Views: 0 Author: Site Editor Publish Time: 2026-08-14 Origin: Site
Intertrochanteric femoral fractures are among the most common hip fractures, particularly in older adults with osteoporosis. Because prolonged conservative treatment can lead to complications such as pressure injuries, pulmonary infection, pulmonary embolism, and deep vein thrombosis, early surgical fixation is generally preferred when the patient's condition permits.
Among the commonly used fixation options, the proximal femoral nail antirotation (PFNA) system is widely used for the surgical management of intertrochanteric fractures.
However, successful fixation does not depend solely on implant selection.
Achieving an appropriate fracture reduction before and during PFNA fixation is critical for maintaining stability and allowing early postoperative mobilization.
One important reduction concept is positive medial cortical support, which can improve construct stability in selected intertrochanteric fracture patterns.
During surgery, fluoroscopic imaging is routinely performed in both the anteroposterior (AP) and lateral views. However, these two projections may sometimes provide apparently contradictory information.
For example:
The AP view may demonstrate positive medial cortical support while the lateral view does not.
The lateral view may demonstrate positive support while the AP view appears non-positive.
Both views may demonstrate positive support.
Both views may demonstrate non-positive support.
This raises an important intraoperative question:
When AP and lateral fluoroscopic assessments disagree, which view should be given greater weight when deciding whether fracture reduction should be revised?
A recent study involving patients with intertrochanteric fractures investigated this question by comparing intraoperative fluoroscopic assessment with postoperative three-dimensional CT.
Intertrochanteric fractures frequently occur in elderly patients and are often associated with osteoporosis and multiple medical comorbidities.
Prolonged immobilization can increase the risk of:
Deep vein thrombosis
Pulmonary embolism
Pulmonary infection
Pressure injuries
Muscle wasting
Loss of independence
Prolonged hospitalization
Therefore, when medically appropriate, early surgical fixation followed by mobilization is an important component of modern hip fracture management.
PFNA provides intramedullary fixation with a proximal helical blade designed to achieve fixation within the femoral head and neck.
However, even a well-positioned implant may fail if the fracture is poorly reduced.
An unacceptable reduction may contribute to:
Varus collapse
Medial displacement
Excessive sliding
Implant migration
Cut-out or cut-through
Loss of fixation
Delayed functional recovery
Therefore, fracture reduction and implant positioning must be evaluated together rather than independently.
Positive medial cortical support is a reduction configuration in which the proximal fragment is positioned in a manner that allows the medial cortex of the proximal femur to provide mechanical support against the distal fragment.
This configuration can help resist:
Varus displacement
Medial migration
Excessive fracture collapse
The concept is particularly relevant to unstable intertrochanteric fractures treated with intramedullary fixation.
Intertrochanteric fracture reduction has traditionally been described using three general configurations:
The proximal fragment provides favorable cortical contact and mechanical support.
The fragments are restored to an approximately anatomical relationship without a clearly positive or negative cortical configuration.
The proximal fragment is positioned in a manner that provides inadequate medial cortical buttress and may predispose the construct to secondary displacement.
The practical goal is therefore not necessarily to achieve perfect anatomical reduction in every case.
Instead, a mechanically stable reduction may be more important than radiographic perfection alone.
An intertrochanteric fracture is a three-dimensional injury.
A conventional AP fluoroscopic image provides information primarily in the coronal plane, while the lateral projection provides information primarily in the sagittal plane.
Consequently, a reduction that appears favorable on one projection may appear less favorable on another.
This is one reason why surgeons routinely obtain both views during PFNA surgery.
Suppose intraoperative imaging shows:
AP view: positive support
Lateral view: non-positive support
Should the surgeon:
Accept the reduction?
Perform another reduction maneuver?
Remove and reposition the implant?
Risk additional soft-tissue injury?
Potentially create a less favorable reduction while attempting to achieve radiographic perfection?
This is a real intraoperative decision-making problem.
A reliable imaging strategy is therefore essential.
The study included 128 patients with hip fractures undergoing surgical treatment.
The investigators focused on whether intraoperative AP and lateral fluoroscopic images could accurately identify positive or non-positive medial cortical support.
The intraoperative AP and lateral fluoroscopic images were independently evaluated by:
One junior physician
One senior physician
Each observer classified the reduction as:
Positive support
Non-positive support
The assessments were performed twice, with an interval between the two evaluations.
