Effect of eccentric exercise on the healing process of injured patellar tendon in rats

Background. Earlier studies have reported positive results from eccentric training in patients with tendon disorders. The reasons for the beneficial clinical effects of eccentric training are not known. Vascularization followed by regression of the vasculature enhances the healing response of injured tendons. Eccentric exercise induces a more beneficial healing response than concentric exercise. Methods. Sixty rats with patellar tendon injuries were divided into three groups: nonexercise controls (group N; n = 20); concentric exercise group (group C; n = 20); eccentric exercise group (group E; n = 20). Each rat was taught to run uphill or downhill for 14 days. Patellar tendons were removed 1, 4, 7, 10, and 14 days following injury. Vascular endothelial growth factor (VEGF), angiopoietin-1, and angiopoietin-2 were measured by reverse transcription polymerase chain reaction. Results. In group C, VEGF mRNA was increased 1 and 4 days following injury but was decreased on days 7, 10, and 14. In group E, VEGF mRNA was elevated only on day 1. In group N, VEGF mRNA remained at a low level throughout all 14 days. The angiopoietin-2/angiopoietin- 1 ratio was higher for group C than for group E. Conclusions. In the presence of VEGF, angiopoietin-1 promotes vessel stability, whereas angiopoietin-2 has the opposite effect. Eccentric exercise contributes to stabilized angiogenesis during the early phase of tendon injury. Conversely, concentric exercise, which induces destabilized angiogenesis, leads to a delayed healing response. Initiation of eccentric exercise immediately after tendon injury may help improve healing by reducing vascularity. © 2008 The Japanese Orthopaedic Association

Frozen allograftの靭帯及び靭帯付着部における超微構造

金沢大学医学部Frozen allograft後の靭帯付着部(enthesis)の再生、修復過程は、北岡が家兎を用いた実験で初めて明らかにしたが、その微細構造に関しては不明である。微細構造に着目して形態学的にどのレベルまで再生されるのかを明らかにすることが、今後のfrozen allograftの研究および臨床応用にあたって必要と考える。(方法)体重3Kg日本白色家兎を用い、ケタラール(40mg/kg)の筋肉内投与後、耳介静脈よりネンブタール持続投与により麻酔を行った。家兎15匹に対し、あらかじめ-80度にて2週間保存した膝蓋靭帯付着部を移植した。これらを2週、4週、6週、8週の時点で透過電顕にて観察した。またコントロールとして正常家兎5匹、凍結保存付着部5肢を透過電顕にて観察した。また正常家兎5匹を用い、走査電顕にて付着部毛細血管レベルの小孔を観察した。(結果)正常付着部電顕像では靭帯から骨にかけて膠原線維に沿って軟骨細胞が出現し徐々に周囲の石灰化が進行する像が認められた。これに対し凍結保存群では靭帯膠原線維の構造、配列に変化はみられないものの軟骨細胞は細胞膜の破壊、細胞内小器官の形成不良、核の濃染、破壊等細胞の壊死像と考えられる像がみられた。移植群では2週、4週では凍結群と比べほぼ変化はみられなかったが6〜8週では細胞内小器官の発達は乏しいもの形状的に軟骨細胞に類似した細胞が出現していた。正常付着部走査電顕では石灰化軟骨層およびtide markにかけて毛細血管レベルの小孔が多数みられたが、非石灰化軟骨層には明かなものはみられなかった。(考察)移植後、enthesisに未成熟な軟骨細胞が6〜8週で出現したがこれが今後成熟軟骨細胞へと分化していくのか今後さらに経時的観察が必要と考える。またこれに並行してenthesisの血行支配に関してfrozen allograftでの再生過程を明らかにする予定である。研究課題/領域番号:08671648, 研究期間(年度):1996出典：研究課題「Frozen allograftの靭帯及び靭帯付着部における超微構造」課題番号08671648（KAKEN：科学研究費助成事業データベース（国立情報学研究所）） （https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-08671648/）を加工して作

冷凍保存同種骨移植における靭帯および靭帯付着部の再生に関する実験的研究

取得学位 : 博士（医学）, 学位授与番号 : 医博乙第1302号, 学位授与年月日：平成6年6月1日,学位授与年：199

Use of bisphosphonates for the treatment of stress fractures in athletes

金沢大学附属病院整形外科A literature review was performed to investigate the potential role of bisphosphonates for the treatment of stress fractures in athletes. Given the inhibitory action on osteoclast-mediated bone resorption, short-term suppression of bone remodeling using bisphosphonates could potentially treat stress fractures and prevent stress fractures from becoming regular fractures. To date, while there are some animal studies showing the scientific basis of bisphosphonates on stress fractures, there is still no conclusive evidence to prove any effect of bisphosphonates on stress fracture healing in humans. Further well-designed clinical trials should be carried out to establish their usefulness and safety. Until the results are available, it is prudent to limit the use of bisphosphonates for the treatment of stress fractures. © 2008 Springer-Verlag.

