Biomechanical analysis of four types of internal fixation in subtrochanteric fracture models

Comparative biomechanical analysis of reconstruction and cephalomedullary nails in the treatment of osteoporotic subtrochanteric fractures

INTRODUCTION

This study aimed to compare the biomechanical properties of two types of intramedullary nails - reconstruction nails (RCN) and cephalomedullary nails (CMN) - each with different proximal fixations, in a model of an osteoporotic subtrochanteric femoral fracture. This study focused on assessing stiffness and load to failure of RCN and CMN nails to provide insight into their clinical applications in osteoporotic fracture treatments.

MATERIALS AND METHODS

Ten synthetic osteoporotic femoral models were used to generate a comminuted subtrochanteric fracture model. Five femurs were fixed using an RCN, and the remaining five were fixed using a CMN. The constructs were subjected to axial compression to measure their structural stiffness, load to failure, and failure modes.

RESULTS

The CMN group demonstrated a slightly higher load to failure (mean, 2250 N) than the RCN group (mean, 2100 N), which was statistically significant (p = 0.008). However, the stiffness in both groups was statistically similar (RCN, 250 N/mm; CMN, 255 N/mm; p = 0.69). Both groups showed a load to failure exceeding 1500 N, a typically exerted load on the femoral head by a 75 kg individual. The failure patterns differed, with CMN failures starting at the nail insertion area and RCN failures starting at the reconstruction screw area.

CONCLUSION

The RCN offers stiffness comparable to that of the CMN; although its load to failure is slightly lower than that of the CMN, it still exceeds the physiological tolerance limit. These findings suggest that the RCN is a viable alternative for treating osteoporotic subtrochanteric fractures.

Intramedullary nail fixation assisted by locking plate for complex subtrochanteric femur fractures: A retrospective study

BACKGROUND

This study aims to compare therapeutic effects of two methods in complicated subtrochanteric femur fractures surgery: intramedullary nail fixation assisted with lateral monocortical locking plate versus intramedullary nail fixation assisted with supplementary cables.

METHODS

From June 2015 to June 2020, seventy-seven patients with complex subtrochanteric fractures (i.e., Seinsheimer's classification type IV or V) were included in this study. Thirty-six patients (plate group) were operated using the intramedullary nail fixation assisted by lateral monocortical locking plate, and forty-one patients (cable group) were using the intramedullary nail fixation assisted by cables. The clinical information and demographic results were collected and compared.

RESULTS

Operation time of plate group was shorter than cable group and the Incisions length of plate group was longer. The fluoroscopy times were 22.8 ± 8.2 in plate group and 33.0 ± 9.0 in cable group (p < 0.01). Compared with the cable group, patients in plate group used less cerclage cables (p < 0.01). Patients in the plate group has less medial cortex displacement compared with the cable group. (p = 0.038). As for the angular difference of neck shaft angle between operated hip and uninjured hip, plate group has less difference compared with the cable group. Time to union was 14.2 ± 3.1 weeks in plate group which is shorter than the cable group (17.9 ± 4.8 weeks). In terms of follow up period, number of malunion, Harris hip score, walking ability and traumatic hip rating scale, no significant differences were detected.

CONCLUSIONS

Our results suggest that using lateral monocortical plate as an auxiliary way may have a longer surgical incision and more intraoperative blood loss, however, the operation time is shorter, the fluoroscopy times is less, and the time to union is shorter. Intramedullary nail fixation assisted by lateral monocortical locking plate may be a new option for patients with complex subtrochanteric femur fractures.

Subtrochanteric fracture in previously treated breast cancer patient handled by proximal femoral nail: A case report

INTRODUCTION

Breast cancer (BC) is the most common and high mortality rate cancer in females. The main complication of BC is metastases, where bone metastases (BM) are present in 90 % of women with distant metastases and commonly recurrence after BC therapy. However, treatment options are numerous, and improving patients' quality of life (QoL) is a priority.

PRESENTATION OF CASE

A 58-year-old female patient presented to the emergency department with pain and movement restriction in the right lower extremity after minor trauma. Clinical history included a surgically resected BC eight years ago, besides chemotherapy and radiotherapy. After clinical and radiographic examination, we encountered a subtrochanteric femoral fracture although the patient is in the end stage, the multidisciplinary team discussed the surgery option with the patient and eventually internally fixed the fracture.

