Femoral neck nonunion: Definition, Uses, and Clinical Overview

Femoral neck nonunion Introduction (What it is)

Femoral neck nonunion means a fracture in the femoral neck has not healed within the expected timeframe.
The femoral neck is the narrow “bridge” of bone between the femoral head and the femoral shaft.
This term is commonly used in orthopedics to describe a difficult healing problem after hip fracture.
It helps clinicians communicate diagnosis, plan treatment, and discuss expected recovery.

Why Femoral neck nonunion used (Purpose / benefits)

Femoral neck nonunion is a diagnostic label that describes a specific complication: the failure of a femoral neck fracture to unite (heal together) as bone. Its purpose is to identify when ongoing pain, weakness, or functional limitation is likely coming from an unhealed fracture rather than typical post-injury stiffness or muscle deconditioning.

Using the term “nonunion” also guides clinical decision-making. Healing problems in the femoral neck raise concerns about:

• Mechanical stability: whether the fracture site is sufficiently stabilized to allow bone to knit together.
• Bone biology: whether the local blood supply and cellular healing response are adequate.
• Joint preservation: whether the femoral head can be maintained or whether joint replacement may be more appropriate in some cases.
• Risk management: whether complications such as avascular necrosis (loss of blood supply to the femoral head) may coexist.

For patients and general readers, the “benefit” of naming Femoral neck nonunion is clarity: it explains why symptoms may persist and why additional imaging, prolonged protection, or further procedures may be considered. The appropriate approach varies by clinician and case.

Indications (When orthopedic clinicians use it)

Femoral neck nonunion is typically considered in scenarios such as:

• Persistent groin or deep hip pain after a known femoral neck fracture
• Pain that continues or returns after surgical fixation (pins, screws, or a plate) of a femoral neck fracture
• Delayed functional progress (difficulty with walking, stairs, or weight-bearing progression) beyond what is expected for the injury pattern
• Imaging that suggests a persistent fracture line, lack of bridging bone, or hardware loosening
• Suspected mechanical problems (loss of reduction, malalignment, or implant failure) after fixation
• Complex clinical contexts that can affect healing (for example, poor bone quality or multiple injuries), as judged by the treating team

Contraindications / when it’s NOT ideal

Femoral neck nonunion is a descriptor, not a treatment, so it is not “contraindicated” in the way a medication is. However, there are situations where labeling symptoms as nonunion may be less appropriate, or where one management path is not ideal:

• Pain from other sources: hip osteoarthritis, labral pathology, lumbar spine referral pain, trochanteric pain syndrome, or muscle/tendon injury can mimic fracture-related pain.
• Normal healing timeline: some fractures heal slowly; “delayed union” (slow healing) may be considered before “nonunion,” depending on timing and imaging.
• Inadequate diagnostic information: limited-quality imaging or unclear prior records can make the diagnosis uncertain.
• When certain reconstruction options may be less suitable:
• Severe collapse of the femoral head, advanced arthritis, or major bone loss may make joint-preserving strategies less favorable.
• Poor bone stock or unstable fixation conditions may reduce the likelihood of success for revision fixation in some cases.
• Medical factors that affect surgical tolerance can influence the choice between procedures.
• Concern for infection (less common in closed hip fractures, but important): suspected infection changes evaluation and treatment priorities.

Which alternative approach is “better” varies by clinician and case.

How it works (Mechanism / physiology)

Femoral neck nonunion reflects a mismatch between the mechanical environment and the biologic capacity needed for bone healing.

The key bone-healing principle

A fracture typically heals when there is:

• Adequate stability (the broken ends do not move too much)
• Adequate blood supply and biology (cells, growth factors, and nutrients can reach the site)
• Appropriate alignment and contact between bone surfaces

If motion at the fracture site is excessive, or if blood supply is compromised, the body may not be able to form durable bridging bone.

Why the femoral neck is a special case

The femoral neck has several features that can make healing more challenging than in many other bones:

• High mechanical load: it transmits forces from the pelvis to the femur during standing and walking.
• Intracapsular location: the femoral neck lies within the hip joint capsule. This environment can limit formation of the robust external callus seen in some other fractures.
• Blood supply considerations: the femoral head depends on blood vessels that can be disrupted by the original fracture and by displacement (movement of the fracture fragments). Reduced blood flow may contribute to both nonunion and avascular necrosis.

Structures involved

• Femoral head: the “ball” of the hip joint
• Femoral neck: the narrowed segment connecting head to shaft
• Acetabulum: the “socket” in the pelvis
• Articular cartilage: smooth surface lining the joint
• Hip capsule and surrounding muscles: influence stability and function
• Fixation hardware (if present): screws, pins, plates, or other devices used to stabilize the fracture

Onset, duration, and reversibility

Femoral neck nonunion is not an acute event; it is recognized over time when healing is not progressing. Its course depends on the underlying cause and chosen management. In some situations, union can still be achieved with further stabilization and/or biologic augmentation; in others, treatment may shift toward pain relief and function restoration through arthroplasty (hip replacement). Outcomes and timelines vary by clinician and case.

