Preoperative "Computed tomography capsular sign" for the detection of occult ipsilateral femoral neck fractures associated with femoral shaft fractures

Femoral shaft displacement and Winquist classification provide predictive characteristics for combined femoral neck and femoral shaft fractures

OBJECTIVES

The goal of this study is to establish radiographic features and characteristics of patient injury in cases of femoral shaft fractures that predict the presence of ipsilateral femoral neck fractures (IFNFs).

METHODS

Patient data was retrospectively assessed from a single level I trauma center through the electronic health record using (Current Procedural Terminology) CPT codes for both isolated and combined ipsilateral femoral shaft and neck fractures. Demographic information, injury characteristics, and independently reviewed radiographic features were collected and compared against the same information from a group of isolated femoral shaft fractures. Multivariable logistic regression was performed to identify risk factors for concomitant IFNFs and their respective odds ratios. A probability algorithm for assessing ipsilateral femoral neck fractures based on independent multivariate predictors was constructed and used.

RESULTS

A total of 113 patients with either isolated femoral shaft fractures or combined femoral shaft and IFNF (n = 33) met inclusion criteria and were identified for this study. Fracture displacement was most strongly associated with increased risk of combined injury with an aOR of 25.64 (95 %CI = 5.96-110.28) for every 100 % displacement. Motorcycle crash (MCC) was the mechanism associated with the highest risk of combined injury, with an aOR of 9.85 (95 % CI = 1.99-48.74). Combined injury was also correlated with lower Winquist score and presentation with a closed fracture, with aORs of 0.38 (95 %CI = 0.21 - 0.68) and 11.61 (95 %CI = 1.93-69.94), respectively. Presence of at least 3 of the statistically significant variables produced a positive predictive value (PPV) of ≥ 89 % for combined femoral shaft and IFNF.

CONCLUSIONS

Identification of combined femoral shaft and IFNF is of critical importance when caring for orthopedic trauma patients. While diagnosis remains a challenging task, MCC mechanism, >100 % fracture displacement, and lower Winquist classification were found to be associated with combined injuries. The combination of these variables might assist in predicting the probability of combined injury and potentially guide decision making on the appropriateness of obtaining single sequence MRI or implementing prophylactic femoral neck fixation.

LEVEL OF EVIDENCE

Level III.

High-energy Femoral Neck Fractures in Young Patients

Femoral neck fractures in physiologically young patients typically occur from high-energy axial loading forces through the thigh with the hip in an abducted position. These fractures have a high rate of associated head, chest, abdominal, and musculoskeletal injuries. High-energy hip fractures differ from traditional geriatric hip fractures regarding incidence, mechanism, management algorithms, and complications. After adequate resuscitation, goals of treatment include anatomic reduction and stable fixation while maintaining vascularity of the femoral head, which can be achieved through a variety of different techniques. Prompt recognition and treatment of these fractures is crucial to achieve a successful outcome because these injuries are often associated with complications such as osteonecrosis, fixation failure, and nonunion.

Characteristics of Femoral Shaft Fractures That Predict Ipsilateral Femoral Neck Fractures

INTRODUCTION

This study aims to characterize radiographic features and fracture characteristics in femoral shaft fractures with associated femoral neck fractures, with the goal of establishing predictive indicators for the presence of ipsilateral femoral neck fractures (IFNFs).

METHODS

A retrospective cohort was collected from the electronic medical record of three level I trauma centers over a 5-year period (2017 to 2022) by current procedural terminology (CPT) codes. Current CPT codes for combined femoral shaft and IFNFs were identified to generate our study group. CPT codes for isolated femur fractures were identified to generate a control group.

RESULTS

One hundred forty patients comprised our IFNF cohort, and 280 comprised the control cohort. On univariate, there were significant differences in mechanism of injury (P < 0.001), Orthopedic Trauma Association (OTA)/Arbeitsgemeinshaft fur Osteosynthesefragen (AO) classification (P = 0.002), and fracture location (P < 0.001) between cohorts. On multivariate, motor vehicle crashes were more commonly associated with IFNFs compared with other mechanism of injuries. OTA/AO 32A fractures were more commonly associated with IFNFs when compared with OTA/AO 32B fractures (adjusted odds ratio = 0.36, P < 0.001). Fractures through the isthmus were significantly more commonly associated with IFNFs than fractures more proximal (adjusted odds ratio = 2.52, P = 0.011).

