Search

Purpose: Simple bone cysts are among the most prevalent benign cystic tumor-like lesions in children. Proximal femoral simple bone cysts may require specific treatment because of increased fracture risk. With limited literature available on this specific localization, consensus regarding optimal treatment is lacking. We present a large international multicenter retrospective cohort study on proximal femoral simple bone cysts. Methods: All consecutive pediatric patients with proximal femoral simple bone cyst from 10 tertiary referral centers for musculoskeletal oncology were included (2000–2021). Demographics, primary treatment, complications, and re-operations were evaluated. Primary outcomes were time until full weight-bearing and failure-free survival. Results: Overall, 74 simple bone cyst patients were included (median age 9 years (range = 2–16), 56 (76%) male). Median follow-up was 2.9 years (range = 0.5–21). Index procedure was watchful waiting (n = 6), percutaneous procedure (n = 12), open procedure (n = 50), or osteosynthesis alone (n = 6). Median time until full weight-bearing was 8 weeks (95% confidence interval = 0.1–15.9) for watchful waiting, 9.5 (95% confidence interval = 3.7–15.3) for percutaneous procedure, 11 (95% confidence interval = −0.7 to 13.7) for open procedure, and 6.5 (95% confidence interval = 5.9–16.1) for osteosynthesis alone (p = 0.58). Failure rates were 33%, 58%, 29%, and 0%, respectively (p = 0.069). Overall failure-free survival at 1, 2, and 5 years was 77.8% (95% confidence interval = 68.2–87.4), 69.5% (95% confidence interval = 58.5–80.5), and 62.0% (95% confidence interval = 47.9–76.1), respectively. Conclusion: A preferred treatment for proximal femoral simple bone cysts remains unclear, with comparable failure rates and times until full weight-bearing. Watchful waiting may be successful in certain cases. If not feasible, osteosynthesis alone can be considered. Treatment goals should be cyst control, minimizing complications and swift return to normal activities. Therefore, an individualized balance should be made between undertreatment, with potentially higher complication risks versus overtreatment, resulting in possible larger interventions and accompanying complications. Level of evidence: Level IV, retrospective multicentre study [ABSTRACT FROM AUTHOR]

Summary: A 4‐week‐old Warmblood foal presented with a rapidly growing firm mass on the dorsomedial aspect of the distal left third metacarpal bone. The initial examination revealed no pain on palpation or associated lameness. Radiography demonstrated a solitary expansile large osseous cyst‐like lesion with a coarse intra‐luminal trabecular pattern associated with the cortical bone. Computed tomographic imaging was performed prior to surgery and revealed a monostotic, eccentric, diaphyseal and likely periosteal nonaggressive osseous lesion. A transcutaneous surgical approach was used to excise the mass followed by curettage of the parent bone. The foal recovered uneventfully and no re‐occurrence of the mass was noted after 12 months. Histopathology of the mass revealed a reactive process consisting of trabecular bone, haemosiderophages, granulation tissue and mesenchymal tissue proliferation consistent with an aneurysmal bone cyst. Aneurysmal bone cysts should be included in the differential diagnosis of rapidly growing masses on long bones in foals and are amenable to surgical resection. [ABSTRACT FROM AUTHOR]

Objective: This article aims to review the epidemiology, etio-pathogenesis and updates in clinical diagnostics and management of unicameral bone cysts (UBC). Methods: A computerized literature search using Cochrane database of systematic reviews, EMBASE and PubMed was performed. MeSH (Medical Subject Headings) terms used in searches included the following sub-headings: "unicameral bone cyst", "epidemiology", "etiology", "pathogenesis", "diagnosis", "management" and "surgery". Studies were analyzed based on clinical relevance for the practicing orthopedic surgeon. Results: UBC accounts for 3% of all bone tumors and is asymptomatic in most cases. Nearly 85% of cases occur in children and adolescents, with more than 90% involving the proximal humerus and proximal femur. Despite multiple theories proposed, the exact etiology is still unclear. Diagnosis is straightforward, with radiographs and MRI aiding in it. While non-surgical treatment is recommended in most cases, in those warranting surgery, combined minimal-invasive techniques involving decompression of cyst and stabilization have gained importance in recent times. Conclusion: There is variation in the diagnosis and treatment of UBCs among surgeons. Due to the vast heterogeneity of reported studies, no one method is the ideal standard of care. As most UBCs tend to resolve by skeletal maturity, clinicians need to balance the likelihood of successful treatment with morbidity associated with procedures and the risks of developing a pathological fracture. Study Design: Review Article. [ABSTRACT FROM AUTHOR]

