Pneumothorax by Penetrating Endplate Screw for Diffuse Idiopathic Skeletal Hyperostosis-Related Thoracolumbar Fracture.

Pneumothorax is a rare surgical complication in spinal surgery with thoracic pedicle screws. The penetrating endplate screw (PES) technique has been developed as a strong alternative spinal anchor to conventional pedicle screws for diffuse idiopathic skeletal hyperostosis (DISH). We present an intraoperative pneumothorax without deviation to the thoracic during the maneuver of the PES. A 56-year-old male who presented with non-union of DISH-related T12 vertebral fracture underwent T12 kyphoplasty and T10-L2 posterior fixation using the PES technique. The left pneumothorax was developed postoperatively without screw deviation to the thorax throughout screw insertion. Postoperative CT suggested that a displaced rib head by the lateral misposition of the screw at the inserting point and the pedicle level might injure the pleura. Spine surgeons should know that the lateral insertion of PES has a potential risk for pneumothorax by the displacement of the rib head because of screw trajectory from caudal to cranial apart from conventional pedicle screw.

Treatment of thigh abscess caused by retroperitoneal perforation of cecal cancer: A case report.

Introduction and importance: Iliopsoas and iliacus abscesses are caused by hematogenous and lymphatic infections and the spread of inflammation in neighboring organs. A small number of cases have been reported in which inflammation spread not only within the iliopsoas muscle but also to the thigh. Here we report a case of retroperitoneal infiltration and perforation of cecal cancer that caused extensive abscess formation from the iliacus muscle to the thigh. Case presentation: An 80-year-old man who had undergone chemotherapy for cecal cancer had abdominal pain and right thigh pain without any particular attraction. CT images showed extensive abscess formation from the iliacus muscle to the subcutaneous part of the thigh due to retroperitoneal infiltration and perforation of cecal cancer. Ileocecal resection, colostomy, and retroperitoneal abscess drainage were performed for perforation of cecal cancer and pelvic abscess. Although the thigh was initially drained by a small incision, the infection did not heal. Extensive debridement and drainage were required for all of the contaminated areas, and after all the infection was completely cured. Clinical discussion: The optimal treatment for an abscess that has spread from the inguinal region to the thigh is unclear. In this case, active debridement and drainage of the infected area were effective and should have been done early. Conclusion: We believed that debridement and drainage should have been performed from the time of the first surgery not only by the small incision drainage but also for all of the contaminated areas when the infection had been widespread.

Role of irisin in effects of chronic exercise on muscle and bone in ovariectomized mice.

INTRODUCTION: Exercise is beneficial for the prevention and treatment of osteoporosis. Skeletal muscle affects other tissues via myokines, the release of which is regulated by acute exercise. However, the effects of chronic exercise on myokines linking muscle to bone have not been fully elucidated. Therefore, we investigated the effects of chronic exercise on bone and myokines using ovariectomized (OVX) mice. MATERIALS AND METHODS: Treadmill exercise with moderate intensity was performed for 8 weeks after OVX or sham surgery. We measured bone mineral density (BMD) at the femurs and tibias of mice by quantitative computed tomography and myokine mRNA levels in the gastrocnemius and soleus muscles. RESULTS: Treadmill exercise ameliorated decreases in trabecular and cortical BMD in the femurs of OVX mice. Irisin is a proteolytic product of fibronectin type III domain-containing 5 (Fndc5). Among the myokines examined, treadmill exercise increased irisin protein and Fndc5 mRNA levels in the gastrocnemius and soleus muscles of sham and OVX mice. Treadmill exercise increased peroxisome proliferator-activated receptor γ coactivator-1α mRNA levels in the gastrocnemius muscles of mice. Fndc5 mRNA levels in the gastrocnemius muscles positively correlated with trabecular BMD, but not with cortical BMD, at the femurs and tibias of mice in simple regression analyses. CONCLUSIONS: We demonstrated that chronic exercise elevated irisin expression in the gastrocnemius and soleus muscles of estrogen-deficient mice. Irisin might be related to increases in trabecular BMD in mice; however, further studies are needed to clarify the involvement of irisin in the effects of chronic exercise on muscle/bone interactions.

