AAOS Comprehensive Orthopaedic Review

Section 6 - Trauma

Chapter 55. Fractures of the Hip

I. General Considerations

A. Epidemiology

 

1. Hip fractures occur most commonly in patients 70 years of age or older.

 

2. The risk of hip fracture increases with decreasing bone mass.

 

3. Hip fractures are more common in women than in men.

 

4. Intertrochanteric femur fractures account for approximately 50% of all proximal femur fractures.

 

5. Femoral neck fractures are slightly less common and account for approximately 40% of proximal femur fractures.

 

B. Anatomy

 

1. Fractures of the proximal femur are distinguished by their anatomic location in relationship to the joint capsule.

 

a. Femoral neck fractures are considered intracapsular fractures, which are at higher risk of nonunion because they can be enveloped by synovial fluid. Because of the absence of periosteal or extraosseous blood supply, no callus forms during healing. Rather, fracture healing occurs by intraosseous bone healing.

 

b. Intertrochanteric fractures are considered extracapsular fractures. Callus formation is common in these fracture patterns, and non-union is rare because of the absence of synovial fluid and the presence of an abundant blood supply.

 

2. Vascular anatomy (

Figure 1)

 

a. The medial femoral circumflex artery is the main blood supply to the femoral head. This artery terminates in the posterior aspect of the extracapsular arterial ring.

 

b. The lateral femoral circumflex artery gives rise to the anterior aspect of the arterial ring.

 

c. The superior and inferior gluteal arteries also contribute branches to the ring.

 

d. The ascending cervical arteries originate from the extracapsular arterial ring and are divided into four distinct groups based on their anatomic relationship to the femoral neck: lateral, medial, posterior, and anterior. The lateral group of ascending branches is the main blood supply to the femoral head.

 

e. The ascending branches give off multiple perforator vessels to the femoral neck and terminate in the subsynovial arterial ring located at the margin of the articular surface of the femoral head. The lateral epiphyseal artery then penetrates the femoral head and is believed to be the dominant blood supply to the femoral head from this system. Fractures that disrupt the ascending blood flow to the lateral epiphyseal vessel have increased risk of osteonecrosis.

 

f. The artery of the ligamentum teres arises from either the obturator or medial femoral circumflex artery. It does not provide sufficient blood supply to maintain the viability of the femoral head.

 

C. Surgical approaches

 

1. The anterior lateral (Watson-Jones) approach is used for open reduction and internal fixation (ORIF) of femoral neck fractures or hemiarthroplasty.

 

a. This approach is based on the interval between the gluteus medius and the tensor fascia lata. There is no internervous plane because both muscles are innervated by the superior gluteal nerve.

 

b. The superior gluteal nerve can be damaged if the intermuscular plane is extended to the iliac crest.

 

2. The anterior (Smith-Peterson) approach can be used for ORIF of the femoral neck or hemiarthroplasty. If used for ORIF, a separate lateral approach to the proximal femur is required for fixation placement.

 

a. The superficial dissection is between the tensor fascia lata (superior gluteal nerve) and the sartorious (femoral nerve).

 

[Figure 1. Vascular anatomy of the femoral head and neck.]

b. The deep dissection is between the gluteus medius (superior gluteal nerve) and the rectus femoris (femoral nerve).

 

c. The lateral femoral cutaneous nerve is at risk with this approach.

 

d. The ascending branch of the lateral femoral circumflex artery is encountered between the tensor and the sartorius and must be sacrificed.

 

3. The lateral (Hardinge) approach is used primarily for hemiarthroplasty. This approach splits both the gluteus medius and the vastus lateralis, reflecting the anterior third of these structures medially. The superior gluteal nerve and artery are at risk in this approach.

 

4. The posterior (Southern) approach is used primarily for partial or total hip arthroplasty (THA).

 

a. The approach splits the gluteus maximus muscle (inferior gluteal nerve) and the fascia lata.

 

b. The tendons of the piriformis, obturator internus, and the superior and inferior gemelli are transected at their point of insertion and retracted posteriorly.

 

c. The sciatic nerve is the main structure at risk with this exposure.

