Surgical Management of Femoral Neck Fractures

Indications

Two different patient populations typically sustain femoral neck fractures: older patients who are usually injured in low-energy falls from standing height and younger patients who generally suffer from high-energy mechanisms.  The indications for surgery and the surgical management differ depending on the type of patient and the type of fracture. The timing or urgency for surgical intervention may also depend on which type of fracture has occurred. In general, most patients with femoral neck fractures benefit from surgical intervention, at least for pain control, even older sedentary patients. Non-operative care is reserved for bedridden patients who are insensate or neurologically impaired, or those with severely limited life expectancy.

Older Patients with Low-Energy Fractures

These fractures generally occur from low-energy mechanisms, such as falls from a standing height, in patients with osteopenia or osteoporosis. The patient will typically present with anterior groin pain and an inability to walk, usually with a shortened and externally rotated leg. Gentle attempts at internal or external rotation will illicit immediate pain. The standard radiographs to screen for a femoral neck fracture are an AP pelvis and frog leg lateral of the hip. It may be useful to obtain a “low” AP pelvis to show more of the proximal femur, which can be helpful in surgical planning. Internal rotation of the hips will help to display the femoral necks and allow comparison of the bony contours, which will help identify subtle and impacted fractures. One can also place a calibration bearing during the AP pelvis to help with preoperative planning for possible hemiarthroplasty or total hip arthroplasty. Finally, in displaced fractures, a traction internal rotation AP view of the proximal femur can be quite helpful in establishing the fracture pattern and help determine treatment.

In general, displaced femoral neck fractures in this patient population are best served with hemiarthroplasty or total hip arthroplasty due to the high risk of avascular necrosis and non-union. However, in physiologically younger patients or in high-demand older patients, it may be reasonable to attempt reduction and fixation initially. As femoral neck fractures are intracapsular fractures, some controversy surrounds the timing of fixation. There is at least a theoretically increased risk of avascular necrosis from delays in surgery; however, this is difficult to prove, and the timing of surgery should be tailored to the individual patient and hospital. Delays to surgery greater than 2-4 days have been shown to significantly increase mortality rates and other complications.

For a non-displaced or impacted femoral neck fracture, percutaneously placed cannulated screws are generally preferred. Attempts at non-operative therapy risk further displacement of the fracture, which could increase the risk of non-union or avascular necrosis. Exceptions would be stress fractures that do not involve the tension side (superior) of the femoral neck or bedridden hospice patients for whom pain can be adequately treated with medication and for whom there is no expectation for mobilization.

Young Patients with High-Energy Fractures

A fracture associated with high-energy trauma in a young patient represents a fracture that is completely distinct from that seen in the older patient's insufficiency fracture. The fracture in the young patient results from very high energy that is absorbed by the soft tissues in addition to the bone. These patients frequently have other injuries. Advanced Trauma Life Support (ATLS) protocols should be followed and transfer to a regional trauma center after stabilization should be considered. Fractures from high-energy trauma tend to be more comminuted and more vertical in nature, which makes them inherently unstable. During the secondary survey, standard work-up is similar to that of the previously discussed fractures, in that an AP pelvis and the frog leg lateral radiographs are obtained. A traction, internal rotation view again helps in defining the fracture pattern.  It should be noted that if the patient is being prepared for transport to a regional trauma center, there is no point in wasting time with additional films or scans, as these will be done by the trauma facility. In this situation, the work-up should end with physical exam and a standard AP pelvis.

Occult femoral neck fractures are common (up to 10%) in trauma patients with femoral shaft fractures and should always be sought. Many centers perform routine CT scans through the femoral neck to identify these fractures. This practice has helped reduce the number of missed femoral neck fractures. However, femoral neck fractures can occasionally be missed by CT scanning, so intraoperative post-fixation fluoroscopic examination while ranging the hip may be helpful to ensure a fracture does not exist.   There is no role for non-operative management of a non-displaced femoral neck fracture in the young patient population; the risk of avascular necrosis or non-union is much higher if the fracture displaces with attempts at conservative management.

