Masakazu Fujii

Publications (10)18.83 Total impact

• Article: In vivo kinematics of high-flex mobile-bearing total knee arthroplasty, with a new post-cam design, in deep knee bending motion.

  Masahiro Kurita, Tetsuya Tomita, Takaharu Yamazaki, Masakazu Fujii, Kazuma Futai, Norimasa Shimizu, Hideki Yoshikawa, Kazuomi Sugamoto
  [show abstract] [hide abstract]
  ABSTRACT: PURPOSE: The objective of this study was to evaluate the in vivo knee kinematics to assess the available functional motion of the characteristic mobile-bearing prosthesis design and to examine whether the artificial joint would work in vivo according to its design concept. METHODS: We studied 14 knees (11 patients) implanted with the Vanguard RP Hi-Flex prosthesis. This prosthesis has a highly original form of post-cam called a PS saddle design with high compatibility, and with a rotating plate mobile-bearing mechanism. The cylinder-type post-cam is designed to enable contact in early flexion ranges, and to prevent paradoxical anterior femoral component movement. Each patient performed weight-bearing deep knee bending under fluoroscopic surveillance. Motion between each component including the polyethylene insert was analyzed using the 2D/3D registration technique. RESULTS: The mean range of motion was 122.0°. The mean femoral component rotation for the tibial tray was 5.0°. No paradoxical anterior movement of the nearest point was confirmed between the femoral component and the tibial tray in the early flexion ranges. Initial contact of the post-cam was confirmed at a knee flexion angle of 33.8°. Subsequently, the wide contact of the post-cam was maintained until flexion reached 120° in all knees, but disengagement of the post-cam was observed in two knees when flexion was ≥130°. CONCLUSIONS: The results of this study demonstrated that the prosthesis design generally works in vivo as intended by its design concept. The present kinematic data may provide useful information for improvement of high-flex type prostheses.
  International Orthopaedics 10/2012; · 2.03 Impact Factor
• Article: Effect of posterior design changes on postoperative flexion angle in cruciate retaining mobile-bearing total knee arthroplasty.

  Shigeyoshi Tsuji, Tetsuya Tomita, Hideo Hashimoto, Masakazu Fujii, Hideki Yoshikawa, Kazuomi Sugamoto
  [show abstract] [hide abstract]
  ABSTRACT: The Dual Bearing Knee (DBK) prosthesis is a new concept which has a mobile-bearing insert. In May 2001, the posterior femoral condyle design of the DBK was changed to become smaller and there was a posterior shift in the base of the insert dish (Hi-Flex). Between 1998 and 2004, 371 DBKs (112 Hi-Flex and 220 Standard) were performed by one surgical team. There was a significant difference in postoperative flexion angle between the Hi-Flex and Standard DBKs (117.0° and 111.3°; p = 0.001). The delta flexion angle in the Hi-Flex (-2.4°) was significantly increased compared with that in the Standard DBK (-9.6°) (p = 0.001). In the Hi-Flex DBK, the postoperative flexion angle (5.7°) and the delta flexion angle (7.2°) were significantly larger than for the Standard DBK (p < 0.001). These results suggest that the flexion is greater for a design with smaller posterior condyle prosthesis and with a posterior shift in the base of the insert dish in CR mobile-bearing TKA.
  International Orthopaedics 05/2011; 35(5):689-95. · 2.03 Impact Factor
• Article: Recurrent allergic bronchopulmonary aspergillosis in a patient with rheumatoid arthritis treated with etanercept and tocilizumab.

