Factors Associated with Revision Surgery after Internal Fixation of Hip Fractures

Background: Femoral neck fractures are associated with high rates of revision surgery after management with internal fixation. Using data from the Fixation using Alternative Implants for the Treatment of Hip fractures (FAITH) trial evaluating methods of internal fixation in patients with femoral neck fractures, we investigated associations between baseline and surgical factors and the need for revision surgery to promote healing, relieve pain, treat infection or improve function over 24 months postsurgery. Additionally, we investigated factors associated with (1) hardware removal and (2) implant exchange from cancellous screws (CS) or sliding hip screw (SHS) to total hip arthroplasty, hemiarthroplasty, or another internal fixation device. Methods: We identified 15 potential factors a priori that may be associated with revision surgery, 7 with hardware removal, and 14 with implant exchange. We used multivariable Cox proportional hazards analyses in our investigation. Results: Factors associated with increased risk of revision surgery included: female sex, [hazard ratio (HR) 1.79, 95% confidence interval (CI) 1.25-2.50; P = 0.001], higher body mass index (fo

Biomechanics of locking plates in femoral neck fixation

Jan Egil Brattgjerd MD described the biomechanical stability of femoral neck fracture fixation with special regard to the novel principle of interlocked pins in a plate developed to promote multi-directional stability and healing. Further aims were to analyse if patient safety requirements were met by investigating the novel implant´s strengths and weaknesses. A definite biomechanical impact was detected with increased multi-directional stability without adverse effects in comparison with other relevant conventional fixation methods in a comprehensive ex vivo evaluation. As intended during implant design development, the physical effect justified introducing the novel implant into the clinics. The profound impact on torsional stability, but also the enhanced bending and compressive stability can be explained by moment of inertia considerations of single beam prisms, where a larger footprint of the bone-implant construct describes the higher resistance to loading. This corresponds with the mechanism of action by interlocked pins to improve load distribution by equal transmission amongst pins from fragile cancellous bone medially in the femoral head to solid cortical bone laterally in the trochanteric area. The modestly improved compressive stability from dynamic testing may be indicative of the role of the interlocking plate to allow for a stabilising controlled intermediate compression by impaction of the fragments during loading with such an implant. However, whether the improved gross stability is sufficient to enhance healing conditions or affect failure patterns in vivo, will be the topic of forthcoming clinical trials. So far, the results are promising and the interlocked pins must be considered a favourable development of the pin concept

The stabilising effect by a novel cable cerclage configuration in long cephalomedullary nailing of subtrochanteric fractures with a posteromedial wedge

Background Clinical studies suggest that an adjunctive cerclage in intramedullary nailing of subtrochanteric fractures improves the outcome. Despite this, to what extent various cerclage configurations influences the fixation strength, remains undocumented. We tested the hypothesis that the stability of subtrochanteric fractures with a posteromedial wedge treated with long cephalomedullary nail varies with cerclage configuration. Methods 40 composite femurs with a subtrochanteric osteotomy including a posteromedial-wedge were locked by cephalomedullary nailing (T2 recon, Stryker) and divided into 4 groups. In Group-A no cerclage was applied. The Group-B received a lateral tension-band (cerclage cable with crimp, Depuy-Synthes). Without any fixation, the wedge-component was removed in these groups. The Group-C was fixed with a cerclage encircling the wedge-component, while in the Group-D a novel figure-of-8 cerclage stabilised the wedge-component. Each femur was tested quasi-static in a material-testing-machine for stiffness calculation, first horizontally to simulate seated-position and then vertically to simulate standing-position. Finally, cyclic testing was performed in the upright-posture to measure deformation over time. Findings In Group-D the mean stiffness in the sitting-position was 6.4, 5.8 and 3.1 times higher than the Groups-A, B and C, respectively, and correspondingly 2.0, 2.1 and 1.7 times higher in the standing-position (p < 0.05). Over time, Group-D demonstrated less mean deformation than tension-band (p = 0.05), while the deformation was not significantly different from the other groups. Interpretation Additional use of cerclage enhances the stability of intramedullary nailed subtrochanteric fractures, and use of the figure-of-8 cerclage configuration, compressing the entire posteromedial-buttress, is the superior technique

