A comparative biomechanical study of proximal femoral nail (InterTAN) and proximal femoral nail antirotation for intertrochanteric fractures

Hip biomechanics in early recovery following fixation of intertrochanteric fractures: Results from a randomised controlled trial

Single and dual integrated screw femoral nails are both commonly used to treat intertrochanteric fractures. This study investigated if using single or dual integrated screw femoral nails result in different post-operative hip joint loading. In the presence of differences, we investigated potential contributing factors. Patients were randomised for treatment via single screw (Stryker, Gamma3) or dual-integrated screw nail (Smith and Nephew, Intertan). Pre-injury mobility levels were collected at enrolment. Hip radiographs and gait data were collected at six weeks (Gamma: 16; Intertan: 15) and six months (Gamma: 14; Intertan: 13) follow-up. The resultant hip joint reaction forces and abductor muscle forces were estimated using electromyography-assisted neuromusculoskeletal modelling during level walking gait. Our primary analysis focused on the resultant hip joint reaction force and abductor muscle forces. We compared between groups, across stance phase of walking gait, using statistical parametric mapping. At six weeks, the Intertan group showed a short (∼5% of stance phase) but substantial (33 % [0.3 × body weight] greater magnitude) resultant hip joint reaction force when compared to the Gamma group (P = 0.022). Higher gluteus medius forces (P = 0.009) were demonstrated in the Intertan group at six weeks. Harris Hip Scores followed the trend seen for the biomechanical outcomes with superior scores for the Intertan group at six weeks postoperative (P = 0.044). The use of dual-integrated screw femoral nails over single screw devices may allow for hip biomechanics more closely resembling normal hip function at earlier post-operative timepoints, but these appear to resolve by six months postoperative.

A novel intramedullary nail design of intertrochanteric fracture fixation improved by proximal femoral nail antirotation

A proper and reliable fracture fixation is important for fracture healing. The proximal femoral intramedullary nail (IN), such as proximal femoral nail anti-rotation (PFNA) or Gamma nail, is widely used for intertrochanteric fracture fixation. However, it still suffers considerable stress concentrations, especially at the junction between the nail and the blade or lag screw. In this study, we propose a novel intramedullary nail design to enhance the intramedullary nail integrity by introducing a bolt screw to form a stable triangular structure composed of the nail, the lag screw, and the bolt screw (PFTN, Proximal femoral triangle nail). Systematic finite element numerical simulations were carried out to compare the biomechanical performances of PFTN and PFNA under both static and dynamic loads during the postures of ascending and descending stairs. The simulation results highlight the advantages of the proposed PFTN design with lower stresses, less stress concentration, and higher structure stability.

Treatment of intertrochanteric fractures using cephalomedullary nail: One or two cephalic screws?

OBJECTIVES

To determine the incidence of cut-out, cut-in, cut-through, Z-effect, and reverse Z-effect in two cephalomedullary nail (CMN) systems: one with single cephalic screw fixation and the other with dual-screw fixation using a lag screw and an anti-rotation screw.

METHODS

A retrospective study from a cohort of patients was conducted between January 2017 and August 2019 in patients with intertrochanteric fractures treated with osteosynthesis using CMN.

RESULTS

One hundred ninety-six patients with intertrochanteric fractures who met the inclusion criteria were recruited. The median age was 81 years [interquartile range (IQR) 12]. Seventy-six percent had fractures classified as Orthopaedic Trauma Association/Arbeitsgemeinschaft für Osteosynthesefragen (OTA/AO) 31A2. Twenty-one mechanical complications occurred, 8.7% (17) was cut-out with a single cephalic screw CMN and 2% (4) was Z-effect with a dual-screw CMN non-integrated. The median tip-apex distance (TAD) was 19.4 mm (IQR 10.8) in patients who experienced cut-out and 19 mm (IQR 10) in those who experienced Z-effect. The median time to cut-out occurrence was 39,5 days (IQR 47,5), while the median time to Z-effect was 90 days (IQR 86).

CONCLUSIONS

The incidence of osteosynthesis failure using CMN is more frequent in patients treated with a single cephalic screw CMN.

LEVEL OF EVIDENCE

Therapeutic, Level III.

Failure of Fixation in Trochanteric Hip Fractures: Does Nail Design Matter?

OBJECTIVE

The objective of this study was to compare clinical outcomes of patients with trochanteric hip fractures treated with specific different cephalomedullary nail (CMN) designs.

METHODS

A scoping review of the English literature was performed. Inclusion criteria were studies comparing perioperative and postoperative outcomes of trochanteric hip fractures fixated by CMNs for one of the following CMN designs: short versus long nails, blade versus screw fixation, dual versus single lag screw fixation, and application of cement augmentation. Inclusion criteria consisted of human comparative clinical trials (randomized and observational). Exclusion criteria included noncomparative studies, studies comparing CMN with non-CMN devices or with arthroplasty, studies with less than 3 months follow-up, studies that did not provide relevant clinical outcome measures, biomechanical, finite element analyses, animal, or in vitro publications. Data regarding reoperations, peri-implant fractures, mechanical failure, nonunion, infection rates, and functional outcomes were reviewed.

RESULTS

Twenty-two studies met the inclusion criteria and formed the basis of this study. Failure of fixation rates and reoperation rates for each of the nail designs selected for evaluation is presented, in addition to specific outcome measures relevant to that nail design which was explored: peri-implant fracture-short versus long nails, and specific mechanism of failure-blade versus plate.

CONCLUSIONS

Decreased failure of fixation and reoperations rates were found for integrated dual lag screw fixation. Similar fixation failure and reoperation rates were found for the long versus short nails and for blade versus screw fixation.

LEVEL OF EVIDENCE

Diagnostic, Level IV.

Dual-screw versus single-screw cephalomedullary nails for intertrochanteric femoral fractures: a systematic review and meta-analysis

BACKGROUND

Internal fixation with cephalomedullary nails has been widely used in the treatment of intertrochanteric femoral fractures (IFF). Yet, the difference in efficacy and safety between the commonly used integrated dual-screw cephalomedullary nail (InterTAN) and single-screw cephalomedullary nail remains inconclusive. Thus we performed the present systematic review and meta-analysis.

METHODS

Randomized controlled trials (RCTs) or observational studies comparing InterTAN with proximal femoral nail anti-rotation (PFNA), the Asian PFNA (PFNA-II), or the Gamma3 nail in treating IFF were searched on PubMed, EMBASE, Web of Science and Cochrane Library from inception to April 30, 2023. The differences in perioperative parameters and clinical and radiological outcomes were evaluated by mean difference (MD) with 95% confidence interval (95%CI). The risks of various complications and mortality were assessed by risk ratio (RR) with 95%CI.

