Traumatic Proximal Femur Fractures

Molly E. Collins, Harvard Medical SchoolGillian Lieberman, MD

Overview of Presentation

• Discuss the importance of fractures affecting the hip joint

• Review anatomy and types of fractures• Introduce a classic patient presentation• Discuss the radiologic evaluation• Address complications and treatment

principles

Falls and Fractures

• More than one-third of those over age 65 fall each year.

• 90% of fractures involving the hip joint occur in those over age 50.

• 90% of falls in the elderly are the result of a simple fall.

• We may think of the scope of this topic as…

Tinetti, NEJM 2003

Scope of Topic

• Fractures affecting hip joint

• Other MSK trauma• Subdural hematoma• Dehydration• Immobility, disability

Falls Complications

Mediating FactorsPrevention

Predisposing Medical Conditions

• Bone strength• Force vector of fall• Medical issues• Baseline function

Risk Factors

Tinetti, NEJM 2003

Background• Epidemiology:

– 250,000 fractures affecting the hip joint in the U.S. each year.– Affects one-third of American women who survive past 80

years old.– Risk factors include: maternal history of fracture, excessive

consumption of alcohol and caffeine, physical inactivity, low body weight, tall stature, previous fracture, use of certain psychotropic medications, residence in an institution, visual impairment, and dementia.

• The bones of the hip joint are among the most common sites of fracture in those with osteoporosis.

• Downward spiral: Mortality rate is 14-36% in the first year following a fracture involving the hip joint.

Eustace, Radiol Clin North Am 1997; Zuckerman, NEJM 1996

Anatomy of Proximal Femur

Netter, http://www2.ma.psu.edu/~pt/384fem1a.gif

Anterior View

Types of Proximal Femur Fractures

Tintinalli, Kelen, Stapczynski, Tintinalli’s Emergency Medicine, 6th Ed.

Intracapsular

Extracapsular

• Fractures may be classified anatomically as intracapsular or extracapsular.

• ~45% of proximal femur fractures occur at the femoral neck (intracapsular), and ~45% are intertrochanteric (extracapsular).

• Subtrochanteric fractures (also (extracapsular) account for 5-10%.

Describing Fractures

• Although there are many different classification systems for proximal femur fractures, it is usually most helpful to identify the fracture anatomically and describe it accurately.

• With proximal femur fractures, it is especially important to note whether there is displacement, as this reflects stability of the fracture and the likelihood of complications.

Our Patient: History and Physical• 84 year-old female presenting with pain

status-post mechanical fall onto left hip.• HPI: No head trauma, loss of

consciousness. No preceding vertigo, lightheadedness.

• PMH: Osteoporosis, atrial fibrillation, hypertension.

• Exam: Left lower extremity shortening and external rotation, peripheral pulses intact.

PACS, BIDMC

Our Patient: Left Femoral Fracture on Pelvis Radiograph

Film Findings• Comminuted

intertrochanteric fracture

• Asymmetric lesser trochanters

• Degenerative changes: sclerosis and joint space narrowing along pubic symphysis, SI joints, and lower lumbar spine

PACS, BIDMC

Our Patient: Fracture on Proximal Femur Radiograph

Film Findings• Comminuted

intertrochanteric fracture lines appearing as lucencies, with communicating fracture planes

• Extension of fracture into the femoral shaft

PACS, BIDMC

Anterior

Our Patient: Fracture on Cross-Table Lateral Radiograph

Film Findings• Film is underexposed and this is, therefore, a limited evaluation of the femoral head

and neck for displacement.• Cortex discontinuity, comminuted fracture.

Our Patient: Fracture Description

• In summary, our patient’s fracture is described as a comminuted left intertrochanteric fracture extending into the proximal femoral shaft with mild varus angulation of the femoral shaft.

• The most common complications of intertrochanteric fractures are malunion and shortening.

• Avascular necrosis and nonunion are rare here given the rich blood supply to the intertrochanteric region from cancellous bone.

Radiologic Evaluation of Suspected Proximal Femur Fractures

• First obtain plain radiographs in anteroposterior and lateral views.– Obtain AP view with 15-20 degrees of internal rotation at the hip

joint to lengthen the femoral neck for the best view.

• Beware of occult fractures, which can be difficult to see, especially when nondisplaced and in osteopenic bone.– In one study of 70 patients with negative plain films, 37% had

proximal femur fractures discovered with MRI.– Delayed diagnosis can lead to complications. In one study of 38

patients with delayed diagnosis, 7 of 9 who had displaced fractures developed avascular necrosis or nonunion.

Bogost, Lizerbram, Crues, Radiololgy 1995; Eustace, Radiol Clin North Am 1997; Ohashi, Brandser, El- Khoury, Radiol Clin North Am 1997

Radiologic Evaluation, Continued• If plain film is nondiagnostic and there is continued clinical suspicion

of a proximal femur fracture, this must be pursued.• Next obtain:

– MRI• Test of choice given high sensitivity and specificity,

approaching 100% within the first 24 hours following a fracture.• Detects marrow edema and hemorrhage.• May distinguish other injuries that mimic fractures clinically,

such as muscle injury.– Bone scan

• 80% detection rate in the first 24 hours, may take up to 72 hours to show radiotracer uptake.

– CT• Less sensitive than MRI, so consider if there is contraindication

to MRI.• Will show fracture lines better than plain film, and can identify

cortical abnormalities.

Conway, Totty, McEnery, Radiology 1996; Eustace, Radiol Clin North Am 1997; Ohashi, Brandser, El- Khoury, Radiol Clin North Am 1997

Occult Fractures

• A demonstration of these concepts…

Courtesy Dr. Shetty

Companion Patient 2: Normal Proximal Femur on Radiograph

Film Findings• Film read as

normal by radiologist.

