Comparison between alkali heat treatment and sprayed hydroxyapatite coating on thermally-sprayed rough Ti surface in rabbit model: Effects on bone-bonding ability and osteoconductivity.

In this study, we investigated the effect of different surface treatments (hydroxyapatite (HA) coating, alkali heat treatment, and no treatment) on the ability of bone to bond to a rough arc-sprayed Ti metal surface, using rabbit models. The bone-to-implant contacts for untreated, HA-coated, and alkali heat-treated implants were 21.2%, 72.1%, and 33.8% at 4 weeks, 21.8%, 70.9%, and 30.0% at 8 weeks, and 16.3%, 70.2%, and 29.9% at 16 weeks, respectively (n = 8). HA -coated implants showed significantly higher bone-to-implant contacts than the untreated and alkali heat-treated implants at all the time point, whereas alkali heat-treated implants showed significantly higher bone-to-implant contacts than untreated implants at 4 and 16 weeks. The failure loads in a mechanical test for untreated, HA coated, alkali heat-treated plates were 65.4 N, 70.7 N, and 90.8 N at 4 weeks, 76.1 N, 64.7 N, and 104.8 N at 8 weeks and 88.7 N, 92.6 N, and 118.5 N at 16 weeks, respectively (n = 8). The alkali heat-treated plates showed significantly higher failure loads than HA-coated plates at 8 and 16 weeks. The difference between HA-coated plates and untreated plates were not statistically significant at any time point. Thus HA coating, although it enables high bone-to-implant contact, may not enhance the bone-bonding properties of thermally-sprayed rough Ti metal surfaces. In contrast, alkali heat treatment can be successfully applied to thermally-sprayed Ti metal to enhance both bone-to-implant contact and bone-bonding strength

Predictive value of heterogeneously enhanced MRI findings with CT evidence of calcification for severe motor deficits in spinal meningioma

OBJECTIVE: Spinal meningioma is mostly benign, but they can exhibit neurological deficit. The relationship between neurological impairment and its radiographic findings, including intratumor magnetic resonance imaging (MRI) gadolinium enhancement and calcification in computed tomography (CT) scan, has not been studied. The purpose of this study was to investigate the association of preoperative image findings with neurological status in spinal meningioma. METHODS: Patients histologically diagnosed with spinal meningioma (n = 24), with an average age of 65.4 years, were included. The patients were classified into 2 groups, the homogeneous and heterogeneous groups, based on the contrast-enhanced T1-weighted MRI findings. Further, baseline demographics (age, sex, presence of preoperative paralysis [manual muscle testing 3 or worse neurological deficit in upper and/or lower limbs], tumor level, tumor length, and tumor occupation ratio), histological findings (Ki-67 index and histological subtypes), and CT findings (presence of intratumor calcification and Hounsfield unit [HU] value) were examined. RESULTS: Preoperative paralysis was observed in 33.3% (8 of 24) of the patients. These patients exhibited frequent heterogeneous contrast-enhanced MRI findings than those without preoperative paralysis (57.1% vs. 14.3%, p = 0.040). Further, preoperative paralysis did not associate with tumor level, tumor length, tumor-occupied ratio, Ki-67 index, and histological subtypes. The heterogeneous group showed 100% intratumor calcification and higher maximum HU than the homogeneous group (1, 109.8 vs. 379.2, p = 0.001). CONCLUSION: The heterogeneous contrast-induced MRI findings in the spinal meningioma were significantly associated with preoperative neurological impairment. Moreover, the intratumor contrast-deficient region in the heterogeneously enhanced tumors reflected marked calcification. The tumor hardness due to calcification may be related to preoperative neurological deficit

In vivo experimental study of anterior cervical fusion using bioactive polyetheretherketone in a canine model

Background: Polyetheretherketone (PEEK) is a widely accepted biomaterial, especially in the field of spinal surgery. However, PEEK is not able to directly integrate with bone tissue, due to its bioinertness. To overcome this drawback, various studies have described surface coating approaches aimed at increasing the bioactivity of PEEK surfaces. Among those, it has been shown that the recently developed sol-gel TiO2 coating could provide PEEK with the ability to bond with bone tissue in vivo without the use of a bone graft. Objective: This in vivo experimental study using a canine model determined the efficacy of bioactive TiO2-coated PEEK for anterior cervical fusion. Methods: Sol-gel–derived TiO2 coating, which involves sandblasting and acid treatment, was used to give PEEK bone-bonding ability. The cervical interbody spacer, which was designed to fit the disc space of a beagle, was fabricated using bioactive TiO2-coated PEEK. Both uncoated PEEK (control) and TiO2-coated PEEK spacers were implanted into the cervical intervertebral space of beagles (n = 5 for each type). After the 3-month survival period, interbody fusion success was evaluated based on μ-CT imaging, histology, and manual palpation analyses. Results: Manual palpation analyses indicated a 60% (3/5 cases) fusion (no gap between bone and implants) rate for the TiO2-coated PEEK group, indicating clear advantage over the 0% (0/5 cases) fusion rate for the uncoated PEEK group. The bony fusion rate of the TiO2-coated PEEK group was 40% according to μCT imaging; however, it was 0% of for the uncoated PEEK group. Additionally, the bone–implant contact ratio calculated using histomorphometry demonstrated a better contact ratio for the TiO2-coated PEEK group than for the uncoated PEEK group (mean, 32.6% vs 3.2%; p = 0.017). Conclusions: The TiO2-coated bioactive PEEK implant demonstrated better fusion rates and bone-bonding ability than did the uncoated PEEK implant in the canine anterior cervical fusion model. Bioactive PEEK, which has bone-bonding ability, could contribute to further improvements in clinical outcomes for spinal interbody fusion

