Ai-Min Wu

Minimum 4-year outcomes of cervical total disc arthroplasty versus fusion: a meta-analysis based on prospective randomized controlled trials.

AbstractThe prevalence of cervical disc disease is high, and the traditional surgical method of anterior cervical discectomy and fusion (ACDF) carries with it the disadvantages of motion loss at the operated level, and accelerated adjacent level disc degeneration. Preliminary results of the efficacy and reoperative rate comparing TDA versus ACDF have been reported; however, the long-term outcomes of TDA versus ACDF still remain a topic of debate.This review was prepared following the standard procedures set forth by the Cochrane Collaboration organization, and preferred reporting items for systematic reviews and meta-analyses (PRISMA). The only studies included were randomized controlled trials with a minimum of 4 years of follow-up data. The meta-analysis included the neck disability index (NDI), visual analog scale (VAS) of neck and arm pain, SF-36 physical component scores (SF-36 PCS), over success, neurological success, work status, implant-related complications, and secondary surgery events.Four randomized controlled trials meet the inclusion criteria. The long-term improvement of NDI, VAS of neck and arm pain, SF-36 PCS, over success, and neurological success favored the TDA group. The TDA group also had a lower incidence of secondary surgery for both the index level (RR: 0.45 [0.28, 0.72]) and adjacent level (RR: 0.53 [0.33, 0.88]).In this meta-analysis of 4 included RCTs with a minimum 4 years of follow-ups, total disc arthroplasty showed improvements over ACDF as measured by the NDI, VAS of neck and arm pain, and SF-36 PCS.

The Relationship between Dietary Protein Consumption and Risk of Fracture: a subgroup and dose-response meta-analysis of prospective cohort studies

It is still debate of the relationship between the dietary protein consumption and risk of fracture. We searched Medline and Embase to assess the effects of dietary protein consumption on risk of fracture. Twelve prospective cohort studies with 407,104 participants were included, higher total protein consumption may be decrease 11% risk of hip fractures, with adj. RR of 0.89 (0.82, 0.97), no significant difference was found for total protein and risk of all fractures and limb fracture; for animal protein consumption and risk of all fractures and hip fracture, with adj.RR of 0.79 (032, 1.96) and 1.04 (0.70, 1.54); for vegetable protein consumption and risk of all fractures, hip fracture and limb fractures with adj.RR of 0.77 (0.52, 1.12), 1.00 (0.53, 1.91), and 0.94 (0.40, 2.22), the subgroup of vegetable protein consumption and risk of all fractures of postmenopausal women with adj.RR of 0.78(0.52,1.16). Dose-response meta-analysis the relationship of total/animal/vegetable protein and hip fracture was consistent to the results of forest plot, the line of total protein and hip fracture was below the Y = 1.0 line. This meta-analysis showed that total dietary protein consumption may be decrease the risk of hip fracture, but not for animal or vegetable protein.

Minimally Invasive Transforaminal Lumbar Interbody Fusion Using Expandable Technology: A Clinical and Radiographic Analysis of 50 Patients.

OBJECTIVEnInterbody cage implantation during minimally invasive surgery for transforaminal lumbar interbody fusion (MIS TLIF) presents challenges. Expandable cages when collapsed facilitate insertion; subsequent expansion in situ optimizes endplate contact. This report describes clinical and radiographic outcomes of MIS TLIF with an expandable cage.nnnMETHODSnResearchers retrospectively analyzed prospective data from 50 patients (62 operative levels) when an expandable interbody spacer was combined with transpedicular posterior stabilization. Clinical outcomes, fusion rates, incidence of reoperation, and device-related complications were obtained from clinical and radiographic records.nnnRESULTSnMean patient age was 58.1 years (56.2% female). In all, 76% (38/50) underwent 1-level fusion, and 24% (12/50) 2-level fusion. Average operative time was 239.9 ± 86.9 minutes for 1-level and 350.3 ± 74.9 minutes for 2-level procedures; average hospital stay overall was 2.5 ± 1.7 days, with no intraoperative complications reported. Mean visual analogue scale and Oswestry Disability Index scores decreased significantly from preoperative to all postoperative assessment times (6, 12, and 24 months) (Pxa0<xa00.05). Intervertebral disc height (8.3 ± 2.7 vs. 11.3 ± 1.9 mm) increased significantly, with increases sustained over 24 months (P < 0.05). Postoperative radiographs showed no evidence of cage migration, subsidence, or collapse and suggested fusion at all operative levels by 12 months and 24 months (93%, 54/58; 97%, 28/29), respectively.nnnCONCLUSIONSnAn expandable interbody cage led to significant improvement in clinical and radiographic outcomes after MIS TLIF, including intervertebral disc height restoration and high fusion rates, with no evidence of device-related complications.

