1st ray ROM

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Long time follower, first time submitter. My question is on first ray ROM. At our hospital we routinely perform a “Cotton” procedure when performing a STJ Arthroeresis or any flatfoot procedure to bring down the medial column. Of course, pre-operatively, all of these patients have a forefoot varus, but is this congenital or is it an adaptive position.
23 years ago I performed a STA-PEG (arthroeresis) on a patient without any additional procedure. She presented back to the office, with an unrelated complaint, and I noticed that her forefoot to rearfoot was neutral.
My question is how do you evaluate this patient pre-op to determine if a medial column procedure is needed. Does Root’s theory still hold.? Can you say that this is an adaptive position if there is no dorsiflexion of the first ray or it’s a congenital varus if there is normal ROM?
John Senatore DPM

 

Hi John :welcome: to podiatry arena.

1st there is lots in your post - most of it not that easy to discuss in a few words.

FF Varus - very rare - congenital

FF supinatus - inverted position of FF developed or addapted, seen alot.

In your patient the GRF( Ground reaction force) acting on the lateral forefoot will have increased after the procedure - as her forefoot was most likely a FF supinatus and the GRF changed from medial to lateral and opposite of what caused the supinatus position of the forefoot occured and with soft tissue adaption and now the FF is " neutral"

Does Roots theory hold up some of it yes, some of it no.

Hope that helps.

As for when to change your operation procedure can´t help as I don´t opperate .

 

Some reading for you - Threads forefoot varus/ forefoot Supinatus

 

Hey John:

Good to see you finally getting your "feet wet" here on Podiatry Arena. I've got some great photos of you wearing a funny looking nose appliance during one of our roasts.

You ask some very good fundamental questions above which we have discussed previously here to some extent on Podiatry Arena. First of all, the Cotton procedure (a dorsal opening wedge osteotomy of the first cuneiform) may be a useful procedure in trying to plantarflex the medial column/first ray when a subtalar joint (STJ) arthroereisis procedure is performed. Without this type of adjunctive surgical procedure to allow the medial column to accept more loading forces from ground reaction force (GRF), there may be excessive lateral column loading which may cause lateral column symptoms or excessive compression forces on the STJ implant.

Compared to what we were taught by the Root disciples at CCPM back about 30 years ago, I view the forefoot to rearfoot relationship as being partly due to structure of the foot and partly due to the prevailing magnitudes of external and internal forces and moments that have been acting on and within the foot over time. In other words, during our era at CCPM, we were taught that forefoot varus was structural and forefoot supinatus was an adaptation of the forefoot to be inverted to the rearfoot due to supination of the longitudinal midtarsal joint axis. However, we were never given any clear-cut, reliable method by which to examine a patient and determine whether that inverted forefoot to rearfoot relationship was congenital (i.e. structural) or acquired (i.e. supinatus). Also we weren't taught that a forefoot valgus could have a forefoot supinatus deformmity also. However, I believe that many feet that have a "forefoot valgus deformity" also have a component of a "forefoot supinatus deformity" since there is excessive pronation moments acting on the foot that cause it to be excessively pronated and the medialy column excessively dorsiflexed during weightbearing activities.

Your observation of the increase in everted forefoot to rearfoot position over time with a STJ arthroereisis procedure is actually one that I have heard from many podiatrists who use this procedure regularly (Don Green uses them regularly). These clinical observations, in addition to the change in forefoot to rearfoot relationship that may be seen with using foot orthoses in children's flatfoot deformity over time, leads me to believe that the forefoot to rearfoot relationship that we measure is a constantly changing relationship that is dependent on structure and the prevailing forces acting on the foot during weightbearing activities. In most individuals, this forefoot to rearfoot relationship changes very little over a period of a year or two since the external and internal forces acting on and within the foot haven't significantly changed over time. However, for example, in the patient that develops posterior tibial tendon dysfunction (PTTD), where there is a significant loss in internal STJ supination moment from the posterior tibial muscle, this change in internal rotational force may, over time, cause an increase in dorsiflexion of the medial column relative to the lateral column and an apparent increase in "forefoot varus deformity". I have seen this occur in a few of my patients that have developed PTTD over the past 25 years of practice.

I believe that you must assume that for your preoperative evaluation, that any changes in forefoot to rearfoot relationship will be fairly slow and gradual unless a radical change in foot structure is made by the surgery you are planning. I would guess that these changes in forefoot to rearfoot relationship will occur more rapidly in younger individuals and may not occur at all in older individuals with lower muscle strength/body weight ratios. In other words, I believe that the vast majority of any surgical correction must be osseous in nature so that the bones are basically in proper alignment so that more normal foot function is achieved postoperatively with the hopes that any minor changes in soft tissue adaptation over time may be further optimized, if necessary, by using conservative therapeutic options such as custom foot orthosis therapy, shoe modifications and/or physical therapy.

Great questions, John. Good to have you contributing to Podiatry Arena!!:drinks

 

I agree pretty much with Kevin's post. The Arthroresis eats up some of the last few degrees of STJ pronation so that the STJ is in a more inverted position after the procedure as opposed to before. So, how do you know if the arthoresis will create symptoms associated with partially compensated varus (lateral column overload). If the heel is inverted more the forefoot will be inverted more.

I've developed a measurement that I call maximum eversion height. Patient is standing in base of gait and asked to evert. (John Weed described placing his fingers under the lateral column of the foot to assess the amount of force there. This works too.) Check to make sure the person does not move their knee to the midline. I will usually say to the patient, if you cannot lift your lateral forefoot off of the floor, this is exactly what I want to know. Measure the height the lateral forefoot can lift off of the floor. There will be a range from 0 to as high an inch.

If you wanted to figure out how much cotton to do, you could invert the heel, in stance, as much as the arthroresis would and then try and and attempt to see how much force there is under the medial forefoot. Or how much distance you need to plantarflex the head of the metatarsal to get load. Not an easy measurement. This might be more "easy" in surgery if you could produce some sterile "ground" or instrument tray, to push upward on the whole foot (taking into account tibial varum) you could see if there is even loading on medial and lateral sides.

Makes you think about the term surgical precision.

Cheers,

Eric

 

Thanks everyone for your response. I love this site and i will post more in the future.

John