Tendon Motion Research Articles

Exosomes From M2 Macrophage Promote Peritendinous Fibrosis Posterior Tendon Injury via the MiR-15b-5p/FGF-1/7/9 Pathway by Delivery of circRNA-Ep400.

Achilles tendon rupture prognosis is usually unsatisfactory. After the tendon is injured, it may not function properly because of the fibrotic healing response, which restrains tendon motion. Inflammatory monocytes and tissue-resident macrophages are indispensable regulators in tissue repair, fibrosis, and regeneration. Exosomes from macrophages are crucial factors in tissue microenvironment regulation following tissue injury. This study therefore aimed to clarify the roles of macrophage exosomes in tendon injury (TI) repair. The results show that macrophages play a role after TI. M1 macrophages were increased relative to peritendinous fibrosis after TI. High-throughput sequencing showed abnormal expression of circular RNAs (circRNAs) between exosomes from M2 and M0 macrophages. Among the abnormal expressions of circRNA, circRNA-Ep400 was significantly increased in M2 macrophage exosomes. The results also show that M2 macrophage-derived circRNA-Ep400-containing exosomes are important for promoting peritendinous fibrosis after TI. Bioinformatics and dual-luciferase reporting experiments confirmed that miR-15b-5p and fibroblast growth factor (FGF)-1/7/9 were downstream targets of circRNA-Ep400. High circRNA-Ep400-containing exosome treatment inhibited miR-15b-5p, but promoted FGF1/7/9 expression in both fibroblasts and tenocytes. Furthermore, high circRNA-Ep400-containing exosome treatment promoted fibrosis, proliferation, and migration in both fibroblasts and tenocytes. Taken together, the results show that M2 macrophage-derived circRNA-Ep400-containing exosomes promote peritendinous fibrosis after TI via the miR-15b-5p/FGF-1/7/9 pathway, which suggests novel therapeutics for tendon injury treatment.

Carpal tunnel syndrome treatment and the subsequent alterations in tendon and connective tissue dynamics

BackgroundCarpal tunnel syndrome patients demonstrate diminished motion of the median nerve and fibrotic changes in the subsynovial connective tissue within the carpal tunnel. Currently, there are few prognostic factors to help predict the outcome of commonly performed treatments including surgical carpal tunnel release and corticosteroid injections. This study aimed to non-invasively assess the changes in the dynamic response of the subsynovial tissue relative to tendon motion after the intervention and to correlate this with disease severity. MethodsA total of 145 patients with carpal tunnel syndrome were recruited into this study. Clinical and demographic data, electrophysiological severity and dynamic ultrasound images were collected before and after treatment, either by injection or surgery. The relative motion of the subsynovial tissue with the underlying middle finger flexor digitorum superficialis tendon was measured using a speckle tracking algorithm and was expressed as a shear index (SI). Baseline and follow-up data, the association between change in SI and severity, and the role of treatment modality were analyzed and statistically compared. FindingsOverall, there was a significant increase (more relative motion) after treatment in the mean shear index from 79.9% (±15.4% SD) to 82.9% (±14.8% SD) (p = 0.03). Secondary analyses showed that this change was mostly present in those with mild disease severity undergoing surgery (p = 0.01). InterpretationThis study shows that the relative subsynovial tissue movement increases in patients after intervention. The present study lays a foundation for future studies to non-invasively assess the role of carpal tunnel dynamics in response to treatment.

Cyclic tensile tests of Shetland pony superficial digital flexor tendons (SDFTs) with an optimized cryo-clamp combined with biplanar high-speed fluoroscopy

