Papers - Iwamoto, Takuji

Intra-Articular Corrective Osteotomy for Distal Radial Intra-Articular Malunion Using Patient-Matched Instruments: A Prospective, Multicenter, Open-Label, Single-Arm Trial

Oka K., Miyamura S., Shiode R., Tanaka H., Iwasaki N., Kawamura D., Sato K., Iwamoto T., Yamamoto M., Nishida K., Shimamura Y., Yamada T., Okada S., Murase T.

Jbjs Open Access 9 ( 3 )  2024.08

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Background:Corrective osteotomy for intra-articular malunion is a challenging procedure. However, recent advancements, including patient-matched instruments created on the basis of preoperative computer simulation, enable accurate intra-articular correction. We hypothesized that intra-articular corrective osteotomy using patient-matched instruments for the treatment of distal radial intra-articular malunion would reduce intra-articular deformity and restore wrist function at 12 months of follow-up.Methods:This prospective study included 12 patients with distal radial intra-articular malunion who underwent intra-articular corrective osteotomy external to the joint using patient-matched instruments. The primary end point was the maximum step-off on the articular surface of the distal radius, measured with use of computed tomography (CT), with an expected postoperative value of ≤1.5 mm. The secondary end points included the gap of the articular surface; range of motion; grip strength; pain evaluated using a visual analog scale (VAS); patient satisfaction; Disabilities of the Arm, Shoulder and Hand (DASH) score; and Patient-Rated Wrist Evaluation (PRWE) score. A mean postoperative step-off of ≤1.5 mm for the primary end point was assessed with use of the 1-sample t test. The secondary end points were assessed with use of the Dunnett multiple comparison test.Results:The average step-off significantly improved from 3.75 ± 1.04 mm preoperatively to 0.51 ± 0.40 mm at the 52-week postoperative follow-up and was maintained within 1.5 mm. The average wrist and forearm range of motion, VAS score, grip strength, DASH score, and PRWE score significantly improved. Eleven patients were either very satisfied or satisfied with their outcomes.Conclusions:The use of patient-matched instruments could contribute to improving postoperative outcomes of intra-articular corrective osteotomy procedures involving the distal radius.Level of Evidence:Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

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Humeral rotational osteotomy for malunion after intramedullary nailing in humeral shaft fracture: a case report

Tsujisaka R., Matsumura N., Kamata Y., Morioka H., Kiyota Y., Suzuki T., Iwamoto T.

Jses Reviews Reports and Techniques 4 ( 3 ) 520 - 525 2024.08

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Alaska Pollock-derived Gelatin Sealant has Higher Sealing Strength than, and Comparable Biocompatibility with, Fibrin Sealant in Porcine and Rat Dural Injury Models

Ono T., Suzuki T., Nagoshi N., Masugi Y., Maeda K., Hashimoto S., Watanabe S., Iwamoto T., Taguchi T., Nakamura M.

Spine 49 ( 13 ) E200 - E207 2024.07

ISSN  03622436

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Study Design. Burst strength study in porcine dural models and functional and histological study in rat dural models. Objective. This study aimed to investigate the sealing strength and biocompatibility of Alaska pollock-derived gelatin (ApGltn) and fibrin sealants in disrupted dural injuries. Summary of Background Data. Disruption of the dura mater occurs during spine surgery, leading to cerebrospinal fluid leakage. Fibrin sealant is usually applied to ruptured sites; however, it lacks sealing strength. A novel biocompatible sealant composed of ApGltn was recently demonstrated to have good burst strength and biocompatibility in the porcine aorta. Methods. Ten porcine dura maters with central holes were covered with ApGltn and fibrin sealants (five samples per group). The maximum burst strength of each sealant was measured, and histological examination was performed after burst testing. Twenty-seven dura maters of male Wistar rats were used for functional and histopathological evaluations. The rats were treated with three surgical interventions: defect + ApGltn sealant; defect + fibrin sealant; defect alone (nine rats per group). Macroscopic confirmation of the sealant, hindlimb motor function analysis, and histopathological examination were performed at two, four, and eight weeks after the procedure. Results. The maximum burst strength of the ApGltn sealant was 4.4 times higher than that of the fibrin sealant (68.1±12.1 vs. 15.6±8.7 mmHg; P<0.001). Histological examination confirmed that the ApGltn sealant showed tight adhesion to the dural surface, whereas a gap was observed between the fibrin sealant and the dura mater. In the rat model, the ApGltn sealant resulted in spinal function and dural histological findings similar to those of the fibrin sealant. Conclusion. The ApGltn sealant had a higher sealing strength than, and comparable effect on dura regeneration with, the fibrin sealant.

