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1.
Article in English | MEDLINE | ID: mdl-38108316

ABSTRACT

OBJECTIVE: This study aimed to biomechanically compare the maximum rotational, axial movements, and compression forces between fracture fragments before and after 1-4 mm fracture site resorption among interlocking nails, compression nails, and newly designed compressive anti-resorption (CARES) nails compressed with tube and coil spring. METHODS: We determined the maximum axial/rotational movements and interfragmentary compression loads between fragments on 10 interlocking nails, 10 compression nails, and 10 CARES nails with 30 composite femurs. Using a compression-distraction testing device, 6 N·m external and internal torques were applied, and we evaluated the maximum rotational and axial displacement between fragments after 1-4 mm fracture site resorption. RESULTS: When 6 N·m of internal-external rotation torque was applied after 2 mm fracture site resorption, the maximum rotational displacement between fragments in the CARES nail was 3 ± 0.52 mm, 101% less than the 6.03 ± 0.83 value in the compression nail and 100% less than the 6 ± 1 mm value measured in the interlocking nail (P=.000). The compression between fragments was 298 ± 72 N in the CARES nail after 1 mm of resorption, while this value was measured as 0 in the other nails. There was a significant difference in rotational, axial stability, and interfragment compression among the different femoral nails after 1-4 mm fracture site resorption. CONCLUSION: The CARES nail having additional coil springs seems significantly biomechanically superior to compression nails and interlocking nails, providing maximum rotational, axial stability, and interfragment compression after fracture site resorption.

2.
Acta Orthop Traumatol Turc ; 57(6): 372-377, 2023 Nov.
Article in English | MEDLINE | ID: mdl-38454216

ABSTRACT

OBJECTIVE: This study aimed to biomechanically compare the maximum rotational, axial movements, and compression forces between fracture fragments before and after 1-4 mm fracture site resorption among interlocking nails, compression nails, and newly designed compressive anti-resorption (CARES) nails compressed with tube and coil spring. METHODS: We determined the maximum axial/rotational movements and interfragmentary compression loads between fragments on 10 interlocking nails, 10 compression nails, and 10 CARES nails with 30 composite femurs. Using a compression-distraction testing device, 6 N·m external and internal torques were applied, and we evaluated the maximum rotational and axial displacement between fragments after 1-4 mm fracture site resorption. RESULTS: When 6 N·m of internal-external rotation torque was applied after 2 mm fracture site resorption, the maximum rotational displacement between fragments in the CARES nail was 3 ± 0.52 mm, 101% less than the 6.03 ± 0.83 value in the compression nail and 100% less than the 6 ± 1 mm value measured in the interlocking nail (P=.000). The compression between fragments was 298 ± 72 N in the CARES nail after 1 mm of resorption, while this value was measured as 0 in the other nails. There was a significant difference in rotational, axial stability, and interfragment compression among the different femoral nails after 1-4 mm fracture site resorption. CONCLUSION: The CARES nail having additional coil springs seems significantly biomechanically superior to compression nails and interlocking nails, providing maximum rotational, axial stability, and interfragment compression after fracture site resorption.


Subject(s)
Femoral Fractures , Fracture Fixation, Intramedullary , Humans , Bone Nails , Femoral Fractures/surgery , Biomechanical Phenomena , Femur
3.
Acta Orthop Belg ; 85(2): 218-223, 2019 Jun.
Article in English | MEDLINE | ID: mdl-31315013

ABSTRACT

Instability increases after fracture site resorption. This study aimed to compare the fracture site stabilities of different femoral nails after fracture site resorption. Thirty composite femurs were divided into three groups of 10 interlocking nails. Using axial compression-distraction machines and a custom-made torsion device, the fracture site rotational and axial stabilities after 1 mm fracture site resorption were determined. Between 6 Nm external and 6 Nm internal rotation torques, the means of the maximum fracture site rotation arc of motion were 5.94 mm for compression nails, 5.9 mm for interlocking nails and 3.5 mm for CAROT nails. Between 2300 N compression and 150 N distraction forces, the means of the fracture site axial motion were 3.15 mm for interlocking nails, 1.26 mm for compression nails and 1.26 mm for CAROT nails. CAROT nails are superior to compression and interlocking nails in fracture site rotational and axial stabilities after 1 mm fracture site resorption.


