Short Term Efficacy Of Tantalum Rod In Treatment Of Early Avascular Necrosis Of The Femoral Head

Because of the complicated mechanism of the early stage of femoral head necrosis, there is still no widely accepted. Tantalum metal and bone structure and mechanical properties of similar, with strong strength and and bone cells have good binding reaction, the bone cells can attach, growth, differentiation, so in the treatment of osteonecrosis of the femoral head have great potential. Tantalum rod as one of the treatment of early stage osteonecrosis of the femoral approach, both at home and abroad has been widely used and it is generally accepted that the suitable for the bone association research circulation (AssociationResearch circulation osseous, Arco) I and II patients and has simple operation process, low risk, recovery, and fewer complications. Due to the tantalum rod in 2008 before entering the Chinese clinical and in clinical research in China, in a few cases, small sample size, follow-up time short, long-term report, the lack of efficacy of tantalum rod and with fibula transplantation:a prospective randomized controlled trial, resulting in a the medical profession on the controversy in tantalum rod curative effect. Long term follow-up of tantalum rod can objectively evaluate the curative effect of the conservative treatment of early femoral head necrosis, and analyze the related factors and failure causes of the treatment and prognosis. With the development of science and technology, the combination of tantalum rod and related biotechnology will inevitably lead to the increase of the treatment rate.Objective (s):To investigate the clinical effect of tantalum rod in the early stage of femoral head necrosis.Methods:1.follow up from January 2012 to December 2014 in the Department of orthopedics of the First Affiliated Hospital of Kunming Medical University, the joint group of patients with femoral head necrosis treated by tantalum rod implantation.2. preoperative evaluation index:name, age, sex, duration of hospital number, side of operation, underlying diseases, the treatment factors, Harris score, imaging evaluation, determination of the University of Pennsylvania stage, extent of necrosis and necrotic index;3. postoperative curative effect evaluation:operation condition, date, amount of bleeding, bone graft follow-up score, Harris score, X-ray film progress evaluation, tantalum rod distance;4. Application of SPSS 19.0 statistical software for analysis and test the level of the two sides a<0.05. variance homogeneity test of bilateral a<0.10 was considered to be uneven; P<0.05 for the difference was statistically significant, P<0.01 was significant difference. Descriptive analysis was used to analyze the data, and the data were analyzed by independent sample T test and variance analysis. Counting data using chi square test. The survival rate was analyzed by Kaplan-Meier method, and the logrank test was used to compare the stratification factors. Multivariate analysis using COX proportional hazards models was performed to determine the prognostic factors associated with failure of the tantalum rod, and all of the statistically significant.Results:1. General:of 34 patients (42 hips of postoperative follow-up, male:13; female:21 people; age:with a mean age of 43 years; after a median follow-up of 29 months; University of Pennsylvania stage:0 stage 1 cases; 7 cases in stage 1; stage Ⅱ 23 cases; 3 cases in stage Ⅲ; etiology:sex hormone:19 cases; alcoholic:4 cases; idiopathic:11 cases;2 Efficacy EvaluationEach follow-up Harris score (each score were removed failed cases), the vast majority of patients with hip pain relieved after operation and satisfactory functional recovery; significant P< 0.05. With statistical significance, which after 6 months,12 months of pain and function have significantly improved.3 failure and progressAfter operation, most patients X-ray showed a stable, three years in 12 cases (15 hips) X-ray progress, appears the earliest X-ray changes in 6 months after the operation, the latest appeared in 24 months, radiographic progression was observed, crescent sign and cystic degeneration of the articular surface of the Xu collapse. Among them, there were 10 cases (13 hips) of the articular surface collapse more than 4mm, the average failure time of the first 12 months, the latest in 30 months.2 cases failed in 10 cases,13 hips and progress, mostly concentrated in the necrotic index of 30 or more, of which the index of avascular necrosis of the femoral head with more than 60% of the hip joint failure in 5 cases, progress in 2 cases, necrosis index within 30-60 necrosis in 6 cases, but the 2 cases has emerged femoral head cartilage collapse, only 1 cases of avascular necrosis of the femoral head index is below 30. In the stage of University of Pennsylvania, the failure occurred in the second and third stages, including 9 cases of C phase Ⅱ,3 cases of failure,2 cases of progression,3 cases of B and Ⅲ C, accounting for more than 70% of all failures.4 statistical results of related risk factorsBased on age, gender, etiology, underlying diseases, necrosis range index, tantalum rod away from the articular surface distance and Pennsylvania staging Cox proportional hazard model multivariable analysis:necrosis range index, tantalum rod away from the articular surface distance and Pennsylvania staging is Gao Weiyin element, on the survival rate analysis using the Kaplan Meier method. It is found that necrosis index is greater than or equal to 52 than< 52 hip surgery after failure rate is high, necrotic area higher than 30% was significantly higher than the failure rate of less than 30%; tantalum rod away from the articular surface distance< 5mm survival rate than the distance from the articular surface> 5mm.Conclusion(s):1 tantalum rod is an effective method to treat the early necrosis of the femoral head, select the appropriate patient and reasonable operation technology, is the key to ensure the effect of tantalum rod surgery;2. Its applicability to the necrosis area of< 30% or necrosis index< 52 following the early avascular necrosis of the femoral head in patients with, and necrosis area is more than or equal to 30% or necrosis index is greater than or equal to more than 52 patients belongs to relative contraindication; and the emergence of the cartilage surface subsidence of the patients are absolute contraindications.3. Operation in tantalum rod requires a pointer to a regional center of necrosis, prompting the tantalum rod most area and necrotic area contact, tantalum rod head as far as possible with the cartilage surface near, but not piercing cartilage, the necrosis area need of impaction bone grafting, increase tantalum rod implantation of initial stability, so that tantalum rod of the femoral articular surface of the bone to mechanical support, and the subsequent necrosis area open repair, and tantalum rod from the articular surface preferably less than 5mm.