Dr. Kevin Yip

Dr Kevin Yip
Orthopaedic Surgeon
MBBS(UK), FRCS(EDIN), FAM(SING), FHKCOS(ORTHO)

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Intertrochanteric Hip Fracture

Basics
Description
  • Fractures of the proximal femur located between the greater and lesser trochanters and external to the capsule of the hip joint
    • The greater and lesser trochanters may be avulsed as separate fragments.
  • Many classification systems have been developed that are unreliable in identifying fracture types, but in general, they are classified as stable or unstable.
    • Stable fractures:
      • Nondisplaced or those in which the femur is broken into 2 or 3 fragments
      • A large lateral buttress must exist, and the lesser trochanter must be intact.
    • Unstable fractures:
      • The femur is broken into >4 fragments
      • The lateral buttress is not intact, or the fracture is reverse oblique.
    • Synonyms: Trochanteric hip fracture; Pertrochanteric hip fracture
General Prevention
  • Use of calcium and vitamin D or bisphosphonates and physical therapy to preserve bone mass
  • Prevention of falls in the elderly:
    • Use of ambulatory aids, such as canes or walkers
    • Home modification strategies, such as hand railings
  • External hip protectors
Epidemiology
Intertrochanteric hip fractures are 2-8 times as common in females than in males, presumably because of postmenopausal loss of bone mass.
 
Incidence
  • Intertrochanteric fractures occur in 34 per 100,000 person years in males and in 63 per 100,000 person years in females.
  • Intertrochanteric fractures account for 40-50% of hip fractures.
  • The increased incidence with advanced age is likely secondary to osteoporosis and the increased risk of falling.
Risk Factors
  • Osteoporosis is a substantial risk factor.
  • Any factor that increases the risk of falling (e.g., unsteady gait) increases the risk.
  • Pathologic fractures may occur in the presence of tumor or metastatic bone lesions.
Etiology
  • Nearly all intertrochanteric fractures are the result of falls.
  • Motor vehicle accidents comprise the 2nd most common cause of this injury.
  • Mechanism of injury:
    • Typically direct axial loading of the femur or direct force over the greater trochanter
    • Indirect forces from muscle insertion on the trochanters also may contribute to the injury and deformity.
Associated Conditions
  • Osteoporosis
  • Frailty
  • Other fractures and soft-tissue injuries of the affected limb, as well as associated neural and vascular injuries, can occur in patients with these fractures.
Diagnosis
Signs and Symptoms
  • Stable fractures:
    • Patients may be ambulatory and experience minimal pain.
    • Patients have pain with weightbearing and motion of the hip.
  • Unstable fractures:
    • The patient is in severe pain and is unable to ambulate.
    • The affected leg is shortened and externally rotated to as much as 90° (more marked than seen with femoral neck fractures) because of the action of the iliopsoas at its insertion distal to the fracture site.
  • Swelling may occur over the hip, and ecchymosis over the greater trochanter.
History
Most commonly, the patient has a history of a low-energy fall.
 