  Hidehiro Honda, Hiroshi Kida, Mitsuhiro Yoshida, Tetsuya Tomita, Masakazu Fujii, Shoichi Ihara, Sho Goya, Isao Tachibana, Ichiro Kawase
  [show abstract] [hide abstract]
  ABSTRACT: We report the case of a 68-year-old woman with Stage III and Class II rheumatoid arthritis (RA) that was resistant to prednisolone, methotrexate, and infliximab. After treatment with etanercept or tocilizumab, suspicious allergic bronchopulmonary aspergillosis (ABPA) repeatedly occurred and then rapidly improved after the withdrawal of each drug. We suspect that administration of etanercept and tocilizumab caused suspicious ABPA in this patient. The relevance to the pathogenesis of ABPA under these biological drugs is also discussed.
  Modern Rheumatology 04/2011; 21(6):660-4. · 1.58 Impact Factor
• Article: Is minimally invasive surgery-total knee arthroplasty truly less invasive than standard total knee arthroplasty? A quantitative evaluation.

  Shigeyoshi Tsuji, Tetsuya Tomita, Masakazu Fujii, Richard S Laskin, Hideki Yoshikawa, Kazuomi Sugamoto
  [show abstract] [hide abstract]
  ABSTRACT: With recent technical advancements, the number of operative manipulations in the knee joint by minimally invasive surgery-total knee arthroplasty (MIS-TKA) is now considered to be the same as that using standard TKA (S-TKA). The question still remains, however, if MIS-TKA improves recovery compared to S-TKA. We compared MIS-TKA and S-TKA patients' physical activity as measured by an accelerometer. Physical activity expressed as cumulative acceleration was significantly higher in the MIS-TKA than in the S-TKA group on postoperative days (POD1, 2, 3, 4, 5, 10, 11) (P < .05). The recovery time, defined as the number of days required to achieve cumulative acceleration of 80% of the preoperative level, was significantly shorter (P < .05) in the MIS-TKA (3.0 +/- 3.3 days) group than in the S-TKA (7.0 +/- 3.5 days) group. Minimally invasive surgery-total knee arthroplasty appears to allow an earlier recovery after the operation than S-TKA. Less invasion to muscle during the surgery appears to contribute to shorter convalescence.
  The Journal of arthroplasty 09/2009; 25(6):970-6. · 1.79 Impact Factor
• Article: Use of hydroxyapatite ceramics for treatment of nonunited osseous defect after open fracture of lower limbs.

  Takanobu Nakase, Masakazu Fujii, Akira Myoui, Noriyuki Tamai, Yasuhisa Hayaishi, Takafumi Ueda, Masayuki Hamada, Hideo Kawai, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: Osseous defects in nonunited open fracture of the lower limbs are difficult to treat. Autogenous bone grafting is a promising treatment options, but a finite amount of autogenous bone graft is available from each individual and donor site morbidity remains a problem. These limitations have prompted the development and use of synthetic biomaterials such as hydroxyapatite (HA) ceramics. However, little information is available regarding the challenging cases such as nonunited open fractures The purpose of the present study is to evaluate the outcomes associated with the treatment of osseous defects in nonunited open fracture using novel HA ceramics. Twelve bones (4 femora and 8 tibias) in 11 patients (10 men and 1 woman), with an average age of 49.1 (range 19-71) years, with nonunited osseous defects after open fracture were treated by the grafting of HA ceramics alone or with autogenous iliac bone followed by internal or external fixation. The patients were followed for an average of 25.2 months in average (range 10.3 -58.1 months). Finally, 11 of 12 fractures united clinically and radiographically, while one fracture required a second procedure for additional autogenous iliac bone grafting. The average time to union from the index surgery was 5.6 months (median 5.3 months, range 2.3-11 months.). Radiographs showed good incorporation of grafted HA into the host bone in most of the united cases. As a complication, transient wound drainage was found in two cases. The current protocol using the HA ceramics appears to be safe and efficacious for the treatment of osseous defects after the open fractures.
  Archives of Orthopaedic and Trauma Surgery 07/2009; 129(11):1539-47. · 1.37 Impact Factor
• Article: Treatment of juxta-articular intraosseous cystic lesions in rheumatoid arthritis patients with interconnected porous calcium hydroxyapatite ceramic.

