Spinal bone marrow necrosis with vertebral compression fracture: differentiation of BMN from AVN

Bone marrow necrosis (BMN) is a rare malignancy-associated hematologic disorder characterized by necrosis of myeloid and stromal marrow elements with preservation of cortical bone. Overlap between the imaging appearances of BMN and avascular necrosis (AVN) raises the potential for diagnostic confusion. We report a case of BMN presenting with a traumatic multi-level vertebral body collapse, and finding that may potentially confound distinction between the two entities. We discuss important pathophysiologic, clinical, and radiologic differences between BMN and AVN with emphasis on features important in the differential diagnosis.

Trends in the surgical treatment for spinal metastasis and the in-hospital patient outcomes in the United States from 2000 to 2009

BACKGROUND CONTEXT

Surgical treatment for spinal metastasis is still controversial. However, with the improvements in treatment for primary tumors, the survival rate of patients with spinal metastasis is enhanced. At the same time, surgical technique for spinal metastasis has also improved.

PURPOSE

The purpose of this study was to examine trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes on a national level.

STUDY DESIGN/SETTING

This was an epidemiologic study using national administrative data from the Nationwide Inpatient Sample (NIS) database.

PATIENT SAMPLE

All discharges in the NIS with a diagnosis code of secondary malignant neoplasm of the spinal cord/brain, meninges, or bone who also underwent spinal surgery from 2000 to 2009 were included.

OUTCOME MEASURES

Trends in the surgical treatment for spinal metastasis, in-hospital complications and mortality, and resource use were analyzed.

METHODS

The NIS was used to identify patients who underwent surgical treatment for spinal metastasis from 2000 to 2009, using the International Classification of Diseases, Ninth revision, Clinical Modification codes. Trends in the surgical treatment for spinal metastasis and in-hospital patient outcomes were analyzed.

RESULTS

From 2000 to 2009, there was an increasing trend in the population growth-adjusted rate of surgical treatment for spinal metastasis (1.15-1.77 per 100,000; p<.001). Average Elixhauser comorbidity score increased over time (2.6-3.8; p<.001), and the overall in-hospital complication rate increased over time (14.8%-27.7%; p<.001), whereas in-hospital mortality rate and length of hospital stay remained stable over time (5.2%-4.6%, p=.413; 10.6-10.8 days, p=.626). Inflation-adjusted mean hospital charges increased more than two-fold over time ($50,390-$110,173; p<.001).

CONCLUSIONS

During the last decade, surgical treatment for spinal metastasis has increased in the United States. The overall in-hospital complication rate and hospital charges increased, whereas the in-hospital mortality rate and length of hospital stay remained stable.

Enhanced immunoprotective effects by anti-IL-17 antibody translates to improved skeletal parameters under estrogen deficiency compared with anti-RANKL and anti-TNF-α antibodies

Activated T cell has a key role in the interaction between bone and immune system. T cells produce proinflammatory cytokines, including receptor activator of NF-κB ligand (RANKL), tumor necrosis factor α (TNF-α), and interleukin 17 (IL-17), all of which augment osteoclastogenesis. RANKL and TNF-α are targeted by inhibitors such as denosumab, a human monoclonal RANKL antibody, and infliximab, which neutralizes TNF-α. IL-17 is also an important mediator of bone loss, and an antibody against IL-17 is undergoing phase II clinical trial for rheumatoid arthritis. Although there are a few studies showing suppression of Th17 cell differentiation and induction of regulatory T cells (Tregs) by infliximab, the effect of denosumab remains poorly understood. In this study, we investigated the effects of anti-TNF-α, anti-RANKL, or anti-IL-17 antibody administration to estrogen-deficient mice on CD4(+) T-cell proliferation, CD28 loss, Th17/Treg balance and B lymphopoesis, and finally, the translation of these immunomodulatory effects on skeletal parameters. Adult Balb/c mice were treated with anti-RANKL/-TNF-α/-IL-17 subcutaneously, twice a week, postovariectomy (Ovx) for 4 weeks. Animals were then autopsied; bone marrow cells were collected for FACS and RNA analysis and serum collected for ELISA. Bones were dissected for static and dynamic histomorphometry studies. We observed that although anti-RANKL and anti-TNF-α therapies had no effect on Ovx-induced CD4(+) T-cell proliferation and B lymphopoesis, anti-IL-17 effectively suppressed both events with concomitant reversal of CD28 loss. Anti-IL-17 antibody reduced proinflammatory cytokine production and induced Tregs. All three antibodies restored trabecular microarchitecture with comparable efficacy; however, cortical bone parameters, bone biomechanical properties, and histomorphometry were best preserved by anti-IL-17 antibody, likely attributable to its inhibitory effect on osteoblast apoptosis and increased number of bone lining cells and Wnt10b expression. Based on the superior immunoprotective effects of anti-IL-17, which appears to translate to a better skeletal preservation, we propose beginning clinical trials using a humanized antibody against IL-17 for treatment of postmenopausal osteoporosis.

Osteomyelitis of the foot and ankle: diagnosis, epidemiology, and treatment

Osteomyelitis of the foot and ankle is a common, potentially devastating condition with diagnostic and treatment challenges. Understanding the epidemiology and pathogenesis of osteomyelitis can raise clinical suspicion and guide testing and treatments. History and physical examination, laboratory studies, vascular studies, histologic and microbiologic analyses, and various imaging modalities contribute to diagnosis and treatment. Treatment including empiric broad-spectrum antibiotics and surgery should take a multidisciplinary approach to optimize patient factors, ensure eradication of the infection, and restore function. Optimization of vascular status, soft tissues, limb biomechanics, and physiologic state of the patient must be considered to accelerate and ensure healing.

DPP IV inhibitor treatment attenuates bone loss and improves mechanical bone strength in male diabetic rats

Dipeptidyl peptidase IV (DPP IV) modulates protein activity by removing dipeptides. DPP IV inhibitors are currently used to improve glucose tolerance in type 2 diabetes patients. DPP IV substrates not only increase insulin secretion but also affect bone metabolism. In this study, the effect of DPP IV inhibitor sitagliptin on bone was evaluated in normal and streptozotocin-induced diabetic rats. This study included 64 male Wistar rats divided into four groups (n = 16): two diabetic and two control groups. One diabetic and one control group received sitagliptin through drinking water. Tibiae were scanned every 3 wk using an in vivo μCT scanner. After 6 and 12 wk, rats were euthanized for histomorphometric analysis of bone parameters. The mechanical resistance of femora to fracture was assessed using a three-point bending test, and serum levels of bone metabolic markers were measured. Efficient DPP IV inhibition was achieved in sitagliptin-treated groups. Trabecular bone loss, the decrease in trabecular number, and the increase in trabecular spacing was attenuated through sitagliptin treatment in diabetic rats, as shown by in vivo μCT. Bone histomorphometry was in line with these results. μCT analysis furthermore showed that sitagliptin prevented cortical bone growth stagnation in diabetic rats, resulting in stronger femora during three-point bending. Finally, the serum levels of the resorption marker CTX-I were significantly lower in sitagliptin-treated diabetic animals compared with untreated diabetic animals. In conclusion, sitagliptin treatment attenuates bone loss and increases bone strength in diabetic rats probably through the reduction of bone resorption and independent of glycemic management.

Anterior ankle arthrodesis with molded plate: technique and outcomes

BACKGROUND

There is still controversy regarding the best technique for ankle arthrodesis to acheive stable rigid fixation along with reconstructing a functional plantigrade foot. Moreover, existing techniques have complictions related to stability, soft tissue covering, fusion rate, and exposure.