The controversy of surgical timing discussed in the previous section applies to these fractures as well. Many trauma surgeons consider high-energy femoral neck fractures to be a surgical emergency due to the high risk of avascular necrosis and non-union; however, it is difficult to prove that emergent surgery affects the patient’s outcome. The surgeon should consider many factors specific to the patient, the injury, the hospital system, and his/her own abilities in deciding when to undertake these sometimes challenging procedures.

Preoperative Planning

Planning the reduction and fixation procedure for a patient with a femoral neck fracture begins with a decision about operative timing, as discussed in the previous section. It will include consideration of other injuries, such as ipsilateral femoral shaft fractures. In most cases, femoral neck fracture will assume a high priority among musculoskeletal injuries, preceded only by dislocations with neurovascular impairment, compartment syndrome, and high-grade open fracture.

High-quality radiographs are required to make a decision about the pattern and displacement of the fracture, as well as for implant selection, which may require an internal rotation film with traction. This film will be more helpful for these purposes than computed tomography. For optimal planning, films of the contralateral hip should be obtained.

For non-displaced or valgus impacted fractures, the fixation should be with three cannulated screws placed in an inverted triangular pattern, with particular emphasis on screws buttressing the inferior and posterior neck cortices. It is not necessary to formally draw out the plan, but it is important to evaluate neck size and width on good biplanar radiographs, as well as the depth of femoral head into which screws can be placed. This will aid in selecting thread length for the screws, as well as in identifying excessively small necks or very proximal fractures that could pose problems in screw placement.

In the case of displaced fractures, an actual pen and paper pre-operative plan is useful. The plan should contain three distinct components:

• Drawing of the preoperative state, in which all fracture lines and fragments can be identified
• Sketch of the postoperative condition, with reduction performed and implant(s) in place
• Surgical tactic describing the steps to make the transition

The surgical tactic will include positioning, approach, reduction maneuvers, temporary stabilization, definitive implants, and any evaluative processes in the OR – films or clinical exams. It should also include lists of trays, instruments and implants necessary; sharing this with the operative team before or at the start of the case will help make things go smoother.

Overlay templates and appropriately scaled radiographs are necessary. One often identifies additional fracture characteristics in the process of planning, and occasionally will recognize sub-optimal imaging that otherwise would not have been appreciated. During each step of the plan, the planner should ask himself/herself, “What is my fall-back plan if this doesn’t work?” Any additional equipment required by the back-up strategy (eg, arthroplasty trays and implants) should be noted on the written plan.

Occasionally, in the process of planning, one may identify a mismatch between implant size or shape and the apparent size or shape of the reconstructed femur. This is particularly a problem with some cephalomedullary nail systems. It may be of benefit to plan the fracture solution with more than one implant system to see which fits better – for example, use of a nail compared to a sliding hip screw; or perhaps blade plates of different angles.

Positioning

Positioning for femoral neck fractures depends on the preference of the surgeon. Some prefer lateral or “floppy” lateral positioning with a bean bag on a radiolucent flat top table. This typically requires an assistant to hold traction and manipulate the operative extremity during the procedure. Alternatively, the patient can be positioned supine on a flat top table with a bump under the operative hip. However, this still typically requires an assistant to aid with reduction and traction intraoperatively. Whether performing a closed reduction and percutaneous fixation or an open approach, the authors’ preference is to position on a fracture table so that no assistance is needed with traction or manipulation through the case.

The patient is typically “scissored” on a fracture table with the non-operative hip extended and the operative hip slightly flexed to allow for lateral fluoroscopy (Figure 1).  An alternative is to flex the non-operative hip and place in a “well leg holder” (Figure 2). This type of hemi-lithotomy position should be used with caution as compartment syndrome has been reported due to elevation of the leg.   Reduction attempts are usually performed at this time using the fracture table to afford traction while in external rotation. The leg is then typically slightly internally rotated. Flouroscopy should be obtained prior to prep and drape as it is easier for the surgeon to directly manipulate the fracture table at this time. Also, one should ensure that adequate images can be obtained as it will not improve following prep and drape and will cause further delays if not noted prior to beginning the procedure.  The lateral view is typically easier to see if the flouro machine is left just outside a full lateral position, such as a 15-degree elevated view (Figure 2).

