Association of the lateral wall integrity with clinical outcomes in older patients with intertrochanteric hip fractures treated with the proximal femoral nail anti-rotation-Asia

The clinical efficacy of Medial Sustain Nail(MSN) and Proximal femoral nail anti-rotation(PFNA) for fixation of medial comminuted trochanteric fractures: a prospective randomized controlled trial

PURPOS

To evaluate the clinical efficacy of the Medial Sustain Nail (MSN) for medial comminuted trochanteric fractures fixation in comparison to Proximal Femoral Nail Antirotation (PFNA) through a clinical study.

METHODS

A non-inferiority randomized controlled trial was conducted at a single centre between July 2019 and July 2020. Fifty patients diagnosed comminuted trochanteric fractures were randomly assigned to either the MSN group (n = 25) or the PFNA group (n = 25). A total of forty-three patients were included in the final study analysis. The primary outcome measure was Short Form 36 health surgery physical component summary (SF-36 PCS) score. Secondary outcomes included the Oxford Hip Scores (OHS), weight bearing, complication relate to implant and so on. This study was not blined to surgeons, but to patients and data analysts.

RESULTS

The MSN demonstrated significantly better functional outcomes as measured by SF-36 PCS and OHS at six months postoperative compared to PFNA (p < 0.05). Union of fractures in the MSN group reached 90.9% at three months after surgery, whereas the PFNA group achieved a union rate of 57.1% (p < 0.05). Furthermore, weight-bearing time of MSN group was earlier than PFNA group (p < 0.05). Additionally, complications related to implant usage were more prevalent in the PFNA group (33.3%) compared to the MSN group (4.5%) (p < 0.05).

CONCLUSION

MSN exhibited superior quality of life outcomes compared to PFNA at six months postoperative. This indicates that MSN effectively reconstructs medial femoral support in patients with comminuted trochanteric fractures, which facilitates early weight-bearing and accelerates the recovery process.

TRIAL REGISTRATION

Trial registration number: NCT01437176, Date of the trial registration:2011-9-1, Date of commencement of the study:2011-9, Date of enrolment/recruitment of the study subjects:2019-7.

Biomechanical evaluation of ortho-bridge system and proximal femoral nail antirotation in intertrochanteric fractures with lateral wall fracture based on finite element analysis

Background

The integrity of the lateral wall in femoral intertrochanteric fractures significantly impacts fracture stability and internal fixation. In this study, we compared the outcomes of treating intertrochanteric fractures with lateral wall involvement using the ortho-bridge system (OBS) combined with proximal femoral nail antirotation (PFNA) versus simple PFNA from a biomechanical perspective.

Methods

Finite-element models of femoral intertrochanteric fractures with lateral wall involvement were subjected to fixation with OBS combined with PFNA and simple PFNA. Von Mises stress measurements and corresponding displacement assessments for each component of the model, including the proximal femur and lateral wall, were used to evaluate the biomechanical effects of OBS fixation on bone and intramedullary nail stability.

Results

Using PFNA alone to fix intertrochanteric fractures with lateral wall involvement resulted in von Mises stress levels on the lateral wall exceeding safe stress tolerances for bone growth. OBS fixation significantly reduced stress on the lateral wall of the femur and minimized the stress on each part of the intramedullary nail, reducing the overall displacement.

Conclusion

In cases of intertrochanteric fractures with lateral wall involvement, PFNA fixation alone may compromise the biomechanical integrity of the lateral femoral wall, increasing the risk of postoperative complications. The addition of OBS to PFNA significantly reduces stress on the lateral femoral wall. Consequently, OBS should be considered for lateral wall fixation when managing intertrochanteric fractures combined with lateral wall fractures.

Finite element analysis of the effect of residual lateral wall volume on postoperative stability in intertrochanteric fractures

BACKGROUND

Lateral wall fractures represent crucial risk factors for postoperative internal fixation failure in intertrochanteric femoral fractures. However, no consensus exists on the type of lateral wall fracture requiring interventional management. This study aimed to investigate the effect of residual lateral wall volume on the postoperative stability of intertrochanteric femur fractures with associated lateral wall fractures, providing valuable reference for the clinical management of the lateral wall.

