佐粧 孝久

足関節捻挫に対してギプス固定を行った59例(男性40例、女性19例、平均年齢17.7±4.5歳)を対象に、これらをギプスカットを行うまでリハビリテーションを介入しなかった28例(非介入群)と、ギプス固定後からギプスカットまでの期間に自動等尺性運動と低周波治療による等尺性運動を施行した31例(介入群)に分け、治療成績を比較検討した。その結果、介入群は非介入群と比べ、ギプスカット時点での足関節可動域の低下が有意に少なかった。スポーツ競技復帰までの日数は介入群が平均48.7±15.7日、非介入群が平均60.1±23.1日と、介入群で約11日間早く復帰可能であったが、統計学的有意差はみられなかった。

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.

We previously reported that osteophytes formed at the posterior condylar notch of the femur could serve as a predictive imaging biomarker for osteoarthritis of the knee joint（KOA）development using magnetic resonance imaging（MRI）. Considering the location in the knee joint, we named the osteophyte as hidden osteophyte formation on plain x-ray（HOPOX）. To apply the findings to general clinical usage, x-rays that are less costly than MRI are a preferred imaging modality. In this study, we examined the feasibility of using the x-ray tunnel view to detect HOPOX. First, the diagnostic ability of the tunnel view was examined in 30 cases using computed tomography（CT）as a standard reference. Then, in a longitudinal study, the timing of HOPOX formation was examined retrospectively with a radiographic follow-up of 28 meniscectomized knees. The tunnel view showed greater diagnostic ability the sensitivity, specificity, positive predictive value, and negative predictive value were 0.73, 0.93, 0.92, and 0.78 respectively. The longitudinal study revealed that HOPOX was the earliest osteophyte in those cases in which osteophytes formed. In conclusion, the x-ray tunnel view was effective in detecting HOPOX, thus feasible way to predict early KOA.

The objective of this research is to mechanically and histologically evaluate the capacity of different PRP concentrations to promote tendon healing. 60 New Zealand white rabbits were used. In 20 rabbits（L-PRP group）, 1.0 mL of low-concentration PRP was applied to the Achilles tendon tear transection site on both hindlimbs of each animal. The other 20 rabbits（H-PRP group）, 1.0 mL of high-concentration PRP and in the remaining 20 rabbits（S group）, 1.0 mL of saline were applied. Ten rabbits from each group were slaughtered at 4 and 8 weeks following the transection surgery, with subsequent histological evaluation of the right legs, and mechanical evaluation of the left legs. Platelet counts were 3.8 times higher for L-PRP and 12.8 times higher for H-PRP than for whole blood. The semi-quantitative Bonar scale（0 is normal）decreased significantly from the S to L-PRP to H-PRP groups（P＝0.03）. The values for ultimate load, ultimate stress, elastic modulus, and stiffness increased from the S to L-PRP to H-PRP groups. A significant difference was observed between the groups for stiffness（P＝0.03）. Our results showed that PRP preparations with a high concentration of platelets were superior in the promotion of histological and mechanical healing of the Achilles tendon.

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.

OBJECTIVE: We investigated the effect of administration of intra-articular mesenchymal stem cells (MSCs) on cartilage repair at different timings, and the distribution of MSCs in the knee. DESIGN: A partial thickness cartilage defect (PTCD) was created on the medial femoral condyle in 14-week-old Sprague-Dawley rats. Intra-articular injection of 1 × 106 MSCs was performed at 3 time points, namely at the time of surgery (0w group), at 1 week after surgery (1w group), and at 2 weeks after surgery (2w group). For the control, 50 μL phosphate-buffered saline was injected at the time of surgery. The femoral condyles were collected at 6 weeks after creation of PTCD and assessed histologically. To investigate the distribution of MSCs, fluorescent-labeled MSCs were injected into the knee joint. RESULTS: In the control group, the cartilage lesion was distinguishable from surrounding cartilage. In the 0w group, hypocellularity and a slight decrease in safranin O stainability were observed around the injured area, but cartilage was restored to a nearly normal condition. In contrast, in the 1w and 2w groups, the cartilage surface was irregular and safranin O stainability in the injured and surrounding areas was poor. Histological score in the 0w group was significantly better than in the control, 1w, and 2w groups. At 1 day postinjection, fluorescent-labeled MSCs were mostly distributed in synovium. However, no migration into the PTCD was observed. CONCLUSIONS: Early intra-articular injection of MSCs was effective in enhancing cartilage healing in a rat PTCD model. Injected MSCs were distributed in synovium, not in cartilage surrounding the PTCD.