 

5. The lateral approach to the proximal femur is used for ORIF of intertrochanteric femur fractures.

 

a. This is a direct lateral approach that splits the fascia lata and either elevates the vastus lateralis from posterior to anterior, or splits the muscle fibers.

 

b. There is no internervous plane; the vastus lateralis is innervated by the femoral nerve.

 

D. Hip biomechanics

 

1. The average neck-shaft angle in the adult femur is 130° ± 7°. The average anteversion of the neck is 10° ± 7°.

 

2. Forces on the proximal aspect of the femur are complex. The osseous structure itself also is complex, consisting of both cortical and cancellous bone.

 

a. The two prime trabecular groups of the proximal femur are the principal tensile group and the principal compressive group. There are also secondary compressive and tensile trabecular groups (

Figure 2). These trabecular bone patterns are the result of bone response to stress, expressed as Wolff's law.

 

b. The weakest area in the femoral neck is located in the Ward triangle.

 

c. The calcar femorale is a medial area of dense trabecular bone that transfers stress from the femoral shaft to the inferior portion of the femoral neck.

 

d. Fractures of the proximal femur follow the path of least resistance.

 

e. The amount of energy absorbed by the bone determines the degree of comminution.

 

3. Standing position

 

a. The center of gravity is located at the midpoint between the two hips.

 

b. The weight of the body is supported equally by both hips.

 

c. The force vector acting on the hip is vertical.

 

d. The Y ligament of Bigelow resists hyperextension. Minimal muscle forces are required for balance in symmetric stance, and the joint reactive force or compressive force across the hip is approximately one half the body weight.

 

4. Single-leg stance

 

a. The center of gravity moves away from the hip. To counter the eccentric lever arm created by the weight of the body, the hip abductors contract to maintain the pelvis in a level position. Because the lever arm created by the lateral offset of the greater trochanter is shorter than the lever arm created by the entire body opposite the hip, the magnitude of muscle contracture is greater than the weight of the body. This results in a compressive load across the hip of approximately 4 times the body weight.

 

[Figure 2. Trabecular groups of the proximal femur. W = the Ward triangle.]

b. The resulting force vector in the standing phase is oriented parallel to the compressive trabeculae of the femoral neck.

 

c. In repetitive load situations, the tensile forces can cause microfractures in the superior femoral neck.

 

i. Failure of these microfractures to heal in conditions of repetitive loading results in stress fracture.

 

ii. Frequency and degree of load influence the fatigue process.

 

5. Trendelenburg gait

 

a. Trendelenburg gait is noted when the hip abductors are no longer sufficient to counter the forces in single-leg stance. Without compensation, the pelvis cannot be maintained in a level position. Weakness of the abductors can be caused by disuse, paralysis, or by a diminished lever arm as a result of decreased femoral offset.

 

b. To compensate for the weakness of the abductors, the center of gravity can be shifted closer to the affected hip. This is done by shifting the upper body over the standing hip in single-leg stance, resulting in the classic waddling gait. Alternatively, a cane used in the opposite hand can diminish the load on the hip in single-leg stance by nearly 40%.

 

E. Mechanism of injury

 

1. Hip fractures in the elderly are generally the result of low-energy trauma. Frequently, the patient

 

[

Figure 3. Radiographic evaluation should include an AP view of the pelvis (A), an AP view of the hip (B), and a cross-table lateral view (C).]

   sustains the fracture as a result of a fall from a standing height.

 

a. A fall to the side that impacts the greater trochanter is more likely to cause a fracture.

 

b. External rotation of the distal extremity and the tethering of the anterior femoral capsule can result in posterior comminution of the femoral neck.

 

c. One method of fracture prevention is training in fall prevention; protective padding has demonstrated efficacy but is often not practical.

 

2. Hip fractures in younger individuals are often the result of high-energy trauma that exerts an axial load on the femoral shaft either through the distal femur or through the foot with the hip and knee extended.

 

F. Clinical evaluation

 

1. The injured extremity is usually shortened and externally rotated. A careful examination of the extremity should be performed, with particular attention given to skin condition and neurologic status.

