经椎板关节突关节螺钉固定的生物力学实验研究

目的:探讨经椎板关节突关节螺钉(简称TLS)固定的可靠性。方法:选用7具腰椎标本,制成两个功能单元,分别在正常、髓核切除和椎间置入融合器(TFC)后行TLS固定,进行前屈、后伸、侧方压缩和轴向旋转实验,最大压缩力矩10Nm、旋转力矩10.8Nm,测量成角运动范围(ROM)。结果:与对照组相比,TLS单侧固定组的前屈、后伸、侧弯、旋转ROM分别减少2.92%、1.78%、5.77%和7.92%,双侧固定组分别减少15.59%、5.72%、15.18%和20.19%;“髓核半切 TLS”组均明显小于“髓核全切 TLS”组和对照组;“TFC TLS”组较TFC组分别减少8.20%、12.55%、9.57%和22.07%。结论:在无明显前中柱不稳时,TLS固定后脊柱的前屈、后伸、侧弯和旋转的稳定性明显增加,尤其旋转增加较多;单纯椎间置入融合器时后伸、旋转稳定性相对较差,TLS可增加其各向稳定性。     

四种脊柱内固定器的生物力学评价

目的：评价四各短节段脊柱内固定器械的生物力学性能。方法：取２４具猪胸腰段（Ｔ１０～Ｌ５）脊柱标本,模拟最严重前中柱损伤模型,通过测定加载方向应变和位移或角度值椎弓根螺钉抗拔出力值,比较短节段器械ＣＹＬ、Ｄｉｃｋ、ＡＦ、ＲＦ四种椎弓根内固定系统在轴向压缩、弯曲和扭转实验的生物力学稳定性及椎弓根螺钉握持能力。结果：器械的稳定性及椎弓根螺钉直径、螺纹特点、螺钉固定装置等结构密切相关。结论：ＣＹＬ具有结构     

The effect of the cortical bone trajectory screw fixation and traditional pedicle screw fixation on surgical site wound infection in posterior lumbar fusion wound: A meta-analysis

A meta-analysis investigation was performed to measure the influence of cortical bone trajectory screw fixation (CBTSF) and traditional pedicle screw fixation (TPSF) on surgical site wound infection (SSWI) in posterior lumbar fusion (PLF). A comprehensive literature inspection till February 2023 was applied and 1657 interrelated investigations were reviewed. The 13 chosen investigations enclosed 1195 individuals with PLF in the chosen investigations' starting point, 578 of them were using CBTSF, and 617 were using TPSF. Odds ratio (OR) in addition to 95% confidence intervals (CIs) were utilised to compute the value of the effect of the CBTSF and TPSF on SSWI in PLF by the dichotomous approaches and a fixed or random model. No significant difference was found between individuals using CBTSF and TPSF in SSWI (OR, 0.68; 95% CI, 0.35–1.33, P = .26), superficial SSWI (OR, 0.62; 95% CI, 0.22–1.79, P = .38), and deep SSWI (OR, 0.30; 95% CI, 0.06–1.50, P = .14) in PLF. No significant difference was found between individuals using CBTSF and TPSF in SSWI, superficial SSWI, and deep SSWI in PLF. However, care must be exercised when dealing with its values because of the small sample sizes of several chosen investigations for this meta-analysis and the low number of selected investigations for a certain type of SSWI.     

What is the best treatment for syndesmosis fixation? Suture-button or syndesmotic screw ? Bilateral CT-based early postoperative analysis

BackgroundThe aim of this study was to compare the effectiveness of syndesmotic screw (SS) and suture button (SB) on the reduction and fixation of syndesmosis via early postoperative bilateral computed tomography (CT).MethodsThis single-center retrospective study included 76 patients aged ≥ 18 years with a unilateral syndesmosis injury. SS was applied to 40 patients and SB to 36 patients. The differences between the sides stabilized using SB or SS and the intact sides were analyzed using the parameters of tibio-fibular clear space (?CS) and anterior or posterior sagittal translation (?ST) depending on the orientation of the fibula. The cases in which the fibula was translocated to the posterior of the tibia after the change of ?ST and ?CS> 2 mm were evaluated as malreduction. Axial CT images taken from the level of syndesmosis fixation were divided into 4 zones according to the orientation angle of the implant sent from the fibula to the tibia.ResultsNo significant difference was found in the analyses performed between total patient group with malreduction and fixation groups in terms of ?CS and ?ST values (p = 0.708, p = 0.289). It was observed that the fixation material was in zone 3 in 54 patients and in zone 2 in 22 patients. No significant difference was found in the analyses performed between the SS and SB groups according to the implant zone (p = 0.191). In the SS group sent from Zone 2, the malreduction rate according to the ?ST value of syndesmosis was found to be significantly higher than in the SB group (p = 0.008, p = 0.003).ConclusionWhen the implant is applied with the correct technique, there is no difference between SS and SB in terms of early postoperative reduction. When the SS is advanced at an inappropriate angle, it negatively affects the reduction of the fibula, while SB can better tolerate angle errors up to certain degrees due to its flexible structure. Therefore, it can be presumed that the suture button system is a more convenient method in the reduction and fixation of syndesmosis than the syndesmotic screw.Level of EvidenceLevel IV     

