Osteoporotic fractures and persistent non-fusion of the hand epiphyses caused by empty sella syndrome in an adult: a case report

We report a case of primary empty sella syndrome (ESS) resulting in osteoporotic fractures and persistent non-fusion of the hand epiphyses, and discuss the potential pathogenesis of this disease. A 41-year-old man presented with pain in the right hand and back after a fall. X-radiographs revealed persistent epiphyses and severe osteoporosis. Serum phosphorus and prolactin levels were above normal levels, and free triiodothyronine, free thyroxine and testosterone levels were below normal limits. Magnetic resonance imaging of the head revealed empty sella. A lumbar bone mineral density examination indicated severe osteoporosis. ESS caused a systemic hormone disorder in this patient, resulting in osteoporotic fractures and persistent non-fusion of the hand epiphyses. Possible causes of this anomaly are chronic or congenital abnormities of the pituitary gland.

[Osteogenetic capacity of cross-linked adjustable anti-tuberculosis drug sustained-release artificial composite]

OBJECTIVE

To explore the osteogenetic capacity of cross-linked adjustable anti-tuberculosis drug sustained-release artificial composite (TPB/SA-RFP/PLA).

METHODS

The model of femur bone defect was established in rabbits.TPB/SA-RFP/PLA complex was implanted into defect parts in the experimental group while TPB/SA/PLA in the blank control group. At Weeks 4, 8 and 12, gross specimens received radiographic, histological and immunohistochemical examinations to determine the osteogenetic performance of TPB/SA-RFP/PLA.

RESULTS

As compared with the control group, TPB/SA-RFP/PLA complex had excellent osteogenic capacities while the TPB/SA/PLA group had no obvious osteogenic difference. Lane-sandhu histological and radiographic ratings demonstrated significant difference between TPB/SA-RFP/PLA (8.3 ± 0.3) and blank groups (2.2 ± 0.4) (P < 0.05). And TPB/SA/PLA showed no significant intragroup significance (P > 0.05). Two groups immunohistochemical Alkaline phosphatase was strongly positive in two test groups and weakly positive in the control group.

CONCLUSION

TPB/ SA-RFP/PLA has excellent profiles of bone conductivity and regeneration.And the incorporation of rifampin does not affect its osteogenetic capacity.

In vitro and in vivo evaluation of zinc-modified ca-si-based ceramic coating for bone implants

The host response to calcium silicate ceramic coatings is not always favorable because of their high dissolution rates, leading to high pH within the surrounding physiological environment. Recently, a zinc-incorporated calcium silicate-based ceramic Ca2ZnSi2O7 coating, developed on a Ti-6Al-4V substrate using plasma-spray technology, was found to exhibit improved chemical stability and biocompatibility. This study aimed to investigate and compare the in vitro response of osteoblastic MC3T3-E1 cells cultured on Ca2ZnSi2O7 coating, CaSiO3 coating, and uncoated Ti-6Al-4V titanium control at cellular and molecular level. Our results showed Ca2ZnSi2O7 coating enhanced MC3T3-E1 cell attachment, proliferation, and differentiation compared to CaSiO3 coating and control. In addition, Ca2ZnSi2O7 coating increased mRNA levels of osteoblast-related genes (alkaline phosphatase, procollagen α1(I), osteocalcin), insulin-like growth factor-I (IGF-I), and transforming growth factor-β1 (TGF-β1). The in vivo osteoconductive properties of Ca2ZnSi2O7 coating, compared to CaSiO3 coating and control, was investigated using a rabbit femur defect model. Histological and histomorphometrical analysis demonstrated new bone formation in direct contact with the Ca2ZnSi2O7 coating surface in absence of fibrous tissue and higher bone-implant contact rate (BIC) in the Ca2ZnSi2O7 coating group, indicating better biocompatibility and faster osseointegration than CaSiO3 coated and control implants. These results indicate Ca2ZnSi2O7 coated implants have applications in bone tissue regeneration, since they are biocompatible and able to osseointegrate with host bone.

