Whole Blood Titanium Concentration after Limb Salvage Surgery with Three-Dimensional-Printed Ti6Al4V Implants

Background@#Three-dimensional (3D)-printed customized implants can be fabricated and utilized for all bones with massive bone defects. The main safety issues with 3D-printed implants made of Ti6Al4V alloy are related to the release of metal debris and residual powder. In this study, we investigated the perioperative titanium concentrations in whole blood and peri-implant fluid samples of patients who underwent limb salvage surgery with a 3D-printed Ti6Al4V implant. @*Methods@#Nineteen patients who underwent limb salvage surgery with 3D-printed Ti6Al4V implants were divided into two groups:the serial samples group and the follow-up group. To observe metal distribution and clearance in the body, serial samples of blood and peri-implant fluid from the surgical drain were prospectively collected for five patients in the serial samples group. For the remaining 14 patients who were followed up for more than a year, blood samples were collected only once. @*Results@#In the serial samples group, the mean baseline titanium concentration was 0.78 μg/L (range, 0.1–2.2 μg/L): 3 patients showed peak concentration before the third postoperative month, while 2 patients still showed an increasing pattern at this point.Total titanium mass in the surgical drain showed a wash-out phenomenon in a week, with a significant uniform decrease (p = 0.04).In 14 patients in the follow-up group, the mean titanium concentration in the whole blood was 10.8 μg/L (range, 0.3–36.6 μg/L). For the 14 patients with a long-term follow-up, the aluminum and vanadium concentrations were all negligible. @*Conclusions@#Whole blood titanium concentrations were higher after surgery using 3D-printed implants than after that using conventional orthopedic implants, but markedly lower than in patients with implant failure. None of the patients developed serious clinical adverse effects during follow-up.

Incidence Patterns and Outcomes of Ewing Sarcoma in South Korea (1999-2017): A Retrospective Analysis Using Korea Central Cancer Registry Data / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Due to low incidence, epidemiologic data of Ewing sarcoma in the Asian population are scarce. We aimed to examine the incidence pattern and outcome of patients with Ewing sarcoma in the Republic of Korea. @*Materials and Methods@#Data of patients with Ewing sarcoma diagnosed between 1999 and 2017 were obtained from the Korea Central Cancer Registry (KCCR). Incidence, clinical characteristics, and survival rates were analyzed and compared between different age groups. @*Results@#There were 788 cases (459 males, 329 females), with a median age at diagnosis of 20 years. The age-standardized rate of Ewing sarcoma was 1.01. The number of cases and incidence rates in each age group were as follows: children, 1.6; adolescents and young adults (AYA), 0.93; adults, 0.44; and elderly, 0.53. There were more male cases in children and the AYA group (p < 0.001). Extraskeletal tumors (p < 0.001), primary sites other than extremity (p=0.007), and presence of metastasis at diagnosis (p=0.031) were more frequent in the adults and elderly group. With a median survival time of 78 months, the 5-year overall survival (OS) rate of the entire cohort was 52%. Children fared best (5-year OS, 75%), and the 5-year OS of AYA patients (51%) approximated the OS of the entire cohort. A two-fold difference of 5-year OS was observed between adults and elderly patients (42% vs. 19%). On univariate and multivariate analyses, age ≥ 15 years and presence of metastasis were adverse prognostic factors. @*Conclusion@#This was the first epidemiologic study of Ewing sarcoma using the KCCR data. With a similar incidence to other Asian countries, the survival rate was slightly lower than that of Euro-American cases. Collaborative clinical studies are necessary to improve the outcome of Ewing sarcoma in low-incidence populations.

Acquired Digital Fibrokeratoma over Nail / 대한정형외과학회잡지

Acquired digital fibrokeratoma is very a rare, benign, fibrous, and hyperkeratotic skin tumor that develops most frequently on the finger or toe. The tumor usually occurs in adults as a solitary, dome-shaped lesion. Sometimes, it appears as a rudimentary supernumerary digit and may be misdiagnosed as an accessory nail (double nail) or verruca vulgaris. The pathophysiology of an acquired digital fibrokeratoma is unknown. On the other hand, trauma has often been proposed as a predisposing factor for an acquired type of digital fibrokeratoma. This paper reports a case of trauma-related acquired digital fibrokeratoma presenting as a supernumerary digit and nail in a 36-year-old male.This case is presented with a 0.5 cm×0.4 cm×1.3 cm sized, firm, hyperkeratotic, protruding mass over the left second finger nail.