METHODS

With the anterior approach exactly on the tibialis anterior sheath, the joint was exposed and previous hardware, if any, was removed and with the safe direct approach, the ankle, hindfoot, and indirectly the subtalar joints were accessed. Then fresh cancellous bone was obtained and complete denudation was preformed. Lastly, a narrow 4.5 millimeter plate was carefully placed on what was determined to be the best final position.In this prospective study, 12 patients with severe ankle pain and arthritis enrolled from February 2010 to January 2012. Eight of them had posttraumatic arthritis and deformity with hardware, two had rheumatoid arthritis, one had poliomyelitis with severe deformity of the foot and knee, and another had chronic ulcerative synovitis of the ankle joint. The patients were assessed clinically and radiographically for an average of two years (range: 13 months to 4 years) for functional recovery, range of motion, stability of the ankle, and imaging evidence of union.

RESULTS

Ankle deformities and pain in all 12 cases were corrected. With a short healing time and rapid recovery period, after six weeks all of the patients could walk independently. Also, scores of the Manchester-Oxford Foot Questionnaire (MOXFQ) improved significantly from 69 preoperatively to 33 postoperatively).

CONCLUSIONS

Anterior ankle arthrodesis with molded plating can be an easy and safe way to manage deformities and it has excellent fusion rate and sufficient rigid fixation.

The effect of dual growing rod instrumentation on the apical vertebral rotation in early-onset idiopathic scoliosis

BACKGROUND AND AIM

Treating progressive early-onset idiopathic scoliosis is challenging. Surgical treatment is indicated in patients whose curves progress despite nonsurgical treatment. Dual growing rod (DGR) technique allows control of the curve while permitting continued spine growth and pulmonary development. Correction in coronal and sagittal planes with this technique has demonstrated both clinically and radiologically in previous studies. It is shown that apical vertebra rotation (AVR) increases with single-rod instrumentation technique. The effect of DGR technique on AVR has not been investigated, yet. The aim of our study was to assess the impact of DGR instrumentation technique on the apical AVR.

METHODS

The study included 12 patients with early-onset idiopathic scoliosis treated with DGR technique. Mean follow-up was 74 months. Vertebral rotation angle in the apex of the curve in preindex surgery was measured with Perdriolle and Stokes' method. As pedicle shadows were masked by rods postoperatively, vertebral rotation angle of same levels in final computed tomography scans was measured using Aaro and Dahlborn's method. Standing anterior-posterior and lateral x-rays were measured for assessing Cobb angle, thoracic kyphosis, lumbar lordosis in coronal and sagittal planes preoperatively, postoperatively, and at the time of final follow-up.

RESULTS

Mean age at the time of growing rod instrumentation was 69 (36 to 108) months. Mean follow-up was 77 (57 to 91) months. The mean preoperative AVR angle was 27 (18 to 38) degrees and decreased to 18 (4 to 35) degrees at the time of final follow-up. The difference between preoperative and final follow-up AVR was found to be significant (P=0.003). Preoperative mean Cobb angles were found to be 63.8 (40 to 98) degrees, 25 (10 to 46) degrees (60%) (P<0.001) after index surgery and at the time of final follow-up 20 (7 to 42) degrees (66%) (P<0.001). The mean thoracic kyphosis and lumbar lordosis angles were found to be 46 (20 to 90) and 34 (16 to 80) degrees at preoperative stage; 25 (12 to 50) and 22 (8 to 35) degrees at immediate postoperative stage; and 38 (16 to 83) and 37 (16 to 60) degrees at the time of final follow-up.

CONCLUSIONS

This study proves that the DGR technique has no negative effect on transverse plane deformities. When compared with preoperative values, correction of the AVR during the treatment period suggests that DGR is effective in controlling the coronal and sagittal planes along with transverse plane deformities. Further studies are needed to prove that DGR treatment definitely prevents progression of AVR.

T regulatory cells and related immunoregulatory factors in polymorphic light eruption following ultraviolet A1 challenge

BACKGROUND

Polymorphic light eruption (PLE) is considered to be an autoimmune-mediated skin condition in which the normal ultraviolet (UV)-induced local immunosuppression appears to be absent, leading to recognition of photoinduced autoantigens and subsequent inflammation.

OBJECTIVES

To investigate T regulatory cells (Tregs) and related immunoregulatory factors in PLE lesions and controls.

METHODS

Skin biopsies were performed in 13 patients with UVA1-challenged PLE, 12 female patients with chronic discoid lupus erythematosus (CDLE) and 11 healthy controls who had exposure to UVA1. Immunohistochemistry and four-colour immunofluorescence studies were performed.

RESULTS

Patients with CDLE and UVA1-exposed controls showed significantly decreased epidermal immunoreactivity for CD1a compared with patients with PLE (P = 0·0001). Four-colour immunofluorescence revealed a median percentage of CD4+CD25+FOXP3+ Tregs of 7·6% (range 3·7-13·6%) in PLE, a median of 11·7% (range 9·5-13·9%) in CDLE and a median of 3·4% (range 0-6·8%) in controls. Compared with UVA1-exposed controls, PLE and CDLE lesions showed significantly decreased transforming growth factor (TGF)-β1 immunoreactivity in the epidermis (P = 0·0003). In PLE lesions, we observed significantly decreased interleukin (IL)-10 expression compared with CDLE (P = 0·022). In the dermis, receptor activator of nuclear factor-κB ligand (RANKL) expression was increased in UVA1-exposed controls compared with PLE and CDLE (P = 0·018).

CONCLUSIONS

Similar to CDLE lesions, UVA1-challenged PLE lesions display an altered immunoregulatory network, as indicated by decreased epidermal or dermal expression of TGF-β1, IL-10 and RANKL, and a relatively low number of Tregs, particularly when compared with other inflammatory skin conditions reported in the literature.

The role of experience level in radiographic evaluation of femoroacetabular impingement and acetabular dysplasia

Accurate radiographic interpretation is essential for properly diagnosing the etiology of pre-arthritic hip pain such as femoroacetabular impingement (FAI) and acetabular dysplasia (AD); however, radiographic interpretation can be significantly influenced by the observer’s experience level. This study assesses the accuracy and inter- and intraobserver reliability in the radiographic evaluation of FAI and AD based on experience level. Fifty-five patients diagnosed with FAI, AD or normal hip morphology were identified from the principal investigator’s institutional database. Four observers performed an independent and blinded radiographic review, assessing 14 radiographic parameters and an interpretation of a final diagnosis. A second radiographic evaluation of 20 preselected cases was completed 6 weeks after the initial reading to assess intraobserver reliability. Inter- and intraobserver reliability was determined using Cohen’s Kappa Coefficient (κ) and intraclass correlation coefficient (ICC) for continuous parameters in a four-rater design. Interobserver reliability was highest across experience levels for lateral centre edge angle (ICC = 0.92) and alpha angle (ICC = 0.90) and lowest (κ < 0.3, ICC < 0.3) for joint congruency and detection of herniation pits. Intraobserver reliability was highest for acetabular depth (κ = 0.89) and alpha angle (ICC = 0.80) and lowest for head–neck offset ratio and Tönnis grade. Final diagnosis was consistent with the original blinded clinical diagnosis 75–84% of the time across four experience levels. The attending orthopaedic hip surgeon demonstrated greatest diagnostic sensitivity but lowest specificity for making an accurate radiographic diagnosis. Subjective parameters must be redefined, and objective parameters must be further developed to improve the reliability of accurately diagnosing FAI or AD.