Purpose Unicameral bone cysts (UBCs) are most often found when accompanied by a pathological fracture. In these cases, the doctor must determine the optimal timing for the surgery. The purpose of this study was to evaluate the outcome of immediate surgery as compared with delayed surgery in paediatric pathological fractures due to UBCs. Methods This retrospective study assessed the medical records of 65 patients between January 2012 and September 2016. Group A included 34 patients who underwent immediate surgery, including curettage, demineralized bone matrix and fixation with elastic stable intramedullary nailing. Group B included 31 patients who underwent the same surgery several months later. The outcome evaluations included the radiological changes, brace fixation time, cyst healing time, at the first-, third- and sixth month, and final visit. Results The mean brace fixation time was 26.3 days (sd 5.7) for group A and 53.8 days (sd .1) for group B (p = 0.012). According to radiological evaluations, 3/34 patients in group A and 5/31 in group B had recurrence after the first surgery. A second surgery was performed in all cases of recurrence, and all fractures were healed at the last visit. There was no significant difference in the recurrence rate between the two groups (p = 0.4631), and healing times were also similar (p = 0.6033). Conclusion Both the immediate and delayed surgery were safe for the treatment of UBCs with fractures. We suggest immediate surgery for shorter fixation time and early activity. [ABSTRACT FROM AUTHOR]

Background: Most patients suffering from distal femoral unicameral bone cysts (UBCs) are adolescents that require an early return to normal activities, including school attendance and sports exercises. However, the optimal choice of implants for such patients remains controversial. This study evaluated the application of pediatric physeal slide-traction plate (PPSP) in the treatment of pathological distal femoral fracture caused by UBCs.Methods: Between Jan 2014 and Jan 2016, 11 (male = 6, female = 5) patients were reviewed retrospectively. Age, sex, operative time, limb-length discrepancy (LLD), and valgus angulation were all recorded for every patient.Results: The average age of 11 patients was 12.2 ± 1.1 years. The operating time was 94.8 ± 7.8 min. The postoperative hospital stay was 5 to 7 days. The epiphyseal morphology in the operative leg was nearly normal. The plate was removed in an average of 19.5 ± 3.1 months. The knee range of motion (ROM) was normal in 9 patients, whereas 2 female patients reported a loss of less than 10 degrees of ROM as compared to the contralateral knee joint. Breakage of plates or refracture did not occur in our cases. All patients had a follow-up of at least 24 months. At the latest follow-up visit, all patients walked without a limp. None of the patients manifested obvious LLD and valgus deformity.Conclusion: PPSP combined with curettage and bone grafting allows early mobilization and produces satisfactory outcomes for pathological fracture of distal femur secondary to UBCs in adolescents. [ABSTRACT FROM AUTHOR]

Background: Unicameral bone cyst (UBC) is a common lesion in skeletally immature patients. Multiple treatments are proposed as curettage and autologous bone graft, percutaneous local corticoids injections, decompression with internal fixation, and injection of bioresorbable cement. Decompression, curettage, and percutaneous bioresorbable cement injection showed interesting results, but until now, no long-term follow-up was reported in pediatric patients with UBC. Methods: We retrospectively evaluated 13 pediatric patients with UBC treated with curettage, decompression, and injection of a calcium phosphate composite (CPC) at a single institution with an average F-U of 5.46 years (range 5–7 years). Functional outcomes were evaluated according to the Musculoskeletal Tumour Society (MSTS) Score. Radiographic healing was assessed with the modified Neer Outcome Rating System. Complications were recorded. Results: The mean MSTS score was 29.61 (range 28–30). No joint limitation or any pain was recorded. All patients returned to their previous level of activity. Complete healed cysts were observed in 76.9% of patients (10 of 13) and partially healed in 23.1% (3 of 13). Three fractures of the humerus occurred without any further consequence. In two cases, CPC overflow in the surrounding soft tissues was reported on post-operative X-rays, but at last follow-up, no CPC remained in the soft tissues. Conclusion: Our observations suggest that the use of curettage, decompression, and injection of CPC results in a high rate of good clinical outcomes with low recurrence rates and complications in the pediatric population with UBC at a long-term follow-up. [ABSTRACT FROM AUTHOR]