Delta-like Factor 1 as a Possible Therapeutic Target for Sarcomas

Background@#Cancer stem cells (CSCs) are cells characterized by their self-renewal and tumorigenic potential. The purpose of this study was to discover the role of the delta-like factor 1 (DLK1) in sarcoma. @*Methods@#mRNA expression of DLK1 from 13 sarcoma cell lines was examined. Isolated CSCs from the tumors were examined using fluorescence-activated cell sorting (FACS) with CD133, the CSC marker, or sphere-forming assay. The relationship between DLK1 and CSCs in sarcoma was examined using cell proliferation and cell invasion assays after they were treated with DLK1 short interfering RNA (siRNA). @*Results@#A high expression of DLK1 mRNA was observed in all sarcoma cell lines. However, CSCs were isolated from over expressed sarcomas of the DLK1 gene, and they have shown to be expressed lower than the wild type. The anti-cancer effects of DLK1 siRNA inhibited cell proliferation and invasion in U2OS, A204, and sw872. In addition, treatment with DLK1 siRNA inhibited cell invasion in sw872 CSCs. DLK1 gene induces tumorigenesis in various sarcoma cells and regulates the invasiveness of liposarcoma. These results suggest that DLK1 could serve as a possible therapeutic target for sarcoma. @*Conclusions@#Our study showed that the DLK1 gene induces tumorigenesis in various sarcomas and is associated with invasive mechanism in sarcoma. These results suggest DLK1 could serve as a possible therapeutic target in a variety of sarcomas.

Usefulness of a Vascular Clipping System to Create an Arteriovenous Fistula

Purpose@#The vascular clipping system (VCS) is beneficial as it is simple and easy to apply for microvascular suturing. Arteriovenous fistula (AVF) creation is a very basic standard technique of microvascular surgery. In this study the VCS and the conventional suture methods were compared in a rabbit model using the carotid artery and vein to create an AVF. @*Methods@#There were 28 rabbits assigned equally into 2 groups using the AVF creation method (conventional suturing or the VCS procedure). Histopathology was performed on fixed samples. The procedure time of the 2 methods and changes in histopathology of tissue samples after surgery were compared. @*Results@#The VCS procedure showed a lower degree of fibrosis and hyperplasia histologically compared with the conventional suture method. The VCS was quicker to perform and no significant anastomosis stricture was observed. @*Conclusion@#In a rabbit model of AVF, the VCS has benefits over the conventional suture method. The VCS provides comparable patency rates, produces fewer side effects such as fibrosis and hyperplasia, and takes less operation time than suturing. The VCS is expected to be useful for cases where renal patients need periodic hemodialysis and thus repetitive access to a vessel.

Compressive Neuropathy of the Deep Motor Branch of the Ulnar Nerve in Amateur Cyclist / 대한스포츠의학회지

A 36-year-old female amateur cyclist developed mononeuropathy of the deep branch of the ulnar nerve due to nerve compression adjacent to the ulnar tunnel (type II Guyon’s canal syndrome) caused by prolonged bicycle riding.The patient’s signs and symptoms persisted even after refraining from cycling for 4 weeks; thus, she underwent decompression of the deep branch of the ulnar nerve in the palm and wrist. Three months postoperation, she recovered nearly full power and function of her left hand.

Usefulness of a Vascular Clipping System to Create an Arteriovenous Fistula

Purpose@#The vascular clipping system (VCS) is beneficial as it is simple and easy to apply for microvascular suturing. Arteriovenous fistula (AVF) creation is a very basic standard technique of microvascular surgery. In this study the VCS and the conventional suture methods were compared in a rabbit model using the carotid artery and vein to create an AVF. @*Methods@#There were 28 rabbits assigned equally into 2 groups using the AVF creation method (conventional suturing or the VCS procedure). Histopathology was performed on fixed samples. The procedure time of the 2 methods and changes in histopathology of tissue samples after surgery were compared. @*Results@#The VCS procedure showed a lower degree of fibrosis and hyperplasia histologically compared with the conventional suture method. The VCS was quicker to perform and no significant anastomosis stricture was observed. @*Conclusion@#In a rabbit model of AVF, the VCS has benefits over the conventional suture method. The VCS provides comparable patency rates, produces fewer side effects such as fibrosis and hyperplasia, and takes less operation time than suturing. The VCS is expected to be useful for cases where renal patients need periodic hemodialysis and thus repetitive access to a vessel.