BackgroundLong-term cyclic tensile testing with equine palmar/plantar tendons have not yet been performed due to problems in fixing equine tendons securely and loading them cyclically. It is well established that the biomechanical response of tendons varies during cyclic loading over time. The aim of this study was to develop a clamping device that enables repetitive cyclic tensile testing of equine superficial digital flexor tendon for at least 60 loading cycles and for 5 min.ResultsA novel cryo-clamp was developed and built. Healthy and collagenase-treated pony SDFTs were mounted in the custom-made cryo-clamp for the proximal tendon end and a special clamping device for the short pastern bone (os coronale). Simultaneously with tensile testing, we used a biplanar high-speed fluoroscopy system (FluoKin) to track tendon movement. The FluoKin system was additionally validated in precision measurements. During the cyclic tensile tests of the SDFTs, the average maximal force measured was 325 N and 953 N for a length variation of 2 and 4 % respectively. The resulting stress averaged 16 MPa and 48 MPa respectively, while the modulus of elasticity was 828 MPa and 1212 MPa respectively. Length variation of the metacarpal region was, on average, 4.87 % higher after incubation with collagenase. The precision of the FluoKin tracking was 0.0377 mm, defined as the standard deviation of pairwise intermarker distances embedded in rigid bodies. The systems accuracy was 0.0287 mm, which is the difference between the machined and mean measured distance.ConclusionIn this study, a good performing clamping technique for equine tendons under repetitive cyclic loading conditions is described. The presented cryo-clamps were tested up to 50 min duration and up to the machine maximal capacity of 10 kN. With the possibility of repetitive loading a stabilization of the time-force-curve and changes of hysteresis and creep became obvious after a dozen cycles, which underlines the necessity of repetitive cyclical testing. Furthermore, biplanar high-speed fluoroscopy seems an appropriate and highly precise measurement tool for analysis of tendon behaviour under repetitive load in equine SDFTs.

Anterolateral Thigh and Vascularized-tensor Fascia Lata Flaps for Long-gap Achilles Tendon Reconstruction.

Summary:We demonstrated our surgical technique of 8-cm segmental loss Achilles tendon reconstruction and repair of posterior heel skin and soft tissue defects with composite anterolateral thigh and 4-layer folding vascularized-tensor fasciae latae flaps of a 15-year-old adolescent boy’s post-traumatic injury and infection after primary repair. This technique highlights the ease of harvesting the flap, short operative time, and facilitation of the strong and sustainable motion of the Achilles tendon after reconstruction.

Attachment devices and the tarsal gland of the bug Coreus marginatus (Hemiptera: Coreidae)

The present ultrastructural investigation using scanning and transmission electron microscopy as well as light and fluorescence microscopy describes in detail the attachment devices and tarsal gland of the bug Coreus marginatus (L.) (Hemiptera: Coreidae). In particular, the fine structure of pulvilli reveals a ventral surface rich with pore channels, consistent with fluid emission, and a folded dorsal surface, which could be useful to enhance the pulvillus contact area during attachment to the substrate. The detailed description of the tarsal gland cells, whose structure is coherent with an active secretory function, allows us to consider the tarsal gland as the plausible candidate for the adhesive fluid production. Scolopidia strictly adhering to the gland cells are also described. On the basis of the fine structure of the tarsal gland, we hypothesise a fluid emission mechanism based on changes of the hydraulic pressure inside the gland, due to the unguitractor tendon movements. This mechanism could provide the fluid release based on compression of the pad and capillary suction, as demonstrated in other insects. The data here reported can contribute to understanding of insect adhesive fluid production, emission and control of its transport.

Measurements of Tendon Movement Within the Bicipital Groove After Suprapectoral Intra-articular Biceps Tenodesis in a Cadaveric Model.

Background:Lesions of the long head of the biceps can be successfully treated with biceps tenotomy or tenodesis when surgical management is elected. The advantage of a tenodesis is that it prevents the potential development of a cosmetic deformity or cramping muscle pain. Proponents of a subpectoral tenodesis believe that “groove pain” may remain a problem after suprapectoral tenodesis as a result of persistent motion of the tendon within the bicipital groove.Purpose/Hypothesis:To evaluate the motion of the biceps tendon within the bicipital groove before and after a suprapectoral intra-articular tenodesis. The hypothesis was that there would be minimal to no motion of the biceps tendon within the bicipital groove after tenodesis.Study Design:Controlled laboratory study.Methods:Six fresh-frozen cadaveric arms were dissected to expose the long head of the biceps tendon as well as the bicipital groove. Inclinometers and fiducials (optical markers) were used to measure the motions of the scapula, forearm, and biceps tendon through a full range of shoulder and elbow motions. A suprapectoral biceps tenodesis was then performed, and the motions were repeated. The motion of the biceps tendon was quantified as a function of scapular or forearm motion in each plane, both before and after the tenodesis.Results:There was minimal motion of the native biceps tendon during elbow flexion and extension but significant motion during all planes of scapular motion before tenodesis, with the most motion occurring during shoulder flexion-extension (20.73 ± 8.21 mm). The motion of the biceps tendon after tenodesis was significantly reduced during every plane of scapular motion compared with the native state (P < .01 in all planes of motion), with a maximum motion of only 1.57 mm.Conclusion:There was a statistically significant reduction in motion of the biceps tendon in all planes of scapular motion after the intra-articular biceps tenodesis. The motion of the biceps tendon within the bicipital groove was essentially eliminated after the suprapectoral biceps tenodesis.Clinical Relevance:This arthroscopic suprapectoral tenodesis technique can significantly reduce motion of the biceps tendon within the groove in this cadaveric study, possibly reducing the likelihood of groove pain in the clinical setting.

