Polymethylmethacrylate-augmented Cannulated Pedicle Screw Fixation for High-energy Vertebral Compression Fracture with Osteoporosis

Background: High-energy vertebral compression fractures (HVCFs) with osteoporosis puts forward higher requirement for the stability of pedicle screw internal fixation system. However, few studies have concentrated on the clinical outcomes of cannulated pedicle screw to augment fixation with polymethylmethacrylate (PMMA) under this condition. This study aims to investigate the mid-term efficacy of bone cement-injectable cannulated pedicle screw (CICPS) in HVCFs with osteoporosis.Methods: Eighteen patients with HVCFs (T < -2.5) were underwent spinal fixation by CICPS from 2012 to 2017. The operation time, blood loss, and hospitalization time were recorded. Pain and functional recovery were evaluated by Visual Analog Scale VAS) and Oswestry Disability Index (ODI), respectively. X-ray films were taken to evaluate the loss of vertebral height, kyphosis angle, pedicle screw loosening, and bony fusion. Surgical related complications were also recorded.Results: The average follow-up time was 18.5 ± 8.7 months (range, 6-54 months). VAS and ODI scores indicated significant improvements in postoperative pain and activity function (P < 0.05). Comparing the last follow-up with the postoperative imaging findings, the loss of vertebral height and kyphosis angle was 3.4 ± 1.2 mm and 7.8 ± 3.8°, respectively. The rate of bone graft fusion was 100% while no case was involved in screw loosening or extraction. 1 case of superficial infection, 2 cases of PMMA leakage, and 1 case of cerebrospinal fluid leakage were found.Conclusions: CICPS fixation using PMMA augmentation may be suggested as a feasible surgical technique in osteoporotic patients with HVCFs.

Anterior Cervical Discectomy and Fusion Using Zero-P System for Treatment of Cervical Spondylosis: A Meta-Analysis

Objective. The current study aimed to explore the efficacy of Zero profile intervertebral fusion system (Zero-P) and traditional anterior plate cage system (PC) in the treatment of cervical spondylotic myelopathy (CSM). Further, the present study evaluated effects of the treatments on medical security, height of intervertebral disc, adjacent-level ossification development (ALOD), and adjacent segmentation disease (ASD) through a systematic retrospective analysis. Methods. Studies on Zero-P system and traditional anterior plate cage system for ACDF in the treatment of CSM were searched in PubMed, Web of Science, Ovid, Embase, and Cochrane Library databases. Two independent researchers screened articles, extracted data, and evaluated the quality of the articles based on the inclusion and exclusion criteria of the current study. RevMan5.3 software was used for meta-analysis following the guidelines of Cochrane collaboration network. Cervical curvature, interbody fusion rate, preoperative and postoperative disc height index (DHI), fusion cage sinking rate, postoperative dysphagia, ASD, ALOD, and loosening of screw were compared between the two groups. Results. A total of 17 literatures were included in the present study, including 6 randomized controlled trials and 11 observational studies. The studies comprised a total of 1204 patients with CSM, including 605 patients in the Zero-P system group (Zero-P group) and 599 patients in the traditional animal plate cage group (PC group). Results of this meta-analysis showed that postoperative dysphagia [OR = 0.40, CI (0.28, 95% 0.58), P < 0.00001], ALOD [OR = 0.09, CI (0.02, 95% 0.39), P = 0.001], ASD [OR = 0.42, CI (0.20, 95% 0.86), P = 0.02], and screw loosening [OR = 0.20, CI (0.08, 95% 0.52), P = 0.0009] of the Zero-P group were significantly lower compared with the PC group. On the other hand, preoperative cervical curvature [WMD = −0.23, CI (−1.38, 95% 0.92), P = 0.69], postoperative cervical curvature [WMD = −0.38, CI (−1.77, 95% 1.01), P = 0.59], cage sinking rate [OR = 1.41, CI [0.52, 95% 3.82], P = 0.50], intervertebral fusion rate [OR = 0.76, CI (0.27, 95% 2.48), P = 0.38], preoperative DHI [WMD = −0.04, CI (−0.14, 95% 0.22), P = 0.65], and postoperative DHI [WMD = 0.06, CI (−0.22, 95% 0.34), P = 0.675] were not significantly different between the two groups. Conclusion. It was evident that the Zero-P system used in ACDF is superior compared with the traditional anterior plate cage system in postoperative dysphagia, avoiding ALOD, ASD, and screw loosening.