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Painful snapping of the middle finger caused by hyperplasia of the ulnar lateral band: A case report

Matsuo A., Suzuki T., Kimura H., Matsumura N., Iwamoto T., Nakamura M.

Modern Rheumatology Case Reports 8 ( 2 ) 391 - 393 2024.07

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Snapping of fingers can be caused by pathologies such as stenosing flexor tenosynovitis. However, snapping symptoms in the metacarpophalangeal (MP) joint caused by hypertension and hyperplasia of the lateral band are rare. We present a 26-year-old female with symptoms of painful snapping of the middle finger. When the finger was actively flexed from the hyperextension of the MP joint, the ulnar lateral band was prominent, and a snapping phenomenon occurred. The cause of the snapping finger was considered to be tightness of the ulnar lateral band, and surgery was planned. Intraoperatively, the ulnar lateral band was tense and hyperplastic. The snapping phenomenon disappeared immediately after the resection of the lateral band. It is important to consider this condition as one of the differential diagnoses of snapping finger when the patient complains of an atypical snapping phenomenon.

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An upper arm ganglion cyst connected to the bicipital groove associated with glenohumeral osteoarthritis: a case report

Tsujisaka R., Matsumura N., Kamata Y., Morioka H., Kiyota Y., Suzuki T., Iwamoto T.

Jses Reviews Reports and Techniques 4 ( 2 ) 272 - 275 2024.05

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Quantitative evaluation of natural progression of fatty infiltration and muscle atrophy in chronic rotator cuff tears without tear extension using magnetic resonance imaging

Matsumura N., Kiyota Y., Suzuki T., Iwamoto T., Nozaki T., Jinzaki M., Nakamura M., Nagura T.

Jses International 8 ( 3 ) 630 - 637 2024.05

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Background: The pathology of and mechanisms underlying muscle degeneration remain unclear. We aimed to quantitatively evaluate the natural changes in fatty infiltration and muscle atrophy in patients with chronic rotator cuff tears using 3-dimensional 2-point Dixon magnetic resonance imaging. Methods: Thirty patients with nonoperatively observed rotator cuff tears without tear extension were evaluated using multiple magnetic resonance imaging examinations with a minimum interval of 2 years. The fatty infiltration ratio (%fat) and muscle volume of the rotator cuff muscles were compared between the 2 examinations in those with supraspinatus (SSP) tear <2 cm (<2 cm SSP group), SSP tear ≥2 cm (≥2 cm SSP group), and massive tear (massive group). The SSP) infraspinatus, and teres minor (ISP + TM), and subscapularis muscles were evaluated. Results: The massive group showed a significantly greater %fat than the <2 and ≥2 cm SSP groups in the SSP (P = .002) and ISP + TM muscles (P < .001). The total muscle volume did not differ among the 3 groups for all rotator cuff muscle components. The %fat values did not change in any rotator cuff components during the follow-up period in all groups. The total muscle volume in the massive group significantly decreased in the SSP (P = .018) and ISP + TM muscles (P = .013). Conclusion: The present results indicate that fatty infiltration of the torn muscle occurs in the early phase after a rotator cuff tear, whereas muscle atrophy appears to progress gradually in chronic rotator cuff tears. Early intervention before muscle degeneration should be considered if the tear involves the infraspinatus tendon.

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Recent advances in unlinked total elbow arthroplasty in Japan

Iwamoto T., Ikegami H., Tanji A., Kiyota Y., Suzuki T., Matsumura N., Sato K.