Femoral neck nonunion Procedure overview (How it’s applied)

Femoral neck nonunion is a condition, not a single procedure. Clinicians use a structured process to confirm the diagnosis and decide on next steps. A typical high-level workflow may include:

1. Evaluation / exam – Review of injury history, prior treatments, and current symptoms (often groin pain with weight-bearing) – Physical exam focusing on gait, hip range of motion, strength, limb length, and pain location – Review of risk factors that can influence bone healing (varies by clinician and case)

2. Preparation (diagnostic planning) – Standard hip and pelvis X-rays to assess fracture alignment, healing signs, and hardware position – Additional imaging when needed (often CT for bony detail; MRI may be used to assess femoral head viability in selected cases) – Laboratory tests in specific contexts (for example, if infection or metabolic bone issues are a concern)

3. Intervention / testing (management pathways) – Nonoperative management may be considered in limited situations (for example, minimal symptoms and stable-appearing fracture), with close monitoring. – Surgical options may be considered when symptoms, imaging, and functional limitation suggest persistent instability or poor healing potential. Common categories include revision fixation, osteotomy, bone grafting strategies, or hip arthroplasty.

4. Immediate checks – Post-intervention imaging to confirm alignment and hardware position (when surgery is performed) – Early assessment of pain control, mobility strategy, and precautions as determined by the care team

5. Follow-up – Scheduled clinical visits and repeat imaging to monitor progress – A rehabilitation plan that addresses gait mechanics, hip strength, and functional goals, tailored to the chosen treatment and stability

Specific protocols vary by surgeon, implant system, and case complexity.

Types / variations

Femoral neck nonunion is often discussed in terms of the fracture pattern, biology, and prior treatment status.

By fracture history and fixation status

• Primary nonunion: the fracture never achieves union after the initial injury management.
• Post-fixation nonunion: nonunion after surgical stabilization, sometimes associated with hardware loosening, breakage, or loss of alignment.
• Nonunion after nonoperative care: less common in certain modern practice patterns but may occur depending on fracture type and patient factors.

By biologic activity (general nonunion concepts)

• Hypertrophic nonunion: more “healing activity” may be seen on imaging, suggesting biology is present but stability may be insufficient.
• Atrophic nonunion: less visible healing response, suggesting limited biology and/or impaired blood supply.

These labels can be helpful, but real cases may not fit neatly into one category.

By displacement and alignment

• Displaced vs nondisplaced original fracture: displacement can be associated with higher risk of blood supply disruption.
• Varus malalignment (neck-shaft angle reduced): can increase mechanical stress across the femoral neck and may affect healing dynamics.

By associated femoral head status

• With concern for avascular necrosis: management discussions often broaden to include joint-surface preservation versus replacement considerations.
• With secondary arthritis: cartilage damage and joint degeneration can shift treatment goals toward pain relief and function rather than union alone.

Pros and cons

Pros:

• Clarifies a specific reason for persistent hip pain after a femoral neck fracture
• Helps structure evaluation (targeted imaging, assessment of fixation stability, and consideration of bone biology)
• Supports clearer communication among orthopedics, radiology, physical therapy, and primary care
• Guides a focused discussion of realistic goals (bone healing vs hip function restoration)
• Encourages identification of contributing factors (alignment, stability, vascular considerations)
• Provides a framework for comparing treatment pathways (revision fixation vs arthroplasty, for example)

Cons:

• The term can be used inconsistently (timing and criteria may differ among clinicians and institutions)
• Imaging findings and symptoms do not always align perfectly; some patients have pain with subtle findings and vice versa
• It can be emotionally stressful for patients to hear “not healed,” especially after prior surgery
• Management decisions can be complex and preference-sensitive, with trade-offs that vary by individual
• The condition may coexist with other problems (hardware irritation, cartilage injury, avascular necrosis), complicating interpretation
• Outcomes and timelines are variable and may be difficult to predict early

Aftercare & longevity

“Aftercare” for Femoral neck nonunion depends on whether the plan is monitoring, revision fixation, osteotomy, bone grafting, or arthroplasty. While specifics are individualized, several general factors commonly influence recovery and long-term results:

• Severity and mechanical stability: alignment, displacement, and whether the fracture environment is stable enough for healing
• Femoral head viability: suspected or confirmed avascular necrosis can affect durability of hip-preserving approaches
• Rehabilitation quality and consistency: gait retraining, hip abductor strengthening, and safe progression of activity are often central themes
• Weight-bearing status: restrictions or progression plans are used to manage load across the healing area; the exact approach varies by clinician and case
• Comorbidities and bone health: osteoporosis, nutritional issues, and other systemic factors can influence healing potential
• Smoking status and medication profile: some exposures can affect bone metabolism; relevance is individualized
• Implant choice and surgical technique (when applicable): device design and fixation strategy differ; performance varies by material and manufacturer, and by case specifics
• Follow-up cadence and imaging: monitoring helps detect loss of fixation, progression of healing, or joint degeneration

Longevity is best thought of in functional terms: pain control, walking tolerance, and hip motion over time. Some pathways aim for bone union; others aim for a stable, durable joint reconstruction. The likely trajectory varies by clinician and case.

