Femoral Neck Stress Fractures

What is a femoral neck stress fracture?

Femoral neck stress fractures represent a significant orthopedic concern, particularly in athletes and individuals engaged in high-impact activities. These fractures, which occur in the proximal portion of the femur (thigh bone), can lead to debilitating symptoms and potential long-term complications if left untreated. This comprehensive discussion delves into the causes, symptoms, diagnosis, and treatment options for femoral neck stress fractures, shedding light on the complexities of managing this challenging musculoskeletal condition.

What causes femoral neck stress fractures?

Femoral neck stress fractures typically result from repetitive mechanical stress and microtrauma to the femoral neck region, leading to the accumulation of fatigue damage within the bone. Various factors may contribute to the development of femoral neck stress fractures, including:

1. Overuse or Repetitive Stress: Athletes and individuals engaged in repetitive weight-bearing activities such as running, jumping, or dancing are at increased risk of femoral neck stress fractures due to the repetitive loading and impact forces placed on the hip joint. Prolonged or intense training regimens without adequate rest periods can lead to cumulative microdamage and weakening of the femoral neck bone.
2. Decreased Bone Density: Osteoporosis, nutritional deficiencies, hormonal imbalances, and certain medical conditions such as osteopenia or female athlete triad (a combination of disordered eating, menstrual dysfunction, and low bone density) can predispose individuals to femoral neck stress fractures by reducing bone density and compromising bone strength.
3. Anatomic Factors: Anatomic variations such as a narrow femoral neck angle, coxa vara (reduced neck-shaft angle), or femoral anteversion (excessive femoral torsion) can increase the mechanical stress and strain on the femoral neck region, predisposing individuals to stress fractures.
4. Training Errors: Rapid increases in training intensity, duration, or frequency without proper conditioning or progression can overload the musculoskeletal system and increase the risk of stress fractures. Training errors such as sudden changes in running surface, improper footwear, or inadequate warm-up and cool-down routines can also contribute to the development of femoral neck stress fractures.

What are the symptoms of femoral neck stress fractures?

The symptoms of femoral neck stress fractures can vary depending on the severity, location, and chronicity of the fracture. While some individuals may experience subtle symptoms initially, others may present with more pronounced signs of injury. Common symptoms associated with femoral neck stress fractures include:

1. Hip or Groin Pain: Persistent or worsening pain in the hip or groin region. The pain may be dull, aching, or sharp in nature and may worsen with activity and improve with rest.
2. Pain with Weight Bearing: Pain or discomfort with weight-bearing activities, including standing, walking, or bearing weight on the affected leg. Individuals may experience pain with specific movements such as rising from a seated position, squatting, or performing single-leg activities.
3. Limited Range of Motion: Stiffness, decreased flexibility, or limited range of motion in the hip joint, which may affect daily activities such as getting in and out of chairs, bending, or performing activities of daily living.
4. Pain at Night: Pain or discomfort that worsens at night or during periods of rest, interfering with sleep and causing nocturnal awakenings. Individuals may experience difficulty finding a comfortable sleeping position due to hip or groin pain.
5. Localized Tenderness: Tenderness, swelling, or bruising over the affected hip or groin region, particularly with palpation or pressure applied to the femoral neck area. Swelling or soft tissue inflammation may accompany the fracture, contributing to local tenderness and discomfort.

It’s essential to recognize the signs and symptoms of femoral neck stress fractures promptly, as delayed diagnosis and treatment can lead to prolonged recovery times, increased risk of complications, and potentially catastrophic consequences such as fracture displacement or nonunion.

How are femoral neck stress fractures diagnosed?

Diagnosing femoral neck stress fractures requires a comprehensive evaluation, including a thorough medical history review, physical examination, and diagnostic imaging studies. Dr. Shane J. Nho maintains a high index of suspicion for stress fractures in individuals presenting with hip or groin pain, particularly athletes or individuals engaged in repetitive weight-bearing activities.

Medical History: A detailed medical history can provide valuable insights into the patient’s activity level, training regimen, previous injuries, nutritional status, menstrual history (in female athletes), and any underlying medical conditions that may predispose them to stress fractures.

Physical Examination: A comprehensive physical examination may reveal localized tenderness, swelling, or bruising over the affected hip or groin region. Dr. Shane J. Nho will assess the range of motion of the hip joint, perform provocative maneuvers such as the log roll test or fulcrum test, and evaluate for signs of hip joint instability or impingement.

Imaging Studies:

1. X-rays: Conventional radiographs of the hip and pelvis may initially appear normal or may show subtle findings such as periosteal reaction, cortical thickening, or trabecular sclerosis. However, early-stage stress fractures may not be visible on plain radiographs, particularly in the absence of significant callus formation.
2. Magnetic Resonance Imaging (MRI): MRI is considered the imaging modality of choice for diagnosing femoral neck stress fractures due to its high sensitivity and specificity. MRI can detect early-stage stress reactions, bone marrow edema, cortical discontinuities, and other signs of fracture pathology. It can also help assess the extent of soft tissue involvement and rule out concomitant intra-articular or extra-articular injuries.