 

2. In the geriatric population, a careful evaluation for medical comorbidities should be undertaken. The number of comorbidities is directly related to 1-year mortality figures: Patients with four or more comorbidities have been reported to have a higher 1-year mortality rate than patients with three or fewer.

 

3. In the high-energy trauma patient, a systematic search for other injuries should be undertaken as well as a careful secondary assessment of the injured extremity for associated fractures.

 

G. Radiographic evaluation

 

1. An AP radiograph of the pelvis, an AP of the hip, and a cross-table or frog lateral are required for diagnosis and preoperative planning (Figure 3).

 

2. Normal radiographs do not exclude a hip fracture; 8% of patients with hip pain have an occult fracture. MRI to evaluate for the presence of an occult fracture is recommended when it can be performed in the acute setting. Alternative imaging studies include CT and bone scan. The sensitivity of bone scan is increased by waiting 24 to 72 hours following injury.

 

H. Surgical indications

 

1. Most, if not all, fractures of the proximal femur should be stabilized surgically to prevent displacement and allow for early mobilization and weight bearing. In the case of displaced fractures of the femoral neck in patients of advanced age or in patients with preexisting arthritis, arthroplasty should be considered.

 

2. In the young patient with high-energy trauma, every effort should be made to obtain and maintain an anatomic reduction of the proximal femur fracture with internal fixation.

 

3. Nonsurgical management should be considered only in nonambulatory patients and in patients who are deemed too medically ill for surgical intervention.

 

I. Timing of surgery

 

1. In the elderly patient with significant comorbidities, it is important to reverse easily correctible medical conditions before surgery, but surgery should be performed as soon as reasonably possible. Surgery should be performed when optimal medical support is available, preferably during normal surgical hours, because surgery performed in less optimal conditions is associated with increased risk of malreduction and other technical errors.

 

2. In the younger trauma population, femoral neck fractures should be addressed as soon as possible after other life-threatening injuries have been stabilized. Performing surgery without delay helps to preserve and maintain the blood flow to the femoral head, preventing or limiting the development of osteonecrosis.

 

J. Anesthesia considerations

 

1. The goal of the anesthetic technique selected is to eliminate pain, allow for appropriate intra-operative positioning, and achieve muscle relaxation to effect the reduction.

 

2. Spinal and general anesthetic techniques result in similar long-term outcomes, but spinal anesthesia may result in less postsurgical confusion, a reduced deep venous thrombosis (DVT) rate, and a diminished risk of early postsurgical death.

 

3. Spinal anesthetics are not successful in 20% of patients and must be converted to a general anesthetic.

 

K. Postoperative management

 

1. Postoperative management should focus on early mobilization of the patient and minimization of complications such as DVT, disorientation, bowel or bladder irregularities, and pressure sores.

 

2. Early hospital discharge with adequate outpatient medical and social assistance has been demonstrated to decrease overall cost and improve recovery. Inpatient rehabilitation stays have not been associated with improved functional outcomes for community ambulators.

 

3. Elderly patients should be allowed to weight bear as tolerated. This population autoregulates their weight bearing based on the stability of the fracture pattern and fixation.

 

4. In younger individuals who sustain a high-energy femoral neck fracture, early weight bearing should be avoided because of the associated soft-tissue injury and the possible risk of fixation failure.

 

5. Antibiotic prophylaxis should be given within 1 hour of surgery and continued no longer than 24 hours following surgery to prevent postoperative wound infection.

 

6. DVT is reported to occur in up to 80% of patients who sustain a proximal femur fracture. Mechanical devices and chemical prophylaxis should be used as prophylactic measures against DVT. The risk of DVT is substantially reduced with prophylaxis, although the exact type of prophylaxis and duration remain controversial.



II. Fractures of the Femoral Neck

A. Classification—Three main classification systems are used for fractures of the femoral neck.

 

1. Pauwels classification system

 

a. Not widely used, this system divides fractures into three groups based on the angle of the femoral neck fracture (

Figure 4).

 

b. This system seems most applicable to high-energy femoral neck fractures.

 

c. Vertical fracture lines were believed to be at highest risk for nonunion and osteonecrosis; however, this system seems to have little predictive value.

