History and physical examination

1. 
   

   Bimodal age distribution.

   
   
   
   
   1. 
      

      Young patient—usually high-energy injury.

      
      
   2. 
      

      Older patient—usually low-energy injury, typically ground-level fall.

   
   
2. 
   

   Preoperative functional activity level, especially important when considering fractures in the elderly.

   
   
3. 
   

   Preexisting hip pain can correlate with pathologic fracture or longstanding hip arthritis, necessitating biopsy or total hip arthroplasty.

   
   
4. 
   

   A complete history and physical examination should be coordinated with the appropriate medical team, especially in the case of an elderly patient with preexisting medical comorbidities.

   
   
5. 
   

   High-energy injuries have a high suspicion for associated femoral head and neck trauma, chest and abdominal injuries, and coexisting extremity injuries.

   
   
6. 
   

   Frail elderly patients may sustain coexisting injuries such as cervical and rib fractures that could adversely affect the treatment outcomes.

   
   
7. 
   

   The affected extremity will be shortened and externally rotated in displaced fractures.

   
   
8. 
   

   A complete neurovascular examination of all extremities is imperative, as well as palpation and range of motion for all joints.

Anatomy

1. 
   

   Femoral neck-shaft angle is approximately 130 degrees with 10 degrees of anteversion.

   
   
2. 
   

   Typical femoral head diameter is between 40 to 60 mm with a 3 to 4 mm hyaline cartilage cap.

   
   
3. 
   

   Femoral head and neck blood supply (▶ Fig. 33.1 ) is predominantly from the branches of the medial femoral circumflex artery, with secondary supply from the lateral femoral circumflex and the artery of the ligamentum teres. Retinacular arteries arise from terminal branches of the medial femoral circumflex artery and provide critical blood supply to the weight-bearing portions of the femoral head.

   

   
   
4. 
   

   The calcar femorale is a strong bony buttress along the posteromedial aspect of the neck.

   
   
5. 
   

   The greater trochanter serves as an attachment for the hip abductors (gluteus medius and minimus).

   
   
6. 
   

   The iliopsoas inserts at the lesser trochanter.

   
   
7. 
   

   A thick capsule encases the femoral neck and head consisting of the iliofemoral, ischiofemoral, and pubofemoral ligaments (see Chapter 32, Hip Dislocation, ▶ Fig. 32.3 ).

   
   
8. 
   

   Congruency of the femoroacetabular joint is increased by the presence of circular fibrocartilaginous labrum.

Imaging

1. 
   

   Plain radiographic imaging (XR) should include views of anteroposterior (AP) pelvis, AP hip, and lateral hip to adequately visualize the fracture morphology.

   
   
2. 
   

   If difficult to differentiate an intertrochanteric fracture from a femoral neck fracture, therefore additional imaging may be required—AP traction view in internal rotation or computerized tomography (CT) scan can be obtained to further categorize the fracture pattern.

   
   
3. 
   

   Full-length femur films (AP, lateral) should be obtained to evaluate for any preexisting deformity, hardware/prosthesis, or excessive anterior bowing which could affect treatment.

   
   
4. 
   

   With a suspected occult femoral neck fracture, MRI is the study of choice as it demonstrates higher sensitivity than CT for detection of nondisplaced fractures.

Classification

1. 
   

   Subcapital—fracture abutting femoral head (▶ Fig. 33.2a ).

   

   
   
2. 
   

   Transcervical—fracture along midneck (▶ Fig. 33.2b ).

   
   
3. 
   

   Basicervical—fracture along base of femoral neck (▶ Fig. 33.2c ).

   
   
4. 
   

   Garden classification ( Fig. 33.3 )—based on displacement and risk of avascular necrosis (AVN), which increases with increasing grade.

   

   
   
   
   
   1. 
      

      Grade I—incomplete, valgus impacted.

      
      
   2. 
      

      Grade II—complete, nondisplaced.

      
      
   3. 
      

      Grade III—complete, partially displaced.

      
      
   4. 
      

      Grade IV—complete, fully displaced.

      
      
   5. 
      

      More accurately defined as nondisplaced Garden I/II and displaced Garden III/IV.