Stretchable triboelectric sensor for measurement of the forearm muscles movements and fingers motion for Parkinson's disease assessment and assisting technologies

AbstractParkinson's disease (PD) is a degenerative, neurological disease that causes motor dysfunctions on the patient. Currently, the symptoms and progression of the disease are assessed by physicians who diagnose through careful observation, according to the Movement Disorder Society (MDS)‐sponsored Revision of the Unified Parkinson's Disease Rating Scale (UPDRS). In this manuscript, we report a portable sensor device based on a flexible Triboelectric Nanogenerator (TENG) formed from a dielectric material with a size of 4 cm × 3.5 cm and an aluminium (Al) electrode with dimensions of 2 mm × 3 mm, to monitor the movement of forearm muscles and tendons. When the hand or fingers extend or flex, the short gap between the dielectric polymer and the small conductor changes, generating a voltage due to triboelectric contact. The device is used to assess localized bradykinesia and rigidity of fingers and hands, as well as wrist and arm tremors. The voltage signal of the proposed sensor shows different waveform shapes, time duration and amplitude for each level of classification from ‘normal’ to ‘moderate’ status, described on the MDS‐UPDRS examination of hand movement, finger tapping and pronation–supination movement. Hence, we demonstrated that the proposed sensor can potentially be used for quantification of the symptoms and diagnosing. In addition, single finger motion tracking is also achieved by placing the triboelectric sensor in different positions around the forearm, close to the tendon connected to the finger under test. This way we avoid the placement of the sensor directly on the fingers, improving comfortability and long‐term wearability. The presented TENG sensor is fully integrated with the processing and the transmission board exploring new opportunities for triboelectric transducers in small motion detection of muscles. The future aim of this research is to provide real‐time monitoring of the disease progression as feedback for personalized treatment of the PD patients.

Biomechanical aspects of Tai Chi Chuan countermeasure against health threats during spaceflight

In support of NASA’s plan to establish human settlements on the Moon and Mars in the near future and the emergence of cutting-edge artificial intelligence as a tool for better health care, we look for ways to help astronauts stay physically and mentally healthy during a long and stressful trip. After reviewing existing aerobic and strength exercise methods available to astronauts, we propose that traditional Tai Chi Chuan (TCC) or Taijiquan can serve as a non-invasive intervention to help astronauts maintain physical and physiological integrity and cope with the impact of microgravity during and after spaceflights. Biomechanical aspects of TCC in terms of neuromuscular and musculoskeletal conditions are presented based on a review of evidence from the scientific literature that defines physiological responses associated specifically with the practice of TCC as relevant to space mission-related effects of microgravity on human physiology. This article provides a comprehensive review and description of the TCC biomechanics and their health influences in microgravity. The mysterious Chi (or Qi) of TCC is scientifically defined as kinesthetic sensations of position, movement, and force of muscles, tendons, and joints throughout body segments in kinetic chain motions. These sensations can be used to judge the correctness of TCC trainings as a countermeasure against microgravity to improve proprioception, kinesthesia, and mind-body coordination for astronauts. This study has far-reaching implications for the integration of TCC practices in complement with the effectiveness of existing countermeasure approaches, and provides direction for future research that might bridge the knowledge gap in improving exercise countermeasures for human spaceflight.

