Nghiên cứu khả năng cố định ổ gãy trên thực nghiệm và kết quả điều trị gãy kín đầu dưới xương đùi người lớn bằng nẹp khóa tt tiếng anh

1 INTRODUCTION Distal femur fractures (DFF) (supra-condyle fracture, inter-condyle fracture, medial condyle fracture, lateral condyle fracture) has a rate from 6% - 7% among all types of femur fracture, of which supracondyle and inter-condyle fractures accounts for 70% of Distal femur fractures cases High-energy fracture (fracture caused by high-energy force) is usually met on younger patients, fracture from traffic accidents accounts for above 50% Older patients usually have low-energy 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: 2 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 pages, Chapter – 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 published studies related to the thesis.There are 125 references including: 21 Vietnamese and 104 English documents 3 Chapter 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 10 0, 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, non-healing 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 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 non-healing while there were 5/57 (9%) intramedullary pin people with non-healing * 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 5 Chapter 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: 7-hole LCP, rigid bone and spongy bone locking screws with sufficient quantities, There are published studies related to the thesis There are 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 supracondyle (type A2) and inter-condyle 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 continuously measured and transmitted to a computer The computer would automatically build a graph showing the 6 relationship between force - deformation of the models From the graph, we could calculate force-bearing level of the models * Study content : Axial compressive force, Horizontal bending forc Torsional bending force * Method of evaluating the result: A graph was drawn and average values of forces acting on the two study sample were calculated by statistical algorithms of Hanoi University of Science and Technology Average values (Independent Sample T test) and medians of forces acting on two samples were compared 2.2 Study on treatment outcomes of DFF closed fracture using locking plate osteosynthesis * Material: 54 patients (26 men, 28 women), with age ranging from 18 - 90 years old and having DFF closed fracture caused by trauma, received locking plate osteosynthesis at Duc Giang hospital, Xanh Pon hospital, Military hospital 103 from June 2011 - 9/2015 * Inclusion criteria: Patients with DFF closed fracture type A and C caused by trauma * Clinical study method - Method: longitudinal, non-controlled, descriptive study - Process: Collecting study records Examinating patients Preparing patient before surgery Do surgerical interventions and surgical records Doing post-operative care and X-ray examination Assessing near outcomes: outcomes of reduction and osteosynthesis after surgery and process of incision Patients was guided to rehabilitation Follow-up sheet was made for each patient Patients was appointed to re-examine at following times: 1, 2, 3, 4, 5, and 12 months after surgery and far outcomes (> 12 months) was aslo assessed - Content: Epidemiological characteristics Cause and mechanism of trauma Taking X-rays before and after surgery, until bone healing occured Classification of DFF fracture based on X-ray images according to AO classification Surgical techniques, Locking plate osteosynthesis indication, treatment outcomes * Treatment of DFF closed fracture using locking plate osteosynthesis - Anesthesia: spinal anesthesia 7 - Surgical technique: patient’s position: patients were on supine position with supporters below poplitei and tourniquets of thigh Phase 1: Incision: lateral incision for simple DFF fractures and lateral anterior