DISCUSSION

Detecting IFNFs in femoral shaft fractures is challenging. Motor vehicle crashes and motorcycle collisions, OTA/AO type 32A fractures, and isthmus fractures are predictive of IFNFs.

Capsular distension in high-energy femoral shaft fractures is associated with occult femoral neck fracture: a preliminary retrospective comparative study

OBJECTIVES

To determine the association between hip capsular distension, the computed tomography (CT) capsular sign, and lipohemarthrosis as they relate to occult femoral neck fracture (FNF) in the setting of ipsilateral femoral shaft fracture (FSF).

DESIGN

Retrospective comparative study.

SETTING

Level 1 trauma center.

PATIENTS/PARTICIPANTS

Two hundred and forty-two patients with high-energy FSF and no evidence of FNF on preoperative radiographs and pelvis CT. All patients were stabilized with non-reconstruction style nails.

INTERVENTION

Pelvis CT scans were examined for hip capsular distension irrespective of the other side, differing side-to-side measurements of capsular distension (i.e., the CT capsular sign), and lipohemarthrosis.

MAIN OUTCOME MEASUREMENTS

FNF was observed for on postoperative radiographs. Relative risk (RR), number needed to treat (NNT), sensitivity (SN), and specificity (SP) were determined.

RESULTS

Fifty-eight patients (24.0%) had capsular distension. Forty-two patients (17.4%) had differing capsular measurements (i.e., the CT capsular sign), and 16 (6.6%) had symmetrical distension from bilateral hip effusions. Eight patients (3.3%) had lipohemarthrosis. Four FNFs (1.7%) were identified. Three patients had capsular distension, 2 had CT capsular signs, and 1 had lipohemarthrosis. The last patient had no CT abnormalities. Only capsular distension (RR = 10, CI = 1.001-90, P = 0.049; SN = 75%, SP = 77%; NNT = 22) and lipohemarthrosis (RR = 23, CI = 1.6-335, P = 0.022; SN = 50%, SP = 96%; NNT = 8) were associated with occult FNF.

CONCLUSIONS

Capsular distension is associated with FNF irrespective of the contralateral hip. Preemptive stabilization using a reconstruction nail could be considered in the setting of capsular distension or lipohemarthrosis to prevent displacement of an occult FNF.

LEVEL OF EVIDENCE

Diagnostic Level III.

What Is the Best Treatment Choice for Concomitant Ipsilateral Femoral Neck and Intertrochanteric Fracture? A Retrospective Comparative Analysis of 115 Consecutive Patients

PURPOSE

Although a concomitant ipsilateral femoral neck and intertrochanteric fracture has been considered to be a rare type of injury, its incidence has been increasing, especially among elderly hip fracture patients. However, there is limited evidence on the optimal treatment option. This study surveys surgical outcomes of different implants in order to assist in selecting the best possible implant for a combined femoral neck and intertrochanteric fracture.

METHODS

The postoperative complications after the treatment of a concomitant ipsilateral femoral neck and intertrochanteric fracture via cephalomedullary nail (CMN), dynamic hip screw (DHS), and hip arthroplasty groups were analyzed by retrospectively reviewing the electronic medical records of 115 consecutive patients.

RESULTS

The patient demographics and perioperative details showed no significant discrepancies amongst different surgical groups, except for the operative time; a CMN had the shortest mean operative time (standard deviation) of 85.6 min (31.1), followed by 94.7 min (22.3) during a DHS, and 107.3 min (37.2) during an HR (p = 0.021). Of the 84 osteosynthesis patients, 77 (91.7%) achieved a fracture union. Only one (3.2%) of the 31 HR cases had a dislocation. The sub-analysis of the different osteosynthesis methods showed a higher incidence of excessive sliding and the nonunion of the fracture fragment in the DHS group than that in the CMN group (p = 0.004 and p = 0.022, respectively). The different surgical methods did not significantly vary in other outcome variables, such as the re-operation rate, mortality, and hip function.

