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Yukihide Iwamoto - One of the best experts on this subject based on the ideXlab platform.

  • Bilateral subchondral insufficiency fracture of the femoral head after renal transplantation: A case report
    Arthritis & Rheumatism, 2020
    Co-Authors: Satoshi Ikemura, Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    This report describes the case of a 47-year-old woman who was found to have subchondral insufficiency fractures in both femoral heads after renal transplantation. Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-Intensity Band on the T1-weighted image of both hips. The patient was treated nonsurgically. Ten months after onset, the pain in both hips disappeared, and plain radiographs and MRI showed no abnormalities. Subchondral insufficiency fracture should be considered in the diagnosis of patients who have hip pain after renal transplantation.

  • mri detected bone marrow changes within 3 weeks after initiation of high dose corticosteroid therapy a possible change preceding the subsequent appearance of low Intensity Band in femoral head osteonecrosis
    Rheumatology International, 2015
    Co-Authors: Yusuke Kubo, Takuaki Yamamoto, Goro Motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Nobuaki Tsukamoto, Hiroyuki Hatanaka, Takeshi Utsunomiya, Yukihide Iwamoto
    Abstract:

    Osteonecrosis of the femoral head is considered to occur early during the course of corticosteroid treatment. However, it remains unclear exactly how early it can develop after initiation of corticosteroid treatment. We report a case of osteonecrosis of the femoral head in which abnormal findings were observed on short-tau inversion recovery (STIR) sequence image performed 2 weeks and 4 days after initiation of high-dose corticosteroid therapy. A 45-year-old man with hemophagocytic syndrome was started on prednisolone, with a maximum dose of 40 mg/day. On day 13 after initiation of this corticosteroid therapy, he transiently experienced left hip pain with no apparent cause. STIR sequence image 5 days after the onset of pain revealed high-Intensity bone marrow lesions at the femoral neck of both hips. At 3 months after initiation of corticosteroid therapy, T1-weighted magnetic resonance imaging revealed concave-shaped low-Intensity Bands, which corresponded to the preceding high-Intensity lesions on both hips. Because of the subsequent progression to collapse of the left femoral head, he underwent prosthetic replacement surgery. The high-Intensity lesions on STIR sequence image indicate the possibility that osteonecrosis can occur within 3 weeks after initiation of high-dose corticosteroid therapy.

  • PROGNOSTIC FACTORS ASSOCIATED WITH A SUBCHONDRAL INSUFFICIENCY FRACTURE OF THE FEMORAL HEAD
    2012
    Co-Authors: Kenyu Iwasaki, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    Introduction Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-Intensity Band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-Intensity Band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Methods Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low Intensity Band on the T1-weighted magnetic resonance images were also examined, with regard to the Band length, Band thickness and Band length ratio; which is defined as a proportion of the Band length to the weight-bearing portion of the femoral head. Results Radiographically, a progression of the collapse was observed in 8 of 17 (47.1%) patients. The Band length in patients with progression of the collapse (mean: 22.6 mm) was significantly larger than that in those without progression of the collapse (mean: 12.3 mm; P Conclusion One of the important differential diagnoses in determining SIF may include osteonecrosis. The shape of the low signal Intensity Band on the T1-weighted MR images is one of the characteristic findings in SIF: namely, it is generally irregular, serpiginous, convex to the articular surface, and often discontinuous. This low-Intensity Band is generally surrounded by bone marrow edema. Histopathologically the Band in SIF represents the fracture line with associated repair tissue. On the other hand, in osteonecrosis, since the low-Intensity Band represents repair tissue, it is generally smooth and circumscribes all of the necrotic segments. In this study, the prognosis of SIF varied even though all the patients received similar non-operative treatments. If the prognosis for SIF can be predicted at the early stage, it would allow the design of optimal treatments in each patient. In this preliminary investigation, both the Band length and Band length ratio were demonstrated to be useful when selecting the optimal treatment for SIF.

  • a histopathological evaluation of a concave shaped low Intensity Band on t1 weighted mr images in a subchondral insufficiency fracture of the femoral head
    Skeletal Radiology, 2010
    Co-Authors: Garida Zhao, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped low-Intensity area just beneath the articular cartilage as well as a low-Intensity Band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-Intensity Band observed on the T1-weighted image.

