Orthopaedic Surgery - The Female Athlete Triad

⸻

Basics

The female athlete triad is a clinical spectrum involving three interrelated abnormalities: low energy availability, menstrual dysfunction, and impaired bone health with reduced bone mineral density (BMD).

Low energy availability may occur with or without a formal eating disorder, and an athlete does not need to demonstrate all three components simultaneously to be at risk of clinically important or potentially irreversible skeletal consequences.

⸻

Components of the Triad

The three major components are menstrual dysfunction, inadequate energy availability relative to exercise expenditure, and decreased bone mineral density.

Each exists along a continuum of severity, and abnormalities in one component can adversely influence the others.

⸻

Menstrual Dysfunction

Menstrual dysfunction is common in affected athletes, with amenorrhea being the classic presentation.

Menstrual abnormalities result largely from hypothalamic suppression caused by inadequate energy availability and subsequent disturbances of reproductive hormone production.

⸻

Low Energy Availability

Low energy availability occurs when dietary energy intake is insufficient to support both the demands of exercise and the body’s normal physiologic functions.

This may result from an eating disorder such as anorexia nervosa or bulimia nervosa, deliberate dietary restriction, extreme dieting, or simply inadequate caloric intake for the athlete’s training load.

⸻

Bone Mineral Density

Reduced energy availability and menstrual dysfunction interfere with normal bone remodeling.

Hypoestrogenism is an important contributor to increased bone resorption, although multiple other metabolic and endocrine abnormalities also affect bone health.

⸻

Importance of Screening

Athletes at risk may have any body habitus and may participate in any sport.

Therefore, screening should not be restricted to athletes who appear underweight or participate only in traditionally high-risk sports.

⸻

Incomplete Triad

All three components do not have to be present for adverse effects to occur.

For example, an athlete may already experience reduced bone formation and stress injury while still having intermittent or apparently normal menstrual cycles.

⸻

Opportunities for Screening

Screening can occur in multiple clinical settings, including primary care, obstetrics and gynecology, pediatric care, sports medicine, and orthopedic clinics.

Preparticipation examinations and preventive health visits provide particularly useful opportunities.

⸻

Epidemiology

The full triad has historically been estimated to occur in approximately 2–5% of the general female population, while individual components are considerably more common.

The prevalence is substantially higher in certain athletic populations.

⸻

High-Risk Sports

Sports emphasizing leanness, low body weight, endurance, or aesthetic appearance are associated with increased risk.

Examples include distance running, gymnastics, ballet and other forms of dance.

⸻

Weight-Class Sports

Athletes participating in sports with formal weight categories are also vulnerable because of pressure to reduce body mass.

Examples include boxing, wrestling, and mixed martial arts.

⸻

Associated Conditions and Complications

The three components of the triad interact with each other, and each can produce additional medical complications.

Persistent energy deficiency is the central driver in many affected athletes.

⸻

Menstrual Dysfunction and Reproductive Health

Chronic menstrual dysfunction may impair reproductive function and can contribute to infertility.

Restoration of adequate energy availability often plays a central role in normalizing hypothalamic and reproductive function.

⸻

Stress Fractures

Stress fractures are among the most clinically important orthopedic complications.

Athletes with the triad have a substantially increased risk of bone stress injury, historically reported at approximately two to four times that of unaffected individuals.

⸻

High-Risk Stress Fracture Sites

Important high-risk locations include the femoral neck, anterior tibial cortex, tarsal navicular, base of the fifth metatarsal, and sesamoids of the first metatarsal.

These sites have greater risks of delayed union, nonunion, displacement, or complete fracture.

⸻

Peak Bone Mass

Adolescence and early adulthood are critical periods for achieving peak bone mass.

Low energy availability and hypoestrogenism during these years may prevent optimal skeletal mineral accumulation and contribute to osteopenia, osteoporosis, and increased fracture susceptibility later in life.

⸻

Hypothalamic Suppression

Low energy availability suppresses normal hypothalamic function.

