Effect of Whitlockite as a new bone substitute for bone formation in spinal fusion and ectopic ossification animal model

Background Bone substrates like hydroxyapatite and tricalcium phosphate have been widely used for promoting spinal fusion and reducing the complications caused by autograft. Whitlockite has been reported to promote better bone formation in rat calvaria models compare with them, but no study investigated its effect on spinal fusion yet. Also, the higher osteoinductivity of whitlockite raised concern of ectopic ossification, which was a complication of spinal fusion surgery that should be avoided. Methods In this study, we compared the osteoinductivity of whitlockite, hydroxyapatite, and tricalcium phosphate porous particles with SD rat spine posterolateral fusion model and investigated whether whitlockite could induce ectopic ossification with SD rat abdominal pouch model. Results The micro-CT result from the posterolateral fusion model showed whitlockite had slightly but significantly higher percent bone volume than tricalcium phosphate, though none of the materials formed successful fusion with surrounding bone tissue. The histology results showed the bone formed on the cortical surface of the transverse process but did not form a bridge between the processes. The result from the abdominal pouch model showed whitlockite did not induce ectopic bone formation. Conclusion Whitlockite had a potential of being a better bone substrate hydroxyapatite and tricalcium phosphate in spinal fusion with low risk of inducing ectopic ossification.

Assessing the Outcome of Transforminal Lumbar Interbody Fusion and Posterolateral Lumbar Fusion with Instrumentation in Treatment of Degenerative Lumbar Disorders

Background Degenerative lumbar disorders are relatively common condition that typically affects persons over the age of 50 and are more common in females. Patients typically present with a constellation of symptoms that include back pain, radiculopathy, and/or neurogenic claudication. Aim of the Work to assess the clinical and radiological outcome of Transforaminal Lumbar Interbody Fusion (TLIF) and posterolateral fusion (PLF) in the treatment of degenerative lumbar disorders. Patients and Methods a prospective study was conducted on patients with degenerative lumbar spondylolisthesis and degenerative lumbar spine stenosis who were admitted to Neurosurgical department at Ain Shams University hospital and Arab contractors medical center and underwent lumbar spine fixation with either transforaminal interbody fusion or posterolateral fusion from February 2017 to February 2019. The patients were divided into two groups according to the operative procedure done for each group. Group A (20 patients) included patients who underwent transforaminal lumbar interbody fusion. Group B (20 patients) included patients who underwent posterolateral fusion. Results We found that both TLIF and PLF provide improvement of disability and pain in patients with degenerative lumbar disorders. TLIF is superior to PLF with regard to achieving radiographic fusion. There is no strong evidence to support the use of TLIF over traditional PLF in treatment of degenerative lumbar disorders, especially with the increased material costs associated with interbody fusion. Conclusion both TLIF and PLF provide improvement of disability and pain in patients with degenerative lumbar disorders. TLIF is superior to PLF with regard to achieving radiographic fusion.

Decompressive laminectomy with instrumented posterolateral fusion for degenerative lumbar disease in elderly, is it safe and beneficial?

Background With improvement of health care in last decades, the age of general population increased. As the elderly with degenerative lumbar disease needs to remain physically active for more years, lumbar decompression surgery with instrumented fusion is further considered and is gaining wide acceptance as it provides good results with relative minimal risk. This study aim to evaluate the safety and efficacy of lumbar decompression with instrumented fusion in elderly Results This is a prospective non-randomized clinical study conducted from July 2014 to July 2019. The included patients had chronic low back pain, radiculopathy, and/or neurogenic claudication due to degenerative lumbar disease with failed conservative management. They underwent lumbar decompression with instrumented posterolateral fusion. All patients were at least 55 years old at time of surgery and were clinically assessed as regard perioperative risk and morbidity, besides assessment of pre- and postoperative visual analog score (VAS) and Oswestry Disability Index (ODI). Data was collected and analyzed. Thirty-five patients were included in this study with mean age of 63 years. All patients presented with back pain, 77.1% with radiculopathy, and 60% with neurogenic claudication. Preoperative comorbidity was present in 60% of cases, where hypertension, diabetes, and cardiac troubles were 31.4%, 31.4%, and 14.3% respectively. The average operated level was 3.1. The complication rate was 11.4% with 2 cases with dural tear (5.7%), 2 cases with CSF leakage (5.7%), 1 case with wound seroma (2.8%), and 1 case with wound infection. Postoperative new comorbidity occurred in 5 cases (14.3%). Visual analog score (VAS) and Oswestry disability index (ODI) were recorded preoperatively and 18 months postoperatively; as regards pain, VAS improved significantly from 7.8 ± 0.87 to 1.8 ± 1.04 (P value< 0.00001), and ODI improved significantly from 58.1 ± 11 to 17.5 ± 8.3 (P value< 0.00001). Conclusion Lumbar decompression surgery with posterolateral instrumented fusion is a safe and effective surgery in elderly, as it provides significant results and gives them a chance for better quality of life. Preoperative comorbidity could be dealt with, and it should not be considered as a contraindication for surgery in this age group.