New insights in the mobilization of hematopoietic stem cells in lymphoma and multiple myeloma patients

Following chemotherapy and/or the administration of growth factors, such as granulocyte-colony stimulated factor (G-CSF), hematopoietic stem cells (HSC) mobilize from bone marrow to peripheral blood. This review aims to systematically present the structure of the HSC "niche" and elucidate the mechanisms of their mobilization. However, this field is constantly evolving and new pathways and molecules have been shown to contribute to the mobilization process. Understanding the importance and the possible primary pathophysiologic role of each pathway is rather difficult, since they share various overlapping components. The primary initiating event for the mobilization of HSC is chemotherapy-induced endogenous G-CSF production or exogenous G-CSF administration. G-CSF induces proliferation and expansion of the myelomonocytic series, which leads to proteolytic enzyme activation. These enzymes result in disruption of various receptor-ligand bonds, which leads to the disanchorage of HSC from the bone marrow stroma. In everyday clinical practice, CXC chemokine receptor-4 (CXCR4) antagonists are now being used as mobilization agents in order to improve HSC collection. Furthermore, based on the proposed mechanisms of HSC mobilization, novel mobilizing agents have been developed and are currently evaluated in preclinical and clinical studies.

The human meniscus: a review of anatomy, function, injury, and advances in treatment

Meniscal injuries are recognized as a cause of significant musculoskeletal morbidity. The menisci are vital for the normal function and long-term health of the knee joint. The purpose of this review is to provide current knowledge regarding the anatomy and biomechanical functions of the menisci, incidence, injury patterns and the advancements in treatment options of meniscal injury. A literature search was performed by a review of PubMed, Google Scholar, MEDLINE, and OVID for all relevant articles published between 1897 and 2014. This study highlights the anatomical and biomechanical characteristics of the menisci, which may be relevant to injury patterns and treatment options. An understanding of the normal anatomy and biomechanical functions of the knee menisci is a necessary prerequisite to understanding pathologies associated with the knee.

Use of a flexible implant and bioabsorbable anchor for deltoid rupture repair in bimalleolar equivalent Weber B ankle fractures

Supination external rotation ankle fractures are the most common ankle fracture subtype. Deltoid ligament injuries have often been associated with this type of injury pattern. A missed injury can lead to post-traumatic arthritis and persistent pain. The current data do not support acute deltoid rupture repair. This has been based primarily on level III and IV studies in which less than satisfactory results were reported. We believe that acute deltoid rupture repair could be indicated in select cases. We have outlined a new deltoid repair technique for use with bimalleolar, equivalent supination external rotation ankle fractures using a flexible implant and bioabsorbable anchor.

Radiographic analysis of the restoration of hip joint center following open reduction and internal fixation of acetabular fractures: a retrospective cohort study

BACKGROUND

Unfavorable reduction is considered one of the key factors leading to joint degeneration and compromised clinical outcome in acetabular fracture patients. Besides the columns, walls, and superior dome, the postoperative position of hip joint center (HJC), which is reported to affect hip biomechanics, should be considered during the assessment of quality of reduction. We aimed to evaluate the radiographic restoration of HJC in acetabular fractures treated with open reduction and internal fixation.

METHODS

Patients with a displaced acetabular fracture that received open reduction and internal fixation in the authors' institution during the past five years were identified from the trauma database. The horizontal and vertical shifts of HJC were measured in the standard anteroposterior view radiographs taken postoperatively. The radiographic quality of fracture reduction was graded according to Matta's criteria. The relationships between the shift of HJC and the other variables were evaluated.

RESULTS

Totally 127 patients with 56 elementary and 71 associated-type acetabular fractures were included, wherein the majority showed a medial (89.0%) and proximal (93.7%) shift of HJC postoperatively. An average of 2.8 mm horizontal and 2.2 mm vertical shift of HJC were observed, which correlated significantly with the quality of fracture reduction (P < 0.001 for both). The horizontal shift of HJC correlated with the fracture type (P = 0.022).

CONCLUSIONS

The restoration of HJC correlates with the quality of reduction in acetabular fractures following open reduction and internal fixation. Further studies are required to address the effects of HJC shift on the biomechanical changes and clinical outcomes of hip joint, especially in poorly reduced acetabular fractures.

Positive selection of Wharton's jelly-derived CD105(+) cells by MACS technique and their subsequent cultivation under suspension culture condition: A simple, versatile culturing method to enhance the multipotentiality of mesenchymal stem cells

OBJECTIVE

Wharton's jelly (WJ), an appropriate source of mesenchymal stem cells (MSCs), has been shown to have a wide array of therapeutic applications. However, the WJ-derived MSCs are very heterogeneous and have limited expression of pluripotency markers. Hence, improvement of their culture condition would promote the efficiency of WJ-MSCs. This study aims to employ a simple method of cultivation to obtain WJ-MSCs which express more pluripotency markers.

METHODS

CD105(+) cells were separated by magnetic-associated (activated) cell sorting from umbilical cord mucous tissue. CD105(+) cells were added to Methocult medium diluted in α-minimum essential medium (α-MEM) and seeded in poly(2-hydroxyethyl methacrylate) (poly-HEMA)-coated plates for suspension culture preparation. Differentiation capacity of isolated cells was evaluated in the presence of differentiation-inducing media. The expression of pluripotency markers such as Oct3/4, Nanog, and Sox2 was also analyzed by RT-PCR and western blot techniques. Moreover, immunocytochemistry was performed to detect alpha-smooth muscle actin (antigene) (α-SMA) protein.

RESULTS

WJ-MSCs grew homogeneously and formed colonies when cultured under suspension culture conditions (Non-adhesive WJ-MSCs). They maintained their growth ability in both adherent and suspension cultures for several passages. Non-adhesive WJ-MSCs expressed Oct3/4, Nanog, and Sox2 both at transcriptional and translational levels in comparison to those cultured in conventional adherent cultures. They also expressed α-SMA protein.

DISCUSSION

In this study, we isolated WJ-MSCs using a slightly modified culture condition. Our simple non-genetic method resulted in a homogeneous population of WJ-MSCs, which highly expressed pluripotency markers.

CONCLUSION

In the future, more multipotent WJ-MSCs can be harnessed as a non-embryonic source of MSCs in MSC-based cell therapy.

The effects of necrotic lesion size and orientation of the femoral component on stress alterations in the proximal femur in hip resurfacing - a finite element simulation

Background

Due to the advantages of its bone-conserving nature, hip resurface arthroplasty (HRA) has recently gained the interest of orthopedic surgeons for the treatment of young and active patients who have osteonerosis of the femoral head. However, in long-term follow-up studies after HRA, narrowing of the femoral neck has often been found, which may lead to fracture. This phenomenon has been attributed to the stress alteration (stress shielding). Studies addressing the effects of necrotic size and the orientation of the implant on stress alterations are lacking.

Methods

Computed tomography images of a standard composite femur were used to create a three-dimensional finite-element (FE) intact femur model. Based on the intact model, FE models simulating four different levels of necrotic regions (0°, 60°, 100°, 115°) and three different implant insertion angles (varus 10°, neutral, valgus 10°) were created. The von Mises stress distributions and the displacement of the stem tip of each model were analyzed and compared for loading conditions that simulated a single-legged stance.

Results

Stress shielding occurred at the femoral neck after HRA. More severe stress shielding and an increased displacement of the stem tip were found for femoral heads that had a wider necrotic lesion. From a biomechanics perspective, the results were consistent with clinical evidence of femoral neck narrowing after HRA. In addition, a varus orientation of the implant resulted in a larger displacement of the stem tip, which could lead to an increased risk of implant loosening.

Conclusions

A femoral head with a wide necrotic lesion combined with a varus orientation of the prosthesis increases the risk of femoral neck narrowing and implant loosening following HRA.