Subject(s)
Bone Nails , Bone Resorption/physiopathology , Femoral Fractures/physiopathology , Femur/physiopathology , Fracture Healing/physiology , Biomechanical Phenomena/physiology , Femoral Fractures/surgery , Femur/surgery , Fracture Fixation, Intramedullary , Humans
4.
Medicine (Baltimore) ; 96(33): e7833, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28816983

ABSTRACT

Psoriatic arthritis (PsA) is a chronic inflamatory disease characterized with axial and peripheral joints involvement. It rarely affects patients older than 65 years old.The purpose of this study is to compare and evaluate the demographic, clinical and laboratory features of elderly-onset psoriatic arthritis (EOPsA) and young-onset (YOPsA) patients.A total of 180 patients diagnosed with PsA according to CASPAR criteria and followed-up in single center were included in this study. The patients with initial symptoms started after age 65 were accepted as EOPsA. Demographic, clinic, and laboratory data and the medications which the patients received were recorded and retrospectively evaluated.Nineteen (10.5%) of 180 patients were diagnosed as EOPsA, and 161 (89.5%) patients were evaluated as YOPsA. The mean patient age was 42.1years for the YOPsA group and 68.3 years for the elderly onset group. Mean duration of disease was 5.6 years for the early onset group and 1.3 years for the elderly onset group (P = .001). Fourteen (73.3%) of 19 EOPsA patients were female and 5 of them were male. Higher rates of fatique, pain scores, comorbid diseases, and acute phase reactants elevation were detected in EOPsA patients comparing to YOPsA (P = .000, P = .000, P = .001, and P = .001, respectively). YOPsA patients have more dactilitis, nail involvement, elevated PASI scores, and smoking habitus when compared with EOPsA patients (P = .019, P = .03, P = .005, P = .004, respectively). In terms of the treatment options chosen, there was no significant difference in the use of nonsteroidal anti-inflammatory drugs (NSAIDs), corticosteroids (CS), methotrexate (MTX), and sulfasalazine (SSL), but there was a more frequent use of anti-tumor necrosis factor-alpha in the YOPsA group.YOPsA and EOPsA patients may presented with different clinical and laboratory features. EOPsA patients are characterized with higher rates of fatigue, pain scores, comorbid diseases, and acute phase reactants and less dactilitis, nail involvement, and anti-TNF-alpha usage.


Subject(s)
Arthritis, Psoriatic/physiopathology , Adolescent , Adult , Age of Onset , Aged , Arthritis, Psoriatic/drug therapy , Comorbidity , Female , Humans , Male , Middle Aged , Retrospective Studies , Young Adult
5.
J Orthop Surg (Hong Kong) ; 25(1): 2309499016684723, 2017 01.
Article in English | MEDLINE | ID: mdl-28142347

ABSTRACT

BACKGROUND: Bursitis of the snapping scapula is commonly a misdiagnosed problem. Extracorporeal shockwave therapy (ESWT) has been used successfully in the treatment of many chronic inflammatory conditions. The aim of this study was to assess and compare the effectiveness of ESWT in the treatment of scapulothoracic bursitis with the outcome of corticosteroid injection. METHODS: Using the randomized controlled trials 43 patients with scapulothoracic bursitis were divided into two groups. Group 1 ( n = 22) received three sessions of ESWT. Group 2 ( n = 21) received a single local injection of 80 mg of methylprednisolone. Visual analogue scale (VAS) scores were recorded at each follow-up, whereas the level of satisfaction was evaluated using the Roles and Maudsley criteria. RESULTS: In group 1, the average VAS scores after 1, 2, 3, and 6 months were 39, 30, 27, and 16, respectively, whereas, in group 2, the average VAS scores were 46, 44, 35, and 36, respectively. There was no statistical significance between the two groups in the first and second months. However, after 3 and 6 months, group 1 revealed lower average VAS scores compared to that of the second group with p-values (0.012 and 0.001), respectively. Roles and Maudsley criteria showed that first group patients were 46% excellent, 36% good, 14% acceptable, and 4% had poor results. However, second group patients were 24% excellent, 33% good, 19% acceptable, and 24% had poor results. CONCLUSION: We believe that ESWT is a beneficial and trustable method of treatment and can be strongly recommended in painful cases of scapulothoracic bursitis.


