Closed Cephalomedullary Nail Fixation of a Reverse Oblique Subtrochanteric Femoral Fracture in the Lateral Position

Abstract

Subtrochanteric femoral fractures commonly present in two different populations under very different circumstances. The elderly are commonly affected by low-energy events, such as a simple fall to the floor, while younger populations are more likely to be involved in high-energy events such as motor vehicle accidents. The majority of elderly injuries can be attributed to fragility fractures due to loss of bone density, but it is important to note an atypical fracture pattern that is present in those who have been taking bisphosphonates. This video demonstrates an intramedullary fixation of a reverse oblique subtrochanteric femoral fracture in the lateral position. There is a classic deformity seen in subtrochanteric fractures due to strong muscular attachments in the region. In this video, we show that while the lateral position may be more difficult for obtaining x-rays, it provides natural external forces that make reduction and fixation easier.

Case Overview

Background

The subtrochanteric region of the femur is defined as the first 5 cm distal to the lesser trochanter.¹ Fractures of this region account for 25% of proximal fractures of the femur.² There are numerous reasons why a fracture in this area can have difficulty healing and lead to complications. The greatest contributing factor is the deforming forces from muscle attachments in the area that lead to a difficult reduction.²

There have been several fracture classification systems that have been used to describe subtrochanteric fractures.^1, 2

Russel-Taylor Classification:³

• Type IA: No extension into piriformis fossa.
• Type IB: No extension into piriformis fossa but with the involvement of the lesser trochanter.
• Type IIA: Extension into piriformis fossa without the involvement of lesser trochanter.
• Type IIB: Extension into piriformis fossa with the involvement of lesser trochanter

AO/OTA Classification:¹

• 32-A3.1 Simple (A) Transverse (3), Subtrochanteric fracture (0.1).
• 32-B3.1 Wedge (B) Fragmented (3), Subtrochanteric fracture (0.1).
• 32-C1.1 Complex (C) Spiral (1), Subtrochanteric fracture (0.1).

Focused History

It is important to determine the mechanism of injury and to review prescribed medications for bisphosphonate use. The patient will report an inability to bear weight and will likely have significant swelling on the affected side. Younger patients are more likely to present with polytrauma and will often require a multidisciplinary approach to determine the best course of action.

Physical Exam

A shortened extremity will likely be noted on the affected side. The common deformity pattern that is seen for the proximal fragment is flexion from the iliopsoas, abduction from the gluteus medius, and external rotation from the external rotators. The distal fragment is pulled into varus by the hip adductors.² Extensive soft tissue swelling may be present from local hemorrhage. The patient’s hemodynamic status must be monitored for shock, and the afflicted area monitored for compartment syndrome.⁴ If the patient is presenting from high-energy trauma, a thorough exam for injuries to the thorax, abdomen, and contralateral cranium should be done. Injury to these areas together is known as Waddell’s triad and is common in pediatric patients struck by motor vehicles.⁵

Imaging

Orthogonal imaging of the entire femur, knee, and hip should be obtained. These views will allow the surgeon to view if there has been an intertrochanteric extension of the fracture, which can influence the starting point for the nail. A traction CT can also help evaluate the fragments and determine whether an open reduction may be necessary.¹ 

Options for Treatment

Surgical management is the definitive approach to treatment. The exception would be in a patient that has many comorbidities that contraindicate surgery.⁶ There are strong muscular forces in the area that will displace the fracture, shorten the leg length, and not allow the patient to ambulate properly if surgical intervention is not taken. The two common surgical approaches are cephalomedullary nailing, as seen in this case and video, and submuscular fixed-angle plating.¹ Cephalomedullary nailing is preferred in most scenarios, except when the fracture extends through the lesser trochanter or piriformis fossa, which interferes with the entry point for the nail.¹ 

Rationale for Treatment

The goal of cephalomedullary nailing is to promote union, avoid rotational malalignment, and provide structural support while preserving vascularity.⁷ Cephalomedullary nailing allows patients to begin weight-bearing as tolerated. Evidence supports that early weight-bearing promotes more rapid time to the union while allowing earlier initiation of physical therapy, leading to an overall faster recovery.⁸

Special Considerations

Studies have shown that the timing of surgery relative to the injury plays an important role in improving outcomes. Data suggests that operations performed within 48 hours had a lower complication rate.⁹

Discussion

This case illustrates a repair of a reverse oblique subtrochanteric fracture using an intramedullary (IM) nail in the lateral position. The alternative position that is commonly used is supine on a fracture table. IM nails have been shown to be superior to submuscular fixed-angle plates in the repair of subtrochanteric fractures.¹⁰ IM nails provide more support, can be inserted through smaller incisions resulting in less blood loss, decrease operative time, and decrease length of hospital stay compared with other methods.^1, 2, 10 The challenge with IM nails is the fracture must be properly reduced before the nail can be inserted. In this case, it is accomplished through manual traction and held by cerclage wires. The general steps of the procedure are exposure and reduction, preparing the medullary canal for insertion of the nail, inserting the nail, and locking the proximal fragment, followed by locking the distal portion of the nail with screws that prevent rotation of the nail within the canal.

Operative time is usually between 40–120 minutes and intraoperative blood loss is within the range of 250–1300 ml.¹¹ The average length of hospital stay is around 15 days, but this can be highly variable depending on other comorbidities.¹² Femoral fractures pose a high risk of mortality in the elderly population with a five-year mortality rate of 25%.² The most common complications are infection, pseudoarthrosis, vicious consolidation, and loss of reduction.² Special consideration must be taken when using the lateral position because the force of gravity, combined with the muscles attached to the distal segment, promotes a varus deformity. 

Fluoroscopy is used throughout the procedure to guide and confirm proper placement of the hardware and to confirm a proper reduction and fixation has been performed. These X-rays are more difficult to obtain in the lateral position, but this position allows better access to the operative site, which results in a better reduction. The initial reduction is done through the use of cerclage wires. Due to the complexity of the fracture in this case, two cerclage wires were ultimately used to achieve and hold proper reduction while the nail was positioned and secured. These wires can be left in place or removed at the end of the procedure. It has been postulated that long-term use of cerclage wires may pose a risk of bone devascularization.^2, 13 Therefore, the surgeon must evaluate on a case-by-case basis whether it will promote a better outcome for the patient if they are left in place. 

The tip-apex distance (TAD) represents the distance from the tip of the screw to the apex of the femoral head measured through anteroposterior and lateral X-rays. Geller et al. recommend a TAD of 25 mm or less.¹⁴ In their study, the mean TAD of those who experienced screw failure was 38 mm compared with 18 mm in those who did not.¹⁴ The goal for the TAD in this patient is 15 mm. Short and long nails can be used for fixation. Advocates for short nails believe that they are more cost-effective, have a shorter operative time, and result in less blood loss. Long nails, however, provide greater stability throughout the entire femur and prevent the complication of distal femur shaft fracture that is associated with short nails.^15, 16

Postoperatively, patients may begin weight-bearing as tolerated.¹ This is one of the advantages of the IM nail over plate fixation. 

The future of IM nailing will likely combine nail technology with the study of fracture healing biology, which will result in surface components of the nail that provide the optimal bone mechanobiological environment for each stage of fracture healing.¹⁷

Equipment

• Ball-tipped guidewire and reamer
• Portable fluoroscopy system
• Cephalomedullary nail
• Interlocking screws
  

Disclosures

Nothing to disclose.

Statement of Consent

The patient referred to in this video article has given their informed consent to be filmed and is aware that information and images will be published online.