Figure 1. Patient is “scissored” on a fracture table with the non-operative hip extended and the operative hip slightly flexed to allow for lateral fluoroscopy

Figure 2. Alternative position in which the the non-operative hip is flexed and placed in a “well leg holder”

Approach

The approach will vary depending on the type of patient – an older patient with a low-energy fracture or a young patient with a high-energy fracture – and the indications and goals of surgery.

Older Patients with Low-Energy Fractures

Displaced femoral neck fractures in older patients are typically treated with hemiarthroplasty or total hip arthroplasty, procedures which are outside the scope of this article. If open reduction internal fixation is chosen for an older patient, the same approach should be used as outlined below for the young, high-energy fracture, as an anatomic reduction will be desired.

Fixation of non-displaced or impacted femoral neck fractures in older patients can typically be done percutaneously. A small, 1- to 2-cm incision is made just lateral to the inferior aspect of the greater trochanter. Dissection is taken through skin and fascia; no significant anatomic structures are at risk in this direct lateral approach. The exact point of incision can be determined fluoroscopically by using a cannulated guide wire and determining trajectory of screw placement (assuming cannulated screws will be used for fixation). If another implant such as a sliding hip screw has been selected, the same approach is used but may be lengthened as needed to allow placement of the implant. Although controversial, a percutaneous capsular release can be done fluoroscopically through this lateral approach by using a small blade such as #15 or #11 and running the blade along the anterior neck. Care should be taken to stay on the femoral neck to avoid injury to more superficial structures such as the femoral vessels or nerve.

Young Patients with High-Energy Fractures

As anatomic reduction is critical to avoid non-union and avascular necrosis, an open approach is typically taken for young patients with high-energy fractures. These fractures tend to be more comminuted, which also makes reduction more difficult by closed means alone. A Smith-Peterson (anterior) approach can be used for direct access to the anterior neck. This may require a separate direct lateral approach, which may be percutaneous stab incicions, to allow placement of implants. Our preferred approach is a modified Watson-Jones (anterolateral) approach, as it allows adequate visualization of the femoral neck while still allowing fixation through the same incision. However, for morbidly obese patients, a Smith-Peterson approach is preferred to avoid struggling with the soft tissues blocking visualization of the femoral neck. The modified Watson-Jones approach is described below.

The patient is typically positioned supine on a flat-top or fracture table with a bump under the hip (see positioning section). The incision follows the anterolateral border of the proximal femur and then curves slightly anteriorly proximal to the greater trochanter to allow better visualization of the femoral neck (Figure 3).  Following skin incision, the fascia lata is incised just posterior to the tensor fascia lata (TFL) and the plane between the TFL and gluteus medius/minimus is developed (Fig 4). If adequate visualization cannot be achieved by working through this interval, a small incision can be made to release the anterior minimus attachment to the greater trochanter. The reflected head of the rectus femoris is tagged for later repair and divided, exposing the anterior joint capsule. A T-shaped capsulotomy is generally performed to allow complete visualization of the femoral neck (Figure 5). Hohman retractors can be gently placed superior and inferior to the neck to aid in visualization.

Figure 3. Incision follows the anterolateral border of the proximal femur and then curves slightly anteriorly proximal to the greater trochanter to allow better visualization of the femoral neck

Figure 4. Fascia lata is incised just posterior to the tensor fascia lata (TFL) and the plane between the TFL and gluteus medius/minimus is developed

Figure 5. T-shaped capsulotomy is generally performed to allow complete visualization of the femoral neck

Techniques

Although recommendations exist based on the age of patients for hip preservation vs. arthroplasty, each patient should be evaluated individually.  If the decision is made to internally fix the femoral neck fracture, surgery should be done as soon as reasonably possible. 