CONCLUSIONS

For the surgical treatment of combined femoral neck and trochanteric fractures, osteosynthesis did not differ significantly from an HR in terms of the overall postoperative complications, reoperation and mortality rate, and hip function, however, the risk of nonunion and more mechanical complications should be considered when choosing a DHS. Our suggestion for the treatment of a femoral neck and ipsilateral trochanteric fracture is that a surgeon should choose wisely between an HR and a CMN depending on the patient's age, the displacement of the femoral neck, and one's expertise.

Ipsilateral femoral neck and shaft fractures: case series from a single Level-I trauma centre and review of literature

INTRODUCTION

Uncommon but increasingly diagnosed, ipsilateral femoral neck and shaft fracture represents a complex injury pattern with challenging management. The conundrum involves optimal diagnostic modality, timing of surgery, sequence of fixation, and the choice of implant.

METHODOLOGY

A retrospective review was conducted at a Level-I trauma centre to assess the outcome of concomitant femoral neck and shaft fractures managed with various implants and attempt to provide solutions to the aforementioned queries. The time between injury and definitive surgery, choice of implant, sequence of fixation, time to fracture union, and complications were documented and analyzed.

RESULTS

A total of 46 patients were included in the study wherein associated neck fracture was identified preoperatively in 93.5% of patients. In patients with isolated limb fractures, the mean time to surgery was 16.7 ± 5 h whereas patients with polytrauma witnessed an average delay of 4.6 days before fracture fixation. 72% of patients were managed by dual implants and in the remaining both the fractures were addressed using a single implant with no union time difference amongst implants. The mean time to the union for neck fracture was 21.7 weeks and 24.2 weeks for shaft femur fracture. 21.7% patients developed delayed union of fracture shaft femur and infection complicated 11% shaft fractures.

CONCLUSION

Although, 6% neck fractures were missed in the series, we advocate that careful pre/intra/post-operative fluoroscopic evaluation of the femoral neck along with a low threshold for a pre-operative CT scan remains the optimal diagnostic modality while avoiding universal employment of computed tomography (CT). With fracture union being unaffected by implant choice, authors suggest that anatomical fixation of the femoral neck is of paramount importance followed by restoration of the length, alignment and rotation of the femoral shaft, and the implant selection primarily depends on surgeon's experience and the pattern of injury.

Prevention of Unplanned Surgery Due to Delayed Diagnosis of Occult Ipsilateral Femoral Neck Fractures Associated with Femoral Shaft Fractures: A Study of the CT Capsular Sign with Lipohemarthrosis

BACKGROUND

The purpose of the present study was to investigate the effectiveness of using the computed tomography (CT) capsular sign with lipohemarthrosis of the hip joint as a selective indicator for preoperative magnetic resonance imaging (MRI) of the hip or prophylactic fixation of the ipsilateral femoral neck for the prevention of unplanned surgery due to delayed diagnosis of occult ipsilateral femoral neck fractures in patients with high-energy femoral shaft fractures.

METHODS

We evaluated the CT capsular sign with lipohemarthrosis in patients with a high-energy femoral shaft fracture without a preoperative diagnosis of an ipsilateral femoral neck fracture. The CT capsular sign with lipohemarthrosis was considered positive when the side-to-side difference in anterior capsular distension was >1 mm and lipohemarthrosis was seen on soft-tissue-window CT images. A positive CT capsular sign with lipohemarthrosis prompts preoperative hip MRI or prophylactic femoral neck fixation with a reconstruction nail.

