Conservative treatment for Distal femurfractures has many disadvantages and complications, so surgeons preferopen reduction and osteosynthesis through many methods:intramedullary pin fix
Trang 1Distal femur fractures (DFF) (supra-condyle fracture, inter-condylefracture, medial condyle fracture, lateral condyle fracture) has a ratefrom 6% - 7% among all types of femur fracture, of which supra-condyle and inter-condyle fractures accounts for 70% of Distal femurfractures cases High-energy fracture (fracture caused by high-energyforce) is usually met on younger patients, fracture from traffic accidentsaccounts for above 50% Older patients usually have low-energyfractures caused by falling Conservative treatment for Distal femurfractures has many disadvantages and complications, so surgeons preferopen reduction and osteosynthesis through many methods:intramedullary pin fixation (upstream or downstream from the knee);osteosynthesis with plates and screws (normal plates and screws, twoplate/screw systems, DCS plate, femoral condyle plate and lockingplate) For complex cases, such as fractures occur near joints,osteosynthesis with condyle plates, and recently, osteosynthesis withlocking plates has become the first choice, overcoming disadvantages ofother devices
Although positive results were achieved in treatment of Distalfemur fractures, some studies show that: osteosynthesis with condyleplates or locking plates still occurs fail (stiff knee, deflective healing,delayed bone healing, pseudarthrosis…) For exact learning of failcauses, we neeed to concern rigid fixation ability after surgery of theseplate types Then, suitable exercise programmes after surgery areestablished 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 betweencondyle plate and locking plate on the same trial pattern in relation toplate – 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:
Trang 21 Determine rigid fixation ability of locking plate on the trial osteosynthesis model.
2 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, reducingcomplication and sequelae rates compared to other methods Lockingplate with outstanding advantages in design, material and shapeovercomes disadvantages of other osteosynthesis measures Tounderstand more about rigid fixation ability of locking plate ontreatment 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, eccentricbending forces torque than condyle plate – bone model, this is a basehelping surgeons choose locking plate to treat Distal femur fractures.After treating 54 patients with Distal femur fractures, relatively highbone healing and rehabilitation outcomes were observed, contributing totheoretical and practical bases
This a practical thesis, deeply studying fracture fixation ability oflocking plate It helps determine ability bearing compression, bendingand torsion forces of trial plate – bone model It permits patients tomove early, reduces complications such as amyotrophy, delayed bonehealing, 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 – literatureoverview (32 pages); Chapter 2 – material and method (22 pages);Chapter 3 – Result (27 pages); Chapter 4 – Discussion (30 pages),Conclusion (2 pages) and Recommendation (1 page) There are 3published studies related to the thesis.There are 125 referencesincluding: 21 Vietnamese and 104 English documents
Trang 3Chapter 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 is24,4% time more rigid than conventional plate, rigid rate of lockingplate/conventional plate is 168,2/127,1 N/mm; p<0,0001) Lockingplate can bear load better than conventional plate (1560N vs 1337 N).Wähnert D et al (2011), compared treatment effectiveness for adultpatients with DFF fracture of intramedullary pin types to that of lockingplate Result: Load beared by SNC pin, AxSOS plate, DFN and T2
were 6400 ± 540N (the highest), 4500 ± 0N, 4400 ± 495N and 3100 ± 545N respectively Granata J.D et al (2012) studied ability bearing load
of locking plate on complex supra-condyle fracture Compression force trial showed that locking plate could bear weight of 1329 ± 106N,
which was 1.9 time of body weight of a 70-kg person Assari S et al(2013) compared biomechanical forces between locking plate LCP anddownstream intramedullary pin of supra-condyle fracture type A3according to AO classification Result: When doing axialcompression, the LCP-bone system (2.46 ± 0.12kN / mm) was stifferthan downstream intramedullary pin - bone system (1.36 ± 0.14kN /
mm on the same type of bone with normal mineral density
1.2 Using locking plate osteosynthesis to treat DFF fracture
* In the world: Syed A.A et al (2004) followed up long-term result