Subject(s)
Bursitis/therapy , Glucocorticoids/therapeutic use , Methylprednisolone/therapeutic use , Scapula , Ultrasonic Therapy , Adult , Female , Humans , Male , Middle Aged , Pain Measurement , Patient Satisfaction , Prospective Studies , Treatment Outcome
6.
J Orthop Surg (Hong Kong) ; 25(1): 2309499016684503, 2017 01.
Article in English | MEDLINE | ID: mdl-28118805

ABSTRACT

INTRODUCTION: Volumetric measurements of benign tumors enable surgeons to trace volume changes during follow-up periods. For a volumetric measurement technique to be applicable, it should be easy, rapid, and inexpensive and should carry a high interobserver reliability. We aimed to assess the interobserver reliability of a volumetric measurement technique using the Cavalier's principle of stereological methods. MATERIALS AND METHODS: The computerized tomography (CT) of 15 patients with a histopathologically confirmed diagnosis of enchondroma with variant tumor sizes and localizations was retrospectively reviewed for interobserver reliability evaluation of the volumetric stereological measurement with the Cavalier's principle, V = t × [((SU) × d) /SL]2 × Σ P. RESULTS: The volumes of the 15 tumors collected by the observers are demonstrated in Table 1. There was no statistical significance between the first and second observers ( p = 0.000 and intraclass correlation coefficient = 0.970) and between the first and third observers ( p = 0.000 and intraclass correlation coefficient = 0.981). No statistical significance was detected between the second and third observers ( p = 0.000 and intraclass correlation coefficient = 0.976). CONCLUSION: The Cavalier's principle with the stereological technique using the CT scans is an easy, rapid, and inexpensive technique in volumetric evaluation of enchondromas with a trustable interobserver reliability.


Subject(s)
Bone Neoplasms/diagnostic imaging , Bone Neoplasms/pathology , Chondroma/diagnostic imaging , Chondroma/pathology , Tomography, X-Ray Computed , Tumor Burden , Adolescent , Adult , Female , Humans , Male , Reproducibility of Results , Retrospective Studies , Young Adult
7.
J Korean Neurosurg Soc ; 59(5): 425-9, 2016 Sep.
Article in English | MEDLINE | ID: mdl-27651858

ABSTRACT

OBJECTIVE: Rod-screw fixation systems are widely used for spinal instrumentation. Although many biomechanical studies on rod-screw systems have been carried out, but the effects of rod contouring on the construct strength is still not very well defined in the literature. This work examines the mechanical impact of straight, 20° kyphotic, and 20° lordotic rod contouring on rod-screw fixation systems, by forming a corpectomy model. METHODS: The corpectomy groups were prepared using ultra-high molecular weight polyethylene samples. Non-destructive loads were applied during flexion/extension and torsion testing. Spine-loading conditions were simulated by load subjections of 100 N with a velocity of 5 mm min(-1), to ensure 8.4-Nm moment. For torsional loading, the corpectomy models were subjected to rotational displacement of 0.5° s(-1) to an end point of 5.0°, in a torsion testing machine. RESULTS: Under both flexion and extension loading conditions the stiffness values for the lordotic rod-screw system were the highest. Under torsional loading conditions, the lordotic rod-screw system exhibited the highest torsional rigidity. CONCLUSION: We concluded that the lordotic rod-screw system was the most rigid among the systems tested and the risk of rod and screw failure is much higher in the kyphotic rod-screw systems. Further biomechanical studies should be attempted to compare between different rod kyphotic angles to minimize the kyphotic rod failure rate and to offer a more stable and rigid rod-screw construct models for surgical application in the kyphotic vertebrae.