RESULTS

Twenty-three studies comprising 3566 patients were included. Compared with single-screw cephalomedullary nails (PFNA/PFNA-II, Gamma3), InterTAN conferred significantly reduced risk of implant failures (RR = 0.37, 95%CI 0.26 to 0.51, P < 0.001), hip and thigh pain (RR = 0.70, 95%CI 0.55 to 0.90, P = 0.006) and all-cause revision/reoperation (RR = 0.38, 95%CI 0.26 to 0.57, P < 0.001). Moreover, patients treated with InterTAN had significantly higher 1-year Harris Hip Score (MD = 0.82, 95%CI 0.20-1.44, P = 0.010) and shorter time to union/healing (MD = - 0.66 days, 95%CI  - 1.16 to  - 0.16, P = 0.009). Femoral neck shortening, time to full bearing, and incidences of non-union, infection, deep venous thrombosis, and mortality were comparable between both groups.

CONCLUSIONS

The integrated dual-screw InterTAN construct has superior performance in reducing risks of complications and improving clinical and functional outcomes in the treatment of IFF. More well-designed, high-quality RCTs are warranted to confirm these findings.

Intertrochanteric Femoral Fractures: A Comparison of Clinical and Radiographic Results with the Proximal Femoral Intramedullary Nail (PROFIN), the Anti-Rotation Proximal Femoral Nail (A-PFN), and the InterTAN Nail

Background and Objectives: The aim of this study was to evaluate retrospectively the radiological and functional outcomes of closed reduction and internal fixation for intertrochanteric femoral fractures (IFF) using three different proximal femoral nails (PFN). Materials and Methods: In total, 309 individuals (143 males and 166 females) who underwent surgery for IFF using a PFN between January 2018 and January 2021 were included in the study. Our surgical team conducted osteosynthesis using the A-PFN® (TST, Istanbul, Turkey) nail, the PROFIN® (TST, Istanbul, Turkey), and the Trigen InterTAN (Smith & Nephew, Memphis, TN, USA) nail. The PFNs were compared based on age, gender, body mass index (BMI), length of stay (LOS) in intensive care, whether to be admitted to intensive care, mortality in the first year, amount of transfusion, preoperative time to surgery, hospitalisation time, duration of surgery and fluoroscopy, fracture type and reduction quality, complication ratio, and clinical and radiological outcomes. The patients’ function was measured with the Harris Hip Score (HHS) and the Katz Index of Independence in Activities of Daily Living (ADL). Results: Pain in the hip and thigh is the most common complication, followed by the V-effect. The Z-effect was seen in 5.7% of PROFIN patients. A-PFN was shown to have longer surgical and fluoroscopy durations, lower HHS values, and much lower Katz ADL Index values compared to the other two PFNs. The V-effect occurrence was significantly higher in the A-PFN group (36.7%) than in the InterTAN group. The V-effect was seen in 33.1% of 31A2-type fractures but in none of the 31A3-type fractures. Conclusions: InterTAN nails are the best choice for IFFs because they have high clinical scores after surgery, there is no chance of Z-effect, and the rate of V-effect is low.

Biomechanical analysis of recently released cephalomedullary nails for trochanteric femoral fracture fixation in a human cadaveric model

BACKGROUND

Recently, two novel concepts for intramedullary nailing of trochanteric fractures using a helical blade or interlocking dual screws have demonstrated advantages as compared to standard single-screw systems. However, these two concepts have not been subjected to a direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone quality (1) the biomechanical competence of nailing with the use of a helical blade versus interlocking screws, and (2) the effect of cement augmentation on the fixation strength of the helical blade.

METHODS

Twelve osteoporotic and osteopenic human cadaveric femoral pairs were assigned for pairwise implantation using either a short TFN-ADVANCED Proximal Femoral Nailing System (TFNA) with a helical blade head element or a short TRIGEN INTERTAN Intertrochanteric Antegrade Nail (InterTAN) with interlocking screws. Six osteoporotic femora, implanted with TFNA, were augmented with bone cement. Four groups were created: group 1 (TFNA) paired with group 2 (InterTAN), both consisting of osteopenic specimens, and group 3 (TFNA augmented) paired with group 4 (InterTAN), both consisting of osteoporotic specimens. An unstable trochanteric AO/OTA 31-A2.2 fracture was simulated and all specimens were tested until failure under progressively increasing cyclic loading.

RESULTS

Stiffness in group 3 was significantly higher versus group 4, p = 0.03. Varus (°) and femoral head rotation around the femoral neck axis (°) after 10,000 cycles were 1.9 ± 1.0/0.3 ± 0.2 in group 1, 2.2 ± 0.7/0.7 ± 0.4 in group 2, 1.5 ± 1.3/0.3 ± 0.2 in group 3 and 3.5 ± 2.8/0.9 ± 0.6 in group 4, being significantly different between groups 3 and 4, p = 0.04. Cycles to failure and failure load (N) at 5° varus or 10° femoral head rotation around the neck axis in groups 1-4 were 21,428 ± 6020/1571.4 ± 301.0, 20,611 ± 7453/1530.6 ± 372.7, 21,739 ± 4248/1587.0 ± 212.4 and 18,622 ± 6733/1431.1 ± 336.7, being significantly different between groups 3 and 4, p = 0.04.

CONCLUSIONS

Nailing of trochanteric femoral fractures with use of helical blades is comparable to interlocking dual screws fixation in femoral head fragments with low bone quality. Bone cement augmentation of helical blades provides significantly greater fixation strength compared to interlocking screws constructs.

The predictive value of the Singh index for the risk of InterTAN intramedullary fixation failure in elderly patients with intertrochanteric fractures

Background

To investigate the predictive value of the Singh index for the risk of InterTAN intramedullary fixation failure in elderly patients with intertrochanteric fracture to guide clinical treatment.

Methods

A total of 360 patients were divided into the Singh (I ~ II) (n = 120), Singh (III ~ IV) (n = 120) and Singh (V ~ VI) (n = 120) groups. Visual analog scale (VAS) and Harris scores were recorded at 1, 6, 12, 18 and 24 months after the operation. The correlation between the Singh index and the T-score of the total hip and femoral neck was analyzed. Logistic regression was used to analyze the relationship between the Singh index and internal fixation failure; the types of internal fixation failure were also analyzed.

Results

The Harris scores of the Singh (I ~ II) group were lower than those of the Singh (III ~ IV) and Singh (V ~ VI) groups 12, 18 and 24 months after surgery (P < 0.05). The Singh index was significantly correlated with the T-score of the total hip and femoral neck (P = 0.00, r = 0.89; P = 0.00, r = 0.83). The Singh (I ~ II) group had the lowest internal fixation survival rate within 24 months (P = 0.01). The Singh index was an independent predictor of internal fixation failure (P < 0.05). Lag screw cutting-out was the main type of internal fixation failure in the three groups (P = 0.00).

