赤坂 朋代

PURPOSE: This study aimed to introduce a novel technique using the extensor pollicis brevis and extensor indicis proprius tendons as power sources for thumb opposition reconstruction in cases of severe carpal tunnel syndrome (CTS) associated with thenar muscle atrophy. Furthermore, the efficacy of this novel method and the traditional Camitz technique was compared. METHODS: Patients with severe CTS and thumb opposition dysfunction who underwent surgery using the novel technique (n = 7 and 9 surgeries) or the Camitz technique (n = 8 and 8 surgeries) were included in the analysis. The pre- and postoperative palmar abduction angle, thumb-ring finger opposition angle, and Kapandji score were assessed. The repeated measures analysis of variance and the Mann-Whitney U test were used for statistical analysis. RESULTS: The novel technique was associated with a significant postoperative improvement in palmar abduction angle, thumb-ring finger opposition angle, and Kapandji score. In particular, the thumb-ring finger opposition angle of patients who underwent surgery using this technique was superior to that of patients who underwent surgery using the Camitz technique. Therefore, the novel technique was highly effective in improving thumb pronation. CONCLUSION: The novel technique using the extensor pollicis brevis and extensor indicis proprius tendons is promising for thumb opposition reconstruction in severe CTS cases. Unlike the traditional Camitz technique, this approach promotes stable thumb opposition function without requiring a pulley, thereby yielding satisfactory outcomes. Nevertheless, further studies with a larger sample size should be conducted to validate these findings. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic 4; Surgical technique.

It is important to know the relationship between flexor tendon traction force and applied finger flexion force generated during the rehabilitation of trigger finger. However, there has been no report on this relationship using the Jamar dynamometer in clinical practice and cadaveric study. Therefore, the purposes of this cadaveric study were to measure the value of flexion force when pulling a tendon via the method used in clinical practice and to investigate the relationship between the traction force of the flexor tendon and the flexion force of the finger output based on the Jamar dynamometer. In this study, each finger of a fresh-frozen cadaver was pulled, and the finger flexion force was measured with the Jamar Plus+ Digital Hand Dynamometer （Performance Health, Chicago, IL, USA）. There was a strong first-order correlation between the flexor tendon traction force and the finger flexion force, and the value of the finger flexion force［N］divided by the flexor tendon traction force［N］was 0.195-0.321. Under the same flexor tendon traction force, the exerted finger flexion force was in the following order: middle finger, index finger, ring finger, and little finger（maximum to minimum）. It is important to consider these findings when performing rehabilitation of trigger finger.

Purpose: Flexor digitorum profundus (FDP) dynamic tenodesis on the distal interphalangeal (DIP) joint is reported as a treatment for FDP tendon injuries. Although good clinical outcomes have been reported, biomechanical study results are unknown. This study aimed to evaluate the flexion range of motion in DIP and proximal interphalangeal (PIP) joints that have undergone dynamic tenodesis using fresh-frozen cadavers. Methods: We obtained 12 fingers from 3 fresh-frozen cadavers. Before and after the procedure, we assessed the relationships between the tension of the flexor tendons and the flexion angles of the DIP and PIP joints. We compared the maximum DIP and PIP joint angles using the Wilcoxon t test. The distal portion of the FDP was split longitudinally and the ulnar slip was resected from the insertion of the tendon. The remaining radial half of the FDP tendon was passed beneath both slips of the flexor digitorum superficialis tendon, which was then sutured to the radial insertion of the FDP tendon using a mattress stitch. Results: Maximum flexion angles of the DIP joint before and after the procedure were 48° ± 12° and 34° ± 8°, respectively; this difference was statistically significant. Maximum flexion angles of the PIP joint before and after the procedure were 74° ± 14° and 80° ± 9°, respectively; this difference was not statistically significant. Conclusions: The flexion angle of the DIP joint was reduced after undergoing dynamic tenodesis. Biomechanically, dynamic tenodesis for the DIP joint using the remaining FDP tendon is a valuable procedure because it results in a flexion angle greater than 30°. Clinical relevance: The DIP joint can be flexed, and the PIP joint maintains good motion after the procedure. Therefore, FDP dynamic tenodesis on the DIP joint may be a choice in case of an isolated FDP tendon injury.

