The Relationship Between BMI And The Damage Degree Of Kneed Cartilage And Synovium

Background:The damage within the knee joint involvs the acute and chronic injury of bone,cartilage which make up the structure of joint and parenchyma including ligament, synovium,cartilage and so on in joint. The mechanical stress intra-articular tissue bear is mainly made up of compression stress, tensile stress, shear stress and fluid static pressure. The injury within the knee is mainly due to mechanical stress distribution imbalance or excessive load which cause cartilage wear. Kneed arthroscope surgery is a minimally invasive and effective surgical method, the most direct, precise reflect can be shown under the arthroscope including the chondral and synovial damage degree of grading, and the development of the internal condition. Many experiments have confirmed the relationship between the obesity and knee osteoarthritis (OA), involves the progress of X-ray results, the severity of symptoms, and biochemical metabolic changes, etc. Whether the obesity, the risk factor which cause joint degenerative diseases or traumatic diseases, is correlative with the arthroscopic macroscopic observation of chondrol and synovial injury or not, is the purpose of this study. This study aims to evaluate the relationship between the gold standard of diagnosis and BMI. The study have guiding values on reasonable assessment of the injury severity within the knee and the risk of OA.Objectives:To evaluate the correlation between BMI and the damage degree of arthroscopic macroscopic observation of chondrol and synovial injury,to evaluate the relationship between the gold standard of diagnosis and obesity. By comparing BMI differences between the different age brackets of healthy kneed group and arthroscopic surgery treatment group to analyse influence of obesity on injury in knee joint.Methods:109 patients with knee joint diseases operated under the arthroscope in shanxi medical university 2nd hospital during the may,2009 to the september 2009, aged 18-77,38 on average, involves 57 male and 52 female.178 people received physical examination in clinical check-up center of shanxi medical university 2nd hospital whose knees have been diagnosed healthy, aged 18-65,38 on average, involves 111 male and 67 female. All people's BMI are calculated. The degree of patients'cartilage injury was assessed with Outerbridge's score system under arthroscope,the degree of patients'synovitis was assessed with Ayral'score system under arthroscope.The data are analyzed by the analysis of variance and Spearman correlation.Results:The results show that BMI of 109 patients with knee joint diseasese are positively related with cumulative Outerbridge's score(r=0.58, p< 0.01), with Outerbridge's top score (r=0.70, p <0.01), with Ayral's score(r=0.47, p< 0.01). The pairwise comparison among three BMI groups show that the differences were statistically significant (p< 0.01). The arthroscopic surgery patients and people without knee diseases are divided respectively according to age into four sections:the first section, aged 18 to 28; The second section, aged 29 to 39, The third section, aged 40 to 50, The fourth section, aged above 51 years old. Within each age section BMI and cumulative Outerbridge's score and Ayral s's score are not related(p> 0.05). In the first age section BMI of arthroscopy group patients are associated with no significant difference with BMI of people without knee diseases(p> 0.05). In the second, third, fourth age section, BMI of arthroscopy group patients have significantly higher BMI than that of people without knee diseases (p<0.05).Conclusion:Obese degree are related with the degree of cartilage injury and synovitis.Obesity has great influence on cartilage, especially on the local damage degree, which indicate that the effect of obesity on the joint may depends largely on the change of body alignment. In the age sections above 29 years old, the risk of damage occurred within the joints raise with increasing obese degree.While in the section aged 18 to 28 show no significant difference(p> 0.05). It may be due to the strength and the sport of youngsters are obviously higher than in the elderly,they experience the higher frequency of injury or violent motion, and their muscles, ligaments, soft capsule have higher strength and toughness,and have strong repair ability of joint cartilage.The damage are most attributed to exercise or violent damage themselves, compared with them obesity dose not have strong association.