Neuroma Journal Club

[ldsrmdude]

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We decided to start our run at journal article discussions (aka Journal Club) with an article about neuromas and the debate over plantar vs dorsal incisions. Since PeaJay recommended the article, we've asked PeaJay to give us a quick synopsis of the article to kick things off. Once PeaJay posts the synopsis, please add in your comments, questions, etc.

Here is a link to the article (if you have trouble accessing the article through pubmed, let me know):
http://www.ncbi.nlm.nih.gov/pubmed/23564425

 

[PeaJay]

A Prospective Randomized Controlled Trial of Plantar Versus Dorsal Incisions for Operative Treatment of Primary Morton's Neuroma

C. Akermark, H. Crone, A. Skoog, and L. Weidenhielm

Level I, Prospective randomized trial.

Foot & Ankle International September 2013
2012 Impact Factor: 1.474
2012 Ranking: 30/63 in Orthopedics

Authors declare no conflict of interest or outside funding.

Introduction:
The interdigital neuroma was described by Morton in 1876. His description centered on the third common digital nerve from the medial plantar nerve, which provides innervation to the third interspace. Clinically, patients commonly present with burning or painful numbness of the forefoot. Discomfort can be elicited with palpation of the soft tissue between the third and fourth metatarsal heads. Other clinical signs used for diagnosis include Mulder's sign and Tinel's sign.

Central Question:
Which operative approach, dorsal or plantar, provides better clinical outcomes?

Material and Methods:
Inclusion criteria- Morton's Neuroma of 3 months duration
Exclusion criteria- Bilateral neuromas, previous neuroma surgery, concurrent foot pathology needing surgical correction, peripheral neuropathy, peripheral vascular disease, diabetes, and rheumatoid arthritis

Diagnosis was made by clinical symptoms, Mulder's sign, and MRI

76 eligible patients were randomized to dorsal (41pts) or plantar (35pts) surgical approach.

Assessment was achieved through patient-administered questionnaire. Outcome was measured with a 100mm visual analog scale (VAS), patient estimation of sensory loss, and overall satisfaction regarding the surgery.

Results:
The metrics utilized by this study failed to identify any significant difference between dorsal and plantar group at final follow-up. Reduction in pain was achieved in both groups, with no significant differences between the groups. Sensory loss was present in both groups at final follow-up with no significant difference between the two study arms. Surgical scar tenderness was comparable between both groups; no significant difference in tenderness was noted. There was no difference in rate of clinically good results between the study groups.

A difference in the types of complications encountered between the study groups was noted. There were 5 complications in the plantar groups and 6 in the dorsal group. Plantar complications included 3 minor hypertrophic scars, 1 large hypertrophic scar, and 1 foreign body reaction. The dorsal incision complications included 1 wound infection, 1 missed nerve, 1 DVT, 1 dehissance, and two failures.

Discussion:
This study demonstrates that the dorsal and plantar surgical approaches both provide good surgical results (83% and 87% respectively). Both surgical approaches were shown to significantly reduce pain with daily activities.

A common noted disadvantage of a plantar approach is the presence of tender surgical scars. This study fails to support this purported disadvantage. The findings of this study show no significant difference in tender surgical scars. The authors note that this is in line with the findings of a Cochran review of Morton's neuromas. It is worth noting that the complications for the plantar group consisted mainly of hypertrophic scarring. While not noted as painful, these complications may undermine the findings relating to plantar surgical scars.

The main difference between the two study arms was the type of complications that were encountered. Cases involving the plantar approach involved hypertrophic scarring and cases involving the dorsal approach consisted of missed nerves and failure to provide adequate relief. The dorsal complications may be explained by the increase in surgical expertise required to complete the surgery. A dorsal approach provides a limited view of the nervous structures, which may account for the missed nerve and failed surgeries. The two failed cases went on to receive nerve resections from a plantar approach.

​

This study confirms that both surgical approaches are viable options for managing Morton's neuroma. Each approach provided good surgical results, but each had a unique set of complications.

 

[josebiwasabi]

i read this article earlier in the week and i think that based on this article, plantar incisions are clearly superior. it would appear that the main arguments commonly used against plantar incisions weren't supported by this study. dorsal incisions have a much more inherent risk, simply due to anatomy. you have to cut the DTML and you are more likely to accidentally cut other neurovascular structures when compared to a plantar approach.

that being said, the percentage of surgeons who do it dorsally probably far outnumber those who do plantar incisions, because that's what they were taught and are comfortable with, and that's what they will probably teach their residents and students.

i'd like to see more studies, perhaps done by a different group of surgeons to see if these results are reproducible and to increase the number of patients so we have more data points.

 

[ldsrmdude]

i read this article earlier in the week and i think that based on this article, plantar incisions are clearly superior. it would appear that the main arguments commonly used against plantar incisions weren't supported by this study. dorsal incisions have a much more inherent risk, simply due to anatomy. you have to cut the DTML and you are more likely to accidentally cut other neurovascular structures when compared to a plantar approach.

that being said, the percentage of surgeons who do it dorsally probably far outnumber those who do plantar incisions, because that's what they were taught and are comfortable with, and that's what they will probably teach their residents and students.

i'd like to see more studies, perhaps done by a different group of surgeons to see if these results are reproducible and to increase the number of patients so we have more data points.

