma is unclear. In this study, the biological role and molecular mechanism of DEPDC1B in chordoma were explored. The function of DEPDC1B in chordoma cells was clarified through loss-of-function assays in vitro and in vivo. Furthermore, molecular mechanism of DEPDC1B in chordoma cells was recognized by RNA sequencing and Co-Immunoprecipitation (Co-IP) assay. The malignant behaviors of DEPDC1B knockdown chordoma cells was significantly inhibited, which was characterized by reduced proliferation, enhanced apoptosis, and hindered migration. Consistently, decreased expression of DEPDC1B suppressed tumor growth in xenograft mice. Mechanically, DEPDC1B affected the ubiquitination of baculoviral inhibitor of apoptosis repeat-containing 5 (BIRC5) through ubiquitin-conjugating enzyme E2T (UBE2T). Simultaneous downregulation of BIRC5 and DEPDC1B may exacerbate the inhibitory effects of chordoma. Moreover, BIRC5 overexpression reduced the inhibitory effects of DEPDC1B knockdown in chordoma cells. In conclusion, DEPDC1B regulates the progression of human chordoma through UBE2T-mediated ubiquitination of BIRC5, suggesting that it may be a promising candidate target with potential therapeutic value.

Incidence and risk factors of proximal junctional kyphosis after internal fixation for adult spinal deformity: a systematic evaluation and meta-analysis.

To investigate the factors associated with proximal junctional kyphosis (PJK). A systematic search was performed. The weighted mean difference (WMD) was pooled for continuous variables, and the odds ratio (OR) was calculated for dichotomous variables. The PJK group had higher values for age (WMD = 2.53, 95%CI = 1.38 ~ 3.68, P < 0.001), female gender (OR = 1.56, 95%CI = 1.29 ~ 1.87, P < 0.001), and diagnosed osteoporosis (OR = 1.58, 95%CI = 1.11 ~ 2.26, P = 0.01). Preoperatively, significant differences were detected in sagittal vertical axis (SVA) (WMD = 19.29, 95%CI = 16.60 ~ 21.98, P < 0.001), pelvic incidence minus lumbar lordosis (PI-LL) (WMD = 2.71, 95%CI = 0.25 ~ 5.18, P = 0.03), pelvic tilt (PT) (WMD = 2.64, 95%CI = 1.38 ~ 3.90, P < 0.001), lumbar lordosis (LL) (WMD = - 1.76, 95%CI = - 2.73 ~ -0.79, P < 0.001), and sacral slope (SS) (WMD = - 2.80, 95%CI = - 5.57 ~ -0.04, P = 0.001). At follow-up, the following were higher in the PJK group: thoracic kyphosis (TK) (WMD = 5.51, 95%CI = 2.23 ~ 8.80, P < 0.001), proximal junctional angle (PJA) (WMD = 9.07, 95%CI = 4.21 ~ 13.92, P < 0.001), and PT (WMD = 1.51, 95%CI = 0.31 ~ 2.72, P = 0.01). However, there was no significant difference in SS (P = 0.49), and SVA (P = 0.11) between groups. Fusion to S1 or pelvis significantly increased the risk of PJK (OR = 2.08, P < 0.001). Ligament augmentation reduced the risk of PJK (OR = 0.34, 95%CI = 0.21 ~ 0.53, P < 0.001) better than the use of laminar hook (OR = 0.46, P < 0.001). Although no difference was detected for preoperative SRS-22 score (P = 0.056), a lower score (WMD = - 0.24, 95%CI = - 0.35 ~ -0.14, P < 0.001) was detected in PJK group at follow-up. The elderly female ASD patients were more susceptible to PJK, especially for those with osteoporosis, high preoperative SVA, low LL, large PT, and LIV extended to pelvis. The use of laminar hook and ligament reinforcement at the proximal end might prevent PJK.

Augmentative locking plate with autologous bone grafting for distal femoral nonunion subsequent to failed retrograde intramedullary nailing.

OBJECTIVE: To explore the indications and efficacy of augmentative locking compression plate (LCP) or less invasive stabilization system (LISS)with autogenous bone grafting (BG) in treating distal femoral nonunion subsequent to failed retrograde intramedullary nailing (RIN). METHODS: A retrospective study was performed for 21 patients with distal femoral nonunion subsequent to failed RIN, who received therapy with either augmentative LCP (n = 11) or LISS with autogenous BG (n = 13). Operation time, time to union, union rate, time to renonunion, complication rate and SF-36 scores a year after hardware removal were compared between the two groups. RESULTS: The bone union occurred in 13/13 (100%) cases in augmentative LISS group versus 9/11 (81.8%) cases in augmentative LCP group [odds ratio (OR) = 3.21, 95% confidence interval (CI) 0.7-13]. Time to union, time to renonunion, complication rate of the augmentative LCP group were significantly more than that of the augmentative LISS with autogenous BG group (p = 0.023, p = 0.021 and p = 0.033). No significant difference was found in the average operation time of two groups (p = 0.121). At the follow-up a year after hardware removal, statistically significant HRQOL improvement in the augmentive LISS group was measured at the level of pain (p = 0.003) and general health perception (p = 0.011), as compared to the augmentive LCP group. CONCLUSIONS: We suggest augmentative LCP, for distal femoral nonunios after RIN, may be optimal for that of typeAO33A fractures, whereas augmentative LISS for that of typeAO33C fractures more.

