Origin of Osteoclasts: Osteoclast Precursor Cells

Osteoclasts are multinucleated bone-resorbing cells and a key player in bone remodeling for health and disease. Since the discovery of osteoclasts in 1873, the structure and function of osteoclasts and the molecular and cellular mechanisms of osteoclastogenesis have been extensively studied. Moreover, it has been well established that osteoclasts are differentiated in vitro from myeloid cells such as bone marrow macrophages or monocytes. The concept showing that osteoclasts are derived from a specific population (named osteoclast precursor cells [OCPs]) among myeloid cells has been long hypothesized. However, the specific precursor population of osteoclasts is not clearly defined yet. A growing body of work provides evidence of the developmental origin and lifespan of murine osteoclasts, particularly in vivo. Here, we review the emerging evidence that supports the existence of OCPs and discuss current insights into their identity.

Calcaneal Fractures: A Soft Tissue Emergency

Calcaneal fractures are quite often seen in patients with axial loading injury. In the tongue-type of calcaneusal fractures or tuberosity avulsion fractures, bone fragments are often superiorly and posteriorly displaced, because of the insertion of the Achilles tendon and pull of the gastroc-soleus complex. The Ddisplaced bone fragment compresses the soft tissues, leading tothat makes skin necrosis. To prevent further soft tissue injury, early recognition of the injury by the emergency physician and immediate orthopedic consultation is needed.

Incidence of Venous Thromboembolism Using 64 Channel Multidetector Row Computed Tomography-Indirect Venography and Anti-Coagulation Therapy after Total Knee Arthroplasty in Korea

PURPOSE: This study evaluated the incidence of a venous thromboembolism (VTE) after total knee arthroplasty (TKA) using multidetector row computed tomography-indirect venography (MDCT-indirect venography) and assessed the efficacy of anti-coagulation therapy. MATERIALS AND METHODS: We enrolled 118 patients with 126 cases of TKA. The average age of the patients was 68.4 years. We used 64 channel MDCT-indirect venography for the detection of VTE. We treated selectively proximal deep vein thrombosis (DVT) or pulmonary thromboembolism (PTE) cases according to the results of MDCT-indirect venography. We re-evaluated the change in VTE using follow-up MDCT-indirect venography after 3 months. RESULTS: We identified VTE in 35.7%. DVT only was identified in 22.2% including 8 cases of proximal DVT and 20 cases of distal DVT. PTE without DVT was identified in 4.8%, and combined DVT and PTE in 8.7%. All patients with PTE were asymptomatic, but 4 DVT patients had signs of leg swelling. After anti-coagulation therapy, 20 patients showed complete resolution in 16 cases, improvement in 3 cases and one case showed a new distal DVT. CONCLUSIONS: The incidence of VTE after primary TKA was 35.7% in Korea. Furthermore, anti-coagulation therapy for proximal DVT and PTE patients may be a useful method for preventing the occurrence of a fatal PTE.

The Effects of Partial Wrist Denervation on Chronic Wrist Pain

PURPOSE: The purpose of this study is to evaluate analgesic benefit, patient satisfaction, range of motion and grip power of the patients after partial wrist denervation. MATERIALS AND METHODS: We retrospectively reviewed the medical records of 12 patients with chronic wrist pain treated with partial denervation. Mean age of the patients was 65 years. The leading cause of the pain was Kienbock's disease (7 cases). Berger's partial denervation technique was used, in which distal branches of the anterior and posterior interosseous nerve were resected through dorsal longitudinal incision. We recorded visual analogue scale (VAS) for pain, and range of motion and grip power for functional evaluation. RESULTS: Preoperative VAS for pain decreased from a mean of 6.1 to 1.5 during early postoperative period and 2.3 at the final follow-up (p<0.01). Flexion-extension and grip power improved significantly after surgery. All the patients could return to their daily activity. Ten patients (83%) showed satisfaction. CONCLUSION: It seems that partial denervation for chronic pain of the wrist is an easy technique that can provide satisfactory pain relief with preserving the wrist motion.

Minimally Invasive Anterior Plating of Humeral Shaft Fractures

PURPOSE: We evaluated the efficacy and results of minimally invasive anterior plating for humeral shaft fracture. MATERIALS AND METHODS: Twenty-two cases of humeral shaft fracture were reviewed, including 8 cases of type A, 8 of type B and 6 of type C (AO/OTA classification). There were three open fractures. The fracture was fixed with MIPO (minimally invasive plate osteosynthesis) technique under C-arm guide. A locking compression plate was located in anterior aspect of the humerus with at least three screws fixed in each fragment. Radiologic and functional results were evaluated. RESULTS: In 20 of 22 cases, bony union was achieved with the mean period of 17.5 weeks, including 2 cases of delayed union. There were 2 cases of nonunion, which needed the further operative procedure. Except one case of distal 1/3 fracture, all cases showed satisfactory elbow and shoulder function with the mean Mayo elbow score of 17.4 and mean UCLA shoulder score of 97.3. In complication, there was one case of radial nerve palsy due to improper traction, but it was completely improved after 3 months. Otherwise, there was no complication including infection. CONCLUSION: Anterior MIPO for humeral shaft fracture may be another option of operative methods with high union and low complication rate.

Charcoal-induced anthracosis of the terminal ileum / 대한내과학회지

Anthracosis is a very common disease of the bronchus, while anthracosis of the gastrointestinal tract is extremely rare. Only a few cases of anthracosis of the esophagus have been reported and no cases of anthracosis of the terminal ileum are known, except one patient in Korea who was described as having melanosis ilei. A black pigmented lesion was detected in the terminal ileum on colonoscopic examination of a 51-year-old woman. Histological examination revealed a pigmented lesion beneath the mucosal epithelial layer and lymphoid follicular hyperplasia. The lesion consisted of an aggregation of histiocytes containing abundant tiny black pigments. She has taken oral charcoal for 7 years. We diagnosed anthracosis of the terminal ileum caused by oral charcoal and report a case of charcoal-induced anthracosis of the terminal ileum.

The antibody responses to newly isolated strain(R19) in Korea & three major serotypes and clinical features of Tsutsugamushi disease / 감염

No abstract available.