Pertrochantäre Femurfrakturen

Perioperative peri-implant fracture after osteosynthesis for geriatric femoral pertrochanteric fracture with the linear compression integrated screw intramedullary nail system (INTERTAN™): a retrospective study

BACKGROUND

Osteosynthesis for geriatric femoral pertrochanteric fractures using the linear compression integrated screw intramedullary nail system (INTERTAN™) has become popular. Nonetheless, cases of perioperative peri-implant fractures have been reported following this surgical technique. The factors responsible for this complication remain unclear. Therefore, we investigated perioperative peri-implant fracture risk factors and incidence, as well as overall outcomes, using the INTERTAN™ system for geriatric femoral pertrochanteric fractures.

METHODS

We retrospectively reviewed 98 consecutive patients with geriatric femoral pertrochanteric fractures after INTERTAN™ fixation, with at least a 12-month follow-up period between May 2020 and April 2022 at a single medical institute. The patients' demographic characteristics, fracture pattern, quality of reduction, quality of fixation, nail length, morphology of the femur, and perioperative complications were recorded and analyzed.

RESULTS

Among the 98 patients, 92 achieved union during follow-up. Twelve perioperative peri-implant fractures (12.2%) were recorded, all of which occurred during or within 1 month of osteosynthesis. Except for one patient who underwent re-osteosynthesis, the others underwent nonoperative treatment, and all achieved union. Multiple regression analysis revealed morphology of the femur with low-lesser trochanter width (odds ratio (OR) 0.532, 95% confidence interval (CI) 0.33-0.86, p = 0.01) to be the only factor contributing to perioperative peri-implant fractures. When the Youden index was used, the optimal cut-off value was 20.2 mm of low-lesser trochanter width. Low-lesser trochanter width < 20.2 mm was found to be a potential factor causing perioperative peri-implant fractures (OR 17.81, 95% CI 1.67-19.76, p = 0.017).

CONCLUSIONS

Morphology of the femur with a low-lesser trochanter width smaller than 20.2 mm was found to be the only potential contributor to perioperative peri-implant fractures when using INTERTAN™ for geriatric femoral pertrochanteric fractures. Care should be taken during osteosynthesis, focusing not only on the fracture site but also on the femoral cortex around the implant. Although perioperative peri-implant fractures were observed within one month following osteosynthesis, the majority of these cases were effectively treated without surgical intervention.

Biomechanical study of extramedullary and intramedullary fixation in the treatment of unstable intertrochanteric reversed-tilt fractures of the femur

Background

To investigate the efficacy of the 135° hip screw, 95° intramedullary hip screw (IMHS) and 95° hip screw in the treatment of intertrochanteric reverse dip fracture of the femur.

Methods

We retrospectively analyzed 125 matched pairs of human femurs (median age 64 years) which were osteotomized at a 33° angle in the left femur and extended downward from the minor trochanter to simulate a reverse oblique intertrochanteric fracture. The right femur served as a control. The left femur (n=4) was implanted with a 135° hip screw, 95° hip screw, or IMHS. A strain detector was placed distal to the fracture site to monitor fragment strain. The lateral displacement of the proximal femur was measured by a linear variable differential transformer. An Instron tester measured stiffness, strain, and lateral displacement at 25° adduction, and 90° adduction with vertical loads on the femoral head. A 2 cm gap was then formed at the fracture site to simulate comminution and the mechanical test was repeated.

Results

Before the formation of the gap, there was no significant difference in stiffness among different bone structures (P>0.05), but after the formation of the gap, the stiffness of all the adduction structures decreased (P=0.03), and the difference in adduction was statistically significant (135° hip screw: 46.6%±3%; 95° hip screw: 22.9%±2%; IMHS: 53.7%±7.8%; P<0.05). Similar results were found for the abduction and buckling positions. There was no significant difference in the lateral displacement of the gap before (P=0.92) and after (P=0.26), but a significant difference in the failure load was found (135° hip screw: 1,222±560 N; 95° hip screw: 2,566±283 N; IMHS: 4,644±518 N; P=0.02).

Conclusions

There was no statistically significant difference in stiffness among different structures (P>0.05). However, in the presence of gaps, IMHS bone implant structures are much stiffer than 135° and 95° structures and have a greater destructive load.