Correlation between Preoperative Serum Levels of Calcium, Phosphate, and Intact Parathyroid Hormone and Radiological Outcomes in Spinal Interbody Fusion among End-Stage Renal Disease Patients

Spinal fusion surgery for end-stage renal disease (ESRD) patients is a clinical challenge. This study aimed to investigate whether postoperative radiological outcomes are related to preoperative serum calcium, phosphate, or intact parathyroid hormone (iPTH) levels in patients with ESRD who underwent spinal interbody fusion surgery. This study included 62-consecutive patients with ESRD who underwent anterior cervical discectomy and fusion (ACDF) or transforaminal lumbar interbody fusion (TLIF) surgery for symptomatic spinal disorder. The most recent preoperative serum calcium, phosphate, and iPTH levels were recorded, and the postoperative radiographic outcomes were assessed. A significant correlation was found between the occurrence of cage subsidence and higher blood phosphate, calcium–phosphate product (Ca × P), and iPTH levels in the TLIF group. The occurrence of pedicle screw loosening was related to higher blood phosphate and Ca × P product in the TLIF group. However, no correlation was found between the fusion grades and the serum levels in either the TLIF or ACDF groups. These results indicated that higher preoperative serum phosphate and Ca × P product are risk factors for both cage subsidence and screw loosening in patients with ESRD who underwent TLIF surgery. Higher iPTH levels are also a possible risk factor for cage subsidence.

Comparison of Pedicle Screw Fixation With or Without Cement Augmentation Combined With Single-segment Isthmic Spondylolisthesis in Osteoporotic Spine

PurposeThis study aims to investigate the necessity of cement-augmented pedicle screw fixation in single-segment isthmic spondylolisthesis with osteoporosis.MethodFifty-nine cases were reviewed retrospectively. Thirty-three cases were in the polymethylmethacrylate-augmented pedicle screw (PMMA-PS) group, and the other 26 cases were in the conventional pedicle screw (CPS) group. Evaluation data included operation time, intraoperative blood loss,hospitalization cost, hospitalization days, rates of fusion, screw loosening, bone cement leakage, visual analog scores (VAS) , Oswestry disability index (ODI) , Lumbar Lordosis（LL）, Pelvic Tilt（PT） and Sacral Slope（SS）. ResultsThe operation time and blood loss in the CPS group decreased significantly compared to the PMMA-PS group (P < 0.05). The average hospitalization cost of the PMMA group was significantly higher than that of the CPS group (P < 0.05). There was no significant difference for the average hospital stay between the 2 groups (P > 0.05). The initial and the last follow-up postoperative VAS and ODI improved significantly in the two groups (P < 0.05). There were no significant differences in VAS and ODI at each time point between the 2 groups (P > 0.05). The last postoperative spine-pelvic parameters were significantly improved compared with preoperation (P < 0.05). In the PMMA-PS group, the fusion rate was 100%. The fusion rate was 96.15% in the CPS group. No significant difference was found between the two groups for the fusion rate (P > 0.05). Nine cases in the PMMA-PS group had bone cement leakage (27.27%). There was not screw loosening in the PMMA-PS group. There were 2 cases of screw loosening in the CPS group. There were no significant differences in screw loosening, postoperative adjacent segment fractures, postoperative infection or postoperative revision between the 2 groups (P > 0.05). ConclusionsThe use of PMMA-PS on a regular basis is not recommended for posterior lumbar interbody fusion for the treatment of single-segment isthmic spondylolisthesis with osteoporosis.