Paraplegia Caused by Multifocal Osteosarcoma With Spinal Lesions

Background: Multifocal osteosarcoma is a rare condition that may be either synchronous or metachronous. Spine involvement of multifocal osteosarcoma is very rare. Synchronous multifocal osteosarcoma is typically described as the occurrence of tumors at two or more sites in the absence of pulmonary metastases. Methods: A 55-year-old man initially presented with low back pain. Multiple osteosclerotic lesions were observed, primarily in the spine and pelvis, as well as in soft tissues. Lung lesions were observed, but they were relatively small at reference. Laboratory tests showed a markedly elevated alkaline phosphatase (ALP) level of 36, 416 U/L (normal range, 115-359 U/L). Based upon a diagnosis of osteosarcoma on biopsy, chemotherapy was administered, resulting in a decrease in ALP to 17, 833 U/L. Results: Decompression of the symptomatic compressed spinal cord and posterior spinal stabilization of T8-12 were performed. However, progressive extensions of multiple lesions to the spinal canal led to paraplegia with urinary dysfunction. Eleven months after the first visit to our hospital, the patient died due to multiple organ failure. Conclusions: Multifocal osteosarcoma accompanied by spinal lesions may lead to paraplegia, a clinical problem that negatively affects the quality of activities of daily living. Level of Evidence 4. Clinical Relevance: Multifocal osteosarcoma accompanied by spinal lesions may lead to paraplegia, a clinical problem that negatively affects the quality of life and activities of daily living

Diffuse idiopathic skeletal hyperostosis (DISH) is a risk factor for further surgery in short-segment lumbar interbody fusion.

First online: 01 October 2014[Purpose] To elucidate the effect of diffuse idiopathic skeletal hyperostosis (DISH) on the clinical results of short-segment lumbar interbody fusion (LIF) for the treatment of degenerative lumbar spinal diseases. [Methods] The 208 patients who underwent one- or two-level LIF were selected as the subjects of this study. Patients with prior lumbar fusion surgery or follow-up <1 year were excluded. Outcome measures were surgery-free survival or the need for further surgery for pseudoarthrosis and/or adjacent segment disease (ASD). The Cox proportional-hazards model was used to identify possible risk factors (DISH, age, sex, number of levels fused, level of the lowest instrumented vertebra, and laminectomy adjacent to the index fused levels) for further surgery. [Results] Among the 208 patients (39 with DISH), 21 patients required further surgery during follow-up. Cox analysis showed that DISH (hazard ratio = 5.46) and two-level fusion (hazard ratio = 2.83) were significant independent predictors of further surgery. Age, sex, level of the lowest instrumented vertebra, and laminectomy adjacent to the index fused levels were not significant predictors. [Conclusions] DISH after short-segment LIF surgery is a significant risk factor for further surgery because of pseudoarthrosis or ASD

Outcome of Surgical Treatment for Metastatic Vertebra Bone Tumor in Advanced Lung Cancer

Background: Spinal metastases of patients with advanced stage lung cancer are an important target for palliative therapy, because their incidence is high, and they often cause severe symptoms and worsen the quality of life. Surgery is one of the most effective treatment options, but the indication of surgery is unclear as the procedure is invasive and patients with spinal metastasis have a rather short life expectancy. Furthermore, there have been few studies that have focused on lung cancer with poor prognosis. Methods: We reviewed all of the cases of lung cancer from January 1999 to July 2007 in the Department of Respiratory Medicine, Kyoto University Hospital, Japan. Thirteen patients with metastatic spinal tumor of lung cancer underwent surgery, and all of them had a poor performance status score (3 or 4). Results: Neurological improvement by at least 1 Frankel grade was seen in 10 of 14 cases (71%). Improvement of the movement capacity was noted in 9 of 14 cases (64%), and pain improvement was noted in 12 of 14 (86%). Median postoperative survival was 5 months (1–25 months). In particular, the group with a good postoperative performance status score (0–2) was shown to have a better median postoperative survival of 13 months. Conclusions: Surgical treatment for symptomatic metastatic spinal tumor of lung cancer can improve quality of life in a substantially high percentage of patients. Surgery should be considered even if preoperative performance status is poor

Stand-Alone Anterior Cervical Discectomy and Fusion Using an Additive Manufactured Individualized Bioactive Porous Titanium Implant without Bone Graft: Results of a Prospective Clinical Trial