Comparative Analysis of Interval, Skipped, and Key-vertebral Pedicle Screw Strategies for Correction in Patients With Lenke Type 1 Adolescent Idiopathic Scoliosis.

Pedicle screw constructs have become the mainstay for surgical correction in patients with spinal deformities. To reduce or avoid the risk of pedicle screw-based complications and to decrease the costs associated with pedicle screw instrumentation, some authors have introduced interval, skipped, and key-vertebral pedicle screw strategies for correction. However, there have been no comparisons of outcomes among these 3 pedicle screw-placement strategies.The aim of this study was to compare the correlative clinical outcomes of posterior correction and fusion with pedicle screw fixation using these 3 surgical strategies.Fifty-six consecutive patients with Lenke type 1 adolescent idiopathic scoliosis were included in this study. Twenty patients were treated with the interval pedicle screw strategy (IPSS), 20 with the skipped pedicle screw strategy (SPSS), and 16 with the key-vertebral pedicle screw strategy (KVPSS). Coronal and sagittal radiographs were analyzed before surgery, at 1 week after surgery, and at the last follow-up after surgery.There were no significant differences among the 3 groups regarding preoperative radiographic parameters. No significant difference was found between the IPSS and SPSS groups in correction of the main thoracic curve (70.8% vs 70.0%; P = 0.524). However, there were statistically significant differences between the IPSS and KVPSS groups (70.8% vs 64.9%) and between the SPSS and KVPSS groups (70.0% vs 64.9%) in correction of the main thoracic curve (P < 0.001 for both). Additionally, there were no significant differences among the 3 strategies for sagittal parameters at the immediate postoperative and last postoperative follow-up periods, though there were significant differences in the Cobb angle between the preoperative and immediate postoperative periods among the 3 groups, but not between the immediate postoperative and last follow-up periods. The amount of hospital charges in the SPSS group was significantly higher than those in the IPSS (P < 0.001) and KVPSS groups (P < 0.001). There were also significant differences in operative time between the IPSS and KVPSS groups (P < 0.001) and between the SPSS and KVPSS groups (P < 0.001).Each of the 3 types of pedicle screw strategies for correction in patients with Lenke type 1 adolescent idiopathic scoliosis are effective, with satisfactory coronal and acceptable sagittal plane results. Although the KVPSS does not provide superior operative correction compared with the IPSS and SPSS, it can achieve a satisfactory clinical outcome and is more cost-effective.

TOB1 Deficiency Enhances the Effect of Bone Marrow-Derived Mesenchymal Stem Cells on Tendon-Bone Healing in a Rat Rotator Cuff Repair Model.

BACKGROUND/AIMS: This study investigated the effect of silencing TOB1 (Transducer of ERBB2, 1) expression in bone marrow-derived mesenchymal stem cells (MSCs) on MSC-facilitated tendon-bone healing in a rat supraspinatus repair model. METHODS: Rat MSCs were transduced with a recombinant lentivirus encoding short hairpin RNA (shRNA) against TOB1. MSC cell proliferation was analyzed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays. The effect of MSCs with TOB1 deficiency on tendon-bone healing in a rat rotator cuff repair model was evaluated by biomechanical testing, histological analysis and collagen type I and II gene expression. An upstream regulator (miR-218) of TOB1 was determined in MSCs. RESULTS: We found that knockdown of TOB1 significantly increased the proliferative activity of rat MSCs in vitro. When MSCs with TOB1 deficiency were injected into injured rat supraspinatus tendon-bone junctions, the effect on tendon-bone healing was enhanced compared to treatment with control MSCs with normal TOB1 expression, as evidenced by elevated levels of ultimate load to failure and stiffness, increased amount of fibrocartilage and augmented expression of collagen type I and type II genes. In addition, we found that the TOB1 3' untranslated region is a direct target of miR-218. Similar to the effect of TOB1 deficiency, overexpression of miR-218 effectively promoted tendon-bone healing in rat. CONCLUSION: These results suggest that TOB1 may play a negative role in the effect of MSCs on tendon-bone healing, and imply that expression of TOB1 may be regulated by miR-218.

Associations between body mass and the outcome of surgery for scoliosis in Chinese adults.