Efficacy of Topical Tranexamic Acid in Reducing Blood Loss after Laminectomy and Posterolateral Fusion of the Spine: A Randomized, Double-Blinded, Placebo-Controlled Clinical Trial

Background: Multi-level spine surgeries are associated with high bleeding during and after surgery. A majority of studies have previously evaluated the effect of tranexamic acid (TXA) in reducing bleeding with a focus on intravenous (IV) administration. The aim of the study was to evaluate the efficacy of topical TXA in decreasing bleeding after laminectomy and spinal fusion. Methods: In this randomized, double-blinded, placebo-controlled clinical trial, 80 patients were enrolled from January 2017 to January 2019. The patients were eligible for laminectomy (2 or more levels) and posterolateral fusion with a pedicle screw. Patients were randomly divided into two equal groups; single-dose TXA (1 g/50 ml) and normal saline. Intergroup comparison was performed for the amount of bleeding during and after surgery, received packed cells, and the number of hospitalization days. Results: The mean age of the patients was 55.51 ± 10.27 years, and 50 of them were women. 18 and 20 patients in control and TXA groups had intraoperative bleeding more than 400 ml, respectively (P ˃ 0.05). The only significant difference was observed in the first and second 12 hours, and total bleeding after surgery in patients who had bleeding above 400 ml (P = 0.011, P = 0.039, P = 0.015, respectively). Conclusion: The application of topical TXA was effective in patients with high amount of hemorrhage during spine surgery for reducing the bleeding rate in the first and second 12 hours, as well as the mean total bleeding rate after surgery. It had no significant effect on total intraoperative hemorrhage, total packed cells, and total hospitalization length.

Incidence and Predictive Factors of Distal Pedicle Screw Loosening Followed Posterior Corrective Surgery for Degenerative Lumbar Scoliosis

BackgroundThe aim of this study was to identify the prevalence of distal pedicle screw loosening (DPSL) following posterior decompression and instrumented fusion for DLS, to search for predictable risk factors for DPSL, and hope to provide references in decision making and surgical planning for spine surgeons. MethodsOne hundred and fifty-three consecutive DLS patients surgically treated between January 2013 and July 2018 were retrospectively reviewed. The diagnostic criteria for DPSL developed by X-ray include the radiolucent area (thicker than 1 mm) around screw and the “double halo” sign defined as the presence of radiolucent area and radiopaque rim at the same X-ray. According to the occurrence of DPSL at two-year follow-up, patients were divided into two groups: study group (screw loosening) and control group (without screw loosening). To investigate predictive factors for distal pedicle screw loosening, three categorized factors were analyzed statistically.ResultsDPSL was detected in 72 of 153 patients (47.1%) at two-year follow up, and were enrolled as study group. Another 81 patients presented no screw loosening at two-year follow up, and were enrolled as control group. Hounsfield unit (HU) value was lower in study group than that in control group. Fusion level was longer in study group than that in control group. Lower instrumented vertebrae on L5 was less in study group than that in control group. Posterolateral fusion was less in study group than that in control group. Preoperative Cobb angle, postoperative Cobb angle, Cobb angle correction, preoperative lumbosacral coronal angle (LSCA), LSCA correction, preoperative thoracolumbar junction (TL), postoperative TL were larger in study group than those in control group. Logistic regression analysis revealed that low Bone mineral density (BMD) (<169 HU), posterolateral fusion, Cobb angle correction (>16 degrees), LSCA correction (>9 degrees) were independently associated with DPSL.ConclusionsThe incidence of DPSL following posterior decompression and instrumented fusion for DLS is 47.1%. Low BMD, large correction of both main curve and fractional curve are predictive factors for DPSL, while posterolateral fusion is a protective factor.