The relationship between weight change and risk of hip fracture: meta-analysis of prospective studies.

The relationship between weight change and risk of hip fracture is still controversial. We searched PubMed and Embase for studies on weight change and risk of hip fracture. Eight prospective studies were included. The weight loss studies included 85592 participants with 1374 hip fractures, and the weight gain studies included 80768 participants with 732 hip fractures. Weight loss is more likely a risk factor of hip fracture, with an adjusted RR (Relative Risk) (95% CI) of 1.84 (1.45, 2.33). In contrast, weight gain can decrease the risk of hip fracture, with an adjusted RR (95% CI) of 0.73 (0.61, 0.89). Dose-response meta-analysis shows that the risk of hip fracture is an ascending curve, with an increase of weight loss above the line of RRu2009=u20091; this trend is consistent with the results of forest plots that examine weight loss and hip fracture. For weight gain and risk of hip fracture, the descending curve below the line of RRu2009=u20091; this trend is consistent with the results of forest plots that examine weight gain and hip fracture. Our meta-analysis suggests that weight loss may be a risk factor for hip fracture and that weight gain may be a protective factor for hip fracture.

Comparison of the more than 5-year clinical outcomes of cervical disc arthroplasty versus anterior cervical discectomy and fusion: A protocol for a systematic review and meta-analysis of prospective randomized controlled trials

Background:Anterior cervical discectomy and fusion (ACDF) was almost the “golden standard” technique in treatment of symptomatic cervical degenerative disc disease, however, it cause motion loss of the indexed level, increase the intradiscal pressure and motion of the adjacent levels, and may accelerate the degeneration of adjacent level. Cervical disc arthroplasty (CDA) was designed to preserve the motion of index level, avoid the over-activity of adjacent levels and reduce the degeneration of adjacent disc levels, the process of degeneration of adjacent level is very slowly, long term follow up studies should be conducted, this study aim to compare the more than 5 years’ long-term clinical outcomes and safety between CDA and ACDF. Methods:A systematic review and meta-analysis that will be performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses). The electric database of Medline, Embase, and Cochrane library will be systematic search. A standard data form will be used to extract the data of included studies. We will assess the studies according to the Cochrane Handbook for Systematic Reviews of Interventions, and perform analysis in software STATA 12.0. Fixed-effects models will be used for homogeneity data, while random-effects will be used for heterogeneity data. The overall effect sizes will be determined as weighted mean difference (WMD) for continuous outcomes and Relative risk (RR) for dichotomous outcomes. Results:The results of study will be disseminated via both international conference and peer-review journal. Conclusion:The conclusion of our study will provide the long-term and updated evidence of clinical outcomes and safety between CDA and ACDF, and help surgeon to change better surgical technique for patients.