Postoperative three-dimensional CT images were reviewed by an experienced orthopedic professor.
The CT assessment classified each case as:
Positive support
Non-positive support
The CT assessment was used as the reference standard for evaluating the diagnostic accuracy of intraoperative fluoroscopy.
This study design allowed the investigators to determine whether the AP or lateral projection more reliably represented the actual three-dimensional reduction.
One of the study's first questions was whether physician experience significantly influenced the interpretation of intraoperative fluoroscopy.
The researchers compared:
Junior versus senior physician assessments
First versus second assessment
Interobserver agreement
Intraobserver consistency
Across both evaluation rounds, there were no statistically significant differences between the junior and senior physicians in terms of:
Sensitivity
Specificity
False-positive rate
False-negative rate
This finding suggests that the difficulty of identifying positive medial cortical support may not simply be a matter of surgical experience.
In other words:
Even experienced surgeons can encounter limitations when interpreting two-dimensional fluoroscopic images of a three-dimensional fracture.
This highlights the importance of standardized imaging criteria rather than relying exclusively on subjective experience.
One of the most clinically useful findings was the situation in which the AP and lateral views provided the same assessment.
If both views demonstrated positive support, the likelihood that postoperative CT would confirm an acceptable positive-support configuration was extremely high.
Similarly, when both views indicated non-positive support, the fluoroscopic assessment showed strong agreement with the CT reference.
According to the study's reported results, when AP and lateral assessments were concordant, the prediction of CT-based reduction quality reached 100% in the evaluated cohort.
This provides an important practical principle:
When AP and lateral fluoroscopy agree, the surgeon can have substantially greater confidence in the intraoperative reduction assessment.
The more difficult situation occurs when AP and lateral fluoroscopy provide conflicting results.
For example:
AP: positive support
Lateral: non-positive support
or:
AP: non-positive support
Lateral: positive support
In these situations, the study found that the lateral view demonstrated greater reliability in predicting the CT-based reduction result.
This is particularly important because it provides surgeons with a practical decision-making reference when the two fluoroscopic projections do not agree.
The reason for the greater predictive value of the lateral projection may relate to the three-dimensional morphology of the proximal femur and the medial cortical relationship involved in positive support.
The AP view primarily evaluates the coronal relationship.
The lateral view provides additional information about the sagittal relationship and anterior-posterior displacement.
Because fracture fragments can rotate or translate in the sagittal plane, an apparently acceptable AP reduction may conceal unfavorable displacement that becomes evident on the lateral projection.
Therefore:
When AP and lateral images disagree, the lateral projection may provide more reliable information about the actual reduction configuration.
This does not mean that the AP view is unimportant.
Rather, the two projections should be interpreted together, with greater attention to the lateral view when discordance occurs.
Not necessarily.
Historically, fracture reduction has often been evaluated according to how closely the fragments reproduce normal anatomy.
However, intertrochanteric fracture fixation introduces another important concept:
Mechanical stability may be more clinically relevant than perfect anatomical appearance.
An anatomical reduction may restore the original geometry of the proximal femur.
However, in some unstable fracture patterns, a carefully controlled positive-support configuration may provide greater resistance to postoperative displacement.
Previous clinical research has suggested that positive medial cortical support may provide favorable functional outcomes compared with anatomical or neutral reduction in selected intertrochanteric fractures.
Therefore, the goal should not simply be:
“Make the X-ray look normal.”
The more important objective is:
“Create a mechanically stable fracture construct that can tolerate early functional loading.”
A small radiographic deviation from perfect anatomy does not automatically mean that the reduction is unacceptable.
For example, a slight positive cortical relationship may appear different from the original anatomy but can still provide a useful mechanical buttress.
This distinction is particularly important during minimally invasive fracture fixation.
Repeatedly manipulating the fracture in an attempt to obtain perfect anatomical alignment may:
Increase soft-tissue trauma
Increase operative time
Increase blood loss
Damage fracture biology
Make the reduction less stable
Increase the risk of unnecessary surgical manipulation
Therefore, surgeons should distinguish between:
Radiographic imperfection
and
Mechanical instability.
They are not necessarily the same thing.
Based on the study findings, a practical approach can be summarized as follows.
Both projections should be obtained after provisional reduction and again after definitive PFNA fixation.
Determine whether the reduction demonstrates:
Positive support
Neutral/anatomical support
Negative support
If AP and lateral views both show positive support:
Accept the reduction if other fixation parameters are satisfactory.