of 25 patients with DFF fracture (average age is 60.9 years old) receivingLISS locking plate osteosynthesis for average follow-up time of 18months (from 12 to 24 months) The result showed that 22 patients hadaverage bone healing time of 3.5 months (from 2 - 5 months) and didn’thave to receive bone graft, 3 patients had delayed bone healing ForsterM.C et al (2006) reported that among 570 patients with DFF fracturereceiving locking plate osteosynthesis, rate of very good and good peoplewas 72 – 88% Yeep E.J et al (2007) reported early result of 10patients with DFF fracture treated by locking plate LCP during 6months Their result showed that there were 4 very good, 4 good, 1
Trang 4average and 1 poor patients Nayak R.M et al (2011) reported usingcompression locking plate with minimally invasive osteosynthesistechnique to treat 31 patients with DFF fracture having average age of
42 (from 22 to 65 years old) Result: there were 29/31 good and verygood and 2 average patients, no patient having folding and axisdisplacement above > 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 4 differentosteosynthesis measure types: Angel plate, DCS plate, condyle plateand locking plate Result: very good and good patient rates of lockingplate, DCS plate, angel plate and condyle plate were 86%, 78%, 66%and 50% respectively Vallier H.A et al (2012) compared Treatmentoutcome of osteosynthesis between 950 angeled plate and LCP (LockingCondylar Plate) during average follow up time of 26 months (9 - 77months) For some complications such as deep infection, non-healingand displacement healing, complication rates of angeled plate and LCPwere 10% and 35% respectively Gupta SKV (2013) comparedTreatment outcome of osteosynthesis between intramedullary pin andLCP After 6 months, his result showed that bone healing rates of bothpatient group were above 75%, average bone healing time ofintramedullary pin and LCP groups were 6.8 and 7.5 monthsrespectively 2/46 (4%) LCP patients had non-healing while there were5/57 (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 verygood, good, average and poor rates were 76.5%, 14.7%, 2.9% and 5.9%respectively
Trang 5Chapter 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 ofScience 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 3 publishedstudies related to the thesis There are 3 published studies related to thethesis Intercus locking plate
- Compression and horizontal and torsion bendings experiment wasperformed 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 inter-supra-condyle fractures (type C2) according to
AO classification Bones were adjusted Plate/screw systems wereplaced on lateral aspect of the bones, plates were clamped with bonepliers 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: Theencorders of the machine would measure compressive, horizontal andtorsion bendings forces acting on the models while measuring thecorresponding deformation level of the models along the axis of actingforce The compressive, bending, torque and deformation parameters atthe fracture were continuously measured and transmitted to a computer.The computer would automatically build a graph showing therelationship 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
Trang 6Torsional 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 andTechnology 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 bytrauma, 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 andsurgical records Doing post-operative care and X-ray examination.Assessing near outcomes: outcomes of reduction and osteosynthesisafter surgery and process of incision Patients was guided to dorehabilitation Follow-up sheet was made for each patient Patients wasappointed to re-examine at following times: 1, 2, 3, 4, 5, 6 and 12months 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 healingoccured Classification of DFF fracture based on X-ray images according
to AO classification Surgical techniques, Locking plate osteosynthesisindication, treatment outcomes
* Treatment of DFF closed fracture using locking plate osteosynthesis
- Anesthesia: spinal anesthesia.
- Surgical technique: patient’s position: patients were on supine
position with supporters below poplitei and tourniquets of thigh
Trang 7Phase 1: Incision: lateral incision for simple DFF fractures and lateral
anterior incision for complicated fractures, joint fracture and difficultreduction
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-edemaafter 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 practicedquadriceps muscle contraction and knee joint flexion and extension.After 2-3 weeks, patient practiced to stand, walk with two crutches.After 4 - 6 weeks, patient practiced to walk with a crutch, then after 6 to
8 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 deepinfections Reduction outcome recovering anatomy and osteosynthesistechnique 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 4 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 studygroups (Independent Sample T test)
Chapter 3 RESULT 3.1.Results of trial study on mechanical strength and rigid fracture fixation for DFF fracture of locking plate.
