Simultaneous Bilateral Proximal Humerus Fractures Treated with Single-Stage Bilateral Reverse Shoulder Arthroplasty.

Introduction: Simultaneous bilateral fractures of the proximal humerus are infrequent, and simultaneous bilateral three- or four-part fractures are even rarer. Reverse shoulder arthroplasty (RSA) is being used increasingly for the treatment of three- and four-part fractures of the proximal humerus. However, treatment of simultaneous bilateral fractures of the proximal humerus is difficult because of concern about postoperative immobilization and rehabilitation. Case Presentation. A 75-year-old woman presented with bilateral shoulder pain subsequent to a fall on the street. Physical examination and radiographs showed simultaneous bilateral fractures of the proximal humerus. The right side fracture was classified as a four-part fracture and the left side fracture as a three-part fracture, according to Neer's classification. The right shoulder had a risk of avascular necrosis of the humeral head. For the left shoulder, the fracture type had caused ischemia of the humeral head. Single-stage bilateral RSA was performed 9 days after the injury. An abduction pillow was applied for 5 weeks postoperatively. Passive motion exercises were permitted starting at 4 weeks postoperatively, and active range of motion exercises were permitted at 6 weeks postoperatively. At the patient's most recent follow-up 30 months after surgery, the patient reported no restriction of the activities of daily living. Radiographs revealed no lucent line on the humerus and glenoid components, although bone resorption and superior retraction of the tuberosities on both sides were observed. Conclusions: Single-stage bilateral RSA improved shoulder function, but healing of the greater tuberosity can affect the improvement in external rotation after the operation. Although a long-term follow-up is needed, single-stage bilateral RSA appears to be a viable treatment option.

Is Chronic Kidney Disease Affecting the Postoperative Complications of Vitrectomy for Proliferative Diabetic Retinopathy?

Chronic kidney disease (CKD) is a well-known risk factor for postoperative complications in several surgical fields. However, although prevalent among diabetic candidates for vitrectomy, the effect of CKD on vitrectomy outcomes remains unclear. This study aimed at clarifying the relationship between CKD and the occurrence of vitrectomy-related complications in patients with proliferative diabetic retinopathy (PDR). The 6-month incidences of vitreous hemorrhage (VH) and neovascular glaucoma (NVG) following vitrectomy for PDR were compared among the following groups: stages 1-2 CKD (60 patients), stages 3-5 CKD (70 patients not on hemodialysis), and hemodialysis (HD; 30 patients). We also determined whether the deterioration of the estimated glomerular filtration rate (eGFR) was associated with post-vitrectomy events. The incidence of VH was significantly higher in the stages 3-5 CKD group (43%) than in the stages 1-2 CKD (10%) and HD (10%) groups. NVG was more common in the stages 3-5 CKD group (17%) than in the stages 1-2 CKD (2%) and HD (0%) groups. The reduced estimated glomerular filtration rate (eGFR) was the only significant variable associated with post-vitrectomy VH and NVG. Patients with PDR and CKD, particularly those with lower eGFR, might be at risk for post-vitrectomy VH and NVG.

Blood flow distribution after end-to-side anastomosis with wide arteriotomy in extremity free flap surgery.

PURPOSE: Although many studies have investigated the optimal anastomotic procedure for the end-to-side (ETS) procedure with a free flap, no study has focused on the size of the arteriotomy. Some surgeons have recently described the effectiveness of ETS with wide arteriotomy, but the postoperative haemodynamics remains unclear for free flaps created using this technique. The aim of this study was to use ultrasonography to evaluate the postoperative blood flow distribution after ETS with a wide arteriotomy in extremity free flap surgery. METHODS: We evaluated 20 free flaps in 18 consecutive patients who received an ultrasonographic examination after free flap surgery using the ETS technique with wide arteriotomy for arterial anastomosis. All flaps were examined after surgery and blood flow was calculated for the flap and recipient vessels. RESULTS: All 20 flaps survived, but one flap developed asymptomatic arterial thrombosis and 19 flaps were analysed. For the ETS technique with wide arteriotomy, peripheral circulation was well preserved in all flaps. Comparison of flap types showed that blood flow was significantly higher in myocutaneous flaps than in fasciocutaneous flaps, but there was no significant difference according to the size of the arteriotomy. CONCLUSIONS: Given the range of arteriotomy performed using the ETS with a wide arteriotomy technique, the blood flow volume in the flap depended on the type of flap but not on the size of the arteriotomy. A steal phenomenon related to the creation of a wide window in the receipt artery was not found in the analysed retrospective cohort.