Unicameral bone cyst (UBC) or simple bone cyst (SBC) is a benign cystic lesion commonly found in the humerus and femur that is mainly encountered during childhood. The currently available treatments for UBC of the hand commonly involve curettage, bone grafting, partial resection with or without grafting, multiple drilling, fracture immobilization and observation alone, and steroid injection. We herein report a case treated with total resection of the cyst and non-vascularized fibular graft in a 9-year-old right-handed female patient. The patient presented with a chief complaint of a large, fast growing lump over the first metacarpal of the left hand. Flexion of the first metacarpophalangeal joint was limited. After the diagnosis was established with plain radiographs followed by biopsy, the cyst was completely removed by resecting the shaft of the metacarpal bone with preservation of the epiphyseal plate. A bone graft was obtained from the fibula and inserted in the gap, distally attached to the epiphyseal plate of the metacarpal and fixed with a Kirshner wire proximally. Radiographs revealed solid union of the bone graft to the epiphyseal plate at the head after 7 weeks, with improving function of the thumb. SBC or UBC of the metacarpal bone is very rare. A more aggressive method, such as in the case presented herein, may be necessary to treat this condition. [ABSTRACT FROM AUTHOR]

Background: pathological fractures in children occur from many aetiology. The physician has to develop an individual strategy for management and rehabilitation, considering the biology of bone and the biomechanics at the fracture site to detect pathology of lesion and to reach perfect bone healing. Time-efficient protection and reconstruction of the child's musculoskeletal system is the aim of the orthopaedic surgeon's intervention. The whole strategy must be individualized to every situation. Objective: The goals of managing a child's pathological fracture are all based on establishing a diagnosis. Fracture management is then based on five points: (a) relief the pain; (b) achieve local control of the pathological lesion; (c) skeletal stabilization, preservation of growth, and maintain anatomical alignment; (d) fracture healing; and (e) restoration of function. Patients and Methods: Our study was done over 20 cases of pathological fracture of lower limb in children in Al-Azhar University Hospitals (Al-Hossin and Saeid Galal hospitals) from January 2016 to December 2018. Imaging and radiology reports were used to determine fracture types. Complete fractures were classified to four major types: transverse, spiral, oblique and comminuted. In our study we use the Musculoskeletal Tumor Society (MSTS) scoring system to assess functional outcome for each patient. For lower extremity function, the MSTS used a 0-5 scale for the following variables: motion, pain, stability, deformity, strength, functional activity and emotional acceptance. Results: According to our study no patients with fractures underwent amputation, affection of neurovascular structures, or tumour progression on therapy. Pathologic fracture was not an indication for any of the amputation procedures, only the tumour pathology in an indication. Two patients refused surgery. Only one patient had a local recurrence after limb salvage surgery, and underwent no further surgical intervention. [ABSTRACT FROM AUTHOR]

