What is the appropriate management for a patient with nonspecified pain and a 9.7 mm leg length discrepancy, with the left lower extremity being shorter than the right, and no appreciable underlying bone deformity?

Management of 9.7 mm Leg Length Discrepancy with Nonspecific Pain

For a patient with nonspecific pain and a 9.7 mm leg length discrepancy without bone deformity, conservative management with a shoe lift or orthosis is the appropriate initial treatment, as this discrepancy falls well below the 20 mm threshold where biomechanical complications and functional limitations typically occur. 1, 2

Initial Conservative Management

• Start with a heel lift or shoe insert to compensate for the 9.7 mm discrepancy, as length differences less than 10 mm are typically asymptomatic and easily compensated 1, 2
• The patient should be fitted with an orthotic device that provides approximately 10 mm of lift on the left side 1
• Most individuals with discrepancies under 20 mm can achieve adequate compensation without surgical intervention 2

Pain Assessment and Monitoring

• Evaluate whether the nonspecific pain is directly related to the leg length discrepancy or represents another musculoskeletal issue 2
• The connection between small leg length discrepancies and pain remains questionable in the literature, though there may be mildly elevated risk of knee arthritis with larger discrepancies 1
• Consider alternative pain sources including hypocalcemia, juvenile idiopathic arthritis, or nonspecific lower leg/foot pain patterns that may benefit from orthotics 3
• Monitor for development of functional scoliosis, which can occur with discrepancies greater than 20 mm but is nonprogressive and typically regresses when the discrepancy is corrected 2

Clinical Follow-Up Strategy

• Reassess the patient after 3-6 months of conservative treatment to evaluate pain response and functional improvement 1
• Obtain standing long-leg radiographs (hip-to-ankle views) if considering future surgical intervention, though this is unlikely needed for a 9.7 mm discrepancy 4
• Document any changes in gait, joint mobility, or pain patterns at follow-up visits 3

When Surgical Intervention Is NOT Indicated

• Surgical treatment is not indicated for this patient as the discrepancy is well below the informal consensus threshold of 20 mm where altered biomechanics and loading patterns cause functional limitations 1, 2
• The 2 cm threshold represents the general cutoff for considering surgical treatment in the literature 1, 5
• Surgical options (epiphysiodesis, osteotomy with distraction, or acute lengthening) are reserved for predicted discrepancies exceeding 20-50 mm 1, 5

Important Caveats

• The decision between conservative and surgical treatment must account for more than just the extent of discrepancy - patient age, growth potential, functional limitations, and patient preferences all factor into treatment decisions 1
• If this patient is still growing, serial measurements should be obtained to predict final leg length discrepancy using established algorithms (accurate to within 2 cm) 1, 6
• Shoe lifts and orthoses can create an acquired limb-length discrepancy on the contralateral side when worn, potentially causing musculoskeletal complaints in the hip or knee 3
• Progressive increase in discrepancy or development of significant functional limitations would warrant reassessment and possible imaging studies 2