Introduction and Objective. Trochanteric fractures are associated with increasing incidence and represent serious adverse effect of osteoporosis. Their cephalomedullary nailing in poor bone stock can be challenging and associated with insufficient implant fixation in the femoral head. Despite ongoing implant improvements, the rate of mechanical complications in the treatment of unstable trochanteric fractures is high. Recently, two novel concepts for nailing with use of a helical blade – with or without bone cement augmentation – or an interlocking screw have demonstrated advantages as compared with single screw systems regarding rotational stability and cut-out resistance. However, these two concepts have not been subjected to direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone density (1) the biomechanical competence of cephalomedullary nailing with use of a helical blade versus an interlocking screw, and (2) the effect of cement augmentation on the fixation strength of the helical blade. Materials and Methods. Twelve osteoporotic and osteopenic femoral pairs were assigned for pairwise implantation using either short TFN-ADVANCED Proximal Femoral Nailing System (TFNA) with a helical blade head element, offering the option for cement augmentation, or short TRIGEN INTERTAN Intertrochanteric Antegrade Nail (InterTAN) with an interlocking screw. Six osteoporotic femora, implanted with TFNA, were augmented with 3 ml cement. Four study groups were created – group 1 (TFNA) paired with group 2 (InterTAN), and group 3 (TFNA augmented) paired with group 4 (InterTAN). An unstable pertrochanteric OTA/AO 31-A2.2 fracture was simulated. All specimens were biomechanically tested until failure under progressively increasing cyclic loading featuring physiologic loading trajectory, with monitoring via motion tracking. Results. T-score in groups 3 and 4 was significantly lower compared with groups 1 and 2, p=0.03. Stiffness (N/mm) in groups 1 to 4 was 335.7+/−65.3, 326.9+/−62.2, 371.5+/−63.8 and 301.6+/−85.9, being significantly different between groups 3 and 4, p=0.03. Varus (°) and femoral head rotation around neck axis (°) after 10,000 cycles were 1.9+/−0.9 and 0.3+/−0.2 in group 1, 2.2+/−0.7 and 0.7+/−0.4 in group 2, 1.5+/−1.3 and 0.3+/−0.2 in group 3, and 3.5+/−2.8 and 0.9+/−0.6 in group 4, both with significant difference between groups 3 and 4, p<=0.04. Cycles to failure and failure load (N) at 5° varus in groups 1 to 4 were 21428+/−6020 and 1571.4+/−301.0, 20611+/−7453 and 1530.6+/−372.7,21739+/−4248 and 1587.0+/−212.4, and 18622+/−6733 and 1431.1+/−336.7, both significantly different between groups 3 and 4, p=0.04. Conclusions. From a biomechanical perspective, cephalomedullary nailing of trochanteric fractures with use of helical blades is comparable to interlocking screw fixation in femoral head fragments with low bone density. Moreover, bone cement augmentation of helical blades considerably improves their fixation strength in poor bone quality

It is common belief that consolidated intramedullary nailed trochanteric femur fractures can result in secondary midshaft or supracondylar fractures, involving the distal screws, when short or long nails are used, respectively. In addition, limited data exists in the literature to indicate when short or long nails should be selected for treatment. The aim of this biomechanical cadaveric study was to investigate short versus long Trochanteric Femoral Nail Advanced (TFNA) fixation in terms of construct stability and generation of secondary fracture pattern following trochanteric fracture consolidation. Eight intact human cadaveric femur pairs were assigned to 2 groups of 8 specimens each for nailing using either short or long TFNA with blade as head element. Each specimen was first biomechanically preloaded at 1 Hz over 2000 cycles in superimposed synchronous axial compression to 1800 N and internal rotation to 11.5 Nm. Following, internal rotation to failure was applied over an arc of 90° within 1 second under 700 N axial load. Torsional stiffness, torque at failure, angle at failure and energy at failure were evaluated. Fracture patterns were analyzed. Outcomes in the groups with short and long nails were 9.7±2.4 Nm/° and 10.2±2.9 Nm/° for torsional stiffness, 119.8±37.2 Nm and 128.5±46.7 Nm for torque at failure, 13.5±3.5° and 13.4±2.6° for angle at failure, and 887.5±416.9 Nm° and 928.3±461.0 Nm° for energy at failure, respectively, with no significant differences between them, P≥0.167. Fractures through the distal locking screw occurred in 5 and 6 femora instrumented with short and long nails, respectively. Fractures through the lateral entry site of the head element were detected in 3 specimens within each group. For short nails, fractures through the distal shaft region, not interfacing with the implant, were detected in 3 specimens. From biomechanical perspective, the risk of secondary peri-implant fracture after intramedullary nailed trochanteric fracture consolidation is similar when using short or long TFNA. Moreover, for both nail versions the fracture pattern does not unexceptionally involve the distal locking screw

Abstract. In aged trauma patients the basic prerequisite is early mobilization and full weight-bearing, as immobilization can trigger various complications such as pressure ulcers, pneumonia, urinary tract infections and others. Mortality of elderly patients increases significantly in fracture patients with partial weight-bearing compared to populations with total weight-bearing. Besides the limited physical strength in these patients, partial-weight bearing is however frequently used for the aftercare of hip fracture patients. Therefore, the present study aims to evaluate mobility of aged hip fracture patients with regards to weight-bearing and postoperative mobility. Methods. An insole mobile force sensor was used to measure the post-operative weight-bearing by assessing the compressive forces between foot and shoe. Only patients (n=15) that suffered a trochanteric fracture >75 years of age were included and compared to a study group of patients (n=18) with fractures of the lower limb <40 years of age. Patients with cognitive disorders such as delirium and other diseases limiting the realization of partial weight-bearing were excluded. Both groups were instructed to maintain partial weight bearing of the affected limb following surgery. Following five days of training by our department of physiotherapy, the patients were requested to perform a gait analysis with the insole mobile force sensor. During gait analysis the maximum load was measured (kg) and the time over which the partial load could be maintained was determined. Results. None of the aged patients in the test group could meet the partial load at all times. 73.33% of patients (11 out of 15) exceeded the specified load by more than twice (> 40 kg). In the control group, 55.56% (10 of 18) of the patients were able to meet the partial load. A further 22.22% of the young patients (4 out of 18) were able to exceed only slightly (<120%, <24 kg). It was also shown that only 11.11% (2 of 18) put more than double of the allowed weight (> 40 kg) on the affected leg in the younger group. Only one of the aged patients was able to exceed the pre-determined weight-bearing restrictions for less than 10% of the measured time. In comparison, significantly more patients in the control group (88,89%; 16 of 18; p<0,05) were able to maintain the partial load for more than 90.0% of the time of gait analysis. Conclusion. Elderly patients seem to be unable to follow partial weight-bearing restrictions as proven in the present trial. As early mobilization of geriatric trauma patients is an important element for a successful rehabilitation, the relict of postoperative partial weight-bearing in these patients should be abandoned. Thus, the surgical therapy should allow immediate full weight bearing following surgery of aged hip fracture patients

Objectives

Intramedullary fixation is considered the most stable treatment for pertrochanteric fractures of the proximal femur and cut-out is one of the most frequent mechanical complications. In order to determine the role of clinical variables and radiological parameters in predicting the risk of this complication, we analysed the data pertaining to a group of patients recruited over the course of six years.