Tendinous Tissue Research Articles

Der Einsatz des Neuro-Fasziokutanen Suralisinsellappens zur Defektdeckung im Bereich des Unterschenkels und des Fußes

BackgroundThe closure of soft tissue defects in areas of the distal third lower leg anterior, ankle, heel and foot dorsum especially with exposed bony or tendinous tissue, in case of infections or difficult healing tendency is still challenging. These defects need a stable and sufficient soft tissue cover.With the introduction of the Neuro-Fasciocutaneus suralis island flap (hereinafter called suralis flap) we do have a good alternative with stable results and less operation complexity. Material and methodsSince 2005 we are using this technique for the coverage of complicated defect wounds, especially for complete heel and extensive foot dorsum defects.The most frequent area was the lateral malleolus and the Achilles tendon area with and maximum dimension of 7cm by 11cm. Results2 suralis flaps get lost; in 6 cases we saw superficial skin necrosis.In most of the harvest areas we could directly close the defects, in 7 cases we had to close the defects with split skin grafts.Technically it is easy to learn the harvest of the suralis flap and none of ourpatient's complaint about the reduces sensitivity after necessitated cutting of the suralis nerve. ConclusionDefects in areas of the distal third lower leg anterior, ankle, heel and foot dorsum does need a stable and sufficient soft tissue cover, especially with exposed bony or tendinous tissue or in case of infections or difficult healing tendency.The suralis flap as an alternative to the commonly used free flaps and reduces the surgical effort.

Ipsilateral free semitendinosus graft with interference screw fixation for surgical management of insertional acute Achilles tendon tears

IntroductionVery distal tears of the Achilles tendon are uncommon, and poor quality tendinous tissue of the calcaneal stump can compromise healing. Little has been published about the characteristics and surgical management of such injuries. We present a surgical technique, developed by the senior author, to restore continuity of the gastrosoleus-Achilles tendon-calcaneus complex using a free ipsilateral semitendinosus graft, and clinical outcomes of a case series of 28 consecutive patients. Our hypothesis was that this is a safe technique, and patients can return to pre-injury occupation and athletic activities. Patients and MethodsA total of 28 patients (mean age 46 years) underwent minimally invasive reconstruction using a free ipsilateral semitendinosus graft for acute insertional rupture of tendo Achillis. The procedure required two small incisions along the course of the Achilles tendon, and one posteromedial incision at level of the ipsilateral knee to harvest the semitendinosus tendon. Patients were assessed at minimum 2 years (range, 2–2.5 years) following the index procedure. ResultsThe median Achilles tendon Rupture Score (ATRS) at the latest follow-up was 88. Two patients developed a superficial wound infection. All patients returned to their preinjury occupation, whilst 22 out of 28 patients (79%), returned to their preinjury level of physical activity at a mean of 6.7 months after surgery, reporting good or excellent overall satisfaction in 88.5% of cases. ConclusionThis minimally invasive technique was safe, and allowed most of patients to return to preinjury daily and sport activities within 9 months from surgery.

Possibilities and limitations of electrospun chitosan-coated polycaprolactone grafts for rotator cuff tear repair.

Acute and chronic rotator cuff tears remain challenging for therapy. A wide range of therapeutic approaches were developed but re-tears and postoperative complications occur regularly. Especially in elderly people, the natural regeneration processes are decelerated, and graft materials are often necessary to stabilize the tendon-to-bone attachment and to improve the healing process. We here investigated in a small animal model a newly developed electrospun polycaprolactone fiber implant coated with a chitosan-polycaprolactone graft copolymer and compared these implants biomechanically and histologically with either a commercially available porous polyurethane implant (Biomerix 3D Scaffold) or suture-fixed tendons. Fifty-one rats were divided into three groups of 17 animals each. In the first surgery, the left infraspinatus tendons of all rats were detached, and the animals recovered for 4 weeks. In the second surgery, the tendons were fixed with suture material only (suture-fixed group; n = 17), whereas in the two experimental groups, the tendons were fixed with suture material and the polyurethane implant (Biomerix scaffold group; n = 17) or the modified electrospun polycaprolactone fiber implant (CS-g-PCL scaffold group; n=17), respectively. The unaffected right infraspinatus tendons were used as native controls. After a recovery of 8 weeks, all animals were clinically inconspicuous. In 12 animals of each group, repaired entheses were biomechanically tested for force at failure, stiffness, and modulus of elasticity, and in five animals, repaired entheses were analyzed histologically. Biomechanically, all parameters did not differ statistically significant between both implant groups, and the entheses failed typically at the surgical site. However, with respect to the force at failure, the median values of the two implant groups were smaller than the median value of the suture-fixed group. Histologically, the modified polycaprolactone fiber implant showed no acute inflammation processes, a good infiltration with cells, ingrowth of blood vessels and tendinous tissue, and a normal fibrous ensheathment. Further improvement of the implant material could be achieved by additional implementation of drug delivery systems. Therewith, the used CS-g-PCL fiber mat is a promising basic material to reach the goal of a clinically usable graft for rotator cuff tear repair.