3.1.1 Compressive strength trial on 2 samples: DFF locking plate bone (KA - N) and condyle plate - bone (LA - N)
Trang 8-Table 3.1: Compressive forces bearing ability on 2 samples of femoral
supra-condyle fracture (KA - N) and (LA - N) (n = 12)
LA – A
(Median
- N)
0.5 mm 1329.90 ± 355.90 1281.21 1121.19 ± 230.17 1115.48 > 0,051.0 mm 1719.48 ± 384.83 1789.93 1552.09 ± 256.04 1611.70 > 0,051.5 mm 2456.16 ± 641.66 2641.24 2074.99 ± 263.24 2113.90 > 0,052.0 mm 3225.50 ± 427.18 3293.35 2865.01 ± 548.70 2814.24 > 0,052.5 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
0 1000 2000 3000 4000 5000 6000
Graph 3.1 Correlation between compressive force and deformation of
2 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 fracturedisplacement of 2.5mm began to break connection, while averagecompressive force on the femoral condyle plate - bone samples was3118.63N with fracture displacement broken connection, with p < 0.05
Trang 9Table 3.2 Compressive forces bearing ability on 2 samples of femoral
LC – N
(Median
- N)
0.5 mm 1194.51 ± 210.07 1184.63 953.97 ± 287.56 995.22 > 0.051.0 mm 2030.63 ± 241.84 2028.99 1597.88 ± 527.67 1686.33 > 0.051.5 mm 3140.14 ± 288.16 3228.73 2738.34 ± 703.88 2919.65 > 0.052.0 mm 3915.8 ± 295.43 3968.29 3498.13 ± 787.61 3524.11 > 0.052.5 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 wasnot significant with p > 0.05
0 1000 2000 3000 4000 5000 6000
Graph 3.2 Correlation between compressive force and deformation of
2 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
of 2.5mm began to break connection, while average compressive force onthe femoral condyle plate - bone samples was 4322.23N with fracturedisplacement of 2.5mm also began to break connection, the difference inforce was not statistically significant with p> 0.05
Trang 10Comment: 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)
LA – U
(Median N)
-1 mm 204.94 ± 70.34 178.04 155.86 ± 48.13 136.84 > 0,05
2 mm 396.37 ± 117.52 365.62 314.52 ± 88.88 340.30 > 0,05
3 mm 537.79 ± 121.16 508.07 499.78 ± 85.32 484.7 > 0,05
4 mm 704.33 ± 110.45 704.08 505.76 ± 62.83 505.82 < 0,05
Comment: From displacement of 4 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 thesample (LA - U): 505.76 ± 62.83N (median: 505.82N), with p < 0.05
-0 100 200 300 400 500 600 700 800 900 1000
Comment: Average horizontal bending forces of 704.08N and 505.82N
acting on DFF locking plate – bone and femoral condyle plate – bone
Trang 11samples respectively caused broken connection (displacement of 4 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)
KC – U
LC – U
Comment: From displacement of 4 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
0 200 400 600 800 1000 1200
Graph 3.4 Correlation between horizontal bending force and
deformation of samples of (KA - N) and (LA - N) with femoral
inter-condyle fracture.
Comment: The graph showed that average horizontal bending forces of
715.89N and 492,44N acting on DFF locking plate – bone and femoralcondyle plate – bone samples respectively caused broken connection
Trang 12(displacement of 4 mm) The difference was statistically significantwith 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)
(Newton - N) (n=6)
KA – X
(Median N)
-LA – X (X SD)
(Newton - N) (n=6)
Comment: From displacement of 4 mm, when broken connection
began happening, the force acting on the DFF locking plate – bonesample of 990.79 ± 166.54N (median: 991.69N) had a difference withthat 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
0 200 400 600 800 1000 1200 1400 1600 1800 2000