Paediatric Lower Extremity Torsional Conditions

Original Editor - User Name

Top Contributors - Stacy Schiurring, Jess Bell and Kim Jackson  

Introduction

objectives for today will be to discuss the pathophysiology and clinical presentation of lower extremity musculoskeletal conditions that often get referred to physical therapy. Perform a history in a systems review and generate hypotheses to determine what the appropriate diagnosis and testing would be during your physical therapy examination. And to also think a little bit about the interventions to manage these musculoskeletal conditions.

Torsional Conditions

Lower-extremity torsional conditions are common in the first decade of life and are often first observed by family due to excessive in-toeing or out-toeing and is one of the most common reasons for orthopaedic referrals.

Torsion of the lower extremity can be the "summation of anatomic axial (transverse) plane tilt or twist between the ends of the bones, capsular laxity or tightness, and muscular control during growth."

ADD IMAGES OF IN AND OUT-TOEING

There can be some mild in-toeing and out-toeing throughout typical development, therefore it is important to differentiate typical or expected versus atypical as part of a lower extremity assessment. Once it has been determined that this is an atypical in or out-toeing, the next step is to determine which components of the lower extremity are the source of the torsional condition and intervene at that level.

What is the Source of the Rotation?

Components that can contribute to in-toeing:

• Femoral anteversion
• Internal tibial rotation
• Metatarsus adductus

Components that can contribute to out-toeing:

• External rotation contractures of the hip
• Femoral retroversion (rare)
• External tibial rotation
• Calcaneovalgus

ADD IMAGE GALLERY OF THESE CONDITIONS?

Rehabilitation Examination for Torsional Conditions

Past Medial History

The evaluation interveiw for torsion considerations is similar to those for most lower extremity orthopaedic concerns.

• Child's birth history (premature versus full term)
• Orthopaedic or neurological concerns
• Developmental milestone history or concerns
• Child's age when in or out-toeing was first observed
• Significant family history, especially sort of torsional or orthopaedic conditions
• Previous interventions
• Child's common sleeping and sitting positions
• When the child started to walk independently and how long they have been walking

Clinical Pearl: how sitting and sleeping position can exacerabate torsion

When we think about torsion, there's certain positions that can actually exacerbate torsion. Or really highlight the fact that a child prefers to sit in a particular position because of a torsion that they have. So for example, individuals who have hip anteversion will prefer to W-sit because it is more comfortable for them.

Physical Assessment

General assessment should include:

• Range of Motion (ROM)
• Strength testing
• Tone assessment
• Balance testing
• Gait and functional movement assessments
• General appearance of the limb to rule out concerns beyond an orthopedic issues such as muscle atrophy, oedema, erythema, or difference in temperature between the lower limbs

When assessing for sources of torsional conditions, it is important to consider factors that could affect the alignment of the lower quarter, this can include:

1. Foot progression angle (FPA) is the angular difference between the axis of the foot and the line of progression during gait.
   1. • In-toeing is expressed as a negative value
      • Out-toeing is expressed as a positive value
      • FPA is variable during infancy
      • Mean value in children: +10° (range -3 to +2-)
      • Severity of in-toeing in children:
        • Mild  −5° to −10°
        • Moderate −10° to −15°
        • Severe more than −15°
2. Femoral version refers to the rotation of the neck of the femur in relation to the femoral condyles at the level of the knee.
   • • Lateral hip rotation (LHR) also known as external rotation of the hip
     • Medial hip rotation (MHR) also known as internal rotation of the hip
3. Thigh-foot angle (TFA) is a means to measure tibial torsion.
   • • To measure internal or external tibial torsion, the patient is positioned in prone lying with knees flexed to 90°. TFA is measured between the line bisecting the posterior thigh and another line bisecting the foot.
       • Normal TFA is between 0° to 30°
       • External tibial torsion is a TFA more than 30°
       • Internal tibial torsion is a TFA less than 0°
4. Transmalleolar axis (TMA)
5. Forefoot alignment

Other Diagnostic Tests

• X-ray imaging
• Magnetic resonance imaging (MRI)
• Computed tomography (CT) scan
• Bone scans
• Laboratory tests such as blood work

The Hip and Femur

So when we think about the hip area, we can see that femoral anteversion can actually cause children to toe in. And we'll look at that a little more in depth if their tibia is torsioned or twisted internally. So internal tibial torsion, that can also cause the toe to point inwards. And if the forefoot is pointing in relative to the hind foot, which we refer to as metatarsus adductus, that can also lead to an in-toeing presentation.

