Published papers

母指は手全体の機能の約40%を担っており,母指の疾患は生活の質に深刻な影響を与える.特に関節リウマチ患者においては,母指の変形や機能障害が顕著で,日常生活動作に支障をきたすことになる.リウマチ母指変形はNalebuffにより6つのTypeに分類され,そのうち,Type Iボタン穴変形とType IIIスワンネック変形が多くみられる変形である.ボタン穴変形は主にMP関節の滑膜炎が原因で発生し,MP関節が屈曲し,IP関節が過伸展する.スワンネック変形は主にCM関節の滑膜炎が原因で発生し,CM関節が橈背側亜脱臼し,MP関節が過伸展,IP関節が屈曲する.リウマチ母指の治療には薬物,理学,手術療法があるが,治療の際には,それぞれの変形が生じるメカニズムを十分に理解することが必要である.そのうえで,IP,MP,CMの各関節の変性や拘縮の程度に応じて,治療法を選択する必要がある.(著者抄録)

外傷を契機としない肘関節痛の診察では原因が神経障害によるものか,骨関節に起因するものかを判断する.急性に発症し強い炎症を伴う場合には小児例も含め化膿性肘関節炎を疑う必要がある.慢性の肘関節炎で関節腫脹を伴う場合には関節リウマチを第一に考えるが,結核性関節炎も稀ではあるが鑑別に挙がる.関節腫脹が軽度の場合には変形性肘関節症を考える.神経障害で最も頻度が高いものは尺骨神経障害(肘部管症候群)である.加齢に伴う肘部管の狭小化以外にも,過去の外傷や尺骨神経の脱臼,上腕三頭筋の肥大も発症の原因となる.また特徴的な神経麻痺として前骨間神経麻痺・後骨間神経麻痺がある.明らかな原因なく生じる特発性のものが多く,前駆症状として上肢の痛みを伴う場合が多いことから何らかの炎症が関与していると考えられている.頸椎疾患との鑑別を要する場合もあり,MRIや筋電図等で総合的に判断する必要がある.(著者抄録)

＜文献概要＞筋骨格系障害を有する患者を評価する際に医療者主導での評価が,以前より行われてきた。近年は,患者自身の主観的な評価も重要視されるようになり,患者立脚型評価(PROMs)は日常臨床や臨床研究での治療効果判定に必要不可欠なものとなっている。PROMsは,妥当性(validity),信頼性(reliability),反応性(responsiveness)といった基本的な尺度特性を有している必要がある。開発されたPROMsはこれらの尺度についての検証が行われた後に,使用が可能となる。また,海外で作成されたPROMsは日本語版のcross-cultural validationを経て,使用可能となる。手・肘領域のPROMsも多く,部位別,疾患別の評価法や,包括的評価法などがあり,目的に応じて使い分ける必要がある。近年,Patient-Reported Outcomes Measurement Information System(PROMIS)が開発され,コンピュータ適応型テスト(CAT)で評価を行うことで,短時間に広範囲の評価を行うことができるようになった。この評価法については,今後,検証が重ねられることで,標準的評価法となる可能性がある。

＜文献概要＞手指拘縮,手根管症候群,狭窄性腱鞘炎,手指変形性関節症などは,しばしば遭遇する主要な手外科疾患である.その発症の危険因子にはさまざまなものが考えられているが,生活習慣病,特に糖尿病や肥満との関連が明らかになっている.特に高血糖状態は終末糖化産物であるadvanced glycation endproduct(AGE)を産生し,AGEがコラーゲンを架橋することで組織硬化をもたらし,手指拘縮,手根管症候群,狭窄性腱鞘炎の原因となり得る.また肥満については,脂肪組織から産生されるサイトカインにより手指変形性関節症を引き起こす可能性も示唆されている.本稿では糖尿病や肥満を中心に,各手外科疾患との関連を疫学や治療成績の観点から述べる.

