Femur Injuries and Fractures

Traumatic causes of femoral fractures include the following:

• Motor vehicle trauma (eg, motor vehicle collision, motorcycle collision, auto/pedestrian collision)

• Sports (eg, high-speed and contact/collision sports with direct trauma, skiing, football, hockey)

• Falls (eg, from height, mountain climbing, pole vaulting)

• Gunshot wounds

• An update to the American Academy of Pediatrics’ 2006 guidelines for differential diagnosis of fractures caused by child abuse reported that abuse causes between 12% and 20% of all fractures in infants and children; however, in children younger than 3 years, physicians misdiagnose as many as 20% of fractures caused by abuse. The femur, humerus, and tibia are the most common long bones fractured in child abuse. The report further added that in the nonambulatory child, femoral fractures are more likely to be caused by child abuse, whereas these fractures in ambulatory children are rarely inflicted by abuse.[7, 8]

Pathologic causes include the following:

• Metabolic bone disease

• Primary bone tumor

• Metastatic tumor

• Infection

• Prolonged bisphosphonate use

Causes of stress fracture include the following:

• Repetitive impact activities such as running (jogging) and jumping

• Metabolic bone disease

• Amenorrheic or oligomenorrheic female runners

• Abnormal bone mineral density

• Improper training

• Improper footwear

United States statistics

The incidence of femoral shaft fractures ranges from 9.5 to 18.9 per 100,000 annually.[9]  From 0.7% to 1.7% of all fractures in children involve the femoral shaft.[10]

Approximately 250,000 proximal femur fractures occur in the United States annually. This number is anticipated to double by the year 2050.[11]

High-energy injuries are most common in younger males. See the images below.

The incidence of femur fractures increases in elderly patients.

Fatigue fractures of the femur occur at a rate of 19.9 per 10,000 persons per year.[12]

Stress fractures as a whole occur in up to 37% of runners.[9] The femur accounts for 11% of stress fractures. Approximately 53% of these fractures occur about femoral shaft.[9]

The femur is the strongest, longest, and heaviest bone in the body and is essential for normal ambulation. The femoral shaft is tubular with a slight anterior bow, extending from the lesser trochanter to the flare of the femoral condyles. The femur is subject to many forces during ambulation including axial loading, bending, and torsional forces. During weight bearing, the medial cortex is subject to compressive forces while tensile forces are placed on the lateral cortex during contraction, the large muscles surrounding the femur account for a large portion of the applied forces.[1, 2, 5, 6, 13]

Several large muscles attach to the femur which can affect displacement of certain fracture patterns. Proximally, the gluteus medius and minimus attach to the greater trochanter. The forces from these muscles may result in an abduction deformity to the proximal fragment of proximal femoral shaft and subtrochanteric femur fractures. The iliopsoas attaches to the lesser trochanter, resulting in a flexion deformity of this same fragment, in fractures occurring below the level of the lesser trochanter. The linea aspera (rough line on the posterior shaft of the femur) reinforces the strength of the femur and is an attachment for the gluteus maximus, adductor magnus, adductor brevis, vastus lateralis, vastus medialis, vastus intermedius, and short head of the biceps. Distally, the large adductor muscle mass attaches medially, resulting in an apex lateral deformity seen in certain distal femur fractures. The medial and lateral heads of the gastrocnemius attach over the posterior femoral condyles, resulting inflexion deformity in distal-third fractures.

The blood supply enters the femur through metaphyseal arteries and branches of the profunda femoris artery, penetrating the diaphysis and forming medullary arteries extending proximally and distally. Healing of femur fracture is enhanced by the surrounding muscles and soft tissues contributing to local recruitment of blood supply around the callus. The femoral artery courses down the medial aspect of the thigh to the adductor hiatus, at which time it becomes the popliteal artery. Injuries to the artery occur at the level of the adductor hiatus, where soft-tissue attachments may cause tethering.

See also Medscape Drugs & Diseases articles Nerve Entrapment Syndromes and Nerve Entrapment Syndromes of the Lower Extremity.