Non-displaced or minimally displaced valgus impacted femoral neck fractures require no reduction and can be internally fixed in situ.&nbsp Options for internal fixation of these fractures include either multiple cannulated screws or a sliding hip screw and plate construct.  For the high-energy, comminuted, vertical fracture typically seen in the young patient, it is imperative that an anatomic reduction be obtained.  Most trauma surgeons will perform an open reduction, as it is difficult to determine if the fracture is anatomically reduced by closed means alone.  For the unstable trauma patient, the excess OR time and blood loss associated with open reduction may put the patient at further risk for systemic injury.  An attempt at closed or minimally invasive reduction with temporary fixation, such as Steinman pins buried under the skin, may help with pain and nursing care while awaiting patient stability for a more lengthy open approach (Figure 6).  As soon as the patient can tolerate it, an attempt should be made to obtain an anatomically reduced fracture with fixation that will allow immediate mobilization. 

Figure 6. Temporary fixation - such as Steinman pins buried under the skin - may help with pain and nursing care until an unstable patient is stable enough for a more lengthy open approach

Although there is support in the literature for sliding hip screw with sideplate, no prospective randomized data demonstrates a difference in clinical outcomes between the two types.  Cannulated screws may be placed through percutaneous incisions or through a formal incision. The position and number of screws has been much debated in mechanical and clinical studies.  The most common pattern used is three screws placed in an inverted triangle, with screws placed along the anterior and posterior femoral neck and a screw placed between these along the inferior neck.  This is adequate for most fractures in older patients.  In higher-energy fractures, cannulated screws in a typical pattern may not be sufficient, given the usual comminuted and vertical nature of these fractures.  A fourth lag screw can be added perpendicular to the fracture plane (Figure 7); another implant such as a blade plate or other fixed angled device might be more appropriate.

Figure 7. In a high-energy fracture, a fourth lag screw can be added perpendicular to the fracture plane for more support

If a fourth screw is being placed orthogonal to a vertical fracture line, it is typically done first to lag the fracture.  Of the three cannulated partially threaded screws placed into the femoral head, the first guide pin is placed along the inferior cortex in the anterior-posterior plane and centrally on the lateral.  This position will resist inferior displacement.  The second and third guide pins are placed proximal to the inferior screw and parallel to one another in the anterior to posterior plane.  In the lateral plane, one of the guide wires is placed along the posterior cortex and the other along the anterior cortex (Figure 8).  This configuration leads to an inverted triangle pattern when completed.  The exact sequence of screw placement may vary, but using a lag screw to gain compression may aid in the reduction of the fracture.  For example, if there is widening of the fracture on the anterior aspect on the lateral image, the anterior screw should be placed first to assist with reduction. 

Figure 8. A lateral fluoroscopic view showing placement of screws along the anterior and posterior femoral neck

The size and thread length may vary as well, but for the screws placed along the femoral neck into the head, the use of at least 6.5-mm screws is recommended. Some surgeons prefer to use a 4.5-mm lag screw placed into the calcar if a fourth screw is needed, but another 6.5- or 7.3-mm cannulated screw is also acceptable.  The thread length will vary according to the location of the fracture line.  The outer cortex may be drilled in younger patients; otherwise, the self-drilling, self-tapping screws are placed using washers.  Zlowodzki et al have found that the use of washers significantly decreases the risk of fixation failure.

In some instances, the amount of valgus displacement can be significant, making placement of multiple pins into the femoral head quite challenging.  The required screw path may be at such an increased angle that the lateral starting point is in the high-stress area of the subtrochanteric region.  Screws that are placed in this area may create stress risers and lead to iatrogenic subtrochanteric femur fractures.   It is important to note that after the screws are placed, fluoroscopic images should be obtained at multiple angles of rotation to ensure there is no joint penetration. 

Fractures occurring at the base of the femoral neck are classified as basicervical fractures.  Because these fractures have a decreased risk of avascular necrosis, it is recommended that internal fixation be performed and not femoral head replacement.  A sliding hip screw has been proven clinically to be very effective in the treatment of these fractures.   After patient positioning, reduction can usually be achieved with traction and internal rotation of the lower extremity.  One may try different degrees of internal rotation under fluoroscopic imaging to determine the best reduction.  If reduction is determined to be adequate, then a guide pin may be placed through a percutaneous incision.  The wire is driven into the femoral head using the appropriate angle guide.  The goal for guide pin placement is for the tip of the pin to be in a central location in both AP and lateral views and deeply inserted, to the subchondral bone of the femoral head. 