＜文献概要＞人工肘関節全置換術(TEA)は有用な治療法であるが,他の人工関節置換術と比較して合併症発生率が高く,術後合併症予防が重要である。主な合併症はインプラントのゆるみ,脱臼,不安定性などであり,初回手術での対策が求められる。当科では,合併症低減を目指し,複数の戦略を実施している。具体的には,セメントレスunlinked型インプラントの選択,三次元術前計画による正確な設置,上腕三頭筋腱の連続性を温存する低侵襲アプローチを導入し,合併症低減に努めている。さらに,術中支援技術として拡張現実(AR)を活用したナビゲーションシステムの開発にも取り組み,TEAの安全性向上と良好な臨床成績の実現を目指している。

関節リウマチ患者の手指MP関節の尺側偏位に対して関節置換術を施行する際,シリコンインプラントを使用する機会は多い.シリコンインプラントは明らかな関節構造を持たない関節スペーサーとして挿入されるが,手指の疼痛,機能,外観の改善をもたらし,再置換が容易であることから,現時点では最も頻用されているインプラントである.一方でシリコンインプラントは高率に折損が生じることも知られており,代表的な合併症である.折損しても臨床的に問題にならないこともあるが,疼痛や変形の再発があれば再置換術が必要となる.シリコンインプラントの折損率や対策については様々な報告があり一定の見解を得ていないが,当科では折損予防のため術後リハビリテーションにおいて過度のMP関節屈曲を制限することが必要と考えている.加えて,術後の尺側偏位の再発予防のため軟部組織再建も重要である.(著者抄録)

人工肘関節置換術・人工手関節置換術は他の人工関節と比べ,合併症率は依然として高く,長期成績についても明らかになっていない点が多い.また近年はインプラントデザインの進化により,その適応は拡大してきており,それに伴い術後の合併症例や再置換術を要する例も増加してきている.安定した良好な長期成績を得るためには,初回手術で適切な関節置換術を行うことが重要である.当科では,適切なインプラント選択,3次元術前計画による正確なインプラント設置,手術手技やアプローチにおける工夫を行ってきており,これらの取り組みが長期的な合併症の低減に寄与すると考えている.本稿では,人工肘関節置換術,人工手関節置換術における主な合併症とそれを予防するための対策について述べる.(著者抄録)

OBJECTIVE: The purpose of this study was to describe the three-dimensional deformities of midshaft clavicle fractures, which had been treated nonoperatively, using computed tomography (CT) surface matching. METHODS: Twenty-one patients with unilateral midshaft clavicle fracture, who had been treated nonoperatively, were enrolled and evaluated retrospectively. The three-dimensional deformity of the fractured clavicle was evaluated by CT surface matching. CT scans of 21 age- and sex-matched patients with initial traumatic shoulder dislocation or proximal humeral fracture were enrolled as a control group, and the differences in three-dimensional deformities and lengths of the clavicles between the fracture group and the control group were evaluated. A correlation analysis was also performed between rotational deformities and clavicular length shortening. RESULTS: The affected clavicle showed 1.3 +/- 6.9 degrees of downward angular deformity, 2.1 +/- 8.0 degrees of anterior angular deformity, and 5.0 +/- 4.9 degrees of anterior rotational deformity. Compared with the control group, the fractured clavicle showed larger anterior rotational deformity (P = 0.021). Shortening of the clavicle demonstrated negative correlation with anterior axial rotation (R = -0.534, P = 0.013), but no correlation was found between clavicular shortening and the other two rotational deformities. CONCLUSION: In cases of midshaft clavicle fracture, the distal fragment usually rotates anteriorly due to its anatomical relationships. Shortening deformity following clavicle fracture was reported to change shoulder kinematics, and anterior rotational deformity might adversely affect scapular motion.

