What are the causes and management of joint pain in young adults?

Causes of Joint Pain in Young Adults

In young adults, joint pain most commonly arises from hip-related conditions (femoroacetabular impingement syndrome, acetabular dysplasia, labral/chondral pathology), athletic injuries, inflammatory arthropathies (rheumatoid arthritis, spondyloarthropathies), trauma, and referred pain from the lumbar spine or hip—but serious pathology including infection, tumors, stress fractures, and slipped capital femoral epiphysis must be excluded first. 1, 2

Systematic Approach to Diagnosis

Step 1: Exclude Red Flags and Serious Pathology

Before considering common musculoskeletal causes, you must rule out conditions requiring immediate intervention 1, 3:

• Infection (septic arthritis) - presents with acute onset, fever, inability to bear weight, elevated inflammatory markers 4, 2
• Tumors - insidious onset, night pain, constitutional symptoms 1
• Stress fractures - history of repetitive loading, focal tenderness, inability to bear weight 1
• Slipped capital femoral epiphysis (SCFE) - particularly in adolescents/young adults with hip/knee pain, external rotation deformity, antalgic gait 3, 4
• Avascular necrosis - risk factors include corticosteroid use, alcohol abuse, IV drug use 2
• Perthes disease - typically younger patients 1

Step 2: Identify the Pain Source

Once red flags are excluded, categorize pain as intraarticular, extraarticular, or referred 2:

Hip-Related Pain (Most Common in Active Young Adults)

The International Hip-related Pain Research Network consensus identifies three primary categories 1:

1. Femoroacetabular Impingement (FAI) Syndrome - groin pain (may radiate to back, buttock, thigh), pain with hip flexion/internal rotation, cam or pincer morphology on imaging 1

2. Acetabular Dysplasia/Hip Instability - misalignment between femoral head and acetabulum causing rim overload, instability symptoms 1

3. Labral, Chondral, or Ligamentum Teres Pathology - intraarticular damage without distinct bony morphology 1

Critical caveat: A negative flexion-adduction-internal rotation test helps rule out hip-related pain, though its clinical utility is limited 1. Neither clinical examination nor imaging alone is sufficient—a comprehensive approach combining symptoms, clinical signs, and imaging is essential 1.

Knee Pain Patterns by Demographics

• Teenage girls/young women - patellar tracking problems (subluxation, patellofemoral pain syndrome) 4
• Teenage boys/young men - knee extensor mechanism problems (Osgood-Schlatter, patellar tendonitis) 4
• Active patients - acute ligamentous sprains, overuse injuries (pes anserine bursitis, medial plica syndrome) 4

Inflammatory Arthropathies

• Rheumatoid arthritis - typically first appears in young adulthood, symmetric joint involvement, morning stiffness 2
• Spondyloarthropathies - more common in younger patients, associated with back pain, enthesitis 2
• Crystal-induced arthropathy - more likely in adults than younger patients 4

Referred Pain

• Lumbar spine pathology - must be screened as competing musculoskeletal source 1
• Hip pathology causing knee pain - particularly SCFE in adolescents 3, 4

Step 3: Diagnostic Workup

Imaging approach 1:

• Initial: AP pelvis and lateral femoral head-neck view radiographs for hip pain
• Advanced imaging (MRI): When further assessment of intraarticular structures or morphology is needed 1, 2

Laboratory studies 2:

• Blood, urine, and synovial fluid analysis for inflammation, infection, and systemic rheumatic disease
• Particularly important when inflammatory arthropathy is suspected

Management Framework

Pharmacologic Treatment (Stepwise Approach) 5, 2

1. Mild pain: Acetaminophen first-line 5, 2
2. Moderate pain with inflammation: NSAIDs or COX-2 inhibitors 5
3. Severe pain: Opioids when appropriate 5, 2
4. Infection: Antibiotics immediately 2

Non-Pharmacologic Treatment 5

• Acute phase: Protection, rest, ice, compression, elevation (PRICE) 5
• Rehabilitation: Physical therapy to prevent recurrence and restore function 5, 2
• Patient education: Essential component of recovery 5, 2

Critical Clinical Pitfalls

Do not miss serious pathology: Fractures, infection, and ischemic necrosis require immediate treatment to prevent permanent joint damage 2. These must be ruled out early in the evaluation.

Beware of referred pain: Hip pathology commonly presents as knee pain, particularly SCFE in adolescents 3, 4. Always examine the hip when evaluating knee pain in young patients.

Imaging findings may be incidental: There is increasing recognition of incidental imaging findings in young active adults that may not correlate with symptoms 1. Clinical correlation is mandatory—do not treat imaging alone.

Long-term implications: Hip trauma at a young age increases osteoarthritis risk, and young adults receiving total hip replacement will likely require revision surgery 2. Conservative management should be optimized before surgical intervention.