Displaced Femoral Neck Fracture: Causes, Surgery & Recovery

A displaced femoral neck fracture is a break across the narrow bridge of bone connecting the ball of the hip to the thighbone shaft, where the broken ends have shifted out of alignment. That displacement is the critical detail: it damages the blood vessels feeding the femoral head and makes the fracture far harder to heal with screws alone, which is why most displaced fractures in older adults are treated with some form of hip replacement rather than internal fixation. The distinction between displaced and undisplaced fractures drives nearly every decision about surgery, recovery expectations, and complication risk.

Why Displacement Changes Everything

The femoral head sits inside the hip socket like a ball in a cup, and it relies on a fragile network of small arteries that travel along the surface of the bone, held in place by thin tissue bands called the retinacular vessels. When a femoral neck fracture displaces, these vessels get stretched, kinked, or torn outright. A severely displaced fracture can destroy the blood supply so completely that there is almost no chance of preserving the natural joint with screw fixation alone.¹ Without adequate blood flow, the bone of the femoral head dies in a process called avascular necrosis, and the joint collapses.

This vulnerability of the blood supply is what gives displaced femoral neck fractures their reputation as one of the most complication-prone injuries in orthopaedics. Internal fixation of displaced fractures carries a high rate of both nonunion (the fracture fails to heal) and avascular necrosis.² The degree of displacement largely determines the treatment path: undisplaced fractures are typically treated with screws or pins to hold the bone in place, while displaced fractures are treated with joint replacement.³

Causes and Risk Factors

In older adults, the most common cause is simply falling from a standing height. Bones weakened by age-related bone loss can snap at the femoral neck from surprisingly little force. In younger people, it usually takes a high-energy impact like a car crash, a fall from a significant height, or a sports injury to break the femoral neck and displace the fragments.

Bone mineral density at the femoral neck is one of the strongest predictors of whether a fracture will happen. In women, hip bone density is a powerful predictor of fracture risk, with each standard-deviation drop roughly doubling the odds of a fracture. Men show a similar pattern, though wrist bone density happens to be a slightly stronger predictor in that population.⁴ Bone loss over time matters independently, too: ongoing loss at the femoral neck raises fracture risk even after accounting for where your bone density started.⁵ Large population analyses have confirmed a strong inverse relationship between femoral neck bone density and the number of osteoporotic fractures a person sustains.⁶

Beyond bone density, the usual suspects increase risk: advanced age, a history of prior fractures, medications that cause dizziness or drowsiness, poor balance, low body weight, and conditions like vitamin D deficiency that silently erode bone over years. For younger patients, the risk factor is exposure to high-energy trauma itself rather than underlying bone fragility.

Surgical Options for Displaced Fractures

The central surgical decision for a displaced femoral neck fracture is whether to try to fix the bone in place (internal fixation) or to replace part or all of the hip joint (arthroplasty). For most older adults with a displaced fracture, the evidence leans firmly toward replacement. One trial comparing the two approaches in patients aged 60 to 80 found that total hip arthroplasty produced substantially better hip function scores, better pain ratings, and higher patient satisfaction at one year. The rate of major reoperations was also much lower in the replacement group, at about 2% compared with roughly 15% in the fixation group.⁷

Another study echoed that pattern, finding that arthroplasty produced higher functional scores and lower reoperation rates than internal fixation for displaced fractures. In the fixation group, about 11% required conversion to a total hip replacement because of nonunion or avascular necrosis, compared with only about 1% in the arthroplasty group needing revision.⁸ The trade-off is that replacement surgery tends to involve more blood loss, a slightly longer operation, and a higher chance of surgical site infection.

Internal fixation still has a role for younger patients, where preserving the natural joint is a high priority. A person in their 30s or 40s with decades of active life ahead faces a very different calculation than someone in their 70s. Replacement implants have a finite lifespan, so avoiding or delaying a hip replacement is worthwhile when the bone has a reasonable chance of healing. The catch is that the complication rates after fixation of displaced fractures in younger adults remain substantial, and surgeons put a premium on getting the fracture perfectly reduced (realigned) before placing the screws.

Total Hip Replacement Versus Hemiarthroplasty

Once the decision is made to replace rather than fix, the next question is whether to replace just the ball of the joint (hemiarthroplasty) or both the ball and the socket (total hip arthroplasty). This question has generated decades of debate and a large volume of research that has not produced a tidy winner.