Jses International 8 ( 3 ) 602 - 607 2024.05

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Background: Total elbow arthroplasty (TEA) is a valuable therapeutic approach for improving function and relieving pain in severely deformed elbow joints. However, TEA is associated with a high incidence of complications. In Japan, the use of unlinked TEA has a long history, with the development of the Kudo prosthesis marking a significant milestone. Subsequently, various unlinked implant designs have been developed. Although favorable long-term clinical results have been reported, complications remain a concern. To further improve the outcome of unlinked TEA, attempts have been made in recent years to develop various surgical approaches and intraoperative support devices. This review focuses on the clinical outcomes and recent advances in unlinked TEA in Japan. Methods: A comprehensive review of clinical results and advancements in unlinked TEA in Japan was conducted. The analysis included trends in the number of TEA, medium-term and long-term results for unlinked TEA, surgical approaches, or preoperative planning techniques. Results: Several implant designs have been developed in Japan. Clinical studies have reported satisfactory long-term outcomes with these implants, but complications, such as infection, fractures, and dislocation, have been observed. In order to enhance the outcomes of unlinked TEA, various triceps-on approaches have been developed as alternatives to the triceps-detaching approach, which compromises the continuity between the triceps tendon and ulna, leading to inevitable complications related to the triceps tendon. Preservation or repair of the surrounding soft tissues is considered critical for preventing postoperative instability due to the absence of a radial head in the current unlinked TEA design. Computed tomography-based 3-dimensional preoperative planning has been pioneered in Japan, demonstrating its effectiveness in predicting implant size and achieving appropriate implant placement. Additionally, augmented reality–assisted surgery is being explored to accurately translate preoperative planning into the surgical procedure. Conclusion: Unlinked TEA for inflammatory arthritis has exhibited promising long-term results in Japan, with ongoing efforts to improve surgical techniques and preoperative planning. Further advancements are anticipated to prevent complications such as dislocation and peri-implant fractures.

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Extra-Articular Stabilization for the Treatment of Recurrent Sternoclavicular Joint Instability: A Report of Two Cases

Kobayashi T., Matsumura N., Tasaki A., Kiyota Y., Suzuki T., Iwamoto T., Matsumoto M., Nakamura M.

Jbjs Case Connector 14 ( 2 )  2024.04

ISSN  21603251

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Case:A 22-year-old man and a 14-year-old adolescent boy, who exhibited moderate general joint laxity, experienced recurrent sternoclavicular joint instability without traumatic events. The patients were successfully treated with extra-articular stabilization using autologous tendon grafts without surgical exposure of the sternoclavicular joint.Conclusion:Atraumatic instability of the sternoclavicular joint is rare but often results in recurrent instability accompanied by discomfort, pain, and limitations in activities. Extra-articular stabilization, which reinforces the anterior capsule of the sternoclavicular joint and prevents anterior displacement of the proximal clavicle at the elevated arm position, could be a viable surgical option for this pathological condition.

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Volar Transfer of the Lateral Band With Transverse Retinacular Ligament for the Correction of Swan Neck Deformity

Suzuki T., Kimura H., Matsumura N., Sato K., Nakamura M., Iwamoto T.

Hand 19 ( 2 ) 241 - 246 2024.03

ISSN  15589447

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Background: This retrospective study was designed to evaluate a surgical treatment for swan neck deformity of the fingers involving the volar transfer of the lateral band using the transverse retinacular ligament. Methods: Ten patients who underwent this surgical procedure for swan neck deformity treatment and were followed up for a mean of 26 months (range: 12-65 months) were included in the study. The dorsally located lateral bands were transferred toward the volar aspect of the finger, and their position was maintained using the transverse retinacular ligament. Improvement of the snapping and swan neck deformity was confirmed by intraoperative active motion of the finger. The active range of motion of the affected finger was evaluated pre- and postoperatively. Results: Extension of the proximal interphalangeal (PIP) joint averaged 30° (range: 20°-40°) preoperatively and improved to -2° (range: -5°-0°) postoperatively. Extension of the distal interphalangeal (DIP) joint averaged -30° (range: -15° to -70°) preoperatively and improved to -15° (range: 0° to -55°) postoperatively. The mean improvement in range of motion of the DIP joint was 15° (range: 10°-25°). The flexion of both the PIP and DIP joint did not significantly change in any of the patients postoperatively. Conclusions: Surgical transfer of the lateral band using the transverse retinacular ligament is effective in correcting mild swan neck deformity. Hyperextension of the PIP joint is corrected well, but the severe extension lag of the DIP joint remains uncorrected postoperatively.

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鎖骨遠位端長斜骨折に対して縫合糸による骨接合を行った1例