Palmar Digital Neuropathy With Anatomical Variation of Median Nerve: Usefulness of Orthodromic Technique: A Case Report

Anatomic variation of palmar digital nerve pathways were reported in several cases. Selective exploration of palmar digital nerves with a nerve conduction study has been challenging, because of technical issues. We report a patient who received bilateral carpal tunnel release operation, complaining of a tingling sensation, and hypoesthesia on the middle and ring fingers. An electrodiagnostic study revealed a sensory neuropathy of palmar digital nerve of the left median nerve, supplying the ulnar side of the middle finger, and radial side of the ring finger. She underwent re-operation of open left carpal tunnel release, and a branching site of common digital nerves of the median nerve was identified not at the palm, but at a far proximal site around the distal wrist crease. Usefulness of an orthodromic sensory conduction study was clarified to eliminate volume conducted response or co-activation of nearby nerves in the patient with selective involvement of palmar digital nerve.

Three Dimensional Printing Technique and Its Application to Bone Tumor Surgery / 대한정형외과학회잡지

Orthopaedics is an area where 3-dimensional (3D) printing technology is most likely to be utilized because it has been used to treat a range of diseases of the whole body. For arthritis, spinal diseases, trauma, deformities, and tumors, 3D printing can be used in the form of anatomical models, surgical guides, metal implants, bio-ceramic body reconstruction, and orthosis. In particular, in orthopaedic oncology, patients have a wide variety of tumor locations, but limited options for the limb salvage surgery have resulted in many complications. Currently, 3D printing personalized implants can be fabricated easily in a short time, and it is anticipated that all bone tumors in various surgical sites will be reconstructed properly. An improvement of 3D printing technology in the healthcare field requires close cooperation with many professionals in the design, printing, and validation processes. The government, which has determined that it can promote the development of 3D printing-related industries in other fields by leading the use of 3D printing in the medical field, is also actively supporting with an emphasis on promotion rather than regulation. In this review, the experience of using 3D printing technology for bone tumor surgery was shared, expecting orthopaedic surgeons to lead 3D printing in the medical field.

Role of CD74 and Its Relationship with Macrophage Migration Inhibitory Factor in Osteosarcoma Tumorigenesis / 대한정형외과학회잡지

PURPOSE: CD74 (cluster of differentiation 74) is a type II transmembrane protein that associates with MHC-II (major histocompatibility complex-II) molecules and binds with the macrophage migration inhibitory factor (MIF), which is known to be associated with tumorigenesis. The purpose of this study was to examine the relationship between CD74 with MIF and the role of CD74 in osteosarcoma tumorigenesis. MATERIALS AND METHODS: A correlation between CD74 with MIF was examined using immunohistochemistry (IHC) of tissues from patients with osteosarcoma (n=45). The mRNA expression of CD74 from patient-derived primary cells of osteosarcoma (n=22) was examined by a real-time polymerase chain reaction. The role of CD74 and in cisplatin-resistance of osteosarcoma was examined using WST-1 and colony forming assay. RESULTS: Of the 45 patients, 25 patients (55.6%) had a high level of expression in both CD74 and MIF by IHC. High level of MIF expression was observed in 40 patients (88.9%). We detected that mRNA expression of CD74 was higher in cells of all osteosarcoma patients (n=22) examined than in the control cells (hFOb 1.19). After cisplatin treatment, the inhibition of cell proliferation and suppression of colony formation were reduced in osteosarcoma cells expressing CD74. Interestingly, the effect of inhibiting anchorage independent growth was activated after cisplatin treatment in the cells with very high expression CD74 mRNA. CONCLUSION: This study suggests that the level of CD74 expression correlates with that of MIF expression. Moreover, CD74 might have a role in cisplatin resistance of osteosarcoma.

Treatment of Scaphoid Nonunion Using 2 Small Diameter (2.2 mm) Headless Compression Screws

PURPOSE: To assess union and complication rates associated with the use of 2 small diameter headless compression screws and volar wedge bone grafting for the treatment of scaphoid fracture waist nonunions with collapse. METHODS: A total of 12 patients (11 male and 1 female) at an average age of 32.5 years were treated with open reduction and internal fixation with 2 small diameter headless compression screws for scaphoid nonunions with a mean follow-up of 11 months. Tricortical wedge shaped autograft were harvested from the iliac crest and placed into the nonunion site to restore length and alignment in all patients. Union was determined by radiographs and computed tomography, and scapholunate and radiolunate angles, and height-to-length ratio were calculated on final radiographs and follow-up computed tomography. RESULTS: All 12 scaphoids united with a mean time for 2.8 months. The mean postoperative scapholunate angle was significantly reduced from 73° preoperatively to 56° postoperatively. The mean radiolunate angle was significantly improved from 21° from neutral preoperatively to 12° postoperatively. The height-to-length ratio was also demonstrated significant improvement from 0.73 preoperatively to 0.60 postoperatively. No hardware problems were identified and no revision procedures have been necessary. CONCLUSION: Our results indicate that the use of 2 small diameter headless compression screws with volar structural bone graft stabilizes the fracture for predictable union, while reducing the deformity reliably from a collapsed scaphoid nonunion. The presented technique is safe and effective, and may provide superior biomechanical stability, especially against the torsional force.