The prognostic value of elevated vascular endothelial growth factor in patients with osteosarcoma: a meta-analysis and systemic review

BACKGROUND

Osteosarcoma is a primary malignancy of bone. Although new therapies continue to emerge, osteosarcoma-related morbidity and mortality remain high. Various studies have evaluated the prognostic value of VEGF levels in osteosarcoma patients, but they have yielded conflicting results.

METHODS

The 5-year survival of each study was aggregated following a methodological assessment, and a systematic review of eligible studies with meta-analysis and univariate analysis was performed to quantitatively review the correlation of VEGF overexpression with 5-year survival in patients with osteosarcoma.

RESULTS

A total of 387 patients in eleven papers were finally considered to be eligible for inclusion in our analysis. Aggregation of the 6 positive results in Kaplan-Meier curve showed a risk ratio of 2.84 (95% CI: 1.39-5.83, P = 0.004) associated with VEGF-positive conditions in comparison with VEGF-negative conditions, suggesting that there was significant association between VEGF positive and the 5-year mortality. But univariate analysis of eleven studies showed that there was a small inverse but not significant relationship between VEGF expression level and the 5-year survival of osteosarcoma patients, but stage III, neo-chemotherapy, the primary tumor location, osteoblastic histological subtype and the source of patients showed a significant impact on the 5-year survival of patients.

CONCLUSIONS

The prognostic significance of VEGF expression in all its isoforms is still unknown based on the limited data available, but we find VEGF165 may play an important role. Future studies should examine the relationship between VEGF isoform expression and patients' survival and the relationship between VEGF isoform expression and EMMPRIN expression, which could be helpful for predicting the prognosis of patients with osteosarcoma. Once the conclusion of whether the VEGF and its isoforms playing a role in osteosarcoma were reached, it would help guide clinical decision-making regarding therapy and outcomes. In addition, we recommend a >25% positive staining of the cells as a VEGF-positive cut-off value in immunohistochemistry, since we find a relatively strict detecting method is likely to yield significant result in the 5-year survival of patients.

Biodegradable Polymer-Coated, Gelatin Hydrogel/Bioceramics Ternary Composites for Antitubercular Drug Delivery and Tissue Regeneration

A simple and effective strategy for the treatment of osteoarticular tuberculosis is proposed through combining tissue engineering approach with anti-tuberculosis drug therapy. A series of tricalcium phosphate bioceramics (TPB) composites, coated by degradable polymer outside and loaded with rifampicin (RFP)-containing gelatin hydrogel inside, were thus fabricated and successfully applied to deliver antitubercular drug RFP into osseous lesion and concomitantly to induce tissue regeneration. RFP-loaded gelatin hydrogel/TPB composites could be readily prepared by filling RFP-containing gelatin solution into TPB and thenin situcrosslinking of gelatin with calcium ions. Depending on the concentrations of RFP, the loading efficiency of RFP in the composites varied in the range from approximately 2% to 5%. Moreover, the surface of these binary composites could be further coated by a biodegradable polymer, yielding biodegradable polymer-coated, RFP-containing gelatin hydrogel/TPB ternary composites. It was shown thatin vitrorelease of RFP from the ternary composites could be effectively sustained for a long period of time. Besides, these composites revealed good biocompatibility towards the survival of MC-3T3 cellsin vitroand could be used for tissue regenerationin vivoin a rabbit model. The results indicate that TPB ternary composites have great potential for the treatment of osteoarticular tuberculosis.