  • Subchondral insufficiency fracture of the femoral head in younger adults.
    Skeletal radiology, 2006
    Co-Authors: Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    We report two cases of subchondral insufficiency fracture of the femoral head observed in younger adults without any history of overexertion. In both cases, MRI revealed an irregular, discontinuous low-Intensity Band on the T1-weighted images. Both patients were treated operatively, and histological examination confirmed the diagnosis of subchondral fracture. A diagnosis of subchondral insufficiency fracture needs to be put in as one of the diagnoses in younger patients with a hip pain.

Takuaki Yamamoto - One of the best experts on this subject based on the ideXlab platform.

  • Bilateral subchondral insufficiency fracture of the femoral head after renal transplantation: A case report
    Arthritis & Rheumatism, 2020
    Co-Authors: Satoshi Ikemura, Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    This report describes the case of a 47-year-old woman who was found to have subchondral insufficiency fractures in both femoral heads after renal transplantation. Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-Intensity Band on the T1-weighted image of both hips. The patient was treated nonsurgically. Ten months after onset, the pain in both hips disappeared, and plain radiographs and MRI showed no abnormalities. Subchondral insufficiency fracture should be considered in the diagnosis of patients who have hip pain after renal transplantation.

  • Computed tomography findings of subchondral insufficiency fractures of the femoral head
    Journal of orthopaedics, 2018
    Co-Authors: Kenyu Iwasaki, Takuaki Yamamoto, Goro Motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yusuke Kubo, Yasuharu Nakashima
    Abstract:

    Abstract Objectives The objective of this study was to describe the appearance of Subchondral insufficiency fracture (SIF) by computed tomography (CT). Methods Images of 52 consecutive patients diagnosed with SIF were retrospectively reviewed. CT was available for five patients (7 cases). Results Corresponding to a low-Intensity Band on MR images, a radiolucent or sclerotic Band was observed on CT images. Conclusion The present study is the first to report CT findings of SIF. A radiolucent or sclerotic Band was observed on CT images. The results of the present study provide useful information for diagnosis of SIF.

  • mri detected bone marrow changes within 3 weeks after initiation of high dose corticosteroid therapy a possible change preceding the subsequent appearance of low Intensity Band in femoral head osteonecrosis
    Rheumatology International, 2015
    Co-Authors: Yusuke Kubo, Takuaki Yamamoto, Goro Motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Nobuaki Tsukamoto, Hiroyuki Hatanaka, Takeshi Utsunomiya, Yukihide Iwamoto
    Abstract:

    Osteonecrosis of the femoral head is considered to occur early during the course of corticosteroid treatment. However, it remains unclear exactly how early it can develop after initiation of corticosteroid treatment. We report a case of osteonecrosis of the femoral head in which abnormal findings were observed on short-tau inversion recovery (STIR) sequence image performed 2 weeks and 4 days after initiation of high-dose corticosteroid therapy. A 45-year-old man with hemophagocytic syndrome was started on prednisolone, with a maximum dose of 40 mg/day. On day 13 after initiation of this corticosteroid therapy, he transiently experienced left hip pain with no apparent cause. STIR sequence image 5 days after the onset of pain revealed high-Intensity bone marrow lesions at the femoral neck of both hips. At 3 months after initiation of corticosteroid therapy, T1-weighted magnetic resonance imaging revealed concave-shaped low-Intensity Bands, which corresponded to the preceding high-Intensity lesions on both hips. Because of the subsequent progression to collapse of the left femoral head, he underwent prosthetic replacement surgery. The high-Intensity lesions on STIR sequence image indicate the possibility that osteonecrosis can occur within 3 weeks after initiation of high-dose corticosteroid therapy.

  • Subchondral Insufficiency Fractures of the Femoral Head
    Clinics in Orthopedic Surgery, 2012
    Co-Authors: Takuaki Yamamoto
    Abstract:

    A subchondral insufficiency fracture (SIF) of the femoral head is a recently proposed concept, which needs to be differentiated from osteonecrosis. Clinically, SIF has generally been observed in the osteoporotic elderly women or renal transplant recipients. Radiographical changes are not obvious in its early phase, however, some cases undergo subchondral collapse (crescent sign). On the T1-weighted magnetic resonance images, a low Intensity Band is one of the characteristic imaging appearances, which corresponds histologically to the fracture line and associated fracture repair tissue. Therefore, the shape of the low Intensity Band generally tends to be irregular, disconnected, and convex to the articular surface. The prognosis of SIF is not clearly established. Some cases show resolution of the symptoms by the conservative treatments, while other cases show rapid progression of the collapse such as rapidly progressive arthrosis of the hip.