Enhancing intervertebral disc repair and regeneration through biology: platelet-rich plasma as an alternative strategy

Intervertebral disc degeneration (IDD) is a common orthopedic disease associated with mechanical changes that may result in significant pain. Current treatments for IDD mainly depend on conservative therapies and spinal surgeries that are only able to relieve the symptoms but do not address the cause of the degeneration and even accelerate the degeneration of adjacent segments. This has prompted research to improve our understanding of the biology of intervertebral disc healing and into methods to enhance the regenerative process. Recently, biological therapies, including active substances, gene therapy and tissue engineering based on certain cells, have been attracting more attention in the field of intervertebral disc repair and regeneration. Early selection of suitable biological treatment is an ideal way to prevent or even reverse the progressive trend of IDD. Growth factors have been enjoying more popularity in the field of regeneration of IDD and many have been proved to be effective in reversing the degenerative trend of the intervertebral disc. Identification of these growth factors has led to strategies to deliver platelet-derived factors to the intervertebral disc for regeneration. Platelet-rich plasma (PRP) is the latest technique to be evaluated for promoting intervertebral disc healing. Activation of the PRP leads to the release of growth factors from the α-granules in the platelet cytoplasm. These growth factors have been associated with the initiation of a healing cascade that leads to cellular chemotaxis, angiogenesis, synthesis of collagen matrix, and cell proliferation. This review describes the current understanding of IDD and related biological therapeutic strategies, especially the promising prospects of PRP treatment. Future limitations and perspectives of PRP therapy for IDD are also discussed.

Bearing surfaces in hip replacement - Evolution and likely future

Total hip arthroplasty has evolved from the first total hip arthroplasty in 1938, through the revolutionization of hip arthroplasty by principles of low friction arthroplasty introduced by Sir John Charnley in 1960s to the present state of the art implants and techniques. The main concern regarding failure of total hip arthroplasty has been the biological response to particulate polyethylene debris generated by conventional metal on polyethylene bearing surfaces leading to osteolysis and aseptic loosening of the prosthesis. Therefore, recent research has been focussing on alternative bearing surfaces to reduce the particulate debris generated. These bearing surfaces include ceramic-polyethylene, metal-metal as well as ceramic-ceramic articulations and have demonstrated lesser friction rates as well as significantly lower wear rates as compared to widely used metal on polyethylene surfaces. Clinical experience until now has shown that metal on metal articulations have significant safety concerns whereas metal-on-highly crosslinked polyethylene, ceramic on ceramic and ceramic on highly crosslinked polyethylene articulations have shown encouraging results to hold promise for wider use in younger and more active patients. This review article discusses positives and drawbacks of various bearing surfaces in current clinical use in total hip arthroplasty as well as briefly explores the newer technologies on the horizon which may even further decrease wear and improve total hip arthroplasty survivorship.

Outcomes of total hip arthroplasty in spastic patients

Patients with spasticity and hip arthritis can present challenges to treatment. This investigation evaluated the effectiveness and safety of THA in patients with upper motor neuron disease. Twenty-seven consecutive patients with history of cerebral palsy (CP) or acquired spasticity (AS) underwent 30 THAs for treatment of hip arthritis. They were followed for an average 2.5 years (range 2.1-12.1). Patients with CP were more likely to require hip adductor release and hip flexor lengthening at the time of THA. Statistically significant improvements were made in Harris Hip Scores, pain scores, range of motion, ambulatory status, and the use ambulatory-assistive devices. There were no dislocations in this group. Patients with spasticity can benefit from THA in terms of pain relief and improved mobility with relatively low complications.

Osteoclasts: more than 'bone eaters'

As the only cells definitively shown to degrade bone, osteoclasts are key mediators of skeletal diseases including osteoporosis. Bone-forming osteoblasts, and hematopoietic and immune system cells, each influence osteoclast formation and function, but the reciprocal impact of osteoclasts on these cells is less well appreciated. We highlight here the functions that osteoclasts perform beyond bone resorption. First, we consider how osteoclast signals may contribute to bone formation by osteoblasts and to the pathology of bone lesions such as fibrous dysplasia and giant cell tumors. Second, we review the interaction of osteoclasts with the hematopoietic system, including the stem cell niche and adaptive immune cells. Connections between osteoclasts and other cells in the bone microenvironment are discussed within a clinically relevant framework.

Cyclin-dependent kinase 9 may as a novel target in downregulating the atherosclerosis inflammation (Review)

Inflammation is a key component of atherosclerosis. Genes coding for inflammatory or anti-inflammatory molecules are considered good candidates for estimating the risk of developing atherosclerosis. Cyclin-dependent kinase 9 (CDK9), the kinase of positive transcription elongation factor b (P-TEFb), is crucial in the cell cycle and apoptosis. Previous studies have focused on its inhibition of immune cells for the resolution of inflammation. Considering the effects of inflammation in the pathogenicity of atherosclerosis, decreasing inflammation through the inhibition of CDK9 may be useful for the prognosis of atherosclerosis. The aim of this review was to examine whether inhibition of the CDK9 monocyte may affect the process of inflammation by acting on the cytokine secretion and interacting with endothelial cells (ECs). Thus, CDK9 may be a novel target for the diagnosis and therapy of atherosclerosis.

Normal anatomical variants of the menisci and cruciate ligaments that may mimic disease

There are many normal anatomical variants of the knee joint. Some are common and others are rare. With continuing improvements in the spatial resolution of MRI, smaller variants are more clearly demonstrated and can be mistaken for disease. They can all be differentiated from pathological conditions by understanding their anatomy and key differentiating features. This review compares normal variants of the menisci and cruciate ligaments with the pathological disorders that can mimic them.

Nailing treatment in bone transport complications

A series of cases of reamed intramedullary nailings carried out after complications in regenerated bone and docking site had occurred in bone transport is presented here. Nine patients (femur = 5; tibia = 4) had treatment with resection after open fractures or infection and underwent bone transport. The mean length of regenerated bone was 9.5 cm (range 6–18 cm). After bone transport, the fixator remained in place for a mean period of 12.8 months (range 8–24 months). In six cases (femur 4; tibia 2), the thickness of the cortical wall of the regenerate column was insufficient, and in two of these, there was, in addition, nonunion of the docking site. In the two tibial cases, nailing was carried out shortly after the fixator had been removed and after refracture of the regenerated bone had occurred due to insufficient cortical thickness. In one femur, nailing was carried out for nonunion of the docking site. Follow-up involved clinical and X-ray checks. The mean follow-up was 3.9 years (range 2–6 years). In all cases, union and with complete corticalization of the regenerate column was observed at an average 6 months after nailing (range 4–11 months). Infection occurred in one tibia 4 months after nailing. The infection was treated with antibiotics, and the nail was subsequently removed. We conclude that nailing is a potential solution for regenerated bone and docking site problems but, if used after prolonged periods of external fixation, may necessitate antibiotic therapy for at least 10 days after the fixator has been removed.

Differentiation of human umbilical cord mesenchymal stem cells into prostate-like epithelial cells in vivo

Although human umbilical cord mesenchymal stem cells (hUC-MSCs) have been identified as a new source of MSCs for potential application in regenerative medicine, their full potential of differentiation has not been determined. In particular, whether they have the capability to differentiate into epithelial cells of endodermal origin such as the prostate epithelial cells is unknown. Here we report that when hUC-MSCs were combined with rat urogenital sinus stromal cells (rUGSSs) and transplanted into the renal capsule in vivo, they could differentiate into prostate epithelial-like cells that could be verified by prostate epithelial cell-specific markers including the prostate specific antigen. The prostatic glandular structures formed in vivo displayed similar cellular architecture with lumens and branching features as seen for a normal prostate. In addition, the human origin of the hUC-MSCs was confirmed by immunocytochemistry for human nuclear antigen. These findings together indicate that hUC-MSCs have the capability to differentiate into epithelial-like cells that are normally derived from the endoderm, implicating their potential applications in tissue repair and regeneration of many endoderm-derived internal organs.

Clinical applications of end-to-side neurorrhaphy: an update

End-to-side neurorrhaphy constitutes an interesting option to regain nerve function after damage in selected cases, in which conventional techniques are not feasible. In the last twenty years, many experimental and clinical studies have been conducted in order to understand the biological mechanisms and to test the effectiveness of this technique, with contrasting results. In this updated review, we consider the state of the art about end-to-side coaptation, focusing on all the current clinical applications, such as sensory and mixed nerve repair, treatment of facial palsy, and brachial plexus injuries and painful neuromas management.