Purpose: Several therapeutic strategies have been used for managing unicameral bone cyst (UBC) of the proximal femur. However, there is insufficient evidence to support one treatment over another, and the optimal treatment is controversial. This study aims at describing our experience with surgical reconstruction of paediatric UBCs of the proximal femur using a proximal locking plate and fibular strut allograft.Methods: In total, 14 consecutive paediatric patients with Dormans types IB (four cases) and IIB (10 cases) UBC were assessed. Mean patient age was 8.6 ± 2.3 years, and mean follow-up period was 41.7 ± 29.8 months. Six patients (42.8%) were referred with a pathologic fracture. Clinical/radiological outcome and complication rates were evaluated at the final follow-up session.Results: No cysts were Capanna's class III (recurrence) or IV (no response). Complete healing (Capanna's class I) was seen in ten cysts, while four other cysts healed with residual radiolucent areas (Capanna's class II). Mean healing period was 14.1 ± 5.1 (9-24 months). One patient had superficial infection, one heterotopic ossification, and one mild coxa vara, and mean Musculoskeletal Tumor Society (MSTS) score was 99.5%.Conclusion: According to our results, locking plate and fibular strut graft in Dormans classification types IB and IIB results in a favorable outcome in managing UBC of the proximal femur in the paediatric population. [ABSTRACT FROM AUTHOR]

Background: Simple bone cysts (SBC) have been documented to occur in adults with closed physeal plates, most commonly affecting the calcaneus in this patient subset. Although most authors theorize an association to trauma, etiology of simple bone cysts remains an enigma up to now. Case presentation: A 26-year-old kickboxing coach sought consult for a painful right shoulder which on radiographs and magnetic resonance (MR) imaging showed a proximal humeral lesion with signs of ossification. The patient was lost to follow-up but again sought consult after 3 years for the recurring complaint. On repeat radiographs, computed tomography (CT) scan, and MR images, tumor enlargement with cystic findings typical of simple bone cyst were documented. Diagnostic aspiration of the lesion was firstly done, revealing straw-colored fluid. The patient then underwent intralesional curettage with alpha-tricalcium phosphate cement reconstruction of the lytic defect. No perioperative complications were incurred, and on latest follow-up at 3 years postoperatively, Musculoskeletal Tumor Society (MSTS) and visual analog scale (VAS) pain scores were 30/30 and 0/10, respectively. Conclusions: The authors believe their report provides support to a possible association to trauma of simple bone cysts occurring in the adult population with closed physes and suggest this subset of patients may require a different treatment approach from that for juvenile simple bone cysts. [ABSTRACT FROM AUTHOR]

Background: To assess the efficacy of ethanol as an adjuvant in the treatment of unicameral bone cyst (UBC). Materials and Methods: Surgically treated patients with UBC lesion were reviewed. Definite treatment of UBC lesions was conducted using a combined four-step alcohol-using approach, consisted of curettage, burring, ethanol 96%, and electrocauterization of the lesion, consecutively. Results: Twenty-one patients (mean age 14, range: 2-30, male 62%) were followed from 1 to 10 years. Among 18 cases, only one recurrence was seen in a 5-year-old boy with UBC of the left calcaneus. Conclusions: Using ethanol as an adjuvant may be a good choice for treatment of UBC lesions. [ABSTRACT FROM AUTHOR]

Background: Medial tibial stress syndrome is one of the most common causes of exertional leg pain in runners whereas musculoskeletal tumors and tumor-like lesions are rare encounters in orthopedic sports medicine practice. Unicameral (simple) bone cyst is a well-known tumor-like lesions of the bone typically affecting children and adolescents. Bilateral occurrence is very rare though and has never been reported before in both tibiae. Failing to accurately diagnose a tumorous lesion can entail far-reaching consequences for both patients and physicians. Case presentation: We report the case of large bilateral unicameral bone cysts of the diaphyseal tibiae mimicking medial tibial stress syndrome in a 17-year old professional athlete. This is the first report of symmetric tibial unicameral bone cysts in the literature. The patient complained about persisting shin splint-like symptoms over 5 months despite comprehensive conservative treatment before MRI revealed extensive osteolytic bone lesions in both diaphyseal tibiae. The patient-tailored, less-invasive surgical procedure, allowing the patient to return to his competitive sports level symptom-free 3 months after surgery and to eventually qualify for this years Biathlon Junior World Championships, is outlined briefly. Pathogenesis and various treatment options for this entity will be discussed. Conclusion: This report will help to raise awareness for musculoskeletal tumors as differential diagnosis for therapy-refractory symptoms in young athletes and encourage medical staff involved in sports medicine and athlete support to perform early high quality imaging and initiate sufficient surgical treatment in similar cases. Moreover, our less-invasive surgical procedure aiming for a fast return to sports might be an optimal compromise between traditional open curettage with low risk of recurrence and a soft tissue-saving and bone-sparing minimal-invasive technique. [ABSTRACT FROM AUTHOR]