OBJECTIVE: We examined the clinical features and functional outcomes of surgically repaired subcutaneous flexor tendon ruptures in patients with rheumatoid arthritis (RA). METHODS: This retrospective study included 41 fingers of 24 RA patients who underwent surgical treatment for flexor tendon ruptures. Evaluations performed at the time of presentation following rupture were C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and disease activity score in 28 joints (DAS28)-ESR, as well as Larsen grading for carpal bone destruction. The ruptured tendon and postoperative active range of motion (ROM) of digits were also examined. RESULTS: The mean CRP was 2.4 mg/dl, ESR was 52 mm/h, and the DAS28-ESR was 4.5. Carpal bone destruction according to Larsen grade IV-V was observed in 18/24 patients. Affected digits were most commonly the thumb (12) and the ring and little fingers (9 each). Tendon ruptures were most common in the carpal tunnel in zone IV. The mean postoperative finger ROM (flexion/extension) was 38 degrees /2 degrees for the interphalangeal (IP) joint of the thumb and 23 degrees /-2 degrees for the distal interphalangeal joint of the other four fingers. CONCLUSIONS: Patients with flexor tendon ruptures present with high disease activity and advanced bone destruction. It is important to reduce the risk of progressive bone destruction and subsequent tendon rupture via tight control of disease activity.

BACKGROUND: An understanding of normal glenohumeral geometry is important for anatomical reconstruction in shoulder arthroplasty. Unfortunately, the details of the glenohumeral joint in Asian populations have not been sufficiently evaluated. The purpose of this study was to evaluate the 3-dimensional geometry of the glenohumeral joint in the normal Japanese population and to clarify its morphologic features. METHODS: Anthropometric analysis of the glenohumeral joint was performed using computed tomography scans of 160 normal shoulders from healthy Japanese volunteers. The glenohumeral dimensions and orientation were analyzed 3-dimensionally. Sex differences and correlations between sides and among the respective parameters in the glenohumeral dimensions were evaluated. RESULTS: The normal Japanese humeral head has an average width of 41.4 mm, thickness of 13.2 mm, diameter of 42.9 mm, retroversion of 32 degrees , and inclination of 135 degrees . The glenoid has an average height of 31.5 mm, width of 23.1 mm, diameter of 62.0 mm, retroversion of 0 degrees , and inferior inclination of 2 degrees . The values of the glenohumeral dimensions were uniform in men and women, and the humeral head and glenoid were larger in men than in women. The glenohumeral size was well correlated between the 2 sides, and there were direct correlations among the heights, humeral length, humeral head size, and glenoid size. CONCLUSIONS: The present study revealed the glenohumeral geometry in the normal Japanese population. The present results would be useful to determine the size of implants and to improve the design of shoulder prostheses that reflect the normal anatomy of the Asian glenohumeral joint.

BACKGROUND: Previous studies have shown that the shoulder internal rotation elbow flexion (SIREF) test, which is a modified elbow flexion (EF) test, has significantly higher sensitivity than the EF test in patients with cubital tunnel syndrome (CubTS). Here, we hypothesized that this increase in sensitivity was due to increase in the ulnar nerve strain around the elbow introduced by the additional shoulder position. METHODS: Ulnar nerve strain at the elbow was intraoperatively measured at both the EF test and SIREF test positions in 20 patients with CubTS before simple decompression. Statistical analysis was performed with the Wilcoxon signed rank test at a confidence level of 99% (P < .001). RESULTS: Mean ulnar nerve strain in the EF test position was 18.9% +/- 12.1%, whereas that in the SIREF test position was 24.7% +/- 14.0%. Ulnar nerve strain was higher in the SIREF than in the EF test position in all cases, and the difference was significant (mean, 5.8% +/- 0.9%; 95% confidence interval, 3.90%-7.73%). CONCLUSION: This study indicated that increased sensitivity in the SIREF test compared with the EF test was due to the increase in ulnar nerve strain around the elbow. To the best of our knowledge, this is the first study showing that shoulder position changes the ulnar nerve strain around the elbow in living patients with CubTS.

© 2018 American Society for Surgery of the Hand A variety of surgical options for chronic tendon mallet fingers have been reported. There are advantages and disadvantages to current surgical approaches. We introduce a surgical treatment for chronic tendon mallet injury that involves anatomical reconstruction of the terminal tendon and lateral band with palmaris longus (PL) tendon grafting. Harvested PL tendon is folded in 2 or divided into 2 slips. The graft is attached to a remnant of the original terminal tendon at the distal interphalangeal joint. Both half-slip tendons are passed under the transverse retinacular ligament and sutured side to side to the lateral band at the level of the proximal phalanx. This surgical technique has these advantages: (1) it provides anatomical reconstruction of the terminal tendon; (2) it is indicated regardless of the condition of the terminal tendon and the interval from the initial injury; and (3) it is easy to determine the tension of the grafted tendon. Anatomical reconstruction of the terminal tendon and both lateral bands with PL tendon grafting is useful for chronic tendon mallet injury.