Pantoea agglomerans lipopolysaccharide maintains bone density in premenopausal women: a randomized, double-blind, placebo-controlled trial

Lipopolysaccharide fromPantoea agglomerans (LPSp) facilitates Ca and P turnover in chicken calvaria and femurs. This study investigated osteoporosis prevention by the oral administration of LPSp in mice and in double-blind clinical tests. Using ovariectomized (OVX) osteoporosis mice model, we investigated the effects of LPSp on the bone density and Ca concentration after ingesting LPSp-containing water for 4 weeks. Oral administration of LPSp tended to suppress the decline in the bone density and the cortical bone thickness in the OVX mice. Moreover, the Ca concentrations were maintained in the OVX-LPSp mice. The effects of LPSp on bone turnover were tested in randomized and double-blind clinical test subjects, who were healthy women aged 40-79 years. The subjects ingested either soy milk without LPSp (control group) or with LPSp (LPSp group) for 3 months. The results showed that the LPSp group on premenopause maintained their bone density compared with the control group pre- and postmenopause. Moreover, these effects were maintained for 2 months postobservation. LPSp maintains bone volume and density in vivo. Thus, a combination of soy milk and LPSp may be useful for osteoporosis prevention.

Preoperative Radiographic and CT Findings Predicting Syndesmotic Injuries in Supination-External Rotation-Type Ankle Fractures

BACKGROUND

The Lauge-Hansen classification system does not provide sufficient data related to syndesmotic injuries in supination-external rotation (SER)-type ankle fractures. The aim of the present study was to investigate factors helpful for the preoperative detection of syndesmotic injuries in SER-type ankle fractures using radiographs and computed tomography (CT).

METHODS

A cohort of 191 consecutive patients (104 male and eighty-seven female patients with a mean age [and standard deviation] of 50.7 ± 16.4 years) with SER-type ankle fractures who had undergone operative treatment were included. Preoperative ankle radiographs and CT imaging scans were made for all patients, and clinical data, including age, sex, and mechanism of injury (high or low-energy trauma), were collected. Patients were divided into two groups: the stable syndesmotic group and the unstable syndesmotic group, with a positive intraoperative lateral stress test leading to syndesmotic screw fixation. Fracture height, fracture length, medial joint space, extent of fracture, and bone attenuation were measured on radiographs and CT images and were compared between the groups. Binary logistic regression analysis was performed to identify the factors that significantly contributed to unstable syndesmotic injuries. Receiver operating characteristic curves were calculated, and cutoff values were suggested to predict unstable syndesmotic injuries on preoperative imaging measurements.

RESULTS

Of the 191 patents with a SER-type ankle fracture, thirty-eight (19.9%) had a concurrent unstable syndesmotic injury. Age, sex, mechanism of injury, fracture height, medial joint space, and bone attenuation were significantly different between the two groups. In the binary logistic analysis, fracture height, medial joint space, and bone attenuation were found to be significant factors contributing to unstable syndesmotic injuries. The cutoff values for predicting unstable syndesmotic injuries were a fracture height of >3 mm and a medial joint space of >4.9 mm on CT scans, and a fracture height of >7 mm and medial joint space of >4.5 mm on radiographs.

CONCLUSIONS

Fracture height, medial joint space, and bone attenuation were useful factors for the preoperative detection of unstable syndesmotic injuries in SER-type ankle fractures.

LEVEL OF EVIDENCE

Diagnostic Level II. See Instructions for Authors for a complete description of levels of evidence.

Relevance of Wnt signaling for osteoanabolic therapy

The Wnt signaling pathway is long known to play fundamental roles in various aspects of embryonic development, but also in several homeostatic processes controlling tissue functions in adults. The complexity of this system is best underscored by the fact that the mammalian genome encodes for 19 different Wnt ligands, most but not all of them acting through an intracellular stabilization of β-catenin, representing the key molecule within the so-called canonical Wnt signaling pathway. Wnt ligands primarily bind to 10 different serpentine receptors of the Fzd family, and this binding can be positively or negatively regulated by additional molecules present at the surface of the respective target cells. One of these molecules is the transmembrane protein Lrp5, which has been shown to act as a Wnt co-receptor. In 2001, Lrp5, and thereby Wnt signaling, entered center stage in the research area of bone remodeling, a homeostatic process controlling bone mass, whose disturbance causes osteoporosis, one of the most prevalent disorders worldwide. More specifically, it was found that inactivating mutations of the human LRP5 gene cause osteoporosis-pseudoglioma syndrome, a rare genetic disorder characterized by impaired bone formation and persistence of hyaloid vessels in the eyeballs. In addition, activating LRP5 mutations were identified in individuals with osteosclerosis, a high bone mass condition characterized by excessive bone formation. Especially explained by the lack of cost-effective osteoanabolic treatment options, these findings had an immediate impact on the research regarding the bone-forming cell type, i.e. the osteoblast, whose differentiation and function is apparently controlled by Wnt signaling. This review summarizes the most important results obtained in a large number of studies, involving tissue culture experiments, mouse models and human patients. While there are still many open questions regarding the precise molecular interactions controlling Wnt signaling in osteoblasts, it is obvious that understanding this pathway is a key to optimize the therapeutic strategies for treating various skeletal disorders, including osteoporosis.

Relevance of Wnt signaling for osteoanabolic therapy

The Wnt signaling pathway is long known to play fundamental roles in various aspects of embryonic development, but also in several homeostatic processes controlling tissue functions in adults. The complexity of this system is best underscored by the fact that the mammalian genome encodes for 19 different Wnt ligands, most but not all of them acting through an intracellular stabilization of β-catenin, representing the key molecule within the so-called canonical Wnt signaling pathway. Wnt ligands primarily bind to 10 different serpentine receptors of the Fzd family, and this binding can be positively or negatively regulated by additional molecules present at the surface of the respective target cells. One of these molecules is the transmembrane protein Lrp5, which has been shown to act as a Wnt co-receptor. In 2001, Lrp5, and thereby Wnt signaling, entered center stage in the research area of bone remodeling, a homeostatic process controlling bone mass, whose disturbance causes osteoporosis, one of the most prevalent disorders worldwide. More specifically, it was found that inactivating mutations of the human LRP5 gene cause osteoporosis-pseudoglioma syndrome, a rare genetic disorder characterized by impaired bone formation and persistence of hyaloid vessels in the eyeballs. In addition, activating LRP5 mutations were identified in individuals with osteosclerosis, a high bone mass condition characterized by excessive bone formation. Especially explained by the lack of cost-effective osteoanabolic treatment options, these findings had an immediate impact on the research regarding the bone-forming cell type, i.e. the osteoblast, whose differentiation and function is apparently controlled by Wnt signaling. This review summarizes the most important results obtained in a large number of studies, involving tissue culture experiments, mouse models and human patients. While there are still many open questions regarding the precise molecular interactions controlling Wnt signaling in osteoblasts, it is obvious that understanding this pathway is a key to optimize the therapeutic strategies for treating various skeletal disorders, including osteoporosis.

A systematic review of studies using pedometers as an intervention for musculoskeletal diseases

Background

Physical activity (PA) plays an important role in the prevention and management of a number of chronic conditions. Aim: to investigate the evidence for effectiveness of pedometer-driven walking programs to promote physical activity among patients with musculoskeletal disorders (MSDs).

Method

A comprehensive systematic review was performed using 11 electronic databases up to 20 February 2014. Keywords and MeSH terms included “musculoskeletal disorders”, “walking”, and “pedometer”. Randomized controlled trials, published in English, that examined the effects of a pedometer-based walking intervention to increase physical activity levels and improve physical function and pain in patients with musculoskeletal disorders were included.