Trauma-induced fractures of the femur occur with contact and during high-speed sports. A significant amount of energy is transferred to the limb in a femur fracture, such as might be generated in skiing, football, hockey, rodeo, and motor sports.

Stress fracture

A femoral stress fracture is the result of cyclic overloading of the bone. With prolonged activity, the muscles that dissipate force to bone begin to fatigue placing increased force on the bone itself. Muscle fatigue may also contribute by altering gait kinematics. Stress becomes concentrated at susceptible areas with eventual weakening and subsequent microfracture, as these repetitive stresses overcome the ability of the bone to remodel. The area most susceptible to stress fractures is the medial junction of the proximal and middle third of the femur. Fractures in this location occur as a result of the compression forces on the medial femur.[2]

A study suggested that the lateral cortex of the femoral shaft may also be susceptible to stress fracture due to tensile forces.[14]

Stress fractures can also occur on the lateral aspect of the femoral neck in areas of distraction and are less likely to heal non-operatively than compression-side stress fractures on the medial side. Stress fractures occur most often in repetitive overload sports such as in runners and basketball players. For more information, refer to the Medscape Drugs & Diseases article Femoral Neck Stress Fracture.

Long-term symptoms after fracture include muscular weakness, limited standing and walking, gait abnormalities, some intermittent pain, and inability to return to preinjury work.

Surgical management is rarely needed to treat femoral stress fractures; however, surgical stabilization is recommended for recalcitrant cases.

Complications

Complications associated with traumatic femoral fractures include the following:

• Nonunion

• Delayed union

• Malunion

• Heterotopic ossification

• Infection

• Venous thromboembolic event (ie, deep venous thrombosis or pulmonary embolism)

• Pain

• Ambulatory dysfunction

• Refracture

• Hardware failure

• Prominent hardware

• Neurologic injury

• Peroneal nerve palsy - Most commonly due to traction

• Pudendal nerve injury - Due to compression at the perineal post

• Sciatic nerve injury

• Vascular injury

• False aneurysm

• Atrioventricular fistula

• Compartment syndrome

Complications associated with femoral stress fractures include the following:

• Progression to a complete fracture

• Refracture

• Nonunion

• Osteonecrosis

• Arthritis

• Continued pain

A thorough history is imperative for all femur fractures, but particularly for fractures that occur with overuse or minimal trauma. The required details of the history will vary based upon the category of fracture (ie, traumatic versus pathologic or overuse). The history should entail a chronological order of events including onset and location of pain. Prodromal pain prior to a traumatic event is suggestive of a pathological or overuse origin. The mechanism of the injury will differentiate between traumatic versus pathologic or overuse etiologies and in cases of trauma, will help determine other body regions that may require evaluation (eg, intracranial injury). The history should entail pain and or deformity in other anatomic areas. Patients should be questioned as to aggravating and alleviating factors. Any interventions prior to presentation should be noted. A detailed past medical, surgical, drug allergy, social, and family history is obtained in all patients. Timing of last meal is imperative to delineate for those who require surgical management. Specifics to each category are listed below.

History of traumatic femoral fractures:

• Significant pain and inability to bear weight are typically present.

• Patients may be noted to have a shortening of one leg, swelling, and gross deformity.

• Fractures are commonly associated with other bony injuries, including tibial shaft fractures, ipsilateral femoral neck fractures, and extension of the fracture into the distal femur.

History of pathologic fractures:

• Patients will typically have an insidious onset of pain and/or deformity in the affected extremity.

• Patients frequently complain of night pain.

• Level of pain and narcotic requirement is important to elicit.

• Prior health screening exam history is essential in evaluation of these patients including a complete review of systems to rule out metastatic or metabolic disease as a cause of pathologic bone disease.

History of femoral stress fractures:

• A detailed training and competition history should be obtained.