Components that can lead to out-toeing are really some of the same things, but the reverse presentation. So you can have retroversion of the femur that causes the femur to point a little more outwards, which can lead to out-toeing if it's not corrected down below. Or you can have an external rotation contracture at the hip. You can also have external tibial torsion or a twisting of the bone in the tibia as it goes down the chain. And then there's also calcaneal valgus, which is when the hind foot is really in this kind of pointed out position that leads to the foot collapsing down and in, and the toes pointing out.

What we can do is we can look at a lot of different ways of gait analysis to be able to figure out why and how much that foot is progressing the way it is, and we can look at what we call the foot progression angle. So this is looking at the total sum of any rotation that's happening from the pelvis and the hip all the way down to the foot so that we get the end presentation of however their foot is aligned in relation to the rest of their body. So that's that foot progression angle that we can really assess with a gait analysis. And once we do that, we need to really think about what component of the lower extremity is driving that torsion or that in-toeing or out-toeing that we're seeing so that we know where to intervene appropriately.

So with the hip, that rotation, we want to check range of motion at the hip. We're going to be checking femoral torsion as well as femoral version, and we'll discuss a little bit about the differences between those two. At the knee, we're going to be looking for tibial torsion, and we'll also be looking at what's called a thigh-foot angle. And at the foot we'll be assessing for metatarsus adductus or adductus to be able to determine if that rotation that we're seeing comes from the hip, the knee, or the foot.

So when we think about our femoral anteversion that leads to toeing in, what we'll see is that that hip is pointed a little more forward, which causes the knees to point a little more in and if that's not corrected, those toes can point in. Another one is that if the hip is really well aligned, but you have a twisting or a torsion of the tibia, an internal tibial torsion, so that tibia twists inward, that can cause the foot to point in. And then lastly, that metatarsus adductus, those toes pointing in.

Evaluation: Bedside Assessments (make table)

So when we think about our torsional conditions for things that affect the alignment of the lower quarter, there are six different measurements that you always want to think about considering to make sure you're looking at every component of what can lead to an in-toeing or an out-toeing or knees pointing in or pointing out sort of presentation.

1. So one is the foot progression angle, lateral and medial hip rotation, the thigh-foot angle, the transmalleolar axis, as well as forefoot alignment. So we'll dive a little more into all of these things.

So when you perform your observational gait analysis, we've chatted before about some of the basics. I did just a little brief review a couple seconds ago, but let's talk about this foot progression angle. So this is really that angular difference between the axis of the foot or the place where the foot is aligned and the line of progression during gait. So what that means is if you were to draw a straight line where each foot should land, centred, if they were to go in a straight line, then also have a line for where their foot lands, how much does their toe and foot point out or in throughout that progression. In-toeing, when we talk about a foot progression angle is expressed as a negative value, and out-toeing is expressed as a positive value.

The foot progression angle, as I said, can be really variable during infancy. So you want to make sure that this isn't something that you're spending too much time on whenever you're looking at an infant, because we do know that we expect to see a little bit of in-toeing whenever they're little, and then that's going to progress and change as they continue to develop.

Overall, the mean value in children for a foot progression angle is slight out-toeing at positive 10 degrees, but the range is minus three to positive 20. The severity of in-toeing in children can be measured as mild, moderate, or severe. So when we think about mild in-toeing, that would be minus five to minus 10, which means if you had that line that goes straight down the centre for where each foot should land, if the line is, the foot would be completely in neutral. We're talking about minus five to minus 10 is that toe is pointing in five to 10 degrees from that neutral line. Moderate is that toe is pointing in minus 10 to minus 15, so 10 to 15 degrees from that line, and severe is more than 15 degrees from that line.

So this up here in the picture just shows you that foot progression angle. So you have that line that goes down the centre, and then you have a line that would bisect the foot, and you're taking that angle between that centred line and that bisection of the foot line.

Over here, you can see in the graph, this just looks at foot progression angle. So we have the median that's right here on this purple line. And then we have the two standard deviations above and below the norm, which is anything that would be considered normal. Outside of that is when we would consider it to be atypical. So you can see earlier on, if we're looking at three years of age, we're looking really at probably around a seven degree, plus seven degree out-toeing, and that's the normal, but anything all the way up to probably around 18 degrees all the way down to minus, probably two degrees, would be considered normal for a three year old because it's within that standard deviation. And so this is a nice little reference point that you have depending on the child that you're assessing and their age.