Conclusion

The Singh index is significantly correlated with the bone mineral density of the femoral neck and total hip. The Singh (I ~ II) group had lower Harris scores and a lower internal fixation survival rate than the other two groups. The Singh index is an independent predictor of internal fixation failure, especially lag screw cutting-out, after InterTAN fixation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-022-05741-8.

Biomechanical Assessment of Cannulated Nails for the Treatment of Proximal Femur Fractures

This article focuses on a type of surgical implant used in orthopaedics and traumatology—cannulated femoral nails. Femoral nails are used in medical treatment for purposes of osteosynthesis, i.e., when treating various types of complicated fractures, in this case fractures of the femur. The article investigates cases in which a nail has been implanted in the proximal part of the femur for a short time (with the fracture still not healed), compared with cases in which the bone has already healed. According to AO classification, examined fractures are described as AO 31B3 AO 32A3. The main focus is on strength-deformation analysis using the finite element method (FEM), which makes it possible to determine the behaviour of the femur-implant system. FEM analysis was used to compare 1.4441 steel nails made by two manufacturers, Medin (Czech Republic) and Tantum (Germany). Boundary conditions including external loading, prescribed supports and elastic foundation are defined. There were solved FEM analyses for five cases of healed femur and five cases of broken femur both including implants with prescribed collo-diaphyseal angles. The results of the analysis were used to assess stress-deformation states from the perspective of appropriateness for clinical treatment, biomechanical reliability and safety. All examined femoral nails are compared, safe and suitable for patient treatment.

Integrated dual lag screws versus single lag screw cephalomedullary nail constructs: a meta-analysis and systematic review

BACKGROUND/AIM

This study aims to determine the safety and efficacy of integrated dual lag screw (IDL) cephalomedullary nails (CMN) when compared with single lag screw (SL) constructs, in the internal fixation of intertrochanteric femoral fractures.

METHODS

The Smith & Nephew InterTan IDL was compared with SL CMN group consisting of the Stryker Gamma-3 (G3) and Synthes Proximal Femoral Nail Antirotation (PFNA) CMN. A multi-database search was performed according to PRISMA guidelines. Data from studies assessing the clinical and radiological outcomes, complications and perioperative parameters of InterTan versus G3 or PFNA CMN in patients with intertrochanteric femoral fractures were extracted and analysed.

RESULTS

15 studies were included in this meta-analysis, consisting of 2643 patients. InterTan was associated with lower complication rates in terms of all-cause revisions (OR 0.34; 95% CI, 0.22-0.51; p < 0.001), cut-outs (OR 0.30; 95% CI, 0.17-0.51; p < 0.001), medial or lateral screw migration (OR 0.19; 95% CI, 0.06-0.65; p = 0.008) as well as persistent hip and thigh pain (OR 0.65; 95% CI, 0.47-0.90; p = 0.008). In terms of perioperative parameters, InterTan is associated with longer operative times (MD 5.57 minutes; 95% CI, 0.37-10.78 minutes, p = 0.04) and fluoroscopy times (MD 38.89 seconds, 95% CI, 15.88-61.91 seconds; p < 0.001). There was no statistically significant difference in terms of clinical Harris Hip Score and radiological outcomes, non-union, haematoma, femoral fractures, varus collapse, length of stay and mean intraoperative blood loss between the 2 groups.

CONCLUSIONS

Integrated dual lag screw cephalomedullary nails are associated with fewer revisions and complications. However, there is insufficient data to suggest that either nail construct is associated with better functional outcomes.

Stabilisation of AO OTA 31-A unstable proximal femoral fractures: Does the choice of intramedullary nail affect the incidence of post-operative complications? A systematic literature review and meta-analysis

OBJECTIVE

To determine if there was a difference in the risk of post-operative complications associated with the use of different intramedullary (IM) devices in the treatment of unstable AO OTA 31-A trochanteric fractures.

DESIGN

Systematic literature review and meta-analysis.

METHODS

A systematic literature review was carried out in January 2022 in the Embase, MEDLINE and Cochrane databases. Studies comparing INTERTAN™ to other intramedullary nails for the treatment of AO OTA 31-A trochanteric fractures were selected for inclusion. After data extraction, meta-analyses were carried out on postoperative outcomes, with specific focus placed on unstable fracture patterns.

RESULTS

Twenty-three studies were suitable for inclusion, of which seventeen reported on outcomes in unstable fractures. INTERTAN reduced the risk of revision/reoperation by 64% (RR 0.36, 95% CI 0.25 to 0.54, p <0.0001), implant failures by 62% (RR 0.38, 95% CI 0.25 to 0.57, p<0.0001) and hip and thigh pain by 50% (RR 0.50, 95% CI 0.35 to 0.71, p=0.0001) in unstable fractures. No differences were noted between IM nail designs for infection rates, healing time, non-union rates, femoral shortening, or Harris Hip Score.

CONCLUSIONS

The INTERTAN IM nail may reduce incidence of implant-related complications, hip and thigh pain, and the need for revision/reoperation without compromising clinical and functional outcomes.

Cemented hemiarthroplasty versus proximal femoral nail antirotation in the management of intertrochanteric femoral fractures in the elderly: a case control study

Background

The treatment for intertrochanteric femoral fractures (IFF) among the elderly has been a controversial topic. Hemiarthroplasty (HA) and proximal femoral nail antirotation (PFNA) have their own advantages in the management of IFF. Hence, this study aims to compare and analyze differences in the effectiveness of both procedures on IFF among the elderly.

Methods

Overall, 99 patients (81.09 ± 8.29 years; 68 women) underwent HA or PFNA from January 2016 to May 2020. IFF were classified according to the Arbeitsgemeins für Osteosynthesefragen (AO) classification. The difference in underlying diseases, the American Society of Anesthesiologists (ASA) grade, Singh index, Harris scores, surgical time, intraoperative bleeding, postoperative blood test results, postoperative number of days to partially bearing weight, and survival outcomes were analyzed. Postoperative follow-ups were performed every 3 months.

Results

There was no significant difference in the AO classification, underlying diseases, ASA grade, Singh index, surgical time, and survival outcomes of the HA (45 patients) group and PFNA group (54 patients). The HA group was associated with earlier partial weight-bearing (HA: 4 [2 ~ 4.5] days, PFNA: 10 [8~14] days). It also had a higher total Harris score than the PFNA group at the 6-month follow-up visit (HA: 86.8 [81.90 ~ 90.23], PFNA: 83.48 [75.13 ~ 88.23]). Harris scores decreased more in patients aged ≥90 years in the PFNA group than in the HA group. The postoperative stress recovery rate in the HA group was faster based on postoperative blood test results.

