Determine rigid fixation ability of locking plate on the trial osteosynthesis model. Evaluate treatment outcomes of closed distal femur fracture of locking plate in adult patients and give some comments about indication and technique.
1 INTRODUCTION Distal femur fractures (DFF) (supracondyle fracture, intercondyle fracture, medial condyle fracture, lateral condyle fracture) has a rate from 6% 7% among all types of femur fracture, of which supra condyle and intercondyle fractures accounts for 70% of Distal femur fractures cases. Highenergy fracture (fracture caused by highenergy force) is usually met on younger patients, fracture from traffic accidents accounts for above 50% Older patients usually have lowenergy fractures caused by falling. Conservative treatment for Distal femur fractures has many disadvantages and complications, so surgeons prefer open reduction and osteosynthesis through many methods: intramedullary pin fixation (upstream or downstream from the knee); osteosynthesis with plates and screws (normal plates and screws, two plate/screw systems, DCS plate, femoral condyle plate and locking plate) For complex cases, such as fractures occur near joints, osteosynthesis with condyle plates, and recently, osteosynthesis with locking plates has become the first choice, overcoming disadvantages of other devices. Although positive results were achieved in treatment of Distal femur fractures, some studies show that: osteosynthesis with condyle plates or locking plates still occurs fail (stiff knee, deflective healing, delayed bone healing, pseudarthrosis…) For exact learning of fail causes, we neeed to concern rigid fixation ability after surgery of these plate types Then, suitable exercise programmes after surgery are established to avoid complications such as broken plate, screw flaking, delayed bone healing, pseudarthrosis and sequelaes limiting movements of knee joint So, for comparison of rigid fixation ability between condyle plate and locking plate on the same trial pattern in relation to plate – bone connection, and eluvation of treatment effectiveness for closed Distal femur fractures of locking plate, we did the thesis: “Study of fracture fixation ability under trial and treatment outcomes of closed distal femur fracture of locking plate in adult patients”.This thesis aims to: Determine rigid fixation ability of locking plate on the trial osteosynthesis model Evaluate treatment outcomes of closed distal femur fracture of locking plate in adult patients and give some comments about indication and technique. New contributions of the thesis Recently, locking plate has been used to treat Distal femur fractures in Vietnam and in the world, achieving some positive results, reducing complication and sequelae rates compared to other methods. Locking plate with outstanding advantages in design, material and shape overcomes disadvantages of other osteosynthesis measures To understand more about rigid fixation ability of locking plate on treatment of Distal femur fractures, especially complex fracture, fracture near joints: we did a trial model and found that locking plate – bone model can bear higher compressive forces along axis, eccentric bending forces torque than condyle plate – bone model, this is a base helping surgeons choose locking plate to treat Distal femur fractures. After treating 54 patients with Distal femur fractures, relatively high bone healing and rehabilitation outcomes were observed, contributing to theoretical and practical bases This a practical thesis, deeply studying fracture fixation ability of locking plate. It helps determine ability bearing compression, bending and torsion forces of trial plate – bone model. It permits patients to move early, reduces complications such as amyotrophy, delayed bone healing, limited movement of knee joint Structure of the thesis: The thesis consists of 116 pages and includes following parts: Introduction of 2 pages, Chapter 1 – literature overview (32 pages); Chapter – material and method (22 pages); Chapter – Result (27 pages); Chapter – Discussion (30 pages), Conclusion (2 pages) and Recommendation (1 page) There are 3 published studies related to the thesis.There are 125 references including: 21 Vietnamese and 104 English documents Chapter 1 LITURATURE OVERVIEW 1.1 Study of stiffness of locking plate on DFF fracture osteosynthesis A study of Wilkens K.J et al (2008) showed that locking plate is 24,4% time more rigid than conventional plate, rigid rate of locking plate/conventional plate is 168,2/127,1 N/mm; p 100, average bone healing time was 3.7 months (from 14 to 26 months) * Some studies compare locking plate osteosynthesis with other osteosynthesis measures used to treat DFF fracture: Supanich V. (2012) treated DFF fracture type C and compared different osteosynthesis measure types: Angel plate, DCS plate, condyle plate and locking plate. Result: very good and good patient rates of locking plate, DCS plate, angel plate and condyle plate were 86%, 78%, 66% and 50% respectively Vallier H.A et al (2012) compared Treatment outcome of osteosynthesis between 950 angeled plate and LCP (Locking Condylar Plate) during average follow up time of 26 months (9 77 months). For some complications such as deep infection, nonhealing and displacement healing, complication rates of angeled plate and LCP were 10% and 35% respectively Gupta SKV (2013) compared Treatment outcome of osteosynthesis between intramedullary pin and LCP. After 6 months, his result showed that bone healing rates of both patient group were above 75%, average bone healing time of intramedullary pin and LCP groups were 6.8 and 7.5 months respectively. 2/46 (4%) LCP patients had nonhealing while there were 5/57 (9%) intramedullary pin people with nonhealing * In Vietnam: In recent years, Vietnamese surgeons have applied locking plate to treat DFF fracture and achieve positive results: Truong Tri Huu et al (2014) treated 34 patients with DFF fracture by locking plate. Result: bone healing rate was 97.1%, while very good, good, average and poor rates were 76.5%, 14.7%, 2.9% and 5.9% respectively. Chapter 2 MATERIAL AND METHOD 2.1. A study on rigid fracture fixation ability of locking plate on a bone combination model trial * Place: Materials Endurance Laboratory Department of Materials and Structural Mechanics Mechanical Institute Hanoi University of Science and Technology * Model design: Bone model: 72 posterior femurs of 36 mature cows. Plate/screw system model: 7hole LCP, rigid bone and spongy bone locking screws with sufficient quantities, There are 3 published studies related to the thesis There are 3 published studies related to the thesis Intercus locking plate Compression and horizontal and torsion bendings experiment was performed on 02 models: LCP model: LCP – cow femur (symbol: K). Condyle plate model cow femur (symbol: L) Plate bone model design: cow’s DFF were sawed to form supra condyle (type A2) and intercondyle fractures (type C2) according to AO classification Bones were adjusted Plate/screw systems were placed on lateral aspect of the bones, plates were clamped with bone pliers. Drilling was implemented to insert screws to fix plates to bones (full screws were inserted to holes in plate) Trial machine: Compression, bending and torsion trials were performed by MTS Alliance RF/300 machine. Working principle: The encorders of the machine would measure compressive, horizontal and torsion bendings forces acting on the models while measuring the corresponding deformation level of the models along the axis of acting force. The compressive, bending, torque and deformation parameters at the fracture were cosion: first phase incision healing: 53 patients (98.15%), superficial infection: 1 patient (1.85%). There was no patient with deep infection or bleeding after surgery. * Reduction outcome: Nondisplacement: 50 patients (92.59%), less displacement: 4 patients (3.70%) * Bone healing outcome Table 3.18. Duration of bone healing (n = 54) Group age 18 – 30 31 – 40 41 – 50 51 – 60 61 70 > 70 Duration of bone healing (week) 14.39 ± 1.98 16.50 ± 4.95 17.00 ± 1.16 19.50 ± 1.76 20.33 ± 1.92 22.42 ± 2.28 Min Max (12 – 18) (13 – 20) (16 – 18) (18 – 22) (18 – 23) (20 – 26) P