Role of Dkk2 in the Muscle/bone Interaction of Androgen-Deficient Mice.

Androgen deficiency is known to cause both osteoporosis and sarcopenia. Myokines, humoral factors secreted from the skeletal muscles, have recently been getting attention as the key factors related to the interactions between muscle and bone. Dickkopf (Dkk) 2 is known as an inhibitor of canonical Wnt/ß-catenin signaling, and Wnt/ß-catenin signaling is crucial for the maintenance of muscle and bone. The present study was therefore performed to investigate the roles of Dkk2 in the alterations of muscle and bone of androgen-deficient mice with orchidectomy (ORX). ORX significantly enhanced Dkk2 mRNA levels, but not other Dkks and secreted frizzled related proteins, in the soleus muscles of mice. Moreover, ORX enhanced serum Dkk2 levels, but not Dkk2 mRNA levels in the tibial bone tissues, the white adipose tissues and liver of mice. In simple regression analyses, serum Dkk2 levels were negatively related to trabecular bone mineral density at the tibias in mice employed in the experiments. In vitro experiments, testosterone suppressed Dkk2 mRNA levels in mouse muscle C2C12 cells. In conclusion, we showed that androgen deficiency enhances Dkk2 expression and secretion in the muscles of mice. Dkk2 might be involved in androgen deficiency-induced muscle wasting and osteopenia as a myokine linking muscle to bone.

Roles of Dkk2 in the Linkage from Muscle to Bone during Mechanical Unloading in Mice.

Mechanical unloading simultaneously induces muscle and bone loss, but its mechanisms are not fully understood. The interactions between skeletal muscle and bone have been recently noted. Although canonical wingless-related integration site (Wnt)/ß-catenin signaling is crucial for bone metabolism, its roles in the muscle and bone interactions have remained unknown. Here, we performed comprehensive DNA microarray analyses to clarify humoral factors linking muscle to bone in response to mechanical unloading and hypergravity with 3 g in mice. We identified Dickkopf (Dkk) 2, a Wnt/ß-catenin signaling inhibitor, as a gene whose expression was increased by hindlimb unloading (HU) and reduced by hypergravity in the soleus muscle of mice. HU significantly elevated serum Dkk2 levels and Dkk2 mRNA levels in the soleus muscle of mice whereas hypergravity significantly decreased those Dkk2 levels. In the simple regression analyses, serum Dkk2 levels were negatively and positively related to trabecular bone mineral density and mRNA levels of receptor activator of nuclear factor-kappa B ligand (RANKL) in the tibia of mice, respectively. Moreover, shear stress significantly suppressed Dkk2 mRNA levels in C2C12 cells, and cyclooxygenase inhibitors significantly antagonized the effects of shear stress on Dkk2 expression. On the other hand, Dkk2 suppressed the mRNA levels of osteogenic genes, alkaline phosphatase activity and mineralization, and it increased RANKL mRNA levels in mouse osteoblasts. In conclusion, we showed that muscle and serum Dkk2 levels are positively and negatively regulated during mechanical unloading and hypergravity in mice, respectively. An increase in Dkk2 expression in the skeletal muscle might contribute to disuse- and microgravity-induced bone and muscle loss.

Role of irisin in androgen-deficient muscle wasting and osteopenia in mice.

Androgen deficiency plays a crucial role in the pathogenesis of male osteoporosis and sarcopenia. Myokines have recently been identified as humoral factors that are involved in the interactions between muscle and bone; however, the influence of androgen deficiency on these interactions remains unclear. Therefore, we herein investigated the roles of humoral factors linking muscle to bone using orchidectomized mice with sarcopenia and osteopenia. Orchidectomy (ORX) significantly reduced muscle mass, grip strength, and trabecular bone mineral density (BMD) in mice. Among the myokines examined, ORX only significantly reduced fibronectin type III domain-containing 5 (Fndc5) mRNA levels in both the soleus and gastrocnemius muscles of mice. In simple regression analyses, Fndc5 mRNA levels in the soleus muscle positively correlated with trabecular BMD, but not cortical BMD. The administration of irisin, a product of Fndc5, significantly protected against the decrease induced in trabecular BMD, but not muscle mass, by androgen deficiency in mice. In conclusion, the present results demonstrated that androgen deficiency decreases the expression of irisin in the skeletal muscle of mice. Irisin may be involved in muscle/bone relationships negatively affected by androgen deficiency.