As fractures heal, immature callus formed in the hematoma is calcified by osteoblasts and altered to mature bone. Although the bone strength in the fracture-healing process cannot be objectively measured in clinical settings, bone strength can be predicted by specimen-specific finite element modeling (FEM) of quantitative computed tomography (qCT) scans. FEM predictions of callus strength would enable an objective treatment plan. The present study establishes an equation that converts material properties to bone density and proposes a specimen-specific FEM. In 10 male New Zealand white rabbits, a 10-mm long bone defect was created in the center of the femur and fixed by an external fixator. The callus formed in the defect was extracted after 3-6 weeks, and formed into a (5 × 5 × 5 mm3) cube. The bone density measured by qCT was related to the Young's modulus and the yield stress measured with a mechanical tester. For validation, a 10-mm long bone defect was created in the central femurs of another six New Zealand white rabbits, and fixed by an external fixator. At 3, 4, and 5 weeks, the femur was removed and subjected to Computed tomography (CT) scanning and mechanical testing. A specimen-specific finite element model was created from the CT data. Finally, the bone strength was measured and compared with the experimental value. The bone mineral density σ was significantly and nonlinearly correlated with both the Young's modulus E and the yield stress σ. The material-property conversion equations were E = 0.2391e8.00ρ and ρ = 30.49σ2.41. Moreover, the experimental bone strength was significantly linearly correlated with the prospective FEM. We demonstrated the Young's moduli and yield stresses for different bone densities, enabling a FEM of the bone-healing process. An FEM based on these material properties is expected to yield objective clinical judgment criteria.

BACKGROUND: A1 pulley stretching is recognized as a clinically beneficial treatment for trigger finger. It is thought to lead to an increase in the cross-sectional area of the A1 pulley luminal region, thus improving trigger finger symptoms. The purpose of the present study was thus to evaluate the resultant forces during stretching that increase the CSA of the A1 pulley luminal region using fresh-frozen cadavers. METHODS: Using seven fingers from three fresh-frozen cadavers to replicate A1 pulley stretching, we investigated the resultant forces during stretching that increase the cross-sectional area of the A1 pulley luminal region. The traction forces of the flexor digitorum profundus tendons were increased in steps to 150 N, and the cross-sectional area and height of the A1 pulley luminal region were measured using ultrasonography. FINDINGS: The cross-sectional area of the A1 pulley luminal region increased with step-wise increases in the flexor digitorum profundus traction. On average, the cross-sectional area and height of the A1 pulley luminal region showed increases of 31.4% and 43.6%, respectively, compared to the unloaded condition. INTERPRETATION: These results confirmed that A1 pulley stretching increases the cross-sectional area of the A1 pulley luminal region. A1 pulley stretching has the potential to reduce the severity of trigger finger in patients facing surgery.

Computed tomography-based finite element analysis（CT-FEA）has widely been used for the mechanical analysis of osteoporotic bones. To perform CT-FEA, a conversion equation of the materials is used however, various conversion equations for bone have been reported previously. Therefore, the result depends on which conversion equation is used. New conversion equations must be created because slight variations in the results of the validity verification test using CT-FEA occur, even if various equations are used. This study aimed to identify a more accurate new conversion equation and compare it with past reports. A total of 102 cylindrical cancellous bones（diameter, 10 mm）were collected from nine fresh frozen cadavers. They were thawed at room temperature immediately before the tests were conducted. CT was performed with a calibration phantom, and bone density（g/cm3）was calculated from the obtained Hounsfield unit value using FEA software. The specimens were loaded using a universal testing machine, and yield stress and Young’s modulus were calculated. The correlation between Young’s modulus, yield stress, and bone density obtained from each specimen was investigated, and the bone material property conversion equation was obtained. Previous material property conversion equations were compared with the conversion equation of this study. Young’s modulus and yield stress were correlated with bone density, and the bone material property conversion equation was obtained from the approximate formula. Furthermore, this study’s equation is similar to the Keller vertebra equation. The equation determined in the present study can partly provide a considerable actual bone strength in the CT-FEM calculation compared with the previous studies.