Physical Exam
  • In addition to assessing the deformity of the proximal femur, the clinician should examine the ipsilateral knee for evidence of ligamentous injury.
  • Neurovascular status of the limb should be assessed carefully.
Tests
Imaging
  • Radiography:
    • Obtain AP radiographs of the affected hip and the pelvis, with the affected hip internally rotated.
    • Obtain a cross-table lateral hip radiograph.
  • If a fracture is not visible on the plain radiographs, obtain an MRI scan.
Treatment
General Measures
Activity
  • Patients with fractures should be kept nonweightbearing and at rest until fracture fixation.
  • Traction has not been found to be helpful preoperatively.
Nursing
  • Care must be taken to avoid pressure points and decubitus ulcers of the sacrum and heels.
  • In the elderly, nursing precautions to avoid delirium, including reorientation and avoidance of sedatives
Special Therapy
Physical Therapy
  • Strengthening and ambulation are the main goals.
  • After surgical fixation, patients should be mobilized quickly and allowed to bear weight as tolerated.
Medication
First Line
Pain should be controlled with opioid analgesics and acetaminophen.
Second Line
  • Most patients are treated surgically.
  • Rarely, nonoperative treatment is selected.
    • Patients who are nonambulatory and at high surgical risk are candidates for nonoperative treatment.
    • Patients must be padded carefully and gently mobilized to avoid pressure sores.
Surgery
  • After open or closed reduction of the fracture, the reduction is maintained by internal fixation.
  • A sliding hip screw with side plate device or an intramedullary hip screw may be used, depending on fracture geometry.
  • The most important factor in fracture fixation is placement of the screw into the femoral head.
    • The lag screw is positioned under fluoroscopy so that the tip-to-apex distance is <24 mm.
      • The tip-to-apex distance is the sum of the distances from the tip of the lag screw to the apex of the femoral head, as measured on AP and lateral radiographs, adjusted for magnification.
      • If the tip-to-apex distance is >24 mm, the rate of failure of fixation increases.
  • A sliding hip screw allows the lag screw to slide through the plate so that the fracture can partially collapse.
    • Sliding of the screw compresses the fracture fragments and promotes healing.
    • For a sliding screw and side plate to be effective, a lateral buttress of bone in the greater trochanteric region must be present to provide a stop point for the screw when sliding.
    • If the buttress does not exist, the fracture is classified as unstable and is best treated with an intramedullary hip screw, which serves as the lateral buttress to stop sliding.
  • Intramedullary fixation devices are indicated when the fracture is unstable, especially those with a reverse oblique pattern or those with subtrochanteric extension.
  • Hip replacement may be considered in patients with extreme comminution or for pre-existing arthritis.
  • Replacement is challenging and requires special techniques.
Follow-up
Disposition
  • Early mobilization is the key goal of rehabilitation after operative treatment.
    • The patient should commence weightbearing as tolerated, using a walker, crutches, or a cane as necessary, on postoperative day 1.
    • Elderly patients often require a postoperative rehabilitation stay to increase strength and ability to ambulate.
Prognosis
  • Although most patients can expect satisfactory results, only ~50% return completely to their previous level of function.
  • Morbidity and mortality are substantial, mainly because of the patients’ advanced age.
Complications
  • The mortality rate in the 1st year is high (secondary to coexisting morbidities), ranging from 10-30%.
  • Mental status change is common during the acute phase of hospitalization.
    • Precautions should be taken to avoid and treat postoperative delirium.
  • DVT is common, and prophylaxis should be given: Warfarin, low-molecular-weight heparin, or factor Xa inhibitors combined with mechanical prophylaxis.
  • Mechanical complications include failure of fixation (usually resulting in impaction or varus angulation), penetration of the fixation device into the hip joint, and stress fractures of the femoral neck, resulting from poor positioning of the fixation device within the femoral head.
  • Nonunion and osteonecrosis are uncommon complications (<2%) because these fractures occur through well-vascularized cancellous bone.
  • Mechanical complications and nonunion usually are treated with a complex total hip replacement.
  • Postoperative wound infection rates of 1-17% have been reported.
Patient Monitoring
  • Patient radiographs should be monitored for at least 1 year after fixation.
  • Fracture healing may be difficult to visualize, and CT scan may be necessary to reveal nonunion.
Miscellaneous
Codes
ICD9-CM
820.21 Intertrochanteric hip fracture
 
Patient Teaching
Activity
Exercise is helpful in increasing bone density.
 
Prevention
  • Patients at risk for osteoporosis should be screened with bone densitometry and treated with calcium and diphosphonate.
  • Fall prevention techniques and a home visit to assess fall risk are important.
FAQ
Q: How are intertrochanteric hip fractures treated?
A: Most fractures are treated with surgery to reduce the fracture, using a hip screw and side plate or an intramedullary hip screw.
Q: How well do patients recover after surgery?
A: ~50% of patients return to their previous level of function. The other 1/2 require more ambulatory aids.
 
Q: Why do some fracture heal with a shortened leg?
A: The sliding hip screw is designed to slide in line with the femoral neck. Controlled collapse of the fracture gives more bony contact and allows for healing. Collapse of the hip does shorten the leg and may result in the need for a heel wedge. Shortening of the hip may result in weakness to the hip abductors and a Trendelenburg-type of limping gait.

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