This alters gonadotropin-releasing hormone signaling and produces multiple downstream endocrine abnormalities.

⸻

Hypoestrogenism and Hypoleptinemia

Reduced estrogen and leptin levels are among the hormonal consequences of persistent energy deficiency.

Both can adversely affect bone metabolism and other organ systems.

⸻

Brain-Bone Interaction

Energy deficiency produces complex feedback changes between the central nervous system, endocrine system, and skeleton.

Unless adequate energy availability is restored, these alterations may perpetuate impaired bone formation and abnormal remodeling.

⸻

Diagnosis

⸻

General Principles

Diagnosis depends on recognizing one or more elements of the triad and determining whether inadequate energy availability is contributing.

A detailed history of menstrual function, nutrition, exercise, body image, previous fractures, and weight change is essential.

⸻

Signs and Symptoms

⸻

Stress Fractures

Recurrent or unusual stress fractures should prompt evaluation for the female athlete triad, particularly when they involve high-risk locations or occur after relatively modest training changes.

⸻

Amenorrhea

Amenorrhea may be classified as primary or secondary.

⸻

Primary Amenorrhea

Primary amenorrhea is traditionally defined as absence of menarche by approximately 15 years of age despite otherwise appropriate development of secondary sexual characteristics.

Delayed pubertal development requires broader endocrine evaluation.

⸻

Secondary Amenorrhea

Secondary amenorrhea refers to absence of menstrual periods for more than approximately 3 months in someone who previously menstruated regularly, although the precise definition depends on the patient’s prior cycle pattern.

⸻

Weight and Body Habitus

Marked thinness may be present but is not required.

Athletes with apparently normal weight or body composition can still have significant energy deficiency.

⸻

Eating Disorder History

A history of anorexia nervosa, bulimia nervosa, restrictive eating, recurrent purging, or substantial concern about weight and body image should increase suspicion.

⸻

Restrictive Diets

Experimentation with extreme or highly restrictive dietary regimens may result in inadequate caloric, protein, calcium, vitamin D, or micronutrient intake.

⸻

Fatigue

Severe or persistent fatigue may reflect chronic under-fueling, anemia, endocrine disturbance, excessive training, or other consequences of low energy availability.

⸻

Screening

⸻

Preventive Visits

Important opportunities for screening include preparticipation sports examinations, annual preventive visits, gynecologic examinations, and visits for musculoskeletal injury.

⸻

Screening Questions

Screening should explore body weight changes, menstrual history, dietary intake, body image, training volume, previous stress fractures, exercise habits, and relevant sexual and reproductive history.

⸻

Screening Tools

Several organizations have developed screening recommendations and questionnaires, including sports medicine, pediatric, and collegiate athletic organizations.

The goal is early recognition before irreversible skeletal consequences develop.

⸻

Physical Examination

⸻

Vital Signs and Anthropometrics

Height, weight, pulse, blood pressure, and other vital signs should be recorded at each relevant visit.

Trends over time may be more informative than a single measurement.

⸻

Musculoskeletal Examination

A thorough musculoskeletal examination should be performed, especially when the athlete reports focal pain.

Localized bony tenderness at a high-risk stress fracture site requires careful evaluation.

⸻

Signs of Hormonal or Nutritional Dysfunction

Possible examination findings include dry skin, hair loss, signs of estrogen deficiency, and delayed development of secondary sexual characteristics.

These findings may indicate significant endocrine or nutritional disturbance.

⸻

Laboratory Tests

⸻

Pregnancy Testing

Pregnancy must be excluded in any reproductive-age athlete presenting with amenorrhea.

A beta-human chorionic gonadotropin test is therefore an important initial investigation.

⸻

Gonadotropins

Follicle-stimulating hormone may be measured to help distinguish hypothalamic suppression from primary ovarian dysfunction.

Depending on the clinical setting, luteinizing hormone may also be assessed.