  • PROGNOSTIC FACTORS ASSOCIATED WITH A SUBCHONDRAL INSUFFICIENCY FRACTURE OF THE FEMORAL HEAD
    2012
    Co-Authors: Kenyu Iwasaki, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    Introduction Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-Intensity Band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-Intensity Band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Methods Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low Intensity Band on the T1-weighted magnetic resonance images were also examined, with regard to the Band length, Band thickness and Band length ratio; which is defined as a proportion of the Band length to the weight-bearing portion of the femoral head. Results Radiographically, a progression of the collapse was observed in 8 of 17 (47.1%) patients. The Band length in patients with progression of the collapse (mean: 22.6 mm) was significantly larger than that in those without progression of the collapse (mean: 12.3 mm; P Conclusion One of the important differential diagnoses in determining SIF may include osteonecrosis. The shape of the low signal Intensity Band on the T1-weighted MR images is one of the characteristic findings in SIF: namely, it is generally irregular, serpiginous, convex to the articular surface, and often discontinuous. This low-Intensity Band is generally surrounded by bone marrow edema. Histopathologically the Band in SIF represents the fracture line with associated repair tissue. On the other hand, in osteonecrosis, since the low-Intensity Band represents repair tissue, it is generally smooth and circumscribes all of the necrotic segments. In this study, the prognosis of SIF varied even though all the patients received similar non-operative treatments. If the prognosis for SIF can be predicted at the early stage, it would allow the design of optimal treatments in each patient. In this preliminary investigation, both the Band length and Band length ratio were demonstrated to be useful when selecting the optimal treatment for SIF.

Hironobu Nakamura - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic MR imaging for extraserosal invasion of advanced gastric cancer
    Abdominal Imaging, 1997
    Co-Authors: H. Oi, Masaki Matsushita, T. Murakami, Hironobu Nakamura
    Abstract:

    Dynamic magnetic resonance (MR) images in 37 patients with gastric cancers were obtained by a two-dimensional fast multiplanar spoiled gradient technique. The degree of tumor invasion was classified into four grades regarding a low-Intensity Band between the stomach and surrounding fat. Advanced gastric cancer was strongly enhanced, appearing as a thickened wall, by the contrast medium during the early to delayed phases of dynamic studies. The extent of invasion of the adjacent organs was diagnosed by the difference in enhancement between the tumor and the parenchyma. The sensitivity of extraserosal invasion was 93%. Dynamic MR diagnosis is useful for evaluating the extent of gastric carcinoma.

  • Extraserosal invasion in advanced gastric cancer: evaluation with MR imaging.
    Radiology, 1994
    Co-Authors: Masaki Matsushita, Takamichi Murakami, H. Oi, Hironobu Nakamura, Naoki Takata, H Kishimoto, Shigeru Okamoto, Jun Okamura
    Abstract:

    PURPOSE: To evaluate the usefulness of magnetic resonance (MR) imaging in the diagnosis of extraserosal invasion in advanced gastric cancer. MATERIALS AND METHODS: MR imaging was performed in 48 patients with advanced gastric cancer, and the results were correlated with the histopathologic findings. Images perpendicular to the gastric wall with cancer were obtained with spoiled gradient-recalled acquisition in the steady state (GRASS). The degree of serosal invasion was classified on the basis of the appearance of a low-signal-Intensity Band around the lesion. RESULTS: Advanced gastric cancer appeared as a thickened wall of high signal Intensity after the administration of contrast material. A low-signal-Intensity Band disappeared or showed irregularity in the area of extraserosal invasion by the gastric cancer. The MR imaging-determined grade correlated with the histopathologic findings for 11 of 14 (79%) pT2 tumors, 23 of 24 (96%) pT3 tumors, and eight of 10 (80%) pT4 tumors. The overall accuracy was 88...