Complications of Surgical Treatment of Adult Scoliosis

Introduction: With the increase in global life expectancy, the number of patients presenting with progressive spinal deformities is also on rise. The increasing frequency of surgical intervention as a treatment of this group of patients is associated with many complications and also with increasing rate of reoperation. Methodology: Seventy-two cases of adult scoliosis were treated surgically in Ain Shams spine unit with a minimum follow-up of five years (average, 76 months). Preoperative clinical and radiological evaluation was done, with special emphasis on the degree of pains (back and leg), Oswestry Disability Index (ODI), scoliosis angle, lumbar lordosis, any instability, and the level of spinal canal stenosis needing decompression. The pelvic incidence was measured preoperatively to plan the amount of lordosis needed to be restored. Result: The mean preoperative scoliosis angle was 22 ± 10.4º (16 to 34º) and the mean preoperative lordosis angle was 20.3 ± 12.7º (–15 to –28º). The mean preoperative ODI score was 54.7 ± 5.5, and the mean postoperative scoliosis angle improved to 7.4 ± 3.3. The mean postoperative lordosis angle became 37.3 ± 8.6, and the mean postoperative ODI score was 21.3 ± 3.8. Conclusion: The list of complications included seven cases of pseudoarthrosis and screw loosening, adjacent segment fracture in nine cases, and one case of spondylodiscitis at a level just proximal to the fused level. These 17 cases needed reoperations (24%). Additionally, there were five cases of dural tear, prolonged graft side pain in one case, and two cases of superficial wound infections.

Paravertebral foramen screw fixation for posterior cervical spine surgery: clinical case series

OBJECTIVE The goal of this study was to clarify the clinical utility of paravertebral foramen screws (PVFSs) and to determine intraoperative indicators for appropriate screw placement during posterior cervical fusion surgery to improve its safety. METHODS The authors included data from 46 patients (29 men and 17 women, mean age 61.7 years) who underwent posterior cervical spine surgery with 94 PVFSs. Of the 94 PVFSs, 77 were used in C6, 9 in C3, 5 in C4, and 3 in C5. According to the cervical lateral radiographic view, the authors divided the 94 PVFSs into 3 groups as follows: a longer group, in which the tip of PVFS was located anteriorly from the line of the posterior wall of the vertebral body (> +0 mm); an intermediate group, in which the screw tip was located up to 2 mm posteriorly to the posterior wall of the vertebral body (–2 to 0 mm); and a shorter group, in which the screw tip was located more than 2 mm posteriorly (< –2 mm). The accuracy of screw placement was assessed using CT imaging in the axial plane, and the proportion of screws penetrating a vertebral foramen or a transverse foramen was compared between the 3 groups. Screw loosening was defined as a lucent zone around the screw evaluated on cervical radiography at 1 year after surgery. Complications related to PVFS insertion and revision surgery related to PVFS were evaluated. RESULTS The authors classified 25 PVFSs into the longer group, 43 into the intermediate group, and 26 into the shorter group. The proportion of screws penetrating a vertebral foramen was largest in the shorter group, and the proportion penetrating a transverse foramen was largest in the longer group. Screw loosening was confirmed for 3 of 94 PVFSs. One PVFS inserted in C6 unilaterally within a long construct from C2 to C7 showed loosening, but it did not cause clinical symptoms. Revision surgery was required for 2 PVFSs inserted in C3 bilaterally as the lower instrumented vertebra in occiput–cervical fusion because they pulled out. There was no neurovascular complication related to PVFS insertion. CONCLUSIONS PVFSs are useful for posterior cervical fusion surgery as alternative anchor screws, and the line of the posterior wall of the cervical body on lateral fluoroscopic images is a potential intraoperative reference to indicate an appropriate trajectory for PVFSs.

Short-term outcome of fragility fractures of the pelvis in the elderly treated with screw osteosynthesis and external fixator

Background The treatment of fragility fractures of the pelvis is rising challenge for orthopedic trauma surgeons. Operative treatment should allow immediate full weight bearing and early mobilisation but should also be as minimal invasive as possible. Sacroiliac (SI) or transsacral transiliac screws (TSTI) alone or depending on the fracture in combination with an external fixator meets both of these criteria. Material and methods The outcome of 121 operatively treated patients with fragility fractures of the pelvis were evaluated in this retrospective study. Depending on the type of fracture the patients were treated with navigated SI screw or TSTI screw alone or in combination with an external fixator. All patients were operated in supine position in a hybrid-OR, which consists of a fixed robotic 3D flatpanel detector (Artis zeego, Siemens Healthineers, Germany) and a navigation system (BrainLab Curve, BrainLab, Germany). Results 37 patients were treated with either one or two SI screws and 57 with one TSTI screw. An additional external fixator was combined with SI screws in 17 patients and with TSTI screws in 10 patients. The preoperative pain score was significantly higher compared to the postoperative score (5.1 ± 2.5 vs 2.2 ± 1.9, p < 0.05). Follow-up at 6 month was possible for 106 patients which showed screw loosening in 16.3% of the SI Screws (n = 49) compared to only 5.2% of TSTI screws (n = 57). No screw loosening was seen in the combination of TSTI-screw and external fixator (n = 10). There were two septic and three aseptic pin loosenings of the external fixator. Overall only one patient needed revision surgery due to screw loosening and local irritation. Overall 75.2% (n = 91) of the patients could be released in their home or in a rehabilitation unit and only 14% (n = 17) were released to a nursing home due to immobility despite the operation. Non-surgical complications rate was 21.5%. Conclusion SI or TSTI screws with possible combination with an external fixator show early pain relief and allows most of the patients to keep their former level of independence. With an also low surgical complication rate, it proved to be a safe and reliable treatment for fragility fractures of the pelvis. Due the effective pain relief and the minimal invasive approach, early mobilisation is possible and might prevent typical non-surgical complications which are very common during conservative treatment.

