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黑田 雄一医学部附属病院 整形外科助教
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■ 論文- 2026年06月, Journal of Joint Surgery and Research研究論文（学術雑誌）
- Accurate, objective assessment of hip joint range of motion (ROM) is essential for orthopedic diagnosis and rehabilitation. Conventional tools, such as goniometers, are limited by subjectivity, inter-observer variability, and poor compatibility with telemedicine applications. This study aimed to develop and validate a markerless, video-based system for estimating hip joint ROM by integrating human pose estimation (MediaPipe) with machine-learning models using inertial sensor data as the reference standard. Twenty healthy adult males performed hip flexion/extension, abduction/adduction, and internal/external rotation movements. Skeletal coordinates extracted from the videos were converted into geometric features and used to train five regression models (linear regression, ElasticNet, support vector regression, random forest, and LightGBM). Model performance was evaluated using the coefficient of determination (R²) and mean absolute error (MAE), and Shapley additive explanations (SHAP) were used to interpret feature contributions. Among the evaluated models, tree-based methods showed high predictive accuracy, and LightGBM was used for subsequent interpretability analyses across all directions of hip ROM (R² up to 0.94; MAE 4-6°), while inertial sensor validation confirmed high measurement accuracy of the reference data. SHAP analysis revealed that distinct geometric descriptors dominated flexion/extension, abduction/adduction, and internal/external rotation, indicating direction-specific biomechanical determinants of hip motion. These findings demonstrate that markerless, video-based estimation of hip ROM is feasible with promising accuracy and highlight the potential of this approach for telemedicine, remote rehabilitation monitoring, and future integration into gait and musculoskeletal modeling workflows.2026年05月, BMC musculoskeletal disorders, 英語, 国際誌研究論文（学術雑誌）
- OBJECTIVES: To identify patient-related factors linked to high multidrug resistance gene 1 (MDR1) expression in RA and assess whether MDR1 expression affects Janus kinase (JAK) inhibitor effectiveness. METHODS: Synovial tissues were obtained from 53 RA patients undergoing total knee arthroplasty between October 2020 and June 2024, with 41 included in the primary analysis after exclusion. MDR1 expression was measured by reverse transcription-PCR (RT-PCR). Correlations with clinical characteristics were evaluated using Pearson's correlation and multiple regression analyses. For secondary analysis, patients with six highest and six lowest MDR1 expression levels were compared. Fibroblast-like synoviocytes from these patients were cultured after treatments with JAK inhibitors (tofacitinib, baricitinib, peficitinib, upadacitinib and filgotinib), bucillamine or the P-glycoprotein inhibitor verapamil, and expression of MMP, inflammatory cytokines and angiogenic factors was quantified by RT-PCR. RESULTS: High MDR1 expression significantly correlated with elevated serum MMP-3 levels (β = -0.0010; 95% CI, -0.0019 to -0.0001; P = 0.030) and increased use of biologic DMARDs (bDMARDs) (β = -0.406; 95% CI, -0.727 to -0.086; P = 0.015). In vitro, bucillamine suppressed MMP1, MMP3, ICAM1 and MCP1 expression less effectively in the high-MDR1 group, an effect reversed by verapamil. In contrast, all JAK inhibitors consistently suppressed cytokine expression regardless of MDR1 status. CONCLUSION: High MDR1 expression correlates with elevated MMP-3 levels and more frequent bDMARDs use. JAK inhibitors remain effective regardless of MDR1 status, potentially bypassing MDR1-mediated cellular drug resistance in RA.2026年02月, Rheumatology (Oxford, England), 65(2) (2), 英語, 国際誌研究論文（学術雑誌）
- PURPOSE: Abnormal bearing movements, including bearing contact with or separation from the vertical wall (VW) of the tibial component, can cause bearing dislocation or spin-out in Oxford mobile-bearing unicompartmental knee arthroplasty. This study aimed to evaluate the influence of varus placement of the tibial component on the bearing orbit in Oxford unicompartmental knee arthroplasty. METHODS: This retrospective study included 75 knees that underwent Oxford unicompartmental knee arthroplasty. The conventional group comprised 43 knees where tibial cuts were made orthogonally to the tibial axis. The varus group included 32 knees where tibial cuts were made slightly varus (targeting 3°). Intraoperative bearing movement was assessed at various knee flexion angles and compared between the groups. RESULTS: In both groups, the mobile bearing shifted posteriorly during knee flexion, tracing a rough C-shaped orbit that was closest to the VW at 60° of flexion. The varus group bearings had shorter mediolateral (ML) movements from 0° to 60° of flexion (1.75 ± 1.10 mm vs. 0.93 ± 1.98 mm, p = 0.008) and were less likely to impinge against the VW (odds ratio = 3.20, p = 0.034). The incidence of bearings separating from the VW (>4 mm) did not differ between groups. CONCLUSIONS: Varus placement of the tibial component reduces intraoperative bearing ML translation during 0-60° of knee flexion and decreases the risk of impingement with the VW, compared with neutral placement along the mechanical axis. LEVEL OF EVIDENCE: Level IV.2026年01月, Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 英語, 国際誌研究論文（学術雑誌）