Vitreous hemorrhage in diabetes patients with proliferative diabetic retinopathy undergoing hemodialysis.

AIMS/INTRODUCTION: For diabetes patients undergoing hemodialysis, vitreous hemorrhage seems to be a hemodialysis-induced hemorrhagic complication because of the effect of systemic anticoagulation. However, it is unclear whether hemodialysis is associated with vitreous hemorrhage in diabetes patients. We therefore carried out this cohort study to clarify the relationship between hemodialysis and vitreous hemorrhage in diabetes patients with proliferative diabetic retinopathy. MATERIALS AND METHODS: This was a single-center, retrospective, cohort study. We compared the incidence of vitreous hemorrhage in non-vitrectomized proliferative diabetic retinopathy eyes between the hemodialysis group (145 eyes) and peritoneal dialysis group (36 eyes), which does not require the use of systemic anticoagulation (parallel-group study), and in hemodialysis patients in the 12-month period before and after the start of hemodialysis (before-after study). We also determined the risk factors for vitreous hemorrhage after the start of hemodialysis based on the patients' systemic and ophthalmic characteristics. RESULTS: There was no significant difference in the first-year incidence of vitreous hemorrhage between the hemodialysis (23.4%) and peritoneal dialysis groups (22.2%, P = 1.000). The incidence of vitreous hemorrhage in the dialysis period (23.4%) was significantly lower than that in the predialysis period (35.2%, P = 0.008). Only application of panretinal photocoagulation within the 6 months immediately before hemodialysis was significantly associated with the incidence of vitreous hemorrhage after the start of hemodialysis (P < 0.001). CONCLUSIONS: Hemodialysis therapy does not seem to be associated with a higher risk of vitreous hemorrhage in diabetes patients with proliferative diabetic retinopathy.

Breast cancer cells expressing cancer-associated sialyl-Tn antigen have less capacity to develop osteolytic lesions in a mouse model of skeletal colonization.

Breast cancer is one of the most prevalent malignancies in women, and approximately 75-80% of patients with advanced breast cancer develop bone metastasis. Expression of the cancer-associated carbohydrate antigen sialyl-Tn (STn) in breast cancer is associated with a poor prognosis; however, involvement of STn in the development of metastatic bone lesions remains unclear. We investigated whether STn expression on breast cancer cells influences intraosseous tumor growth and bone response in mice models of skeletal colonization. STn-positive (STn+) breast cancer cells were generated by stable transfection of an expression vector encoding ST6GaLNAc I into the breast cancer cell line MDA-MB-231. Parental MDA-MB-231 cells not expressing STn antigen were used as STn-negative (STn-) breast cancer cells. Contrary to expectations, STn expression attenuated the development of destructive bone lesions in the in vivo mice models. An in vitro study demonstrated that STn expression impaired adhesion of MDA-MB-231cells to bone marrow stromal cells. This finding in vitro was also confirmed by another breast cancer cell line MCF-7. Cell adhesion to fibronectin and type I collagen was also impaired in STn+ MDA-MB-231 cells compared to that in STn- MDA-MB-231 cells, suggesting integrin dysfunction. Given that the integrin ß1 subunit is the main carrier of the STn epitope, it is likely that changes in glycan structure impaired the adhesive capacity of ß1 integrin in the bone environment, leading to attenuation of tumor cell engraftment. In conclusion, breast cancer cells expressing STn antigen had less capacity for skeletal colonization, possibly due to impaired adhesive capability.

Renal function after intravitreal administration of vascular endothelial growth factor inhibitors in patients with diabetes and chronic kidney disease.