内側型の変形性膝関節症あるいは膝関節特発性骨壊死に対して人工膝関節単顆置換術を行った13例14膝(U群)と、内側開大型高位脛骨骨切り術を行った7例9膝(H群)の術後成績をForgotten Join Score 12(FJS)を用いて比較し、FJSに影響を及ぼす患者因子について検討した。平均観察期間はU群21.9ヵ月、H群20.9ヵ月で、いずれも良好な可動域(ROM)とKOOSが得られ、平均FJSはU群65.3±22.8点、H群71.1±15.8点であった。患者背景、客観的評価、患者立脚型評価を比較した結果、年齢はU群が有意に高く、Body Mass Index(BMI)とKOOSのADL項目はH群が高い傾向にあったが、性別、術前大腿脛骨角、術後ROM、KOOS、FJSに有意差はなかった。また、年齢、BMIを含めたいずれの項目もFJSとの有意な相関を認めなかった。

2019年1月に千葉大学医学部附属病院にスポーツメディクスセンター(SMC)が設置された。SMCは地域に根差しスポーツと医療の連携にある課題を吸い上げる。病院内・自治体・三師会・スポーツ協会・各スポーツ団体・アカデミアなどと連携し、組織横断的に課題を解決に導き、スポーツと医療の連携の深化、スポーツを起点とした健康増進など地域への貢献を目的とする。当面はスポーツ現場の課題である安全救護の充実に取り組み、スポーツイベントや団体の緊急時行動計画立案、医療者・関係者への救護医療の技術支援などを行い安全なスポーツ環境を創出する。2020年以降は、アスリートのみならず地域住民も対象に、公衆衛生学的観点も含めたスポーツと医療に関する研究と実践を行う。これらから得られた知見や実践の知恵を地域社会へ還元し貢献する。本報告では『地域密着の医療・スポーツ連携で未来を拓く』を掲げるSMCの理念と取組・今後の展望について解説した。(著者抄録)

PURPOSE: The purpose of this study was to clarify radiographic and clinical outcomes, as well as their association, of ankle sprain in children. METHODS: Patients who sustained a first-time ankle sprain were prospectively surveyed. Patients underwent radiography of the ankle in the mortise, lateral, anterior talofibular ligament (ATFL), and calcaneofibular ligament views at the first clinic visit to assess avulsion fractures of the distal fibula. Patients with avulsion fractures underwent radiography after 8 weeks to assess bone union. The treatment method was not standardized and was determined by the patient, their parents, and the treating physician. Recurrent sprain and quality of life were evaluated by using the Self-Administered Foot Evaluation Questionnaire and reviewing the medical records of patients. The association between avulsion fracture and recurrent sprain was assessed using univariate and multivariate analyses. RESULTS: A total of 143 patients with a median age of 9 (range 6-12) years were analyzed. Avulsion fractures were present in 89 (62%) patients. The sensitivity of the ATFL view for the diagnosis of avulsion fractures was 0.94, whereas that for the anteroposterior and lateral views was significantly lower at 0.46 (P < 0.001). Only 17% of fractures united at 8 weeks. Of 114 (follow-up rate, 80%) patients who were followed up for a median period of 24 months, recurrent sprain occurred in 41 (36%) patients. The incidence rate was significantly higher in patients with avulsion fractures than in patients without the fractures (44 vs. 23%, P = 0.027). In multivariate logistic regression analysis, avulsion fracture was independently associated with recurrent sprain (P = 0.027). CONCLUSION: More than one-third of patients experienced recurrent sprain. The presence of avulsion fracture was associated with an increased risk of recurrent sprain. Patients with avulsion fracture and their parents should be informed about the risk of recurrent sprain and subsequent ankle instability, and careful follow-up is needed for these patients. LEVEL OF EVIDENCE: III.