Chemical stability and antimicrobial activity of plasma sprayed bioactive Ca2ZnSi2O7 coating

Calcium silicate ceramic coatings have received considerable attention in recent years due to their excellent bioactivity and bonding strength. However, their high dissolution rates limit their practical applications. In this study, zinc incorporated calcium silicate based ceramic Ca(2)ZnSi(2)O(7) coating was prepared on Ti-6Al-4V substrate via plasma spraying technology aiming to achieve higher chemical stability and additional antibacterial activity. Chemical stability of the coating was assessed by monitoring mass loss and ion release of the coating after immersion in the Tris-HCl buffer solution and examining pH value variation of the solution. Results showed that the chemical stability of zinc incorporated coating was improved significantly. Antimicrobial activity of the Ca(2)ZnSi(2)O(7) coating was evaluated, and it was found that the coating exhibited 93% antibacterial ratio against Staphylococcus aureus. In addition, in vitro bioactivity and cytocompatibility were confirmed for the Ca(2)ZnSi(2)O(7) coating by simulated body fluid test, MC3T3-E1 cells adhesion investigation and cytotoxicity assay.

Preparation and properties of calcium phosphate cements incorporated gelatin microspheres and calcium sulfate dihydrate as controlled local drug delivery system

To develop high macroporous and degradable bone cements which can be used as the substitute of bone repairing and drug carriers, cross-linked gelatin microspheres (GMs) and calcium sulfate dihydrate (CSD) powder were incorporated into calcium phosphate bone cement (CPC) to induce macropores, adjust drug release and control setting time of α-TCP-liquid mixtures after degradation of GMs and dissolution of CSD. In this study, CSD was introduced into CPC/10GMs composites to offset the prolonged setting time caused by the incorporation of GMs, and gentamicin sulphate (GS) was chosen as the model drug entrapped within the GMs. The effects of CSD amount on the cement properties, drug release ability and final macroporosity after GMs degradation were studied in comparison with CPC/GMs cements. The resulting cements presented reduced setting time and increased compressive strength as the content of CSD below 5 wt%. Sustained release of GS was obtained on at least 21 days, and release rates were found to be chiefly controlled by the GMs degradation rate. After 4 weeks of degradation study, the resulting composite cements appeared macroporous, degradable and suitable compressive strength, suggesting that they have potential as controlled local drug delivery system and for cancellous bone applications.

Spinal balance failure: a potential cause of spinal ligament ossification

Ossification of the posterior longitudinal ligament (OPLL) and of the ligamentum flavum (OLF), as well as calcification of ligamentum nuchae in the cervical spine and ossification of ligamentum flavum in the thoracic spine, are common types of spinal ligament ossification. As is known, the pathogenesis of OPLL and OLF has been unclear until recently, and mechanical stress assumably plays an important role. In this paper, we try to make a hypothesis that spinal balance failure (characterized by the gravity line, spinal curvature and flexion/extension in the sagittal plane), may play more important roles than any other factors in the development of ligament ossified diseases. Moreover, different stress thresholds and flexion/extension frequency may induce various ossification regions. It is supported by the conclusions that drawn from literature review: (1) OPLL and OLF seldom occur in lumbar spine which is of stiffer and lower-frequency motion than cervical spine, although its range of motion (ROM) was relatively great. (2) Spinal ligament ossification often appears in the cervical spine, which is significantly flexible with a larger motion range. (3) OLF is often seen in the thoracic spine, which is farthest away from the gravity line for thoracic kyphosis. (4) Many OPLL or OLF patients are often found with a local kyphosis or high segmental ROM. (5) The prevalence of ossification is higher in the larger stress regions, as described above, indicating that there may be a stress threshold for the spinal ligaments.

[Morphologic and apoptotic changes of cervical posterior longitudinal ligament fibroblasts in response to in vitro mechanical stretch]

OBJECTIVE

To investigate the effect of mechanical stretch force on the morphologic and apoptotic changes of fibroblasts derived from the OPLL (ossification of posterior longitudinal ligaments) patients.

