The evaluation of a de novo biplanar distal humerus plate: A biomechanical study.

OBJECTIVES: The aim of this study was to compare the stability of a novel biplanar distal humerus plate with the single- and double-columns J-plating techniques. MATERIALS AND METHODS: Eighteen sawbones humera were divided into three groups. In Groups 1, 2 and 3, biplanar plate, single lateral J-plate and double J-plate, were used, respectively. Transverse osteotomies at the upper portion of the olecranon fossa were made. Blocks of 10-mm was removed from each sample. Axial, torsional, and extensional stiffness of each group were measured. RESULTS: The mean axial stiffness values in Groups 1, 2, and 3 were 64.80±6.75, 33.70±5.71, and 171.48±9.53 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.032), whereas Group 3 showed a statistically significant difference compared to Groups 1 and 2 (p=0.025 and p=0.014, respectively). The mean torsional stiffness values of Groups 1, 2, and 3 were 0.23±0.01, 0.14±0.008, and 0.30±0.007 N/ degree, respectively. Groups 1 and 3 demonstrated a statistically significant difference compared to Group 2 (p=0.042 and p=0.028, respectively). No statistically significant difference was detected between Groups 1 and 3 (p=0.27). The mean extensional bending stiffness values of Groups 1, 2 and 3 were 2.64±0.31, 1.17±0.13, and 3.2±0.1 N/mm, respectively. Group 1 demonstrated a statistically significant difference compared to Group 2 (p=0.041). There was no statistically significant difference between Groups 1 and 3 (p=0.083). CONCLUSION: Biplanar plate allows applying enough numbers of long sagittal screws and offers more biomechanical stability than lateral column J-plate and in some aspects strong as dual J-plating in torsional and bending tests.

The correlation between posterior cruciate ligament buckling sign and meniscofemoral ligaments: A radiological study.

OBJECTIVES: This study aims to investigate the correlation between posterior cruciate ligament (PCL) buckling phenomena and the presence or absence of the anterior meniscofemoral ligament (aMFL). PATIENTS AND METHODS: Between January 2012 and January 2019, magnetic resonance imaging of a total of knee joints of 199 patients (163 males, 16 females; mean age: 31.5±5.3 years; range, 18 to 40 years) were reviewed retrospectively. The patients were divided into four groups. The first group included 32 patients with a ruptured anterior cruciate ligament (ACL) and absent aMFL. The second group included 67 patients with a ruptured ACL and apparent aMFL. The third group included 23 patients with an intact ACL and absent aMFL, and the fourth group included 77 patients with an intact ACL and apparent aMFL. The PCL angle was used to measure the buckling degree of the ligament, as calculated as the angle between two lines drawn through the tibial and femoral central portions of the PCL insertions. We assessed the buckling phenomena of the PCL in ACL-ruptured and ACL-intact knees and examined a possible correlation between the PCL buckling angle and the presence or absence of the aMFL of Humphrey. RESULTS: In the ruptured ACL groups (Groups 1 and 2), the mean PCL buckling angle values were 133.88±6.32 and 104.83±7.34 degrees, respectively. A significant difference was detected between both groups (p=0.026). In the intact ACL groups (Groups 3 and 4), the mean PCL buckling angle values were 143.47±5.96 and 116.77±8.38 degrees, respectively. A significant difference was detected between both groups (p=0.039). No statistically significant difference was observed between Groups 1 and 3 (p=0.13) and between Groups 2 and 4 (p=0.088). CONCLUSION: The PCL buckling sign is not specific for ACL ruptures, and can be seen frequently in normal knee joints which it is strongly associated with the presence of aMFL of Humphrey.

Biomechanical comparison of pullout strengths of six pedicle screws with different thread designs.

