[Commentary on relevant issues in surgical treatment of spinal metastatic tumors].

The multidisciplinary treatment model led by surgery has become a comprehensive strategy and overall concept for the treatment of spinal metastatic tumors. But the surgical treatment of spinal metastatic tumors is different from primary malignant tumors of the spine. Surgery is only a part of the multidisciplinary comprehensive treatment. Therefore, the following aspects need to be evaluated comprehensively based on the survival assessment, evaluation of spinal stability damage, nerve dysfunction, and oncological characteristics of the metastatic tumors with a reasonable surgical intervention. The attention should be paid to the minimally invasive treatment of spinal metastases, progress of new radiotherapy technology, neoadjuvant chemotherapy, targeted drug therapy and other medical treatment to make a comprehensive and individualization decision which is benefit to relieve patients ' pain, reconstruct spinal stability and avoid paralysis. While improving patient survival, increasing local tumor control rate and possibly prolonging survival time, avoiding excessive surgery as much as possible.

Efficacy of Biocage in treating single-segment lumbar degenerative disease in patients with high risk of non-fusion: a prospective controlled study with at least 2 years' follow-up.

OBJECTIVE: To evaluate the clinical efficacy of an allogeneic bone cage (Biocage; Beijing Datsing Bio-Tech Co., Ltd., Beijing, China) for treatment of single-segment lumbar degenerative disease in patients with a high risk of non-fusion. METHODS: From January 2013 to December 2016, 67 patients who underwent lumbar fusion were divided into the Biocage group (n = 33) and polyether ether ketone (PEEK) group (n = 34). The patients were followed up for 24 to 48 months. The mean intervertebral height of the fusion level, fusion rate, height of the intervertebral foramen, visual analog scale score, and Oswestry disability index were compared. RESULTS: The PEEK group had a lower fusion rate than the Biocage group (88.24% vs. 90.91%), although the difference was not statistically significant. During follow-up, the height of the intervertebral space was similar between the Biocage and PEEK groups (12.88 ± 0.45 and 12.84 ± 1.01 mm, respectively). The height of the intervertebral foramen was larger in the Biocage than PEEK group (20.67 ± 1.34 vs. 20.00 ± 2.05 mm). Good clinical efficacy was achieved in both groups. CONCLUSION: The Biocage is efficient and safe for treatment of single-segment lumbar degenerative disease in patients with a high risk of non-fusion.

Clinical Efficacy of Three Surgical Approaches for the Treatment of Cervicothoracic Tuberculosis: A Multicenter Retrospective Study.

OBJECTIVE: To evaluate the efficacy of three surgical approaches for the treatment of cervicothoracic tuberculosis. METHODS: This is a multicenter retrospective study. We analyzed 74 patients with cervicothoracic tuberculosis who were treated in six institutions between January 2000 and January 2015. There were 37 male and 37 female patients, with an average age of 24 years (range, 5-62 years). The operative method was selected according to the indications. A total of 33 patients underwent one-stage anterior surgery (group A); 16 underwent a combined anterior and posterior surgery (group B) and 25 underwent one-stage posterior surgery (group C). Clinical outcomes, laboratory indexes, and radiological results were analyzed. RESULTS: All cases were followed up for approximately 36-96 months post-surgery (average, 39 months). At the last follow-up, patients in all three groups had achieved bone fusion, with pain relief and neurological recovery. No major vessel and nerve injuries were found during the operation. There were significant differences before and after treatment for visual analogue scale (VAS), neck disability index (NDI), and Japanese Orthopedic Association (JOA) score (P < 0.001). Three surgical strategies significantly improved kyphosis (P < 0.001). CONCLUSION: The choice of operation for cervicothoracic tuberculosis should be selected based on the pathological changes, scope, and general physical condition of the patient. The indication for a posterior approach is narrow and it should be used selectively. The combined anterior and posterior approach involved a longer operating time, larger blood loss, and greater trauma, and also required a higher level of surgical skill. Therefore, the indications for this approach should be strictly controlled. Anterior approach surgery for the treatment of cervicothoracic tuberculosis showed excellent efficacy and fewer complications.