Proximal Femoral Plate, Intramedullary Nail Fixation Versus Hip Arthroplasty for Unstable Intertrochanteric Femoral Fracture in the Elderly: A Meta-analysis

INTRODUCTION

Multiple operative modalities are available for management of unstable intertrochanteric femoral fractures. This meta-analysis was conducted to find out if there is superiority of surgical fixation by proximal femoral plate or surgical fixation by intramedullary nail over hip arthroplasty for management of unstable intertrochanteric femoral fractures in the elderly.

METHODS

A search for relevant studies that published from January 2000 to November 2018 through the electronic literature database of Cochrane library, Medline, Trip Database and Wiley online library.

RESULTS

A total of 19 studies including 14 prospective RCTs, and five retrospective studies. This meta-analysis showed that nail group had shorter operative time than plate group (P < 0.0001), and less blood loss than the plate and arthroplasty groups (P < 0.0001), cut-out was higher in nail group than the plate group (P < 0.0001), mortality rate was higher in hip arthroplasty compared to other groups (P < 0.0001), Harris hip score within 6 months of the operation was higher in the arthroplasty group compared with the nail and plate groups, while within 1 year of the operation, nail group had higher Harris hip score than arthroplasty group (P < 0.0001).

CONCLUSIONS

This meta-analysis suggested that the intramedullary nail fixation method is a preferred method for management of unstable intertrochanteric femoral fractures in the elderly over hip arthroplasty and proximal femoral plate fixation.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-021-00426-1.

Benefit of lag screw placement by a single- or two-screw nailing system in elderly patients with AO/OTA 31-A2 trochanteric fractures

Objective

To retrospectively analyze the clinical outcomes of two intramedullary fixation devices, the INTERTAN nail and Gamma3 nail, for treatment of AO/OTA 31-A2 trochanteric fractures in elderly patients.

Methods

In total, 165 elderly patients underwent treatment for AO/OTA 31-A2 trochanteric fractures in our hospital from June 2017 to June 2018 (INTERTAN group, n = 79; Gamma3 group, n = 86). All patients underwent radiological and clinical investigations and were followed up for an average of 12 months. Age, sex, fracture type, surgical time, intraoperative blood loss, fracture healing time, and complications were compared between the two groups.

Results

The surgical time was significantly shorter and the intraoperative blood loss volume was significantly lower in the Gamma3 than INTERTAN group (58.2 ± 2.5 vs. 81.7 ± 14.2 minutes and 170 ± 29 vs. 220 ± 16 mL, respectively). However, there were no significant differences in the reduction quality, hospital stay, fracture healing time, Harris hip score, postoperative complications, or 1-year postoperative mortality.

Conclusion

Both INTERTAN and Gamma3 nails may be effective for surgical treatment of AO/OTA 31-A2 trochanteric fractures in elderly patients. However, the Gamma3 nail was superior to the INTERTAN nail in terms of surgical time and intraoperative blood loss.

Standardized artificially created stable pertrochanteric femur fractures present more homogenous results compared to osteotomies for orthopaedic implant testing

Background

With regard to biomechanical testing of orthopaedic implants, there is no consensus on whether artificial creation of standardized bone fractures or their simulation by means of osteotomies result in more realistic outcomes. Therefore, the aim of this study was to artificially create and analyze in an appropriate setting the biomechanical behavior of standardized stable pertrochanteric fractures versus their simulation via osteotomizing.

Methods

Eight pairs of fresh-frozen human cadaveric femora aged 72.7 ± 14.9 years (range 48–89 years) were assigned in paired fashion to two study groups. In Group 1, stable pertrochanteric fractures AO/OTA 31-A1 were artificially created via constant force application on the anterior cortex of the femur through a blunt guillotine blade. The same fracture type was simulated in Group 2 by means of osteotomies. All femora were implanted with a dynamic hip screw and biomechanically tested in 20° adduction under progressively increasing physiologic cyclic axial loading at 2 Hz, starting at 500 N and increasing at a rate of 0.1 N/cycle. Femoral head fragment movements with respect to the shaft were monitored by means of optical motion tracking.

Results

Cycles/failure load at 15° varus deformation, 10 mm leg shortening and 15° femoral head rotation around neck axis were 11324 ± 848/1632.4 ± 584.8 N, 11052 ± 1573/1605.2 ± 657.3 N and 11849 ± 1120/1684.9 ± 612.0 N in Group 1, and 10971 ± 2019/1597.1 ± 701.9 N, 10681 ± 1868/1568.1 ± 686.8 N and 10017 ± 4081/1501.7 ± 908.1 N in Group 2, respectively, with no significant differences between the two groups, p ≥ 0.233.

