| Background:Shoulder is one of the common incidence of musculoskeletal system disease. According to statistics, the incidence of Britain is 16%, second only to the spine (23%) and knee (19%); the incidence in the United States also leads the 3rd, the first two digits are the knee (14.9%) and spine (8.2%), The rotator cuff accounted for 17%-41% in the shoulder joint diseases. Rotator cuff injury is one of the most common clinical musculoskeletal system the soft tissue injury, complete thickness rotator cuff tear is the main reasons of shoulder pain and dysfunction, often severely affected patients'live and work. Bioremediation of tendon is very slow. Experiment in monkey confirmed that tendon strength the repair after the operation2 months recovered to 55%, to 80% of the 1-year recovery. Therefore, from a long-term perspective,It is larger significance regulating tendon itself fix by biological way than simple surgical suturing tendon.To manipulate injury the difficult key point still is the reconstruction of the interface of the tendon and bone. The repair process was still lack of in-depth research, Methods to promoting its repair was very limited.Clinical research has found just the right amount of postop training can contribute to the muscles, ligaments and tendons, and other soft tissue injury. However, according to the current repair and rehabilitation principle, the effect was often lower than expected and may lead to recurrence of injury and secondary instability.In Clinical Anatomy, supraspinatus muscle and infraspinatus muscle, subscapularis muscle and tendon of small circular muscle fiber round on, before, behind the humeral head and form a sleeve-like structure, that is, rotator cuff, also called tendon sleeve. Rotator cuff tendon is the most important parts of the structure, in the rotator cuff injury, supraspinatus tendon injury was the most common, often happened near the greater tubercle only points of the humerus about 1cm. There are many treatment methods for rotator cuff injury in clinical, the difficulty of the repair is the reconstruction of the tendon-bone interface. Data confirmed appropriate post-operative stress stimuli can promote its reconstruction, but the mechanism is not clear.Current scholars on the rotator cuff injury mechanism were generally divided into two points:endogenous and exogenous damage injury mechanisms. Endogenous injury is due to excessive weight-bearing and muscle degeneration or other damage caused to loss of tendon. Exogenous damage mechanism refers to the tendon due to surrounding tissues, especially the coracoacromial bow pressure caused to the tendon injury.In Imaging, through the shoulder joint double contrast, can learn the thickness, size, location of rotator cuff tear and articular cartilage degeneration, for complete thickness rotator cuff injury diagnostic accuracy rate is 90%, and magnetic resonance imaging and high frequency high resolution ultrasound, played a great role for rotator cuff and its morphological studies. When the rotator cuff injury happened, because internal tendon liquid exists, in T2-weighted magnetic resonance image performanced a higher signal. Rotator cuff tear not only performance enhancements for the signal of the tendon, also showed the exceptions of shape and the interrupt of the continuity, rotator cuff tendon incomplete tear performanced part of the signal intensity limitations increase but continuity still exist. Ultrasonographic examination of the rotator cuff injury, its potential was that it could provide more shoulder lesions of the anatomy of the details than other conventional technology scholars in China made similar studies and resulted the same conclusion. In addition, there were a number of independent study reported that ultrasonic and diagnosis of magnetic resonance in the rotator cuff tear had a higher degree of accuracy. From the physical models, tendon-bone interface is a mechanical weak point. When the mechanical effect conducted in relatively flexible, scalable and relatively hard, not scalable organizations, because of both mechanical characteristics, the interface stress concentration will be formed and fracture. In physiological situations, the special structure of the tendon can make the regional tissue has better tensile strength. Tendon-bone interface between the four layers of structure, has no clear boundaries and the mechanical properties of four levels of tissue gradually transited, from the tendon to bone gradually passed or from the tendon to bone gradually passed, avoiding stress concentrated at a certain point on,so preventing tendon rupturing in the insertion. To repair the tendon we need to reconstruction the tendon, which was extremely important for restoring shoulder, preventing further tearing. the aim of rotator cuff tendon reconstruction should be to restore the tendon-bone interface normal composite structure. Some animal and human tissue research found that, although current surgical techniques to rebuild the tendon-bone interface composite structure have greatly facilitated, but in terms of repair recent or advanced, tendon and bone cannot form a mature connected composite; either between the tendon and bone lacked normal transitional layer, or the end of the fiber weight of the tendon, arranged disorder, its tensile strength is still major gaps compared with normal tissue. Because the complexity of the tendon-bone interface structure, the current reconstruction technology. does not guarantee that the tendon and bone healed strongly, cannot entirely avoid avulsion. Therefore, It's a need to find new therapies.In Biomechanics research, clinical has already found just the right amount of exercise can promote the muscles, ligaments and tendons, and other soft tissue injury. Many previous studies have evaluated the effect of the increase or decrease the stress load on normal tendon and ligament and healing of tendons and ligaments. However, according to the current repair and rehabilitation principle, the effect was often lower than expected and may lead to recurrence of injury and secondary instability. Therefore, explicitly