The present study aimed to determine whether intravitreal administration of vascular endothelial growth factor inhibitors is associated with deterioration of renal function, as seen with systemic administration, in patients with diabetes and chronic kidney disease. Estimated glomerular filtration rates before and after 160 intravitreal injections of vascular endothelial growth factor inhibitors (aflibercept, bevacizumab or ranibizumab) were compared in 69 patients with diabetes and with a baseline estimated glomerular filtration rate <60 mL/min/1.73 m2 . We also determined the incidence of acute kidney injury. The data showed no significant difference in the estimated glomerular filtration rate before and after vascular endothelial growth factor inhibitor administration in all patients and in patient subgroups based on each inhibitor. Furthermore, no episodes of acute kidney injury occurred. In conclusion, intravitreal administration of vascular endothelial growth factor inhibitors is unlikely to be associated with a deterioration of renal function in patients with diabetes and chronic kidney disease.

Giant retinal pigment epithelial tear associated with fluid overload due to end-stage diabetic kidney disease.

PURPOSE: To report a case of a giant retinal pigment epithelial (RPE) tear associated with fluid overload in a patient with diabetic macular edema (DME) and kidney disease. OBSERVATIONS: A 60-year-old man with type 2 diabetes mellitus and end-stage diabetic kidney disease who had gained weight because of fluid overload complained of a visual disturbance in the left eye that had started a few days earlier. The left fundus showed a RPE defect in two temporal quadrants under an extensive serous retinal detachment (SRD) with exacerbation of the original DME. Seven days later, he was admitted for severe edema and pleural effusion. No overt signs of congestive heart failure were noted. On admission, the RPE defect had markedly widened to involve the macula. Spectral-domain optical coherence tomography images showed substantial intraretinal fluid and an extensive SRD with rolled edges of the retinal pigment epithelium, which led to the diagnosis of a RPE tear. The fluid under the SRD was absorbed on the fourth hospital day and the substantial intraretinal fluid resolved on the eleventh day after systemic management of fluid overload only without ophthalmic treatment. The change in the appearance of the RPE area was minimal and the visual field defect remained even after 6 months. CONCLUSIONS AND IMPORTANCE: A RPE tear may develop in association with fluid overload in patients with diabetes.

Viability of Cells From Displaced Fragments of the Elbow Osteochondritis Dissecans: Alternative Source of Autologous Chondrocyte Implantation.

PURPOSE: To assess the histological properties of cells from displaced fragments obtained from patients with advanced osteochondritis dissecans (OCD) of the elbow and to examine whether these displaced fragments could be used as cell sources for autologous chondrocyte implantation. METHODS: We harvested 6 displaced fragments from 6 patients who underwent osteochondral mosaicplasty for OCD of the elbow. The displaced fragments were examined histologically and digested to obtain chondrocytes. The cells obtained from young patients and skeletally matured cadaveric donors were examined using quantitative reverse transcription polymerase chain reaction analysis to quantify the expression of chondrocyte marker genes. The cells were cultured in atelocollagen, and the properties of 3-dimensional cultured cartilage were examined. RESULTS: All 6 displaced fragments contained hyaline cartilage tissue. Chondrocyte marker genes were examined using cells from only 4 patients, because we obtained enough cells in only 4 patients. The relative expression levels of aggrecan, type II, Sox 9 were 2.61, 4.03, and 1.71, respectively. Three-dimensional cultured cartilage from all 6 displaced fragments contained 62.0 pg/cell (range, 22.8-91.3 pg/cell) of glycosaminoglycan and expressed type II collagen in the superficial and middle layer. CONCLUSIONS: The chondrocytes obtained from the displaced fragments remained viable and exhibited chondrogenic features. These cells may potentially be a cell source of autologous chondrocytes implantation. CLINICAL RELEVANCE: We have shown that displaced fragments from OCD of the elbow have potential for a cell source for generating 3-dimensional cultured cartilage.

Predictive factors of long head of the biceps tendon disorders-the bicipital groove morphology and subscapularis tendon tear.

