Large leg length inequalities can be treated by staged lengthenings or by simultaneous ipsilateral femoral and tibial lengthenings. Additionally, lengthenings can be combined with appropriately timed epiphysiodesis in an effort to produce leg length equality. Staged lengthenings are often used for congenital deficiencies such as fibular hemimelia, in which 15 cm or more may be needed to produce leg length equality. We typically plan for the final lengthening to be completed by age 13 or 14 years, and allow at least 3 years between lengthenings. Lengthening of both the tibia and femur simultaneously requires aggressive therapy and treatment of soft tissue contractures. Curran et al reported the need for surgical release of soft tissue contractures in 3 of 8 patients treated with simultaneous ipsilateral femoral and tibial lengthenings. Lengthening over an IM nail can be done in an effort to decrease the amount of time the fixator needs to be worn and to prevent angular malalignment. This technique requires that the patient be skeletally mature and it carries a higher risk of osteomyelitis (up to 15%). Additionally, if premature consolidation occurs, a repeat corticotomy is more difficult.
The causes of LLD are many, including a previous injury, bone infection, bone diseases (dysplasias), inflammation (arthritis) and neurologic conditions. Previously broken bones may cause LLD by healing in a shortened position, especially if the bone was broken in many pieces (comminuted) or if skin and muscle tissue around the bone were severely injured and exposed (open fracture). Broken bones in children sometimes grow faster for several years after healing, causing the injured bone to become longer. Also, a break in a child?s bone through a growth center (located near the ends of the bone) may cause slower growth, resulting in a shorter extremity. Bone infections that occur in children while they are growing may cause a significant LLD, especially during infancy. Bone diseases may cause LLD, as well; examples are neurofibromatosis, multiple hereditary exostoses and Ollier disease. Inflammation of joints during growth may cause unequal extremity length. One example is juvenile rheumatoid arthritis. Osteoarthritis, the joint degeneration that occurs in adults, very rarely causes a significant LLD.
Often there are few or no symptoms prior to the age of 25-35. The most common symptom is chronic lower back pain, but also is frequently middle and upper back pain. Same-sided and repeated injury or pain to the hip, knee and/or ankle is also a hallmark of a long-standing untreated LLD. It is not uncommon to have buttock or radiating hip pain that is non-dermatomal (not from a disc) and tends to go away when lying down.
A doctor will generally take a detailed medical history of both the patient and family, including asking about recent injuries or illnesses. He or she will carefully examine the patient, observing how he or she moves and stands. If necessary, an orthopedic surgeon will order X-ray, bone age determinations and computed tomography (CT) scans or magnetic resonance imaging (MRI).
Non Surgical Treatment
Treatment is based on an estimate of how great the difference in leg length will be when the child grows up, Small differences (a half inch or less) do not need treatment. Differences of a half to one inch may require a lift inside the shoe.
Bone growth restriction (epiphysiodesis) The objective of this surgical procedure is to slow down growth in the longer leg. During surgery, doctors alter the growth plate of the bone in the longer leg by inserting a small plate or staples. This slows down growth, allowing the shorter leg to catch up over time. Your child may spend a night in the hospital after this procedure or go home the same day. Doctors may place a knee brace on the leg for a few days. It typically takes 2 to 3 months for the leg to heal completely. An alternative approach involves lengthening the shorter bone. We are more likely to recommend this approach if your child is on the short side of the height spectrum.