If AP and lateral views both show non-positive support:
Consider additional reduction or fixation optimization.
If AP and lateral views disagree:
Give greater attention to the lateral projection, based on the study's CT comparison findings.
Reduction should never be assessed in isolation.
Also evaluate:
Cephalic screw/blade position
Tip-apex distance
Femoral neck alignment
Varus or valgus alignment
Nail position
Distal locking
Lateral cortical integrity
If the fracture demonstrates acceptable mechanical support and stable fixation, minor radiographic imperfections may not justify repeated manipulation.
| Intraoperative Situation | Preferred Interpretation |
|---|---|
| AP positive + lateral positive | Strong evidence of positive support |
| AP non-positive + lateral non-positive | Strong evidence of non-positive support |
| AP positive + lateral non-positive | Give greater weight to lateral assessment |
| AP non-positive + lateral positive | Lateral assessment may be more predictive |
| Unclear fluoroscopic findings | Consider additional imaging or 3D assessment |
| Complex fracture morphology | CT/3D imaging may provide additional information |
The key message is therefore not that one projection completely replaces the other.
Rather:
AP and lateral fluoroscopy should be interpreted as complementary views, but when they conflict, the lateral view may provide greater predictive value for the actual three-dimensional reduction configuration.
For surgeons performing PFNA fixation, this study provides several practical lessons.
A satisfactory AP image does not guarantee satisfactory three-dimensional reduction.
The lateral projection may reveal sagittal displacement that cannot be appreciated on the AP image.
The objective is not necessarily perfect anatomical reconstruction.
A stable positive-support configuration may be preferable in selected unstable fractures.
If the lateral view demonstrates satisfactory positive support while the AP view is less convincing, unnecessary additional reduction may not always be beneficial.
The decision should consider:
Fracture pattern
Bone quality
Cortical contact
Implant position
Overall alignment
Stability of the construct
Both are important because they evaluate different planes. However, when AP and lateral assessments disagree, the lateral view may have greater predictive value for CT-confirmed reduction quality according to the study discussed here.
Positive medial cortical support refers to a reduction configuration in which the proximal and distal fracture fragments create a favorable cortical buttress that can improve mechanical stability.
Not necessarily. In selected unstable intertrochanteric fractures, a mechanically stable positive-support configuration may provide better resistance to postoperative displacement than a purely anatomical but mechanically less favorable reduction.
Not automatically. Because the lateral view may better predict CT-confirmed reduction in discordant cases, the surgeon should carefully reassess the lateral projection and the overall mechanical stability before deciding whether additional reduction is necessary.
Fluoroscopy is highly useful intraoperatively, but CT provides more comprehensive three-dimensional information. In complex or uncertain cases, additional three-dimensional imaging may be valuable.
The assessment of fracture reduction during PFNA fixation of intertrochanteric fractures is fundamentally a three-dimensional problem.
AP and lateral fluoroscopy provide complementary information, but they may occasionally produce conflicting interpretations.
The findings discussed in this study suggest three practical conclusions:
When AP and lateral views agree, fluoroscopic assessment can be highly reliable.
When the two projections disagree, the lateral view may have greater predictive value compared with the postoperative CT reference.
The surgical goal should be mechanical stability rather than unnecessary pursuit of perfect anatomical appearance.
For unstable intertrochanteric fractures, achieving appropriate positive medial cortical support may provide a favorable mechanical environment for PFNA fixation and early postoperative mobilization.
Ultimately, the most reliable intraoperative strategy is not to ask whether the AP or lateral view is universally “better,” but to understand what each projection tells us about the three-dimensional fracture reduction.
Study evaluating the diagnostic accuracy of intraoperative AP and lateral fluoroscopy for positive medial cortical support in intertrochanteric fractures using postoperative three-dimensional CT as the reference standard.
Relevant clinical studies on positive medial cortical support and reduction quality in intertrochanteric femoral fractures treated with intramedullary fixation.
Relevant literature on proximal femoral nail antirotation (PFNA) fixation, fracture reduction, implant positioning, and postoperative mechanical stability.
Relevant orthopedic trauma literature on three-dimensional imaging and fluoroscopic assessment of intertrochanteric fracture reduction.
Clinical studies comparing anatomical reduction, neutral support, and positive medial cortical support in unstable intertrochanteric fractures.
