Leg Length Difference (LLD) is a common condition diagnosed by orthopedic surgeons. But how important is it, and how should we handle it if it is? This blog will attempt to provide answers to some of the most important questions you may have regarding the treatment of leg length differences based on evidence from scientific studies.
The most frequently asked questions are as follows:
- – To what extent do LLDs cause symptoms?
- – What is the best test for LLD?
- – When does treatment become necessary for an LLD?
- – Is a lift implemented all at once or gradually?
- – When is an external heel build-up required?
1. The occurrence of LLD
Ninety percent of the population may show signs of LLD, with a mean inequality of 5.2 millimeters.
2. Factors that contribute to LLD
LLD has two main causes, and some patients show signs of both:
The anatomical causes could have been present at birth (like a hip dislocation, for example), or they could have developed later in life (like a fracture, degeneration, or surgery, for example).
Some of the functional causes of this condition are lower crossed syndrome, weak hip abductors, feet that turn in too much, and problems in the sacroiliac joint.
3. Effects of LLD
While most LLDs are asymptomatic and of no clinical significance, others can cause or exacerbate health problems like low back pain, scoliosis, and osteoarthritis in the hips and knees.
4. LLD imaging examination
The most dependable and accurate method for locating and measuring LLD is imaging. Several choices are:
Anteroposterior Radiograph: There is strong empirical support for the use of full-length standing anteroposterior radiograph as the gold standard for LLD determination.
Pelvic Radiograph: There is substantial evidence suggesting that pelvic radiographs using pelvic landmarks have a very low level of validity.
CT scanogram: There is some evidence that LLD can be reliably measured using a CT scanogram.
There are a lot of LLDs that don’t matter much from a medical standpoint.
Even when an LLD is applicable, the resulting functional shortfall typically results from a number of interrelated factors that are constantly shifting.
Most of the time, the diagnostic result will not determine the precise intervention, such as the height of the heel lift at the outset or the final height of the heel lift.
5. Evaluation of LLD in a Clinical Setting
The “direct” clinical method for determining LLD involves using a tape measure to determine the length of each lower extremity by gauging the distance between the anterior superior iliac spine (ASIS) and the medial malleolus.
6. Treatment requirement for LLD
Leg length discrepancy, also known as LLD, is a relatively common condition. There is currently no universal consensus regarding the LLD threshold that is considered to be of clinical significance. This threshold can vary from study to study.
Most people have LLD to some extent, and most people get used to the imbalance and don’t notice any negative effects. Unfortunately, some don’t and will need help.
LLDs greater than 6 mm were previously suspected. Recent findings suggest that inequalities of up to 20 mm may not be significant at all. The process of determining which LLDs need to be managed is highly patient-specific, given that each patient is a case study of one. It is common practice for clinicians to only address a patient’s LLDs if the patient’s symptoms continue to worsen despite the application of first-line treatments designed to correct biomechanical and functional deficits, such as manual therapy and rehabilitation.
7. The usefulness of heel lifts for treating LLD
Correction of clinically significant LLDs has the potential to influence outcomes. A 2019 study of symptomatic workers with LLD found that wearing insoles with heel lifts significantly decreased the severity of LLD, leading to significantly improved physical function and fewer sick days.
8. Internal heel lifts vs. heel build-up for LLD
When a greater amount of heel elevation is needed, doctors must decide how much of that elevation can be achieved through in-shoe modifications before resorting to an external heel buildup. You should think about whether you want a lace-up or a slip-on shoe, as well as the size and shape of your feet.
Internal lifts of up to 9 mm are commonly recommended by experts. On the other hand, patients who need more than 10 mm will likely need external heel build-up from a professional orthopedic shoe-lift specialist.
9. Implementing a heel lift
There is widespread agreement amongst experts that heel lifts should be phased in. Small but clinically significant LLDs can be treated by starting with a lift of 1-3 mm and increasing that amount every week until the goal is reached or the symptoms improve. As a rule of thumb, larger discrepancies shouldn’t accumulate at a rate faster than 5-7 mm per month to give the body time to accommodate and respond.
10. Conclusions about LLDs
Most people have LLD to some extent, and most people get used to the imbalance and don’t notice any negative effects. Unfortunately, there are always those who don’t and end up requiring assistance. Not all situations require imaging. The PALM caliper inclinometer block test is a valid non-invasive method of evaluation and tracking. If lifts are necessary, they should be introduced gradually until the expected clinical result is reached.
Contact American Heelers to have the necessary height added to the sole of your shoes if you or a member of your family has been diagnosed with LLD and is advised to wear heel-lifts.