Management of acute combination atlas–axis fractures with percutaneous triple anterior screw fixation in elderly patients

INTRODUCTIONnPatients with combined C1-2 fractures were often treated by posterior arthrodesis. However, elderly patients with multiple injuries (such as brain injury), the large surgical trauma of posterior arthrodesis will increase the risk of perioperative mortality. A minimally invasive technique may be better for them, and decrease the risk of perioperative mortality.nnnMATERIALS AND METHODSnSeven patients with combined C1-2 fractures underwent percutaneous anterior odontoid screw and anterior C1-2 transarticular screws (percutaneous triple anterior screws fixation). The surgical technique of percutaneous triple anterior screws fixation is described.nnnRESULTSnThe operation performed on all patients successfully without technical difficulties, and no intra-operative surgery-related complications such as vertebral artery, nerve injury and soft tissue complications occurred. No pullout, loosening, or breakage of internal screws was observed. C1/2 stable was found in all cases and radiographic union achieved in all odontoid fractures.nnnCONCLUSIONnUsing the appropriate instruments allied to intra-operative image-intensification, we suggest that percutaneous triple anterior screw fixation is reliable, effective and minimally invasive procedure for elderly and brain injured patients suffering of combined atlas-axis fractures.nnnLEVEL OF EVIDENCEnLevel IV. Retrospective study.

Biomechanical Role of the Thoracolumbar Ligaments of the Posterior Ligamentous Complex: A Finite Element Study

OBJECTIVESnTo investigate the effect of sequential ligament failure on the range of motion (ROM) and location of the instantaneous axes of rotation (IAR) of the thoracolumbar spine (T12-L1) finite element (FE) model, and to verify the role of the supraspinous ligament (SSL) in maintaining the stability of the injured thoracolumbar spine.nnnMETHODSnAn FE model of the fractured thoracolumbar spine was developed and validated against published data. The posterior ligamentous complex (PLC) in the fractured T12-L1 segment was then reduced in a sequential manner from the facet capsular ligament (FCL), part of the interspinous ligament (ISL), SSL, and entire ISL, to the ligamentum flavum (LF). The ROM and IAR of the T12-L1 segment were measured at the fracture and at each reduced ligament step under 4 directions of flexion, extension, lateral bending, and rotation, and 4 bending motions of 1.5, 3.0, 4.5, 6.0 Nm.nnnRESULTSnThe FE model showed a consistent increase in the ROM and location of the IAR as the ligaments were removed sequentially. Furthermore, failure of the SSL had the most significant influence on the change in the ROM and IAR in flexion. In extension, removal of the FCL caused the largest shift.nnnCONCLUSIONSnThe SSL is a significant ligament that allows the PLC to maintain the stability of the thoracolumbar spine during injury.

Acceptable Chin–Brow Vertical Angle for Neutral Position Radiography: Preliminary Analyses Based on Parameters of the Whole Sagittal Spine of an Asymptomatic Chinese Population

OBJECTIVEnWe sought to acquire the whole sagittal spine parameters and investigated the acceptable chin-brow vertical angle (CBVA) for neutral position radiography in an asymptomatic Chinese population.nnnMETHODSnThe parameters measured in 257 asymptomatic volunteers included CBVA, occipital slope, orbital tilt, occipital incidence, C0-C2 Cobb angle, C2-C7 Cobb angle, C1-C7 Cobb angle, C2-C7 sagittal vertical axis and absolute rotation angle, cervical tilt, cranial tilt, T1 slope, and thoracic kyphosis, and others. We used Pearson correlation analyses to find relationships between CBVA and other variables. The subjects were divided into 5 groups according to the CBVA percentile: group A, 0%-20% CBVA; group B, 20%-40% CBVA; group C, 40%-60% CBVA; group D, 60%-80% CBVA; and group E, 80%-100% CBVA. We used analysis of variance to analyze differences among the 5 groups.nnnRESULTSnOrbital tilt, Occipital incidence, C1-C7 Cobb angle, C2-C7 sagittal vertical axis, and cranial tilt all increased with increasing CBVA (P < 0.001). The occipital slope, C2-C7 Cobb angle, C2-C7 absolute rotation angle, cervical tilt, T1 slope, and thoracic kyphosis decreased with decreasing CBVA (P < 0.05). No correlations between other sagittal parameters and the CBVA were found. A slight deviation was found in groups B-D, with a greater deviation in groups A, C, and E.nnnCONCLUSIONSnAn acceptable range ofxa0-1.5° to 5.8° is recommended for the CBVA for cervical radiography in the neutral position. When spinal surgeons evaluate the cervical plane, the effects of the CBVA deviation on cervical curvature must be considered.