Local hyperalgesia, normal endogenous modulation with pain report beyond its origin: a pilot study prompting further exploration into plantar fasciopathy.

Background and aims Persistent tendinopathies were previously considered solely as peripheral conditions affecting the local tendinous tissue until quantitative sensory testing identified involvement of altered pain processing. In similar fashion, pain in patients with persistent plantar fasciopathy may also involve more than local tissue. The aim of this pilot study was to investigate potential differences in conditioned pain modulation and pressure and thermal pain thresholds, between individuals with PF and healthy pain-free controls, as a precursor to a larger-scale study. Methods We assessed 16 individuals with plantar fasciopathy and 11 pain-free controls. Plantar fasciopathy diagnosis was: palpation pain of the medial calcaneal tubercle or the proximal plantar fascia, duration ≥3 months, pain intensity ≥2/10, and ultrasound-measured plantar fascia thickness ≥4 mm. Quantitative sensory tests were performed locally at the plantar heel and remotely on the ipsilateral elbow. Assessments included pain thresholds for pressure, heat and cold, and conditioned pain modulation measured as change in local resting pressure pain threshold with cold water hand immersion. Participants rated pain intensity at pain threshold. Additionally, the area and distribution of plantar fasciopathy pain was drawn on a digital body chart of the lower limbs. Descriptive analyses were performed and between-group differences/effects expressed as standardised mean differences (d). Results There was no conditioned pain modulation difference between participants with plantar fasciopathy and controls (d = 0.1). Largest effects were on local pressure pain threshold and reported pain intensity on pressure pain threshold (d > 1.8) followed by pain intensity for heat and cold pain thresholds (d = 0.3-1.5). According to the digital body chart, pain area extended beyond the plantar heel. Conclusions The unlikelihood of a difference in conditioned pain modulation yet a pain area extending beyond the plantar heel provide a basis for exploring altered pain processing in a larger-scale study. Implications This was the first study to investigate the presence of altered pain processing in individuals with plantar fasciopathy using a conditioned pain modulation paradigm and thermal pain thresholds. We found no indication of an altered pain processing based on these measures, however, patients rated pain higher on thresholds compared to controls which may be important to clinical practice and warrants further exploration in the future.

Muscle-Tendon Interaction During Human Dolphin-Kick Swimming.

Without high impact forces, it is not clear how humans can utilize tendon elasticity during low-impact activities. The purpose of the present study was to examine the muscle-tendon behavior together with the electromyographic (EMG) activities of the vastus lateralis (VL) muscle during the human dolphin-kicking. In a swimming pool, each subject (n = 11) swam the 25 m dolphin-kicking at two different speeds (NORMAL and FAST). Surface EMGs were recorded from the VL and biceps femoris (BF) muscles. Simultaneous recordings of the knee joint angle by electro-goniometer and of the VL fascicle length by ultrasonography were used to calculate the muscle-tendon unit and tendinous length of VL (LMTU and LTT, respectively). In the dolphin-kicking, the stretching and shortening amplitudes of VL LMTU did not differ significantly between the two kicking speed conditions. However, both stretching and shortening amplitudes of the VL fascicle length were lower at FAST than at NORMAL speed whereas the opposite was found for the VL LTT values. At FAST, the contribution of the VL tendinous length to the entire VLMTU length changes increased. The EMG analysis revealed at FAST higher agonist VL activation from the late up-beat (MTU stretching) to the early down-beat phases as well as increased muscle co-activation of VL and BF muscles from the late down-beat to early up-beat phases of dolphin-kicking. These results suggest that at increasing kicking speeds, the VL fascicles and tendinous tissues during aquatic movements can utilize tendon elasticity in a similar way than in terrestrial forms of locomotion. However, these activation profiles of VL and BF muscles may differ from their activation pattern in terrestrial locomotion.