The use of a surgical planning tool for evaluating the optimal surgical accessibility to the stapedius muscle via a retrofacial approach during cochlear implant surgery: a feasibility study

PurposeDuring cochlear implant (CI) surgery, visual detection of the stapedius reflex as movements of the stapes tendon, electrically elicited via the CI, is a standard measure to confirm the system's functionality. Direction visualization of the stapedius muscle (SM) movements might be more reliable, but a safe access to the small SM is not defined. A new surgical planning tool for pre-operative evaluation of the accessibility to the stapedius muscle (SM) during a cochlear implantation (CI) via a retrofacial approach was now evaluated.MethodsA surgical planning tool was developed in MATLAB using an image processing algorithm to evaluate drilling feasibility. A flat-panel computed tomography (CT) combining a rotational angiographic C-arm units with flat-panel detectors (Dyna-CT) was used. In total, 30 3D Dyna-CT-based temporal bone reconstructions were evaluated by automatized algorithms, generating a series of trajectories and comparing their feasibility and safety to reach the SM via a retrofacial approach. The predictability of the surgical planning tool results was tested in 5 patients.ResultsThe surgical planning tool showed that a retrofacial access to the SM would be feasible in 25/30 cases. Moreover, the evaluation of the predictability of the results obtained with the surgical planning tool conducted during 5 CI surgeries confirmed the results. Both the surgical planning tool and the results on SM accessibility via retrofacial approach during CI showed that this is safe and feasible only when the SM-exposed area was > 25% of its total, the distance between the SM and the facial nerve was > 0.8 mm, and the surgical corridor diameter was > 3 mm.ConclusionThe surgical planning tool seems to be useful for the pre-operative evaluation of the accessibility to the SM during a CI surgery via a retrofacial approach. Further prospective studies are needed to validate the results in larger cohorts.

Automated detection of electrically evoked stapedius reflexes (eSR) during cochlear implantation

IntroductionIn cochlear implantation, objective fitting methods are needed to optimize audiological results in small children or patients with poor compliance. Intraoperatively measured electrically evoked stapedius reflexes (eSR) can be used as a marker for the patient’s discomfort level. The aim of this study was to develop and evaluate an automated detection method for eSR and to compare it to the detection rate of the surgeon and independent observers.MethodsCochlear implantation using a fully digital surgical microscope was performed. Movements of the stapedius tendon were recorded and analyzed by means of computer vision technique. Differences in eSR elicited by stimulating electrodes at different cochlear locations (basal, middle and apical) were analyzed. The eSR detection rate of the image processing algorithm was compared to the surgeon’s detection rate and to those of two less experienced observers.ResultsA total of 387 electrically impulses were applied. The stimulation of middle turn electrodes showed significantly higher detection rates (50.4%) compared to the basal (40.0%; p = 0.001) and apical (43.6%; p = 0.03) turn. The software identified significantly more of the applied stimuli (58.4%) compared to the surgeon (46.3%; p = 0.0007), the intermediate observer (37.7%; p < 0.0001) and the unexperienced observer (41.3%; p < 0.0001).ConclusionThe feasibility of an automated intraoperative software-based detection of eSR is demonstrated. By improving the eSR detection methods and their clinical applicability, their utility in objective cochlear implant fitting may be substantially increased.

Relative Motion of the Connective Tissue in Carpal Tunnel Syndrome: The Relation with Disease Severity and Clinical Outcome

Excursion of the median nerve and the surrounding subsynovial connective tissue (SSCT) is diminished in patients with carpal tunnel syndrome (CTS). This study sought to determine if SSCT excursion could be utilized to predict surgical outcome. Idiopathic CTS patients were reviewed with ultrasound and electrodiagnostic tests at baseline. A speckle tracking algorithm was used to determine SSCT relative to tendon motion (shear index). Analysis of variance tests were used to compare SSCT motion with disease severity at baseline. Adjusted linear regressions were used to test the association with patient-reported outcome. A total of 90 CTS patients were analyzed and found to have an average shear index of 79% (95% confidence interval: 76.3%–81.6%). SSCT motion was lower in CTS patients with increasing electrophysiological severity (p = 0.0475). There was no significant association of pre-operative SSCT motion with symptomatic improvement (p = 0.268). Overall, SSCT motion is decreased in CTS patients, but exhibits limited correlation with clinical severity.

