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. Methods. A total of 571 patients were included in this study, which analysed the incidence of cut-out in relation to several clinical variables: age; gender; the AO Foundation and Orthopaedic Trauma Association classification system (AO/OTA); type of nail; cervical-diaphyseal angle; surgical wait times; anti-osteoporotic medication; complete post-operative weight bearing; and radiological parameters (namely the lag-screw position with respect to the femoral head, the Cleveland system, the tip-apex distance (TAD), and the calcar-referenced tip-apex distance (CalTAD)). Results. The incidence of cut-out across the sample was 5.6%, with a higher incidence in female patients. A significantly higher risk of this complication was correlated with lag-screw tip positioning in the upper part of the femoral head in the anteroposterior radiological view, posterior in the latero-lateral radiological view, and in the Cleveland peripheral zones. The tip-apex distance and the calcar-referenced tip-apex distance were found to be highly significant predictors of the risk of cut-out at cut-offs of 30.7 mm and 37.3 mm, respectively, but the former appeared more reliable than the latter in predicting the occurrence of this complication. Conclusion. The tip-apex distance remains the most accurate predictor of cut-out, which is significantly greater above a cut-off of 30.7 mm. Cite this article: G. Caruso, M. Bonomo, G. Valpiani, G. Salvatori, A. Gildone, V. Lorusso, L. Massari. A six-year retrospective analysis of cut-out risk predictors in cephalomedullary nailing for pertrochanteric fractures: Can the tip-apex distance (TAD) still be considered the best parameter?. Bone Joint Res 2017;6:481–488. DOI: 10.1302/2046-3758.68.BJR-2016-0299.R1

Background. Cephalomedullary nails are widely used for fixation of unstable pertrochanteric fractures. In 2018, the Depuy Synthes Trochanteric Fixation Nail - Advanced (TFNA) implant was introduced at a level I academic trauma center. Thereafter, the TFNA swiftly replaced the older implant models used at the time. Subsequently, clinical concerns were raised about the use of the TFNA due to reports of nail breakage. The purpose of this study was to investigate whether the concerns raised about the performance of the TFNA were valid and to assess long-term outcomes. Methods. The data consisted of 2397 patients who had undergone a proximal femoral hip fracture procedure between 2014 and 2020. Data were handpicked from patient records. TFNA was compared with TFN, PFNA, Gamma3, and Intertan regarding nail breakage, breakage time and long-term outcomes. Results. After exclusion a total of 23/1667 (1.4%) nails broke during the follow-up period. The TFNA broke the most often with 15 cases (2.0%), followed by the Gamma3 with five cases (1.1 %) and the PFNA with three cases (1.3%). Overall, the mean (SD) nail breakage time was 233 (147.8) days. However, for the TFNA, PFNA, and Gamma3, the mean breakage times were 176.8 days (109.9), 419 days (108.6), and 291.8 (153.4), respectively. In cox regression analysis we observed significant reduction in nail breakage when using PFNA with adjusted hazard risk of 0.081 [95% Ci, 0.011-0.576, p=0.011]. Conclusions. In our data, the TFNA had a slightly higher risk for nail breakage when compared to the PFNA and the Gamma3, with a risk difference of 0.7% and 0.9%, respectively. On average, the TFNA broke nearly four months earlier than the Gamma3 and more than eight months earlier than the PFNA. It should be noted, however, that implant breakage is a relatively infrequent complication