When we do that foot progression angle, we're observing the child walking. You can either do a foot progression angle subjectively, just watch them walk, kind of get a visual, see where their foot points, maybe you have a line of tape on the floor and you're kind of looking at how much their foot is pointed out compared to it. You can also do a footprint technique, so for that, what you can do is, let's say you have like a big long roll of paper, or maybe you're outside on a sidewalk that you can use. You can have paint or something that comes off a little more easily that you put on their feet, and then you have them, you have a line that goes down the centre of the paper that they're going to walk along, and then you're going to look at their footprints that the paint is able to deposit on that paper. And then you can go through and you can measure that. Sometimes you can get away with this with chalk if you have a lot of powdered chalk, and you can do it outside or on a piece of paper. So really look at your resources, but anything that's going to leave that footprint. And you really ideally want to do this with bare feet because a shoe can definitely change how that foot is presenting. It also lets you see how much of an arch they have versus how flat their foot lands. So it's a really nice way to do that footprint technique. You can also look at their resting stance position and how much natural out-toeing or in-toeing they have in stance, and then also assess it during gait. So something to consider.

So then we're going to be looking at some of these different angles. So the thigh-foot angle that we are going to be assessing to determine where torsion is coming from, looks at the bisection of the foot. And this line when you bisect a foot, is going to go through the second toe. So always remember when we're bisecting the foot to look at any sort of measurement that that line goes through the second toe along the centre of the foot. And then you're also going to have a line that bisects the thigh. You're going to look at the difference between those two lines to get your thigh-foot angle.

For the transmalleolar axis, and we're going to look at all of these a little bit more. You're going to take a line that goes through the medial and lateral malleolus and then draw a line perpendicular to that. And then you're going to take the line that bisects through the thigh and you're going to use this line that was perpendicular to the line you drew between the malleoli. And look at that line that bisects the thigh, and that's going to give you your transmalleolar axis.

And then last, you're going to have your Craig's test or femoral anteversion test that looks at that line that bisects the thigh and then looks at the line of the shin when their hip is most prominent. So this lets you, Craig's test lets you look at femoral anteversion or retroversion. So where does that hip sit naturally? The transmalleolar axis lets you look at how much that shin and ankle are twisted down below compared to the thigh. And the thigh-foot angle is going to compare that full thigh to the foot in its position. So any torsion that happens from the thigh down to the foot.

First, let's talk about femoral version. So what femoral version refers to when we talk about this anteversion and retroversion is really the rotation of the neck of the femur in relation to the femoral condyles at the level of the knee. And actually this femoral version is really looking at the location of the head of the femur in the acetabulum and how far forward that head of the femur sits. And when you have femoral version without torsion, then what you'll see is this sort of anteversion position. So what happens is, is there's this decreased angle between the femoral neck and the condyles, which makes the head of the femur sit much more anteriorly in the acetabulum unless they sit in a corrected position naturally, which a lot of them do. And when someone with femoral anteversion sits in a corrected position, what you'll see is that their knees point in.

So basically like if you have your head of your femur here and the neck of the femur, and here's the rest of your femur. So what happens is, is when we talk about anteversion, it's when the head of the femur sits forward in the socket. If the person naturally corrects to try to get that hip to sit in the socket, what happens, you can see with my finger down here is that when that head of the femur sits in the socket a little bit better, instead of sitting anteriorly. If they do sit here, what happens is you'll see that their femur in the rest of their leg looks like it's almost pointed inwards. And then retroversion is when the head of the femur, so it's really posteriorly in the socket or their knee would look normal if the head of the femur sits in the posterior part of the socket. But oftentimes people will naturally correct and try to get their hip to sit in the socket, which would relatively look like their knees point outwards.

So, this femoral version sometimes then gets combined with femoral torsion, which is really that twist that we talk about of the actual femoral shaft. And when you have that twist of the femoral shaft, what you see is a change in the angle between the femoral neck and the condyle. So again, with anteversion or torsion being that there's this twist so that there's a decreased angle between the femoral neck and the condyles, or this retroversion where there's an increased angle between the femoral neck and the condyles.

Regardless the way that you're going to do this is by Craig's test, so you're going to have your patient sit in prone, and then you are going to palpate their greater trochanter, and what you're going to do is you are going to internally and externally rotate their leg while their hip is in neutral, knee is at 90 degrees of flexion, and you're going to feel for when that greater trochanter is the most prominent in your finger. And then you're going to measure that angle of the shin versus straight vertical. So you'll be able to get both of those measurements. You can also look at total range of motion of external rotation and internal rotation. Just remember, external rotation of the hip is when the shin and the foot are pointing inwards. Internal rotation of the hip is when the shin and the foot are actually pointing outwards.