• Patient positioned well, with good visualization of femoral neck.

• Plain film obtained for suspected femoral fracture.

Courtesy Dr. Shetty

Companion Patient 2: Proximal Femur Fracture on MRI

T2 Fat Saturation, Coronal View

Film Findings• Low signal fracture line• Fluid in soft tissue, likely blood• Significant bone marrow edema

MRI• Fractures are seen as low signal in all

sequences.• American College of Radiology

appropriateness criteria guidelines recommend coronal T1-weighted sequence to evaluate suspected occult fracture.

• MRI can facilitate appropriate early intervention or discharge and can also aid in surgical planning by showing the axis of fracture and the extent of injury.

Complications of Femoral Neck Fractures

• Common complications of femoral neck fractures include avascular necrosis and nonunion.

• Incidence varies by fracture location, degree of fracture displacement, and is decreased with appropriate treatment.

PACS, BIDMC

Companion Patient 3: Right Femoral Neck Fracture on Pelvis Radiograph

Film Findings• Minimally

displaced femoral neck fracture

• 88 year-old woman s/p mechanical fall.

Courtesy Dr. Wu

Companion Patient 3: Femoral Neck Fracture on Femur Radiograph

Film Findings• Minimally

displaced femoral neck fracture

PACS, BIDMC

Anterior

Companion Patient 3: Fracture on Cross-Table Lateral Radiograph

Film Findings• Femoral neck fracture• Femoral head with

slight posterior rotation/displacement

• Ischial tuberosity• Pubic symphysis

• Even minor displacement may be associated with avascular necrosis (AVN) due to the anatomy of the vascular supply of the femoral neck.

Vascular Anatomy

Jones, http://home.pacific.net.au/~rossjones/Avn.htm

• The femoral head and neck are supplied by the medial and lateral femoral circumflex arteries, with a minor contribution from a branch of the obturator artery.

Vascular Anatomy, Continued

Wheeless, http://www.wheelessonline.com/ortho/medial_femoral_circumflex_artery

• Vessels may be kinked, torn, or compressed by a displaced fracture, leading to AVN.

Treatment Principles• Stabilize the patient:

– Correct fluid and electrolyte abnormalities if present.– Prevent weight-bearing on injured hip until work-up is

complete.• Early surgery followed by early mobilization:

– If indicated, surgery should be performed within 24-48 hours, as longer intervals increase post-operative complications and mortality at one year.

• Return patient to prior level of function:– 50-65% regain prior level of ambulation.

• Address osteoporosis:– In a recent study only 13% of women >65 with a

recent fracture received adequate treatment.

Morrison, Siu, UpToDate 2008; Zuckerman, NEJM 1996

Our Patient: Hospital Course

• Taken to the OR for open reduction internal fixation.

• Our patient was able to ambulate with a walker upon discharge.

PACS, BIDMC

Our Patient: Post-Op Fixation on Pelvis RadiographFilm Findings• Intramedullary

nail in femoral shaft

• Gamma nail in femoral head

PACS, BIDMC

Our Patient: Post-Op Fixation on Femur Radiograph

Film Findings• Intramedullary

nail in femoral shaft

• Gamma nail in femoral head

• Screw fixing intramedullary nail

• Screws prevent migration of the intermedullary nail.

Summary• Proximal femur fractures are common, and can

be life-changing events with significant associated morbidity and mortality.

• Early radiological identification of fractures with radiograph and follow-up studies is critical.

• Detection rate of subtle or occult fractures has been improved with MRI.

• Accurate description of fractures allows appropriate and timely treatment to avoid long- term complications and improve outcomes.

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bone and soft-tissue injury. Radiology 197: 263-267, 1995.Conway WF, Totty WG, McEnery, KW. CT and MR imaging of the hip. Radiology 198: 297-307, 1996.Eustace S. MR imaging of acute orthopedic trauma to the extremities. Radiologic Clinics of North America 35: 615 -

629, 1997.Jones, R. Arthritis and other joint problems - AVN, 2001. http://home.pacific.net.au/~rossjones/Avn.htmJude CM, Modaressi S. Radiologic evaluation of the painful hip in adults. UpToDate, 2008.Lyles KW, Colon-Emeric CS, Magaziner JS, et al. Zoledronic acid and clinical fractures and mortality after hip

fractures. New England Journal of Medicine 357: 1799-1809, 2007.Martin JS, and Marsh JL. Current classification of fractures. Radiologic Clinics of North America 35: 491 - 506, 1997.Mitchell MJ, Ho C, Resnick D, et al. Diagnostic imaging of lower extremity trauma. Radiologic Clinics of North America

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Radiologic Clinics of North America 35: 591-613, 1997.Tinetti ME. Preventing falls in elderly persons. New England Journal of Medicine 348: 42-49, 2003.Tintinalli JE, Kelen GD, Stapczynski JS. Classification of proximal femur fractures. Tintinalli’s Emergency Medicine: A

Comprehensive Study Guide, 6th Ed. http://accessemergencymedicine.comWheeless CR. Medial femoral circumflex artery. Wheeless’ Textbook of Orthopaedics.

http://www.wheelessonline.com/ortho/medial_femoral_circumflex_arteryZuckerman JD. Hip fracture. New England Journal of Medicine 334: 1519-1525, 1996.

Acknowledgments

I would like to sincerely thank:Dr. Ferris HallDr. Gillian LiebermanDr. Sanjay ShettyDr. Jim Wu