廣瀬 怜, 松村 昇, 清田 康弘, 鈴木 拓, 岩本 卓士, 中村 雅也

関東整形災害外科学会雑誌 (関東整形災害外科学会)  55 ( 臨増号外 ) 141 - 141 2024.03

ISSN  0389-7087

【RAに対する整形外科的治療の動向と進歩2023】手肘における人工関節全置換術の最近の進歩

岩本 卓士

臨床リウマチ ((一社)日本臨床リウマチ学会)  36 ( 1 ) 25 - 31 2024.03

ISSN  0914-8760

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薬物療法の進歩に伴いRA関連手術は減少傾向が見られつつも適応が変化し,小関節手術の需要は高まっている.人工肘関節全置換術では日本においては歴史的に非連結型の開発と成績向上に向けての取り組みがなされており,良好な治療成績が得られている一方で,高率な合併症発生が課題である.これに対して近年はコンピュータ支援手術の導入や手術アプローチの改良が行われている.手関節では2017年より人工関節が臨床使用可能となり,新たな治療選択肢として加わった.複雑な形状を有する手根骨にインプラントを良好な位置に固定することが手技上の重要な点となるため,コンピューター支援手術は重要な役割を果たすと考える.手肘の人工関節は症例数が少ないためインプラントの開発,技術の進歩が進みにくい領域であるが,今後さらに合併症を低減し臨床成績を向上するためには,インプラント及び手術手技のさらなる進歩が期待される.(著者抄録)

上腕骨近位部骨折続発症に対する人工肩関節置換術の治療経験

辻阪 亮介, 松村 昇, 松尾 知樹, 清田 康弘, 鈴木 拓, 岩本 卓士

骨折 ((一社)日本整形外傷学会)  46 ( 2 ) 306 - 310 2024.03

ISSN  0287-2285

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【背景】上腕骨近位部骨折は高齢者に好発する骨折であり,保存的治療で良好な治療成績が期待できる.しかし,偽関節や変形癒合などの骨折続発症が生じた場合,疼痛や著しい機能低下により関節置換が必要となることがある.しかし,本邦での続発症症例に対する手術成績に関する報告は少なく,その有用性については明らかではない.【目的】上腕骨近位部骨折続発症に対する人工肩関節置換術の治療成績を明らかにすること.【研究デザイン】ケースシリーズ.【設定】大学附属病院1施設での後向き研究.【対象】2015～22年に初期治療で保存的治療が選択された上腕骨近位部骨折続発症に対し人工肩関節全置換術を施行し,術後1年以上経過観察が可能であった9例(女性6例,男性3例).平均手術時年齢は75±10歳,受傷から手術までの期間は平均50±104ヵ月,平均経過観察期間19±16ヵ月であった.【曝露】上腕骨近位部骨折続発症のBoileau分類において,type 1の2例に対しては解剖学的人工肩関節が,type 3の4例とtype 4の3例に対しては結節の骨切りを併用したリバース型人工肩関節置換術が選択された.【主要アウトカム】術後の合併症,術前と最終経過観察時での自動可動域,結節癒合率,臨床スコア,合併症を検討した.【結果】肩関節可動域は挙上が術前66±41°から術後115±28°へ,下垂位外旋は術前2±13°から術後22±10°へ改善した.結節の骨切りを行った6例全例で骨癒合が確認できた.最終経過観察時のASESスコアは73点であった.感染症や脱臼などの合併症や再手術となった症例はなかった.【結論】上腕骨近位部骨折続発症9例に対し人工関節置換術を施行し,比較的良好な治療成績が得られた.関節置換で除痛とある程度の機能回復が期待できるが,新鮮例に対する骨接合や関節置換より治療成績が劣るため,初期治療において適切な治療法を選択する必要があると考えられた.(著者抄録)

In-vivo kinematics of the trapeziometacarpal joint in dynamic pinch motion using four-dimensional computed tomography imaging

Inaba N., Oki S., Nagura T., Sato K., Jinzaki M., Iwamoto T., Nakamura M.

Skeletal Radiology 53 ( 1 ) 129 - 140 2024.01

ISSN  03642348

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Objective: CT imaging precisely and quantitatively analyzes the kinematics of the carpal bones to evaluate the etiology of related osteoarthritis. Previous studies have investigated the kinematics of the trapeziometacarpal joint using static CT scans of various postures including the pinch position. This study analyzed the in-vivo kinematics of the trapeziometacarpal joint during dynamic pinch motion in young healthy volunteers using four-dimensional CT. Materials and methods: Twelve healthy young volunteers participated in this study. Each participant held the pinch meter between their thumb and index finger and pinched it with maximum force for a period of 6 s. This series of movement was recorded using a four-dimensional CT. The surface data of the trapezium and first metacarpal of all frames were reconstructed, and bone movement at the trapeziometacarpal joint was calculated using sequential three-dimensional registration. The instantaneous pinch force of each frame was measured using a pointer on a pinch meter that was reconstructed from the CT data. Results: The first metacarpal was abducted (15.9 ± 8.3°) and flexed (12.2 ± 7.1°) relative to the trapezium, and significantly translated to the volar　(0.8 ± 0.6 mm) and ulnar directions (0.9 ± 0.8 mm) with maximum pinch force. This movement consistently increased with the pinch force. Conclusion: This study successfully employed 4D-CT to precisely demonstrate changes in rotation and translation at the trapeziometacarpal joint during pinch motion for various instantaneous forces.