- BACKGROUND: Kinematically aligned total knee arthroplasty has gained popularity. This study aimed to evaluate kinematic alignment targeting the neutral ground mechanical axis (ground kinematic alignment) through a comparison between two modern prostheses. METHODS: This cohort study included 82 consecutive patients (46 Persona® and 36 ATTUNE® prostheses) who underwent unilateral ground kinematically aligned total knee arthroplasty using a portable navigation system for varus osteoarthritis. After 1:1 propensity score matching, 56 patients with comparable demographic data were matched between groups. Patellar orientation, hip-knee-ankle angle, coronal femoral/tibial component alignment, and joint line orientation angle were compared between the groups. Intra-operative patellar tracking and soft tissue balance, including joint component gap and varus/valgus balance, were also compared. At 1 year postoperatively, clinical outcomes, including range of motion and 2011 Knee Society Score, were compared. FINDINGS: Radiological parameters including patellar shift and tilt were not significantly different between the groups, however the ratio of intraoperative lateral retinacular release to adjust patellar tracking was significantly higher in the Persona group than in the ATTUNE group. While both groups showed similar pattern of intra-operative soft tissue balance, the ATTUNE group showed a more stable joint component gap in the shallow range of flexion and a smaller lateral laxity in deep flexion than the Persona group (p < 0.05). There were no significant differences in clinical outcomes between the groups. INTERPRETATION: Ground kinematically aligned total knee arthroplasty using Persona or ATTUNE prostheses showed similar intra-operative and postoperative results; however, consideration should also be given to the characteristics between the models.2026年01月, Clinical biomechanics (Bristol, Avon), 131, 106710 - 106710, 英語, 国際誌研究論文（学術雑誌）
- Knee osteoarthritis (OA) causes pain and disability, and autologous adipose-derived stem cell (ASC) therapy has emerged as a regenerative treatment option. This retrospective cohort study compared short-term outcomes of intra-articular ASC injections between patients with moderate (Kellgren-Lawrence [KL] 2/3) and severe (KL 4) OA. Among 242 treated patients, 98 in each group were analyzed after propensity score matching for age, sex, and body mass index. Pain (VAS) and Knee Injury and Osteoarthritis Outcome Score (KOOS) subscales were evaluated at baseline and 1, 3, and 6 months. Both groups showed significant improvements in pain and function, with KL 2/3 patients exhibiting greater gains in KOOS Total, Activities of Daily Living, Sports/Recreation, Quality of Life, and VAS pain compared with KL 4. KOOS pain and symptoms improved similarly in both groups. Analgesic effects increased over time, and no serious adverse events were observed. Mild transient swelling or discomfort occurred in about 5% to 6% of cases. ASC injections provided meaningful symptom relief and functional improvement, particularly in moderate OA, suggesting that preserved joint structure benefits therapeutic efficacy. In advanced OA, benefits were present but attenuated, indicating limited regenerative potential in end-stage disease.2026年, Cell transplantation, 35, 9636897251414212 - 9636897251414212, 英語, 国際誌研究論文（学術雑誌）
- PURPOSE: Accurate prediction of postoperative coronal alignment is essential for successful outcomes following medial unicompartmental knee arthroplasty (UKA). Traditionally, valgus stress femorotibial angle (FTA) has been used to estimate the correctability of varus deformity; however, its reliability is limited by dependence on soft tissue behavior and examiner technique. In contrast, the arithmetic hip-knee-ankle angle (aHKA), calculated from bony anatomy, offers an objective and reproducible measure of constitutional limb alignment. While early studies suggest aHKA correlates well with postoperative alignment, direct comparison with valgus stress FTA has been lacking. This study aimed to compare the predictive accuracy of aHKA and valgus stress FTA for postoperative alignment and alignment correction (ΔHKA) in medial UKA. METHODS: This retrospective study included 125 knees undergoing medial fixed-bearing UKA. Preoperative aHKA was calculated from long-leg radiographs, and valgus stress FTA was measured using a Telos arthrometer. Postoperative hip-knee-ankle angle (HKA) was obtained from standardized radiographs. Correlation analyses were performed between postoperative HKA and both aHKA and 360°-valgus stress FTA. Similarly, correlations were assessed between ΔHKA and (aHKA-preoperative HKA) as well as (360°-valgus stress FTA-preoperative HKA). Fisher's Z-test was used to assess differences in correlation strengths. RESULTS: Postoperative HKA showed stronger correlation with aHKA (R2 = 0.5003, P < 0.001) than with 360°-valgus stress FTA (R2 = 0.1157, P < 0.001), with a statistically significant difference (Z = -4.12, P < 0.001). ΔHKA was more strongly associated with aHKA-preoperative HKA (R2 = 0.3805, P < 0.001) than with 360°-valgus stress FTA-preoperative HKA (R2 = 0.1111, P < 0.001) (Z = -2.92, P = 0.0036). CONCLUSION: aHKA demonstrated superior predictive accuracy for both postoperative alignment and alignment correction compared to valgus stress FTA. As a bone-based and examiner-independent parameter, aHKA is a valuable tool for preoperative planning in medial UKA and may reduce the need for stress radiography. Video Abstract.2025年12月, Arthroplasty (London, England), 7(1) (1), 65 - 65, 英語, 国際誌研究論文（学術雑誌）