incision for complicated fractures, joint fracture and difficult reduction Phase 2: Exposure and reduction of fracture Phase 3: Placement of locking plate Phase 4: Closing the incision * Post-operative treatment: After surgery, patient’s leg would put on the Braun Antibiotics were used for 5-7 days, combining analgesics, anti-edema after surgery Band was replaced and drainage was done after 48 hours * Movement practice after surgery: patients were guided to move early: On the second day after surgery, patients sat up, and practiced quadriceps muscle contraction and knee joint flexion and extension After 2-3 weeks, patient practiced to stand, walk with two crutches After - weeks, patient practiced to walk with a crutch, then after to weeks patient practiced to walk with no crutch * Method of outcome assessment * Assessment of near outcome: According to standard of Larson Bostman: incision process: First phase healing or superifical and deep infections Reduction outcome recovering anatomy and osteosynthesis technique Early complications (Bleeding, thrombosis, embolism) * Assessment of far outcome: Follow-up for at least 12 months We used assessment method of Sanders R (1991) Assessment of outcomes by levels: Very good, good, average and poor * Methods of data processing: According to the medical statistics program SPSS 20.0 Comparison between average values of study groups (Independent Sample T test) Chapter RESULT 3.1.Results of trial study on mechanical strength and rigid fracture fixation for DFF fracture of locking plate 8 3.1.1 Compressive strength trial on samples: DFF locking plate bone (KA - N) and condyle plate - bone (LA - N) Table 3.1: Compressive forces bearing ability on samples of femoral supra-condyle fracture (KA - N) and (LA - N) (n = 12) Compres Plate – bone sample with femoral supra-condyle fracture sive force KA – N LA – N KA – N LA – A P (X ± SD) (Median (X ± SD) (Median Fracture - N) (Newton - N) (Newton - N) displace - N) (n=6) (n=6) ment 0.5 mm 1329.90 ± 355.90 1281.21 1121.19 ± 230.17 1115.48 > 0,05 1.0 mm 1719.48 ± 384.83 1789.93 1552.09 ± 256.04 1611.70 > 0,05 1.5 mm 2456.16 ± 641.66 2641.24 2074.99 ± 263.24 2113.90 > 0,05 2.0 mm 3225.50 ± 427.18 3293.35 2865.01 ± 548.70 2814.24 > 0,05 2.5 mm 4010.37 ± 509.50 4179.34 3200.04 ± 243.62 3118.63 < 0,05 Comment: From displacement of 2.5 mm, there was a significant change and difference of forces acting on sample (KA - N): 4010.37 ± 509.50N (median: 4179.34N) and on sample (LA - N): 3200.04 ± 243.62N (median: 3118.63N) with the same femoral fracture model, with p < 0.05 Graph 3.1 Correlation between compressive force and deformation of samples (KA - N) and (LA - N) with femoral supra-condyle fracture Comment: The graph showed that average compressive force on DFF locking plate - bone samples was 4179.34N with fracture displacement of 2.5mm began to break connection, while average 9 compressive force on the femoral condyle plate - bone samples was 3118.63N with fracture displacement broken connection, with p < 0.05 Table 3.2 Compressive forces bearing ability on samples of femoral inter-condyle fracture (n=12) Compres Plate – bone sample with femoral inter-condyle fracture sive KC – N LC – N force KC – N LC – N P (X ± SD) (Median (X ± SD) (Median Fracture - N) - N) ( Newton - N) (Newton - N) displace (n=6) (n=6) ment 0.5 mm 1194.51 ± 210.07 1184.63 953.97 ± 287.56 995.22 > 0.05 1.0 mm 2030.63 ± 241.84 2028.99 1597.88 ± 527.67 1686.33 > 0.05 1.5 mm 3140.14 ± 288.16 3228.73 2738.34 ± 703.88 2919.65 > 0.05 2.0 mm 3915.8 ± 295.43 3968.29 3498.13 ± 787.61 3524.11 > 0.05 2.5 mm 4620.27 ± 315.85 4728.87 4139.28 ± 766.53 4322.23 > 0.05 Comment: From displacement of 2.5mm, there was a change and difference of forces acting on the sample (KC - N): 4620.27 ± 315.85N (median: 4728.87N) and on sample (LC - N): 4139.28 ± 766.53N (median: 4322.23N) on femoral inter-condyle fracture model, which was not significant with p > 0.05 