Conclusion

From a biomechanical perspective, by resulting in more consistent outcomes under dynamic loading, standardized artificial stable pertrochanteric femur fracture creation may be more suitable for orthopaedic implant testing compared to osteotomizing the bone.

Medial sustainable nail versus proximal femoral nail antirotation in treating AO/OTA 31-A2.3 fractures: Finite element analysis and biomechanical evaluation

OBJECTIVES

Using finite element analysis and biomechanical tests, the biomechanical behaviors of Medial Sustainable Nail (MSN) and Proximal Femoral Nail Antirotation (PFNA) were compared for the fixation of fracture type of AO/OTA 31-A2.3.

METHODS

Finite element software Abaqus 6.14 was used to conduct axial loading of 2100 N and we analyzed the von Mises stress distribution and the model displacement of two implant models. Biomechanical tests were separately conducted in the axial stiffness test and axial cyclical loading test on a mechanical testing machine.

RESULTS

The results indicate that von Mises stress of MSN was lower than that of PFNA, and the model displacement in the MSN group was lower than that in the PFNA group. In the axial stiffness tests, MSN group was stiffer than PFNA construct. With respect to the axial load to ultimate failure, the PFNA construct exhibited higher loads exceeding 4000 N while the MSN construct withstood 3313.8 ± 92.8 N. Specifically, F_10mm was 2178.6 ± 133.2 N of the MSN group and 1822.6 ± 93.1 N of the PFNA group (P = 0.001). Additionally, X_2100N was 9.8 ± 0.5 mm of the MSN group and 11.7 ± 0.7 mm of the PFNA group (P = 0.002). The MSN group exhibited superior performances in terms of the mean value of the vertical displacement, frontal rotation angle, and lateral rotation angle.

CONCLUSIONS

The results indicated that the MSN construct might exhibit a better biomechanical performance when compared with that of the PFNA in reducing displacement and anti-varus in fracture type of AO/OTA 31-A2.3.

Comparison of clinical outcomes with InterTan vs Gamma nail or PFNA in the treatment of intertrochanteric fractures: A meta-analysis

Intertrochanteric fractures are common injuries in the elderly. Conventional intramedullary nails including Gamma 3 locking nail and proximal femoral nail antirotation (PFNA) were designed for unstable intertrochanteric fractures. The InterTan (IT) nail system, introduced in 2005, has been reported superior biomechanical and clinical outcomes compared with 1-screw nailing system. However, some recent studies have reported that IT did not improve functional recovery in patients with intertrochanteric fractures. Randomized controlled trials (RCTs) or prospective cohort studies were included in our meta-analysis. We used the PRISMA guidelines and Cochrane Handbook to evaluate the quality of included studies to ensure that the pooled data of our meta-analysis were reliable and veritable. Our pooled data analysis demonstrated that IT was as effective as the control group in terms of Harris Hip Score (HHS), blood loss, total complications, union time, length of hospital stay, revision rate, and fluoroscopy time. IT shows less implant cut-out rate and femoral fractures when compared with control groups.

Comparison of intramedullary fixation and arthroplasty for the treatment of intertrochanteric hip fractures in the elderly: A meta-analysis

BACKGROUND

More and more studies conduct to compare intramedullary fixation (IMF) with arthroplasty in treating intertrochanteric hip fractures, but it remains controversy. The aim of this meta-analysis was to find out whether IMF or arthroplasty was more appropriate for treating intertrochanteric hip fractures in elderly patients.

METHODS

Relevant studies were searched in the electronic databases of PubMed, Embase, and The Cochrane Central Register of Controlled Trials from January 1980 to September 2016 with English language restriction. Surgical information and postoperative outcomes were analyzed using RevMan 5.3 version.

RESULTS

A total of 1239 patients from 11 studies which satisfied the eligibility criteria were included. Compared with IMF, the use of arthroplasty reduced implant-related complications (odds ratio [OR]: 2.05, P = .02) and reoperation rate (OR: 7.06, P < .001), and had similar length of hospital stay (weighted mean difference [WMD]: -0.41, P = .63). However, IMF reduced blood loss (WMD: -375.01, P = .001) and transfusion requirement (OR: 0.07, P < .001), shorter operation time (WMD: -18.92, P = .010), higher Harris hip score (WMD: 4.19, P < .001), and lower rate of 1-year mortality (OR: 0.67, P = .02) compared with arthroplasty.

