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Yasutaka Tashiro, Ken Okazaki, Yukihide Iwamoto Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan Purpose: We aimed to clarify the distance between the anteromedial (AM) bundle and posterolateral (PL) bundle tunnel-aperture centers by simulating the anatomical femoral tunnel placement during double-bundle anterior cruciate ligament reconstruction using 3-D computer-aided design models of the knee, in order to discuss the risk of tunnel overlap. Relationships between the AM to PL center distance, body height, and sex difference were also analyzed. Patients and methods: The positions of the AM and PL tunnel centers were defined based on previous studies using the quadrant method, and were superimposed anatomically onto the 3-D computer-aided design knee models from 68 intact femurs. The distance between the tunnel centers was measured using the 3-D DICOM software package. The correlation between the AM–PL distance and the subject's body height was assessed, and a cutoff height value for a higher risk of overlap of the AM and PL tunnel apertures was identified. Results: The distance between the AM and PL centers was 10.2±0.6 mm in males and 9.4±0.5 mm in females (P

Yasuharu Nakashima,1 Masakazu Kondo,2 Hisaaki Miyahara,3 Yukihide Iwamoto11Department of Orthopaedic Surgery, Kyushu University, Fukuoka, Japan; 2Kondo Clinic of Rheumatology and Orthopaedic Surgery, Fukuoka, Japan; 3Department of Orthopaedic Surgery and Rheumatology, Clinical Research Institute, National Hospital Organization Kyushu Medical Center, Fukuoka, JapanAbstract: Rheumatoid arthritis (RA) is a chronic, progressive, inflammatory disease associated with joint destruction. Tocilizumab (TCZ) is a humanized monoclonal anti-interleukin-6 receptor antibody that was initially developed for use as an intravenous (IV) infusion. Previous studies have shown that TCZ-IV is an important treatment option in patients with moderate-to-severe RA. A subcutaneous (SC) formulation of 162 mg TCZ that was recently developed and approved provides an additional treatment option for RA patients. In the present review, we provide an update on the efficacy and safety of TCZ-SC, compared with TCZ-IV. The TCZ-SC doses of 162 mg every 2 weeks (q2w) or weekly (qw) were selected based on pharmacokinetic and pharmacodynamic studies. Both TCZ-SC q2w and qw regimens showed equivalent effects to TCZ-IV in most patients; however, the TCZ-SC qw regimen consistently showed a more rapid effect in terms of C-reactive protein normalization. Randomized controlled studies showed that TCZ-SC monotherapy or combined with disease-modifying antirheumatic drugs demonstrated comparable efficacy to TCZ-IV in patients who were both biologic-naïve and refractory to tumor necrosis factor inhibitors. TCZ-SC at both qw and q2w were generally well-tolerated for up to 24 weeks. There was a low rate of withdrawal due to adverse events, and their incidence was comparable with that seen with TCZ-IV. An injection site reaction was seen in approximately 10% of patients who received the subcutaneous formulation. In conclusion, although clinical results are still limited, the currently available evidence suggests that TCZ-SC is a promising treatment for moderate-to-severe RA, both as monotherapy and combination therapy. More data is needed to determine the optimal dosing schedule.Keywords: rheumatoid arthritis, tocilizumab, subcutaneous injection, review

Yasutaka Tashiro,1 Ken Okazaki,1 Munenori Uemura,2 Kazutaka Toyoda,2 Kanji Osaki,1 Hirokazu Matsubara,1 Makoto Hashizume,2 Yukihide Iwamoto1 1Department of Orthopaedic Surgery, 2Department of Advanced Medical Initiatives, Kyushu University Hospital, Fukuoka, Japan Purpose: The purpose of this study was to assess the differences in bone tunnel apertures between the trans-accessory medial portal (trans-AMP) technique and the transtibial (TT) technique in double-bundle anterior cruciate ligament reconstruction. The extent of ovalization and the frequency of overlap of the two tunnel apertures were compared. Methods: The simulation of femoral tunnel drilling with the TT and the trans-AMP techniques was performed using three-dimensional computer aided design models from two volunteers. The incidence angle of drilling against the intercondylar wall, the femoral tunnel position, the ovalization, and the overlap were analyzed. The aperture and location of the tunnels were also examined in real anterior cruciate ligament reconstruction cases (n=36). Results: The surgical simulation showed that a lower drill incident angle induced by the TT technique made the apertures of two tunnels more ovalized, located anteromedial tunnels in a shallower position to prevent posterior wall blow out, and led to a higher frequency of tunnel overlap. The trans-AMP group had tunnel places within the footprint and had less ovalization and overlap. The results of analysis for tunnels in the clinical cases were consistent with results from the surgical simulation. Conclusion: In the TT technique, the shallow anteromedial tunnel location and more ovalized tunnel aperture can lead to a higher frequency of tunnel overlap. Compared with the TT technique, the trans-AMP technique was more useful in preparing femoral tunnels anatomically and avoiding tunnel ovalization and overlapping in double-bundle anterior cruciate ligament reconstruction. Keywords: anterior cruciate ligament, transtibial, transaccessory medial portal, computer aided design, surgical simulation, tunnel aperture

Goro Motomura1, Takuaki Yamamoto1, Sanshiro Inoue2, Yasuharu Nakashima1, Taro Mawatari1, Yukihide Iwamoto11Department of Orthopaedic Surgery, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan; 2Department of Orthopaedic Surgery, Miyazaki Prefectural Miyazaki Hospital, Miyazaki, JapanAbstract: Infected nonunion of the transtrochanteric osteotomy site is an uncommon complication of transtrochanteric anterior rotational osteotomy. A 45-year-old male underwent anterior rotational osteotomy for osteonecrosis of the left femoral head. A radiograph obtained 4 months after surgery showed the presence of osteolytic lesions around the trochanteric wire, and the transtrochanteric osteotomy site appeared to be fuzzy. In spite of the continuation of partial weight bearing, osteolytic changes progressed. An open biopsy was performed 13 months after surgery. Samples were taken from multiple sites, including osteolytic lesions, one of which was confirmed to contain coagulase-negative staphylococcus. Nineteen days after performing thorough debridement and irrigation, the patient underwent a refixation of the osteotomy site using an iliac bone graft and a sliding hip screw system. A radiograph obtained at the final follow-up revealed bone union at the site of osteotomy.Keywords: osteonecrosis, infected nonunion, osteotomy

Radiation monitoring at high energy proton accelerators poses a considerable challenge due to the complexity of the encountered stray radiation fields. These environments comprise a wide variety of different particle types and span from fractions of electron-volts up to several terra electron-volts. As a consequence the use of Monte Carlo simulation programs like FLUKA is indispensable to obtain appropriate field-specific calibration factors. At many locations of the LHC a large contribution to the particle fluence is expected to originate from high-energy neutrons and thus, benchmark experiments with mono-energetic neutron beams are of high importance to verify the aforementioned detector response calculations. This paper summarizes the results of a series of benchmark experiments with quasi mono-energetic neutrons of 100, 140, 200, 250 and 392 MeV that have been carried out at RCNP - Osaka University, during several campaigns between 2006 and 2014.