Comparison of Anterior only and Combined Anterior and Posterior Approach in Treating Lumbosacral Tuberculosis.

A combined anterior and posterior (AP) surgical approach is a popular treatment modality of lumbosacral tuberculosis, but it is often traumatic and complicated. The present study aims to find whether the anterior only approach with the ARCH plate system is less invasive than the AP approach in treating lumbosacral tuberculosis. The ARCH plate system is an innovative anatomic lumbosacral anterior multi-directional locking plate system which was devised with due consideration to the anatomic features of the lumbosacral spine and irregular destruction of involved vertebral endplates. In this retrospective study, 32 patients with lumbosacral tuberculosis underwent surgeries via either the anterior only approach (ARCH group, 18 patients) using the ARCH system or the conventional combined anterior and posterior approach (AP group, 14 patients). American Spinal Injury Association (ASIA) scores, Visual Analogue Scale (VAS) scores, Oswestry Disability Index (ODI), bone union status, ESR, CRP, intervertebral foraminal height between L5 and S1, the vertical height between the anterior upper edge of L5 and S1 vertebral body, lumbosacral angle, and the physiological lordosis of between L1 and S1 from both groups were recorded and compared. All patients were followed up for at least two years. The average duration of operation, blood loss, and length of hospital admission of the ARCH group (154.6 min, 361.1 ml&18.3days) was significantly smaller and shorter(p < 0.001, p < 0.001 & p = 0.008) that those of the AP group(465.5 min, 814.3 ml & 24.6days). The ODI score(p = 0.08, 0.471, 0.06, 0.07, 0.107), the VAS score(p = 0.099, 0.249, 0.073, 0.103, 0.273), the intervertebral foraminal height between L5 and S1(p = 0.826, 0.073, 0.085), L5-S1 height(p = 0.057, 0.234, 0.094), lumbosacral angle(p = 0.052, 0.242, 0.825), and L5-S1 lordosis(p = 0.146, 0.129, 0.053) of both groups showed no significant difference in any of the time points. The anterior only approach using the ARCH system is as effective as the combined anterior and posterior approach and is less traumatic in treating lumbosacral tuberculosis.

Surgical treatment of thoracolumbar spinal tuberculosis-a multicentre, retrospective, case-control study.

BACKGROUND: The purpose of this multicentre, retrospective study was to evaluate the safety and efficacy of different surgical approaches for treating thoracolumbar tuberculosis. METHODS: This study reviewed 132 patients with thoracolumbar tuberculosis in six institutions between January 1999 and January 2015 surgically treated by an anterior-only approach (n = 22, group A), an anterior combined with posterior approach (n = 79, group B), and a posterior-only approach (n = 31, group C). All patients were treated with standard antituberculosis drugs pre- and postoperatively and were followed regularly after surgery. Clinical symptoms, nerve function, and the erythrocyte sedimentation rate were observed, and kyphosis correction and bone fusion were evaluated by X-ray or computed tomography. RESULTS: At the last follow-up, all patients had achieved bone fusion, relief from pain, and neurological recovery. The Cobb angle was improved; however, the Cobb angle showed a degree of loss at the final follow-up after all three surgical approaches. Further comparisons revealed a difference in angle loss at the final follow-up among the three groups; groups B and C were superior to group A in maintenance of the correction. The posterior-only approach was characterized by a shorter operative time and reduced blood loss. CONCLUSIONS: Surgery by a posterior-only approach is superior to that by an anterior-only approach and anterior combined with posterior approach in terms of permanent kyphosis correction and spinal stability maintenance. Therefore, we recommend surgery by a posterior-only approach as the optimized treatment for thoracolumbar tuberculosis if the indications for this treatment are met.