9.
Acta Orthop Traumatol Turc ; 50(5): 514-518, 2016 Oct.
Article in English | MEDLINE | ID: mdl-27666141

ABSTRACT

OBJECTIVES: The aim of this study was to analyze the effect of tibial tunnel positioning in single bundle and double bundle ACL reconstructions on lateral meniscus anterior root. MATERIALS: Twelve single knee cadavers were used, 6 for a single bundle ACL reconstruction, which were reamed gradually starting from 8 mm, 9 mm and ended with a 10 mm reamers, while the other 6 were prepared for a double bundle ACL reconstruction in which 7 mm reamer for the AM tunnel and 6 mm reamer for the PL tunnel were used. After drilling, changes of lengths and thicknesses of anterior horns of the lateral menisci were recorded. RESULTS: Before drilling, the groups were homogenous for the lateral menisci dimensions. After drilling, no statistically significant difference was noticed between the two groups. However, in single bundle group, 2 anterior horns width injury (1.44 mm and 2.13 mm) with the 9 mm reamer and 3 anterior horns width injury (2.51 mm, 3.55 mm and 4.28 mm) with the 10 mm reamer were recorded. However in double bundle group a single anterior horn width injury (2.82 mm) was recorded. CONCLUSION: Using a greater size reamer in single bundle reconstruction, causes a relatively higher risk of lateral meniscal anterior root injury. Lateral meniscus stability should be examined arthroscopically after reaming with large reamers.


Subject(s)
Anterior Cruciate Ligament Reconstruction/adverse effects , Iatrogenic Disease , Knee Joint/surgery , Surgical Instruments/adverse effects , Tibial Meniscus Injuries/etiology , Aged , Biomechanical Phenomena , Cadaver , Humans , Male , Middle Aged
10.
Rheumatol Int ; 36(11): 1585-1589, 2016 Nov.
Article in English | MEDLINE | ID: mdl-27587294

ABSTRACT

Gouty arthritis is a chronic erosive autoinflammatory disease. Pyrin has anti-inflammatory effects in the regulation of inflammasome and is encoded by the MEFV gene. The relationship between different rheumatic diseases and the MEFV gene mutations was demonstrated. The aim of this study was to determine the frequency of MEFV gene mutations in patients with gouty arthritis and identify a possible correlation with disease phenotype. Ninety-three patients with gouty arthritis and 102 healthy controls, compatible with age, gender and ethnicity, were included in the study. MEFV gene mutations were investigated by PCR method. Out of 93 patients with gouty arthritis, 36 (38.7 %) showed MEFV gene mutations carriage, whereas 20.6 % in healthy control group. Distribution of mutations identified in patients with gouty arthritis was as; R202Q in 18 (19.3 %), E148Q in 5 (5.4 %), K695R in 4 (4.3 %), M680I in 2 (2.1 %), V726A in 2 (2.1 %), P369S in 2 (2.1 %), R408Q in 2 (2.1 %), M694 V in 1 (1.1 %), respectively. Three patients were identified with compound heterozygosity. Distribution of MEFV gene mutations carriage in healthy controls was; E148Q in 11 (10.7 %), M694 V in 2 (1.9 %), M694I in 1 (0.9 %), M680I in 2 (1.9 %), V726A in 1 (0.9 %), A744S in 1 (0.9 %), K695R in 2 (1.9 %), and P369S in 1 (0.9 %) patients, respectively. Higher MEFV gene mutations carrier frequency was observed in patients with gouty arthritis, compared with the control group (p = 0.009). Heterozygous R202Q was the most common mutation detected in patients with gouty arthritis, while heterozygous E148Q in healthy control group. Statistically significant difference was not detected between clinical findings of gouty arthritis and the MEFV gene mutations (p > 0.05). We determined higher prevalence of MEFV gene mutations in patients with gouty arthritis compared with the healthy control group. The most frequently detected mutation was heterozygous R202Q, whereas E148Q in healthy controls. High carriage rates of MEFV gene mutations in gouty arthritis suggest that it may play an important role in the pathogenesis of the disease and predisposition to the disease.