Influence Of Plyometric Training On Tendinous Tissue Elongation During Initial Phase Of Explosive Power Exertion

Influence Of Plyometric Training On Tendinous Tissue Elongation During Initial Phase Of Explosive Power Exertion

Quantitative Assessment of Muscle Strength Following "Slow" Surgical Lengthening of the Medial Hamstring Muscles in Children With Cerebral Palsy.

Classic teaching for surgical lengthening of muscle contractures in children with cerebral palsy (CP) has emphasized complete correction of the deformity acutely, with immobilization of the targeted muscles in the fully corrected position. Clinical experience has led to the impression that the muscles are invariably weakened by this approach. We have developed an alternative technique for correction of contractures called slow surgical lengthening (SSL). The goal of the study was to determine the physical examination, kinematic, and muscle strength outcomes following SSL of the medial hamstring muscles in children with CP. The study group included 41 children with CP who underwent SSL of the medial hamstring muscles as part of a comprehensive single-event multilevel surgery, who had preoperative and 1-year postoperative evaluations in our Motion Analysis Center, which included quantitative assessment of isometric and isokinetic muscle strength. All subjects were Gross Motor Function Classification System I and II. Mean age at the time of surgery was 10.8 years. The mean popliteal angle improved by 16.2 degrees (P<0.001) following SSL of the medial hamstrings. Sagittal plane kinematics following SSL of the medial hamstrings showed improvement of knee extension at initial contact of 10.2 degrees (P<0.001), decrease of peak knee flexion in mid-swing of 3.6 degrees (P=0.014), improved minimum knee flexion in stance of 4.9 degrees (P=0.002), and no significant change in mean anterior pelvic tilt (P=0.123). Mean peak isometric knee flexion torque remained unchanged from preoperative to postoperative studies (P=0.154), whereas mean peak isokinetic knee flexion torque significantly increased by 0.076 Nm/kg (P=0.014) following medial hamstring SSL. SSL was developed based upon clinical experience and improved understanding of the pathophysiology of skeletal muscle in children with CP. The SSL technique allows the tendinous tissue to separate spontaneously at the time of recession, but does not force further acute lengthening by intraoperative manipulation, thereby minimizing the damage to the underlying muscle. It is broadly believed that muscle weakness is inevitable following surgical lengthening. The current study shows that the SSL technique does not cause weakness. Level IV-therapeutic.

Age-dependent variations in the expression of myosin isoforms and myogenic factors during the involution of the proximal sesamoidean ligament of sheep

In ungulates the stability of the fetlock joint is dependent on several muscles, which are exposed to high stress and strain. Among those muscles, the proximal sesamoidean ligament or PSL (also known as the suspensory ligament or Ruini's elasto-tendinous organ) is organized at birth in layers of muscle fibres alternated with abundant tendinous tissue that, during the postnatal development, becomes the predominant tissue.In this study we analysed the PSL of the sheep at the age of 1, 30 and 180 days and determined the expression of several genes which either (a) are markers of muscle fibre growth and maturation, or (b) play a role as signal molecules. We observed an accelerated maturation, as indicated by the transition of MyHC isoform expression towards the slow isoforms and a reduced regenerative potential indicated by the low Pax7 expression and the altered Wnt signalling. We also found a specific myogenic expression pattern of MyoD, Myf5 and Myogenin in the developing PSL and high mRNA levels of specific fibrogenic factors, as TGF-β1, that, undoubtedly, stimulate the growth of connective tissue. Our observations confirmed, at molecular level, the peculiarity of the fast involution observed in PSL a muscle that undergoes a very specific active differentiation process during early development, which implies myofibres involution and their replacement with connective tissue.

Neuromuscular and Perceptual Responses to Sub-Maximal Eccentric Cycling.