  Kohji Kuriyama, Jun Hashimoto, Tsuyoshi Murase, Masakazu Fujii, Akihide Nampei, Makoto Hirao, Hideki Tsuboi, Akira Myoui, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: In patients with rheumatoid arthritis (RA), juxta-articular intraosseous cystic lesions may cause spontaneous pathological fractures. The outcome of curettage and the packing of such lesions with interconnected porous calcium hydroxyapatite ceramic (IP-CHA) was investigated. Twelve lesions were treated in ten RA patients (three men and seven women with a mean age of 59 years). Ten lesions were associated with impending pathological fracture involving the articular surface. In all patients, curettage and packing of the bone cavity with IP-CHA were done. Assessment was based on final radiographs obtained an average of 30 months after surgery (range 10-47 months). Absorption of the implanted IP-CHA, expansion of the lesion, implant incorporation into host bone, and postoperative fractures were investigated. At final follow-up, there was no absorption of the implanted IP-CHA in any of the lesions. Expansion of the radiolucent area was only noted in one lesion. Seven of the other 11 lesions showed major incorporation of IP-CHA into host bone, while minor incorporation was seen in four lesions. There were no postoperative fractures. In conclusion, curettage and packing with IP-CHA is a feasible method of preventing pathological fracture due to juxta-articular intraosseous cystic lesions in RA patients.
  Modern Rheumatology 02/2009; 19(2):180-6. · 1.58 Impact Factor
• Article: Total ankle replacement in rheumatoid arthritis.

  Masataka Nishikawa, Tetsuya Tomita, Masakazu Fujii, Tetsu Watanabe, Jun Hashimoto, Kazuomi Sugamoto, Takahiro Ochi, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: We reviewed 21 patients with rheumatoid arthritis who had a total ankle replacement between 1984 and 2000. The average follow-up was 72 (15-169) months. Clinical results were evaluated using the American Orthopaedic Foot and Ankle Society (AOFAS) score. At the latest review, three ankles had been revised. Two ankles were excellent, seven good, three fair, and 12 poor. Eleven patients with 13 ankles had residual pain, with radiographs showing a high incidence of radiolucent lines. Migration of the tibial component was seen in 13 ankles and collapse of talus in nine. Although clinical results were poor, patient satisfaction was not.
  International Orthopaedics 05/2004; 28(2):123-6. · 2.03 Impact Factor
• Article: The value and limitation of gadopentetate-enhanced magnetic resonance imaging in detecting the condition of anterior cruciate ligament in rheumatoid knee: comparative study with histology.