DISCUSSION

Subtrochanteric femur fractures represent a challenging orthopedic issue, ranging from 10 % to 34 % of all hip fractures. Hence, after a detailed discussion, the proximal femoral nail (PFN) was the procedure of choice acording to the patient's preferences and tumor prognosis. Proximal femoral metastasis treatment aims to improve the quality of life (QoL), alleviate bone pain, and rehabilitate skeletal function.

CONCLUSION

In this case report, we highlight the surgical decision consequences for a patient with end-stage cancer, as it may put their life at risk or improve their QoL, likewise the patient in this report.

The Influence of Static Load and Sideways Impact Fall on Extramedullary Bone Plates Used to Treat Intertrochanteric Femoral Fracture: A Preclinical Strength Assessment

Hip fracture accounts for a large number of hospitalizations, thereby causing substantial economic burden. Majority (> 90%) of all hip fractures are associated to sideways fall. Studies on sideways fall usually involve loading at quasi-static or at constant displacement rate, which neglects the physics of actual fall. Understanding femur resonance frequency and associated mode shapes excited by dynamic loads is also critical. Two commercial extramedullary implants, proximal femoral locking plate (PFLP) and variable angle dynamic hip screw (VA-DHS), were chosen to carry out the preclinical assessments on a simulated Evans-I type intertrochanteric fracture. In this study, we hypothesized that the behavior of the implant depends on the loading types-axial static and transverse impact-and a rigid implanted construct will absorb less impact energy for sideways fall. The in silico models were validated using experimental measurements of full-field strain data obtained from a 2D digital image correlation (DIC) study. Under peak axial load of 3 kN, PFLP construct predicted greater axial stiffness (1.07 kN/mm) as opposed to VA-DHS (0.85 kN/mm), although the former predicted slightly higher proximal stress shielding. Further, with greater mode 2 frequency, PFLP predicted improved performance in resisting bending due to sideways fall as compared to the other implant. Overall, the PFLP implanted femur predicted the least propensity to adverse stress intensities, suggesting better structural rigidity and higher capacity in protecting the fractured femur against fall.

[Lateral decubitus position assisted plate internal fixation through a lateral incision to assist reduction combined with intramedullary nail in treatment of complicated subtrochanteric femoral fracture]

Objective

To investigate the effectiveness of lateral decubitus position assisted plate internal fixation through a lateral incision to assist reduction combined with intramedullary nail in the treatment of complicated subtrochanteric femoral fracture.

Methods

The clinical data of 16 patients with complicated subtrochanteric femoral fractures (Seinsheimer type Ⅲ-Ⅴ) treated with lateral decubitus position assisted plate internal fixation through a lateral incision to assist reduction combined with intramedullary nail between September 2017 and August 2020 were retrospectively analyzed. There were 13 males and 3 females with an average age of 47 years (range, 26-85 years). There were 12 cases of high-energy injury and 4 cases of low-energy injury. According to Seinsheimer classification, there were 3 cases of type ⅢA, 2 cases of type ⅢB, 7 cases of type Ⅳ, and 4 cases of type Ⅴ. The time from injury to operation ranged from 2 to 6 days, with an average of 4.7 days. The operation time, intraoperative blood loss, postoperative drainage volume, hospitalization stay, surgical complications, fracture healing time, and collodiaphyseal angle of the affected and healthy sides before and after operation were recorded. Hip fracture Harris score was used to evaluate hip function.