Intramedullary Nailing for Pathological Fractures of the Proximal Humerus

BACKGROUND: Endoprosthetic reconstruction is widely applied for pathological fractures of the proximal humerus; however, functional impairment is usually unsatisfactory. The aims of the current study are to evaluate the reliability of interlocking intramedullary (IM) nailing with cement augmentation as a fixation method in proximal humeral lesions and to assess functional outcomes. METHODS: We reviewed 32 patients with pathological fractures of the proximal humerus who underwent interlocking IM nailing and cement augmentation. Functional scores and pain relief were assessed as outcomes. RESULTS: The mean follow-up period was 14.2 months. The mean Musculoskeletal Tumor Society functional score and Karnofsky performance status scale score were 27.7 and 75.6, respectively. Improvement of pain assessed using the visual analogue scale was 6.2 on average. Thirty-one patients (97%) experienced no pain after surgery. The mean ranges of forward flexion and abduction were 115° and 112.6°, respectively. All patients achieved stability and had no local recurrence without failure of fixation until the last follow-up. CONCLUSIONS: Proximal interlocking IM nailing with cement augmentation appears to be a reliable treatment option for pathological or impending fractures of the proximal humerus in selected patients with metastatic tumors, even with extensive bone destruction.

Updated Surgical Techniques and Expanded Indications of Free Vascularized Fibular Graft

Free or pedicled vascularized fibular grafts (VFG) are useful for the reconstruction of large skeletal defects, particularly in cases of scarred or avascular beds, or in patients with combined bone and soft tissue defects. Compared to non-VFG, VEG, which contains living osteocytes and osteoblasts, maintains its own viability and serves as good osteoconductive and osteoinductive graft. Due to its many structural and biological advantages, the free fibular osteo- or osteocutaneous graft is considered the most suitable autograft for the reconstruction of long bone defects in the injured extremity. The traditional indication of VFG is the long bone and soft tissue defect, which cannot be reconstructed using a conventional operative method. Recently, the indications have been widely expanded not only for defects of midtibia, humerus, forearm, distal femur, and proximal tibia, but also for the arthrodesis of shoulder and knee joints. Because of its potential to allow further bone growth, free fibular epiphyseal transfer can be used for the hip or for distal radius defects caused by the radical resection of a tumor. The basic anatomy and surgical techniques for harvesting the VFG are well known; however, the condition of the recipient site is different in each case. Therefore, careful preoperative surgical planning should be customized in every patient. In this review, recently expanded surgical indications of VFG and surgical tips based on the author's experiences in the issues of fixation method, one or two staged reconstruction, size mismatching, overcoming the stress fracture, and arthrodesis of shoulder and knee joint using VFG are discussed with the review of literature.

Reconstruction of a Traumatic Soft Tissue Defect

Soft tissue defect combined with an open fracture is a very challenging problem to the orthopaedic surgeon. Many complicated open fractures remain with soft tissue defect, chronic osteomyelitis, and sometimes terminate with major limb amputation. Soft tissue defect should be reconstructed as soon as possible, particularly when the bone, tendon, or neurovascular structures are exposed. Exposure for longer than a week significantly increases the risk of secondary infection and tissue necrosis. For the simple soft tissue defect, negative pressure wound closure technology has been introduced and many superficial wounds have been treated successfully using this method. For the more complicated wounds, many kinds of local flaps, pedicled flaps, muscle and fascisocutaneous flaps can be indicated according to the characteristics of the wounds. The free flaps including free vascularized bone graft can be considered as a final choice for the most difficult wound problems. In this article, various reconstruction strategies for soft tissue defect after traumatic open fracture are reviewed.

A new bite block for panoramic radiographs of anterior edentulous patients: A technical report

PURPOSE: Panoramic radiographs taken using conventional chin-support devices have often presented problems with positioning accuracy and reproducibility. The aim of this report was to propose a new bite block for panoramic radiographs of anterior edentulous patients that better addresses these two issues. MATERIALS AND METHODS: A new panoramic radiography bite block similar to the bite block for dentulous patients was developed to enable proper positioning stability for edentulous patients. The new bite block was designed and implemented in light of previous studies. The height of the new bite block was 18 mm and to compensate for the horizontal edentulous space, its horizontal width was 7 mm. The panoramic radiographs using the new bite block were compared with those using the conventional chin-support device. RESULTS: Panoramic radiographs taken with the new bite block showed better stability and bilateral symmetry than those taken with the conventional chin-support device. Patients also showed less movement and more stable positioning during panoramic radiography with the new bite block. CONCLUSION: Conventional errors in panoramic radiographs of edentulous patients could be caused by unreliability of the chin-support device. The newly proposed bite block for panoramic radiographs of edentulous patients showed better reliability. Further study is required to evaluate the image quality and reproducibility of images with the new bite block.