⸻

Thyroid Function

Thyroid-stimulating hormone should be measured because thyroid disease can cause menstrual disturbance and systemic symptoms that resemble components of the triad.

⸻

Prolactin

Serum prolactin should be considered during evaluation of amenorrhea because hyperprolactinemia can suppress reproductive function.

⸻

Estradiol

Estradiol measurement may provide evidence of hypoestrogenism.

Results should be interpreted in conjunction with menstrual history and other endocrine studies.

⸻

Progesterone Challenge

A progesterone withdrawal challenge has historically been used in selected patients to assess estrogen status and outflow tract function, although its role depends on the broader gynecologic evaluation.

⸻

CBC and Metabolic Studies

A complete blood count and comprehensive metabolic panel may help identify anemia, electrolyte abnormalities, nutritional deficiencies, or systemic complications of disordered eating.

Additional laboratory testing should be guided by history and examination.

⸻

Imaging

⸻

Dual-Energy X-Ray Absorptiometry

Dual-energy X-ray absorptiometry (DXA or DEXA) is used to evaluate bone mineral density when reduced bone mass is suspected.

The lumbar spine and hip are commonly assessed.

⸻

Interpretation in Younger Patients

In premenopausal women and adolescents, Z-scores rather than T-scores are generally emphasized because bone density is compared with age-matched controls.

Bone-density results must also be interpreted in the context of clinical risk factors and fracture history.

⸻

Low Bone Mineral Density

A Z-score between approximately −1 and −1.9 in the presence of relevant clinical risk factors may indicate clinically important low BMD in an athlete.

A Z-score of −2.0 or lower is particularly concerning and warrants comprehensive evaluation.

⸻

Plain Radiographs

AP and lateral radiographs may be obtained when focal bone tenderness raises concern for stress fracture.

Early stress injuries may not be visible on radiographs.

⸻

MRI

MRI is the preferred advanced imaging modality for suspected extremity stress fractures because of its excellent sensitivity and specificity.

It can detect bone stress reactions before a visible fracture line develops.

⸻

Comparison With Other Modalities

MRI generally provides more useful information for bone stress injury than nuclear scintigraphy, CT, or ultrasound in most clinical settings.

⸻

Differential Diagnosis

⸻

Hypothalamic Disorders

Amenorrhea may result from hypothalamic disorders unrelated to athletic energy deficiency.

Important considerations include Kallmann syndrome, anorexia nervosa, severe systemic stress, and medication-related suppression.

⸻

Pituitary Disorders

Pituitary causes include prolactinoma, Sheehan syndrome, infiltrative disease such as sarcoidosis, and other pituitary dysfunction.

⸻

Ovarian Disorders

Potential ovarian causes include polycystic ovary syndrome, primary ovarian insufficiency, and Turner syndrome.

⸻

Endocrine Disorders

Other endocrine diseases, including Cushing syndrome and thyroid disorders, can affect menstruation, body composition, and bone health.

⸻

Treatment

⸻

General Principles

Management is complex and requires correction of the underlying energy deficit, treatment of menstrual and skeletal consequences, and management of any associated eating disorder or psychological condition.

A multidisciplinary strategy is often most effective.

⸻

Multidisciplinary Care

The treatment team may include a sports medicine physician, primary-care clinician, dietitian, mental-health professional, gynecologist or endocrinologist, athletic trainer, and orthopedic specialist when bone stress injury is present.

⸻

Nutritional Rehabilitation

The cornerstone of treatment is restoration of adequate energy availability.

This generally requires increasing caloric intake, decreasing excessive exercise expenditure when necessary, or both.

⸻

Nutritional Quality

Dietary counseling should emphasize adequate intake of protein, calcium, vitamin D, carbohydrates, fats, and micronutrients, rather than focusing solely on total calories.

⸻

Psychological Treatment

Psychological counseling is important when body-image disturbance, disordered eating, anxiety, depression, or compulsive exercise is present.

