Partial Sacral Resection for the Treatment of Isolated Testicular Tumor Metastasis.

We encountered an uncommon case of a non-seminomatous germ cell tumor with solitary bone metastasis at the initial presentation. A 30-year-old male patient with testicular cancer underwent an orchidectomy and was diagnosed with non-seminoma. Positron emission tomography-computed tomography detected an isolated metastatic lesion in the right sacral wing, which disappeared after a series of chemotherapy. En-bloc surgical resection was performed as curative local treatment, and the patient was able to perform his activities of daily living with no apparent recurrence. Therefore, this surgical method is considered safe and beneficial for the treatment of sacral wing lesions.

Analysis of implants for metastatic bone tumors of the proximal femur: A retrospective study.

AIM: To investigate the relationship between surgical techniques used in our hospital to treat metastatic bone tumors of the proximal femur and activity level and prognosis of patients and whether the location of the tumor is considered when selecting surgical techniques. METHODS: We retrospectively reviewed 82 patients with metastatic bone tumors of the proximal femur who underwent intramedullary nail fixation (IMN), bipolar hip arthroplasty (BHP) or modular megaprosthesis (MMP) in our hospital from 2007 to 2020. We measured the distance from the center of femoral head to the proximal (x) and distal (y) end of the of tumor, using preoperative computed tomography images to determine the location of metastasis. We also measured revised Katagiri score at the time of fracture, postoperative ISOLS/MSTS (functional outcome) scores, and overall survival. RESULTS: The value of x was significantly different among the three groups. The value of y showed a significant difference between the IMN and BHP groups and the BHP and MMP groups. The functional outcome score was significantly lower in the IMN group. The survival rate of the patient tended to be higher in the BHP and MMP groups than in the IMN group 1 year postoperatively. CONCLUSION: IMN was favored when the distance from the center of femoral head to the proximal end of the tumor was ≥15 mm. In the case of prosthetic replacement, BHP was chosen if the distance from the center of femoral head to the distal end of the tumor was ≤70 mm. BHP and MMP were preferred over IMN functionally.

Cardiac Arrest Due to Pulmonary Embolism After Posterior Spinal Fusion in a Patient With Acute Paraplegia Caused by a Metastatic Spinal Tumor Associated With Congenital Antithrombin III Deficiency.

Congenital antithrombin (AT) III deficiency has a high incidence of deep vein thrombosis and pulmonary embolism due to reduced anticoagulation. In this study, we report a case of a patient who experienced cardiac arrest due to pulmonary embolism after emergency posterior spinal fusion for acute paraplesia due to a metastatic spinal tumor associated with AT III deficiency. A 49-year-old man with a history of familial AT III deficiency visited our hospital due to difficulty in walking caused by a progressive paralysis of the lower limbs. Clinical examination revealed multiple bone metastases due to prostate cancer and spinal cord compression caused by a pathological fracture of the T1 vertebral body. He had low AT III activity levels and high D-dimer levels. The following day, he underwent posterior spinal decompression and fusion. However, he had pulmonary embolism with cardiac arrest three days after surgery. He recovered without sequelae after emergency thrombectomy following resuscitation. Patients with AT III deficiency who cannot walk due to a metastatic spinal tumor inevitably develop deep vein thrombosis and pulmonary embolism. To avoid lethal pulmonary embolism, preventing deep vein thrombosis should be prioritized before surgery, even in the presence of acute progressive paraplegia.

Characteristic imaging findings predicting the risk of conservative treatment resistance in fresh osteoporotic vertebral fractures with poor prognostic features on magnetic resonance imaging.