A large randomized trial published in the New England Journal of Medicine compared total hip arthroplasty to hemiarthroplasty in over 1,400 fracture patients. The main outcome, a composite of death and serious complications, was essentially the same in both groups. Function was modestly better with total hip replacement based on patient-reported scores, but the difference was small.⁹ A separate meta-analysis of randomized trials found no significant differences in revision rates at up to five years or functional outcomes at up to three years.¹⁰

Real-world data from a large Medicare cohort told a somewhat different story. In that analysis, total hip arthroplasty carried roughly double the dislocation rate and double the reoperation rate compared with hemiarthroplasty within two years.¹¹ The discrepancy between trial data and real-world data likely reflects patient selection: randomized trials carefully screen participants, while the Medicare cohort includes all comers, including very frail patients who may fare worse with a longer, more complex total hip procedure.

In practice, surgeons often choose based on the patient’s overall health and activity level. An active, cognitively intact person who can follow hip precautions (specific positions to avoid while the joint heals) is often offered a total hip replacement for its slightly better long-term function and lower risk of socket-side wear. A very elderly or frail patient, or someone with dementia, is often better served by a hemiarthroplasty, which is a faster, simpler operation with less risk of dislocation.

Cemented Versus Uncemented Implants

When a hemiarthroplasty is chosen, surgeons must decide whether to cement the implant’s stem into the thighbone or press-fit it without cement. A major randomized trial found that cemented hemiarthroplasty produced modestly better quality of life and a substantially lower risk of fracture around the implant compared with uncemented stems. Periprosthetic fractures occurred in about 0.5% of the cemented group and about 2% of the uncemented group.¹²

A meta-analysis of randomized trials reinforced those findings: cemented stems had lower rates of residual pain, implant loosening, periprosthetic fracture, and revision, though the operation takes a bit longer.¹³ For most older hip fracture patients, cemented fixation is now the preferred approach. The worry about cement, a rare but real risk of a dangerous drop in blood pressure during insertion (sometimes called bone cement implantation syndrome), means the decision is still individualized in patients with serious heart or lung disease.

Avascular Necrosis and Nonunion

These are the two complications that define the natural history of femoral neck fractures when the bone is kept in place with screws. Avascular necrosis, where the femoral head dies from loss of blood flow, occurs in roughly one in five patients whose displaced fracture is internally fixed. A meta-analysis found a pooled avascular necrosis rate of about 21% in displaced fractures, compared with about 5% in undisplaced fractures.¹⁴ In one series of internally fixed femoral neck fractures, avascular necrosis developed in about 25% of hips, appearing on average around 19 months after surgery. The strongest predictors were not patient age or the time elapsed before the operation, but rather the initial degree of displacement and the quality of the fracture reduction achieved in the operating room. Poor reduction carried more than thirteen times the odds of avascular necrosis.¹⁵

Two mechanisms drive the bone death. The obvious one is direct damage to the blood vessels at the moment of injury. The subtler one is a tamponade effect: bleeding inside the hip joint capsule builds pressure, squeezing shut whatever vessels survived the initial trauma.¹⁶ This is one reason some surgeons aspirate (drain) the joint at the time of fixation, though debate continues about whether that maneuver prevents late avascular necrosis.

Nonunion, where the fracture simply never knits together, shares overlapping risk factors. A systematic review and meta-analysis found that inadequate fracture reduction, female sex, smoking, age over 50, and the use of simple screws rather than fixed-angle devices all increased the odds of fixation failure.¹⁷ Other work has identified kidney impairment as an independent risk factor for nonunion, likely because of its effects on bone metabolism.¹⁸ The screw configuration matters, too: placing screws in a triangle pattern rather than an inverted triangle has been linked to higher nonunion rates in one study, along with displacement and poor reduction.¹⁹

When either complication occurs, the outcome is almost always a second operation, usually conversion to a hip replacement. This is a harder surgery than a primary replacement, with higher complication rates and worse functional outcomes, which is precisely why avoiding fixation failure by choosing arthroplasty upfront matters for patients whose fractures are severely displaced.

Does Surgical Timing Affect Outcomes?

There is a widely held belief that hip fracture surgery must happen within a specific window, often cited as 24 or 48 hours, to reduce the risk of death. The reality is less clear-cut than the headlines suggest. A study of patients who arrived at a hospital within six hours of their injury found a significant reduction in the risk of death within one year compared with those who arrived later.²⁰ Getting to the hospital quickly appears to matter more than the precise number of hours between admission and surgery.

One study that divided patients into groups by surgical delay found higher mortality rates when surgery was postponed beyond 12 hours, but the increase did not reach statistical significance after adjusting for other risk factors.²¹ The best interpretation of the evidence is that unnecessary delays should be avoided, but a short delay to stabilize a patient’s heart condition or blood thinners is not the catastrophe it is sometimes made out to be. The real danger is prolonged immobility: lying in bed for days before surgery increases the risk of blood clots, pneumonia, pressure sores, and confusion.