OBJECTIVES: This study aims to assess the pullout strength of six different pedicle screw thread patterns. MATERIALS AND METHODS: A total of 36 sheep spines were divided into six groups including six spines in each group: fully threaded cortical (Type A), fully threaded spongeous (Type B), fully cortical threads in the proximal half and fully spongeous threads in the distal half (Type C), fully spongeous threads in the proximal half and fully cortical threads in the distal half (Type D), unthreaded proximal half with fully spongeous threads in the distal half (Type E), and unthreaded proximal half with fully cortical threads in the distal half (Type F). The axial compression-traction machine was used for biomechanical testing at a pullout rate of 1 mm/min. RESULTS: The mean values of pullout strength of the groups A, B, C, D, E, and F were 1112±7.52 N, 986±8.34 N, 646±3.88 N, 676±7.16 N, 609±9.52 N, and 769±6.49 N, respectively. There was a statistically significant difference between the screw groups A and B, C, D, E and F (p=0.036, p=0.028, p=0.04, p=0.039, and p=0.046, respectively). A statistically significant difference was observed between the groups B versus C and E (p=0.037 and p=0.021, respectively). There was no statistically significant difference between the groups B versus D and F (p=0.35 and p=0.61, respectively). CONCLUSION: Fully threaded cortical pedicular screw design exhibited the strongest bone grasp compared to other thread designs. Further studies should be conducted in multidirectional force pattern on human spine to assess the six screw thread designs in a closer real-life setting simulation model.

Biomechanical comparison of fracture site stabilities of femur nails after fracture site resorption.

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.

Straight-Forward versus Bicortical Fixation Penetrating Endplate in Lumbosacral Fixation-A Biomechanical Study.

OBJECTIVE: Many lumbosacral fixation techniques have been described to offer a more screw-bone purchase. The forward anatomical fixation parallel to the endplate is still the most preferred method. Literature revealed little knowledge regarding the mechanical stability of lumbosacral trans-endplate fixation compared to the traditional trans-pedicular screw fixation method. The aim of this study is to assess the pull-out strength of lumbosacral screws penetrating the end plate and comparing it to the conventional trans-pedicular screw insertion method. METHODS: Eight lumbar and eight sacral vertebrae, with average age 69.4 years, Left pedicles of the 5th lumbar vertebrae were used for trans-endplate screw fixation, group 1A, right pedicles were used for anatomical trans-pedicular screw fixation, group 1B. In the sacral vertebrae, the right side S1 pedicles were used for trans-endplate fixation, group 2A, left side pedicles were used for anatomical trans-pedicular screw fixation, group 2B. The biomechanical tests were performed using the axial compression testing machine. All tests were applied using 2 mm/min traction speed. RESULTS: The average pull-out strength values of groups 1A and 1B were 403.78±11.71 N and 306.26±17.55 N, respectively. A statistical significance was detected with p=0.012. The average pull-out strength values of groups 2A and 2B were 388.73±17.03 N and 299.84±17.52 N, respectively. A statistical significance was detected with p=0.012. CONCLUSION: The trans-endplate lumbosacral fixation method is a trustable fixation method with a stronger screw-bone purchase and offer a good alternative for surgeons specially in patients with osteoporosis.

Behavior of Injured Lamina in Lumbar Burst Fractures during Reduction Maneuvers: A Biomechanical Study.

STUDY DESIGN: An experimental biomechanical study. PURPOSE: This study aims to investigate the behavior of a lamina injury in lumbar burst fractures during reduction maneuvers. OVERVIEW OF LITERATURE: Lumbar burst fractures are frequently accompanied by a lamina fracture. Many researchers concluded that any reduction maneuver will close the fractured lamina edges and possibly crush the entrapped neural elements. This conclusion did not rely on solid biomechanical trials and was based primarily on clinical experience. METHODS: Eighteen fresh-frozen lamb spines were randomly divided into three groups. Using the preinjury and the dropped-mass technique, a burst fracture model was developed. A central laminectomy of 5 mm of the L3 lumbar spine was created to mimic a complete type of lamina fracture. To measure the movement of the fractured laminar edges, two holes were drilled on both sides of the upper and lower regions of the lamina to allow for optic marker placement. A single specific spine movement was applied to each group: traction, flexion, and extension. Gap changes were measured by camera extensometers. RESULTS: After traction, the average values of the upper and lower aspects of the lamina interval showed narrowing of 1.65±0.82 mm and 1.97±1.14 mm, respectively. No statistical significance was detected between the two aspects. The upper and lower regions of the lamina gap behaved differently during extension. At 10°, 20°, and 30°, the upper part of the lamina interval was widened by an average of 0.016±0.024, 0.29±0.32, and 1.73±1.45 mm, respectively, whereas the lower part was narrowed by an average of 0.023±0.012, 0.47±0.038, and 1.94±1.46 mm, respectively. CONCLUSIONS: Neural element crushing may take place, particularly at the lower aspect of the fractured lamina gap during extension and throughout the whole lamina gap during traction. The lamina gap widens during flexion. Reduction maneuvers should be attempted after exploring the fractured lamina to prevent further neurological compromise.

