Quantitative tissue parameters of Achilles tendon and plantar fascia in healthy subjects using a handheld myotonometer

Objective

The aim of the study was to examine the quantitative tissue properties of the Achilles tendon and plantar fascia using a handheld, non-invasive MyotonPRO device, in order to generate normal values and examine the biomechanical relationship of both structures.

同种异体肌腱移植重建跖腱膜32例

文章对承德医学院附属医院足底跖腱膜缺损的32例患者进行回顾性病例分析,所有患者应用同种异体肌腱重建跖腱膜,以期最大限度地恢复足的外观,保留足的功能.手术分2期进行:一期完成足底创面的覆盖和修复,根据患者足底损伤的情况,20例患者应用小腿内侧皮瓣修复足底创面.其余12例患者的撕脱皮瓣进行了原位缝合,在创面完全愈合后1个月,进行2期手术.2期手术根据跖腱膜的损伤情况,26例跖腱膜完全缺失的患者应用3条同种异体肌腱进行修复,其余6例跖腱膜部分缺损的患者应用2条同种异体肌腱进行了重建,修复的同时均应用钢丝进行了辅助固定.术后6周,患者扶拐下地行功能锻炼,术后6个月抽出钢丝.32例患者未出现排斥反应,创面均1期愈合.26例术后6个月复查,患者已部分负重行走,X射线平片示足弓彤状维持良好;1年后复查,患者已完全负重行走,X射线半片示足弓形状维持良好;2年后复查,患足功能良好,外形满意,X射线平片示足弓形状维持良好.可见,应用同种异体肌腱重建跖腱膜,不损坏正常的组织结构,不涉及到肌腱粘连的问题,可以维持足的基本形态结构,保留足的功能,是一种可行术式.     

Effects of foot orthoses on Achilles tendon load in recreational runners

Background

Achilles tendon pathology is a frequently occurring musculoskeletal disorder in runners. Foot orthoses have been shown to reduce the symptoms of pain in runners but their mechanical effects are still not well understood.

Methods

This study aimed to examine differences in Achilles tendon load when running with and without orthotic intervention. Twelve male runners ran at 4.0 m·s^− 1. Ankle joint moments and Achilles tendon forces were compared when running with and without orthotics.

Findings

The results indicate that running with foot orthotics was associated with significant reductions in Achilles tendon load compared to without orthotics.

Interpretation

In addition to providing insight into the mechanical effects of orthotics in runners, the current investigation suggests that via reductions in Achilles tendon load, foot orthoses may serve to reduce the incidence of chronic Achilles tendon pathologies in runners.     

Effect of Achilles tendon lengthening on ankle muscle performance in people with diabetes mellitus and a neuropathic plantar ulcer

BACKGROUND AND PURPOSE: The effect of a tendo-Achilles lengthening (TAL) procedure on ankle muscle performance has not been clearly established. The purpose of this study was to compare the effects of TAL and total-contact casting (TCC) with TCC alone on ankle muscle performance in subjects with diabetes mellitus (DM) and a neuropathic plantar ulcer. SUBJECTS: Subjects were randomly assigned to either a TAL group (3 female and 12 male subjects) or a TCC group (4 female and 10 male subjects). METHODS: Muscle performance measurements were obtained using an isokinetic dynamometer. RESULTS: Concentric plantar-flexor peak torque decreased 31% after TAL but returned to the baseline level after 8 months. Dorsiflexor peak torque did not change in either group. Plantar-flexor passive torque at 0 degrees of dorsiflexion decreased after TAL but increased to 60% of the baseline level after 8 months. Maximal dorsiflexion angle increased 11 degrees after TAL and remained increased at 8 months. DISCUSSION AND CONCLUSION: The TAL resulted in an increase in ankle dorsiflexion range of motion and a temporary reduction in concentric plantar-flexor peak torque and passive torque at 0 degrees of dorsiflexion. If TAL is being considered for people with DM and a neuropathic forefoot ulcer, the initial compromise in plantar-flexor muscle performance should be addressed.     