ObjectiveEccentric (ECC) cycle-ergometers have recently become commercially-available, offering a novel method for rehabilitation training. Many studies have reported that ECC cycling enables the development of higher levels of muscular force at lower cardiorespiratory and metabolic loads, leading to greater force enhancements after a training period. However, fewer studies have focused on the specific perceptual and neuromuscular changes. As the two latter aspects are of major interest in clinical settings, this review aimed to present an overview of the current literature centered on the neuromuscular and perceptual responses to submaximal ECC cycling in comparison to concentric (CON) cycling.DesignNarrative review of the literature.ResultsAt a given mechanical workload, muscle activation is lower in ECC than in CON while the characteristics of the musculo-articular system (i.e., muscle-tendon unit, fascicle, and tendinous tissue length) are quite similar. At a given heart rate or oxygen consumption, ECC cycling training results in greater muscular hypertrophy and strength gains than CON cycling. On the contrary, CON cycling training seems to enhance more markers of muscle aerobic metabolism than ECC cycling performed at the same heart rate intensity. Data concerning perceptual responses, and neuromuscular mechanisms leading to a lower muscle activation (i.e., neural commands from cortex to muscular system) at a given mechanical workload are scarce.ConclusionEven though ECC cycling appears to be a very useful tool for rehabilitation purposes the perceptual and neural commands from cortex to muscular system during exercise need to be further studied.

Grafting with double-layered polypropylene mesh for gap healing of mid-metacarpal superficial digital flexor tendon in Equus asinus: clinical and pathological evaluations

Tendon injury is one of the most common causes of wastage in equine. The superficial digital flexor tendon (SDFT) gets affected the most, especially in the mid-metacarpal region. Several studies have focused on the grafting of severed SDFT, but no ideal grafting material has been approved for clinical application. The present study aimed to evaluate the grafting of the mid-metacarpal SDFT in donkeys with a double-layered polypropylene mesh clinically, ultrasonically, macro/microscopically. Clinically healthy adult donkeys (n = 24) were divided randomly and equally into two groups: control (C) and study (S) groups. Tenotomy was performed on all animals by excising a full-thickness segment from the mid-metacarpal SDFT. In the C group, a suture tenorrhaphy was performed. While in the S group, SDFT was grafted with the double-layered polypropylene mesh. The S group showed faster clinical improvements, and earlier appearance of normal newly formed tendinous tissue ultrasonically compared with the C group. Macroscopically, the grafted tendons showed a rapid restoration of normal color and consistency. Moreover, they had minimal peri-tendinous adhesions compared with the non-grafted tendons. Microscopically, the grafted tendons showed earlier vascularization and more mature collagen fibers compared with the non-grafted tendons. In the present study, we have succeeded to graft the gap of the mid-metacarpal SDFT of a donkey using the double-layered polypropylene mesh. This method is an economical way to accelerate the healing process of the SDFT and enhance the clinical recovery in donkeys.

Morphological and mechanical properties of the human triceps surae aponeuroses taken from elderly cadavers: Implications for muscle-tendon interactions.

The human triceps surae (two gastrocnemii and soleus) has aponeuroses in the proximal and distal aspects, the latter of which insert into the calcaneus by sharing the common Achilles tendon. These tendinous tissues are known to have elasticity and upon muscle contraction the aponeurosis is stretched both longitudinally (along the muscle’s line of action) and transversely. Higher aponeurosis transverse deformability has been documented, but there is a paucity of information on the morphology and mechanical properties of human aponeurosis. This study aimed to identify morphological and mechanical characteristics of the human triceps surae aponeuroses. Twenty-five triceps surae muscle-tendon units were procured from 13 human donors (formalin fixed, 6 males, 7 females) aged 67–91 years. Specimens of aponeuroses were excised from the eight regions (posterior and anterior regions of the gastrocnemius medialis and lateralis, medial and lateral parts of soleus; proximal, middle, and distal sites each, 2–4 cm × 2–4 cm). Aponeurosis thickness was measured using a digital caliper. Uniaxial tensile tests were implemented to determine the mechanical properties of specimens loaded longitudinally (along the muscle’s line of action) and transversely. The aponeurosis thickness showed significant differences between muscles and sites, while Young’s modulus showed direction-dependent (longitudinal vs. transverse) differences within sites. Results show different morphology and mechanical properties of aponeuroses between synergist muscles. The reason for site-dependent differences in stiffness is due to a reduced aponeurosis thickness rather than a reduction in the material property. The anisotropic elastic feature (differences between longitudinal and transverse directions) of the aponeuroses was more pronounced than previous in vivo findings, suggesting inherent material design of the aponeurosis that matches three-dimensional contractile behavior of muscle fibers.

