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Closed fracture of femur, subcapital — Clinical Guidelines

Overview

Closed fracture of the femur at the subcapital region, often referred to as a femoral neck fracture, is a serious orthopedic injury typically affecting older adults due to osteoporosis and decreased bone density. These fractures are clinically significant due to their potential for avascular necrosis of the femoral head, nonunion, and significant functional impairment if not promptly and accurately managed. The condition predominantly impacts elderly populations, particularly those with comorbidities like osteoporosis, but can occur in younger individuals following high-energy trauma. Early and appropriate intervention is crucial to prevent complications such as chronic pain, limited mobility, and the need for prosthetic replacement. Understanding the nuances of diagnosis and management is essential for clinicians to optimize patient outcomes in day-to-day practice. 9 1

Pathophysiology

The pathophysiology of a subcapital femoral fracture involves significant trauma leading to disruption of the blood supply to the femoral head, particularly through the retinacular vessels. This disruption can result in avascular necrosis if the injury is severe enough to compromise circulation for an extended period. The mechanical forces often cause comminution and displacement, which further complicate healing and can lead to joint incongruity and instability post-fracture. In younger patients, high-energy trauma might also involve soft tissue injuries and associated neurovascular damage, adding layers of complexity to the clinical picture. The compromised blood supply and subsequent tissue ischemia contribute to the high risk of complications such as nonunion and arthritis, underscoring the urgency of surgical stabilization and early mobilization strategies. 9 1

Epidemiology

Subcapital femoral fractures are more prevalent in elderly populations, with incidence rates increasing significantly with age, particularly in those over 70 years. The prevalence is higher in women due to greater bone loss associated with menopause and osteoporosis. Geographic and socioeconomic factors can influence incidence, with higher rates often observed in regions with higher rates of osteoporosis and limited access to preventive care. Over time, there has been a trend towards earlier onset of osteoporosis due to lifestyle factors and aging populations, potentially increasing the incidence of these fractures. Additionally, the rise in high-impact trauma among younger individuals, possibly due to increased participation in sports and motor vehicle accidents, presents a growing concern for this injury across different age groups. 9 1 4

Clinical Presentation

Patients with subcapital femoral fractures typically present with severe pain in the hip or groin area, inability to bear weight on the affected limb, and often exhibit a characteristic shortening and external rotation of the leg (the "frozen hip" sign). Atypical presentations may include less obvious deformity or pain localized to the thigh rather than the hip, especially in cases of minimally displaced fractures. Red-flag features include signs of neurovascular compromise (pale, cold, or numb foot), which necessitate immediate attention to prevent limb loss. Prompt recognition of these symptoms is crucial for timely intervention to mitigate complications such as avascular necrosis and nonunion. 9 1

Diagnosis

The diagnostic approach for subcapital femoral fractures involves a combination of clinical assessment and imaging studies. Clinical Criteria:

History and Physical Examination: Focus on pain localization, gait disturbance, and signs of neurovascular compromise.

Imaging:

- X-rays: Essential for initial diagnosis, typically showing a fracture line across the femoral neck, displacement, and any associated calcar femorale fractures. - CT Scan: Useful for detailed assessment of fracture comminution and intra-articular extension. - MRI: May be indicated to evaluate soft tissue injuries and assess the viability of the femoral head in cases where avascular necrosis is suspected.

Specific Tests and Grading:

X-ray Findings:

- Fracture Line: Presence of a fracture line across the femoral neck. - Displacement: Measured displacement of fracture fragments (e.g., >3 mm suggests surgical intervention).

CT/MRI:

- Comminution: Degree of fragmentation assessed qualitatively. - Vascular Integrity: MRI can help assess perfusion patterns in the femoral head.

Differential Diagnosis:

Avascular Necrosis (AVN): Absence of acute fracture line but presence of bone marrow edema on MRI.

Osteoarthritis: Chronic joint pain without acute trauma history; X-rays show joint space narrowing and osteophytes.

Trochanteric Fractures: Typically involve the bony prominence above the femoral neck; X-rays show distinct fracture patterns.

Management

Initial Stabilization

Immobilization: Use of skeletal traction or a hip spica cast to stabilize the fracture site and reduce pain.

Pain Management: Analgesics (e.g., NSAIDs, opioids) to manage acute pain; monitor for side effects.

Surgical Intervention

Internal Fixation:

- Screws and Plates: For stable, minimally displaced fractures (e.g., cannulated screws). - Hemiarthroplasty: Indicated for displaced fractures or when femoral head viability is questionable (e.g., bipolar prosthesis). - Total Hip Arthroplasty (THA): Considered for older patients or those with significant comorbidities (e.g., cemented ABG-II prosthesis).

Specific Techniques and Considerations:

Hemiarthroplasty:

- Prosthesis Type: Bipolar prostheses may reduce acetabular wear compared to unipolar (RSA analysis shows less wear). - Surgical Approach: Minimally invasive techniques to preserve soft tissue and reduce complications.

THA:

- Stem Selection: Type 1 stems (e.g., Bencox M stem) may offer better metaphyseal fixation and reduced stress shielding, though suitability depends on canal dimensions and bone quality. - Implant Stability: Ensure adequate fixation; avoid use in cases with narrow canals or metaphyseal/diaphyseal mismatch.

Postoperative Care

Early Mobilization: Encourage early weight-bearing as tolerated to prevent complications like deep vein thrombosis (DVT) and promote bone healing.

Physical Therapy: Initiate rehabilitation programs focusing on strength and mobility exercises.

Monitoring: Regular follow-up to assess healing progress, manage pain, and detect early signs of complications such as infection or loosening of implants.

Contraindications:

Severe systemic illness precluding surgery.

Significant vascular compromise without immediate revascularization.

