What treatment options are available for a patient with a 17 mm leg length discrepancy due to shortening of the left tibia?

Treatment Recommendations for 17mm Leg Length Discrepancy

For a 17mm leg length discrepancy due to left tibial shortening, a contralateral shoe lift is the recommended first-line treatment, as this magnitude falls within the conservative management range and avoids surgical risks while effectively addressing the biomechanical consequences. 1, 2, 3

Conservative Management (Primary Recommendation)

Shoe Lift Prescription

• A contralateral (right-sided) shoe lift of approximately 17-20mm should be prescribed to compensate for the discrepancy and the 25mm femoral head level difference. 1, 4
• Low-heeled shoes are preferable as the base footwear to maintain proper biomechanical alignment and balance. 1
• The shoe lift immediately normalizes gait kinematics, corrects lateral pelvic drop, reduces compensatory lumbar bending, and prevents long-term complications. 4

Evidence Supporting Conservative Approach

• Leg length discrepancies up to 20mm in adults are generally well-tolerated with shoe lifts or orthoses. 2, 3
• Research demonstrates that orthotic correction instantly normalizes spinal gait kinematics, eliminating the increased lumbar bending, pelvic obliquity, and hip adduction angles seen in untreated LLD. 4
• While the connection between LLD and back pain remains questionable, there is a mildly elevated incidence of knee arthritis with untreated discrepancies, making correction reasonable. 3

Monitoring Requirements

• If the patient is skeletally immature, serial measurements should be obtained to track progression, as the final discrepancy may increase and require surgical intervention if it exceeds 50mm. 2, 3
• Predictive algorithms can estimate final leg length discrepancy to within 20mm accuracy during growth. 3

Surgical Options (Reserved for Specific Scenarios)

Indications for Surgery

• Surgical intervention should be considered only if the discrepancy progresses beyond 50mm, if conservative treatment fails to provide adequate symptom relief, or if the patient refuses to wear external lifts. 2, 3, 5
• The decision for surgery is always elective and must account for patient preference, cosmetic concerns, and functional limitations—not solely the magnitude of discrepancy. 3

Surgical Techniques Available

For Skeletally Immature Patients

• Percutaneous epiphysiodesis of the contralateral (right) distal femur and proximal tibia is the first-choice surgical option for discrepancies between 20-50mm. 2, 5
• This technique offers minimal incisions, simple execution, and low complication rates compared to Blount stapling. 2
• Critical pitfall: Precise timing is essential—the procedure must be performed at the exact skeletal age to achieve the desired correction, requiring careful calculation of remaining growth potential. 2, 5

For Skeletally Mature Patients

• Tibial shortening osteotomy can correct up to 30mm of discrepancy, though femoral shortening is generally considered safer. 5
• Shortening procedures involve lower costs and fewer complications than lengthening, but result in reduced final height. 2, 5
• Closed intramedullary shortening with proximal and distal locking is recommended to prevent malrotation and functional loss. 5

Lengthening Procedures (Generally Not Indicated for 17mm)

• The Ilizarov method achieves 86.5% primary union rates but carries a 42.2% refracture rate and requires prolonged treatment duration (8.3 months mean union time). 6, 7
• Combined Ilizarov with intramedullary fixation reduces refracture rates to 22.3% and achieves 84-93.3% union rates, representing the gold standard for complex cases. 6, 7
• Lengthening is typically reserved for discrepancies exceeding 50mm or when shortening would result in unacceptable height loss. 2, 3

Clinical Pitfalls to Avoid

• Do not delay conservative treatment—even during growth, discrepancies over 10mm should be addressed to prevent compensatory lumbar scoliosis and gait abnormalities. 2
• Do not perform surgical shortening exceeding 60mm in the femur or 30mm in the tibia due to muscle insufficiency and compartment syndrome risk. 2
• Do not base surgical timing on age alone—use predictive algorithms and serial measurements to determine optimal intervention timing in growing patients. 2, 3
• The evidence base for treatment thresholds remains poor, with only informal consensus recommendations available rather than high-quality randomized trials. 3