Alternatives / comparisons

Because Femoral neck nonunion is a diagnosis rather than a single therapy, “alternatives” usually refer to different management strategies after the condition is identified.

Observation and monitoring vs intervention

• Observation/monitoring may be considered when symptoms are mild, the fracture appears stable, and there are signs of ongoing healing. It emphasizes repeat assessment rather than immediate surgery.
• Intervention is more commonly considered when pain is significant, function is limited, or imaging suggests instability, failure of fixation, or low likelihood of union without changes.

Revision fixation (with or without grafting) vs joint replacement

• Revision fixation approaches aim to preserve the native femoral head by improving stability and sometimes adding biologic support (such as bone graft). This pathway may be more appealing in younger or more active patients, but candidacy depends on anatomy, bone quality, and femoral head status.
• Arthroplasty (hip replacement) shifts the goal from fracture healing to joint reconstruction for pain relief and function, particularly when the femoral head or joint surface is compromised. Implant selection and expected longevity vary by material and manufacturer, and by patient factors.

Osteotomy (realignment) vs fixation alone

• Valgus intertrochanteric osteotomy (a realignment procedure) may be used in selected cases to change force direction across the nonunion site, potentially improving the mechanical environment for healing.
• Fixation alone focuses on compressing and stabilizing the fracture without changing overall hip geometry; suitability depends on the fracture pattern and alignment.

Imaging comparisons (X-ray vs CT vs MRI)

• X-rays are the common starting point for tracking alignment and visible healing.
• CT can better define bone continuity, subtle gaps, and hardware position.
• MRI may be used selectively to evaluate femoral head viability and soft tissues, but interpretation can be affected by hardware and other factors.

Femoral neck nonunion Common questions (FAQ)

Q: What does Femoral neck nonunion feel like?
Symptoms commonly include deep groin pain that worsens with standing or walking. Some people notice a persistent limp, weakness, or pain with twisting movements. The exact pattern can vary, especially if arthritis, hardware irritation, or muscle issues are also present.

Q: How is Femoral neck nonunion diagnosed?
Diagnosis usually combines symptoms, physical exam findings, and imaging. X-rays are often first-line, and CT may be used to better assess whether bone has bridged the fracture. MRI may be considered in selected cases to evaluate the femoral head’s blood supply and surrounding structures.

Q: Does a nonunion always mean something “went wrong” with the first treatment?
Not necessarily. Femoral neck fractures can be biologically and mechanically challenging, especially when displaced or when blood supply is affected. Nonunion can occur even with appropriate initial care, and risk depends on injury characteristics and patient-specific factors.

Q: Is Femoral neck nonunion dangerous?
Clinicians take it seriously because an unhealed femoral neck can remain mechanically vulnerable and painful. It may also be associated with other complications, such as fixation failure or femoral head blood supply problems, depending on the case. The clinical significance varies by symptoms, stability, and imaging findings.

Q: What treatments are typically considered?
Treatment categories include continued monitoring in select situations, revision fixation strategies (sometimes with bone grafting), realignment procedures (osteotomy) in selected cases, and hip arthroplasty when joint preservation is unlikely to provide durable function. The choice depends on age, bone quality, fracture pattern, alignment, femoral head status, and goals of care.

Q: How long does recovery take after treatment for Femoral neck nonunion?
Timelines vary widely by treatment type and individual factors. Bone-healing pathways may require extended periods of protected loading and repeated imaging, while arthroplasty has different milestones focused on mobility, strength, and function. Your care team’s protocol will reflect stability, tissue healing, and overall health considerations.

Q: Will I be non-weight-bearing if I have a nonunion?
Weight-bearing status is determined by the stability of the fracture or reconstruction and the chosen management plan. Some approaches require limiting load to protect fixation and promote healing, while others allow earlier weight-bearing depending on implant stability and surgical goals. Specific instructions vary by clinician and case.

Q: Can physical therapy fix a femoral neck nonunion?
Physical therapy can improve strength, gait mechanics, balance, and function, and it is commonly part of recovery. However, therapy does not mechanically unite bone if the fracture remains unstable or biologically unable to heal without additional intervention. In practice, rehabilitation is often paired with medical or surgical management decisions.

Q: What about pain control—does pain usually go away once it heals?
If pain is primarily coming from motion at the nonunion site, achieving stability and/or union can reduce pain. But pain may also come from cartilage damage, avascular necrosis, muscle weakness, or hardware irritation. Because multiple factors can contribute, symptom improvement varies by clinician and case.

Q: How much does evaluation or treatment cost?
Costs vary widely by region, facility type, imaging needs, insurance coverage, and whether surgery is performed. Even within the same category (for example, CT vs MRI, or fixation vs arthroplasty), pricing can differ substantially. A hospital billing team or insurer can usually provide the most accurate, case-specific estimates.

Q: When can someone drive or return to work after Femoral neck nonunion treatment?
This depends on which side is affected, pain control, mobility, reaction time, medication use, and the physical demands of the job. Desk-based work may resume earlier than physically demanding work, but clearance is individualized. Clinicians often base recommendations on safe function and the stability of the healing or reconstruction.