Masahiro Horita

Dr. Masahiro Horita


Research Focus & Metrics

Academic Career Length

6Years (2021-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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HOHideki Ohashi
Hideki Ohashi
KNKeiichiro Nishida
Keiichiro Nishida
YNYoshihisa Nasu
Yoshihisa Nasu
KSKenta Saiga
Kenta Saiga
RNRyuichi Nakahara
Ryuichi Nakahara
TOToshifumi Ozaki
Toshifumi Ozaki
Dorsal dislocation of metatarsophalangeal (MTP) joints of the lesser toe frequently occurs in patients with rheumatoid arthritis (RA), and may cause painful and uncomfortable plantar callosities and ulceration. The current study examined the reliability and clinical relevance of a novel radiographic parameter (the MTP overlap distance [MOD]) in evaluating the severity of MTP joint dislocation. The subjects of the current study were 147 RA patients (276 feet; 1104 toes). MOD, defined as the overlap distance of the metatarsal head and the proximal end of the phalanx, was measured on plain radiographs. The relationship between the MOD and clinical complaints (forefoot pain and/or callosity formation) was analyzed to create a severity grading system. As a result, toes with callosities had a significantly larger MOD. ROC analysis revealed that the MOD had a high AUC for predicting an asymptomatic foot (−0.70) and callosities (0.89). MOD grades were defined as follows: grade 1, 0 ≤ MOD < 5 mm; grade 2, 5 ≤ MOD < 10 mm; and grade 3, MOD ≥ 10 mm. The intra- and inter-observer reliability of the MOD grade had high reproducibility. Furthermore, the MOD and MOD grade improved significantly after joint-preserving surgeries for lesser toe deformities. Our results suggest that MOD and MOD grade might be useful tools for the evaluation of deformities of the lesser toe and the effect of surgical intervention for MTP joints in patients with RA.

11 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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KNKeiichiro Nishida
Keiichiro Nishida
YNYoshihisa Nasu
Yoshihisa Nasu
RHRyozo Harada
Ryozo Harada
RNRyuichi Nakahara
Ryuichi Nakahara
MHMasahiro Horita
Masahiro Horita
TOToshifumi Ozaki
Toshifumi Ozaki
Background/Objectives: Launched in Japan in 2022, ozoralizumab (OZR) is a novel, anti-tumour necrosis factor (TNF)-α inhibitor for treating rheumatoid arthritis (RA) that is refractory to conventional therapies. However, there is a lack of evidence regarding its perioperative management. Methods: This retrospective case series included nine patients with RA who underwent a total of 12 either RA-related (n = 9) or unrelated (n = 3) orthopaedic procedures. We reviewed patient demographics, surgical procedures, perioperative OZR discontinuation periods, and postoperative complications. Results: The mean preoperative OZR discontinuation period was 15.8 days (range, 2–25 days). Sutures were removed at a mean of 12.8 days postoperatively (range, 11–14 days) after adequate wound healing had been confirmed. The mean total discontinuation period was 34.9 days (range, 27–43 days). No cases of surgical site infection (SSI) or delayed wound healing (DWH) were observed during a minimum follow-up period of three months. One patient experienced a disease flare before OZR was restarted. Conclusions: Preoperative OZR discontinuation for up to four weeks appeared to be safe in this cohort. These findings may assist orthopaedic surgeons in determining an appropriate perioperative discontinuation strategy for OZR that minimises SSI and DWH risk while reducing the likelihood of RA flare.

28 February 2026 in Journal of Clinical Medicine
Verified
Journal Article
Open access
PDF file
MHMasahiro Horita
Masahiro Horita
YKYohei Kiso
Yohei Kiso
YNYoshihisa Nasu
Yoshihisa Nasu
RNRyuichi Nakahara
Ryuichi Nakahara
KSKenta Saiga
Kenta Saiga
KNKeiichiro Nishida
Keiichiro Nishida
Background: The number of patients with rheumatoid arthritis (RA) undergoing forefoot arthroplasty has increased to better control the disease. Despite patients frequently expressing concerns regarding postoperative foot appearance and footwear-related expectations, no study has investigated postoperative changes in foot length and width in patients with RA. The aim of this study was to evaluate the effect of surgical procedures for rheumatoid forefoot deformities on variations in radiologically determined foot length and width. Methods: In total, 72 feet of 50 women and 3 men (average age: 66.7 years) underwent joint-preserving arthroplasty (n = 33) and arthrodesis of the first metatarsophalangeal joint with shortening osteotomy of the lesser metatarsals or resection arthroplasty of the lesser metatarsal heads (n = 39); procedures were carried out in our institute from August 2013 to February 2020. The mean disease duration was 23.5 years, and the average follow-up period was 17.5 months. Pre- and postoperative hallux valgus angle (HVA), intermetatarsal angle (IMA) of the first and second metatarsals (M1M2A), and IMA of the first and fifth metatarsals (M1M5A) were measured on weightbearing radiographs as well as foot length and width. We also evaluated the correlation between changes in radiographic parameters and variations in radiologically determined foot length and width. Results: Radiologically determined foot width changed significantly from 10.1 cm to 9.7 cm (p < 0.01), while no significant difference was found between pre- and postoperative radiologically determined foot length. HVA, M1M2A, and M1M5A were significantly improved after the surgery (p < 0.01, p < 0.01, and p < 0.01, respectively). A significant negative correlation was found between the variation in radiologically determined foot length and changes in HVA (r = −0.29, p = 0.02) and M1M5A (r = −0.23, p < 0.05), while a significant positive correlation was found between the variation in the foot width and changes in HVA (r = 0.34, p < 0.01), M1M2A (r = 0.55, p < 0.01), and M1M5A (r = 0.45, p < 0.01). There were no significant differences between operative procedures regarding variation in radiologically determined foot length and width. Conclusions: Surgical procedure for rheumatoid forefoot deformity improved radiographic parameters and reduced radiographic foot width while maintaining foot length.