CONCLUSION

The main treatment of intertrochanteric hip fractures is internal fixation using IMF. In the absence of concrete evidence, arthroplasty should be undertaken with caution in carefully selected patient and surgeon should be aware of the increased complexity of doing the arthroplasty in these elderly patients. Further high-quality randomized controlled trials (RCTs) are needed to provide robust evidence and evaluate the treatment options.

Anchorage strategies in geriatric hip fracture management

There is an enormous humanitarian and socioeconomic need to improve the quality and effectiveness of care for patients with hip fracture. To reduce mechanical complications in the osteosynthesis of proximal femoral fractures, improved fixation techniques have been developed including blade or screw-anchor devices, locked minimally invasive or cement augmentation strategies. However, despite numerous innovations and advances regarding implant design and surgical techniques, systemic and mechanical complication rates remain high. Treatment success depends on secure implant fixation in often-osteoporotic bone as well as on patient-specific factors (fracture stability, bone quality, comorbidity, and gender) and surgeon-related factors (experience, correct reduction, and optimal screw placement in the head/neck fragment). For fracture fixation, the anchorage of the lag screw within the femoral head plays a crucial role depending on the implant’s design. Meta-analyses and randomized controlled studies demonstrate that there is a strong trend towards arthroplasty treating geriatric femoral neck fractures. However, for young adults as well as older patients with less compromised bone quality, or in undisplaced fractures, head-preserving therapy is preferred as it is less invasive and associated with good functional results. This review summarizes the evidence for the internal fixation of femoral neck fractures and trochanteric femoral fractures in elderly patients. In addition, biomechanical considerations regarding implant anchorage in the femoral head including rotation, migration, and femoral neck shortening are made. Finally, cement augmentation strategies for hip fracture implants are evaluated critically.

[Pertrochanteric femoral fractures in the elderly]

Pertrochanteric fractures are one of the most common injuries in the elderly and due to the demographic changes the incidence and importance of this fracture entity will even increase in the future. The dynamic hip screw (DHS) has been used as the gold standard implant in the treatment of pertrochanteric femoral fractures for many years but recent studies have shown that cephalomedullary nails have some advantages. Due to the high incidence, operative treatment of these fractures is part of the standard repertoire of trauma surgeons and this article therefore provides an overview of existing knowledge and new trends in the treatment of pertrochanteric femoral fractures.

[The rotationally stable screw-anchor with trochanteric stabilizing plate (RoSA/TSP) : First results in unstable trochanteric femur fractures]

BACKGROUND

In unstable trochanteric fractures, the extramedullary rotationally stable screw-anchor (RoSA) combines the benefits of the load and rotational stability of the blade with the advantages of the screw (pull-out resistance, compression capability) in a single load carrier, and was designed to prevent femoral neck shortening by using an additional locked trochanteric stabilizing plate (TSP).

OBJECTIVES

The aim of the current prospective cohort study was the clinical evaluation of the RoSA/TSP system regarding the mechanical re-operation rate and the amount of postoperative femoral neck shortening.

METHODS

From September 2011 to January 2014 80 patients with unstable trochanteric fractures underwent internal extramedullary fixation with the RoSA/TSP (Königsee Implantate GmbH, Allendorf, Germany). Due to fracture stability and after induction of compression, additional long locked antitelescoping screws (AT, n = 1-4) were placed reaching the femoral head. Radiological (femoral neck shortening) and clinical re-examination of patients (n = 61) was performed 6-10 weeks and 6-10 months later.

RESULTS

In the 61 re-examined patients (76 %) femoral neck shortening was very low with 2 mm 6-10 months after operation. Re-operations occurred in 8 % (n = 6) and in 4 % (n = 3) as prophylactic surgical intervention. Whereas one-third (4 %) of re-operations occurred due to iatrogenic surgical problems from the first operation two-thirds of patients (8 %) had a re-operation due to delay of bone union (3× nonunion, 3 planned removals of AT-screws to improve healing). The in-hospital mortality was 3 % (n = 2).

CONCLUSIONS

The fixation of unstable trochanteric femur fractures using the RoSA/TSP in a first clinical setting led to a great primary stability, with significant advantages with regard to limited femoral neck shortening. However, the rigidity of the construct with its consequences regarding bone healing can be challenging for the surgeon. Nevertheless, in some cases of revision it could be beneficial for stability.

