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

Intramedullary Nail Failure in a Subtrochanteric Fracture in a 62-Year-Old Woman

Subtrochanteric fractures in older patients are typically due to low-energy falls. The standard of care is intramedullary nailing. The Smith & Nephew Trigen Intertan (Memphis, TN, US) is an intramedullary nail with a novel design that incorporates two integrated compression screws. We present a case of intramedullary nail failure in a patient with a subtrochanteric fracture. A 62-year-old woman with osteoporosis, a 40-year history of smoking, and consumption of two to three alcoholic beverages daily, weighing 177 pounds and five feet two inches tall (BMI 32.4), experienced a low-energy fall in her home. She presented to the emergency department (ED) with a shortened and externally rotated right leg with pain on manipulation. Her neurovasculature was intact. An X-ray revealed a comminuted, right subtrochanteric femur fracture. The patient underwent open reduction and internal fixation with a Trigen Intertan nail with no intraoperative complications. Her leg returned to pre-injury length, and she resumed ambulating at her pre-injury level. Six weeks later, the patient experienced pain upon standing. She was transported to the ED by ambulance where she presented with a shortened externally rotated right leg with pain on manipulation. An X-ray revealed failure of the intramedullary nail with breakage at the lag screw hole. Her care was transferred to another orthopedic surgeon (JC), where she underwent hardware removal and conversion to a total hip arthroplasty. Postoperatively, her legs were of equal length, and her neurovasculature remained intact. Four months later, at her final follow-up, she was ambulating unassisted at her pre-fracture level. Subtrochanteric fractures in elderly patients pose serious threats to morbidity, mortality, and quality of life. Surgery with intramedullary nail placement and rapid ambulation have generally favorable outcomes. Failure rates are generally very low. Such circumstances generally require hardware removal and total hip arthroplasty, which are generally curative but can confer small risks of morbidity and mortality.

Key factors for increased tip-apex distance when treating intertrochanteric fractures with InterTAN nails

Background

The tip-apex distance is a key factor in predicting implant cut-out after intramedullary fixation for intertrochanteric fractures. This study aimed to evaluate the factors associated with an increased tip-apex distance when treating intertrochanteric fractures using an InterTAN nail.

Methods and Material

We retrospectively analyzed patients with intertrochanteric fractures who underwent InterTAN nail insertion between January 2017 and March 2022 at our hospital. Medical and radiological data were collected. Measurements of preoperative factors and postoperative factors were performed accordingly. Multivariate logistic regression analysis was performed to determine the statistically significant variables of the tip-apex distance.

Results

This study included 102 patients with intertrochanteric fractures. The average tip-apex distance measured 22.4 ± 7.1 mm, ranging from 9.3 to 48.0 mm. The length of the femoral neck on the non-fractured side, lag screw placement in the sagittal plane (center-inferior, superior) and coronal plane (posterior), and the angle between the line of the proximal nail axis and the femoral long axis were identified to be statistically significant factors for the tip-apex distance.

Conclusion

To obtain a shorter tip-apex distance, we recommend a medial trochanteric entry point to minimize the angle between the line of the proximal nail axis and the femoral long axis. Additionally, sufficiently deep central insertion of the lag screw was advised in both the sagittal and coronal planes.

Biomechanical evaluation of a modified intramedullary nail for the treatment of unstable femoral trochanteric fractures

Background

The Proximal Femoral Nail Antirotation (PFNA) device is the most commonly used implant to fix unstable femoral trochanteric fractures (UFTFs), but it has a relatively high incidence of complications. Due to this factor, the modified intramedullary nail (MIN) was created to treat patients with UFTFs. The aim was to exhibit the MIN and make a comparison with PFNA and InterTAN using biomechanical methods.

Methods

An adult UFTF model was developed using Mimics software. The PFNA, InterTAN nail, and MIN models were drawn referring to the corresponding parameters and installed in the fracture models. Vertical, anteroposterior (AP) bending, and torsion loads of the femoral head were set in advance and loaded onto the fracture models. The value of maximal displacement and von Mises stress was evaluated via finite element analysis (FEA).

Results

The MIN model had smaller values for maximal displacement than that of the PFNA model, and the increase in displacement was less pronounced for the MIN compared to PFNA under increasing vertical loads. For the indicator of von Mises stress, the MIN model showed lower stress compared with the PFNA model in vertical loads ranging from 300 N to 2100 N. Except for the maximal stress at implants under AP bending loads, the MIN demonstrated the most superior biomechanical properties under AP bending and torsional loads.

Conclusion

The MIN offered obvious advantages in terms of mechanical stability and stress distribution among the three studied implants, providing a promising implant option for patients with UFTFs.

Biomechanical evaluation of a new intramedullary nail compared with proximal femoral nail antirotation and InterTAN for the management of femoral intertrochanteric fractures

