Finite element analysis of the stability of AO/OTA 43-C1 type distal tibial fractures treated with distal tibia medial anatomic plate versus anterolateral anatomic plate.

BACKGROUND: The treatment of a pilon fracture type is possible from a medial, an anterolateral approach or both medial and lateral. The aim of study was compare the stability of two different plate fixation of a tibia pilon AO-43C1 type fractures. MATERIAL AND METHODS: In this study, three-dimensional finite element stress analysis was applied using isotropic materials and static linear analysis. Loading of 400 N force was applied to the model of a patient fixed in a standing position. In the model, first the fibula was treated by plating and then in one group the pilon fracture was treated by medial plating, and in the other by anterolateral plating. The displacement and stress values of the fragments of the fracture line were compared of the same points in each model. RESULTS: The magnitude of the displacement of fragments in the total displacement magnitudes of X, Y, Z axis were measured in the medial plate and anterolateral plate. The anterolateral plate results were similar to those of the medial plate and the displacement values in the Y axis were determined to be lower than in the medial plate. CONCLUSION: In AO 43 C1 distal tibia fractures, medial or anterolateral plates can be used, and the results of this study showed similar biomechanical stiffness in the two plates.

Performance of modified anatomic plates is comparable to proximal femoral nail, dynamic hip screw and anatomic plates: finite element and biomechanical testing.

AIM: To establish whether the modified anatomic plate (MAP) performs as well as the anatomic plate (AP), dynamic hip screw (DHS) and proximal femoral nail (PFN) from a biomechanical perspective. MATERIALS AND METHODS: The, AP, MAP, DHS and PFN were assessed using finite element (FE) methods and biomechanical tests. A solid model was created based on the fracture lines and results were assessed using analyses of variance. MAIN OUTCOME MEASUREMENTS: Independent variables were the implants (n=4) and axial loads: 0-1000 Newton (N) in 100 N increments. Dependent variables were loads at the intertrochanteric fracture line as measured by load cells. RESULTS: Axial loads ≤400 N generated significantly (p<0.05) greater stress at the fracture line in both the FE model and biomechanical settings: the PFN generated the highest forces at the fracture line followed by the AP, MAP and DHS. For axial loads ≥400 N, the AP and DHS generated nonsignificant (p>0.5) lower forces (almost 50% less) compared with the MAP and PFN. At 1000 N, the DHS generated the highest (p<0.05) load at the fracture line. CONCLUSION: The biomechanical features of the MAP were similar to those of the PFN. The MAP generated optimal loads at both the fracture site and the proximal femur. FE methods and biomechanical tests revealed that the MAP is associated with both intra- and extra-medullary fixation features, even though the load was applied as an extramedullary stimulus.

Gait symmetry in patients with unilateral partial hip arthroplasty.

OBJECTIVES: In this study gait deviations symmetry and asymmetry in patients with unilateral partial hip arthroplasty was determined. PATIENTS AND METHODS: Gait characteristics and time since operation (11.9+/-6.1; range 7 to 29 months) of 16 patients (9 females, 7 males; mean age 61.5+/-16.5 years; range 27 to 86 years) with unilateral partial hip arthroplasty were evaluated. Ten healthy volunteers (3 females, 7 males; mean age 54.1+/-11.9 years; range 35 to 65 years) were included in the study as control group. Quantitative gait data was collected with the Vicon 370 System (Oxford Metrics, Oxford, UK). Spatio-temporal (walking velocity, cadence, step time, step length, double support time) and kinematic (joint rotation angles of pelvis and hip in sagittal plane) data were processed by using Vicon Clinical Manager software package. Spatio-temporal and kinematic gait symmetry indices of both groups were calculated. RESULTS: Spatio-temporal and kinematic gait characteristics, but not the symmetry indices, of patients with unilateral partial hip arthroplasty were different from the control group (p>0.05). CONCLUSION: Findings of this study reveal that patients with unilateral partial hip arthroplasty had various gait deviations compared to healthy subjects, but that symmetry was preserved.

The short-term efficacy of laser, brace, and ultrasound treatment in lateral epicondylitis: a prospective, randomized, controlled trial.

The aims of this study were to evaluate the effects of low-level laser therapy (LLLT) and to compare these with the effects of brace or ultrasound (US) treatment in tennis elbow. The study design used was a prospective and randomized, controlled, single-blind trial. Fifty-eight outpatients with lateral epicondylitis (9 men, 49 women) were included in the trial. The patients were divided into three groups: 1) brace group-brace plus exercise, 2) ultrasound group-US plus exercise, and 3) laser group-LLLT plus exercise. Patients in the brace group used a lateral counterforce brace for three weeks, US plus hot pack in the ultrasound group, and laser plus hot pack in the LLLT group. In addition, all patients were given progressive stretching and strengthening exercise programs. Grip strength and pain severity were evaluated with visual analog scale (VAS) at baseline, at the second week of treatment, and at the sixth week of treatment. VAS improved significantly in all groups after the treatment and in the ultrasound and laser groups at the sixth week (p<0.05). Grip strength of the affected hand increased only in the laser group after treatment, but was not changed at the sixth week. There were no significant differences between the groups on VAS and grip strength at baseline and at follow-up assessments. The results show that, in patients with lateral epicondylitis, a brace has a shorter beneficial effect than US and laser therapy in reducing pain, and that laser therapy is more effective than the brace and US treatment in improving grip strength.