Delayed recognition of an ipsilateral femoral neck and shaft fracture leading to preventable subsequent complications: a case report

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.

Conversion hip arthroplasty for failed internal fixation of ipsilateral femoral neck and shaft fractures: a case report

BACKGROUND

Ipsilateral femoral neck and hip fractures are uncommon high energy injuries. In the literature no single method of treatment has emerged as superior to the others. A recent publication has documented the successful application of the rendezvous technique using dual-implants for treating these injuries. However in some cases, this technique may fail and revision surgery is required.

CASE PRESENTATION

A 67-year old man sustained ipsilateral fractures of his femur and femoral neck in a road traffic accident. His injuries were treated by a dual construct consisting of a retrograde femoral nail and dynamic hip screw. Three months after surgery the hip screw cut out of the femoral head necessitating revision to a total hip arthroplasty. Surgery was carried out using a single stage two part procedure on a standard operating table without having to reposition or redrape the patient. There were no postoperative complications and at 1 year from surgery the patient is satisfied with the result and has returned to work.

CONCLUSION

Conversion hip arthroplasty in the presence of dual implants is a technically challenging and unpredictable procedure, with an increased risk of complications. Our surgical approach provides a framework for orthopedic surgeons to safely perform this complex procedure.

External Validation of Deep Learning Algorithm for Detecting and Visualizing Femoral Neck Fracture Including Displaced and Non-displaced Fracture on Plain X-ray

This study aimed to develop a method for detection of femoral neck fracture (FNF) including displaced and non-displaced fractures using convolutional neural network (CNN) with plain X-ray and to validate its use across hospitals through internal and external validation sets. This is a retrospective study using hip and pelvic anteroposterior films for training and detecting femoral neck fracture through residual neural network (ResNet) 18 with convolutional block attention module (CBAM) +  + . The study was performed at two tertiary hospitals between February and May 2020 and used data from January 2005 to December 2018. Our primary outcome was favorable performance for diagnosis of femoral neck fracture from negative studies in our dataset. We described the outcomes as area under the receiver operating characteristic curve (AUC), accuracy, Youden index, sensitivity, and specificity. A total of 4,189 images that contained 1,109 positive images (332 non-displaced and 777 displaced) and 3,080 negative images were collected from two hospitals. The test values after training with one hospital dataset were 0.999 AUC, 0.986 accuracy, 0.960 Youden index, and 0.966 sensitivity, and 0.993 specificity. Values of external validation with the other hospital dataset were 0.977, 0.971, 0.920, 0.939, and 0.982, respectively. Values of merged hospital datasets were 0.987, 0.983, 0.960, 0.973, and 0.987, respectively. A CNN algorithm for FNF detection in both displaced and non-displaced fractures using plain X-rays could be used in other hospitals to screen for FNF after training with images from the hospital of interest.

Femoral Neck Nonunion Associated With Delayed Union of Ipsilateral Femoral Shaft Fracture

We report the case of a 36-year-old man, who presented to us five months after the initial trauma. He had been treated elsewhere with a cephalomedullary femoral nail. He described severe pain in his right thigh and groin that confined him to a wheelchair. He had shortening of the right lower limb and painful restriction of movements of the right hip. Radiographs demonstrated hypertrophic callus with a gap at the femoral shaft while the neck fracture was in varus malalignment with bone resorption; the neck fracture been fixed using two hip screws that were missing the nail. The patient was managed with removal of the previous hardware, reamed retrograde nailing and Pauwels’ intertrochanteric valgus osteotomy fixed using a 120^o double-angled condylar blade plate. Both the fracture sites were not opened. Postoperatively, the femoral shaft showed radiographic evidence of union at three months, while the femoral neck and the intertrochanteric osteotomy site had united at five months. As per the Friedman and Wyman criteria, our patient has a “good” outcome at the four-year follow-up.

Dynamic Stress Fluoroscopy for Evaluation of the Femoral Neck After Intramedullary Nails: Improved Sensitivity for Identifying Occult Fractures

OBJECTIVES

To report on the use of dynamic stress fluoroscopy (DSF) for detection of occult fractures of the femoral neck associated with femoral shaft fractures. To compare DSF with a fully static imaging protocol in detecting occult femoral neck fractures.

DESIGN

Multicenter retrospective cohort study.

SETTING

Two urban level I trauma centers.

PARTICIPANTS/INTERVENTION

A consecutive series of 1273 femoral shaft fractures were included. Inclusion criteria were patients treated with an intramedullary rod (antegrade/retrograde), age ≥18 years, a fine-cut (2 mm) preoperative computed tomography and hip radiographs, intraoperative anteroposterior (AP)/lateral fluoroscopic view of the femoral neck before femoral nailing, and a minimum follow-up of 3 months. Patients were divided into 2 groups based on the technique used to identify the presence of a femoral neck fracture after intramedullary fixation of the femoral shaft: DSF or static intraoperative radiographs.

MAIN OUTCOME MEASURES

Sensitivity, specificity, positive predictive value, and negative predictive value.

RESULTS

Both the static imaging protocol and DSF had high specificity (100%; 100%), positive predictive value (100%; 100%), and negative predictive value (99.5%; 99.6%). Sensitivity was poor (73.7%) for the static protocol group versus high (92.3%) for the DSF group.

CONCLUSIONS

Compared with a fully static imaging protocol, DSF is a more sensitive and highly specific technique, enabling intraoperative detection of occult fractures of the femoral neck.

LEVEL OF EVIDENCE

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