Tenosynovitis With Psammomatous Calcifications: A Distinctive Trauma-Associated Subtype of Idiopathic Calcifying Tenosynovitis With a Predilection for the Distal extremities of Middle-Aged Women-A Report of 23 Cases.

The term "idiopathic calcifying tenosynovitis" (ICT) refers to a clinically and radiologically defined syndrome of pain and tendinous calcifications, most often involving the shoulder joint. A distinctive subset of ICT cases, termed "tenosynovitis with psammomatous calcifications" (TPC), occurs in the distal extremities and shows characteristic morphology, in particular psammomatous calcifications. As only 14 cases have been reported to date, TPC remains poorly recognized by both pathologists and clinicians. Twenty-three well-characterized cases of TPC along with all available radiologic and clinical information, including follow-up, were collected. Cases occurred in 21 females and 1 male (1 patient of unknown sex), aged 16 to 75 years (mean: 41), and almost exclusively involved the fingers and toes, except for one case in the elbow and one in the knee joint. The lesions ranged from 2 to 30 mm in size (mean: 10 mm). Pain was the most common presenting symptom (12/16 patients). A history of trauma or repetitive activity was present in 6 of 15 patients. None of the individuals was known to have disorders in calcium or phosphate metabolism. Radiographic studies showed a nonspecific, calcified mass. Typical morphologic features of TPC were invariably present, with degenerating tendinous tissue containing psammomatous calcifications, surrounded by a variably cellular, CD68/CD163/CD4-positive histiocyte-rich granulomatous host reaction. HUMARA assay in one case showed a polyclonal pattern. Clinical follow-up (19 patients; mean: 5.2 y; range: 1 to 14 y) showed no local recurrences. In this, the largest study of TPC to date, we confirm striking predilection of this distinctive pseudoneoplasm for the fingers and toes of young to middle-aged women. TPC should be rigorously distinguished from other forms of ICT, which typically involve large, proximal joints, and show simply dystrophic calcification involving tendinous tissues, and from tumoral calcinosis, which also involves large joints and often is associated with calcium and/or phosphate abnormalities. TPC appears to be related to trauma and/or repetitive activity and is cured with simple excision.

Tibialis anterior tendinous tissue plays a key role in energy absorption during human walking.

The elastic tendinous tissues of distal lower limb muscles can improve the economy of walking and running, amplify the power generated by a muscle and absorb energy. This paper explores the behaviour of the tibialis anterior (TA) muscle and its tendinous tissue during gait, as it absorbs energy during contact and controls foot position during swing. Simultaneous measurements of ultrasound, surface electromyography and 3D motion capture with musculoskeletal modelling from 12 healthy participants were recorded as they walked at preferred and fast walking speeds. We quantified the length changes and velocities of the TA muscle-tendon unit (MTU) and its fascicles across the stride at each speed. Fascicle length changes and velocities were relatively consistent across speeds, although the magnitude of fascicle length change differed between the deep and superficial regions. At contact, when the TA is actively generating force, the fascicles remained relatively isometric as the MTU actively lengthened, presumably stretching the TA tendinous tissue and absorbing energy. This potentially protects the muscle fibres from damage during weight acceptance and allows energy to be returned to the system later in the stride. During early swing, the fascicles and MTU both actively shortened to dorsiflex the foot, clearing the toes from the ground; however, at the fast walking velocity, the majority of shortening occurred through tendinous tissue recoil, highlighting its role in accelerating ankle dorsiflexion to power rapid foot clearance in swing.

Cigarette smoking intensifies tendinopathy of the LHBT. A microscopic study after arthroscopic treatment.