   
   
5. 
   

   Pauwels classification (▶ Fig. 33.4 ) is based on fracture inclination and with reference to the horizontal plane which determines classification. Increased verticality is associated with increased instability due to shear forces transferred during weight bearing.

   

   
   
   
   
   1. 
      

      Type I: < 30 degrees.

      
      
   2. 
      

      Type II: 30 to 50 degrees.

      
      
   3. 
      

      Type III: > 50 degrees.

   
   
6. 
   

   Femoral neck stress fractures—fatigue fracture that occurs when bone is subjected to repetitive abnormal forces which overcome innate reparative biology.

   
   
   
   
   1. 
      

      High-risk patients

      
      
      
      
      • 
        

        i. Military recruits, runners, and females.

        
        
      • 
        

        ii. Young recreational athletes with rapid increase in activity duration, frequency, or intensity.

        
        
      • 
        

        iii. Female athlete triad—eating disorder, amenorrhea, and osteoporosis.

      
      
   2. 
      

      Workup

      
      
      
      
      • 
        

        i. History

        
        
        
        
        • 
          

          Menstrual irregularities.

          
          
        • 
          

          Assess calcium and vitamin D levels and supplement accordingly.

        
        
      • 
        

        ii. XR—initially nondiagnostic, but may show endosteal/periosteal changes or a thin black line as the fatigue fracture progresses.

        
        
      • 
        

        iii. Magnetic resonance imaging (MRI)—gold standard imaging modality.

        
        
      • 
        

        iv. Bone scan—sensitive but nonspecific.

      
      
   3. 
      

      Types

      
      
      
      
      • 
        

        i. Compression—fracture initiating on inferior aspect of the femoral neck.

        
        
        
        
        • 
          

          Conservative treatment with nonweight bearing until asymptomatic, followed by gradual return to activities.

          
          
        • 
          

          If fatigue line > 50% neck diameter, treat with percutaneous pinning (as described in operative management section).

        
        
      • 
        

        ii. Tension—fracture initiating on superior aspect of the femoral neck–treat with percutaneous pinning.

        
        
      • 
        

        iii. Displaced—open reduction and internal fixation.

Initial management

1. 
   

   Management in the emergency department begins with a complete history and physical examination, and assessment of associated injuries and medical comorbidities.

   
   
2. 
   

   More than half (50–70%) of nonelderly patients sustaining high-energy injuries with femoral neck fractures will have significant coexisting injuries.

   
   
3. 
   

   Excessive manipulation of the hip should be avoided to decrease unnecessary discomfort and risk of further fracture displacement.

   
   
4. 
   

   A foley catheter should be placed for patient comfort; transferring to a bedpan can be difficult and painful.

   
   
5. 
   

   Judicious use of pain medication is advised, especially among elderly patients who are prone to excessive sedation.

Definitive management

1. 
   

   Nonoperative treatment:

   
   
   
   
   1. 
      

      An option for stable, nondisplaced, valgus-impacted fractures.

      
      
      
      
      • 
        

        i. Around 6 to 12 weeks of touchdown weight-bearing with a walker should be allowed for sufficient healing.

        
        
      • 
        

        ii. Associated with an increased risk of future displacement resulting in nonunion, AVN, and a poor functional outcome.

      
      
   2. 
      

      Elderly patients with extensive medical comorbidities at high risk of perioperative cardiopulmonary complications.

      
      
      
      
      • 
        

        i. Renders mobilization more difficult.

        
        
      • 
        

        ii. Consider supplemental pain management via regional anesthesia (nerve blocks and catheters).

        
        
      • 
        

        iii. This route of management should be discussed with the patient and family, emphasizing the high risk of associated medical complications associated with prolonged immobility.

        
        
      • 
        

        iv. The consideration of transfer to end of life/comfort care is a real discussion for these patients.

   
   
2. 
   

   Operative management and fixation:

   
   
   
   
   1. 
      

      Standard of care.

      
      
   2. 
      

      A stabilized fracture allows more rapid mobilization and decreases morbidity and mortality, which often occurs with prolonged bed rest, and improves patient function.

      
      
   3. 
      