Rotationally Stable Screw-Anchor With Locked Trochanteric Stabilizing Plate Versus Proximal Femoral Nail Antirotation in the Treatment of AO/OTA 31A2.2 Fracture: A Biomechanical Evaluation

OBJECTIVES

Third-generation cephalomedullary nails currently represent the gold standard in the treatment of unstable trochanteric femur fractures. Recently, an extramedullary rotationally stable screw-anchor system (RoSA) has been developed. It was designed to combine the benefits of screw and blade and to improve stability using a locked trochanteric stabilizing plate (TSP). The purpose of this study was to compare the biomechanical behavior of RoSA/TSP and the proximal femoral nail antirotation (PFNA).

METHODS

Standardized AO/OTA 31A2.2 fractures were induced by an oscillating saw in 10 paired human specimens (n = 20; mean age = 85 years; range: 71-96 years). The fractures were stabilized by either the RoSA/TSP (Koenigsee Implants, Allendorf, Germany) or the PFNA (DePuy Synthes, Zuchwil, Switzerland). Femurs were positioned in 25 degrees of adduction and 10 degrees of posterior flexion and were cyclically loaded with axial sinusoidal pattern at 0.5 Hz, starting at 300 N, with stepwise increase by 300 N every 500 cycles until bone-implant failure occurred. After every load step, the samples were measured visually and radiographically. Femoral head migration was assessed.

RESULTS

The stiffness at the load up to the clinically relevant load step of 1800 N (639 ± 378 N/mm (RoSA/TSP) vs. 673 ± 227 N/mm (PFNA); P = 0.542) was comparable, as was the failure load (3000 ± 787 N vs. 3780 ± 874 N; P = 0.059). Up to 1800 N, no femoral head rotation, head migration, or femoral neck shortening were observed either for RoSA/TSP or PFNA. Whereas failure of the PFNA subsumed fractures of the greater trochanter and the lateral wall, a posterior femoral neck fracture with a significantly increased femoral neck shortening (1.7 mm vs. 0 mm; P = 0.012) was the cause of failure with RoSA/TSP. This specific kind of failure was induced by a femoral neck weakening caused by the posterior TSP stabilizing screw.

CONCLUSIONS

There was no significant difference in biomechanical properties between the RoSA/TSP and the PFNA for the fracture pattern tested. However, failure modes differed between the 2 implants with greater femoral neck shortening observed in the RoSA/TSP group.

Locked minimally invasive plating versus fourth generation nailing in the treatment of AO/OTA 31A2.2 fractures: A biomechanical comparison of PCCP(®) and Intertan nail(®)

INTRODUCTION

Locked minimally invasive plating and fourth generation nailing potentially could reduce the complication rate in the treatment of trochanteric femur fractures by its rotational stability and providing better lateral cortical support. The purpose of this study was (1) to compare the biomechanical properties of the Percutaneous compression plate (PCCP) and the Intertan nail (IT) with regards to implant failure and (2) to assess dynamic stability coefficients in an unstable AO/OTA 31A2.2 fracture model.

METHODS

In paired femurs, a standardised unstable trochanteric femur fracture was induced by an oscillating saw. The fractures were stabilised by either the PCCP (Orthofix, McKinney, TX, USA) or the IT (Smith & Nephew, Memphis, TN, USA). All femurs were loaded with 300N, followed by an increase in load until failure using 300N each time (2000 cycles each, 0.5Hz). After every load step the samples were assessed visually and radiographically. We measured migration and performed a survival analysis.

RESULTS

16 fractures were induced in 8 paired human specimens (mean age: 84 years, 61-100 years). The mean stiffness (PCCP vs. IT: 249±124N/mm vs. 273±153N/mm; p=0.737) was comparable. The IT proved superior to the PCCP with regard to the number of cycles reached before failure occurred (PCCP vs. IT: 12,691±4733 vs. 15,313±4875 cycles; p=0.023). Except for a higher axial migration of the IT at failure point (PCCP vs. IT: 1.3mm vs. 4.3mm; p=0.028) there were no differences between the intra- and extramedullary implants, not even in terms of rotational stability along the femoral neck axis. A fracture of the femoral neck caused test abortion in both implants in most cases.