A Novel Knotless Barbed Suture Technique for Traumatic Thoracolumbar Fracture in Posterior Surgery

BACKGROUNDnSurgical wound closure directly influences spinal surgical efficiency and several postoperative complications. The traditional suture technique is time-consuming and associated with greater rates of complications. Bidirectional absorbable barbed sutures seem to compensate for some of the limitations of traditional suture; however, they rarely are reported in spinal surgery. We designed a novel suture technique for use in thoracolumbar spinal surgery.nnnMETHODSnThe data of 189 patients with traumatic thoracolumbar fractures were analyzed between bidirectional barbed suture closure and traditional interrupted suture closure. Data of operative time, wound closure time, length of incision, intraoperative blood loss, complications of wound dehiscence and postoperative hematoma, cost, and neurologic status were collected.nnnRESULTSnNo significant differences were observed in the baseline demographics of included patients. Compared with the traditional suturing group, the barbed sutures decreased the mean operative time (Pxa0= 0.037), suture time (P < 0.01), and mean suturing time (P < 0.01) significantly, although no statistically significant differences were found in blood loss (Pxa0= 0.724) and neurologic functional scores (preoperative: Pxa0= 0.901; 3 months after surgery: Pxa0= 0.208; final follow-up assessments: Pxa0= 0.163), and no statistically significant differences were found in rates of postoperative infection, hematoma, and wound dehiscence.nnnCONCLUSIONSnOur findings suggest that the novel knotless barbed suture has comparable strength to traditional sutures, with the advantage of less suturing time. It is an efficient, safe technique, and alternative choice for patients with thoracolumbar fracture after posterior surgery.

Factors associated with cervical spine alignment in an asymptomatic population

BACKGROUNDnCervical sagittal imbalance compromises health-related quality of life and can lead to myriad incapacitating symptoms through compression of the spinal cord. Questions regarding which parameters play primary roles in the progression of cervical sagittal imbalance and which might be compensatory factors remain unanswered.nnnMETHODSnThis study enrolled 246 asymptomatic volunteers from July 2016 to June 2018. After demographic and radiologic parameters were measured, the data were analyzed using correlation coefficient test and multiple regression analysis. A predictive equation was assessed with variance analysis, residual analysis, collinearity analysis, and a paired t test.nnnRESULTSnAverage values are as follows: orbital tilt, 64xa0± 6°; orbital slope (OS), 15 ± 6°; C0-C2 lordosis (C0C2), 28xa0± 8°; cervical lordosis (CL), 5 ± 11°; C2-C7 sagittal vertical axis (C2C7SVA), 15 ± 8 mm; T1 slope (TS), 17 ± 6°; thoracic inlet angle, 69 ± 8°; thoracic kyphosis, 34 ± 9°; lumbar lordosis, 50 ± 10°; sacral slope, 38 ± 7°; pelvic index, 48 ± 9°; sagittal vertical axis, 10 ± 19 mm. Correlations of C2C7SVA were observed with body mass index (BMI), OS, C0C2, CL, and TS. The validated predictive equation was: C2C7SVA = 0.38 × BMI - 0.73 × OS + 0.73xa0× C0C2 + 0.15 × CL + 0.18 × TS - 6.53.nnnCONCLUSIONSnBMI, OS, C0C2, CL, and TS were primary influencers in the progression of cervical sagittal imbalance and established a predictive equation of asymptomatic population, which can provide clinical advice and remind surgeons of the primary influencers of reconstructive surgery for better prognoses.