Changes in plantar pressure distribution after Achilles tendon augmentation with flexor hallucis longus transfer

BACKGROUND: Augmentation of the Achilles tendon with flexor hallucis longus is an established method to treat neglected ruptures and severe cases of chronic tendinopathy. After transfer of the muscle/tendon, good pain reduction and improved plantar flexion have been reported. To date, only one study has investigated the effect of FHL transfer on forefoot biomechanics. Theoretically, there should be a partial transfer of forefoot loading towards the lateral metatarsal heads during push-off, resulting in an asymmetric gait. METHODS: 13 patients were examined clinically and using pedobarography with a mean follow-up of 46 months (minimum 24) after Achilles tendon augmentation with flexor hallucis longus. Parameters of the forefoot were investigated to detect differences in pressure and force distribution, load transfer to other areas of the forefoot, and asymmetries compared to the non-operated leg. The results are discussed with regard to clinical relevance. FINDINGS: Clinically, there were no subjective or objective gait asymmetries. All patients were free of pain and without restrictions during normal walking. In general, pedobarography showed an unloading of the first toe with a load transfer to the metatarsal heads on the operated side. All results featured high inter-subject and within-subject variability. INTERPRETATION: Due to the high within-subject variability, there is inconsistency within the results making interpretation difficult. However, the results confirm the hypothesis that unloading of the first toe during push-off and an asymmetrical loading pattern can be measured after harvesting of the flexor hallucis longus. The clinical situation of the patients did not reflect a visible amount of gait asymmetry. Differences in loading patterns 2 years after flexor hallucis longus transfer for Achilles tendon augmentation appear to be well compensated.     

应用等离子刀生物学特征完成内窥镜下跖筋膜松解术

目的:观察等离子刀在内窥镜下跖筋膜松解中的应用效果及优势。方法:选取2002-01/2005-02南京医科大学附属南京第一医院骨科收治的12例患者,跖筋膜炎7例,先天性高弓仰趾足畸形3例,马蹄内翻足2例。分别在跟骨内外侧建立两个入路,引入关节镜和等离子刀。等离子刀由内向外切开跖筋膜,直到显示跖筋膜下的疏松结缔组织或可见到拇展肌、趾短屈肌等的肌纤维。对于高弓足和马蹄内翻足,在切开处的远端用Saber等离子刀再作数个横行切开,并且用蓝钳切除掉部分跖筋膜组织,也可以用等离子刀进行汽化消融。对于跖筋膜炎,只切开跖筋膜内侧的2/3。在高弓足和马蹄内翻足的病例,同时施行截骨矫形、跟腱延长或肌腱转移等其他手术。记录手术时间并观察足跟局部反应和畸形矫正效果。结果:12例患者均成功完成手术进入结果分析。①手术时间5￣20min。②术后足底肿胀较轻,渗出少,未见皮肤的坏死和感染。③术后随访≥14个月。7例跖筋膜炎的病例,有4例疼痛完全缓解,或仅在走高低不平的路时有不适感;3例疼痛较术前有好转,但仍然有隐痛的感觉,不过能接受,不需要服用止痛药。3例高弓足的病例,术后高弓畸形明显改善,足底和趾背胼胝、疼痛消失,能穿皮鞋行走,其中有1例主诉足趾背伸肌力减弱。马蹄内翻足的病例,术后对外形的矫正都很满意。结论:等离子刀用于内窥镜下跖筋膜松解具有明显的优点:①等离子刀具有止血的作用,术后基本没有什么渗血。②创伤小,损伤反应轻,康复快。③操作简便,手术时间短。④安全性高。     

Spontaneous distal rupture of the plantar fascia

Spontaneous ruptures of the plantar fascia are uncommon injuries. They typically occur at its calcaneal insertion and usually represent a complication of plantar fasciitis and local treatment with steroid injections. In contrast, distal ruptures commonly result from traumatic injuries. We describe the case of a spontaneous distal rupture of the plantar fascia in a 48‐year‐old woman with a low level of physical activity and no history of direct injury to the foot, plantar fasciitis, or steroid injections.     

Biomechanics of the Achilles tendon

Purpose. Tendons behave viscoelastically and exhibit adaptive responses to conditions of increased loading and disuse. Strain patterns in tendons may not be uniform, as tendons show stress-shielded areas and areas subjected to compressive loading at the enthesis. These areas correspond to the sites where tendinopathic characteristics are typically seen.

Method. We review the biomechanic literature on Achilles tendon, trying to interpret it on the basis that classic inflammatory changes are not frequently seen in chronic athletic tendon conditions.

Results. Biomechanical studies show that the strains within the tendons near their insertion site are not uniform. If the material properties are similar throughout the tendon, forces transferred through the insertion site preferentially load the side of the tendon that is usually not affected initially in tendinopathy. In that case, the side affected by tendinopathy is generally ‘stress shielded’.

Conclusion. The presence of differential strains opens the possibility of alternative biomechanical explanations for the pathology found in these regions of the tendon. The traditional concept of tensile failure may not be the essential feature of the pathomechanics of insertional tendinopathy. Additional work is needed ascertain whether such principles should be incorporated in current rehabilitation.     

Effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity

BackgroundThe plantar fascia is exposed to repetitive tensile stress induced by cyclic loads associated with daily activities, such as walking and running. Due to overuse or abnormal foot alignment, insertional and distal (i.e., mid-substance) regions within the plantar fascia may exhibit microtears, which leads to plantar fasciopathy. Ultrasound shear wave elastography is an imaging technique to measure shear wave velocity propagating through biological tissues, considered herein as an index of tensile stress. This study aimed to quantify the effect of toe dorsiflexion on the regional distribution of plantar fascia shear wave velocity.MethodsShear wave velocity of the plantar fascia was measured in the insertional and distal regions using ultrasound shear wave elastography in sixteen healthy participants (7 males and 9 females). The measurements were performed while the toes were maintained in neutral or dorsiflexed positions.FindingsWhen considering the insertional region, there was no significant difference in shear wave velocity between neutral toe position [mean (SEM): 5.4 (0.6) m/s] and dorsiflexed toe position [5.5 (0.5) m/s] (P = 0.88; effect size = 0.05). When considering the distal region, there was a significant difference in shear wave velocity between the neutral position [7.8 (0.4) m/s] and dorsiflexed position [9.9 (0.3) m/s] (P = 0.002; effect size = 0.88). The difference in shear wave velocity between the insertional and distal regions showed a large effect size for either neutral (P = 0.010; effect size = 0.75) or dorsiflexed toe position (P = 0.003; effect size = 0.86).InterpretationIn contrast to clinical beliefs, these findings suggest that toe dorsiflexion induces non-homogeneous changes in tensile stress within the plantar fascia.     

The influence of metatarsal support height and longitudinal axis position on plantar foot loading

BACKGROUND: Metatarsal supports are effective at decreasing plantar foot pressures at the metatarsal heads, however, little is known about the dependence of this decrease upon height and position. METHODS: Barefoot static stance pressure measurements were recorded during standing in single limb support (n=22). Two metatarsal support heights (5mm, 10mm) were evaluated in six positions at 5mm increments (0, 5, 10, 15, 20, 25 mm) proximal to the metatarsal heads along the longitudinal axis of the foot. The barefoot condition with no metatarsal support served as the control. Mean force was measured for each test condition. The findings of this study are limited to the barefoot (unshod) condition. FINDINGS: Mean plantar force decreased significantly under the second metatarsal head with both 5 and 10mm metatarsal supports compared to the control, and 10mm metatarsal support compared with 5mm metatarsal support (P<0.05) while no statistically significant differences were noted relative to longitudinal axis position. INTERPRETATION: The results of this study suggest that the thickness of a metatarsal support is a determinant factor in regulating plantar loading. Surprisingly, the longitudinal axis location of a metatarsal support does not appear to be as important as clinically presumed since the data showed that the force decrease was similar for all positions from 5 to 25 mm. Thus, the orthotic induced effect of a metatarsal support seems to have a sizable interaction range that has not previously been reported. We speculate that the metatarsal support's fulcrum and lift effect can be sustained at a more proximal position due to the foot's rigidity as a lever and the manner in which a metatarsal support interacts with the plantar aponeurosis.     

Achilles tendon morphology,plantar flexors torque and passive ankle stiffness in spastic hemiparetic stroke survivors

BackgroundThe present study compared the Achilles tendon morphological characteristics, plantar flexor toque and passive ankle stiffness between hemiparetic spastic stroke survivors and healthy subjects.MethodsThe Achilles tendon length was measured at the affected and contralateral limbs of twelve hemiparetic stroke survivors with ankle spasticity and twelve healthy subjects. The ankle was held at three different angles (20° plantar flexion, 0° and maximum dorsiflexion) while an ultrasound system was used to capture images from the Achilles tendon. Active and passive plantar flexor torque production was measured using an isokinetic dynamometer.FindingsThere was no significant difference in tendon length and Achilles tendon complacency between stroke survivors [affected limb: 20.8 (1.59) cm at 0° and 0.11 (0.09) cm/N; contralateral limb: 20.8 (1.7) cm at 0° and 0.12 (0.08) cm/N] and healthy subjects [20 (2.78) cm at 0° and 0.15 (0.1) cm/N]. The contralateral limb was stronger than the affected limb, while healthy participants presented larger active torque in relation to stroke survivors. There was no significant difference in passive ankle stiffness between the affected [0.43 (0.08) N/°] and the contralateral limb [0.40 (0.11) N/°], but affected limb was significantly stiffer than the healthy subjects [0.32 (0.07) N/°].InterpretationThe larger passive torque and ankle joint stiffness from stroke survivors with similar Achilles tendon length compared to healthy subjects seem to be unrelated to tendon extensibility.     

