Kiyota, Yasuhiro



School of Medicine, Department of Orthopaedic Surgery (Shinanomachi)




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  • Normal values and ranges of the lateral capitello-humeral angle in healthy children

    Kiyota Y., Suzuki T., Inaba N., Nishiwaki M., Kimura H., Matsumura N., Sato K., Nakamura M., Matsumoto M., Iwamoto T.

    Journal of Pediatric Orthopaedics Part B (Journal of Pediatric Orthopaedics Part B)  30 ( 4 ) 381 - 384 2021.07

    ISSN  1060152X

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    The lateral capitello-humeral angle (LCHA), which is an index of sagittal alignment of the elbow, has gradually been adopted for the postoperative assessment of radiographic results. However, the normal values and ranges of the LCHA remain unclear. A retrospective cohort study was performed to evaluate the normal values and ranges of the LCHA in a sample of healthy children with even distributions of age, sex and laterality. A total of 168 radiographs of the elbows of healthy children (age range, 0–11 years) with even distributions of age, sex and laterality were reviewed. The primary aim was to analyze the normal values and ranges of the LCHA categorized by age, sex and laterality. The secondary aim was to assess the association of the LCHA with increasing age. The LCHA between sex or laterality in each age category was also compared. The mean LCHA of the 168 patients was 47.1º(range, 27º–63º). There was a weak association between the LCHA and increasing age (r = 0.41). The mean LCHA in females (49.1º) was significantly larger than that in males (45.1º). Significant sex-related differences were observed in age categories between 2 and 7 years. Results of this study will be useful in the postoperative radiographic assessment of sagittal alignment of the elbow in children.

  • A Prospective Randomized Comparison of Variable-Angle and Fixed-Angle Volar Locking Plating for Intra-Articular Distal Radius Fractures

    Nishiwaki M., Terasaka Y., Kiyota Y., Inaba N., Koyanagi T., Horiuchi Y.

    Journal of Hand Surgery (Journal of Hand Surgery)  46 ( 7 ) 584 - 593 2021.07

    ISSN  03635023

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    Purpose: To compare clinical and radiographic outcomes of using a variable-angle volar locking plate (VAVLP) with those of using a fixed-angle volar locking plate (FAVLP) for treating unstable intra-articular fractures of the distal radius. Methods: One hundred twenty patients with unstable intra-articular fractures of the distal radius were randomized to open reduction and internal fixation with a VAVLP (n = 60) or an FAVLP (n = 60). Supplementary methods (eg., Kirschner wire fixation) were required in 4 patients with a VAVLP and 9 with an FAVLP. Clinical outcomes were evaluated at 6 weeks, 3 months, 6 months, and 1 year after surgery. Posteroanterior and lateral radiographs were used to measure standard radiographic parameters before surgery, in the immediate postoperative period, and at 1 year. Plate prominence and articular congruity were quantified using computed tomography at 6 months. Results: There were no significant differences in any clinical outcome between the groups at any follow-up time. Volar tilt was significantly greater in patients treated with a FAVLP in the immediate postoperative period (8° vs 6°) and at 1 year (8° vs 5°). Although significant differences were not found in articular gap or stepoff between the 2 plates, the distal and volar prominence of the VAVLP was significantly greater than that of the FAVLP at 6 months. Significantly more patients treated with a VAVLP had a complication (38% vs 19%). However, most secondary surgeries were performed for hardware removal, and no patients from either group had complex regional pain syndrome or tendon rupture. Conclusions: Patients with intra-articular distal radius fractures can expect good functional and radiographic outcomes with VAVLP or FAVLP fixation. The VAVLP may be more prone to technical errors, leading to complications, whereas the FAVLP is more likely to require supplementary fixation. Type of study/level of evidence: Therapeutic I