 

[Figure 4. Pauwels classification of femoral neck fractures. A, in type I patterns, the fracture is relatively horizontal (<30°) and compressive forces caused by the hip joint reactive force predominate. B, In type II patterns, shear forces at the fracture are predicted. C, In type III patterns, when the fracture angle is 50° or higher, shear forces predominate. Arrows indicate joint reactive force.]

[

Figure 5. Garden classification of femoral neck fractures. Stage I is an incomplete, impacted fracture in valgus malalignment (generally stable). Stage II is a nondisplaced fracture. Stage III is an imcompletely displaced fracture in varus malalignment. Stage IV is a completely displaced fracture with no engagement of the two fragments. The compression trabeculae in the femoral head line up with the trabeculae on the acetabular side. Displacement is generally more evident on the lateral view in stage IV. For prognostic purposes, these groupings can be lumped into nondisplaced/impacted (stages I and II) and displaced (stages III and IV), as the risks of non-union and aseptic necrosis are similar within these grouped stages.]

2. Garden classification

 

a. This system divides fractures into four types based on the degree of displacement (Figure 5).

 

b. The interobserver agreement for this classification scheme as originally described is poor.

 

c. Interobserver agreement increases significantly, however, when type I and type II fractures are combined and considered nondisplaced, and type III and type IV patterns are combined and considered displaced. The risk of nonunion and osteonecrosis is similar within the combined classification schemes.

 

3. AO/OTA classification

 

a. This classification system subdivides fractures based on location in the femoral neck and degree of displacement.

 

b. The femoral neck is divided into subcapital, transcervical, and basicervical regions.

 

c. This system is used mostly for research purposes.

 

B. Nonsurgical treatment

 

1. Nonsurgical treatment is reserved for the nonambulatory patient or the patient in the terminal stages of life. In general, acute pain can be controlled with narcotic medication and will subside in the first few days to a week, allowing transfers in the nonambulatory patient that are tolerable for the staff and patient.

 

2. Nonsurgical treatment can be considered for a nondisplaced femoral neck fracture, but the reported incidence of late displacement is between 15% and 30%.

 

3. Compression-related stress fractures can also be considered for nonsurgical treatment, but close follow-up and restricted weight bearing are required.

 

C. Surgical treatment

 

1. Nondisplaced fractures

 

a. The outcome is poor for displaced femoral neck fractures, so nondisplaced fractures should be stabilized to prevent late displacement. In surgically treated nondisplaced femoral neck fractures, the risk of late displacement is between 1% and 6%.

 

b. Transcervical and subcapital fractures are best treated with percutaneous placement of three partially threaded compression screws. The screws should be started at or above the level of the lesser trochanter on the lateral cortex to minimize the risk of subsequent subtrochanteric fracture. Screws should be placed in the periphery of the femoral neck to gain the support of the residual cortical bone to resist shear forces and within 5 mm of the articular surface to gain purchase in the subchondral bone. Care should be taken not to penetrate the articular surface, and multiplanar fluoroscopy should be used to confirm that no intraarticular penetration has occurred.

 

c. Basicervical fractures behave like intertrochanteric femur fractures and should be surgically stabilized with a sliding hip screw that allows controlled compression of the fracture. This fracture pattern has less inherent rotational stability than an intertrochanteric fracture, so an additional parallel screw should be placed to resist rotational forces.

 

2. Displaced fractures

 

a. Open reduction and internal fixation

 

i. In the young patient with high-energy trauma or in the active elderly patient without preexisting arthritis, reduction and fixation of the displaced femoral neck fracture with the previously described techniques should be attempted.

 

ii. The key factor in preventing nonunion, loss of fixation, and osteonecrosis is the quality and maintenance of the reduction. Closed reduction can be attempted, but the reduction needs to be anatomic. If closed reduction is unsuccessful, open reduction with an anterolateral or anterior approach to the hip should be performed.

 

iii. When closed reduction techniques are used in high-energy fractures, a capsular release may help to diminish the risk of osteonecrosis by relieving the capsular pressure on the ascending branches.

 

b. Hemiarthroplasty

 

i. Hemiarthroplasty should be considered in the low-demand individual of advanced physiologic age or chronologic age older than 80 years.