Introduction. Hip fractures, with a global age-standardised incidence rate (per 100,000 population) of 187.2 (2019), are a major public health problem. With a 7.71 billion population worldwide in 2019, hip fractures, in general, are affecting around 14.43 million people per year globally. We aim to provide a nationwide epidemiological analysis of trochanteric fractures and their respective surgical treatments. In this study we research the epidemiology of trochanteric and subtrochanteric fractures, as well as their most common kinds of osteosynthesis, on a nationwide scale in Germany. Method. Data was retrieved from the national database of the German Ministry of Interior. ICD-10-GM and OPS-data from the period of 2006-2020 were analyzed, all patients with trochanteric/subtrochanteric fractures were included. Patients were grouped by age/gender and linear-regression was performed to calculate statistically significant correlations between variables/incidences. Result. 985,104 trochanteric and 178,810 subtrochanteric-fractures were reported during the analyzed period. This calculates to a mean incidence of 80.08±6.34 for pertrochanteric and 14.53±1.50 for subtrochanteric fractures per-million-inhabitants. In both fracture-types, a distinct dependence of incidence on age can be seen. Incidence rates equally rise in both sexes through the age groups with an increase of about 288-fold from those under 60 to those over the age of 90 in pertrochanteric fractures. Intramedullary nailing was the most common kind of treatment for both fracture types with augmentative cerclages on the rise throughout the whole period. Dynamic compression screws were decreasing in frequency. Conclusion. We found an ongoing increase of incidence among the elderly and an increase in intramedullary nailing as well as augmentative cerclages. Not only could we show an age-dependence of the incidences, but also a sex-dependence that seems to remain consistent in its development. While younger males (<60 years) are at a higher risk than their female peers, older females are at significantly higher risk than their male peers

Introduction. Cephalomedullary nailing (CMN) is commonly used for unstable pertrochanteric fracture. CMN is relatively safe method although various complications can potentially occur needing revision surgery. Commonly used salvage procedures such as renailing, hemiarthroplasty, conservative treatment or total hip arthroplasty (THA) are viable alternatives. The aim was to investigate the rate of THA after CMN and evaluate the performance on conversion total hip arthroplasty (cTHA) after failure of CMN. Method. Collected data included patients from two orthopedic centers. Data consisted of all cTHAs after CMN between 2014-2020 and primary cementless THA operations between 2013-2023. Primary THA operations were treated as a control group where Oxford Hip Score (OHS) was the main compared variable. Result. From 2398 proximal femoral hip procedures 1667 CMN procedures were included. Altogether 46/1667 (2.8%) CMNs later received THA. Indications for THA after CMN failure were 13 (28.3%) cut-outs, nine (19.6%) cut-throughs, eight (17.4%) nail breakages, seven (15.2%) post traumatic arthrosis, seven (15.2%) nonunions, one (2.2%) malunion and one (2.2%) collum screw withdrawal. Mean (SD) time to complication after CMN operation is 5.9 (6.8) months. Mean (SD) time from nail procedure to THA was 10.4 (12.0) months. Total complication rate for cTHA after CMN was 17.4%. Reported complications were infection with seven (15.2%) cases and one (2.2%) nerve damage. Mean (SD) time to cTHA complication was 3.6 (6.1) months. One-sample T-test showed OHS to be significantly better (P<.001) for primary cementless THA compared to cTHA after one year. Conclusion. Altogether 2.8% of CMN were converted to THA. Nearly half (47.8%) of the cTHA procedures were due to CMN cut-out or cut-through. OHS was significantly better in primary cementless THA compared to cTHA. Prosthetic joint infection was the most frequent complication related to cTHA

Background. A large proportion of the expense incurred due to hip fractures arises due to secondary factors such as duration of hospital stay and additional theatre time due to surgical complications. Studies have shown that the use of intramedullary (IM) nail fixation presents a statistically higher risk of re-fracture than plating, which has been attributed to the stress riser at the end of the nail. It is not clear, however, if this situation also applies to unstable fractures, for which plating has a higher fixation failure rate. Moreover, biomechanical studies to date have not considered newer designs of IM nails which have been specifically designed to better distribute weight-bearing loads. This aim of this experimental study was to evaluate the re-fracture risk produced by a newer type of nailing system compared to an equivalent plate. Methods. Experimental testing was conducted using fourth generation Sawbones composite femurs and X-Bolt IM hip nail (n=4) and fracture plate (n=4) implants. An unstable pertrochanteric fracture pattern was used (AO classification: 31-A1 / 31-A2). Loading was applied along the peak loading vector experienced during walking, up to a maximum load of 500N. The risk of re-fracture was evaluated from equivalent strains measured using four rosette strain gauges on the surface of the bone at known stress riser locations. Results. Strain gauge readings determined that the equivalent strains in the femoral diaphysis were approximately 25% larger for the nail than the plate (p < 0.005). The strain levels at the location coinciding with the end of the plate were also larger for the nail, but not significantly (p > 0.26). Conclusions. Although the risk of re-fracture for displaced tronchantaric fractures was found to be larger for nailing than plating, measured strains were substantially lower than the failure strain of cortical bone (even when scaled for full weight-bearing loads of 1800N). This indicates that fracture risk is not present in either implant for bone of healthy quality, but may still become problematic in highly osteoporotic patients. Level of Evidence. IIb - Evidence from at least one well designed experimental trial