METHODS

Eleven bone defect models of intertrochanteric femur fractures with varying residual lateral wall volumes were constructed using finite element analysis. These models were fixed with proximal femoral nail antirotation (PFNA). Simulations of von Mises stress and displacement distribution of the PFNA and femur during normal walking were conducted. Statistical analysis was performed to assess the correlation between volume and the maximum von Mises stresses and displacements of the PFNA and femur.

RESULTS

In all 11 models, the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and femur occurred at the same locations. As residual lateral wall volume increased, the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and maximum femoral displacement gradually decreased. However, the overall trend of the maximum femoral von Mises stress gradually decreased. At 70% retention of the residual lateral wall volume, there was a more pronounced change in the value of the maximum stress change of the helical blade and the intramedullary nail. Statistical analysis, including the Shapiro-Wilk test and Pearson correlation analysis, demonstrated a significant negative correlation between volume and the maximum von Mises stress and displacement of the helical blade, intramedullary nail, and femur. Linear regression analysis further confirmed this significant negative correlation.

CONCLUSION

Finite element analysis of the residual lateral wall revealed a significant correlation between volume and the postoperative stability of intertrochanteric femur fractures. A volume of 70% may serve as the threshold for stabilizing the residual lateral wall. Volume emerges as a novel index for evaluating the strength of the residual lateral walls.

Traction images heavily influence lateral wall measurement in trochanteric hip fractures. A prospective study

INTRODUCTION

hip fracture represents a global health problem, with a high morbidity and mortality rate and an increasing incidence. The treatment of trochanteric fractures is reduction and osteosynthesis, and implant selection depends mainly on the stability of the fracture and lateral wall competence. Lateral wall competence has gained relevance in recent years, which led to the modification of the AO/OTA classification. However, determination of lateral wall integrity is difficult from plain radiographs; the influence of images with traction on its measurement has not been evaluated.

METHODS

prospective concordance study, emergency and post-traction radiographs of 65 patients with trochanteric fracture were evaluated by six orthopedic surgeons independently, measuring the lateral wall, classifying the fracture according to the AO/OTA 2018 classification and selecting the implant for osteosynthesis. A comparison of incompetent to intact lateral wall proportion between each image set was made. Secondary outcomes were the inter-observer correlation of lateral wall measurement and inter-observer agreement of classification and implant choice.

RESULTS

the proportion of patients with an incompetent lateral wall in emergency x-ray was 37.43% (CI 95% 0.326-0.422), while the proportion in post-traction fluoroscopy was 15% (CI 95% 0.115-0.185), with a statistically significant difference (p < 0.001). 40.1% of patients with an incompetent lateral wall changed to an intact one. Inter-observer correlation for the lateral wall thickness was 0.399 (CI 95% 0.292-0.519) in emergency x-ray and 0.658 (CI 95% 0.564-0.748) in post-traction fluoroscopy, with a substantial agreement. Inter-observer agreement for the fracture classification was fair to moderate using emergency x-ray (κ 0.369 95%CI 0.330-0.408) and fair to moderate with post-traction fluoroscopy (κ 0.400, 95% CI 0.334-0.466).

CONCLUSION

traction images significantly change the measurement of the lateral wall in trochanteric fractures, changing from an incompetent to a competent wall in 40% of patients. The correct classification of trochanteric fractures is crucial to make the best decision when deciding which implant to use, and the measurement of the lateral wall is determinant in the actual AO/OTA classification. Therefore, traction images appear as necessary for correct decision-making.

The importance of the thickness of femoral lateral wall for treating intertrochanteric fractures: a finite elements analysis

To explore how the thickness of the femoral lateral wall influences the effectiveness of internal fixation systems used to treat intertrochanteric fractures. CT images of the pelvis and femur of a male adult were used to construct an intertrochanteric fracture model (AO/OTA 31-A2) with various thicknesses of the femoral lateral wall (FLW). Four finite element (FE) models were created with the lateral femoral walls being 10 mm, 20 mm, 30 mm, and 40 mm thick. The fracture models were fixed with a dynamic hip screw (DHS), a proximal femoral nail anti-rotation (PFNA), and a proximal femoral locking compression plate (P-FLCP). A simulated vertical load was applied to the femoral head. The stress and displacement of the implant and femur in each model were recorded for comparison. The FE analysis of the intertrochanteric fracture models showed that the PFNA system could provide better stability than the DHS and P-FLCP with the same thickness of FLW. The FLW provided buttress support to the femoral head and neck when using a DHS and PFNA, and the buttress strength was proportional to the thickness of FLW. The maximum stress in the DHS model was recorded on the DHS plate which accommodated the lag screw. For the PFNA model, the maximum stress appeared at the connection between the nail and blade. In the P-FLCP model, the maximum stresses were highly concentrated at the connection between the cephalic nails and the proximal plate. The thickness of the femoral lateral wall should be considered an important factor when selecting a suitable internal fixation system for intertrochanteric fractures. Based on the FE analysis, intramedullary fixation, such as PFNA, experiences lower stress levels and a moderate displacement in comparison to DHS and P-FCLP when used to treat intertrochanteric fractures.

