Kenta Saiga

Dr. Kenta Saiga


Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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5 March 2020 in Foot & Ankle International
Verified
Journal Article
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KSKenta Saiga
Kenta Saiga
SYSuguru Yokoo
Suguru Yokoo
HOHideki Ohashi
Hideki Ohashi
MHMasahiro Horita
Masahiro Horita
TFTakayuki Furumatsu
Takayuki Furumatsu
TOToshifumi Ozaki
Toshifumi Ozaki
Recently, arthroscopic ankle arthrodesis has been performed for moderate-to-severe varus-deformed ankle osteoarthritis. However, the effect of osteophyte resection in the lateral gutter in arthroscopic ankle arthrodesis has not been clarified. We hypothesized that a varus-deviated ankle with lateral gutter osteophytes can be corrected by osteophyte resection. Thirty-nine ankles of 38 patients were included. The mean age of patients was 70.0 (45-83) years. The patients were divided into the following groups: group with an osteophyte in the lateral gutter (osteophyte) and group with no osteophytes (nonosteophyte). Preoperative and postoperative tibiotalar angle, tibial plafond angle, and tibiotalar angle under valgus stress, as well as the Japanese Society for Surgery of the Foot (JSSF) ankle/hindfoot scale, were recorded. Twelve ankles underwent lateral gutter osteophyte resection, whereas the other 27 ankles did not require osteophyte resection. Preoperative tibiotalar angle was higher in the osteophyte group than in the nonosteophyte group (21.8 vs 11.2 degrees, P = .01). The tibiotalar angle in the preoperative valgus stress imaging was higher in the osteophyte group (12.9 vs 5.7, P < .01). However, the postoperative tibiotalar angle was similar between the 2 groups (7.1 vs 5.4, P = .183). JSSF ankle/hindfoot scale improved in both groups. Lateral gutter osteophyte resection enabled correction of the varus malalignment in arthroscopic ankle arthrodesis. Level III, retrospective comparative series.

Verified
Journal Article
Open access
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HKHirose Kazuki
Hirose Kazuki
MKMiho Kuwahara
Miho Kuwahara
ENEiji Nakata
Eiji Nakata
TTTomonori Tetsunaga
Tomonori Tetsunaga
KYKazuki Yamada
Kazuki Yamada
THTakako Hattori
Takako Hattori
Osteoarthritis (OA) occurs not only in the knee but also in peripheral joints throughout the whole body. Previously, we have shown that the expression of cellular communication network factor 3 (CCN3), a matricellular protein, increases with age in knee articular cartilage, and the misexpression of CCN3 in cartilage induces senescence-associated secretory phenotype (SASP) factors, indicating that CCN3 promotes cartilage senescence. Here, we investigated the correlation between CCN3 expression and OA degenerative changes, principally in human femoral head cartilage. Human femoral heads obtained from patients who received total hip arthroplasty were categorized into OA and femoral neck fracture (normal) groups without significant age differences. Gene expression analysis of RNA obtained from femoral head cartilage revealed that CCN3 and MMP-13 expression in the non-weight-bearing part was significantly higher in the OA group than in the normal group, whereas the weight-bearing OA parts and normal cartilage showed no significant differences in the expression of these genes. The expression of COL10A1, however, was significantly higher in weight-bearing OA parts compared with normal weight-bearing parts, and was also higher in weight-bearing parts compared with non-weight-bearing parts in the OA group. In contrast, OA primary chondrocytes from weight-bearing parts showed higher expression of CCN3, p16, ADAMTS4, and IL-1β than chondrocytes from the corresponding normal group, and higher ADAMTS4 and IL-1β in the non-weight-bearing part compared with the corresponding normal group. Acan expression was significantly lower in the non-weight-bearing group in OA primary chondrocytes than in the corresponding normal chondrocytes. The expression level of CCN3 did not show significant differences between the weight-bearing part and non-weight-bearing part in both OA and normal primary chondrocytes. Immunohistochemical analysis showed accumulated CCN3 and aggrecan neoepitope staining in both the weight-bearing part and non-weight-bearing part in the OA group compared with the normal group. The CCN3 expression level in cartilage had a positive correlation with the Mankin score. X-ray analysis of cartilage-specific CCN3 overexpression mice (Tg) revealed deformation of the femoral and humeral head in the early stage, and immunohistochemical analysis showed accumulated aggrecan neoepitope staining as well as CCN3 staining and the roughening of the joint surface in Tg femoral and humeral heads. Primary chondrocytes from the Tg femoral head showed enhanced expression of Ccn3, Adamts5, p16, Il-6, and Tnfα, and decreased expression of Col2a1 and -an. These findings indicate a correlation between OA degenerative changes and the expression of CCN3, irrespective of age and mechanical loading. Furthermore, the Mankin score indicates that the expression level of Ccn3 correlates with the progression of OA.

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.

5 September 2025 in Journal of Orthopaedic Science
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Journal Article
Closed access
MMMasatake Matsuoka
Masatake Matsuoka
YMYasutaka Murahashi
Yasutaka Murahashi
SKSeiji Kimura
Seiji Kimura
TOTomohiro Onodera
Tomohiro Onodera
KSKousuke Shiwaku
Kousuke Shiwaku
SYSatoshi Yamaguchi
Satoshi Yamaguchi

22 June 2022 in European Journal of Orthopaedic Surgery & Traumatology
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Journal Article
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SYSuguru Yokoo
Suguru Yokoo
KSKenta Saiga
Kenta Saiga
KDKoji Demiya
Koji Demiya
HOHideki Ohashi
Hideki Ohashi
MHMasahiro Horita
Masahiro Horita
TOToshifumi Ozaki
Toshifumi Ozaki

1 December 2023 in The Journal of Foot and Ankle Surgery
Verified
Journal Article
Closed access
KTKatsunori Takahashi
Katsunori Takahashi
KSKousuke Shiwaku
Kousuke Shiwaku
SYSatoshi Yamaguchi
Satoshi Yamaguchi
KAKentaro Amaha
Kentaro Amaha
KSKenta Saiga
Kenta Saiga
KWKota Watanabe
Kota Watanabe