So here we have what I was kind of talking about with that anteversion and then where people tend to actually sit when they have anteversion. So normal anteversion of the femoral neck is approximately 15 degrees. So again, we're looking at that angle of the femoral neck in relation to the femoral condyles and the shaft of the femur. So when you have femoral anteversion, that head of the femur is going to sit anteriorly in the acetabulum, and you can see that there's this decreased angle between the shaft of the femur and the femoral head and neck.

Often what is physically presented as though is this sort of position in stance and this sort of resting position. So you can see there's still this decreased angle, but the femoral head is now sitting much more in a neutral position in the acetabulum. And what that relatively will end up looking like is an in-toe position and knees pointed inward.

With retroversion, what you'll see is that that head of the femur tends to sit more posteriorly in the acetabulum, and there's this bigger angle between the femoral head and neck and the shaft of the femur. So in this case, if they did not correct where that femoral head sat in the acetabulum, their foot would still look straight. But most of the time what we see is that this femoral head, people will rotate their hips so that their femoral head sits in the acetabulum much more comfortably, and that will relatively look like an out-toeing position.

So when we do that assessment of the hip anteversion retroversion, that Craig's test, again, you're going to put that person in the prone position, flex their knee to 90 degrees. You're going to feel for that greater trochanter on the tested side. And then you're going to internally and externally rotate the hip and you're going to feel for when the greater trochanter is at its most prominent position, most lateral position on your finger, and then you're going to measure the leg in that position when the greater trochanter is the most prominent. And that is going to be an angle that's the shaft of the tibia, and then a line that is straight up and down or perpendicular to the table that they're sitting on. And that's going to give you your degree of anteversion. For most people, this is going to be eight to 15 degrees of internal rotation. So what you'll see is that the foot and the shin point outwards from the body a little, and your measurement is on this lateral aspect compared to midline of the thigh. If you feel that the greater trochanter is most prominent when their foot is all the way over here pointing towards the midline of their body, that would indicate that they probably have some retroversion of their hip.

You're also going to get just general hip rotation range of motion. So you have that child in prone, hip is in neutral, knee is flexed to 90 degrees, and you're going to be looking at how much internal rotation they have and how much external rotation they have. Again, internal rotation, toe and foot points outwards. But it's looking at the internal rotation of the hip and the femur, and then you have your external rotation, foot and shin point inwards, and that's going to cause you to be able to get both your internal and external hip range of motion. Most of the time with anteversion, you're going to see increased internal hip range of motion.

So what do you do about femoral anteversion? Because again, this is the most common. Femoral retroversion is very uncommon to see, but if you do have femoral anteversion, there's a lot of different things that have been tried. So some things are bracing or what they're called TheraTogs. So kind of a strapping and compression method that you can do to help correct the alignment.

Functionally, you might observe that their gait looks better, how much that really leads to any sort of efficacy long term is still a little bit up in the air with studies, but their gait often will look better when you put these items on. The question oftentimes is how much is that going to get translated to use in the home, and how consistently is it going to be able to be used? If they just use this in the clinic, it's probably not going to have great carryover. If they're using this at home consistently, it can potentially have greater improvements, but a lot of times these braces are fairly cumbersome, so the carryover is often not the best.

Another thing that you can do is try to encourage ring sitting, or at least avoid W-sitting because we know that if we are still in those early modelling stages of development where that hip is being modelled based on these ground reaction forces, that getting them into more external rotation, avoiding this force, this ground reaction force that's going to encourage more femoral anteversion, more internal rotation is going to be better. So encouraging external rotation or side sitting, but just avoiding W-sitting can be really helpful if we are, again, in those early modelling stages. As long as they have a variety of movements, it's fine if they do this every once in a while, but you don't want this to be their obligatory position that they always go to.

If significant femoral anteversion is still present when the child is 10 to 14 years old, a lot of where they are structurally is probably pretty close to where it's going to be. And there's either a lot of issues with tripping, falling, safety, or if there's still that significant in-toeing and it's affecting them cosmetically, surgical correction can be considered. It is a really big surgery though, so this is something that shouldn't be taken lightly. It's a femoral derotation osteotomy where basically what they do is they make a cut in the femur in order to rotate the femur in counterclockwise directions to be able to improve alignment of the knee relative to the hip. Mostly you want to think about doing this if you're having lots of tripping, lots of falls, issues with children keeping up with their peers, safety concerns, or they're reporting significant pain. A lot of times we'll see hip pain, knee pain that can be associated with this significant femoral anteversion as it can be associated later on with femoral acetabular impingement.