What makes femoral neck fractures different from intertrochanteric fractures is that there are fewer muscle attachments and thus no stabilizing effect to resist rotational forces.  It is possible that during reaming or lag screw insertion, loss of reduction may occur.  Therefore, after placement of the guide pin in the center of the femoral neck and confirmation on the AP and lateral views, it is recommended that a second, “anti-rotation” pin be placed prior to reaming, especially in fractures prone to being rotationally unstable.  This may include transcervical, comminuted, or widely displaced fractures.  The pin is typically placed proximal to where the lag screw will be placed and parallel to it.  Location is confirmed using fluoroscopic imaging.  The pin may be removed after the sliding hip screw is placed, or a cannulated screw may be placed over it if a guide pin has been used (Figure 9). 

Figure 9. An "anti-rotational" cannulated screw has been placed proximal to the sliding hip screw for rotational stability

After pin placement for the lag screw is confirmed, the incision is extended distally 4-5 cm and down to bone.  The soft tissues are gently spread apart, and a periosteal elevator is used to clear soft tissue off the bone, attempting to leave the periosteum intact.  The guide wire is measured and the reamer set to the appropriate depth.  Intermittent flouro shots should be taken during reaming and placement of the lag screw, as the guide wire will sometimes become bound and can penetrate the joint, even going into the pelvis if not noted.  The lag screw is then placed, followed by the appropriate angled side plate. 

After securing the side plate, traction should be let off and the screw retightened.  This may lead to improved compression at the fracture site.  A compression screw is routinely used to gain further compression and protect the lag screw from becoming disengaged from the barrel of the side plate.

If adequate reduction is not obtained by closed means, one should consider an open reduction to ensure that an anatomic reduction is obtained (see Approach section).  An incision is made similar to that for placement of a sliding hip screw.  Occasionally, the fracture may have an apex posterior deformity.  One can start the guide pin placement and advance it to the fracture site.  At this point, an angled ball spiked pusher or Cobb elevator may be used to correct the deformity by applying a posterior to anterior force.  Once fracture reduction is confirmed under fluoroscopy the guide wire is advanced. 

Another common deformity that may present is varus alignment after traction is released, particularly when there has been a medial fracture gap during traction application.  Again, in addressing this deformity, the guide wire is started and advanced to the fracture site.  A bone hook is then placed around the medial cortex and a ball spike pusher is placed on the lateral cortex.  A push-pull technique is applied to reduce the gap in correct alignment, and the guide wire is advanced. 

Multiple techniques may be used to assist with reduction, including Schanz pins into the subtrochanteric region and femoral neck.  A Schanz pin placed into the subtrochanteric region may assist with rotation.  This will allow for improved exposure of the fracture site to debride any bone fragments and hematoma.  Schanz pins or threaded Kirschner wires in the femoral neck may be used as joysticks to assist with reduction. 

Once the reduction is performed, guide wires are then advanced into the femoral head (Figures 10 and 11).  Reduction and guide wire placement are confirmed on fluoroscopic imaging and cannulated screws or a sliding hip screw may be placed after measurement for length.  Other instruments that may assist with holding the reduction include Weber or Jeungbleuth clamps.  Although larger Schanz pins may be used in the subtrochanteric region, it is recommended that small-diameter wires be used in the femoral head, such as 2.5-mm terminally threaded Kirschner wires.

Figure 10. Comminuted high-energy femoral neck fracture with multiple guide wires placed just lateral to fracture site to be ready for advancement once reduction is achieved

Figure 11. Reduction achieved and guide wires advanced to hold reduction until definitive fixation is completed

A cephalomedullary nail may also be used for the treatment of femoral neck fractures.  One difference between using a cephalomedullary nail and other constructs is that it is more difficult to place the provisional or derotational guide wires/pins in the intramedullary canal, as these have to be placed anterior or posterior to the nail path.  It is recommended that the pin be placed anterior so as not to risk damage to the femoral head blood supply, which runs posteriorly.  The pin is started on the lateral cortex and advanced either through the anterior aspect of the neck, or even outside of the neck and into the head. 

