SLR - July 2020 - Muhammed Sharoz Shamim

Five-Year Follow-up of Minimally Invasive Distal Metatarsal Chevron Osteotomy in Comparison with the Open Technique

Reference: Kaufmann, G., Mörtlbauer, L., Hofer-Picout, P., Dammerer, D., Ban, M., & Liebensteiner, M. (2020). Five-Year Follow-up of Minimally Invasive Distal Metatarsal Chevron Osteotomy in Comparison with the Open Technique: A Randomized Controlled Trial. JBJS, 102(10), 873-879.

Scientific Literature Review

Reviewed By: Muhammed Sharoz Shamim, DPM
Residency Program: Detroit Medical Center – Detroit, MI

Podiatric Relevance: One of the most common conditions treated by podiatrists is hallux abducto valgus deformity. Classically, there have been many procedures described in the literature including osteotomies, arthroplasty or  arthrodesis. One of the most common osteotomies utilized by foot and ankle surgeons across the world is a Chevron osteotomy.  However, there has been a surge in the use of minimally invasive techniques for the surgical treatment of this deformity. This is a therapeutic Level I, randomized controlled trial that compares minimally invasive chevron osteotomy (MIS) with an open repair technique (OC), and the first of it’s kind. The study has an adequate follow up time at six and 12 weeks, nine months and five years.

Methods: Patients were randomly divided in to the two groups. In the open chevron technique, the metatarsal head was fixated with one cannulated screw and a lateral release was performed for all patients. In the MIS group, the Chevron osteotomy was approached via a 3-5mm dorsomedial incision and fixated with a 1.2mm K wire. Post operative course was similar for all patients: Immediate weight bearing with a ready-made hallux valgus shoe permitted for six weeks. Outcome measures included AOFAS forefoot scores, VAS pain scores, patient satisfaction scores, range of motion and radiographic parameters assessed at six and 12 weeks, nine months and five years.

Results: Twenty feet were randomized to the open chevron osteotomy group while 19 feet were included in the MIS group. Similar age groups, sex and laterality were shown between groups. The MIS group showed a 52 percent correction in hallux interphalangeus angle as compared to 37% correction in the OC group. There was no statistical differences in AOFAS Forefoot Scores and VAS scores between the two groups. Lastly, patient satisfaction was comparable for both groups. Eighty-nine percent of the individuals in the MIS group reported to be “Very satisfied” as compared to 70 percent of individuals in the OC group. Complications included one patient undergoing lateral metatarsal head necrosis and one patient having recurrent hallux valgus deformity, both in the OC group. Two patients in the MIS group had recurrence of hallux valgus deformity. Sixteen of 19 individuals in the MIS group experienced severe soft tissue irritation due to the K wire, requiring removal. Conversely, four of 20 individuals required screw removal in the OC group. 

Conclusions: The study has appropriate follow up time for comparing open vs minimally invasive technique. However, there remains varying methods of fixation in both groups. Two screw fixation, one screw fixation, one K wire and crossing K wires are just some of the fixation methods used for both MIS and open Chevron osteotomy. The important finding of this study is that patient’s had comparable outcomes for both procedures. There was no statistical significance in the AOFAS forefoot score and VAS score. Radiographic correction was achieved in both groups. With increasing patient demand for minimally invasive surgery, this study suggests that the MIS approach is comparable to the classic open technique. 

Educational Opportunities