Results

The operation time was 90-180 minutes (mean, 135.9 minutes), the intraoperative blood loss was 200-400 mL (mean, 288.8 mL), the postoperative drainage volume was 120-220 mL (mean, 140.0 mL), and the hospitalization stay was 12-22 days (mean, 15.8 days). All the 16 patients were followed up 9-12 months (mean, 9.9 months). There was 1 case of incision superficial infection after operation, which healed after anti-infection treatment; no complication such as deep venous thrombosis of lower limbs, coxa vara deformity, re-fracture, or broken nails occurred. All the fractures healed successfully, the healing time ranged from 12 to 20 weeks, with an average of 17.5 weeks. At 6 months after operation, the Harris score was 87-96, with an average of 91.5; the results were excellent in 11 cases and good in 5 cases, with the excellent and good rate of 100%. The collodiaphyseal angle of the affected side was (124.0±5.7)°, while that of the healthy side was (132.0±2.1)°, showing significant difference between the two sides ( t=-7.376, P=0.001). At last follow-up, the collodiaphyseal angle of the affected side was (129.0±3.2)°, which significantly improved when compared with that before operation ( t=-6.175, P=0.002), and there was no significant difference between the affected side and the healthy side ( t=-2.648, P=0.181).

Conclusion

Lateral decubitus position assisted plate internal fixation through a lateral incision to assist reduction combined with intramedullary nail is a reliable internal fixation method for the treatment of complicated subtrochanteric femoral fractures. The use of plate reduction is conducive to maintaining the force line of the femoral trochanter. The enlargement of the incision is conducive to the accurate implantation of intramedullary nails without affecting fracture healing.

Biomechanical Study of Intramedullary Versus Extramedullary Implants for Four Types of Subtrochanteric Femoral Fracture

Objectives

To compare the biomechanical performance of proximal femoral nail anti‐rotation (PFNA), the “upside‐down” less invasive plating system (LISS), and proximal femoral locking plate (PFLP) in fixing different fracture models of subtrochanteric fractures.

Methods

Thirty composite femurs were divided into three equal groups (PFNA, PFLP, and reverse LISS). The implant‐femur constructs were tested under axial compression load (0–1400 N) from models I to IV, which represented the Seinsheimer type I subtrochanteric fracture, type IIIa subtrochanteric fracture with the posteromedial fragment reduced; type IIIa subtrochanteric fracture with the posteromedial fragment lost; and type IV subtrochanteric fracture, respectively. Axial stiffness was analyzed for each group. Each group was then divided into two subgroups, one of which underwent torsional and axial compression failure testing, while the other subgroup underwent axial compression fatigue testing. The torsional stiffness, failure load, and cycles to failure were analyzed.

Results

PFNA had the highest axial stiffness (F = 761.265, p < 0.0001) and failure load (F = 48.801, p < 0.0001) in model IV. The axial stiffness and failure load of the PFLP were significantly higher than those of the LISS (p < 0.0001, p = 0.001). However, no significant difference in axial stiffness was found between models I to III (model I: F = 2.439, p = 0.106; model II: F = 2.745, p = 0.082; model III: F = 0.852, p = 0.438) or torsional stiffness in model IV (F = 1.784, p = 0.187). In fatigue testing, PFNA did not suffer from construct failure after 90,000 cycles of axial compression. PFLP and LISS were damaged within 14,000 cycles, although LISS withstood more cycles than PFLP (t = 3.328, p = 0.01).

Conclusion

The axial stiffness of the three implants was similar in models I to III. The biomechanical properties of PFNA were the best of the three implants in terms of axial stiffness, failure load, and fatigue testing cycles in model IV. The axial stiffness and failure load of the PFLP were better than those of the reverse LISS, but PFLP had fewer cycles in the fatigue tests than the reverse LISS.

Bilateral atypical femoral fractures treated with compression hip screw and intramedullary nail fixation

Atypical femoral fractures (AFF) are more difficult to treat than typical femoral fractures; they require strong fixation and good reduction. Intramedullary (IM) nailing is the first option for the treatment of complete AFF; however, there are few reports comparing IM nailing and extramedullary fixation. Moreover, there are no reports on the outcomes of bilateral atypical subtrochanteric femoral fractures treated with an IM nail on one side and a compression hip screw (CHS) on the other. We report the case of a 69-year-old woman who had been on risedronate sodium once a month since she was 58 years old. She reportedly felt pain in both her thighs due to an undiagnosed cause. Six months later, she fell and was diagnosed with bilateral complete atypical femoral subtrochanteric fractures (right side: Seinsheimer type IIC; left side: Seinsheimer type IIA). Four days later, she underwent CHS on the right side and IM nailing after open reduction surgery on the left. The reduction was successful. The left side healed 6 months after surgery, but the right side healed only after 14 months, despite assistance with low-intensity pulsed ultrasound. In atypical femoral subtrochanteric fractures, good reduction is important for healing, but, in this case, the CHS side healed slowly despite achievement of good reduction because of the difference in the fixation force between IM nailing and CHS, in addition to a probable occurrence of severely suppressed bone turnover (SSBT). Furthermore, reaming was not done on the CHS side, which may have contributed to the delay in bony union. IM nailing is the first option for atypical femoral subtrochanteric fractures because of faster union and lower reoperation rate than extramedullary fixation. Based on our findings, we recommend IM nailing as the first option for atypical femoral subtrochanteric fractures when good reduction can be achieved.