  Masakazu Fujii, Tetsuya Tomita, Katsuyuki Nakanishi, Motoharu Kaneko, Kenji Hayashida, Kazuomi Sugamoto, Takahiro Ochi, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: The aim of this study was to elucidate the utility and limitation of gadopentetate (Gd)-enhanced MRI as a method for evaluating the anterior cruciate ligament (ACL) in the rheumatoid arthritis (RA) knee, using both surgical macro findings and histological findings to ascertain the pathological condition of the affected knee. Thirty-six knees of 25 RA patients were studied in this study. Four imaging protocols were employed: protocol A, T1-weighted and T2-weighted sagittal images; protocol B, T1-weighted sagittal image, after infusion of Gd-DTPA (0.2 mmol/kg, i.v.); protocol C, T1-weighted angled coronal image, parallel to the ACL; and protocol D, T1-weighted angled coronal image, parallel to the ACL, after infusion of Gd-DTPA. Sagittal image was determined as previously described. Angle coronal image was newly determined as coronal image parallel to the ACL. Surgical and MRI findings of the ACL were classified into four types: Type I (normal group) indicated that the thickness of the ACL was almost normal, adequate tension was maintained (surgical findings),and the ACL had thick and a more complex appearance with a homogeneous signal intensity and well-defined borders (MRI findings). Type II (degenerated group): the ACL had degenerated and tension was reduced (surgical findings), and the ACL had thin and a more complex appearance with a less homogeneous signal intensity and less well-defined borders. This appearance was more evident on Type II than Type I (MRI findings). Type III (ruptured group): the parenchyma of the ACL remained but lacked continuity (surgical findings), and the ACL appeared as partial lack of low signal intensity (MRI findings). Type IV (absent group): the parenchyma of the ACL was practically absent (surgical findings), and the ACL appeared as complete lack of signal low signal intensity (MRI findings). The concordance rate between surgical and MRI findings was investigated. Moreover, we investigated the extent to which histological changes of the ACL could be discriminated using MRI. In RA knees, the overall concordance rate between surgical and MRI findings was 41.7% under imaging protocol A. The overall rate improved up to 69.4% under imaging protocol B. But the overall rate dropped to 36.1% under imaging protocol C. The overall rate improved up to 83.3% under imaging protocol D. Especially, significant differences between imaging protocols A and B ( p<0.05), and imaging protocols C and D ( p<0.01), with respect to ACL degenerated group, were recognized. But significant differences between imaging protocols A and C, and imaging protocols B and D, with respect to ACL degenerated group, were not recognized. The concordance rate between histological and MRI findings was 41.7% in ACL normal group, and 61.5% in ACL degenerated group. The concordance rate between surgical and MRI findings was 100% in ACL normal group, and 78.9% in ACL degenerated group. There was a significant difference in the concordance rates between histological, surgical, and MRI findings in normal group ( p<0.05). The results of this study suggested that with Gd-enhanced MRI, the degree of synovial proliferation around the ACL and the degree of degradation of the ACL in the RA knee can be evaluated more accurately than with conventional MRI; however, in RA knees with severe synovial proliferation, it may be difficult to discriminate between the invasive synovium going into the ligament from synovium surrounding the ligament. This may be a limitation of Gd-enhanced MRI at present. In the clinical setting, the present imaging technique does allow the ligament to be evaluated to a certain degree, and may prove useful in the evaluation of temporal changes in the RA knee.
  European Radiology 07/2003; 13(7):1728-34. · 3.22 Impact Factor
• Article: Periprosthetic fracture of the tibia associated with osteolysis caused by failure of rotating patella in low-contact-stress total knee arthroplasty.

  Tetsu Watanabe, Tetsuya Tomita, Masakazu Fujii, Motoharu Kaneko, Hironobu Sakaura, Eiji Takeuchi, Kazuomi Sugamoto, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: Periprosthetic fracture of the tibial plateau associated with osteolysis resulting from mechanical failure of the rotating patellar component after total knee arthroplasty with the New Jersey Low-Contact-Stress (LCS) knee (DePuy, Warsaw, IN) has not been reported previously. A 67-year-old woman with rheumatoid arthritis of the left knee had a LCS prosthesis implanted without cement, using a rotating patellar component. Seven years later, a fracture of the lateral tibial plateau occurred owing to an osteolytic defect with no traumatic accident. The rotating patellar bearing over-rotated and locked; consequently, wear occurred between the patellar metal tray and the femoral component. Immunohistochemistry revealed CD68-positive macrophages in the osteolytic region and phagocytosis of metal particles. The osteolytic region was filled with autogenous bone, and all components were exchanged and cemented. The patient's condition became satisfactory with relief of pain.
  The Journal of Arthroplasty 01/2003; 17(8):1058-62. · 2.38 Impact Factor
• Article: Sciatic nerve palsy after cementless total hip arthroplasty. Treatment by modular neck and calcar shortening: a case report.

  Takashi Sakai, Nobuhiko Sugano, Masakazu Fujii, Takashi Nishii, Kenji Ohzono, Hideki Yoshikawa
  [show abstract] [hide abstract]
  ABSTRACT: This is a case report of sciatic nerve palsy after total hip arthroplasty. Although the patient's symptoms became worse postoperatively, full recovery occurred after shortening of the calcar and femoral neck length. For acute sciatic nerve palsy patients with worsening of symptoms in the postoperative course in spite of hip and knee flexion, reexposure for early recognition of the sciatic nerve condition and reoperation by shortening the femoral neck may be an option.
  Journal of Orthopaedic Science 02/2002; 7(3):400-2. · 0.84 Impact Factor