Leg Length Discrepancy (LLD)


Leg Length Discrepancy (LLD)

Leg Length Discrepancy (LLD) is a condition where one leg is shorter than the other. LLD is quite common in pediatric and adult individuals. It can be due to a condition the person was born with (congenital), or acquired, for example, after infection or trauma. When the discrepancy is less than 1-2cm, it can be easily managed with an insole or raise on the shoe, but a larger difference may require a different approach and more complex solutions.


There are many congenital causes of LLD. The more common conditions include fibular hemimelia, hemihypertrophy, hip dysplasia and neurofibromatosis. There may be other associated problems with these conditions. Acquired causes can be due to conditions or interventions that affect the growing part of the bone (the physis), such as infection, trauma and surgery, or tumors including cancer. The leg length difference could be due to asymmetry in the length of the bones, most commonly the shin bone (tibia), the thigh bone (femur) or the joints, or it could be an apparent difference due to an abnormal walking pattern. 19


While a child is still growing, it is common for the difference in length of the two limbs to increase and become more noticeable over time. However, LLD is often asymptomatic, as the growing child adapts and may tiptoe on the short leg, or bend the long leg, to compensate. Sometimes patients may complain of pain or fatigue in the back, hip or knee area due to the imbalance in muscle forces. There may be a bend in the spine (scoliosis) as the body tries to correct for the leg length difference.


Assessment of LLD requires a reliable clinical evaluation and accurate imaging including X-rays. Sometimes more specialized scans or opinions are required to diagnose the underlying cause and decide on the best treatment. 20

Treatment Options

The choice of nonsurgical or surgical treatment depends on many factors, among these are the size of the discrepancy (the current and the expected difference once the child has fully grown) and if the patient is having problems.

A shoe raise should be worn to prevent secondary problems from the discrepancy, and may be the only treatment required. However, it can be difficult to tolerate a large shoe raise. If the expected difference is more than 2cm, a surgical procedure to slow down the growth of the longer leg may be considered. This may involve a temporary surgical plate over the growing part of the bone, or permanent fusion of the growth plate.

If the final discrepancy is expected to be more than 5cm, the option to lengthen the shorter leg may be discussed. This involves a big operation to break the shorter bone (osteotomy) and attach an external or internal device to slowly grow the bone. 21 Children and adolescents can continue to go to school and socialize during this treatment, however they will need multiple hospital appointments for physiotherapy.

The orthopedic surgeon will discuss these options with the family and consider the patient’s overall status. There can be some flexibility in the timing of the surgery to suit schooling and family life. 22


In time, untreated LLD may lead to painful arthritis of the leg joints and spine.

If children are treated at the right time, they may recover full and normal function. If they have surgery, the risks are greatest if they choose to have the shorter leg lengthened. Complications after surgery include an angular deformity of the leg, infections, fracture, problems with the bone failing to heal, or not healing in the intended position, joint subluxation and dislocation or failure of the bone to continue to grow.

As it is difficult to predict how much the child will continue to grow, there is no guarantee that surgery will lead to equal leg lengths in adulthood. 23


Important safety information: Download the Product Instructions For Use.

The Fitbone™ Intramedullary Limb-Lengthening System was developed in partnership with Professor Baumgart. The product was launched in 1997.  Since then, this innovative treatment concept has grown into a global success story. The Fitbone TAA Intramedullary Lengthening system is intended for limb lengthening of the femur and tibia. With appropriate pre-operative planning, it is possible to ensure good limb alignment so that the limb is correct at the end of lengthening.

LRS ADVanced™

Important safety information: Download the Product Instructions For Use.

The Orthofix Limb Reconstruction System™ (LRS) is a series of modular monolateral external fixators used in reconstructive procedures for treatment of short stature, bone loss, open fractures, non-union, and angular deformities.

TL-HEX TrueLok Hexapod System™

Important safety information: Download the Product Instructions For Use.

TL-HEX is a dynamic, 3D external fixation system that combines hardware and software to correct bone deformities. This hexapod-based system functions as a 3D bone segment-repositioning module. In essence, the system consists of circular and semi-circular external supports secured to the bones by wires and half-pins, interconnected by six struts.


Important safety information: Download the Product Instructions For Use.

The Ilizarov System has experienced many modifications over the last fifty years. The TrueLok™ Ring Fixation System, developed at Texas Scottish Rite Hospital for Children (TSRHC) in Dallas, Texas, is one of the modern variants of the original fixator, but preserves many of the original principles of Professor Ilizarov. It consists of aluminum rings available in different sizes, connected to the bone through metal wires or/and bone screws. The relative movements of the rings allow the correction of almost all the bone deformities in upper and lower limbs and in the foot.

19. D’amico J. 2014. Keys To Recognizing And Treating Limb Length Discrepancy. Podiatry Today; 27(5):66-75.
20. Sabharwal S. 2008. Methods for assessing Leg Length Discrepancy. Clin Orthop Relat Res; 466(12):2910-2922.
21. Steiger CN, Lenze U et al. 2018. A new technique for correction of length discrepancies in combination with complex axis deformities of the lower limb using a lengthening nail and a locking plate. J Child Orthop; 12(5):515-525.
22. Birch JB, Samchukov ML. 2004. Use of Ilizarov method to correct lower limb deformities in children and adolescents. J Am Acad Orthop Surg; 12(3):144-54.
23. Mckean J. 2020. Leg Length Discrepancy. www.orthobullets.com