PURPOSE: To evaluate and compare the femoral tunnel aperture position, graft bending angle and the magnetic resonance imaging (MRI) graft signal intensity after anatomical double-bundle anterior cruciate ligament (ACL) reconstruction between transtibial and transportal drilling techniques of the femoral tunnel. METHODS: Eighty-seven patients who underwent anatomic double-bundle ACL reconstruction with hamstring tendon autograft between January 2012 and December 2014 were included in this retrospective study. Forty-one patients underwent reconstruction using a transportal technique (TP group) and 46 patients underwent reconstruction using a transtibial technique (TT group). The anteromedial (AM) femoral aperture position and the graft bending angle were assessed using transparent three-dimensional CT 2 weeks postoperatively. MRI assessment was performed with proton density-weighted images in an oblique coronal plane 6 and 12 months postoperatively. Signal/noise quotient was calculated for two specific graft sites (femoral tunnel site and mid-substance site). Femoral aperture position, the graft bending angle and signal/noise quotient were compared between the TP and TT groups. RESULTS: There was no significant difference in the aperture position between the two groups. The graft bending angle of the AM tunnel in the axial plane was significantly greater in the TP group (p < 0.001). On the other hand, the TP group had a significantly more acute angle in the coronal plane (p < 0.001). There was no significant difference at either site in the signal/noise quotient of the graft between the two groups at 6 months. However, the TT group had a lower signal/noise quotient at 12 months at both sites (femoral aperture: p = 0.04, mid-substance: p = 0.004). CONCLUSION: There was a significant difference in signal/noise quotient between the two drilling techniques 12 months postoperatively. There was no significant difference in femoral tunnel aperture position between the two groups. However, graft bending angle at the femoral tunnel aperture was significantly different between the two groups, indicating the possibility that graft bending angle is a factor that influences graft maturation. This indicates that the TT technique has an advantage over the TP technique in terms of graft maturation.

症例は14歳、男性。2年前から繰り返す右膝関節痛の精査目的に当科へ紹介となった。右膝関節内側に限局する圧痛を認めたが、経過を通して明らかな腫脹、関節血症は生じなかった。MRIで右膝関節内側谷部に腫瘍性病変を認め、関節鏡下腫瘍切除術を行った。切除検体の病理学的検査で海綿状血管腫の確定診断となった。術後症状は軽快し再発なく経過している。若年者のスポーツ整形外科診療では膝関節痛を主訴に受診する例が多くみられるが、繰り返す膝関節痛を呈する場合には腫脹や関節血症のエピソードがなくとも本疾患を念頭に置く必要がある。(著者抄録)

BACKGROUND: The purpose of this study was to evaluate the associations of the shape of the first metatarsal head with (1) the presence of osteoarthritis in the sesamoid-metatarsal joint and (2) the pronation angle of the first metatarsal head on foot radiographs. METHODS: A total of 121 patients, with the mean age of 61 years, underwent weight-bearing dorsoplantar, lateral, and first metatarsal axial radiographs. The shape of the first metatarsal head's lateral edge was classified as either rounded, intermediate, or angular in shape in the dorsoplantar view. The presence of osteoarthritis in the sesamoid-metatarsal joint and the pronation angle of the first metatarsal head were assessed in the first metatarsal axial view. Other variables that could affect the first metatarsal shape, including the lateral first metatarsal inclination angle, were also assessed. Univariate and multivariate analyses were performed to determine the associations. RESULTS: The prevalence of sesamoid-metatarsal osteoarthritis was significantly higher (77%, 27%, and 29% for rounded, intermediate, and angular, respectively, P < .001), and the metatarsal pronation angle was significantly larger (14°, 8°, and 4° for rounded, intermediate, and angular, respectively, P < .001) in feet with a rounded metatarsal head. These associations were also significant in the multiple regression analysis. CONCLUSION: A rounded metatarsal head was associated with a higher prevalence of osteoarthritis within the sesamoid-metatarsal joint, as well as a larger first metatarsal head pronation angle. A negative round sign can be used as a simple indicator of an effective correction to the first metatarsal pronation angle during hallux valgus surgery. However, in feet with sesamoid-metatarsal osteoarthritis, surgeons will need to be cautious as overcorrection may occur.