Biomechanical study on the stability and strain conduction of intertrochanteric fracture fixed with proximal femoral nail antirotation versus triangular supporting intramedullary nail

OBJECTIVES

Based on the features of the three-dimensional spatial structure of the proximal femoral trabeculae, we developed a bionic triangular supporting intramedullary nail (TSIN) for the treatment of the femoral intertrochanteric fracture. The current study aimed to compare the mechanical stability and restoration of mechanical conduction between proximal femoral nail antirotation (PFNA) and TSIN to fix the intertrochanteric fractures.

METHODS

Firstly, five sets of PFNA and TSIN with the same size were selected and fixed on a biomechanical testing machine, and strain gauges were pasted on the main nail, lag screw, and supporting screw to load to the vertical load to 600 N, and the displacement and strain values were recorded. Secondly, formalin-preserved femurs were selected, and the left and right femurs of the same cadaver were randomly divided into two groups to prepare intertrochanteric femur fractures (AO classification 31-A1), which were fixed with PFNA (n = 15) and TSIN (n = 15), respectively. Sixteen sites around the fracture line were chosen to paste strain gauges and loaded vertically to 600 N, and then, the fracture fragment displacement and strain values were recorded. Finally, a 10,000-cycle test ranging from 10 to 600 N was conducted, and the cycle number and displacement value were recorded.

RESULTS

The overall displacement of PFNA was 2.17 ± 0.18 mm, which was significantly greater than the displacement of the TSIN group (1.66 ± 0.05 mm, P < 0.05) under a vertical load of 600 N. The strain below the PFNA lag screw was 868.29 ± 147.85, which was significantly greater than that of the TSIN (456.02 ± 35.06, P < 0.05); the strain value at the medial side of the PFNA nail was 444.00 ± 34.23, which was significantly less than that of the TSIN (613.57 ± 108.00, P < 0.05). Under the vertical load of 600 N, the displacement of the fracture fragments of the PFNA group was 0.95 ± 0.25 mm, which was significantly greater than that of the TSIN group (0.41 ± 0.09 mm, P < 0.05). The femoral specimens in the PFNA group showed significantly greater strains at the anterior (1, 2, and 4), lateral (7, 9, and 10), posterior (11), and medial (15 and 16) sites than those in the TSIN group (all P < 0.05). In the cyclic compression experiment, the displacements of the PFNA group at 2000, 4000, 6000, 8000, and 10,000 cycles were 1.38 mm, 1.81 mm, 2.07 mm, 2.64 mm, and 3.58 mm, respectively, which were greater than the corresponding displacements of the TSIN group: 1.01 mm, 1.48 mm, 1.82 mm, 2.05 mm, and 2.66 mm (P₈₀₀₀ = 0.012, P₁₀₀₀₀ = 0.006).

CONCLUSIONS

The current study showed that TSIN had apparent advantages in stability and stress conduction. TSIN enhanced the stability of intertrochanteric fractures, particularly in superior fracture fragments, improved stress conduction, reduced the stress in the anterior and medial femur, and restored the biomechanical properties of the femur.

Dynamic hip screw fixation of subtrochanteric femoral fractures

Introduction

A subtrochanteric proximal femur fracture occurs in the 5 cm of bone immediately distal to the lesser trochanter. UK national guidelines advise that adults with subtrochanteric fractures should be treated with an intramedullary nail (IMN). This study aims to compare peri-operative outcome measures of patients with subtrochanteric fractures treated with either an IMN or a dynamic hip screw (DHS) construct.