Some would say cutting the DTML is an advantage of the dorsal approach.

I'm interested in hearing you expound on how the plantar approach is "clearly superior" when there was no difference in outcomes or number of complications in this study.

 

[dtrack22]

Some would say cutting the DTML is an advantage of the dorsal approach

This was going to be my comment/question. I think your approach only depends on what you believe the etiology to be or if you feel that the DTML is playing a roll in your patients presentation.

 

[PeaJay]

I feel that each technique has its place, as does nerve decompression.

The fact that this study shows no significant difference in scar tenderness may lead me to utilize a plantar approach. It seems the plantar approach provides a greater amount of visibility and control compared to the dorsal approach. This could lead to less followup trips to the OR for re-dos. In addition, a plantar scar may provide a more visually pleasing result. In the end a successful surgery is one that the patient is happy with and if there is minimal visual evidence of surgery, I believe the pt will be happier.

 

[ldsrmdude]

Another side note...

On my journeys during clerkships I've seen quite of few neuroma cases. Out of all those neuroma cases I've seen more podiatrists not just excise one "supposed" neuroma but bilateral. Statistically speaking bilateral neuromas are RARE but I've seen pods take out bilateral neuromas like they are going out of style. Pain in both feet? Screw it...I'll just remove your nerves...no biggie.

Interestingly enough, as this study shows, the overall patient satisfaction rate for neuroma excision is pretty high, so I'm going to just carry that over to bilateral neuroma excision (feel free to argue that I shouldn't extrapolate like that) and say the "success" rate is probably high for bilateral neuroma excision. So maybe bilateral neuromas aren't that rare, statistically speaking. Or maybe there's something else going on that is fixed by the surgery...

Thoughts?

 

[josebiwasabi]

Some would say cutting the DTML is an advantage of the dorsal approach.

I'm interested in hearing you expound on how the plantar approach is "clearly superior" when there was no difference in outcomes or number of complications in this study.

i'm only a 3rd year student so i have very little "real life" experience to base my opinions on. however i will try to respond to the best of my ability.

the authors of the paper state that in their operative technique, they sectioned the DTML with the dorsal technique but not the plantar. however, the outcomes at an avg of 34 months were actually slightly better for the plantar incision (87% "excellent/good" vs 83%, though this is probably not statistically significant). this would lead me to believe that cutting the DTML actually has very little benefit. in my opinion, less soft tissue trauma is always a better thing.

while the outcomes and number of complications were similar, the paper states that the type of complications differed.

The type of complications occurring in the 2 groups of this study are similar to those presented in our earlier published retrospective study.1 Mostly minor, scar-related complications occurred in the plantar group of both studies, 14% and 5%, respectively, whereas in the dorsal groups, different types of complications were recorded, 15% and 17%, respectively. This means that if you allow for an unorthodox merge of both studies, there were no complications such as amputation neuromas or missed nerves out of 108 neurectomies (0%) in the plantar groups versus 12
complications (such as missed nerves, DVT, amputation neuromas, and persistent pain) out of 100 neurectomies (12%) in the dorsal groups. This complication pattern is strikingly similar to the study of Wilson and Kuwada,24 who compared plantar transverse incisions with dorsal incisions for excisions of neuromas. They experienced 4 wound related complications out of 15 cases in the plantar group versus 10 complications (including 6 amputation neuromas and 1 DVT) out of 29 cases in the dorsal group.

therefore my rationale for my original statement is that decreased rate of serious complications = clearly a better procedure.

 

[ldsrmdude]

therefore my rationale for my original statement is that decreased rate of serious complications = clearly a better procedure.

Even though, even when taking the different types of complications into account, there was no difference in the outcomes?

 

[ldsrmdude]

Not absolutely sure if the podiatrists, I was shadowing on clerkships, actually utilized an MRI before diving into surgery but that's something I'd absolutely utilize before taking out nerves for no reason. If it's really bothering the pt they will get the MRI so I can be sure the nerve is bulbous and most likely a neuroma.

Yes there are mulder's sign, tinnel's, etc. but are there any recent papers out there discussing how specific and sensitive these clinical exams are? Maybe the patient is over 300 lbs and they have pain everywhere, even when you do these clinical exams. Does that mean they have neuromas and we should take them to OR?

I totally understand where you are coming from with this. However, there are a few comments I'd make. With the way things are going in medicine, I'm imagining that getting insurance companies to pay for MRI's for every neuroma is going to be difficult. In addition, there are several articles that demonstrate the short comings of MRI for neuromas. Ultrasound might be better (cheaper for sure). Even then, clinical exam is probably your best bet for diagnosis. This is from a review from August of this year in Foot and Ankle Specialist:

Although both USS and MRI can help provide a diagnosis in difficult cases, they are less sensitive than clinical examination and can predict neither symptom severity nor outcome.34

(Here is the pubmed link to the article http://www.ncbi.nlm.nih.gov/pubmed/23811947)

I share your frustration, but the fact of the matter is that neuroma excision is largely successful and outcomes on average are pretty good. There are certainly surgeons who take nerves out like it's going out of style, no doubt, and I have no doubt that some of those surgeries were unnecessary. But with a good history and physical, +/- imaging if it's warranted, and good surgical technique (dorsal or plantar incision), it's not a bad procedure per se.