BACKGROUND: Disorders of the long head of the biceps (LHB) tendon contribute to anterior shoulder pain. Although LHB tendon disorders are associated with rotator cuff disease, distinguishing between biceps and rotator cuff pathology is difficult. The objective was to identify the predictors of LHB tendon disorders associated with a supraspinatus tear. METHODS: In 55 patients (average age, 65 years) undergoing arthroscopic rotator cuff repair, bicipital groove morphology were assessed using computed tomography, and subscapularis tear and bicipital groove effusion were assessed using magnetic resonance imaging, retrospectively. The LHB tendon was evaluated arthroscopically according to the Lafosse classification. Univariate and multivariate ordinal logistic regression analyses were conducted for injury grade with all covariates. RESULTS: The arthroscopic evaluation of the LHB tendon showed that there were 23 shoulders classified as grade 0, 15 as grade 1, and 17 as grade 2. Univariate logistic regression analysis showed that the width and depth, a medial spur of the bicipital groove, and a subscapularis tear were significantly associated with LHB tendon disorders. Multivariate ordinal logistic regression analysis identified a medial spur and subscapularis tear as significant predictors of LHB tendon disorders. CONCLUSIONS: The preoperative computed tomography and magnetic resonance images, notably the presence of a spur on the bicipital groove or a subscapularis tear, were useful for identifying LHB tendon disorders. When these are found in preoperative images, the clinician should evaluate the patient for the presence of an LHB tendon disorder as a pain generator.

Teriparatide Improves Trabecular Osteoporosis but Simultaneously Promotes Ankylosis of the Spine in the Twy Mouse Model for Diffuse Idiopathic Skeletal Hyperostosis.

Diffuse idiopathic skeletal hyperostosis (DISH) is a common skeletal disorder in the elderly, which can develop into periosteal hyperostosis and paradoxically into immobilization-associated trabecular osteoporosis. The bone anabolic agent, teriparatide (TPD), seems to be a rational treatment for the immobilization-associated osteoporosis. However, it can lead to development of hyperostosis lesions in DISH patients. Here, we demonstrate TPD effectively treats trabecular osteoporosis while simultaneously promoting ankylosis of the spine in DISH model tiptoe-walking Yoshimura (twy) mice, compared with the ICR mice. Eighteen male twy mice were divided into three groups, and ICR mice were used as a normal control. Subcutaneous injections of TPD or phosphate-buffered saline (PBS) were performed according to three dosing regimens; 40 µg/kg once daily (TPD × 1 group), 40 µg/kg three times daily (TPD × 3 group), and PBS (control; Ctl group). Treatment was commenced at the age of 7 weeks and continued for 5 weeks. Micro-computed tomography (µCT) and histological analysis were performed. Longitudinal µCT study revealed that trabecular bone volume in both the vertebral body and distal femur decreased with time in the Ctl group, but increased dramatically in the TPD × 3 group. The twy mice developed ankylosis of the spine, the progression of which was accelerated with TPD therapy. We also confirmed that TPD therapy promoted ossification of spinal ligaments. Histomorphometrical study revealed that TPD treatment increased bone formation at the vertebrae enthesis region and in the trabecular bone. TPD therapy effectively treats trabecular osteoporosis, but potentially promotes ankylosis of the spine in patients with DISH.

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) mediates periarticular bone loss, but not joint destruction, in murine antigen-induced arthritis.

Osteoclastogenesis requires immunoreceptor tyrosine-based activation motif signaling. Multiple immunoreceptors associated with immunoreceptor tyrosine-based activation motif adaptor proteins, including DNAX-activating protein 12 kDa (DAP12) and Fc receptor common γ (FcRγ), have been identified in osteoclast lineage cells, and some are involved in arthritis-induced bone destruction. Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immunoreceptor that regulates osteoclast development and bone resorption in association with DAP12. Whether Siglec-15 is involved in arthritis-induced bone lesions, however, remains unknown. Here we used a murine antigen-induced arthritis model to examine the role of Siglec-15 in the development of bone lesions induced by joint inflammation. Arthritis was unilaterally induced in the knee joints of 8-week-old female wild-type (WT) and Siglec-15(-/-) mice, and the contralateral knees were used as a control. The degree of joint inflammation, and cartilage and subchondral bone destruction in Siglec-15(-/-) mice was comparable to that in WT mice, indicating that Siglec-15 is not involved in the development of arthritis and concomitant cartilage and subchondral bone destruction. On the other hand, the degree of periarticular bone loss in the proximal tibia of the arthritic knee was significantly lower in Siglec-15(-/-) mice compared to WT mice. Although osteoclast formation in the metaphysis was enhanced in both WT and Siglec-15(-/-) mice after arthritis induction, mature multinucleated osteoclast formation was impaired in Siglec-15(-/-) mice, indicating impaired osteoclast bone resorptive function in the periarticular regions of the arthritic joint in Siglec-15(-/-) mice. Confirming this result, Siglec-15(-/-) primary unfractionated bone marrow cells harvested from arthritic femurs and tibiae failed to develop into mature multinuclear osteoclasts. Our findings suggest that Siglec-15 is a therapeutic target for periarticular bone loss, but not for joint destruction, in inflammatory arthritis, such as rheumatoid arthritis.