Smoking has adamaging effect on the musculoskeletal system, which was presented by authors in the rotator cuff and Achilles tendons studies; however, there are alack of data about the effect of smoking on disorders of the long head of the biceps tendon (LHBT), particularly at the microscopic level. The purpose of this study was to investigate the effect of the tobacco smoking on the histopathologic alterations of the LHBT. Thirty-six patients with preoperatively diagnosed tendinopathy of the LHBT were referred to the Orthopaedics Department. All patients underwent arthroscopic treatment with further macroscopic and microscopic evaluation of biceps tendon samples. The active and former smokers were characterised by more advanced degenerative process of the tendinous tissue; moreover, it was intensified in the group of former smokers. Subjects who smoke more than 20 cigarettes per day also had more advanced microscopic alterations. The most severe microscopic alterations occurred in the former smokers who used tobacco for more than 20 years. However, the non-smokers group revealed moderate degeneration in all LHBT samples. Tobacco smoking is an important risk factor of the LHBT disease, which essentially intensifies the degeneration of the tendinous tissue.

Muscle-tendon behaviour during sprint in road cyclists: effect of the force-velocity condition

Muscle-tendon behaviour during sprint in road cyclists: effect of the force-velocity condition

Anatomie et tendinopathie patellaire : un malentendu

The anatomical structure linking the patella and the tibia is called the “patellar ligament” in the international nomenclature. This term is well accepted yet can be a source of confusion for non-specialists. This is because the priority role of this structure is not to maintain joint stability, the primary role of the cruciate ligaments and the collateral ligaments, but rather to prolong the mechanical action of the quadriceps muscle onto the leg skeleton beyond the “patellar sesmoid”. Patellar tendon injuries are a common observation in sports medicine. The proximal third of the tendon below the patella is most generally involved. This highly frequent tendinopathy sometimes termed an “insertion” tendiopathy. Based on 100 consecutive magnetic resonance imaging studies and cadaveric dissection, we confirm that the insertion of the patellar tendon is situated on the anterior aspect of the patella and not the tip. We describe two anatomical variants of the healthy patellar tendon (type 1 and 2) that should not be confused with a site of tendinopathy. The anatomical limits between tendinous tissue and infrapatellar adipose body (the Hoffa adipose ligament), notably on the upper third is still debated and merits further work.

Interactions between fascicles and tendinous tissues in gastrocnemius medialis and vastus lateralis during drop landing.

Animal tendons have been shown to act as shock absorbers to protect muscle fascicles from exercise-induced damage during landing tasks. Meanwhile, the contribution of tendinous tissues to damping activities such as landing has been less explored in humans. The aim of this study was to analyze in vivo fascicle-tendon interactions during drop landing to better understand their role in energy dissipation. Ultrafast ultrasound images of the gastrocnemius medialis (GM) and vastus lateralis (VL), lower limb electromyographic activity, 2-D kinematics, and ground reaction forces were collected from twelve participants during single- and double-leg drop landings from various heights. For both muscles, length changes were higher in tendinous tissues than in fascicles, demonstrating their key role in protecting fascicles from rapid active lengthening. Increasing landing height increased lengthening and peak lengthening velocity of VL fascicle and GM architectural gear ratio, whereas GM fascicle displayed similar length and velocity patterns. Single-leg landing lengthens the tendinous tissues of GM and, to a greater degree, VL muscles, without affecting the fascicles. These findings demonstrate the adjustment in fascicle-tendon interactions to withstand mechanical demand through the tendon buffer action and fascicle rotation. The higher VL fascicle contribution to negative work as the drop height increases would suggest muscle-specific damping responses during drop landing. This can originate from the distal-to-proximal sequence of joint kinetics, from differences in muscle and tendon functions (one- and two-joint muscles), architectural and morphological properties (eg, tendon stiffness), as well as from the muscle activity of the GM and VL muscles.

Tendinous Tissue Adaptation to Explosive- vs. Sustained-Contraction Strength Training.