Biomechanical comparison of suture-button,bioabsorbable screw,and metal screw for ankle syndesmotic repair: A meta-analysis

BackgroundTo compare biomechanically metal screw fixation to suture-button or bioabsorbable screw fixation for ankle syndesmotic injuries.MethodsA literature search of the comparison studies in Pubmed and Google Scholar was conducted. The biomechanical outcomes of interest were syndesmotic stability in the coronal, sagittal, and axial planes as well as torque and rotation at failure.ResultsA total of 11 cadaveric studies were included. In the suture-button group, coronal displacement (MD 1.72 mm, p = 0.02) and sagittal displacement (MD 2.65 mm, p = 0.0003) were increased relative to the metal screw group. In contrast, no difference was found with axial rotation (MD 0.35 degrees, p = 0.57). Bioabsorbable screws exhibited equivalent failure torque (MD ?3.04 Nm, p = 0.53) and rotation at failure (MD 3.77 degrees, p = 0.48) in comparison to metal screws.ConclusionsSuture-button provide less rigidity when compared to metal screw fixation. They afford flexible syndesmotic micromotion which may more closely resemble a physiological state and be helpful for ligament healing. Bioabsorbable screws demonstrate similar mechanical strength properties to metal screws.     

Anthropometric Measurement About the Safe Zone for Transacetabular Screw Placement in Total Hip Arthroplasty in Asian Middle-Aged Women: In Vivo Three-Dimensional Model Analysis

BackgroundAlthough the pelvic vascular injury caused by a transacetabular screw is rare, it is a major local complication of total hip arthroplasty. We aimed to obtain anthropometric data about the safe zone for the placement of transacetabular screws by analyzing the three-dimensional (3D) reconstruction model and determine the safe length of transacetabular screws by performing the 3D simulated surgery.MethodsWe reviewed 50 hips of 25 patients who underwent lower extremity angiographic computed tomography scans retrospectively. We reconstructed the 3D models of 50 hips with normal pelvic bone and vascular status using the customized computer software. We measured the central angle and safe depth of the safe zone of the transacetabular screws on the 3D models. We also performed the 3D simulated surgery to confirm the safe length of screws in each hole of the customized cup implant.ResultsThe measured central angle of the posterior-superior area was 79.5°. And we determined a mean safe depth of 49.8 mm in the safe zone, with a central angle of 47.7°. During the 3D simulated surgery, we determined a mean safe length of the transacetabular screw of 43.3 mm when applied to a lateral hole on a line bisecting the posterior-superior area.ConclusionAlthough our study was limited by the use of a virtual computer program, the quantitative measurements obtained can help reduce the incidence of pelvic vascular injury during transacetabular screw fixation in total hip arthroplasty.     

Good functional outcome in patients suffering fragility fractures of the pelvis treated with percutaneous screw stabilisation: Assessment of complications and factors influencing failure

BackgroundLow energy pelvic ring fractures in the elderly have traditionally been treated conservatively, a treatment with potential long-term complications and loss of self-independence. Percutaneous screw stabilisation of the posterior pelvic ring is a new treatment modality that enables immediate mobilisation. The aim of this study was to assess the functional outcome after sacroiliac stabilisation in the elderly.MethodsAll elderly patients with a surgically stabilised low energy pelvic fracture between 2010 and 2015 were included. In 2016 a radiographic follow up and functional test was performed at least one year postoperative.ResultsThe 50 operated patients had a mean age of 79 years and a one-year mortality of 10% (5/50). Only six patients lost independency after the pelvic fracture and moved to nursing home. The mean Timed Up and Go test was 16 s at follow-up. The operation of the posterior pelvic ring averaged 63 min with a radiation equal to a diagnostic pelvic CT. One intra-foraminally placed screw was immediately removed and 9 patients were later re-operated on due to symptomatic loosening of one or more screws. No loosening of screws was seen in 11 patients where both S1 and S2 were stabilised and out of 23 trans-sacral screws (crossing both sacroiliac joints) only two loosened.DiscussionCT guided stabilisation of the posterior pelvis is safe and most patients resumed good function and independent living. The risk of a revision operation was 20%, but trans-sacral screw stabilisation in both S1 and S2 could reduce the risk of implant loosening.