Siglec-15 is a potential therapeutic target for postmenopausal osteoporosis.

Sialic acid-binding immunoglobulin-like lectin 15 (Siglec-15) is an immunoreceptor that regulates osteoclast development and bone resorption in association with an immunoreceptor tyrosine-based activation motif (ITAM) adaptor protein, DNAX-activating protein 12kDa (DAP12). Although Siglec-15 has an important role in physiologic bone remodeling by modulating RANKL signaling, it is unclear whether it is involved in pathologic bone loss in which multiple osteoclastogenic factors participate in excessive osteoclastogenesis. Here we demonstrated that Siglec-15 is involved in estrogen deficiency-induced bone loss. WT and Siglec-15(-/-) mice were ovariectomized (Ovx) or sham-operated at 14wk of age and their skeletal phenotype was evaluated at 18 and 22wk of age. Siglec-15(-/-) mice showed resistance to estrogen deficiency-induced bone loss compared to WT mice. Although the number of tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts increased after ovariectomy in both WT and Siglec-15(-/-) mice, the increase was lower in Siglec-15(-/-) mice than in WT mice. Importantly, osteoclasts in Siglec-15(-/-) mice were small and failed to spread on the bone surface, indicating impaired osteoclast differentiation. Because upregulated production of TNF-α as well as RANKL is mainly responsible for estrogen deficiency-induced development of osteoclasts, we examined whether Siglec-15 deficiency affects TNF-α-induced osteoclastogenesis in vitro. The TNF-α mediated induction of TRAP-positive multinucleated cells was impaired in Siglec-15(-/-) cells, suggesting that Siglec-15 is involved in TNF-α induced osteoclastogenesis. We also confirmed that signaling through osteoclast-associated receptor/Fc receptor common γ chain, which is an alternative ITAM adaptor to DAP12, rescues multinucleation but not cytoskeletal organization of TNF-α and RANKL-induced Siglec-15(-/-) osteoclasts, indicating that the Siglec-15/DAP12 pathway is especially important for cytoskeletal organization of osteoclasts in both RANKL and TNF-α induced osteoclastogenesis. The present findings indicate that Siglec-15 is involved in estrogen deficiency-induced differentiation of osteoclasts and is thus a potential therapeutic target for postmenopausal osteoporosis.

Vitamin K-dependent carboxylation of osteocalcin affects the efficacy of teriparatide (PTH(1-34)) for skeletal repair.

Teriparatide (PTH1-34) promotes skeletal repair and increases bone mass. Vitamin K is involved in bone mineralization as a coenzyme of γ-carboxylase for Gla proteins, and therefore vitamin K insufficiency caused by malnutrition or therapeutic intake of the vitamin K antagonist warfarin could affect the efficacy of PTH1-34 therapy for bone repair. In the present study, we investigated whether vitamin K influences the efficacy of PTH1-34 therapy for bone repair in a rat osteotomy model. Female 12-week-old Sprague-Dawley rats were subjected to a closed midshaft osteotomy of the femur and randomized into four groups (n=10 per group): vehicle, PTH1-34 (daily 30 µg/kg/day subcutaneous injection)+solvent (orally, three times a week), PTH1-34+warfarin (0.4 mg/kg/day orally, three times a week), and PTH1-34+vitamin K2 (menatetrenone, 30 mg/kg/day orally, three times a week). Serum γ-carboxylated and uncarboxylated osteocalcin (Gla-OC and Glu-OC) levels and radiographic healing were monitored every 2 weeks. Skeletal repair was assessed by micro-computed tomography, mechanical testing, and histology at 8weeks after surgery. PTH1-34 amplified the osteotomy-induced increase in Gla-OC and improved the mechanical properties as well as the volumetric bone mineral tissue density of the fracture callus. Concurrent use of warfarin decreased the response to PTH1-34 therapy in terms of mechanical recovery, probably by impairing mineralization due to the lack of Gla-OC. Although the effects of combination therapy with PTH1-34 and vitamin K2 on bone repair did not significantly exceed those of PTH1-34 monotherapy in rats fed sufficient dietary vitamin K, postoperative Gla-OC levels were correlated with the mechanical properties of the osteotomized femur in PTH1-34-treated rats regardless of the use of warfarin or vitamin K2. These findings suggest the importance of vitamin K dependent γ-carboxylation of OC for realizing the full effects of PTH1-34 on skeletal repair.