Incidence of Screw Loosening in Cortical Bone Trajectory Fixation Technique between Single- and Dual-Threaded Screws

Purpose: This study aims to elucidate the radiological outcome after Cortical bone trajectory (CBT) screw fixation and whether dual-threaded (DT) screws should be used in the fusion surgery. Methods: 159 patients with degenerative lumbar disorder who had undergone midline lumbar inter-body fusion surgery by CBT screw-fixation technique (2014 to 2018). Patient subgroups were based on single-threaded (ST) or DT screw, fixation length, as well as whether fixation involved to sacrum level (S1). Serial dynamic plain films were reviewed and an appearance of a halo phenomenon between screw–bone interfaces was identified as a case of screw loosening. Results: 29 patients (39.7%) in ST group and 10 patients (11.6%) in DT group demonstrated a halo phenomenon (p < 0.0001 ****). After subgrouping with fixation length, the incidence rates of a halo phenomenon in each group were 11.1%:3% (ST-1L vs. DT-1L), 37%:13.8% (ST-2L vs. DT-2L), and 84.2%:23.5% (ST-3L vs. DT-3L). Among the 85 patients with a fixation involved in S1, 26 patients (52%) with single-threaded screw (STS group) and 8 patients (22.8%) with dual-threaded screw (DTS group) demonstrated a halo appearance (p = 0.0078 **). After subgrouping the fixation level, the incidence of a halo appearance in each group was 25%:0% (STS-1L vs. DTS-1L), 40.9%:26.3% (STS-2L vs. DTS-2L), and 87.5%: 30% (STS-3L vs. DTS-3L). Conclusion: Both fixation length and whether fixation involved to S1 contribute to the incidence of screw loosening, the data supports clinical evidence that DT screws had greater fixation strength with an increased fixative stability and lower incidence of screw loosening in CBT screw fixation compared with ST screws. Level of evidence: 2.

Correlation of bone density to screw loosening in dynamic stabilization: an analysis of 176 patients

Although osteoporosis has negative impacts on lumbar fusion, its effects on screw loosening in dynamic stabilization remain elusive. We aimed to correlate bone mineral density (BMD) with screw loosening in Dynesys dynamic stabilization (DDS). Consecutive patients who underwent 2- or 3-level DDS for spondylosis, recurrent disc herniations, or low-grade spondylolisthesis at L3-5 were retrospectively reviewed. BMD was assessed by the Hounsfield Unit (HU) in vertebral bodies (VB) and pedicles with and without cortical bone (CB) on pre-operative computed tomography (CT). Screw loosening was assessed by radiographs and confirmed by CT. HU values were compared between the loosened and intact screws. 176 patients and 918 screws were analyzed with 78 loosened screws found in 36 patients (mean follow-up: 43.4 months). The HU values of VB were similar in loosened and intact screws (p = 0.14). The HU values of pedicles were insignificantly less in loosened than intact screws (including CB: 286.70 ± 118.97 vs. 297.31 ± 110.99, p = 0.45; excluding CB: 238.48 ± 114.90 vs. 240.51 ± 108.91, p = 0.88). All patients had clinical improvements. In conclusion, the HU values, as a surrogate for BMD, were unrelated to screw loosening in DDS. Therefore, patients with compromised BMD might be potential candidates for dynamic stabilization rather than fusion.