The effect of different strength training regimes, and in particular training utilizing brief explosive contractions, on tendinous tissue properties is poorly understood. This study compared the efficacy of 12 weeks of knee extensor explosive-contraction (ECT; n = 14) vs. sustained-contraction (SCT; n = 15) strength training vs. a non-training control (n = 13) to induce changes in patellar tendon and knee extensor tendon–aponeurosis stiffness and size (patellar tendon, vastus-lateralis aponeurosis, quadriceps femoris muscle) in healthy young men. Training involved 40 isometric knee extension contractions (three times/week): gradually increasing to 75% of maximum voluntary torque (MVT) before holding for 3 s (SCT), or briefly contracting as fast as possible to ∼80% MVT (ECT). Changes in patellar tendon stiffness and Young’s modulus, tendon–aponeurosis complex stiffness, as well as quadriceps femoris muscle volume, vastus-lateralis aponeurosis area and patellar tendon cross-sectional area were quantified with ultrasonography, dynamometry, and magnetic resonance imaging. ECT and SCT similarly increased patellar tendon stiffness (20% vs. 16%, both p < 0.05 vs. control) and Young’s modulus (22% vs. 16%, both p < 0.05 vs. control). Tendon–aponeurosis complex high-force stiffness increased only after SCT (21%; p < 0.02), while ECT resulted in greater overall elongation of the tendon–aponeurosis complex. Quadriceps muscle volume only increased after sustained-contraction training (8%; p = 0.001), with unclear effects of strength training on aponeurosis area. The changes in patellar tendon cross-sectional area after strength training were not appreciably different to control. Our results suggest brief high force muscle contractions can induce increased free tendon stiffness, though SCT is needed to increase tendon–aponeurosis complex stiffness and muscle hypertrophy.

Reconstruction of Kuwada grade IV chronic achilles tendon rupture by minimally invasive technique

Category: Trauma Introduction/Purpose: Transfer of a flexor hallucis longus (FHL) tendon can not only reconstruct the Achilles tendon but also provide ischemic tendinous tissues with a rich blood supply to enhance wound healing. This retrospective study aims to investigate clinical outcomes in patients who underwent repair of Kuwada grade IV chronic Achilles tendon rupture with long hallucis longus tendons harvested using a minimally invasive technique. Methods: 35 patients who were treated for Kuwada grade IV Achilles tendon injuries from July 2006 to June 2011 were included in this retrospective study. The age ranged between 23 and 71 years. The duration from primary injury to surgery ranged from 29 days to 34 months (mean value, 137.6 days). All 35 patients had difficulties in lifting their calves. 32 were followed up for a mean 32.2 months (range 18-72 months), whereas 3 were lost to follow-up. Magnetic resonance imaging (MRI) showed that the tendon rupture gap ranged from 6.0 to 9.2 cm. Postoperative appearance and function were evaluated by physiotherapists based American Orthopedic Foot and Ankle Society-ankle and hindfoot score (AOFAS-AH), and Leppilahti Achilles tendon ratings. Results: Results were assessed in 32 patients. Except for one patient who suffered complications because of wound disruption 10 days after the operation, all other patients had primary wound healing, with 28 of 32 able to go up on their toes at last follow-up. The AOFAS-AH score was increased from preoperative (51.92 ± 7.08) points to (92.56 ± 6.71) points; Leppilahti Achilles tendon score was increased from preoperative (72.56 ± 7.43) to (92.58 ± 5.1). There were statistically significant differences. The result of the total excellent and good rate was 93.8% (30/32). MRI of Achilles tendon showed even signal without evidence of tear or cystic degeneration. Conclusion: Reconstruction of a chronic Achilles tendon rupture with an FHL tendon harvested using a minimally invasive technique showed good outcomes.

Specialized properties of the triceps surae muscle-tendon unit in professional ballet dancers.

This study compared professional ballet dancers (n=10) to nonstretching controls (n=10) with the purpose of comparing muscle and tendon morphology, mechanical, neural, and functional properties of the triceps surae and their role for ankle joint flexibility. Torque-angle and torque-velocity data were obtained during passive and active conditions by use of isokinetic dynamometry, while tissue morphology and mechanical properties were evaluated by ultrasonography. Dancers displayed longer gastrocnemius medialis fascicles (55±5 vs 47±6mm) and a longer (207±33 vs 167±10mm) and more compliant (230±87 vs 364±106N/mm) Achilles tendon compared to controls. Greater passive ankle dorsiflexion range of motion (40±7 vs 17±9°) was seen in dancers, resulting from greater fascicle strain and greater elongation of the muscle. Peak electromyographic (EMG) activity recorded during passive stretching was lower in dancers, and at common joint angles, dancers displayed lower EMG amplitude and lower passive joint stiffness. No differences between groups were seen in maximal isometric plantar flexor torque, isokinetic peak torque, angle of peak torque, or work. In conclusion, the greater ankle joint flexibility of professional dancers seems attributed to multiple differences in morphological and mechanical properties of muscle and tendinous tissues, and to factors related to neural activation.