 

ii. Short-term outcomes are similar for unipolar and bipolar prosthetic designs, but in patients followed for >7 years, those with a bipolar prosthesis appeared to have better function.

 

iii. A cemented technique is preferable in most patients who are ambulatory. Uncemented technique is associated with greater postsurgical pain and higher revision rates. An uncemented prosthesis has usually been reserved for minimal ambulators.

 

c. Total hip arthroplasty

 

i. The primary indication for THA has been an arthritic, symptomatic hip joint.

 

ii. Recent studies suggest that for displaced femoral neck fractures, functional outcomes are better with THA than with hemiarthroplasty. This topic remains controversial.

 

iii. Pathologic fracture of the femoral neck is also an indication for THA.

 

D. Surgical pearls

 

1. Pathologic fractures of the femoral neck should be treated with hemiarthroplasty or THA.

 

2. Screw fixation below the level of the lesser trochanter increases the risk of subtrochanteric femur fracture.

 

3. In patients between the ages of 65 and 80, surgical decision making should be based on physiologic, not chronologic, patient age.

 

4. Reversible medical comorbidities in geriatric patients should be minimized promptly. Surgical delay beyond 72 hours has been reported to increase the risk of 1-year mortality.

 

E. Complications

 

1. Osteonecrosis

 

a. In nondisplaced fractures, the incidence of osteonecrosis can be as high as 15%. In displaced fractures fixed appropriately, the rate of osteonecrosis has been reported to range between 20% and 30%.

 

b. Osteonecrosis alone is not necessarily of clinical significance unless late segmental collapse ensues. Segmental collapse can be seen as early as 6 to 9 months following injury, but it is most likely to be recognized in the second year following surgery. In most cases it can be excluded following the third year.

 

2. Nonunion

 

a. Nonunion rates are reported to be from 5% in the elderly to 30% in the young, high-energy trauma population.

 

b. Nonunion is generally associated with more vertically oriented fracture patterns and loss of reduction with varus collapse.

 

c. Nonunion repair is based on reorientation of the fracture line to a more horizontal position. A valgus osteotomy of the proximal femur is the treatment of choice in the physiologically young patient.



III. Intertrochanteric Fractures

A. Classification

 

1. The Evans classification system divides intertrochanteric fractures into stable and unstable fracture patterns (

Figure 6). The distinction between stable and unstable fractures is based on the integrity of the posterior medial cortex. The Evans classification also recognizes the reverse obliquity fracture pattern, which is prone to medial displacement of the distal fragment.

 

2. All other intertrochanteric fracture classification schemes, including the AO/OTA classification, are variations on the Evans classification.

 

3. No classification of intertrochanteric fractures has gained wide acceptance, and all demonstrate suboptimal observer agreement.

 

[Figure 6. The Evans classification of intertrochanteric fracture.]

4. Intertrochanteric fractures may be best classified as either stable or unstable based on the ability to resist compressive loads.

 

5. In general, when the posterior medial cortex is comminuted, fractures are considered unstable secondary to the likelihood the fracture will collapse into varus and retroversion.

 

B. Nonsurgical treatment

 

1. Nonsurgical treatment should be reserved for the nonambulatory patient or the patient who is at significant risk for perioperative mortality related to anesthesia or surgery.

 

2. These patients should receive adequate analgesics and be mobilized to a chair.

 

3. Nonsurgical treatment is associated with an increased mortality rate and an increased risk for decubiti, urinary tract infection, contracture, pneumonia, and DVT.

 

C. Surgical treatment

 

1. General considerations

 

[

Figure 7. The tip-apex distance (TAD) is estimated by combining the distance from the guide-pin tip to the apex of the femoral head on the AP and lateral fluoroscopic views (A). The risk for cutout failure increases dramatically when the TAD exceeds 25 mm (B).]

a. Surgical fixation of intertrochanteric fractures is based on reestablishing normal femoral neck-shaft alignment angle and allowing for controlled collapse of both stable and unstable fracture types.