METHODS

The third passage cells were collected and subjected to 10% elongations cyclic mechanical stretching for 6 h and 24 h with Flexercell 4000(TM) strain unit. Their morphologic changes were observed and the post-stretching apoptotic rates quantified by flow cytometer. The gene expressions of alkaline phosphatase (ALP), collagen types I (COL I) and osteocalcin (OC) were examined.

RESULTS

The treated cells were arranged along the vertical direction of force. Stretch force led to a slight increase of apoptosis rate at 6 h and a significant increase of apoptosis rate at 24 h. No significant difference in cellular senescence was observed between control group and treated group. The mRNA expressions of ALP, COL I and OC were positively up-regulated by cyclic stretch at 24 h.

CONCLUSION

Stretching force can affect the cellular morphology, promote the osteogenic differentiation and enhance the cellular apoptosis.

Multilevel myelopathy associated with pseudohypoparathyroidism simulating diffuse skeletal hyperostosis: a case report and literature review

STUDY DESIGN

A case report and review of previous literature are presented.

OBJECTIVE

The objective of this manuscript was to report a case of pseudohypoparathyroidism (PHP) 1a simulating diffuse idiopathic skeletal hyperostosis and resulting in spinal cord compression, and discuss the pathogenesis of this disease.

SUMMARY OF BACKGROUND DATA

Spinal cord compression due to PHP is not common, to the authors' knowledge, none of the previous reported cases simulated diffuse idiopathic skeletal hyperostosis.

METHODS

The patient's history, clinical examination, imaging findings, and treatment were reported; and the pathogenesis was discussed.

RESULTS

Characteristic findings were revealed from imaging studies, a multiplane reconstruction of the computed tomography images, and magnetic resonance imaging. The patient was treated by 2-stage posterior decompression on the basis of the images. A mild improvement was observed after the surgeries and the patient's neurology was not completely restored after 6 months.

CONCLUSION

We reported a rare case of skeletal and ligamentous abnormality resulting in spinal cord compression associated with PHP. A multiplane reconstruction of the computed tomography images was very necessary for diagnosis and treatment of this case. The unfavorable neurologic restoration might be due to the severe injury of the spinal cord caused by diffuse ossification of the posterior longitudinal ligament and ligamentum flavum.

Spinal-cord compression related to pseudohypoparathyroidism

We report a 24-year-old male with pseudohypoparathyroidism and a 6-month history of sensory disturbance in both legs which was associated with difficulty in walking. His physical signs included a short stature, a thick neck, short fourth metacarpals and metatarsals, a spastic paraparesis and sphincteric disturbance. His serum electrolytes included low serum calcium and high serum phosphorus levels. CT reconstruction showed compression of the spinal cord in association with ossified ligamentum flavum at the C2-7 and T9-10 levels. These findings were confirmed by MRI scans.

[Biomechanical performance of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability]

OBJECTIVE

To compare the biomechanical performances of different wires and cable fixation devices in posterior instrumentation for atlantoaxial instability, and test the effect of different fixation strengths and fixation approaches on the surgical outcomes.

METHODS

Six specimens of the atlantoaxial complex (C0-C3) were used to establish models of the normal complex, unstable complex (type II odontoid fracture) and fixed complex. On the wd-5 mechanical testing machine, the parameters including the strength and rigidity of anti-rotation, change and strength of stress, and stability were measured for the normal complex, atlantoaxial instability complex, the new type titanium cable fixation system, Atlas titanium cable, Songer titanium cable, and stainless wire.

RESULTS

The strength and rigidity of anti-rotation, change and strength of stress, stability of flexion, extension and lateral bending of the unstable atlantoaxial complex fixed by the new double locking titanium cable fixation system were superior to those of the Songer or Atlas titanium cable (P<0.05) and medical stainless wire (P<0.05). Simultaneous cable fastening on both sides resulted in better fixation effect than successive cable fastening (P<0.05). Better fixation effect was achieved by fastening the specimen following a rest (P<0.05).