Kinetic dysfunction of the wrist with chronic scapholunate dissociation. A cadaver study

BackgroundMost laboratory studies investigating scapholunate dissociations are based on normal cadaver arms with serially sectioned ligaments. It is assumed that the kinetic behavior of a ligament-sectioned wrist is similar to a scapholunate dissociation. We tested five cadaver wrists with real injuries. The goal of this research was to evaluate the biomechanical behavior of scapholunate advanced collapse wrists compared to an experimental group with simulated injuries. Methods: Using a magnetic 6-degree of freedom motion tracking device, changes in scaphoid alignment induced by isometric loading 5 wrist motor tendons in two groups of specimens were monitored. Twelve fresh cadaver wrists in which scapholunate injury was simulated by sectioning the scapholunate ligament were compared to 5 arms with chronic scapholunate dissociation.Findings: The behavior of the scaphoid is the same in both groups, but the magnitude of displacement is greater in chronic scapholunate dissociation wrists, although not statistically significant. The extensor carpi ulnaris is the only muscle that provokes scaphoid pronation; all other muscles induce its supination. Interpretation: Different factors may play a role in the amount of scaphoid rotation observed in wrists with chronic scapholunate dissociation. Ligament sectioning alone in the experimental setup can only partially replicate the behavior of real scapholunate dissociations. The extensor carpi ulnaris has a major role in destabilizing scapholunate advanced collapse wrists; therefore, isometric contraction of this muscle should be avoided in the conservative treatment. The experimental setup designed is useful to evaluate the biomechanical behavior of the carpus under traction load.

A Sequenced and Team Approach to Surface Anatomy Education in Physical Therapy in Preparation for Clinical Practice and Collaborative Care

A deep understanding of anatomy is foundational in the clinical practice of physical therapy, and is key to discovery and scholarly work in movement sciences. Similar to several other health science professions, education of the physical therapist begins with prerequisite coursework in an undergraduate program, continues with doctoral‐level courses in a graduate program, and often post‐licensure residency or fellowship training. Anatomy and physiology are prerequisites for many DPT programs, and anatomy is included in the required elements for accreditation of DPT programs, residencies and fellowships. Surface anatomy is foundational for clinical work in physical therapy and is honed over years of practice.In the DPT curriculum, surface anatomy is incorporated into early courses in gross anatomy and skills acquisition, including training in goniometry and assessment of muscle strength and vital signs. Surface anatomy continues into advanced gross anatomy courses and education in physical examination, neuromusculoskeletal assessment, and movement science. Early on, students identify bony landmarks, arterial pulses and muscle bulk, similar to early learners in medical curricula. As they progress, DPT students learn to observe subtle contours and shadows, identify muscle weaknesses and joint restrictions through observation of movement, assess muscle contraction and tendon motion using ultrasound imaging, and palpate delicate superficial nerves, millimeter differences in joint motion, and directional restrictions in layers of fascia.Licensed physical therapists gain additional knowledge of anatomy through continuing education courses, residency and fellowship training. Courses may include advanced training in such areas as pelvic health, oncological care, prosthetics, or vestibular rehabilitation. Residencies and fellowships enable clinical specialization, such as in pediatrics, orthopedics or cardiopulmonary care. Each of these courses and specialty certifications includes advanced training in surface observation of underlying anatomy.In this talk, Dr. Topp will describe a sequenced approach to surface anatomy education in physical therapy, and how surface anatomy is used in clinical physical therapy. As budding experts in anatomy, students in physical therapy may provide guidance in surface anatomy for physicians in training, and the talk will include examples of near‐peer learning of surface anatomy and case‐based musculoskeletal examinations.Support or Funding InformationNo funding was required.

Mechanics of Psoas Tendon Snapping. A Virtual Population Study

Internal snapping of the psoas tendon is a frequently reported condition, especially in young adolescents involved in sports. It is defined as an increased tendon excursion over bony or soft tissue prominence causing local irritation and inflammation of the tendon leading to groin pain and often is accompanied by an audible snap. Due to the lack of detailed dynamic visualization means, the exact mechanism of the condition remains poorly understood and different theories have been postulated related to the etiology and its location about the hip. In the present study we simulated psoas tendon behavior in a virtual population of 40,000 anatomies and compared tendon movement during combined abduction, flexion and external rotation and back to neutral extension and adduction. At risk phenotyopes for tendon snapping were defined as the morphologies presenting with excess tendon movement. There were little differences in tendon movement between the male and female models. In both populations, abnormal tendon excursion correlated with changes in mainly the femoral anatomy (male r = 0.72, p < 0.001, female r = 0.66, p < 0.001): increased anteversion and valgus as well as a decreasing femoral offset and ischiofemoral distance. The observed combination of shape components correlating with excess tendon movement in essence presented with a medial positioning of the minor trochanter. This finding suggest that psoas snapping and ischiofemoral impingement are possibly two presentations of a similar underlying rotational dysplasia of the femur.