The purpose of this study was to introduce our patient-specific bioactive porous titanium implant manufactured using selective laser melting (SLM) and to establish the efficacy and safety of the implant for stand-alone anterior cervical discectomy and fusion (ACDF) based on a prospective clinical trial. We designed a customized ACDF implant using patient-specific data and manufactured the implant using SLM. We produced a bioactive surface through a specific chemical and thermal treatment. Using this implant, we surgically treated four patients with cervical degenerative disc disease and evaluated the clinical and radiological results. We achieved successful bony union in all but one patient without autologous bone grafting within 1 year. We observed no implant subsidence during the follow-up period, and all clinical parameters improved significantly after surgery, with no reported implant-related adverse effects. Our customized bioactive porous titanium implant is a safe and promising implant for stand-alone ACDF

The relationship between spino-pelvic-hip mobility and quality of life before and after total hip arthroplasty

Introduction Total hip arthroplasty (THA) can significantly improve quality of life (QOL) in patients with hip osteoarthritis. A relationship exists between activity levels and postoperative QOL, but its determinants are not well known. The aim of this work was to investigate the relationship between hip, pelvis and lumbar spine mobility and alignment before and after THA with QOL. Material and methods Consecutive patients with hip arthrosis and an indication for THA were included prospectively between July 2019 and December 2020, and they underwent lateral radiographs in free-standing, extension, relaxed- and flexed-seated position. Spinopelvic and hip parameters were measured, as well as their changes between positions to assess hip, pelvis and lumbar spine mobility. Patients were also administered QOL questionnaires. Data were collected preoperatively and 6 and 12 months postoperatively. Results Seventy patients were included; QOL significantly increased 6 months after THA (from 18 [10; 27] to 61 [48; 72], p < 0.001). QOL further increased by 10 points or more after 6 months in 18% of patients, while it decreased in 16%. The latter showed higher pelvic range of motion (between flexion and extension) than the former. Conclusions This study confirmed that QOL is significantly improved by THA, and that spinopelvic alignment and function can play a role. Future work should elucidate how to better predict postoperative QOL from preoperative patient characteristics to improve patient treatment and establish early postoperative physical therapy for patients who could benefit from postoperative improvement of activity-related QOL

Synergistic effect of sulfonation followed by precipitation of amorphous calcium phosphate on the bone-bonding strength of carbon fiber reinforced polyetheretherketone

Sulfonation and applications of amorphous calcium phosphate are known to make polyetheretherketone (PEEK) bioactive. Sulfonation followed by precipitation of amorphous calcium phosphate (AN-treatment) may provide PEEK with further bone-bonding strength. Herein, we prepared a carbon-fiber-reinforced PEEK (CPEEK) with similar tensile strength to cortical bone and a CPEEK subjected to AN-treatment (CPEEK-AN). The effect of AN-treatment on the bone-bonding strength generated at the interface between the rabbit’s tibia and a base material was investigated using a detaching test at two time-points (4 and 8 weeks). At 4 weeks, the strength of CPEEK-AN was significantly higher than that of CPEEK due to the direct bonding between the interfaces. Between 4 and 8 weeks, the different bone forming processes showed that, with CPEEK-AN, bone consolidation was achieved, thus improving bone-bonding strength. In contrast, with CPEEK, a new bone was absorbed mainly on the interface, leading to poor strength. These observations were supported by an in vitro study, which showed that pre-osteoblast on CPEEK-AN caused earlier maturation and mineralization of the extracellular matrix than on CPEEK. Consequently, AN-treatment, comprising a combination of two efficient treatments, generated a synergetic effect on the bonding strength of CPEEK

Prevalence and Distribution of Ossified Lesions in the Whole Spine of Patients with Cervical Ossification of the Posterior Longitudinal Ligament A Multicenter Study (JOSL CT study)

Ossification of the posterior longitudinal ligament (OPLL) can cause severe and irreversible paralysis in not only the cervical spine but also the thoracolumbar spine. To date, however, the prevalence and distribution of OPLL in the whole spine has not been precisely evaluated in patients with cervical OPLL. Therefore, we conducted a multi-center study to comprehensively evaluate the prevalence and distribution of OPLL using multi-detector computed tomography (CT) images in the whole spine and to analyze what factors predict the presence of ossified lesions in the thoracolumbar spine in patients who were diagnosed with cervical OPLL by plain X-ray. Three hundred and twenty-two patients with a diagnosis of cervical OPLL underwent CT imaging of the whole spine. The sum of the levels in which OPLL was present in the whole spine was defined as the OP-index and used to evaluate the extent of ossification. The distribution of OPLL in the whole spine was compared between male and female subjects. In addition, a multiple regression model was used to ascertain related factors that affected the OP-index. Among patients with cervical OPLL, women tended to have more ossified lesions in the thoracolumbar spine than did men. A multiple regression model revealed that the OP-index was significantly correlated with the cervical OP-index, sex (female), and body mass index. Furthermore, the prevalence of thoracolumbar OPLL in patients with a cervical OP-index ≥ 10 was 7.8 times greater than that in patients with a cervical OP-index ≤ 5. The results of this study reveal that the extent of OPLL in the whole spine is significantly associated with the extent of cervical OPLL, female sex, and obesity