Conclusions

PFNA and HA have good therapeutic effects in the treatment of IFF. The advantages of HA were reflected in short-term weight bearing, faster recovery from stress, and better joint function in the long term. This advantage is more obvious in the patient population aged over 90 years. Therefore, we suggest that surgeons should consider the benefit of HA in the treatment of IFF among the elderly.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000035814. Registered 17 August 2020, https://www.chictr.org.cn/showproj.aspx?proj=57083

Biomechanical evaluation of internal fixation for the treatment of comminuted subtrochanteric femur fractures

BACKGROUND

Several biomechanical studies on subtrochanteric femur fractures have reported that use of an intramedullary nail is superior to extramedullary implant. However, the optimal choice of intramedullary nail for the treatment of comminuted subtrochanteric femur fracture remains unclear. Here, we evaluated the biomechanical properties of comminuted subtrochanteric femur fracture treated with four different internal fixations.

METHODS

A comminuted subtrochanteric femur fracture model was created with a 2-cm gap below the lessor trochanter in 20 synthetic femurs. The fractures were fixed with one of four implants - Antegrade Femoral Nail (AFN), Trochanteric Fixation Nail Advanced with a femoral neck blade (TFNA blade), TFNA with a femoral neck screw (TFNA screw), and the reversed distal femoral locking compression plate (DF-LCP) - all manufactured by DePuy Synthes. Axial compression tests and torsion tests were performed and the stiffness of each implant was compared.

RESULTS

For compression, the TFNA blade, TFNA screw, and AFN provided significantly higher stiffness than DF-LCP (p < 0.001, p < 0.001, p = 0.001, respectively), and the TFNA blade provided significantly higher stiffness than AFN (p = 0.049). For torsion, there were no significant differences among the groups in internal rotation, while the TFNA screw had significantly lower torsional stiffness than the AFN, TFNA blade and DF-LCP in external rotation (p = 0.036, p = 0.034, p = 0.037, respectively).

CONCLUSIONS

These findings could help to provide biomechanical evidence regarding choice of implant for the treatment of comminuted subtrochanteric femur fracture. The TFNA blade may be more suitable for the treatment of comminuted subtrochanteric femur fracture.

Comparison of clinical and radiological outcomes in intertrochanteric fractures treated with InterTAN nail against conventional cephalomedullary nails: a systematic review

Intertrochanteric fractures, accountable for 50% of hip fractures, can be fixed with cephalomedullary devices such as Proximal Femoral Nail Antirotation (PFNA™), Gamma3 nailing system and TRIGEN™ InterTAN™ nail (IT). IT uniquely uses two cephalocervical screws that allow for linear compression and provide additional resistance to femoral head rotation. A literature review assessing clinical outcomes of these devices was conducted, with 14 studies enrolling 3104 patients meeting the inclusion criteria. PFNA and Gamma3 had better intraoperative outcomes compared with IT; however, IT had superior implant-related outcomes of cut-out and screw migration. No difference was found between IT and PFNA or Gamma3 in Harris Hip Scores, time to union, malunion and nonunion. Further long-term studies are needed to evaluate clinical outcomes and cost–effectiveness of cephalomedullary devices.

Hip Replacement as Alternative to Intramedullary Nail in Elderly Patients with Unstable Intertrochanteric Fracture: A Systematic Review and Meta-Analysis

Objective

To evaluate the efficacy and safety of hip replacement and intramedullary nails for treating unstable intertrochanteric fractures in elderly patients.

Methods

Randomized clinical trials (RCTs) to compare hip replacement with intramedullary nail in the management of elderly patients with unstable intertrochanteric femur fracture were retrieved from Cochrane Library (up to January 2018), CNKI (China National Knowledge Infrastructure), Wanfang Data, PubMed, and Embase. The methodological quality of the included trials was assessed using the Cochrane risk of bias assessment tool, and relevant data was extracted. Statistical analysis was performed by Revman 5.3. Where possible, we performed the limited pooling of data.

Results

Fourteen trials including a total of 1067 participants aged 65 and above were included for qualitative synthesis and meta‐analysis. The methodological quality of the included study was poor. The meta‐analysis indicated that the hip replacement group benefited more than the intramedullary nail group in terms of the bearing load time (WMD ‐14.61, 95% CI −21.51 to −7.7, P < 0.0001), mechanical complications (OR 0.34, 95% CI 0.21 to 0.57, P < 0.0001), and post‐operative complications (OR 0.46, 95% CI 0.22 to 0.93, P = 0.03). While the intramedullary nail was superior to arthroplasty regarding the intraoperative blood loss (WMD 58.36, 95% CI 30.77 to 85.94, P < 0.0001). However, there were no statistical significances in the length of surgery (WMD 5.27, 95% CI 4.23 to 14.77, P = 0.28), units of blood transfusion (WMD 0.34, 95% CI ‐0.16 to 0.85, P = 0.18), length of hospital stay (WMD ‐1.00, 95% CI ‐2.93 to 0.93, P = 0.31), Harris hip score (WMD 0.31, 95% CI ‐0.39 to 1.01, P = 0.38), and mortality (OR 1.24, 95% CI 0.12 to 13.10, P = 0.86).

Conclusions

This systematic review and meta‐analysis provided evidence for the efficacy and safety of hip replacement and intramedullary nail in treating unstable intertrochanteric fractures. However, the results should be interpreted cautiously because of methodological limitations and publication bias.

Single screw type of lag screw results higher reoperation rate in the osteosynthesis of basicervical hip fracture

BACKGROUND

Basicervical hip fractures are relatively rare with greater biomechanical instability compared to the other types of hip fractures. Several studies have reported ambivalent surgical outcomes of basicervical hip fractures. The purpose of this multicenter study was to analyze surgical outcomes of basicervical hip fractures according to the fixation type of proximal femur and lag screw type.

METHODS

Among 3220 hip fractures, 145 were classified as basicervical hip fractures. Of those, 106 patients treated with osteosynthesis were included to analyze the surgical complications according to fixation type of proximal femur: sliding hip screw(SHS) and cephalomedullary nail (CMN) groups. Surgical complications including the excessive displacement of fracture and the occurrence of reoperation were evaluated at the final follow up. We further evaluated surgical complications according to lag screw type with subgroup analysis in CMN group: single screw type, blade type and two integrated screw type.