 

[ldsrmdude]

I will have to check out the literature. Thanks for the references. I'm sure once residency starts my point of view about a lot of things will absolutely change. You can make theoretical arguments about a lot of things but once you actually go out in the real world and apply it I'm sure I will soon realize what works and what doesn't.

I've learned an open mind is a very good thing.

As an aside (and back to the article in question), here is a thread from a few years ago discussing plantar vs dorsal incisions for neuromas.

http://forums.studentdoctor.net/showthread.php?t=756201

 

[JR2011]

i read this article earlier in the week and i think that based on this article, plantar incisions are clearly superior. it would appear that the main arguments commonly used against plantar incisions weren't supported by this study. dorsal incisions have a much more inherent risk, simply due to anatomy. you have to cut the DTML and you are more likely to accidentally cut other neurovascular structures when compared to a plantar approach.

that being said, the percentage of surgeons who do it dorsally probably far outnumber those who do plantar incisions, because that's what they were taught and are comfortable with, and that's what they will probably teach their residents and students.

i'd like to see more studies, perhaps done by a different group of surgeons to see if these results are reproducible and to increase the number of patients so we have more data points.

You can think they are clearly superior until you have a pt walk all over your plantar incision and dehisce. Have fun tripling your OR time dissecting/ removing fat to find the nerve. You will likely change your mind when you are doing the surgery. It's easier to get farther proximal with a plantar incision but quicker and easier with easier anatomy going dorsal. Not to mention the ease of patient position. You have to have common sense with most things surgical.

Side note...

Fallet (1999) had a retrospective study investigating what kinds of trauma and elective F/A procedures cause pts to get CRPS. For trauma, fracture was the most common etiology that caused cases of CRPS. For elective surgery, excision of neuroma was the most common elective procedure that ended up causing CRPS in patients.

Source: Anderson DJ, Fallat LM. Complex regional pain syndrome of the lower extremity: a retrospective study of 33 patients. J Foot Ankle Surg. 1999; 38(6): 381-7.

.

I don't think its surprising that a study found higher number of CRPS while cutting out a nerve. Contrast this to most procedures we do where we try to leave the nerve the F alone.

On my side note:
As far as ordering MRI's for all neuromas....this is silly. It should be a clinical diagnosis. Recent literature shows that US can be more sensitive anyway and substantially cheaper. The age of ordering MRIs for every pt with neuroma symptoms is limited. A 5K test with marginal sensitivity for a clinical diagnosis is one of the problems with healthcare today. Diagnostic injections and US if in doubt.

 

[NatCh]

Plantar incision = better clinical outcomes (?)
Dorsal incision = better patient acceptance

I have done this surgery from both approaches have had each go very well but at other times have had each become a scavenger hunt looking for the affected nerve. As far as I know, none of my patients who have had a plantar incision have had incisional pain unless of course they went elsewhere for follow-up unbeknownst to me.

Regardless of what the above cited article says, these days it seems that EVERY patient will consult with his or her brother, sister, uncle, aunt, and the entire Internet forum community to verify if what you told them was correct. Since the most common approach to neuroma excisions is via a dorsal approach, when you present a plantar approach you will get second-guessed by everyone and his cousin. If you do a plantar approach and everything goes 100% well then you can say, "See, I told you I knew what I was doing." However, if anything during the recovery is difficult or sub optimal then you will be accused of doing things wrong even though you're not technically or actually wrong.

If you want to go by the evidence then you are justified doing the plantar approach for sure, but whether or not you want to pick that battle is a decision that can affect your blood pressure.

83% and 87% success rates suggests that over time you will likely have several neuroma surgeries not go exactly as hoped regardless of where you place your incision. At least with the dorsal incision if your patient needs revisional surgery then you can progress to a plantar incision and explain yourself to the patient. If you start off with the plantar approach and your patient needs a revision, then there's a good chance they may end up in somebody else's office because everyone they know will have accused you of being a nut. I just had someone else's post-op last week who has residual pain via a plantar approach and she is furious that the first surgeon chose the plantar approach.

Edit:
As far as ordering an MRI for every neuroma goes, I think it would really be overkill and a huge waste of your patient's money. Although you would not be wrong for ordering an MRI, and it would give you more diagnostic information, you can almost always make this diagnosis from clinical findings. Our office has been seeing insurance companies change their coverage to divert more expenses towards the patient, so a lot of patients have to pay 20% or more of their bill even after having met their deductible. An MRI plus radiologist's reading fee can run around $1800, so your patient would have to pay $360 out-of-pocket for something that you should have been able to do clinically (in most cases).

 

[josebiwasabi]

Thank you for the feedback. Really interesting stuff!