- Rheumatoid arthritis (RA) causes bone destruction by activating inflammatory cytokines and osteoclasts. Cyclin-dependent kinase inhibitor 1 (p21), a cell cycle regulator, may influence this process; however, its role remains unclear. Therefore, we investigated the effect and potential mechanisms of p21 deficiency in bone loss in a mouse model of arthritis. Collagen antibody-induced arthritis (CAIA) was established in p21 knockout (p21 -/- ) and wild-type mice. Bone destruction was analyzed using histology, micro-computed tomography, and bone strength testing; osteoclast formation and activity were evaluated using tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemistry for cathepsin K. The expression of inflammatory cytokines and osteoclast-related genes was examined using immunohistochemistry and real-time polymerase chain reaction, respectively. p21 - / - mice exhibited greater bone destruction and lower bone strength than wild-type mice. Additionally, TRAP and cathepsin K staining revealed significantly higher osteoclast count in p21 - / - mice. Interleukin (IL)-6, IL-1β, tumor necrosis factor-alpha (TNF-α), and phosphorylated signal transducer and activator of transcription 3 (STAT3) levels were considerably higher in bone tissues of p21 - / - mice than in those of wild-type mice. In vitro osteoclast differentiation in bone marrow macrophages (BMMs) was examined after IL-6 stimulation; osteoclast differentiation and osteoclast marker gene expression were significantly enhanced in p21 -/- BMMs. Western blotting confirmed increased STAT3 phosphorylation in p21 -/- BMMs; IL-6 treatment further amplified osteoclastogenesis in p21 -/- BMMs. In conclusion, p21 deficiency exacerbates bone destruction in arthritis by promoting osteoclast differentiation and inflammatory cytokine expression via the IL-6/STAT3 pathway. Targeting p21 may offer therapeutic potential for preventing arthritis-related bone loss, such as in RA.2025年12月, Bone reports, 27, 101892 - 101892, 英語, 国際誌研究論文（学術雑誌）
- BACKGROUND: The use of cementless stems in patients with stovepipe-type femoral morphology (Dorr type C) remains controversial. Limited data are available on the clinical and radiological outcomes of cementless total hip arthroplasty using the Polarstem, particularly with proximal femoral bone morphology. This study compared clinical and radiological outcomes following Polarstem total hip arthroplasty (THA) based on medullary canal morphology, with a secondary aim of evaluating short-term findings. METHODS: This retrospective study included 101 consecutive patients who underwent Polarstem THA. Inclusion criteria required a minimum 2-year postoperative follow-up. We excluded patients with incomplete clinical data, pathological fractures, or severe comorbidities. Resulting in 95 patients (112 hips) for final analysis. Radiographic findings and Japanese Orthopaedic Association (JOA) hip scores were compared among the three Dorr-type classifications. RESULTS: Postoperative JOA scores showed significant improvement compared to preoperative values (p < 0.001). No significant differences were observed among Dorr types preoperative and postoperative JOA scores, subsidence incidence, or cortical hypertrophy (p = 0.199, 0.061, 0.623, and 0.384, respectively). No cases exhibited radiolucent lines. Pedestal formation occurred in 64 hips, with significantly higher occurrence in Dorr type C (p < 0.009). Stress shielding was observed in 47 hips, with significantly higher grade 2 incidence in Dorr type A and lower incidence type B (p < 0.001). CONCLUSIONS: The Polarstem demonstrated favorable short-term clinical outcomes regardless of proximal femoral morphology. However, grade 2 stress shielding occurred more frequently in Dorr type A femurs, suggesting that medullary canal morphology should be considered when selecting this stem design.2025年11月, Indian journal of orthopaedics, 59(11) (11), 1823 - 1829, 英語, 国際誌研究論文（学術雑誌）
- PURPOSE: The aim of this study was to compare total perioperative blood loss in patients undergoing total knee arthroplasty (TKA) in different ABO blood types. METHODS: This study was approved by the Institutional Review Board of our hospital (IRB No. 1510) on 2 February 2015. A total of 260 knees undergoing unilateral primary cemented cruciate-retaining TKA for knee osteoarthritis were retrospectively registered. Perioperative total blood loss was calculated for each blood types based on the change in hematocrit from pre- to postoperative day 7, preoperative height and weight. Differences in blood loss among the four ABO blood types were assessed. The association between blood type (O versus others) and total blood loss was further evaluated after adjusting for baseline characteristics through inverse probability of treatment weighting (IPTW). RESULTS: The study population was divided based on the ABO blood type: type O, 87; type A, 82; type B, 54; and type AB, 37. The mean total blood loss was 829 ± 370 ml for type O, 702 ± 384 ml for type A, 574 ± 361 ml for type B, and 528 ± 282 ml for type AB. Patients with blood Type O had significantly higher blood loss than all other blood types. After IPTW adjustment, mean total blood loss remained higher in type O (790 ± 370 ml) compared to other blood types (613 ± 364 ml). CONCLUSION: These findings suggest that blood type O may be associated with increased perioperative blood loss in TKA.2025年07月, Knee surgery & related research, 37(1) (1), 32 - 32, 英語, 国際誌研究論文（学術雑誌）
