[Minimally invasive forefoot surgery: concept and techniques]

Minimally invasive surgery (MIS) has advanced to an established approach in the correction of all deformities of the forefoot. For the first ray the minimally invasive chevron and Akin osteotomy (MICA) shows very good clinical results and provides a broad spectrum of indications in comparison to the classical chevron osteotomy. The minimally invasive treatment of hallux rigidus also seems to achieve comparable results to the open techniques, although the surgical indications must be thoroughly evaluated. Lesser toe deformities are often easier to treat with minimally invasive osteotomy, capsule release and tendon lengthening than with complex open procedures and usually do not require any internal fixation material. Compared to the classical Weil osteotomy, distal metatarsal osteotomy shows a reduced rate of cock-up deformities and does not require internal fixation. In relation to open procedures, minimally invasive approaches should be accepted as a valuable addition and alternative to the classical open techniques due to the reduced rate of wound healing disorders and postoperative pain.

3rd generation MICA with the "K-wires-first technique" - a step-by-step instruction and preliminary results

BACKGROUND

Minimally-invasive techniques for hallux valgus correction are becoming increasingly popular. In the last decades, multiple techniques for minimally-invasive hallux valgus correction have been described. MICA (Minimally-invasive Chevron & Akin), representing the 3rd generation of minimally-invasive hallux valgus correction, combines the advantages of an extraarticular osteotomy, stable internal fixation, and high potential for correction. This report aims to provide a step-by-step instruction of the surgical technique with the "K-wires-first" MICA modification, illustrated by detailed imaging of both intraoperative fluoroscopy and clinical imaging as well as corresponding sawbone models for each step. Preliminary results including radiological outcome and complications of the first 50 cases will be discussed.

METHODS

Between May 2018 and May 2021, 50 consecutive MICAs in 47 patients were performed with the K-wires-first technique. There were 40 women and 7 men with an average of 57.4y (range 25-78). The mean preoperative IMA was 16.2° (range 11.0-21.5), the HVA 30.6° (range 21.8-42.1).

RESULTS

There was one intraoperative conversion to an open surgical bunion correction corresponding to a 2% conversion rate respectively (1/50). On 3 feet (2 patients), removal of the Chevron screws was performed after 7, 9, and 12 months due to prominent and disturbing screw heads at the level of the medial cortex, accounting for a revision rate of 6% (3/50). There were no other secondary revision surgeries. The IMA decreased after MICA by a mean of 10.8° from 16.2° to 5.4° and the HVA by a mean of 22.1° from 30.6° to 8.5°, demonstrating MICA's high potential for correction.

CONCLUSIONS

Compared to other MICA techniques, the K-wires-first modification helps to reduce hardware malpositioning and the risk of conversion to open surgery. Furthermore, our preliminary results demonstrate a high potential for correction even for severe hallux deformities.

TRIAL REGISTRATION

Retrospectively registered, swissethics BASEC-ID 2021-01537, July 16th, 2021 ( www.raps.swissethics.ch ).

Percutaneous hallux valgus treatment: Unilaterally or bilaterally

INTRODUCTION

Currently there is no consensus regarding the use of bilateral simultaneous percutaneous surgery for Hallux valgus treatment. Although the technique described in M. Prado's book, recommends operating only one foot at a time there are no published studies confirming it. The aim of this study was to evaluate whether there is a difference between the results of patients that have been percutaneously operated on one foot and those operated on both feet at the same surgical time for mild to moderate Hallux valgus correction.

MATERIAL/METHODS

We did a retrospective single centre evaluation of 93 feet (61 patients) with Hallux valgus operated percutaneously. 29 patients were operated unilaterally (group I) and 32 bilaterally simultaneously (group II) between 2005 and 2009. The Metatarsophalangeal angle (MPA), Intermetatarsal angle (IMA) and Distal metatarsal articular angle (DMAA) were evaluated pre- and postoperatively. The AOFAS score, the degree of patients' satisfaction and the complications were evaluated postoperatively.

RESULTS

The mean follow-up was 24.0 months in group I, and 28.0 in group II. The average postoperative AOFAS score was 86.8, 82.9 in group I and 88.6 in group II (p>0.05). 90.6% were satisfied or very satisfied in group I, and 89.7% in group II (p>0.05). There was no statistically significant difference (p>0.05) in the average correction of MPA, DMAA, and IMA. The complications rate was similar in both groups.

CONCLUSIONS

The similar results obtained in both groups suggest that the simultaneous bilateral percutaneous surgery gives equivalent results to the unilateral, which has an important socioeconomic impact since there is only one recovery time for both feet. Further research is needed.

Percutaneous Hindfoot and Midfoot Fusion

Hindfoot and midfoot fusions can be performed with percutaneous techniques. Preliminary results of these procedures are encouraging because they provide similar results than those obtained with open techniques with less morbidity and quick recovery. The best indications are probably fusions for mild-to-moderate reducible hindfoot and midfoot deformities in fragile patients with general or local bad conditions. The main limit is linked to the surgeon's experience in percutaneous foot surgery because a learning curve with the specific tools is necessary before doing these procedures.

Percutaneous Pediatric Foot and Ankle Surgery

The techniques for performing percutaneous osteotomies in treating deformities of the foot in children are presented along with a detailed description of the operative details. The author's use of minimal-access surgery for tibial, os calcis, and midfoot osteotomies is described using a cooled side-cutting burr that has not previously been described for use in the child's foot. The cancellous nature of the bones in the child are easily cut with the burr and the adjacent soft tissues are not damaged. The early experience of the healing times are not impaired and the complications associated with percutaneous scars seem to be negligible.