The impact of medial cuneiform bone variant measures on the severity of hallux valgus: A radiological study.

PURPOSE: The aetiology of hallux valgus (HV) is multifactorial in nature. The first metatarsocuneiform joint obliquity is a well-known factor in the development of the deformity. The purpose of this study is to assess the correlation of different medial cuneiform radiological measures on the severity of HV. METHODS: Full weight-bearing anteroposterior views of 152 feet with different clinical severity are divided into four groups: without deformity and with mild, moderate and severe deformities. Three medial cuneiform angles were assessed, namely, the first metatarsocuneiform angle (MCA), the first metatarsocuneiform slope angle (MCSA) and the medial cuneiform lateral tilt angle (MCLTA). RESULTS: The first MCA average values of groups 1, 2, 3 and 4 were (25.16 ± 5.74°, 27.38 ± 6.14°, 30.27 ± 5.62° and 34.28 ± 6.81°), respectively. Statistical differences were detected between groups (1, 3) and (1, 4) with p values of 0.034 and 0.001, respectively. The average values of the first MCSA of groups 1, 2, 3 and 4 were 19.26 ± 4.97°, 22.54 ± 5.62°, 26.13 ± 6.36° and 32.17 ± 5.85°, respectively. Significant differences were detected between groups (1, 3) and (1, 4) with p values of 0.04 and 0.023, respectively. Average values of the MCLTA of groups 1, 2, 3 and 4 were 80.85 ± 4.49°, 74.56 ± 5.28°, 62.38 ± 6.34° and 58.78 ± 6.25°, respectively. Statistical significances were detected between groups (1, 2), (1, 3) and (1, 4) with p values of 0.026, 0.018 and 0.001, respectively. CONCLUSIONS: Increasing the medial cuneiform lateral tilt increases the first metatarsocuneiform articulation obliquity demonstrated by the increase in the first MCSA which in term enhances the progression of varus deformity of the first metatarsal bone explained by the increase in the first MCA.

The assessment of portal-tract healing after knee arthroscopy.

OBJECTIVE: The aim of this study was to analyse the pattern of portal-tract healing, to compare the healing time of anteromedial and anterolateral portal tracts and to assess the impact of portal-tract delayed healing on the post-operative sub-acute and chronic anterior knee tenderness. METHODS: The study included 104 patients (68 males and 36 females; mean age: 49 ± 3.16 years (range; 17-66)) who have undergone knee arthroscopy. Puncture wounds were divided into two groups, (1) anteromedial and (2) anterolateral groups. Each group contained 104 portal-tracts. Healing of portal tracts was evaluated using sequential superficial ultrasonographic examinaitons. Visual analogue scale (VAS) was used to measure pain related to delayed tract healing and its association with the post-operative sub-acute and chronic anterior knee tenderness. RESULTS: Anteromedial and anterolateral tracts total healing time average values were 47 days and 28 days respectively. The VAS average values of anteromedial tracts after 2 weeks, one month, three months, six months and one year were 8.2, 6.3, 4, 1.9 and 0.6 respectively, and for the anterolateral tracts 7.4, 5.5, 2.8, 1.2 and 0.2 respectively. A statistical significance was detected between the two groups at the first and third months with P values 0.042 and 0.0035 respectively. CONCLUSIONS: Anteromedial tracts closed later than anterolateral tracts. Both portal-tracts delayed closure is a potential for post-operative sub-acute and chronic anterior knee tenderness after arthroscopic surgery. Four grades of tract healing were recognized. Portal-tract ultrasonography is advised in persistent post-operative sub-acute and chronic anterior knee tenderness. LEVEL OF EVIDENCE: Level III, Therapeutic study.

A novel anatomical patellar plate for transverse patellar fracture - A biomechanical in-vitro study.

