Dear Ezequiel

I am orthopedist with experience in traums. I did a review of the literature and as yet there are no studies with level of evidence A for this type of procedure.

See below two abstracts: Critical review in 2013 and Systematic review in 2011

Minimally invasive hallux valgus surgery: a critical review of the evidence.

Trnka HJ, Krenn S, Schuh R.

Int Orthop. 2013 Sep;37(9):1731-5. doi: 10.1007/s00264-013-2077-0.

Abstract

This systematic review aims to illustrate the published results of "minimally invasive" procedures for correction of hallux valgus. Based on former systematic reviews on that topic, the literature search was organised by two independent investigators. MEDLINE was systematically searched for available studies. The keywords used were "hallux valgus", "bunion", "percutaneous surgery", "minimally invasive surgery", "arthroscopy", "Bosch" and "SERI". Studies were assessed using the level of evidence rating. A total of 21 papers were included in this review. These studies described a total of 1,750 patients with 2,195 instances of percutaneous, minimally invasive or arthroscopic hallux valgus surgery. Clinical reports of results after minimally invasive hallux valgus surgery at meetings are common. Published results in peer-reviewed journals are less common and the majority of papers are level IV studies according to the level of evidence ratings. We found one level II and three level III studies. Reported complications seem to be less than one may see in one's own clinical practice. This possible bias may be related to the fact that most studies are published by centres performing primarily minimally invasive hallux valgus surgery

Hallux valgus: effectiveness and safety of minimally invasive surgery. A systematic review.

Br Med Bull. 2011;97:149-67. doi: 10.1093/bmb/ldq027.

Maffulli N, Longo UG, Marinozzi A, Denaro V.

Abstract

Minimally invasive techniques for hallux valgus correction include arthroscopy, percutaneous and minimum incision surgery. In the last few decades, several techniques have been increasingly used. We performed a comprehensive search of CINAHL, Embase, Medline, HealthSTAR and the Cochrane Central Registry of Controlled Trials, from inception of the database to 4 January 2010, using various combinations of the keywords terms 'Bosch', 'PDO', 'percutaneous distal osteotomy', 'SERI', 'percutaneous', 'minimal incision', 'minimum incision', 'minimally invasive', 'less invasive', 'mini-invasive', 'hallux valgus', 'bunion', 'surgery', 'arthroscopy', 'metatarsal' 'forefoot'. Only articles published in peer reviewed journals were included in this systematic review. Several new techniques are available for minimally invasive correction of the hallux valgus. Minimally invasive correction of the hallux valgus may provide better outcome for patients who would not recover well from traditional open approaches, because of decreasing recovery and rehabilitation times, as surgical exposure and deep tissue dissection are smaller and gentler to the soft tissues. Data are lacking to allow definitive conclusions on the use of these techniques for routine management of patients with hallux valgus. Given the limitations of the current case series, especially the extensive clinical heterogeneity, it is not possible to determine clear recommendations regarding the systematic use of minimally invasive surgery for hallux valgus correction, even though preliminary results are encouraging. Studies of higher levels of evidence, concentrating on large adequately powered randomized trials, should be conducted to help answer these questions

I used minimal invasive technique where the K wire is placed on the medial side of the distal fragment (subperiosteally) and in the medullary cavity of the proximal fragment. The technique, in my hands, was not as good as the traditional mini open technique which I routinely use.

In my technique, I use around 3 cm medial incision, shave off the medial bunion, perform chevron displacement osteotomy, release soft tissues on the lateral side through the same incision, and fix the osteotomy with a Herbertz screw (Zimmer).

I give removable splint for 6 weeks followed by full weight bearing.

Though i donot have any personal experience, but strongly feel against it necessity as this surgery require proper balancing and care of both bone as well as soft tissues.

MIS is possible but not recommendable. Hallux valgus is a complex deformity of the forefoot which needs a precise 3D correction. I would not try it because we have excellent results with the traditional surgical procedures. Furthermore, currently used mini-plating ensures a good stability of the corrected position.

I am a foot and ankle surgeon. In the past 12 years I have used Scarf and Chevron osteotomy a lot.

I have been against these percutaneous surgeries for correcting hallux valgus up  until 3 year ago where I was introduced by some italian orthopedist.This Bosch technique of correcting hallux valgus was very intriguing to me, so I have done 10 cases until now.

Results are very good and easy straight forward case for the surgeon.

You need a dental burr to perform the osteotomy percutaneously and fix with a Kirschner wire that is intramedullary proximal but subcutaneously in the distal part.

I always tell the patient that the Xray will look like not correct,  in case patient shows the Xray to another doctor who does not know the technique.

I perform the lateral release and second toe correction if needed.

The interesting part is that I tell the patient to fully weightbear the foot the next day or after 2 days with the help of the high heel surgical shoe ( Barok Shoes).This will align the metatarsal head in the proper position as it heals over the weeks.Early weight bearing models the 1st metatarsal head position in the cascade position with other 4 metatarsals, not too much in flextion, not too much in extension.

I remove the Kirschner wire after 5 or 6 weeks.

I am very pleased with this technique  

Dear Ezequiel! You already got detailed information and experience with this technique. It was invented by Prof. Bösch in Austria in the 80ies of the last century. (Hallux valgus correction by the method of Bösch: a new technique with a seven-to-ten-year follow-up.

Foot Ankle Clin. 2000 Sep;5(3):485-98, v-vi.)

Currently it is only performed in a few hospitals in the eastern regions of austria.

I also started my career as foot surgeon with the "classics" (Austin, Ludloff, Lapidus) but got to know this technique 7 years ago. Indeed it is a very rough technique without the chance of any "fine tuning" or ligament balancing during the operation. So i prefer this technique rather at low demanding, older patients which benefit from the minimal soft tissue damage, reduced swelling and the avoidance of wound healing problems. Up to now i performed about 50 cases with surprisingly good results and a low complication rate. Compared to the "classics" i saw an increased risk of non unions which is also demonstrated in the literature. 

Up to now i a performing an anatomical study to identify the anatomical structures at risk during this technique. Watch out for our results and my publication within the next 6 months ... 

best regards, 

Martin Kaipel 

My question is why?  A normal bunionectomy procedure is done through a very small incision and you can protect all anatomic structures as well as insert stable fixation.  

Dear Ezequiel, dear Brian, why not?

Where would we be now if we did everything the way everybody else does since the beginning of time? Nowhere near any kind of bunion surgery I guess.

MIS foot and ankle surgery can provide a helpful tool to treat your patients better if you find the right indication and know the limits of the indivdual procedure and your skills. Go to a wetlab, visit special MIS courses, get your hands dirty, study the literature and try to stay open minded. And by the way, MIS bunion surgery allows for stable fixation as well :-) Cheers, Andreas

Lots of complications with minimally invasive hallux valgus repairs https://journals.lww.com/techfootankle/Abstract/2017/03000/Treatment_of_Minimally_Invasive_Hallux_Valgus.4.aspx