Hip fractures constitute the most debilitating complication of osteoporosis with a steadily increasing incidence in an aging population. Intramedullary nailing of osteoporotic proximal femoral fractures can be challenging because of poor implant anchorage in the femoral head. Recently, cement augmentation of PFNA blades with Polymethylmethycrylate (PMMA) has shown promising results by enhancing the cutout resistance in proximal femoral fractures. The aim of this biomechanical study was to assess the impact of cement augmentation on the fixation strength of TFNA blades and screws within the femoral head, and compare its effect with head elements placed in a center or antero–posterior off–center positions. Eight groups were formed out of 96 polyurethane foam specimens with low density, simulating isolated femoral heads with severe osteoporotic bone. The specimens in each group were implanted with either non–augmented or PMMA–augmented TFNA blades or screws in a center or antero–posterior off–center position, 7 mm anterior or 7 mm posterior. They were mechanically tested in a setup simulating an unstable pertrochanteric fracture with lack of postero–medial support and load sharing at the fracture gap. All specimens underwent progressively increasing cyclic loading until catastrophic construct failure. Varus–valgus and head rotation angles were monitored by an inclinometer mounted on the head. A varus collapse of 5° or a 10° head rotation were defined as the clinically relevant failure criterion. Load at failure for specimens with augmented TFNA head elements (screw center: 3799 N ± 326 (mean ± SD); blade center: 3228 N ± 478; screw off–center: 2680 N ± 182; blade off–center: 2591 N ± 244) was significantly higher compared to the respective non–augmented specimens (blade center: 1489 N ± 41; screw center: 1593 N ± 120; blade off–center: 1018 N ± 48; screw off–center: 515 N ± 73), p<0.001. In both non–augmented and augmented specimens, the failure load in center position was significantly higher compared to the respective off–center position, regardless of head element, p<0.001. Non–augmented TFNA blades in off–center position revealed significantly higher load at failure versus non–augmented screws in off–center position, p<0.001. Cement augmentation clearly enhances fixation stability of TFNA blades and screws. Non–augmented blades outperformed screws in antero–posterior off–center position. Positioning of TFNA blades in the femoral head is more forgiving than TFNA screws in terms of failure load. Augmentation with TFNA has not been approved by FDA

Summary. Biomechanically, a 2° screw deviation from the nominal axis in the PFLCP leads to significantly earlier implant failure. Screw deviation relies on a technical error on insertion, but in our opinion cannot be controlled intraoperatively with the existing instrumentation devices. Background. Several cases of clinical failure have been reported for the Proximal Femoral Locking Compression Plate (PFLCP). The current study was designed to investigate the failure mode and to explore biomechanically the underlying mechanism. Specifically, the study sought to determine if the observed failure was due to technical error on insertion or due to implant design. Methods. To exclude patient and fracture type related factors, an abstract foam block model simulating an unstable pertrochanteric fracture was created for three study groups with six specimens each (n=6). Group 1 was properly instrumented according to the manufacturer's guidelines. In Group 2 and 3, the first or second screw was placed in a posterior or anterior off-axis orientation by 2° measured in the transversal plane, respectively. Each construct was tested cyclically until failure using a test setup and protocol simulating complex axial and torsional loading. Radiographs were taken prior to and after the tests. Force, number of cycles and failure mode were compared. Results. The 2° screw deviation from the nominal axis led to significantly earlier construct failure in Group 2 and 3. The failure mode consisted of loosening of the off-axis screw due to disengagement with the plate, resulting in loss of construct stiffness and varus collapse of the fracture. Conclusions. In our biomechanical test setup, a screw deviation of only 2° from the nominal axis consistently led to the failure mode observed clinically. In our opinion, screw deviation mostly relies on technical error on insertion. But, proper screw insertion may be difficult or impossible with the existing instrumentation devices, especially as it cannot be controlled or guaranteed intraoperatively