Result

Of the 1996 articles retrieved, seven studies ranging in date of publication from 1998 to 2013 met the inclusion criteria, allowing data extraction on 484 participants with an age range of 40 to 82 years. Interventions lasted from 4 weeks to 12 months and the results across studies showed significant increases in step count (p < 0.05) following the intervention. Across these studies, there was a mean increase in PA of 1950 steps per day relative to baseline. Four studies reported improved scores for pain and/or physical function at the intervention completion point relative to controls.

Conclusion

This study provides strong evidence for the effectiveness of pedometer walking interventions in increasing PA levels for patients with MSDs. Our findings suggest that a combination of interventions is likely to be the most effective strategy to maximize health benefits in the short term. Further research should include larger sample sizes, and longer intervention durations are required to support the role of pedometer walking interventions as a long term intervention for management of musculoskeletal disorders.

SHIP1 regulates MSC numbers and their osteolineage commitment by limiting induction of the PI3K/Akt/β-catenin/Id2 axis

Here, we show that Src homology 2-domain-containing inositol 5'-phosphatase 1 (SHIP1) is required for the efficient development of osteoblasts from mesenchymal stem cells (MSCs) such that bone growth and density are reduced in mice that lack SHIP1 expression in MSCs. We find that SHIP1 promotes the osteogenic output of MSCs by limiting activation of the PI3K/Akt/β-catenin pathway required for induction of the MSC stemness factor Id2. In parallel, we demonstrate that mice with myeloid-restricted ablation of SHIP1, including osteoclasts (OCs), show no reduction in bone mass or density. Hence, diminished bone mass and density in the SHIP1-deficient mice results from SHIP deficiency in MSC and osteolineage progenitors. Intriguingly, mice with a SHIP-deficient MSC compartment also exhibit decreased OC numbers. In agreement with our genetic findings we also show that treatment of mice with an SHIP1 inhibitor (SHIPi) significantly reduces bone mass. These findings demonstrate a novel role for SHIP1 in MSC fate determination and bone growth. Further, SHIPi may represent a novel therapeutic approach to limit bone development in osteopetrotic and sclerotic bone diseases.

Roles of osteoclasts in the control of medullary hematopoietic niches

Bone marrow is the major site of hematopoiesis in mammals. The bone marrow environment plays an essential role in the regulation of hematopoietic stem and progenitor cells by providing specialized niches in which these cells are maintained. Many cell types participate to the composition and regulation of hematopoietic stem cell (HSC) niches, integrating complex signals from the bone, immune and nervous systems. Among these cells, the bone-resorbing osteoclasts (OCLs) have been described as main regulators of HSC niches. They are not limited to carving space for HSCs, but they also provide signals that affect the molecular and cellular niche components. However, their exact role in HSC niches remains unclear because of the variety of models, signals and conditions used to address the question. The present review will discuss the importance of the implication of OCLs focusing on the formation of HSC niches, the maintenance of HSCs in these niches and the mobilization of HSCs from the bone marrow. It will underline the importance of OCLs in HSC niches.

Fixation with C-2 laminar screws in occipitocervical or C1-2 constructs in children 5 years of age or younger: a series of 18 patients

OBJECT.: There are rare indications for upper cervical spine fusion in young children. Compared with nonrigid constructs, rigid instrumentation with screw fixation increases the fusion rate and reduces the need for halo fixation. Instrumentation may be technically challenging in younger children. A number of screw placement techniques have been described. Use of C-2 translaminar screws has been shown to be anatomically feasible, even in the youngest of children. However, there are few data detailing the clinical outcome. In this study, the authors describe the clinical and radiographic follow-up of 18 children 5 years of age or younger who had at least one C-2 translaminar screw as part of an occipitocervical or C1-2 fusion construct.

METHODS

A retrospective review of all children treated with instrumented occipitocervical or C1-2 fusion between July 1, 2007, and June 30, 2013, at Riley Children's Hospital and Texas Children's Hospital was performed. All children 5 years of age or younger with incorporation of at least one C-2 translaminar screw were identified.

RESULTS

Eighteen children were studied (7 boys and 11 girls). The mean age at surgery was 38.1 months (range 10-68 months). Indications for surgery included traumatic instability (6), os odontoideum (3), destructive processes (2), and congenital instability (7). A total of 24 C-2 translaminar screws were placed; 23 (95.8%) of 24 were satisfactorily placed (completely contained within the cortical walls). There was one medial cortex breach without neurological impingement. There were no complications with screw placement. Three patients required wound revisions. Two patients died as a result of their original condition (trauma, malignant tumor). The mean follow-up duration for the surviving patients was 17.5 months (range 3-60 months). Eleven (91.7%) of the 12 patients followed for 6 months or longer showed radiographic stability or completed fusion.

CONCLUSIONS

Use of C-2 translaminar screws provides an effective anchor for internal fixation of the upper cervical spine. In this study of children 5 years of age or younger, the authors found a high rate of radiographic fusion with a low rate of complications.

Hospital costs of total hip arthroplasty for developmental dysplasia of the hip

BACKGROUND

Developmental dysplasia of the hip (DDH) is a leading cause of total hip arthroplasty (THA) in younger patients. It is unknown how the hospital costs of THA in patients with DDH compare with patients with degenerative arthritis.

QUESTIONS/PURPOSES

We undertook this study to determine (1) the hospital cost and length of stay associated with primary THA in patients with dysplasia compared with nondysplastic control subjects; (2) the hospital cost and length of stay of THA in severely dysplastic hips compared with mildly dysplastic hips; and (3) perioperative complications in patients with DDH compared with patients without dysplasia.

METHODS

This matched-cohort study included 354 patients undergoing primary THA for DDH and 1029 age-, sex-, and calendar year-matched patients undergoing THA for primary osteoarthritis between 2000 and 2008. DDH severity was measured by the Crowe classification. An institutional database was used to calculate the cost of care. Using line item details (date, type, frequency, and billed charge) for every procedure or service billed at our institution for each patient, bottom-up microcosting valuation techniques were used to generate standardized inflation-adjusted estimates of the cost of each service or procedure in constant dollars. Generalized linear random effects models were used to compare length of stay and costs during hospitalization and the 90-day period after surgery. Query of a longitudinal institutional database was used to identify documented complications.

RESULTS

Patients with DDH undergoing primary THA incurred higher hospital costs than patients with primary osteoarthritis (USD 16,949 versus USD 16,485, p = 0.012). Operating room costs (USD 3471 versus USD 3417, p = 0.0085) and implant costs (USD 3896 versus USD 3493, p < 0.001) were higher in the DDH group compared with the osteoarthritis group. Length of stay was not different between the two groups (4 versus 4 days, p = 0.46). Crowe 4 hips had higher hospital costs than Crowe 1 hips (USD 21,246 versus USD 16,345, p < 0.001) with an associated longer length of stay (5 days versus 4 days, p = 0.0011) and higher implant costs (USD 4380 versus USD 3788, p = 0.0012). There was no detectible difference in 90-day complications in the case group compared with patients undergoing THA for osteoarthritis.

CONCLUSIONS

Hospital cost of primary THA is approximately USD 450 higher in patients with DDH compared with osteoarthritis. Increased severity of dysplasia (Crowe classification) was associated with higher costs.

LEVEL OF EVIDENCE

Level IV, economic and decision analyses. See Guidelines for Authors for a complete description of levels of evidence.