Application of New Allogeneic Lumbar Fusion Cage (Biocage) in Single-Segment Lumbar Degenerative Disease: A Prospective Controlled Study with Follow-Up for ≥2 Years.

OBJECTIVE: We evaluated the clinical efficacy of the Biocage in lumbar fusion surgery and its safety and effectiveness. METHODS: A total of 431 patients with single-segment lumbar degenerative disease diagnosed from January 2013 to December 2016 were considered for the present prospective, nonrandomized, and controlled study; 52 patient met the exclusion criteria and were excluded. The patients were divided into 2 groups according to their cage choice: Biocage (n = 206) and polyether ether ketone (PEEK) cage (n = 173). The patients were followed up for 24-48 months (average, 32). The operative time, blood loss, hospitalization duration, mean intervertebral fusion segment height, height of intervertebral foramen, fusion time, fusion rate, internal fixation failure rate, visual analog scale score, and Oswestry disability index were compared between the 2 groups. RESULTS: All the patients underwent surgery successfully. No significant differences were found in gender, age, clinical diagnosis, lesion segment, operative time, blood loss, visual analog scale score, or Oswestry disability index between the 2 groups. No significant differences were found in the fusion rate; however, the Biocage group had a greater fusion rate and shorter fusion time than the PEEK group. During follow-up, the mean intervertebral height recovered significantly in the Biocage group compared with the PPEK group (P < 0.05). The height of the intervertebral foramen was significantly different between the 2 groups, and recovery was better in the Biocage group (P < 0.05). The Cobb angle of fusion segment in both groups improved significantly postoperatively compared with preoperatively (P < 0.05). The improvement in Cobb angle was significantly different between the 2 groups (P < 0.05). CONCLUSIONS: The Biocage has excellent clinical efficacy in the treatment of lumbar degenerative disease. Although the Biocage achieved good therapeutic effects, it did not show obvious advantages compared with the PEEK cage. Therefore, the Biocage can only be used as a choice of bone graft materials for lumbar fusion surgery and should not completely replace the PEEK cage.

Surgical treatment of lumbosacral tuberculosis by one-stage debridement and anterior instrumentation with allograft through an extraperitoneal anterior approach.

BACKGROUND: This study was aimed to investigate the clinical outcome of lumbosacral tuberculosis treatment by one-stage radical debridement with bone allograft reconstruction and anterior instrumentation via a retroperitoneal approach. METHODS: We retrospectively analyzed a series of 43 patients with lumbosacral tuberculosis in whom the lumbosacral junction was exposed via an anterior midline retroperitoneal approach. After radical debridement, two parallel tricortical iliac crest bone allografts were placed to reconstruct the anterior column, and then anterior fixation was performed. RESULTS: The mean follow-up period was 34 months (range, 24-91 months), during which no obvious loss of correction was observed. No case experienced recurrence, tuberculous peritonitis, erectile dysfunction, or retrograde ejaculation. CONCLUSIONS: The midline retroperitoneal approach provides direct and safe access to lesions of lumbosacral tuberculosis. Two parallel structural iliac crest allografts and anterior instrumentation effectively stabilize the lumbosacral junction.

Prevascularisation with endothelial progenitor cells improved restoration of the architectural and functional properties of newly formed bone for bone reconstruction.

PURPOSE: The aim of this study was to examine whether the addition of endothelial progenitor cells (EPCs) contributes to restoring the architectural and functional properties of newly formed bone for reconstruction of bone defects. METHODS: Bone marrow-derived EPCs and mesenchymal stem cells (MSCs) were co-seeded onto demineralized bone matrix (DBM) as a prevascularized tissue-engineered bone (TEB) for the repair of segmental bone defects to evaluate the effects of prevascularization of TEB on ameliorating morphological, haemodynamic and mechanical characteristics. RESULTS: The restoration of the intraosseous vasculature and medullary cavity was improved markedly compared to the non-prevascularized groups. The blood supply, biomechanical strength, and bone mineral density of the prevascularized group were significantly higher than those of the non-prevascularized groups during bone reconstruction. CONCLUSIONS: The present study indicates that EPC-dependent prevascularization contributes to bone healing with structural reconstruction and functional recovery and may improve the understanding of correlation between angiogenesis and osteogenesis.