Outcome of buttress plate-nail construct used for reconstruction of broken lateral wall in intertrochanteric fractures

PURPOSE

Intramedullary implants are well accepted fixation of all types of intertrochanteric (IT) fractures, both stable and unstable types. Intramedullary nails have an ability to effectively support the posteromedial part, but fail to buttress the broken lateral wall requiring lateral augmentation. The aim of this study was to evaluate the outcome of proximal femoral nail augmented with trochanteric buttress plate for broken lateral wall with IT fractures, which was fixed to the femur through hip screw and anti-rotation screw nail.

METHODS

Of 30 patients, 20 had Jensen-Evan type III and 10 had type V fractures. Patients with IT fracture of broken lateral wall and aged more than 18 years, in whom satisfactory reduction was achieved by closed methods, were included in the study. Patients with pathologic or open fractures, polytrauma, prior hip surgery, non-ambulatory prior to surgery, and those who refused to participate were excluded from the study. The operative time, blood loss, radiation exposure, quality of reduction, functional outcome and union time were evaluated. All data were coded and recorded in Microsoft Excel spread sheet program. SPSS 20.0 was used for data analysis and normality of the continuous data was checked using Kolmogorv Smirnov test.

RESULTS

The mean age of patients in the study was 60.3 years. The mean duration of surgery (min), mean intra-operative blood loss (mL) and mean number of exposures were 91.86 ± 12.8 (range 70 - 122), 144.8 ± 3.6 (range 116 - 208), and 56.6 (range 38 - 112), respectively. The mean union time was 11.6 weeks and the mean Harris hip score was 94.1.

CONCLUSION

Lateral trochanteric wall in IT fractures is significantly important, and needs to be reconstructed adequately. Nail-plate construct of trochanteric buttress plate fixed with hip screw and anti-rotation screw of proximal femoral nail can be successfully used to augment, fix or buttress the lateral trochanteric wall giving excellent to good results of early union and reduction.

Predictors of and predictive nomogram for cut-out of proximal femur nail anti-rotation device in intertrochanteric fractures

PURPOSE

This study determined independent predictors and developed a predictive nomogram for failed correction of intertrochanteric fractures due to cut-out of the proximal femur nail anti-rotation (PFNA) device.

METHODS

Demographic and radiological data of 592 adult patients with intertrochanteric fractures (AO 31A) treated by PFNA were collected retrospectively. Independent predictors of cut-out were obtained through univariate and multivariate analyses, and a predictive nomogram was established. The discrimination, calibration, and clinical utility of the nomogram were based on receiver operating characteristic curve (AUC), concordance index (C-index), calibration curve, and decision curve analysis, respectively.

RESULTS

Overall, 18 (3.04%) cases of cut-out occurred. Independent predictors according to the multivariate analysis were body mass index (BMI), poor-to-acceptable quality of reduction, PFNA blade position, and tip-apex distance (TAD). AUC of the nomogram was 0.849, and C-index was 0.849 (95% CI [0.844-0.854]). Bootstrapping yielded a corrected C-index of 0.849. The calibration and decision curves indicated good agreement and clinical benefit of the nomogram.

CONCLUSION

A reliable predictive nomogram was developed for cut-out of the PFNA in intertrochanteric fractures, based on BMI, quality of reduction, blade position, and TAD.