Purpose: Surgical treatment is the main treatment method for femoral intertrochanteric fractures (FIFs), however, there are lots of implant-related complications after surgery. Our team designed a new intramedullary nail (NIN) to manage such fractures. The purpose of this study was to introduce this new implant and compare it with proximal femoral nail antirotation (PFNA) and InterTAN for treating FIFs. Methods: An AO/OTA 31-A1.3 FIF model was built and three fixation models were created via finite element method, comprising PFNA, InterTAN, and the NIN. Vertical, anteroposterior (A-P) bending, and torsional loads were simulated and applied to the three fixation models. Displacement and stress distribution were monitored. In order to compare PFNA and the NIN deeply, finite element testing was repeated for five times in vertical load case. Results: The finite element analysis (FEA) data indicated that the NIN possessed the most outstanding mechanical properties among the three fixation models. The NIN model had lower maximal stress at implants compared to PFNA and InterTAN models under three load conditions. The trend of maximal stress at bones was similar to that of maximal stress at implants. Besides, the NIN model showed smaller maximal displacement compared with PFNA and InterTAN models under vertical, A-P bending, and torsional load cases. The trend for maximal displacement of fracture surface (MDFS) was almost identical with that of maximal displacement. In addition, there was significant difference between the PFNA and NIN groups in vertical load case (p < 0.05). Conclusion: Compared with PFNA and InterTAN, the NIN displayed the best mechanical properties for managing FIFs, including the lowest von Mises stress at implants and bones, and the smallest maximal displacement and MDFS under vertical, A-P bending, and torsional load cases. Therefore, this study might provide a new choice for patients with FIFs.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Study protocol: biomechanical testing, finite element analysis and prospective, randomized, clinical study of single screw cephalomedullary nailing versus integrated dual interlocking screw fixation for unstable (31A21-3) intertrochanteric fractures in patients > 70 years old

BACKGROUND

Hip fractures are an increasingly common consequence of falls in older people that are associated with a high risk of death and reduced function. The vast majority of intertrochanteric fractures require surgical treatment to withstand early mobilization and weight bearing, which prevents complications due to prolonged bed rest and aids in fracture healing.

METHODS

This study is compromised by two parts, the experimental study and the clinical part. In the first part, a standard 130° nail will be used with the appropriate lag screw(s) and dynamic distal locking in synthetic osteoporotic femurs and the transmission of forces in the proximal femur, measured by a cortical surface-strain distribution, will be evaluated using digital image correlation. Finite element parametric models of the bone, the nails and their interface will be also developed. Finite element computations of surface strains in implanted femurs, after being validated against biomechanical testing measurements, will be used to assist the comparison of the nails by deriving important data on the developed stress and strain fields, which cannot be measured through biomechanical testing. In the other part, will set up a prospective, randomized, comparative clinical study among the Gamma3 and IT cephalomedullary nailing, in order to investigate if there are any statistical important differences in the main radiological measurements and functional status in closed unstable intertrochanteric fractures (A21-3) in patients aged over 70 years old at the 24-week follow-up evaluation using patient reported disease-specific outcomes.

DISCUSSION

This study will be the first to compare clinical, radiological and biomechanical measurements of the two different cephalomedullary nails. Our main hypothesis is that the IT nail would provide better radiological outcome and probably better clinical results than the Gama3 nail. Clinical trial registration International Standard Randomized Controlled Trial Number (ISRCTN): https://doi.org/10.1186/ISRCTN15588442 , registered on 19/4/2022.

Treatment of Trochanteric Hip Fractures with Cephalomedullary Nails: Single Head Screw vs. Dual Integrated Compression Screw Systems

Extracapsular hip fractures are very common in the elderly. They are mainly treated surgically with an intramedullary nail. Nowadays, both endomedullary hip nails with single cephalic screw systems and interlocking double screw systems are available on the market. The latter are supposed to increase rotational stability and therefore decrease the risk of collapse and cut-out. A retrospective cohort study was carried out, in which 387 patients with extracapsular hip fracture undergoing internal fixation with an intramedullary nail were included to study the occurrence of complications and reoperations. Of the 387 patients, 69% received a single head screw nail and 31% received a dual integrated compression screw nail. The median follow-up was 1.1 years, and in that time, a total of 17 reoperations were performed (4.2%; 2.1% for single head screw nails vs. 8.7% for double head screws). According to the multivariate logistic regression model adjusted for age, sex and basicervical fracture, the adjusted hazard risk of reoperation required was 3.6 times greater when using double interlocking screw systems (p = 0.017). A propensity scores analysis confirmed this finding. In conclusion, despite the potential benefits of using two interlocking head screw systems and the increased risk of reoperation in our single center, we encourage to other researchers to explore this question in a wider multicenter study.

A comparison of functional and radiological outcome of combine compression antegrade intertrochanteric nail (InterTan) and proximal femoral nail anti-rotation II (PFNA-II) in elderly patients with intertrochanteric fractures

Objective

To compare the functional and radiological outcome of combine compression interlocking intramedullary nail (InterTan) and proximal femoral nail anti-rotation II (PFNA-II) in the treatment of elderly patients with intertrochanteric fractures.

Methods

As a retrospective cohort study, records of 88 patients with intertrochanteric fractures treated in our hospital from January 1st, 2019 to July 31st, 2021 were retrospectively reviewed. According to treatment records, it included 45 patients treated with InterTan (Group-A) and 43 patients treated with PFNA-II (Group-B). The operation safety and functional rehabilitation of the two groups were compared and analyzed.

Results

This study included 88 patients with intertrochanteric fractures (mean [SD] age, 68.72 [0.10] years at baseline), of whom 52 (59.09%) were males and 36 (40.91%) were females. Operation time and intraoperative blood loss in Group-B were less than Group-A, while fracture healing time was shorter in Group-A. The fracture separation distance was measured four weeks after the operation. The widening rate of the fracture line in Group-A was lower than Group-B (4.4% vs.18.6%; P<0.05). The incidence of complications in Group-A was lower than Group-B (4.4% vs.18.6%; P<0.05). At three, six and twelve months after the operation, the Harris hip score of the two groups was higher than at discharge (P<0.05), with no significant difference between groups (P>0.05).

Conclusions

We found no significant difference in the functional outcome in elderly patients with intertrochanteric fractures treated with InterTan and PFNA-II. Early fracture healing and reduced complication rate however has been noted with InterTan.