RESULTS

Ten patients (9.4%) sustained surgical complications (5 excessive displacements and 5 reoperations). For fixation type of proximal femur, SHS group showed higher tendency of excessive displacement despite no statistical difference between the two groups (p = 0.060). For lag screw type with subgroup analysis in CMN group, single screw type showed statistically high rates of reoperation compared to the other types of lag screw (p = 0.022).

CONCLUSION

Basicervical hip fractures treated with osteosynthesis resulted to high rates of surgical complications in this study. However, they could be drastically reduced if CMN with blade type or two integrated screw type were used in the osteosynthesis of basicervical hip fractures.

COMPARATIVE ANALYSIS FOR THREE FIXTURES OF PAUWELLS-II BY THE BIOMECHANICAL FINITE ELEMENT METHOD

Little is known about why and how biomechanics govern the hypothesis that three-Lag-Screw (3LS) fixation is a preferred therapeutic technique. A series models of surgical internal-fixation for femoral neck fractures of Pauwells-II will be constructed by an innovative approach of finite element so as to determine the most stable fixation by comparison of their biomechanical performance. Seventeen sets of CT scanned femora were imported onto Mimics extracting 3D models; these specimens were transferred to Geomagic Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; three sorts of internal fixators were expressed virtually by Pro-Engineer. Processed by Hypermesh, all compartments were assembled onto three systems actually as “Dynamic hip screw (DHS), 3LS and DHS+LS”. Eventually, numerical models of Finite Elemental Analysis (FEA) were exported to AnSys for solution. Three models for fixtures of Pauwells-II were established, validated and analyzed with the following findings: Femoral-shaft stress for [Formula: see text](3LS) is the least; Internal-fixator stress (MPa) for [Formula: see text]; Integral stress (MPa) for [Formula: see text]; displacement of femoral head (mm) for a[Formula: see text](DHS+LS) = 0.735; displacement of femoral shaft (mm) for [Formula: see text]; and displacement of fixators for [Formula: see text]. Mechanical comparisons for other femoral parks are insignificantly different, and these data can be abstracted as follows: the stress of 3LS-system was checked to be the least, and an interfragmentary displacement of DHS+LS assemblages was assessed to be the least”. A 3LS-system should be recommended to clinically optimize a Pauwells-II facture; if treated by this therapeutic fixation, breakage of fixators or secondary fracture is supposed to occur rarely. The strength of this study is that it was performed by a computer-aided simulation, allowing for design of a preoperative strategy that could provide acute correction and decrease procedure time, without harming to humans or animals.

Is rotation the mode of failure in pertrochanteric fractures fixed with nails? Theoretical approach and illustrative cases

PURPOSE

The present article reviews data from biomechanical and clinical studies which indicate that rotational instability can cause failure of fixation due to the particular characteristics of the fracture, the mechanical properties of the chosen implant or flaws in surgical technique.

METHODS

Although radiographs give a similar impression in failure of fractures fixed with cephalomedullary nails, different mechanisms involving rotation of the femoral head may play a key role.

RESULTS

The incidence of failure in pertrochanteric fracture fixation is decreasing as implants continue to evolve. It is possible that currently reported low failure rates do not apply equally to all subtypes of this diverse group of fractures. Since the introduction of sliding hip screws, "cut-out" due to varus collapse of the proximal fracture fragment has been the only reported mode of failure.

CONCLUSION

Excessive rotation leading to eventual "cut-out" has not been adequately studied, and thus, available evidence is not sufficient to definitely prove this theoretical approach. As nailing is gradually overtaking extramedullary fixation as the treatment of choice, especially for comminuted pertrochanteric fractures which can be rotationally unstable, further research is warranted to improve our understanding of the pathogenetic mechanisms of failure.

Comparative analysis for five fixations of Pauwels-I by the biomechanical finite-element method

Background: Little is known about how biomechanics govern the five fixtures such as DHS, MLS, DHS + LS, LP, and HA are accepted as common therapeutic techniques. Aims and objectives: A series of numerical models for a femoral neck fracture of Pauwels-I will be constructed by innovative approach of finite element in order to determine the most optimized option in comparison with biomechanical performance. Method: Twenty sets of computer tomography scanned femora were imported onto Mimics to extract 3 D models; these specimens were transferred to Geomagic-Studio for a simulative osteotomy and kyrtograph; then, they underwent UG to fit simulative solid models; 5 sorts of fixture were then expressed by Pro-Engineer virtually. After processing with HyperMesh, all compartments (fracture model + internal implant) were assembled onto 5 systems: "Dynamic Hip Screw (DHS), Multiple Lag screw (MLS), DHS + LS, femoral Locking Plate (LP) and HemiArthroplasty (HA)." Eventually, numerical models of the finite-elemental analysis were exported to AnSys to determine the solution. Result: Four models of fixation and a simulation of HA for Pauwels-I were established, validated, and analyzed with the following findings: In term of displacement, these 5 fixtures ranged between 0.3801 and 0.7536 mm have no significant difference; in term of stress, the averages of peaks for integral assemblage are b(MLS) = 43.5766 ≈< d(LP) = 43.6657 ≈< e(Ha) = 43.6657 < c(DHS + LS) = 66.5494 < a(DHS) = 105.617 in MPa indicate that MLS, LP and HA are not significantly different, but less than DHS + LS or DHS in each. Conclusion: A fixture of MLS or LP with optional HA should be recommended to clinically optimize a Pauwels-I facture.

Comparison of effects of four treatment methods for unstable intertrochanteric fractures: A network meta-analysis

PURPOSE

The optimal internal fixation device for unstable intertrochanteric fracture remains a matter of controversy. By performing network meta-analysis, we developed a ranking of the following four surgical methods: proximal femoral nail antirotation, InterTan nail, gamma nail (GN) and sliding hip screws. We compare the complication rates in patients with unstable intertrochanteric fractures.

MATERIALS AND METHODS

After an exhaustive search of MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials for relevant studies, randomized controlled trials meeting selection criteria were entered into our network meta-analysis. Statistical analyses were conducted using Stata software, version 13.0 (Stata Corporation, College Station, Texas, USA).

RESULTS

We included 12 randomized controlled trials. Compared to Sliding hip screw, there were no substantial differences in rates of complications in unstable intertrochanteric fractures patient undergoing various treatments (all p > 0.05). Nevertheless, the surface under the cumulative ranking curve (SUCRA) for GN (80.6%) was significantly higher than those of the other three methods.

CONCLUSION

GN had the highest probability of reducing the total incidence of complications among the four interventions for treating unstable intertrochanteric fractures.

Helical Blade or the Integrated Lag Screws: A Matched Pair Analysis of 100 Patients With Unstable Trochanteric Fractures

OBJECTIVES

To compare the radiological and clinical results with PFNA-II and InterTan in the treatment of unstable trochanteric fractures in the elderly.