 

b. Devices that allow controlled collapse have eliminated the need for restoring medial cortical contact either by direct reduction techniques or medial displacement osteotomies. Regardless of the device, the main technical factors that eliminate complications of treatment are accurate restoration of alignment and placement of the lag screw in the femoral head. The lag screw should be placed in the center aspect of the head and in the subchondral bone. Measurement of the tip-apex distance (TAD) is predictive of fixation failure (Figure 7). A TAD >25 mm has been associated with fixation failure.

 

2. Internal fixation techniques—The two main devices used for internal fixation are the sliding hip screw/side plate and the intramedullary hip screw.

 

[

Figure 8. Reverse obliquity fracture. A, AP view showing a four-part comminuted intertrochanteric fracture with reverse obliquity. B, The same hip after treatment with an intramedullary hip screw.]

   Both devices have theoretical advantages, but no data indicate one device is superior to the other.

 

a. Sliding hip screw

 

i. Advantages: ease of application, surgeon familiarity, availability, high success rate, minimal complications, cost

 

ii. Disadvantages: open technique, increased blood loss, increased failure in reverse obliquity or subtrochanteric extension patterns, excessive collapse resulting in limb shortening and fracture deformity in unstable fracture patterns

 

b. Intramedullary hip screw

 

i. Advantages: percutaneous application, limited blood loss, lateral buttress allowing limited collapse, increased resistance to varus forces

 

ii. Disadvantages: periprosthetic fracture, increased incidence of screw cutout, cost

 

3. Arthroplasty

 

a. Traditional arthroplasty is not effective for most intertrochanteric fractures secondary to the comminuted nature of the proximal femur.

 

b. A calcar-replacing prosthesis or a proximal femoral component is frequently required for reconstruction.

 

c. Secure fixation of the greater trochanter is problematic.

 

d. Because of the extensive nature of proximal femoral replacement and the associated increased surgical stress, arthroplasty is not warranted in most fractures.

 

e. Proximal femoral replacement should be reserved for salvage of failed ORIF or pathologic fractures.

 

D. Unusual fractures

 

1. Reverse obliquity fracture

 

a. The reverse obliquity fracture is an unstable fracture pattern that does not have an intact lateral cortex to support controlled compaction with a sliding hip screw (Figure 8).

 

b. These fractures are best thought of as subtrochanteric femur fractures and therefore should be treated with either an intramedullary nail or a fixed-angle device such as a blade plate or dynamic condylar screw.

 

2. Fractures of the greater trochanter

 

a. Fractures of the greater trochanter are usually the result of a direct blow.

 

b. The primary deforming force is the external hip rotators, not the hip abductors.

 

c. Most of these fractures can be treated nonsurgically, regardless of the degree of displacement, but in the younger, more active patient, repair should be considered for fracture displacement >1 cm.

 

3. Fractures of the lesser trochanter

 

a. Isolated fractures of the lesser trochanter are rare; they are seen in adolescents and generally represent an avulsion of the trochanter by the iliopsoas.

 

b. A more common etiology is a pathologic fracture as a result of tumor metastasis.

 

E. Complications

 

1. Loss of fixation

 

a. Usually occurs during the first 3 months following fracture treatment and is the most common complication.

 

b. Varus malalignment at the time of fracture fixation, advanced age, and osteopenia are all contributory factors to screw cutout of the femoral head.

 

c. The most important predictor of cutout is the TAD. According to one study, a TAD <27 mm was not associated with screw cutout, but a TAD >45 mm was associated with a failure rate of 60%.

 

2. Nonunion

 

a. Occurs in <2% of patients and is most commonly associated with unstable fracture patterns

 

b. Nonunion can be associated with fixation failure and varus collapse.

 

c. Failure of controlled impaction at the fracture site is also contributory.

 

d. Revision internal fixation and valgus osteotomy versus proximal femoral replacement are the treatment options for this complication.

 

3. Malunion in the form of a varus deformity or a rotational deformity is common.

 

a. Comminuted unstable fracture patterns are at greatest risk for an internal rotation deformity.

 

b. Corrective osteotomy is the best salvage procedure for this condition.



IV. Subtrochanteric Femur Fractures

A. Classification

 

1. Seinsheimer

 

a. The Seinsheimer classification system is a comprehensive scheme that subdivides the fracture patterns into eight groups (

Figure 9).