• These are observed with increasing frequency in joggers.[15, 16, 17]

• Factors involved in stress fractures include a sudden increase in mileage, intensity, or frequency of training.[18]

• A change in terrain or running surface may contribute.[19, 20]

• Patients should be evaluated for and questioned about improper footwear and poor biomechanics.

• Pain is typically insidious; however, it may be sudden or severe.

• Patients may report groin, thigh or knee pain.

• Pain from femoral shaft stress fracture is most frequently located in the anterior thigh.[21]

• Symptoms of stress fractures are aggravated by activity and relieved by rest.

• Female runners may have an abnormal menstrual history and a history of disordered eating.

For more information, see Medscape Drugs & Diseases topics Female Athlete Triad, Low Energy Availability in Female Athletes, and Nutrition for the Female Athlete.

Physical examination of traumatic femoral fractures involves the following:

• Associated injuries must be addressed, and Advanced Trauma Life Support (ATLS) guidelines must be followed.

• A head-to-toe examination is indicated.

• Palpate the pelvis as well as bilateral lower and upper extremities observing for any deformity, instability, crepitation or pain generation.

• Palpate the lumbar spine and heels if the injury involved a fall from a height to rule out vertebral compression fractures and/or calcaneal fractures.

• Assess the patient’s skin for any abrasions, lacerations or other disruptions; it is imperative that open fracture is ruled out.

• Assess all joints for deformity and any blocks to motion or pain with motion.

• Correct any lower extremity deformity by applying inline longitudinal traction.

• A distal vascular assessment is necessary to rule out a vascular injury.

• A distal neurologic assessment is indicated to rule out a nerve injury.

Physical examination of pathologic fracture involves the following:

• A head to toe complete physical examination is imperative

• Assess involved and uninvolved extremities for masses, deformity and tenderness

• A thorough neurovascular examination of all extremities is required

• Pain out of proportion to the injury could suggest an acute compartment syndrome and/or muscle ischemia due to a hematoma or an arterial injury. This would constitute a surgical emergency (within 6 hours of injury) to prevent loss of limb.

Physical examination of femoral stress fractures involves the following:

• A complete examination of the involved and uninvolved extremity including complete strength testing and neurovascular examination should be preformed.

• Palpation of the thigh may display subtle tenderness and/or swelling.

• Muscle bulk and tone is typically normal.

• The point of maximum tenderness with palpation is often difficult to elicit given the large muscle envelope surrounding the femoral shaft.

• Pain may be present at the extremes of passive range of motion.

• Pain may be reported with forced rotation or axial loading.

• Pain usually radiates into the groin area in cases of femoral neck fracture.

• Observe gait: patient may ambulate with a limp.

• Hop test: Single leg hop will on the involved extremity often reproduce symptoms in approximately 70% of patients.[22]

• Torsional or bending stress to the thigh may elicit pain in shaft fractures (see Fulcrum test below).

• Fulcrum test: Patient seated while the examiner applies gentle downward pressure on the knee while the other arm is used as a fulcrum producing an anterior force vector on the posterior thigh.[23]  This test may reproduce the patients symptoms.

Laboratory workup in cases of traumatic femur fractures includes the following:

• Complete blood cell (CBC) count

• Chemistry panel

• Prothrombin time (PT) / activated partial prothrombin time (aPTT)

• Urinalysis (UA)

• Type and screen or cross-match

• Vitamin D*[24, 25, 26, 27, 28, 29, 30]

Pathologic fracture laboratory studies include the following:

• CBC count

• Chemistry panel

• Erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP)

• TSH, CEA, CA 19-9, CA 125 if concern exists for metastatic disease

• Vitamin D levels*[24, 25, 26, 27, 28, 29, 30]

*Both patients with traumatic and pathologic stress fractures require thorough metabolic bone workup, including vitamin D and calcium levels.[24, 25, 26, 27, 28, 29, 30]

Imaging studies in cases of traumatic femur fractures include the following:

• Radiograph of the chest

• Spine radiograph series

• Anteroposterior (AP) radiograph of the pelvis

• AP and lateral radiograph of the entire femur, hip, and knee[31]

• Computed tomography (CT) of the head, neck, abdomen and pelvis if indicated

• CT scan of the fracture for preoperative surgical planning if indicated (eg, comminuted intra-articular fracture)

• CT of the pelvis is imperative in cases of high-energy femoral shaft fractures to rule out femoral neck fracture[32]

  Full length AP radiograph of an intertrochanteric fracture.

