Canale & Beaty: Campbell's Operative

Orthopaedics, 11th ed.

Copyright 2007 Mosby, An Imprint of Elsevier

Chapter 52 Fractures and Dislocations of the Hip

David G. LaVelle

Hip fractures 3237

Intertrochanteric femoral fractures 3239

Classification 3239

Nonoperative treatment 3240

Operative treatment 3241

Subtrochanteric femoral fractures 3262

Classification 3262

Treatment 3263

Fractures of the femoral neck 3271

Fracture fixation 3271

Classification 3274

Treatment 3276

Failures after internal fixation of the hip 3282

Stress fractures of the femoral neck 3283

Pathological fractures of the femoral neck 3283

Postirradiation fractures of the femoral neck 3284

Fractures of the femoral neck with ipsilateral femoral shaft fractures 3285

Dislocation and fracture-dislocation of the hip 3286

Posterior dislocation and fracture-dislocation 3287

Type I posterior dislocation 3287

Type II, III, or IV posterior dislocation 3291

Type V posterior fracture-dislocation with femoral head fracture 3291

Posterior dislocation of the hip with fracture of the femoral neck or shaft

3295

Anterior dislocation of the hip 3296

Prognosis and complications 3296

Fractures of the proximal femur and hip are relatively common injuries in adults. Several

epidemiological studies have suggested that the incidence of fractures of the proximal

femur is increasing, which is not unexpected because the general life expectancy of the

population has increased significantly during the past few decades. More than 280,000 hip

fractures occur in the United States every year, and this incidence is expected to double by

2050. These fractures are associated with substantial morbidity and mortality; 30% of

elderly patients die within 1 year of fracture. After 1 year, patients seem to resume their

age-adjusted mortality rate.

Most proximal femoral fractures occur in elderly individuals as a result of only moderate or

minimal trauma. In younger patients, these fractures usually result from high-energy

trauma. Despite similar locations of the fracture, the differences in low-velocity and high-

velocity injuries in older compared with younger patients outweigh the similarities. More

often than not, high-velocity injuries are more difficult to treat and are associated with

more complications than low-velocity injuries.

This chapter discusses intertrochanteric and subtrochanteric femoral fractures, fractures of

the head and neck of the femur, and dislocation and fracture-dislocation of the hip,

including classification of fractures and some commonly used methods of operative

management.

HIP FRACTURES

Fractures of the proximal femur, generally referred to as fractures of the hip, are classified

first according to their anatomical location. Isolated fractures of the lesser or greater

trochanter are uncommon and rarely require surgery; they can be associated with

pathological disease. Avulsions of the lesser trochanter occur in immature children from the

pull of the iliopsoas muscle and can be treated nonoperatively. Fractures of the greater

trochanter often result from direct trauma to the trochanter, usually are minimally

displaced, and can be treated nonoperatively with protected weight bearing on crutches

until symptoms subside. If a fracture of the greater trochanter is obvious on routine

radiographs, CT or MRI should be obtained to rule out an intertrochanteric element before

the decision is made for nonoperative treatment. An unsuspected intertrochanteric fracture

can drift into varus or displace completely without open reduction and internal fixation.

Femoral neck fractures and intertrochanteric fractures occur with about the same

frequency. Nearly nine of 10 hip fractures occur in patients older than 65 years old. Both

fractures are more common in women than in men by a margin of three to one. Other risk

factors include white race, neurological impairment, malnutrition, impaired vision,

malignancy, and decreased physical activity. Osteoporosis, although present in the

population at risk, has not been shown to be more prevalent in patients with fractures than

in age-matched controls. Subtrochanteric fractures, which account for 10% to 15% of

proximal femoral fractures, have a bimodal distribution pattern, occurring commonly in

patients 20 to 40 years old and in patients older than 60. Fractures in younger patients

usually result from high-energy trauma. Hip fractures in elderly individuals are the result of

falls about 90% of the time. Causes of falls include impaired ambulation before injury,

decreased reaction time, and poor vision.

The prognosis for each of the three major categories of hip fractures is entirely different.

Intertrochanteric fractures usually unite if reduction and fixation are properly done, and

although malunions may be a problem, late complications are rare. A wide area of bone is

involved, most of which is cancellous, and both fragments are well supplied with blood.

Fractures of the neck of the femur are intracapsular and involve a constricted area with

comparatively little cancellous bone and a periosteum that is thin or absent. Although the

blood supply to the distal fragment is sufficient, the blood supply to the femoral head may

be impaired or entirely lacking; for this reason, osteonecrosis and later degenerative

changes of the femoral head or nonunion often follow femoral neck fractures. The

substance of the bone in the subtrochanteric region changes consistency as it progresses

from the vascular cancellous bone of the intertrochanteric region to the less vascular

diaphyseal cortical bone of the proximal shaft. Subtrochanteric fractures are associated with

high rates of nonunion and implant fatigue failure because of the greater mechanical

stresses in this region.

If the diagnosis of a hip fracture is questionable in an acutely painful hip, bone scanning and

MRI have shown excellent sensitivity in identifying these injuries (Fig. 52-1). In a study by

Quinn and McCarthy, T1-weighted MRI was found to be 100% sensitive in patients with

equivocal radiographic findings. Traditionally, bone scan has been thought to be unreliable

before 48 to 72 hours after fracture, but a study by Holder et al. found a sensitivity of 93%

regardless of time from injury, including fractures less than 24 hours old.