Graph 3.2 Correlation between compressive force and deformation of samples (KA - N) and (LA - N) with femoral inter-condyle fracture Comment: The graph showed that average compressive force on DFF locking plate - bone samples of 4728.87N with fracture displacement 10 10 of 2.5mm began to break connection, while average compressive force on the femoral condyle plate - bone samples was 4322.23N with fracture displacement of 2.5mm also began to break connection, the difference in force was not statistically significant with p> 0.05 Comment: femoral condyle plate - bone sample showed that the axial force bearing ability was lower than that of DFF locking plate - bone system 3.1.2 Trial of horizontal bending strength on samples of DFF locking plate - bone sample (KA - U) and femoral condyle plate bone (LA - U) Table 3.3 Horizontal bending strength on samples of (KA - U) and (LA - U) with femoral supra-condyle fracture (n=12) Horizontal bending force Plate – bone sample with femoral supra-condyle fracture P KA – U LA – U KA – U LA – U (X ± SD) (Media (X ± SD) (Median Fracture n N) N) (Newton - N) (Newton - N) displacement (n=6) (n=6) mm 204.94 ± 70.34 178.04 155.86 ± 48.13 136.84 > 0,05 mm 396.37 ± 117.52 365.62 314.52 ± 88.88 340.30 > 0,05 mm 537.79 ± 121.16 508.07 499.78 ± 85.32 484.7 > 0,05 mm 704.33 ± 110.45 704.08 505.76 ± 62.83 505.82 < 0,05 Comment: From displacement of mm, when broken connection began happening, horizontal bending force acting on the sample (KA U): 704.33 ± 110.45N (median: 704.08N) was higher than that of the sample (LA - U): 505.76 ± 62.83N (median: 505.82N), with p < 0.05 11 11 Graph 3.3 Correlation between horizontal bending force and deformation of samples of (KA - N) and (LA - N) with femoral supracondyle fracture Comment: Average horizontal bending forces of 704.08N and 505.82N acting on DFF locking plate – bone and femoral condyle plate – bone samples respectively caused broken connection (displacement of mm), with p < 0.05 Table 3.4 Horizontal bending strength on samples of (KA - U) and (LA - U) with femoral inter-condyle fracture (n=12) Horizontal Plate – bone sample with femoral inter-condyle bending fracture P force KC – LC – KC - U (X ± LC - U (X ± U U SD) SD) (Media (Media ( Newton - N) ( Newton - N) Fracture n - N) n - N) (n=6) (n=6) displacemen t mm 139.43 ± 39.09 137.38 105.3 ± 35.22 99.65 > 0,05 mm 271.34 ± 124.77 343.84 216.28 ± 97.57 226.3 > 0,05 mm 447.57 ± 107.14 499.22 416.75 ± 134.66 376.7 > 0,05 mm 699.26 ± 125.60 715.89 476.05 ± 59.18 492.44 < 0,05 Comment: From displacement of mm, when broken connection began happening, the force acting on the sample (KA - U): 699.26 ± 125.60N (median: 715.89N) had significant differences with that of the sample (LA - U): 476.05 ± 59.18N (median: 492.44N), with p < 0.05 12 12 Graph 3.4 Correlation between horizontal bending force and deformation of samples of (KA - N) and (LA - N) with femoral intercondyle fracture Comment: The graph showed that average horizontal bending forces of 715.89N and 492,44N acting on DFF locking plate – bone and femoral condyle plate – bone samples respectively caused broken connection (displacement of mm) The difference was statistically significant with p < 0.05 Comment: bending stiffness of locking plate (K) was much higher than that of condyle plate (L) on samples Concurrently, locking plate (K) also had a higher horizontal bending strength 3.1.3 Trial of torsional bending strength on samples of DFF locking plate - bone (KA - X) and femoral condyle plate - bone(LA- X) Table 3.5: Torsional bending strength on samples of (KA - X) and (LA - X) with femoral supra-condyle fracture (n=12) Torsional Plate – bone sample with femoral supra-condyle bending fracture force P KA – X KA – X LA – X LA – X Fracture (Median (Media (X ± SD) (X ± SD) displacemen N) n - N) (Newton - N) (Newton - N) t (n=6) (n=6) mm 421.64 ± 54.73 429.33 390.70 ± 81.15 419.76 > 0,05 mm 589.57 ± 88.51 608.27 533.90 ± 95.10 559.96 > 0,05 mm 777.02 ± 134.66 809.40 686.91 ± 80.48 699.84 > 0,05 mm 990.79 ± 166.54 991.69 888.84 ± 89.02 905.38 > 0,05 Comment: From displacement of mm, when broken connection began happening, the force acting on the DFF locking plate – bone sample of 990.79 ± 166.54N (median: 991.69N) had a difference with that of femoral condyle plate – bone sample of 888.84 ± 89.02N (median: 905.38N) on the same femoral supra-condyle fracture model, with p < 0.05 13 13 Graph 3.5 Correlation between torsional bending force and deformation of samples of (KA - N) and (LA - N) with femoral supracondyle fracture Comment: The graph showed that average horizontal bending forces of 991.69N and 905.38N acting on DFF locking plate – bone and femoral condyle plate – bone samples respectively caused broken connection (displacement of mm) The difference wasn’t statistically significant with p > 0.05 Table 3.6 Torsional bending strength on samples of (KA - X) and (LA - X) with femoral inter-condyle fracture (n=12) Torsional Plate – bone sample with femoral inter-condyle fracture bending force P KC – X (X ± SD) ( Newton - N) (n=6) KC – X (Media n - N) LC – X (X ± SD) ( Newton - N) (n=6) LC – X (Media n - N) Fracture displacemen t mm 514.21 ± 135.30 538.79 489.13 ± 81.64 464.88 > 0.05 mm 707.42 ± 213.60 691.70 664.43 ± 98.04 622.82 > 0.05 mm 829.03 ± 162.50 845.21 826.02 ± 112.04 785.43 > 0.05 mm 1071.00 ± 222.38 1091.79 986.26 ± 116.33 972.38 > 0.05 Comment: From displacement of mm, when broken connection began happening, the force acting on the DFF locking plate – bone sample of 1071.00 ± 222.38N (median: 1091.79N) had a difference with that of 14 14 femoral condyle plate – bone sample of 986.26 ± 116.33N (median: 972.38N), with p > 0.05 Graph 3.6 Correlation between torsional bending force and deformation of samples of (KA - N) and (LA - N) with femoral intercondyle fracture Comment:The graph and calculation results showed that the converted stiffness of femoral condyle plate – bone system was less than 5% lower than that of DFF locking plate – bone system, however the limited force value of DF locking plate – bone system reached 1850N while that of femoral condyle plate – bone system was only about 1450N (lower than 27.58%) This showed that DFF locking plate system had the same stiffness but higher force-bearing limit than that of femoral condyle plate system 3.2 Treatment outcomes of DFF closed fracture using locking plate osteosynthesis 3.2.1 Characteristics of studied patient group Age and gender: Average age: 51.04 ± 22.30 years old (18 - 90 years old), male to female ratio: Male 26 patients (48.15%); Female 28 patients (51.85%) Elderly group ≥ 60 years old: 26 patients (48.15%), group with age from 18 - 44 years old: 20 patients (37.04%), group of 45 - 59 years old: patients (14.81%) 3.2.2 Accident’s causet: Daily activities accidents accounted for the highest rate with 27 patients (50%), 24 patients with traffic accident was (44.44%) and people had labor accident (5.56%) 15 15 3.2.3 Trauma mechanism: Direct and indirect mechanism had same rate (50%) 3.2.4 Location, morphology and nature of injury * Affected-side of thigh Left DFF fracture of 30 patients (55.56%) was more than the right fractur of 24 patients (44.44%) * Nature of the fracture: Simple fracture: 31 patients (57.41%), complex fracture: 23 patients (42.59%) 3.2.5 Classification of fracture according to AO Table 3.10 Classification of fracture according to AO (n = 54) Fracture Type A Total Type C Total type A1 A2 A3 C1 C2 C3 Number 16 22 42 12 of patients Rate (%) 29.63 40.7 7.41 77.78 5.56 12.96 3.7 22.22 Table 3.11 Classification of fractures by cause of accident (n = 54) Cause Fracture type Type A Type C Total Rate (%) Traffic accident Labor accident 18 24 44.44 5.56 Daily activities accident 22 27 50.0 3.2.6 Soft tissue injury 100% of patients had DFF closed fracture No patient had open fracture 3.2.7 Accompanied injuries