Subject(s)
Arthritis, Gouty/genetics , Genetic Predisposition to Disease , Mutation , Pyrin/genetics , Adult , Aged , Female , Genetic Association Studies , Humans , Longitudinal Studies , Male , Middle Aged , Phenotype
11.
Bosn J Basic Med Sci ; 16(4): 276-279, 2016 Nov 10.
Article in English | MEDLINE | ID: mdl-27357501

ABSTRACT

Nucleotide binding and oligomerization domains/caspase recruitment domain-containing protein 15 (NOD2/CARD15) is a cytoplasmic molecule controlling apoptosis and inflammatory processes by recognizing some microbial components. We aimed to identify the frequencies of NOD2/CARD15 gene mutations in patients with gouty arthritis and to determine their possible correlation with the disease phenotype. The study included 93 patients with gouty arthritis and 51 healthy controls matched for age, gender, and ethnicity. The NOD2/CARD15 R702W and G908R gene mutations were explored by the polymerase chain reaction restriction fragment length polymorphism method while the 3020insC mutation was analyzed by DNA sequencing. The mean patient age was 54.2 ± 14.2 years and mean duration of the disease was 3.1 ± 2.9 years. The first metatarsophalangeal and finger joint involvements were detected in 72 (77.4%) and 18 (19.5%) patients, respectively. Ankle arthritis and knee arthritis were detected in 43 (46.2%) and 20 (21.5%) patients, respectively. In total, 4 (9%) heterozygous mutations were detected in the G908R and R702W genes, while no mutation was detected in the 3020insC gene. Compared to the control group, there were no significant differences in all three DNA regions (G908R, R702W, and 3020insC; p = 0.452, p = 0.583, and p = 0.350, respectively). No correlation between the NOD2/CARD15 variants and clinical or laboratory findings (p > 0.05) was found. The frequencies of the NOD2/CARD15 gene mutations in the patients were similar to healthy control group. No association between clinical or laboratory findings and the NOD2/CARD15 gene mutations was observed.


Subject(s)
Arthritis, Gouty/genetics , Mutation/genetics , Nod2 Signaling Adaptor Protein/genetics , Adult , Aged , Ankle/pathology , Arthritis, Gouty/pathology , DNA/genetics , Female , Fingers/pathology , Humans , Joints/pathology , Knee/pathology , Male , Middle Aged , Young Adult
12.
Indian J Orthop ; 50(1): 94-8, 2016.
Article in English | MEDLINE | ID: mdl-26955183

ABSTRACT

BACKGROUND: Proximal locking screw deformation and screw fracture is a frequently seen problem for femur interlocking nailing that affects fracture healing. We realized that there is lack of literature for the right level for the proximal locking screw. We investigated the difference of locking screw bending resistance between the application of screws on different proximal femoral levels. MATERIALS AND METHODS: We used a total of 80 proximal locking screws for eight groups, 10 screws for each group. Three-point bending tests were performed on four types of screws in two different trochanteric levels (the lesser trochanter and 20 mm proximal). We determined the yield points at three-point bending tests that a permanent deformation started in the locking screws using an axial compression testing machine. RESULTS: The mean yield point value of 5 mm threaded locking screws applied 20 mm proximal of lesser trochanter was 1022 ± 49 (range 986-1057) (mean ± standard deviation, 95% confidence interval). On the other hand, the mean yield point value of the same type of locking screws applied on the lesser trochanteric level was 2089 ± 249 (range 1911-2268). Which means 103% increase of screw resistance between two levels (P = 0.000). In all screw groups, on the lesser trochanter line we determined 98-174% higher than the yield point values of the same type of locking screws in comparison with 20 mm proximal to the lesser trochanter (P = 0.000). CONCLUSION: According to our findings, there is twice as much difference in locking screw bending resistance between these two application levels. To avoid proximal locking screw deformation, locking screws should be placed in the level of the lesser trochanter in nailing of 1/3 middle and distal femur fractures.

13.
Case Rep Orthop ; 2016: 3145343, 2016.
Article in English | MEDLINE | ID: mdl-26977327

ABSTRACT

A case of a bilateral simultaneous traumatic obturator dislocation of both hip joints in an 18-year-old young man following a traffic accident is presented. We reduced the dislocated femoral heads immediately under general anesthesia followed by passive and active exercises and early full-weight bearing mobilization. After 5 years, the result was excellent.