Background: Medial tibial stress syndrome is one of the most common causes of exertional leg pain in runners whereas musculoskeletal tumors and tumor-like lesions are rare encounters in orthopedic sports medicine practice. Unicameral (simple) bone cyst is a well-known tumor-like lesions of the bone typically affecting children and adolescents. Bilateral occurrence is very rare though and has never been reported before in both tibiae. Failing to accurately diagnose a tumorous lesion can entail far-reaching consequences for both patients and physicians. Case presentation: We report the case of large bilateral unicameral bone cysts of the diaphyseal tibiae mimicking medial tibial stress syndrome in a 17-year old professional athlete. This is the first report of symmetric tibial unicameral bone cysts in the literature. The patient complained about persisting shin splint-like symptoms over 5 months despite comprehensive conservative treatment before MRI revealed extensive osteolytic bone lesions in both diaphyseal tibiae. The patient-tailored, less-invasive surgical procedure, allowing the patient to return to his competitive sports level symptom-free 3 months after surgery and to eventually qualify for this years Biathlon Junior World Championships, is outlined briefly. Pathogenesis and various treatment options for this entity will be discussed. Conclusion: This report will help to raise awareness for musculoskeletal tumors as differential diagnosis for therapy-refractory symptoms in young athletes and encourage medical staff involved in sports medicine and athlete support to perform early high quality imaging and initiate sufficient surgical treatment in similar cases. Moreover, our less-invasive surgical procedure aiming for a fast return to sports might be an optimal compromise between traditional open curettage with low risk of recurrence and a soft tissue-saving and bone-sparing minimal-invasive technique. [ABSTRACT FROM AUTHOR]

Background Distal radius fractures (DRF) are often referred to as osteoporosis indicator fractures as their incidence increases from age 45. In the group of young adults, distal radius fractures normally result from high-energy trauma. Wrist fractures in young patients without adequate trauma thus raise suspicion of a pathologic fracture. In this report we present the case of a fractured unicameral bone cyst (UBC) at the distal radius in a young adult. To the author's best knowledge, this is the first detailed report in an UBC at the distal radius causing a pathologic DRF in an adult patient. Case presentation A 25-year-old otherwise healthy male presented to our Emergency Department after a simple fall on his right outstretched hand. Extended diagnostics revealed a pathologic, dorsally displaced, intra-articular distal radius fracture secondary to a unicameral bone cyst occupying almost the whole metaphysis of the distal radius. To stabilize the fracture, a combined dorsal and volar approach was used for open reduction and internal fixation. A tissue specimen for histopathological examination was gathered and the lesion was filled with an autologous bone graft harvested from the ipsilateral femur using a reamer-irrigator-aspirator (RIA) system. Following one revision surgery due to an intra-articular step-off, the patient recovered without further complications. Conclusions Pathologic fractures in young patients caused by unicameral bone cysts require extended diagnostics and adequate treatment. A single step surgical treatment is reasonable if fracture and bone cyst are treated appropriately. Arthroscopically assisted fracture repair may be considered in intra-articular fractures or whenever co-pathologies of the carpus are suspected. [ABSTRACT FROM AUTHOR]

Background Unicameral bone cyst (UBC) is the most common benign lytic bone lesion seen in children. The aim of this study is to investigate clinical factors affecting pathological fracture and healing of UBC. Methods We retrospectively reviewed 155 UBC patients who consulted Nagoya musculoskeletal oncology group hospitals in Japan. Sixty of the 155 patients had pathological fracture at presentation. Of 141 patients with follow-up periods exceeding 6 months, 77 were followed conservatively and 64 treated by surgery. Results The fracture risk was significantly higher in the humerus than other bones. In multivariate analysis, ballooning of bone, cyst in long bone, male sex, thin cortical thickness and multilocular cyst were significant adverse prognostic factors for pathological fractures at presentation. The healing rates were 30% and 83% with observation and surgery, respectively. Multivariate analysis revealed that fracture at presentation and history of biopsy were good prognostic factors for healing of UBC in patients under observation. Conclusion The present results suggest that mechanical disruption of UBC such as fracture and biopsy promotes healing, and thus watchful waiting is indicated in these patients, whereas patients with poor prognostic factors for fractures should be considered for surgery. [ABSTRACT FROM AUTHOR]