Brain injury: patients, chest injury: patients, other fractures: 11 patients Total 42 12 54 100 16 16 3.2.8 Blood vessel and nerve injuries There was no person with blood vessel and nerve injuries 3.2.9 Surgical intervention with locking plate osteosynthesis 3.2.9.1 Period of surgery : 1st day: 32 patients (59.26%), 2nd – 6th day: 14 patients (25.93%), > days: patients (14.81%) 3.2.9.2 Anesthesia method: spinal anesthesia 3.2.9.3 Incision: Anterolateral incision 32 patients (59.26%), lateral incision: 22 patients (40.74%) 3.2.9.4 Surgical duration Surgery duration from 60 - 90 minutes (87.04%), type A: 39 patients, type C: patients Surgery duration from 90 - 120 minutes: patients (9.26%), both surgery durations of 120 - 150 minutes and 150 180 minutes had patient (1.85%) 3.2.9.5 Osteosynthesis with locking plate combined with other osteosynthesis measures: Using porous screw with locking plate: 12 patients (22.22%), porous screw with steel sutures and locking plate: patients (3.70%) 3.2.9.6 Number of transfusion There were 36 patients receiving transfusion with total blood volume of 18200 ml 19 patients were transfused 500 ml of blood, 11 patients were transfused 250 ml of blood, patient was transfused 750 ml of blood Patients who were transfused more blood were who had with poly-trauma or internal-organ trauma 3.2.10 Treatment outcome 3.2.10.1 Near outcome: * Incision: first phase incision healing: 53 patients (98.15%), superficial infection: patient (1.85%) There was no patient with deep infection or bleeding after surgery * Reduction outcome: Non-displacement: 50 patients (92.59%), less displacement: patients (3.70%) * Bone healing outcome Table 3.18 Duration of bone healing (n = 54) Duration of bone healing Min - Max Group age P (week) 17 17 18 – 30 14.39 ± 1.98 (12 – 18) 31 – 40 16.50 ± 4.95 (13 – 20) 41 – 50 17.00 ± 1.16 (16 – 18) < 0,05 51 – 60 19.50 ± 1.76 (18 – 22) 61 - 70 20.33 ± 1.92 (18 – 23) > 70 22.42 ± 2.28 (20 – 26) Comment: Average bone healing duration: 18,33 ± 3,78 weeks (12 26 weeks), younger people had bone healing faster than elderly people, the difference with statistical significance with p < 0.05 * Result of rehabilitation Table 3.19 Time to remove crutches (n = 54) Group age Time to remove crutches (week) Min - Max p 18 – 30 4.42 ± 0.58 (4,00 – 6,00) 31 – 40 4.50 ± 0.71 (4,00 – 5,00) 41 – 50 4.75 ± 0.65 (4,00 – 5,50) < 0.05 51 – 60 4.25 ± 0.27 (4,00 – 4,50) 61 – 70 5.50 ± 0.71 (4,50 – 6,50) > 70 6.83 ± 1.01 (5,00 – 8,00) Comment: Average time to remove crutches: 5.20 ± 1.19 weeks (from to weeks) The group of young people removed crutches earlier than the elderly, the difference was statistically significant with p 70 5.58 ± 0.79 (4.50 – 6.50) Comment: Average normal-walking time: 4.62 ± 1.03 months (from 2.5 to 6.5 months) The group of young people walking normally faster than the elderly group, the difference was statistically significant with p < 0.05 3.2.10.2 Far outcome 18 18 * Far outcome follow up: Average follow up time: 34.58 ± 8.38 months (12 – 48 months), far outcome follow up: 38/54 patients (70.37%) * Surgical scar: Surgical scar was soft and not inflamed: 36 patients (94.7%) Hypertrophic scars: patients (5.3%) * Result of rehabilitation - Pain: 28 patients with no pain (73,68%) 10 patients sometimes had pain (26,32%) - Knee flexion degreet: Knee flexion degree ≥ 125 : 22 patients (57.89%), 1000 - 1240 : 12 patients (31.58 %), from 900 - 990 : patients (10.53%), there was no case < 900 - Knee extension degree: 36 patients with knee extension degree to 0 (94.74%), patients with knee extension degree < (5.26%), there was no case with knee extension degree > 50 - Ankle joint movement: 35 patients with normal ankle joint movement (92.11%), patients with limited ankle joint movement (7.89%) No case of ankylosis - Limb deformation + Folding deformation: 34 patients had no folding deformation (89.47%), patients had folding deformation 100 + Short limbs: In our study, there were no case of short limbs + Ability to walk after surgery:Walking as normal: 31 patients (81.58%), walking from 30 – 60 minutes: patients (18.42%) + Ability to go up stairs:Ability to go upstairs as normal: 28 patients (73.68%), using handrail 10 patients (26.32%) + Ability of working and doing daily activities:27 patients (young people worked and elderly did daily activities normally - 71.05%); patients (young people worked hard and elderly people needed to be supported partly – 18.42%) There were patients (young people had to change previous jobs and elderly people had be supported with living activities - 10.53%) 3.2.10.3 Far outcome after surgery 19 19 * Assessment of far outcome according to AO fracture classification Table 3.30 Assessment of far outcome according to AO fracture classification (n = 38) Rate Group A Group C Result Total % A1 A2 A3 + C1 C2 C3 + Very good 18 22 57.89 Good 2 12 31.58 TB 4 10.53 Poor Total 13 26 12 38 100 Comment: Type A: Very good: 18 patients (47.36%), good: patients (21.05%), Type C: Very good patients (10.53%), good: patients (10.53%), average: patients (10.53%) * Assessment of common outcome: Comment: Very good 57.89%, good: 31.58%, average: 10.53%, poor: patient Chapter DISCUSSION 4.1 Rigid fracture fixation ability rigid DFF fracture of locking plate * Compressive strength of DFF locking plate – bone sample: From displacement of 2.5mm on femoral supra-condyle fracture model, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 4010.37 ± 509.50N (medium 4179.34N) and 3200.04 ± 243.62N (Median 3118.63N) respectively The difference was statistically significant with p < 0.05 From displacement of 2.5mm on femoral inter- condyle fracture model, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 4620.27 ± 315.85N (median: 4728.87N) and 4139.28 ± 766.53N (median: 4322.23N) respectively The difference wasn’t statistically significant with p > 0.05 20 20 * Horizontal bending strength of DFF locking plate – bone sample: From displacement of mm, when broken connection began happening on plate – bone sample with femoral supra-condyle fracture, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 704.33 ± 110.45N (median: 704.08N) and 505.76 ± 62.83N (median: 505.82N) respectively, the difference was statistically significant with p < 0.05 From displacement of mm, when broken connection began happening on plate – bone sample with femoral inter-condyle fracture, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 699.26 ± 125.60N (Median: 715.89N) and 476.05 ± 59.18N (Median: 492.44N) respectively, the difference was statistically significant * Torsional bending strength of DFF locking plate – bone sample: From displacement of mm, when broken connection began happening on plate – bone sample with femoral supra-condyle fracture, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 990.79 ± 166.54N (median: 991.69N) and 888.84 ± 89.02N (median: 905.38N) respectively, the difference wasn’t statistically significant with p > 0.05 From displacement of mm, when broken connection began happening on plate – bone sample with femoral inter-condyle fracture, the forces acting on the DFF locking plate – bone and femoral condyle plate – bone samples were 1071.00 ± 222.38N (median: 1091.79N) and 986.26 ± 116.33N (median: 972.38N) respectively, the difference wasn’t statistically significant with p > 0.05 4.2 Treatment outcome of DFF closed fracture using locking plate osteosynthesis 4.2.1 Common characteristics of studied group * Age, gender: There were 54 patients with DFF closed fracture, average age: 51.04 ± 22.30 years old (18 - 90 years old), male: 26 patients (48.15%); female: 28 patients (51.85%), male to female ratio was nearly equal Elderly group ≥ 60 years old: 26 patients (48.15%), group with age from 18 - 44 years old: 20 patients (37.04%), group of 45 - 59 years old: patients (14.81%) 21 21 * Cause and mechanism of trauma: Daily