CONCLUSIONS

The fixation effects can be enhanced by increased fastening strengths. The new type double locking titanium cable fixation system has better biomechanical performance than the conventional Songer and Atlas titanium cables. Fastening the unstable specimens after a rest following simultaneous fastening of the specimen on both sides produces better fixation effect.

A cervical myelopathy caused by invaginated anomaly of laminae of the axis in spina bifida occulta with hypoplasia of the atlas: case report

STUDY DESIGN

A case report and review of previous literature are presented.

OBJECTIVE

The objective of this manuscript was to report a case of cervical myelopathy caused by invaginated anomalous laminae of the axis in a spina bifida occulta patient with hypoplasia of the arch of the atlas and to discuss the etiology of this disease.

SUMMARY OF BACKGROUND DATA

To the authors' knowledge, few cases of cervical myelopathy due to invaginated anomalous laminae of the axis have been reported, none of which is combined with hypoplasia of the arch of atlas. Treatment was surgical removal of the invaginated laminae.

METHODS

The patient's history, clinical examination, imaging findings, and treatment were reported, and the etiology was discussed.

RESULTS

Characteristic findings were revealed from imaging studies and multiplane reconstruction of the computed tomography images. The patient was treated with a posterior decompressive operation based on the images. A rapid improvement was observed after the surgery, and the patient's neurology was completely restored 1 month later.

CONCLUSION

We reported a rare characteristic anomaly of the laminae of the axis with hypoplasia of the posterior arch of atlas. A multiplane reconstruction of the computed tomography images was very necessary for treatment of this case. Possible causes of this anomaly may be the failure of ossification or fusion of the embryological term, whereas invagination of the osteophyte may be associated with the traction of the dense fibrous band during growth and development. Surgical removal of the laminae could result in a satisfactory outcome.

Combined anterior C2-C3 fusion and C2 pedicle screw fixation for the treatment of unstable hangman's fracture: a contrast to anterior approach only

STUDY DESIGN

A retrospective clinical study was used to evaluate the effect of a new surgical treatment of the hangman's fractures.

OBJECTIVE

To determine the treatment efficacy of combined anterior C2-C3 reduction and fusion and posterior compressive C2 pedicle screw fixation for the management of unstable hangman's fractures.

SUMMARY OF BACKGROUND DATA

The classification of hangman's fractures as proposed by Levine-Edwards was used to classify and guide the treatment of these injuries. Most of these fractures respond to a variety of conservative therapies, but recently, earlier surgery has been increasingly advocated by authors from several countries for the rapid stabilization of these fractures. If surgery is indicated, an anterior approach using a C2-C3 reduction and fusion is preferred usually. Another well-accepted surgical method is the direct transpedicular osteosynthesis by the dorsal approach. However, there was rare report of the combined use of these 2 techniques.

METHODS

A group of 45 surgical patients were all diagnosed with radiograph, magnetic resonance imaging (MRI), and 3D CT scans. Initial and final radiographs were measured for anterior translation and angulation of the C2-C3 complex. Initial external skull traction with extension was used in all patients after admission to reduce the fracture. Then an anterior C2-C3 discectomy followed by an interbody fusion and locking plate fixation was performed. Intraoperative reduction was confirmed by fluoroscopic control. About 29 patients therefore received anterior surgeries only since satisfactory reduction was achieved during the procedure. For the 16 patients who had persistent large residual gaps after the anterior procedure, additional same stage posterior C2 compressive pedicle screws were placed. Clinical and radiologic comparisons were performed in these 2 groups.

RESULTS

The follow-up ranged from 24 to 54 months, with an average 33.6 months. There was radiographic evidence of continuity of the fracture and the bone graft seen at 4.7 months on average. Neck pain and neurologic deficits resolved in nearly all patients after surgery. The anterior translation of anterior-posterior surgery group decreased more significant compared to anterior surgery group, although with no statistical significance. The fractures were closed with a slight gap no more than 2 mm in anterior-posterior surgery group. The residual kyphosis in anterior-posterior surgery group was still a little larger than it in anterior surgery group. No internal fixation failures or infections were observed.