Pearls and Pitfalls

Evaluation

• In older patients with pain and inability to bear weight despite normal plain films, a screening MRI will identify occult fractures
• In high-energy trauma patients with femoral shaft fracture, consider a CT scan of the femoral neck as part of the protocol.
• For displaced fractures, an AP hip traction film with internal rotation of the foot will often clarify the fracture pattern and may be more useful than CT scanning for that purpose.

Closed Reduction Percutaneous Pinning (CRPP)

• Be gentle in moving and positioning the patient to avoid displacement.
• Lag screw insertion should follow basic principles: parallel alignment of screws perpendicular to the fracture line, all screw threads should be across the fracture line, and use washers in the metaphysis.
• Three screws are adequate for fixation: one against the posterior neck cortex, one against the inferior neck cortex, and one placed anterior to form an inverted triangle in cross section.
• Do not start the screw more distal on the lateral cortex than the level of the lesser trochanter, due to risk of subtrochanteric fracture postoperatively.
• Experimental studies suggest that intracapsular bleeding leading to tamponade and increased pressure may contribute to the risk of avascular necrosis. Currently, there is insufficient evidence to recommend routine capsulotomy to decompress the hip, but this could be done percutaneously at the time of fixation.  Percutaneous capsulotomy or aspiration of the hip at the time of the procedure is a low risk procedure, and has been shown to reduce the pressure in the hip and in the bone.

Open Reduction Internal Fixation (ORIF)

• Anatomic reduction is the goal, and adequate visualization is required.
• Reduction is facilitated by full muscle relaxation
• During an open procedure, reduction of the fragments is facilitated by using joysticks: a Schanz screw in the femur and a 2.5-mm threaded-tip K-wire in the femoral head
• In the case of vertical fracture patterns (Pauwels 3) fixed with multiple screws, consider using a more horizontal lag screw, perpendicular to the fracture line, in addition to screws closer to the neck axis.  All screws should have a washer when necessary due to metaphyseal cortex.  Alternatively, use of a compression hip screw or a cephalomedullary nail may provide superior resistance to displacement for these fractures.
• When using a sliding compression screw or cephalomedullary nail, remember the tip-apex distance, and keep the summed value on AP and lateral radiographs below 25 mm.

Postoperative Care

Mobilization

• Patients should sit up and get out of bed as soon as possible after surgery, preferably on the day of the operation.
• Early ambulation is associated with accelerated recovery and shorter length of stay, so mobilization with transfer training and ambulation with aids is begun on POD # 1.   Occupational therapy consultation for activities of daily living is also helpful.
• Older patients who are allowed to bear weight as tolerated after fixation of a hip fracture appear to voluntarily limit loading on the leg, and to progressively increase over the first 6 weeks.   It has been known for decades that unrestricted weight bearing does not lead to increased complications.

Physical Therapy

• A prospective study from the 1980’s showed that patients who had early hospital discharge and home rehabilitation achieved quicker and more effective recovery than patients kept in the hospital for treatment.
• In another study, discharge to an inpatient rehabilitation facility resulted in more overall days in the facilities, without an improvement walking ability, place of residence, need for home assistance or independence in activities of daily living at 6 or 12 months.
• In a study of Medicare beneficiaries, subacute rehab in a skilled nursing facility was shown to be less costly and have similar or better outcomes in most measures compared with inpatient rehabilitation facilities.

Outcome

• Unfortunately, the 1-year mortality following hip fractures in older patients still approaches 25% (OKU 10, Mullis and Anglen, “Hip Trauma”).  Surgery for these patients should be done with the goal of pain control and early mobilization to avoid further complications. 
• Approximately 40% of patients will not return to their previous level of ambulation even after 1 year, and more than 20% of patients will need to move to a more dependent state of living long term.
• For the young, healthy population, there is a significant risk of avascular necrosis of the femoral head (10-15%) and femoral neck non-union (10-30%) following surgery.