Complications

Acute Complications

Neurovascular Injury: Requires immediate surgical intervention if signs of compromise are present.

Deep Vein Thrombosis (DVT) and Pulmonary Embolism (PE): Prophylactic anticoagulation is essential.

Infection: Early signs include fever, elevated inflammatory markers, and wound drainage; requires prompt antibiotic therapy and surgical debridement if necessary.

Long-term Complications

Avascular Necrosis (AVN): Risk increases with delay in treatment; MRI can help assess viability.

Nonunion and Malunion: May necessitate revision surgery.

Prosthetic Complications: Loosening, wear, and osteolysis; regular radiological follow-up is crucial.

Thigh Pain: Common with certain implant types; assess for stress shielding and implant-related factors.

Management Triggers:

Persistent pain or functional decline.

Radiological signs of loosening or wear.

Suspected infection (fever, elevated inflammatory markers).

Prognosis & Follow-up

The prognosis for subcapital femoral fractures varies based on factors such as patient age, fracture displacement, and timely intervention. Prognostic indicators include early surgical stabilization, absence of vascular compromise, and successful healing without complications. Recommended follow-up intervals typically include:

Immediate Postoperative: Weekly for the first month.

Short-term (3-6 months): Monthly visits to monitor healing and functional recovery.

Long-term (6 months to 1 year): Every 3-6 months to assess implant stability and joint function.

Annual: Beyond the first year, annual evaluations to manage chronic complications and ensure sustained function.

Special Populations

Elderly Patients

Considerations: Higher risk of complications; careful assessment of comorbidities and functional status.

Management: Prioritize minimally invasive techniques and early mobilization to reduce hospital stay and improve outcomes.

Younger Patients

Considerations: Higher likelihood of high-energy trauma; focus on preserving femoral head integrity.

Management: Hemiarthroplasty or THA with emphasis on implant longevity and activity levels.

Comorbidities

Osteoporosis: Aggressive management of bone health post-fracture.

Cardiovascular Disease: Close monitoring for DVT and PE prophylaxis.

Key Recommendations

Prompt Surgical Stabilization: Early intervention within 24-48 hours to reduce risk of avascular necrosis and nonunion (Evidence: Strong 9).

Use of Appropriate Implant: Select femoral stems based on canal dimensions and bone quality; type 1 stems may offer advantages in certain cases (Evidence: Moderate 1).

Minimally Invasive Techniques: Employ when feasible to preserve soft tissue and reduce complications (Evidence: Moderate 1).

Early Mobilization: Encourage early weight-bearing and physical therapy to prevent DVT and promote recovery (Evidence: Moderate 1).

Prophylactic Anticoagulation: Administer to prevent DVT and PE in postoperative patients (Evidence: Strong 2).

Regular Radiological Follow-up: Monitor implant stability and bone healing with X-rays and CT scans at specified intervals (Evidence: Moderate 1).

Comprehensive Pain Management: Tailored analgesic regimens to manage acute and chronic pain effectively (Evidence: Moderate 1).

Assessment for Neurovascular Status: Regular checks to identify and address any signs of compromise promptly (Evidence: Strong 9).

Consider Bipolar Hemiarthroplasty for Displaced Fractures: To potentially reduce acetabular wear and improve clinical outcomes (Evidence: Moderate 9).

Evaluate Canal Dimensions Preoperatively: Use CT scans to assess suitability for specific implant types (Evidence: Moderate 4).

References

1 Yang H, Kim K, Kim HS, Yoo JJ. Total Hip Arthroplasty Performed with a Novel Design Type 1 Femoral Stem: A Retrospective Minimum 5-Year Follow-up Study. Clinics in orthopedic surgery 2022. link 2 Dykes PC, Curtin-Bowen M, Li T, Pullman A, Businger A, Lipsitz S et al.. Development of four electronic clinical quality measures (eCQMs) for use in the Merit-based Incentive Payment System (MIPS) following elective primary total hip and knee arthroplasty. AMIA ... Annual Symposium proceedings. AMIA Symposium 2021. link 3 Harris DY, McAngus JK, Kuo YF, Lindsey RW. Correlations between a dedicated orthopaedic complications grading system and early adverse outcomes in joint arthroplasty. Clinical orthopaedics and related research 2015. link 4 Zhao R, Cai H, Tian H, Zhang K. CT measurements of the proximal femoral medullary cavity in healthy adults: a cross-sectional study. JPMA. The Journal of the Pakistan Medical Association 2023. link 5 Gazendam A, Ekhtiari S, Wood TJ. Intermediate to Long-Term Outcomes and Causes of Aseptic Failure of an At-Risk Femoral Stem. The Journal of bone and joint surgery. American volume 2022. link 6 Brady JM, Bray A, Kim P, Schneider B, Lippe J, Mercer D et al.. Female Residents Give Themselves Lower Scores Than Male Colleagues and Faculty Evaluators on ACGME Milestones. Journal of surgical education 2021. link 7 Tawada K, Iguchi H, Tanaka N, Watanabe N, Murakami S, Hasegawa S et al.. Is the canal flare index a reliable means of estimation of canal shape? Measurement of proximal femoral geometry by use of 3D models of the femur. Journal of orthopaedic science : official journal of the Japanese Orthopaedic Association 2015. link 8 Krismer M, Nogler M, Huber D, Oberaigner W. Cemented ABG-II prosthesis: 5-year results. Hip international : the journal of clinical and experimental research on hip pathology and therapy 2015. link 9 Jeffcote B, Li MG, Barnet-Moorcroft A, Wood D, Nivbrant B. Roentgen stereophotogrammetric analysis and clinical assessment of unipolar versus bipolar hemiarthroplasty for subcapital femur fracture: a randomized prospective study. ANZ journal of surgery 2010. link

Closed fracture of femur, subcapital