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Three-dimensional Visualization of the Brachial Plexus

Suzuki T., Hayakawa K., Iwamoto T.

Internal Medicine 63 ( 19 ) 2715 2024

ISSN  09182918

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Comprehensive Segmental Revision Systemを用いて再建した人工肘関節再々置換術の1例

肥沼 直子, 岩本 卓士, 望月 猛, 矢野 紘一郎, 猪狩 勝則

関節の外科 (日本リウマチの外科学会)  51 ( 2 ) 91 - 91 2024

ISSN  0285-6255

Augmented reality補助下での人工肘関節置換術により再建した上腕骨遠位部転移性骨腫瘍の1例

佐藤 みのり, 岩本 卓士, 森 智章, 清田 康弘, 鈴木 拓, 松村 昇, 中村 雅也, 丹治 敦

日本肘関節学会雑誌 (日本肘関節学会)  31 ( 1 ) S102 - S102 2024

ISSN  1349-7324

病変の再発と骨折により治療に難渋した肘関節滑膜軟骨腫症の1例

御子柴 直紀, 岩本 卓士, 清田 康弘, 鈴木 拓, 佐藤 和毅

日本肘関節学会雑誌 (日本肘関節学会)  31 ( 1 ) S107 - S107 2024

ISSN  1349-7324

Schwann cell-encapsulated chitosan-collagen hydrogel nerve conduit promotes peripheral nerve regeneration in rodent sciatic nerve defect models

Takeya H., Itai S., Kimura H., Kurashina Y., Amemiya T., Nagoshi N., Iwamoto T., Sato K., Shibata S., Matsumoto M., Onoe H., Nakamura M.

Scientific Reports 13 ( 1 ) 11932 2023.12

ISSN  2045-2322

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Chitosan has various tissue regeneration effects. This study was designed to investigate the nerve regeneration effect of Schwann cell (SC)-encapsulated chitosan-collagen hydrogel nerve conduit (CCN) transplanted into a rat model of sciatic nerve defect. We prepared a CCN consisting of an outer layer of chitosan hydrogel and an inner layer of collagen hydrogel to encapsulate the intended cells. Rats with a 10-mm sciatic nerve defect were treated with SCs encapsulated in CCN (CCN+), CCN without SCs (CCN−), SC-encapsulated silicone tube (silicone+), and autologous nerve transplanting (auto). Behavioral and histological analyses indicated that motor functional recovery, axonal regrowth, and myelination of the CCN+ group were superior to those of the CCN− and silicone+ groups. Meanwhile, the CCN− and silicone+ groups showed no significant differences in the recovery of motor function and nerve histological restoration. In conclusion, SC-encapsulated CCN has a synergistic effect on peripheral nerve regeneration, especially axonal regrowth and remyelination of host SCs. In the early phase after transplantation, SC-encapsulated CCNs have a positive effect on recovery. Therefore, using SC-encapsulated CCNs may be a promising approach for massive peripheral nerve defects.

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Rupture of the Flexor Pollicis Longus Tendon Involved between the Radial Shaft and the Volar Locking Plate

Hiraishi, Y; Kimura, H; Suzuki, T; Matsumura, N; Iwamoto, T; Matsumoto, M; Nakamura, M

JOURNAL OF WRIST SURGERY 12 ( 06 ) 540 - 542 2023.12

ISSN  2163-3916

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Long-standing Ulnar Wrist Pain Caused by an Anatomic Variant of the Ulnar Nerve: A Case Report

Nakui R., Iwamoto T., Kimura H., Suzuki T., Matsumura N., Nakamura M.

Jbjs Case Connector 13 ( 4 )  2023.11

ISSN  21603251

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Case:We present a 28-year-old woman with long-standing left ulnar wrist pain. Physical examination revealed severe tenderness over the pisiform; imaging findings were normal. Surgical exploration revealed compression of an aberrant branch, likely Kaplan's accessory branch, around the pisiform. Complete symptom relief was achieved after nerve decompression.Conclusion:Clinical symptoms associated with Kaplan's accessory branch are rare, indicating that many branches may be asymptomatic or overlooked despite the presence of symptoms. Kaplan's accessory branch should be considered as a potential differential diagnosis for refractory ulnar wrist pain.

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