RESULTS

One hundred and fifty-six consecutive patients were included. Eight patients were preoperatively diagnosed with a displaced or hairline ipsilateral femoral neck fracture, whereas the remaining 148 patients showed no ipsilateral femoral neck fracture on radiographs and bone-window CT images. On soft-tissue-window CT images, 29 (19.6%) of the 148 patients had a positive CT capsular sign with lipohemarthrosis. We performed preoperative MRI for 3 patients; in the remaining 26 patients, prophylactic femoral neck fixation was performed with a reconstruction nail. We identified 5 occult ipsilateral femoral neck fractures among the 29 patients with a positive sign: 2 on preoperative MRI scans, 2 on immediate postoperative radiographs, and 1 on radiographs made 6 weeks postoperatively. In 119 patients with a negative sign, no occult ipsilateral femoral neck fracture was identified. All occult ipsilateral femoral neck fractures healed without further displacement of the femoral neck. Consequently, additional unplanned surgery for delayed diagnosis of occult ipsilateral femoral neck fracture was not required.

CONCLUSIONS

The use of the CT capsular sign with lipohemarthrosis as a selective indicator for preoperative hip MRI or prophylactic femoral neck fixation with a reconstruction nail in patients with high-energy femoral shaft fractures is effective for preventing unplanned surgery due to delayed diagnosis of occult ipsilateral femoral neck fractures.

LEVEL OF EVIDENCE

Diagnostic Level I. See Instructions for Authors for a complete description of levels of evidence.

Ipsilateral femoral neck and shaft fractures. When do we need further image screening of the hip?

OBJECTIVE

The objective of the present study was to identify patterns of femoral diaphyseal fractures which are associated with fractures of the ipsilateral femoral neck according to the AO classification. We propose an algorithm of investigation based on plain radiographs, recognizing cases that need additional screening with computed tomography.

PATIENTS AND METHODS

This observational retrospective study included patients with combined diaphyseal and femoral neck fractures. These patients were retrieved from a total of 1398 patients with the diagnoses of diaphyseal fractures of the femur, who were admitted to our hospital for surgical treatment between January 2009 and October 2019. All included cases had both fractures analyzed for their geometry and were classified according to the AO Classification, seeking to find a correlation between the types of fractures.

RESULTS

Sixteen diaphyseal fractures associated with ipsilateral neck fractures were detected during the period. The distribution of the diaphyseal fractures according to the AO Classification was as follows: 5 of type A3 (31,2%) 6 type B2 (37.5%), 1 type B3 (6,2%), 2 type C2 (12,5%) and 2 type C3 (12,5%). One A2 femoral fracture occurred during the surgical procedure. No type A1 fractures were detected.

CONCLUSION

The patterns of high-energy diaphyseal fractures (A3, B and C) have a higher prevalence of associated ipsilateral neck fractures. Our study suggests that routine additional methods of image investigation of femoral neck fractures may be unnecessary for diaphyseal fractures type A1 and A2.

Advantages and limitations of intramedullary nailing for the surgical treatment of ipsilateral intertrochanteric and femoral shaft fractures: a retrospective comparative study based on propensity score matching

INTRODUCTION

The aim of the present study was to introduce surgical technique using long PFNA for the treatment of ipsilateral intertrochanteric and femoral shaft fractures, and evaluate the characteristics of this fracture by comparing its surgical outcomes with those of isolated intertrochanteric and femoral shaft fractures.

MATERIALS AND METHODS

Between March 2013 and December 2018, 38 patients with ipsilateral intertrochanteric and femoral shaft fracture were identified at two institutions. Twenty-eight patients with ipsilateral intertrochanteric and femoral shaft fractures were enrolled in the present study. After propensity score matching, fifty-six patients with isolated intertrochanteric (group B) and femoral shaft (group C) fractures were finally enrolled in the present study for 1:2 matching to compare surgical outcomes to that of ipsilateral intertrochanteric and femoral shaft fractures (Group A).

RESULTS

All 28 patients achieved union of intertrochanteric fractures, while two experienced non-union of femoral shaft fractures. The union time of intertrochanteric fractures in group A was significantly shorter than that in group B. The union time of femoral shaft fractures in group A was significantly longer than that in group C.

CONCLUSIONS

The surgical treatment of ipsilateral intertrochanteric and femoral shaft fractures using long PFNA was advantageous as it allowed both fractures on the same femur to be fixed in one go and showed good surgical outcomes. However, fixation of femoral shaft fractures might be insufficient depending on the fracture level and configuration, and can be a cause of hypertrophic non-union.