DESIGN

Retrospective, multicenter, matched pair.

SETTING

Three tertiary level trauma centers.

PATIENTS

Hundred elderly patients who underwent intramedullary stabilization with either the PFNA-II or the InterTan for osteoporotic unstable trochanteric fractures.

INTERVENTIONS

Fifty matched pairs consisting of OTA/AO-A2 and A3 fractures were created from a cohort of 290 patients who underwent internal fixation for unstable trochanteric fractures with the PFNA-II or InterTan nails.

OUTCOME MEASUREMENTS

Radiological assessment was performed to compare union rates, varus collapse, medial or lateral screw/blade migration, and cut-out. Functional outcome at 1 year was assessed and compared using Harris hip score, Timed Up and Go test, and the mobility score.

RESULTS

Union rates, fracture reduction, neck shaft angle, and tip-apex distance were similar in both groups. The PFNA-II group had a significantly higher degree of lateral sliding of the helical blade (P < 0.001). The InterTan group had a better Harris hip score, mobility score, Timed Up and Go test scores, and abductor strength (P < 0.05) at 1 year. The incidence of varus collapse and medial blade migration were higher in the PFNA-II group (P > 0.05). The need for repeat surgery to address surgery-related complications were significantly high in the PFNA-II group (P = 0.045).

CONCLUSIONS

The InterTan may provide superior functional outcome and reduced complications than does the Proximal Femur Nail - Antirotation in elderly patients with unstable trochanteric fractures.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Limited Dynamic Hip Screw for Treatment of Intertrochanteric Fractures: A Biomechanical Study

Background

Material/Methods

Results

Conclusions

Optimizing stability in AO/OTA 31-A2 intertrochanteric fracture fixation in older patients with osteoporosis

Objectives

To compare the functional and radiographic outcomes of InterTAN nail (IT) and proximal femoral nail anti-rotation (PFNA) for managing primary AO/OTA 31-A2 intertrochanteric hip fractures (IHFs) in older osteoporotic patients.

Methods

Patients aged 60 years or older who received surgical treatment for IHFs (AO/OTA 3.1A2.1-A2.3) with IT or PFNA were retrospectively evaluated. The primary outcome was the postoperative treatment failure rate. The secondary outcome was the Harris Hip Score (HHS).

Results

A total of 326 osteoporotic cases (326 hips: IT, n = 162; PFNA, n = 164) were assessed with a mean follow-up of 43.5 months (range, 38–48 months). For the entire cohort, the incidence of postoperative treatment failure (periprosthetic fracture and reoperation) was 29/326 (8.9%); the IT-treated cohort (7/162, 4.3%) had a significantly lower rate compared with the PFNA-treated cohort (22/165, 13.3%). The incidence of postoperative periprosthetic fractures was significantly lower in the IT-treated cohort than in the PFNA-treated cohort (2.5% vs 7.9%). The postoperative HHS at the final follow-up was not significantly different between the groups.

Conclusion

IT might show a better outcome in managing osteoporotic AO/OTA 31-A2 IHFs in terms of periprosthetic fracture and reoperation compared with PFNA.

Biomechanical study on different lengths of PFNA fixation for unstable intertrochanteric femoral fractures

OBJECTIVE

The aim of our study was to compare the biomechanical stability of the Proximal Femoral Nail Antirotation (PFNA) (with 200 mm, 240 mm and 280 mm-long main nails) for the management of unstable intertrochanteric femoral fractures.

METHODS

Tronzo-Evans Type IV and V fractures were built by applying a three-dimensional finite element model. Further, PFNA-II with 200 mm, 240 mm and 280 mm-long main nails were applied for fixation. The above model is the creation of 3 researchers designed in order to obtain average values of numerical stress. Von Mises stress distribution and medial and lateral stress peak of the femur and PFNA were compared.

RESULTS

240 mm and 280 mm PFNA medial stress peak was reduced significantly in comparison to 200 mm PFNA (p⟨0.05). However, there was no difference between 240 mm and 280 mm PFN. Also, no statistical difference was observed with any of 3 lengths in both medial and lateral stress peak for Evans Type IV and V PFNA.

CONCLUSION

240 mm and 280 mm PFNA could reduce femur fixation medial stress peak. Further, they were more efficient in comparison to the 200 mm PFNA, and their biomechanical stability was similar to that of the 280 mm nail.

Cephalomedullary Nail Fixation of Intertrochanteric Femur Fractures: Are Two Proximal Screws Better Than One?

OBJECTIVES

To analyze radiographic changes in intertrochanteric (IT) fracture alignment after treatment with either a single sliding lag screw or an integrated compressed and locked, dual screw, cephalomedullary nail construct.

DESIGN

Retrospective comparative study.

SETTING

Level 1 regional trauma center.

PATIENTS

1004 OTA/AO 31A, 31B2.1 fractures treated with either a single screw cephalomedullary nail (Gamma 3) or an integrated dual screw cephalomedullary nail (InterTAN) between February 1, 2005, and June 30, 2013. Four hundred thirteen remained after exclusion criteria; 130 were treated with a single screw device (79 stable and 51 unstable), and 283 with an integrated dual screw device (155 stable and 128 unstable).

INTERVENTION

Cephalomedullary nail insertion.

OUTCOME MEASURES

Radiographic analysis included fracture pattern, fracture reduction, neck-shaft angle (NSA), and femoral neck shortening (FNS) differences at 3, 6, and 12 months. Measurements were normalized using known lag screw dimensions, digitally corrected for magnification. Rotation between x-rays was controlled using a ratio of known to measured dimensions. The Mann-Whitney U test was used for statistical analysis.

RESULTS

The single screw device resulted in 2.5 times more varus collapse (NSA) and 2 times more FNS over 1 year, as compared to the locked, integrated dual screw device, regardless of stability (P < 0.001). NSA and FNS changes were greater for both devices in unstable fracture patterns, but significantly less movement occurred with the dual screw device (P < 0.001).

