Leg Length Discrepancy- Treatment Indications and Strategies

Abstract

Background: Many people have leg-length discrepancies of greater or lesser severity. No evidence-based studies on the need for treatment are currently available.

Methods: This review is based on publications retrieved by a selective search in the PubMed database, as well as on published recommendations from Germany and abroad and on the authors' own clinical experience.

Results: If the two legs are of different lengths, this is generally because one leg is too short. It is debated whether leg-length discrepancy causes pain or long-term musculoskeletal disturbances. A direct connection to back pain is questionable, but a mildly elevated incidence of knee arthritis seems likely. The evidence base on the indications for treatment of leg-length discrepancy is poor; only informal consensus recommendations are available. There are a wide variety of conservative and surgical treatment options. The final extent of a leg-length discrepancy first noted during the growing years can be estimated with predictive algorithms to within 2 cm. The treatments that can be considered include a shoe insert, a high shoe, or an orthosis, surgically induced slowing of growth by blockade of the epiphyseal plates around the knee joint, or leg lengthening with osteotomy and subsequent distraction of the bone callus with fully implanted or external apparatus. Changes in leg length exert marked mechanical stress on the soft tissues. If the predicted leg-length discrepancy exceeds 5 cm, initial leg-lengthening treatment can already be considered during the patient's growing years.

Conclusion: It must be discussed with each patient individually whether the treatment should be conservative or surgical. The extent of the discrepancy is not the sole determining factor for the mode of treatment. The decision to treat is always elective.

Figure 1:

Left: Double-leg stance with equal weight distribution in the presence of leg length discrepancy. Right: Single-leg stance with balancing of the pelvis by the gluteal muscles

Figure 2:

Measuring leg length discrepancy using the block method: Level pelvis is achieved by equalization with blocks of 4 cm in total height.

Figure 3:

Growth arrest by physeal stapling

Figure 4:

Distraction osteogenesis of the femur with a total length of 4.0 cm, using a magnetically controlled intramedullary lengthening nail: a) 2 weeks after surgery (distraction 1.0 cm); b) 4 weeks after surgery (distraction 3.0 cm); c) 6 weeks after surgery (distraction 4.0 cm); d) After complete consolidation at 6 months after surgery