What are the causes of hip pain in adolescents?

Causes of Hip Pain in Adolescents

Critical Red Flags to Exclude First

In adolescents presenting with hip pain, you must immediately rule out slipped capital femoral epiphysis (SCFE), infection, tumors, and stress fractures before considering other diagnoses. 1, 2

• SCFE is the most critical diagnosis to exclude in adolescents aged 10-15 years, particularly in obese males, presenting with hip, thigh, or even isolated knee pain with an external rotation deformity and antalgic gait 2, 3
• Septic arthritis requires emergency open drainage within 4 days of symptom onset to prevent permanent joint damage 3
• Tumors and stress fractures present with insidious onset, night pain, constitutional symptoms, and inability to bear weight 1, 4
• Perthes disease must be excluded as a serious pathological condition in this age group 1

Primary Causes by Age Group

Early Adolescence (10-15 years)

SCFE should be your preferential diagnosis in this age range, especially in limping obese boys, as it represents an inferior and posterior displacement of the proximal femoral epiphysis requiring emergency screw fixation 3

• SCFE can present as medial thigh or knee pain rather than hip pain, making it easy to miss 1, 2
• External rotation deformity of the affected limb is a key physical finding 2, 3

Mid-Adolescence (Ages 4-15 years overlap)

• Legg-Calvé-Perthes disease (LCPD) causes idiopathic avascular necrosis of the femoral head, leading to flattening and deformity depending on necrosis extent 3, 5
• Transient synovitis is the most frequent hip disorder between ages 4-10 years, presenting as self-limiting noninfectious joint effusion without serious consequences, though septic arthritis must be differentiated 3

Late Adolescence (15+ years transitioning to young adult)

Femoroacetabular impingement (FAI) syndrome becomes the predominant diagnosis, characterized by groin pain with hip flexion, adduction, and internal rotation, associated with cam, pincer, or mixed morphology on imaging 1, 6

• Acetabular labral tears present with sharp, catching medial hip/groin pain and mechanical symptoms, often coexisting with FAI or dysplasia 6, 7
• Acetabular dysplasia causes misalignment between the femoral head and acetabulum, resulting in instability and rim overload during normal activities 1

Referred and Extra-Articular Causes

Always screen the lumbar spine as a competing musculoskeletal source in all adolescent hip pain evaluations 1, 4, 6

• Lumbar spine pathology presents as sharp lancinating pain radiating down the leg, induced by sitting, standing, or walking, often present at rest and improved by position change 4, 6
• Iliopsoas tendinopathy causes anterior/medial groin pain with pain on resisted hip flexion 6

Diagnostic Algorithm

Step 1: Immediate Assessment

• Determine if red flag features are present: night pain, constitutional symptoms, inability to bear weight, fever, or external rotation deformity 1, 2, 3
• Assess whether pain is activity-related or present at rest 1

Step 2: Physical Examination

• Perform FADIR test (flexion-adduction-internal rotation): a negative test helps rule out hip-related pain, though clinical utility is limited 1, 6
• Evaluate hip range of motion, particularly internal rotation, which is limited in osteoarthritis and FAI 4, 6
• Mandatory lumbar spine screening in all cases to exclude referred pain 1, 6
• Check for external rotation deformity suggesting SCFE 2, 3

Step 3: Imaging Protocol

• First-line: AP pelvis and lateral femoral head-neck radiographs 6, 8
• MRI or MRA for advanced imaging when radiographs are inconclusive or intra-articular pathology is suspected, particularly for labral tears, early LCPD, or when surgery is considered 6, 7, 8
• MRI provides superior morphologic information and is as sensitive as bone scan for early LCPD diagnosis 8
• Bone scan reliably indicates revascularization in LCPD follow-up, which MRI cannot demonstrate 8

Critical Clinical Pitfalls

Incidental imaging findings are extremely common in asymptomatic adolescent athletes—clinical correlation is mandatory 1

• Hip pathology frequently presents as knee pain, and spine pathology can present as hip pain 4, 6
• Multiple pathologies often coexist: labral tears commonly occur with FAI or dysplasia 6, 7
• Age-specific vigilance is essential: SCFE must be considered in all adolescents 10-15 years with hip/groin pain 6, 2, 3
• A comprehensive approach combining clinical examination and imaging is essential, as neither has adequate diagnostic utility alone 1