Osteoclast fusion is based on heterogeneity between fusion partners

Bone-resorbing osteoclasts are formed through fusion of mononucleated precursors. Their choice of partners during the fusion process remains unclear. We hypothesized that osteoclasts are selective in their choice of fusion partner and that this selectivity is based on heterogeneity among the cells with respect to their maturation stage and their expression and cellular organization of fusion factors. Support for this hypothesis was found from immunofluorescence staining of the osteoclast fusion factors CD47, dendritic cell-specific transmembrane protein (DC-STAMP), and syncytin-1. These stainings revealed heterogeneous localization patterns of all three factors within a given culture of osteoclasts. CD47 was found to be localized primarily in small osteoclasts and preosteoclasts, which were also positive for DC-STAMP but negative for cathepsin K expression. A role of CD47 in the early osteoclast fusion steps was also suggested from experiments with a CD47 blocking antibody, which resulted in an inhibition of the fusion of small osteoclasts. Conversely, blocking of connexin 43 affected the fusion of larger osteoclasts with four or more nuclei. The suggestion that different fusion factors function at different stages of osteoclast fusion supports the idea of heterogeneity in the osteoclast population; our results suggest that osteoclast fusion is indeed based on heterogeneity. Considering the in vivo environment in which osteoclasts develop and fuse, our findings seem very applicable and provide novel, important insight into key issues in bone and fusion research.

Osteoporosis detection in postmenopausal women using axial transmission multi-frequency bone ultrasonometer: clinical findings

The objective of this study was to evaluate if the Bone UltraSonic Scanner (BUSS) can detect osteoporosis in postmenopausal women. BUSS is an axial transmission multi-frequency ultrasonometer for acquisition of wave propagation profiles along the proximal anterior tibia. We derived 10 diagnostically significant BUSS parameters that were then compared with the DXA spine T-score, which was used in this study as the "gold standard" for the assessment of osteoporosis (T-score<-2.5). BUSS wave parameters were studied in 331 postmenopausal women examined by 9 trained operators at 3 clinical sites with use of 3 devices. The efficiency of each BUSS parameter in osteoporosis detection was assessed using a receiver operating characteristic curve analysis. Area under the curve (AUC) for each of 10 parameters ranged from 58.1% to 70.2%. Using these parameters a linear classifier was derived which provided at its output 83.0% AUC, 87.7% sensitivity and 63.2% specificity to DXA-identified osteoporosis. The results of this study confirm BUSS's capability to detect osteoporosis in postmenopausal women.

Stochastic resonance whole-body vibration improves postural control in health care professionals: a worksite randomized controlled trial

Slip, trip, and fall injuries are frequent among health care workers. Stochastic resonance whole-body vibration training was tested to improve postural control. Participants included 124 employees of a Swiss university hospital. The randomized controlled trial included an experimental group given 8 weeks of training and a control group with no intervention. In both groups, postural control was assessed as mediolateral sway on a force plate before and after the 8-week trial. Mediolateral sway was significantly decreased by stochastic resonance whole-body vibration training in the experimental group but not in the control group that received no training (p < .05). Stochastic resonance whole-body vibration training is an option in the primary prevention of balance-related injury at work.

Stochastic resonance whole-body vibration improves postural control in health care professionals: a worksite randomized controlled trial

Slip, trip, and fall injuries are frequent among health care workers. Stochastic resonance whole-body vibration training was tested to improve postural control. Participants included 124 employees of a Swiss university hospital. The randomized controlled trial included an experimental group given 8 weeks of training and a control group with no intervention. In both groups, postural control was assessed as mediolateral sway on a force plate before and after the 8-week trial. Mediolateral sway was significantly decreased by stochastic resonance whole-body vibration training in the experimental group but not in the control group that received no training (p < .05). Stochastic resonance whole-body vibration training is an option in the primary prevention of balance-related injury at work.

Cellular behavior as a dynamic field for exploring bone bioengineering: a closer look at cell-biomaterial interface

Bone is a highly dynamic and specialized tissue, capable of regenerating itself spontaneously when afflicted by minor injuries. Nevertheless, when major lesions occur, it becomes necessary to use biomaterials, which are not only able to endure the cellular proliferation and migration, but also to substitute the original tissue or integrate itself to it. With the life expectancy growth, regenerative medicine has been gaining constant attention in the reconstructive field of dentistry and orthopedy. Focusing on broadening the therapeutic possibilities for the regeneration of injured organs, the development of biomaterials allied with the applicability of gene therapy and bone bioengineering has been receiving vast attention over the recent years. The progress of cellular and molecular biology techniques gave way to new-guided therapy possibilities. Supported by multidisciplinary activities, tissue engineering combines the interaction of physicists, chemists, biologists, engineers, biotechnologist, dentists and physicians with common goals: the search for materials that could promote and lead cell activity. A well-oriented combining of scaffolds, promoting factors, cells, together with gene therapy advances may open new avenues to bone healing in the near future. In this review, our target was to write a report bringing overall concepts on tissue bioengineering, with a special attention to decisive biological parameters for the development of biomaterials, as well as to discuss known intracellular signal transduction as a new manner to be explored within this field, aiming to predict in vitro the quality of the host cell/material and thus contributing with the development of regenerative medicine.

Dissecting the role of bone marrow stromal cells on bone metastases

Tumor-induced bone disease is a dynamic process that involves interactions with many cell types. Once metastatic cancer cells reach the bone, they are in contact with many different cell types that are present in the cell-rich bone marrow. These cells include the immune cells, myeloid cells, fibroblasts, osteoblasts, osteoclasts, and mesenchymal stem cells. Each of these cell populations can influence the behavior or gene expression of both the tumor cells and the bone microenvironment. Additionally, the tumor itself can alter the behavior of these bone marrow cells which further alters both the microenvironment and the tumor cells. While many groups focus on studying these interactions, much remains unknown. A better understanding of the interactions between the tumor cells and the bone microenvironment will improve our knowledge on how tumors establish in bone and may lead to improvements in diagnosing and treating bone metastases. This review details our current knowledge on the interactions between tumor cells that reside in bone and their microenvironment.

Summary of the various treatments for osteonecrosis of the femoral head by mechanism: A review

Osteonecrosis of the femoral head (ONFH), also known as femoral head avascular necrosis, is a pathological state with a number of possible etiologies including steroid administration, alcohol abuse, traumatic events, vascular injury and idiopathic origins. ONFH causes a reduction in the vascular supply to the subchondral bone of the femoral head, which results in osteocyte death and the collapse of the articular surface. Treatments for ONFH include non-weight-bearing therapy, physical support, the promotion of osteoclast apoptosis, and the reduction of osteoblast and osteocyte apoptosis. The aim of the present review was to summarize the treatments for ONFH by mechanism from a new perspective and to describe the condition with an emphasis on treatment options.

Effects of JSOG-6 on protection against bone loss in ovariectomized mice through regulation of osteoblast differentiation and osteoclast formation

Background

JSOG-6 is used as a traditional medicine to relieve the symptoms associated with inflammation, rheumatism, and osteoporosis in Korea. In the present study, we investigated the effects of JSOG-6 on bone loss prevention both in in vitro and in vivo as well as its underlying mechanism of action.

Methods

Protection against bone loss was assessed in an ovariectomized (OVX) mouse model. Bone microarchitecture was measured using a micro-computed tomography to detect the parameters of three-dimensional structure of a trabecular bone. Serum biomarkers were also evaluated in an OVX-induced model. Osteoclasts derived from mouse bone marrow cells (BMCs) and osteoblastic MC3T3-E1 cells were also employed to investigate the mechanism of action.

Results

Oral administration of JSOG-6 significantly increased the bone mineral density (BMD) of the femur in OVX mice in vivo. Especially, the reduced Tb.No (trabecular bone number) in the OVX group was significantly recovered by JSOG-6 treatment. The serum levels of alkaline phosphatase (ALP), osteocalcin, C-terminal telopeptide, and tartrate-resistant acid phosphatase, biomarkers of bone resorption, were significantly elevated in OVX mice, but JSOG-6 effectively inhibited the increase in OVX mice. JSOG-6 was also found to enhance the osteoblastic differentiation and maturation with the increase of the density and ALP activity, a marker of osteoblastic differentiation, as well as calcium deposition, a marker of osteoblastic maturation in MC3T3-E1 cells. The effects of JSOG-6 on osteoblastic differentiation were also associated in part with the increase of ALP and OPN mRNA expressions and the decrease of RANKL mRNA expression in MC3T3-E1 cells.