Comparison of the reproducibility of panoramic radiographs between dentulous and edentulous patients

PURPOSE: This study was performed to evaluate the reproducibility of panoramic radiographs of dentulous and edentulous patients. MATERIALS AND METHODS: The reproducibility of panoramic radiographs was evaluated using the panoramic radiographs acquired from 30 anterior dentulous patients by using a common biting positioning device (dentulous group) and 30 anterior edentulous patients by using chin-support devices to take a panoramic radiograph (edentulous group), respectively; these patients had undergone 3 or more panoramic radiographs. The widths and angles between the designated landmarks were measured on the panoramic radiographs, and the reproducibility was evaluated using the intraclass correlation coefficient (ICC) and the coefficient of variation. RESULTS: In the dentulous and edentulous groups, the ICCs of the mandibular ramus and mandibular angle areas were higher than the condylar head and zygomatic areas. The mandibular ramus and angle areas showed statistically lower mean coefficients of variation than the condylar head and zygomatic areas in the dentulous group. The mandibular angle area showed a significantly lower mean coefficient of variation than the zygomatic area in the edentulous group. By comparing the two groups, each ICC of the edentulous group was lower than that of the dentulous group, and the mean coefficients of variation of the mandibular ramus area, zygomatic area, left condylar inclination, and ramus ratio between the right and the left in the edentulous group were significantly higher than those in the dentulous group. CONCLUSION: Biting positioning for dentulous patients provided better positioning reproducibility than chin-support positioning when performing panoramic radiography for edentulous patients.

Surgical Techniques for Repairing Foveal Tear of the Triangular Fibrocartilage Complex: Arthroscopic Transosseous Repair

As the importance of the foveal attachment of the triangular fibrocartilage complex (TFCC) on the stability of the distal radioulnar joint (DRUJ) is emphasized, the traditional repair techniques such as arthroscopic capsular repair for the 1B TFCC tear become accepted as ineffective method for treating DRUJ instability. Recently, several techniques which repair the TFCC directly to the ulnar fovea have been developed and introduced. Further advances of the techniques will be expected with increasing knowledge of the anatomy and biomechanics of the TFCC and DRUJ. Regardless of the techniques, fundamental principle of anatomical repair of the TFCC to the ulnar fovea is utmost important. Herein we present our technique of arthroscopic transosseous repair by making a drill hole in the ulnar and securing the sutures with Pushlock anchors.

Complications of Distal Radius Fracture / 대한정형외과학회잡지

Fracture of the distal radius is one of the most common fractures encountered in the emergency room. Although selection of a proper treatment modality is important for successful management of this fracture, early detection, prevention, and adequate treatment for its complications is also important. Complications associated with fracture of the distal radius can occur at any time during the treatment process and the prevalence rate is up to 27% of all distal radius fractures. This article provides a review of possible complications associated with distal radius fracture, along with a discussion of prevention and appropriate treatment methods.

Non-amputative Surgical Management of Subungal Melanoma in Situ / 대한피부과학회지

Subungual melanoma is a variant of acral lentiginous melanoma and is thought to carry a poor prognosis due to difficulties in early diagnosis. Classical management of subungual melanoma is based on the radical surgery of distal phalanx amputation. Instead, conservative treatment with non-amputative wide excision of the nail unit followed by reconstruction has been insufficiently reported, especially in Korea. A 71-year-old woman presented with dark brownish longitudinal bands on her right thumbnail. Punch biopsies from the nail matrix and nail bed showed proliferation of atypical melanocytes without dermal involvement. We describe a case of subungual melanoma in situ of the right thumb, and a non-amputative surgical management which aims to provide adequate clearance of the lesion with minimal morbidity and satisfactory preservation of function for the patient.

Metal Associated Angiosarcoma of the Distal Femur / 대한정형외과학회잡지

Malignant vascular tumors (angiosarcoma) of bone are rare and represent a less than 1% of malignant bone tumors. The authors report a case of a patient with angiosarcoma misdiagnosed as infection, which developed adjacent to a stainless steel intra-medullary nail used for fixation of a femur fracture.