- This study examined the impact of preoperative coronal plane alignment of the knee (CPAK) classification on intraoperative soft tissue balance and postoperative clinical outcomes in patients undergoing modified kinematically aligned (mKA) and mechanically aligned (MA) total knee arthroplasty (TKA). A total of 90 knees treated with mKA-TKA and 63 knees treated with MA-TKA were classified based on CPAK. After adjusting for confounding factors, intraoperative soft tissue balance, including varus/valgus balance and joint component gap, range of motion (ROM), and the 2011 Knee Society score (KSS), were compared 1 year postoperatively using one-way ANOVA. The analysis included 69 knees classified as type I and 18 type II in the mKA group, and 52 type I and 11 type II in the MA group. Varus balance at 30 and 60 degrees flexion was significantly larger in mKA type I and MA type I compared to mKA type II (p < 0.001, 0.005, <0.001, 0.008). At 90 degrees, mKA type I showed a larger varus balance than both MA type I and mKA type II (p = 0.008, 0.002), while at 120 degrees, mKA type I demonstrated a larger varus balance than MA type I (p < 0.001). The improved ROM in mKA type I was greater than in MA type I (p = 0.04). Improvement in the objective indicator of the 2011 KSS was better in mKA type I than in mKA type II, and patient satisfaction was significantly better in mKA type I compared to both mKA type II and MA type I (p = 0.01, <0.001, 0.03). mKA type I preserved lateral laxity in mid- and deep flexion compared to both mKA type II and MA type I, potentially contributing to improved ROM and clinical outcomes.2025年07月, The journal of knee surgery, 38(9) (9), 440 - 447, 英語, 国際誌研究論文（学術雑誌）
- 2025年07月, Asia-Pacific Journal of Sports Medicine, Arthroscopy, Rehabilitation and Technology研究論文（学術雑誌）
- AIMS: Evaluating plantar pressure distribution and coronal lower limb alignment, including the hindfoot, using the hip-to-calcaneus axis, known as the ground mechanical axis (GA), is valuable in total knee arthroplasty (TKA). This study aimed to compare postoperative changes in plantar pressure distribution and lower limb alignment between mechanically aligned TKA (MA-TKA) and ground kinematically aligned TKA (gKA-TKA), targeting neutral GA. METHODS: After 1:1 propensity score matching, 35 pairs of patients with end-stage osteoarthritis of the knee, who underwent gKA-TKA and MA-TKA with similar preoperative disability between September 2019 and March 2022, were compared. Plantar pressure distribution during walking and unipedal stance was measured preoperatively and one year postoperatively using a pressure plate. The hip-knee-calcaneus angle (HKC) (positive values = valgus) and the percentage of the GA passing position at the knee joint (%GA; medial edge, 0%; lateral edge, 100%) were assessed on long-leg radiographs in unipedal stance. RESULTS: MA-TKA showed a medial loading pattern in the hindfoot. gKA-TKA exhibited a nearly equal pressure distribution in the coronal plane of the hindfoot. Postoperative centre-of-pressure path length during unipedal stance was significantly better for gKA-TKA than MA-TKA (p = 0.043). Furthermore, mean HKC angle and mean %GA of the MA-TKA were 2.0° (SD 2.4°) and 54.2% (SD 9.0%), respectively; those of the gKA-TKA were -0.2° (SD 1.0°) and 49.6% (SD 5.0%), respectively. Significant correlations were observed between the HKC angle (r = 0.391 (95% CI 0.172 to 0.573)) or %GA (r = 0.343 (95% CI 0.117 to 0.535)) and the hindfoot plantar pressure pattern in the coronal plane, indicating that postoperative lower limb valgus deformity in the hip-to-calcaneus axis results in a medial loading pattern. CONCLUSION: gKA-TKA can provide more neutral weightbearing in the GA, more equal coronal hindfoot pressure during walking, and improved stability in unipedal stance compared with MA-TKA.2025年06月, The bone & joint journal, 107-B(6) (6), 604 - 614, 英語, 国際誌研究論文（学術雑誌）
- INTRODUCTION: The amount of change in coronal alignment by unicompartmental knee arthroplasty (UKA) is important when considering its long-term results. This study investigated whether the amount of change in mechanical hip-knee-ankle (mHKA) angle by medial fixed-bearing UKA can be predicted based on the arithmetic hip-knee-ankle (aHKA) angle, an indicator of bony nature that is independent of soft tissue balance. MATERIALS AND METHODS: The research involved 101 patients (125 knees) who underwent medial fixed-bearing UKA with the spacer-block technique. Pre- and postoperative mHKA angles, aHKA angle (180°- lateral distal femoral angle + medial proximal tibial angle), insert thickness, and the amount of bone cuts were measured. The component gap in extension was measured using a UKA tensor, and the pre-osteotomy gap was calculated. The correlation between aHKA angle minus preoperative mHKA angle and changes in mHKA angle, as well as the pre-osteotomy gap, were analysed. Additionally, changes in mHKA angle and total osteotomy volume were compared based on insert thickness. RESULTS: A positive correlation was found between aHKA angle minus preoperative mHKA angle and the change in mHKA angle. The pre-osteotomy gap was also positively correlated with aHKA angle minus preoperative HKA angle. Greater changes in mHKA angle occurred in cases with inserts ≥ 9 mm compared to 8 mm inserts, though osteotomy volume did not significantly differ between the groups. CONCLUSIONS: In fixed-bearing UKA, postoperative changes in mHKA angle are likely to be more pronounced when there is a significant difference between aHKA angle and preoperative mHKA angle. Surgical planning should account for this factor to optimise outcomes.2025年04月, Archives of orthopaedic and trauma surgery, 145(1) (1), 271 - 271, 英語, 国際誌研究論文（学術雑誌）