14.
Strategies Trauma Limb Reconstr ; 11(1): 25-9, 2016 Apr.
Article in English | MEDLINE | ID: mdl-26837377

ABSTRACT

Nailing of tibial shaft fractures is considered the gold standard surgical method by many surgeons. The aim of this retrospective study was to investigate and compare the clinical outcome of tibial shaft fractures treated with intramedullary nails compressed by proximal tube and conventional intramedullary interlocking nails. Fifty-seven patients with tibial shaft fractures, treated with intramedullary nails compressed by proximal tube (n = 32) and the conventional interlocking nails (n = 25), were reviewed. All fractures except for one were united without any additional surgical intervention in the proximal compression tube nail group, whereas in the conventional interlocking nail group, six patients needed dynamization surgery (p = 0.005) and three cases of nonunion were recorded. In the proximal compression tube nail group, faster union occurred in 20 ± 2 (16-24) weeks (mean ± SD; range) without failure of locking screws and proximal nail migration, whereas in the conventional interlocking nail group, union occurred in 22 ± 2.5 (17-27) weeks (p = 0.001) with two failures of locking screws and two proximal nail migration. The proximal compression tube nail system is safer than the conventional nailing methods for the treatment for transverse and oblique tibial shaft fractures with a less rate of nonunion, proximal locking screw failure and proximal nail migration.

15.
Acta Orthop Traumatol Turc ; 50(1): 89-96, 2016.
Article in English | MEDLINE | ID: mdl-26854055

ABSTRACT

OBJECTIVE: One of the problems for interlocking nailing of the femur is interfragment rotation motion, affecting fracture healing. The nails with single distal locking screw are advantageous for decreasing operation time and radiation exposure. We investigated which single distal screw nail is the best for interfragment rotational stability. METHODS: We used a total of 30 composite femurs, ten for each group. We determined interfragment rotational displacement of composite femurs with three types of single distal screw nails (10 interlocking nails, 10 compression nails and 10 Mehmet anti-rotation nails compressed by tube) at 6-Nm external- 6 Nm internal and 10 Nm extern- 6 Nm internal torques, which imitating respectively the level walking and descending stairs, using an axial distraction testing machine and a custom designed rotation apparatus. RESULTS: Between 10 Nm external and 6 Nm internal torques with single distal locking screw, the interfragment rotational displacement in the Mehmet nail compressed by the 8 Nm torque wrench was mean 1.14 mm and 540% less than mean 7.31 mm in interlocking nails and 400% less than 5.72 mm in compression nails compressed by the 2.5 Nm torque wrench. CONCLUSION: The single distal screw Mehmet nail is superior than other single (or even some double) distal screw nails for maximum rotational stability, with no interfragment distraction gap, no superior nail migration, decreased operation time, and less radiation exposure in axially stable transverse and short oblique femur fractures in daily activities like stair descending or level walking.

16.
Eklem Hastalik Cerrahisi ; 27(1): 22-8, 2016.
Article in English | MEDLINE | ID: mdl-26874631

ABSTRACT

OBJECTIVES: This study aims to biomechanically evaluate and compare four well-known types of terminal spinal constructs to a novel construct composed of a transpedicular screw with a lateral hook screw in terms of axial pullout strength in terminal vertebral segment fixation. MATERIALS AND METHODS: Forty fresh-frozen lamb spines were divided into five groups with eight spines each. To stabilize the transverse process, a pedicular screw alone was used in group 1, a sublaminar hook alone was used in group 2, a sublaminar hook and a pedicular screw were used in group 3, claw hook alone was used in group 4, and a pedicular screw with a lateral hook screw was used in group 5. Biomechanical tests were performed using an axial compression testing machine and two noncontact camera systems. RESULTS: The mean pullout strength value was 927 N for group 1, 626 N for group 2, 988 N for group 3, 972 N for group 4, and 1194 N for group 5. Pullout strength values were statistically significantly higher in groups 3 and 4 compared to groups 1 and 2. There was no statistically significant difference between groups 3 and 4. Pullout strength value of group 5 was statistically significantly higher than the other groups. CONCLUSION: Pedicular screw with a lateral hook screw had the highest fixation value. Lateral hook screw may assist to prevent pullout in patients with pullout risk and hyperkyphosis and after hyperkyphosis surgery. Further prospective clinical studies are needed to show the benefit of such a construct in reducing the risk of distal instrumentation pullout.


