Functional Leg Length Discrepancy Pelvic Obliquity

posted on 27 Apr 2015 07:27 by goodqueue316
Overview

A Leg Length Inequality or Leg Length Discrepancy is exactly as it sounds. One or more bones (the Femur or thigh bone, the Tibia or shin bone, and/or the joint spacing within the knee) are unequal in total length when measured in comparison to the same structures on the opposite side. It is common for people to have one leg longer than the other. In fact, it is more typical to be asymmetrical than it is to be symmetrical.Leg Length Discrepancy

Causes

Leg length discrepancies can be caused by poor alignment of the pelvis or simply because one leg is structurally longer than the other. Regardless of the reason, your body wants to be symmetrical and will do its best to compensate for the length difference. The greater the leg length difference, the earlier the symptoms will present themselves to the patient. Specific diagnoses that coincide with leg length discrepancy include: scoliosis, lumbar herniated discs, sacroiliitis, pelvic obiliquity, greater trochanteric bursitis, hip arthritis, piriformis syndrome, patellofemoral syndrome and foot pronation. Other potential causes could be due to an injury (such as a fracture), bone disease, bone tumors, congenital problems (present at birth) or from a neuromuscular problem.

Symptoms

If your child has one leg that is longer than the other, you may notice that he or she bends one leg. Stands on the toes of the shorter leg. Limps. The shorter leg has to be pushed upward, leading to an exaggerated up and down motion during walking. Tires easily. It takes more energy to walk with a discrepancy.

Diagnosis

The most accurate method to identify leg (limb) length inequality (discrepancy) is through radiography. It?s also the best way to differentiate an anatomical from a functional limb length inequality. Radiography, A single exposure of the standing subject, imaging the entire lower extremity. Limitations are an inherent inaccuracy in patients with hip or knee flexion contracture and the technique is subject to a magnification error. Computed Tomography (CT-scan), It has no greater accuracy compared to the standard radiography. The increased cost for CT-scan may not be justified, unless a contracture of the knee or hip has been identified or radiation exposure must be minimized. However, radiography has to be performed by a specialist, takes more time and is costly. It should only be used when accuracy is critical. Therefore two general clinical methods were developed for assessing LLI. Direct methods involve measuring limb length with a tape measure between 2 defined points, in stand. Two common points are the anterior iliac spine and the medial malleolus or the anterior inferior iliac spine and lateral malleolus. Be careful, however, because there is a great deal of criticism and debate surrounds the accuracy of tape measure methods. If you choose for this method, keep following topics and possible errors in mind. Always use the mean of at least 2 or 3 measures. If possible, compare measures between 2 or more clinicians. Iliac asymmetries may mask or accentuate a limb length inequality. Unilateral deviations in the long axis of the lower limb (eg. Genu varum,?) may mask or accentuate a limb length inequality. Asymmetrical position of the umbilicus. Joint contractures. Indirect methods. Palpation of bony landmarks, most commonly the iliac crests or anterior iliac spines, in stand. These methods consist in detecting if bony landmarks are at (horizontal) level or if limb length inequality is present. Palpation and visual estimation of the iliac crest (or SIAS) in combination with the use of blocks or book pages of known thickness under the shorter limb to adjust the level of the iliac crests (or SIAS) appears to be the best (most accurate and precise) clinical method to asses limb inequality. You should keep in mind that asymmetric pelvic rotations in planes other than the frontal plane may be associated with limb length inequality. A review of the literature suggest, therefore, that the greater trochanter major and as many pelvic landmarks should be palpated and compared (left trochanter with right trochanter) when the block correction method is used.

Non Surgical Treatment

A personalized approach to leg length discrepancy treatment works best for each patient. Your child's doctor will consider many factors when deciding on a course of treatment for this condition. Such factors can include your child's age, extent of the leg length discrepancy, medical history, how your child tolerates certain treatments and procedures, your child's health and prognosis, growth rate, and parental preferences. There is no cookie cutter treatment for each child, or even each centimeter of leg difference. Once all of these factors have been carefully considered, your child's physician will come up with an appropriate course of care. In situations of a very small leg length discrepancy, no treatment, only periodic medical evaluation, may be necessary.

Leg Length Discrepancy Insoles

Surgical Treatment

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[57] 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.