Conclusions

The findings demonstrate that JSOG-6 induced protection against bone loss in OVX mice, and its anti-osteoporotic property might be, in part, a function of the stimulation of osteoblast differentiation and the inhibition of osteoclast formation. These findings suggest that JSOG-6 might be an applicable therapeutic traditional medicine for the regulation of the osteoporotic response.

Clinically relevant complications related to posterior atlanto-axial fixation in atlanto-axial instability and their management

BACKGROUND

The Magerl transarticular technique and the Harms-Goel C1 lateral mass-C2 isthmic screw technique are the two most commonly used surgical procedures to achieve fusion at C1-C2 level for atlanto-axial instability. Despite recent technological advances with an increased safety, several complications may still occur, including vascular lesions, neurological injuries, pain at the harvested bone graft site, infections, and metallic device failure.

METHODS

We retrospectively analyzed all patients (n=42 cases) undergoing a Harms-Goel C1-C2 fixation surgery with polyaxial C1 lateral mass screws and C2 isthmic screws at two different institutions between 2003 and 2012 and report clinical and radiological complications. One patient was lost to follow-up. The mean follow-up of the remaining 41 patients was 18.7 months (range 12-90). A clinically relevant complication was defined as a complication determining the onset of a new neurological deficit or requiring the need for a revision surgery.

RESULTS

A total of 14 complications occurred in 10 patients (24.4% of 41 patients). Greater occipital nerve neuralgia was evident in 4 patients (9.8%). All but one completely resolved at the end of the follow-up. Persistent neck pain was reported by 3 patients (7.3%), hypoesthesia by 1 patient (2.4%), and anesthesia in the C2 area on both sides in 1 patient (2.4%). Furthermore, a superficial, a deep, and a combined superficial and deep wound infection occurred in 1 patient each (2.4%). One patient (2.4%) had pain at the iliac bone graft donor site for several weeks with spontaneous resolution. A posterior progressive intestinal herniation through the iliac scar was seen in 1 case (2.4%), which required surgical repair. No vascular damages occurred. Altogether, 5/41 patients (12.2%) had a clinically relevant complication including 4 patients necessitating a revision surgery at the C1-C2 level (9.8%).

CONCLUSIONS

Atlanto-axial fixation surgery remains a challenging procedure because of the proximity of important neurovascular structures. Nevertheless, on the basis of our current experience, the C1 lateral mass-C2 isthmic screw technique appears to be safe with a low incidence of clinically relevant complications. Postoperative C2 neuralgia, as the most frequent problem, is due to surgical manipulation during preparation of the C1 screw entry point.

Influence of ankle loading on the relationship between temporal pressure and motor coordination during a whole-body paired task

We investigated whether ankle loading modifies the relationship between temporal pressure and motor coordination during a whole-body paired task. Eight young healthy adults standing in an erect posture performed multiple series of simultaneous rapid leg flexions paired with ipsilateral index finger extensions. They repeated the task ten times in three load conditions: unloaded, loaded (where additional 5-kg inertia was attached to the ankles), and post-loaded (immediately following the loaded condition). These conditions were conducted in two blocks of temporal pressure: self-initiated (SI) versus reaction time (RT). When participants were unloaded, the results showed that index finger extension preceded swing heel-off in RT, and conversely in SI. By contrast, when the participants were loaded, swing heel-off preceded index finger extension in both SI and RT, showing that loading modified the relationship between temporal pressure and movement synchronization in RT only. However, loading did not induce any increase in the error of synchronization. Furthermore, in both the unloaded and loaded conditions, the duration of "anticipatory postural adjustments" (APA) was shorter when the temporal pressure was increased. Interestingly, the shorter APA duration was compensated by an increase in APA amplitude. Thus, loading did not modify the relationship between temporal pressure and anticipatory postural dynamics. Post-loaded and unloaded conditions produced the same results. These results show that the central nervous system optimally adapts the relationship between temporal pressure and motor coordination to transitory changes in the mechanical properties of the lower limbs, here due to ankle loading.

Human umbilical cord-derived mesenchymal stem cells do not undergo malignant transformation during long-term culturing in serum-free medium

BACKGROUND

Human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) are in the foreground as a preferable application for treating diseases. However, the safety of hUC-MSCs after long-term culturing in vitro in serum-free medium remains unclear.

METHODS

hUC-MSCs were separated by adherent tissue culture. hUC-MSCs were cultured in serum-free MesenCult-XF medium and FBS-bases DMEM complete medium. At the 1st, 3rd, 5th, 8th, 10th, and 15th passage, the differentiation of MSCs into osteogenic, chondrogenic, and adipogenic cells was detected, and MTT, surface antigens were measured. Tumorigenicity was analyzed at the 15th passage. Conventional karyotyping was performed at passage 0, 8, and 15. The telomerase activity of hUC-MSCs at passage 1-15 was analyzed.

RESULTS

Flow cytometry analysis showed that very high expression was detected for CD105, CD73, and CD90 and very low expression for CD45, CD34, CD14, CD79a, and HLA-DR. MSCs could differentiate into osteocytes, chondrocytes, and adipocytes in vitro. There was no obvious chromosome elimination, displacement, or chromosomal imbalance as determined from the guidelines of the International System for Human Cytogenetic Nomenclature. Telomerase activity was down-regulated significantly when the culture time was prolonged. Further, no tumors formed in rats injected with hUC-MSCs (P15) cultured in serum-free and in serum-containing conditions.

CONCLUSION

Our data showed that hUC-MSCs met the International Society for Cellular Therapy standards for conditions of long-term in vitro culturing at P15. Since hUC-MSCs can be safely expanded in vitro and are not susceptible to malignant transformation in serum-free medium, these cells are suitable for cell therapy.

National trends in revision spinal fusion in the USA

Using the United States Nationwide Inpatient Sample, we identified national trends in revision spinal fusion along with a comprehensive comparison of comorbidities, inpatient complications and surgical factors of revision spinal fusion compared to primary spinal fusion.

In 2009, there were 410 158 primary spinal fusion discharges and 22 128 revision spinal fusion discharges. Between 2002 and 2009, primary fusion increased at a higher rate compared with revision fusion (56.4% vs 51.0%; p < 0.001). In 2009, the mean length of stay and hospital charges were higher for revision fusion discharges than for primary fusion discharges (4.2 days vs 3.8 days, p < 0.001; USD $91 909 vs. $87 161, p < 0.001). In 2009, recombinant human bone morphogenetic protein (BMP) was used more in revision fusion than in primary fusion (39.6% vs 27.6%, p < 0.001), whereas interbody devices were used less in revision fusion (41.8% vs 56.6%, p < 0.001).

In the multivariable logistic regression model for all spinal fusions, depression (odds ratio (OR) 1.53, p < 0.001), psychotic disorders (OR 1.49, p < 0.001), deficiency anaemias (OR 1.35, p < 0.001) and smoking (OR 1.10, p = 0.006) had a greater chance of occurrence in revision spinal fusion discharges than in primary fusion discharges, adjusting for other variables. In terms of complications, after adjusting for all significant comorbidities, this study found that dural tears (OR 1.41; p < 0.001) and surgical site infections (OR 3.40; p < 0.001) had a greater chance of occurrence in revision spinal fusion discharges than in primary fusion discharges (p < 0.001). A p-value < 0.01 was considered significant in all final analyses.

Cite this article: Bone Joint J 2014;96-B:807–16.