Endoscopic surgery of the Achilles tendon

The value of endoscopic surgery as a minimally invasive treatment is well recognized and includes less perioperative pain, less scarring, minimal blood loss, and faster recovery. While open surgery on the Achilles tendon is notorious for wound complications, the tendon is situated in a well-formed tunnel allowing surgical procedures to be performed endoscopically. Various endoscopic techniques have been successfully applied to the treatment of non-insertional Achilles tendinopathy, Haglund's syndrome, Achilles tendon rupture, and equinus contracture. Although the evidence is currently limited, results from authors acquainted with the techniques have been encouraging. Both an understanding of surgical anatomy of the hindfoot and familiarity in soft tissue endoscopy are required to achieve successful outcomes while minimizing complications.     

Changes in physical function and ambulatory state after Achilles tendon lengthening for diabetic foot ulcers

[Purpose] The recurrence rate of diabetic foot ulcers is high and is related to kinematic factors. Achilles tendon lengthening has been shown to reduce the recurrence rate of foot ulcers by increasing the range of motion in the ankle joint and decreasing the plantar load. However, there are few reports on the effects of Achilles tendon lengthening in Japanese patients, but the results are yet to be clarified. This study aims to investigate the effects of Achilles tendon lengthening on physical function and ambulatory state in patients with diabetic foot ulcers. [Participants and Methods] This study initially included 10 patients with diabetic ulcers who had undergone Achilles tendon lengthening between April 2013 and March 2020. We retrospectively evaluated the factors available from the medical records. [Results] The dorsiflexion range of motion in the ankle joint increased by 10.5 degrees on average after surgery, while the plantar load decreased by 19.1 percent, while gait speed and stride length remained unchanged. [Conclusion] Achilles tendon lengthening for diabetic foot ulcers increased the range of motion in the ankle joint and decreased the plantar load without changing the ambulatory state.     

Relationships between clinical measures of static foot posture and plantar pressure during static standing and walking

Background

Information is limited about the relationships between clinical measures of static foot posture and peak plantar pressures under the medial column of the foot. The purpose was to examine these relationships during static standing and walking.

Methods

A single-group exploratory design using correlation and regression was used to determine relationships. Ninety-two healthy volunteers participated. Clinical measures of static foot posture including arch index, navicular drop and navicular drift were obtained during static standing. Peak plantar pressures under the hallux, medial forefoot, medial midfoot, and medial rearfoot were obtained during standing and walking.

Findings

Static foot posture was related to peak plantar pressures during standing and walking, but the strengths of relationships ranged from poor to fair. During standing, navicular drop was correlated (P ≤ 0.05) with hallux (r = 0.29) and medial forefoot (r = − 0.17) pressures, while arch index (r = − 0.17) and navicular drift (r = 0.25) were correlated (P ≤ 0.05) with hallux pressure. During walking, arch index, navicular drop and navicular drift were correlated (P ≤ 0.05) with hallux and medial forefoot pressures (r range − 0.30 to 0.41), while arch index (r = − 0.15) and navicular drop (r = 0.16) were correlated (P ≤ 0.05) with medial midfoot pressure. Regression models predicted (P ≤ 0.05) hallux (R² = 0.08) and medial midfoot (R² = 0.05) pressures during standing, and hallux (R² = 0.18), medial forefoot (R² = 0.07), and medial rearfoot (R² = 0.05) pressures during walking.

Interpretation

In healthy participants, lower arch foot postures are associated with greater pressures under the hallux and medial mid-foot and lower pressures under the medial forefoot, but the strength of these relationships may be only poor to fair.     

大鼠跟腱应力屏蔽对转化生长因子β的影响

背景：应力屏蔽引起的肌腱组织内各种细胞因子的改变与肌腱挛缩密切相关,其中转化生长因子β的改变情况尚不清楚。目的：观察应力屏蔽对跟腱转化生长因子β浓度的影响。方法：取雄性SD大鼠20只随机分为2组,左后肢行跟腱应力屏蔽后分别饲养2周和4周,随机抽取的10只大鼠的右后肢正常跟腱组织做对照。以ELISA定量检测各组转化生长因子β的质量浓度。结果与结论：造模组转化生长因子β均比正常组显著升高（P均〈0.01）;造模2周与4周组间差异无显著性意义（P〉0.05）。结果表明跟腱应力屏蔽2周后转化生长因子β已明显升高,到屏蔽4周未见下降,肌腱的合成代谢增强。