mechanical environment in tendon attachment point injury healing, will greatly improve clinical doctor for a proper postoperative treatment. Therefore, identifying the effect of the mechanical environment in tendon attachment point injury healing, would greatly improve the clinical doctor to ask for a proper postoperative treatment.The experiments were divided into three parts:(1) Biomechanical response to acute rotator cuff repair process under different intensity stress stimuli Objective:In order to explore the biomechanics different intensity stress stimuli performance of in acute rotator cuff injury Methods:The supraspinatus tendon was cut off at the osteotendinous iunction(OTJ) and then sutured in situ(Tunnel Act). The two experimental groups started after one week plaster immobility, and the control group were free in the cage. All animals were sacrificed at 4 time points(2,3 and 4 weeks after operation). The largest tensile strength and severity at OTJ were compared between the 3 groups. Results:In the control group, the maximum tensile intensity of the supraspinatus tendon was (112.17±6.18) N, the stiffness was (20.28±2.22) N/mm. In high-intensity stimulation group, the maximum tensile intensity of t supraspinatus tendon was (99.74±2.10) N, the stiffness was (18.31±1.99) N/mm, In low-intensity stimulation group, the maximum tensile intensity of t supraspinatus tendon was (140.25±10.04) N, the stiffness was (22.35±1.97) N/mm,all ruptured through the intra-articular portion of the graft. At each time points, the largest tensile strength and stiffness of the small intensity of the training group were higher than the control group and high-intensity training group. Conclusion:Small intensity of stress stimulation in the early repair of acute rotator cuff injury had a better effect, while high-intensity stimulation in the early repair of acute rotator cuff injury played the role of harm in early rehabilitation.(2) MRI performance of acute rotator cuff repair process under different intensity stress stimuli Objective:In order to observe the MRI perfprmance of acute rotator cuff repair process under different intensity stress stimuli and difference. Methods: The selection of experimental animals, surgical treatment and postoperative functional exercise were the same with the first part, in the animals randomly selected four before the normal rotator cuff MRI. The animals were randomly selected (one each time point for 4)2,3,4 weeks after operation for MRI. Results:The normal supraspinatus tendon on MRI performance smooth edges, was a low signal homogeneous band in the T2WI,which taper from the inside to the outer, ends large nodules. During the supraspinatus tendon injury, tendon shape appeared less smooth, tendon-muscle belly connections retracted, muscle atrophy and associated with increased signal intensity. Control group which shows high signal within the tendon, performanced a gradual reduction in tendon shape is always invisible smooth shadow, intra-articular high signal gradually reduced; CPM group in the tendon signal limited signal increased visible within the shadow gradually reduced, tendon shape shoued slightly smooth shadow, intra-articular signal increased shadow diminished, with relatively small strength training group was the most uniform, the tendon of the signal shape smooth, was barely intra-articular high signal shadow. Conclusion: Postoperative CPM for passive joint flexion exercises, the speed of rotator cuff injury healing was significantly faster than the control moving group, the effect of small strength training group was the most obvious. Magnetic resonance technology used to display a rotator cuff injury postoperative healing process had a strong sensitivity and accuracy. It had important significance on the direction of recovery and estimating long-term effects.(3) X-ray and ultrasound performance of acute rotator cuff repair process under different intensity stress stimuli Objective:In order to observe the X-ray and ultrasound perfprmance of acute rotator cuff repair process under different intensity stress stimuli and difference Methods:The selection of experimental animals, surgical treatment and postoperative functional exercise were the same with the first part, in the animals randomly selected four before the normal rotator cuff MRI. The animals were randomly selected (one each time point for 4)2,3,4 weeks after operation for X-ray and ultrasound. Result:x-ray findings of rotator cuff injury were: (1) joint degeneration, acromioclavicular spur; (2) the subacromial spur, the subacromial calcification, acromion concave, hook acromion; (3) the glenohumeral degeneration; (4) of the humerus large sulcus is too large, the humerus and the greater tubercle irregular, cystic change, calcification; (5) standard-on-shoulder peak and the humeral head spacing is less than 7 mm. Results showed that compared with thecontrol group, the CPM group was average less two x-ray positive discovery, while between the two groups of CPM group had not been significant differences. Normally a rotator cuff ultrasound imaging was:banded structure between the deltoid muscle and the humeral head, in the subacromial was screened by the bone tissue echogenic, disappear at the greater tubercle humerus, shaped like a " bill ". States, rotator cuff internal echo is uniform, and stronger than the echo of triangular muscle; ultrasound results showed the free control group ultrasonic performanced the whole layer completely penetrating hypoechoic district, among the rotator cuff myogenic uniform echo and the two CPM group rotator cuff myogenic uniform echo intermediate hypoechoic district was not penetrating all layers, but between intensive group and small strength group in ultrasound could not show significant differences. Conclusion:Postoperative CPM for passive joint flexion exercises, the speed of rotator cuff injury healing was significantly faster than the free control group. X-ray and ultrasound could find damage repair after postop exercise, but theirs sensitivity and accuracy of were less than MRI. |
PDF Full Text Request