- PURPOSE: In unicompartmental knee arthroplasty (UKA), the tibial component tends to be placed in a mildly varus position because of the expected improvement in stress distribution and load transfer across the tibia. With the spacer block technique in UKA, if a tibial osteotomy is performed in the varus position, the femoral component is placed in the valgus position. Therefore, this study aimed to evaluate the impact of valgus positioning of the femoral component on the short-term postoperative clinical outcomes in fixed-bearing UKA using the spacer block technique. METHODS: We analyzed 77 knees of 70 patients who underwent fixed-bearing UKA using the spacer block technique for medial compartment osteoarthritis and spontaneous osteonecrosis of the knee. Patients were categorized based on femoral component alignment: the neutral group (-3° to + 3°, mean 0.5° ± 1.7° valgus) and the valgus group (> 3°, mean 5.7° ± 1.7° valgus). Postoperative outcomes, including the femorotibial angle (FTA), component sagittal alignment, knee range of motion, and 2011 Knee Society Score (KSS), were compared between the two groups. RESULTS: No significant differences were found between the neutral and valgus groups regarding the postoperative FTA, component sagittal alignment, knee range of motion (neutral vs. valgus group; extension,°: - 1.9 ± 2.9 vs. - 1.6 ± 2.9; flexion,°: 133.0 ± 6.9 vs. 131.3 ± 7.9), or 2011 KSS (objective knee indicators: 95.0 ± 8.9 vs. 96.8 ± 3.5; functional activities: 78.9 ± 15.3 vs. 78.2 ± 12.9). CONCLUSION: These findings support the safety of valgus positioning in fixed-bearing UKA, offering flexibility in component placement without compromising short-term clinical outcomes.2025年04月, European journal of orthopaedic surgery & traumatology : orthopedie traumatologie, 35(1) (1), 165 - 165, 英語, 国際誌研究論文（学術雑誌）
- 2024年12月, Archives of Orthopaedic and Trauma Surgery研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2024年12月, Archives of Orthopaedic and Trauma Surgery, 145(1) (1)研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2024年09月, Archives of Orthopaedic and Trauma Surgery, 144(11) (11), 5005 - 5012研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2024年07月, Archives of Orthopaedic and Trauma Surgery, 144(7) (7), 3083 - 3090研究論文（学術雑誌）
- Abstract Background Both kinematically-aligned (KA) total knee arthroplasty (TKA) and bicruciate stabilized (BCS) TKA aim to reproduce the physiological knee kinematics. In this study, we compared the femoro-tibial component rotational mismatch between patients who underwent modified KA-TKA and those who received guided-motion BCS-TKA, and its influence on the clinical outcomes. Methods In this retrospective study, 77 consecutive patients were included and divided into two groups: subjects who underwent modified KA-TKA with Persona (KA Group; n = 42) and those who received BCS-TKA with JOURNEY II (BCS group; n = 35). Range of motion, the 2011 Knee Society Score (KSS), the rotational alignment of the femoral and tibial components, and the correlations between the rotational mismatch and the 2011 KSS subscales were examined. Results The postoperative objective knee indicators (P = 0.0157), patient satisfaction (P = 0.0039) and functional activity scores (P = 0.0013) in the KA group were significantly superior to those in the BCS group 1 year postoperatively. There was no significant difference between the two groups observed in the rotational mismatch. In the BCS group, significant negative correlations were identified between the rotational mismatch and objective indicators, patient satisfaction, and functional activity scores but not in the KA group. Conclusions The short-term clinical results following KA-TKA showed superior objective knee indicators, patient satisfaction and functional activity scores. A negative correlation was observed between component rotational mismatch and the 2011 KSS subscales in the BCS group, compared to no relationship found between the two in the KA group. These findings suggested that KA-TKA has a relatively higher tolerance for rotational mismatch than BCS-TKA.Springer Science and Business Media LLC, 2024年07月, Arthroplasty, 6(1) (1)研究論文（学術雑誌）
- Springer Science and Business Media LLC, 2024年06月, Cureus研究論文（学術雑誌）
- INTRODUCTION: Bone maintenance after total hip arthroplasty (THA) is important for implant success. This study aimed to investigate the relationship between patient characteristics and periprosthetic bone maintenance after THA for better implant selection. MATERIALS AND METHODS: This retrospective cohort study enrolled 112 consecutive patients who underwent THA using full hydroxyapatite (HA) compaction with short (n = 55) or short-tapered wedge (n = 61) stems. Periprosthetic bone mineral density (BMD) was compared between the two groups after propensity score matching, and the relationship between periprosthetic BMD changes and patient background was analyzed. RESULTS: Both groups showed similar periprosthetic BMD changes after adjusting for patient background using propensity score matching. Canal flare index > 3.7 in patients that underwent THA using tapered-wedge stem (odds ratio (OR), 3.2; 95% confidence interval (CI), 1.3-7.9, p = 0.013) and baseline zone 1 BMD > 0.65 in patients that received with short HA compaction stems (OR, 430.0; 95% CI 1.3-1420, p = 0.040) were associated with proximal periprosthetic bone maintenance after THA. CONCLUSION: Considering their predictive value, canal flare index and zone 1 BMD assessment might be useful strategies for implant selection during THA.2024年06月, Archives of orthopaedic and trauma surgery, 144(6) (6), 2881 - 2887, 英語, 国際誌研究論文（学術雑誌）