Complications

The surgical complications of femoral neck fracture fixation include the following:

Avascular Necrosis

The reported incidence of avascular necrosis in the literature has ranged from 0-86%,   and is generally agreed to be higher in displaced fractures.  In non-displaced or impacted fractures, the incidence of avascular necrosis is approximately 5% or less, despite some reports of higher rates.

A recent meta-analysis found the incidence of avascular necrosis in displaced fractures to be 22%.   One study found only a third of femoral heads with some avascular necrosis to be significantly symptomatic.   There may be a lower incidence of avasculasr necrosis with a sliding hip screw than with five types of cannulated screw constructs, but there does not seem to be any difference in re-operation.

No difference in avascular necrosis rates has been consistently proven in early versus late reduction, although this information is based only on case series report, as there are no controlled trials or population based studies.   Many surgeons believe that early reduction of displaced femoral neck fractures in young patients reduces the likelihood of avascular necrosis.

Non-union/Loss of fixation

In non-displaced or impacted fractures, loss of fixation is uncommon, occurring mostly in severely osteopenic bone with suboptimal screw placement.  A recent prospective level II study of over 1,000 femoral neck fractures treated with internal fixation in the UK found undisplaced fractures had a non-union rate of 8.5%.   One study suggested that cancellous screw fixation is associated with fewer non-unions than sliding hip screw fixation, which in turn has fewer non-unions than archaic devices such as nail plates.   However, a 2011 meta-analysis did not support a difference in healing between these two implants. &nbsp In these mostly older patients, non-union should be treated with prosthetic replacement.

In displaced fractures, the risk of non-union is higher, approximately 30% higher in the study mentioned above.  Non-union was more common in women than men (21% vs. 12%) and progressively increased with age, when analyzed with < 1 yr mortalities excluded.   In physiologically older patients, non-union or loss of fixation is treated with arthroplasty, while in younger and active patients, the femoral head can be salvaged with valgus intertrochanteric osteotomy.

Hardware Prominence or Penetration 

Unrecognized penetration of the femoral head by screws can occur in up to 10% of cases, and is more common in valgus impacted fractures (Garden I) than in other types. Care should be taken to visualize the head of the femur through its full circumference using the C-arm intraoperatively.  If identified, the offending screw should be replaced rather than simply backed up.

Surgical Site Infection 

Superficial or deep infection may occur in as many as 5% of patients after femoral neck fracture fixation.  Perioperative prophylactic antibiotics may reduce the incidence.  When identified, wound infections should be treated promptly with irrigation, debridement, secondary closure, and antibiotics.  If the implants are stable and the fracture is not healed, they should be left in place.  If the hardware is loose or non-functional, or the infection is in the joint, removal of metal and excisional arthroplasty should be considered.

Medical Complications in Older Patients

Older hip fracture patients are at risk for many medical complications, involving a wide range of bodily systems.  A recent review of hip fracture complications reported by candidates for the American Board of Orthopaedic Surgery oral examination revealed incidence rates for pneumonia, renal failure, deep venous thrombosis, congestive heart failure, myocardial infarction, anemia, delirium, arrhythmia, and pulmonary embolus between 0.5% and 2.5% (personal communications, J. Anglen, manuscript in preparation).  Involvement of a hospitalist or medical consultant in the perioperative care of these patients is prudent.

Delirium is a syndrome characterized by acute onset of fluctuating levels of alertness or consciousness and a variety of other mental symptoms. The incidence of this problem following semi urgent hip fracture repair may be up to 35%, and it can persist as long as 6 months postoperatively.   Delirium is associated with prolonged hospitalization, increased cost, and poorer outcomes in terms of activities of daily living.  Although the knee-jerk response to a patient suspected of being delirious may be to stop all medications, inadequate pain control is a risk factor for delirium.  The mainstay of treatment is prevention, and a proactive geriatric consultation may decrease delirium incidence by more than a third in hip fracture patients.

References

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