 

b. Interobserver agreement is relatively low, and the system is not widely used.

 

2. Russell-Taylor

 

a. The Russell-Taylor classification system divides subtrochanteric fractures into four types, based on the involvement of the lesser trochanter and the piriformis fossa (

Figure 10).

 

b. This system provides guidance for treatment: whether to treat the fracture with a nail, the type of nail to use, and when nailing should be avoided.

 

c. The Russell-Taylor classification has not been subjected to reliability tests.

 

B. Nonsurgical treatment—Nonsurgical treatment is appropriate only for the nonambulatory patient.

 

C. Surgical treatment

 

1. General considerations

 

a. Evaluation of the anatomic location and orientation of the fracture pattern guides selection of the most appropriate device and its application for these fractures.

 

b. The goals of internal fixation should be anatomic restoration of femoral alignment, maintenance of alignment, and minimization of the surgical insult.

 

2. Intramedullary nailing

 

a. Intramedullary nailing can be used for all subtrochanteric femur fractures that do not extend to the piriformis fossa or greater trochanter.

 

b. A standard nail with locking screws that do not enter the femoral head can be used in fractures that are below the level of the lesser trochanter as long as the device offers an oblique proximal locking option.

 

c. For fractures that extend to or involve the lesser trochanter, a cephalomedullary nail is required for adequate fixation.

 

d. Nailing can be performed in fractures that extend into the nail starting point, but it is not the preferred technique for most surgeons.

 

e. The main pitfall of intramedullary nailing is varus deformity with the proximal fragment

 

[Figure 9. Seinsheimer classification of subtrochanteric femur fractures. Type I fractures (not shown) are nondisplaced.]

   also assuming a flexed position. Alignment must be restored before reaming and placement of the intramedullary nail.

 

f. Fracture reduction and intramedullary nailing can be facilitated by positioning the patient laterally on the fracture table. This allows the femur to be flexed in relation to the hip, matching the unopposed flexion of the proximal fragment.

 

g. Intramedullary nails are load-sharing devices, and early weight bearing can frequently be initiated.

 

3. Plate fixation

 

a. Plate fixation with a fixed-angle device such as a blade plate or a dynamic condylar screw can be used on all subtrochanteric femur fractures regardless of location, but the open nature of the technique and the associated blood loss make its practical use limited to the most proximal fractures.

 

b. The surgical approach is a direct lateral approach to the proximal femur.

 

c. Dissection of the medial fragments during fracture reduction should be avoided because of the relatively high rate of nonunion (30%) with excessive periosteal dissection.

 

d. Fixed-angle plates are load-bearing devices, and early weight bearing should be avoided.

 

D. Complications

 

1. The deforming forces involved in subtrochanteric fractures of the femur are significant; obtaining and maintaining an adequate reduction in subtrochanteric fractures while performing internal fixation can be difficult. Malunion in the form of varus and proximal fragment flexion is not uncommon.

 

2. Nonunion is associated with fracture comminution and excessive dissection in the area of the medial femur. Supplemental bone grafting is recommended when medial dissection is performed.

 

[Figure 10. Russell-Taylor classification of subtrochanteric fractures.]

Top Testing Facts

Fractures of the Femoral Neck

1. Fractures of the femoral neck can result from direct or indirect force (fall onto the proximal thigh or a rotational force).

 

2. The main blood supply to the femoral head comes from the medial femoral circumflex artery.

 

3. The structure at risk during the anterior approach to the hip is the lateral femoral cutaneous nerve.

 

4. The Y ligament of Bigelow resists hip hyperextension.

 

5. Pathologic fractures of the femoral neck should be treated with hemiarthroplasty or THA.

 

6. Screw fixation below the level of the lesser trochanter increases the risk of subtrochanteric femur fracture.

 

Intertrochanteric Fractures

1. A TAD <25 mm should be maintained when placing the lag screw of a plate or nail device.

 

2. Lesser trochanteric fractures are often associated with tumor metastasis.

 

3. Reverse obliquity fractures should be treated with an intramedullary nail or a fixed-angle plate.

 

Subtrochanteric Fractures

1. When using an open technique, medial dissection should be avoided.



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