CONCLUSIONS

A cephalomedullary nail with 2 integrated proximal screws that can be compressed and then locked seems to maintain initial IT fracture reduction and subsequent position over time, with less varus collapse and less shortening than a single screw device.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

INTERTAN nail versus proximal femoral nail antirotation-Asia for intertrochanteric femur fractures in elderly patients with primary osteoporosis

Objectives To compare the long-term functional and radiographic outcomes of the proximal femoral nail antirotation-Asia (PFNA-II) and INTERTAN nail (IT) in the management of intertrochanteric femoral fractures (IFFs) (AO/OTA Type 31A1.1-A2.3) in elderly patients with primary osteoporosis. Methods A retrospective comparative study was performed in our institution. From January 2009 to March 2012, 243 patients with osteoporosis (243 hips) with IFFs (AO/OTA Type 3.1A1.1-A2.3) underwent repair with either a PFNA-II or IT. Follow-up assessments were performed 1, 3, 6, 9, and 12 months postoperatively and every year thereafter. All implant position changes were noted. Patient-related functional outcomes were evaluated based on the Harris hip score. Results In total, 174 patients with osteoporosis (IT, n = 86; PFNA-II, n = 88) were evaluated during a mean follow-up period of 40 months (range, 38-60 months). An increased risk of femoral shaft fracture after implant removal was observed at month 9 of follow-up in 0.0% and 4.4% of the IT and PFNA-II groups, respectively. This difference remained over time with rates of 1.1% and 6.8%, respectively, at the last follow-up. Conclusion The IT nail appears to be a reliable implant in the management of IFFs (AO/OTA Type 3.1A1.1-A2.3) in elderly patients with primary osteoporosis.

Comparison of Second and Third-Generation Nails in the Treatment of Intertrochanteric Fracture: Screws versus Helical Blades

OBJECTIVE

The aim of this study was to compare the radiological and functional outcomes of anti-rotation trochanteric nails (ATNs) with proximal femoral nail anti-rotation (PFNA) in the treatment of intertrochanteric femur fractures in elderly patients.

MATERIALS AND METHODS

In total, 165 intertrochanteric fractures were treated between January 2007 and January 2010. One hundred forty patients were included. The operation time, amount of blood loss, fluoroscopy screening time, and length of hospitalization were recorded. The radiological position of the implant, quality of fracture reduction, and tip-apex distance were evaluated, and the postoperative complications as well as functional condition of the patients were assessed.

RESULTS

There were no significant differences between the ATN and PFNA groups for the presence of general complications, length of hospitalization, and functional capacity. The mean operation time, blood loss amount, and fluoroscopy screening time were more in the ATN group than in the PFNA group. Reoperation was needed for nine and two patients in the ATN and PFNA groups, respectively, because of implant-related complications.

CONCLUSION

Both ATNs and PFNA were suitable for the fixation of intertrochanteric fractures, but the risk of complication occurrence and need for reoperation were found to be higher in patients who were treated with ATNs.

Wiring technique for lesser trochanter fixation in proximal IM nailing of unstable intertrochanteric fractures: A modified candy-package wiring technique

INTRODUCTION

The purpose of this study was to introduce a new surgical technique, that involves modified Candy-package wiring followed by IM nailing fixation and to determine the clinical and radiological results obtained in patients with unstable intertrochanteric fractures with a lesser trochanter fragment.

MATERIALS AND METHODS

This study included 22 patients who were undergone proximal IM nailing with lesser trochanter wiring between January 2014 to June 2015. All patients were treated with minimally invasive technique of candy-package wiring for lesser trochanter fragments. The mean age was 75.8 years (range, 53-88) and average follow-up period was 15.1 months (range, 12-24). Each patient was followed up for a minimum of 12 months and their clinical and radiological results were analyzed.

RESULTS

The mean period required for fracture union was 16.6 weeks. (range, 8-25) and union was successfully completed in all cases. The WOMAC scores at the last F/U visit (average; 45.4, range; 21-75) were not significantly different to pre-trauma status (average; 36.5, range; 19-59) (p=0.087). In comparison of ambulatory capacity prior to trauma, ambulatory aggravation was noted in four cases (18.2%), and eighteen cases (81.8%) was sustained walking ability of prior of trauma. Wiring breakage was found in two cases and heterotrophic ossification in one case. There were no functional deficeit related to the radiologic finding in these patients. With regard to postoperative complications, were no cut-outs, breakage, or pullout of screws.

CONCLUSION

When surgically repairing unstable intertrochanteric fractures with lesser trochanter comminution using proximal IM nailing method, the modified Candy-packaging wiring technique increases the fixation force at the fracture site. Thus, through this technique, both firm fixation of the lesser trochanter and more stable bony union were obtained.

[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.

Comparison of Femoral Head Rotation and Varus Collapse Between a Single Lag Screw and Integrated Dual Screw Intertrochanteric Hip Fracture Fixation Device Using a Cadaveric Hemi-Pelvis Biomechanical Model

OBJECTIVE

This study compared the stabilizing effect of 2 intertrochanteric (IT) fracture fixation devices in a cadaveric hemi-pelvis biomechanical model.

METHODS

Eleven pairs of cadaveric osteopenic female hemi-pelves with intact hip joint and capsular ligaments were used. An unstable IT fracture (OTA 31-A2) was created in each specimen and stabilized with a single lag screw device (Gamma 3) or an integrated dual screw (IDS) device (InterTAN). The hemi-pelves were inverted, coupled to a biaxial apparatus and subjected to 13.5 k cycles of loading (3 months) using controlled, oscillating pelvic rotation (0-90 degrees) plus cyclic axial femoral loading at a 2:1 body weight (BW) ratio. Femoral head rotation and varus collapse were monitored optoelectonically. For specimens surviving 3 months of loading, additional loading was performed in 0.25 × BW/250 cycle increments to a maximum of 4 × BW or failure.

RESULTS

Femoral head rotation with IDS fixation was significantly less than the single lag screw construct after 3 months of simulated loading (P = 0.016). Maximum femoral head rotation at the end of 4 × BW loading was 7× less for the IDS construct (P = 0.006). Varus collapse was significantly less with the IDS construct over the entire loading cycle (P = 0.021).

CONCLUSIONS

In this worst-case model of an osteopenic, unstable, IT fracture, the IDS construct, likely owing to its larger surface area, noncylindrical profile, and fracture compression, provided significantly greater stability and resistance to femoral head rotation and varus collapse.

A retrospective analysis of the InterTan nail and proximal femoral nail anti-rotation-Asia in the treatment of unstable intertrochanteric femur fractures in the elderly

BACKGROUND

The purpose of this study was to compare the clinical outcomes of elderly patients undergoing surgery for treatment of unstable trochanteric fractures receiving either proximal femoral nails anti-rotation-Asia (PFNA-IIs) or InterTan nails (ITs).

METHODS

Between January 1, 2012, and June 31, 2015, 168 elderly patients with unstable intertrochanteric femur fractures enrolled in this study. The only intervention was ITs or PFNA-IIs of the unstable trochanteric femur fractures. Follow-up was at 1, 3, 6, and 12 months postoperatively and yearly thereafter. Intraoperative variables and postoperative complications were compared between the two groups.