Pathologic fracture imaging studies include the following:

• AP and lateral radiographs of the full length femur

• Radiographs of the contralateral femur if concern for metastatic disease

• CT if concern for tumor

• MRI if concern for tumor or infection

• Chest radiograph for both suspected primary or metastatic femur tumor

• CT chest to look for metastases from a primary bone tumor

• CT chest, abdomen and pelvis if concern for metastatic bone tumor

• Bone scan or positron emission tomography–computed tomography (PET-CT) to assess for other areas of involvement if concern for a tumor

Imaging studies in cases of femoral stress fractures include the following[33] :

• AP and lateral radiographs of the femur: Findings are typically delayed for 2-6 weeks after the onset of symptoms; these films are still useful for making a late confirmation of the diagnosis.

• Radionucleotide scanning: This is the criterion standard for the diagnosis of stress fractures; these studies are more sensitive than and may show abnormalities 3 weeks before plain radiographs.

• Magnetic resonance imaging (MRI): MRIs reveal bone marrow signal earlier in the stress-reaction process than standard radiographs and radionuclide scanning

• Bone mineral density evaluation: Use this test to rule out osteoporosis or osteopenia.

  MRI of a patient with a stress fracture at the base of the femoral neck.

Femur fractures in the younger patient population are typically the result of high-energy injuries. These fractures are often accompanied by other injuries. The first priority in treatment is to rule out other life-threatening injuries and stabilize the patient. Advanced Trauma Life Support (ATLS) guidelines should be followed.

The emergent management of femur injuries in the sports setting is intended to restore alignment. If limb deformity is present, inline longitudinal traction is applied, realigning the extremity and maintaining limb perfusion. A splint is applied to maintain the alignment as the patient is transported to the hospital for definitive treatment.

Treatment for acute trauma-related femoral fractures and displaced femoral stress fractures is performed by an orthopedic surgeon and usually involves surgical stabilization (see Surgical Intervention).[1, 2]

For non-displaced femoral shaft stress fractures, protected crutch-assisted weight bearing is implemented for a minimum of 1-4 weeks, based on the resolution of symptoms and radiographic evidence of healing (callus formation). Progression to full weight bearing can gradually commence once pain has resolved. Patients must avoid running for 8-16 weeks while the low-impact training program/phase is completed. The progression can include (1) cycling, (2) swimming, and (3) running in chest-deep water before resuming more intensive weight-bearing training. Patients must maintain upper extremity and cardiovascular fitness and avoid lower extremity exercise early in the healing process.

Compression sided femoral neck stress fractures are typically treated conservatively with a period of protected crutch-assisted weight bearing until symptoms resolve. Tension-sided (lateral) femoral neck stress fractures are at risk for displacement and surgical stabilization with percutaneous screws should be considered versus bed rest.

Medical Issues/Complications

Patients sustaining a femur fracture as a part of a major traumatic event (eg, vehicular trauma) should be evaluated and stabilized by the trauma and/or medical team prior to surgical intervention. ATLS guidelines should always be followed. Life threatening injuries should be cared for by the appropriate specialists.

In cases of traumatic femur fractures, the trauma surgeon implements multisystem stabilization and clearance for surgical intervention. Consultations with appropriate specialists must be arranged for specific systems. Traction may be necessary for initial stabilization for pain control before impending surgery.

Before definitive operative management of a femur fracture, the patient should be hemodynamically stable and fully resuscitated. Current literature suggests serum lactate levels, base deficit and gastric mucosal pH may be the most reliable measures of resuscitation.[34] The goal time to definitive surgical stabilization is generally 24 hours. However, if the patient is hemodynamically unstable and has not been adequately resuscitated, femoral fixation should be delayed and temporized with an external fixator, skeletal traction or a splint.