BACKGROUND: Recent studies have reported that confined high-intensity and diffuse low-intensity on sagittal T2-weighted magnetic resonance imaging (MRI) are distinctive features that are highly predictive of delayed union or nonunion on osteoporotic vertebral fracture (OVF). The objective of this study was to identify the characteristics of imaging findings predicting the risk for requiring surgical treatment in fresh OVF with poor prognostic features on MRI. METHODS: We conducted a retrospective study of 74 patients (17 men and 57 women with a mean age of 81.1 years) of OVF with the poor prognostic MRI findings. We compared the imaging findings between the surgery group (16 patients) and the conservative group (58 patients): vertebral instability defined as the difference between the vertebral collapse ratio in dynamic X-rays, and the grade of posterior wall injury (Grade I, no spinal canal encroachment; Grade II, <2 mm; Grade III, ≥2 mm) as well as the presence or absence of pedicle fracture (Grade I, none; Grade II, unilateral; Grade III, bilateral) on computed tomography. RESULTS: The mean vertebral instability was 24.0% ± 10.1% in the surgery group and 13.0% ± 7.8% in the conservative group, which was significantly different. Posterior wall injury in the surgery and conservative groups was Grade I in 0 and 29 cases, Grade II in 5 and 21 cases, and Grade III in 11 and 8 cases, respectively, constituting a significant difference. Pedicle fracture in the surgery and conservative groups was Grade I in 5 and 55 cases, Grade II in 6 and 2 cases, and Grade III in 5 and 1 case, respectively, also constituting a significant difference. CONCLUSIONS: The most high-risk OVF patients with poor prognostic MRI findings who required surgical treatment were those who exhibited greater vertebral instability as well as either more severe posterior wall injury or pedicle fracture. STUDY DESIGN: Retrospective clinical study.

Doxorubicin Combined With Ifosfamide for Sarcoma Induces Muscle Atrophy and Sleep Disruption.

BACKGROUND/AIM: There are no reports evaluating sleep disturbance and skeletal muscle loss in response to the treatment of soft tissue sarcoma (STS) with chemotherapy. This study investigated the effects of combined doxorubicin (DXR) and ifosfamide (IFM) on sleep and skeletal muscle. PATIENTS AND METHODS: This retrospective cohort study included 14 patients with high-grade STS. Participants underwent five 7-day hospitalizations during which they received chemotherapy for 5 consecutive days. Sleep analysis and muscle-volume evaluation were investigated using a wearable device during hospitalization and by bioelectrical impedance analysis at each chemotherapy course. RESULTS: Chemotherapy significantly impeded sleep, increased wake-time after sleep onset, and aggravated movement index during hospitalization. In long-term body composition assessment, chemotherapy induced muscle-mass loss and fat-mass gain. CONCLUSION: Combination of DXR and IFM for STS induces skeletal muscle loss and sleep disruption.

The Thioredoxin Reductase Inhibitor Auranofin Suppresses Pulmonary Metastasis of Osteosarcoma, But Not Local Progression.

BACKGROUND/AIM: Auranofin (AUR), a thioredoxin reductase (TXNRD) inhibitor, shows anticancer activity against several cancers. This study investigated the effects of AUR on the local progression and pulmonary metastasis of osteosarcoma (OS). MATERIALS AND METHODS: Publicly available expression cohorts were analysed to study the relationship between TXNRD-2 expression and the survival of patients with OS. The murine OS cell line LM8 was stimulated with AUR. Cell viability, apoptosis-related protein levels, caspase activity, and wound healing were analysed. Tumor progression and pulmonary metastasis were investigated in C3H mice implanted with LM8 cells. RESULTS: High-level expression of TXNRD-2 represented a negative prognostic factor for metastasis and overall survival in patients with OS. AUR induced apoptosis of OS cells via the oxidative stress-MAPK-Caspase 3 pathway, and suppressed the migration of OS cells. AUR inhibited the pulmonary metastasis of OS, but not local progression. CONCLUSION: AUR represents a potential therapeutic drug for suppressing pulmonary metastasis of OS.

Poor Efficacy of Postoperative Radiotherapy in Infiltrative High-grade Soft Tissue Sarcomas.

BACKGROUND/AIM: We aimed to investigate the effectiveness of postoperative radiotherapy (RT) on local recurrence-free survival (LRFS) in high-grade infiltrative soft tissue sarcomas (STSs) and determine its prognostic factors. PATIENTS AND METHODS: This was a retrospective cohort study and included 132 patients with high-grade STSs. Patients were divided into two groups: Group RT (n=48) who underwent postoperative RT and Group No-RT (n=84) who underwent only surgery. We analysed 5-year LRFS and its prognostic factors between these groups. Furthermore, 5-year LRFS in infiltrative and non-infiltrative STSs were evaluated. RESULTS: Five-year LRFS was not significantly different in Group RT (83.6%) and Group No-RT (79.6%) (p=0.698). Overall, significant prognostic factors influencing LRFS were age at diagnosis (p=0.02) and tumour growth pattern (p=0.04). Postoperative RT was less effective in the infiltrative than in non-infiltrative pattern of STSs. CONCLUSION: Postoperative RT does not influence local recurrence outcomes in infiltrative STSs.

CDK4 overexpression is a predictive biomarker for resistance to conventional chemotherapy in patients with osteosarcoma.