- Charcot arthropathy is a rapidly progressive and destructive form of arthropathy caused by various neurological diseases. Total hip arthroplasty (THA) is usually contraindicated in patients with Charcot arthropathy; however, recent studies have reported good results following THA in this patient population. Herein, we report a case of Charcot arthropathy secondary to syphilis in a patient who was successfully treated with constrained THA, a new type of THA. A 56-year-old man was injured in a car accident, and a displaced acetabular fracture was revealed three weeks later. He was treated conservatively but soon developed greater displacement of the fracture and femoral head destruction. The patient was referred to our hospital for further treatment. The patient had pelvic pseudarthrosis secondary to Charcot arthropathy at the time of the first visit to our hospital. First, THA was performed with the acetabular reconstruction of the deficient bone. However, the acetabular implant was displaced one week postoperatively. THA revision was performed using a constrained cup. Postoperatively, the patient exhibited good hip stability without dislocation. However, displacement of the acetabular cup occurred one year after the second surgery. We performed a re-revision of THA using a new type of constrained cup that offers a high level of constraint to maintain range of motion (ROM) and prevent dislocations. The patient was able to walk with a T-cane one year postoperatively. Herein, we report a difficult case of revision THA in a patient with Charcot arthropathy concomitant with syphilis. THA is usually contraindicated in patients with Charcot arthropathy; however, we propose that THA using constrained cups that offer a wider ROM may be a useful therapeutic strategy for the treatment of Charcot arthropathy.2023年11月, Cureus, 15(11) (11), e48295, 英語, 国際誌研究論文（学術雑誌）
- INTRODUCTION: This study compared the accuracy of three dimensional (3D) mini-optical navigation and accelerometer-based portable navigation systems for cup positioning during a total hip arthroplasty (THA) in the supine position. MATERIALS AND METHODS: This retrospective cohort study assessed data for 77 hips using 3D mini-optical navigation (n = 37) and accelerometer-based portable navigation (n = 40). The patients underwent THA through the mini-anterolateral approach in the supine position using a portable navigation system. We assessed the preoperative target angles, recorded intraoperative cup angles, postoperative CT imaging angles, cup angle measurement errors, and other clinical parameters. RESULTS: The mean absolute differences in radiographic inclination were similar between 3D mini-optical navigation and accelerometer-based portable navigation systems during THA in the supine position (2.8° ± 1.7° vs 2.8° ± 1.9°, p = 0.637). The mean absolute differences in radiographic anteversion were also similar (2.6° ± 2.3° vs 2.5° ± 1.9°, p = 0.737). Cup malalignment (absolute difference of inclination or anteversion between postoperative CT and preoperative target angle of > 5°) was significantly associated with body mass index (BMI) in accelerometer-based portable navigation but not in 3D mini-optical navigation. CONCLUSIONS: This is the first study to compare the accuracy of cup positioning between 3D mini-optical and accelerometer-based navigations in THA in the supine position. Both portable navigation systems accurately identified the orientation of cup placement. The accuracy of 3D mini-optical navigation is not affected by high BMI and may be preferred over other options in such patients.2023年07月, Archives of orthopaedic and trauma surgery, 143(7) (7), 3759 - 3766, 英語, 国際誌研究論文（学術雑誌）
- The purpose of this study was to determine whether the transplantation of human cells from a non-reattached injured anterior cruciate ligament (ACL) remnant could enhance tendon-bone healing. Human ACL remnant tissue was classified into two groups based on the morphologic pattern as per Crain's classification: (1) non-reattachment group (Crain Ⅳ) and (2) reattachment group (Crain Ⅰ-Ⅲ). Seventy-five 10-week-old immunodeficient rats underwent ACL reconstruction followed by intracapsular administration of one of the following: (1) ACL-derived cells from the non-reattached remnant (non-reattachment group) (n = 5), (2) ACL-derived cells from the reattached tissue (reattachment group) (n = 5), or (3) phosphate-buffered saline (PBS) only (PBS group) (n = 5). Histological (Weeks 2, 4, and 8), immunohistochemical (Week 2), radiographic (Weeks 0, 2, 4, and 8), and biomechanical (Week 8) assessments were performed. Histological evaluation showed high and early healing, induction of endochondral ossification-like integration, and mature bone ingrowth at Week 4 in the non-reattachment group. Microcomputed tomography at Week 4 showed that the tibial bone tunnels in the non-reattachment group were significantly reduced compared to those in the reattachment and PBS groups. Moreover, biomechanical testing showed that ultimate load-to-failure in the non-reattachment group tended to be larger than that in the reattachment group, though not statistically significant. The enhanced healing potential in the non-reattachment group was explained by the increase in intrinsic angiogenesis/osteogenesis. In the subacute phase, the ACL-derived cells with the non-reattached morphologic pattern showed greater and earlier tendon bone healing compared with the cells obtained from the reattached morphologic pattern.2023年03月, Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 41(3) (3), 500 - 510, 英語, 国際誌研究論文（学術雑誌）