Materials and Methods

We retrospectively reviewed subtrochanteric fractures presenting at our institution over 4.5 years (October 2014–May 2019), classifying them into two treatment groups; IMN and DHS. These groups were compared on outcome measures including surgical time, blood loss, radiation dose area product (DAP), length of stay, re-operation rate and mortality.

Results

During the time period studied, 86 patients presented with a subtrochanteric fracture of the femur; with 74 patients (86%) receiving an IMN and 12 (14%) receiving a DHS. The comparative outcome measures reaching statistical significance were blood loss and radiation DAP. The DHS group showed a significantly lower mean blood loss of 776 ml compared to 1029 ml in the IMN group. Also, the DHS group showed a significantly lower mean DAP of 150.30 mGy cm² compared to 288.86 mGy cm² in the IMN group.

Conclusion

Although UK national guidelines recommend treating all subtrochanteric fractures with an IMN; the outcome measures assessed in our study did not show use of an IMN to be superior to a DHS. The DHS group showed a lower estimated blood loss and a reduced DAP. This, along with the reduced financial cost associated with a DHS, may support the use of DHS over IMN for certain subtrochanteric fractures of the femur. There may not be a single favourable implant for the treatment of subtrochanteric fractures as a whole; instead different subtypes of fracture may be amenable to a number of fixation devices. Choice of implant should be determined locally and based on existing and future clinical and health economic research.

Subtrochanteric femur fractures: current review of management

Subtrochanteric (ST) femur fractures are proximal femur fractures, which are often difficult to manage effectively because of their deforming anatomical forces.

Operative management of ST fractures is the mainstay of treatment, with the two primary surgical implant options being intramedullary (IM) nails and extramedullary plates.

Of these, IM nails have a biologic and biomechanical superiority, and have become the gold standard for ST femur fractures.

The orthopaedic surgeon should become familiar and facile with several reduction techniques to create anatomical alignment in all unique ST fracture patterns.

This article presents a comprehensive and current review of the epidemiology, anatomy, biomechanics, clinical presentation, diagnosis, and management of subtrochanteric femur fractures.

Cite this article: EFORT Open Rev 2021;6:145-151. DOI: 10.1302/2058-5241.6.200048

Biomechanical design prognosis of two extramedullary fixation devices for subtrochanteric femur fracture: a finite element study

The design rationale of extramedullary fixation for femur fracture has remained a matter of debate in the orthopaedic community. The present work provides a comparative preclinical assessment between two standard fracture fixation techniques: dynamic hip screw (DHS) and proximal femoral locking plate (PFLP), by employing finite element (FE)-based in silico models. The study attempts to evaluate and compare the two implants on following biomechanical behaviours: (1) stress variation on the femur and implant, (2) axial displacement of the fixated femur constructs, (3) postoperative stress shielding and longer term external remodelling of the host bone. We hypothesised that, of the two implants, PFLP has better biomechanical characteristics when used for subtrochanteric femoral fracture (SFF) fixation considering long-term adaptation. A comminuted fracture, simulated as two-part fracture gap of 20 mm, was created in the subtrochanteric region of a femur CAD model. Non-uniform physiological load cases were considered. External bone adaptation was modelled mathematically using stress analysis coupled with a growth model, in which strain energy density (SED) acted as feedback control variable. The computational results predicted lower stress shielding (by ~ 6%) and relatively less cortical thinning beneath the plate for PFLP as compared to DHS. DHS-fixated femur, on the other hand, predicted superior postoperative rigidity. Graphical Abstract FE-based comparative assessment between two extramedullary femur fixation devices-dynamic hip screw (DHS) and proximal femoral locking plate (PFLP).

Comparative finite element analysis of three implants fixing stable and unstable subtrochanteric femoral fractures: Proximal Femoral Nail Antirotation (PFNA), Proximal Femoral Locking Plate (PFLP), and Reverse Less Invasive Stabilization System (LISS)

BACKGROUND

The optimal type of fixation implant for managing subtrochanteric fractures (STFs) is debated, as uncertainty continues to surround the comparative biomechanical performance of the proximal femoral nail antirotation (PFNA), proximal femoral locking plate (PFLP), and reverse less invasive stabilisation system (LISS). No studies have used finite element analysis (FEA) to compare these three devices. The objective of this study was to use FEA to compare the PFNA, PFLP, and LISS used to treat STFs based on the following criteria: (1) stress distribution on the femur and implant, (2) peak stress and stress on the medial side of the femur near the fracture site, and (3) smallest axial displacement of the femoral head.