RESULTS

Eight patients died, six were too infirmed for follow-up, and seven were lost during follow-up, leaving 147 patients meeting the criteria were evaluated at a mean follow-up of 20 months (range 16-26 months). Significant differences were observed between the two groups regarding local complications (IT, n = 10 vs. PFNA-II, n = 20), varus collapse of the head/neck or femoral shaft fractures at the tip of the nail (IT, n = 1 vs. PFNA-II, n = 8), femoral neck shortening (IT, 4.4 ± 1.1 mm vs. PFNA-II, 7.4 ± 2.4 mm), fracture healing time (IT, 14.7 ± 2.1 weeks vs. PFNA-II, 15.7 ± 2.4 weeks), femoral shaft fractures (IT, n = 0 vs. PFNA-II, n = 4), rotational loss of reduction (IT, n = 0 vs. PFNA-II, n = 9), lateral cortex fractures of the proximal femur or lateral greater trochanter fractures (IT, n = 8 vs. PFNA-II, n = 1), operative time (IT, 71.9 ± 6.8 min vs. PFNA-II, 52.3 ± 4.0 min), intraoperative blood loss (IT, 190.6 ± 6.0 mL vs. PFNA-II, 180.9 ± 10.8 mL), fluoroscopy time (IT, 5.0 ± 0.48 min vs. PFNA-II, 2.8 ± 0.33 min), hospital stay (IT, 9.65 ± 0.95 days vs. PFNA-II, 8.58 ± 0.93 days), cut-out (IT, n = 0 vs. PFNA-II, n = 6), and tip-apex distance (IT, 26.7 ± 0.91 mm vs. PFNA-II, 23.2 ± 1.22 mm). No significant differences existed for the other observation indexes (p > 0.05).

CONCLUSIONS

The IT nail may have more advantage for patients with unstable intertrochanteric fractures of the femur. However, for those complicated with lateral greater trochanter fractures, lateral cortex fractures of the proximal femurs, or unfit for surgery, the PFNA-II nail could be a good option. In addition, a large-sample, multicenter observational study is required for evaluation of its long-term efficacy, and optimal management strategies for specific unstable fracture patterns, different sorts of bone quality, and different levels of patient demand.

Variations of treatment in selected proximal femur fractures among surgeons with different surgical experience--A survey at an international AO course

INTRODUCTION

Different modalities of treatment for hip fractures have been discussed in the literature; however, practice may vary between centres. A survey was conducted on participants at an international AO course to assess the current management of pertrochanteric fractures (AO/OTA 31-A2) and displaced, non-impacted, subcapital fractures (AO/OTA 31-B3) in a 35-year-old patient and an 85-year-old patient.

METHODS

Surgeons taking part in an international orthopaedic course were invited to participate in a survey and were divided into two groups: inexperienced (one-to-three years since qualification) and experienced (four or more years). A survey was conducted to assess the management modalities used for pertrochanteric fractures (AO/OTA 31-A2) and displaced, non-impacted, subcapital fractures (AO/OTA 31-B3) in a 35-year-old patient and an 85-year-old patient.

RESULTS

Fifty-two surgeons participated: 18 were inexperienced and 34 were experienced. The method of operative fixation for the pertrochanteric fracture was gamma-nailing for 95% of the surgeons in the inexperienced group; in the experienced group, 56% opted for gamma-nailing and 38% for dynamic hip screw (DHS). For the displaced subcapital fracture in a 35-year-old, screw fixation was the dominant treatment option for both groups. For the displaced subcapital fracture in an 85-year-old, most of the surgeons in both groups preferred hemiarthroplasty: 59% in the inexperienced group chose cemented bipolar hemiarthroplasty and 12% uncemented, whereas 56% of the experienced group suggested cemented bipolar hemiarthroplasty and 25% uncemented.

DISCUSSION

This survey shows that a variety of methods are used to treat femoral neck fractures. A prospective randomised trial has shown the DHS to be the implant of choice for pertrochanteric fractures; however, this was not considered an option in the inexperienced group of surgeons and was the treatment of choice in only 13 out of 34 experienced surgeons. There is a general consensus for femoral head-conserving surgery in young patients with displaced subcapital fractures. Replacement arthroplasty was considered in the 85-year-old with a subcapital fracture. In the inexperienced group, 10 of 17 surgeons would cement the prosthesis, as would 27 of 36 in the experienced 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.

A Biomechanical Comparison of Two Intramedullary Implants for Subtrochanteric Fracture in Two Healing Stages: A Finite Element Analysis

Background. The biomechanical effect of two implants, namely, proximal femoral nail antirotation for Asia (PFNA-II) and Expert Asian Femoral Nail (A2FN), for treating subtrochanteric fracture during healing stages, is still unclear. Methods. A 3D finite element model of an intact femur was constructed and validated. The fractured and postoperative models were accordingly produced. The postoperative models were loaded with the peak joint forces during gait for the soft and hard callus stages. The effects of stress distribution on the implants, femoral head and callus, and the deformation of the proximal femur were examined. Results. Both implants showed similar biomechanical effect in two healing stages. As the healing duration increased, the von Mises stress of two implants and the tensile stress of the femoral head decreased, whereas the compressive stress of the femoral head increased. However, the PFNA-II operation resulted in higher stress on the implant, lower stress on the proximal femur, and lower compressive stress and higher tensile stress on the callus than A2FN operation. Conclusions. The A2FN implant may provide a biomechanically superior construct for subtrochanteric fracture healing. However, the upper screw of the A2FN implant may be more likely to be loose in the healing process.

Prospective randomised controlled trial of an intramedullary nail versus a sliding hip screw for intertrochanteric fractures of the femur

PURPOSE

The purpose of this prospective randomised trial was to assess whether an intramedullary nail is superior to a sliding hip screw in the treatment of multifragmentary intertrochanteric fractures

METHODS

Eighty patients with a 31-A2.2 or A2.3 Arbeitsgemeinschaft für Osteosynthesefragen/Orthopaedic Trauma Association (AO/OTA) intertrochanteric fracture were randomly allocated to fixation with either the Gamma nail or the AMBI sliding hip screw device.

RESULTS

All patients were followed up at one, three, six and 12 months postoperatively, except for nine who died. There was no statistical difference in Parker mobility score between groups. The Gamma nail group had significantly higher Barthel Index and EuroQol-5D (EQ-5D) scores than the AMBI group at 12 months. At the same time, the EQ-5D score had returned to its pre-operative values in the Gamma nail group but not in the AMBI group. There were no differences in mortality, radiation time and hospital stay. Duration of the operation, incision length and hip pain occurrence were significantly less in the Gamma nail group.

CONCLUSIONS

Few failures occur when unstable 31-A2.2 and A2.3 AO/OTA fractures are fixed with a sliding hip screw. Nevertheless, an intramedullary nail seems superior in reconstituting patients to their pre-operative state.