Recovery and Early Mobilization

Getting up and moving as soon as possible after surgery is one of the clearest findings in the hip fracture rehabilitation literature. A multicenter cohort study found that patients who took their first steps within two days of surgery were more than three times as likely to be walking independently at one week and at discharge compared with those who waited longer.²² Early mobilization also shortened hospital stays and doubled the share of patients who went home rather than to a rehabilitation facility.

These benefits appear to persist: a single-center study found that patients who mobilized early were nearly four times as likely to be walking independently a full year after surgery.²³ A separate study confirmed that early mobilization was at least as safe as delayed mobilization, countering the lingering worry that pushing patients to walk sooner might cause falls or implant problems.²⁴

For older adults who received a joint replacement, the approach is generally full weight bearing as tolerated right away. A narrative review found strong support for putting weight through the leg within 24 to 48 hours post-surgery to enhance mobility and reduce complications like pneumonia, pressure ulcers, and deep vein thrombosis. Partial weight bearing, by contrast, led to poor compliance and often amounted to no weight bearing at all in frail older patients.²⁵

The picture is different for younger adults whose fractures were internally fixed. In that group, one multicenter study found that delayed weight bearing actually produced better outcomes than early weight bearing, presumably because the healing bone needs protection from load in the weeks after screw fixation.²⁶ This is an important distinction: the advice to get moving early applies most forcefully to older patients who received a replacement. If you are younger and had screws placed, your surgeon will likely have you limit how much weight you put through the leg for several weeks.

Mortality and Long-Term Prognosis

Hip fractures in older adults carry a sobering mortality rate. In one study of displaced femoral neck fractures treated with arthroplasty, overall one-year mortality was 24%. A simple scoring system that accounts for age, cognitive status, living situation, and walking ability before the fracture stratified patients sharply: those in the lowest-risk group had a 5% one-year mortality, while those in the highest-risk group faced 51%.²⁷

The excess deaths are concentrated in the first few months after injury. A study examining factors influencing mortality after hemiarthroplasty found that median survival for men dropped from about 5 years in age-matched controls to about 1.6 years, and for women from about 6.6 years to about 2.8 years. Nearly all of the excess mortality occurred in the first three months. Cardiac complications, dementia, and male sex were the strongest negative predictors.²⁸

Postoperative delirium, a sudden state of confusion that can last days, is another common complication in elderly hip fracture patients. It lengthens hospital stays and is associated with higher in-hospital mortality. In one prospective study, patients who developed delirium had a longer average hospital stay (about 11 days versus 9 days) and more in-hospital deaths.²⁹ This is one reason orthogeriatric co-management, where a geriatrician works alongside the surgeon, has become standard at many hospitals: catching delirium early and managing pain appropriately can make a real difference.

Fear of Falling After Hip Fracture

An underappreciated barrier to full recovery is psychological rather than physical. Fear of falling is extremely common after a hip fracture, and it independently predicts worse functional outcomes. A systematic review found that this fear was consistently linked to poorer balance, slower walking speed, and lower self-reported physical function.³⁰ Another review found associations between fear of falling and loss of mobility, institutionalization, and even mortality, with fearful patients spending less time exercising and paradoxically falling more often.³¹

The impact varies by the patient’s pre-injury function level. For people who were highly functional before the fracture, fear of falling at 12 weeks after surgery was linked to significantly lower odds of recovering to their prior level by one year. For patients who already had impaired daily function before the fracture, fear of falling did not show the same association.³² In other words, the patients who have the most physical capacity to recover are the ones most hurt by the psychological fallout. Addressing fear of falling through structured rehabilitation, gradual exposure to walking challenges, and sometimes cognitive behavioral techniques is an important and often overlooked part of the recovery process.

Exercise-Based Rehabilitation

Once the immediate post-surgical phase is past, structured exercise programs aim to rebuild strength, improve balance, and restore walking ability. A systematic review of exercise-based rehabilitation programs found evidence of improved functional recovery across multiple studies, though the type and intensity of exercise varied widely between programs.³³ What the research has not yet shown convincingly is that these programs prevent future falls. The two studies in that review that tracked secondary falls found no significant difference between intervention and control groups.

That gap in the evidence is worth flagging. People often assume that physical therapy after a hip fracture will make them fall-proof. The reality is that rehabilitation clearly helps you walk better and regain independence, but whether it actually reduces the risk of a second fall remains unproven. Fall prevention likely requires a broader strategy that includes home modifications, medication review, vision correction, and in some cases balance-specific training that goes beyond standard post-fracture physiotherapy. If you or a family member is recovering from a displaced femoral neck fracture, structured exercise is essential for regaining function, but do not treat it as a substitute for addressing the environmental and medical factors that contributed to the original fall.