A hip fracture is a break in the upper portion of the femur (thighbone), near where it joins the pelvis to form the hip joint. Hip fractures are most commonly seen in older adults with osteoporosis and are considered a serious medical event due to their impact on mobility, independence, and overall health. Prompt surgical treatment is almost always required.
Hip fractures occupy a spectrum with related bone injuries of the proximal femur. At the less severe end, a femoral neck stress reaction represents bone fatigue without complete fracture — the precursor injury that, if unrecognized, can progress to a complete fracture requiring surgery. Displaced femoral neck fractures carry a substantial risk of avascular necrosis (AVN) of the femoral head, because the same blood vessels disrupted by the fracture are those that supply the bone. Patients who sustain hip fractures in the setting of low bone density should be evaluated for underlying subchondral insufficiency fracture patterns and initiated on osteoporosis treatment to prevent contralateral hip fracture.
Causes
Fall-related fracture.
The vast majority of hip fractures in older adults result from a simple fall — often from standing height — onto the side of the hip. Reduced bone mineral density from osteoporosis makes the femoral neck and intertrochanteric region unable to absorb the impact of what would be a trivial injury in a younger person. Approximately 300,000 hip fractures occur annually in the United States, with women accounting for roughly 75% of cases — reflecting the accelerated bone loss that follows menopause. Risk factors for falls that compound the fracture risk include poor vision, balance and gait disorders, lower extremity weakness, sedative and antihypertensive medications, and environmental hazards such as loose rugs and poor lighting.
High-energy trauma.
In younger patients with normal bone density, hip fractures require significant force — a motor vehicle accident, a fall from height, or a high-energy sports collision. These fractures are often more complex, displaced, and comminuted, and may be associated with acetabular fractures, knee ligament injuries, and other polytrauma. Pathologic fractures through weakened bone — due to metastatic disease, primary bone tumors, or long-term bisphosphonate use (atypical subtrochanteric fractures) — represent a third category that requires simultaneous oncologic and orthopedic management.
Symptoms
A displaced hip fracture causes immediate, severe pain in the groin or hip that prevents any weight-bearing or walking. The affected leg typically appears shortened and externally rotated — a classic clinical picture that allows experienced clinicians to diagnose a displaced hip fracture at the bedside before X-rays are obtained. Bruising and swelling may develop over the lateral hip within hours. Nondisplaced or impacted fractures present more subtly — the patient may still bear weight with significant pain, which commonly delays diagnosis and allows the fracture to displace further if activity is not restricted. Any older adult who falls and reports persistent hip or groin pain should be evaluated with MRI if X-rays are negative, since occult nondisplaced fractures are not reliably visible on plain films.
Diagnosis
A physical exam by a doctor assesses limb position, pain with passive log-roll and axial loading, and neurovascular status of the extremity. X-rays are the initial imaging tool and identify most displaced hip fractures. An MRI is the gold standard when a fracture is clinically suspected but not visible on X-ray — a scenario that occurs in 2–9% of hip fractures, particularly nondisplaced femoral neck fractures, impacted fractures in osteoporotic bone, and stress fractures in younger patients. MRI detects occult fractures with near 100% sensitivity, demonstrating a low-signal fracture line surrounded by bone marrow edema on T2-weighted sequences, and allows prompt surgical planning before the fracture displaces. MRI also identifies associated injuries including acetabular fractures, soft tissue tears, and concurrent subchondral insufficiency fractures that may not be evident on X-ray. CT is used for surgical planning in complex or comminuted fractures where three-dimensional anatomy must be precisely characterized.
Fracture classification
Doctors classify hip fractures by anatomic location, which directly determines the surgical approach and the risk of complications.
- Femoral neck fracture: Break in the narrow segment of the femur between the femoral head and the trochanters. The most surgically consequential type — displacement of the fracture disrupts the terminal blood supply to the femoral head and carries a significant risk of avascular necrosis and nonunion, particularly in displaced fractures in older patients.
- Intertrochanteric fracture: Break through the region between the greater and lesser trochanters. Because this zone has a rich blood supply from large perforating vessels, healing rates are high with appropriate fixation and avascular necrosis is not a concern.
- Subtrochanteric fracture: Break just below the lesser trochanter in the proximal femoral shaft. Often associated with high-energy injury in younger patients or with atypical fracture pattern in patients on long-term bisphosphonates. These fractures are biomechanically challenging to stabilize due to high deforming forces from the hip flexors and abductors.
Treatments
Treatment depends on the location and displacement of the fracture, patient age, pre-injury activity level, bone quality, and overall medical condition. Surgery is almost always required and is typically performed within 24–48 hours of injury — delays beyond 48 hours are associated with significantly increased rates of complications including pneumonia, deep vein thrombosis, pressure ulcers, and mortality.
Before surgery, adequate pain management with a fascia iliaca nerve block or intravenous analgesia, optimization of medical comorbidities including anticoagulation reversal when necessary, and prophylaxis against venous thromboembolism are priorities. Intraoperative and postoperative anesthesia and medical team coordination are essential given that most hip fracture patients are medically complex.
Nondisplaced femoral neck fracture: In situ fixation with two or three percutaneous cannulated screws or a sliding hip screw preserves the native femoral head and is the preferred treatment when the fracture has not displaced. The risk of subsequent displacement is eliminated once the fracture is fixed, and avascular necrosis rates are substantially lower than with displaced fractures. A structured physical therapy program with progressive weight-bearing is critical to restoring mobility and preventing deconditioning.
Displaced femoral neck fracture in older patients
Hemiarthroplasty (replacing the femoral head with a prosthetic component while retaining the native acetabulum) or total hip arthroplasty is the preferred treatment for displaced femoral neck fractures in older adults, because internal fixation carries unacceptably high rates of nonunion and avascular necrosis in this setting. Total hip arthroplasty is preferred over hemiarthroplasty for active, ambulatory older adults due to better long-term function, lower rates of acetabular erosion, and fewer revision surgeries — provided the patient can safely tolerate the longer operative time.
Displaced femoral neck fracture in younger patients
Urgent open reduction and internal fixation is strongly advised in younger patients — ideally within 6–12 hours of injury — to maximize blood flow restoration to the femoral head and minimize the risk of AVN. Despite urgent anatomic reduction and stable fixation, the risk of avascular necrosis and nonunion remains significant, and these patients require close long-term radiographic follow-up with serial X-rays and MRI monitoring to detect early AVN before femoral head collapse occurs.
Intertrochanteric and subtrochanteric fractures
Intertrochanteric fractures are treated with intramedullary nailing (cephalomedullary nail) or a sliding hip screw and side plate, depending on fracture pattern and surgeon preference. Subtrochanteric fractures are almost universally treated with long intramedullary nailing, which controls the powerful deforming muscle forces acting at this level. Because blood supply is preserved in both fracture types, healing rates are high and joint replacement is rarely needed. Early weight-bearing as tolerated and aggressive physical therapy and rehabilitation are essential for restoring ambulation and preventing the systemic complications of prolonged immobility in elderly patients.
Get an MRI to Confirm Your Diagnosis
Before surgical planning or starting treatment, a clear MRI diagnosis ensures the right path forward. First Look MRI offers self-pay Hip MRI scans — no doctor's order or insurance required — at our locations in Georgia, Texas, and Colorado.