activities accident: 27 patients (50%), elderly group ≥ 60 years old: 18/27 people, group of 18 - 44 years old: 4/27 people and group of 45 - 59 years old: 5/27 people Traffic accident: 24 patients (44.44%), group of 18 - 44 years old: 15/24 people, group ≥ 60 years old: 6/24 people and group of 45 - 59 years old: 3/24 people Labor accident: patients (5.56%), all of them were young people Number of patients with left and right DFF fracture were 30 (55.56%) and 24 (44.44%) respectively * Characteristics, natures and classification of fracture: Simple fracture: 31 patients (57.41%), complex fracture: 23 patients (42.59%) Non-articular fracture: 42 patients (77.78%), articular fracture: 12 patients (22.22%) 4.2.2 Indications of locking plate osteosynthesis: DFF closed fracture of type A and C (according to AO classification), articular and complex fractures Same-side proximal tibia fracture DFF fracture in elderly patients, people with osteoporosis 4.2.3 Period of surgery 1st day: 32 patients (59.26%), 2nd – 6th day: 14 patients (25.93%), > days: patients (14.81%) Patients receiving early surgical intervention are people with closed and simple fracture, no accompanied injury, less soft tissue injury and fine status 4.2.4 Locking plate osteosynthesis technique for treatment of DFF fracture * Incision: Lateral incision (through inter-muscular wall) was indicated for femoral supra-condyle and simple inter-condyle fractures.Anterolateral incision was selected for femoral inter-condyle fracture with condyle injury needing reduction Among 54 patients, lateral incision: 22 patients (40.74%), anterolateral incision: 32 patients (59.26%) * Selection of osteosynthesis measures: locking plate was selected to treat DFF fracture for following reasons: It had a design suitable for anatomy shape of DFF with different screw directions which made it easy to place the plate and fix fracture fragments easily Materials were good and had high stiffness, together with thread system on screw’s tip 22 22 helping overcome disadvantages of femoral condyle plate, while promoting advantages compared to other types of plate * Locking plate osteosynthesis technique for treatment of DFF fracture: In 54 patients with DFF fracture of type A and C according to AO classification: We used porous screw with locking plate on 12 patients (22.22%), porous screws combined with steel sutures and locking plate for patients (3.70%) * Surgical duration and transfusion: Our study found that: Surgery duration from 60 - 90 minutes (87.04%), type A: 39 patients, type C: patients Surgery duration from 90 - 120 minutes: patients (9.26%), both surgery durations of 120 - 150 minutes and 150 - 180 minutes had patient (1.85%) There was no patient with surgery duration > 180 minutes.There were 36/54 patients receiving transfusion with total blood volume of 18200 ml 4.2.5 Assessment of treatment outcome of DFF fracture * Bone healing: long outcomes of 38 patients were followed up more than 12 months, average follow-up time: 34.58 ± 8.38 months (from 12 to 48 months), average healing time: 18.33 ± 3.78 weeks (from 12 - 26 weeks) No patient had pseudarthrosis, delayed healing and non-healing * Result of rehabilitation: Thanks to rigid locking plate osteosynthesis and rehabilitation, in our study group, the patient could walk early without crutch, the earliest as weeks, and the latest as weeks, the average time to remove crutch was 5.20 ± 1.19 weeks Young people could walk without crutch earlier than the elderly, even in case young patients with complex fractures, the difference was statistically significant with p < 0.05 * Result of osteosynthesis to anatomy recovery: non-displacement: 50 patients (92.59%), less displacement: patients (7.41%, seen in patients with type C fracture), no folding deformation: 34 patients (89.47%), folding deformation with angle 10 and no case with short legs 23 23 * Result of knee-joint rehabilitation In the