  • Appearance of low Intensity Band seen around the abdominal organs on gradient echo image
    Nihon Igaku Hōshasen Gakkai zasshi. Nippon acta radiologica, 1993
    Co-Authors: Takamichi Murakami, Matushita M, Hideji Igarashi, H. Oi, Hideya Yamazaki, Hironobu Nakamura, Takahiro Kozuka
    Abstract:

    To clarify the mechanism of appearance of low Intensity Band seen around the abdominal organ, we performed phantom study. The resected intestine, which filled with water and fixed in the salad oil, was obtained by spoiled GRASS MR imaging with variable TEs and fixed TR. On in phase image, low Intensity Band was seen in low frequency side of frequency encoding direction of surface of the intestine, and high Intensity Band in high frequency side. On out of phase image, low Intensity Band is seen all around the intestine. Our phantom study verified that the appearance of low Intensity Band on out of phase gradient echo image is due to both the misregistration and signal void caused by chemical shift artifact.

  • MR imaging evaluation of plica synoviallis mediopatellaris of the knee joint
    Nihon Igaku Hōshasen Gakkai zasshi. Nippon acta radiologica, 1992
    Co-Authors: Katsuyuki Nakanishi, Takamichi Murakami, Inoue M, Kyo Tsuda, Mitani T, Hashimoto T, Maeshima S, Kaname Tomoda, Shinichi Hori, Hironobu Nakamura
    Abstract:

    To evaluate the diagnostic ability of MR imaging for plica synoviallis mediopatellaris (PSM), we retrospectively reviewed the MR imaging findings of patellofemoral space in 20 knee joints of 11 patients. In all 20 knee joints, arthroscopy and MR imaging were available. MR imaging was performed with a 1.5 Tesla Magnetom (Siemens) using a round surface coil. Pulse sequences were SE (TR 600 ms/TE 26 ms), SE (TR 200 ms/TE 26, 70 ms) and FLASH (TR 450 ms/TE 15 ms/FA 90 degrees). In six of the 20 knees with PSM proved by arthroscopy, a low Intensity Band was shown above the medial condyle of the femur on both T1- and T2-weighted MR images, and on FLASH images this Band was shown as intermediate Intensity. In the other 14 knees with no PSM observed by arthroscopy, the low Intensity Band was not shown on MR imaging. In all 20 knees, a similar low Intensity Band was shown about 1 cm cranial to the medial condyle of the femur. This should not be diagnosed as PSM. The low Intensity Band seen on T1- and T2-weighted MR images and its anatomical relation to the medial condyle are important in diagnosing PSM.

Satoshi Ikemura - One of the best experts on this subject based on the ideXlab platform.

  • Bilateral subchondral insufficiency fracture of the femoral head after renal transplantation: A case report
    Arthritis & Rheumatism, 2020
    Co-Authors: Satoshi Ikemura, Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    This report describes the case of a 47-year-old woman who was found to have subchondral insufficiency fractures in both femoral heads after renal transplantation. Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-Intensity Band on the T1-weighted image of both hips. The patient was treated nonsurgically. Ten months after onset, the pain in both hips disappeared, and plain radiographs and MRI showed no abnormalities. Subchondral insufficiency fracture should be considered in the diagnosis of patients who have hip pain after renal transplantation.

  • The depth of the low-Intensity Band on the T1-weighted MR image is useful for distinguishing subchondral insufficiency fracture from osteonecrosis of the collapsed femoral head.
    Archives of Orthopaedic and Trauma Surgery, 2018
    Co-Authors: Satoshi Ikemura, Taro Mawatari, Matsui, Takahiro Iguchi, Hiroaki Mitsuyasu
    Abstract:

    Purpose To verify the hypothesis that depth of the low-Intensity Band on T1-weighted MR image is useful for distinguishing subchondral insufficiency fracture (SIF) from osteonecrosis of the collapsed femoral head (ON).

  • Subchondral insufficiency fracture of the femoral head: a report of two cases with a history of internal fixation of a femoral neck fracture
    Skeletal Radiology, 2013
    Co-Authors: Satoshi Ikemura, Toshihiko Hara, Tetsuro Nakamura, Kuniyoshi Tsuchiya
    Abstract:

    We report our experience in two cases of subchondral insufficiency fracture of the femoral head with a history of internal fixation of the femoral neck fracture. Both cases were young females (26 and 43 years old, respectively). Their hip pain occurred more than 2 years and 1 year after the primary surgical treatment, respectively. MRI revealed bone marrow edema pattern, as well as a low-Intensity Band on the T1-weighted images, which are commonly observed in osteonecrosis. However, the low-Intensity Bands were parallel to the subchondral bone end-plate, which are characteristic findings of subchondral insufficiency fracture. Both patients were administered anti-inflammatory drugs and/or bisphosphonate. One patient underwent a transtrochanteric curved varus osteotomy 1 year and 9 months after the onset, and the other healed without collapse of the femoral head. Our cases indicate that subchondral insufficiency fractures may need to be considered as one of the possible conditions after the internal fixation of a femoral neck fracture, in addition to posttraumatic osteonecrosis.