      Improved outcomes are associated with surgical fixation within 24 to 48 hours of presentation.

Surgical approaches and fixation techniques (▶ Fig. 33.5 )

1. 
   

   Open reduction internal fixation—ideal for a young patient with displaced femoral neck fracture.

   
   
   
   
   1. 
      

      Anterolateral approach (Watson-Jones) (▶ Fig. 33.6 ).

      

      
      
      
      
      • 
        

        i. Lateral incision centered over the greater trochanter, extending 6 to 8 cm distally along the femoral shaft and 6 to 10 cm proximally curving slightly anterior (incision remains 3 cm posterior to the anterior superior iliac spine [ASIS]).

        
        
      • 
        

        ii. Superficial dissection: Incise the iliotibial band at the distal extent of the incision and proceed toward the anterior half of the greater trochanter. Proximally, incise fascia along the posterior border of the tensor fascia lata.

        
        
      • 
        

        iii. Deep dissection: Retract tensor fascia lata (superior gluteal nerve) anteriorly and gluteus medius (superior gluteal nerve) posteriorly. Mobilize the reflected head of the rectus femoris (femoral nerve) medially, as needed, to expose the anterior hip capsule.

        
        
      • 
        

        iv. Externally rotate the femur and perform a capsulotomy to expose the femoral neck.

        
        
      • 
        

        v. To improve visualization of the base of the femoral neck, incise the anterior 1 to 2 cm of the gluteus medius insertion and vastus lateralis origin. This also facilitates placement of a lateral side plate (for sliding hip screw fixation) or insertion of cancellous screws.

        
        
      • 
        

        vi. Be aware that this approach provides only limited visualization of subcapital femoral neck fractures.

      
      
   2. 
      

      Anterior approach (Smith-Petersen) (▶ Fig. 33.7 ).

      

      
      
      
      
      • 
        

        i. Anterior incision from the iliac crest 2 to 3 cm proximal to the ASIS, extending toward the ASIS and then 10 cm distal toward the lateral border of the patella.

        
        
      • 
        

        ii. Superficial dissection: Identify and the develop the interval between the sartorius (femoral nerve) medially and tensor fascia lata (superior gluteal nerve) laterally.

        
        
      • 
        

        iii. Avoid injury to the lateral femoral cutaneous nerve that pierces the fascia near the ASIS and lies superficial to the sartorius.

        
        
      • 
        

        iv. Ligate ascending branches of the lateral femoral circumflex artery as needed.

        
        
      • 
        

        v. Deep dissection: Retract the gluteus medius (superior gluteal nerve) laterally and the two heads of the rectus femoris (femoral nerve) medially off the hip capsule.

        
        
        
        
        • 
          

          The direct (straight) head arises from the AIIS and should be mobilized medially.

          
          
        • 
          

          The indirect (reflected) head originates on the superior acetabulum and may need to be detached to expose subcapital femoral neck fractues and femoral head fractures.

        
        
      • 
        

        vi. Adduct and externally rotate the femur to place the hip capsule on stretch.

        
        
      • 
        

        vii. Perform a capsulotomy to expose the femoral neck.

        
        
      • 
        

        viii. This approach provides excellent exposure for most femoral neck fractures and facilitates fracture reduction; however, a separate lateral incision is typically required for implant fixation.

   
   
2. 
   

   Percutaneous screw fixation (▶ Fig. 33.8 ):

   

   
   
   
   
   1. 
      

      Placement of multiple cancellous (typically cannulated) screws via a limited lateral incision provides stable fixation in anatomically-reduced or valgus-impacted fractures.

      
      
   2. 
      

      If further reduction of the fracture is required, extension of the incision to an anterolateral approach (Watson-Jones) or a separate anterior approach (Smith-Petersen) to the hip is required for access to the femoral neck.

      
      
   3. 
      

      Patient is positioned supine on a fracture table and the contralateral leg is either scissored or placed in the lithotomy position, allowing appropriate fluoroscopic imaging access (▶ Fig. 33.9a ).

      

      
      
   4. 
      

      C-arm is brought in from the nonoperative side at approximately 45 degrees to obtain adequate AP and lateral images of the affected hip (▶ Fig. 33.9b ).

