A Research On The Feasibility Of Polypropylene Patch For Joint Capsule Defect

Research Aims:The experiment aims to study the treatment effects of polypropylenepatches in repair of rabbits’ knee joint capsule defects, and taking popliteal cystas an example to explore its feasibility in the treatment of human knee jointcapsule defects.Research Methods:1. Choose4rabbits for experiment, and make the standard bio-mechanicalmodels of knee joint capsule. Use Biomechanical machine for tensile tests, andanalyze the data.2. Select8rabbits of the same weight for experiment, and make theartificial knee joint capsule defects with the diameter of3mm, let them healnaturally. Make the biomechanical tests1month after, and draw the two-sidedbody displacement stress curve of the same individual.3.30rabbits are divided into three groups for experiments, and makeartificial one-sided capsule defect models of knee joint, and then use meshpolypropylene patches for treatment.4．Kill the three sets of rabbits after4weeks,8weeks,12weeksrespectively, and observe their movementr function changes, healings and thenanalyze biomechanically.5. Select56cases of popliteal cyst of traffic type, and cut the cyst and use polypropylene patches to repair the capsule back wall defects with surgicaltreatment. Eat the medicine for swelling and pain release with partialcompression bandage without the restriction of capsule movement. Visit afterevery3months. Use lysolm to evaluate the knee functions and color Dopplerultrasound to confirm whether popliteal cyst reoccurs.Research Results:1. For different individual rabbits, the maximum displacement of the kneejoint capsule model under stress varies greatly, but it is not the case for thesame rabbit’s bilateral knee capsules.2. After natural healing of the knee joint capsule, compared with the sameindividual’s other healthy side, its stress drops25.1%±3.1within the maximumelastic deformation.3. Polypropylene patches are applied after the capsule of knee jointdefects in rabbits, and there is no significant influence on rabbits’ movementfunctions. No excluded response and adhesion appear. For different groups, themaximum stress rise almost the same around61.0%±5.7%, the experimentedside compared with the healthy side.4. All the cases are chosen as popliteal cyst cases. With the pathologicaltests after surgery, all are proved to be popliteal cyst. The average visit time is11.6months within the56successful cases. The average score by lysolm is89.6, with no falling compared with the data before the surgery. Color Dopplerultrasound tests show that there is no popliteal cyst reoccurrence. Results:1.The natural healing process will lower the intensity of joint capsule. Inthe experiment, the maximum stress drops25.1%±3.1%.2. Applying polypropylene patches in repair of knee joint capsule defectsmakes no partial tissue adhesion or impact on the movement function of rabbits’ knee joint.3. Applying polypropylene patches in repair of knee joint capsule defectscan increase the intensity of local joint capsule, compared with the othernormal side, the maximum stress can increase reached61.0%±5.7%.4. Applying polypropylene patches in repair of popliteal cyst can increasethe intensity of joint capsule, reduces the reoccurrence rate. Within the54patiences， the average visiting frequency is11.6months. There is noreoccurrence, which is much lower than other kinds of surgeries.5、Applying polypropylene patches in repair of the defects in the kneejoint back wall, there is no influence on the activities of knee joint one yearafter the surgery. Lysolm shows no decrease compared with the conditions ofknee joints before surgery.Applying polypropylene patches in repair of knee joint capsule defectsmakes no damage to movement functions, and can increase the intensity ofthe capsule, which is feasible.