How to Evaluate a Bunion

https://youtu.be/PhVT9b4p7_s

Other bunion posts:

http://www.drblakeshealingsole.com/2012/07/how-to-conservatively-treat-bunions.html

http://www.drblakeshealingsole.com/2016/06/bunion-exercise-to-slow-progression.html

http://www.drblakeshealingsole.com/2015/06/help-for-bunions-and-hammertoes-correct.html

First Metatarsal Position: Important to Know with Metatarsal Problems

One important measurement that bio mechanic specialists evaluate is the relationship of the first metatarsal to the second metatarsal head. The foot should be centered under the ankle joint (therefore not pronated or supinated). One thumb on bottom and index finger on top grab the second metatarsal head and stabilize it. This will be the reference point. With the other hand, grab the first metatarsal head also from top and bottom. See where the first metatarsal head lies in relation to the second metatarsal head when the thumb fingernails are parallel. Then move the first metatarsal head up and down noting the overall motion and position. The motion is ideally 5 mm up and 5 mm down. In this patient, the left first metatarsal moved only 2 mm total (4 mm down and -2 mm up). This is called a stable plantar flexed first ray. Ideally the first and fifth metatarsal heads are lower than their adjacent metatarsals.

On this patient's right foot, the first metatarsal rested 3 mm above the second metatarsal. The overall motion with 6 mm (6 mm up and 0 mm down). This is called an elevated first ray or metatarsus primus elevatus (I love to talk like I am smart!!) This is an unstable first metatarsal that will not hold up the arch, and causes instability in the foot. It can be the cause of bunions or produced by the formation of a bunion. When recognized, orthotic modifications like the Cluffy Wedge or Morton's Extension  can be used, and if surgery is being done, corrections for the elevated bone can be done. With an elevated first metatarsal, the weight goes more to the second and sometimes third metatarsals leading to pain syndromes like metatarsalgia, capsulitis, neuromas, and hammertoes. 

Bunion Pain: Medially on the Bump or Laterally in the Joint

This is an AP Foot Xray with highlighting of the big toe joint. The metatarsal head is rounded and the toe has slipped off the joint on the side of the 2nd toe. This is very painful. The soft tissue on the lateral side (2nd toe side) is pinched and causes pain called capsulitis. Treatment is partially accomplished with toe separators and bunion taping to straighten the toe. 

This same xray shows that the joint dislocation is measured at 4 mm. This patient was in for a 2nd opinion following failed bunion surgery. Failed from the standpoint that 3 years after the first bunion surgery, the bump is coming back and pain is settling into the joint with activity. 

In this xray the numbers do not mean anything. I wanted another way of showing that 4 mm  dislocation of the toe on the metatarsal head. This patient did great with toe separators to push the big toe medially back onto the top of the normal part of the joint. 

Importance of the Positioning of the First Metatarsal

It is extremely important to know where the first metatarsal lies in relationship to the other metatarsals, especially the second. These photos to follow show the classic Root evaluation of the first metatarsal in relationship to the second metatarsal. Normally, the first metatarsal lies mainly plantar to the second metatarsal. In the first photo below see how the first metatarsal lies 3 mm above the first metatarsal, even though I have pushed it down as far as it can go!! This is called an elevated first metatarsal, producing a hypermobile first ray which does not bear weight well, allowing for more pronation to occur. 

The above photo shows the same observation of the first metatarsal in its most elevated position. When you see the 2 positions, maximally up and maximally down, you can tell this is elevated from the second--also called metatarsus primus elevatus (elevated first ray). 

The photo above shows the more normal right foot where the first metatarsal is 5 mm below the second when pushed down. It is so crucial to keep your thumbs parallel when doing this maneuver.