Osteosarcoma (OS) is the most common malignant bone tumor, and its sensitivity to preoperative chemotherapy is a significant prognostic factor. The present study aimed to identify potential genomic markers for the prediction of chemosensitivity in patients with OS using a genomic approach. A total of 50 pediatric and adolescent patients diagnosed with high­grade OS were selected. Each pre­therapeutic biopsy sample was subjected to comparative genomic hybridization array analysis and targeted exome sequencing. Although no recurrent gene mutation was observed in chemoresistant tumors, copy number analysis detected recurrent gain of chromosome 12q14.1, which was significantly more frequent (5/21; 24%) in the poor responder cohort than in the good responder cohort (0/29; 0%; P<0.01). Subsequent expression analysis revealed that CDK4 was the only gene in the 12q14.1 gained region with an expression level that was positively associated with copy number gains. In order to elucidate the effect of CDK4 on drug sensitivity, CDK4­overexpressing OS cell lines were treated with cisplatin (CDDP); significant attenuation of CDDP sensitivity, demonstrated by increased cell viability and decreased expression of cleaved caspase­9, was induced by enforced expression of CDK4. In addition, treatment with CDK4/6 inhibitor palbociclib in CDK4­overexpressing U2OS cells facilitated apoptosis and a significant decrease in cell viability in a dose­dependent manner. In conclusion, the results of the present study showed that higher expression and amplification of CDK4 in tumors is a predictive biomarker for resistance to conventional chemotherapy in patients with OS and that palbociclib is a promising drug for this therapeutically challenging cohort.

Effectiveness of Salvage Knee Rotationplasty on Sarcoma Around the Knee in Adolescents and Young Adults.

BACKGROUND/AIM: This study aimed to investigate the effectiveness of knee rotationplasty (KRP) as salvage surgery for uncontrolled infection and implant failure of total knee arthroplasty (TKA) for sarcoma around the knee in adolescents and young adults (AYA). PATIENTS AND METHODS: This retrospective cohort study included 33 patients who underwent KRP and were grouped based on the treatment received: initial surgery for sarcoma around the knee (n=18) or as salvage surgery (n=15). Musculoskeletal Tumor Society (MSTS) score, range of motion (ROM) and postoperative results were analyzed. RESULTS: All 15 patients who underwent salvage KRP had TKA as an initial surgery. Although there were five infections in salvage KRP, which originated from the initial TKA, all cases were controllable, no implant failure occurred. MSTS score and ROM were deemed acceptable in both groups. CONCLUSION: Salvage KRP is an effective option for uncontrolled complications of initial TKA for sarcoma around the knee.

Giant Protruding High-Grade Undifferentiated Pleomorphic Sarcoma Arising in a Keloid Scar on the Abdominal Wall.

Undifferentiated pleomorphic sarcoma (UPS) is a high-grade, aggressive, soft tissue sarcoma that is often fatal. Although there are reports describing associations of sarcoma and skin lesions such as burns, radiation, and trauma, to our knowledge, UPS development in a keloid scar has not been reported. Herein, we present the case of a 76-year-old woman who had undergone surgery for endometrial cancer, 5 years before. She presented with a protruding lesion that was continuous to a keloid scar on the abdominal wall. The tumor appeared clinically malignant as it was protruding and doubled in size within three weeks, reaching approximately 6 × 6 × 2 cm. Since the tumor was diagnosed as UPS after pathological evaluation by needle biopsy, wide resection was performed. Intraoperatively, the tumor was apparently continuous to the keloid, protruding and pedunculated outside the body, and had not invaded the abdominal cavity. Histopathological examination of the resected tumor showed evidence of UPS and no suspicion of metastasis of endometrial cancer. No recurrence, metastases, or other complications were noted 6 months after surgery. The current case study reminds us that keloids may cause high-grade sarcoma such as UPS, and careful follow-up is required.

Successful Treatment of a Massive Desmoplastic Fibroma of the Ilium without Surgery: A Case Report with Long-Term Follow-Up.