Clinical outcomes of patients with primary malignant bone and soft tissue tumor aged 65 years or older.

The number of elderly patients with sarcoma (65 years or older) has increased with the rise in the aging of society. As it is difficult to treat elderly sarcoma patients in the same manner as younger patients, the present study sought to compare treatment options currently available for elderly patients. The present study was comprised 34 Japanese patients (21 men and 13 women) with malignant bone or soft tissue tumors who underwent surgery in our department from September 2004 to March 2014. The median patient age was 72 years (range, 65-86 years). Histologically, 23 cases were categorized as high-grade and 11 as low-grade. Treatments included surgery with adequate margins (25 cases), surgery with inadequate margins and radiotherapy (4 cases), surgery with inadequate margins and chemotherapy (3 cases) and intralesional resection (2 cases). The postoperative follow-up period ranged from 7 to 112 months (average, 49 months). The 5-year survival rates were determined and compared using the Kaplan-Meier method and log-rank test, respectively. Eastern Cooperative Oncology Group Performance Status (ECOG-PS) and Anesthesiologists-Physical Status (ASA-PS) scores were also determined. The overall 5-year survival rate was 86.02%; it differed significantly between patients with high-grade (100%) vs. low-grade (74.3%) neoplasms P<0.001), but not between patients aged 65-69 (76.9%) vs. ≥70 (90.2%) years-old (P=0.65). Tumor status was classified as follows: i) Continuously disease-free, n=24 cases; ii) alive with disease, n=3 cases; iii) and dead of disease, n=7 cases. The ECOG-PS status scores were 0 in 9 cases, 1 in 21 cases, and 2 in 4 cases. ASA-PS scores were also I in 9 cases and II in 23 cases. Thus, the primary treatment for elderly patients with sarcoma should be surgery alone as no additional benefits were obtained when radiotherapy or chemotherapy was also performed. Adequate margins should be confirmed along with the histology of surgical specimens.

Treatment of a patient suffering from posttraumatic painful neuromas formed at the bilateral digital nerves of the left middle finger using two neurovascular island flaps.

Hand surgeons often encounter painful posttraumatic neuromas in daily practice and the treatment of these neuromas is still challenging for them, because of the tendency of recurrence.1,2 The patient injured his left middle finger and was treated by amputation in a previous hospital. After this operation, the patient started to feel pain at the fingertip and complained of severe electric radiating pain when the radial and ulnar ends of the finger were touched. We treated painful neuromas formed on both palmar digital nerve stumps using a reverse pedicle island flap containing subcutaneous nerves, which were connected to the nerve stumps after removal of the neuromas of the finger. This maneuver relieved the finger pain completely. Removal of finger digital nerve neuromas, connecting the nerve stumps to the subcutaneous nerves included in a skin island flap and, covering the neurorrhaphy sites with the flap may have reduced the chance of the recurrence of neuromas and resulted in restoration of considerable function of the hand.

Salmonella Osteomyelitis of the Distal Tibia in a Healthy Woman.

Salmonella osteomyelitis is extremely rare; only a few cases have been reported in healthy adults. We describe a case of salmonella osteomyelitis in an otherwise healthy 20-year-old Japanese woman who presented with distal tibial pain. X-ray and magnetic resonance imaging showed a lesion suspected to be a bone cyst. Osteomyelitis was diagnosed when pus was observed during an open biopsy. The bacterial culture examination yielded salmonella. Surgical drainage and antibiotic treatment were performed, after which no recurrence was observed. To our best knowledge, this is the first report of salmonella osteomyelitis of the distal tibia in an otherwise healthy individual.