A unicameral bone cyst (UBC), also known as a simple or solitary bone cyst, is benign tumor that consists of a cavity filled with a yellow-colored fluid. It is typically seen in children aged 5 to 15, and affects males twice more than females. Although UBC can be located in any bone of the body, the most common location of the lesions is the proximal humerus, followed by the proximal femur. Both account for nearly 90% of all UBC sites. Other sites involve the tibia, pelvis, calcaneus, scapula, spine, patella, metatarsals. But, according to our knowledge, four cases of lesions in the hand have been reported in the literature before. And also only two of them were in phalanx of the hand. We herein reported two cases with UBC of the proximal phalanx of the hand. We also reviewed the literature related to UBC with special emphasis on general characteristic of the lesions. [ABSTRACT FROM AUTHOR]

Unicameral bone cysts (UBCs) are benign, osteolytic lesions which are often asymptomatic and are commonly seen in the proximal of humerus and femur. The average age at diagnosis is 9-11 years and there is a male preponderance with a male-to-female ratio of approximately 2-2.5 to 1. We describe a case of 5-year-old girl who presented to orthopedic clinic with a 4-month history of painful limping. Plain radiography of the right knee demonstrated a well-defined lytic lesion in the proximal of the tibia. Open biopsy and then curettage and bone grafting with bone- substitute was performed. The diagnosis of this condition requires a high index of suspicion. This report demonstrates that all UBCs do not have the same clinical patterns and with adequate attention good results can be achieved. [ABSTRACT FROM AUTHOR]

The purpose of this paper is to perform an evidence based review for treatment of unicameral bone cysts. A search of MEDLINE (1966 to 2009) was conducted and the studies were classified according to levels of evidence. This review includes only comparative Level IIII studies. The systematic review identified 16 studies. There is one level I study, one level II study and the remaining 14 studies are level III. Seven of the sixteen studies had statistically different results: three studies indicated that steroid injection was superior to bone marrow injection or curettage and bone grafting; one study indicated that cannulated screws were superior to steroid injections; one study indicated resection and myoplasty was superior to steroid injection; one study indicated a combination of steroid, demineralized bone matrix and bone marrow aspirate, and curettage and bone grafting were superior to steroid injection; and one study indicated that curettage and bone grafting was superior to non-operative immobilization. Based on one Level I study, including a limited number of individuals, steroid injection seems to be superior to bone marrow injection. As steroid injections have already demonstrated superiority over bone marrow injections in a randomized clinical trial, the next step would be a prospective trial comparing steroid injections with other treatments. [ABSTRACT FROM AUTHOR]

A 17-year-old girl was admitted to the hospital for surgery of an enlarging, painful mass of the left calcaneus. Preoperative imaging studies suggested either a simple (unicameral) or aneurysmal bone cyst. Intraoperative biopsy of the lesion revealed a simple bone cyst with extensive cholesterol clefts. Such cysts are not uncommon in the calcaneus. However, the pathology of this case is unusual and often overlooked. The typical presentation, treatment, and pathology of these lesions are reviewed. [ABSTRACT FROM AUTHOR]

Introduction: Unicameral bone cysts (UBC), also known as simple bone cysts, are common benign bone lesions filled with fluid, primarily occurring in children and adolescents. Although they can develop in any bone, UBCs usually affect the long bones. Materials & Methods: A 53 year old male patient was found incidentally to have a calvarian lesion in the parietal region overlying the superior sagittal sinus (SSS) (Figure 1). The differential diagnosis included a large arachnoid granulation, haemangioma of bone, a giant cell tumour or tuberculous infection. The patient was planned for elective surgery to remove the lesion and establish the diagnosis. Surgery was uneventful. Conclusion: To the best of our knowledge we describe the first case of UBC affecting the cranial vault. The patient underwent surgery. [ABSTRACT FROM AUTHOR]