Desmoplastic fibroma of the bone (DFB) is a notably rare, lytic, locally aggressive but nonmetastatic, primary benign bone tumor in patients less than 30 years old. As the recommended primary treatment for DFB, wide resection is preferred to curettage from the perspective of recurrence but wide resection of DFB in the pelvis such as in the acetabulum could result in greater functional loss, suggesting the need for conservative treatments. However, there is no report on long-term follow-up following conservative treatment for DFB. The present case involved a 21-year-old woman with right hip pain. Radiological evaluation revealed a massive lesion throughout the right ilium and acetabulum with partial osteolysis, cortical destruction, marginal sclerosis, slight pseudotrabeculation, and bone expansion. Open biopsy from the ilium showed the proliferation of spindle cells in an abundant collagenous matrix without atypia and mitosis, suggesting a diagnosis of DFB. Conservative treatment was selected considering the risk of greater functional loss following wide ilium resection. An evaluation 10 years after follow-up showed a partially sclerotic lesion of the ilium and the absence of pain. The current case demonstrates that conservative therapy may be effective even in some cases of aggressive DFB.

Synovitis, Acne, Pustulosis, Hyperostosis, and Osteitis Syndrome with Purely Osteolytic, Not Osteosclerotic, Lesions Mimicking a Malignant Tumor.

Synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome is a rare inflammatory disorder with multiple phenotypes. The syndrome has identifiable radiologic characteristics that are the most important when making a diagnosis. X-rays of cases diagnosed with SAPHO syndrome reveal sclerotic lesions or mixed lytic and sclerotic lesions. Pure osteolytic lesions in SAPHO syndrome are rare, and to the best of our knowledge, no study has reported the radiologic change of purely osteolytic lesions to osteosclerotic lesions over time. Herein, we report on the case of a woman experiencing severe left thigh acute pain and having a medical history of palmoplantar pustulosis. Although SAPHO syndrome was suspected because of palmoplantar pustulosis, based on radiologic findings, bone metastasis of a malignant tumor or chronic bacterial osteomyelitis owing to a purely osteolytic lesion was suspected. However, needle biopsy revealed no malignancy and bacterial culture was negative, thus suggesting SAPHO syndrome. Nonsteroidal anti-inflammatory drugs, bisphosphonates, and corticosteroids were administered, which improved the left thigh pain. Furthermore, the radiologic change of osteolytic lesions to osteosclerotic lesions over time was confirmed, leading to the diagnosis of SAPHO syndrome. Our case demonstrates that knowledge of atypical radiologic findings is necessary to diagnose initial SAPHO syndrome.

Successful Neurological Recovery with Multimodality Therapy without Surgery for Spinal Metastases from Advanced Gastric Cancer.

Advanced gastric cancer with bone metastasis has a very poor prognosis with short median survival. To the best of our knowledge, no reports in literature have described extensive recovery of paralysis with multimodality treatment without surgery in these cases. This report describes the case of a 52-year-old severely paralyzed female patient with spinal metastasis from advanced gastric cancer. She was inoperable, owing to a large thrombus in the inferior vena cava; alternative multimodality treatments, including chemotherapy and radiotherapy, were administered. The paralysis and the bladder and rectal dysfunction improved considerably. In addition, the performance status (PS) and Frankel grade also improved dramatically, from 4 to 1 and grade B to D, respectively. At 1 year after initiation of treatment, she is ambulatory. Patients with poor PS are often offered palliative therapy. However, this case demonstrates that poor PS solely due to paralysis from spinal metastasis may necessitate multimodality treatment instead of palliative care.

Factors Linked to Prognosis in Patients with Leptomeningeal Metastasis Diagnosed by Spinal Magnetic Resonance Imaging.

INTRODUCTION: Leptomeningeal metastasis (LM) is known to demonstrate a very poor prognosis. The purpose of this study was to evaluate the prognostic factors in LM cases diagnosed by spinal magnetic resonance imaging (MRI). METHODS: We retrospectively analyzed 19 patients with LM detected by spinal MRI between 2010 and 2017. RESULTS: The primary tumors were breast carcinoma (n = 7), lung carcinoma (n = 6), lymphoma (n = 3), colorectal carcinoma (n = 2), and gastric carcinoma (n = 1). Thirteen patients exhibited preceding brain metastasis, and 11 of these exhibited metastasis in the posterior fossa. Ten patients exhibited limb paralysis. Performance status at diagnosis was 0-1 in 6 patients, 2 in 9 patients, and 3-4 in 4 patients. Testing of cerebrospinal fluid revealed malignant cells in 9 patients. On MRI, 11 patients demonstrated disseminated tumor lesions at the cervical cord level, 15 patients at the thoracic cord level, and 11 patients below the conus level. Eleven patients received radiation therapy, while intrathecal chemotherapy was performed in 9 patients. Univariate analysis revealed cervical cord level lesions, intrathecal chemotherapy, paralysis, and performance status as prognostic factors. Multivariate analysis identified existence of a cervical cord lesion as associated with a poor prognosis (hazards ratio (HR) 3.46, 95% confidence interval (CI) 1.12-12.2), while administration of intrathecal chemotherapy was associated with a good prognosis (HR 0.15, 95% CI 0.026-0.67). CONCLUSIONS: In LM patients, cervical cord level lesions are a negative factor for prognosis, and performance of intrathecal chemotherapy is a positive factor for prognosis.