      
      
   5. 
      

      Appropriate placement of the incision and guide pin entry can be marked by the intersection of the lines created by laying a guide pin on the skin in line with the central femoral head and neck in the both the AP and lateral projections (▶ Fig. 33.9c, d ).

      
      
   6. 
      

      A straight lateral incision is made through skin and through the fascia lata for placement of the guide pins which are later replaced by cannulated screws.

      
      
   7. 
      

      The first screw is placed in a central inferior location within 3 mm of the stronger cortical bone followed by 2 parallel superior screws (anterosuperior and posterosuperior) in an inverted triangle position.

      
      
   8. 
      

      Pin length is then measured with the appropriate depth gauge, and the appropriate size cancellous screws (6.5–8.0 mm) are then chosen.

      
      
   9. 
      

      Partially threaded screws allow adequate compression of the fracture.

      
      
      
      
      • 
        

        i. Washers can be placed along the lateral cortex to increase the purchase of the screw head or adjust for excessive screw length.

      
      
   10. 
       

       Fully threaded screws can subsequently be placed for length stability, if needed.

   
   
3. 
   

   Sliding hip screw (▶ Fig. 33.10 )

   

   
   
   
   
   1. 
      

      Patient positioned supine on the fracture table.

      
      
   2. 
      

      A straight lateral incision is made along the proximal lateral thigh, deep to fascia. A slightly large incision is required compared to the technique described for percutaneous screws.

      
      
   3. 
      

      Using the device appropriate aiming guide (based on the neck-shaft angle), a guide pin is placed in a central position on both the AP and lateral projections to within 5 mm of subchondral bone.

      
      
   4. 
      

      Consider inserting an antirotation screw to prevent rotary displacement of the fracture.

      
      
   5. 
      

      The pin is overdrilled with care to keep the tip of the pin engaged in the subchondral bone.

      
      
   6. 
      

      The screw path is then tapped.

      
      
   7. 
      

      The appropriate length compression screw is then placed followed by placement of the slide plate which is secured by two or more screws.

      
      
   8. 
      

      This technique may provide more stable fixation for vertical fracture patterns and basicervical fractures.

   
   
4. 
   

   Arthroplasty (▶ Fig. 33.11 ):

   

   
   
   
   
   1. 
      

      Displaced femoral neck fractures in physiologically older patients may be treated definitively with prosthetic replacement.

      
      
   2. 
      

      Hemiarthroplasty is generally reserved for elderly patients with low demands and without preexisting hip arthritis.

      
      
   3. 
      

      Total hip arthroplasty (THA) should be considered for the more active patient.

      
      
      
      
      • 
        

        i. Better pain relief.

        
        
      • 
        

        ii. Improved functional outcomes compared to hemiarthroplasty.

        
        
      • 
        

        iii. Decreased risk of requiring revision surgery as osteoarthritis progresses on the acetabulum.

      
      
   4. 
      

      There are a variety of surgical approaches (anterior, anterolateral, direct lateral, and posterior), each with distinct advantages and disadvantages. The anterior and anterolateral approaches are described above; the posterior approach is described in detail in the acetabular chapter).

      
      
   5. 
      

      Posterolateral approach:

      
      
      
      
      • 
        

        i. Split iliotibial fascia and gluteus maximus. Requires take down of the short external rotators.

        
        
      • 
        

        ii. Familiar to most surgeons.

        
        
      • 
        

        iii. Requires secure posterior capsule and short external rotator repair to minimize dislocation risk.

      
      
   6. 
      

      Anterior approach:

      
      
      
      
      • 
        

        i. Interval between sartorius (femoral nerve) and tensor fascia lata (superior gluteal nerve).

        
        
      • 
        

        ii. Improved early mobilization in some studies.

        
        
      • 
        

        iii. More difficult femoral exposure and increased risk of intraoperative femur fracture.

        
        
      • 
        

        iv. Steep learning curve.

      
      
   7. 
      

      Anterolateral approach:

      
      
      
      
      • 
        

        i. Interval between tensor fascia lata and gluteus medius.

        
        
      • 
        

        ii. Decreased dislocation risk.