  • PROGNOSTIC FACTORS ASSOCIATED WITH A SUBCHONDRAL INSUFFICIENCY FRACTURE OF THE FEMORAL HEAD
    2012
    Co-Authors: Kenyu Iwasaki, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    Introduction Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-Intensity Band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-Intensity Band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Methods Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low Intensity Band on the T1-weighted magnetic resonance images were also examined, with regard to the Band length, Band thickness and Band length ratio; which is defined as a proportion of the Band length to the weight-bearing portion of the femoral head. Results Radiographically, a progression of the collapse was observed in 8 of 17 (47.1%) patients. The Band length in patients with progression of the collapse (mean: 22.6 mm) was significantly larger than that in those without progression of the collapse (mean: 12.3 mm; P Conclusion One of the important differential diagnoses in determining SIF may include osteonecrosis. The shape of the low signal Intensity Band on the T1-weighted MR images is one of the characteristic findings in SIF: namely, it is generally irregular, serpiginous, convex to the articular surface, and often discontinuous. This low-Intensity Band is generally surrounded by bone marrow edema. Histopathologically the Band in SIF represents the fracture line with associated repair tissue. On the other hand, in osteonecrosis, since the low-Intensity Band represents repair tissue, it is generally smooth and circumscribes all of the necrotic segments. In this study, the prognosis of SIF varied even though all the patients received similar non-operative treatments. If the prognosis for SIF can be predicted at the early stage, it would allow the design of optimal treatments in each patient. In this preliminary investigation, both the Band length and Band length ratio were demonstrated to be useful when selecting the optimal treatment for SIF.

  • a histopathological evaluation of a concave shaped low Intensity Band on t1 weighted mr images in a subchondral insufficiency fracture of the femoral head
    Skeletal Radiology, 2010
    Co-Authors: Garida Zhao, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped low-Intensity area just beneath the articular cartilage as well as a low-Intensity Band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-Intensity Band observed on the T1-weighted image.

Yasuharu Nakashima - One of the best experts on this subject based on the ideXlab platform.

  • Bilateral subchondral insufficiency fracture of the femoral head after renal transplantation: A case report
    Arthritis & Rheumatism, 2020
    Co-Authors: Satoshi Ikemura, Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    This report describes the case of a 47-year-old woman who was found to have subchondral insufficiency fractures in both femoral heads after renal transplantation. Initially, plain radiographs showed no obvious changes, but magnetic resonance imaging (MRI) revealed an irregular, discontinuous, low-Intensity Band on the T1-weighted image of both hips. The patient was treated nonsurgically. Ten months after onset, the pain in both hips disappeared, and plain radiographs and MRI showed no abnormalities. Subchondral insufficiency fracture should be considered in the diagnosis of patients who have hip pain after renal transplantation.

  • Computed tomography findings of subchondral insufficiency fractures of the femoral head
    Journal of orthopaedics, 2018
    Co-Authors: Kenyu Iwasaki, Takuaki Yamamoto, Goro Motomura, Kazuyuki Karasuyama, Kazuhiko Sonoda, Yusuke Kubo, Yasuharu Nakashima
    Abstract:

    Abstract Objectives The objective of this study was to describe the appearance of Subchondral insufficiency fracture (SIF) by computed tomography (CT). Methods Images of 52 consecutive patients diagnosed with SIF were retrospectively reviewed. CT was available for five patients (7 cases). Results Corresponding to a low-Intensity Band on MR images, a radiolucent or sclerotic Band was observed on CT images. Conclusion The present study is the first to report CT findings of SIF. A radiolucent or sclerotic Band was observed on CT images. The results of the present study provide useful information for diagnosis of SIF.