HYPOTHESIS

Of the three implants, the PFNA has the best biomechanical performance when used for STF fixation.

METHODS

FEA was used to assess synthetic bone responses to the three implants used to fix three STF types, namely, Seinsheimer I, III, and IV, characterised by increasing bone loss and/or comminution with subsequent instability. Loading was with 1400N axial compression force.

RESULTS

The LISS and PFLP exhibited similar biomechanical properties in all three fracture types. However, with the Seinsheimer IV fracture, the triangular configuration of the PFLP resulted in stress concentration at the medial and lateral sides of the implant junction. With the Seinsheimer I and III fractures, the PFNA resulted in higher peak stress (183.85MPa and 364.58MPa, respectively) compared to the PFLP (102.90MPa and 177.52MPa) and LISS (116.55MPa and 227.97MPa). With the Seinsheimer IV fracture, peak stress was highest with LISS (2310.40MPa) and was higher with PFLP (2054.90MPa) than with PFNA (1313.30MPa). With the Seinsheimer I and III fractures, the axial femoral head displacement was greater with the PFNA (0.74mm and 1.13mm, respectively) than with the PFLP (0.48mm and 1.02mm) and LISS (0.52mm and 0.92mm). With the Seinsheimer IV fracture, in contrast, the PFNA produced less axial femoral head displacement (4.1mm) compared to the PFLP (12.03mm) and LISS (16.56mm).

DISCUSSION

With unstable (Seinsheimer IV) STFs, fixation stability was better with the PFNA compared to the PFLP and LISS. In contrast, with stable STFs (Seinsheimer I and III), the PFLP and LISS offered greater stability, with similar biomechanical effects. However, with Seinsheimer III fractures, the stress on the implant-femur interface was greater with the LISS.

LEVEL OF EVIDENCE

IV, basic science study.

The effect of implant choice on varus angulation and clinical results in the management of subtrochanteric fractures

Introduction

The aim of this study was to evaluate the effects of implant choice on varus angulation in the management of subtrochanteric fractures.

Methods

Between 2011 and 2016, 58 patients were included in the study and femur locking plate (PF-LCP; Group 1 = 27) and proximal femoral nails (PFN; Group 2 = 31) were compared retrospectively.

Results

In group 1, femoral NSA was measured 131,37 ± 1,95 and last follow-up angle was 127,33 ± 2,40. (p = 0,025). The mean Harris hip score was 67.59 ± 17.74 and 63.29 ± 13.83 in Group 1 and Group 2, respectively (p = 0.406).

Conclusions

Plate fixation is not as successful as proximal nails at preventing varus angulation.

The use of a proximal femoral nail as a hip prosthesis: A biomechanical analysis of a newly designed implant

Complication rates of hip fractures after proximal femoral nail are not rare. In such fractures, treatment invariably comprises the extraction of proximal femoral nail and the introduction of a different hip prosthesis. To solve this problem, we aimed to develop a new implant, the modular nail prosthesis, which combines an intramedullary nail with a hip prosthesis. The aim of this study was to determine the effect of stress load distribution on the stem using finite element analysis under laboratory conditions. For this, the shortest stem of 175 mm was chosen. In addition, six proximal femoral nail–hip prosthesis combinations were produced and tested with a biomechanical test device and passed 2300-N load bearing. According to the test results, our newly developed modular nail prosthesis can be converted to hip prosthesis securely.