- This study aimed to evaluate the relationship between the radiographical features of combination of the acetabular coverage and the femoral head-neck shape and the occurrence of femoroacetabular impingement (FAI). In this study, 114 patients who had FAI with or without labral tear and mild osteoarthritis were analyzed. Plain radiographs and computed tomography (CT) were taken for evaluation of acetabular coverage and femoral head-neck measurements. The relationship between the combination angle of acetabular coverage and femoral head-neck measurements and the occurrence of FAI was evaluated. The prevalence of FAI patients with the combination angle of CT-anterior CE + α angle ≥100° was 6.1% (7/114 patients). Receiver operator characteristic curve analysis demonstrated a higher area under the curve for combination of CT-anterior center edge angle (ACEA) with the α angle at 0.94 (CT-ACEA +α angle). A threshold for the occurrence of FAI was determined using the combination CT-ACEA + α angle at 100°. The frequency of FAI surgery was significantly higher in patients with a combination angle ≥100° than in those with a smaller angle. The average modified Harris hip score was significantly lower in patients with a combination angle ≥100° than in those with a smaller angle. We suggest that the combination of lateral center edge angle ≥40°, α angle ≥50° and combined angles of CT-ACEA and α angle ≥100° may help diagnosis of FAI. Level of evidence III: retrospective cohort study.2022年12月, Journal of hip preservation surgery, 9(4) (4), 252 - 258, 英語, 国際誌研究論文（学術雑誌）
- PURPOSE: We aimed to investigate the differences in peri-prosthetic bone remodelling between the full hydroxyapatite (HA)-collared compaction short stem and the short tapered-wedge stem. METHODS: This retrospective cohort study enrolled 159 consecutive patients (159 joints) undergoing total hip arthroplasty (THA) using the full HA compaction short (n = 64) and short tapered-wedge (n = 95) stems. Body mass index (BMI), peri-prosthetic bone mineral density (BMD), and clinical factors, including the Japanese Orthopaedic Association score and the University of California Los Angeles (UCLA) activity score were assessed and compared. RESULTS: Stem related complications were seen in three cases. Both groups showed similar peri-prosthetic BMD changes. Peri-prosthetic BMD was almost maintained in the distal femur and Gruen zone 6 with both type of stems, but significant BMD loss was found in zones 1 and 7 in both groups and in zone 2 of the full HA compaction stem group. No significant correlations were found between the proximal femoral BMD changes and the age, BMI, and UCLA score in both the full HA compaction and tapered-wedge stem groups. Femoral bone shape affected the peri-prosthetic BMD changes in the tapered-wedge stem group but not in the full HA compaction group. The stem collar of the full HA compaction stem did not affect peri-prosthetic BMD, but unique bone remodelling in the calcar region was observed in 27.6% cases. A significant difference in the peri-prosthetic BMD changes at Gruen zone 2 was found in patients with or without thigh pain. CONCLUSION: Peri-prosthetic bone remodelling remained unaffected by clinical and radiographic factors after THA with the new short full HA compaction stem. Therefore, this new stem may be useful in a variety of cases.2022年10月, Archives of orthopaedic and trauma surgery, 142(10) (10), 2903 - 2910, 英語, 国際誌研究論文（学術雑誌）
- INTRODUCTION: The presence of tibiofemoral subluxation (TFS) in patients with unicompartmental arthritis, a potential contraindication to unicompartmental knee arthroplasty (UKA), remains controversial and is not commonly discussed. This study aimed to determine the predictability of postoperative TFS before surgery and the effect of TFS on clinical outcomes after fixed-bearing UKA. MATERIALS AND METHODS: In total, 70 patients with anteromedial osteoarthritis and osteonecrosis of the knee who underwent fixed-bearing UKA from January 2015 to January 2017 were included. The preoperative TFS was assessed using plain anteroposterior and valgus stress radiographs. The patients were classified into three groups as follows: group A (acceptable TFS, n = 36) comprising patients with preoperative TFS less than 5.0 mm; group C (correctable TFS, n = 17) comprising patients with preoperative TFS of more than 5.0 mm but corrected to less than 5.0 mm under valgus stress; and group U (uncorrectable TFS, n = 17) comprising patients with preoperative TFS of more than 5.0 mm under valgus stress. Patient-derived clinical scores were assessed with the 2011 Knee Society Score preoperatively and 2 years postoperatively. The results were compared among the three groups using analysis of variance. RESULTS: Group U showed significantly higher postoperative TFS than groups A and C. Improvements in "symptoms" and "patient satisfaction" scores 2 years after surgery were significantly higher in groups A and C than in group U. CONCLUSION: Preoperative assessment of TFS under valgus stress could be a predictor of postoperative TFS. Furthermore, preoperative uncorrectable TFS could increase pain and decrease patient satisfaction 2 years after undergoing fixed-bearing UKA.2022年10月, Archives of orthopaedic and trauma surgery, 142(10) (10), 2865 - 2874, 英語, 国際誌研究論文（学術雑誌）