Freeze-Dried Platelet-Rich Plasma Induces Osteoblast Proliferation via Platelet-Derived Growth Factor Receptor-Mediated Signal Transduction.

STUDY DESIGN: Controlled laboratory study. PURPOSE: This study aimed to evaluate the in vitro pharmacological activity of growth factors (GFs) in freeze-dried platelet-rich plasma (FD-PRP) after storage for 4 weeks. OVERVIEW OF LITERATURE: Freshly prepared PRP is a rich source of many GFs. We reported that FD-PRP stored for 8 weeks accelerated bone union in a rat posterolateral fusion model equally well as fresh-PRP. However, the pharmacological activity of FD-PRP after longterm storage has not been shown in vitro. METHODS: Immediately after preparation, as well as 4 weeks after freeze-dried storage, the platelet count was measured. Human osteoblasts were treated with fresh-PRP and FD-PRP, respectively. Western blotting was used to assess the phosphorylation of the platelet-derived growth factor (PDGF) receptor (PDGFR) and its downstream target, extracellular signal-regulated kinase (ERK). The proliferation rates of osteoblasts were investigated by immunocytochemistry and MTT cell viability assays. Furthermore, we used western blotting to evaluate the effect of PDGFR knockdown on the phosphorylation of ERK stimulated with fresh-PRP and FD-PRP. RESULTS: Platelet counts in both the fresh-PRP and FD-PRP samples were approximately 10-fold higher than in peripheral blood samples. The phosphorylation and activation of the PDGFR and ERK were evenly induced by fresh-PRP and FD-PRP stimulation. Both freshPRP and FD-PRP significantly induced osteoblast proliferation in MTT cell viability assays. Furthermore, osteoblast PDGFR knockdown attenuated the downstream ERK activation by fresh PRP and FD-PRP. CONCLUSIONS: We demonstrated the pharmacological activity of PDGF in FD-PRP in vitro after 4 weeks of storage.

A novel unidirectional porous ß-tricalcium phosphate grafting for vertebral fracture in the elderly: preliminary case series.

Objective: To treat vertebral fractures with posterior wall injury in the elderly, vertebral bone grafting is generally performed through a posterior transpedicular approach, combined with pedicle screw fixation. An autologous bone is ideal to treat this disorder. However, harvesting autologous bones from the elderly with osteoporosis is limited by the amount and quality of available autologous bone. Thus, we developed a bone-grafting substitute. The newly developed unidirectional porous ß-tricalcium phosphate, with a porosity of 57% (UDPTCP; Affinos®, Kuraray Co., Ltd., Tokyo, Japan), is used in the bone-grafting procedure. This is the first report of UDPTCP used as an artificial bone graft in patients with an acute vertebral burst fracture. Materials and Methods: UDPTCP (mean: 4.2 g) was implanted through the pedicle, and posterior instrumentation was achieved with pedicle screws in five elderly patients. Resorption of UDPTCP and substitution with the autologous bone were evaluated on computed tomography (CT) and plain X-ray performed immediately and at 3, 6, and 12 months after the operation. Results: In case 1, the pedicle screws did not loosen, and UDPTCP was completely resorbed and replaced with the autologous bone at 3 postoperative months. In the other four cases, although the pedicle screws or the caudal part loosened because of osteoporosis, resorption of UDPTCP was observed at 3 postoperative months. At 6 postoperative months, progressive substitution with the autologous bone was confirmed, and at 12 postoperative months, formation of the good autologous bone was confirmed. Conclusion: This preliminary case series demonstrated that the newly developed UDPTCP shows good clinical potential as a bone-graft substitute for acute vertebral burst fractures in the elderly, including patients with osteoporosis.

Giant Protruding Nodular Fasciitis of the Anterior Chest Wall Clinically Mimicking a Soft Tissue Sarcoma.