Elderly patients require evaluation by the medicine team for management of any acute or chronic medical conditions.

Surgical Intervention

Proximal femur fractures are treated based upon fracture pattern. Femoral neck fractures are typically treated with percutaneous pinning, a sliding hip screw or arthroplasty in elderly patients. Peritrochanteric fractures are typically treated with a sliding hip screw or a cephalomedullary nail. Subtrochanteric fractures are typically treated with an intramedullary nail or a fixed angle device. Treatment of proximal femur fractures is discussed in further detail the article Fractures, Hip.

Intramedullary nailing (see image below) is the treatment of choice for the majority of femoral shaft fractures occurring in adults. Nailing can be preformed in an antegrade or retrograde fashion. Other treatment options include plate and screw fixation as well as external fixation. The method of fixation is dependent upon the personality of the fracture as well as associated injuries. For more detail on the treatment of diaphyseal femur fractures see the article Fractures, Femur.

A systematic review and meta-analysis by van Cruchten et al showed that compared to spica casting, treatment with intramedullary nails was associated with better outcomes in children aged 2-10 years with closed femoral shaft fractures. Pediatric patients who underwent intramedullary nailing had significantly lower rates of malunion and leg length discrepancy.[35]

Traumatic distal femurs may be treated with intramedullary nailing, plate and screw fixation or arthroplasty. These fractures are further discussed in the article Fractures, Knee .

In cases of pathologic fracture, treatment is dictated by not only location, but also tumor type. In primary bone tumors, the goal of surgical treatment is curative where as in metastatic tumors the goal is palliative.

In the case of femoral shaft stress fracture, operative treatment is reserved for those infrequent cases that have been recalcitrant to a long course of conservative treatment. Intramedullary nailing, whether antegrade or retrograde, is the treatment of choice for these cases.

Tension sided femoral neck stress fractures are typically treated with percutaneous screw fixation. For further details see the article Femoral Neck Stress Fracture.

Consultations

Consultation with orthopedic surgeons is required in cases of femoral fractures, and a definitive treatment plan is left to their judgment.

Physical Therapy

With trauma-related femur fractures, physical therapy following stable fixation of the fracture to improve hip and knee range of motion, strengthening and gait training is recommended. Weight-bearing status is dependent upon fracture pattern and surgical intervention. Ambulatory aids, such as crutches, are used in the initial stages. The goal of the therapy program should be eventual full weight-bearing and restoration of normal function. Pulmonary therapy is often needed in patients sustaining major trauma requiring prolonged bed rest.

For femoral stress fractures, discontinue crutches once pain-free walking is possible. Increase low-impact lower extremity aerobic training (eg, swimming, biking, elliptical trainer) as symptoms permit. Attempt to identify causative factors of the femoral stress fractures (eg, improper training techniques, footwear, diet).

One treatment algorithm that has been suggested consists of a graduated four-phase program, each of which last 3 weeks in duration.[36] Transfer to the next phase is based on the result of fulcrum and hop tests carried out at the end of each phase. If the tests were positive (i.e., a failed test), the patient was returned to the beginning of that phase. In the first phase athletes walked with the help of crutches and were instructed to be non-weight-bearing on the affected leg. In the second phase normal walking was permitted, and swimming and exercising on the unaffected extremities was allowed. In the third phase the patients performed exercises with both upper and lower extremities using light weights. Patients were also permitted to run in a straight line every other day and ride a stationary bicycle. The distance that the subjects were allowed to run was gradually increased. In the fourth phase the patient resumed normal training. In this study all seven patients returned to normal activity within 12-18 weeks, with no recurrences noted at 48-96 month follow-up.[36]

Rehabilitation Program

Physical Therapy

With trauma-related femur fractures, physical therapy following stable fixation of the fracture to improve hip and knee range of motion, strengthening and gait training is recommended. Weight-bearing status is dependent upon fracture pattern and surgical intervention. Ambulatory aids, such as crutches, are used in the initial stages. The goal of the therapy program should be eventual full weight-bearing and restoration of normal function. Pulmonary therapy is often needed in patients sustaining major trauma requiring prolonged bed rest.