⸻

Cognitive Behavioral Therapy

Cognitive behavioral therapy can help address maladaptive beliefs and behaviors surrounding food, body weight, and exercise.

⸻

Hormonal Therapy

The primary treatment of functional hypothalamic menstrual disturbance is correction of energy deficiency.

Hormonal therapy may be considered in selected patients when menstrual dysfunction or impaired bone health persists despite nutritional rehabilitation.

⸻

Combined Oral Contraceptives

Estrogen-containing oral contraceptives can produce withdrawal bleeding, but they may mask persistent hypothalamic dysfunction and are not a substitute for restoring adequate energy availability.

They should not be relied upon as the primary strategy for improving bone density in energy-deficient athletes.

⸻

Transdermal Estrogen

Physiologic transdermal estrogen replacement may be considered in selected patients with persistent hypoestrogenism and low bone density after adequate nutritional intervention, usually with specialist involvement.

⸻

Calcium and Vitamin D

Adequate calcium and vitamin D intake should be ensured.

A commonly cited target for premenopausal adults is approximately 1,000 mg of calcium and 600 IU of vitamin D daily, although requirements may vary according to age, dietary intake, vitamin D status, and clinical circumstances.

⸻

Medication

⸻

SSRIs

Selective serotonin reuptake inhibitors may be useful when depression, anxiety, or certain eating-disorder-related psychiatric symptoms coexist.

They do not correct low energy availability itself.

⸻

Bisphosphonates

Bisphosphonates are generally used very cautiously in young women because of their long skeletal retention and reproductive considerations.

They may be considered only in unusual severe cases under specialist supervision rather than as routine treatment for the triad.

⸻

Stress Fracture Treatment

Most stress injuries are treated initially with activity modification, protection from impact loading, correction of nutritional and hormonal abnormalities, and gradual return to activity after healing.

Management depends strongly on fracture site and risk of progression.

⸻

Surgery

Surgery may be required when a stress fracture fails appropriate nonoperative treatment or when the fracture occurs at a high-risk location with substantial potential for delayed healing, displacement, or nonunion.

⸻

High-Risk Stress Fractures

Sites traditionally considered high risk include the femoral neck, anterior tibial cortex, medial malleolus, patella, tarsal navicular, and base of the fifth metatarsal.

The exact need for fixation depends on fracture orientation, displacement, symptoms, and athletic demands.

⸻

Follow-Up

⸻

Team Communication

Close communication among members of the multidisciplinary team is essential.

Nutritional, psychological, menstrual, and orthopedic issues should be managed together rather than independently.

⸻

Clinical Monitoring

Follow-up should assess energy intake, body weight trends, menstrual recovery, psychological health, training volume, pain, stress injuries, and return-to-sport readiness.

⸻

Repeat Laboratory Studies

Laboratory studies may be repeated as needed to assess improvement in endocrine, nutritional, or metabolic abnormalities.

⸻

Repeat Bone Density Testing

DXA may be repeated periodically when clinically indicated.

In persistent or severe cases, reassessment at approximately yearly intervals may be appropriate because meaningful changes in bone density occur slowly.

⸻

Prognosis

Outcome depends heavily on early recognition and restoration of adequate energy availability.

Menstrual function and many metabolic abnormalities may recover with treatment, but loss of peak bone mass during adolescence may not be completely reversible.

This makes early screening particularly important.

⸻

Complications

Potential complications include recurrent stress fractures, delayed or incomplete bone healing, low peak bone mass, osteopenia or osteoporosis, reproductive dysfunction, chronic fatigue, and psychological consequences of disordered eating.

Severe energy deficiency may also affect cardiovascular, gastrointestinal, immune, and endocrine function.

⸻

Patient Monitoring

Long-term monitoring should continue until energy availability is adequate, menstrual function is stable, bone stress injuries have healed, and skeletal health is improving.

Athletes should return to unrestricted sport progressively, with decisions based on medical stability, nutritional recovery, bone health, and risk of recurrent injury.