陳旧性の腱断裂の治療に際しては,多くの場合,Pulvertaft法が用いられる.しかし,術後のリハビリテーションによる伸長の量は渉猟する限りでは報告がない.本研究ではその伸長を検討した.新鮮凍結屍体を使用し,総指伸筋腱,示指伸筋腱,小指伸筋腱を用いてPulvertaft法を行なった.2,3,4,5 weavesで比較・検討を行なった.各検体数は6ずつであった.5-15N,1000cycleで繰り返し牽引試験を行ない,伸長した長さを求めた.その後に破断強度も測定した.2,3,4,5 weaves群における繰り返し牽引負荷後の伸長距離(平均±SD)は,3.48±0.29mm,2.69±0.33mm,2.24±0.17mm,2.52±0.23mmであった.2 weavesでは有意に伸びたが他の各群間に有意差は認めなかった.2,3,4,5 weaves群における破断強度は,それぞれ38.44±3.73N,67.86±6.15N,99.75±14.67N,96.58±10.62Nであった.こちらも2 weavesのみで他と有意差を認めるのみであった.Pulvertaft法を使用した腱縫合では術後のリハビリテーションにより3,4,5 weavesの場合には2〜3mmは伸びる可能性があることが示唆された.術後の緩みを含め,罹患指,利き手・非利き手,筋の短縮の有無などを考慮して手技を行うことで,より良い成績を来すことが期待できる.(著者抄録)

高度な外傷性肘関節骨軟部欠損に対し,肩甲皮弁および人工肘関節置換術を施行し良好な機能改善を認めた症例を経験した.症例は62歳女性.交通事故にて右肘関節開放骨折を受傷した.受傷当日,前医にて洗浄デブリードマン,創外固定術を受けるも肘関節の高度骨軟部組織欠損をきたした.当院搬送後,受傷14日目に初期治療として肩甲皮弁を用いた軟部組織再建を行った.受傷後11ヵ月にて人工肘関節挿入術を行った.受傷後15ヵ月時点で,可動域は他動伸展0°,自動屈曲100°,前腕自動回外90°,回内30°まで改善した.本症例では肩甲皮弁による軟部組織修復を行い感染を来すことなく術後リハビリテーションが可能であった.また高度な骨欠損による上肢の短縮を認めたが,人工肘関節挿入にて短縮を解消し肘の自動屈曲力の改善を得た.肘関節周囲の高度な骨軟部組織欠損に対して肩甲皮弁および人工肘関節を併用した治療選択は時に有用である.(著者抄録)

Orthopedic trauma surgeons often encounter Smith's fracture in patients who report that they have fallen on the palms of their hands. The aim of this study was to clarify the pathogenesis of Smith's fracture in basic clinical aspects. First, a survey was conducted for investigating the mechanism of injury and arm position at the time of injury among patients with Smith's fractures who consulted at our outpatient clinic. Second, we created three-dimensional finite element models (FEMs) to predict the influence of arm position on the type of injury resulting from a fall. These predictions were then used in ten freshly frozen cadavers to provide experimental proof of Smith's fractures resulting from the impact on the palmar side. Twenty-six patients (5 males and 21 females) with Smith's fractures were enrolled in this study. Injury resulting from a fall on the palm of the hand, the dorsum, or ulno-dorsum of the hand, and fisting handle was observed in 16 cases (61%), 3 cases (12%), and 1 case (4%), respectively. Six patients were uncertain of their arm position at the time of injury. FEM analysis showed that Smith's fractures occurred when the angle between the long axis of the forearm and the ground was 30°-45° in the sagittal plane and 75°-90° in the coronal plane. Smith's fractures occurred in 7 of 10 wrists in the experimental study, whereas no Colles' fractures were observed. This study demonstrated that Smith's fracture results from falling on the palm of the hand. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2435-2441, 2017.