For femoral stress fractures, discontinue crutches once pain-free walking is possible. Increase low-impact lower extremity aerobic training (eg, swimming, biking, elliptical trainer) as symptoms permit. Attempt to identify causative factors of the femoral stress fractures (eg, improper training techniques, footwear, diet).

One treatment algorithm that has been suggested consists of a graduated four-phase program, each of which last three weeks in duration.[36] Transfer to the next phase is based on the result of fulcrum and hop tests carried out at the end of each phase. If the tests were positive (ie, a failed test), the patient was returned to the beginning of that phase. In the first phase athletes walked with the help of crutches and were instructed to be non-weight-bearing on the affected leg. In the second phase normal walking was permitted, and swimming and exercising on the unaffected extremities was allowed. In the third phase the patients performed exercises with both upper and lower extremities using light weights. Patients were also permitted to run in a straight line every other day and ride a stationary bicycle. The distance that the subjects were allowed to run was gradually increased. In the fourth phase the patient resumed normal training. In this study all seven patients returned to normal activitywithin 12-18 weeks with no recurrences noted at 48-96 month follow-up.[36]

Rehabilitation Program

Physical Therapy

Patients should continue with therapy as needed with the goal of improving strength, motion, endurance and ambulatory ability. Continue to monitor with radiographs in an outpatient setting.

Attempt to identify causative factors of the femoral stress fractures (eg, improper training techniques, footwear, diet). Implementation of an injury prevention program may be beneficial.

In cases of traumatic femur fractures, schedule a clinic follow-up visit at 2 weeks, 6 weeks, 3 months, 6 months, and 1 year. The femur fracture should be healed by 3 months. Once bony union is complete, treatment is focused on muscle rehabilitation. Progressive strengthening of all lower extremity musculature is initiated and continued until strength is 95% of the contralateral extremity.[37]

Sports-specific rehabilitation is initiated once strength has been regained. The athlete should be back to preinjury status at 1 year postinjury.

For femoral stress fractures, a minimum time of 6 weeks is necessary for bone healing to occur before the patient is able to resume full activity. The athlete should resume activities in a very gradual fashion over the course of several weeks. If symptoms recur during training, the athlete should return to the previous phase of treatment for a minimum of 3 weeks.

Stress fractures of the femur can be prevented or minimized by proper training techniques. Gradual increase in activity intensity and duration allow the body to respond to the increase load stresses. Maintaining proper footwear and not allowing footwear to break down, adequate rest periods in training, and good nutrition are also important aspects of prevention.

Medication for trauma-related fractures includes pain medication as indicated for reasonable pain. Anticoagulants are used for a short course following traumatic fracture and operatively treated fractures to prevent venous thromboembolism.[1] Vitamin D and calcium supplementation is recommended for patients found to be deficient on laboratory evaluation.

Animal studies have suggested nonsteroidal anti-inflammatory medications (NSAIDs) may have a detrimental effect on bone healing.[38] These medications are typically avoided in the early stages of fracture healing.

For more information, see Medscape Drugs & Diseases topics Opioid Toxicity and Nonsteroidal Anti-inflammatory Agent Toxicity.

Class Summary

Pain control is essential to quality patient care. Analgesics ensure patient comfort, promote pulmonary toilet, and have sedating properties, which are beneficial for patients with trauma.

Codeine/acetaminophen (Tylenol With Codeine)

Indicated for mild to moderate pain.

Hydrocodone and acetaminophen (Lortab, Norcet, Vicodin)

Drug combination for moderate to severe pain.

Propoxyphene/acetaminophen (Darvocet N-100, Propacet)

Drug combination for mild to moderate pain.