CONCLUSION

We believe that the need for single stage 360° fusion of hangman's fractures can be somewhat predicted by a combination of high resolution imaging. For hangman's fractures with significant deformity and gapping, it is our experience that immediate single-stage anterior-posterior reduction, instrumentation, and arthrodesis achieve superior postoperative reduction and long-term functional outcomes.

Preparation and biocompatibility evaluation of apatite/wollastonite-derived porous bioactive glass ceramic scaffolds

An apatite/wollastonite-derived (A/W) porous glass ceramic scaffold with highly interconnected pores was successfully fabricated by adding a plastic porosifier. The morphology, porosity and mechanical strength were characterized. The results showed that the glass ceramic scaffold with controllable pore size and porosity displayed open macropores. In addition, good in vitro bioactivity was found for the scaffold obtained by soaking it in simulated body fluid. Mesenchymal stem cells (MSCs) were cultured, expanded and seeded on the scaffold, and the adhesion and proliferation of MSCs were determined using MTT assay and environmental scanning electron microscopy (ESEM). The results revealed that the scaffold was biocompatible and had no negative effects on the MSCs in vitro. The in vivo biocompatibility and osteogenicity were investigated by implanting both the pure scaffold and the MSC/scaffold construct in rabbit mandibles and studying histologically. The results showed that the glass ceramic scaffold exhibited good biocompatibility and osteoconductivity. Moreover, the introduction of MSCs into the scaffold observably improved the efficiency of new bone formation, especially at the initial stage after implantation. However, the glass ceramic scaffold showed the same good biocompatibility and osteogenicity as the hybrid one at the later stage. These results indicate that porous bioactive scaffolds based on the original apatite-wollastonite glass ceramic fulfil the basic requirements of a bone tissue engineering scaffold.

[Combined anterior C2,3 reduction and fusion with posterior compressive C2 pedicle screw fixation for the treatment of unstable Hangman's fractures: 16 cases review]

OBJECTIVE

To determine the outcome of combined anterior C2,3 reduction and fusion with posterior compressive C2 pedicle screw fixation for the management of unstable Hangman's fractures.

METHODS

Sixteen cases of unstable Hangman's fractures were retrospectively reviewed through X-ray, MRI and three dimensional CT scans. Pre- and postoperative radiographs were measured for translation and angulation of C2,3. Skull traction under extension poison was conducted in all the patients right after their admission. Then anterior C2,3 discectomy followed by interbody fusion, either with iliac autograft or with box cage, and locking plate fixation were performed in each case. Because dissatisfied reduction, mainly residual large fracture gap or kyphosis, was found by the C-arm fluoroscopy during operations, posterior compressive C2 pedicle screw fixation was performed in one stage. According to the Levine-Edwards classification, there were 12 cases of type II, 2 of type I a and 2 of type III in this group.

RESULTS

Follow-up ranged 6-38 months, averaged 26 months. Fracture union and bone graft fusion were completed in an average of 4 months after operation. Complaints of neck pain and numbness of limbs disappeared in all patients after surgery, but range of neck motion decreased compared with normal people. Translation of C2 decreased from (4.2 +/- 1.4) mm preoperatively to (2.3 +/- 1.1) mm postoperatively, while angulation of C2,3 decreased from 8.6 degrees +/- 2.1 degrees preoperatively to 2.6 degrees +/- 1.0 degrees postoperatively. Both have statistical significance (P < 0.05). No implant failure or infection was observed.

CONCLUSIONS

The classification of Hangman's fracture should be modified in combination with MRI and CT scans to determine the stability of the fracture. Combined anterior C2,3 reduction and fusion with posterior compressive C2 pedicle screw fixation is the treatment of choice for patients with unstable Hangman's fractures.