study, knee movement degree > 1250: 22 patients (57.89%), from 1000-1240 12 patients (31.58%), from 900 - 990: patients (10.53%), < 900: person * Ability to walk and return to daily activities: The goal of fracture treatment was movement recovery and good quality of life for patients Far outcomes of 38 patients: No pain: 28 patients (73.68%), sometimes pain or pain when weather changing: 10 patients (26.32%) Normal walking: 31 patients (81.58%), walking for 30-60 minutes: patients (18.42%), no case with walking < 30 minutes, less movement or without walking * Assessment of outcomes after surgery- According to AO fracture classification: type A: Very good: 18 patients (47.36%), good: patients (21,05%) Type C: Very good patients (10.53%), good: patients (10,53%), average: patients (10,53%) - Assessment of far outcome according to Sander R Very good and good: 89.47% (34/38 patients), average: 10.53% (4/34 patients), no patient had poor outcome Our study was similar to that of other domestic authors such as: Truong Tri Huu, good: 91.2%, average: 2.9%, poor: 5.9% Ngo Quoc Hoan (2016), good and very good: 89.48% and some foreign authors: Nagy M.H (2007), Forster M.C (2006), Yeep E.J et al (2007), Supanich V (2012), Shriharsha R.V (2015), Ranjan R et al (2017) (very good: 75%), Kumar G.N.K et al (2014) (very good: 86%) * Accidents and complications - Accidents: Among our study patients, there was no major accident affecting to treatment outcome - Complications: Superficial infection at incision site: patient (1.85%) - Surgical scar: patients (3.70%) with hypertrophic scar - Loosed screws, broken screws, bent plate: case - Delayed bone healing, pseudarthrosis, non-healing: case - Degenerative joint: case CONCLUSION By studying rigid fracture fixation ability of compressive locking plate on experimental model at Hanoi University of Science and 24 24 Technology and evaluating treatment outcomes of 54 patients with DFF closed fracture of type A and C (according to AO) with locking plate, we had some conclusions: Determination of rigid fracture fixation ability rigid of compressive locking plate on experimental model - Femoral supra-condyle fracture model: There is broken plate – bone connection with: Compressive force: 4010.37 ± 509.50N (median: 4179.34N), converted stiffness: 1269.74N / mm (displacement of 2.5mm); Horizontal bending force: 704.33 ± 110.45N (median: 704.08N), converted horizontal bending stiffness 332.92N / mm (displacement of 4mm); Torsional bending force: 990.79 ± 166.54N (median: 991.69N), converted torsional bending stiffness: 379.42N / mm (displacement of 4mm) - Femoral inter-condyle fracture model: There was broken plate – bone connection with: Compressive force: 4620.27 ± 315.85N (median: 4728.87N), converted compressive stiffness: 1814.19N / mm (displacement of 2.5mm); Horizontal bending force: 699.26 ± 125.60N (median: 715.89N), converted horizontal bending stiffness 373.22N / mm (displacement of 4mm); Torsional bending force: 1071.00 ± 222.38N (median: 1091.79N), converted torsional bending stiffness: 379.42N / mm (displacement of 4mm) On the same experiment model, DFF locking plate had a more rigid fracture fixation ability than that of femoral condyle plate Treatment outcome of DFF closed fracture using locking plate * Near outcome: first phase incision healing: 53/54 patients (98.15%), superficial infection: patient (1.85%) There was no patient with deep infection 100% of reduction met requirements, nondisplacement: 92.59%, less displacement: 7.41% Average bone healing time was 18.33 ± 3.78 weeks (from 12-26 weeks) * Far outcome: On 38 patients, soft scar: 94.7%, hypertrophic scar: 5.3% Bone healing: 100% - Movement function: knee flexion > 125 0: 57.89%, from 1000 124 : 31.58%, from 900 - 990: 10.53%, < 900: 0% Knee extension into 00: 94.74%, 50: 0% Normal ankle movement: 92.11%, less limited movement: 7.89% 25 25 - Non-folding deformation: 89.47%, folding deformation