- The aim of this simulation study was to evaluate the relationship of elements of anterior acetabular coverage and femoral head-neck shape with the occurrence of postoperative anterior impingement after curved periacetabular osteotomy (PAO). Sixty-two patients with symptomatic developmental dysplasia of the hip who had undergone curved PAO were selected. The likelihood of developing postoperative anterior impingement was explored through simulations of the range of motion by collision detection of the pelvis and femur. Postoperative anterior impingement was defined as impingement that occurred during postoperative bone flexion <105° or postoperative internal rotation <20° at 90° flexion. The three-dimensional center-edge (CE) angles, acetabular and femoral versions, radiographic alpha angles of the femoral head, combination angles of anterior CE and alpha angles, and combined anteversions of acetabular and femoral versions were compared between patients with postoperative anterior impingement and nonimpingement. A receiver operator characteristic (ROC) analysis was conducted to determine thresholds of the examined radiographic parameters and calculate their accuracy for predicting postoperative anterior impingement. A multivariate analysis was performed to test whether combined anteversion, anterior CE angle, and combination angle are associated with excellent modified Harris Hip Scores (mHHSs). ROC analysis demonstrated a combination angle ≥108° was predictive of the occurrence of postoperative anterior impingement after curved PAO, which can lead to impaired clinical outcomes. Conversely, a combination angle <108° was significantly associated with mHHS ≥ 90 points. To avoid postoperative anterior impingement, osteochondroplasty of the femoral head or anterior CE angle control should be performed for patients with preoperative combination angles ≥90°.2022年10月, Journal of orthopaedic research : official publication of the Orthopaedic Research Society, 40(10) (10), 2440 - 2447, 英語, 国際誌研究論文（学術雑誌）
- BACKGROUND: JOURNEY II bi-cruciate stabilized (BCS) knee system, a guided motion total knee arthroplasty (TKA), has been reported to reproduce physiological knee kinematic motion with good clinical outcomes. However, this guided system may be sensitive to the femorotibial rotational alignment. METHOD: Forty-four patients (50 knees) who underwent JOURNEY II BCS TKA were included in this retrospective study. The 2011 Knee Society Score (KSS) and range of motion were assessed pre-operatively and one year postoperatively. The femoral component rotational angle relative to the surgical epicondylar axis and the tibial component rotational angle relative to Akagi's line were measured postoperatively. The absolute difference between the femoral and tibial component rotational angles was defined as femorotibial component rotational mismatch. The correlation between the parameters of these rotational alignments and postoperative clinical outcomes was evaluated. Additionally, receiver operating characteristic curve analysis was performed to determine the optimal cut-off point of the femorotibial component rotational mismatch. RESULTS: Mean femoral and tibial component rotational angles were 0.4° (internal rotation) and 0.7° (external rotation), respectively. The rotational mismatch of the femorotibial component was 3.2°. There were negative correlations between femorotibial rotational mismatch and clinical outcomes, including objective knee indicators, patient satisfaction, functional activities, and total 2011 KSS. The area under the curve of the femorotibial component rotational mismatch was 0.768 and the cut-off value identified by the Youden index was 2.8°. CONCLUSIONS: Excessive rotational mismatch between the femoral and tibial components can negatively influence the clinical outcomes of JOURNEY II BCS TKA.2022年10月, The Knee, 38, 69 - 75, 英語, 国際誌研究論文（学術雑誌）
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- Springer Science and Business Media {LLC}, 2021年12月, Scientific Reports, 11(1) (1), 英語研究論文（学術雑誌）
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- Springer Science and Business Media {LLC}, 2021年05月, Knee Surgery, Sports Traumatology, Arthroscopy, 29(5) (5), 1483 - 1493, 英語研究論文（学術雑誌）
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- 2020年, Indian Journal of Orthopaedics, 54(4) (4)研究論文（学術雑誌）
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- 2020年, BMC Musculoskeletal Disorders, 21(1) (1)研究論文（学術雑誌）
- 2019年, Journal of Orthopaedic Science, 24(4) (4)研究論文（学術雑誌）
- 2019年, Journal of Orthopaedic Research, 37(6) (6)研究論文（学術雑誌）
- 2019年, Clinical Biomechanics, 68研究論文（学術雑誌）
- 2018年, Knee Surgery, Sports Traumatology, Arthroscopy, 26(6) (6)研究論文（学術雑誌）
- 2018年, International Journal of Molecular Medicine, 42(3) (3)研究論文（学術雑誌）
- 2018年, Knee Surgery, Sports Traumatology, Arthroscopy, 26(11) (11)研究論文（学術雑誌）
- 2016年, Knee, 23(6) (6)研究論文（学術雑誌）
- 2015年, Knee Surgery, Sports Traumatology, Arthroscopy, 23(11) (11)研究論文（学術雑誌）
- 2015年, Orthopedics, 38(12) (12)研究論文（学術雑誌）
- 2014年, International Orthopaedics, 38(3) (3)研究論文（学術雑誌）
- 2014年, Knee Surgery, Sports Traumatology, Arthroscopy, 22(10) (10)研究論文（学術雑誌）
- 2013年, Knee Surgery, Sports Traumatology, Arthroscopy, 21(10) (10)研究論文（学術雑誌）
- 1995年, Circulation Research, 76(6) (6)研究論文（学術雑誌）