Poor relation between biomechanical and clinical studies for the proximal femoral locking compression plate

Background and purpose - The proximal femur locking compression plate (PF-LCP) is a new concept in the treatment of hip fractures. When releasing new implants onto the market, biomechanical studies are conducted to evaluate performance of the implant. We investigated the relation between biomechanical and clinical studies on PF-LCP. Methods - A systematic literature search of relevant biomechanical and clinical studies was conducted in PubMed on December 1, 2015. 7 biomechanical studies and 15 clinical studies were included. Results - Even though the biomechanical studies showed equivalent or higher failure loads for femoral neck fracture, the clinical results were far worse, with a 37% complication rate. There were no biomechanical studies on pertrochanteric fractures. Biomechanical studies on subtrochanteric fractures showed that PF-LCP had a lower failure load than with proximal femoral nail, but higher than with angled blade plate. 4 clinical studies had complication rates less than 8% and 9 studies had complication rates between 15% and 53%. Interpretation - There was no clear relation between biomechanical and clinical studies. Biomechanical studies are generally inherently different from clinical studies, as they examine the best possible theoretical use of the implant without considering the long-term outcome in a clinical setting. Properly designed clinical studies are mandatory when introducing new implants, and they cannot be replaced by biomechanical studies.

Subtrochanteric femur fracture treated by intramedullary fixation

PURPOSE

To discuss surgical technique, operative efficacy and clinical outcome of intramedullary fixation in the treatment of subtrochanteric femur fractures.

METHODS

From February 2011 to February 2013, 76 cases of subtrochanteric femur fractures were treated by intramedullary fixation in our hospital, including 53 males and 23 females, with the age range of 37 -72 years (mean 53.5 years). According to Seinsheimer classification, there were 2 cases of type I, 7 type II, 15 type III, 23 type IV and 29 type V. Firstly, all patients underwent closed reduction with the guidance of C-arm fluoroscopy in a traction table. Two cases of type I and 3 cases of type III fractures had ideal closed reduction followed by internal fixation. The others needed additional limited open reduction. Radiographic examination was used to evaluate callus formation and fracture healing in postoperative 1, 3, 6 and 12 months follow-up. Functional recovery was evaluated by Harris Hip Scoring (HHS) system.

RESULTS

Patients were followed up for 6-12 months. All fractures were healed except one patient with delayed union. The average bone union time was 4.5 months. According to HHS system, 65 cases were considered as excellent in functional recovery, 8 good, 2 fair and 1 poor. The proportion of the patients with excellent and good recovery was 96.05%.

CONCLUSION

Intramedullary fixation is feasible for the treatment of subtrochanteric femur fracture. The accuracy of intraoperative reduction and surgical skill are important for the clinical outcome and the patients' prognosis.

Reducing subtrochanteric femur fractures: tips and tricks, do's and don'ts

Treatment of subtrochanteric fracture remains a challenge, but evolution of strategy has allowed for reliable results with low complications. Although several fixation options exist, reamed, antegrade intramedullary nailing (IMN) has evolved as the standard of care. Cognizant effort to achieve anatomic reduction before IMN passage allows for desired outcomes. Several reduction techniques can be used to overcome the deforming forces present in the proximal femur to allow for proper IMN placement. The purpose of this article is to review the tips, tricks, and pitfalls to avoid in the treatment of subtrochanteric femur fractures with IMN.

Expert tibia nail for subtrochanteric femoral fracture to prevent thermal injury

INTRODUCTION

Subtrochanteric femoral fractures are relatively uncommon, accounting for 7-15% of all hip fractures and treatment of these fractures are considered challenge for orthopaedic surgeons. Although several treatment options are reported with up to 90% of satisfactory results, the choice of the appropriate implant is still a matter of debate. Some authors reported thermal injury after reaming for intramedullary nail fixation in patients with narrow medullary canal.

PRESENTATION OF CASE

A 21-year-old female patient was admitted to our hospital because of right subtrochanteric femoral fracture. The narrowest diameter of medullary canal of her femur was about 7mm but she refused open reduction and internal fixation with plate due to large scar formation. We used expert tibia nail instead of femoral intramedullary nail to prevent thermal injury.

DISCUSSION

Subtrochanteric femoral fractures are difficult to treat because of their biomechanical and anatomical characteristics. Although several implants are reported for the surgical treatment of these fractures, intramedullary nails have been advocated due to their biological and biomechanical advantages. However, under certain circumstances with associated injury or anatomic difference we might consider another treatment options.

CONCLUSION

Expert tibia nail may be considered one of the treatment options for subtrochanteric femoral fracture with narrow medullary canal. We also emphasize the importance of preoperative evaluation of the medullary canal size for these risky fractures.