Tibial Torsions

Moving down the chain from the hip to now look at the tibia. Tibial torsion is another thing that you want to consider. Internal tibial torsion is a pretty common condition in children who are less than four years old, and it typically presents as that internal rotation of the tibia and in-toeing gait.

So you can make this diagnosis clinically. A lot of times with this, you're looking at the thigh-foot angle. So before we were looking at femoral anteversion, Craig's test. Looking at that rotation and alignment of the hip. Now we are going to move down the chain and look at this thigh-foot angle to determine if the rotation is coming from the tibia. So you've checked your hip. That all looks neutral. Now you're going to go down, you're going to check for tibial torsion, you're going to get your thigh-foot angle. So when you have a thigh-foot angle that is more than 10 degrees of internal rotation, and the patient presents with an in-toeing gait, you can be fairly confident that you're looking at a tibial torsion, a twisting of the tibia.

Oftentimes at the beginning, you want to just observe because this condition often resolves spontaneously by the age of four. Again, because of all of the modelling that happens with biomechanical alignment, with gait, with working on crawling, working on standing, working on higher developmental skills. So most of the time this will resolve spontaneously. Less than 1% of torsional deformities fail to resolve in childhood. However, you do want to make sure that you're keeping an eye on whether or not this is resolving. Surgical management can be indicated for children that are greater than six to eight years old who have functional problems and a thigh-foot angle of more than 15 degrees.

So let's look a little bit about how you obtain this thigh-foot angle measurement. So what you're going to do is you're going to look at the difference between the thigh and a line that you would draw down the midline of the thigh, and that line that you're drawing down the midline of the foot, typically going through that second toe, and you're going to obtain that angle.

So patient's prone, knee's flexed to 90, let the foot rest in its natural position. And then what you're going to do is you're going to make that angular measurement. If the foot is pointing outwards anywhere from zero, so they're neutral all the way up to 15 degrees of pointing outwards. That's normal. That's that external thigh-foot angle. If you have internal tibial torsion, you will see that that foot points inwards. And so that is when we're concerned. So anything that is zero degrees or negative.

You can also look at the transmalleolar axis for tibial torsion. So for this one, you're looking at the angle formed by the axis of the femoral condyles and the axis through the medial and lateral malleoli. So this one's just a little trickier to obtain because there's three different lines that you have to draw to get it first. So the first line that you have to find is that longitudinal axis of the thigh. Very easy. You're just going to go straight down the thigh. But next, the one that's the two step process is you have to draw a line that bisects between the two malleoli, and then what you're going to do is you're going to draw a line that's perpendicular to it. And what you're going to look at then is this angle between this perpendicular line to the line that bisects medial and lateral malleoli. And the line that bisects the thigh and that angle right there is your transmalleolar axis. A positive value indicates external tibial torsion. A negative value indicates internal tibial torsion.

Tibial Torsion Treatment

So what do we do about tibial torsion? So there is some controversy over the most appropriate treatment for internal tibial torsion. A lot of orthopaedists think you should just watch, let it happen. It's part of natural history and you'll see gradual improvement over time. However, because there is a small percentage of children who do not improve and can have significant functional deficits because of it, and might need surgery later on, an external rotational osteotomy of the tibia and fibula. So again, think about that one that we were talking about at the femur that we're talking about cutting into the bone and rotating it so that it sits in better alignment. You can actually do some interventions to try to prevent that from happening. So if you do end up intervening earlier on, what you can do is if you see this tibial torsion past 18 months, you can try corrective orthotics or shoes for about six months and see what they look like.

So one is a Friedman counter splint. This is actually a flexible leather strap that can go between the feet. There's also the Denis Browne bar, which is a metal bar that you can wear at nighttime, and then the Wheaton brace. Any sort of bracing that's going to help hold that foot into a little bit of that out-toeing position relative to the rest of the leg in order to help maintain and provide, again, these forces that as the child is developing, as their bone is developing, we are forcing them into that external position so that we can over time see that that modelling happens. Think about Wolff's law, to allow for the bone to model into the more appropriate position.

When we do have that surgical correction, that tibial and fibular osteotomy that's really happening when the child is at least eight years old, has significant functional deformities, and the thigh-foot angle is greater than three standard deviations beyond the mean.

Really when we think about tibial torsions, one of the things that we can see is a lot of complications at the knee. So especially with external tibial torsion, it is associated with increased incidence of knee osteoarthritis later in life. Increased incidence of osteochondritis dissecans, which we'll talk about in just a little bit, and it might be a predisposing factor for the onset of Osgood-Schlatter syndrome in male athletes which we'll also talk about in just a little bit.

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