CONCLUSION

This study showed a superiority of the IT compared with the PCCP with regards to number of cycles achieved under sequential load increases for unstable trochanteric femur fractures. The stiffness was comparable. Both implants showed a high rotational stability and a support of the lateral wall.

STUDY TYPE

Biomechanical study.

Combined bilateral femoral head necrosis and pertrochanteric fracture: a case report

INTRODUCTION

Modular femoral implants have become a regular feature of revision hip surgery. However, for a primary hip arthroplasty, such as a femoral neck fracture case, the implant of choice is a standard femoral component, while compelling literature evidence have made osteosynthesis the standard procedure for the vast majority of trochanteric fractures.

CASE PRESENTATION

We present the case of a 66-year-old Caucasian woman presenting with two trochanteric fractures associated with primary and secondary hip osteoarthritis that were treated with an uncemented total hip replacement with a modular femoral component.

CONCLUSIONS

We found that a modular femoral component can address the issues of stability and, in our case, proved to be a viable solution for treating cases that are complicated by concomitant acetabular or femoral head and neck pathology.

InterTan nail versus Gamma3 nail for intramedullary nailing of unstable trochanteric fractures

BACKGROUND

Trochanteric fractures (TF) have become a major source of morbidity and mortality in elderly. We conducted this study to compare the outcomes of unstable trochanteric fractures treated with the InterTan nail and Gamma3 nail.

METHODS

Between January 2008 and May 2013, patients aged 60 years or older with a diagnosis of unstable TF treated with InterTan nail or Gamma3 nail were included. Patients treated with InterTan nail were pair-matched to patients treated with Gamma3 nail in a 1:2 ratio. Radiographs were obtained at 1, 3, 6, and 12 months follow-up, and all implant position changes, complications, fixation failures and functional scores were recorded.

RESULTS

Eighty-seven patients were included in the InterTan nail group, and 174 pair-matched patients were included in the Gamma3 nail group. Preoperative scores were similar between the 2 groups. There are significant improvements postoperatively in both groups. The incidence of cut-out and femoral shaft fracture were significantly higher in the Gamma3 nail group than the InterTan nail group (P=0.024 and P=0.044, respectively). Patients treated with the InterTan nail experienced longer fluoroscopy and operative times.

CONCLUSIONS

The InterTan nail may have a tendency in better outcomes for patients with unstable TF. However, the limited period of follow-up and inherent defects of nonrandomized trials indicate that better-designed randomized controlled trials will be required.

VIRTUAL SLIDES

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/13000_2014_191.

Malpositioning of the lag screws by 1- or 2-screw nailing systems for pertrochanteric femoral fractures: a biomechanical comparison of gamma 3 and intertan

OBJECTIVES

The aim of this investigation was to perform a biomechanical comparison between 1- and 2-screw systems used for the treatment of intertrochanteric fractures for centralized and decentralized placement of femoral neck screws of failure loads, stiffness, survival rates, tip apex distance (TAD), and failure mode.

METHODS

As fracture model, an AO 31A2.3 fracture was used. Twelve pairs of human cadaver femora were tested. Femoral neck screws were implanted in the femoral head in center/center, posterior/central, and anterior/superior position in axial/frontal plane. A single-screw system (Gamma 3 Locking Nail; Stryker GmbH & Co. KG) and a 2-screw system (Trigen-Intertan; Smith & Nephew GmbH) were used. To simulate the load in situ, a cyclic load was carried for 10,000 cycles in a material testing machine. If no cyclic failure occurred, femora were loaded until the failure. The systems were compared according to the stiffness, survivability through 10 k cycles, TAD, and load to failure.

RESULTS

None of the tested bones failed at center/center location in the decentralized positions 3 Gamma Nail and 2 Intertan specimens failed during cyclic testing. The 2-screw system resisted higher forces in all positions (Gamma: 5370N ± 1924, Intertan: 7650N ± 2043; P = 0.014).

CONCLUSIONS

Based on these data, it is clear that both the nail systems showed a higher biomechanical stability with a lower TAD. The 2 specimens that failed with the Intertan in the cyclic tests had a TAD ≥49 mm. The cutout failures that we detected during cyclic testing in the Gamma system had a TAD ≥30 mm. Thus, it is clear that the TAD affects failure independent of the implant used. With a less than ideal lag screw placement, however, the Intertan system with 2 integrated screws was able to withstand higher loads in this study.