© 2018, Springer-Verlag France SAS, part of Springer Nature. Purpose: Surgical procedures for impaired forearm rotation such as for chronic radial head dislocation remain controversial. We hypothesized that the morphological axis of the proximal radius is important for stable forearm rotation, and we aimed to clarify the relationship between the morphological axis and the kinematic axis of the proximal radius using four-dimensional computed tomography (4DCT). Methods: Ten healthy volunteers were enrolled. Four-dimensional CT of the dominant forearm during supination and pronation was obtained. The rotation axis of forearm rotation was calculated from all frames during supination and pronation. The principle axis of inertia, which represents the most stable rotation axis of a rigid body, was calculated for the proximal radius by extending its surface data incrementally by 1% from the proximal end. The angle between the kinematic rotation axis and the morphological rotation axis of each length was calculated. Results: The rotation axis of the forearm was positioned on the radial head 0.0 mm radial and 0.4 mm posterior to the center of the radial head proximally and 2.0 mm radial and 1.2 mm volar to the fovea of the ulnar head distally. The principle axis at 15.9% of the length of the proximal radius coincided with the forearm rotation axis (kinematic axis). Individual differences were very small (SD 1.4%). Conclusion: Forearm rotation was based on the axis at 16% of the length of the proximal radius. This portion should be aligned in cases of severe morphological deformity of the radial head that cause “rattling motion” of the radial head after reduction procedures.

© The Author(s) 2018. The purpose of this study was to evaluate the mid- to long-term clinical outcomes of total finger joint arthroplasty using a costal osteochondral autograft for joint ankylosis. Twenty-three joints (three metacarpophalangeal joints, 20 proximal interphalangeal joints) in 23 patients (19 men and four women) were treated with a costal osteochondral autograft and were evaluated after a mean follow-up of 77 months (60–138). Mean age was 33 years (18 to 55). Significant improvement in active finger extension/flexion was seen from a preoperative mean of −24°/26° (arc: 2°) to −13°/75° (arc: 63°) at latest follow-up. Mean preoperative Japanese Society for Surgery of the Hand version of the Disability of the Arm, Shoulder and Hand score was initially 24 and improved significantly to 5 at latest follow-up. Conclusion: total finger arthroplasty using a costal osteochondral autograft gave an anatomical and biological reconstruction and provided stable improvement at a mean follow-up of 77 months. Level of evidence: IV.

Purpose: To identify the risk factors associated with early implant fracture of silicone metacarpophalangeal (MCP) joint arthroplasty using the volar hinge silicone implant for patients with rheumatoid arthritis. Methods: We retrospectively reviewed 113 fingers of 31 hands that underwent MCP joint arthroplasty between 2008 and 2014, with a minimum follow-up of 3 years,. An implant fracture within 3 years after surgery was regarded as an early implant fracture. Patient records were reviewed for potential risk factors of age, affected fingers, ulnar drift angle, and range of motion of the MCP joint before surgery and 1 year after surgery. Candidate risk factors were compared at the level of the digit and at the patient level. Results: With fracture of the implants as the end point, Kaplan–Meier estimated survival rate was 74.3% at 3 years and 67.9% at 5 years. Early implant fracture was detected in 29 fingers. Bivariate analyses showed significant associations between early implant fracture and MCP joint arc of motion before surgery, MCP joint flexion range 1 year after surgery, and MCP joint arc of motion 1 year after surgery. Multiple logistic regression analysis showed that increased MCP joint flexion range 1 year after surgery was an independent risk factor for early implant fracture. Conclusions: Increasing MCP joint flexion range was associated with increased fractures of the implants. We propose that the MCP joint flexion range should be restricted to less than 60° in postoperative rehabilitation; it is necessary to educate the patient to permanently avoid excessive flexion of the MCP joint. Type of study/level of evidence: Therapeutic IV.