Radial extracorporeal shock wave therapy for patients with subacromial impingement syndrome

Objective To analyze the short-term therapeutic efficacy of radial extracorporeal shock wave therapy for patients with subacromial impingement syndrome. Methods A total of 106 patients diagnosed as having subacromial impingement syndrome between October 2017 and April 2019 were randomized into a radial extracorporeal shock wave therapy (rESWT) group of 36, an exercise rehabilitation group of 35 and a conventional therapy group of 35. In addition to family exercise therapy, the rESWT group underwent 2000 to 2500 shots of extracorporeal shock wave therapy at 10 Hz and a pressure of 1.5-2.5 bar, once a week for four consecutive weeks. The exercise group was given range of motion exercises, joint control training and tendon movement training for 45 minutes, three times a week for four consecutive weeks. The conventional therapy group was treated with a laser apparatus and low-frequency electrotherapy, once a day, three times a week. Constant-Murle scores (CMSs) and the short form health survey (SF-36) were used to evaluate the clinical efficacy before and after 1 month of treatment. Results Before the treatment there were no significant differences among the 3 groups in any of the measurements. After one month of treatment the average CMS pain score and total score of the exercise rehabilitation group were significantly better than the conventional therapy group′s averages. Moreover, the average body pain score, daily life ability, range of motion, muscle strength and total score of the rESWT group were all significantly better than the exercise and conventional therapy groups′ averages. In the SF-36 the average physical function, bodily pain, general health, and mental health scores of the rESWT groups were also significantly better than the other 2 groups′ averages. Conclusions Radial extracorporeal shock wave therapy is superior to exercise therapy and conventional therapy for patients with subacromial impingement syndrome. It can restore shoulder joint function and improve the quality of life in one month. Key words: Radial extracorporeal shock wave therapy; Subacromial impingement syndrome; Constant-Murley scoring; Shock wave therapy

Evaluation of Hand Tendon Movement by Using High-Frequency Ultrasound Vector Doppler Imaging.

Injuries to the hands, wrists, and fingers often involve damage to the tendons. The ability to measure tendon movements during the rehabilitation process can provide clinicians with important information in the quantification of tendon injuries. Conventionally, the tendon is considered a single spring-like structure during force transmission, and its twisted structure is neglected. Recently, clinicians believed that the twisted fiber structure (which enables tendon rotation during movement) of the tendon can provide it with a degree of elasticity and improve the efficiency of force transmission. However, observation of the hand tendon rotation in vivo by using the current imaging modalities is difficult. In this study, a 40-MHz high-frequency vector Doppler imaging (HFVDI) was used to visualize the movement of the hand tendon during muscle contraction. The performance of HFVDI was verified using a rotation phantom experiment. Two human experiments were designed in the present study: 1) participants were allowed to bend their distal and proximal interphalangeal (DIP and PIP) joints of fingers freely and 2) the PIP joint of the finger was fixed such that only the DIP could be moved. The HFVDIs of the flexor digitorum superficialis (FDS) and flexor digitorum profundus (FDP) tendons were obtained in the transverse and longitudinal views to observe the movements of the hand tendon during finger movements. The average longitudinal displacements of the FDS and FDP were approximately 3-4mm for free bending of the finger; however, it was reduced when only the DIP was moved. The rotational phenomenon of the FDS and FDP tendons was observed in the transverse view, which demonstrated the different rotational behaviors of the FDS and FDP fibers during muscle contraction. All the results validated the potential of HFVDI as a novel tool for visualizing tendon rotation and would be useful in providing quantitative information regarding tendon function to determine the rehabilitation process following injuries.