Subject(s)
Kyphosis/surgery , Lumbar Vertebrae/surgery , Orthopedic Procedures/instrumentation , Pedicle Screws , Postoperative Complications , Surgical Instruments , Thoracic Vertebrae/surgery , Animals , Biomechanical Phenomena , Bone Screws , Comparative Effectiveness Research , Orthopedic Procedures/adverse effects , Orthopedic Procedures/methods , Postoperative Complications/etiology , Postoperative Complications/prevention & control , Sheep
18.
J Clin Orthop Trauma ; 7(Suppl 2): 177-183, 2016.
Article in English | MEDLINE | ID: mdl-28053382

ABSTRACT

INTRODUCTION: Locking compression plate (LCP) system was designed to provide bone stability and to enhance bone healing. However, implant failure, nonunion and instability are still frequently encountered complications. The purpose of this study was to assess and compare the biomechanical characteristics of a novel adjustable dynamic plate (ADP) with the commonly used LCP. MATERIALS AND METHODS: Twelve 4th generation composite artificial femoral bones were used. Transverse fracture was created in all bones, 6 femurs were fixated using the novel ADP, whereas the other 6 femurs were fixated using the traditional LCP. All samples had undergone a non-destructive repetitive different forces (axial compression, bending and torsion), to evaluate the biomechanical differences between the two plating systems. RESULTS: Under axial load the mean stiffness value was 439.0 N/mm for the ADP and 158.9 N/mm for the LCP, ADP showed a statistically significant stiffness value than LCP with a P value of 0.004. There was no significant difference in flexion/extension bending strain values between ADP and LCP. However LCP provided significantly stiffer fixation in medial and lateral bending tests than ADP (P = 0.037) and (P = 0.016) respectively. But no significant difference was detected between the two plating system in the applied torsional stress. CONCLUSION: These results do not show any significant biomechanical difference in the applied torsional and bending stresses between LCP and ADP. However the remarkably increased persistent compression effect of the ADP created a considerable stress on fracture edges which may accelerate bone healing.

20.
Acta Orthop Traumatol Turc ; 49(5): 552-7, 2015.
Article in English | MEDLINE | ID: mdl-26422352

ABSTRACT

OBJECTIVE: A frequent problem for interlocking nailing that affects the treatment of the fracture is locking screw deformation. The aim of this study is to determine whether bending resistance is different between high, low, and unthreaded locking screws of interlocking femoral nails. METHODS: Ninety screws were used in this experimental study, with 10 screws used in each of 9 groups. Three-point bending tests were performed on 6 groups of 5 mm screws (titanium, stainless steel, crossed with unthreaded, low threaded, and high threaded) and the same 3 thread types of 5.5 mm stainless steel screws in a 30-mm inner diameter steel tube, imitating the level of the lesser trochanter. An axial compressor was used to determine the yield points for permanent deformation in the locking screws by way of 3-point bending tests. RESULTS: The mean yield point value of the 3-point bending tests of 5-mm low threaded stainless steel locking screws was 2071 N, 53% less than that of unthreaded screws (3169 N). The mean yield point value of 5-mm high threaded stainless steel locking screws was 556 N, 272% less than that of low threaded screws (2071 N). CONCLUSION: To avoid locking screw deformation, high threaded screws must not be used as locking screws. In cases of unreliable patients, 5-mm low threaded screws should not be used in the nailing of comminuted or oblique femur shaft fractures. All 5-mm unthreaded screws and 5.5-mm low threaded stainless steel screws can be used safely in full weight-bearing conditions of unreliable patients.


Subject(s)
Bone Screws , Fracture Fixation, Intramedullary/instrumentation , Materials Testing/methods , Biomechanical Phenomena , Equipment Design , Equipment Failure Analysis , Reproducibility of Results , Tensile Strength , Weight-Bearing
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