Rotationally stable screw-anchor versus sliding hip screw plate systems in stable trochanteric femur fractures: a biomechanical evaluation

OBJECTIVES

The rotationally stable screw-anchor plate system (RoSA) is unique in using a novel screw-blade combination. This investigation tested the hypothesis whether RoSA is advantageous over the sliding hip screw plate system (SHS) with regard to stiffness, failure load, displacement, and migration in stable trochanteric femur fractures (OTA 31A1.1).

METHODS

Thirteen femur pairs (mean age = 79 years; range, 64-92 years) received implants of either the RoSA or SHS (Koenigsee Implants, Allendorf, Germany). Beginning with 300 N and under consecutive 300 N load-increase steps (2000 cycles, 0.5 Hz) the femurs were cycled until failure. Specimens were evaluated for fragment displacement in both frontal and rotational planes and for migration. A survival analysis was carried out.

RESULTS

With regard to stiffness (526 ± 195 N/mm vs 358 ± 143 N/mm; P = 0.006) and the failure load (2838 ± 781 N vs 2262 ± 863 N; P = 0.012), the RoSA proved superior to the SHS. Furthermore, RoSA demonstrated higher rotational stability in comparison to the SHS (1800 N: 0 ± 0 degrees vs 1.1 ± 1.3 degrees; P = 0.015; failure point: 0 ± 0 degrees vs 2.3 ± 2.6 degrees; P = 0.008), measuring rotation about femoral neck axis over time. Whereas cutout occurred only in the RoSA system (n = 3; P = 0.110), the SHS underwent plastic deformation in 7 cases (n = 7; P = 0.003). In one case (7%), the insertion of the RoSA blade resulted in iatrogenic cut-through caused by a jamming of the screw and the blade.

CONCLUSIONS

The fixation of stable trochanteric femur fractures with RoSA in cadavers led to greater primary stability under cyclic load, with significant advantages with regard to stiffness, failure load, and rotational stability, compared with the SHS. A detrimental effect was its migration tendency, which began at 1800 N and occurred in the cranial direction. A meticulous insertion technique was a prerequisite to avoid iatrogenic perforation of the femoral head. Our results will have to be substantiated by further biomechanical and clinical trials using an optimized RoSA system.

Use of the Gamma3™ nail in a teaching hospital for trochanteric fractures: mechanical complications, functional outcomes, and quality of life

BACKGROUND

Trochanteric fractures are common fractures in the elderly. Due to characteristic demographic changes, the incidence of these injuries is rapidly increasing. Treatment of these fractures is associated with high rates of complications. In addition, the long-term results remain poor, with high morbidity, declines in function, and high mortality. Therefore, in this study, complication rates and patients' outcomes were evaluated after fixation of geriatric trochanteric fractures using the Gamma3™ nail.

METHODS

Patients aged 60 years old or older, with pertrochanteric and subtrochanteric femoral fractures, were included. Patients with polytrauma or pathological fractures were excluded. Age, sex, and fracture type were collected on admission. In addition, data were recorded concerning the surgeon (resident vs. consultant), time of operation, and local or systemic perioperative complications. Complications were also collected at the 6- and 12-month follow-ups after trauma. Barthel Index, IADL, and EQ-5D measurements were evaluated retrospectively on admission, as well as at discharge and during the follow-up.

RESULTS

Ninety patients were prospectively included between April 2009 and September 2010. The patients' average age was 81 years old, and their average ASA score was 3. The incision/suture time was 53 min (95% CI 46-60 min). Hospital mortality was 4%, and overall mortality was 22% at the 12-month follow-up. Eight local complications occurred (4 haematomas, 1 deep infection, 1 cutting out, 1 irritation of the iliotibial tract, 1 periosteosynthetic fracture). The incidence of relevant systemic complications was 6%. Forty-two percent of the patients were operated on by residents in training, without significant differences in duration of surgery, complication rate, or mortality rate. The Barthel Index (82 to 71, p < .001), IADL (4.5 to 4.3, p = .0195) and EQ-5-D (0.75 to 0.66, p = .068) values did not reach pre-fracture levels during the follow-up period of 12 months.

CONCLUSION

The results showed a relatively low complication rate using the Gamma3™ nail, even if the nailing was performed by residents in training. The high mortality, declines in function, and low quality of life could probably be attributed to pre-existing conditions, such as physical status.In summary, the Gamma3™ nail seems to be a useful implant for the nailing of trochanteric fractures, although further studies are necessary comparing different currently available devices.