Nodular fasciitis (NF) is a benign reactive proliferation of myofibroblasts that predominantly occurs subcutaneously. Commonly, it presents as a rapidly growing swelling in 4-8 weeks. NF mostly occurs in adults aged 20-50 years and usually has a diameter < 3-4 cm. Giant NF with a diameter > 4 cm is rare. Owing to its rapidly growing nature, a precise clinical diagnosis is difficult; it is frequently misdiagnosed as an aggressive or malignant tumor. Herein, we present the case of a 15-year-old male who presented with a large protruding mass on the anterior chest wall. The tumor appeared clinically malignant as it was protruding and had doubled in size within a few weeks, reaching approximately 8 × 6 cm. Furthermore, the tumor separated and fell off spontaneously due to its large size. As the remaining tumor continued to grow rapidly, surgery was performed. Following wide tumor resection, no recurrence, metastases, or other complications were noted 1 year postsurgery. NF was diagnosed after pathological evaluation, including immunohistochemical analysis, molecular genetic testing, and cytogenetic testing via fluorescence in situ hybridization analysis. Knowledge of the atypical clinical course and a combination of histopathological examinations are necessary to accurately diagnose NF.

Giant Muscle Invasive Dermatofibroma Clinically Mimicking a Malignant Tumor.

Dermatofibromas are common benign fibrohistiocytic lesions, usually appearing as slow growing firm dermal nodules with a predilection for the extremities (mostly the lower legs). They are found mostly in middle-aged women and are usually smaller than 2 cm in diameter. Giant dermatofibromas exceeding 5 cm in diameter are rare. In recent years, reports have suggested a relationship between the primary size of dermatofibromas and rates of local recurrence and metastases after surgery. This relationship is however debated. The present report describes the case of a giant muscle invasive tumor in a 51-year-old female patient who presented with a large ulcerated mass in the right upper arm. The tumor appeared clinically malignant, measuring approximately 12 cm × 6 cm in size, with ulceration and invasion of surrounding muscle. Wide resection of the tumor was performed with myocutaneous flap-plasty. Histopathological examination showed evidence of a dermatofibroma. No recurrence, metastases, or other complications were noted at 5 years after surgery. The present case demonstrates that although dermatofibromas are essentially benign, they may present with atypical features including large size, ulceration, and muscle invasion, clinically mimicking malignant tumors.

Successful total en bloc spondylectomy of the L3 vertebra with a paravertebral giant cell tumor following preoperative treatment with denosumab: a case report.

BACKGROUND: Giant cell tumor is known to be a benign neoplasm that arises most commonly in the long bones, while cases in the spine are rare. Recently, denosumab, a monoclonal antibody that inhibits receptor activator of nuclear factor-kappa ß ligand, has been used to treat patients with giant cell tumor. However, there are few reports of total en bloc spondylectomy being used for paravertebral giant cell tumor lesions following denosumab therapy. CASE PRESENTATION: Our patient was a 20-year-old Japanese woman with a 4-month history of lower back pain. A spinal computed tomography scan and magnetic resonance imaging of her lumbar spine revealed an osteolytic lesion involving the L3 vertebral body, and the tumor extended toward the left side of the paravertebral soft tissue and into the left pedicle. The lesion was diagnosed as a giant cell tumor by needle biopsy. Denosumab treatment calcified the paravertebral giant cell tumor lesion and the tumor vertebral body was removed completely by total en bloc spondylectomy. CONCLUSION: This case report describes a patient with a paravertebral giant cell tumor who was successfully treated by preoperative denosumab injection followed by total en bloc spondylectomy.

Novel Unidirectional Porous ß-Tricalcium Phosphate Used as a Bone Substitute after Excision of Benign Bone Tumors of the Hand: A Case Series.

Unidirectional porous ß-tricalcium phosphate (UDPTCP; Affinos®, Kuraray, Tokyo, Japan) has been in clinical use since 2015. Animal studies have confirmed the excellent potential of UDPTCP with regard to bone formation and material absorption. We present the first three clinical cases using UDPTCP as a bone substitute after curettage of benign bone tumors of the hand. All three patients were males, 29-, 30- and 81-years-old, two having a diagnosis of enchondroma and the other, a bone ganglion, with a pathological fracture identified in one case. Over a mean follow-up of 10 months, all patients achieved satisfactory clinical result, with no adverse events of UDPTCP noted. Radiographic evidence of good bone formation and material absorption was observable over the postoperative course. UDPTCP provided satisfactory clinical results, with good biocompatibility and fast resorption characteristics. Therefore, UDPTCP could provide a safe and reliable filling substitute for bone defects following curettage of small bone tumors.