Biomechanical comparison of tension band wiring and plate fixation with locking screws in transverse olecranon fractures

Background: Tension band wiring (TBW) is the standard method for treating transverse olecranon fractures, but high rates of complications and reoperations have been reported. Plate fixation (PF) with locking screws has been introduced as an alternative method that may retain the fracture reduction better with a higher load to failure. Methods: Twenty paired cadaveric elbows were used. All soft tissues except for the triceps tendon were removed. A standardized transverse fracture was created, and each pair was allocated randomly to TBW or PF with locking screws. The triceps tendon was mounted to the materials testing machine with the elbow in 90° of flexion. Construct stiffness was compared 3 times. Then, the elbows underwent a chair lift-off test by loading the triceps tendon to 300 N for 500 cycles. Finally, a load-to-failure test was performed, and failure mechanism was recorded. Results: The construct stiffness of PF was higher in the first of 3 measurements. No difference was observed in the cyclic test or in load to failure. Hardware failure was the failure mechanism in 8 of 10 TBW constructs, and all failures occurred directly under the twists of the metal wire. Hardware failure was the cause of failure in only 1 elbow in the PF group (P < .01). Conclusion: There was no difference in fracture displacement following fixation with TBW and PF with locking screws in transverse olecranon fractures. However, assessment of the mode of hardware failure identified the metal cerclage twist as the weakest link in the TBW construct

A novel instrument for ligament balancing: a biomechanical study in human cadaveric knees

Abstract Purpose Ligament balancing is a prerequisite for good function and survival in total knee arthroplasty (TKA). Various balancing techniques exist, but none have shown superior results. The pie‐crusting technique by Bellemans of the medial collateral ligament is commonly utilized; however, it can be difficult to achieve repeatable ligament lengthening with this technique. Therefore, we invented a novel instrument to standardize the pie‐crusting technique of the superficial and deep medial collateral ligament (hereafter MCL). The purpose was to examine if pie‐crusting with the instrument could produce repeatable ligament lengthening. Methods The MCL was isolated in 16 human cadaveric knees, and subjected to axial tension. The instrument was composed of a specific grid of holes in rows, used to guide sequential pie‐crusting puncturing of the MCL with a Ø1.6 mm end‐cutting cannula. Ligament lengthening was measured after each row of punctures. Regression analysis was performed on the results. Results Mean lengthening ± SD in human cadaveric MCL for puncturing of row 1 in the instrument was 0.06 ± 0.09 mm, 0.06 ± 0.04 mm for row 2, 0.09 ± 0.08 mm for row 3, 0.06 ± 0.05 mm for row 4 and 0.06 ± 0.04 mm for row 5, giving a mean total lengthening of 0.33 ± 0.20 mm. Linear regression revealed that MCLs were repeatably lengthened by 0.07 mm per row when punctured using the instrument. Conclusions MCLs showed linear lengthening in human cadavers for subsequent use of the instrument. Our instrument shows promising results for repeatable ligament lengthening

Fracture fixation in the operative management of hip fractures (FAITH): an international, multicentre, randomised controlled trial

Background Reoperation rates are high after surgery for hip fractures. We investigated the effect of a sliding hip screw versus cancellous screws on the risk of reoperation and other key outcomes. Methods For this international, multicentre, allocation concealed randomised controlled trial, we enrolled patients aged 50 years or older with a low-energy hip fracture requiring fracture fixation from 81 clinical centres in eight countries. Patients were assigned by minimisation with a centralised computer system to receive a single large-diameter screw with a side-plate (sliding hip screw) or the present standard of care, multiple small-diameter cancellous screws. Surgeons and patients were not blinded but the data analyst, while doing the analyses, remained blinded to treatment groups. The primary outcome was hip reoperation within 24 months after initial surgery to promote fracture healing, relieve pain, treat infection, or improve function. Analyses followed the intention-to-treat principle. This study was registered with ClinicalTrials.gov, number NCT00761813. Findings Between Mar