OBJECTIVE: The aim of this study was to assess the safety and stability of our novel anatomical patella plate and to compare its stability with tension band-wire technique. METHODS: A total of 12 cadaveric preserved knees (six right and six left patellae) with close patellar size were chosen to form two groups of six samples. Each group received either plate or tension band-wiring fixation for an experimentally created patella fracture. Cyclic load of an average of 350 N was applied for all specimens and after accomplishing 50 cycles the displacements of all fracture edges were recorded. RESULTS: After completing 50 cycles in each group, the average fracture edges displacement measured in the plate group was 1.98 ± 0.299 mm, whereas the average fracture edges displacement measured in the tension band-wire group was 2.85 ± 0.768 mm (p = 0.016). CONCLUSION: In the operative treatment of displaced transverse patellar fractures, the strength of fixation obtained by titanium curved plates is highly stronger when compared to the fixation with a tension band-wire technique. Fixation with titanium curved plates provides satisfactory stability at the fracture site which allow withstanding the cyclic loads during the postoperative rehabilitation.

Low-energy versus middle-energy extracorporeal shockwave therapy for the treatment of snapping scapula bursitis.

OBJECTIVE: Extracorporeal shockwave therapy (ESWT) has been used successfully in treatment of musculoskeletal disorders. Our objective was to assess the effectiveness of low versus middle-energy ESWT on snapping scapula bursitis. METHODS: Thirty-five patients, divided into two groups, group (L), received low-energy ESWT, group (M) received middle-energy ESWT. Groups were evaluated at 1,3,6 and 12 months using the Visual Analogue Scale (VAS), the Constant-Murley scoring (CMS) and the Roles and Maudsley criteria. RESULTS: In groups (L) and (M), VAS average values after 1,3,6 months and one year were (43±5.17, 38±4.33, 28±4.18 and 19±3.39) and (37±4.85, 26±4.74, 21±4.45 and 7±3.42) respectively. At six and twelve months, statistical difference was detected, P (0.034, 0.026) respectively. After one year of completing the treatment, the average values of CMS were (83.5±6.44 and 91±5.33) respectively, P=0.046. Roles and Maudsley criteria demonstrated that, patients in group (L), 6 (35%) excellent, 5 (29%) good, 4 (24%) acceptable and 2 (12%) had poor results. Whereas, patients in group (M), 11 (61%) excellent, 3 (17%) good, 3 (17%) acceptable and 1 (5%) had poor results. CONCLUSION: Although low-energy ESWT showed good early-term results, but middle-energy ESWT protocol demonstrated better early-term, Mid-term, and late-term results.

The effectiveness of extracorporeal shock wave therapy in snapping scapula.

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.

The reliability of Cavalier's principle of stereological method in determining volumes of enchondromas using the computerized tomography tools.

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.

Biomechanical comparison of pullout strengths of five cortical screw types: An innovative measurement method.

OBJECTIVES: This study aims to assess five different cortical screw types using artificial femurs, under equated testing conditions. MATERIALS AND METHODS: We investigated the maximum force needed to cause deformation at screw-bone interface using fourth generation composite femurs by conducting separate pullout tests for each screw type. We normalized obtained results with traditional methods and cross-comparison. To conduct pullout tests dependent on screw dimensions, we eliminated the effect of bicortical bone thickness by equalizing the conditions of screw insertion. RESULTS: Non-locking screws with larger diameter and pitch depth required larger pullout forces to be extracted, showing statistically superior performance compared to locking screws with smaller dimensions. However, the statistical differences between the absolute pullout forces decreased after the traditional normalization of the results. We proposed a new normalization method based on solid geometric reasoning. CONCLUSION: This novel approach showed that a screw type that appeared to show average performance, in fact, did not have statistically significantly different results than the top performers. Surgeons are not required to prefer larger dimension screws in small dimension host bones.

The Mechanical Effect of Rod Contouring on Rod-Screw System Strength in Spine Fixation.

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.

Iatrogenic lateral meniscus anterior horn injury in different tibial tunnel placement techniques in ACL reconstruction surgery - A cadaveric study.

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.

A Bilateral Traumatic Hip Obturator Dislocation.

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.

The functional results of tibial shaft fractures treated with intramedullary nail compressed by proximal tube.

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.

A novel adjustable dynamic plate for treatment of long bone fractures: An in vitro biomechanical study.

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.