手根管開放術の際に母指球皮線に沿った皮切を置くと,しばしば母指球筋が尺側に張り出していることがある.本研究の目的は母指球皮線に対する母指球筋の尺側縁の位置を検討することである.新鮮凍結屍体16体31手.男性15手女性16手.平均年齢89歳.母指球皮線と母指球筋の最尺側縁をC点M点とし,中指中線をY軸,有鉤骨鉤を通るY軸への垂線をX軸,橈側を+とする座標上に鋼線でマーキングしてX線撮影した.C(X)とM(X)の値を比較し,関連性を検討した.C(X)とM(X)の平均座標は1.2±2.9mm,0.3±4.4mmであった.C(X)とM(X)の相関係数はr=0.33で相関は低かった.C(X)とM(X)の相関は小さく,皮線は筋の尺側縁を反映していないと考えられた.母指球皮線形成に影響する因子については筋肉や動きの要素よりも遺伝的要因が大きいとの報告があるが,本研究ではこの説を支持する結果を得た.(著者抄録)

CHIBA MEDICAL JOURNAL Open Access Paper[SUMMARY] Pain reduction effect of vibratory stimulation has been controversial. In previous studies, reseachers evaluated the effect for injection pain. However, as injection procedures differ with the skills of individual doctors, the uniformity of'identical'pain stimulation attempted in these studies remains unverified. In the present study, we used well-controlled electrical stimulation on the pulp of the finger to simulate superficial somatic pain. 24 healthy subjects were studied. In each trial, 50-mA electrical stimulation was applied for 2 ms on the middle finger. We compared three trials: without vibration, with vibration on the ipsilateral metacarpophalangeal joint and with vibration on the contralateral metacarpophalangeal joint. Statistical analysis was performed using the Wilcoxon signed-rank test for comparison. The trial of vibration on the ipsilateral metacarpophalangeal joint showed a significantly lower minimum pain score, implying positive effects of vibratory stimulation

Extensile EDC splittingアプローチは肘関節前外側の良好な視野が得られ、terrible triad損傷のアプローチ法として応用可能である。本研究の目的は、本アプローチを用いて尺骨鉤状突起を露出するための解剖学的検討を行うことである。新鮮凍結屍体8肢を用いた。尺骨鉤状突起の露出に必要なEDC切離量は43.9±6.0mm、短橈側手根伸筋(ECRB)-長橈側手根伸筋(ECRL)付着部切離量は27.4±2.4mmであった。展開を拡大し、遠位では後骨間神経(PIN)、近位では橈骨神経(RN)を露出した。EDC切離最遠位部からPINが橈骨骨幹部前面を通る点までの距離は6.4±5.6mm、ECRB-ECRL付着部切離最近位部からRNが上腕骨骨幹部前面を通る点までの距離は45.0±5.2mmであった。EDC切離最遠位部とPIN最短部位までの距離は約6mmと接近するので注意が必要である。(著者抄録)

当科において分離受動術および有茎血管柄付き脂肪弁挿入を行った先天性橈尺骨癒合症例における術後の腕橈関節アライメントと成績との関連につき検討した.1年以上経過観察可能であった7例8肢を対象とした.腕橈関節アライメントは単純X線側面像で前方脱臼型,中間型,後方脱臼型に分類した.術前では前方脱臼型が5肢,中間型が2肢,後方脱臼型が1肢であった.術直後では前方脱臼型が2肢,中間型が3肢,後方脱臼型が3肢であった.最終診察時では前方脱臼型が2肢,中間型が1肢,後方脱臼型が5肢であった.前腕回内外可動域は,最終診察時には自動で前方脱臼型において回内37.5±8.0°,回外20.0±10°,後方脱臼型において回内44.0±23°,回外29.0±20°であり,腕橈関節アライメントによる成績には有意差を認めなかった.整復位を保持することは困難であり,橈骨頭脱臼への対策が必要であると思われた.(著者抄録)