Abstract: Unicameral bone cyst (UBC) is a benign cystic lesion in children which is prone to fracture. Various treatments are available, but recurrence after different types of percutaneous injection therapy can cause bone destruction and pathologic fracture. The potential therapeutic effects of anti-resorptive agents, such as bisphosphonates, have not been investigated for UBC. The objective of this study was to characterize the cells from the fibro-cellular membrane of unicameral bone cyst (UBC cells) and to determine whether zoledronate, a nitrogen-containing bisphosphonate, could induce apoptosis in UBC cells. Flow cytometry and immunoblotting were performed in order to determine whether zoledronate induced apoptosis. Cells derived from normal human trabecular bones were used as controls against UBC cells to compare the effect of zoledronate in inducing apoptosis. Immunohisto/cytochemistry (IHC/ICC) and mini-array analyses were performed on tissues and cultured cells. Isolated peripheral blood mononuclear cells were incubated with conditioned media from the UBC cells to determine whether they are capable of inducing osteoclastogenesis. UBC membrane is composed of cells staining positively with CD68, SDF-1, STRO-1 and RANKL, but in vitro cells showed no staining with antibodies to CD68 and STRO-1, suggesting that there was a clonal selection of stromal cells during cell culture. UBC cells also express RUNX2 (runt-related transcription factor-2, core binding factor-1), a key transcription factor for osteoblastic differentiation. In addition, media collected from UBC cells induced a generation of multi-nucleated osteoclast-like cells of peripheral blood mononuclear cells. Zoledronate induced apoptosis of UBC cells in a dose-dependent manner. Apoptosis was evidenced by induction of the active cleaved form of caspase-3. The baseline apoptotic fractions were similar in UBC cells and trabecular bone cells. However, in the overall apoptotic fractions in this study, trabecular bone cells showed 17.2% of apoptosis, significantly lower than 24.2% of UBC cells (p-value=0.007). With the various zoledronate concentrations, mean apoptotic fractions of trabecular bone cells was 19.2%, significantly lower than 27.8% of UBC cells (p-value=0.040). With GGOH co-treatment in various zoledronate concentrations, 15.1% apoptosis was shown in trabecular bone cells, which was not significantly lower than 20.6% of UBC cells (p-value=0.076). This data suggests that zoledronate causes apoptosis in both UBC and trabecular bone cells by inhibition of the mevalonate pathway. In addition to the known anti-osteoclastogenic effect of bisphosphonates, the GGOH inhibitory effects of zoledronate were more prominent in UBC cells than trabecular bone cells, indicating their potential therapeutic role in UBC. [Copyright &y& Elsevier]

Abstract: Calcaneal unicameral bone cysts often contain fluid, but rarely contain fluid–fluid levels. We present a case focusing on the CT findings of a large calcaneal bone cyst with a fluid–fluid level and a review of the literature. [Copyright &y& Elsevier]

Unicameral bone cysts are fluid-filled benign lesions that occur mostly in the long bones. Unicameral bone cysts in the pelvis are extremely rare. Continuous decompression using titanium or hydroxyapatite screws has been reported as a treatment. Screws made from a composite of unsintered hydroxyapatite particles and poly- l -lactide can be used for the treatment. An adolescent male patient presented with a unicameral bone cyst in the ilium extending to a region adjacent to the hip joint. As initial treatment, the cortex was fenestrated when the patient was 13 years old and β-tricalcium phosphate implanted. The cyst first reoccurred when the patient was 15 years old and again when he was 17 years old. During the most recent treatment, unsintered hydroxyapatite particles and poly- l -lactide composite screws were placed, and no recurrence was observed during 2 years of follow-up. The slow biodegradability and absorbability of the screws may allow continuous drainage of unicameral bone cysts. [ABSTRACT FROM AUTHOR]