Does augmentation of intramedullary nails by a buttress plate effectively restore lateral wall integrity in intertrochanteric fractures

BACKGROUND

Recent studies have proved the importance of intact lateral trochanteric wall, thus buttressing/fixing the broken lateral trochanteric wall irrespective of the implant, is likely to improve the alignment and outcome. We compared the outcome of lateral wall buttressing by trochanteric buttress plate (TBP) supplemented to proximal femoral nailing versus proximal femoral nailing alone in patients of broken lateral wall intertrochanteric fractures.

MATERIAL AND METHOD

Sixty patients of intertrochanteric factures (IT) of femur with broken lateral wall were randomized into group A or B and were treated with either proximal femoral nail (PFN) alone or proximal femoral nail augmented with trochanteric buttress plate (PFN + TBP), respectively. The TBP plate used was primarily fixed to proximal femur via 8 mm hip screw and 6.4 mm antirotation screw of the PFN. Operative time, blood loss, radiation exposure, quality of reduction, functional outcome, union time, and complications were compared.

RESULT

The mean age was 60.03 + 7.60 (range 42 to 70 years), with male to female ratio of 4:1 and left to right ratio of approximately 1:1. The mean follow up in the series was 16.2 months (range 13 to 36 months). Mean duration of surgery, mean intra-operative blood loss, and mean number of exposures in group A (PFN alone) were 64.88 + 12.24 min (48 to 88), 93 + 1.18 ml (60 to 120), and 32.13 (24 to 46) and in group B (PFN with TBP plate) were 91.86 + 12.78 min (70 to 122 min), 144.8 + 3.6 ml (116 to 208 ml), and 56.6 (38 to 112), respectively. Twenty-five patients and 28 patients in groups A and B respectively achieved score of 4 Chang quality reduction. Mean union time was 13.4 weeks in group A whereas in group B was 11.6 weeks. Mean HHS score in group A was 87.86 with 90% patients in comparison to 94.13 and 97% cases having excellent to good results in group B. In group A, 24 patients, while 29 patients in group B, had excellent to good results. Four patients had hip pain, four had impingement of screws, two had screw migration, three had Z/reverse effect, and four patients had shortening of more than 1 cm in group A. In group B, only one patient had impingement and none of the patient had hip pain, infection, implant failure, Z effect, or shortening.

CONCLUSION

The lateral trochanteric wall in IT fractures is significantly important, and when the lateral wall is broken, it can lead to poor results. TBP plate which is applied laterally on femur along with nail and fixing the plate with hip screw and antirotational screw provides faster union, early weight bearing, better reduction, and so better hip functions. TBP can be used successfully to augment, fix, or buttress the lateral trochanteric wall giving excellent to good results but at the cost of surgical time, blood loss, and radiation exposure.

Conversion of failed proximal femoral nail antirotation to uncemented or cemented femoral component fixation: a multicentre retrospective study with a median 10-year follow-up

Background

Conversion of a failed proximal femoral nail antirotation (PFNA) to a total hip arthroplasty (THA) is becoming increasingly universal. However, consensus has not been reached regarding which device (uncemented or hybrid THA) to use. The aim of this retrospective study was to compare the clinical outcomes of the conversion of failed PFNAs to uncemented versus hybrid THAs in the elderly population.

Methods

Consecutive elderly patients with prior failed PFNAs treated with uncemented or hybrid THA from January 2008 to December 2019 were retrospectively identified from two medical centres. The primary outcome was implant survival after THA revision; secondary outcomes were the functional outcomes assessed using the Harris Hip Score (HHS) and the incidence of key THA-related complications.

Results

A total of 236 patients (uncemented THA, n = 116; hybrid THA, n = 120) were eligible for this study. Kaplan–Meier survival curves demonstrated that the 10-year cumulative survival rates were 0.801 (95% confidence interval [CI], 0.783–0.852) in the uncemented THA group versus 0.925 (95% CI, 0.861–0.964) in the hybrid THA group (hazard ratio [HR] 0.36 [95% CI 0.24–0.56], p = 0.004). From the 72nd month after the revision to the last follow-up, functional outcomes differed considerably between cohorts (each p < 0.05), and the rate of key THA-related complications was comparable between cohorts (p = 0.004).

Conclusion

For elderly patients with prior failed PFNAs who experienced uncemented or hybrid THA, hybrid THA revision may provide a clinically significant improvement over uncemented THA revision with regard to implant survival, functional outcomes, and THA-related complications compared to uncemented THA revision.