Caspase 3 silencing inhibits biomechanical overload-induced intervertebral disk degeneration.

Intervertebral disk (IVD) degeneration causes debilitating low back pain in much of the worldwide population. No efficient treatment exists because of an unclear pathogenesis. One characteristic event early in such degeneration is the apoptosis of nucleus pulposus (NP) cells embedded in IVDs. Excessive biomechanical loading may also be a major etiology of IVD degeneration. The present study used in vitro and in vivo models of compressive loading to elucidate the underlying mechanism of IVD degeneration. In addition, we investigated whether the inhibition of apoptosis is a potential clinical therapeutic strategy for the treatment of IVD degeneration induced by biomechanical stress. A TUNEL assay showed that NP cell-agarose three-dimensional composite cultures subjected to uniaxial, unconfined, static, compressive loading exhibited a time-dependent increase in apoptosis. Western blot analysis revealed the up-regulation of several extracellular matrix-degrading enzymes and down-regulation of tissue inhibitor of metalloproteinase 1. These responses to compressive loading were all significantly inhibited by caspase 3 siRNA. In the in vivo model of compressive loading-induced IVD degeneration, a single local injection of caspase 3 siRNA significantly inhibited IVD degeneration by magnetic resonance imaging, histological findings, IHC, and TUNEL assay. The present study suggests that caspase 3 siRNA attenuates overload-induced IVD degeneration by inhibiting NP cell apoptosis and the expression of matrix-degrading enzymes.

Siglec-15 regulates osteoclast differentiation by modulating RANKL-induced phosphatidylinositol 3-kinase/Akt and Erk pathways in association with signaling Adaptor DAP12.

Siglecs are a family of sialic acid-binding immunoglobulin-like lectins that regulate the functions of cells in the innate and adaptive immune systems through glycan recognition. Here we show that Siglec-15 regulates osteoclast development and bone resorption by modulating receptor activator of nuclear factor κB ligand (RANKL) signaling in association with DNAX-activating protein 12 kDa (DAP12), an adaptor protein bearing an immunoreceptor tyrosine-based activation motif (ITAM). Among the known Siglecs expressed in myeloid lineage cells, only Siglec-15 was upregulated by RANKL in mouse primary bone marrow macrophages. Siglec-15-deficient mice exhibit mild osteopetrosis resulting from impaired osteoclast development. Consistently, cells lacking Siglec-15 exhibit defective osteoclast development and resorptive activity in vitro. RANKL-induced activation of phosphatidylinositol 3-kinase (PI3K)/Akt and Erk pathways were impaired in Siglec-15-deficient cells. Retroviral transduction of Siglec-15-null osteoclast precursors with wild-type Siglec-15 or mutant Siglec-15 revealed that the association of Siglec-15 with DAP12 is involved in the downstream signal transduction of RANK. Furthermore, we found that the ability of osteoclast formation is preserved in the region adjacent to the growth plate in Siglec-15-deficient mice, indicating that there is a compensatory mechanism for Siglec-15-mediated osteoclastogenesis in the primary spongiosa. To clarify the mechanism of this compensation, we examined whether osteoclast-associated receptor (OSCAR)/Fc receptor common γ (FcRγ) signaling, an alternative ITAM-mediated signaling pathway to DAP12, rescues impaired osteoclastogenesis in Siglec-15-deficient cells. The ligands in type II collagen activate OSCAR and rescue impaired osteoclastogenesis in Siglec-15-deficient cells when cultured on bone slices, indicating that Siglec-15-mediated signaling can be compensated for by signaling activated by type II collagen and other bone matrix components in the primary spongiosa. Our findings indicate that Siglec-15 plays an important role in physiologic bone remodeling by modulating RANKL signaling, especially in the secondary spongiosa.