ABSTRACT
To study the stress-strain relationships of intervertebral discs and vertebrae when using a plate-rod system for scoliosis, a mechanical model of scoliosis was built based on the similarity principle. The stress variation on the spine, which was under the coactions of lengthwise load and correcting load, was measured by photoelastic and strain gauge methods. The model test results indicate that the added value of compressive stress on the concave side of the spine (0-1.5 MPa) is larger than the added values of compressive stresses on the spine's convex side and concave ligament (0-200 N). This demonstrates that the lengthwise load (weight) can increase the seriousness of scoliosis. In addition, it was shown that tensile stress is formed on the concave side of the scoliosis model when the compressive stress decreases (1.5-0 MPa), due to the effect of the correcting load. It can be seen that plate-rod systems can correct scoliosis effectively.
Subject(s)
Internal Fixators , Models, Biological , Prosthesis Design , Scoliosis/therapy , Stress, Mechanical , Compressive Strength , Elasticity , Humans , Intervertebral Disc/physiology , Poisson Distribution , Scoliosis/surgeryABSTRACT
OBJECTIVE: To report the rationale and primary results of application of Chinese universal spinal instrumentation (CHN-USI) in spinal surgery. METHODS: From September 1998 to June 2000, 70 patients with scoliosis, including 30 congenital scoliosis, 36 idiopathic scoliosis and 4 other disorders, were treated with CHN-USI in our hospital. All patients got follow-up after surgery with roentgenogram. RESULTS: The average follow-up time was 8.9 months. On average, the primary scoliotic curve was reduced from 70.5 degrees (40 degrees-103 degrees) to 32.5 degrees with an average correction rate of 55.6%. The average increases in body height and the length of corrective segment were 6.5 cm and 5 mm respectively. The kyphotic curve was corrected from average 80.5 degrees to 29 degrees. No serious complication was found in our group. CONCLUSIONS: The CHN-USI which has no need of spinal fusion and will elongate together with the children's growth is a new effective instrumentation for correcting scoliosis, especially in case of growing children. It can also be used in the treatment for kyphosis, anterior derotation spondylodesis, spondylolisthesis and spinal fracture.
Subject(s)
Internal Fixators , Scoliosis/surgery , Spinal Fusion/instrumentation , Surgical Instruments/standards , Adolescent , Adult , Child , Child, Preschool , Equipment Design , Female , Follow-Up Studies , Humans , Male , Spinal Fusion/methods , Treatment OutcomeABSTRACT
This paper presents the preliminary investigation on chondromalacia patella at our department in recent years. A random cluster sampling survey covering 2743 normal persons was carried out. The prevalence rate is 36.2%. It was found that, applying transmission electron microscope and immunohistochemical methods on to cartilage tissues of the abnormal region, articular cartilage necrosis was in direct proportion with the abnormal pressure, while the restoration capability of local chondrocytes was in inverse proportion with pathological changes and the pressure. The chondromalacia patella was produced by repeated abnormal stress acting on the cartilage. The stress derived from the uncongruency and the decreasing in the contact area of patellofemoral joint when the subluxation or tilt of patellae was caused by the abnormal anatomical and biomechanical relationship. The initial lesion was at the matrix of cartilage, the collagen network was disrupted, then proteoglycan was lost. The microenvironment of chondrocytes was changed with degradation of matrix. So the chondrocytes became degenerative and necrosis from superficial to deep layer, then feed back the matrix again. Finally, the total cartilage layer might disappear, and the bone under cartilage might proliferate. At late stage, the cartilage was completely destroyed and had no self-restorative ability. Therefore, early diagnosis and treatment are necessary. It is highly suggested axis radiograph of the knee with the tibiae tuberositas localization are helpful to early diagnosis. Furthermore, JKY-Muscle Rehabilitation Instrument is invented for non-operative therapy. It enhances muscle power by selective training of the vastus medialis muscle using electrical stimulator to relieve pain and correct subluxation of patella with 90% efficiency (63% of excellent-effective rate). In late stage, patellofemoral replacement is recommended. The excellent-effective rate is 86.3%.
Subject(s)
Cartilage Diseases , Patella , Arthroplasty, Replacement, Knee/methods , Cartilage Diseases/diagnosis , Cartilage Diseases/etiology , Cartilage Diseases/therapy , Electric Stimulation Therapy , Humans , Patella/pathologyABSTRACT
An investigation of the morbidity of scoliosis has been carried out in Beijing area including both urban and rural area. The survey involved 21759 elementary school students aged 8 to 14. The result showed that the morbidity of scoliosis was 1.06 per cent. Most patients had idiopathic scoliosis while congenital scoliosis possessed only 5.19% of the whole patients. Prevalence in female students was slightly higher than in males. In terms of morbidity of scoliosis, there was no significant difference seen in the areas of study. The use of Adam-forward-bending test for original examination in the investigation seemed to be simple and effective. The spine measure ruler is qiute simple in production and easy to handle. Using the ruler, one will get less exposure to X-ray. The film which shows the whloe spinal AP and lateral view would lay a final and ture basis for diagnosis.
Subject(s)
Scoliosis/epidemiology , Adolescent , Child , China/epidemiology , Female , Humans , Logistic Models , Male , Mass Screening , MorbidityABSTRACT
Fifteen patients with scoliosis were treated by a dual channel surface stimulator made in China. After an 18.5 month treatment, their curves decreased by 3 degrees to 15 degrees. The effective rate was 93.3%.