  • PROGNOSTIC FACTORS ASSOCIATED WITH A SUBCHONDRAL INSUFFICIENCY FRACTURE OF THE FEMORAL HEAD
    2012
    Co-Authors: Kenyu Iwasaki, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    Introduction Subchondral insufficiency fracture of the femoral head (SIF) often occurs in osteoporotic elderly patients. Patients usually suffer from acute hip pain without any obvious antecedent trauma. Radiologically, a subchondral fracture is seen mainly in the superolateral portion of the femoral head. The T1-weighted magnetic resonance (MR) images show a low-Intensity Band in the subchondral area of the femoral head, which tends to be irregular, disconnected, and convex to the articular surface. This low-Intensity Band in SIF was histologically proven to correspond to the fracture line with associated repair tissue. Some cases of SIF resolve after conservative treatment, while others progress until collapse, thereby requiring surgical treatment. The prognosis of SIF remains unclear. This study investigated the risk factors that influence the prognosis of SIF based on the progression of the collapse. Methods Between June 2002 and June 2008, seventeen patients diagnosed as SIF were included in this study. Sequential radiographs were evaluated for the presence of progression of the collapse. The clinical profiles, including the age, body mass index (BMI), follow-up period and Singh index were examined. The morphological characteristics of the low Intensity Band on the T1-weighted magnetic resonance images were also examined, with regard to the Band length, Band thickness and Band length ratio; which is defined as a proportion of the Band length to the weight-bearing portion of the femoral head. Results Radiographically, a progression of the collapse was observed in 8 of 17 (47.1%) patients. The Band length in patients with progression of the collapse (mean: 22.6 mm) was significantly larger than that in those without progression of the collapse (mean: 12.3 mm; P Conclusion One of the important differential diagnoses in determining SIF may include osteonecrosis. The shape of the low signal Intensity Band on the T1-weighted MR images is one of the characteristic findings in SIF: namely, it is generally irregular, serpiginous, convex to the articular surface, and often discontinuous. This low-Intensity Band is generally surrounded by bone marrow edema. Histopathologically the Band in SIF represents the fracture line with associated repair tissue. On the other hand, in osteonecrosis, since the low-Intensity Band represents repair tissue, it is generally smooth and circumscribes all of the necrotic segments. In this study, the prognosis of SIF varied even though all the patients received similar non-operative treatments. If the prognosis for SIF can be predicted at the early stage, it would allow the design of optimal treatments in each patient. In this preliminary investigation, both the Band length and Band length ratio were demonstrated to be useful when selecting the optimal treatment for SIF.

  • a histopathological evaluation of a concave shaped low Intensity Band on t1 weighted mr images in a subchondral insufficiency fracture of the femoral head
    Skeletal Radiology, 2010
    Co-Authors: Garida Zhao, Satoshi Ikemura, Taro Mawatari, Takuaki Yamamoto, Yasuharu Nakashima, Goro Motomura, Yukihide Iwamoto
    Abstract:

    A 73-year-old female suffered from right hip pain without any history of antecedent trauma. The initial radiograph showed a slight narrowing of the joint space in the right hip. The patient was treated by non-weight bearing for 5 weeks. Radiographs obtained 3 months after the onset of pain showed the progression of both the joint-space narrowing and subchondral collapse at the superior portion. T1-weighted MR (magnetic resonance) images obtained 3 months after the onset revealed an irregular-shaped low-Intensity area just beneath the articular cartilage as well as a low-Intensity Band, which was concave to the articular surface. A total hip replacement was performed. A histopathological examination revealed fracture callus and granulation tissue in the subchondral area. This subchondral fractured area was surrounded by vascular rich granulation tissue and fibrous tissue, which corresponded to the concave-shaped low-Intensity Band observed on the T1-weighted image.

  • Subchondral insufficiency fracture of the femoral head in younger adults.
    Skeletal radiology, 2006
    Co-Authors: Takuaki Yamamoto, Yasuharu Nakashima, Toshihide Shuto, Seiya Jingushi, Yukihide Iwamoto
    Abstract:

    We report two cases of subchondral insufficiency fracture of the femoral head observed in younger adults without any history of overexertion. In both cases, MRI revealed an irregular, discontinuous low-Intensity Band on the T1-weighted images. Both patients were treated operatively, and histological examination confirmed the diagnosis of subchondral fracture. A diagnosis of subchondral insufficiency fracture needs to be put in as one of the diagnoses in younger patients with a hip pain.