Paediatric Lower Extremity Torsional Conditions

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Top Contributors - Stacy Schiurring, Jess Bell and Kim Jackson  

Introduction

Paediatric lower extremity and gait concerns are common reasons for visits to the paediatrician and therapy services, and can account for up to 16% of all new paediatric orthopaedic surgeonn referrals. The most common concern for parents is in-toeing and fear of delayed meeting of developmental milestones. Typically in-toeing improves and resolves itself with skeletal maturity, however out-toeing can be a more persistent condition.An understanding of typical and atypical lower extremity development, and when to initiate a pediatrician or orthopaedic referral is an important skill for paediatric rehabiliation professionals.

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."

This article will summarise the pathophysiology, clinical presentation, and assessment and basic treatment interventions of lower extremity musculoskeletal conditions commonly referred to therapy services.

Torsional Conditions

Femoral Torsion

• In newborns, internal femoral torsion up to 40° can be considered typical, and external femoral torsion can also be prominent and considered typical at birth.

Special Topic: what is the Difference between femoral torsion and femoral version?

Version and torsion are not identical conditions, however they may both occur at the same time.

Torsion is a "structural, osseous state of twist in a bone along its longitudinal axis."

• Femoral antetorsion (medial femoral torsion) is when the femur demonstrates a medial twist of the distal-on-proximal ends.
• Femoral retrotorsion (lateral femoral torsion) describes a deformity ranging from a lack of typical femoral medial torsion to a true lateral twist of the distal-on-proximal ends of the femur.

Version describes "a position in space relative to a plane" of motion and refers to the rotation of the neck of the femur in relation to the femoral condyles at the level of the knee.

• Femoral anteversion – Decreased angle between the neck of the femur and femoral condyles. Normal anteversion of the femoral neck is approximately 15°. Femoral anteversion is more common than femoral retroversion.
• Femoral retroversion -Increased angle between the neck of the femur and femoral condyles

Tibial Torsion

• Internal tibial torsion is common in children less than four years old, and it typically presents as internal rotation of the tibia and in-toeing gait
• Often resolves spontaneously by four-years of age, less than 1% of torsional deformities fail to resolve in childhood
• Tibial torsions are often associated with (1) increased incidence of knee osteoarthritis later in life, (2) increased incidence of osteochondritis dissecans, and be a predisposing factor for (3) Osgood-Schlatter syndrome in male athletes

What is the Source of the Rotation?

There can be some mild in-toeing and out-toeing throughout typical development, therefore it is important to differentiate typical versus atypical as part of a lower extremity assessment. If it is determined to be 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.

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? plus in/out toeing

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 analysis and functional movement assessment
• 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. Femoral version at times is combined with femoral torsion (a physical torsion or twist in the shaft of the femur). Femoral torsion will also cause a change in the angle between the neck of the femur and the femoral condyles.
   • • Craig's test (also known as Trochanteric Prominence Angle Test)is a passive test that is used to measure femoral anteversion or forward torsion of the femoral neck. Optional additional Physiopedia page reading: Craig's test to gain further insight and how to perform this exam.
3. Hip rotation range of motion
   • • Lateral hip rotation (LHR) also known as external rotation of the hip. Femoral retroverison indicated by increased external rotation compared to internal rotation
     • Medial hip rotation (MHR) also known as internal rotation of the hip. Femoral anteverison indicated by increased internal rotation compared to external rotation
4. 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°
5. Transmalleolar axis (TMA) is another means to measure tibial torsion.
   1. • To measure internal or external tibial torsion, the patient is positioned in prone lying with knees flexed to 90°, the ankle in the neutral position, and the sole of the foot parallel to the floor. TMA is measured between the line bisecting the longitudinal axis of the thigh and the line perpendicular to the axis between the most prominent portions of the medial and lateral malleolus.
6. Forefoot alignment

Other Diagnostic Tests

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

Rehabilitation Treatment for Torsional Conditions

Femoral Torsion Treatment

1. Bracing with strapping and compression. Example: TheraTogs
   • Can improve gait quality when wearing the device, however lacking evidence based support. Carryover and consistency with device outside of the clinic is vital for long-time positive outcomes.
2. Encourage ring-sitting and avoid W-sitting
   • 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.
3. Surgical correctionIf 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 Torsion Treatment

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.

1. Splinting and/or bracing
   • 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.
2. 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. 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.

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