Promotion of rabbit ligament healing by local delivery of hepatocyte growth factor

Background: Extracapsular ligament injuries of the knee and ankle are common injuries. Ligaments heal slowly, usually over months or longer by scar formation rather than by tissue regeneration. This study was performed to evaluate the therapeutic effect of locally delivered recombinant hepatocyte growth factor (HGF) on the early healing of ligaments in a rabbit model. Methods: Japanese white rabbits were subjected to a standardized gap injury in the medial collateral ligaments (MCLs) of both knees. Each rabbit underwent bilateral transection of the midsubstance of the MCL, which was not repaired. During postoperative days 0-6, the rabbits were injected with 10 μg human recombinant HGF into the right MCL, while the left MCL was injected with saline alone. One, 3, 6, and 12 weeks after surgery, experimental rabbits were sacrificed. The structural properties of the femur-MCL-tibia complex were then assessed and the tissue was subjected to histological evaluation. To see the distribution of cells that express c-Met receptor, the tissue was subjected to immunohistochemistry. Results: Immunohistochemical evaluation revealed that c-Met expression was observed particularly at opposing ligament ends in the HGF-treated limbs 1 week after surgery. Histological evaluation revealed earlier neovascularization and more aligned collagen fibers in the MCLs of the HGF-treated group than the control group. In mechanical evaluations, similar ligament failure modes were noted in the two groups. After 3 weeks, HGF-treated limbs had significantly improved structural properties than the paired control limbs. Conclusions: Our findings indicate local administration of recombinant HGF promotes early steps in ligament healing and the repair of structural properties in a rabbit model. Local administration of HGF may represent a new therapeutic approach to accelerating healing and rehabilitation after ligament injury. © 2011 The Japanese Orthopaedic Association

Functional shoulder radiography with use of a dynamic flat panel detector

Our purpose in this study was to develop a functional form of radiography and to perform a quantitative analysis for the shoulder joint using a dynamic flat panel detector (FPD) system. We obtained dynamic images at a rate of 3.75 frames per second (fps) using an FPD system. Three patients and 5 healthy controls were studied with a clinically established frontal projection, with abduction of the arms. The arm angle, glenohumeral angle (G-angle), and scapulothoracic angle (S-angle) were measured on dynamic images. The ratio of the G-angle to the S-angle (GSR) was also evaluated quantitatively. In normal subjects, the G-angle and S-angle changed gradually along with the arm angle. The G-angle was approximately twice as large as the S-angle, resulting in a GSR of 2 throughout the abduction of the shoulder. Changes in G-angle and S-angle tended to be irregular in patients with shoulder disorders. The GSR of the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis were 3-7.5, 4-9.5, and 3.5-7.5, respectively. The GSR of the anterior serratus muscle paralysis improved to approximately 2 after orthopedic treatment. Our preliminary results indicated that functional radiography by FPD and computer-aided quantitative analysis is useful for diagnosis of some shoulder disorders, such as the thoracic outlet syndrome, recurrent dislocation of the shoulder joint, and anterior serratus muscle paralysis. The technique and procedures described comprise a simple, functional shoulder radiographic method for evaluation of the therapeutic effects of surgery and/or rehabilitation. © 2014 The Author(s)

Effect of heat shock preconditioning on ROS scavenging activity in rat skeletal muscle after downhill running