Clinical application of M-Tang tendon suture technique in repairing flexor digitorum profundus tendon in zone II and analysis of influencing factors

Objective To analyze the clinical efficacy of M-Tang tendon suture technique for repair of flexor digitorum profundus tendon in zone Ⅱ. Methods From November 2013 to December 2016, 77 patients (96 fingers) with rupture of flexor digitorum profundus tendon in zone Ⅱ were treated with M-Tang tendon suture technique. The protective active and passive functional exercises were performed early after the operation. The range of active motion of the affected finger was followed up and measured. The function of the affected finger was evaluated by Strickland and Glogovac criteria. The influencing factors such as age, gender, A2 pulley treatment, concomitant injury, follow-up time and time from injury to operation were analyzed statistically. Results Nineteen cases were lost, while 58 cases (70 fingers) were follow-up for 4 to 27 months, with an average of 16 months. Among the 70 fingers, the results were rated as excellent in 43 fingers, good in 13 fingers, fair in 10 fingers and poor in 4 fingers. The excellent and good rate was 80%. No finger tendon rupture occurred. Among the patients, male patients younger than 37 years old had better functional recovery after partial opening of A2 pulley (P<0.05). Conclusion M-Tang tendon suture technique is a simple, safe and effective method for repairing flexor digitorum profundus tendon in zone Ⅱ. It can meet the needs of early protective and active tendon movement. The age, gender and A2 pulley incision have significant influences on the treatment outcome. Key words: Tendon injuries; Treatment outcome; M-Tang technique; Flexor digitorum profundus tendon

Wrist kinetics after scaphoidectomy

BackgroundThe scaphoid cannot be excised without generating substantial carpal dysfunction. The extent and nature of such a destabilizing procedure, however, has never been properly studied in the laboratory. MethodsWe used a six-degrees-of-freedom motion tracking device to quantify the changes in carpal alignment produced by isometric simultaneous loading of five wrist motor tendons in 12 fresh normal cadaver arms, before and after excising the entire scaphoid. FindingsIn the intact wrist, tendon loading consistently extended and supinated the capitate while flexing the triquetrum. After scaphoidectomy, the opposite rotations were always found: the capitate collapsed into flexion and pronation, whereas the triquetrum migrated proximally, while extending and radial deviating. All these changes were statistically significant. InterpretationUnless it is supplemented by some sort of midcarpal stabilization, scaphoidectomy alone is much too aggressive as a procedure to be considered a treatment option for wrist osteoarthritis. Level of evidenceLaboratory study. Not applicable.

Design and Manufacturing of Tendon-Driven Soft Foam Robots

SummaryA design and manufacturing method is described for creating a motor tendon–actuated soft foam robot. The method uses a castable, light, and easily compressible open-cell polyurethane foam, producing a structure capable of large (~70% strain) deformations while requiring low torques to operate (&lt;0.2 N·m). The soft robot can change shape, by compressing and folding, allowing for complex locomotion with only two actuators. Achievable motions include forward locomotion at 13 mm/s (4.3% of body length per second), turning at 9◦/s, and end-over-end flipping. Hard components, such as motors, are loosely sutured into cavities after molding. This reduces unwanted stiffening of the soft body. This work is the first demonstration of a soft open-cell foam robot locomoting with motor tendon actuators. The manufacturing method is rapid (~30 min per mold), inexpensive (under $3 per robot for the structural foam), and flexible, and will allow a variety of soft foam robotic devices to be produced.

Zone 2 flexor tendon repairs using a tensioned strong core suture, sparse peripheral stitches and early active motion: results in 60 fingers.

We report the outcomes of zone 2 tendon repairs in 60 fingers using a strong core suture, sparse peripheral stitches and early active motion. From January 2014 to April 2016, we repaired 60 flexor digitorum profundus tendons with a tensioned 4-strand or 6-strand core suture and three to four peripheral stitches. The A2 or A4 pulleys were vented as necessary. Following early active flexion of the repaired tendons, no repairs ruptured and 52/60 (87%) fingers recovered to good or excellent function using the Tang criteria after follow-up of 8-33 months. We conclude that tensioned multi-strand strong core repairs only require sparse peripheral stitches and are safe for early active flexion. Standard peripheral sutures are not necessary. The core sutures should be properly tensioned to prevent gapping at tendon repair site and pulleys should be sufficiently vented to allow tendon motion. Level of evidence: IV.