Purpose: Our aims were 1) to estimate the duration of short interfering RNA (siRNA) effect on matrix metalloproteinase-13 (Mmp-13) levels by a single intra-articular injection using a mouse knee osteoarthritis (OA) model and 2) to test whether repeated injections results in any additional suppressive effect on cartilage degradation compared to a single injection. Materials and Methods: OA was induced in 9 weeks old male C57BL/6 mice by destabilization of medial meniscus (DMM). Chemically modified siRNA targeted for Mmp-13 was injected into the knee joint at 1 week post-DMM surgery. Control group of knees received that for non-targeted genes. Synovial tissue was collected to measure Mmp-13 expression levels by quantitative polymerase chain reaction (qPCR) at 2, 3, and 6 weeks after surgery in each group. To test the effect of multiple injections, we created four experiment groups according to the number of injections. Histological assessment of articular cartilage was performed at 8 weeks post-DMM surgery. Results: In the Mmp-13 siRNA-treated group, expression levels of Mmp-13 mRNA were decreased by 40% compared to the control group at 2 weeks after surgery (p = 0.04), before returning to baseline at 3 weeks after surgery. A significant improvement in the histological score was observed in all Mmp-13 siRNA-treated groups compared to the control group (p < 0.05). However, no significant differences were seen between the single and multiple injection group. Conclusions: Our results suggested that the duration of siRNA effect in the knee joint lasts for at least 1 week, and that no further benefit is achieved by multiple injections.

本研究の目的は、前向き縦断研究によって小学3年生から中学3年生において膝痛を新規に発症する危険因子を解明することである。5月時点で膝痛を認めなかった835名を対象に、下肢柔軟性や下肢形態を評価するとともに、年に3回の身体測定を行い身長の変化率を算出した。さらに毎月の自己記入式アンケートによって運動量と膝痛の有無を調査した。5月から1月までの膝の新規疼痛発症の有無を目的変数とし、学年、性別、身長の変化率、HSS Pedi-FABSに換算した活動量、大腿骨内側顆間距離、Q角、foot posture index、踵臀距離、下肢伸展挙上角、足関節背屈角度を説明変数として多変量解析を行った。小学3年生に比べて小学6年生と中学3年生で膝痛の発症が多く、活動量が高いほど膝痛の発症率が高かった。年齢と活動量が膝痛の新規発症について危険因子となることが示唆された。(著者抄録)

The objectives of this study are (1) to examine age-dependent longitudinal differences in histological responses after creation of partial-thickness articular cartilage defects (PTCDs) in rats and to use this model (2) to objectively evaluate the effectiveness of interventions for cartilage repair. Linear PTCDs were created at a depth of 100 μm in the weight-bearing region of the medial femoral condyle in rats of different ages (3 weeks, 6 weeks, 10 weeks and 14 weeks). One day, one week, two weeks, four weeks and twelve weeks after PTCD generation, spontaneous healing was evaluated histologically and immunohistochemically. Effects of interventions comprising mesenchymal stem cells (MSCs) or platelet-rich plasma (PRP) or both on 14-week-old PTCD rats were evaluated and compared with natural courses in rats of other ages. Younger rats exhibited better cartilage repair. Cartilage in 3-week-old and 6-week-old rats exhibited nearly normal restoration after 4-12 weeks. Cartilage in 14-week-old rats deteriorated over time and early signs of cartilage degeneration were observed. With injection of MCSs alone or MSCs + PRP, 14-week-old PTCD rats showed almost the same reparative cartilage as 6-week-old rats. With injection of PRP, 14-week-old PTCD rats showed almost the same reparative cartilage as 10-week-old rats. This model will be of great use to objectively compare the effects of interventions for small cartilage lesions and may help to advance the development of disease-modifying osteoarthritis drugs.