金沢大学附属病院整形外科The mechanisms of the protective effect conferred by heat shock preconditioning (HS) are currently unknown. The purpose of this study was to determine the effect of HS on muscle injury after downhill running and to address the mechanism of the effect. Female Wistar rats were assigned to three groups: HS, downhill running (E), and downhill running after heat shock preconditioning (HS + E). The HS and HS + E rats were placed in a heat chamber for 60 min (ambient temperature 42 ± 1.0°C) 48 h before downhill running. Reactive oxygen species (ROS) scavenging activity was determined by electron spin resonance (ESR), and heat shock protein 72 (HSP72) mRNA expression was measured in rat quadriceps femoris. Leukocyte infiltration and degenerated muscle fibers were determined histopathologically. ROS scavenging activity significantly increased at 3 days after HS (151 ± 18%) and HSP72 mRNA expression increased immediately after HS (1750 ± 1914%). No decrease in ROS scavenging activity was observed in the HS + E rats at 2 days after exercise compared with the E rats (102 ± 9% vs. 79 ± 5%). Degenerated muscle fibers in HS + E rats were significantly less than in E rats at 2, 3, and 7 days after exercise (0.8 ± 1.0 vs. 2.8 ± 1.6, 0.8 ± 1.0 vs. 1.8 ± 1.6, 0 vs. 0.3 ± 0.6, respectively). These data demonstrated that HS can reduce muscle injury after downhill running, and this effect may be mediated by increased ROS scavenging activity. Furthermore, HS may protect the antioxidant defense system in skeletal muscle by enhancing the adaptive HSP72 mRNA response.全文公開20091

Outcomes and failure factors in surgical treatment for osteochondritis dissecans of the capitellum

BACKGROUND: Osteochondritis dissecans (OCD) of the capitellum is an intra-articular lesion and one of the leading causes of permanent elbow disability. The treatment of advanced capitellar OCD remains challenging because of the limited potential of the articular cartilage for self-repair. The purpose of this study was to investigate the outcome of surgical treatment for OCD of the capitellum. METHODS: From 2000 to 2010, 32 male patients who had advanced lesions of capitellar OCD were treated operatively. The mean age of the patients was 14.4 years at the time of surgery. Twenty-nine patients played baseball and 3 played other sports. The lesions were of the centralized type in 9 patients, the lateral type in 4 patients, and the widespread type in 19 patients. For the surgical procedure, osteochondral peg fixation was selected for 13 patients and osteochondral autograft transplantation for 19 patients. Clinical outcome was measured with the elbow rating system including range of motion, and the number of patients who returned to active sports participation within 1 year after surgery was determined. RESULTS: The mean total arc of elbow motion increased from 123±17 degrees preoperatively to 132±14 degrees postoperatively. The mean clinical score improved significantly from 133±24 to 177±27. Within the first year after surgery, 81.3% of the patients returned to active sports playing. However, 4 of 8 patients (50%) in which osteochondral peg fixation was performed for lesions of the lateral widespread type required reoperation. CONCLUSIONS: Our results indicate that osteochondral peg fixation and osteochondral autograft transplantation may improve elbow rating score, and may facilitate a return to active sports participation. However, osteochondral peg fixation may be insufficient for lesions of the widespread type because of their poor stability. The large lateral condyle lesions had a worse outcome, and future studies will need to develop improved treatment for these defects. Copyright © 2013 by Lippincott Williams & Wilkins

Oblique coronal and oblique sagittal MRI for diagnosis of anterior cruciate ligament tears and evaluation of anterior cruciate ligament remnant tissue

Background: The purpose of this study was to investigate the efficacy of additional oblique magnetic resonance imaging (MRI) for the diagnosis of anterior cruciate ligament (ACL) tear and evaluation of ACL remnant tissue. Methods: We retrospectively reviewed the records of 54 knees. Three independent readers evaluated the MR images by the use of three methods: orthogonal sagittal images only (method A); orthogonal sagittal and additional oblique sagittal images (method B); and orthogonal sagittal and oblique coronal images (method C). The sensitivity, specificity, and accuracy for the diagnosis of an ACL tear and the detection of the condition of the ACL remnant tissue by the use of each method were calculated in comparison with arthroscopic findings as the reference standard. Results: The arthroscopic records revealed 27 knees with intact ACLs and 27 with torn ACLs. Among the 27 knees with torn ACLs, 9 did not have continuous remnant tissue and 18 had certain remnant tissue attached to the femur or the posterior cruciate ligament. The specificities and accuracies of methods B and C for diagnosing an ACL tear were higher than those for method A. The sensitivity, specificity, and accuracy of method C for the detection of ACL remnant tissue were higher than those for method A and B. Conclusions: Additional use of oblique MRI improved the accuracy of diagnosis of ACL tear and showed a reasonable level of efficacy in detecting ACL remnant tissue. Level of evidence: Level IV (case series). © 2013 Elsevier B.V