Effects of initial cell density and hydrodynamic culture on osteogenic activity of tissue-engineered bone grafts.

This study aimed to study the effects of initial cell density and in vitro culture method on the construction of tissue-engineered bone grafts and osteogenic activities. Human mesenchymal stem cells (hMSCs) were seeded onto cubic scaffolds prepared from demineralized bone matrix (DBM) by three methods - static, hydrodynamic, or fibrin hydrogel-assisted seeding. The resulting cell-scaffold constructs were cultured in vitro by static flask culture or hydrodynamic culture. The initial cell density and the subsequent in vitro proliferation and alkaline phosphate activities of the constructs were analyzed. The constructs were also subcutaneously implanted in nude mice to examine their in vivo osteogenic activities. Hydrogel-assisted seeding gave the highest seeding efficiency, followed by hydrodynamic and conventional static seeding. During in vitro culture, hydrodynamic culture produced higher plateau cell densities, alkaline phosphatase (ALP) activities, and extracellular matrix production than static culture. After subcutaneous implantation in nude mice, the implants prepared by the combination of hydrogel-assisted seeding and hydrodynamic culture produced higher wet weight and bone mineral density than implants prepared by other methods. The results suggest that the hydrogel-assisted seeding can substantially increase the initial seed cell density in scaffolds. Subsequent hydrodynamic culture can promote the proliferation and osteoblastic differentiation of the seeded cells. Correspondingly, bone grafts produced by the combination of these two methods achieved the highest osteogenic activity among the three methods employed.

Co-culture with endothelial progenitor cells promotes survival, migration, and differentiation of osteoclast precursors.

In this study, we report the effect of endothelial progenitor cells (EPCs) on the biological behavior of osteoclast precursors in vitro by establishing an indirect co-culture system of mice EPCs and RAW 264.7 monocyte cells. Results show that the survival, migration, and differentiation of osteoclast precursors were greatly enhanced when co-cultured with EPCs. These phenotypic changes coincide with the upregulation of multiple genes affected cell behavior, including phospho-VEGFR-2, CXCR4, phospho-Smad2/3, phospho-Akt, phospho-ERK1, and phospho-p38 MAPK. The results collectively suggest that EPCs could modulate the survival, migration, and differentiation potential of osteoclast precursors, thus providing new insights in understanding of correlation between angiogenesis and bone homeostasis.

Repair of large segmental bone defects using bone marrow stromal cells with demineralized bone matrix.

OBJECTIVE: The aim of the present study was to evaluate the effect of tissue-engineered constructs on repair of large segmental bone defects in goats. METHODS: Allogenic demineralized bone matrix (aDBM) was seeded with autologous marrow stromal cells (aMSC) for seven days to construct DBM-MSC grafts prior to implantation. 24 goats were randomly divided into three groups (eight in each). In each group, 3 cm diaphyseal femoral defects were created unilaterally, and subsequently filled with the DBM-MSC grafts, DBM alone and an untreated control, respectively. Radiological analysis and biomechanical evaluation were performed at 12 and 24 weeks after operation. RESULTS: Obvious increases in radiological scoring and biomechanical strength were found in the DBM-MSC group when compared to the DBM group. X-ray examination showed excellent bone healing in the DBM-MSC group, whereas only partial bone repair was seen in the DBM group, and no healing in untreated controls. Histologically, a tendency to bone regeneration and remodeling was far more obvious for the DBM-MSC group than the DBM only and untreated controls. CONCLUSION: Our results strongly suggest that transplantation of bone MSC within a DBM could have advantages for the bone repair of large segmental defects.