        
        
      • 
        

        iii. Violates abductors and may lead to postoperative limp.

      
      
   8. 
      

      Direct lateral approach:

      
      
      
      
      • 
        

        i. Splits gluteus medius and vastus lateralis.

        
        
      • 
        

        ii. Decreased risk of dislocation.

        
        
      • 
        

        iii. Violates abductors and may lead to postoperative limp and higher rates of heterotopic ossification.

Complications

1. 
   

   Avascular necrosis:

   
   
   
   
   1. 
      

      10 to 30%.

      
      
   2. 
      

      Intracapsular femoral neck fractures disrupt the blood supply to the femoral head to varying degrees.

      
      
   3. 
      

      Increased risk with increasing displacement and subcapital fracture.

      
      
   4. 
      

      Decreased risk with timely anatomic reduction.

   
   
2. 
   

   Fixation failure:

   
   
   
   
   1. 
      

      10 to 20%.

      
      
   2. 
      

      Increased risk with posterior comminution, initial displacement, age, and osteoporosis.

   
   
3. 
   

   Nonunion:

   
   
   
   
   1. 
      

      10 to 20%.

      
      
   2. 
      

      Same risk factors as fixation failure.

   
   
4. 
   

   Dislocation:

   
   
   
   
   1. 
      

      1 to 10%.

      
      
   2. 
      

      Higher dislocation rates of THA for fracture compared to elective THA for arthritis.

      
      
      
      
      • 
        

        i. Lack of preoperative stiffness associated with arthritis.

        
        
      • 
        

        ii. Baseline cognitive dysfunction (i.e., dementia and alcoholism).

      
      
   3. 
      

      Higher dislocation rates of THA compared to hemiarthroplasty—larger femoral heads utilized in hemiarthroplasty have increased jump distance.

   
   
5. 
   

   Acetabular erosion (hemiarthroplasty):

   
   
   
   
   1. 
      

      10 to 40%.

      
      
   2. 
      

      Less of an issue if hemiarthroplasty is selected for lower demand patients.

   
   
6. 
   

   Prosthesis failure (component wear and loosening)—2 to 8%.

   
   
7. 
   

   Infection:

   
   
   
   
   1. 
      

      1 to 5%.

      
      
   2. 
      

      Increased risk with arthroplasty.

   
   
8. 
   

   Mortality—30% at one year for the elderly patient.

Rehabilitation

1. 
   

   Optimal treatment of femoral neck fractures allows early mobilization with immediate weight-bearing in an effort to decrease medical complications associated with recumbency.

   
   
2. 
   

   Typically, elderly patients are weight-bearing as tolerated immediately following surgery, as they are unable to comply with more limited restrictions.

   
   
3. 
   

   Younger patients sustain higher energy and comminuted fractures and are typically prescribed a period of touchdown weight-bearing for 6 to 12 weeks.

   
   
4. 
   

   Weight-bearing as tolerated is recommended following arthroplasty. Range of motion precautions are dependent upon the surgical approach chosen.

   
   
5. 
   

   Most physiologically older patients require a prolonged stay in a rehabilitation facility. Half of these patients will require permanent gait aids and experience some decrease in overall mobility and function.

Outcomes

1. 
   

   Debate exists in the literature regarding optimal treatment of femoral neck fractures:

   
   
   
   
   1. 
      

      Fixation with cancellous (cannulated) screws versus sliding hip screw in young adults (< 50 years old).

      
      
   2. 
      

      Fixation versus arthroplasty for middle-aged adults (50–65 years old).

      
      
   3. 
      

      Type of arthroplasty in elderly patients.

   
   
2. 
   

   In general, anatomic restoration of the native femoral head and neck will produce optimal results; however, as age increases and the quality of bone decreases, results of fixation are not as reliable due to potential loss of fixation, nonunion, and AVN.

   
   
3. 
   

   In a physiologically older patient, prosthetic replacement with THA will produce satisfactory results and decrease the need for future surgery if fixation were to fail.

   
   
4. 
   

   In the low demand, elderly patient, treatment with hemiarthroplasty may suffice, and is associated with a lower risk of dislocation when compared to THA