Fig. 52-1 Nondisplaced intertrochanteric fracture is not visible on anteroposterior radiograph (A), but can be identified on T1-

weighted MRI (B).

Reports and opinions on the effect of delay of operative treatment on patient mortality are

conflicting. Many elderly patients have multiple medical problems, and spending 12 to 24

hours in medical evaluation and treatment before surgery is advantageous and well

supported; however, excessive delay should not be tolerated. Zuckerman et al. found that

delaying fixation for more than 3 days doubled the mortality rate within the first year after

surgery. McGuire noted a 15% increase in immediate mortality in patients in whom fixation

was delayed for more than 2 days compared with patients whose hips were fixed within 2

days.

The general recommendation of using Buck traction has been shown by Jerre et al. to be

unhelpful in reducing pain preoperatively and does not improve the ease of fracture

reduction. In femoral neck fractures, traction may reduce blood flow to the femoral head

preoperatively. These patients tolerate bed confinement poorly, and every effort should be

made to fix the fracture operatively as soon as possible. Internal fixation can be done with

the patient under general, spinal, or epidural anesthesia, with no proven difference in

perioperative mortality.

The goal of treating hip fractures is to return patients to their prefracture levels of function

without long-term disability and avoiding medical complications. In 1996, Koval et al.

reported that positive predictors of independence after fracture included age younger than

85 years, three or fewer comorbidities, prefracture independence, and ambulation with

therapy on discharge. Koval et al. later found fracture type (classification) not to be a

predictor of mortality or of ambulatory ability.

Open reduction and internal fixation of hip fractures should be done with the aim of

obtaining rigid and stable internal fixation that would permit patients to be ambulatory and

at least bearing some weight on their affected hip within a short period (usually the next

day). Mobilization is advantageous in preventing pulmonary complications, venous

thrombosis, pressure sores, and generalized deconditioning. Bony continuity should be

reestablished so that the bone itself assumes a significant portion of the load. Internal

fixation devices should be inserted such that the construct of metal and bone is rigid. Rydell,

Frankel and Burstein, and others showed that the forces applied to the femoral head and

proximal femur with activities such as lifting the leg and getting on and off a bedpan often

equal or exceed the load applied during protected ambulation. Experience has confirmed

that when the fracture is well reduced and internally fixed, weight bearing can begin almost

immediately. In a classic study of femoral neck fractures treated with multiple Knowles pins,

Arnold found no adverse effects of early weight bearing on healing rates of fractures with

acceptable reductions. Koval et al. measured actual amounts of weight placed on injured

limbs and determined that patients voluntarily limited loading until fracture healing. Despite

this information, many authors still advocate only touch-down or weight-of-leg weight

bearing until radiographic signs of healing are evident. Nonoperative treatment of displaced

hip fractures usually is reserved for patients who were nonambulatory before the fracture

and who are experiencing only mild pain.

Intertrochanteric Femoral Fractures

Intertrochanteric femoral fractures have been estimated to occur in more than 200,000

patients each year in the United States, with reported mortality rates ranging from 15% to

30%. Most intertrochanteric femoral fractures occur in patients older than 70 years old. Hip

fractures (intertrochanteric and femoral neck fractures) account for 30% of all hospitalized

patients in the United States, and the estimated cost for treatment is approximately $10

billion a year.

Classification

At our institution, Boyd and Griffin (1949) classified fractures in the peritrochanteric area of

the femur into four types. Their classification, which included fractures from the

extracapsular part of the neck to a point 5 cm distal to the lesser trochanter, follows (Fig.

52-2):

Type 1: Fractures that extend along the intertrochan-teric line from the greater to the

lesser trochanter. Reduction usually is simple and is maintained with little difficulty.

Results generally are satisfactory.

Type 2: Comminuted fractures, the main fracture being along the intertrochanteric

line, but with multiple fractures in the cortex. Reduction of these fractures is more

difficult because the comminution can vary from slight to extreme. A particularly

deceptive form is the fracture in which an anteroposterior linear intertrochanteric

fracture occurs, as in type 1, but with an additional fracture in the coronal plane, which

can be seen on the lateral radiograph.

Type 3: Fractures that are basically subtrochanteric with at least one fracture passing

across the proximal end of the shaft just distal to or at the lesser trochanter. Varying

degrees of comminution are associated. These fractures usually are more difficult to

reduce and result in more complications at operation and during convalescence.

Type 4: Fractures of the trochanteric region and the proximal shaft, with fracture in at

least two planes, one of which usually is the sagittal plane and may be difficult to see

on routine anteroposterior radiographs. If open reduction and internal fixation are

used, two-plane fixation is required because of the spiral, oblique, or butterfly fracture

of the shaft.

Fig. 52-2 Types of trochanteric fractures.

(From Boyd HB, Griffin LL: Classification and treatment of trochanteric fractures, Arch Surg 58:853, 1949.)

The most difficult types to manage, types 3 and 4, accounted for only about one third of the

trochanteric fractures in Boyd and Griffin's series.

Evans devised a widely used classification system based on the division of fractures into

stable and unstable groups (Fig. 52-3). He divided unstable fractures further into those in

which stability could be restored by anatomical or near-anatomical reduction and those in

which anatomical reduction would not create stability. In an Evans type I fracture, the

fracture line extends upward and outward from the lesser trochanter. In type II, reverse

obliquity fracture, the major fracture line extends outward and downward from the lesser

trochanter. Type II fractures have a tendency toward medial displacement of the femoral

shaft because of the pull of the adductor muscles.