BACKGROUND: In this study we intended to prove that being overweight has an unfavorable impact on the surgical treatment outcome of adult idiopathic scoliosis (AdIS). METHODS: This is a retrospective study on the surgical treatment of seventy-one more than 30 years old (58 females and 13 males; mean age 42.9±12.2) idiopathic scoliotic patients with a minimum follow up of at least 2 years. The patients were divided into an overweight group (BMI≥23) and a non-overweight group (BMI<23). Preoperative, postoperative first erect and final follow-up radiographic measures, perioperative data, the Oswestry disability index (ODI), and the visual analog scale (VAS) were reviewed and compared. FINDINGS: In the overweight group, no significant differences in radiographic measures, perioperative data, preoperative comorbidities, or postoperative complications, except for the more frequent concomitance of preoperative thoracic kyphosis 37.9±7.7 vs. 26.5±11.8 (P = 0.000) and thoracolumbar kyphosis 14.9±10.1 overweighted group vs. 6.5±9.9 non-overweighted group respectively (P = 0.002) were found. A higher morbidity of hypertension 36.8% vs. 9.6% (P = 0.004) was also observed in the overweight group. Postoperative ODI and VAS improved significantly in both groups compared to pre-operative values. The postoperative ODI of the overweight group (19.6±12.4) was significantly higher than that of the non-overweight group (12.4±7.9) (P = 0.022). CONCLUSIONS: Overweight adult idiopathic scoliotic patients had more frequent concomitance of preoperative thoracic kyphosis and thoracolumbar kyphosis and more serious postoperative pain. However, BMI did not affect the outcomes of surgical correction for coronal and sagittal scoliotic deformity and their postoperative complication rates were not significantly affected.

Using side-bending radiographs to determine the distal fusion level in patients with single thoracic idiopathic scoliosis undergoing posterior correction with pedicle screws.

STUDY DESIGN: Prospective. OBJECTIVES: To evaluate a strategy to determine the distal fusion level in posterior pedicle screw correction of single thoracic idiopathic scoliosis. SUMMARY OF BACKGROUND DATA: No standard method for selecting the lowest instrumented vertebra (LIV) for the correction of thoracic adolescent idiopathic scoliosis with posterior all-pedicle screw instrumentations exists. METHODS: Thirty-eight patients with single right thoracic (Lenke 1A) adolescent idiopathic scoliosis undergoing posterior pedicle screw fixation were studied. The LIV was determined using guidelines based on preoperative side-bending radiographs. In brief, (1) the whole thoracic Cobb curve should be included in the fusion mass, and the LIV should not be superior to the lower-end vertebra of the Cobb measurement. (2) On the right side-bending radiographs, the LIV should be derotated to neutral in skeletally immature (Risser 0 to 3) patients and the disc immediately below the LIV must open on the left side by at least 5 degrees. (3) On the left side-bending radiographs, the disc immediately below the LIV must be open on the right side by at least 0 degree. The first segment meeting the criteria when proceeding from the lower-end vertebra caudally is chosen as the LIV. Outcomes were based on the standing radiographs. RESULTS: Minimum follow-up was 2 years. The mean preoperative thoracic curve was 48.4±9.2 degrees and 12.6±6.1 degrees at final follow-up, resulting in a mean correction of 74.7%±8.5%. The mean preoperative compensatory lumbar curve of 23.7±7.5 degrees was 6.3±4.8 degrees at final follow-up. A change in lumbar lordosis from -41.2±11.9 degrees preoperatively to -38.2±9.9 degrees at final follow-up occurred. All patients achieved coronal balance and no decompensation or adding-on phenomenon was observed. Compared with the recommended fusion end by the Harrington stable zone method, 86.9% patients were saved 1 or more motion segment. CONCLUSIONS: The method described was effective in obtaining satisfactory curve correction, adequate trunk balance, and preservation of motion segments.

The effect of differing spinal fusion instrumentation on the occurrence of postoperative crankshaft phenomenon in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective. OBJECTIVE: To compare the occurrence of the crankshaft phenomenon in patients with adolescent idiopathic scoliosis (AIS) who underwent hybrid, consecutive pedicle screw or interval pedicle screw instrumentation for posterior spinal fusion. SUMMARY OF BACKGROUND DATA: Scoliosis may progress after posterior spinal fusion in skeletally immature patients with AIS. The crankshaft phenomenon occurs when the anterior column continues to grow in the face of posterior fusion causing characteristic twisting of the fused segment. The optimal surgical method for preventing the occurrence of this complication has not been determined. METHODS: Sixty seven patients with AIS who underwent posterior fusion over a 6-year period were divided into groups according to fixation method: hybrid instrumentation, interval pedicle screw placement, or consecutive pedicle screw placement. Preoperative, postoperative, and follow-up radiographic measures, including Cobb angle, apical vertebral rotation (AVR), apical vertebral transposition (AVT), rib vertebral angle difference (RVAD) and trunk shift (TS) were assessed. The occurrence of the crankshaft phenomenon was determined. RESULTS: The mean follow-up duration was 36 months. There were no between-the-group differences in demographics or preoperative or immediate postoperative measures. At the last follow-up, significant differences among the groups were apparent for Cobb angle, AVR, AVT, RVAD, and TS (all P<0.05). Cobb angle, AVR, AVT, RVAD, and TS significantly increased between the postsurgery and the last follow-up in the hybrid instrumentation group (all P<0.0167). Only TS increased significantly in the 2 other groups. There were 7 cases of crankshaft phenomenon occurrence in the hybrid instrumentation group (33%), but none in the other 2 groups. CONCLUSIONS: These findings suggest that in skeletally immature patients with AIS, hybrid instrumentation cannot effectively prevent occurrence of the crankshaft phenomenon, whereas interval and consecutive pedicle screw instrumentation may be more (and equally) efficacious in this regard.